Systemic venous drainage: can we help Newton?
Corno, Antonio F
2007-06-01
In recent years substantial progress occurred in the techniques of cardiopulmonary bypass, but the factor potentially limiting the flexibility of cardiopulmonary bypass remains the drainage of the systemic venous return. In the daily clinical practice of cardiac surgery, the amount of systemic venous return on cardiopulmonary bypass is directly correlated with the amount of the pump flow. As a consequence, the pump flow is limited by the amount of venous return that the pump is receiving. On cardiopulmonary bypass the amount of venous drainage depends upon the central venous pressure, the height differential between patient and inlet of the venous line into the venous reservoir, and the resistance in the venous cannula(s) and circuit. The factors determining the venous return to be taken into consideration in cardiac surgery are the following: (a) characteristics of the individual patient; (b) type of planned surgical procedure; (c) type of venous cannula(s); (d) type of circuit for cardiopulmonary bypass; (e) strategy of cardiopulmonary bypass; (f) use of accessory mechanical systems to increased the systemic venous return. The careful pre-operative evaluation of all the elements affecting the systemic venous drainage, including the characteristics of the individual patient and the type of required surgical procedure, the choice of the best strategy of cardiopulmonary bypass, and the use of the most advanced materials and tools, can provide a systemic venous drainage substantially better than what it would be allowed by the simple "Law of universal gravitation" by Isaac Newton.
Venous Return and Clinical Hemodynamics: How the Body Works during Acute Hemorrhage
ERIC Educational Resources Information Center
Shen, Tao; Baker, Keith
2015-01-01
Venous return is a major determinant of cardiac output. Adjustments within the venous system are critical for maintaining venous pressure during loss in circulating volume. This article reviews two factors that are thought to enable the venous system to compensate during acute hemorrhage: 1) changes in venous elastance and 2) mobilization of…
Right atrial pressure: determinant or result of change in venous return?
Bendjelid, Karim
2005-11-01
According to the concept of Guyton, cardiac output is largely controlled by venous return, which is determined by the difference between mean systemic venous pressure and right atrial pressure. In the analysis of the venous return curve, other authors have suggested that right atrial pressure is the dependent variable and venous return is the independent variable (right atrial pressure decreased because cardiac output increased). The present report analyzes this historical debate, which has already lasted > 50 years.
Hepatic venous connection to a persistent inferior caval vein in left isomerism.
Guenthard, J; Carvalho, J S; Anderson, R H; Rigby, M L
1990-09-01
In 22 cases of left atrial isomerism studied at the Brompton Hospital, four cases were found to have an unusual arrangement of the abdominal vessels. There was persistence of an inferior caval vein, partially anomalous hepatic venous connection and additional continuation of part of the venous return from the lower body through the azygos venous system. This venous pattern had surgical implications in our index case, since redirection of the inferior caval venous return was necessary.
Turkoz, Riza; Ayabakan, Canan; Vuran, Can; Omay, Oğuz
2010-08-01
A 7-month-old boy with heterotaxy syndrome had partial atrioventricular septal defect and interrupted inferior vena cava with hemiazygos continuation to a left superior vena cava. The left side of the common atrium receiving all the venous drainage was in connection with the left ventricle and the aorta. The small atrium and the proximity of the pulmonary and hepatic vein orifices precluded complete baffling. This report describes an intraatrial baffle repair of anomalous systemic venous return without hepatic venous drainage. This resulted in good oxygenation postoperatively, with oxygen saturation ranging from 93% to 98%.
A 1D pulse wave propagation model of the hemodynamics of calf muscle pump function.
Keijsers, J M T; Leguy, C A D; Huberts, W; Narracott, A J; Rittweger, J; van de Vosse, F N
2015-07-01
The calf muscle pump is a mechanism which increases venous return and thereby compensates for the fluid shift towards the lower body during standing. During a muscle contraction, the embedded deep veins collapse and venous return increases. In the subsequent relaxation phase, muscle perfusion increases due to increased perfusion pressure, as the proximal venous valves temporarily reduce the distal venous pressure (shielding). The superficial and deep veins are connected via perforators, which contain valves allowing flow in the superficial-to-deep direction. The aim of this study is to investigate and quantify the physiological mechanisms of the calf muscle pump, including the effect of venous valves, hydrostatic pressure, and the superficial venous system. Using a one-dimensional pulse wave propagation model, a muscle contraction is simulated by increasing the extravascular pressure in the deep venous segments. The hemodynamics are studied in three different configurations: a single artery-vein configuration with and without valves and a more detailed configuration including a superficial vein. Proximal venous valves increase effective venous return by 53% by preventing reflux. Furthermore, the proximal valves shielding function increases perfusion following contraction. Finally, the superficial system aids in maintaining the perfusion during the contraction phase and reduces the refilling time by 37%. © 2015 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.
[Anomalous pulmonary venous return in a pregnant woman identified by cardiac magnetic resonance].
Souto, Fernanda Maria; Andrade, Stephanie Macedo; Barreto, Ana Terra Fonseca; Souto, Maria Júlia Silveira; Russo, Maria Amélia; de Mendonça, José Teles; Oliveira, Joselina Luzia Menezes; Gonçalves, Luiz Flávio Galvão
2014-06-01
Anomalous pulmonary venous return (APVR) is a rare cardiac anomaly defined as one or more pulmonary veins draining into a structure other than the left atrium, with venous return directly or indirectly to the right atrium. The most common form is partial APVR, in which one to three pulmonary veins drain into systemic veins or into the right atrium. We report the case of a woman diagnosed with partial APVR by magnetic resonance imaging during pregnancy. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.
A New Technique for Femoral Venous Access in Infants Using Arterial Injection Venous Return Guidance
Ebishima, Hironori; Kitano, Masataka; Kurosaki, Kenichi; Shiraishi, Isao
2017-01-01
Objectives: Although venography guidance is helpful for central venous catheter placement, it is sometimes difficult to place a peripheral intravenous cannula for enhancement. We designed a new technique for establishing femoral venous access using venography guidance in the return phase of peripheral arteriography. This new technique was named arterial injection venous return guidance. Here we assessed the efficacy and safety of arterial injection venous return guidance. Methods: We reviewed data of 29 infants less than 6 months old undergoing catheter intervention at our institute in 2014. Of the 29 patients, femoral venous cannulation was performed using arterial injection venous return guidance in 5 patients, venography in 20 patients, and the landmark method in 4 patients. The technical success rates and incidence of complications were compared. Results: The overall success rates were 100% in the arterial injection venous return-guided and venography-guided groups. The mean procedure duration and mean contrast material injection time were similar between the groups. The contrast effect on the femoral vein in the arterial injection venous return-guided group was lower than that in the venography-guided group, but adequate for surgery. The overall complication rate was 17%, and obstruction of previously placed intravenous catheters was the most common complication. Conclusions: Therefore, the arterial injection venous return guidance technique was as safe and efficient as venography for establishing venous access. PMID:29034015
Vacuum-assisted venous return reduces blood usage.
Banbury, Michael K; White, Jennifer A; Blackstone, Eugene H; Cosgrove, Delos M
2003-09-01
To determine whether vacuum-assisted venous return has clinical advantages over conventional gravity drainage apart from allowing the use of smaller cannulas and shorter tubing. A total of 150 valve operations were performed at our institution between February and July 1999 using vacuum-assisted venous return with small venous cannulas connected to short tubing. These were compared with (1) 83 valve operations performed between April 1997 and January 1998 using the initial version of vacuum-assisted venous return, and (2) 124 valve operations performed between January and April of 1997 using conventional gravity drainage. Priming volume, hematocrit value, red blood cell usage, and total blood product usage were compared multivariably. These comparisons were covariate and propensity adjusted for dissimilarities between the groups and confirmed by propensity-matched pairs analysis. Priming volume was 1.4 +/- 0.4 L for small-cannula vacuum-assisted venous return, 1.7 +/- 0.4 L for initial vacuum-assisted venous return, and 2.0 +/- 0.4 L for gravity drainage (P <.0001). Smaller priming resulted in higher hematocrit values both at the beginning of cardiopulmonary bypass (27% +/- 5% compared with 26% +/- 4% and 25% +/- 4%, respectively, P <.0001) and at the end (30% +/- 4% compared with 28% +/- 4% and 27% +/- 4%, respectively, P <.0001). Red cell transfusions were used in 17% of the patients having small-cannula vacuum-assisted venous return, 27% of the initial patients having vacuum-assisted venous return, and 37% of the patients having gravity drainage (P =.001); total blood product usage was 19%, 27%, and 39%, respectively (P =.002). Although ministernotomy also was associated with reduced blood product usage (P <.004), propensity matching on type of sternotomy confirmed the association of vacuum-assisted venous return with lowered blood product usage. Vacuum-assisted venous return results in (1) higher hematocrit values during cardiopulmonary bypass and (2) decreased red cell and total blood product usage.
Cross-sectional echocardiographic diagnosis of systemic venous return.
Huhta, J C; Smallhorn, J F; Macartney, F J; Anderson, R H; de Leval, M
1982-01-01
To determine the sensitivity and specificity of cross-sectional echocardiography in diagnosing anomalous systemic venous return we used the technique in 800 consecutive children with congenital heart disease and whom the diagnosis was ultimately confirmed by angiography. Cross-sectional echocardiography was performed without prior knowledge of the diagnosis in all but 11 patients, who were recalled because of a known abnormality of atrial situs. The sensitivity of cross-sectional echocardiographic detection of various structures was as follows: right superior vena cava 792/792 (100%); left superior vena cava 46/48 (96%); bilateral superior vena cava 38/40 (95%); bridging innominate vein with bilateral superior vena cava 13/18 (72%); connection of superior caval segment to heart (coronary sinus or either atrium) (100%); absence of suprarenal inferior vena cava 23/23 (100%); azygos continuation of the inferior vena cava 31/33 (91%); downstream connection of azygos continuation, once seen, 21/21 (100%); partial anomalous hepatic venous connection (one hepatic vein not connected to the inferior vena cava) 1/1 (100%); total anomalous hepatic venous connection (invariably associated with left isomerism) 23/23 (100%). The specificity of each above diagnoses was 100% except in one infant with exomphalos in whom absence of the suprarenal inferior vena cava was incorrectly diagnosed. Thus cross-sectional echocardiography is an extremely specific and highly sensitive method of recognizing anomalous systemic venous return. It is therefore of great value of planning both cardiac catheterisation and cannulation for open heart surgery. Images PMID:6751361
Effects of abdominal pressure on venous return: abdominal vascular zone conditions.
Takata, M; Wise, R A; Robotham, J L
1990-12-01
The effects of changes in abdominal pressure (Pab) on inferior vena cava (IVC) venous return were analyzed using a model of the IVC circulation based on a concept of abdominal vascular zone conditions analogous to pulmonary vascular zone conditions. We hypothesized that an increase in Pab would increase IVC venous return when the IVC pressure at the level of the diaphragm (Pivc) exceeds the sum of Pab and the critical closing transmural pressure (Pc), i.e., zone 3 conditions, but reduce IVC venous return when Pivc is below the sum of Pab and Pc, i.e., zone 2 conditions. The validity of the model was tested in 12 canine experiments with an open-chest IVC bypass. An increase in Pab produced by phrenic stimulation increased the IVC venous return when Pivc-Pab was positive but decreased the IVC venous return when Pivc - Pab was negative. The value of Pivc - Pab that separated net increases from decreases in venous return was 1.00 +/- 0.72 (SE) mmHg (n = 6). An increase in Pivc did not influence the femoral venous pressure when Pivc was lower than the sum of Pab and a constant, 0.96 +/- 0.70 mmHg (n = 6), consistent with presence of a waterfall. These results agreed closely with the predictions of the model and its computer simulation. The abdominal venous compartment appears to function with changes in Pab either as a capacitor in zone 3 conditions or as a collapsible Starling resistor with little wall tone in zone 2 conditions.
NASA Astrophysics Data System (ADS)
Santhanakrishnan, Arvind; Johnson, Jacob; Kotz, Monica; Tang, Elaine; Khiabani, Reza; Yoganathan, Ajit; Maher, Kevin
2012-11-01
The Fontan procedure is a palliative surgery performed on patients with single ventricle (SV) congenital heart defects. The SV is used for systemic circulation and the venous return from the inferior vena cava (IVC) and superior vena cava (SVC) is routed to the pulmonary arteries (PA), resulting in a total cavopulmonary connection (TCPC). Hepatic venous hypertension is commonly manifested in the Fontan circulation, leading to long-term complications including liver congestion and cirrhosis. Respiratory intrathoracic pressure changes affect the venous return from the IVC to the PA. Using a physical model of an idealized TCPC, we examine placement of a unidirectional bovine venous valve within the IVC as a method of alleviating hepatic venous hypertension. A piston pump is used to provide pulsatility in the internal flow through the TCPC, while intrathoracic pressure fluctuations are imposed on the external walls of the model using a pair of linear actuators. When implanted in the extrathoracic position, the hepatic venous pressure is lowered from baseline condition. The effects of changing caval flow distribution and intrathoracic pressure on TCPC hemodynamics will be examined.
Partial anomalous pulmonary venous return in Turner syndrome.
van den Hoven, Allard T; Chelu, Raluca G; Duijnhouwer, Anthonie L; Demulier, Laurent; Devos, Daniel; Nieman, Koen; Witsenburg, Maarten; van den Bosch, Annemien E; Loeys, Bart L; van Hagen, Iris M; Roos-Hesselink, Jolien W
2017-10-01
The aim of this study is to describe the prevalence, anatomy, associations and clinical impact of partial anomalous pulmonary venous return in patients with Turner syndrome. All Turner patients who presented at our Turner clinic, between January 2007 and October 2015 were included in this study and underwent ECG, echocardiography and advanced imaging such as cardiac magnetic resonance or computed tomography as part of their regular clinical workup. All imaging was re-evaluated and detailed anatomy was described. Partial anomalous pulmonary venous return was diagnosed in 24 (25%) out of 96 Turner patients included and 14 (58%) of these 24 partial anomalous pulmonary venous return had not been reported previously. Right atrial or ventricular dilatation was present in 11 (46%) of 24 partial anomalous pulmonary venous return patients. When studied with advanced imaging modalities and looked for with specific attention, PAPVR is found in 1 out of 4 Turner patients. Half of these patients had right atrial and/or ventricular dilatation. Evaluation of pulmonary venous return should be included in the standard protocol in all Turner patients. Copyright © 2017. Published by Elsevier B.V.
Venous return curves obtained from graded series of valsalva maneuvers
NASA Technical Reports Server (NTRS)
Mastenbrook, S. M., Jr.
1974-01-01
The effects were studied of a graded series of valsalva-like maneuvers on the venous return, which was measured transcutaneously in the jugular vein of an anesthetized dog, with the animal serving as its own control. At each of five different levels of central venous pressure, the airway pressure which just stopped venous return during each series of maneuvers was determined. It was found that this end-point airway pressure is not a good estimator of the animal's resting central venous pressure prior to the simulated valsalva maneuver. It was further found that the measured change in right atrial pressure during a valsalva maneuver is less than the change in airway pressure during the same maneuver, instead of being equal, as had been expected. Relative venous return curves were constructed from the data obtained during the graded series of valsalva maneuvers.
Effect of PEEP, blood volume, and inspiratory hold maneuvers on venous return.
Berger, David; Moller, Per W; Weber, Alberto; Bloch, Andreas; Bloechlinger, Stefan; Haenggi, Matthias; Sondergaard, Soren; Jakob, Stephan M; Magder, Sheldon; Takala, Jukka
2016-09-01
According to Guyton's model of circulation, mean systemic filling pressure (MSFP), right atrial pressure (RAP), and resistance to venous return (RVR) determine venous return. MSFP has been estimated from inspiratory hold-induced changes in RAP and blood flow. We studied the effect of positive end-expiratory pressure (PEEP) and blood volume on venous return and MSFP in pigs. MSFP was measured by balloon occlusion of the right atrium (MSFPRAO), and the MSFP obtained via extrapolation of pressure-flow relationships with airway occlusion (MSFPinsp_hold) was extrapolated from RAP/pulmonary artery flow (QPA) relationships during inspiratory holds at PEEP 5 and 10 cmH2O, after bleeding, and in hypervolemia. MSFPRAO increased with PEEP [PEEP 5, 12.9 (SD 2.5) mmHg; PEEP 10, 14.0 (SD 2.6) mmHg, P = 0.002] without change in QPA [2.75 (SD 0.43) vs. 2.56 (SD 0.45) l/min, P = 0.094]. MSFPRAO decreased after bleeding and increased in hypervolemia [10.8 (SD 2.2) and 16.4 (SD 3.0) mmHg, respectively, P < 0.001], with parallel changes in QPA Neither PEEP nor volume state altered RVR (P = 0.489). MSFPinsp_hold overestimated MSFPRAO [16.5 (SD 5.8) vs. 13.6 (SD 3.2) mmHg, P = 0.001; mean difference 3.0 (SD 5.1) mmHg]. Inspiratory holds shifted the RAP/QPA relationship rightward in euvolemia because inferior vena cava flow (QIVC) recovered early after an inspiratory hold nadir. The QIVC nadir was lowest after bleeding [36% (SD 24%) of preinspiratory hold at 15 cmH2O inspiratory pressure], and the QIVC recovery was most complete at the lowest inspiratory pressures independent of volume state [range from 80% (SD 7%) after bleeding to 103% (SD 8%) at PEEP 10 cmH2O of QIVC before inspiratory hold]. The QIVC recovery thus defends venous return, possibly via hepatosplanchnic vascular waterfall. Copyright © 2016 the American Physiological Society.
Sandblom, Erik; Axelsson, Michael; Farrell, Anthony P
2006-11-01
Subambient central venous pressure (Pven) and modulation of venous return through cardiac suction (vis a fronte) characterizes the venous circulation in sharks. Venous capacitance was estimated in the dogfish Squalus acanthias by measuring the mean circulatory filling pressure (MCFP) during transient occlusion of cardiac outflow. We tested the hypothesis that venous return and cardiac preload can be altered additionally through adrenergic changes of venous capacitance. The experiments involved the surgical opening of the pericardium to place a perivascular occluder around the conus arteriosus. Another control group was identically instrumented, but lacked the occluder, and was subjected to the same pharmacological protocol to evaluate how pericardioectomy affected cardiovascular status. Routine Pven was negative (-0.08+/-0.02 kPa) in control fish but positive (0.09+/-0.01 kPa) in the pericardioectomized group. Injections of 5 microg/kg body mass (Mb) of epinephrine and phenylephrine (100 microg/kg Mb) increased Pven and MCFP, whereas isoproterenol (1 microg/kg Mb) decreased both variables. Thus, constriction and relaxation of the venous vasculature were mediated through the respective stimulation of alpha- and beta-adrenergic receptors. Alpha-adrenergic blockade with prazosin (1 mg/kg Mb) attenuated the responses to phenylephrine and decreased resting Pven in pericardioectomized animals. Our results provide convincing evidence for adrenergic control of the venous vasculature in elasmobranchs, although the pericardium is clearly an important component in the modulation of venous function. Thus active changes in venous capacitance have previously been underestimated as an important means of modulating venous return and cardiac performance in this group.
NASA Technical Reports Server (NTRS)
Mukkamala, R.; Cohen, R. J.; Mark, R. G.
2002-01-01
Guyton developed a popular approach for understanding the factors responsible for cardiac output (CO) regulation in which 1) the heart-lung unit and systemic circulation are independently characterized via CO and venous return (VR) curves, and 2) average CO and right atrial pressure (RAP) of the intact circulation are predicted by graphically intersecting the curves. However, this approach is virtually impossible to verify experimentally. We theoretically evaluated the approach with respect to a nonlinear, computational model of the pulsatile heart and circulation. We developed two sets of open circulation models to generate CO and VR curves, differing by the manner in which average RAP was varied. One set applied constant RAPs, while the other set applied pulsatile RAPs. Accurate prediction of intact, average CO and RAP was achieved only by intersecting the CO and VR curves generated with pulsatile RAPs because of the pulsatility and nonlinearity (e.g., systemic venous collapse) of the intact model. The CO and VR curves generated with pulsatile RAPs were also practically independent. This theoretical study therefore supports the validity of Guyton's graphical analysis.
Unilateral Loss of Spontaneous Venous Pulsations in an Astronaut
NASA Technical Reports Server (NTRS)
Mader, Thomas H.; Gibson, C. Robert; Lee, Andrew G.; Patel, Nimesh; Hart, Steven; Pettit, Donald R.
2014-01-01
Spontaneous venous pulsations seen on the optic nerve head (optic disc) are presumed to be caused by fluctuations in the pressure gradient between the intraocular and retrolaminar venous systems. The disappearance of previously documented spontaneous venous pulsations is a well-recognized clinical sign usually associated with a rise in intracranial pressure and a concomitant bilateral elevation of pressure in the subarachnoid space surrounding the optic nerves. In this correspondence we report the unilateral loss of spontaneous venous pulsations in an astronaut 5 months into a long duration space flight. We documented a normal lumbar puncture opening pressure 8 days post mission. The spontaneous venous pulsations were also documented to be absent 21 months following return to Earth.. We hypothesize that these changes may have resulted from a chronic unilateral rise in optic nerve sheath pressure caused by a microgravity-induced optic nerve sheath compartment syndrome.
Cardiac veins: collateral venous drainage pathways in chronic hemodialysis patients.
Ozmen, Evrim; Algin, Oktay
2016-07-12
Venous anomalies are diagnostic and therapeutic challenges. Subclavian or superior vena cava stenosis can be developed and venous return can be achieved via cardiac veins and coronary sinus in patients with central venous catheter for long-term hemodialysis. These types of abnormalities are not extremely rare especially in patients with a history of central venous catheter placement. Detection of these anomalies and subclavian vein stenosis before the surgical creation of hemodialysis fistulae or tunneled central venous catheter placement may prevent unnecessary interventions in those patients. Multidetector computed tomography (MDCT) technique can give further information when compared with fluoroscopy or digital subtraction angiography in the management of these patients. This case report describes interesting aspects of central vein complications in hemodialysis patients. As a conclusion, there are limited data about thoracic venous return, and further prospective studies with large patient number are required. MDCT with 3D reconstruction is particularly useful for the accurate evaluation of venous patency, variations, and collateral circulation. Also it is an excellent tool for choosing and planning treatment.
Vida, V L; Bhattarai, A; Speggiorin, S; Zanella, F; Stellin, G
2014-01-01
To observe how vacuum assisted venous drainage (VAVD) may influence the flow in a cardiopulmonary bypass circuit with different size of venous lines and cannulas. The experimental circuit was assembled to represent the cardiopulmonary bypass circuit routinely used during cardiac surgery. Wall suction was applied directly, modulated and measured into the venous reservoir. The blood flow was measured with a flow-meter positioned on the venous line. The circuit prime volume was replaced with group O date expired re-suspended red cells and Plasmalyte 148 to a hematocrit of 28% to 30%. In an open circuit with gravity siphon venous drain, angled cannulae drain more than straight ones regardless the amount of suction applied to the venous line (16 Fr straight cannula (S) drains 90 ml/min less than a 16 Fr angled (A) with a siphon gravity). The same flow can be obtained with lower cannula size and higher suction (i.e. 12 A with and -30 mmHg). Tables have been created to list how the flow varies according to the size of the cannulas, the size of the venous tubes, and the amount of suction applied to the system. Vacuum assisted venous drainage allows the use of smaller cannulae and venous lines to maintain a good venous return, which is very useful during minimally invasive approaches. The present study should be considered as a preliminary attempt to create a scientific-based starting point for a uniform the use of VAVD.
[Horseshoe lung with normal pulmonary venous return].
Gondra Sangroniz, A; Elorz Lambarri, J; Villar Alvarez, M A; Lecumberri Cortes, I; Ayala Curiel, J
2010-09-01
Horseshoe lung is a rare congenital anomaly characterised by a midline isthmus of pulmonary parenchyma connecting the posterior basal segments of the lungs behind the heart in conjunction with unilateral pulmonary hypoplasia. Of all cases, 80% are associated with scimitar syndrome, consisting of right anomalous pulmonary venous drainage, pulmonary hypoplasia of the right lung and systemic arterial perfusion to some lung areas. A six year old girl who had recurrent lower respiratory infections since birth. Chest Rx, angioCT and MR showed: hypoplasia of the right lung, dextrocardia and pulmonary isthmus bridging both lungs behind the pericardium. The right hypoplastic lung had little systemic supply coming from the abdominal aorta. The right pulmonary artery was hypoplastic. The right pulmonary venous drainage was normal. We present a case of horseshoe lung without abnormal venous drainage. 2010 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.
Cannulation for veno-venous extracorporeal membrane oxygenation
2018-01-01
Extracorporeal membrane oxygenation (ECMO) is described as a modified, smaller cardiopulmonary bypass circuit. The veno-venous (VV) ECMO circuit drains venous blood, oxygenate the blood, and pump the blood back into the same venous compartment. Draining and reinfusing in the same compartment means there are a risk of recirculation. The draining position within the venous system, ECMO pump flow, return flow position within the venous system and the patients cardiac output (CO) all have an impact on recirculation. Using two single lumen cannulas or one dual lumen cannula, but also the design of the venous cannula, can have an impact on where within the venous system the cannula is draining blood and will affect the efficiency of the ECMO circuit. VV ECMO can be performed with different cannulation strategies. The use of two single lumen cannulas draining in inferior vena cava (IVC) and reinfusing in superior vena cava (SVC) or draining in SVC and reinfusing in IVC, or one dual lumen cannula inserted in right jugular vein is all possible cannulation strategies. Independent of cannulation strategy there will be a risk of recirculation. Efficiency can be reasonable in either strategy if the cannulas are carefully positioned and monitored during the dynamic procedure of pulmonary disease. The disadvantage draining from IVC only occurs when there is a need for converting from VV to veno-arterial (VA) ECMO, reinfusing in the femoral artery. Then draining from SVC is the most efficient strategy, draining low saturated venous blood, and also means low risk of dual circulation. PMID:29732177
A postscript to Circulation of the blood: men and ideas.
Riley, R L
1982-10-01
Since 1964, when Fishman and Richards published Circulation of the Blood: Men and Ideas, Guyton's model of the circulation, in which mean circulatory pressure serves as the upstream pressure for venous return, has been extended, and the concept of vascular smooth muscle tone acting like the pressure surrounding a Starling resistor has been postulated. According to this scheme, the positive zero flow intercepts of rapidly determined arterial pressure-flow curves are the effective downstream pressures for arterial flow to different tissues. The arterioles, like Starling resistors, determine the downstream pressures and are followed by abrupt pressure drops, or "waterfalls." Capillary pressures are closely linked to those of the venules into which they flow. Capillary-venular pressures are the upstream pressures for venous return. In exercising muscles, reduced arteriolar tone lowers arteriolar pressure and increases arterial flow. This, in turn, raises capillary-venular pressure and increases venous flow. The arteriolar-capillary waterfall is decreased or eliminated. Total blood flow is increased by diversion of blood from tissues with slow venous drainage to muscles with fast venous drainage (low resistance X compliance). The heart pumps away the increased venous return by shifting to a new ventricular function curve.
Portal hemodynamic responses after oral intake of glucose in patients with cirrhosis.
Tsunoda, T; Ohnishi, K; Tanaka, H
1988-04-01
Changes of portal, superior mesenteric, and splenic venous flows, and portohepatic gradient (portal vein pressure minus free hepatic vein pressure) after a meal were studied in patients with cirrhosis using the duplex ultrasonic Doppler flowmeter, and portal and hepatic vein catheterizations after ingestion of 227 ml of 33% glucose solution (300 kcal). As a control, changes of portal venous flow and portohepatic gradient after drinking 227 ml of water, were studied. Portal and superior mesenteric venous flows increased significantly at 30 min after glucose intake, and they returned gradually to the basal values, whereas no significant postprandial change occurred in splenic venous flow. The sum of superior mesenteric and splenic venous flows was greater than the estimated portal venous flow before glucose intake, and the difference widened during post-prandial mesenteric hyperemia, indicating an increase of blood flow into the portal-systemic shunts. After glucose intake, portohepatic gradient elevated immediately, in parallel with an increase of portal venous flow, and these changes persisted for the 30 min studied; however, no significant change occurred in these parameters after drinking water. 1) In patients with cirrhosis, hyperemia occurs in the intestine but not in the spleen after glucose intake, and 2) postprandial mesenteric hyperemia causes an increase of portal venous inflow, portal-systemic collateral flow, portal venous flow, and an elevation of portohepatic gradient.
Cardiac transplantation in situs inversus: two cases reports.
Chang, Y L; Wei, J; Chang, C-Y; Chuang, Y-C; Sue, S-H
2008-10-01
The challenge of heart transplantation in patients with situs inversus is reconstruction of the systemic venous return. Herein we have presented 2 cases of complex congenital heart disease with atriovisceral situs inversus. Both of the patients shared many common cardiac anomalies, such as a single ventricle, a single AV valve with severe regurgitation, and severe pulmonary stenosis. We completed the venous connection in 2 different ways. In the first case, the donor inferior vena cava (IVC) was anastomosed to the recipient left-sided IVC directly, making the heart slightly counterclockwise rotated. In the second case, the IVC venous reconnection was accomplished by a composite conduit made of recipient right atrium.
James, H; Witte, M H; Bernas, M; Barber, B
2016-09-01
In Fontan circulations created for univentricular hearts, systemic venous return is diverted to the lungs before returning to the heart. The Total Cavopulmonary Connection (TCPC) is often the preferred surgical procedure whereby a 4-way anastomosis is created with inflow from the superior vena cava (SVC) and inferior vena cava (IVC) and outflow to the right and left branches of the pulmonary artery. In this arrangement, the systemic venous pressure must be elevated sufficiently to perfuse the lungs passively without the normal boost of the right ventricle. Hence, unlike surgical corrections for other congenital heart conditions, the systemic venous pressures in a Fontan circuit must be elevated to make the circulation work. It is proposed here that the incidence of PLE/LLE is directly related to elevated venous and lymphatic pressures, which cause leakage of proteins/lymph into the gastrointestinal tract (GIT) and expulsion from the body. It is commonly held that elevated venous pressures are relatively better tolerated in the upper body, but much less so in the heptatosplanchnic circulation and the lower body. It is also well established that elevated venous pressure increases lymph formation, most of which is produced in the hepatosplanchnic region (liver and intestine). It is further argued here that the increase in lymph filling pressure arising from the higher lymph flow, in association with the backpressure exerted by elevated venous pressure at the main drainage point into the venous system, results in a substantial increase in pressure in the thoracic duct. This pressure is transmitted back to the intestinal lymphatics, causing dilatation with lacteal rupture and protein or bulk lymph leakage into the intestine. We propose in this paper a new approach, based on experimental evidence, to prevent and/or alleviate this condition by draining or redirecting the thoracic duct (or, alternatively, a more localized intestinal lymphatic vessel) into one of the pulmonary veins or the left atrium, which are typically at near-normal pressure in a Fontan circulation. This “lymphatic-venous right-to-left” shunt maneuver would significantly reduce the venous backpressure on the lymphatics as well as improve lymph circulation, resulting in a decrease in the intestinal lymphatic pressure and thereby prevent or alleviate protein/lymph loss, i.e. lymph balance would be restored. Moreover, the greatly facilitated lymphatic flow would encourage further capillary filtration to relieve excessive venous pressure in the hepatosplanchnic region and protect the liver and kidneys. This paper is intended as a discussion document for elicitation of comments on the soundness and viability of this proposal as well as on technical challenges and steps to explore and advance it.
Anomalies of the systemic venous return: a review.
Mazzucco, A; Bortolotti, U; Stellin, G; Gallucci, V
1990-06-01
Congenital anomalies of the systemic venous connection to the heart represent a rather wide and heterogeneous group of malformations, whose physiological consequences may vary from nil to the most severe form of systemic arterial desaturation. The malformations may be summarized as follows: (1) Left superior vena cava connected to the coronary sinus, interrupted inferior vena cava and absent right superior vena cava that do not indicate surgical repair 'per se', but require some technical attention during open heart surgery performed for other anomalies; (2) Left superior vena cava connected to the left atrium, due to incorporation of the coronary sinus into the left atrial cavity, resulting in a right-to-left-shunt; (3) Right superior vena cava or inferior vena cava draining into the left atrium, both are extremely rare and require treatment for the ensuing right-to-left shunt; (4) Total anomalous systemic venous connection to the left atrium, usually combined with atrial isomerism and other very complex heart malformations; (5) Cor triatriatum dexter, which has been frequently diagnosed as an anomalous venous connection for its similar hemodynamic consequences. Such anomalies are reviewed with particular respect to their surgical implications.
NASA Astrophysics Data System (ADS)
Zhang, Xiancheng; Noda, Shigeho; Himeno, Ryutaro; Liu, Hao
2017-06-01
We present a novel methodology and strategy to predict pressures and flow rates in the global cardiovascular network in different postures varying from supine to upright. A closed-loop, multiscale mathematical model of the entire cardiovascular system (CVS) is developed through an integration of one-dimensional (1D) modeling of the large systemic arteries and veins, and zero-dimensional (0D) lumped-parameter modeling of the heart, the cardiac-pulmonary circulation, the cardiac and venous valves, as well as the microcirculation. A versatile junction model is proposed and incorporated into the 1D model to cope with splitting and/or merging flows across a multibranched junction, which is validated to be capable of estimating both subcritical and supercritical flows while ensuring the mass conservation and total pressure continuity. To model gravitational effects on global hemodynamics during postural change, a robust venous valve model is further established for the 1D venous flows and distributed throughout the entire venous network with consideration of its anatomically realistic numbers and locations. The present integrated model is proven to enable reasonable prediction of pressure and flow rate waveforms associated with cardiopulmonary circulation, systemic circulation in arteries and veins, as well as microcirculation within normal physiological ranges, particularly in mean venous pressures, which well match the in vivo measurements. Applications of the cardiovascular model at different postures demonstrate that gravity exerts remarkable influence on arterial and venous pressures, venous returns and cardiac outputs whereas venous pressures below the heart level show a specific correlation between central venous and hydrostatic pressures in right atrium and veins.
Pi, Hongying; Ku, Hong'an; Zhao, Ting; Wang, Jie; Fu, Yicheng
2018-04-01
Active ankle movement is recommended intervention for preventing deep vein thrombosis effectively and easily by promoting venous return from the lower limbs. The active ankle dorsiflexion and plantar flexion movement guided by deep breathing is considered the most effective method, although outstanding problems remain, including low patient compliance and difficult motion essentials. The aims of this study were to compare the influence of different ankle active movements on venous return from the lower limbs and to suggest the optimal movement for preventing deep venous thrombosis in the lower limbs. A self-controlled study on 130 subjects was undertaken. The femoral venous hemodynamics of the left femoral vein and changes in pulse oxygen saturation and heart rate were compared among the three states of quiescent, active ankle 30° dorsiflexion movement, and active ankle 30° dorsiflexion with active plantar 45° flexion movement. The immediate master rates of the two ankle movements were examined before the study. The femoral venous hemodynamics of the left femoral vein were significantly higher in both movement states compared with the quiescent state. Moreover, no significant difference was found among the three states in terms of pulse oxygen saturation and heart rate. The immediate master rate was significantly higher in the active ankle 30° dorsiflexion movement than in the active ankle 30° dorsiflexion and active plantar 45° flexion movement. Therefore, active ankle 30° dorsiflexion movement guided by inspiration was found in this study to increase femoral venous hemodynamics, which heightened the immediate master rate but had no obvious influence on pulse oxygen saturation and heart rate. Active ankle 30° dorsiflexion movement guided by inspiration effectively promotes venous return from the lower limbs and is a better method to prevent deep vein thrombosis of the lower limbs.
Guo, Liang; Tabrizchi, Reza
2008-05-31
The arteriovenous fistula model of circulation can produce a high output and low peripheral resistance situation. Here, we have examined the effects of noradrenaline, vasopressin and sodium nitroprusside on cardiac index, mean arterial blood pressure, venous tone, resistance to venous return, arterial resistance, and blood volume in chronically shunted anaesthetized rats. The cardiac index of rats with chronic arteriovenous fistula (AVF) was significantly higher (36.65+/-2.28 ml/min per 100 g; (mean+/-S.E.M.; n=24) in comparison to sham-operated rats (20.04+/-0.86 ml/min per 100 g; mean+/-S.E.M.; n=8). Cardiac index did not significantly change during the infusion of noradrenaline (1.0, 3.0 and 10 microg/kg per min), vasopressin (10, 30, 100 ng/kg per min) or sodium nitroprusside (0.1, 0.3 and 1.0 microg/kg per min) compared to saline infusion in AVF animals. Infusion of noradrenaline significantly increased heart rate, dP/dt, mean circulatory filling pressure (Pmcf) and resistance to venous return without affecting mean arterial blood pressure when compared to saline infusion. Administration of vasopressin significantly increased dP/dt, mean arterial blood pressure, and Pmcf without affecting heart rate, resistance to venous return or arterial resistance compared to saline infusion. Infusion of sodium nitroprusside did not significantly affect any haemodynamic parameter measured when compared to saline infusion. The results indicate that the presence of chronic AVF alters responsiveness of the various segments of the circulatory system to vasoactive agents. Moreover, it produces a major impediment to overall changes that can normally be induced following the infusion of such agents.
2004-06-01
Abstract. The venous blood flow during stretching and deep breathing in the sitting posture was examined in the present study. First, an...increase in the venous return. Therefore, we suggest that stretching and deep breathing can be used sometimes as preventive measures for deep vein...thrombosis during prolonged sitting. Keywords. Venous blood flow, Near infrared spectroscopy, Deep vein thrombosis. 1. Introduction It has been
Ishikawa, N; Taki, K; Hojo, Y; Hagino, Y; Shigei, T
1978-09-01
The dog heart-lung preparations were prepared. The "equilibrium point", which could be defined as the point at which the cardiac output (CO)-curve and the venous return (VR)-curve crossed, when the CO and VR were plotted against the right atrial pressure, was recorded directly by utilizing an X-Y recorder. The CO-curve was obtained, as a locus of the equilibrium point, by raising and lowering the level of blood in the venous reservoir (competence test). The meaning of the procedure was shown to increase or decrease the mean systemic pressure, and to cause the corresponding parallel shift in the VR-curve. The VR-curve was obtained by changing myocardial contractility. When heart failure was induced by pentobarbital or by chloroform, the equilibrium point shifted downwards to the right, depicting the VR-curve. During development of the failure, the slopes of CO-curves decreased gradually. Effects of cinobufagin and norepinephrine were also analyzed. Utilization of the X-Y recorder enabled us to settle the uniform experimental conditions more easily, and to follow the effects of drugs continuously on a diagram equating the CO- and VR-curves (Gyton's scheme).
Hypoplastic left heart syndrome and pulmonary veno-occlusive disease in an infant.
D'Souza, Marise; Vergales, Jeffrey; Jayakumar, K Anitha
2013-01-01
This report describes an infant with heterotaxy syndrome and severe hypoplasia of the left heart who presented with profound cyanosis at birth despite a large patent ductus arteriosus. Pulmonary venous return was difficult to demonstrate by echocardiography. Angiography showed total anomalous pulmonary venous return via a plexus that drained through the paravertebral veins and bilateral superior vena cavae. Autopsy confirmed these findings, and histopathology demonstrated severe occlusive changes within the pulmonary veins.
Malone, P Colm; Agutter, P S
2009-08-01
According to the valve cusp hypoxia hypothesis (VCHH), deep venous thrombosis is caused by sustained non-pulsatile (streamline) venous blood flow. This leads to hypoxemia in the valve pockets; hypoxic injury to the inner (parietalis) endothelium of the cusp leaflets activates the elk-1/egr-1 pathway, leading to leukocyte and platelet swarming at the site of injury and, potentially, blood coagulation. Here, we propose an extension of the VCHH to account for chronic venous insufficiency. First, should the foregoing events not proceed to frank thrombogenesis, the valves may nevertheless be chronically injured and become incompetent. Serial incompetence in lower limb valves may then generate ''passive'' venous hypertension. Second, should ostial valve thrombosis obstruct venous return from muscles via tributaries draining into the femoral vein, as Virchow illustrated, ''active'' venous hypertension may supervene: muscle contraction would force the blood in the vessels behind the blocked ostial valves to re-route. Passive or active venous hypertension opposes return flow, leading to luminal hypoxemia and vein wall distension, which in turn may impair vasa venarum perfusion; the resulting mural endothelial hypoxia would lead to leukocyte invasion of the wall and remodelling of the media. We propose that varicose veins result if gross active hypertension stretches the valve ''rings'', rendering attached valves incompetent caudad to obstructed sites, replacing normal centripetal flow in perforating veins with centrifugal flow and over-distending those vessels. We also discuss how hypoxemia-related venous/capillary wall lesions may lead to accumulation of leukocytes, progressive blockage of capillary blood flow, lipodermosclerosis and skin ulceration.
1991-07-30
of etiologies that reduce cardiac output by mechanically obstructing venous return. E Central venous catheterization can be performed rapidly and...is planned that this will be tested in early August 1991. Data acquired will include arterial and venous blood pressure, heart rate, temperature...appropriate for PE acconplaned by rise in ZT02 & Increased venous pressures 17 No End rtIfact Yes Examine 7aveforn -changefilter 7 A5 DECLSION TREE FOR RM IN
Kotovskaia, A R; Fomina, G A
2010-01-01
The work was aimed at analysis and generalization of the hemodynamic data collected over 20 years from 26 cosmonauts flown 8 to 438 days aboard orbital stations Salyut 7 and Mir. The paper presents the results of ultrasonic investigations of the heart, arterial and venous peripheral vessels in different parts of human body, and measurements of leg veins capacity with the use of occlusive plethysmograpy. It was shown that in the resting condition such prime hemodynamic parameters as the pumping function of the heart and blood supply of the brain, and integral parameters, i.e. arterial pressure and heat rate, were best "protected" as they demonstrated stability throughout long exposure in microgravity. In the absence of gravitational stimulation, arterial resistance went down in essentially all vascular regions below the heart level; to put it differently, the anti-gravity distribution of the vascular tone was annulled gradually as unneeded in microgravity. Compared with the data about arteries, venous hemodynamics was found to be particularly sensitive considering the early advent and significance of changes. Venous return slowed down, resistance of the lower body vessels declined and capacity of the leg venous net increased. Functional testing with the lower body negative pressure revealed degradation of the gravity-dependent reactions that became more conspicuous as flight duration extended further. Cardiovascular deconditioning showed itself clearly on return to Earth's gravity by decreased g-tolerance during re-entry and orthostatic instability post flight. These investigations provided objective evidence for multifactorial genesis of orthostatic instability during space flight including blood redistribution, altered tone regulation of leg's venous and arterial vessels and hypovolemia.
Technical considerations in percutaneous hepatic perfusion--a multi-center experience.
Antoine, Radcliffe A
2011-03-01
Patients diagnosed with primary or metastatic liver cancer face a daunting future that is complicated by limited treatment options. Percutaneous hepatic perfusion is a novel approach to chemotherapy delivery that offers significant benefits over contemporary modalities. Percutaneous hepatic perfusion is a procedure in which a chemotherapeutic agent is administered at high doses via the hepatic artery where it perfuses the liver, is extracted and filtered using a veno-veno bypass circuit, a fenestrated multi-lumen double-balloon catheter, and two biocompatible hemoperfusion filters. Venous access is gained at the groin through the femoral vein after which the catheter is advanced and positioned in the inferior vena cava just below the right atrium.The catheter's proximal and distal balloons are inflated to occlude the inferior vena cava above and below the hepatic veins. The occlusion isolated the chemo-rich venous outflow of the liver from the systemic venous circulation. This maneuver also diverts venous blood returning to the heart from lower extremities of the azygos vein. Once the patient is on bypass, the agent is infused through the hepatic artery where it saturates the liver. The chemo-rich venous outflow is extracted through the double-balloon catheter by the bypass circuit. The blood is continuously filtered and cleared of the agent as it passes through the filters and returned to the patient through a catheter placed in the right internal jugular vein. A phase I study demonstrated efficacy with an overall radiographic response rate of 30% observed in treated patients. In 10 patients with ocular melanoma, a 50% overall response rate was observed, including two complete responses. The technique is minimally invasive and can be performed safely by a well-trained multi-disciplinary team. It offers significant benefits including multiple procedures without risks commonly associated with open abdominal surgery.
Technical Considerations in Percutaneous Hepatic Perfusion—A Multi-Center Experience
Antoine, Radcliffe A.
2011-01-01
Abstract: Patients diagnosed with primary or metastatic liver cancer face a daunting future that is complicated by limited treatment options. Percutaneous hepatic perfusion is a novel approach to chemotherapy delivery that offers significant benefits over contemporary modalities. Percutaneous hepatic perfusion is a procedure in which a chemotherapeutic agent is administered at high doses via the hepatic artery where it perfuses the liver, is extracted and filtered using a veno-veno bypass circuit, a fenestrated multi-lumen double-balloon catheter, and two biocompatible hemoperfusion filters. Venous access is gained at the groin through the femoral vein after which the catheter is advanced and positioned in the inferior vena cava just below the right atrium. The catheter’s proximal and distal balloons are inflated to occlude the inferior vena cava above and below the hepatic veins. The occlusion isolated the chemo-rich venous outflow of the liver from the systemic venous circulation. This maneuver also diverts venous blood returning to the heart from lower extremities of the azygos vein. Once the patient is on bypass, the agent is infused through the hepatic artery where it saturates the liver. The chemorich venous outflow is extracted through the double-balloon catheter by the bypass circuit. The blood is continuously filtered and cleared of the agent as it passes through the filters and returned to the patient through a catheter placed in the right internal jugular vein. A phase I study demonstrated efficacy with an overall radiographic response rate of 30% observed in treated patients. In 10 patients with ocular melanoma, a 50% overall response rate was observed, including two complete responses. The technique is minimally invasive and can be performed safely by a well-trained multi-disciplinary team. It offers significant benefits including multiple procedures without risks commonly associated with open abdominal surgery. PMID:21449232
The influence of tumour necrosis factor-alpha on the cardiovascular system of anaesthetized rats.
Tabrizchi, R
2001-03-01
The effects of two vasoactive agents (adenosine A2A agonist, CGS 21680, and adrenoceptor agonist, noradrenaline) were examined on cardiac output (CO), heart rate (HR), blood pressure (BP), mean circulatory filling pressure (Pmcf), resistance to venous return, arterial resistance, dP/dt, plasma levels of NO2-/NO3-, and inducible nitric oxide synthase (iNOS) activity in lungs ex vivo, following treatment with tumour necrosis factor-alpha (TNF-alpha; 30 microg/kg) in anaesthetized rats. Treatment with TNF-alpha produced significant reduction in CO (41+/-2%), dP/dt (26+/-3%), BP (26+/-2%) and Pmcf (27+/-4%; n=6; mean+/-SEM), but increased arterial resistance. There were no significant changes in the plasma levels of NO2-/NO3-levels over time following treatment with TNF-alpha, but there was a significant increase (approximately twofold) in the activity of the iNOS in the lungs of animals treated with TNF-alpha. Administration of CGS 21680 (1.0 microg/kg per min) significantly increased CO (44+/-6%), HR (12+/-2%), Pmcf (24+/-4%) and dP/dt (24+/-5%) in TNF-alpha-treated rats. CGS 21680 also significantly reduced arterial resistance (33+/-2%) without altering resistance to venous return in TNF-alpha-treated rats. While noradrenaline (1.0 microg/kg per min) infusion did not significantly increase CO, it did significantly increase HR (12+/-1%), BP (55+/-9%), Pmcf (47+/-5%), dP/dt (65+/-7%), resistance to venous return (64+/-20%), and arterial resistance (41+/-16%) in TNF-alpha-treated animals. The reduction in BP due to administration of TNF-alpha is the result of significant reduction in CO. Consequently, the decline in CO can be attributed to a combination of a negative inotropic effect as well as a reduction in Pmcf. It is evident that infusion with CGS 21680 could reverse the negative impact of TNF-alpha on CO by increasing dP/dt, Pmcf and HR as well as a reduction in arterial resistance. The fact that noradrenaline did not significantly increase CO in TNF-alpha-treated rats can be attributed to increased arterial resistance as well increase in resistance to venous return.
Hill, S. L.; Holt, D. W.
2007-01-01
Abstract: There has been much advancement in perfusion technology over its 50 years of progression. One of these techniques is vacuum-assisted venous drainage (VAVD). Many perfusionists augment venous drainage using VAVD, typically from a wall vacuum source. This study explores alternates to providing VAVD if the wall vacuum fails. In two porcine laboratories, ∼36 in. of 3/16-in. tubing was connected to a sucker return port and placed into the roller head next to the arterial pump. The vacuum was monitored with a DLP pressure monitoring system (Medtronic). This system was connected to small-bore tubing and attached to a stopcock on top of the reservoir. The vacuum was regulated using another stopcock connected to a non-filtered luer lock port on top of the reservoir or by a segment of 3 × 0.25-in.-diameter tubing attached to the vent port with a c-clamp. Vacuum drainage was achieved, ranging from −18 mmHg to −71 mmHg by manipulating the stopcock or c-clamp. Changes in venous drainage were seen by volume fluctuations in the venous reservoir. The vacuum was adjusted to account for dramatic changes. Augmented venous drainage using a roller pump can be achieved successfully during cardiopulmonary bypass (CPB). This method of active drainage can be used in lieu of wall suction or during times of emergency if wall suction fails. PMID:18293812
Segmental Blood Flow and Hemodynamic State of Lymphedematous and Nonlymphedematous Arms
Montgomery, Leslie D.; Dietrich, Mary S.; Armer, Jane M.; Stewart, B. R.
2011-01-01
Abstract Background Findings regarding the influence hemodynamic factors, such as increased arterial blood flow or venous abnormalities, on breast cancer treatment-related lymphedema are mixed. The purpose of this study was to compare segmental arterial blood flow, venous blood return, and blood volumes between breast cancer survivors with treatment-related lymphedema and healthy normal individuals without lymphedema. Methods and Results A Tetrapolar High Resolution Impedance Monitor and Cardiotachometer were used to compare segmental arterial blood flow, venous blood return, and blood volumes between breast cancer survivors with treatment-related lymphedema and healthy normal volunteers. Average arterial blood flow in lymphedema-affected arms was higher than that in arms of healthy normal volunteers or in contralateral nonlymphedema affected arms. Time of venous outflow period of blood flow pulse was lower in lymphedema-affected arms than in healthy normal or lymphedema nonaffected arms. Amplitude of the venous component of blood flow pulse signal was lower in lymphedema-affected arms than in healthy or lymphedema nonaffected arms. Index of venular tone was also lower in lymphedema-affected arms than healthy or lymphedema nonaffected arms. Conclusions Both arterial and venous components may be altered in the lymphedema-affected arms when compared to healthy normal arms and contralateral arms in the breast cancer survivors. PMID:21417765
Challenges of univentricular physiology in heterotaxy.
Jacobs, Marshall L; Mavroudis, Constantine
2011-04-01
Patients with heterotaxy syndrome exhibit an extensive constellation of congenital cardiac malformations, making these patients a challenging group to manage surgically. Many of these patients' hearts do not lend themselves to separation of the pulmonary and systemic circulations except by some modification of the Fontan procedure. Palliative procedures early in life are directed at creating a satisfactory balance of pulmonary and systemic blood flow and at the same time ensuring unobstructed pulmonary venous return. Early conversion from parallel pulmonary and systemic circulations to superior cavopulmonary connections is important, to reduce volume work of the systemic ventricle. Heterotaxy patients are generally considered a high-risk population with respect to eventual Fontan procedure. It is important to appreciate the unique and variable anatomy of the sinus node and conduction system and the potential for occult pulmonary venous obstruction, atrioventricular valve regurgitation, and recurrent cyanosis, which may be related to the development of pulmonary arteriovenous malformations.
Case report: Unilateral conduction hearing loss due to central venous occlusion.
Ribeiro, Phillip; Patel, Swetal; Qazi, Rizwan A
2016-05-07
Central venous stenosis is a well-known complication in patients with vascular access for hemodialysis. We report two cases involving patients on hemodialysis with arteriovenous fistulas who developed reversible unilateral conductive hearing loss secondary to critical stenosis of central veins draining the arteriovenous dialysis access. A proposed mechanism for the patients' reversible unilateral hearing loss is pterygoid venous plexus congestion leading to decreased Eustachian tube patency. Endovascular therapy was conducted to treat the stenosis and the hearing loss of both patients was returned to near normal after successful central venous angioplasty.
Total anomalous pulmonary venous return
... the heart do not attach normally to the left atrium (left upper chamber of the heart). Instead, they attach ... returns through the pulmonary (lung) veins to the left side of the heart, which sends blood out ...
NASA Technical Reports Server (NTRS)
Elliott, Morgan; Martin, David
2015-01-01
For my summer internship project, I organized a pilot study to analyze the effects of a cephalic fluid shift on venous return and right ventricular mechanics to increase right ventricular and venous knowledge. To accomplish this pilot study, I wrote a testing protocol, obtained Institutional Review Board (IRB) approval, completed subject payment forms, lead testing sessions, and analyzed the data. This experiment used -20deg head down tilt (20 HDT) as the ground based simulation for the fluid shift that occurs during spaceflight and compared it to data obtained from the seated and supine positions. Using echocardiography, data was collected for the right ventricle, hepatic vein, internal jugular vein, external jugular vein, and inferior vena cava. Additionally, non-invasive venous pressure measurements, similar to those soon to be done in-orbit, were collected. It was determined that the venous return from below the heard is increased during 20 HDT, which was supported by increased hepatic vein velocities, increased right ventricular inflow, and increased right ventricular strain at 20 HDT relative to seated values. Jugular veins in the neck undergo an increase in pressure and area, but no significant increase in flow, relative to seated values when a subject is tilted 20 HDT. Contrary to the initial expectations based on this jugular flow, there was no significant increase in central venous pressure, as evidenced by no change in Doppler indices for right arterial pressure or inferior vena cava diameter. It is suspected that these differences in pressure are due to the hydrostatic pressure indifference point shifting during tilt; there is a potential for a similar phenomenon with microgravity. This data will hopefully lead to a more in-depth understanding of the response of the body to microgravity and how those relate to the previously mentioned cardiovascular risk of fluid shift that is associated with spaceflight. These results were presented in greater detail to the Cardiovascular Laboratory and the Space Life Science Summer Institute, which helped me prepare for future graduate school research presentations. This internship allowed me to apply and expand the anatomy, physiology, and mechanics information I learned during my undergraduate degree in Biomedical Engineering to the cardiovascular system with the unique zero gravity perspective. Additionally, I was able to develop skills with data analysis techniques involving speckle tracking for ventricular strain and Doppler waveforms for blood velocities. Additionally, I was able to expand upon my previous work in the Cardiovascular Laboratory by writing a literature review on a data analysis project I completed last summer. Ultimately, this internship and venous relationship comparison project provided me with a significant learning experience and additional skill sets, which are applicable to my goals of attaining a Ph.D. in biomedical engineering with a focus on tissue engineering and the cardiovascular system.
Stroke Volume During Concomitant Apnea and Exercise: Influence of Gravity and Venous Return
NASA Astrophysics Data System (ADS)
Hoffmann, Uwe; Drager, Tobias; Steegmanns, Ansgar; Koesterer, Thomas; Linnarsson, Dag
2008-06-01
The responses of the cardiovascular system to intensive exercise (hiP) and combined stimuli by hiP and breath-hold (hiP-BH) for 20 s were examined during changing gravity (parabolic flight) and constant gravity (1g). The basic response to microgravity (μg) during low-intensity exercise was an increase in cardiac output (CO) and stroke volume (SV) as a result of augmented venous return. When onset of hiP was superimposed, the initial augmentation of CO and SV were increased further. In contrast, when BH was added, the increases of CO and SV were slowed. We propose that this was due to a transient increase of the pulmonary blood volume with the combination of μg and BH at large lung volume, creating a temporary imbalance between right ventricular input and left ventricular output. In addition, the BH- induced relative bradycardia may have contributed to a prolongation of the right-to- left indirect ventricular interdependence.
Early Ambulation After Microsurgical Reconstruction of the Lower Extremity.
Orseck, Michael J; Smith, Christopher Robert; Kirby, Sean; Trujillo, Manuel
2018-06-01
Successful outcomes after microsurgical reconstruction of the lower extremity include timely return to ambulation. Some combination of physical examination, ViOptix tissue oxygen saturation monitoring, and the implantable venous Doppler have shown promise in increasing sensitivity of current flap monitoring. We have incorporated this system into our postoperative monitoring protocol in an effort to initiate earlier dependency protocols. A prospective analysis of 36 anterolateral thigh free flap and radial forearm flaps for lower extremity reconstruction was performed. Indications for reconstruction were acute and chronic wounds, as well as oncologic resection. Twenty-three patients were able to ambulate and 3 were able to dangle their leg on the first postoperative day. One flap showed early mottling that improved immediately after elevation. After reelevation and return to baseline, the dependency protocol was successfully implemented on postoperative day 3. All flaps went on to successful healing. Physical examination, implantable venous Doppler, and ViOptix can be used reliably as an adjunct to increase the sensitivity of detecting poorly performing flaps during the postoperative progression of dependency.
Ercan, Sabriye; Çetin, Cem; Yavuz, Turhan; Demir, Hilmi M; Atalay, Yurdagül B
2018-05-01
Objective The aim of this study was to observe the change of the ankle joint range of motion, the muscle strength values measured with an isokinetic dynamometer, pain scores, quality of life scale, and venous return time in chronic venous insufficiency diagnosed patients by prospective follow-up after 12-week exercise program including isokinetic exercises. Methods The patient group of this study comprised 27 patients (23 female, 4 male) who were diagnosed with chronic venous insufficiency. An exercise program including isokinetic exercise for the calf muscle was given to patients three days per week for 12 weeks. At the end of 12 weeks, five of the patients left the study due to inadequate compliance with the exercise program. As a result, control data of 22 patients were included. Ankle joint range of active motion, isokinetic muscle strength, pain, quality of life, and photoplethysmography measurements were assessed before starting and after the exercise program. Results Evaluating changes of the starting and control data depending on time showed that all isokinetic muscle strength measurement parameters, range of motion, and overall quality of life values of patients improved. Venous return time values have also increased significantly ( p < 0.05). Conclusion In conclusion, increase in muscle strength has been provided with exercise therapy in patients with chronic venous insufficiency. It has been determined that the increase in muscle strength affected the venous pump and this ensured improvement in venous function and range of motion of the ankle. In addition, it has been detected that pain reduced and quality of life improved after the exercise program.
Strasberg, Steven M; Bhalla, Sanjeev; Sanchez, Luis A; Linehan, David C
2011-11-01
The risks of developing sinistral portal hypertension as a result of occlusion of the splenic vein close to its termination during a Whipple procedure are unclear. Our purpose was to compare the pattern of venous collateral development after splenic vein ligation in an extended Whipple procedure with the pattern of collateral development in cases of sinistral portal hypertension. Five patients underwent an extended Whipple procedure in which the splenic vein was divided and not reconstructed. Six to eight months later detailed mapping of venous return from the spleen was determined by contrast-enhanced multidetector computed tomography or in one case by 3D contrast-enhanced MRI. Spleen size and length of residual patent splenic vein were also measured. The literature on sinistral portal hypertension was evaluated to ascertain whether the venous collateral pattern in cases of left-sided portal hypertension was similar to the pattern that developed when the splenic vein was ligated at its termination in the Whipple procedure. A length of splenic vein remained patent in all five patients, measuring 4.5 to 11.5 cm from the spleen. Splenomegaly did not develop. Blood returned from the spleen by multiple collaterals including collaterals in the omentum and mesocolon. These types of collaterals do not develop in sinistral portal hypertension, nor is residual patent splenic vein seen. Ligation of the splenic vein close to its termination in five patients resulted in a pattern of venous return different from patients that have developed left-sided portal hypertension.
Biochemical Assessment of Stress in Cardiac Tissue in Response to Weightless Space Travel
NASA Technical Reports Server (NTRS)
Brunton, Laurence L.; Meszaros, J. Gary; Lio, Francisco M.
1997-01-01
The absence of unit gravity may cause physiological changes in the cardiovascular system. For instance, in the absence of Earth's gravity, venous return to the heart may increase due, in pan, to decreased pooling of the blood in the extremities. We hypothesize that this would produce an increase in the heart's work load ultimately resulting in hypertrophy.
Calf pump activity influencing venous hemodynamics in the lower extremity.
Recek, Cestmir
2013-03-01
Calf muscle pump is the motive force enhancing return of venous blood from the lower extremity to the heart. It causes displacement of venous blood in both vertical and horizontal directions, generates ambulatory pressure gradient between thigh and lower leg veins, and bidirectional streaming within calf perforators. Ambulatory pressure gradient triggers venous reflux in incompetent veins, which induces ambulatory venous hypertension in the lower leg and foot. Bidirectional flow in calf perforators enables quick pressure equalization between deep and superficial veins of the lower leg; the outward (into the superficial veins) oriented component of the bidirectional flow taking place during calf muscle contraction is no pathological reflux but a physiological centripetal flow streaming via great saphenous vein into the femoral vein. Calf perforators are communicating channels between both systems making them conjoined vessels; they are not involved in the generation of pathological hemodynamic situations, nor do they cause ambulatory venous hypertension. The real cause why recurrences develop has not as yet been cleared. Pressure gradient arising during calf pump activity between the femoral vein and the saphenous remnant after abolition of saphenous reflux triggers biophysical and biochemical events, which might induce recurrence. Thus, abolition of saphenous reflux removes the hemodynamic disturbance, but at the same time it generates precondition for reflux recurrence and for the comeback of the previous pathological situation; this chain of events has been called hemodynamic paradox.
Heparin or 0.9% sodium chloride to maintain central venous catheter patency: a randomized trial.
Schallom, Marilyn E; Prentice, Donna; Sona, Carrie; Micek, Scott T; Skrupky, Lee P
2012-06-01
To compare heparin (3 mL, 10 units/mL) and 0.9% sodium chloride (NaCl, 10 mL) flush solutions with respect to central venous catheter lumen patency. Single-center, randomized, open label trial. Medical intensive care unit and Surgical/Burn/Trauma intensive care unit at Barnes-Jewish Hospital, St. Louis, MO. Three hundred forty-one patients with multilumen central venous catheters. Patients with at least one lumen with a minimum of two flushes were included in the analysis. Patients were randomly assigned within 12 hrs of central venous catheter insertion to receive either heparin or 0.9% sodium chloride flush. The primary outcome was lumen nonpatency. Secondary outcomes included the rates of loss of blood return, inability to infuse or flush through the lumen (flush failure), heparin-induced thrombocytopenia, and catheter-related blood stream infection. Assessment for patency was performed every 8 hrs in lumens without continuous infusions for the duration of catheter placement or discharge from intensive care unit. Three hundred twenty-six central venous catheters were studied yielding 709 lumens for analysis. The nonpatency rate was 3.8% in the heparin group (n = 314) and 6.3% in the 0.9% sodium chloride group (n = 395) (relative risk 1.66, 95% confidence interval 0.86-3.22, p = .136). The Kaplan-Meier analysis for time to first patency loss was not significantly different (log rank = 0.093) between groups. The rates of loss of blood return and flush failure were similar between the heparin and 0.9% sodium chloride groups. Pressure-injectable central venous catheters had significantly greater rates of nonpatency (10.6% vs. 4.3%, p = .001) and loss of blood return (37.0% vs. 18.8%, p <.001) compared to nonpressure-injectable catheters. The frequencies of heparin-induced thrombocytopenia and catheter-related blood stream infection were similar between groups. 0.9% sodium chloride and heparin flushing solutions have similar rates of lumen nonpatency. Given potential safety concerns with the use of heparin, 0.9% sodium chloride may be the preferred flushing solution for short-term use central venous catheter maintenance.
Forbes, Thomas L; Harris, Jeremy R; Kribs, Stewart W
2012-06-01
The debate regarding the possible link between chronic cerebrospinal venous insufficiency and multiple sclerosis (MS) is continuously becoming more and more contentious due to the current lack of level 1 evidence from randomized trials. Regardless of this continued uncertainty surrounding the safety and efficacy of this therapy, MS patients from Canada, and other jurisdictions, are traveling abroad to receive central venous angioplasty and, unfortunately, some also receive venous stents. They often return home with few instructions regarding follow-up or medical therapy. In response we propose some interim, practical recommendations for post-procedural surveillance and medical therapy, until further information is available.
A Simple Model of the Pulmonary Circulation for Hemodynamic Study and Examination.
ERIC Educational Resources Information Center
Gaar, Kermit A., Jr.
1983-01-01
Describes a computer program allowing students to study such circulatory variables as venus return, cardiac output, mean circulatory filling pressure, resistance to venous return, and equilibrium point. Documentation for this Applesoft program (or diskette) is available from author. (JM)
Postural effects on the noninvasive baselines of ventricular performance
NASA Technical Reports Server (NTRS)
Lance, V. Q.; Spodick, D. H.
1977-01-01
The effects of posture on time-based noninvasive measurements were determined utilizing the sequence supine-sitting-standing in a formal protocol in which observer biases were eliminated by blinding the measurement and calculation phases. Compared to the supine posture, the sitting and standing postures produced significant increases in heart rate, isovolumic contraction time, pre-ejection period and pre-ejection period/left-ventricular ejection time and significant decreases in ejection time and ejection time index. The response patterns are consistent with the hemodynamic correlates cited in the literature which show increased adrenergic activity and decreased venous return in the sitting and standing postures, the effect on venous return being dominant.
Vukicevic, M; Conover, T; Jaeggli, M; Zhou, J; Pennati, G; Hsia, TY; Figliola, RS
2014-01-01
Respiration influences the subdiaphragmatic venous return in the total cavopulmonary connection (TCPC) of the Fontan circulation whereby both the inferior vena cava (IVC) and hepatic vein flows can experience retrograde motion. Controlling retrograde flows could improve patient outcomes. Using a patient-specific model within a Fontan mock circulatory system with respiration, we inserted a valve into the IVC to examine its effects on local hemodynamics while varying retrograde volumes by changing vascular impedances. A bovine valved conduit reduced IVC retrograde flow to within 3% of antegrade flow in all cases. The valve closed only under conditions supporting retrograde flow and its effects on local hemodynamics increased with larger retrograde volume. Liver and TCPC pressures improved only while the valve leaflets were closed while cycle-averaged pressures improved only slightly (italic>1 mm Hg). Increased pulmonary vascular resistance raised mean circulation pressures but the valve functioned and cardiac output improved and stabilized. Power loss across the TCPC improved by 12–15% (pbold>0.05) with a valve. The effectiveness of valve therapy is dependent on patient vascular impedance. PMID:24814833
NASA Astrophysics Data System (ADS)
Moore, James E., Jr.; Bertram, Christopher D.
2018-01-01
The supply of oxygen and nutrients to tissues is performed by the blood system and involves a net leakage of fluid outward at the capillary level. One of the principal functions of the lymphatic system is to gather this fluid and return it to the blood system to maintain overall fluid balance. Fluid in the interstitial spaces is often at subatmospheric pressure, and the return points into the venous system are at pressures of approximately 20 cmH2O. This adverse pressure difference is overcome by the active pumping of collecting lymphatic vessels, which feature closely spaced one-way valves and contractile muscle cells in their walls. Passive vessel squeezing causes further pumping. The dynamics of lymphatic pumping have been investigated experimentally and mathematically, revealing complex behaviors that indicate that the system performance is robust against minor perturbations in pressure and flow. More serious disruptions can lead to incurable swelling of tissues called lymphedema.
Aydın, Kutlay; Tokur, Murat Emre; Ergan, Begüm
2018-01-01
A persistent left-sided superior vena cava (PLSVC) is the most frequent abnormality of the venous system; however, it is not a very well-known variation among physicians. Herein we report the case of a patient with a PLSVC who was diagnosed after central venous catheterization (CVC). An 80-year-old man was admitted to the emergency room with cardiopulmonary arrest. After the return of spontaneous circulation, CVC was blindly performed from the left jugular vein without any complications. However, routine chest X-ray after catheterization revealed that the catheter was moving down directly to the left heart. Thoracic computed tomography showed the right brachiocephalic vein draining into the left brachiocephalic vein and forming the left superior vena cava in front of the aortic arch. The left superior vena cava merged into the right atrium after crossing the left pulmonary artery. CVC is widely used in clinical practice, and therefore clinicians should be aware of possible variations in central veins, particularly during blind catheterization.
Influence of Gravity on Blood Volume and Flow Distribution
NASA Technical Reports Server (NTRS)
Pendergast, D.; Olszowka, A.; Bednarczyk, E.; Shykoff, B.; Farhi, L.
1999-01-01
In our previous experiments during NASA Shuttle flights SLS 1 and 2 (9-15 days) and EUROMIR flights (30-90 days) we observed that pulmonary blood flow (cardiac output) was elevated initially, and surprisingly remained elevated for the duration of the flights. Stroke volume increased initially and then decreased, but was still above 1 Gz values. As venous return was constant, the changes in SV were secondary to modulation of heart rate. Mean blood pressure was at or slightly below 1 Gz levels in space, indicating a decrease in total peripheral resistance. It has been suggested that plasma volume is reduced in space, however cardiac output/venous return do not return to 1 Gz levels over the duration of flight. In spite of the increased cardiac output, central venous pressure was not elevated in space. These data suggest that there is a change in the basic relationship between cardiac output and central venous pressure, a persistent "hyperperfusion" and a re-distribution of blood flow and volume during space flight. Increased pulmonary blood flow has been reported to increase diffusing capacity in space, presumably due to the improved homogeneity of ventilation and perfusion. Other studies have suggested that ventilation may be independent of gravity, and perfusion may not be gravity- dependent. No data for the distribution of pulmonary blood volume were available for flight or simulated microgravity. Recent studies have suggested that the pulmonary vascular tree is influenced by sympathetic tone in a manner similar to that of the systemic system. This implies that the pulmonary circulation is dilated during microgravity and that the distribution of blood flow and volume may be influenced more by vascular control than by gravity. The cerebral circulation is influenced by sympathetic tone similarly to that of the systemic and pulmonary circulations; however its effects are modulated by cerebral autoregulation. Thus it is difficult to predict if cerebral perfusion is increased and if there is edema in space. Anecdotal evidence suggests there may be cerebral edema early in flight. Cerebral artery velocity has been shown to be elevated in simulated microgravity. The elevated cerebral artery velocity during simulated microgravity may reflect vasoconstriction of the arteries and not increased cerebral blood flow. The purpose of our investigations was to evaluate the effects of alterations in simulated gravity (+/-), resulting in changes in cardiac output (+/-), and on the blood flow and volume distribution in the lung and brain of human subjects. The first hypothesis of these studies was that blood flow and volume would be affected by gravity, but their distribution in the lung would be independent of gravity and due to vasoactivity changing vascular resistance in lung vessels. The vasodilitation of the lung vasculature (lower resistance) along with increased "compliance" of the heart could account for the absence of increased central venous pressure in microgravity. Secondly, we postulate that cerebral blood velocity is increased in microgravity due to large artery vasoconstriction, but that cerebral blood flow would be reduced due to autoregulation.
Duff, D F; Nihill, M R; McNamara, D G
1977-06-01
Twenty-eight cases of infradiaphragmatic total anomalous pulmonary venous return are presented, 17 without associated complex intracardiac anomalies (group A), and 11 with additional complex lesions (group B). The anomalous site of connection was to the portal vein in 19 cases (68%), to the inferior vena cava in 4 (14%), the ductus venosus in 2 (7%), to the left hepatic vein in 2 (7%), and unknown in one. A patent foramen ovale was present in 82 per cent of cases in group A and 40 per cent in group B and was frequently associated with a small left atrium and left ventricle. Nine cases (8 in group A; 1 in group B) had surgical correction, with 3 long-term survivors. The surgical mortality was 66 per cent. The postoperative haemodynamic status of the 3 surviving patients is very satisfactory, though 1 had a residual atrial septal defect. Factors which adversely affected the surgical outcome were: (1) a critically ill infant, (2) small left atrium and left ventricle, (3) a patent foramen ovale rather than atrial septal defect, (4) systemic arterial oxygen saturation less than 70 per cent, and (5) pulmonary arterial pressure in excess of systemic arterial pressure. The mortality for the entire series was 93 per cent.
Stirbys, Petras
2006-01-01
Cardiac resynchronization therapy appears to be useful for patients with severe chronic congestive heart failure. However, many questions still arise concerning the effectiveness of this kind of therapy since hemodynamic improvement is not observed in all patients. Heterogeneity of conclusions reported by several multicenter clinical trials and prominent experts demonstrates that many uncertainties related to cardiac resynchronization therapy still exist. We tried to reveal some inadequacies in clinical results by focusing on cardiac venous blood return which is likely complicated by the presence of lead inside the coronary sinus and its branches. Downstream traversing lead may occlude (partially or completely) the ostia of minor tributaries and target vein of lead final positioning. Thrombosis may also be incited within the coronary sinus itself. Remaining lumen predetermined by the lead body and subsequent thrombosis may be insufficient to provide adequate blood flow. Resulting detrimental venous return presumably may slightly depress myocardial contractility which may be significant in very sensitive group of patients assigned to the New York Heart Association class III or IV. Cardiac venous blood pumping conditions (or venous drainage) are likely also complicated by abnormal activation of left ventricle. The contributory role of these two subtle causes unfavorably influencing venous drainage is still unknown. It may be treated as a hypothetical attempt to find the clue and needs future studies for verification.
A review of the hemodynamic effects of external leg and lower body compression.
Helmi, M; Gommers, D; Groeneveld, A B J
2014-03-01
External leg and lower body compression (ELC) has been used for decades in the prevention of deep vein thrombosis and the treatment of leg ischemia. Because of systemic effects, the methods have regained interest in anesthesia, surgery and critical care. This review intends to summarize hemodynamic effects and their mechanisms. Compilation of relevant literature published in English as full paper and retrieved from Medline. By compressing veins, venous stasis is diminished and venous return and arterial blood flow are increased. ELC has been suggested to improve systemic hemodynamics, in different clinical settings, such as postural hypotension, anesthesia, surgery, shock, cardiopulmonary resuscitation and mechanical ventilation. However, the hemodynamic alterations depend upon the magnitude, extent, cycle, duration and thus the modality of ELC, when applied in a static or intermittent fashion (by pneumatic inflation), respectively. ELC may help future research and optimizing treatment of hemodynamically unstable, surgical or critically ill patients, independent of plasma volume expansion.
Olivier, L C; Ostovan, D; Heywinkel, W; Kendoff, D; Wolfhard, U
2007-11-01
Despite the broad use of low molecular weight heparin, deep vein thrombosis is still a relevant risk for immobilized patients in orthopedic surgery. Patients can reduce this risk by active training exercises with a muscle pump. The aim of this study was to test the acceptance and effect of a self-developed training device to accelerate venous return as well as a technical optimization. The device was installed for in-patients in orthopedic and traumatology departments. A simple pillow-like device was developed, which can be positioned against the foot end of the patient's bed (Phlebostep). The device gives a sound-based feedback to the patient while pushing actively against it with complete ankle flexion. A digital integrated counter device allows direct feedback to the physician and nursing staff at any time. Initial testing including duplex sonography for venous flow measurements were done on 10 orthopedic in-patients. Prior testing on 7 healthy volunteers was carried out to define the effect of various amounts of pressure on the Phlebostep on the venous blood flow. Additionally, a questionnaire on the general acceptance and user-friendliness was filled out by 84 patients who had used the Phlebostep. The optimal pressure force was defined as 35 mmHg for further measurements. The venous flow measurements in the 10 postoperative patients revealed an increased venous blood flow in the affected leg by an average of 99.9%. Analysis of the questionnaire from the 84 patients showed a high degree of acceptance. In addition to the technical feasibility, this study showed that use of the Phlebostep resulted on average in a doubling of venous return. The increase of venous flow offers an additional effective device for thrombosis prophylaxis through patient's own active movements and is clearly superior to the use of devices such as antithrombosis stockings alone. The Phlebostep found a high degree of acceptance with the patients.
Palada, Ivan; Bakovic, Darija; Valic, Zoran; Obad, Ante; Ivancev, Vladimir; Eterovic, Davor; Shoemaker, J Kevin; Dujic, Zeljko
2008-04-30
Involuntary breathing movements (IBM) that occur in the struggle phase of maximal apneas produce waves of negative intrathoracic pressure. This could augment the venous return, increasing thereby the cardiac output and gas exchange, and release the fresh blood from venous pools of spleen and liver. To test these hypotheses we used photoplethysmography and ultrasound for assessment of hemodynamics and spleen size before, during and after maximal dry apneas at large lung volume in 7 trained divers. During the easy-going phase cardiac output was reduced about 40%, due to reduction in stroke volume and in presence of reduced inferior vena cava venous return, while the spleen contracted for about 60 ml. Towards the end of the struggle phase, in presence of intense IBM, the spleen volume further decreased for about 70 ml, while cardiac output and caval flow almost renormalized. In conclusion, IBM coincide with splenic volume reduction and restoration of hemodynamics, likely facilitating the use of the last oxygen reserves before apnea cessation.
A System Approach to Navy Medical Education and Training. Appendix 22. Otolaryngology Technician.
1974-08-31
PROCEDURES TO PATIENT 12 PEXPLAIN LUMBAR PUNCTURE PROCEDURES TO PATIENT 13 IMEASURE/WEIGH PATIENT OR PERSONNEL 14 ICHECK CENTRAL VENOUS PRESSURE 15 TAKE...BLOOD PRESSURE 16 [CHECK RADIAL AWRIST) PULSE 17 ICHECK FEMORAL PULSE FOR PRESENCE AND QUALITY 8 IDETERMINE APICAL PULSE RATE/RHYTHM WITH STETHESCOPE 19... ICHECK PATIENTS TEMPERATURE 2U ICHECK /COUNT RESPIRATIONS 21 IPERFORM CIRCULATION CHECK, E.G. COLOR, PULSE, TEMPERATURE OF ISKIN, CAPILLARY RETURN 22
Yavorcik, K. J.; Reighard, D. A.; Misra, S. P.; Cotter, L. A.; Cass, S. P.; Wilson, T. D.
2009-01-01
Considerable data show that the vestibular system contributes to blood pressure regulation. Prior studies reported that lesions that eliminate inputs from the inner ears attenuate the vasoconstriction that ordinarily occurs in the hindlimbs of conscious cats during head-up rotations. These data led to the hypothesis that labyrinthine-deficient animals would experience considerable lower body blood pooling during head-up postural alterations. The present study tested this hypothesis by comparing blood flow though the femoral artery and vein of conscious cats during 20–60° head-up tilts from the prone position before and after removal of vestibular inputs. In vestibular-intact animals, venous return from the hindlimb dropped considerably at the onset of head-up tilts and, at 5 s after the initiation of 60° rotations, was 66% lower than when the animals were prone. However, after the animals were maintained in the head-up position for another 15 s, venous return was just 33% lower than before the tilt commenced. At the same time point, arterial inflow to the limb had decreased 32% from baseline, such that the decrease in blood flow out of the limb due to the force of gravity was precisely matched by a reduction in blood reaching the limb. After vestibular lesions, the decline in femoral artery blood flow that ordinarily occurs during head-up tilts was attenuated, such that more blood flowed into the leg. Contrary to expectations, in most animals, venous return was facilitated, such that no more blood accumulated in the hindlimb than when labyrinthine signals were present. These data show that peripheral blood pooling is unlikely to account for the fluctuations in blood pressure that can occur during postural changes of animals lacking inputs from the inner ear. Instead, alterations in total peripheral resistance following vestibular dysfunction could affect the regulation of blood pressure. PMID:19793952
Model of complete separation of the hepatic veins from the systemic venous system.
Brizard, C P; Goussef, N; Chachques, J C; Carpentier, A F
2000-12-01
In patients undergoing a Fontan operation, partial diversion of the hepatic veins to the pulmonary venous atrium has been tried with various techniques. They failed because of the development of intrahepatic collaterals leading to an unacceptable right-to-left shunting. We postulate that to avoid the formation of intrahepatic collaterals, the totality of the liver has to be drained into the same pressure compartment. We have designed a model of cavopulmonary anastomosis in which a prosthetic conduit reproduces an azygos continuation, associated with the diversion of the totality of the hepatic venous return. This article reports on the early hemodynamics and the fate of the separation of the two venous compartments in long-term survivors. Eighteen goats were operated on; the pulmonary artery and hepatic vein pressures were recorded. During month 2, an opacification of the inferior vena cava and the cavopulmonary connection was performed. Between months 6 and 14, another opacification was performed, together with pressure recording at both ends of the conduit. Postoperatively the pulmonary artery pressure was pulsatile with a mean of 10 mm Hg and the hepatic vein pressure was 0 mm Hg. The first angiogram showed patent tubes with fast progression of the contrast. Throughout the inferior vena cava injection, there was no opacification of the portal or hepatic veins. The late study showed a narrowed conduit in all animals. During the injection, a collateral was injected, feeding into the inferior mesenteric vein. No collateral circulation could be seen draining directly into the liver. The median gradient between the two ends of the conduit was 11 mm Hg. The isolation of the entire hepatic venous drainage is feasible and efficient for the separation of two pressure compartments. No intrahepatic collaterals are observed with this model at short- or long-term follow-up. The separation of the hepatic venous drainage should persist without collateral circulation as long as the inferior vena cava pressure stays at the levels observed in Fontan circulation.
Liu, Lin; He, Yihua; Li, Zhian; Gu, Xiaoyan; Zhang, Ye; Zhang, Lianzhong
2014-07-01
The use of low-frequency high-definition power Doppler in assessing and defining pulmonary venous connections was investigated. Study A included 260 fetuses at gestational ages ranging from 18 to 36 weeks. Pulmonary veins were assessed by performing two-dimensional B-mode imaging, color Doppler flow imaging (CDFI), and low-frequency high-definition power Doppler. A score of 1 was assigned if one pulmonary vein was visualized, 2 if two pulmonary veins were visualized, 3 if three pulmonary veins were visualized, and 4 if four pulmonary veins were visualized. The detection rate between Exam-1 and Exam-2 (intra-observer variability) and between Exam-1 and Exam-3 (inter-observer variability) was compared. In study B, five cases with abnormal pulmonary venous connection were diagnosed and compared to their anatomical examination. In study A, there was a significant difference between CDFI and low-frequency high-definition power Doppler for the four pulmonary veins observed (P < 0.05). The detection rate of each pulmonary vein when employing low-frequency high-definition power Doppler was higher than that when employing two-dimensional B-mode imaging or CDFI. There was no significant difference between the intra- and inter-observer variabilities using low-frequency high-definition power Doppler display of pulmonary veins (P > 0.05). The coefficient correlation between Exam-1 and Exam-2 was 0.844, and the coefficient correlation between Exam-1 and Exam-3 was 0.821. In study B, one case of total anomalous pulmonary venous return and four cases of partial anomalous pulmonary venous return were diagnosed by low-frequency high-definition power Doppler and confirmed by autopsy. The assessment of pulmonary venous connections by low-frequency high-definition power Doppler is advantageous. Pulmonary venous anatomy can and should be monitored during fetal heart examination.
Development of Meharry Medical College Prostate Cancer Research Program
2010-03-01
breakfast until their blood was drawn the next morning before 9:00 a.m. by a certified phlebotomist/registered nurse. 30 ml fasting venous blood was drawn...for each participnats. Participants were asked to return the next day without taking breakfast , and at the second visit 30 ml fasting venous blood...Ogunkua continue to develop their research laboratories with great success. They have independent funding and their laboratory continues to grow to
1994-04-01
that the peripheral vasoconstriction resulting from cold exposure leads to an increase in central venous return, increased central venous pressure, and...AD-A279 775 -; lilli IIIIIII lIII 11lU~lMuli/II I IIIll 1993 COMMAND HISTORY Compiled by R. E. Gadolin and K. S. Mayer DTIC SL ELECTE MAYSI11941) v F...distribution unlimited. NAVAL AEROSPACE MEDICAL RESEARCH LABORATORY 51 HOVEY ROAD, PENSACOLA, FLORIDA 32508-1046 1993 COMMAND HISTORY Compiled by R.E. Gadolin
The pathophysiology of heart failure.
Kemp, Clinton D; Conte, John V
2012-01-01
Heart failure is a clinical syndrome that results when the heart is unable to provide sufficient blood flow to meet metabolic requirements or accommodate systemic venous return. This common condition affects over 5 million people in the United States at a cost of $10-38 billion per year. Heart failure results from injury to the myocardium from a variety of causes including ischemic heart disease, hypertension, and diabetes. Less common etiologies include cardiomyopathies, valvular disease, myocarditis, infections, systemic toxins, and cardiotoxic drugs. As the heart fails, patients develop symptoms which include dyspnea from pulmonary congestion, and peripheral edema and ascites from impaired venous return. Constitutional symptoms such as nausea, lack of appetite, and fatigue are also common. There are several compensatory mechanisms that occur as the failing heart attempts to maintain adequate function. These include increasing cardiac output via the Frank-Starling mechanism, increasing ventricular volume and wall thickness through ventricular remodeling, and maintaining tissue perfusion with augmented mean arterial pressure through activation of neurohormonal systems. Although initially beneficial in the early stages of heart failure, all of these compensatory mechanisms eventually lead to a vicious cycle of worsening heart failure. Treatment strategies have been developed based upon the understanding of these compensatory mechanisms. Medical therapy includes diuresis, suppression of the overactive neurohormonal systems, and augmentation of contractility. Surgical options include ventricular resynchronization therapy, surgical ventricular remodeling, ventricular assist device implantation, and heart transplantation. Despite significant understanding of the underlying pathophysiological mechanisms in heart failure, this disease causes significant morbidity and carries a 50% 5-year mortality. Copyright © 2012 Elsevier Inc. All rights reserved.
Kishore, R; Sankar, T Bavani; Anandi, A; Nedunchezhian, S; Murugan, Valarmathy
2016-10-01
Perforators are those which connect the superficial and deep venous system either directly to main veins or indirectly through the muscular and soleal venous plexus. The emergence of minimally invasive techniques like ambulatory phlebectomy (AP) and foam sclerotherapy (FS) has led to increasing interest about the appropriate therapy for the treatment of isolated perforator incompetence. There have been no studies which have compared the effectiveness of these in-office procedures in isolated perforator incompetence due to the low prevalence of cases. The primary goal of this study is to compare the clinical parameters (return to normal activity, primary symptom relief), functional parameters (procedure time, change in disease severity, course of venous ulcer), and duplex parameters (recurrence in treated veins, complete occlusion of treated veins) in the management of leg varicosities having isolated primary perforator incompetence by ambulatory phlebectomy and duplex guided foam sclerotherapy. Though the procedure time was shorter with FS than AP, the other parameters of primary symptom relief such as change in disease severity, faster healing of venous ulcer, complete occlusion of treated veins in follow-up duplex examination, and lower recurrence of treated veins are better with AP than FS. In conclusion, the interruption of perforators is effective in decreasing the symptoms of chronic venous insufficiency and for the rapid healing of ulcers. The interruption of the incompetent perforating veins appears to be essential to decrease ambulatory venous hypertension. It is apparent from this study that ambulatory phlebectomy stands distinct with enormous benefits and serves as a superior alternative to foam sclerotherapy in treating patients with isolated perforator incompetence.
Cardiac Pressure Changes with Venous Gas Embolism and Decompression
1994-04-01
inferior vena cava via the left femoral vein for venous access. Airway pressure was measured from a connector at the proximal end of the endotracheal...Hartley), mount- ed in a 7-9 m acrylic cuff was surgically placed around the inferior vena cava via laparotomy, approximately 1-2 cm above the renal...pressure and decreasing cardiac output which in return may cause the left atrial pressure to fall below that of the right atrium . Recent studies have
Neonatal venous cerebral hemorrhage. Report of two cases.
Misra, Sanjay N; Misra, Ashish K
2003-10-15
Intracranial pathological changes can occur as a result of impaired craniocervical venous return. Thrombosis of central venous access catheters was demonstrated in two neonates born at 38 and 27 weeks' gestation. Neither infant developed hemorrhage of prematurity as confirmed on cranial ultrasonography. Clinical evidence of vena cava thrombosis and associated spontaneous intraventricular hemorrhage developed on Day 24 and 36, respectively, and these findings were confirmed on imaging studies. In one infant the hemorrhage was accompanied by communicating hydrocephalus. The cause of the intracranial disease was attributable to the retrograde cerebral venous congestion. This, together with the primitive venous bed developing in the periventricular region, was associated with the spontaneous hemorrhage in the region of the foramen of Monro. To the authors' knowledge, this is the first report in the English-language literature of spontaneous neonatal intracerebral hemorrhage, due to thrombosis of the superior or inferior vena cava. The natural history of this condition is resolution without sequelae after appropriate therapeutic intervention for the vena cava thrombosis.
Transposition of the great arteries
... that carry blood away from the heart -- the aorta and the pulmonary artery -- are switched (transposed). ... side of the heart and travels out the aorta to the body. In TGA, venous blood returns ...
Cardiopulmonary Changes with Moderate Decompression in Rats
NASA Technical Reports Server (NTRS)
Robinson, R.; Little, T.; Doursout, M.-F.; Butler, B. D.; Chelly, J. E.
1996-01-01
Sprague-Dawley rats were compressed to 616 kPa for 120 min then decompressed at 38 kPa/min to assess the cardiovascular and pulmonary responses to moderate decompression stress. In one series of experiments the rats were chronically instrumented with Doppler ultrasonic probes for simultaneous measurement of blood pressure, cardiac output, heart rate, left and right ventricular wall thickening fraction, and venous bubble detection. Data were collected at base-line, throughout the compression/decompression protocol, and for 120 min post decompression. In a second series of experiments the pulmonary responses to the decompression protocol were evaluated in non-instrumented rats. Analyses included blood gases, pleural and bronchoalveolar lavage (BAL) protein and hemoglobin concentration, pulmonary edema, BAL and lung tissue phospholipids, lung compliance, and cell counts. Venous bubbles were directly observed in 90% of the rats where immediate post-decompression autopsy was performed and in 37% using implanted Doppler monitors. Cardiac output, stroke volume, and right ventricular wall thickening fractions were significantly decreased post decompression, whereas systemic vascular resistance was increased suggesting a decrease in venous return. BAL Hb and total protein levels were increased 0 and 60 min post decompression, pleural and plasma levels were unchanged. BAL white blood cells and neutrophil percentages were increased 0 and 60 min post decompression and pulmonary edema was detected. Venous bubbles produced with moderate decompression profiles give detectable cardiovascular and pulmonary responses in the rat.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dhainaut, J.F.; Devaux, J.Y.; Monsallier, J.F.
1986-07-01
Continuous positive pressure ventilation is associated with a reduction in left ventricular preload and cardiac output, but the mechanisms responsible are controversial. The decrease in left ventricular preload may result exclusively from a decreased systemic venous return due to increased pleural pressure, or from an additional effect such as decreased left ventricular compliance. To determine the mechanisms responsible, we studied the changes in cardiac output induced by continuous positive pressure ventilation in eight patients with the adult respiratory distress syndrome. We measured cardiac output by thermodilution, and biventricular ejection fraction by equilibrium gated blood pool scintigraphy. Biventricular end-diastolic volumes weremore » then calculated by dividing stroke volume by ejection fraction. As positive end-expiratory pressure increased from 0 to 20 cm H/sub 2/O, stroke volume and biventricular end-diastolic volumes fell about 25 percent, and biventricular ejection fraction remained unchanged. At 20 cm H/sub 2/O positive end-expiratory pressure, volume expansion for normalizing cardiac output restored biventricular end-diastolic volumes without markedly changing biventricular end-diastolic transmural pressures. The primary cause of the reduction in left ventricular preload with continuous positive pressure ventilation appears to be a fall in venous return and hence in right ventricular stroke volume, without evidence of change in left ventricular diastolic compliance.« less
[Experts consensus on the management of the right heart function in critically ill patients].
Wang, X T; Liu, D W; Zhang, H M; Long, Y; Guan, X D; Qiu, H B; Yu, K J; Yan, J; Zhao, H; Tang, Y Q; Ding, X; Ma, X C; Du, W; Kang, Y; Tang, B; Ai, Y H; He, H W; Chen, D C; Chen, H; Chai, W Z; Zhou, X; Cui, N; Wang, H; Rui, X; Hu, Z J; Li, J G; Xu, Y; Yang, Y; Ouyan, B; Lin, H Y; Li, Y M; Wan, X Y; Yang, R L; Qin, Y Z; Chao, Y G; Xie, Z Y; Sun, R H; He, Z Y; Wang, D F; Huang, Q Q; Jiang, D P; Cao, X Y; Yu, R G; Wang, X; Chen, X K; Wu, J F; Zhang, L N; Yin, M G; Liu, L X; Li, S W; Chen, Z J; Luo, Z
2017-12-01
To establish the experts consensus on the right heart function management in critically ill patients. The panel of consensus was composed of 30 experts in critical care medicine who are all members of Critical Hemodynamic Therapy Collaboration Group (CHTC Group). Each statement was assessed based on the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) principle. Then the Delphi method was adopted by 52 experts to reassess all the statements. (1) Right heart function is prone to be affected in critically illness, which will result in a auto-exaggerated vicious cycle. (2) Right heart function management is a key step of the hemodynamic therapy in critically ill patients. (3) Fluid resuscitation means the process of fluid therapy through rapid adjustment of intravascular volume aiming to improve tissue perfusion. Reversed fluid resuscitation means reducing volume. (4) The right ventricle afterload should be taken into consideration when using stroke volume variation (SVV) or pulse pressure variation (PPV) to assess fluid responsiveness.(5)Volume overload alone could lead to septal displacement and damage the diastolic function of the left ventricle. (6) The Starling curve of the right ventricle is not the same as the one applied to the left ventricle,the judgement of the different states for the right ventricle is the key of volume management. (7) The alteration of right heart function has its own characteristics, volume assessment and adjustment is an important part of the treatment of right ventricular dysfunction (8) Right ventricular enlargement is the prerequisite for increased cardiac output during reversed fluid resuscitation; Nonetheless, right heart enlargement does not mandate reversed fluid resuscitation.(9)Increased pulmonary vascular resistance induced by a variety of factors could affect right heart function by obstructing the blood flow. (10) When pulmonary hypertension was detected in clinical scenario, the differentiation of critical care-related pulmonary hypertension should be a priority. (11) Attention should be paid to the change of right heart function before and after implementation of mechanical ventilation and adjustment of ventilator parameter. (12) The pulmonary arterial pressure should be monitored timingly when dealing with critical care-related pulmonary hypertension accompanied with circulatory failure.(13) The elevation of pulmonary aterial pressure should be taken into account in critical patients with acute right heart dysfunction. (14) Prone position ventilation is an important measure to reduce pulmonary vascular resistance when treating acute respiratory distress syndrome patients accompanied with acute cor pulmonale. (15) Attention should be paid to right ventricle-pulmonary artery coupling during the management of right heart function. (16) Right ventricular diastolic function is more prone to be affected in critically ill patients, the application of critical ultrasound is more conducive to quantitative assessment of right ventricular diastolic function. (17) As one of the parameters to assess the filling pressure of right heart, central venous pressure can be used to assess right heart diastolic function. (18). The early and prominent manifestation of non-focal cardiac tamponade is right ventricular diastolic involvement, the elevated right atrial pressure should be noticed. (19) The effect of increased intrathoracic pressure on right heart diastolic function should be valued. (20) Ttricuspid annular plane systolic excursion (TAPSE) is an important parameter that reflects right ventricular systolic function, and it is recommended as a general indicator of critically ill patient. (21) Circulation management with right heart protection as the core strategy is the key point of the treatment of acute respiratory distress syndrome. (22) Right heart function involvement after cardiac surgery is very common and should be highly valued. (23) Right ventricular dysfunction should not be considered as a routine excuse for maintaining higher central venous pressure. (24) When left ventricular dilation, attention should be paid to the effect of left ventricle on right ventricular diastolic function. (25) The impact of left ventricular function should be excluded when the contractility of the right ventricle is decreased. (26) When the right heart load increases acutely, the shunt between the left and right heart should be monitored. (27) Attention should be paid to the increase of central venous pressure caused by right ventricular dysfunction and its influence on microcirculation blood flow. (28) When the vasoactive drugs was used to reduce the pressure of pulmonary circulation, different effects on pulmonary and systemic circulation should be evaluated. (29) Right atrial pressure is an important factor affecting venous return. Attention should be paid to the influence of the pressure composition of the right atrium on the venous return. (30) Attention should be paid to the role of the right ventricle in the acute pulmonary edema. (31) Monitoring the difference between the mean systemic filling pressure and the right atrial pressure is helpful to determine whether the infusion increases the venous return. (32) Venous return resistance is often considered to be a insignificant factor that affects venous return, but attention should be paid to the effect of the specific pathophysiological status, such as intrathoracic hypertension, intra-abdominal hypertension and so on. Consensus can promote right heart function management in critically ill patients, optimize hemodynamic therapy, and even affect prognosis.
Fantidis, P; Fernández Ruiz, M A; Madero Jarabo, R; Moreno Granados, F; Cordovilla Zurdo, G; Sanz Galeote, E
1990-11-01
In order to find out the validity of the vascular waterfall mechanism in coronary venous circulation, the role of coronary sinus pressure in the regulation of coronary return volume via the coronary sinus is studied in healthy animals. An experimental model of pressure regulation in the coronary sinus was prepared, and aortic pressure, EKG and the cardiac output (measured by thermodilution) were recorded. The return volume via the coronary sinus was measured at coronary sinus pressure of 10 or less, 15, 20, and 25 mmHg or more, for a total of 36 determinations. Increased coronary sinus pressure did not produce significant changes in aortic pressure, heart rate, cardiac index or coronary return volume via coronary sinus. When coronary sinus pressure was 25 mmHg or more, there was a significant decline in the average of coronary return volume via coronary sinus. Nevertheless, stepwise variant regression showed that the coronary sinus pressure per se does not condition the volume of coronary return via the coronary sinus. Our results suggest that in the healthy animals, the vascular waterfall mechanism in coronary venous circulation is not valid. Our results suggest that in the correction of congenital cardiac malformations using atriopulmonary anastomosis procedures, employing techniques that ensure coronary sinus drainage into the left atrium, in order to avoid the hemodynamic repercussions attributable to the vascular waterfall mechanism, is not justified.
Srinivasa, Ravi Nara; Majdalany, Bill S; Chick, Jeffrey Forris Beecham; Meadows, J Matthew; Fenlon, Jordan Bruce; Brewerton, Charles; Saad, Wael E
2018-01-01
In the setting of portal hypertension, the body responds by creating portosystemic venous shunts, which may lead to the development of varices. Endoscopic treatment of these varices is often warranted to prevent catastrophic bleeding. During the course of variceal treatment, 1 or more portosystemic shunts may be sacrificed, which may acutely exacerbate portal hypertension and reduce systemic venous return. This report describes percutaneous creation of a mesocaval shunt and balloon-occluded retrograde transvenous obliteration (BRTO) in a patient with cavernous transformation of the portal vein. The patient had previously undergone an unsuccessful attempt at transjugular intrahepatic portosystemic shunt (TIPS) creation with postoperative bleeding requiring splenectomy. As TIPS was not feasible, creation of a percutaneous mesocaval shunt provided an alternate pathway for portosystemic decompression, facilitating safe treatment of gastric varices with BRTO via a gastrorenal shunt. These procedures were performed simultaneously to reduce the risk of variceal bleeding from acute changes in portal venous pressures and redirect blood flow through the shunt to maintain patency. This is the first reported case of combined mesocaval shunt placement and BRTO in a single session. Copyright © 2017 Elsevier Inc. All rights reserved.
A blood circulation model for reference man
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leggett, R.W.; Eckerman, K.F.; Williams, L.R.
This paper describes a dynamic blood circulation model that predicts the movement and gradual dispersal of a bolus of material in the circulation after its intravascular injection into an adult human. The main purpose of the model is to improve the dosimetry of internally deposited radionuclides that decay in the circulation to a significant extent. The total blood volume is partitioned into the blood contents of 24 separate organs or tissues, right heart chambers, left heart chambers, pulmonary circulation, arterial outflow to the systemic tissues (aorta and large arteries), and venous return from the systemic tissues (large veins). As amore » compromise between physical reality and computational simplicity, the circulation of blood is viewed as a system of first-order transfers between blood pools, with the delay time depending on the mean transit time across the pool. The model allows consideration of incomplete, tissue-dependent extraction of material during passage through the circulation and return of material from tissues to plasma.« less
Current concepts in repair of extremity venous injury.
Williams, Timothy K; Clouse, W Darrin
2016-04-01
Extremity venous injury management remains controversial. The purpose of this communication is to offer perspective as well as experiential and technical insight into extremity venous injury repair. Available literature is reviewed and discussed. Historical context is provided. Indication, the decision process for repair, including technical conduct, is delineated. In particular, the authors' experiences in both civilian and wartime injury are used for perspective. Extremity venous injury repair was championed within data from the Vietnam Vascular Registry. However, patterns of extremity venous injury differ between combat and civilian settings. Since Vietnam, civilian descriptive series opine the benefits and potential complications associated with both venous injury repair and ligation. These surround extremity edema, chronic venous insufficiency, thromboembolism, and limb loss. Whereas no clear superiority in either approach has been identified to date, there appears to be no increased risk of pulmonary embolism or chronic venous changes with repair. Newer data from the wars in Iraq and Afghanistan and meta-analysis have reinforced this and also have suggested limb salvage benefit for extremity venous repair in combined arterial and venous injuries in modern settings. The patient's physiologic state and associated injury drive five triage categories suggesting vein injury management. Vein repair thrombosis occurs in a significant proportion, yet many recanalize and possibly have a positive impact on limb venous return. Further, early decompression favors reduced blood loss, acute edema, and inflammation, supporting collateral development. Large soft tissue injury minimizing collateral capacity increases the importance of repair. Constructs of repair are varied with modest differences in patency. Venous shunting is feasible, but specific roles remain nebulous. An aggressive posture toward extremity venous injury repair seems justified today because of the likely role in reducing venous hypertensive sequelae as well as a potential role in limb salvage. Appropriate triage selection for extremity vein repair is essential. Copyright © 2016 Society for Vascular Surgery. All rights reserved.
Dodge-Khatami, Ali; Chancellor, William Z; Gupta, Bhawna; Seals, Samantha R; Ebeid, Makram R; Batlivala, Sarosh P; Taylor, Mary B; Salazar, Jorge D
2015-07-01
Results of surgical management of hypoplastic left heart syndrome (HLHS) and related anomalies are often compared to published benchmark data which reflect the use of a variety of surgical and hybrid protocols. We report encouraging results achieved in an emerging program, despite a learning curve at all care levels. Rather than relying on a single preferred protocol, surgical management was based on matching surgical strategy to individual patient factors. From 2010 to 2014, a total of 47 consecutive patients with HLHS or related anomalies with ductal-dependent systemic circulation underwent initial surgical palliation, including 30 Norwood stage I, 8 hybrid stage I, and 9 salvage-to-Norwood procedures. True hybrid procedures entailed bilateral pulmonary artery banding and ductal stenting. In the salvage-to-Norwood strategy, ductal stenting was withheld in favor of continued prostaglandin infusion in anticipation of a deferred Norwood procedure. Cardiac comorbidities (obstructed pulmonary venous return, poor ventricular function, and atrioventricular valve regurgitation) and noncardiac comorbidities influenced the choice of treatment strategies and were analyzed as potential risk factors for extracorporeal membrane oxygenation (ECMO) support or in-hospital mortality. Overall hospital survival was 81% (Norwood 83.3%, hybrid 88%, "salvage" 67%; P = .4942). Extracorporeal membrane oxygenation support was used for eight (17%) patients with two survivors. For cases with obstructed pulmonary venous return (n = 10, 21%), management choices favored a hybrid or salvage strategy (P = .0026). Aortic atresia (n = 22, 47%) was treated by a Norwood or salvage-to-Norwood. No cardiac, noncardiac, or genetic comorbidities were identified as independent risk factors for ECMO or discharge mortality in a multivariable analysis. Our emerging program achieved outcomes that compare favorably to published benchmark data with respect to hospital survival. These results reflect rigorous interdisciplinary teamwork and a flexible approach to surgical palliation based on matching surgical strategy to patient factors. With major associated cardiac/noncardiac comorbidity and antegrade coronary flow, a true hybrid with ductal stenting was our preferred strategy. For high-risk situations such as aortic atresia with obstructed pulmonary venous return, the salvage hybrid-bridge-to-Norwood strategy may help achieve survival albeit with increased resource utilization. © The Author(s) 2015.
Ryan, Colin P.; Mouawad, Nicolas J.; Vaccaro, Patrick S.; Go, Michael R.
2018-01-01
Controversies in the treatment of venous thoracic outlet syndrome (VTOS) have been discussed for decades, but still persist. Calls for more objective reporting standards have pushed practice towards comprehensive venous evaluations and interventions after first rib resection (FRR) for all patients. In our practice, we have relied on patient-centered, patient-reported outcomes to guide adjunctive treatment and measure success. Thus, we sought to investigate the use of thrombolysis versus anticoagulation alone, timing of FRR following thrombolysis, post-FRR venous intervention, and FRR for McCleery syndrome (MCS) and their impact on patient symptoms and return to function. All patients undergoing FRR for VTOS at our institution from 4 April 2000 through 31 December 2013 were reviewed. Demographics, symptoms, diagnostic and treatment details, and outcomes were collected. Per “Reporting Standards of the Society for Vascular Surgery for Thoracic Outlet Syndrome”, symptoms were described as swelling/discoloration/heaviness, collaterals, concomitant neurogenic symptoms, and functional impairment. Patient-reported response to treatment was defined as complete (no residual symptoms and return to function), partial (any residual symptoms present but no functional impairment), temporary (initial improvement but subsequent recurrence of any symptoms or functional impairment), or none (persistent symptoms or functional impairment). Sixty FRR were performed on 59 patients. 54.2% were female with a mean age of 34.3 years. Swelling/discoloration/heaviness was present in all but one patient, deep vein thrombosis in 80%, and visible collaterals in 41.7%. Four patients had pulmonary embolus while 65% had concomitant neurogenic symptoms. In addition, 74.6% of patients were anticoagulated and 44.1% also underwent thrombolysis prior to FRR. Complete or partial response occurred in 93.4%. Of the four patients with temporary or no response, further diagnostics revealed residual venous disease in two and occult alternative diagnoses in two. Use of thrombolysis was not related to FRR outcomes (p = 0.600). Performance of FRR less than or greater than six weeks after the initiation of anticoagulation or treatment with thrombolysis was not related to FRR outcomes (p = 1). Whether patients had DVT or MCS was not related to FRR outcomes (p = 1). No patient had recurrent DVT. From a patient-centered, patient-reported standpoint, VTOS is equally effectively treated with FRR regardless of preoperative thrombolysis or timing of surgery after thrombolysis. A conservative approach to venous interrogation and intervention after FRR is safe and effective for symptom control and return to function. Additionally, patients with MCS are effectively treated with FRR. PMID:29360741
Venous Access Devices: Clinical Rounds
Matey, Laurl; Camp-Sorrell, Dawn
2016-01-01
Nursing management of venous access devices (VADs) requires knowledge of current evidence, as well as knowledge of when evidence is limited. Do you know which practices we do based on evidence and those that we do based on institutional history or preference? This article will present complex VAD infection and occlusion complications and some of the controversies associated with them. Important strategies for identifying these complications, troubleshooting, and evaluating the evidence related to lack of blood return, malposition, infection, access and maintenance protocols, and scope of practice issues are presented. PMID:28083553
Cerebral venous circulatory system evaluation by ultrasonography.
Zavoreo, Iris; Basić-Kes, Vanja; Zadro-Matovina, Lucija; Lisak, Marijana; Corić, Lejla; Cvjeticanin, Timon; Ciliga, Dubravka; Bobić, Tatjana Trost
2013-06-01
Venous system can be classified as pulmonary veins, systemic veins and venous sinuses that are present only within the skull. Cerebral venous system is divided into two main parts, the superficial and the deep system. The main assignment of veins is to carry away deoxygenated blood and other maleficient materials from the tissues towards the heart. Veins have thinner walls and larger lumina than arteries. Between 60% and 70% of the total blood volume is found in veins. The major factors that influence venous function are the respiratory cycle, venous tone, the function of the right heart, gravity, and the muscle pump. Venous system, in general, can be presented by selective venography, Doppler sonography, computed tomography (CT) venography and magnetic resonance (MR) venography, and cerebral venous system can be displayed by selective venography, cerebral CT venography, cerebral MR venography, and specialized extracranial and transcranial Doppler sonography. The aim of this paper is to show the possibilities of intracranial and extracranial ultrasound evaluation of the head and neck venous circulation and chronic cerebrospinal venous insufficiency as one of the most common pathologies evaluated as part of neurodegenerative processes in the central nervous system.
Edemagenic gain and interstitial fluid volume regulation.
Dongaonkar, R M; Quick, C M; Stewart, R H; Drake, R E; Cox, C S; Laine, G A
2008-02-01
Under physiological conditions, interstitial fluid volume is tightly regulated by balancing microvascular filtration and lymphatic return to the central venous circulation. Even though microvascular filtration and lymphatic return are governed by conservation of mass, their interaction can result in exceedingly complex behavior. Without making simplifying assumptions, investigators must solve the fluid balance equations numerically, which limits the generality of the results. We thus made critical simplifying assumptions to develop a simple solution to the standard fluid balance equations that is expressed as an algebraic formula. Using a classical approach to describe systems with negative feedback, we formulated our solution as a "gain" relating the change in interstitial fluid volume to a change in effective microvascular driving pressure. The resulting "edemagenic gain" is a function of microvascular filtration coefficient (K(f)), effective lymphatic resistance (R(L)), and interstitial compliance (C). This formulation suggests two types of gain: "multivariate" dependent on C, R(L), and K(f), and "compliance-dominated" approximately equal to C. The latter forms a basis of a novel method to estimate C without measuring interstitial fluid pressure. Data from ovine experiments illustrate how edemagenic gain is altered with pulmonary edema induced by venous hypertension, histamine, and endotoxin. Reformulation of the classical equations governing fluid balance in terms of edemagenic gain thus yields new insight into the factors affecting an organ's susceptibility to edema.
Oiwa, H; Kawauchi, M; Chikada, M; Yagyu, K; Kotsuka, Y; Furuse, A
1995-01-01
A pulsatile total cavopulmonary shunt was successfully performed on a 5-year-old girl with hypoplastic right heart syndrome associated with abnormal systemic venous return; at the same time, modified mitral valve replacement was performed for mitral regurgitation. The right atrium, tricuspid valve and right ventricle were all extremely dimunitive. The diameter of the tricuspid valve was 50% of normal and the volume of the right ventricle was 8.6% of normal. In addition, there were severe subpumonary stenosis, a restrictive ventricular septal defect (VSD) and an atrial septal defect (ASD). The bilateral superior venae cavae (SVCs) and the hepatic vein drained to the left atrium, and the inferior vena cava was infrahepatically interrupted with a hemiazygos connection to the left superior vena cava. At the operation, each SVC was anastomosed end-to-side to each branch of the pulmonary artery (PA). The restrictive ventricular septal defect and stenotic subpulmonary lesion were left. The diameter of the ASD was reduced from 12 mm to 7 mm. The main PA was neither divided nor banded. The pulsatile blood flow from the left heart to the PA was regurated by a native restrictive VSD and stenotic subpulmonary lesion, and that from the right heart via the ASD was limited by reducing the size of the ASD. These described anatomic arrangements produced adequate antegrade pulsatile flow in the PA, which might prevent the development of pulmonary arteriovenous fistulae and, besides permit transfer of drainage of the hepatic vein from the left to the right atrium via the ASD in future.
Manning, James E
2013-08-01
Aortic catheter-based resuscitation therapies are emerging with laboratory investigations showing benefit in models of trauma-related noncompressible torso hemorrhage and nontraumatic cardiac arrest. For these investigational aortic catheter-based therapies to reach their greatest potential clinical benefit, the ability to initiate them in the prehospital setting will be important. Feasibility of prehospital aortic catheterization without imaging capability supports this potential and is described in this report. A physician prehospital response system was created in cooperation with the local emergency medical services system to provide invasive hemodynamic monitoring during cardiac arrest. Physicians were dispatched to all known or suspected prehospital cardiac arrests covered by the emergency medical services system. Physicians responded with a specialized vascular catheterization pack and a monitor with invasive pressure monitoring capability. The physicians performed blind thoracic aortic and central venous catheterizations in cardiac arrest patients in the prehospital setting to measure coronary perfusion pressure, to optimize closed-chest cardiopulmonary resuscitation technique, and to administer intra-aortic epinephrine. During a 2-year period, 22 medical cardiac arrest patients underwent prehospital invasive hemodynamic monitoring to guide resuscitation. Most patients had both aortic and central venous catheters inserted. The combination of intra-aortic epinephrine and adjustments in closed-chest cardiopulmonary resuscitation technique resulted in improved coronary perfusion pressure. Return of spontaneous circulation with survival to hospital admission was achieved in 50% (11 of 22) of these patients. This report demonstrates the feasibility of successful blind aortic and central venous catheterizations in the prehospital environment and supports the potential feasibility of other emerging aortic catheter-based resuscitation therapies.
Hemodialysis Catheters: How to Keep Yours Working Well
... Catheters have two openings inside; one is a red (arterial) opening to draw blood from your vein and out of your body into the dialysis pathway and the other is a blue (venous) opening that allows cleaned blood to return ...
Air contamination during hemodialysis should be minimized.
Stegmayr, Bernd
2017-04-01
During preparation of the hemodialysis (HD) extracorporeal circuit (ECC) a priming solution is used to remove air from the tubes and dialyzer. Ultra sound techniques have verified micro embolic signals (MES) in the ECC that may derive from clots or gas embolies. In vitro studies could clarify that embolies of air develop within the ECC and also pass the safety systems such as air traps and enter the venous line that goes into the patient. Clinical studies have confirmed the presence of MES within the ECC that pass into the return-venous-line during conventional HD without inducing an alarm. In addition, studies confirmed that such MES were present within the AV fistula and subclavian vein, but also detected within the carotid artery. Autopsy studies revealed the presence of gas embolies surrounded by clots within the lung but also brain and myocardial tissue. This review will focus on how the MES develop and measures of how the exposure can be limited. © 2016 International Society for Hemodialysis.
Development of the jugular bulb: a radiologic study.
Friedmann, David R; Eubig, Jan; McGill, Megan; Babb, James S; Pramanik, Bidyut K; Lalwani, Anil K
2011-10-01
Jugular bulb (JB) abnormalities such as JB diverticulum and high-riding JBs of the temporal bone can erode into the inner ear and present with hearing loss, vestibular disturbance, and pulsatile tinnitus. Their cause and potential to progress remain to be studied. This comprehensive radiologic study investigates the postnatal development of the venous system from transverse sinus to internal jugular vein (IJV). Academic medical center. PATIENTS, INTERVENTION, MAIN OUTCOME MEASURE: Measurements of the transverse and sigmoid sinus, the JB, IJV, and carotid artery were made from computed tomographic scans of the neck with intravenous contrast in infants (n = 5), children (n = 13), adults (n = 35), and the elderly (n = 15). Jugular bulbs were not detected in patients younger than 2 years, enlarged in adulthood, and remained stable in the elderly. The venous system was larger in men than in women. From transverse sinus to IJV, the greatest variation in size was just proximal and distal to the JB with greater symmetry observed as blood returned to the heart. Right-sided venous dominance was most common occurring in 70% to 80% of cases. The JB is a dynamic structure that forms after 2 years, and its size stabilizes in adulthood. The determinants in its exact position and size are multifactorial and may be related to blood flow. Improved understanding of this structure's development may help to better understand the cause of the high-riding JB and JB diverticulum, both of which may cause clinical symptoms.
Gibson, Kathleen; Ferris, Brian
2017-04-01
Purpose Cyanoacrylate closure of the great saphenous vein with the VenaSeal™ Closure System is a relatively new modality. Studies have been limited to moderate-sized great saphenous veins and some have mandated postoperative compression stockings. We report the results of a prospective study of cyanoacrylate closure for the treatment of great saphenous vein, small saphenous veins, and/or accessory saphenous veins up to 20 mm in diameter. Methods Fifty subjects with symptomatic great saphenous vein, small saphenous veins, and/or accessory saphenous veins incompetence were each treated at a single session. Compression stockings were not used post-procedure. Subjects returned to clinic at week 1 and again at one month. Post-procedure evaluations were performed at seven days and one month and included numerical pain rating score, revised venous clinical severity score, the Aberdeen Varicose Vein Questionnaire score, and time to return to work and normal activities. Duplex ultrasound was performed at each visit. Findings Procedural pain was mild (numerical pain rating scale 2.2 ± 1.8). All treated veins (48 great saphenous vein, 14 accessory saphenous veins, and 8 small saphenous veins) had complete closure by duplex ultrasound at seven days and one month. Mean time to return to work and normal activities was 0.2 ± 1.1 and 2.4 ± 4.1 days, respectively. The revised venous clinical severity score was improved to 1.8 ± 1.4 ( p < .001) and Aberdeen Varicose Vein Questionnaire score to 8.9 ± 6.6 ( p < .001) at one month. Phlebitis in the treatment area or side branches occurred in 10 subjects (20%) and completely resolved in all but one subject (2%) by one month; 98% of subjects were "completely" or "somewhat" satisfied, and 2% "unsatisfied" with the procedure at one month, despite the protocol disallowance of concomitant side branch treatment. Conclusions Cyanoacrylate closure is safe and effective for the treatment of one or more incompetent saphenous or accessory saphenous veins. Closure rates were high even in the absence of the use of compression stockings or side branch treatment. Time back to work or normal activities was short and improvements in venous severity scores and QOL were significant, comparing favorably with alternative treatment methods.
Hocking, Kyle M; Sileshi, Ban; Baudenbacher, Franz J; Boyer, Richard B; Kohorst, Kelly L; Brophy, Colleen M; Eagle, Susan S
2016-10-01
Unrecognized hemorrhage and unguided resuscitation is associated with increased perioperative morbidity and mortality. The authors investigated peripheral venous waveform analysis (PIVA) as a method for quantitating hemorrhage as well as iatrogenic fluid overload during resuscitation. The authors conducted a prospective study on Yorkshire Pigs (n = 8) undergoing hemorrhage, autologous blood return, and administration of balanced crystalloid solution beyond euvolemia. Intra-arterial blood pressure, electrocardiogram, and pulse oximetry were applied to each subject. Peripheral venous pressure was measured continuously through an upper extremity standard peripheral IV catheter and analyzed with LabChart. The primary outcome was comparison of change in the first fundamental frequency (f1) of PIVA with standard and invasive monitoring and shock index (SI). Hemorrhage, return to euvolemia, and iatrogenic fluid overload resulted in significantly non-zero slopes of f1 amplitude. There were no significant differences in heart rate or mean arterial pressure, and a late change in SI. For the detection of hypovolemia the PIVA f1 amplitude change generated an receiver operator curves (ROC) curve with an area under the curve (AUC) of 0.93; heart rate AUC = 0.61; mean arterial pressure AUC = 0.48, and SI AUC = 0.72. For hypervolemia the f1 amplitude generated an ROC curve with an AUC of 0.85, heart rate AUC = 0.62, mean arterial pressure AUC = 0.63, and SI AUC = 0.65. In this study, PIVA demonstrated a greater sensitivity for detecting acute hemorrhage, return to euvolemia, and iatrogenic fluid overload compared with standard monitoring and SI. PIVA may provide a low-cost, minimally invasive monitoring solution for monitoring and resuscitating patients with perioperative hemorrhage.
The echocardiographic diagnosis of totally anomalous pulmonary venous connection in the fetus.
Allan, L D; Sharland, G K
2001-04-01
Infants with isolated totally anomalous pulmonary venous return often present severely decompensated, such that they are at high risk for surgical repair. On the other hand, if surgical repair can be safely accomplished, the outlook is usually good. Thus prenatal diagnosis would be expected to improve the prognosis for the affected child. To describe the features of isolated totally anomalous pulmonary venous drainage in the fetus. Four fetuses with isolated totally anomalous pulmonary venous connection were identified and the echocardiographic images reviewed. Measurements of the atrial and ventricular chambers and both great arteries were made and compared with normal values. Referral centre for fetal echocardiography. There were two cases of drainage to the coronary sinus, one to the right superior vena cava, and one to the inferior vena cava. Right heart dilatation relative to left heart structures was a feature of two cases early on, and became evident in some ratios late in pregnancy in the remaining two. Ventricular and great arterial disproportion in the fetus can indicate a diagnosis of totally anomalous pulmonary venous connection above the diaphragm. However, in the presence of an atrial septal defect or with infradiaphragmatic drainage, right heart dilatation may not occur until late in pregnancy. The diagnosis of totally anomalous pulmonary venous drainage in fetal life can only be reliably excluded by direct examination of pulmonary venous blood flow entering the left atrium on colour or pulsed flow mapping.
Walters, Elizabeth Lea; Morawski, Kyle; Dorotta, Ihab; Ramsingh, Davinder; Lumen, Kelly; Bland, David; Clem, Kathleen; Nguyen, H Bryant
2011-04-01
Patients who present to the emergency department (ED) with return of spontaneous circulation after cardiac arrest generally have poor outcomes. Guidelines for treatment can be complicated and difficult to implement. This study examined the feasibility of implementing a care bundle including therapeutic hypothermia (TH) and early hemodynamic optimization for comatose patients with return of spontaneous circulation after out-of-hospital cardiac arrest. The study included patients over a 2-year period in the ED and intensive care unit of an academic tertiary-care medical center. The first year (prebundle) provided a historical control, followed by a prospective observational period of bundle implementation during the second year. The bundle elements included (a) TH initiated; (b) central venous pressure/central venous oxygen saturation monitoring in 2 h; (c) target temperature in 4 h; (d) central venous pressure greater than 12 mmHg in 6 h; (e) MAP greater than 65 mmHg in 6 h; (f) central venous oxygen saturation greater than 70% in 6 h; (g) TH maintained for 24 h; and (h) decreasing lactate in 24 h. Fifty-five patients were enrolled, 26 patients in the prebundle phase and 29 patients in the bundle phase. Seventy-seven percent of bundle elements were completed during the bundle phase. In-hospital mortality in bundle compared with prebundle patients was 55.2% vs. 69.2% (P = 0.29). In the bundle patients, those patients who received all elements of the care bundle had mortality 33.3% compared with 60.9% in those receiving some of the bundle elements (P = 0.22). Bundle patients tended to achieve good neurologic outcome compared with prebundle patients, Cerebral Performance Category 1 or 2 in 31 vs. 12% patients, respectively (P = 0.08). Our study demonstrated that a post-cardiac arrest care bundle that incorporates TH and early hemodynamic optimization can be implemented in the ED and intensive care unit collaboratively and can achieve similar clinical benefits compared with those observed in previous clinical trials.
2013-01-01
Background The role of the extracranial venous system in the pathology of central nervous system (CNS) disorders and aging is largely unknown. It is acknowledged that the development of the venous system is subject to many variations and that these variations do not necessarily represent pathological findings. The idea has been changing with regards to the extracranial venous system. Discussion A range of extracranial venous abnormalities have recently been reported, which could be classified as structural/morphological, hemodynamic/functional and those determined only by the composite criteria and use of multimodal imaging. The presence of these abnormalities usually disrupts normal blood flow and is associated with the development of prominent collateral circulation. The etiology of these abnormalities may be related to embryologic developmental arrest, aging or other comorbidities. Several CNS disorders have been linked to the presence and severity of jugular venous reflux. Another composite criteria-based vascular condition named chronic cerebrospinal venous insufficiency (CCSVI) was recently introduced. CCSVI is characterized by abnormalities of the main extracranial cerebrospinal venous outflow routes that may interfere with normal venous outflow. Summary Additional research is needed to better define the role of the extracranial venous system in relation to CNS disorders and aging. The use of endovascular treatment for the correction of these extracranial venous abnormalities should be discouraged, until potential benefit is demonstrated in properly-designed, blinded, randomized and controlled clinical trials. Please see related editorial: http://www.biomedcentral.com/1741-7015/11/259. PMID:24344742
Arterio-venous anastomoses in the human skin and their role in temperature control
Walløe, Lars
2016-01-01
ABSTRACT Arterio-venous anastomoses (AVAs) are direct connections between small arteries and small veins. In humans they are numerous in the glabrous skin of the hands and feet. The AVAs are short vessel segments with a large inner diameter and a very thick muscular wall. They are densely innervated by adrenergic axons. When they are open, they provide a low-resistance connection between arteries and veins, shunting blood directly into the venous plexuses of the limbs. The AVAs play an important role in temperature regulation in humans in their thermoneutral zone, which for a naked resting human is about 26°C to 36°C, but lower when active and clothed. From the temperature control center in the hypothalamus, bursts of nerve impulses are sent simultaneously to all AVAs. The AVAs are all closed near the lower end and all open near the upper end of the thermoneutral zone. The small veins in the skin of the arms and legs are also contracted near the lower end of the thermoneutral zone and relax to a wider cross section as the ambient temperature rises. At the cold end of the thermoneutral range, the blood returns to the heart through the deep veins and cools the arterial blood through a countercurrent mechanism. As the ambient temperature rises, more blood is returned through the superficial venous plexuses and veins and heats the skin surface of the full length of the 4 limbs. This skin surface is responsible for a large part of the loss of heat from the body toward the upper end of the thermoneutral zone. PMID:27227081
Chessa, Massimo; Carminati, Mario; Cinteză, Eliza Elena; Butera, Gianfranco; Giugno, Luca; Arcidiacono, Carmelo; Piazza, Luciane; Bulescu, Nicolae Cristian; Pome, Giuseppe; Frigiola, Alessandro; Giamberti, Alessandro
2016-01-01
Abnormal connection of the right superior caval vein to the left atrium is an uncommon systemic vein drainage anomaly, with only a few cases reported among congenital heart disease (CHD), around 20 cases published in the medical literature. The inferior vena cava connection with the left atrium, also very rare, can appear directly or in heterotaxy. Clinical suspicion arises due to the presence of cyanosis in the absence of other specific clinical signs (without other associated CHD). We present the cases of two children with abnormal superior and inferior systemic venous return. The first case is an abnormal connection of right superior vena cava to the left atrium associated with persistent left superior vena cava draining into the right atrium through the coronary sinus. The second case is an interruption of the inferior vena cava with hemiazygos continuation, drained into the left superior vena cava, which drained into the left atrium. The diagnosis was imagistic - echocardiography and angiography. Surgical treatment solutions vary from one case to another, usually following anatomic correction. Hypoxia accompanied by cyanosis must bring into question the pathology of systemic venous drainage anomaly, after other common causes have been excluded. Surgery is indicated in all cases due to the risk associated with the presence of right-to-left shunt.
Cardiovascular reflexes during rest and exercise modified by gravitational stresses
NASA Astrophysics Data System (ADS)
Bonde-petersen, Flemming
The hypotheses tested were whether variations in central venous pressure via the low pressure baroreceptors would take over or modify the arterial baroreceptor function, and further to which extent local and "whole body" hydrostatic stresses influence blood flow distribution. We investigated total forearm and skin blood flow (venous occlusion plethysmography and 133-Xe clearance) and cardiac output (rebreathing method) among other parameters. Hypo-and hypergravitational stresses were simulated by LBNP, LBPP, water immersion and lowering of the arm. The changes in flow distribution in the arm were ascribed to arterial baroreceptor function and not to low pressure baroreceptor activity. The enhancement of venous return during water immersion increased exercise tolerance during heat stress presumably due both to increased stroke volume and decreased venous pooling. The response to sustained handgrip exercise during LBNP and LBPP was not different from control measurements and the effects explained by arterial baroreceptor function. Application of exercise and local hydrostatic stresses in combination with gravitational stresses represent an interesting model for further study of the mechanisms behind the distribution of cardiac output to the peripheral organs.
Honey, M
1977-10-01
Six new cases of the "scimitar syndrome" are described. The anatomical and haemodynamic features of these and other reported cases are reviewed. Within the spectrum of the disorder there is a group of patients in whom the bronchopulmonary manifestations are relatively unimportant. In five of our patients there was a left-to-right shunt exceeding 2:1 and the anomalous pulmonary venous connection was corrected surgically. The presence or absence of an associated atrial septal defect may be difficult to establish but influences the choice of surgical technique. When the atrial septum is intact, the anomalous vein should be reimplanted if possible into the back of the left atrium; otherwise a pericardial or teflon patch can be used to redirect the anomalous venous return through an existing or created atrial septal defect to the left atrium.
Wright, Thomas C; Mossaad, Bassem M; Chummun, Shaheel; Khan, Umraz; Chapman, Thomas W L
2013-07-01
The proximally pedicled medial plantar flap is well described for coverage of wounds around the ankle and heel. This flap is usually based on the deep venae comitantes for venous drainage, with the superficial veins divided during dissection. Usually any disruption of the deep venous system of the flap would result in abandoning this choice of flap. Venous congestion is a recognised complication of medial plantar flaps. The patient described in this case report had a medial ankle defect with exposed bone, for which a proximally pedicled medial plantar flap was used. As we raised the flap, both venae comitantes of the medial planter artery were found to be disrupted. The flap was raised based on the superficial veins draining into the great saphenous, as the only system for venous drainage, with no evidence of venous congestion. The flap was successfully transposed into the defect and healed with no complications. The proximally pedicled medial plantar flap can safely rely on the superficial venous system alone for drainage. In addition, preserving the superficial veins minimise the risk of venous congestion in this flap. We recommend preservation of superficial venous system when possible. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Investigation of cerebral venous outflow in microgravity.
Taibi, A; Gadda, G; Gambaccini, M; Menegatti, E; Sisini, F; Zamboni, P
2017-10-31
The gravitational gradient is the major component to face when considering the physiology of venous return, and there is a growing interest in understanding the mechanisms ensuring the heart filling, in the absence of gravity, for astronauts who perform long-term space missions. The purpose of the Drain Brain project was to monitor the cerebral venous outflow of a crew member during an experiment on the International Space Station (ISS), so as to study the compensatory mechanisms that facilitate this essential physiological action in subjects living in a microgravity environment. Such venous function has been characterized by means of a novel application of strain-gauge plethysmography which uses a capacitive sensor. In this contribution, preliminary results of our investigation have been presented. In particular, comparison of plethysmography data confirmed that long duration spaceflights lead to a redistribution of venous blood volume, and showed interesting differences in the amplitude of cardiac oscillations measured at the level of the neck veins. The success of the experiment has also demonstrated that thanks to its easy portability, non-invasiveness, and non-operator dependence, the proposed device can be considered as a novel tool for use aboard the ISS. Further trials are now under way to complete the investigation on the drainage function of the neck veins in microgravity.
Facts about Total Anomalous Pulmonary Venous Return or TAPVR
... and the right atrium. The goal of the surgical repair of TAPVR is to restore normal blood flow through the heart. To repair this defect, doctors usually connect the pulmonary veins to the left atrium, close off any abnormal connections between blood vessels, and close the atrial septal ...
Recent findings in cardiovascular physiology with space travel.
Hughson, Richard L
2009-10-01
The cardiovascular system undergoes major changes in stress with space flight primarily related to the elimination of the head-to-foot gravitational force. A major observation has been that the central venous pressure is not elevated early in space flight yet stroke volume is increased at least early in flight. Recent observations demonstrate that heart rate remains lower during the normal daily activities of space flight compared to Earth-based conditions. Structural and functional adaptations occur in the vascular system that could result in impaired response with demands of physical exertion and return to Earth. Cardiac muscle mass is reduced after flight and contractile function may be altered. Regular and specific countermeasures are essential to maintain cardiovascular health during long-duration space flight.
Novel Biomarkers of Arterial and Venous Ischemia in Microvascular Flaps
Nguyen, Gerard K.; Monahan, John F. W.; Davis, Gabrielle B.; Lee, Yong Suk; Ragina, Neli P.; Wang, Charles; Zhou, Zhao Y.; Hong, Young Kwon; Spivak, Ryan M.; Wong, Alex K.
2013-01-01
The field of reconstructive microsurgery is experiencing tremendous growth, as evidenced by recent advances in face and hand transplantation, lower limb salvage after trauma, and breast reconstruction. Common to all of these procedures is the creation of a nutrient vascular supply by microsurgical anastomosis between a single artery and vein. Complications related to occluded arterial inflow and obstructed venous outflow are not uncommon, and can result in irreversible tissue injury, necrosis, and flap loss. At times, these complications are challenging to clinically determine. Since early intervention with return to the operating room to re-establish arterial inflow or venous outflow is key to flap salvage, the accurate diagnosis of early stage complications is essential. To date, there are no biochemical markers or serum assays that can predict these complications. In this study, we utilized a rat model of flap ischemia in order to identify the transcriptional signatures of venous congestion and arterial ischemia. We found that the critical ischemia time for the superficial inferior epigastric fasciocutaneus flap was four hours and therefore performed detailed analyses at this time point. Histolgical analysis confirmed significant differences between arterial and venous ischemia. The transcriptome of ischemic, congested, and control flap tissues was deciphered by performing Affymetrix microarray analysis and verified by qRT-PCR. Principal component analysis revealed that arterial ischemia and venous congestion were characterized by distinct transcriptomes. Arterial ischemia and venous congestion was characterized by 408 and 1536>2-fold differentially expressed genes, respectively. qRT-PCR was used to identify five candidate genes Prol1, Muc1, Fcnb, Il1b, and Vcsa1 to serve as biomarkers for flap failure in both arterial ischemia and venous congestion. Our data suggests that Prol1 and Vcsa1 may be specific indicators of venous congestion and allow clinicians to both diagnose and successfully treat microvascular complications before irreversible tissue damage and flap loss occurs. PMID:23977093
[Oral contraception and the vascular risk].
Garnier, L F; Gruel, Y
1989-01-01
Vascular risk, mainly thromboembolitic risk, attributed to oral contraceptives (OCs) since 1962, has been primarily linked to ethinyl estradiol (EE). OCs which combine estrogen and have been associated with cerebral vascular accidents. A 1977 study showed a 40% increase of mortality due to cardiovascular complications in women taking OCs. There were of both an arterial and a venous character. The risk of myocardial infarction was 3 times more frequent among OC users. Deep venous thrombosis and pulmonary embolism were more numerous. Some other risk factors include smoking, hypertension, diabetes, and age 35. The risk of heart attack vanishes a few years after stopping OC use. The reduction of EE (and similarly progesterone) dosage from 100-50 mcg also lower the risk of hypertension, cerebral vascular accidents, and venous thrombosis. Prolonged use of OCs causes disorders of hemostasis affecting the walls of blood vessels, modifying the viscosity of blood flow (increase of hematocrits, reduction of venous tonus), modifying plasmatic coagulation (increase of platelets, increase of factors VII and X and plasma fibrinogen, and decrease of antithrombin III activity), and increased fibrinolysis. These anomalies are exclusively associated with high doses of estrogens. 5% of women using OCs develop moderate hypertension of 5-10 mm Hg of systolic pressure 5 years later, but after cessation it is reversed. OCs stimulate the renin-angiotensin-aldosterone system causing accelerated production of angiotensin II with the resultant forceful vasotension. 3 months after quitting OC use, high blood pressure returns to normal. EE can provoke diabetes; it increases very low density lipoprotein (VLDL) and high density lipoprotein (HDL) production, but total cholesterol is hardly affected. The androgenic property of progestogens reduces HDL. Combined OCs are contraindicated for women with hypertension, hyperlipidemia, diabetes, and a family history of vascular accidents.
Barncord, Kristin; Stauthammer, Christopher; Moen, Sean L; Hanson, Melissa; Gruenstein, Daniel H
2016-03-01
An 11 month old spayed, female dog presented with exercise intolerance and cyanosis upon exertion. Echocardiography revealed an imperforate cor triatriatum dexter with mild tricuspid valve dysplasia, an underfilled right ventricle and significant right to left shunting across a presumptive patent foramen ovale. Balloon dilation of the abnormal atrial membrane was initially successful in creating a communication between the right atrial chambers, but stenosis of the original perforation and persistent clinical signs prompted a second intervention. A balloon expandable biliary stent was placed across the abnormal partition, improving caudal venous return to the right ventricle and reducing the right to left shunt. Three months after stent placement, resting oxygen saturation had normalized. Six months after stent placement, exercise tolerance had improved and exertional cyanosis had resolved. Long term follow up will be necessary to assess for remodeling of the right ventricle with improved venous return. Stent placement can be considered as a palliative treatment option for cor triatriatum dexter, especially for stenosis post-balloon dilation. Copyright © 2015 Elsevier B.V. All rights reserved.
Medial gastrocnemius vein aneurysm development after compressive trauma in the knee.
De Santis, Francesco; Candia, Silvia; Scialpi, Renzo; Piccinin, Alfredo; Bruni, Antonio; Morettini, Giuseppe; Loreni, Giorgio
2017-06-01
Objectives Venous aneurysms are uncommon. They can involve both superficial and deep venous systems. We hereby present a unique case of gastrocnemius venous aneurysm developed after compressive knee trauma. Report A large venous aneurysm in the left popliteal fossa was detected by chance in a 44-year-old woman one month after a compressive trauma to the posterior surface of the knee. Magnetic resonance-imaging of the same knee had documented normal venous anatomy one year earlier. The venous aneurysm involved the medial gastrocnemius vein near its confluence in the popliteal vein and was surgically resected. Histopathology evidenced a true venous aneurysm. The patient was discharged under oral anticoagulation for three months. At one year follow-up, neither complications nor new venous aneurysm development was detected. Conclusions An accurate evaluation of the venous system is always mandatory after limb traumas which may lead to post-traumatic venous pseudo-aneurysms, as well as more rarely, true venous aneurysms in the lower extremities.
Rodent Studies of Cardiovascular Deconditioning
NASA Technical Reports Server (NTRS)
Shoukas, Artin A.
1999-01-01
Changes in blood pressure can occur for two reasons: 1) A decrease in cardiac output resulting from the altered contractility of the heart or through changes in venous filling pressure via the Frank Starling mechanism or; 2) A change in systemic vascular resistance. The observed changes in cardiac output and blood pressure after long term space flight cannot be entirely explained through changes in contractility or heart rate alone. Therefore, alterations in filling pressure mediated through changes in systemic venous capacitance and arterial resistance function may be important determinants of cardiac output and blood pressure after long term space flight. Our laboratory and previous studies have shown the importance of veno-constriction mediated by the carotid sinus baroreceptor reflex system on overall circulatory homeostasis and in the regulation of cardiac output. Our proposed experiments test the overall hypothesis that alterations in venous capacitance function and arterial resistance by the carotid sinus baroreceptor reflex system are an important determinant of the cardiac output and blood pressure response seen in astronauts after returning to earth from long term exposure to microgravity. This hypothesis is important to our overall understanding of circulatory adjustments made during long term space flight. It also provides a framework for investigating counter measures to reduce the incidence of orthostatic hypotension caused by an attenuation of cardiac output. We continue to use hind limb unweighted (HLU) rat model to simulate the patho physiological effects as they relate to cardiovascular deconditioning in microgravity. We have used this model to address the hypothesis that microgravity induced cardiovascular deconditioning results in impaired vascular responses and that these impaired vascular responses result from abnormal alpha-1 AR signaling. The impaired vascular reactivity results in attenuated blood pressure and cardiac output responses to an orthostatic challenge. We have used in vitro vascular reactivity assays to explore abnormalities in vascular responses in vessels from HLU animals and, cardiac output (CO), blood pressure (BP) and heart rate (HR) measurements to characterize changes in hemodynamics following HLU.
Cross-sectional imaging of congenital and acquired abnormalities of the portal venous system
Özbayrak, Mustafa; Tatlı, Servet
2016-01-01
Knowing the normal anatomy, variations, congenital and acquired pathologies of the portal venous system are important, especially when planning liver surgery and percutaneous interventional procedures. The portal venous system pathologies can be congenital such as agenesis of portal vein (PV) or can be involved by other hepatic disorders such as cirrhosis and malignancies. In this article, we present normal anatomy, variations, and acquired pathologies involving the portal venous system as seen on computed tomography (CT) and magnetic resonance imaging (MRI). PMID:27731302
Anomalous azygos venous system in a south Indian cadaver: a case report
2009-01-01
Introduction The posterior thoracic wall, an area drained by the azygos venous system, is a common site for surgical intervention. Since the venous part of the cardiovascular system is subject to most common variation, abnormalities in the azygos venous system are often reported. Case presentation During routine dissection classes for undergraduate medical students, we encountered a variation in the azygos venous system in a 65 years old south Indian male cadaver. We observed that there was no accessory azygos vein, and left 4th, 5th, 6th and 7th posterior intercostal veins terminated directly into azygos vein. Conclusion Identifying these types of variations is important during imaging this region and surgical operations of mediastinum. PMID:20181176
Quantitative evaluation of hand cranking a roller pump in a crisis management drill.
Tomizawa, Yasuko; Tokumine, Asako; Ninomiya, Shinji; Momose, Naoki; Matayoshi, Toru
2008-01-01
The heart-lung machines for open-heart surgery have improved over the past 50 years; they rarely break down and are almost always equipped with backup batteries. The hand-cranking procedure only becomes necessary when a pump breaks down during perfusion or after the batteries have run out. In this study, the performance of hand cranking a roller pump was quantitatively assessed by an objective method using the ECCSIM-Lite educational simulator system. A roller pump connected to an extracorporeal circuit with an oxygenator and with gravity venous drainage was used. A flow sensor unit consisting of electromagnetic sensors was used to measure arterial and venous flow rates, and a built-in pressure sensor was used to measure the water level in the reservoir. A preliminary study of continuous cranking by a team of six people was conducted as a surprise drill. This system was then used at a perfusion seminar. At the seminar, 1-min hand-cranking drills were conducted by volunteers according to a prepared scenario. The data were calculated on site and trend graphs of individual performances were given to the participants as a handout. Preliminary studies showed that each person's performance was different. Results from 1-min drills showed that good performance was not related to the number of clinical cases experienced, years of practice, or experience in hand cranking. Hand cranking to maintain the target flow rate could be achieved without practice; however, manipulating the venous return clamp requires practice. While the necessity of performing hand cranking during perfusion due to pump failure is rare, we believe that it is beneficial for perfusionists and patients to include hand-cranking practice in periodic extracorporeal circulation crisis management drills because a drill allows perfusionists to mentally rehearse the procedures should such a crisis occur.
Crisóstomo, R S S; Candeias, M S; Armada-da-Silva, P A S
2017-03-01
To evaluate the effect of manual lymphatic drainage (MLD) on venous flow when applied to the medial and lateral aspects of the thigh and leg in patients with chronic venous insufficiency (CVI) and healthy subjects. Cross-sectional study. Participants were assessed in a school-based health community attendant service. Fifty-seven subjects participated in this study {mean age: 43 [standard deviation (SD) 14] years, 38 women and 19 men}. Of these, 28 subjects had CVI [mean age 47 (SD 12) years] and 29 subjects did not have CVI [mean age 39 (14) years]. MLD was applied by a certificated physical therapist to the medial and lateral aspects of the thigh and leg. Cross-sectional area; blood flow velocities in the femoral vein, great saphenous vein, popliteal vein and small saphenous vein at baseline and during MLD, measured by duplex ultrasound. Flow volume in the femoral vein increased from baseline [5.19 (SD 3.25)cm 3 /second] when MLD was applied to the medial [7.03 (SD 3.65)cm 3 /second; P≤0.001; mean difference -1.69; 95% confidence interval (CI) -2.42 to -0.97] and lateral [6.16 (SD 3.35)cm 3 /second; P≤0.001; mean difference -1.04; 95% CI -1.70 to -0.39] aspects of the thigh. Venous flow augmentation in the femoral vein and great saphenous vein was higher when MLD was applied to the medial aspect of the thigh (P<0.001), while MLD had a similar effect on venous blood flow regardless of whether it was applied to the medial or the lateral aspect of the leg (P=0.731). MLD increases blood flow in deep and superficial veins. MLD should be applied along the route of the venous vessels for improved venous return. Copyright © 2016 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.
[The daily life of men who lives with chronic venous ulcer: phenomenological study].
da Silva, Marcelo Henrique; de Jesus, Maria Cristina Pinto; Merighi, Miriam Aparecida Barbosa; de Oliveira, Deise Moura; Biscotto, Priscilla Ribeiro; Silva, Greyce Pollyne Santos
2013-09-01
The chronic venous leg ulcer is the major therapeutic problem of lower limb injuries, which can trigger changes in the daily life of the person affected by it. This study aimed to understand the daily life of men who lives with chronic venous ulcers. A phenomenological study was conducted with eight men, who were interviewed during June and July of 2001. The study asked questions related to: "Restrictions in social life" and "Recovering the skin integrity and restart the activities affected by the wound". The answers revealed that men with these ulcers have social implications in the areas of productivity and sexuality. This leads to restrictions in everyday life with loss in performance of socially established roles for men, leading to anxiety for his return at full performance of his social role. The findings suggest significant experiential aspects that may guide professionals in the planning and implementation of health actions aimed to treat these patients.
Abnormal location of umbilical venous catheter due to Scimitar syndrome
Mart, Christopher R; Van Dorn, Charlotte S
2014-01-01
Scimitar syndrome is a rare congenital anomaly where the right pulmonary veins return to the inferior vena cava (IVC) just below the diaphragm. On chest X-ray (CXR), an IVC catheter will be in a bizarre location outside the heart if it inadvertently passes into the scimitar vein rather than into the right atrium. PMID:25298705
Greaves, Spencer W; Holubar, Stefan D
2015-08-01
An important factor in the pathophysiology of venous thromboembolism is blood stasis, thus, preoperative hospitalization length of stay may be contributory to risk. We assessed preoperative hospital length of stay as a risk factor for venous thromboembolism. We performed a retrospective review of patients who underwent colorectal operations using univariate and multivariable propensity score analyses. This study was conducted at a tertiary referral hospital. Data on patients was obtained from the American College of Surgeons National Surgical Quality Improvement Program 2005-2011 Participant Use Data Files. Short-term (30-day) postoperative venous thromboembolism was measured. Our analysis included 242,670 patients undergoing colorectal surgery (mean age, 60 years; 52.9% women); of these, 72,219 (29.9%) were hospitalized preoperatively. The overall rate of venous thromboembolism was 2.07% (1.4% deep vein thrombosis, 0.5% pulmonary embolism, and 0.2% both). On multivariable analysis, the most predictive independent risk factors for venous thromboembolism were return to the operating room (OR, 1.62 (95% CI, 1.44-1.81); p < 0.001) and chronic steroid use (OR, 1.59 (95% CI, 1.41-1.80); p < 0.001); preoperative hospitalization also independently predicted venous thromboembolism (OR, 1.39 (95% CI, 1.28-1.51); p < 0.001), whereas the use of laparoscopy was protective (OR, 0.75 (95% CI, 0.67-0.83); p < 0.001). Propensity score stratification (capped at 7 days, 100 strata, area under the curve = 0.73) indicated that each day of preoperative hospitalization increased the odds of venous thromboembolism (OR, 1.42 (95% CI, 1.32-1.53); p < 0.001). All of the analyses showed a dose-response relationship between preoperative lengths of stay and risk of postoperative venous thromboembolism (p < 0.001). Patients who experienced venous thromboembolism had a higher 30-day mortality rate (3.7% vs 8.9%; p < 0.001). This study has limited potential generalizability and a retrospective design. Preoperative hospitalization is an independent risk factor for venous thromboembolism and its associated increase in mortality after colorectal surgery, whereas laparoscopy is a strong protective variable. Further research into preoperative screening for highest-risk patients is indicated.
Maximal venous outflow velocity: an index for iliac vein obstruction.
Jones, T Matthew; Cassada, David C; Heidel, R Eric; Grandas, Oscar G; Stevens, Scott L; Freeman, Michael B; Edmondson, James D; Goldman, Mitchell H
2012-11-01
Leg swelling is a common cause for vascular surgical evaluation, and iliocaval obstruction due to May-Thurner syndrome (MTS) can be difficult to diagnose. Physical examination and planar radiographic imaging give anatomic information but may miss the fundamental pathophysiology of MTS. Similarly, duplex ultrasonographic examination of the legs gives little information about central impedance of venous return above the inguinal ligament. We have modified the technique of duplex ultrasonography to evaluate the flow characteristics of the leg after tourniquet-induced venous engorgement, with the objective of revealing iliocaval obstruction characteristic of MTS. Twelve patients with signs and symptoms of MTS were compared with healthy control subjects for duplex-derived maximal venous outflow velocity (MVOV) after tourniquet-induced venous engorgement of the leg. The data for healthy control subjects were obtained from a previous study of asymptomatic volunteers using the same MVOV maneuvers. The tourniquet-induced venous engorgement mimics that caused during vigorous exercise. A right-to-left ratio of MVOV was generated for patient comparisons. Patients with clinical evidence of MTS had a mean right-to-left MVOV ratio of 2.0, asymptomatic control subjects had a mean ratio of 1.3, and MTS patients who had undergone endovascular treatment had a poststent mean ratio of 1.2 (P = 0.011). Interestingly, computed tomography and magnetic resonance imaging results, when available, were interpreted as positive in only 53% of the patients with MTS according to both our MVOV criteria and confirmatory venography. After intervention, the right-to-left MVOV ratio in the MTS patients was found to be reduced similar to asymptomatic control subjects, indicating a relief of central venous obstruction by stenting the compressive MTS anatomy. Duplex-derived MVOV measurements are helpful for detection of iliocaval venous obstruction, such as MTS. Right-to-left MVOV ratios and postengorgement spectral analysis are helpful adjuncts to duplex imaging for leg swelling. The MVOV maneuvers are well tolerated by patients and yields physiological data regarding central venous obstruction that computed tomography and magnetic resonance imaging fail to detect. Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.
Long-term venous access using a subcutaneous implantable drug delivery system.
Soo, K. C.; Davidson, T. I.; Selby, P.; Westbury, G.
1985-01-01
To facilitate long-term venous access in patients receiving chemotherapy, a subcutaneous totally implantable system (Port-a-Cath, Phamacia) has been used in 14 patients. The method of implantation and the advantages over conventional central venous catheters are discussed. The expense of the system necessitates careful patient selection. PMID:4037644
Mortimer, Alex; Stubbs, Euan; Cookson, Daniel; Dawson, Raymond; Fleet, Mustafa
2009-01-01
Vertebro-vertebral arteriovenous fistulae occur infrequently. We report on such a case with delayed presentation following penetrating neck injury. This was successfully treated via coil embolisation. A 40-year-old woman presented with a subjective tinnitus that was abolished by turning her head to the right. She had sustained penetrating neck trauma 6 months earlier. Doppler Ultrasound and magnetic resonance angiogram confirmed the presence of a vertebral arterio-venous fistula. Using a trans-femoral arterial approach, the left vertebral artery was embolised by deployment of multiple coils. The patient had no return of symptoms at 3 months follow up. Radiological diagnosis and endovascular management of this condition is discussed. PMID:22470664
Mortimer, Alex; Stubbs, Euan; Cookson, Daniel; Dawson, Raymond; Fleet, Mustafa
2009-01-01
Vertebro-vertebral arteriovenous fistulae occur infrequently. We report on such a case with delayed presentation following penetrating neck injury. This was successfully treated via coil embolisation. A 40-year-old woman presented with a subjective tinnitus that was abolished by turning her head to the right. She had sustained penetrating neck trauma 6 months earlier. Doppler Ultrasound and magnetic resonance angiogram confirmed the presence of a vertebral arterio-venous fistula. Using a trans-femoral arterial approach, the left vertebral artery was embolised by deployment of multiple coils. The patient had no return of symptoms at 3 months follow up. Radiological diagnosis and endovascular management of this condition is discussed.
In vitro validation of a self-driving aortic-turbine venous-assist device for Fontan patients.
Pekkan, Kerem; Aka, Ibrahim Basar; Tutsak, Ece; Ermek, Erhan; Balim, Haldun; Lazoglu, Ismail; Turkoz, Riza
2018-03-11
Palliative repair of single ventricle defects involve a series of open-heart surgeries where a single-ventricle (Fontan) circulation is established. As the patient ages, this paradoxical circulation gradually fails, because of its high venous pressure levels. Reversal of the Fontan paradox requires an extra subpulmonic energy that can be provided through mechanical assist devices. The objective of this study was to evaluate the hemodynamic performance of a totally implantable integrated aortic-turbine venous-assist (iATVA) system, which does not need an external drive power and maintains low venous pressure chronically, for the Fontan circulation. Blade designs of the co-rotating turbine and pump impellers were developed and 3 prototypes were manufactured. After verifying the single-ventricle physiology at a pulsatile in vitro circuit, the hemodynamic performance of the iATVA system was measured for pediatric and adult physiology, varying the aortic steal percentage and circuit configurations. The iATVA system was also tested at clinical off-design scenarios. The prototype iATVA devices operate at approximately 800 revolutions per minute and extract up to 10% systemic blood from the aorta to use this hydrodynamic energy to drive a blood turbine, which in turn drives a mixed-flow venous pump passively. By transferring part of the available energy from the single-ventricle outlet to the venous side, the iATVA system is able to generate up to approximately 5 mm Hg venous recovery while supplying the entire caval flow. Our experiments show that a totally implantable iATVA system is feasible, which will eliminate the need for external power for Fontan mechanical venous assist and combat gradual postoperative venous remodeling and Fontan failure. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
Towards the development of active compression bandages using dielectric elastomer actuators
NASA Astrophysics Data System (ADS)
Pourazadi, S.; Ahmadi, S.; Menon, C.
2014-06-01
Disorders associated with the lower extremity venous system are common and significantly affect the quality of life of a large number of individuals. These disorders include orthostatic hypotension, oedema, deep vein thrombosis and a number of other conditions related to insufficient venous blood return. The common recommended treatment for these disorders is the use of hosiery compression stockings. In this research, an active compression bandage (ACB) based on the technology of dielectric elastomeric actuators (DEA) was designed, prototyped and tested. A customized calf prototype (CP) was developed to measure the pressure applied by the ACB. Experimental results performed with the CP showed that the pressure applied by the ACB could be electrically controlled to be either below or above the pressure exerted by commercially available compression stockings. An analytical model was used to provide the design criteria. A finite element model (FEM) was also developed to simulate the electromechanical behaviour of the DEA. Comparison of the experimental results with the FEM and analytical models showed that the modelling could accurately predict the behaviour of the ACB. The FEM was subsequently used to study how to improve the ACB performance by varying geometrical parameters such as the ACB thickness.
Baroreflex-Mediated Heart Rate and Vascular Resistance Responses 24 h after Maximal Exercise
2003-01-01
of normal physiological function in bedridden patients and astronauts. The implication for failure of CVP and plasma volume to return to baseline... FUNCTION , BLOOD PRES- SURE, CENTRAL VENOUS PRESSURE, PHENYLEPHRINE, NECK PRESSURE, LOWER BODY NEGATIVE PRESSURE, COUNTERMEASURES Increased incidence of...orthostatic hypotension and intol-erance in humans is associated with vascular hypovole-mia and attenuated cardiovascular reflex functions
Intrathoracic Pressure Regulator for Blood Loss
2016-05-24
AFRL-SA-WP-SR-2016-0006 Intrathoracic Pressure Regulator for Blood Loss Richard D. Branson, RRT University of Cincinnati...Special Report 3. DATES COVERED (From – To) September 2011 – October 2013 4. TITLE AND SUBTITLE Intrathoracic Pressure Regulator for Blood Loss 5a...used to treat hypovolemia and cardiac arrest. Preclinical trials demonstrate that ITPR increases venous return and thereby restores blood pressure and
Intrathoracic Pressure Regulator for Blood Loss
2016-05-01
AFRL-SA-WP-SR-2016-0006 Intrathoracic Pressure Regulator for Blood Loss Richard D. Branson, RRT University of Cincinnati...Special Report 3. DATES COVERED (From – To) September 2011 – October 2013 4. TITLE AND SUBTITLE Intrathoracic Pressure Regulator for Blood Loss 5a...used to treat hypovolemia and cardiac arrest. Preclinical trials demonstrate that ITPR increases venous return and thereby restores blood pressure and
Cardiovascular transition at birth: a physiological sequence.
Hooper, Stuart B; Te Pas, Arjan B; Lang, Justin; van Vonderen, Jeroen J; Roehr, Charles Christoph; Kluckow, Martin; Gill, Andrew W; Wallace, Euan M; Polglase, Graeme R
2015-05-01
The transition to newborn life at birth involves major cardiovascular changes that are triggered by lung aeration. These include a large increase in pulmonary blood flow (PBF), which is required for pulmonary gas exchange and to replace umbilical venous return as the source of preload for the left heart. Clamping the umbilical cord before PBF increases reduces venous return and preload for the left heart and thereby reduces cardiac output. Thus, if ventilation onset is delayed following cord clamping, the infant is at risk of superimposing an ischemic insult, due to low cardiac output, on top of an asphyxic insult. Much debate has centered on the timing of cord clamping at birth, focusing mainly on the potential for a time-dependent placental to infant blood transfusion. This has prompted recommendations for delayed cord clamping for a set time after birth in infants not requiring resuscitation. However, recent evidence indicates that ventilation onset before cord clamping mitigates the adverse cardiovascular consequences caused by immediate cord clamping. This indicates that the timing of cord clamping should be based on the infant's physiology rather than an arbitrary period of time and that delayed cord clamping may be of greatest benefit to apneic infants.
Flap monitoring after head and neck reconstruction: evaluating an observation protocol.
Devine, J C; Potter, L A; Magennis, P; Brown, J S; Vaughan, E D
2001-01-01
This study evaluated the postoperative free-flap monitoring frequency protocol used in a maxillofacial unit for patients receiving free-tissue transfer for reconstruction following orofacial cancer. All free-tissue transfers undertaken in the unit between January 1992 and October 1998 were reviewed retrospectively. Of the 370 patients evaluated, 46 returned to theatre with compromised free flaps. The compromise was purely venous in origin in 37 of these cases, arterial in three and due to a combination of arterial and venous problems in six. Thirty-five of the flaps were successfully salvaged. On average, the clinical manifestation of the problem occurred 25.5 hours postoperatively. However, there was a significant time difference between flaps that were salvaged successfully and those that were not: in the salvaged group the compromise was identified 17.5 hours postsurgery compared with 51 hours for the unsuccessful group. The timing of the return to theatre following the identification of the compromise was a significant factor in the success rate: 71 minutes for those salvaged and 103 minutes for those not salvaged. It is recommended that flaps are monitored hourly for the first 72 postoperative hours and observations recorded on a chart.
Rommel, Sentiel A; Caplan, Heather
2003-01-01
Although Florida manatees (Trichechus manatus latirostris) have relatively low basal metabolic rates for aquatic mammals of their size, they maintain normal mammalian core temperatures. We describe vascular structures in the manatee tail that permit countercurrent heat exchange (CCHE) to conserve thermal energy. Approximately 1000 arteries juxtaposed to 2000 veins are found at the cranial end of the caudal vascular bundle (CVB); these numbers decrease caudally, but the 1 : 2 ratio of arteries to veins persists. Arterial walls are relatively thin when compared to those previously described in vascular countercurrent heat exchangers in cetaceans. It is assumed that CCHE in the CVB helps manatees to maintain core temperatures. Activity in warm water, however, mandates a mechanism that prevents elevated core temperatures. The tail could transfer heat to the environment if arterial blood delivered to the skin were warmer than the surrounding water; unfortunately, CCHE prevents this heat transfer. We describe deep caudal veins that provide a collateral venous return from the tail. This return, which is physically outside the CVB, reduces the venous volume within the bundle and allows arterial expansion and increased arterial supply to the skin, and thus helps prevent elevated core temperatures. PMID:12739612
Rommel, Sentiel A; Caplan, Heather
2003-04-01
Although Florida manatees (Trichechus manatus latirostris) have relatively low basal metabolic rates for aquatic mammals of their size, they maintain normal mammalian core temperatures. We describe vascular structures in the manatee tail that permit countercurrent heat exchange (CCHE) to conserve thermal energy. Approximately 1000 arteries juxtaposed to 2000 veins are found at the cranial end of the caudal vascular bundle (CVB); these numbers decrease caudally, but the 1:2 ratio of arteries to veins persists. Arterial walls are relatively thin when compared to those previously described in vascular countercurrent heat exchangers in cetaceans. It is assumed that CCHE in the CVB helps manatees to maintain core temperatures. Activity in warm water, however, mandates a mechanism that prevents elevated core temperatures. The tail could transfer heat to the environment if arterial blood delivered to the skin were warmer than the surrounding water; unfortunately, CCHE prevents this heat transfer. We describe deep caudal veins that provide a collateral venous return from the tail. This return, which is physically outside the CVB, reduces the venous volume within the bundle and allows arterial expansion and increased arterial supply to the skin, and thus helps prevent elevated core temperatures.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gutzeit, A., E-mail: andreas.gutzeit@ksw.ch; Zollikofer, Ch. L., E-mail: Christoph.Zollikofer@ksb.ch; Dettling-Pizzolato, M., E-mail: Mira.Dettling@ksw.ch
Venous stenting has been shown to effectively treat iliofemoral venous obstruction with good short- and mid-term results. The aim of this study was to investigate long-term clinical outcome and stent patency. Twenty patients were treated with venous stenting for benign disease at our institution between 1987 and 2005. Fifteen of 20 patients (15 female, mean age at time of stent implantation 38 years [range 18-66]) returned for a clinical visit, a plain X-ray of the stent, and a Duplex ultrasound. Four patients were lost to follow-up, and one patient died 277 months after stent placement although a good clinical resultmore » was documented 267 months after stent placement. Mean follow-up after stent placement was 167.8 months (13.9 years) (range 71 (6 years) to 267 months [22 years]). No patient needed an additional venous intervention after stent implantation. No significant difference between the circumference of the thigh on the stented side (mean 55.1 cm [range 47.0-70.0]) compared with the contralateral thigh (mean 54.9 cm [range 47.0-70.0]) (p = 0.684) was seen. There was a nonsignificant trend toward higher flow velocities within the stent (mean 30.8 cm/s [range 10.0-48.0]) and the corresponding vein segment on the contralateral side (mean 25.2 cm/s [range 12.0-47.0]) (p = 0.065). Stent integrity was confirmed in 14 of 15 cases. Only one stent showed a fracture, as documented on x-ray, without any impairment of flow. Venous stenting using Wallstents showed excellent long-term clinical outcome and primary patency rate.« less
2013-01-01
The extra-cranial venous system is complex and not well studied in comparison to the peripheral venous system. A newly proposed vascular condition, named chronic cerebrospinal venous insufficiency (CCSVI), described initially in patients with multiple sclerosis (MS) has triggered intense interest in better understanding of the role of extra-cranial venous anomalies and developmental variants. So far, there is no established diagnostic imaging modality, non-invasive or invasive, that can serve as the “gold standard” for detection of these venous anomalies. However, consensus guidelines and standardized imaging protocols are emerging. Most likely, a multimodal imaging approach will ultimately be the most comprehensive means for screening, diagnostic and monitoring purposes. Further research is needed to determine the spectrum of extra-cranial venous pathology and to compare the imaging findings with pathological examinations. The ability to define and reliably detect noninvasively these anomalies is an essential step toward establishing their incidence and prevalence. The role for these anomalies in causing significant hemodynamic consequences for the intra-cranial venous drainage in MS patients and other neurologic disorders, and in aging, remains unproven. PMID:23806142
Left atrial isomerism in the adolescence: report of two cases.
Liu, C Y; Chiu, I S; Chen, J J; Hung, C R; Lien, W P
1991-01-01
Atrial isomerism is very rare in adolescence. Two cases of left atrial isomerism are reported here in 2 females, aged 21 and 19 years. They had presented with cyanosis and dyspnea since childhood. High kilovoltage filter films showed a bilateral morphologically left bronchus. Cardiac catheterization in Case 1 revealed normal pulmonary artery pressure, severe subvalvular pulmonic stenosis, a double outlet right ventricle, a significant oxygen step-up at the atrial level and moderate systemic oxygen desaturation; while Case 2 disclosed pulmonary hypertension and mild systemic oxygen desaturation. Both cases had the following anatomical features: ipsilateral connection of pulmonary veins to the bilateral morphological left atrium; interrupted inferior vena cave with azygos or hemiazygos continuation; total anomalous hepatic venous return to the right-sided atrium; complete atrioventricular canal. The diagnoses were confirmed in both cases at surgical correction.
Medical management of venous ulcers.
Pascarella, Luigi; Shortell, Cynthia K
2015-03-01
Venous disease is the most common cause of chronic leg ulceration and represents an advanced clinical manifestation of venous insufficiency. Due to their frequency and chronicity, venous ulcers have a high socioeconomic impact, with treatment costs accounting for 1% of the health care budget in Western countries. The evaluation of patients with venous ulcers should include a thorough medical history for prior deep venous thrombosis, assessment for an hypercoagulable state, and a physical examination. Use of the CEAP (clinical, etiology, anatomy, pathophysiology) Classification System and the revised Venous Clinical Severity Scoring System is strongly recommended to characterize disease severity and assess response to treatment. This venous condition requires lifestyle modification, with affected individuals performing daily intervals of leg elevation to control edema; use of elastic compression garments; and moderate physical activity, such as walking wearing below-knee elastic stockings. Meticulous skin care, treatment of dermatitis, and prompt treatment of cellulitis are important aspects of medical management. The pharmacology of chronic venous insufficiency and venous ulcers include essentially two medications: pentoxifylline and phlebotropic agents. The micronized purified flavonoid fraction is an effective adjunct to compression therapy in patients with large, chronic ulceration. Copyright © 2015 Elsevier Inc. All rights reserved.
Nitzsche, Björn; Lobsien, Donald; Seeger, Johannes; Schneider, Holm; Boltze, Johannes
2014-01-01
Cerebrovascular diseases are significant causes of death and disability in humans. Improvements in diagnostic and therapeutic approaches strongly rely on adequate gyrencephalic, large animal models being demanded for translational research. Ovine stroke models may represent a promising approach but are currently limited by insufficient knowledge regarding the venous system of the cerebral angioarchitecture. The present study was intended to provide a comprehensive anatomical analysis of the intracranial venous system in sheep as a reliable basis for the interpretation of experimental results in such ovine models. We used corrosion casts as well as contrast-enhanced magnetic resonance venography to scrutinize blood drainage from the brain. This combined approach yielded detailed and, to some extent, novel findings. In particular, we provide evidence for chordae Willisii and lateral venous lacunae, and report on connections between the dorsal and ventral sinuses in this species. For the first time, we also describe venous confluences in the deep cerebral venous system and an ‘anterior condylar confluent’ as seen in humans. This report provides a detailed reference for the interpretation of venous diagnostic imaging findings in sheep, including an assessment of structure detectability by in vivo (imaging) versus ex vivo (corrosion cast) visualization methods. Moreover, it features a comprehensive interspecies-comparison of the venous cerebral angioarchitecture in man, rodents, canines and sheep as a relevant large animal model species, and describes possible implications for translational cerebrovascular research. PMID:24736654
Solodov, A A; Petrikov, S S; Krylov, V V
2016-01-01
Positive end-expiratory pressure is one of the main parameters of respiratory support influencing the gas exchange. However, despite the number ofpositive effects, PEEP can compromise venous outflow from the cranial cavity, increased intracranial pressure, decreased venous return and cardiac output and, consequently, reduced blood pressure and cerebral perfusion. The article presents the results of a survey of 39 patients with intracranial hemorrhage in critical state, undergoing respiratory support with different levels of positive end-expiratory pressure. Increasing of PEEP to 15 cm H2O had no adverse effect on mean arterial pressure, heart rate and cerebral perfusion pressure and led only to an clinical insignificant increase (maximum on 2.4 +/- 5.1 mmHg) in intracranial pressure. The greatest hemodynamic changes were observed with increasing PEEP up to 20 cm H2O in patients with preserved compliance ofthe respiratory system. The instability of cerebral perfusion and intracranial pressure associated with a decrease in cardiac output and preload and the exhaustion of compensatory mechanism of peripheral vascular resistance. High levels of PEEP despite the trend towards Cstat reduction will not lead to an increase in the content of extravascular lung water Thus a gradual increase of PEEP to 15 cm H2O can be safe and effective method of improving pulmonary gas exchange in patients with intracranial hemorrhage in critical state.
Mediratta, Neeraj; Barker, Diane; McKevith, James; Davies, Peter; Belchambers, Sandra; Rao, Archana
2012-07-01
Cardiac resynchronization therapy is an established therapy for heart failure, improving quality of life and prognosis. Despite advances in technique, available leads and delivery systems, trans-venous left ventricular (LV) lead positioning remains dependent on the patient's underlying venous anatomy. The left phrenic nerve courses over the surface of the pericardium laterally and may be stimulated by the LV pacing lead, causing uncomfortable diaphragmatic twitch. This paper describes a video-assisted thoracoscopic (VATS) procedure to correct phrenic nerve stimulation secondary to cardiac resynchronization therapy. Most current ways of avoiding phrenic stimulation involve either electronic reprogramming to distance the phrenic nerve from the stimulation circuit or repositioning the lead. We describe a case where the phrenic nerve was surgically insulated from the stimulating current by insinuating a patch of bovine pericardium between the epicardium and native pericardium of the heart thus completely resolving previously intolerable and incessant diaphragmatic twitch. The procedure was performed under general anaesthesia with single-lung ventilation and minimal use of neuromuscular blocking agents. Surgical patch insulation of the phrenic nerve was performed using minimally invasive VATS surgery, as a short-stay procedure, with no complications. No diaphragmatic twitch occurred post-surgery and the patient continued to gain symptomatic benefit from cardiac synchronization therapy (New York Heart Association Class III to II), enabling return to work. In cases where the trans-venous position of a LV lead is limited by troublesome phrenic nerve stimulation, thoracoscopic surgical patch insulation of the phrenic nerve could be considered to allow beneficial cardiac resynchronization therapy.
Temperature and blood flow distribution in the human leg during passive heat stress.
Chiesa, Scott T; Trangmar, Steven J; González-Alonso, José
2016-05-01
The influence of temperature on the hemodynamic adjustments to direct passive heat stress within the leg's major arterial and venous vessels and compartments remains unclear. Fifteen healthy young males were tested during exposure to either passive whole body heat stress to levels approaching thermal tolerance [core temperature (Tc) + 2°C; study 1; n = 8] or single leg heat stress (Tc + 0°C; study 2; n = 7). Whole body heat stress increased perfusion and decreased oscillatory shear index in relation to the rise in leg temperature (Tleg) in all three major arteries supplying the leg, plateauing in the common and superficial femoral arteries before reaching severe heat stress levels. Isolated leg heat stress increased arterial blood flows and shear patterns to a level similar to that obtained during moderate core hyperthermia (Tc + 1°C). Despite modest increases in great saphenous venous (GSV) blood flow (0.2 l/min), the deep venous system accounted for the majority of returning flow (common femoral vein 0.7 l/min) during intense to severe levels of heat stress. Rapid cooling of a single leg during severe whole body heat stress resulted in an equivalent blood flow reduction in the major artery supplying the thigh deep tissues only, suggesting central temperature-sensitive mechanisms contribute to skin blood flow alone. These findings further our knowledge of leg hemodynamic responses during direct heat stress and provide evidence of potentially beneficial vascular alterations during isolated limb heat stress that are equivalent to those experienced during exposure to moderate levels of whole body hyperthermia. Copyright © 2016 the American Physiological Society.
Temperature and blood flow distribution in the human leg during passive heat stress
Chiesa, Scott T.; Trangmar, Steven J.
2016-01-01
The influence of temperature on the hemodynamic adjustments to direct passive heat stress within the leg's major arterial and venous vessels and compartments remains unclear. Fifteen healthy young males were tested during exposure to either passive whole body heat stress to levels approaching thermal tolerance [core temperature (Tc) + 2°C; study 1; n = 8] or single leg heat stress (Tc + 0°C; study 2; n = 7). Whole body heat stress increased perfusion and decreased oscillatory shear index in relation to the rise in leg temperature (Tleg) in all three major arteries supplying the leg, plateauing in the common and superficial femoral arteries before reaching severe heat stress levels. Isolated leg heat stress increased arterial blood flows and shear patterns to a level similar to that obtained during moderate core hyperthermia (Tc + 1°C). Despite modest increases in great saphenous venous (GSV) blood flow (0.2 l/min), the deep venous system accounted for the majority of returning flow (common femoral vein 0.7 l/min) during intense to severe levels of heat stress. Rapid cooling of a single leg during severe whole body heat stress resulted in an equivalent blood flow reduction in the major artery supplying the thigh deep tissues only, suggesting central temperature-sensitive mechanisms contribute to skin blood flow alone. These findings further our knowledge of leg hemodynamic responses during direct heat stress and provide evidence of potentially beneficial vascular alterations during isolated limb heat stress that are equivalent to those experienced during exposure to moderate levels of whole body hyperthermia. PMID:26823344
1980-05-01
abnormalities in pressure tracings of the systemic, the central venous or pulmonary arterial circulation. At some sites (especially the Latter-Day Saints...accurate measurement of central venous pressure has been by direct venous cannulation. However, a group of Swiss doctors has extended the principle of... venous stop flow pressure to develop a noninvasive method of measuring central venous pressure. The method consists of venous auscultation at the thoracic
Clinical risk factors for venous thrombosis associated with air travel.
Kesteven, P J; Robinson, B J
2001-02-01
Recent reports have linked air travel with venous thrombo-embolism (VTE). Risk factors and associated features of this link are poorly understood. We have accumulated clinical data from a relatively large cohort of patients with traveler's thrombosis. A total of 86 patients who developed venous thromboembolism within 28 d of flying were questioned concerning traveling habits, medical history (including risk factors for VTE) and characteristics of the index flight. Of the patients, 72% had at least one risk factor for VTE (excluding thrombophilia) prior to their flight. Of interest, 87% of VTE cases occurred following either a return trip or after an outward journey involving long trips made up of sequential flights. In only two cases could no identifiable risk factor or earlier journey be found. Duration of flights ranged from 2 to 30 h. Of responders, 38% presented with chest symptoms; 92% with VTE developed symptoms within 96 h of their flight. We conclude that the majority of VTE associated with air travel occur in those with identifiable risk factors prior to their flight, and that sequential flights may increase this risk.
Cardiovascular physiology - Effects of microgravity
NASA Technical Reports Server (NTRS)
Convertino, V.; Hoffler, G. W.
1992-01-01
Experiments during spaceflight and its groundbase analog, bedrest, provide consistent data which demonstrate that numerous changes in cardiovascular function occur as part of the physiological adaptation process to the microgravity environment. These include elevated heart rate and venous compliance, lowered blood volume, central venous pressure and stroke volume, and attenuated autonomic reflex functions. Although most of these adaptations are not functionally apparent during microgravity exposure, they manifest themselves during the return to the gravitational challenge of earth's terrestrial environment as orthostatic hypotension and instability, a condition which could compromise safety, health and productivity. Development and application of effective and efficient countermeasures such as saline "loading," intermittent venous pooling, pharmacological treatments, and exercise have become primary emphases of the space life sciences research effort with only limited success. Successful development of countermeasures will require knowledge of the physiological mechanisms underlying cardiovascular adaptation to microgravity which can be obtained only through controlled, parallel groundbased research to complement carefully designed flight experiments. Continued research will provide benefits for both space and clinical applications as well as enhance the basic understanding of cardiovascular homeostasis in humans.
Venous compliance and fluid shift measurements on Spacelab IML-1
NASA Technical Reports Server (NTRS)
Leiski, D.; Thirsk, R. B.; Charles, J. B.; Bennett, B.
1992-01-01
During the first few hours of a human spaceflight mission, a headward fluid shift out of the abdomen, pelvis, and legs initiates a number of adaptive cardiovascular responses, including a loss of intravascular and extravascular fluid volume. On return to earth, these cardiovascular changes may lead to debilitating symptoms of orthostatic intolerance in an unprotected astronaut. To test the hypothesis that an inflight increase in compliance of the leg veins may contribute to this condition, measurements of lower leg fluid shift and bulk venous compliance were collected from crew members during the eight-day First International Microgravity Laboratory shuttle mission. An ultrasonic limb plethysmograph, in conjunction with two compression cuffs encircling the calf and thigh, was used to determine bulk compliance of the underlying veins over a range of negative and positive transmural pressures. The data from inflight experiment sessions were compared to preflight and postflight sessions. The preliminary results indicate that the volume of the lower leg decreased by over 10 percent by the sixth day of flight, but there was no apparent change in venous compliance.
Total anomalous systemic venous drainage in left heterotaxy syndrome.
Khandenahally, Ravindranath S; Deora, Surender; Math, Ravi S
2013-04-01
Total anomalous systemic venous drainage is an extremely rare congenital heart defect. In this study we describe an 11-year-old girl who presented with a history of fatigue and central cyanosis that she had had since early childhood with unremarkable precordial examination results. Investigations revealed left heterotaxy with all systemic venous drainage to the left-sided atrium with non-compaction of the left ventricle.
Fam, Maged Nassef Abdalla; Attia, Khaled Mostafa Elgharib; Khalil, Safaa Maged Fathelbab
2014-07-01
Gas within the portal circulation has been known to be associated with a number of conditions most commonly mesenteric ischemia and necrosis. Systemic venous gas is described with few conditions and is mostly iatrogenic in nature. We describe a case of combined portal and systemic venous gas detected by computed tomography in a patient with perforated duodenal ulcer.
Cerebral venous hypertension and blindness: a reversible complication.
Cuadra, Salvador A; Padberg, Frank T; Turbin, Roger E; Farkas, Jeffrey; Frohman, Larry P
2005-10-01
A 57-year-old woman developed blindness during treatment for sarcoidosis-induced end-stage renal disease. An initial renal transplantation failed, and hemoaccess was maintained with multiple central catheters and upper extremity prosthetic arteriovenous grafts. A successful second transplantation eliminated her need for hemodialysis, but a right brachial to internal jugular graft remained patent. Progressive visual loss 2 years after transplantation prompted ophthalmic evaluation which initially revealed unilateral left optic nerve edema and visual loss, ultimately worsening over several months to no light perception in the left eye, 20/60 vision in the right eye, and bilateral papilledema. Arteriography demonstrated cerebral venous hypertension attributed to the functioning hemoaccess graft. Permanent graft occlusion normalized the papilledema, and visual field defects in the right eye and visual acuity returned to 20/20 in the right eye.
2012-04-26
ISS030-E-257690 (26 April 2012) --- European Space Agency astronaut Andre Kuipers, Expedition 30 flight engineer, prepares for IMMUNE venous blood sample draws in the Columbus laboratory of the International Space Station. Following the blood draws, the samples were temporarily stowed in the Minus Eighty Laboratory Freezer for ISS 1 (MELFI-1) and later packed together with saliva samples on the Soyuz TMA-22 for return to Earth for analysis.
Effects of the Abnormal Acceleratory Environment of Flight
1974-12-01
vision Return of arteriolar pulsa- tion and temporary venous distension Visual failure is a continuum from loss of peripheral vision (grey- out) to...distance); intrathoracic pressure is increased by strong muscular expiratorv efforts against a partially closed glottis; and the contraction of...vigorous skeletal muscular tensing (Valsalva maneuver) can reduce +GZ tolerance and lead to an episode of unconsciousness at extremely low G levels
Venous Thromboembolism Within Professional American Sport Leagues.
Bishop, Meghan; Astolfi, Matthew; Padegimas, Eric; DeLuca, Peter; Hammoud, Sommer
2017-12-01
Numerous reports have described players in professional American sports leagues who have been sidelined with a deep vein thrombosis (DVT) or a pulmonary embolism (PE), but little is known about the clinical implications of these events in professional athletes. To conduct a retrospective review of injury reports from the National Hockey League (NHL), Major League Baseball (MLB), the National Basketball Association (NBA), and the National Football League (NFL) to take a closer look at the incidence of DVT/PE, current treatment approaches, and estimated time to return to play in professional athletes. Descriptive epidemiology study. An online search of all team injury and media reports of DVT/PE in NHL, MLB, NBA, and NFL players available for public record was conducted by use of Google, PubMed, and SPORTDiscus. Searches were conducted using the professional team name combined with blood clot , pulmonary embolism , and deep vein thrombosis . A total of 55 venous thromboembolism (VTE) events were identified from 1999 through 2016 (NHL, n = 22; MLB, n = 16; NFL, n = 12; NBA, n = 5). Nineteen athletes were reported to have an upper extremity DVT, 15 had a lower extremity DVT, 15 had a PE, and 6 had DVT with PE. Six athletes sustained more than 1 VTE. The mean age at time of VTE was 29.3 years (range, 19-42 years). Mean (±SD) time lost from play was 6.7 ± 4.9 months (range, 3 days to career end). Seven athletes did not return to play. Players with upper extremity DVT had a faster return to play (mean ± SD, 4.3 ± 2.7 months) than those with lower extremity DVT (5.9 ± 3.8 months), PE (10.8 ± 6.8 months), or DVT with PE (8.2 ± 2.6 months) ( F = 5.69, P = .002). No significant difference was found regarding time of return to play between sports. VTE in professional athletes led to an average of 6.7 months lost from play. The majority of athletes were able to return to play after a period of anticoagulation or surgery. Those with an upper extremity DVT returned to play faster than those with other types of VTE. Further study is needed to look into modifiable risk factors for these events and to establish treatment and return-to-play guidelines to ensure the safety of these athletes.
Modarai, Bijan; Blume, Ulrike; Humphries, Julia; Patel, Ashish S.; Phinikaridou, Alkystis; Evans, Colin E.; Mattock, Katherine; Grover, Steven P.; Ahmad, Anwar; Lyons, Oliver T.; Attia, Rizwan Q.; Renné, Thomas; Premaratne, Sobath; Wiethoff, Andrea J.; Botnar, René M.; Schaeffter, Tobias; Waltham, Matthew; Smith, Alberto
2014-01-01
Background The magnetic resonance longitudinal relaxation time (T1) changes with thrombus age in humans. In this study, we investigate the possible mechanisms that give rise to the T1 signal in venous thrombi and whether changes in T1 relaxation time are informative of the susceptibility to lysis. Methods and Results Venous thrombosis was induced in the vena cava of BALB/C mice, and temporal changes in T1 relaxation time correlated with thrombus composition. The mean T1 relaxation time of thrombus was shortest at 7days following thrombus induction and returned to that of blood as the thrombus resolved. T1 relaxation time was related to thrombus methemoglobin formation and further processing. Studies in inducible nitric oxide synthase (iNOS−/−)–deficient mice revealed that inducible nitric oxide synthase mediates oxidation of erythrocyte lysis–derived iron to paramagnetic Fe3+, which causes thrombus T1 relaxation time shortening. Studies using chemokine receptor-2–deficient mice (Ccr2−/−) revealed that the return of the T1 signal to that of blood is regulated by removal of Fe3+ by macrophages that accumulate in the thrombus during its resolution. Quantification of T1 relaxation time was a good predictor of successful thrombolysis with a cutoff point of <747 ms having a sensitivity and specificity to predict successful lysis of 83% and 94%, respectively. Conclusions The source of the T1 signal in the thrombus results from the oxidation of iron (released from the lysis of trapped erythrocytes in the thrombus) to its paramagnetic Fe3+ form. Quantification of T1 relaxation time appears to be a good predictor of the success of thrombolysis. PMID:23820077
Chin-Dusting, J P; Rasaratnam, B; Jennings, G L; Dudley, F J
1997-12-01
In patients with cirrhosis, portosystemic shunts allow intestinal bacteria and endotoxin to enter the systemic circulation. Endotoxemia may induce increased synthesis of nitric oxide, thereby contributing to arterial vasodilation. To test the hypothesis that the antibiotic norfloxacin blocks the effects of nitric oxide. Placebo-controlled, double-blind, crossover study. Alfred Hospital, Melbourne, Australia. 9 patients with alcohol-related cirrhosis and 10 healthy controls. Norfloxacin, 400 mg twice daily, for 4 weeks. Peripheral blood flow was measured by using forearm venous occlusion plethysmography. Basal forearm blood flow was higher in patients with cirrhosis than in controls (3.69 +/- 0.27 mL/100 mL per minute and 2.47 +/- 0.40 mL/100 mL per minute; P = 0.014) but returned toward normal after norfloxacin was given (2.64 +/- 0.31 mL/100 mL of tissue per minute in patients with cirrhosis). Responses to NG-monomethyl-L-arginine were greater in patients with cirrhosis but returned to normal after norfloxacin was given. Bacterial endotoxemia in patients with cirrhosis induces increased synthesis of nitric oxide that can be corrected with norfloxacin.
A global multiscale mathematical model for the human circulation with emphasis on the venous system.
Müller, Lucas O; Toro, Eleuterio F
2014-07-01
We present a global, closed-loop, multiscale mathematical model for the human circulation including the arterial system, the venous system, the heart, the pulmonary circulation and the microcirculation. A distinctive feature of our model is the detailed description of the venous system, particularly for intracranial and extracranial veins. Medium to large vessels are described by one-dimensional hyperbolic systems while the rest of the components are described by zero-dimensional models represented by differential-algebraic equations. Robust, high-order accurate numerical methodology is implemented for solving the hyperbolic equations, which are adopted from a recent reformulation that includes variable material properties. Because of the large intersubject variability of the venous system, we perform a patient-specific characterization of major veins of the head and neck using MRI data. Computational results are carefully validated using published data for the arterial system and most regions of the venous system. For head and neck veins, validation is carried out through a detailed comparison of simulation results against patient-specific phase-contrast MRI flow quantification data. A merit of our model is its global, closed-loop character; the imposition of highly artificial boundary conditions is avoided. Applications in mind include a vast range of medical conditions. Of particular interest is the study of some neurodegenerative diseases, whose venous haemodynamic connection has recently been identified by medical researchers. Copyright © 2014 John Wiley & Sons, Ltd.
Evaluation of an Impedance Threshold Device as a VIIP Countermeasure
NASA Technical Reports Server (NTRS)
Ebert, D.; Macias, B.; Garcia, K.; Stenger, M.; Hargens, A.; Johnston, S.
2016-01-01
Visual Impairment /Intracranial Pressure (VIIP) is a top human spaceflight risk for which NASA does not currently have a proven mitigation strategy. Thigh cuffs (Braslets) and lower body negative pressure (LBNP; Chibis) devices have been or are currently being evaluated as a means to reduce VIIP signs and symptoms, but these methods alone may not provide sufficient relief of cephalic venous congestion and VIIP symptoms. Additionally, current LBNP devices are too large and cumbersome for their systematic use as a countermeasure. Therefore, a novel approach is needed that is easy to implement and provides specific relief of symptoms. This investigation will evaluate an impedance threshold device (ITD) as a VIIP countermeasure. The ITD works by providing up to 7 cm H2O (approximately 5 mmHg) resistance to inspiratory air flow, effectively turning the thorax into a vacuum pump upon each inhalation which lowers the intrathoracic pressure (ITP) and facilitates venous return to the heart. The ITD is FDA-approved and was developed to augment venous return to the central circulation and increase cardiac output during cardiopulmonary resuscitation (CPR) and in patients with hypotension. While the effect of ITD on CPR survival outcomes is controversial, the ITD's ability to lower ITP with a concomitant decrease in intracranial pressure (ICP) is well documented. A similar concept that creates negative ITP during exhalation (intrathoracic pressure regulator; ITPR) decreased ICP in 16 of 20 patients with elevated ICP in a hospital pilot study. ITP and central venous pressure (CVP) have been shown to decrease in microgravity however ITP drops more than CVP, indicating an increased transmural CVP. This could explain the paradoxical distention of jugular veins (JV) in microgravity despite lower absolute CVP and also suggests that JV transmural pressure is not dramatically elevated. Use of an ITD may lower JV pressure enough to remove or relieve cephalic venous congestion. During spaceflight experiments with Braslet thigh cuffs and modified (open-glottis) Mueller maneuvers, Braslets alone reduced cardiac preload but only reduced the internal JV (IJV) cross sectional area by 23%. The addition of Mueller maneuvers resulted in an IJV area reduction of 48%. This project will test if ITD essentially applies a Mueller maneuver with added negative ITP in every respiratory cycle, acting to: 1) reduce venous congestion in the neck and 2) potentially lower ICP. The expected mechanism of action is that in microgravity (or an analog) blood is relocated toward the heart from vasculature in the head and neck. Once validated, the ITD would be an exceptionally easy countermeasure to deploy and test on the ISS. Dosage could be altered though 1) duration of application and 2) inspiratory resistance set point. Effects could be additionally enhanced through co-application with other countermeasures such as thigh cuffs or LBNP.
Evaluation of an Impedance Threshold Device as a VIIP Countermeasure
NASA Technical Reports Server (NTRS)
Ebert, Douglas; Macias, Brandon; Sargsyan, Ashot; Garcia, Kathleen; Stenger, Michael; Hargens, Alan; Johnston, Smith; Kemp, David; Danielson, Richard
2016-01-01
Visual Impairment/Intracranial Pressure (VIIP) is a top human spaceflight risk for which NASA does not currently have a proven mitigation strategy. Thigh cuffs (Braslets) and lower body negative pressure (LBNP; Chibis) devices have been or are currently being evaluated as a means to reduce VIIP signs and symptoms, but these methods alone may not provide sufficient relief of cephalic venous congestion and VIIP symptoms. Additionally, current LBNP devices are too large and cumbersome for their systematic use as a countermeasure. Therefore, a novel approach is needed that is easy to implement and provides specific relief of symptoms. This investigation will evaluate an impedance threshold device (ITD) as a VIIP countermeasure. The ITD works by providing up to 7 cm H2O (approximately 5 mmHg) resistance to inspiratory air flow, effectively turning the thorax into a vacuum pump upon each inhalation which lowers the intrathoracic pressure (ITP) and facilitates venous return to the heart. The ITD is FDA-approved and was developed to augment venous return to the central circulation and increase cardiac output during cardiopulmonary resuscitation (CPR) and in patients with hypotension. While the effect of ITD on CPR survival outcomes is controversial, the ITD's ability to lower ITP with a concomitant decrease in intracranial pressure (ICP) is well documented. A similar concept that creates negative ITP during exhalation (intrathoracic pressure regulator; ITPR) decreased ICP in 16 of 20 patients with elevated ICP in a hospital pilot study. ITP and central venous pressure (CVP) have been shown to decrease in microgravity however ITP drops more than CVP, indicating an increased transmural CVP. This could explain the paradoxical distention of jugular veins (JV) in microgravity despite lower absolute CVP and also suggests that JV transmural pressure is not dramatically elevated. Use of an ITD may lower JV pressure enough to remove or relieve cephalic venous congestion. During spaceflight experiments with Braslet thigh cuffs and modified (open-glottis) Mueller maneuvers, Braslets alone reduced cardiac preload but only reduced the internal JV (IJV) cross sectional area by 23%. The addition of Mueller maneuvers resulted in an IJV area reduction of 48%. This project will test if ITD essentially applies a Mueller maneuver with added negative ITP in every respiratory cycle, acting to: 1) reduce venous congestion in the neck and 2) potentially lower ICP. The expected mechanism of action is that in microgravity (or an analog) blood is relocated toward the heart from vasculature in the head and neck. Once validated, the ITD would be an exceptionally easy countermeasure to deploy and test on the ISS. Dosage could be altered though 1) duration of application and 2) inspiratory resistance set point. Effects could be additionally enhanced through co-application with other countermeasures such as thigh cuffs or LBNP.
Thrombosis of the Portal Venous System in Cirrhotic vs. Non-Cirrhotic Patients.
Cruz-Ramón, Vania; Chinchilla-López, Paulina; Ramírez-Pérez, Oscar; Aguilar-Olivos, Nancy E; Alva-López, Luis F; Fajardo-Ordoñez, Ericka; Acevedo-Silva, Ileana; Northup, Patrick G; Intagliata, Nicolas; Caldwell, Stephen H; Ponciano-Rodríguez, Guadalupe; Qi, Xingshun; Méndez-Sánchez, Nahum
2018-04-09
Thrombosis is a vascular disorder of the liver often associated with significant morbidity and mortality. Cirrhosis is a predisposing factor for portal venous system thrombosis. The aim of this study is to determine differences between cirrhotics and non-cirrhotics that develop thrombosis in portal venous system and to evaluate if cirrhosis severity is related to the development of portal venous system thrombosis. We studied patients diagnosed with portal venous system thrombosis using contrast-enhanced computed tomography scan and doppler ultrasound at Medica Sur Hospital from 2012 to 2017. They were categorized into two groups; cirrhotics and non-cirrhotics. We assessed the hepatic function by Child-Pugh score and model for end-stage liver disease. 67 patients with portal venous system thrombosis (25 with non-cirrhotic liver and 42 with cirrhosis) were included. The mean age (± SD) was 65 ± 9.5 years in cirrhotic group and 57 ± 13.2 years (p = 0.009) in non-cirrhotic group. Comparing non-cirrhotics and cirrhotics, 8 non-cirrhotic patients showed evidence of extra-hepatic inflammatory conditions, while in the cirrhotic group no inflammatory conditions were found (p < 0.001). 27 (64.29%) cirrhotic patients had thrombosis in the portal vein, while only 9 cases (36%) were found in non-cirrhotics (p = 0.02). In cirrhotic patients, hepatocellular carcinoma and cirrhosis were the strongest risk factors to develop portal venous system thrombosis. In contrast, extrahepatic inflammatory conditions were main risk factors associated in non-cirrhotics. Moreover, the portal vein was the most frequent site of thrombosis in both groups.
Aziz, Faisal; Lehman, Erik; Blebea, John; Lurie, Fedor
2017-01-01
Background Deep venous thrombosis after any surgical operations is considered a preventable complication. Lower extremity bypass surgery is a commonly performed operation to improve blood flow to lower extremities in patients with severe peripheral arterial disease. Despite advances in endovascular surgery, lower extremity arterial bypass remains the gold standard treatment for severe, symptomatic peripheral arterial disease. The purpose of this study is to identify the clinical risk factors associated with development of deep venous thrombosis after lower extremity bypass surgery. Methods The American College of Surgeons' NSQIP database was utilized and all lower extremity bypass procedures performed in 2013 were examined. Patient and procedural characteristics were evaluated. Univariate and multivariate logistic regression analysis was used to determine independent risk factors for the development of postoperative deep venous thrombosis. Results A total of 2646 patients (65% males and 35% females) underwent lower extremity open revascularization during the year 2013. The following factors were found to be significantly associated with postoperative deep venous thrombosis: transfusion >4 units of packed red blood cells (odds ratio (OR) = 5.21, confidence interval (CI) = 1.29-22.81, p = 0.03), postoperative urinary tract infection (OR = 12.59, CI = 4.12-38.48, p < 0.01), length of hospital stay >28 days (OR = 9.30, CI = 2.79-30.92, p < 0.01), bleeding (OR = 2.93, CI = 1.27-6.73, p = 0.01), deep wound infection (OR = 3.21, CI = 1.37-7.56, p < 0.01), and unplanned reoperation (OR = 4.57, CI = 2.03-10.26, p < 0.01). Of these, multivariable analysis identified the factors independently associated with development of deep venous thrombosis after lower extremity bypass surgery to be unplanned reoperation (OR = 3.57, CI = 1.54-8.30, p < 0.01), reintubation (OR = 8.93, CI = 2.66-29.97, p < 0.01), and urinary tract infection (OR = 7.64, CI = 2.27-25.73, p < 0.01). Presence of all three factors was associated with a 54% incidence of deep venous thrombosis. Conclusions Development of deep venous thrombosis after lower extremity bypass is a serious but infrequent complication. Patients who require unplanned return to the operating room, reintubation, or develop a postoperative urinary tract are at high risk for developing postoperative deep venous thrombosis. Increased monitoring of these patients and ensuring adequate deep venous thrombosis prophylaxis for such patients is suggested.
Paudel, Kalyan; Hoffer, Eric K.
2015-01-01
Intrahepatic shunts between the portal and systemic venous systems with associated aneurysms are extremely rare. A middle aged woman presented with hepatic encephalopathy and was found to have two intrahepatic portosystemic venous shunts with associated aneurysms. Diagnosis was made by duplex ultrasound and was confirmed with contrast enhanced MRI. Treatment was performed percutaneously with an Amplatzer vascular plug. PMID:26257785
Drescher, U; Koschate, J; Schiffer, T; Schneider, S; Hoffmann, U
2017-06-01
The aim of the study was to compare the kinetics responses of heart rate (HR), pulmonary (V˙O 2 pulm) and predicted muscular (V˙O 2 musc) oxygen uptake between two different pseudo-random binary sequence (PRBS) work rate (WR) amplitudes both below anaerobic threshold. Eight healthy individuals performed two PRBS WR protocols implying changes between 30W and 80W and between 30W and 110W. HR and V˙O 2 pulm were measured beat-to-beat and breath-by-breath, respectively. V˙O 2 musc was estimated applying the approach of Hoffmann et al. (Eur J Appl Physiol 113: 1745-1754, 2013) considering a circulatory model for venous return and cross-correlation functions (CCF) for the kinetics analysis. HR and V˙O 2 musc kinetics seem to be independent of WR intensity (p>0.05). V˙O 2 pulm kinetics show prominent differences in the lag of the CCF maximum (39±9s; 31±4s; p<0.05). A mean difference of 14W between the PRBS WR amplitudes impacts venous return significantly, while HR and V˙O 2 musc kinetics remain unchanged. Copyright © 2017 Elsevier B.V. All rights reserved.
Normal venous anatomy and physiology of the lower extremity.
Notowitz, L B
1993-06-01
Venous disease of the lower extremities is common but is often misunderstood. It seems that the focus is on the exciting world of arterial anatomy and pathology, while the topic of venous anatomy and pathology comes in second place. However, venous diseases such as chronic venous insufficiency, leg ulcers, and varicose veins affect much of the population and may lead to disability and death. Nurses are often required to answer complex questions from the patients and his or her family about the patient's disease. Patients depend on nurses to provide accurate information in terms they can understand. Therefore it is important to have an understanding of the normal venous system of the legs before one can understand the complexities of venous diseases and treatments. This presents an overview of normal venous anatomy and physiology.
Maas, Jacinta J.; de Wilde, Rob B.; Aarts, Leon P.; Pinsky, Michael R.; Jansen, Jos R.
2012-01-01
Background Mean systemic filling pressure (Pmsf) can be determined at the bedside by measuring central venous pressure (Pcv) and cardiac output (CO) during inspiratory hold maneuvers. Critical closing pressure (Pcc) can be determined using the same method measuring arterial pressure (Pa) and CO. If Pcc > Pmsf there is then a vascular waterfall. In this study we assessed the existence of a waterfall and its implications for the calculation of vascular resistances by determining Pmsf and Pcc at the bedside. Methods In 10 mechanically ventilated postcardiac surgery patients inspiratory hold maneuvers were performed, transiently increasing Pcv and decreasing Pa and CO to four different steady-state levels. For each patient values of Pcv and CO were plotted in a venous return curve to determine Pmsf. Similarly, Pcc was determined with a ventricular output curve plotted for Pa and CO. Measurements were performed in each patient before and after volume expansion with 0.5 l colloid and vascular resistances were calculated. Results For every patient the relationship between the four measurements of Pcv and CO and of Pa and CO was linear. Baseline Pmsf was 18.7±4.0 (mean±SD) mmHg and differed significantly from Pcc 45.5±11.1 mmHg; (p<0.0001). The difference of Pcc and Pmsf was 26.8±10.7 mmHg, indicating the presence of a systemic vascular waterfall. Volume expansion increased Pmsf (26.3±3.2 mmHg), Pcc (51.5±9.0 mmHg) and CO (5.5±1.8 to 6.8±1.8 l·min−1). Arterial (upstream of Pcc) and venous (down-stream of Pmsf) vascular resistance were 8.27±4.45 and 2.75±1.23 mmHg·min·l−1; the sum of both (11.01 mmHg·min·l−1) was significantly different from total systemic vascular resistance (16.56±8.57 mmHg·min·l−1, p=0.005). Arterial resistance was related to total resistance. Conclusions Vascular pressure gradients in cardiac surgery patients suggest the presence of a vascular waterfall phenomenon, which is not affected by CO. Thus measures of total systemic vascular resistance may become irrelevant in assessing systemic vasomotor tone. PMID:22344243
McElhinney, Doff B; Marx, Gerald R; Newburger, Jane W
2011-01-01
Published case reports suggest that congenital portosystemic venous connections (PSVC) and other abdominal venous anomalies may be relatively frequent and potentially important in patients with polysplenia syndrome. Our objective was to investigate the frequency and range of portal and other abdominal systemic venous anomalies in patients with polysplenia and inferior vena cava (IVC) interruption who underwent a cavopulmonary anastomosis procedure at our center, and to review the published literature on this topic and the potential clinical importance of such anomalies. Retrospective cohort study and literature review were used. Among 77 patients with heterotaxy, univentricular heart disease, and IVC interruption who underwent a bidirectional Glenn and/or modified Fontan procedure, pulmonary arteriovenous malformations were diagnosed in 33 (43%). Bilateral superior vena cavas were present in 42 patients (55%). Despite inadequate imaging in many patients, a partial PSVC, dual IVCs, and/or renal vein anomalies were detected in 15 patients (19%). A PSVC formed by a tortuous vessel running from the systemic venous system to the extrahepatic portal vein was found in six patients (8%). Abdominal venous anomalies other than PSVC were documented in 13 patients (16%), including nine (12%) with some form of duplicated IVC system, with a large azygous vein continuing to the superior vena cava and a parallel, contralateral IVC of similar or smaller size, and seven with renal vein anomalies. In patients with a partial PSVC or a duplicate IVC that connected to the atrium, the abnormal connection allowed right-to-left shunting. PSVC and other abdominal venous anomalies may be clinically important but under-recognized in patients with IVC interruption and univentricular heart disease. In such patients, preoperative evaluation of the abdominal systemic venous system may be valuable. More data are necessary to determine whether there is a pathophysiologic connection between the polysplenia variant of heterotaxy, PSVC, and cavopulmonary anastomosis-associated pulmonary arteriovenous malformations. © 2011 Copyright the Authors. Congenital Heart Disease © 2011 Wiley Periodicals, Inc.
Personal Computer System for Automatic Coronary Venous Flow Measurement
Dew, Robert B.
1985-01-01
We developed an automated system based on an IBM PC/XT Personal computer to measure coronary venous blood flow during cardiac catheterization. Flow is determined by a thermodilution technique in which a cold saline solution is infused through a catheter into the coronary venous system. Regional temperature fluctuations sensed by the catheter are used to determine great cardiac vein and coronary sinus blood flow. The computer system replaces manual methods of acquiring and analyzing temperature data related to flow measurement, thereby increasing the speed and accuracy with which repetitive flow determinations can be made.
The influence of the nasal mucosa and the carotid rete upon hypothalamic temperature in sheep
Baker, Mary Ann; Hayward, James N.
1968-01-01
1. In chronically-prepared sheep, intracranial temperatures were measured in the cavernous sinus among the vessels of the carotid rete and at the circle of Willis extravascularly, and in the preoptic area and in other brain stem regions. Extracranial temperatures were measured intravascularly in the carotid or internal maxillary arteries and on the nasal mucosa and the skin of the ear. 2. At 20° C ambient temperature, shifts in temperature of the hypothalamus and of other brain sites paralleled temperature shifts in the cerebral arterial blood which was cooler than central arterial blood. During periods of arousal and of paradoxical sleep, vasoconstriction of the nasal mucosa and the ear skin occurred and temperatures at the cerebral arteries and in the brain rose without a comparable rise in central arterial blood temperature. 3. Anaesthetic doses of barbiturate abolished the temperature oscillations in the cerebral arterial blood and the brain. When air was blown rapidly over the nasal mucosa in anaesthetized animals, temperatures dropped precipitously in the cavernous sinus, at the cerebral arteries, and in the brain, while central arterial temperature fell only slightly. Injections of latex into the facial venous system demonstrated a venous pathway from the nasal mucosa to the cavernous sinus. 4. When sheep were exposed to 45-50° C ambient temperature, respiratory rate increased 5-10 times and the temperature gradient between central and cerebral arterial blood widened. 5. It is concluded that venous blood returning from the nasal mucosa and the skin of the head to the cavernous sinus cools the central arterial blood in the carotid rete. This is an important factor in the maintenance of hypothalamic temperature in the wool-covered, long-nosed, panting sheep and undoubtedly affects hypothalamic thermoreceptors and temperature regulation in artiodactyls. PMID:5685288
Kinaci, Erdem; Kayaalp, Cuneyt; Yilmaz, Sezai; Otan, Emrah
2014-01-01
Hepatic venous outflow obstruction following liver transplantation is rare but disastrous. Here we described a 14-year-old boy who underwent a split right lobe liver transplantation with modified (side-to-side) piggyback technique which resulted in hepatic venous outflow obstruction. When the liver graft was lifted up, the outflow drainage returned to normal but when it was placed back into the abdomen, the outflow obstruction recurred. Because reanastomosis would have resulted in hepatic reischemia, alternatively, a second infrahepatic cavocavostomy was planned without requiring hepatic reischemia. During this procedure, the first assistant hung the liver up to provide sufficient outflow and the portal inflow of the graft continued as well. We only clamped the recipient's infrahepatic vena cava and the caudal cuff of the graft cava. After the second end-to-side cavocaval anastomosis, the graft was placed in its orthotopic position and there was no outflow problem anymore. The patient tolerated the procedure well and there were no problems after three months of follow-up. A second cavocavostomy can provide an extra bypass for some hepatic venous outflow problems after piggyback anastomosis by avoiding hepatic reischemia.
Kinaci, Erdem; Kayaalp, Cuneyt; Yilmaz, Sezai; Otan, Emrah
2014-01-01
Hepatic venous outflow obstruction following liver transplantation is rare but disastrous. Here we described a 14-year-old boy who underwent a split right lobe liver transplantation with modified (side-to-side) piggyback technique which resulted in hepatic venous outflow obstruction. When the liver graft was lifted up, the outflow drainage returned to normal but when it was placed back into the abdomen, the outflow obstruction recurred. Because reanastomosis would have resulted in hepatic reischemia, alternatively, a second infrahepatic cavocavostomy was planned without requiring hepatic reischemia. During this procedure, the first assistant hung the liver up to provide sufficient outflow and the portal inflow of the graft continued as well. We only clamped the recipient's infrahepatic vena cava and the caudal cuff of the graft cava. After the second end-to-side cavocaval anastomosis, the graft was placed in its orthotopic position and there was no outflow problem anymore. The patient tolerated the procedure well and there were no problems after three months of follow-up. A second cavocavostomy can provide an extra bypass for some hepatic venous outflow problems after piggyback anastomosis by avoiding hepatic reischemia. PMID:24959369
Free Flap Survival Despite Internal Jugular Vein Thrombosis in Head and Neck Reconstruction
Kiya, Koichiro; Seike, Shien; Hosokawa, Ko
2018-01-01
Summary: Microvascular free tissue transfer is one of the most common techniques of reconstruction for complex head and neck surgical defects. Generally, venous thrombosis is more likely to occur than arterial thrombosis in vascular anastomosis. Thus, recipient veins must be chosen carefully. Although the internal jugular vein is preferred as a recipient vein by many microsurgeons, internal jugular vein thrombosis is a potential complication, as shown in our report. Therefore, we consider that the external jugular vein still is an option as a recipient for venous anastomosis and that it is better to perform multiple vein anastomoses with 2 different venous systems, such as the internal and external jugular systems, than anastomoses within the same venous system. PMID:29464172
Computer-aided diagnostic detection system of venous beading in retinal images
NASA Astrophysics Data System (ADS)
Yang, Ching-Wen; Ma, DyeJyun; Chao, ShuennChing; Wang, ChuinMu; Wen, Chia-Hsien; Lo, ChienShun; Chung, Pau-Choo; Chang, Chein-I.
2000-05-01
The detection of venous beading in retinal images provides an early sign of diabetic retinopathy and plays an important role as a preprocessing step in diagnosing ocular diseases. We present a computer-aided diagnostic system to automatically detect venous beading of blood vessels. It comprises of two modules, referred to as the blood vessel extraction module and the venus beading detection module. The former uses a bell-shaped Gaussian kernel with 12 azimuths to extract blood vessels while the latter applies a neural network-based shape cognitron to detect venous beading among the extracted blood vessels for diagnosis. Both modules are fully computer-automated. To evaluate the proposed system, 61 retinal images (32 beaded and 29 normal images) are used for performance evaluation.
Evolution of congenital malformations of the umbilical-portal-hepatic venous system.
Scalabre, Aurelien; Gorincour, Guillaume; Hery, Geraldine; Gamerre, Marc; Guys, Jean-Michel; de Lagausie, Pascal
2012-08-01
The objective of this study is to describe the evolution of 8 cases of congenital malformations of the umbilical-portal-hepatic venous system diagnosed before the first month of life. All cases of congenital malformation of the portal and hepatic venous system diagnosed prenatally or during the first month of life in our institution were systematically reviewed since November 2000. Clinical features, imaging, and anatomical findings were reviewed, focusing primarily on clinical and radiologic evolution. Eight cases of congenital malformation of the umbilical-portal-hepatic venous system were studied. Fifty percent of these malformations were diagnosed prenatally. We report 4 portosystemic shunts. Three involuted spontaneously, and the fourth one required surgical treatment. We report a variation of the usual anatomy of portal and hepatic veins that remained asymptomatic, an aneurysmal dilatation of a vitelline vein causing portal vein thrombosis that needed prompt surgical treatment with good result, a complex portal and hepatic venous malformation treated operatively, and a persistent right umbilical vein that remained asymptomatic. Prenatal diagnosis of malformations of the umbilical-portal-hepatic venous network is uncommon. Little is known about the postnatal prognosis. Clinical, biologic, and radiologic follow-up by ultrasonography is essential to distinguish pathologic situations from normal anatomical variants. Copyright © 2012 Elsevier Inc. All rights reserved.
Vukicevic, M.; Chiulli, J.A.; Conover, T.; Pennati, G.; Hsia, T.Y.; Figliola, R.S.
2013-01-01
We describe an in vitro model of the Fontan circulation with respiration to study subdiaphragmatic venous flow behavior. The venous and arterial connections of a total cavopulmonary connection (TCPC) test section were coupled with a physical lumped parameter (LP) model of the circulation. Intrathoracic and subdiaphragmatic pressure changes associated with normal breathing were applied. This system was tuned for two patients (5 years, 0.67 m2; 10 years, 1.2 m2) to physiological values. System function was verified by comparison to the analytical model on which it was based and by consistency with published clinical measurements. Overall, subdiaphragmatic venous flow was influenced by respiration. Flow within the arteries and veins increased during inspiration but decreased during expiration with retrograde flow in the inferior venous territories. System pressures and flows showed close agreement with the analytical LP model (p < 0.05). The ratio of the flow rates occurring during inspiration to expiration were within the clinical range of values reported elsewhere. The approach used to setup and control the model was effective and provided reasonable comparisons with clinical data. PMID:23644612
Congenital intrahepatic portohepatic venous shunt: treatment with coil embolisation.
Kim, I O; Cheon, J E; Kim, W S; Chung, J W; Yeon, K M; Yoo, S J; Seo, J K; Choi, J H
2000-05-01
Congenital abnormalities of the portal venous system are rare. There are few radiological descriptions of intrahepatic portosystemic venous shunt detected in the perinatal period. We report a congenital portosystemic shunt that was detected by US and treated with coil embolisation in the neonatal period.
2010-01-01
Background The incidence of venous ulceration is rising with the increasing age of the general population. Venous ulceration represents the most prevalent form of difficult to heal wounds and these problematic wounds require a significant amount of health care resources for treatment. Based on current knowledge multi-layer high compression system is described as the gold standard for treating venous ulcers. However, to date, despite our advances in venous ulcer therapy, no convincing low cost compression therapy studies have been conducted and there are no clear differences in the effectiveness of different types of high compression. Methods/Design The trial is designed as a pilot multicentre open label parallel group randomised trial. Male and female participants aged greater than 18 years with a venous ulcer confirmed by clinical assessment will be randomised to either the intervention compression bandage which consists of graduated lengths of 3 layers of elastic tubular compression bandage or to the short stretch inelastic compression bandage (control). The primary objective is to assess the percentage wound reduction from baseline compared to week 12 following randomisation. Randomisation will be allocated via a web based central independent randomisation service (nQuery v7) and stratified by study centre and wound size ≤ 10 cm2 or >10 cm2. Neither participants nor study staff will be blinded to treatment. Outcome assessments will be undertaken by an assessor who is blinded to the randomisation process. Discussion The aim of this study is to evaluate the efficacy and safety of two compression bandages; graduated three layer straight tubular bandaging (3L) when compared to standard short stretch (SS) compression bandaging in healing venous ulcers in patients with chronic venous ulceration. The trial investigates the differences in clinical outcomes of two currently accepted ways of treating people with venous ulcers. This study will help answer the question whether the 3L compression system or the SS compression system is associated with better outcomes. Trial Registration ACTRN12608000599370 PMID:20214822
Venous Thromboembolism Within Professional American Sport Leagues
Bishop, Meghan; Astolfi, Matthew; Padegimas, Eric; DeLuca, Peter; Hammoud, Sommer
2017-01-01
Background: Numerous reports have described players in professional American sports leagues who have been sidelined with a deep vein thrombosis (DVT) or a pulmonary embolism (PE), but little is known about the clinical implications of these events in professional athletes. Purpose: To conduct a retrospective review of injury reports from the National Hockey League (NHL), Major League Baseball (MLB), the National Basketball Association (NBA), and the National Football League (NFL) to take a closer look at the incidence of DVT/PE, current treatment approaches, and estimated time to return to play in professional athletes. Study Design: Descriptive epidemiology study. Methods: An online search of all team injury and media reports of DVT/PE in NHL, MLB, NBA, and NFL players available for public record was conducted by use of Google, PubMed, and SPORTDiscus. Searches were conducted using the professional team name combined with blood clot, pulmonary embolism, and deep vein thrombosis. Results: A total of 55 venous thromboembolism (VTE) events were identified from 1999 through 2016 (NHL, n = 22; MLB, n = 16; NFL, n = 12; NBA, n = 5). Nineteen athletes were reported to have an upper extremity DVT, 15 had a lower extremity DVT, 15 had a PE, and 6 had DVT with PE. Six athletes sustained more than 1 VTE. The mean age at time of VTE was 29.3 years (range, 19-42 years). Mean (±SD) time lost from play was 6.7 ± 4.9 months (range, 3 days to career end). Seven athletes did not return to play. Players with upper extremity DVT had a faster return to play (mean ± SD, 4.3 ± 2.7 months) than those with lower extremity DVT (5.9 ± 3.8 months), PE (10.8 ± 6.8 months), or DVT with PE (8.2 ± 2.6 months) (F = 5.69, P = .002). No significant difference was found regarding time of return to play between sports. Conclusion: VTE in professional athletes led to an average of 6.7 months lost from play. The majority of athletes were able to return to play after a period of anticoagulation or surgery. Those with an upper extremity DVT returned to play faster than those with other types of VTE. Further study is needed to look into modifiable risk factors for these events and to establish treatment and return-to-play guidelines to ensure the safety of these athletes. PMID:29318176
To what extent might N2 limit dive performance in king penguins?
Fahlman, A; Schmidt, A; Jones, D R; Bostrom, B L; Handrich, Y
2007-10-01
A mathematical model was used to explore if elevated levels of N2, and risk of decompression sickness (DCS), could limit dive performance (duration and depth) in king penguins (Aptenodytes patagonicus). The model allowed prediction of blood and tissue (central circulation, muscle, brain and fat) N2 tensions (P(N2)) based on different cardiac outputs and blood flow distributions. Estimated mixed venous P(N2) agreed with values observed during forced dives in a compression chamber used to validate the assumptions of the model. During bouts of foraging dives, estimated mixed venous and tissue P(N2) increased as the bout progressed. Estimated mean maximum mixed venous P(N2) upon return to the surface after a dive was 4.56+/-0.18 atmospheres absolute (ATA; range: 4.37-4.78 ATA). This is equivalent to N2 levels causing a 50% DCS incidence in terrestrial animals of similar mass. Bout termination events were not associated with extreme mixed venous N2 levels. Fat P(N2) was positively correlated with bout duration and the highest estimated fat P(N2) occurred at the end of a dive bout. The model suggested that short and shallow dives occurring between dive bouts help to reduce supersaturation and thereby DCS risk. Furthermore, adipose tissue could also help reduce DCS risk during the first few dives in a bout by functioning as a sink to buffer extreme levels of N2.
Nitzan, Meir; Nitzan, Itamar
2013-08-01
The oxygen saturation of the systemic arterial blood is associated with the adequacy of respiration, and can be measured non-invasively by pulse oximetry in the systemic tissue. The oxygen saturation of the blood in the pulmonary artery, the mixed venous blood, reflects the balance between oxygen supply to the systemic tissues and their oxygen demand. The mixed venous oxygen saturation has also clinical significance because it is used in Fick equation for the quantitative measurement of cardiac output. At present the measurement of the mixed venous oxygen saturation is invasive and requires insertion of a Swan-Ganz catheter into the pulmonary artery. We suggest a noninvasive method for the measurement of the mixed venous oxygen saturation in infants, pulmonary pulse oximetry. The method is similar to the systemic pulse oximetry, which is based on the different light absorption curves of oxygenated and deoxygenated hemoglobin and on the analysis of photoplethysmographic curves in two wavelengths. The proposed pulmonary pulse oximeter includes light-sources of two wavelengths in the infrared, which illuminate the pulmonary tissue through the thoracic wall. Part of the light which is scattered back from the pulmonary tissue and passes through the thoracic wall is detected, and for each wavelength a pulmonary photoplethysmographic curve is obtained. The pulmonary photoplethysmographic curves reflect blood volume increase during systole in the pulmonary arteries in the lung tissue, which contain mixed venous blood. The ratio R of the amplitude-to-baseline ratio for the two wavelengths is related to the mixed venous oxygen saturation through equations derived for the systemic pulse oximetry. The method requires the use of extinction coefficients values for oxygenated and deoxygenated hemoglobin, which can be found in the literature. Copyright © 2013 Elsevier Ltd. All rights reserved.
Kotoda, Atsushi; Akimoto, Tetsu; Sugase, Taro; Yamamoto, Hisashi; Kusano, Eiji
2013-01-01
Central venous stenosis (CVS) is a serious complication for chronic hemodialysis (HD) patients. Previous reports of CVS have focused on prior central venous catheterization, because of the higher prevalence and potential for prevention of such an event. However, recent studies have demonstrated that CVS may also develop without a history of central venous catheterization. Although information about the etiological backgrounds regarding the development of CVS without previous central venous catheterization have gradually accumulated, the clinical impact of the chronic compression of the central venous system by the surrounding structures, which may likely determine the central venous susceptibility to CVS, remains poorly understood. This study proposes the hypothesis that the combination of chronic venous compression at the level of thoracic outlet characterized by the natural physique and elevated venous flow induced by the creation of vascular access should be evaluated as a potential factor for the development of CVS, since they may accelerate the development of venous stenosis, presumably through the stimulation of intimal hyperplasia, and thereby the subclavian venous susceptibility to CVS should be determined. Copyright © 2012 Elsevier Ltd. All rights reserved.
Pan, Yu-Ning; Tang, Yi-Fan; Zhang, Jie; Wang, Guo-Yao; Huang, Qiu-Li
2017-01-01
The present study aims to investigate and compare the diagnostic and prognostic value of cavernosography with 320-row dynamic volume computed tomography (DVCT) versus conventional cavernosography in men with erectile dysfunction (ED) caused by venous leakage. A total of 174 patients diagnosed with ED were enrolled and received cavernosography with 320-row DVCT (DVCT group) and conventional cavernosography scans (control group) respectively. The diagnosis, complications, and prognosis of patients were evaluated. The DVCT group provided high-resolution images with less processing and testing time, as well as lowered radiological agent and contrast agent compared with the control group. In the DVCT group, 89 patients who were diagnosed with venous ED had six various venous leakage, namely superficial venous leakage, profundus venous leakage, the mixed type, cavernosal venous leakage, crural venous leakage, and also venous leakage between the penis and urethra cavernosum (9, 21, 32, 6, 18, and 3 cases respectively). Similarly, 74 patients out of the 81 who suffered from venous ED were classified to have superficial venous leakage (11), profundus venous leakage (14), the mixed type venous leakage (26), and middle venous leakage (23). Six out of 25 patients in the DVCT group, had improvements in ED while the remaining 19 achieved full erectile function recovery with no penile fibrosis and erectile pain. Cavernosography with 320-row DVCT is a reliable system that can be used to diagnose ED caused by venous leakage. This is especially useful in accurately determining the type of venous and allows for a better prognosis and direction of treatment. PMID:28424371
The anatomy of the cardiac veins in mice
Ciszek, Bogdan; Skubiszewska, Daria; Ratajska, Anna
2007-01-01
Although the cardiac coronary system in mice has been the studied in detail by many research laboratories, knowledge of the cardiac veins remains poor. This is because of the difficulty in marking the venous system with a technique that would allow visualization of these large vessels with thin walls. Here we present the visualization of the coronary venous system by perfusion of latex dye through the right caudal vein. Latex injected intravenously does not penetrate into the capillary system. Murine cardiac veins consist of several principal branches (with large diameters), the distal parts of which are located in the subepicardium. We have described the major branches of the left atrial veins, the vein of the left ventricle, the caudal veins, the vein of the right ventricle and the conal veins forming the conal venous circle or the prepulmonary conal venous arch running around the conus of the right ventricle. The venous system of the heart drains the blood to the coronary sinus (the left cranial caval vein) to the right atrium or to the right cranial caval vein. Systemic veins such as the left cranial caval, the right cranial caval and the caudal vein open to the right atrium. Knowledge of cardiac vein location may help to elucidate abnormal vein patterns in certain genetic malformations. PMID:17553104
Circulation-Enhancing Device Improves CPR
NASA Technical Reports Server (NTRS)
2007-01-01
Advanced Circulatory Systems, Inc. and NASA's Kennedy Space Center collaborated for five years on impedance threshold device technology. The resulting technology is encapsulated in a device called the ResQPOD Circulatory Enhancer, which improves the standard of care provided to patients with a variety of clinical conditions due to low blood flow. ResQPOD generates negative intrathoracic pressure during respiration to increase blood flow to the body's vital organs. It is unique in that it non-invasively enhances the body's biophysical performance without depending on pharmaceutical or other outside agents. ResQPOD uses the relationship of the heart, brain, lungs and chest cavity in a manner similar to a bellows to increase venous blood return to the heart. Multiple studies have shown a significant improvement in cardiac output and blood flow to the brain with the use of the impedance threshold device, as well as the device's ability to prevent shock secondary to blood loss. ResQPOD has been added to the set of medical equipment that is available for returning astronaut crews, and commercial applications have fallen into two categories: Non-spontaneously breathing patients who can benefit from enhanced circulation, and spontaneously breathing patients who suffer from transient hypotension or low blood pressure.
Use of ultraportable vacuum therapy systems in the treatment of venous leg ulcer.
Cuomo, Roberto; Nisi, Giuseppe; Grimaldi, Luca; Brandi, Cesare; D'Aniello, Carlo
2017-10-23
The high incidence of venous leg ulcers and the difficult to give a complete healing involves in an increase of costs for National Health System. Main therapies to obtain a fast healing are compressive bandages, treatment of abnormal venous flow and in-situ-strategies of wound care. Negative pressure therapy does not conventionally used, because these systems not allow the use of compression bandages. Recently the development of ultraportable devices has improved the compliance and the results. Ten patients with venous chronic ulcer on the lower extremities were recruited for this study: all patients had venous leg ulcers from at least one year. We treated the patients with autologous partial thickness skin graft and subsequently we applied NANOVA device included in compressive bandage. We used NANOVA for fourteen days and after we made traditional medications. We submitted a questionnaire to evaluate the impact of dressing and NANOVA device in the quality of life of patients. The device contributed to the formation of granulation tissue and increased the success rate of autologous skin graft without limiting mobility of patient. In addition to this, we have been able to perform compression bandages thanks to small size of this device. Eight ulcers healed within 90 days of medication. We believe that ultraportable negative pressure systems are useful devices for treatment of venous leg ulcers because them allows to realize a compressive bandage without mobility limitations.
The study of human venous system dynamics using hybrid computer modeling
NASA Technical Reports Server (NTRS)
Snyder, M. F.; Rideout, V. C.
1972-01-01
A computer-based model of the cardiovascular system was created emphasizing effects on the systemic venous system. Certain physiological aspects were emphasized: effects of heart rate, tilting, changes in respiration, and leg muscular contractions. The results from the model showed close correlation with findings previously reported in the literature.
Ropacka-Lesiak, Mariola; Kasperczak, Jarosław; Breborowicz, Grzegorz H
2012-12-01
The venous system alters its function in pregnancy--the changes are both functional and structural. It becomes particularly vulnerable to the development of venous thrombosis and related complications. These adverse factors acting on the veins in pregnancy include: an increase in circulating blood volume, expansion of the uterus, weight gain, reduced physical activity hormonal changes. The changes in the plasma have a significant impact on the venous system. In pregnancy an increased level of fibrinogen and coagulation factors VII, VIII, IX and X, and von Willenbrand factor can be observed. Smooth muscle relaxation and relaxation of collagen fibers are caused by progesterone and estrogen, and it may result in the development of varicose veins, venous thrombosis and venous insufficiency The relationships between the hormones and the muscle pump efficiency has not been proven as yet. Estrogens cause an increase in the synthesis of coagulation proteins and it may result in the high risk of venous thrombosis and its consequences. Progesterone inhibits smooth muscle contraction, while estrogens cause relaxation and loosening of the bonds between the collagen fibers. The increase in the level of progesterone is of particular importance. It has a relaxing effect on the muscle, resulting in disorders of the vein shrinkage, affecting the increase of their capacity and valvular insufficiency, and valvular edges are not in contact with each other due to the vasodilatation. Estrogens have a similar effect, and additionally it may also cause an impairment in the collagen fibers connection and synthesis. This can result in the formation of telanglectasia without venous hypertension. Estrogens may also affect the synthesis of prostaglandins and nitric oxide. Estradiol inhibits vascular smooth muscle cell proliferation and stimulates cell migration and secretion of matrix proteins, as well as regeneration of the damaged vessels. Estrogen inhibits the production of cytokines, adhesion molecules, and reduce platelet response, i.e. the aggregation and adhesion in the presence of monocytes. Estradiol increases the production, activity and bioavailability of nitric oxide, a molecule with a strong vasodilating effect. Additionally adverse affects may appear due to short intervals between pregnancies, genetics, presence of venous thrombosis or venous insufficiency in the superficial and deep system in anamnesis. Caesarean section is also a risk factor for venous thrombosis. Family factors are associated with inheritance of the formation of varicose changes and venous insufficiency in both ways, dominant and recessive, and also sex-related. Among other factors affecting the development of venous insufficiency during pregnancy the following can be distinguished: type of work (standing, sitting, in forced positions and vibration), interval between pregnancies (determining the possibility of regeneration of physiological regeneration of the system). In case of women who were pregnant more than once, the risk of developing varicose veins and other venous insufficiency is doubled.
Investigation of postural hypotension due to static prolonged standing in female workers.
Kabe, Isamu; Tsuruoka, Hiroko; Tokujitani, Yoko; Endo, Yuichi; Furusawa, Mami; Takebayashi, Toru
2007-07-01
The "Just-in-Time system" improves productivity and efficiency through cost reduction while it makes workers work in a standing posture. The aim of this study was to investigate the prevalence of postural hypotension in females during prolonged standing work, and to discuss preventive methods. Twelve female static standing workers (mean age+/-standard deviation; 32+/-14 yr old), 6 male static standing workers (30+/-4 yr old), 10 female walking workers (27+/-7 yr old) and 9 female desk workers (31+/-5 yr old) in a certain telecommunications equipment manufacturing factory agreed to participate in this study. All participants received an interview with an occupational physician, and performed the standing up test before working and ambulatory blood pressure monitoring (ABPM) while working. Although the blood pressure of the standing up test did not differ among the groups, mean pulse rates on standing up significantly increased in every group. Hypotension rates in the female standing workers' group by ABPM were 9 persons of 12 participants (75%) for systolic blood pressure (SBP), and were 11 persons of 12 participants (92%) for diastolic blood pressure (DBP). There were significantly higher than those in the female desk workers' group, none of 9 participants (0%) for SBP and 2 of 9 participants (22%) for DBP. The hypotension rates both male standing and female walking worker groups did not differ. Because all 8 workers who were found to have postural hypotension by the standing up test had decreased SBP and/or DBP by ABPM, it is suggested that persons at high risk of postural hypotension during standing work could be screened by the standing up test. The mechanism of postural hypotension may be a decrease of venous return due to leg swelling, and neurocardiogenic or vasovagal response. Preventing the congestion of the lower limbs by walking, managing standing time and wearing elastic hose to keep the amount of the venous return could prevent postural hypotension during prolonged standing work.
Immediate ventilatory response to sudden changes in venous return in humans.
Cummin, A R; Iyawe, V I; Jacobi, M S; Mehta, N; Patil, C P; Saunders, K B
1986-01-01
We changed venous return transiently by postural manoeuvres, and by lower body positive pressure, to see what happened simultaneously to ventilation. Cardiac output was measured by a Doppler technique. In seven subjects, after inflation of a pressure suit to 80 and 40 mmHg at 30 deg head-up tilt, both cardiac output and ventilation increased. Ventilation increased rapidly to a peak in the first 5 s, cardiac output more slowly to a steady state in about 20 s, at 80 mmHg inflation. After inflation to 80 mmHg in six subjects at 12.5 deg head-up and 30 deg head-down tilt, cardiac output did not change in the first, and fell in the second case. There were no significant changes in ventilation. On release of pressure there were transient increases in both cardiac output and ventilation, with ventilation lagging behind cardiac output, in contrast to (2) above. In five subjects, elevation of the legs at 30 deg head-up tilt caused a rise in both cardiac output and ventilation, but in two subjects neither occurred. In all seven subjects there was a transient increase in cardiac output and ventilation when the legs were lowered. Ventilation and cardiac output changes were approximately in phase. We were therefore unable to dissociate entirely increasing cardiac output from increasing ventilation. The relation between them was certainly not a simple proportional one. PMID:3612571
Anomalous pulmonary venous connection: An underestimated entity.
Magalhães, Sara P; Moreno, Nuno; Loureiro, Marília; França, Manuela; Reis, Fernanda; Alvares, Sílvia; Ribeiro, Manuel
2016-12-01
Anomalous pulmonary venous connection is an uncommon congenital anomaly in which all (total form) or some (partial form) pulmonary veins drain into a systemic vein or into the right atrium rather than into the left atrium. The authors present one case of total anomalous pulmonary venous connection and two cases of partial anomalous pulmonary venous connection, one of supracardiac drainage into the brachiocephalic vein, and the other of infracardiac anomalous venous drainage (scimitar syndrome). Through the presentation of these cases, this article aims to review the main pulmonary venous developmental defects, highlighting the role of imaging techniques in the assessment of these anomalies. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.
Surgical implications of portal venous system malformation
Marks, Charles
1974-01-01
The significance of congenital abnormalities in predisposing to portal hypertension and variceal haemorrhage needs to be remembered when these effects manifest in childhood, as portal venography will permit elucidation of the complicated congenital developmental abnormalities underlying the pathological condition and permit rational surgical amelioration. In the presence of portal hypertension the development of a collateral venous circulation may be represented by a hepatopetal or hepatofugal circulatory pattern and will closely parallel the developmental areas where portal and systemic venous circulations meet, being representative of the embryological anastomosis between the vitelloumbilical system and the posterior cardinal system of veins. ImagesFig. 3Fig. 5Fig. 6 PMID:4614690
Momose, Naoki; Yamakoshi, Rie; Kokubo, Ryo; Yasuda, Toru; Iwamoto, Norio; Umeda, Chinori; Nakajima, Itsuro; Yanagisawa, Mitsunobu; Tomizawa, Yasuko
2010-03-01
We developed a simple device that stabilizes the blood level in the reservoir of the extracorporeal circulation open circuit system by measuring the hydrostatic pressure of the reservoir to control the flow rate of the arterial pump. When the flow rate of the venous return decreases, the rotation speed of the arterial pump is automatically slowed down. Consequently, the blood level in the reservoir is stabilized quickly between two arbitrarily set levels and never falls below the pre-set low level. We conducted a basic experiment to verify the operation of the device, using a mock circuit with water. Commercially available pumps and reservoir were used without modification. The results confirmed that the control method effectively regulates the reservoir liquid level and is highly reliable. The device possibly also functions as a safety device.
[Atrio-ventricular pressure difference associated with mitral valve motion].
Wang, L M; Mori, H; Minezaki, K; Shinozaki, Y; Okino, H
1990-05-01
Pressure difference (PD) across the mitral valve was analyzed by a computer-aided catheter system in dogs. Positive PD (PPD) was consistently traced in the initial phase of rapid filling. While heart rate (HR) was below 100 beat/min, a negative PD (NPD) followed the above PPD. In the period between the NPD and the 2nd PPD due to atrial contraction, PD was kept at zero, while LA and LV pressures were gradually elevated by pulmonary venous return. As HR exceeded 100, 2 positive peaks of PD merged into M-shaped or mono-peaked PD. Through higher inflow resistance produced by artificial mitral stenosis, PPD peak decayed without NPD. In mitral regurgitation with an acute volume overload, all of the PD amplitudes were exaggerated. Thus the quick reversal of PD suggested the effect in blood filling process across the mitral valve.
Vinson, David R; Ballard, Dustin W; Huang, Jie; Reed, Mary E; Lin, James S; Kene, Mamata V; Sax, Dana R; Rauchwerger, Adina S; Wang, David H; McLachlan, D Ian; Pleshakov, Tamara S; Silver, Matthew A; Clague, Victoria A; Klonecke, Andrew S; Mark, Dustin G
2017-12-13
Outpatient management of emergency department (ED) patients with acute pulmonary embolism is uncommon. We seek to evaluate the facility-level variation of outpatient pulmonary embolism management and to describe patient characteristics and outcomes associated with home discharge. The Management of Acute Pulmonary Embolism (MAPLE) study is a retrospective cohort study of patients with acute pulmonary embolism undertaken in 21 community EDs from January 2013 to April 2015. We gathered demographic and clinical variables from comprehensive electronic health records and structured manual chart review. We used multivariable logistic regression to assess the association between patient characteristics and home discharge. We report ED length of stay, consultations, 5-day pulmonary embolism-related return visits and 30-day major hemorrhage, recurrent venous thromboembolism, and all-cause mortality. Of 2,387 patients, 179 were discharged home (7.5%). Home discharge varied significantly between EDs, from 0% to 14.3% (median 7.0%; interquartile range 4.2% to 10.9%). Median length of stay for home discharge patients (excluding those who arrived with a new pulmonary embolism diagnosis) was 6.0 hours (interquartile range 4.6 to 7.2 hours) and 81% received consultations. On adjusted analysis, ambulance arrival, abnormal vital signs, syncope or presyncope, deep venous thrombosis, elevated cardiac biomarker levels, and more proximal emboli were inversely associated with home discharge. Thirteen patients (7.2%) who were discharged home had a 5-day pulmonary embolism-related return visit. Thirty-day major hemorrhage and recurrent venous thromboembolism were uncommon and similar between patients hospitalized and those discharged home. All-cause 30-day mortality was lower in the home discharge group (1.1% versus 4.4%). Home discharge of ED patients with acute pulmonary embolism was uncommon and varied significantly between facilities. Patients selected for outpatient management had a low incidence of adverse outcomes. Copyright © 2017 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.
Mechanical thrombectomy: an alternative for treating cerebral venous sinus thrombosis.
Izura Gómez, Marta; Misis Del Campo, Maite; Puyalto de Pablo, Paloma; Castaño Duque, Carlos
2018-01-01
We report the use of mechanical venous thrombectomy in 2 cases of cerebral venous sinus thrombosis in which the usual first-choice treatment with systemic anticoagulants was contraindicated. Our aim is to present this treatment as an alternative to consider when anticoagulants therapy is too risky or is contraindicated in critically ill patients.
Helke, C J; Phillips, E T; O'Neill, J T
1987-07-01
Regional central nervous system and peripheral hemodynamic effects of the intrathecal (i.t.) administration of a substance P (SP) receptor antagonist, [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-substance P ([D-Arg]-SP), were studied in anesthetized rats. It was found that [D-Arg]-SP (3.3 nmol i.t.) reduced mean arterial pressure and cardiac output due to a reduction in stroke volume. Total peripheral resistance was not altered. Whereas most vascular beds showed no alterations in vascular resistance, a renal vasoconstriction was noted. The hypotensive effect of [D-Arg]-SP was blocked by phentolamine (10 mg/kg i.v.) but not by propranolol (1 mg/kg i.v.). In the absence of changes in vascular arterial resistance due to [D-Arg]-SP, it appears that a change in venous return may contribute to the [D-Arg]-SP-induced reduction in stroke volume. These data provide evidence that a spinal cord SP system may tonically affect sympathetic neurons controlling venous, but not arterial, vasomotor tone. [D-Arg]-SP (i.t.) did not alter brain blood flow but significantly decreased blood flow in the thoracolumbar spinal cord 15 to 20 min after administration. The reduction in spinal cord flow did not appear to be responsible for the [D-Arg]-SP-induced hypotension because kainic acid (i.t.), an agent that interacts with glutamate receptors, produced similar pressor responses in the presence and absence of [D-Arg]-SP. In addition, whereas the pressor effect of low doses of a SP agonist [pGlu5, MePhe8, MeGly9]-substance P (5-11) were blocked by [D-Arg]-SP, a higher dose produced the typical pressor effect.(ABSTRACT TRUNCATED AT 250 WORDS)
Jones, Roy Wesley; Parkerson, Godfrey Ross; Ottinger, Mary; Rodriguez, Eduardo; Park, Brian
2017-01-01
We present a case of recurrent bilateral lower extremity venous stasis ulcers in association with a superficial venous aneurysm at the right saphenofemoral junction that was misdiagnosed on preoperative duplex scanning. A 53-year-old female presented to our clinic with 6-year history of bilateral lower extremity venous stasis ulcers. Her past medical history was significant for refractory venous stasis ulcers of the bilateral lower extremities present for 6 years and morbid obesity. Preoperative venous duplex demonstrated severe venous insufficiency of the superficial and deep systems, but a venous aneurysm was not appreciated. During the high ligation of the right saphenofemoral junction, a 3 × 4 × 5 cm aneurysm was encountered. Repair consisted of aneurysm resection, high ligation of the greater saphenous vein, dissociation of the great saphenous and anterior saphenous veins, and stab phlebectomy of large varicose veins of the thigh and lower leg. The patient recovered uneventfully and experienced complete healing of the venous stasis ulcer in several weeks. Superficial venous aneurysms of the lower extremity are rare and can be often missed on preoperative duplex ultrasound imaging. Large diameter measurements of the proximal greater saphenous vein and obesity increase the risk of misdiagnosing venous aneurysms with duplex imaging; therefore, clinical suspicion must remain high. These aneurysms can be associated with significant symptoms for which repair is indicated.
Resolution of brainstem edema after treatment of a dural tentorial arteriovenous fistula.
Alvarez, Hortensia; Sasaki-Adams, Deanna; Castillo, Mauricio
2015-10-01
We report a patient with a petrosal arterio-venous dural fistula draining into the ponto-mesencephalic and medullary venous systems presenting with edema of the brain stem and complete reversal of magnetic resonance imaging (MRI) abnormalities after combined endovascular and surgical treatments. The venous anatomy of the posterior fossa and the significance of the venous involvement as the cause of clinical symptoms and imaging abnormalities in cerebro-medullary vascular lesions are discussed. © The Author(s) 2015.
Acute Lower Extremity Deep Venous Thrombosis: The Data, Where We Are, and How It Is Done.
Ramaswamy, Raja S; Akinwande, Olaguoke; Giardina, Joseph D; Kavali, Pavan K; Marks, Christina G
2018-06-01
The incidence of venous thromboembolism, including both deep vein thrombosis and pulmonary embolism, is estimated at 300,000-600,000 per year. Although thrombosis may occur anywhere, it is thrombosis of the deep veins of the lower extremities that is of interest as this is where thrombosis occurs most often within the venous system. This article discusses the evaluation and interventions, including endovascular catheter-direct treatments, for patients with acute deep venous thrombosis. Published by Elsevier Inc.
Noninvasive optoacoustic system for rapid diagnosis and management of circulatory shock
NASA Astrophysics Data System (ADS)
Petrov, Irene Y.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. N.; Seeton, Roger; Esenaliev, Rinat O.; Prough, Donald S.
2013-03-01
Circulatory shock can lead to death or severe complications, if not promptly diagnosed and effectively treated. Typically, diagnosis and management of circulatory shock are guided by blood pressure and heart rate. However, these variables have poor specificity, sensitivity, and predictive value. Early goal-directed therapy in septic shock patients, using central venous catheterization (CVC), reduced mortality from 46.5% to 30%. However, CVC is invasive and complication-prone. We proposed to use an optoacoustic technique for noninvasive, rapid assessment of peripheral and central venous oxygenation. In this work we used a medical grade optoacoustic system for noninvasive, ultrasound image-guided measurement of central and peripheral venous oxygenation. Venous oxygenation during shock declines more rapidly in the periphery than centrally. Ultrasound imaging of the axillary [peripheral] and internal jugular vein [central] was performed using the Vivid e (GE Healthcare). We built an optoacoustic interface incorporating an optoacoustic transducer and a standard ultrasound imaging probe. Central and peripheral venous oxygenations were measured continuously in healthy volunteers. To simulate shock-induced changes in central and peripheral oxygenation, we induced peripheral vasoconstriction in the upper extremity by using a cooling blanket. Central and peripheral venous oxygenations were measured before (baseline) and after cooling and after rewarming. During the entire experiment, central venous oxygenation was relatively stable, while peripheral venous oxygenation decreased by 5-10% due to cooling and recovered after rewarming. The obtained data indicate that noninvasive, optoacoustic measurements of central and peripheral venous oxygenation may be used for diagnosis and management of circulatory shock with high sensitivity and specificity.
Bickel, Amitai; Shturman, Alexander; Sergeiev, Michael; Ivry, Shimon; Eitan, Arieh; Atar, Shaul
2014-10-01
Pneumatic leg sleeves are widely used after prolonged operations for prevention of venous stasis. In healthy volunteers they increase cardiac function. We evaluated the hemodynamic effects and safety of intermittent sequential pneumatic compression (ISPC) leg sleeves in patients with chronic congestive heart failure (CHF). We studied 19 patients with systolic left ventricular dysfunction and CHF. ISPC leg sleeves, each with 10 air cells, were operated by a computerized compressor, exerting 2 cycles/min. Hemodynamic and echocardiographic parameters were measured before, during, and after ISPC activation. The baseline mean left ventricular ejection fraction was 29 ± 9.2%, median 32%, range 10%-40%. Cardiac output (from 4.26 to 4.83 L/min; P = .008) and stroke volume (from 56.1 to 63.5 mL; P = .029) increased significantly after ISPC activation, without a reciprocal increase in heart rate, and declined after sleeve deactivation. Systemic vascular resistance (SVR) decreased significantly (from 1,520 to 1,216 dyne-s/cm5; P = .0005), and remained lower than the baseline level throughout the study. There was no detrimental effect on diastolic function and no adverse clinical events, despite increased pulmonary venous return. ISPC leg sleeves in patients with chronic CHF do not exacerbate symptoms and transiently improve cardiac output through an increase in stroke volume and a reduction in SVR. Copyright © 2014 Elsevier Inc. All rights reserved.
Gregory, Shaun D; Stevens, Michael C; Pauls, Jo P; Schummy, Emma; Diab, Sara; Thomson, Bruce; Anderson, Ben; Tansley, Geoff; Salamonsen, Robert; Fraser, John F; Timms, Daniel
2016-09-01
Preventing ventricular suction and venous congestion through balancing flow rates and circulatory volumes with dual rotary ventricular assist devices (VADs) configured for biventricular support is clinically challenging due to their low preload and high afterload sensitivities relative to the natural heart. This study presents the in vivo evaluation of several physiological control systems, which aim to prevent ventricular suction and venous congestion. The control systems included a sensor-based, master/slave (MS) controller that altered left and right VAD speed based on pressure and flow; a sensor-less compliant inflow cannula (IC), which altered inlet resistance and, therefore, pump flow based on preload; a sensor-less compliant outflow cannula (OC) on the right VAD, which altered outlet resistance and thus pump flow based on afterload; and a combined controller, which incorporated the MS controller, compliant IC, and compliant OC. Each control system was evaluated in vivo under step increases in systemic (SVR ∼1400-2400 dyne/s/cm(5) ) and pulmonary (PVR ∼200-1000 dyne/s/cm(5) ) vascular resistances in four sheep supported by dual rotary VADs in a biventricular assist configuration. Constant speed support was also evaluated for comparison and resulted in suction events during all resistance increases and pulmonary congestion during SVR increases. The MS controller reduced suction events and prevented congestion through an initial sharp reduction in pump flow followed by a gradual return to baseline (5.0 L/min). The compliant IC prevented suction events; however, reduced pump flows and pulmonary congestion were noted during the SVR increase. The compliant OC maintained pump flow close to baseline (5.0 L/min) and prevented suction and congestion during PVR increases. The combined controller responded similarly to the MS controller to prevent suction and congestion events in all cases while providing a backup system in the event of single controller failure. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.
Soderdahl, D W; Henderson, S R; Hansberry, K L
1997-05-01
Intermittent pneumatic compression of the calf and/or thigh effectively decreases the incidence of deep venous thrombosis and other thrombotic sequelae but clinical data comparing these modalities are currently lacking. A total of 90 patients undergoing major urological surgery was randomly assigned to receive calf length or thigh length pneumatic compression for antithrombotic prophylaxis. Duplex ultrasound of the lower extremities was performed preoperatively and twice postoperatively to evaluate for deep venous thrombosis. Health care providers in the operating room, recovery room and ward were asked to compare the compression systems, and a cost analysis was performed. A total of 47 patients wore the thigh length sequential pneumatic sleeves and 43 wore calf length uniform compression systems. A pulmonary embolus without evidence of deep venous thrombosis was detected in 1 patient (2%) using the thigh length system. A thrombus was detected in the common femoral vein by duplex ultrasonography in 1 patient (2%) with the calf length system. Nursing personnel found the calf length sleeves easier to apply and more comfortable by patient account but they were satisfied with both systems. There was a significant cost savings with the calf length pneumatic compression system. Calf and thigh length pneumatic compression systems similarly decrease the risk of deep venous thrombosis in patients undergoing urological surgery. The calf length system has the added advantage of being less expensive and easier to use.
Biacchi, Daniele; Sammartino, Paolo; Sibio, Simone; Accarpio, Fabio; Cardi, Maurizio; Sapienza, Paolo; De Cesare, Alessandro; Atta, Joseph Maher Fouad; Impagnatiello, Alessio; Di Giorgio, Angelo
2016-02-01
Totally implantable venous access ports (TIVAP) are eventually explanted for various reasons, related or unrelated to the implantation technique used. Having more information on long-term explantation would help improve placement techniques. From a series of 1572 cancer patients who had TIVAPs implanted in our center with the cutdown technique or Seldinger technique, we studied the 542 patients who returned to us to have their TIVAP explanted after 70 days or more. As outcome measures we distinguished between TIVAPs explanted for long-term complications (infection, catheter-, reservoir-, and patient-related complications) and TIVAPs no longer needed. Univariate and multivariate analyses were run to investigate the reasons for explantation and their possible correlation with implantation techniques. The most common reason for explantation was infection (47.6 %), followed by catheter-related (20.8 %), patient-related (14.7 %), and reservoir-related complications (4.7 %). In the remaining 12.2 % of cases, the TIVAP was explanted complication free after the planned treatments ended. Infection correlated closely with longer TIVAP use. Univariate and multivariate analyses identified the Seldinger technique as a major risk factor for venous thrombosis and catheter dislocation. The need for long-term TIVAP explantation in about one-third of cancer patients is related to the implantation techniques used.
Congenital heart defects in Williams syndrome.
Yuan, Shi-Min
2017-01-01
Yuan SM. Congenital heart defects in Williams syndrome. Turk J Pediatr 2017; 59: 225-232. Williams syndrome (WS), also known as Williams-Beuren syndrome, is a rare genetic disorder involving multiple systems including the circulatory system. However, the etiologies of the associated congenital heart defects in WS patients have not been sufficiently elucidated and represent therapeutic challenges. The typical congenital heart defects in WS were supravalvar aortic stenosis, pulmonary stenosis (both valvular and peripheral), aortic coarctation and mitral valvar prolapse. The atypical cardiovascular anomalies include tetralogy of Fallot, atrial septal defects, aortic and mitral valvular insufficiencies, bicuspid aortic valves, ventricular septal defects, total anomalous pulmonary venous return, double chambered right ventricle, Ebstein anomaly and arterial anomalies. Deletion of the elastin gene on chromosome 7q11.23 leads to deficiency or abnormal deposition of elastin during cardiovascular development, thereby leading to widespread cardiovascular abnormalities in WS. In this article, the distribution, treatment and surgical outcomes of typical and atypical cardiac defects in WS are discussed.
das Graças C de Souza, Maria; Cyrino, Fatima Zga; de Carvalho, Jorge J; Blanc-Guillemaud, Vanessa; Bouskela, Eliete
2018-05-01
To assess protective effects of micronized purified flavonoid fraction (MPFF) on microcirculation in an original chronic model of hind limb venous hypertension with low blood flow in small animals. Vein ligatures were performed on male hamsters, as follows: A-right femoral vein; A + B-right femoral vein and its right branch; A + C-right femoral vein and its left branch; A + B + C-right femoral and its right and left branches; D-external right iliac vein. In sham operated groups, similar vascular dissections were performed without ligatures. Superficial (epigastric) and central (jugular) venous pressure evaluations were made during a 10 week period. Hamsters subjected to A + B + C and D ligatures were selected for leukocyte rolling and sticking, functional capillary density (FCD), and venular and arteriolar diameter observations. D ligature was selected to evaluate pharmacological treatment efficacy. MPFF (100 mg/kg), concomitant active flavonoids of MPFF (diosmetin, hesperidin, linarin, and isorhoifolin) (10 mg/kg), diosmin (100 mg/kg) or drug vehicle were administered orally during 2 weeks before vein ligature and 6 weeks thereafter. A, A + B and A + C models maintained venous return through collaterals. From the 2 nd to the 10 th weeks after vein ligatures, A + B + C and D models elicited a progressive increase of superficial venous pressure (3.83 ± 0.65 vs. 8.56 ± 0.72 mmHg, p < .001 and 4.13 ± 0.65 vs. 9.35 ± 0.65 mmHg, p < .001, respectively) with significant changes to the microcirculation. As D model significantly increased superficial venous pressure without affecting central venous pressure, it was used to evaluate the long-term effects of treatment. Compared with vehicle, MPFF, concomitant active flavonoids of MPFF, and diosmin, significantly decreased leukocyte-endothelium interaction and prevented FCD reduction. Only MPFF significantly prevented venular enlargement as observed in the vehicle treated group. MPFF was more effective than diosmin in improving all microvascular variables. The superiority of MPFF over diosmin alone can be explained by the synergistic beneficial effects of the association between diosmin and active flavonoids of MPFF. Copyright © 2018 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.
Neurological sequelae from brachiocephalic vein stenosis.
Herzig, David W; Stemer, Andrew B; Bell, Randy S; Liu, Ai-Hsi; Armonda, Rocco A; Bank, William O
2013-05-01
Stenosis of central veins (brachiocephalic vein [BCV] and superior vena cava) occurs in 30% of hemodialysis patients, rarely producing intracranial pathology. The authors present the first cases of BCV stenosis causing perimesencephalic subarachnoid hemorrhage and myoclonic epilepsy. In the first case, a 73-year-old man on hemodialysis presented with headache and blurry vision, and was admitted with presumed idiopathic intracranial hypertension after negative CT studies and confirmatory lumbar puncture. The patient mildly improved until hospital Day 3, when he experienced a seizure; emergency CT scans showed perimesencephalic subarachnoid hemorrhage. Cerebral angiography failed to find any vascular abnormality, but demonstrated venous congestion. A fistulogram found left BCV occlusion with jugular reflux. The occlusion could not be reopened percutaneously and required open fistula ligation. Postoperatively, symptoms resolved and the patient remained intact at 7-month follow-up. In the second case, a 67-year-old woman on hemodialysis presented with right arm weakness and myoclonic jerks. Admission MRI revealed subcortical edema and a possible dural arteriovenous fistula. Cerebral angiography showed venous engorgement, but no vascular malformation. A fistulogram found left BCV stenosis with jugular reflux, which was immediately reversed with angioplasty and stent placement. Postprocedure the patient was seizure free, and her strength improved. Seven months later the patient presented in myoclonic status epilepticus, and a fistulogram revealed stent occlusion. Angioplasty successfully reopened the stent and she returned to baseline; she was seizure free at 4-month follow-up. Central venous stenosis is common with hemodialysis, but rarely presents with neurological findings. Prompt recognition and endovascular intervention can restore normal venous drainage and resolve symptoms.
Bleyl, Steven B.; Saijoh, Yukio; Bax, Noortje A.M.; Gittenberger-de Groot, Adriana C.; Wisse, Lambertus J.; Chapman, Susan C.; Hunter, Jennifer; Shiratori, Hidetaka; Hamada, Hiroshi; Yamada, Shigehito; Shiota, Kohei; Klewer, Scott E.; Leppert, Mark F.; Schoenwolf, Gary C.
2010-01-01
Total anomalous pulmonary venous return (TAPVR) is a congenital heart defect inherited via complex genetic and/or environmental factors. We report detailed mapping in extended TAPVR kindreds and mutation analysis in TAPVR patients that implicate the PDGFRA gene in the development of TAPVR. Gene expression studies in mouse and chick embryos for both the Pdgfra receptor and its ligand Pdgf-a show temporal and spatial patterns consistent with a role in pulmonary vein (PV) development. We used an in ovo function blocking assay in chick and a conditional knockout approach in mouse to knock down Pdgfra expression in the developing venous pole during the period of PV formation. We observed that loss of PDGFRA function in both organisms causes TAPVR with low penetrance (∼7%) reminiscent of that observed in our human TAPVR kindreds. Intermediate inflow tract anomalies occurred in a higher percentage of embryos (∼30%), suggesting that TAPVR occurs at one end of a spectrum of defects. We show that the anomalous pulmonary venous connection seen in chick and mouse is highly similar to TAPVR discovered in an abnormal early stage embryo from the Kyoto human embryo collection. Whereas the embryology of the normal venous pole and PV is becoming understood, little is known about the embryogenesis or molecular pathogenesis of TAPVR. These models of TAPVR provide important insight into the pathogenesis of PV defects. Taken together, these data from human genetics and animal models support a role for PDGF-signaling in normal PV development, and in the pathogenesis of TAPVR. PMID:20071345
Quantitative Studies of Microembolization in Man during Surgical Trauma.
1979-03-01
diphosphoglyceric acid in the red blood cells, and the level of lactate in the blood r1vl constant. There was close correlation be- tween increases In PaCO...he noted that the high SF’ measured in stored blood used during heart-lung bypass was falling to normal levels after passage of the blood through the...blood but not in arterial blood of ether anesthetized rats. The increased micro- emboli ini venous blood returned to control levels within three
Nishite, Yoshiaki; Takesawa, Shingo
2016-01-01
Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity. In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan. The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds. Thus, we can conclude that a simulator system using an extracorporeal circulation system can be set to different models of dialyzers, and that the reproduced treatment scenarios can be used for simulation training.
Parsaee, Mozhgan; Pouraliakbar, Hamidreza; Ghadrdoost, Behshid; Moosavi, Jamal; Behjati, Mohaddeseh
2018-06-10
The most commonly reported collateral systems in the setting of superior vena cava obstruction are azygos venous system, vertebral venous system, external and internal thoracic venous system based on McLntire and Sykes classification. A 49-year-old female with renal disease complained dyspnea on exertion. Transesophageal echocardiography showed significant mitral annular calcification, large multi-lobulated mass at posterior aspect of RA, and complete obstruction of superior vena cava by thrombus formation. Computed tomography angiography showed a collateral vein to the left atrium (LA) roof. This case report is the first one which shows development of collateral vein from right subclavian to LA. © 2018 Wiley Periodicals, Inc.
Rozen, Warren Matthew; Chowdhry, Muhammad; Patel, Nakul Gamanlal; Chow, Whitney T.H.; Griffiths, Matthew; Ramakrishnan, Venkat V.
2016-01-01
Background Venous couplers are ubiquitous around the world and are a useful tool for the reconstructive microsurgeon. A systematic review of coupler performance studies demonstrated a thrombosis rate range of 0% to 3%, whilst the average time of using the device is 5 minutes. There is sparse published data on cost analysis and the impact of operator experience on the anastomotic coupler device success. Improvements in outcomes other than time benefits have also not been shown. This study aims to address these deficiencies in the literature. Methods A retrospective clinical study was undertaken, aiming to compare equivalent groups of patients that had free flap surgery with venous micro-anastomoses with those that had sutured anastomoses. The cohort comprised all patients undergoing microsurgical breast reconstruction at the St Andrew’s Centre for Plastic Surgery & Burns from January 2009 to December 2014. Results Between January 2010 to December 2014, 1,064 patients underwent 1,206 free flap breast reconstructions. The average age of patients was 50 years. Seventy percent of patients underwent mastectomy and immediate reconstruction during this period with the remaining 30% having a delayed reconstruction. The 1,206 free flaps comprised of 83 transverse myocutaneous gracilis (TMG) flaps, and 1,123 deep inferior epigastric artery perforator (DIEP) flaps. In total the coupler was used in 319 flaps, 26% of the cohort. There was a statistically significant clinical benefit in using the anastomotic coupler for venous anastomosis. Overall, the return to theatre rate was 12.69% whilst the overall flap loss rate was 0.75%. The overall coupler failure rate was significantly less at 1.4% whilst sutured vein failure rate was 3.57% (P=0.001). Conclusions The anastomotic coupler for venous anastomosis in free flap surgery is associated with reduced operating times, reduced take-backs to theatre and cost benefits. This is the first study to demonstrate clear clinical benefits to anastomotic couplers, and suggests that these may be the gold standard for venous microanastomosis. With increasing experience with their use and technological advances, these outcomes may continue to improve. PMID:27047776
Effect of venous stenting on intracranial pressure in idiopathic intracranial hypertension.
Matloob, Samir A; Toma, Ahmed K; Thompson, Simon D; Gan, Chee L; Robertson, Fergus; Thorne, Lewis; Watkins, Laurence D
2017-08-01
Idiopathic intracranial hypertension (IIH) is characterised by an increased intracranial pressure (ICP) in the absence of any central nervous system disease or structural abnormality and by normal CSF composition. Management becomes complicated once surgical intervention is required. Venous sinus stenosis has been suggested as a possible aetiology for IIH. Venous sinus stenting has emerged as a possible interventional option. Evidence for venous sinus stenting is based on elimination of the venous pressure gradient and clinical response. There have been no studies demonstrating the immediate effect of venous stenting on ICP. Patients with a potential or already known diagnosis of IIH were investigated according to departmental protocol. ICP monitoring was performed for 24 h. When high pressures were confirmed, CT venogram and catheter venography were performed to look for venous stenosis to demonstrate a pressure gradient. If positive, venous stenting would be performed and ICP monitoring would continue for a further 24 h after deployment of the venous stent. Ten patients underwent venous sinus stenting with concomitant ICP monitoring. Nine out of ten patients displayed an immediate reduction in their ICP that was maintained at 24 h. The average reduction in mean ICP and pulsatility was significant (p = 0.003). Six out of ten patients reported a symptomatic improvement within the first 2 weeks. Venous sinus stenting results in an immediate reduction in ICP. This physiological response to venous stenting has not previously been reported. Venous stenting could offer an alternative treatment option in correctly selected patients with IIH.
[Butcher's Broom, in the treatment of venous insufficiency].
Bylka, Wiesława; Kornobis, Joanna
2005-08-01
Numerous extracts of the plants, natural compounds and their derivatives, acting on the venous system, including horse-chestnut seed extracts aescin, rutin, troxerutin, diosmin and hesperidine. They have a long tradition in herbal medicine for their venotonic and anti-oedematous properties. This review is concerning Rusci aculeati rhizoma, which recently taken in Poland on the symptoms of chronic venous insufficiency and hemorrhoids.
Ames, Jennifer T; Federle, Michael P
2011-07-01
Our purpose was to review the clinical and imaging findings in a series of patients with septic thrombophlebitis of the portal venous system in order to define criteria that might allow more confident and timely diagnosis. This is a retrospective case series. The clinical and imaging features were analyzed in 33 subjects with septic thrombophlebitis of the portal venous system. All 33 patients with septic thrombophlebitis of the portal venous system had pre-disposing infectious or inflammatory processes. Contrast-enhanced CT studies of patients with septic thrombophlebitis typically demonstrate an infectious gastrointestinal source (82%), thrombosis (70%), and/or gas (21%) of the portal system or its branches, and intrahepatic abnormalities such as a transient hepatic attenuation difference (THAD) (42%) or abscess (61%). Septic thrombophlebitis of the portal system is often associated with an infectious source in the gastrointestinal tract and sepsis. Contrast-enhanced CT demonstrates an infectious gastrointestinal source, thrombosis or gas within the portal system or its branches, and intrahepatic abnormalities such as abscess in most cases. We report a THAD in several of our patients, an observation that was not made in prior reports of septic thrombophlebitis.
Computer model of cardiovascular control system responses to exercise
NASA Technical Reports Server (NTRS)
Croston, R. C.; Rummel, J. A.; Kay, F. J.
1973-01-01
Approaches of systems analysis and mathematical modeling together with computer simulation techniques are applied to the cardiovascular system in order to simulate dynamic responses of the system to a range of exercise work loads. A block diagram of the circulatory model is presented, taking into account arterial segments, venous segments, arterio-venous circulation branches, and the heart. A cardiovascular control system model is also discussed together with model test results.
Congenital portosystemic vascular malformations.
Guérin, Florent; Blanc, Thomas; Gauthier, Frédéric; Abella, Stephanie Franchi; Branchereau, Sophie
2012-08-01
Congenital portosystemic shunts are developmental abnormalities of the portal venous system resulting in the diversion of portal blood away from the liver to the systemic venous system. Such malformations are believed to come from an insult occurring between the fourth and eighth week of gestation during the development of hepatic and systemic venous systems, and could explain their frequent association with cardiac and other vascular anomalies. They are currently categorized into end-to-side shunts (type I) or side-to-side shunts (type II). This article aims to review the common symptoms and complications encountered in congenital portosystemic shunts, the surgical and endovascular treatment, and the role of liver transplantation in this disease. We will also focus on the current controversies and the areas where there is potential for future studies. Copyright © 2012. Published by Elsevier Inc.
Thakar, Madhuri; Angira, Francis; Pattanapanyasat, Kovit; Wu, Alan H.B.; O’Gorman, Maurice; Zeng, Hui; Qu, Chenxue; Mahajan, Bharati; Sukapirom, Kasama; Chen, Danying; Hao, Yu; Gong, Yan; Indig, Monika De Arruda; Graminske, Sharon; Orta, Diana; d’Empaire, Nicole; Lu, Beverly; Omana-Zapata, Imelda; Zeh, Clement
2017-01-01
Background: The BD FACSPresto™ system uses capillary and venous blood to measure CD4 absolute counts (CD4), %CD4 in lymphocytes, and hemoglobin (Hb) in approximately 25 minutes. CD4 cell count is used with portable CD4 counters in resource-limited settings to manage HIV/AIDS patients. A method comparison was performed using capillary and venous samples from seven clinical laboratories in five countries. The BD FACSPresto system was assessed for variability between laboratory, instrument/operators, cartridge lots and within-run at four sites. Methods: Samples were collected under approved voluntary consent. EDTA-anticoagulated venous samples were tested for CD4 and %CD4 T cells using the gold-standard BD FACSCalibur™ system, and for Hb, using the Sysmex® KX-21N™ analyzer. Venous and capillary samples were tested on the BD FACSPresto system. Matched data was analyzed for bias (Deming linear regression and Bland-Altman methods), and for concordance around the clinical decision point. The coefficient of variation was estimated per site, instrument/operator, cartridge-lot and between-runs. Results: For method comparison, 93% of the 720 samples were from HIV-positive and 7% from HIV-negative or normal subjects. CD4 and %CD4 T cells venous and capillary results gave slopes within 0.96–1.05 and R2 ≥0.96; Hb slopes were ≥1.00 and R2 ≥0.89. Variability across sites/operators gave %CV <5.8% for CD4 counts, <1.9% for %CD4 and <3.2% for Hb. The total %CV was <7.7% across instrument/cartridge lot. Conclusion: The BD FACSPresto system provides accurate, reliable, precise CD4/%CD4/Hb results compared to gold-standard methods, irrespective of venous or capillary blood sampling. The data showed good agreement between the BD FACSPresto, BD FACSCalibur and Sysmex systems. PMID:29290885
Thakar, Madhuri; Angira, Francis; Pattanapanyasat, Kovit; Wu, Alan H B; O'Gorman, Maurice; Zeng, Hui; Qu, Chenxue; Mahajan, Bharati; Sukapirom, Kasama; Chen, Danying; Hao, Yu; Gong, Yan; Indig, Monika De Arruda; Graminske, Sharon; Orta, Diana; d'Empaire, Nicole; Lu, Beverly; Omana-Zapata, Imelda; Zeh, Clement
2017-01-01
The BD FACSPresto ™ system uses capillary and venous blood to measure CD4 absolute counts (CD4), %CD4 in lymphocytes, and hemoglobin (Hb) in approximately 25 minutes. CD4 cell count is used with portable CD4 counters in resource-limited settings to manage HIV/AIDS patients. A method comparison was performed using capillary and venous samples from seven clinical laboratories in five countries. The BD FACSPresto system was assessed for variability between laboratory, instrument/operators, cartridge lots and within-run at four sites. Samples were collected under approved voluntary consent. EDTA-anticoagulated venous samples were tested for CD4 and %CD4 T cells using the gold-standard BD FACSCalibur ™ system, and for Hb, using the Sysmex ® KX-21N ™ analyzer. Venous and capillary samples were tested on the BD FACSPresto system. Matched data was analyzed for bias (Deming linear regression and Bland-Altman methods), and for concordance around the clinical decision point. The coefficient of variation was estimated per site, instrument/operator, cartridge-lot and between-runs. For method comparison, 93% of the 720 samples were from HIV-positive and 7% from HIV-negative or normal subjects. CD4 and %CD4 T cells venous and capillary results gave slopes within 0.96-1.05 and R 2 ≥0.96; Hb slopes were ≥1.00 and R 2 ≥0.89. Variability across sites/operators gave %CV <5.8% for CD4 counts, <1.9% for %CD4 and <3.2% for Hb. The total %CV was <7.7% across instrument/cartridge lot. The BD FACSPresto system provides accurate, reliable, precise CD4/%CD4/Hb results compared to gold-standard methods, irrespective of venous or capillary blood sampling. The data showed good agreement between the BD FACSPresto, BD FACSCalibur and Sysmex systems.
Positive Fungal Cultures in Burn Patients: A Multicenter Review
2008-02-01
These factors include neutropenia, systemic ste- roids, central venous access,39 TPN, hemodialysis, diabetes mellitus, and urinary catheterization .40...burn treatment exposes patients to multiple other risks for fungal infection, including central venous lines, uri- nary catheters, prolonged...patients with central venous *See appendix for complete list of participants and institutions. This work was supported in part by a grant from Merck & Co
Hypercoagulability in athletes.
Meyering, Christopher; Howard, Thomas
2004-04-01
Risk factors for thromboembolism are well known, and athletes are placed under conditions that can result in exposure to several of these risk factors, which include travel, trauma, immobilization, hemoconcentration, and polycythemia. Presence of a genetic hypercoagulable disorder adds additional risk. Overall management is no different than in nonathletes. Thrombolysis is strongly recommended for upper extremity deep venous thrombosis (DVT) coupled with surgical decompression of obstructive structures if indicated. Thrombolytic therapy does not appear to be necessary for treatment of lower extremity DVT. Prevention of DVT with travel can be achieved through general techniques such as leg exercises, hydration, and loose fitting clothes. Aspirin before travel shows some benefits of protection, but individuals at higher risk may need low molecular weight heparin. Athletes should be screened during preparticipation physicals for thromboembolic risk. Individuals on anticoagulation therapy should not participate in collision or contact sports. Return to play with gradual increase in intensity is recommended with careful monitoring for recurrent venous thromboembolism and management of post-thrombotic symptoms.
Infusion of noradrenaline through the proximal line of a migrated central venous catheter.
Freer, M; Noble, S
2012-08-01
A 41-year-old, obese, patient was admitted to Accident and Emergency with a history of leg cellulitis. A central line was inserted. Documented aspiration of blood from all lines, central venous pressure trace obtained and correct position noted on the chest X-ray (CXR). The patient became increasingly septic despite antibiotic therapy. He was subsequently commenced on a noradrenaline infusion; however, the blood pressure was unresponsive. On admission to the intensive care unit (ICU), it was noted he had an area of white skin over the right clavicle. The infusions were stopped and a CXR confirmed proximal migration of the line. The central line was re-sited and his noradrenaline recommenced with an improvement in his blood pressure. Acute renal failure developed which required haemofiltration for 24 hours. The condition improved and the patient was discharged from ICU. It took several weeks for his renal function to return to normal, but he was discharged home with no permanent damage.
Karahan, Oguz; Kutas, H Barıs; Gurbuz, Orcun; Tezcan, Orhan; Caliskan, Ahmet; Yavuz, Celal; Demirtas, Sinan; Mavitas, Binali
2016-10-01
Deep venous thrombosis (DVT) is a life-threatening and morbid pathology. This study aimed to investigate the efficacy of an early thrombolysis procedure using a rotator thrombolysis device. Sixty-seven patients with acute proximal DVT were enrolled in the study. Patients' data were recorded retrospectively. Initially, an infrarenal retrievable vena cava filter was placed through the femoral vein. Then, a rotator thrombolysis device and a thrombolytic agent injection were applied to the occluded segments of the deep veins by puncturing the popliteal vein. The identified reasons were trauma (43.3%), pregnancy (20.9%), undiagnosed (11.9%), major surgical operation (10.5%), immobilization (7.5%), and malignancy (5.9%). Immediate total recanalization was conducted in all patients, and the leg diameters returned to normal ranges in the early postoperative period. Hospital mortality or severe complications were not detected. New thrombolytic devices seem to reduce in-hospital mortality risks and may potentially decrease post-thrombotic morbidity. © The Author(s) 2015.
Acute venous sinus thrombosis after chickenpox infection.
Sardana, Vijay; Mittal, Lal Chand; Meena, S R; Sharma, Deepti; Khandelwal, Girish
2014-08-01
Chickenpox is one of the classic childhood diseases. Recently chicken pox has been reported in adults with more severe systemic and neurological complications. Cerebral venous thrombosis (CVT) is a life threatening disorder if not treated in time. We report a patient with post varicella CVT as a rare complication of primary Varicella zoster virus. Vasculitic arterial infarction is known while venous stroke has rarely been reported with Varicella-zoster virus infection. Here, we report an immunocompetent 30 yr old male who developed chickenpox after contact with his daughter two month back. He presented with acute neurological deficit, one week after onset of skin lesion. MR venography revealed non-visualisation of left transverse sinus and left sigmoid sinus suggestive of venous sinus thrombosis. Varicella infection is rarely associated with venous sinus thrombosis. Possibly hypercoagulable state produced by the infection or direct invasion of virus in venous endothelial wall with subsequent damage to endothelium leading to thrombosis could be the cause.
Stasis Dermatitis: Pathophysiology, Evaluation, and Management.
Sundaresan, Swaminathan; Migden, Michael R; Silapunt, Sirunya
2017-06-01
Stasis dermatitis commonly occurs in older age. It is caused by venous hypertension resulting from retrograde flow due to incompetent venous valves, valve destruction, or obstruction of the venous system. Further tissue changes arise from an inflammatory process mediated by metalloproteinases, which are up-regulated by ferric ion from extravasated red blood cells. Stasis dermatitis presents initially as poorly demarcated erythematous plaques of the lower legs bilaterally, classically involving the medial malleolus. It is one of the spectrum of cutaneous findings that may result from chronic venous insufficiency. Its mimics include cellulitis, contact dermatitis, and pigmented purpuric dermatoses. Duplex ultrasound is useful in demonstrating venous reflux when the clinical diagnosis of stasis dermatitis is inadequate. Conservative treatment involves the use of compression therapy directed at improving ambulatory venous pressure. Interventional therapy currently includes minimally invasive techniques such as endovenous thermal ablation and ultrasound-guided foam sclerotherapy, which have supplanted the use of open surgical techniques.
[Venous tone of the limbs. Methods and comparison of 2 areas].
Journo, H; London, G; Pannier, B; Safar, M
1989-07-01
The limb venous tone, index of local venous compliance, was studied with mercury strain gauge plethysmography on 28 male normal subjects (40 +/- 17 years, +/- SD) simultaneously on upper and lower limbs. Measurements were done after 20 mn rest in supine position. Venous tone (VT) equals the slope of the pressure-volume curve established by simultaneous recording of the forearm and calf relative volumes for successive steps of pressure lower than or equal to 30 mmHg. Limb venous capacitance was expressed by means of the maximal limb relative volume (V30) reached for a pressure of 30 mmHg applied through cuffs in standardized conditions. The upper limb venous tone was greater than the lower limb venous tone: 24.3 +/- 8.2 mmHg/ml/100 vs 17.5 +/- 7.9 mmHg/ml/100, p = 0.001. V30 was greater in lower limb than in upper limb: 1.5 +/- 0.5 ml/100 vs 1.1 +/- 0.4 ml/100, p = 0.001. In conclusion, it appears that upper and lower limbs venous distensibility and capacitance are different. They are greater in the lower limb in baseline conditions. Thus simultaneous studies of both these limb venous systems seems important for physiological experiments because of their baseline differences.
Contrast-enhanced ultrasound in portal venous system aneurysms: a multi-center study.
Tana, Claudio; Dietrich, Christoph F; Badea, Radu; Chiorean, Liliana; Carrieri, Vincenzo; Schiavone, Cosima
2014-12-28
To investigate contrast-enhanced ultrasound (CEUS) findings in portal venous system aneurysms (PVSAs). In this multi-center, retrospective, case series study, we evaluated CEUS features of seven cases of PVSAs that were found incidentally on conventional ultrasound in the period 2007-2013. Three Ultrasound Centers were involved (Chieti, Italy, Bad Mergentheim, Germany, and Cluj-Napoca, Romania). All patients underwent CEUS with Sonovue(®) (Bracco, Milan, Italy) at a standard dose of 2.4 mL, followed by 10 mL of 0.9% saline solution. The examinations were performed using multifrequency transducers and low mechanical index. We considered aneurysmal a focal dilatation of the portal venous system with a size that was significantly greater than the remaining segments of the same vein, and that was equal or larger than 21 mm for the extrahepatic segments of portal venous system, main portal vein and bifurcation, and 9 mm for the intrahepatic branches. After contrast agent injection, all PVSAs were not enhanced in the arterial phase (starting 8-22 s). All PVSAs were then rapidly enhanced in the early portal venous phase (starting three to five seconds after the arterial phase, 11-30 s), with persistence and slow washout of the contrast agent in the late phase (starting 120 s). In all patients, CEUS confirmed the presence of a "to-and-fro" flow by showing a swirling pattern within the dilatation in the early portal venous phase. CEUS also improved the delineation of the lumen, and was reliable in showing its patency degree and integrity of walls. In one patient, CEUS showed a partial enhancement of the lumen with a uniformly nonenhancing area in the portal venous and late phases, suggesting thrombosis. In our case series, we found that CEUS could be useful in the assessment and follow-up of a PVSA. Further studies are needed to validate its diagnostic accuracy.
Ito, Hiroki; Murata, Masaya; Ide, Yujiro; Sugano, Mikio; Kanno, Kazuyoshi; Imai, Kenta; Ishido, Motonori; Fukuba, Ryohei; Sakamoto, Kisaburo
2016-01-01
OBJECTIVES Fontan candidates with mixed totally anomalous pulmonary venous connection often have postoperative pulmonary venous obstruction after cavopulmonary anastomosis. Because some pulmonary venous obstructions have no intimal hypertrophy at reoperation, we considered such pulmonary venous obstructions to be caused by 3D deformities arising from dissection or mobilization of the vessels, and hypothesized that keeping the pulmonary venous branches in a natural position could avoid such obstruction. Here, we evaluated a modified hemi-Fontan strategy consisting of minimal dissection with no division of vessels and patch separation between systemic and pulmonary venous flow. METHODS We retrospectively reviewed clinical records of infants with a functional single ventricle and supracardiac anomalous pulmonary venous connection who had undergone this procedure between 2002 and 2012. RESULTS Nine infants underwent this procedure (median age, 5.6 months; range 3.2–30), all with right atrial isomerism and several pulmonary venous branches directly and separately connecting to the superior vena cava. In 5 patients, all pulmonary veins drained into the superior vena cava; in 1, the right pulmonary veins drained into the superior vena cava and in 3, a pulmonary venous branch drained into the superior vena cava. The median follow-up was 6.9 years (0.8–13 years). Three patients underwent reoperation for postoperative pulmonary venous obstruction caused by intimal hypertrophy; however, we confirmed no pulmonary venous obstruction caused by 3D deformities on the pulmonary venous branches connecting separately to the superior vena cava. Although 2 patients were effectively relieved from pulmonary venous obstruction, 1 died due to recurrent pulmonary venous obstruction. There was no late death and no sinus-node dysfunction. Eight patients underwent successful Fontan operation and catheterization. The median interval from the Fontan operation to the latest catheterization was 3.7 years (0.9–3.7 years). The median arterial oxygen saturation was 94% (91–97%) and the central venous pressure was 12 mmHg (8–14 mmHg); no deficiency of pulmonary arteries and veins was noted. CONCLUSIONS For patients with functional single ventricle and anomalous pulmonary venous connections to the superior vena cava, our novel strategy of second-stage palliation could avoid postoperative pulmonary venous obstruction caused by 3D deformities, but may not eliminate pulmonary venous obstruction caused by intimal hypertrophy. PMID:26860898
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pua, Uei, E-mail: druei@yahoo.com
2015-10-15
Intra-tumoral arterio-hepatic venous shunting (AHVS) poses an impediment to transarterial chemoembolization of liver tumors. Not only does it present a potential hazard for systemic shunting and embolization, but also the altered flow dynamics may also result in poor delivery of drug/embolics to the target tumor bed. Current available techniques to overcome AVHS include arterial embolization (particles, coils, glue, etc.) or temporary venous occlusion using balloons. We hereby illustrate the use of radiofrequency ablation to obliterate a complex AHVS consisting of a varix-like venous aneurysm.
Yeste Sánchez, Luis; Galbis Caravajal, José M; Fuster Diana, Carlos A; Moledo Eiras, Enrique
2006-10-01
The cannulation of suitable peripheral veins may be a very painful experience. Implantable venous access systems have to some degree relieved this problem and help to provide an improvement in terms of quality of life. We have evaluated 560 patients during a follow up period of two years. A low overall complication percentage of 7.32% was seen when using the venous access device. Complications and treatments were: pneumothorax; portal rotation or infection; catheter infection; embolism and migration; extravasation; partial or total obstruction of the device; rupture of the catheter or the membrane. There is no other system that allows repeated venous access on such a long term basis. Placing the devices completely under the skin allows the patient to conduct a normal life style, and its maintenance does not need any special care, with the exception of the monthly heparinised serum infusion. The preferred option is to insert the catheter through the cephalic vein in the delto pectoral groove.
Resection of a Large Innominate Vein Aneurysm in a Patient with Neurofibromatosis Type 1.
Bartline, Peter B; McKellar, Stephen H; Kinikini, Daniel V
2016-01-01
Venous aneurysms are exceedingly rare manifestations of neurofibromatosis type 1 (NF1). There are only a handful of cases reported, and no prior cases describing treatment of mediastinal venous aneurysms in this patient population exist. A 58-year-old woman with NF1 presented with a right neck mass. The mass had recently doubled in size and was associated with cough, hoarseness of voice, and pain. Her pertinent medical history included untreated obstructive sleep apnea, severe pulmonary hypertension, and a recent hospital admission for pneumonia. On physical examination, numerous cutaneous neurofibromas were noted. The mass encompassed her right neck and supraclavicular area with marked respiratory variation. Computed tomography showed a complex 7-cm venous aneurysm including her right innominate, internal jugular, and subclavian veins. Surgical approach involved median sternotomy with right cervical extension and a right infraclavicular counter incision. Extracorporeal circulation was established through the left groin. Ligation of the right internal jugular vein was required. The aneurysm was completely excised, and venous reconstruction consisted of cryopreserved femoral vein anastomosed to right innominate and infraclavicular subclavian veins. Intraoperatively, her preexisting pulmonary hypertension resulted in acute right heart failure requiring placement of a right ventricular assist device (RVAD). She subsequently returned to the operating room for RVAD weaning and sternal closure. Her postoperative course was lengthy; however, many of her aneurysm-related symptoms resolved. This case represents management of the only innominate vein aneurysm in the setting of NF1 described in the literature. Vascular reconstruction is possible, however difficult. Careful preoperative planning and use of extracorporeal circulation was necessary in this case. Copyright © 2016 Elsevier Inc. All rights reserved.
Patterning mechanisms of the sub-intestinal venous plexus in zebrafish
Goi, Michela; Childs, Sarah J.
2017-01-01
Despite considerable interest in angiogenesis, organ-specific angiogenesis remains less well characterized. The vessels that absorb nutrients from the yolk and later provide blood supply to the developing digestive system are primarily venous in origin. In zebrafish, these are the vessels of the Sub-intestinal venous plexus (SIVP) and they represent a new candidate model to gain an insight into the mechanisms of venous angiogenesis. Unlike other vessel beds in zebrafish, the SIVP is not stereotypically patterned and lacks obvious sources of patterning information. However, by examining the area of vessel coverage, number of compartments, proliferation and migration speed we have identified common developmental steps in SIVP formation. We applied our analysis of SIVP development to obd mutants that have a mutation in the guidance receptor PlexinD1. obd mutants show dysregulation of nearly all parameters of SIVP formation. We show that the SIVP responds to a unique combination of pathways that control both arterial and venous growth in other systems. Blocking Shh, Notch and Pdgf signaling has no effect on SIVP growth. However Vegf promotes sprouting of the predominantly venous plexus and Bmp promotes outgrowth of the structure. We propose that the SIVP is a unique model to understand novel mechanisms utilized in organ-specific angiogenesis. PMID:26477558
Nishite, Yoshiaki; Takesawa, Shingo
2016-01-01
Background: Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. Objectives: The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity. Materials and Methods: In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan. Results: The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds. Conclusions: Thus, we can conclude that a simulator system using an extracorporeal circulation system can be set to different models of dialyzers, and that the reproduced treatment scenarios can be used for simulation training. PMID:26981503
Woller, Scott C; Stevens, Scott M; Evans, R Scott; Wray, Daniel G; Christensen, John C; Aston, Valerie T; Wayne, Matthew H; Lloyd, James F; Wilson, Emily L; Elliott, C Gregory
2016-10-01
Venous thromboembolism chemoprophylaxis remains underutilized in hospitalized medical patients at high risk for venous thromboembolism. We assessed the effect of a health care quality-improvement initiative comprised of a targeted electronic alert, comparative practitioner metrics, and practitioner-specific continuing medical education on the rate of appropriate venous thromboembolism chemoprophylaxis provided to medical inpatients at high risk for venous thromboembolism. We performed a multicenter prospective observational cohort study in an urban Utah hospital system. All medical patients admitted to 1 of 2 participating hospitals from April 1, 2010 to December 31, 2012 were eligible. Patients were members of the "control" (April 1, 2010 to December 31, 2010), "intervention" (January 1, 2011 to December 31, 2011), or "subsequent year" (January 1, 2012 to December 31, 2012) group. The primary outcome was the rate of appropriate chemoprophylaxis among patients at high risk for venous thromboembolism. Secondary outcomes included rates of symptomatic venous thromboembolism, major bleeding, all-cause mortality, heparin-induced thrombocytopenia, physician satisfaction, and alert fatigue. The rate of appropriate chemoprophylaxis among patients at high risk for venous thromboembolism increased (66.1% control period vs 81.0% intervention period vs 88.1% subsequent year; P <.001 for each comparison). A significant reduction of 90-day symptomatic venous thromboembolism accompanied the quality initiative (9.3% control period, 9.7% intervention period, 6.7% subsequent year; P = .009); 30-day venous thromboembolism rates also significantly decreased. A multifaceted intervention was associated with increased appropriate venous thromboembolism chemoprophylaxis among medical inpatients at high risk for venous thromboembolism and reduced symptomatic venous thromboembolism. The effect of the intervention was sustained. Copyright © 2016 Elsevier Inc. All rights reserved.
Applegate, Richard L; Ramsingh, Davinder S; Dorotta, Ihab; Sanghvi, Chirag; Blood, Arlin B
2013-06-01
Early and aggressive treatment of circulatory failure is associated with increased survival, highlighting the need for monitoring methods capable of early detection. Vasoconstriction and decreased oxygenation of the splanchnic circulation are a sentinel response of the cardiovasculature during circulatory distress. Thus, we measured esophageal oxygenation as an index of decreased tissue oxygen delivery caused by three types of ischemic insult, occlusive decreases in mesenteric blood flow, and hemodynamic adaptations to systemic hypoxia and simulated hemorrhagic stress. Five anesthetized lambs were instrumented for monitoring of mean arterial pressure, mesenteric artery blood flow, central venous hemoglobin oxygen saturation, and esophageal and buccal microvascular hemoglobin oxygen saturation (StO2). The sensitivities of oximetry monitoring to detect cardiovascular insult were assessed by observing responses to graded occlusion of the descending aorta, systemic hypoxia due to decreased FIO2, and acute hemorrhage. Decreases in mesenteric artery flow during aortic occlusions were correlated with decreased esophageal StO2 (R = 0.41). During hypoxia, esophageal StO2 decreased significantly within 1 min of initiation, whereas buccal StO2 decreased within 3 min, and central venous saturation did not change significantly. All modes of oximetry monitoring and arterial blood pressure were correlated with mesenteric artery flow during acute hemorrhage. Esophageal StO2 demonstrated a greater decrease from baseline levels as well as a more rapid return to baseline levels during reinfusion of the withdrawn blood. These experiments suggest that monitoring esophageal StO2 may be useful in the detection of decreased mesenteric oxygen delivery as may occur in conditions associated with hypoperfusion or hypoxia.
Non-contact hemodynamic imaging reveals the jugular venous pulse waveform
NASA Astrophysics Data System (ADS)
Amelard, Robert; Hughson, Richard L.; Greaves, Danielle K.; Pfisterer, Kaylen J.; Leung, Jason; Clausi, David A.; Wong, Alexander
2017-01-01
Cardiovascular monitoring is important to prevent diseases from progressing. The jugular venous pulse (JVP) waveform offers important clinical information about cardiac health, but is not routinely examined due to its invasive catheterisation procedure. Here, we demonstrate for the first time that the JVP can be consistently observed in a non-contact manner using a photoplethysmographic imaging system. The observed jugular waveform was strongly negatively correlated to the arterial waveform (r = -0.73 ± 0.17), consistent with ultrasound findings. Pulsatile venous flow was observed over a spatially cohesive region of the neck. Critical inflection points (c, x, v, y waves) of the JVP were observed across all participants. The anatomical locations of the strongest pulsatile venous flow were consistent with major venous pathways identified through ultrasound.
Induced venous pooling and cardiorespiratory responses to exercise after bed rest
NASA Technical Reports Server (NTRS)
Convertino, V. A.; Sandler, H.; Webb, P.; Annis, J. F.
1982-01-01
Venous pooling induced by a specially constructed garment is investigated as a possible means for reversing the reduction in maximal oxygen uptake regularly observed following bed rest. Experiments involved a 15-day period of bed rest during which four healthy male subjects, while remaining recumbent in bed, received daily 210-min venous pooling treatments from a reverse gradient garment supplying counterpressure to the torso. Results of exercise testing indicate that while maximal oxygen uptake endurance time and plasma volume were reduced and maximal heart rate increased after bed rest in the control group, those parameters remained essentially unchanged for the group undergoing venous pooling treatment. Results demonstrate the importance of fluid shifts and venous pooling within the cardiovascular system in addition to physical activity to the maintenance of cardiovascular conditioning.
Non-contact hemodynamic imaging reveals the jugular venous pulse waveform
Amelard, Robert; Hughson, Richard L.; Greaves, Danielle K.; Pfisterer, Kaylen J.; Leung, Jason; Clausi, David A.; Wong, Alexander
2017-01-01
Cardiovascular monitoring is important to prevent diseases from progressing. The jugular venous pulse (JVP) waveform offers important clinical information about cardiac health, but is not routinely examined due to its invasive catheterisation procedure. Here, we demonstrate for the first time that the JVP can be consistently observed in a non-contact manner using a photoplethysmographic imaging system. The observed jugular waveform was strongly negatively correlated to the arterial waveform (r = −0.73 ± 0.17), consistent with ultrasound findings. Pulsatile venous flow was observed over a spatially cohesive region of the neck. Critical inflection points (c, x, v, y waves) of the JVP were observed across all participants. The anatomical locations of the strongest pulsatile venous flow were consistent with major venous pathways identified through ultrasound. PMID:28065933
[Interventional radiology treatment of extensive pulmonary embolism and thromboembolic diseases].
Battyáni, István; Dósa, Edit; Harmat, Zoltán
2015-04-26
The authors discuss interventional radiological methods in the field of vascular interventions applied in venous system diseases. Venous diseases can be life threatening without appropriate treatment and can lead to chronic venous diseases and venous insufficiency with long-term reduction in the quality of life. In addition, recurrent clinical symptoms require additional treatments. Interventional radiology has several methods that can provide fast and complete recovery if applied in time. The authors summarize these methods hoping that they will be available for a wide range of patients through the establishment of Interventional Radiological Centres and will be a part of the daily routine of patient care. Regarding the frequency of venous diseases and its influance on life quality the authors would like to draw attention to interventional radiological techniques and modern therapeutic possibilities.
1999-08-01
immediately, re- ducing venous return artifacts during the first beat of the simulation. tn+1 - W+ on c+ / \\ W_ on c_ t 1 Xi-l Xi+1 Figure 4...s) Figure 5: The effect of network complexity. The aortic pressure is shown in Figure 5 during the fifth beat for the networks with one and three...Mechanical Engineering Department, Uni- versity of Victoria. [19] Huyghe J.M., 1986, "Nonlinear Finite Element Models of The Beating Left
Tri-functional cannula for retinal endovascular surgery
Weiss, Jonathan D [Albuquerque, NM
2010-07-27
A tri-functional cannula combines the functions of tissue Plasminogen Activator (tPA) solution delivery, illumination and venous pressure measurement. The cannula utilizes a tapered hollow-core optical fiber having an inlet for tPA solution, an attached fiber optic splitter configured to receive illumination light from an optical source such and a LED. A window in the cannula transmits the light to and from a central retinal vein. The return light is coupled to an optical detector to measure the pressure within the vein and determine whether an occlusion has been removed.
Arndt, Andreas; Nüsser, Peter; Graichen, Kurt; Müller, Johannes; Lampe, Bernhard
2008-10-01
A control strategy for rotary blood pumps meeting different user-selectable control objectives is proposed: maximum support with the highest feasible flow rate versus medium support with maximum ventricular washout and controlled opening of the aortic valve (AoV). A pulsatility index (PI) is calculated from the pressure difference, which is deduced from the axial thrust measured by the magnetic bearing of the pump. The gradient of PI with respect to pump speed (GPI) is estimated via online system identification. The outer loop of a cascaded controller regulates GPI to a reference value satisfying the selected control objective. The inner loop controls the PI to a reference value set by the outer loop. Adverse pumping states such as suction and regurgitation can be detected on the basis of the GPI estimates and corrected by the controller. A lumped-parameter computer model of the assisted circulation was used to simulate variations of ventricular contractility, pulmonary venous pressure, and aortic pressure. The performance of the outer control loop was demonstrated by transitions between the two control modes. Fast reaction of the inner loop was tested by stepwise reduction of venous return. For maximum support, a low PI was maintained without inducing ventricular collapse. For maximum washout, the pump worked at a high PI in the transition region between the opening and the permanently closed AoV. The cascaded control of GPI and PI is able to meet different control objectives and is worth testing in vitro and in vivo.
Chronic leg ulceration in homozygous sickle cell disease: the role of venous incompetence.
Clare, Andrea; FitzHenley, Michael; Harris, June; Hambleton, Ian; Serjeant, Graham R
2002-11-01
Chronic leg ulceration is a common cause of morbidity in Jamaican patients with homozygous sickle cell (SS) disease. Ulcers heal more rapidly on bed rest and deteriorate on prolonged standing, suggesting a role of venous hypertension in their persistence. This hypothesis has been tested by Doppler detection of venous competence in SS patients and in matched controls with a normal haemoglobin (AA) genotype in the Jamaican Cohort Study. Venous incompetence was significantly more frequent in SS disease [137/183 (75%)] than in non-pregnant AA controls [53/137 (39%)]. Past or present ulceration occurred in 78 (43%) SS patients, with a highly significant association between leg ulceration and venous incompetence in the same leg (P < 0.001). Prominence and/or varicosities of the veins and spontaneous leg ulcers were more common among patients with multiple sites of incompetence. The association of venous incompetence with chronic leg ulceration identifies a further pathological mechanism contributing to the morbidity of SS disease. The cause of venous incompetence is unknown but the sluggish circulation associated with dependency, turbidity and impaired linear flow at venous valves, hypoxia-induced sickling, the rheological effects of high white cell counts, and activation of components of the coagulation system may all contribute. Venous hypertension in SS patients with leg ulceration suggests that firm elastic supportive dressings might promote healing of chronic leg ulcers.
Corbacioglu, Aytul; Aslan, Halil; Dagdeviren, Hediye; Ceylan, Yavuz
2012-01-01
Ductus venosus connecting the portal and embryonic venous circulation into the inferior vena cava has a crucial role in fetal circulation. The absence of ductus venosus is a rare anomaly, in which the umbilical vein connection to the venous system may be extrahepatic, bypassing the liver or intrahepatic via the portal venous system. We report three cases of ductus venosus agenesis with associated anomalies. In two of them the connection was directly to the right atrium, whereas the umbilical vein drained to the left internal iliac artery in the third case. Copyright © 2012 Wiley Periodicals, Inc.
VanWye, William R; Pinerola, Jase; Ogle, Karen Craig; Wallmann, Harvey W
2016-08-01
Screening for referral, regardless of setting, is the responsibility of all physical therapists. A serious condition that sports physical therapists may encounter is upper extremity (UE) deep venous thrombosis (DVT), which can result in the important and sometimes fatal complication of pulmonary embolism. A 22 year-old male right-hand dominant collegiate pitcher was referred for physical therapist evaluation and treatment secondary to acute right UE pain and swelling. The athlete described the onset of these symptoms as insidious, denying any form of trauma. The athlete had undergone testing, which included UE Doppler ultrasound of the bilateral UE veins and a computed tomography (CT) scan of the chest without contrast; both of which were deemed negative. He was subsequently diagnosed with thoracic outlet syndrome and referred to the team physical therapist. After examination, the physical therapist hypothesized the athlete was presenting with a possible vascular compromise. Findings leading to this decision were: 1) insidious onset, 2) inability to account for the athlete's pain with ROM, strength, neurological, or provocation testing, 3) significant swelling of the right UE (arm and forearm), 4) increased discomfort with palpation in the supraclavicular region, and 5) history of strenuous UE use. The athlete was referred back to the orthopedist. A venogram CT was ordered, which revealed an axillary and subclavian DVT and the presence of venous collaterals. The athlete was referred to a vascular surgeon who performed a right first rib removal. The athlete was able to complete post-operative rehabilitation and successfully return to competitive throwing the following spring. The delay in the initial diagnosis may have been due to the vague symptomology associated with venous complications and negative findings upon initial diagnostic testing. This case report highlights the importance of subjective and physical examination findings and use of diagnostic testing for timely identification of an UE DVT. Ultimately, the physical therapist in this case was able to screen for referral, which led to the correct diagnosis and allowed the athlete to safely and successfully return to sport. Physical therapists should include effort thrombosis in their upper quarter differential diagnosis list for athletes who perform strenuous UE activity. 4.
Use of an Intravascular Fluorescent Continuous Glucose Sensor in ICU Patients.
Strasma, Paul J; Finfer, Simon; Flower, Oliver; Hipszer, Brian; Kosiborod, Mikhail; Macken, Lewis; Sechterberger, Marjolein; van der Voort, Peter H J; DeVries, J Hans; Joseph, Jeffrey I
2015-07-01
Hyperglycemia and hypoglycemia are associated with adverse clinical outcomes in intensive care patients. In product development studies at 4 ICUs, the safety and performance of an intravascular continuous glucose monitoring (IV-CGM) system was evaluated in 70 postsurgical patients. The GluCath System (GluMetrics, Inc) used a quenched chemical fluorescence mechanism to optically measure blood glucose when deployed via a radial artery catheter or directly into a peripheral vein. Periodic ultrasound assessed blood flow and thrombus formation. Patient glucose levels were managed according to the standard of care and existing protocols at each site. Reference blood samples were acquired hourly and compared against prospectively calibrated sensor results. In all, 63 arterial sensors and 9 venous sensors were deployed in 70 patients. Arterial sensors did not interfere with invasive blood pressure monitoring, sampling or other aspects of patient care. A majority of venous sensors (66%) exhibited thrombus on ultrasound. In all, 89.4% (1383/1547) of arterial and 72.2% (182/252) of venous measurements met ISO15197:2003 criteria (within 20%), and 72.7% (1124/1547) of arterial and 56.3% (142/252) of venous measurements met CLSI POCT 12-A3 criteria (within 12.5%). The aggregate mean absolute relative difference (MARD) between the sensors and the reference was 9.6% for arterial and 14.2% for venous sensors. The GluCath System exhibited acceptable accuracy when deployed in a radial artery for up to 48 hours in ICU patients after elective cardiac surgery. Accuracy of venous deployment was substantially lower with significant rates of intravascular thrombus observed using ultrasound. © 2015 Diabetes Technology Society.
NASA Astrophysics Data System (ADS)
Petrov, Andrey; Prough, Donald S.; Petrov, Irene Y.; Petrov, Yuriy; Deyo, Donald J.; Henkel, Sheryl N.; Seeton, Roger; Esenaliev, Rinat O.
2013-03-01
Monitoring of cerebral venous oxygenation is useful to facilitate management of patients with severe or moderate traumatic brain injury (TBI). Prompt recognition of low cerebral venous oxygenation is a key to avoiding secondary brain injury associated with brain hypoxia. In specialized clinical research centers, jugular venous bulb catheters have been used for cerebral venous oxygenation monitoring and have demonstrated that oxygen saturation < 50% (normal range is 55-75%) correlates with poor clinical outcome. We developed an optoacoustic technique for noninvasive monitoring of cerebral venous oxygenation. Recently, we designed and built a novel, medical grade optoacoustic system operating in the near-infrared spectral range for continuous, real-time oxygenation monitoring in the superior sagittal sinus (SSS), a large central cerebral vein. In this work, we designed and built a novel SSS optoacoustic probe and developed a new algorithm for SSS oxygenation measurement. The SSS signals were measured in healthy volunteers during voluntary hyperventilation, which induced changes in SSS oxygenation. Simultaneously, we measured exhaled carbon dioxide concentration (EtCO2) using capnography. Good temporal correlation between decreases in optoacoustically measured SSS oxygenation and decreases in EtCO2 was obtained. Decreases in EtCO2 from normal values (35-45 mmHg) to 20-25 mmHg resulted in SSS oxygenation decreases by 3-10%. Intersubject variability of the responses may relate to nonspecific brain activation associated with voluntary hyperventilation. The obtained data demonstrate the capability of the optoacoustic system to detect in real time minor changes in the SSS blood oxygenation.
NASA Technical Reports Server (NTRS)
Hagan, Ronald Donald; Soller, Babs R.; Shear, Michael; Walz, Matthias; Landry, Michelle; Heard, Stephen
2006-01-01
We evaluated the use of a small, fiber optic sensor to measure pH, PCO2 and PO2 from forearm muscle interstitial fluid (IF) during handgrip dynamometry. PURPOSE: Compare pH, PCO2 and PO2 values obtained from venous blood with those from the IF of the flexor digitorum superficialis (FDS) during three levels of exercise intensity. METHODS: Six subjects (5M/1F), average age 29+/-5 yrs, participated in the study. A venous catheter was placed in the retrograde direction in the antecubital space and a fiber optic sensor (Paratrend, Diametrics Medical, Inc.) was placed through a 22 G catheter into the FDS muscle under ultrasound guidance. After a 45 min rest period, subjects performed three 5-min bouts of repetitive handgrip exercise (2s contraction/1 s relaxation) at attempted levels of 15%, 30% and 45% of maximal voluntary contraction. The order of the exercise bouts was random with the second and third bouts started after blood lactate had returned to baseline. Venous blood was sampled every minute during exercise and analyzed with an I-Stat CG-4+ cartridge, while IF fiber optic sensor measurements were obtained every 2 s. Change from pre-exercise baseline to end of exercise was computed for pH, PCO2 and PO2. Blood and IF values were compared with a paired t-test. RESULTS: Baseline values for pH, PCO2 and PO2 were 7.37+/-0.02, 46+/-4 mm Hg, and 36+/-6 mm Hg respectively in blood and 7.39+/-0.02, 44+/-6 mm Hg, and 35+/-14 mm Hg in IF. Average changes over all exercise levels are noted in the Table below. For each parameter the exercise-induced change was at least twice as great in IF as in blood. In blood and IF, pH and PCO2 increases were directly related to exercise intensity. Change in venous PO2 was unrelated to exercise intensity, while IF PO2 decreased with increases in exercise intensity. CONCLUSIONS: Measurement of IF pH, PCO2 and PO2 is more sensitive to exercise intensity than measurement of the same parameters in venous blood and provides continuous assessment during and after exercise.
Placement of a Port Catheter Through Collateral Veins in a Patient with Central Venous Occlusion
DOE Office of Scientific and Technical Information (OSTI.GOV)
Teichgraeber, Ulf Karl-Martin, E-mail: ulf.teichgraeber@charite.de; Streitparth, Florian, E-mail: florian.streitparth@charite.d; Gebauer, Bernhard, E-mail: bernhard.gebauer@charite.d
Long-term utilization of central venous catheters (CVCs) for parenteral nutrition has a high incidence of central venous complications including infections, occlusions, and stenosis. We report the case of a 31-year-old woman presenting with a malabsorption caused by short gut syndrome due to congenital aganglionic megacolon. The patient developed a chronic occlusion of all central neck and femoral veins due to long-term use of multiple CVCs over more than 20 years. In patients with central venous occlusion and venous transformation, the implantation of a totally implanted port system by accessing collateral veins is an option to continue long-term parenteral nutrition whenmore » required. A 0.014-in. Whisper guidewire (Terumo, Tokyo) with high flexibility and steerability was chosen to maneuver and pass through the collateral veins. We suggest this approach to avoid unfavorable translumbar or transhepatic central venous access and to conserve the anatomically limited number of percutaneous access sites.« less
Optoacoustic technique for noninvasive monitoring of blood oxygenation: a feasibility study
NASA Astrophysics Data System (ADS)
Esenaliev, Rinat O.; Larina, Irina V.; Larin, Kirill V.; Deyo, Donald J.; Motamedi, Massoud; Prough, Donald S.
2002-08-01
Replacement of invasive monitoring of cerebral venous oxygenation with noninvasive techniques offers great promise in the management of life-threatening neurologic illnesses including traumatic brain injury. We developed and built an optoacoustic system to noninvasively monitor cerebral venous oxygenation; the system includes a nanosecond Nd:YAG laser and a specially designed optoacoustic probe. We tested the system in vitro in sheep blood with experimentally varied oxygenation. Our results demonstrated that (1) the amplitude and temporal profile of the optoacoustic waves increase with blood oxygenation in the range from 24% to 92%, (2) optoacoustic signals can be detected despite optical and acoustic attenuation by thick bone, and (3) the system is capable of real-time and continuous measurements. These results suggest that the optoacoustic technique is technically feasible for continuous, noninvasive monitoring of cerebral venous oxygenation.
A Life-Threatening Mediastinal Hematoma After Central Venous Port System Implantation
Sarach, Janine; Zschokke, Irin; Melcher, Gian A.
2015-01-01
Patient: Female, 68 Final Diagnosis: Mediastinal hematoma Symptoms: Agitation • severe hemodynamic instability • severe respiratory distress Medication: — Clinical Procedure: Cardiopulmonary resuscitation • reintubation • thoracic drain Specialty: Surgery Objective: Diagnostic/therapeutic accidents Background: We report a case of surgical central venous port system implantation using Seldinger’s technique with a life-threatening mediastinal hematoma due to the perforation of the superior vena cava. Case Report: A 68-year-old woman was admitted to our institution for port implantation. Open access to the cephalic vein and 2 punctures of the right subclavian vein were unsuccessful. Finally, the port catheter could be placed into the superior vena cava using Seldinger’s technique. As blood aspiration via the port catheter was not possible, fluoroscopy was performed, revealing mediastinal contrast extravasation without contrasting the venous system. A new port system could be placed in the correct position without difficulties. After extubation, the patient presented with severe respiratory distress and required consecutive cardiopulmonary resuscitation and reintubation. The CT scan showed a significant hematoma in the lower neck and posterior mediastinum with tracheal compression. We assumed a perforation of the superior vena cava with the tip of the guidewire using Seldinger’s technique. Long-term intensive treatment with prolonged ventilation and tracheotomy was necessary. The port system had to be subsequently explanted due to infection. Conclusions: Mediastinal hematoma is a rare but life-threatening complication associated with central venous catheterization using Seldinger’s technique. Perforation occurs most often during central venous catheterization in critical care. Mediastinal hematoma is an example of a mechanical complication occurring after central venous catheterization, which has been described only a few times in the literature to date. This case highlights the importance of awareness of possible, rare, life-threatening complications during port implantation, mostly performed in multimorbid patients by surgeons in training. PMID:26703924
Rudofsky, G
1989-06-30
The drug combination of Ruscus-extract and hesperidine methyl chalcone (HMC) involves two basic mechanisms in the treatment of venous diseases: increase in venous tonicity and edema protection. This was shown in a double-blind study on 20 healthy volunteers by comparing the effectiveness of the individual substances, the combination and a placebo on the venous hemodynamics and the volume of the foot. Ruscus-extract augments the tonicity of the venous wall. This is expressed by a decrease in venous capacity (p less than 0.01), a reduction in the blood pool in the lower leg under orthostatic conditions, and a decrease in tissue volume of the foot and ankle (p less than 0.01). HMC lowers the capillary filtration rate (p less than 0.01) but augmented the blood pool. The increase in blood volume can be explained by dehydration of the tissue of the lower leg lowering the pressure of tissue on the venous system and increasing the blood pool in the limb. After administration of the combination, the blood volume was between the Ruscus and HMC volumes, while the effects on filtration rate, venous capacity and tissue volume corresponded to the changes seen after administration of HMC and Ruscus extract alone.
Taniguchi, Daisuke; Nakajima, Sho; Hayashida, Arisa; Kuroki, Takuma; Eguchi, Hiroto; Machida, Yutaka; Hattori, Nobutaka; Miwa, Hideto
2017-09-26
Acute necrotizing encephalopathy is one of the most devastating neurological complications of influenza virus infection. Acute necrotizing encephalopathy preferentially affects the thalamus bilaterally, as does deep cerebral venous thrombosis, which can lead to misdiagnosis. A 52-year-old Japanese woman infected with seasonal influenza B virus presented to the emergency care unit in our hospital with progressive alteration of her level of consciousness. Bilateral thalamic lesions were demonstrated by magnetic resonance imaging, leading to a tentative diagnosis of acute necrotizing encephalopathy. However, she had deep cerebral venous thrombosis, and the presence of diminished signal and enlargement of deep cerebral veins on T2*-weighted imaging contributed to a revised diagnosis of deep cerebral venous thrombosis. Anticoagulant therapy was initiated, leading to her gradual recovery, with recanalization of the deep venous system and straight sinus. To the best of our knowledge, these results represent the first report of deep cerebral venous thrombosis associated with influenza infection. It is clinically important to recognize that deep cerebral venous thrombosis, although rare, might be one of the neurological complications of influenza infection. In the presence of bilateral thalamic lesions in patients with influenza infection, deep cerebral venous thrombosis should be considered in addition to acute necrotizing encephalopathy. Delays in diagnosis and commencement of anticoagulant therapy can lead to unfavorable outcomes.
Folguera-Álvarez, Carmen; Garrido-Elustondo, Sofia; Verdú-Soriano, José; García-García-Alcalá, Diana; Sánchez-Hernández, Mónica; Torres-de Castro, Oscar German; Barceló-Fidalgo, Maria Luisa; Martínez-González, Olga; Ardiaca-Burgués, Lidia; Solano-Villarrubia, Carmen; Lebracón-Cortés, Pilar Raquel; Molins-Santos, Carmen; Fresno-Flores, Mar; Cánovas-Lago, Maria Carmen; Benito-Herranz, Luisa Fernanda; García-Sánchez, Maria Teresa; Castillo-Pla, Olga; Morcillo-San Juan, María Sol; Ayuso-de la Torre, Maria Begoña; Burgos-Quintana, Pilar; López-Torres-Escudero, Ana; Ballesteros-García, Gema; García-Cabeza, Piedad; de Francisco-Casado, Maria Ángeles; Rico-Blázquez, Milagros
2016-01-01
Chronic venous insufficiency, in its final stage can cause venous ulcers. Venous ulcers have a prevalence of 0.5 % to 0.8 % in the general population, and increases starting at 60 years of age. This condition often causes increased dependency in affected individuals, as well as a perceived reduced quality of life and family overload. Local Treating chronic venous ulcers has 2 components: topically healing the ulcer and controlling the venous insufficiency. There is evidence that compressive therapy favours the healing process of venous ulcers. The studies we have found suggest that the use of multilayer bandage systems is more effective than the use of bandages with a single component, these are mostly using in Spain. Multilayer compression bandages with 2 layers are equally effective in the healing process of chronic venous ulcers as 4-layer bandages and are better tolerated and preferenced by patients. More studies are needed to specifically compare the 2-layer bandages systems in the settings where these patients are usually treated. Randomised, controlled, parallel, multicentre clinical trial, with 12 weeks of follow-up and blind evaluation of the response variable. The objective is to assess the efficacy of multilayer compression bandages (2 layers) compared with crepe bandages, based on the incidence of healed venous ulcers in individuals treated in primary care nursing consultations, at 12 weeks of follow-up. The study will include 216 individuals (108 per branch) with venous ulcers treated in primary care nursing consultations. The primary endpoint is complete healing at 12 weeks of follow-up. The secondary endpoints are the degree of healing (Resvech.2), quality of life (CCVUQ-e), adverse reactions related to the healing process. Prognosis and demographic variables are also recorder. Effectiveness analysis using Kaplan-Meier curves, a log-rank test and a Cox regression analysis. The analysis was performed by intention to treat. The study results can contribute to improving the care and quality of life of patients with venous ulcers, decreasing healing times and healthcare expenditure and contributing to the consistent treatment of these lesions. This study has been recorded in the Clinical Trials.gov site with the code NCT02364921. 17 February 2015.
Ulcer due to chronic venous disease: a sociodemographic study in northeastern Brazil.
de Souza, Edson Marques; Yoshida, Winston Bonetti; de Melo, Valdinaldo Aragão; Aragão, José Aderval; de Oliveira, Luiz Augusto Bitencurt
2013-07-01
Venous ulcers account for 70% of chronic leg ulcers and affect about 2-7% of the population, causing much socioeconomic impact and reducing patients' quality of life. In this study we aimed to describe the clinical features of venous ulcers and sociodemographic characteristics of patients with ulcers due to chronic venous disease (CVD). This cross-sectional, observational study was conducted at the Vascular Surgery Service, Universidade Federal de Sergipe, in northeastern Brazil. The study included a consecutive series of 154 patients with active venous ulcers (CEAP C6) in the lower limb due to CVD. Sociodemographic characteristics (age, gender, race, monthly income, education, occupation, and caregiver) and clinical data (affected limb, ulcer site, etiopathogenesis, recurrence, and time elapsed since the first episode of ulcer) were collected. A possible correlation of time elapsed since the first episode of ulcer and number of recurrences with primary or secondary etiology was analyzed by Mann-Whitney U-test. Of the 154 patients analyzed, 79% were female, 94% were ethnically black or brown, 90% had a monthly income less than or equal to minimum wage, 47% were illiterate, 35% had not completed elementary school, 50% had informal jobs, 19.5% were retired, and 18.2% received sick pay from the social security system. The mean age was 53.7 years. Both limbs were affected similarly, and venous ulcers were located predominantly on the medial aspect of the leg (84%). The median time elapsed since the first episode of ulcer was 36 months, being significantly higher in patients with venous ulcers of secondary etiology (P < 0.0003). The prevalence of recurrence was also significantly higher in patients with venous ulcers of secondary etiology (P < 0.001). According to CEAP classification, 65% of ulcers were primary (Ep), 94.1% demonstrated reflux involving the superficial system (As), 92% had incompetent perforators (Ap), 35% demonstrated reflux involving the deep system (Ad), and all ulcers showed reflux without obstruction (Pr). Venous ulcers were more prevalent among low-income patients, especially chronic, recurrent ulcers of primary etiology. This finding highlights the need for improvements in patient care and surgical treatment in most cases aimed at ulcer healing and reduced recurrence. Better care would improve patients' quality of life and reduce social security expenditures. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.
Compression therapy in patients with venous leg ulcers.
Dissemond, Joachim; Assenheimer, Bernd; Bültemann, Anke; Gerber, Veronika; Gretener, Silvia; Kohler-von Siebenthal, Elisabeth; Koller, Sonja; Kröger, Knut; Kurz, Peter; Läuchli, Severin; Münter, Christian; Panfil, Eva-Maria; Probst, Sebastian; Protz, Kerstin; Riepe, Gunnar; Strohal, Robert; Traber, Jürg; Partsch, Hugo
2016-11-01
Wund-D.A.CH. is the umbrella organization of the various wound care societies in German-speaking countries. The present consensus paper on practical aspects pertinent to compression therapy in patients with venous leg ulcers was developed by experts from Germany, Austria, and Switzerland. In Europe, venous leg ulcers rank among the most common causes of chronic wounds. Apart from conservative and interventional wound and vein treatment, compression therapy represents the basis of all other therapeutic strategies. To that end, there are currently a wide variety of materials and systems available. While especially short-stretch bandages or multicomponent systems should be used in the initial decongestion phase, ulcer stocking systems are recommended for the subsequent maintenance phase. Another - to date, far less common - alternative are adaptive Velcro bandage systems. Medical compression stockings have proven particularly beneficial in the prevention of ulcer recurrence. The large number of treatment options currently available enables therapists to develop therapeutic concepts geared towards their patients' individual needs and abilities, thus resulting in good acceptance and adherence. Compression therapy plays a crucial role in the treatment of patients with venous leg ulcers. In recent years, a number of different treatment options have become available, their use and application differing among German-speaking countries. The present expert consensus is therefore meant to outline concrete recommendations for routine implementation of compression therapy in patients with venous leg ulcers. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.
Beta-Blockers: An Abstracted Bibliography.
1989-04-04
on subjects in the supine position. Blood flow was measured by venous occlusion plethys- mography. Prugs were administered via indwelling catheter (one...PROCEDURES: Noninvasive measuremert of maximum oxygen intake, invasive measurement of systemic and pulmonary arterial pressures, arterial and mixed venous ...ratio was approximately 0.1:1. Central nervous system-related effects associated with propranolol and metoprolol appear to be the result of high brain
Novel optoacoustic system for noninvasive continuous monitoring of cerebral venous blood oxygenation
NASA Astrophysics Data System (ADS)
Petrov, Yuriy; Petrov, Irene Y.; Prough, Donald S.; Esenaliev, Rinat O.
2012-02-01
Traumatic brain injury (TBI) and spinal cord injury are a major cause of death for individuals under 50 years of age. In the USA alone, 150,000 patients per year suffer moderate or severe TBI. Moreover, TBI is a major cause of combatrelated death. Monitoring of cerebral venous blood oxygenation is critically important for management of TBI patients because cerebral venous blood oxygenation below 50% results in death or severe neurologic complications. At present, there is no technique for noninvasive, accurate monitoring of this clinically important variable. We proposed to use optoacoustic technique for noninvasive monitoring of cerebral venous blood oxygenation by probing cerebral veins such as the superior sagittal sinus (SSS) and validated it in animal studies. In this work, we developed a novel, medical grade optoacoustic system for continuous, real-time cerebral venous blood oxygenation monitoring and tested it in human subjects at normal conditions and during hyperventilation to simulate changes that may occur in patients with TBI. We designed and built a highly-sensitive optoacoustic probe for SSS signal detection. Continuous measurements were performed in the near infrared spectral range and the SSS oxygenation absolute values were automatically calculated in real time using a special algorithm developed by our group. Continuous measurements performed at normal conditions and during hyperventilation demonstrated that hyperventilation resulted in approximately 12% decrease of cerebral venous blood oxygenation.
Circulatory failure during severe hyperthermia in dog.
Miki, K; Morimoto, T; Nose, H; Itoh, T; Yamada, S
1983-01-01
The effect of acute hyperthermia on circulatory function was studied in 6 mongrel dogs. At a core temperature of about 40 degrees C, central venous pressure and stroke volume were maintained at almost normal level. Cardiac output significantly increased (26 ml/(kg . min)) while systemic vascular resistance significantly decreased (1.2 mmHg . sec/ml). In addition, significant decrease in vascular compliance by 40% was observed. When body temperature was raised further (severe hyperthermia), an abrupt fall of arterial pressure was observed at the rectal temperature of about 41-42 degrees C. Concomitant decreases in central venous pressure (3 mmHg), stroke volume (2.1 ml/beat) and cardiac output (29 ml/(kg . min)) were observed while heart rate increased (48 beats/min). These results suggest that the decrease in cardiac output during severe hyperthermia is due to the fall of central venous pressure, and the fall was attributed to the increase in unstressed vascular volume of systemic circulation due to the heat-induced cutaneous vasodilation. The observed decrease in systemic vascular compliance is considered to have a significant role in the maintenance of central venous pressure under hyperthermia.
Lang, Elvira V; Reyes, Jorge; Faintuch, Salomao; Smith, Amy; Abu-Elmagd, Kareem
2005-09-01
To assess feasibility and success of venous recanalization in patients with short gut syndrome who have lost their traditional central venous access and required intestinal or multivisceral transplantation. Twelve patients between the ages of 7 and 55 years with short gut syndrome and long-standing total parenteral nutrition (TPN) dependency and/or hypercoagulability were treated. All had extensive chronic central venous occlusions and survival was dependent on restoration of access and planned transplantation. Central venous recanalizations were obtained via sharp needle recanalization techniques, venous reconstructions with stents, and/or extraanatomic access to the central venous system for placement of central venous tunneled catheters. Central venous access was restored in all patients without operative-related mortality. Three major hemodynamic perioperative technical complications were recorded and successfully treated. There were three self-limited early infectious complications. With a mean follow-up of 22 months, eight of the 12 patients were alive with successful small bowel or multivisceral transplantation; six of those became independent of TPN. The remaining four patients died of complications related to TPN (n = 3) or transplantation (n = 1). With a mean follow-up of 20 months, all but two of the recanalized venous accesses were maintained, for a success rate of 83%. Recanalizations of extensive chronic vein occlusions are feasible but associated with high risk. The technique is life-saving for TPN-dependent patients and can restore candidacy for intestinal and multivisceral transplantation. This approach is likely to be increasingly requested because of the current clinical availability of the transplant procedure.
Mean circulatory filling pressure: its meaning and measurement.
Rothe, C F
1993-02-01
The volume-pressure relationship of the vasculature of the body as a whole, its vascular capacitance, requires a measurement of the mean circulatory filling pressure (Pmcf). A change in vascular capacitance induced by reflexes, hormones, or drugs has physiological consequences similar to a rapid change in blood volume and thus strongly influences cardiac output. The Pmcf is defined as the mean vascular pressure that exists after a stop in cardiac output and redistribution of blood, so that all pressures are the same throughout the system. The Pmcf is thus related to the fullness of the circulatory system. A change in Pmcf provides a uniquely useful index of a change in overall venous smooth muscle tone if the blood volume is not concomitantly changed. The Pmcf also provides an estimate of the distending pressure in the small veins and venules, which contain most of the blood in the body and comprise most of the vascular compliance. Thus the Pmcf, which is normally independent of the magnitude of the cardiac output, provides an estimate of the upstream pressure that determines the rate of flow returning to the heart.
Rosidal K: a short-stretch compression bandage system.
Williams, C
Management of venous leg ulcers account for a large proportion of the work of healthcare professionals, especially for those who are community based. Multilayer and long-stretch bandage systems have been used successfully for many years in venous leg ulcer management. Rosidal K, a short-stretch bandage, is now also becoming more widely accepted in this country as an effective and cost-effective bandage system. This product focus looks at bandage systems and examines the research supporting the use of short-stretch bandages and Rosidal K.
Mathur, S; Symons, S P; Huynh, T J; Muthusami, P; Montanera, W; Bharatha, A
2017-01-01
Spinal epidural AVFs are rare spinal vascular malformations. When there is associated intradural venous reflux, they may mimic the more common spinal dural AVFs. Correct diagnosis and localization before conventional angiography is beneficial to facilitate treatment. We hypothesize that first-pass contrast-enhanced MRA can diagnose and localize spinal epidural AVFs with intradural venous reflux and distinguish them from other spinal AVFs. Forty-two consecutive patients with a clinical and/or radiologic suspicion of spinal AVF underwent MR imaging, first-pass contrast-enhanced MRA, and DSA at a single institute (2000-2015). MR imaging/MRA and DSA studies were reviewed by 2 independent blinded observers. DSA was used as the reference standard. On MRA, all 7 spinal epidural AVFs with intradural venous reflux were correctly diagnosed and localized with no interobserver disagreement. The key diagnostic feature was arterialized filling of an epidural venous pouch with a refluxing radicular vein arising from the arterialized epidural venous system. First-pass contrast-enhanced MRA is a reliable and useful technique for the initial diagnosis and localization of spinal epidural AVFs with intradural venous reflux and can distinguish these lesions from other spinal AVFs. © 2017 by American Journal of Neuroradiology.
[Prophylaxis of thrombosis induced by chemotherapy or central venous catheters].
Voog, Eric; Lazard, Eric; Juhel, Laurence
2007-02-01
Deep venous thrombosis and pulmonary embolism are well-recognized complications of cancer, especially in patients with a venous access device or receiving chemotherapy. The pathogenic mechanisms of thrombosis in cancer patients involve a complex interaction between the patient's tumor cells and hemostatic system. Chemotherapy and central venous catheters increase the risk of thromboembolism. Prophylactic treatment for these patients remains controversial. We conducted a systematic literature review using the Medline database and abstract books for meetings of the American Society of Clinical Oncology and the American Society of Hematology since 2000. Our search focused on clinical trials of primary prevention of venous catheter-related thrombosis or prevention of chemotherapy-related venous thromboembolism in cancer patients. Ten studies evaluating primary prevention of patients with central catheters were identified, and their results are contradictory. Currently only one study has examined prevention of chemotherapy-related venous thromboembolism, in women with metastatic breast cancer. Its results cannot be extrapolated to other tumors. Systematic prophylaxis cannot yet be recommended. In the near future we must improve our knowledge of the risk factors of these complications. Prophylaxis should be individualized for each patient. New anticoagulant drugs should be tested in cancer patients.
[Sequelae of unilateral deep venous thrombosis in plethysmography of the calf].
Zicot, M; Depairon, M
1982-01-01
Twenty four patients suffering from unilateral venous disturbances revealed by Doppler and secondary to a deep venous thrombosis were examined. The calf venous haemodynamics was analyzed by use of a strain-jauge plethysmograph. We determined the increase in venous volume due to the inflation of a thigh pneumatic cuff (pressure at 20, 40 and 60 mm Hg; delta V20, delta V40, delta V60). The maximal venous output (Vout) was measured after a quick release of the 60 mm Hg pressure. The maximal venous drainage (VMM) was assessed during a rhythmic exercise (tiptoeing) while standing; delta V20, delta V40 and delta V60 were nearly constantly reduced on the abnormal side (t of Student respectively 3.49; 6.09 and 5.07). Vout dropped proportionaly to delta V60. Some abnormalities due to valvular insufficiency were frequently present in the beginning of the inflation curve at the level of the abnormal limbs. VMM was nearly always largely decreased on the affected side (t = 5.43). The unilateral flow disturbances displayed by the Doppler were regularly going with abnormalities of the capacitive system, well demonstrated by comparison with the non-affected limbs.
Lesimple, T; Béguec, J F; Levêque, J M
1998-10-31
Many treatments administered to cancer patients require venous access either via a peripheral vein or a larger central vein at the risk of local or systemic infection, thrombus formation or venous occlusion and dysfunction. Insertion of a central catheter is an invasive procedure which must be conducted under conditions of rigorous asepsia. Strict rules based on well-defined protocols must be applied throughout its use. Local or systemic infectious complications account for 18 to 25% of all nosocomial infections and are often related to colonisation of the puncture site by a Gram positive germ. In case of infection, ablation of the central catheter is not mandatory for diagnosis or antibiotic treatment. Reported at varying frequencies in the literature from 4 to 42%, thrombus formation is unpredictable and often difficult to diagnose. Anticoagulants or fibrolytic agents are indicated but it may also be necessary to withdraw the catheter. Displacement, rupture, obstruction and extravasation are frequent complications. Back flow must be checked in all venous accesses and free flow carefully verified. The access must remain patent throughout the period of use, guaranteed by a standard heparinization and rinsing protocol. This complications must not mask the important progress achieved with the use of central venous access for specific and symptomatic treatment in cancer patients.
Spanos, K; De Maeseneer, M; Nicolaides, A; Giannoukas, A D
2015-04-01
Venous training in Europe is lacking a formal curriculum among various specialties related to management of venous diseases. We conducted a survey in order to have a snapshot on the actual education and training level among physicians practicing currently venous surgery and phlebology in Europe. From April 7, 2014 to June 11, 2014 a survey was carried out using the Survey Monkey system, including 11 main questions covering all the domains of training and education in venous surgery and phlebology. The questionnaire was sent to all physicians included in the current mailing list of the European Venous Forum (EVF) and the Mediterranean League of Angiology and Vascular Surgery. Two questions were particularly addressed to those physicians who had attended the EVF hands-on workshop (HOW) at least once. The response rate was 24% (97/400) and 51.5% of them were practicing in a hospital service. Most responders were vascular surgeons (67.7%), followed by angiologists (19.4%). Only half of the responders felt as being competent to manage the whole spectrum of venous diseases successfully after completion of their training, while a few were able to perform endovenous ablations and even less more advanced venous interventions. Formal training in Duplex ultrasound was undertaken only in 55.2%. The majority suggested that a venous training program should be a separate part of their specialty rotation and should be organized at a national or European level, or even by a specific scientific society. Over 95% of those physicians who already participated in the EVF HOW considered the knowledge they acquired there as useful for their practice. There is currently an important need for more specialized venous training for all physicians involved in the diagnosis and management of venous diseases. Therefore all local, national and international initiatives should be encouraged to improve education in this field.
Che, J; Tian, M; Ding, G; Huai, Q; Dong, P; Li, Y; Li, S
2013-08-01
The aim of this study was to investigate the contribution of the perioperative cell salvage process to the changes in erythrocyte 2,3-disphosphoglycerate (2,3-DPG) and glucose-6-phosphate dehydrogenase (G-6-PD) levels and phosphatidylserine (PS) expression using a self-control study comparing washed blood with venous blood. Thirty patients undergoing elective heart and blood vessel surgery were enrolled. Blood was collected and processed using a Fresenius continuous autotransfusion system device. 2,3-DPG and G-6-PD activities, as well as PS expression, from both venous and washed red blood cells (RBC) were measured. We also compared these indicators among washed RBC at 6 h, washed RBC at 0 h, and venous RBC. 2,3-DPG and G-6-PD activities in washed blood at 0 h were significantly higher than in venous RBC (2,3-DPG, venous vs. washed blood P < 0.05; G-6-PD, venous vs. washed blood P < 0.05). Flow cytometry results showed no differences between venous blood and washed RBC at 0 h (n = 23, P > 0.05). 2,3-DPG activity in washed RBC that were allowed to stand for 6 h decreased compared with that in venous blood (venous vs. washed blood at 6 h P < 0.01), whereas no significant difference was observed in G-6-PD activity (venous. vs. washed blood at 6 h P > 0.05). Compared with venous RBC, washed RBC from intraoperative cell salvage exhibited good oxygen-carrying and antioxidant capacities. However, the oxygen-carrying capacity of washed RBC that were allowed to stand for 6 h was not as good as that of venous RBC. Thus, we suggest that washed RBC that were left to stand for more than 6 h should not be reinfused. © 2012 John Wiley & Sons Ltd.
Systemic venous anomalies in the Middle East
Corno, Antonio F.; Alahdal, Sami A.; Das, Karuna Moy
2013-01-01
Introduction: Systemic venous anomalies are quite rare and can be associated with congenital heart disease requiring surgery. Materials and Methods: All consecutive patients (pts) undergoing surgery for congenital heart defects were retrospectively analyzed for presence of systemic venous anomalies: (a) Persistent left superior vena cava (PLSVC)(b) Inferior vena cava (IVC) interruption(c) Retro-aortic innominate vein Results: From 9/2010 to 5/2012 155 pts, median age 7 months, mean age 1.3 years (3 days–50 years), median weight 4 kg, mean weight 7.2 kg (0.6–110 kg) underwent congenital heart surgery. Twenty-nine systemic venous anomalies were identified in 28/155 patients (=18.1%). PLSVC was present in 21 pts (=13.5%), median age 4 months, mean age 2.7 years (3 days–22 years), median weight 6 kg, mean weight 10.1 kg (2.4–43.0 kg). IVC interruption was identified in 5 pts (=3.2%), median age 2 months, mean age 5.4 years (30 days–26 years), median weight 3.7 kg, median weight 17 kg (2.3–68.0 kg). Retro-aortic innominate vein was diagnosed in 3 pts (=1.9%), median age 5 years, mean age 3.7 years (10 months–5 years), median weight 12 kg, mean weight 10.1 kg (4.5–14 kg). Complete pre-operative diagnosis was obtained in 14/28 (=50%) pts with echocardiography and in other 8/28 (=28.6%) only after computed tomography (CT) scan, for a total of 22/28 (=78.6%) correct pre-operative diagnosis. In 6/28 (=21.4%) patients the diagnosis was intra-operative. Total incidence of systemic venous anomalies was 18.1% (vs. 4% in the literature, P = 0.0009), with presence of PLSVC = 13.5% (vs. 0.3–4.0%, respectively P = 0.0004 and P = 0.0012), IVC interruption = 3.2% (vs. 0.1–1.3%, N.S.), and retro-aortic innominate vein = 1.9% (vs. 0.2–1%, N.S.). Conclusions: Our study showed an incidence of systemic venous anomalies in Middle Eastern pts with congenital heart defects higher than previously reported. In 78.6% of pts the diagnosis was correctly made before surgery (echocardiography or CT scan), with 21.4% of complete diagnosis made at surgery. A careful pre-operative screening should be performed in all pts with congenital heart defects from this region to better identify all systemic venous anomalies for a more accurate surgical planning. PMID:24400249
[Venous Doppler color echography: importance and inconveniences].
Laroche, J P; Dauzat, M; Muller, G; Janbon, C
1993-01-01
Color Doppler is a technique which performs a real-time opacification of the vascular system with blue indicating reverse flow and red indicating forward flow (directional color coding). In venous pathology, the use of color Doppler improves significantly the anatomical evaluation of the inferior vena cava, the iliac vein, the deep femoral vein, and the sural system. Color Doppler facilitates the study of deep venous thrombosis (providing useful information to differentiate ancient from most recent thrombus) and also the study of post-thrombotic conditions (assessment of reverse flow, repermeation phenomena). Finally, color Doppler produces a better insight for the study of varicose veins, especially with regard to mapping, identification of communicante veins, and study of the external saphenous vein.
Zheng, Da-Wei; Li, Zhang-Can; Shi, Rong-Jian; Sun, Feng; Xu, Li; Shou, Kui-Shui
2016-02-01
Salvage repair after complex upper limb traumatic injury is surgically challenging due to underlying major arterial impairment with complicating a large-sized soft tissue defect. The purpose of this study was to evaluate the effectiveness and safety of using a giant-sized (≥100 cm(2)) flow-through venous flap for reconstruction of dual or multiple forearm, metacarpal, or digital arteries after complex upper limb traumatic injury. Seven patients were consecutively hospitalized for emergency salvage repair after complex upper limb traumatic injury between March 2012 and May 2014. The forearm and palmar artery defects were repaired using the calf great saphenous vein flap and the volar forearm venous flap, respectively. The flow-through venous flap ranged from 9.5 cm × 12.0 cm to 12.0 cm × 20.0 cm (mean, 158.4 cm(2)) in size. The flaps and affected limbs survived uneventfully in five patients, with one patient experiencing distal flap marginal necrosis and a second patient requiring amputation of the affected limb. Computed tomography angiography showed patent vessels in all patients. The mean total active motion of the repaired fingers was 199.5° versus 258.8° for the contralateral counterpart (77.1%). The sensory return was determined to be S2 in 2 patients, S3 in 3 patients and S3+ in 1 patient. The disability scores for the arm, shoulder, and hand ranged from 4.6-18.2 (mean, 11.3), and the mean Michigan hand outcomes questionnaire score was 7.8 ± 0.9. The flow-through venous flap is an effective and safe treatment alternative for salvage therapy of a ≥100-cm(2) complex upper limb traumatic injury with dual or multiple major arterial impairment. This technique allows simultaneous reconstruction of dual or multiple artery injuries and an extensive soft tissue defect. Serious surgical site infection remains a major safety concern and necessitates radical debridement in complicating cases. Copyright © 2015 Elsevier Ltd. All rights reserved.
Arterial and venous plasma levels of bupivacaine following epidural and intercostal nerve blocks.
Moore, D C; Mather, L E; Bridenbaugh, P O; Bridenbaugh, L D; Balfour, R I; Lysons, D F; Horton, W G
1976-07-01
Arterial and peripheral venous plasma levels of bupivacaine were determined in 30 patients following epidural anesthesia using 150 and 225 mg, as well as following intercostal nerve block with 400 mg. Arterial levels were consistently higher than levels in simultaneously sampled venous blood, and the highest levels occurred with bilateral intercostal nerve block. No evidence of systemic toxicity was observed. The results suggest that bupivacaine may have a wider margin of safety in man than is now stated.
Chang, Michael C.; Shim, John J.
2012-01-01
Indications for hysterosalpingography (HSG) include evaluation of infertility, spontaneous abortions, postoperative evaluation of tubal ligation, pre-myomectomy evaluation, and more recently, evaluation of tubal occlusion after placement of the Essure Permanent Birth Control System. Here we report a case of venous intravasation during a routine post-Essure HSG, a phenomenon in which contrast transits from the uterine cavity, through the myometrium, and directly into draining pelvic veins. Venous intravasation is a potential pitfall in interpretation of HSGs. PMID:23378884
Deep venous thrombosis and postthrombotic syndrome: invasive management.
Comerota, A J
2015-03-01
Invasive management of postthrombotic syndrome encompasses the two ends of the deep vein thrombosis spectrum, patients with acute iliofemoral deep vein thrombosis and those with chronic postthrombotic iliofemoral venous obstruction. Of all patients with acute deep vein thrombosis, those with involvement of the iliofemoral segments have the most severe chronic postthrombotic morbidity. Catheter-based techniques now permit percutaneous treatment to eliminate thrombus, restore patency, potentially maintain valvular function, and improve quality of life. Randomized trial data support an initial treatment strategy of thrombus removal. Failure to eliminate acute thrombus from the iliofemoral system leads to chronic postthrombotic obstruction of venous outflow. Debilitating chronic postthrombotic symptoms of the long-standing obstruction of venous outflow can be reduced by restoring unobstructed venous drainage from the profunda femoris vein to the vena cava. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Venous thromboembolism and arterial complications.
Prandoni, Paolo; Piovella, Chiara; Pesavento, Raffaele
2012-04-01
An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, smoking, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Cardiovascular and fluid volume control in humans in space.
Norsk, Peter
2005-08-01
The human cardiovascular system and regulation of fluid volume are heavily influenced by gravity. When decreasing the effects of gravity in humans such as by anti-orthostatic posture changes or immersion into water, venous return is increased by some 25%. This leads to central blood volume expansion, which is accompanied by an increase in renal excretion rates of water and sodium. The mechanisms for the changes in renal excretory rates include a complex interaction of cardiovascular reflexes, neuroendocrine variables, and physical factors. Weightlessness is unique to obtain more information on this complex interaction, because it is the only way to completely abolish the effects of gravity over longer periods. Results from space have been unexpected, because astronauts exhibit a fluid and sodium retaining state with activation of the sympathetic nervous system, which subjects during simulations by head-down bed rest do not. Therefore, the concept as to how weightlessness affects the cardiovascular system and modulates regulation of body fluids should be revised and new simulation models developed. Knowledge as to how gravity and weightlessness modulate integrated fluid volume control is of importance for understanding pathophysiology of heart failure, where gravity plays a strong role in fluid and sodium retention.
Sustained compression and healing of chronic venous ulcers.
Blair, S. D.; Wright, D. D.; Backhouse, C. M.; Riddle, E.; McCollum, C. N.
1988-01-01
STUDY OBJECTIVE--Comparison of four layer bandage system with traditional adhesive plaster bandaging in terms of (a) compression achieved and (b) healing of venous ulcers. DESIGN--Part of larger randomised trial of five different dressings. SETTING--Outpatient venous ulcer clinic in university hospital. PATIENTS--(a) Pressure exerted by both bandage systems was measured in the same 20 patients. (b) Healing with the four layer bandage was assessed in 148 legs in 126 consecutive patients (mean age 71 (SE 2); range 30-96) with chronic venous ulcers that had resisted treatment with traditional bandaging for a mean of 27.2 (SE 8) months. INTERVENTIONS--(a) Four layer bandage system or traditional adhesive plaster bandaging for pressure studies; (b) four layer bandaging applied weekly for studies of healing. END POINTS--(a) Comparison of pressures achieved at the ankle for up to one week; (b) complete healing within 12 weeks. MEASUREMENTS AND MAIN RESULTS--(a) Four layer bandage produced higher initial pressures at the ankle of 42.5 (SE 1) mm Hg compared with 29.8 (1.8) for the adhesive plaster (p less than 0.001; 95% confidence interval 18.5 to 6.9). Pressure was maintained for one week with the four layer bandage but fell to 10.4 (3.5) mm Hg at 24 hours with adhesive plaster bandaging. (b) After weekly bandaging with the four layer bandage 110 of 48 venous ulcers had healed completely within 12 (mean 6.3 (0.4)) weeks. CONCLUSION--Sustained compression of over 40 mm Hg achieved with a multilayer bandage results in rapid healing of chronic venous ulcers that have failed to heal in many months of compression at lower pressures with more conventional bandages. PMID:3144330
Venous and Arterial Thromboses: Two Sides of the Same Coin?
Lippi, Giuseppe; Favaloro, Emmanuel J
2018-04-01
Arterial and venous thromboses are sustained by development of intraluminal thrombi, respectively, within the venous and arterial systems. The composition and structure of arterial and venous thrombi have been historically considered as being very different. Arterial thrombi (conventionally defined as "white") have been traditionally proposed to be composed mainly of fibrin and platelet aggregates, whilst venous thrombi (conventionally defined as "red") have been proposed as mostly being enriched in fibrin and erythrocytes. This archaic dichotomy seems ever more questionable, since it barely reflects the pathophysiology of thrombus formation in vivo. Both types of thrombi are actually composed of a complex fibrin network but, importantly, also contain essentially the same blood-borne cells (i.e., red blood cells, leukocytes, and platelets), and it is only the relative content of these individual elements that differ between venous and arterial clots or, otherwise, between thrombi generated under different conditions of blood flow and shear stress. Convincing evidence now suggests that either white or red intracoronary thrombi may be present in patients with myocardial infarction and, even more importantly, red thrombi may be more prone to distal embolization during percutaneous coronary intervention than those with lower content of erythrocytes. Conversely, it is now accepted that components traditionally considered to be involved "only" in arterial thrombosis are also represented in venous thrombosis. Thus, platelets comprise important components of venous clots, although they may be present in lower amounts here than in arterial thrombi, and von Willebrand factor is also represented in both arterial and venous thrombi. Of importance, such evidence thus supports the concept that adjunctive treatment normally associated to prevention of arterial thrombosis (e.g., aspirin) may have a role also in prevention and treatment of venous thrombosis. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Topsy-turvy: Turning the counter-current heat exchange of leatherback turtles upside down
Davenport, John; Jones, T. Todd; Work, Thierry M.; Balazs, George H.
2015-01-01
Counter-current heat exchangers associated with appendages of endotherms feature bundles of closely applied arteriovenous vessels. The accepted paradigm is that heat from warm arterial blood travelling into the appendage crosses into cool venous blood returning to the body. High core temperature is maintained, but the appendage functions at low temperature. Leatherback turtles have elevated core temperatures in cold seawater and arteriovenous plexuses at the roots of all four limbs. We demonstrate that plexuses of the hindlimbs are situated wholly within the hip musculature, and that, at the distal ends of the plexuses, most blood vessels supply or drain the hip muscles, with little distal vascular supply to, or drainage from the limb blades. Venous blood entering a plexus will therefore be drained from active locomotory muscles that are overlaid by thick blubber when the adults are foraging in cold temperate waters. Plexuses maintain high limb muscle temperature and avoid excessive loss of heat to the core, the reverse of the accepted paradigm. Plexuses protect the core from overheating generated by muscular thermogenesis during nesting.
Topsy-turvy: turning the counter-current heat exchange of leatherback turtles upside down.
Davenport, John; Jones, T Todd; Work, Thierry M; Balazs, George H
2015-10-01
Counter-current heat exchangers associated with appendages of endotherms feature bundles of closely applied arteriovenous vessels. The accepted paradigm is that heat from warm arterial blood travelling into the appendage crosses into cool venous blood returning to the body. High core temperature is maintained, but the appendage functions at low temperature. Leatherback turtles have elevated core temperatures in cold seawater and arteriovenous plexuses at the roots of all four limbs. We demonstrate that plexuses of the hindlimbs are situated wholly within the hip musculature, and that, at the distal ends of the plexuses, most blood vessels supply or drain the hip muscles, with little distal vascular supply to, or drainage from the limb blades. Venous blood entering a plexus will therefore be drained from active locomotory muscles that are overlaid by thick blubber when the adults are foraging in cold temperate waters. Plexuses maintain high limb muscle temperature and avoid excessive loss of heat to the core, the reverse of the accepted paradigm. Plexuses protect the core from overheating generated by muscular thermogenesis during nesting. © 2015 The Author(s).
Spaceflight-Induced Intracranial Hypertension: An Overview
NASA Technical Reports Server (NTRS)
Traver, William J.
2011-01-01
This slide presentation is an overview of the some of the known results of spaceflight induced intracranial hypertension. Historical information from Gemini 5, Apollo, and the space shuttle programs indicated that some vision impairment was reported and a comparison between these historical missions and present missions is included. Optic Disc Edema, Globe Flattening, Choroidal Folds, Hyperopic Shifts and Raised Intracranial Pressure has occurred in Astronauts During and After Long Duration Space Flight. Views illustrate the occurrence of Optic Disc Edema, Globe Flattening, and Choroidal Folds. There are views of the Arachnoid Granulations and Venous return, and the question of spinal or venous compliance issues is discussed. The question of increased blood flow and its relation to increased Cerebrospinal fluid (CSF) is raised. Most observed on-orbit papilledema does not progress, and this might be a function of plateau homeostasis for the higher level of intracranial pressure. There are seven cases of astronauts experiencing in flight and post flight symptoms, which are summarized and follow-up is reviewed along with a comparison of the treatment options. The question is "is there other involvement besides vision," and other Clinical implications are raised,
Disha, Bansal; Prakashini, Koteshwara; Shetty, Ranjan K
2014-01-01
The most common venous abnormality of the thorax is persistent left superior vena cava (PLSVC), incidence being less than 0.5%. However, with congenital heart disease, it is about 6.1%. When the coronary sinus is dilated always search for PLSVC. The coronary sinus may communicate with the left atrium. This is known as an unroofed coronary sinus (UCS) and preoperatively documenting it is important. Of all the congenital cardiac anomalies, the sinus venosus defect (SVD) type of atrial septal defect (ASD) is most commonly associated with PLSVC and accounts for 4–11% of all ASDs. Multidetector CT can easily show all these abnormalities along with haemodynamics. On transoesophageal echocardiography it is difficult to characterise SVD and visualise a coronary sinus because of a limited window, contrast resolution and poor patient compliance. The complex of UCS and PLSVC is one such abnormality and its treatment requires careful assessment of other concomitant cardiac abnormalities to prevent post-treatment haemodynamic complications. PMID:24850552
Evaluation of a Reverse Gradient Garment for prevention of bed-rest deconditioning
NASA Technical Reports Server (NTRS)
Sandler, H.; Dolkas, D.; Newsom, B.; Webb, P.; Annis, J.; Pace, N.; Grunbaum, B. W.
1983-01-01
A Reverse Gradient Garment (RGG) was used to intermittently induce venous pooling in the extremities of a magnitude similar to that seen in going from a lying to standing position during the course of a 15-d period of horizontal bed rest. Venous pooling failed to improve bed-rest-induced losses in +2.5 Gz and +3.0 Gz centrifugation tolerance or to prevent increased heart-rate responses to lower-body negative pressure (LBNP). Four subjects served as controls, four were treated. Tests during the 7-d recovery period showed fluid/electrolyte and body composition values to have returned to pre-bed-rest levels with continued depression of acceleration tolerance times (56% decreased at +2.5 Gz and 74% decreased at +3.0 Gz compared to pre-bed-rest levels) and exaggerated blood insulin response on glucose tolerance testing (blood insulin for treated group increased 95% at 1 h before bed rest and 465% during recovery). This study demonstrates that the physiologic changes after bed rest persist for significant periods of time. Acceleration tolerance time proved to be a sensitive test for the deconditioning process.
Lee, Sun Hee; Jung, Ji Mi; Song, Min Seob; Choi, Seok jin; Chung, Woo Yeong
2013-08-01
Turner syndrome is well known to be associated with significant cardiovascular abnormalities. This paper studied the incidence of cardiovascular abnormalities in asymptomatic adolescent patients with Turner syndrome using multidetector computed tomography (MDCT) instead of echocardiography. Twenty subjects diagnosed with Turner syndrome who had no cardiac symptoms were included. Blood pressure and electrocardiography (ECG) was checked. Cardiovascular abnormalities were checked by MDCT. According to the ECG results, 11 had a prolonged QTc interval, 5 had a posterior fascicular block, 3 had a ventricular conduction disorder. MDCT revealed vascular abnormalities in 13 patients (65%). Three patients had an aberrant right subclavian artery, 2 had dilatation of left subclavian artery, and others had an aortic root dilatation, aortic diverticulum, and abnormal left vertebral artery. As for venous abnormalities, 3 patients had partial anomalous pulmonary venous return and 2 had a persistent left superior vena cava. This study found cardiovascular abnormalities in 65% of asymptomatic Turner syndrome patients using MDCT. Even though, there are no cardiac symptoms in Turner syndrome patients, a complete evaluation of the heart with echocardiography or MDCT at transition period to adults must be performed.
Venous and autonomic function in formerly pre-eclamptic women and BMI-matched controls.
Heidema, Wieteke M; van Drongelen, Joris; Spaanderman, Marc E A; Scholten, Ralph R
2018-03-25
Pre-pregnancy reduced plasma volume increases the risk on subsequent pre-eclamptic pregnancy. Reduced plasma volume is thought to reflect venous reserve capacity, especially when venous vasculature is constricted and sympathetic tone is elevated. As obesity might affect these variables and also relates to pre-eclampsia, increased body weight may underlie these observations. We hypothesized that the relationship between reduced venous reserve and preeclampsia is independent of body mass index (BMI). We compared the non-pregnant venous reserve capacity in 30 formerly pre-eclamptic women, equally divided in 3 BMI-classes (BMI 19.5-24.9, BMI 25-29.9, BMI ≥30) to 30 controls. Cases and controls were matched for BMI, age and parity. The venous reserve capacity was quantified by assessing plasma volume and venous compliance. The autonomic nervous system regulating the venous capacitance was evaluated with heart rate variability analysis in resting supine position and during positive head-up tilt (HUT). Formerly pre-eclamptic women had in supine position lower plasma volume than controls (1339 ± 79 vs 1547 ± 139 ml/m 2 (p<0.001)), lower venous compliance (0.04 ± 0.02 vs 0.07 ± 0.02 ml/dl/mmHg (p<0.001)), higher sympathetic tone (1.9 ± 0.1 vs 1.2 ± 0.7 mmHg 2 (p=0.002)) and lower baroreceptor sensitivity (8.7 ± 3.8 vs 19.0 ± 1.7 ms/mmHg (p<0.001)). During HUT, women with a history of preeclampsia have less modulatory capacity over venous compliance and baroreceptor sensitivity, while heart rate and sympathetic tone remain consistently higher. Women with a history of pre-eclampsia have, compared to BMI-matched controls, reduced venous reserve capacity. This is reflected by lower plasma volume and venous compliance, the autonomic balance is shifted towards sympathetic dominance and lower baroreceptor sensitivity. This suggests that not BMI, but underlying reduced venous reserve relates to pre-eclampsia. This article is protected by copyright. All rights reserved.
Lower Body Negative Pressure: Historical Perspective, Research Findings, and Clinical Applications.
Crystal, George J; Salem, M Ramez
2015-04-01
Lower body negative pressure (LBNP) is a technique that redistributes blood from the upper body to the dependent regions of the pelvis and legs, thus reducing central venous pressure and venous return. The subject is placed in a cylindrical air-tight metal tank, which is sealed at the level of the iliac crests, and subatmospheric pressure is produced using a vacuum pump. This article reviews the historical background, physiological effects, research findings, and clinical applications of LBNP. LBNP is found in both the basic science and clinical literature, encompassing its diverse investigational and clinical applications. The first references to LBNP were in 1952 describing its effectiveness in inducing hypotensive anesthesia. Major interest in LBNP began in the mid 1960s when it was used to characterize the cardiovascular responses to hemorrhage and orthostatic stress, especially that associated with the weightlessness of space flight; these studies have continued to the present day. Advantages of LBNP for such experimental studies include the following: (1) The degree of central hypovolemia is easily controlled and has a rapid onset and reversal. (2) The technique is repeatable, reproducible, and noninvasive. (3) No exogenous pharmacologic agent is required to produce venous pooling. (4) The findings are independent of gravity. In recent years, a few institutions have applied LBNP clinically to diagnose abnormalities in cardiovascular autonomic function and, when combined with echocardiography, to uncover changes in cardiac performance through analysis of Starling curves. Copyright © 2015 Anesthesia History Association. Published by Elsevier Inc. All rights reserved.
Septic knee-induced deep venous thrombosis in a young adult.
Backes, Jeffrey; Taylor, Benjamin C; Clayton, Matthew D
2010-10-11
This article describes a case of a 26-year-old man presenting with left knee pain of 1 week's duration, fever, and acute onset of shortness of breath the day of admission. An arthrocentesis of the knee joint was grossly positive for methicillin-resistant Staphylococcus aureus. A left lower extremity venous duplex showed thrombosis of the superficial femoral, popliteal, posterior tibial, peroneal, and gastrocnemius veins. Pulmonary computed tomography-angiography was positive for acute pulmonary emboli. Initial management consisted of anticoagulation, intravenous antibiotics, and 2 arthroscopic irrigation and debridement procedures. After a normal transesophageal echocardiogram, a diagnosis of septic knee-induced deep venous thrombosis (DVT) of the left lower leg with subsequent septic pulmonary emboli was established. The patient was discharged to a long-term care facility for a 6-week monitored course of intravenous antibiotics. His DVT and pulmonary emboli were managed successfully with oral warfarin. Two months after his initial presentation, the patient returned with acute worsening knee pain. A knee arthrocentesis was unremarkable; however, radiographic imaging revealed fulminant osteomyelitis of the distal femur. He has since undergone open arthrotomy with excisional irrigation and debridement and is on a chronic oral antibiotic regimen. Sparse pediatric literature has shown an association between musculoskeletal sepsis and thrombosis. Only 1 case of septic knee-induced DVT exists in the adult literature, and it was not associated with pulmonary emboli. Our case provides evidence that DVT must be considered by the treating physician as a possible and devastating complication of septic arthritis. Copyright 2010, SLACK Incorporated.
Proof of concept non-invasive estimation of peripheral venous oxygen saturation.
Khan, Musabbir; Pretty, Chris G; Amies, Alexander C; Balmer, Joel; Banna, Houda E; Shaw, Geoffrey M; Geoffrey Chase, J
2017-05-19
Pulse oximeters continuously monitor arterial oxygen saturation. Continuous monitoring of venous oxygen saturation (SvO 2 ) would enable real-time assessment of tissue oxygen extraction (O 2 E) and perfusion changes leading to improved diagnosis of clinical conditions, such as sepsis. This study presents the proof of concept of a novel pulse oximeter method that utilises the compliance difference between arteries and veins to induce artificial respiration-like modulations to the peripheral vasculature. These modulations make the venous blood pulsatile, which are then detected by a pulse oximeter sensor. The resulting photoplethysmograph (PPG) signals from the pulse oximeter are processed and analysed to develop a calibration model to estimate regional venous oxygen saturation (SpvO 2 ), in parallel to arterial oxygen saturation estimation (SpaO 2 ). A clinical study with healthy adult volunteers (n = 8) was conducted to assess peripheral SvO 2 using this pulse oximeter method. A range of physiologically realistic SvO 2 values were induced using arm lift and vascular occlusion tests. Gold standard, arterial and venous blood gas measurements were used as reference measurements. Modulation ratios related to arterial and venous systems were determined using a frequency domain analysis of the PPG signals. A strong, linear correlation (r 2 = 0.95) was found between estimated venous modulation ratio (R Ven ) and measured SvO 2 , providing a calibration curve relating measured R Ven to venous oxygen saturation. There is a significant difference in gradient between the SpvO 2 estimation model (SpvO 2 = 111 - 40.6*R) and the empirical SpaO 2 estimation model (SpaO 2 = 110 - 25*R), which yields the expected arterial-venous differences. Median venous and arterial oxygen saturation accuracies of paired measurements between pulse oximeter estimated and gold standard measurements were 0.29 and 0.65%, respectively, showing good accuracy of the pulse oximeter system. The main outcome of this study is the proof of concept validation of a novel pulse oximeter sensor and calibration model to assess peripheral SvO 2 , and thus O 2 E, using the method used in this study. Further validation, improvement, and application of this model can aid in clinical diagnosis of microcirculation failures due to alterations in oxygen extraction.
McGovern, Eimear; Kelleher, Eoin; Snow, Aisling; Walsh, Kevin; Gadallah, Bassem; Kutty, Shelby; Redmond, John M; McMahon, Colin J
2017-09-01
In recent years, three-dimensional printing has demonstrated reliable reproducibility of several organs including hearts with complex congenital cardiac anomalies. This represents the next step in advanced image processing and can be used to plan surgical repair. In this study, we describe three children with complex univentricular hearts and abnormal systemic or pulmonary venous drainage, in whom three-dimensional printed models based on CT data assisted with preoperative planning. For two children, after group discussion and examination of the models, a decision was made not to proceed with surgery. We extend the current clinical experience with three-dimensional printed modelling and discuss the benefits of such models in the setting of managing complex surgical problems in children with univentricular circulation and abnormal systemic or pulmonary venous drainage.
[Haemorrhoidal disease: from pathophysiology to clinical presentation].
Zeitoun, Jean-David; de Parades, Vincent
2011-10-01
Hemorrhoidal disease is the first cause of proctological consultation although epidemiology is poorly documented. Pathophysiology is complex and involves a fragmentation of supporting tissues as well as vascular changes with hypervascularization and/or impaired venous return. The only complication of external hemorrhoids is thrombosis, which is responsible for acute anal pain irrespective of bowel movements. Internal hemorrhoids most frequently cause prolapse and/or bleeding which is easily recognizable. Physical examination always confirms the diagnosis and a colonoscopy is required after 40 or 45 in order to rule out colorectal cancer. Copyright © 2011 Elsevier Masson SAS. All rights reserved.
Specchi, Swan; d'Anjou, Marc-André; Carmel, Eric Norman; Bertolini, Giovanna
2014-01-01
Collateral venous pathways develop in dogs with obstruction or increased blood flow resistance at any level of the caudal vena cava in order to maintain venous drainage to the right atrium. The purpose of this retrospective study was to describe the sites, causes of obstruction, and configurations of venous collateral pathways for a group of dogs with caudal vena cava obstruction. Computed tomography databases from two veterinary hospitals were searched for dogs with a diagnosis of caudal vena cava obstruction and multidetector row computed tomographic angiographic (CTA) scans that included the entire caudal vena cava. Images for each included dog were retrieved and collateral venous pathways were characterized using image postprocessing and a classification system previously reported for humans. A total of nine dogs met inclusion criteria and four major collateral venous pathways were identified: deep (n = 2), portal (n = 2), intermediate (n = 7), and superficial (n = 5). More than one collateral venous pathway was present in 5 dogs. An alternative pathway consisting of renal subcapsular collateral veins, arising mainly from the caudal pole of both kidneys, was found in three dogs. In conclusion, findings indicated that collateral venous pathway patterns similar to those described in humans are also present in dogs with caudal vena cava obstruction. These collateral pathways need to be distinguished from other vascular anomalies in dogs. Postprocessing of multidetector-row CTA images allowed delineation of the course of these complicated venous pathways and may be a helpful adjunct for treatment planning in future cases. © 2014 American College of Veterinary Radiology.
Congestive renal failure: the pathophysiology and treatment of renal venous hypertension.
Ross, Edward A
2012-12-01
Longstanding experimental evidence supports the role of renal venous hypertension in causing kidney dysfunction and "congestive renal failure." A focus has been heart failure, in which the cardiorenal syndrome may partly be due to high venous pressure, rather than traditional mechanisms involving low cardiac output. Analogous diseases are intra-abdominal hypertension and renal vein thrombosis. Proposed pathophysiologic mechanisms include reduced transglomerular pressure, elevated renal interstitial pressure, myogenic and neural reflexes, baroreceptor stimulation, activation of sympathetic nervous and renin angiotensin aldosterone systems, and enhanced proinflammatory pathways. Most clinical trials have addressed the underlying condition rather than venous hypertension per se. Interpreting the effects of therapeutic interventions on renal venous congestion are therefore problematic because of such confounders as changes in left ventricular function, cardiac output, and blood pressure. Nevertheless, there is preliminary evidence from small studies of intense medical therapy or extracorporeal ultrafiltration for heart failure that there can be changes to central venous pressure that correlate inversely with renal function, independently from the cardiac index. Larger more rigorous trials are needed to definitively establish under what circumstances conventional pharmacologic or ultrafiltration goals might best be directed toward central venous pressures rather than left ventricular or cardiac output parameters. Copyright © 2012 Elsevier Inc. All rights reserved.
Involvement of systemic venous congestion in heart failure.
Rubio Gracia, J; Sánchez Marteles, M; Pérez Calvo, J I
2017-04-01
Systemic venous congestion has gained significant importance in the interpretation of the pathophysiology of acute heart failure, especially in the development of renal function impairment during exacerbations. In this study, we review the concept, clinical characterisation and identification of venous congestion. We update current knowledge on its importance in the pathophysiology of acute heart failure and its involvement in the prognosis. We pay special attention to the relationship between abdominal congestion, the pulmonary interstitium as filtering membrane, inflammatory phenomena and renal function impairment in acute heart failure. Lastly, we review decongestion as a new therapeutic objective and the measures available for its assessment. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.
Pant, Deepanjali; Narani, Krishan Kumar; Sood, Jayashree
2010-01-01
Significant venous air embolism may develop acutely during the perioperative period due to a number of causes such as during head and neck surgery, spinal surgery, improper central venous and haemodialysis catheter handling, etc. The current trend of using self collapsible intravenous (IV) infusion bags instead of the conventional glass or plastic bottles has several advantages, one of thaem being protection against air embolism. We present a 56-year-old man undergoing kidney transplantation, who developed a near fatal venous air embolism during volume resuscitation with normal saline in collapsible IV bags used with rapid infuser system. To our knowledge, this problem with collapsible infusion bags has not been reported earlier. PMID:20532073
A Predictive Framework to Elucidate Venous Stenosis: CFD & Shape Optimization.
Javid Mahmoudzadeh Akherat, S M; Cassel, Kevin; Boghosian, Michael; Hammes, Mary; Coe, Fredric
2017-07-01
The surgical creation of vascular accesses for renal failure patients provides an abnormally high flow rate conduit in the patient's upper arm vasculature that facilitates the hemodialysis treatment. These vascular accesses, however, are very often associated with complications that lead to access failure and thrombotic incidents, mainly due to excessive neointimal hyperplasia (NH) and subsequently stenosis. Development of a framework to monitor and predict the evolution of the venous system post access creation can greatly contribute to maintaining access patency. Computational fluid dynamics (CFD) has been exploited to inspect the non-homeostatic wall shear stress (WSS) distribution that is speculated to trigger NH in the patient cohort under investigation. Thereafter, CFD in liaison with a gradient-free shape optimization method has been employed to analyze the deformation modes of the venous system enduring non-physiological hemodynamics. It is observed that the optimally evolved shapes and their corresponding hemodynamics strive to restore the homeostatic state of the venous system to a normal, pre-surgery condition. It is concluded that a CFD-shape optimization coupling that seeks to regulate the WSS back to a well-defined physiological WSS target range can accurately predict the mode of patient-specific access failure.
One dimensional blood flow in a planetocentric orbit
NASA Astrophysics Data System (ADS)
Haranas, Ioannis; Gkigkitzis, Ioannis
2012-05-01
All life on earth is accustomed to the presence of gravity. When gravity is altered, biological processes can go awry. It is of great importance to ensure safety during a spaceflight. Long term exposure to microgravity can trigger detrimental physiological responses in the human body. Fluid redistribution coupled with fluid loss is one of the effects. In particular, in microgravity blood volume is shifted towards the thorax and head. Sympathetic nervous system-induced vasoconstriction is needed to maintain arterial pressure, while venoconstriction limits venous pooling of blood prevents further reductions in venous return of blood to the heart. In this paper, we modify an existing one dimensional blood flow model with the inclusion of the hydrostatic pressure gradient that further depends on the gravitational field modified by the oblateness and rotation of the Earth. We find that the velocity of the blood flow VB is inversely proportional to the blood specific volume d, also proportional to the oblateness harmonic coefficient J2, the angular velocity of the Earth ωE, and finally proportional to an arbitrary constant c. For c = -0.39073 and ξH = -0.5 mmHg, all orbits result to less blood flow velocities than that calculated on the surface of the Earth. From all considered orbits, elliptical polar orbit of eccentricity e = 0.2 exhibit the largest flow velocity VB = 1.031 m/s, followed by the orbits of inclination i = 45°and 0°. The Earth's oblateness and its rotation contribute a 0.7% difference to the blood flow velocity.
Goo, Hyun Woo
2007-07-01
Congenital absence of the portal vein is a rare malformation in which mesenteric and splenic venous flow bypasses the liver and drains into various sites in the systemic venous system via an extrahepatic portosystemic shunt. In an 11-year-old girl with congenital absence of the portal vein, the detailed anatomy of the extrahepatic portosystemic shunt is demonstrated by time-resolved contrast-enhanced MR angiography.
Nowak-Göttl, Ulrike; Kenet, Gili; Mitchell, Lesley G
2009-03-01
Acute lymphoblastic leukaemia (ALL) is the most common malignancy associated with venous thromboembolism (VTE) in children. The prevalence of symptomatic VTE ranges from 0% to 36%, and the variation can be explained, at least in part, by differences in chemotherapeutic protocols. The mechanism for increased risk of VTE is associated with alterations in the haemostatic system by use of L-asparaginase (ASP) alone or in combination with vincristine or prednisone, presence of central venous lines (CVLs) and/or inherited thrombophilia. The children at greatest risk are generally those receiving Escherichia coli ASP concomitant with prednisone. The majority of symptomatic VTEs occur in the central nervous system or in the upper venous system. In the majority of cases, asymptomatic VTEs are associated with CVLs. External CVLs are affected more often than internal CVLs. Evidence-based guidelines on prevention and treatment guidelines for ALL-related VTE are lacking, and carefully designed clinical trials are needed urgently.
New single-layer compression bandage system for chronic venous leg ulcers.
Lee, Gillian; Rajendran, Subbiyan; Anand, Subhash
A new single-layer bandage system for the treatment of venous leg ulcers has been designed and developed at the University of Bolton. This three-dimensional (3D) knitted spacer fabric structure has been designed by making use of mathematical modelling and Laplace's law. The sustained graduated compression of the developed 3D knitted spacer bandages were tested and characterized, and compared with that of commercially available compression bandages. It was observed that the developed 3D single-layer bandage meets the ideal criteria stipulated for compression therapy. The laboratory results were verified by carrying out a pilot user study incorporating volunteers from different age groups. This article examines the insight into the design and development of the new 3D knitted spacer bandage, along with briefly discussing the issues of compression therapy systems intended for the treatment of venous leg ulcers.
Dreha-Kulaczewski, Steffi; Joseph, Arun A; Merboldt, Klaus-Dietmar; Ludwig, Hans-Christoph; Gärtner, Jutta; Frahm, Jens
2017-03-01
CSF flux is involved in the pathophysiology of neurodegenerative diseases and cognitive impairment after traumatic brain injury, all hallmarked by the accumulation of cellular metabolic waste. Its effective disposal via various CSF routes has been demonstrated in animal models. In contrast, the CSF dynamics in humans are still poorly understood. Using novel real-time MRI, forced inspiration has been identified recently as a main driving force of CSF flow in the human brain. Exploiting technical advances toward real-time phase-contrast MRI, the current work analyzed directions, velocities, and volumes of human CSF flow within the brain aqueduct as part of the internal ventricular system and in the spinal canal during respiratory cycles. A consistent upward CSF movement toward the brain in response to forced inspiration was seen in all subjects at the aqueduct, in 11/12 subjects at thoracic level 2, and in 4/12 subjects at thoracic level 5. Concomitant analyses of CSF dynamics and cerebral venous blood flow, that is, in epidural veins at cervical level 3, uniquely demonstrated CSF and venous flow to be closely communicating cerebral fluid systems in which inspiration-induced downward flow of venous blood due to reduced intrathoracic pressure is counterbalanced by an upward movement of CSF. The results extend our understanding of human CSF flux and open important clinical implications, including concepts for drug delivery and new classifications and therapeutic options for various forms of hydrocephalus and idiopathic intracranial hypertension. SIGNIFICANCE STATEMENT Effective disposal of brain cellular waste products via CSF has been demonstrated repeatedly in animal models. However, CSF dynamics in humans are still poorly understood. A novel quantitative real-time MRI technique yielded in vivo CSF flow directions, velocities, and volumes in the human brain and upper spinal canal. CSF moved upward toward the head in response to forced inspiration. Concomitant analysis of brain venous blood flow indicated that CSF and venous flux act as closely communicating systems. The finding of a human CSF-venous network with upward CSF net movement opens new clinical concepts for drug delivery and new classifications and therapeutic options for various forms of hydrocephalus and ideopathic intracranial hypertension. Copyright © 2017 the authors 0270-6474/17/372395-08$15.00/0.
NASA Astrophysics Data System (ADS)
Goo, Eun-Hoe; Kim, Sun-Ju; Dong, Kyung-Rae; Kim, Kwang-Choul; Chung, Woon-Kwan
2016-09-01
The purpose of this study is to evaluate the image quality in delineation of the portal venous systems with two different methods, breath-hold and non-breath-hold by using the 3D FLASH sequence. We used a 1.5 T system to obtain magnetic resonance(MR)images. Arterial and portal phase 3D FLASH images were obtained with breath-hold after a bolus injection of GD-DOTA. The detection of PVS on the MR angiograms was classified into three grades. First, the angiograms of the breath-hold method showed well the portal vein, the splenic vein and the superior mesenteric vein systems in 13 of 15 patients (86%) and the inferior mesenteric vein system in 6 of 15 patients (40%), Second, MR angiograms of the non-breath-hold method demonstrated the PVS and the SMV in 12 of 15 patients (80%) and the IMV in 5 of 15 patients (33%). Our study showed contrast-enhanced 3D FLASH MR angiography, together with the breath-hold technique, may provide reliable and accurate information on the portal venous system.
Heart failure: when form fails to follow function.
Katz, Arnold M; Rolett, Ellis L
2016-02-01
Cardiac performance is normally determined by architectural, cellular, and molecular structures that determine the heart's form, and by physiological and biochemical mechanisms that regulate the function of these structures. Impaired adaptation of form to function in failing hearts contributes to two syndromes initially called systolic heart failure (SHF) and diastolic heart failure (DHF). In SHF, characterized by high end-diastolic volume (EDV), the left ventricle (LV) cannot eject a normal stroke volume (SV); in DHF, with normal or low EDV, the LV cannot accept a normal venous return. These syndromes are now generally defined in terms of ejection fraction (EF): SHF became 'heart failure with reduced ejection fraction' (HFrEF) while DHF became 'heart failure with normal or preserved ejection fraction' (HFnEF or HFpEF). However, EF is a chimeric index because it is the ratio between SV--which measures function, and EDV--which measures form. In SHF the LV dilates when sarcomere addition in series increases cardiac myocyte length, whereas sarcomere addition in parallel can cause concentric hypertrophy in DHF by increasing myocyte thickness. Although dilatation in SHF allows the LV to accept a greater venous return, it increases the energy cost of ejection and initiates a vicious cycle that contributes to progressive dilatation. In contrast, concentric hypertrophy in DHF facilitates ejection but impairs filling and can cause heart muscle to deteriorate. Differences in the molecular signals that initiate dilatation and concentric hypertrophy can explain why many drugs that improve prognosis in SHF have little if any benefit in DHF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.
Law, Stephanie; Ghag, Daljit; Grafstein, Eric; Stenstrom, Robert; Harris, Devin
2016-09-01
Patients with venous thromboembolism (VTE) (deep vein thrombosis [DVT] and pulmonary embolism [PE]) are commonly treated as outpatients. Traditionally, patients are anticoagulated with low-molecular-weight heparin (LMWH) and warfarin, resulting in return visits to the ED. The direct oral anticoagulant (DOAC) medications do not require therapeutic monitoring or repeat visits; however, they are more expensive. This study compared health costs, from the hospital and patient perspectives, between traditional versus DOAC therapy. A chart review of VTE cases at two tertiary, urban hospitals from January 1, 2010 to December 31, 2012 was performed to capture historical practice in VTE management, using LMWH/warfarin. This historical data were compared against data derived from clinical trials, where a DOAC was used. Cost minimization analyses comparing the two modes of anticoagulation were completed from hospital and patient perspectives. Of the 207 cases in the cohort, only 130 (63.2%) were therapeutically anticoagulated (international normalized ratio 2.0-3.0) at emergency department (ED) discharge; patients returned for a mean of 7.18 (range: 1-21) visits. Twenty-one (10%) were admitted to the hospital; 4 (1.9%) were related to VTE or anticoagulation complications. From a hospital perspective, a DOAC (in this case, rivaroxaban) had a total cost avoidance of $1,488.04 per VTE event, per patient. From a patient perspective, it would cost an additional $204.10 to $349.04 over 6 months, assuming no reimbursement. VTE management in the ED has opportunities for improvement. A DOAC is a viable and cost-effective strategy for VTE treatment from a hospital perspective and, depending on patient characteristics and values, may also be an appropriate and cost-effective option from a patient perspective.
Central venous access: techniques and indications in oncology.
Marcy, Pierre-Yves
2008-10-01
Long lines can be inserted centrally or peripherally through patent veins into the central venous system down to the atrial caval junction. Traditionally surgeons, anesthetists, cardiologists and more recently interventional radiologists have been placing them using vein cutdown or percutaneous needle puncture techniques. Typical candidates for implanted venous catheters are cancer patients undergoing long-term chemotherapy. The most important issues, in addition to the patency of central veins and the history of previous indwelling catheters, pacewires or venous thrombosis, are the patient's performance status, body mass index, medical history and respiratory status, and the relevant technique. The present article will give an overview of the radiological and surgical implantation techniques and will highlight the impact of imaging means on the technical feasibility, assessment and treatment of device-related complications.
Morrison, James; Kaufman, John
2016-12-01
Vascular access is invaluable in the treatment of hospitalized patients. Central venous catheters provide a durable and long-term solution while saving patients from repeated needle sticks for peripheral IVs and blood draws. The initial catheter placement procedure and long-term catheter usage place patients at risk for infection. The goal of this project was to develop a system to track and evaluate central line-associated blood stream infections related to interventional radiology placement of central venous catheters. A customized web-based clinical database was developed via open-source tools to provide a dashboard for data mining and analysis of the catheter placement and infection information. Preliminary results were gathered over a 4-month period confirming the utility of the system. The tools and methodology employed to develop the vascular access tracking system could be easily tailored to other clinical scenarios to assist in quality control and improvement programs.
Baronaite Hansen, Renata; Jacobsen, Søren
2014-09-01
Infections and thromboses are known complications of systemic lupus erythematosus (SLE). We investigated if infectious episodes in patients with SLE were followed by an increased risk of thrombotic events. A cohort of 571 patients with prevalent or incident SLE was followed for a mean of 8.9 ± 7.6 years. All episodes of hospitalized infections or episodes of cutaneous herpes zoster as well as arterial and venous thrombotic events were identified by retrospective chart review and prospective updating of a clinical database. For time-dependent analyses adjusted for age, sex, and ever-presence of antiphospholipid antibodies, thrombotic events were classified as occurring during the time at risk of 1 year after an infection or during the remaining control observation time. Of 271 infections identified, 104 were respiratory, 41 cutaneous herpes zoster, and 126 others. Of 159 thromboses identified, 98 were arterial. Incidence for arterial and venous thromboses within 1 year after infection was 2.18% and 2.56%, respectively, compared to patients who never had an infection (0.58 and 0.67). The adjusted 1-year risk of arterial and venous thrombosis after any infection was increased [relative rate (RR) 2.5, 95% CI 1.4-4.6, and RR 2.8, 95% CI 1.3-5.9, respectively]. Venous thromboses were in particular more prevalent after respiratory infections (RR 5.4, 95% CI 2.3-13). The temporal associations observed in this study indicate that infections could be risk factors for arterial or venous thromboses in patients with SLE, although causality was not addressed by this study.
Postural effects on intracranial pressure: modeling and clinical evaluation.
Qvarlander, Sara; Sundström, Nina; Malm, Jan; Eklund, Anders
2013-11-01
The physiological effect of posture on intracranial pressure (ICP) is not well described. This study defined and evaluated three mathematical models describing the postural effects on ICP, designed to predict ICP at different head-up tilt angles from the supine ICP value. Model I was based on a hydrostatic indifference point for the cerebrospinal fluid (CSF) system, i.e., the existence of a point in the system where pressure is independent of body position. Models II and III were based on Davson's equation for CSF absorption, which relates ICP to venous pressure, and postulated that gravitational effects within the venous system are transferred to the CSF system. Model II assumed a fully communicating venous system, and model III assumed that collapse of the jugular veins at higher tilt angles creates two separate hydrostatic compartments. Evaluation of the models was based on ICP measurements at seven tilt angles (0-71°) in 27 normal pressure hydrocephalus patients. ICP decreased with tilt angle (ANOVA: P < 0.01). The reduction was well predicted by model III (ANOVA lack-of-fit: P = 0.65), which showed excellent fit against measured ICP. Neither model I nor II adequately described the reduction in ICP (ANOVA lack-of-fit: P < 0.01). Postural changes in ICP could not be predicted based on the currently accepted theory of a hydrostatic indifference point for the CSF system, but a new model combining Davson's equation for CSF absorption and hydrostatic gradients in a collapsible venous system performed well and can be useful in future research on gravity and CSF physiology.
Splanchnic venous thrombosis and pancreatitis.
Nadkarni, Nikhil A; Khanna, Sahil; Vege, Santhi Swaroop
2013-08-01
Pancreatitis is an inflammatory process with local and systemic manifestations. One such local manifestation is thrombosis in splanchnic venous circulation, predominantly of the splenic vein. The literature on this important complication is very sparse. This review offers an overview of mechanism of thrombosis, its pathophysiology, diagnosis, and management in the setting of acute as well as chronic pancreatitis.
Surgical management of tricuspid atresia and anomalous left brachiocephalic vein.
Koutlas, T C; Wernovsky, G; Slack, M C; Weinberg, P M; Spray, T L
1998-06-01
An anomalous left brachiocephalic vein is an uncommon systemic venous anomaly, which usually has no clinical significance. We describe a case of tricuspid atresia with such an anomalous left brachiocephalic vein. The presence of this unusual venous anomaly had a number of implications in the surgical management of the tricuspid atresia.
Total anomalous systemic with partial anomalous pulmonary venous connections.
Vallath, Gopakumar; Gajjar, Trushar; Desai, Neelam
2013-12-01
A 9-year-old girl with cyanosis, dyspnea, and grade II clubbing was diagnosed by contrast transthoracic echocardiography and angiocardiography to have an anomalous connection of the venae cavae to the physiologic left atrium with partial anomalous pulmonary venous connection. Successful surgical correction was achieved, and the patient's recovery was uneventful.
Venous thromboembolism after major venous injuries: Competing priorities.
Frank, Brian; Maher, Zoё; Hazelton, Joshua P; Resnick, Shelby; Dauer, Elizabeth; Goldenberg, Anna; Lubitz, Andrea L; Smith, Brian P; Saillant, Noelle N; Reilly, Patrick M; Seamon, Mark J
2017-12-01
Venous thromboembolism (VTE) after major vascular injury (MVI) is particularly challenging because the competing risk of thrombosis and embolization after direct vessel injury must be balanced with risk of bleeding after surgical repair. We hypothesized that venous injuries, repair type, and intraoperative anticoagulation would influence VTE formation after MVI. A multi-institution, retrospective cohort study of consecutive MVI patients was conducted at three urban, Level I centers (2005-2013). Patients with MVI of the neck, torso, or proximal extremities (to elbows/knees) were included. Our primary study endpoint was the development of VTE (DVT or pulmonary embolism [PE]). The 435 major vascular injury patients were primarily young (27 years) men (89%) with penetrating (84%) injuries. When patients with (n = 108) and without (n = 327) VTE were compared, we observed no difference in age, mechanism, extremity injury, tourniquet use, orthopedic and spine injuries, damage control, local heparinized saline, or vascular surgery consultation (all p > 0.05). VTE patients had greater Injury Severity Score (ISS) (17 vs. 12), shock indices (1 vs. 0.9), and more torso (58% vs. 35%) and venous (73% vs. 48%) injuries, but less often received systemic intraoperative anticoagulation (39% vs. 53%) or postoperative enoxaparin (47% vs. 61%) prophylaxis (all p < 0.05). After controlling for ISS, hemodynamics, injured vessel, intraoperative anticoagulation, and postoperative prophylaxis, multivariable analysis revealed venous injury was independently predictive of VTE (odds ratio, 2.7; p = 0.002). Multivariable analysis of the venous injuries subset (n = 237) then determined that only delay in starting VTE chemoprophylaxis (odds ratio, 1.3/day; p = 0.013) independently predicted VTE after controlling for ISS, hemodynamics, injured vessel, surgical subspecialty, intraoperative anticoagulation, and postoperative prophylaxis. Overall, 3.4% of venous injury patients developed PE, but PE rates were not related to their operative management (p = 0.72). Patients with major venous injuries are at high risk for VTE, regardless of intraoperative management. Our results support the immediate initiation of postoperative chemoprophylaxis in patients with major venous injuries. Therapeutic/care management, level IV.
Decompression from Saturation Using Oxygen: Its Effect on DCS and RNA in Large Swine
2010-01-01
mask. The external jugular vein was catheter- ized with a 14-Ga., 30-cm single lumen catheter ( Central Venous Catheterization Set; Arrow... venous catheterization for sequential blood sampling from the pig. J Invest Surg 1991; 4:103-7. 3. Behnke AR. The isobaric (oxygen window) principle of...pressures may lead to toxicity that involves the pulmonary system and/ or the central nervous system (CNS). There is evidence that 100% oxygen in
The Portal Theory Supported by Venous Drainage–Selective Fat Transplantation
Rytka, Julia M.; Wueest, Stephan; Schoenle, Eugen J.; Konrad, Daniel
2011-01-01
OBJECTIVE The “portal hypothesis” proposes that the liver is directly exposed to free fatty acids and cytokines increasingly released from visceral fat tissue into the portal vein of obese subjects, thus rendering visceral fat accumulation particularly hazardous for the development of hepatic insulin resistance and type 2 diabetes. In the present study, we used a fat transplantation paradigm to (artificially) increase intra-abdominal fat mass to test the hypothesis that venous drainage of fat tissue determines its impact on glucose homeostasis. RESEARCH DESIGN AND METHODS Epididymal fat pads of C57Bl6/J donor mice were transplanted into littermates, either to the parietal peritoneum (caval/systemic venous drainage) or, by using a novel approach, to the mesenterium, which confers portal venous drainage. RESULTS Only mice receiving the portal drained fat transplant developed impaired glucose tolerance and hepatic insulin resistance. mRNA expression of proinflammatory cytokines was increased in both portally and systemically transplanted fat pads. However, portal vein (but not systemic) plasma levels of interleukin (IL)-6 were elevated only in mice receiving a portal fat transplant. Intriguingly, mice receiving portal drained transplants from IL-6 knockout mice showed normal glucose tolerance. CONCLUSIONS These results demonstrate that the metabolic fate of intra-abdominal fat tissue transplantation is determined by the delivery of inflammatory cytokines to the liver specifically via the portal system, providing direct evidence in support of the portal hypothesis. PMID:20956499
Baltsavias, Gerasimos; Parthasarathi, Venkatraman; Aydin, Emre; Al Schameri, Rahman A; Roth, Peter; Valavanis, Anton
2015-04-01
We reviewed the anatomy and embryology of the bridging and emissary veins aiming to elucidate aspects related to the cranial dural arteriovenous fistulae. Data from relevant articles on the anatomy and embryology of the bridging and emissary veins were identified using one electronic database, supplemented by data from selected reference texts. Persisting fetal pial-arachnoidal veins correspond to the adult bridging veins. Relevant embryologic descriptions are based on the classic scheme of five divisions of the brain (telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon). Variation in their exact position and the number of bridging veins is the rule and certain locations, particularly that of the anterior cranial fossa and lower posterior cranial fossa are often neglected in prior descriptions. The distal segment of a bridging vein is part of the dural system and can be primarily involved in cranial dural arteriovenous lesions by constituting the actual site of the shunt. The veins in the lamina cribriformis exhibit a bridging-emissary vein pattern similar to the spinal configuration. The emissary veins connect the dural venous system with the extracranial venous system and are often involved in dural arteriovenous lesions. Cranial dural shunts may develop in three distinct areas of the cranial venous system: the dural sinuses and their interfaces with bridging veins and emissary veins. The exact site of the lesion may dictate the arterial feeders and original venous drainage pattern.
Magro, Elsa; Gentric, Jean-Christophe; Talagas, Matthieu; Alavi, Zarrin; Nonent, Michel; Dam-Hieu, Phong; Seizeur, Romuald
2015-07-01
The anatomical arrangement of the venous system within the transverse foramen is controversial; there is disagreement whether the anatomy consists of a single vertebral vein or a confluence of venous plexus. Precise knowledge of this arrangement is necessary in imaging when vertebral artery dissection is suspected, as well as in surgical approaches for the cervical spine. This study aimed to better explain anatomical organization of the venous system within the transverse foramen according to the Trolard hypothesis of a transverse vertebral sinus. This was an anatomical and radiological study. For the anatomical study, 10 specimens were analyzed after vascular injection. After dissection, histological cuts were prepared. For the radiological study, a high-resolution MRI study with 2D time-of-flight segment MR venography sequences was performed on 10 healthy volunteers. Vertebral veins are arranged in a plexiform manner within the transverse canal. This arrangement begins at the upper part of the transverse canal before the vertebral vein turns into a single vein along with the vertebral artery running from the transverse foramen of the C-6. This venous system runs somewhat ventrolaterally to the vertebral artery. In most cases, this arrangement is symmetrical and facilitates radiological readings. The anastomoses between vertebral veins and ventral longitudinal veins are uniform and arranged segmentally at each vertebra. These findings confirm recent or previous anatomical descriptions and invalidate others. It is hard to come up with a common description of the arrangement of vertebral veins. The authors suggest providing clinicians as well as anatomists with a well-detailed description of components essential to the understanding of this organization.
Cardiorespiratory responses to orthostasis and the effects of propranolol
NASA Technical Reports Server (NTRS)
Loeppky, J. A.
1975-01-01
Cardiac output and gas exchange were determined serially using the single-breath method of Kim et al. before, during, and after orthostasis on six subjects after beta-adrenergic blockage and in duplicate controls. In the latter, heart rate increased and pulse pressure dropped immediately on tilting to 60 deg and remained stable while cardiac output and stroke volume declined gradually over 21 min upright. On propranolol, heart rate was 10 bpm lower supine and 20 bpm less at 60 deg but cardiac output was only slightly lower before and following tilt-up. However, after 15 min upright, stroke volume and cardiac output recovered on propranolol exceeding the controls after 21 min without change in heart rate. Returning to supine, heart rate dropped in all tests with a transitory increase in stroke volume, cardiac output and arteriovenous O2 difference. At the same time, apparent O2 uptake increased temporarily, reflecting the return of pooled venous blood to the lungs. Orthostatic tolerance did not appear to be affected by beta-adrenergic blockade.
Mosti, Giovanni; Crespi, Aldo; Mattaliano, Vincenzo
2011-05-01
Compression therapy is standard treatment for venous leg ulcers. The authors prefer multi-layer, multi-component, stiff, high-pressure bandages to treat venous leg ulcers. The Unna boot (UB) is an example of this type of bandage. The aim of this study was to compare the effectiveness and tolerability of UB to a new, two-component bandage. One hundred (100) patients with venous ulcers were randomized into two groups: group A (n = 50) received UB and group B (n = 50) 3M™ Coban™ 2 Layer Compression System (C2L). All patients were followed weekly for 3 months and then monthly until complete healing was achieved. The primary outcomes were: ulcer healing or surface reduction; pain; and exudate control. The secondary outcomes were: ease of application and removal of the bandage, pressure exerted in the supine and standing position after application and before removal, and bandage comfort. C2L was associated with 100% ulcer healing; 47 out of 50 cases healed within the first 3 months after application of the bandage. Compared with the UB, there was no statistically significant difference. In both groups the effect of compression on pain and overall well being was excellent; pain decreased by 50% within 1-2 weeks and remained low throughout the duration of treatment and overall well being improved significantly. There was no significant difference between the two systems concerning level of comfort. C2L proved to be effective in treating venous ulcers due to its stiffness and pressure. Its effectiveness was similar to UB, which is often considered the gold-standard compression device for venous ulcers. This fact, in combination with high tolerability and ease of application and removal, make this new bandage particularly suitable for the treatment of venous leg ulcers. .
Blood flow velocity in the popliteal vein using transverse oscillation ultrasound
NASA Astrophysics Data System (ADS)
Bechsgaard, Thor; Hansen, Kristoffer Lindskov; Brandt, Andreas Hjelm; Holbek, Simon; Lönn, Lars; Strandberg, Charlotte; Bækgaard, Niels; Nielsen, Michael Bachmann; Jensen, Jørgen Arendt
2016-04-01
Chronic venous disease is a common condition leading to varicose veins, leg edema, post-thrombotic syndrome and venous ulcerations. Ultrasound (US) is the main modality for examination of venous disease. Color Doppler and occasionally spectral Doppler US (SDUS) are used for evaluation of the venous flow. Peak velocities measured by SDUS are rarely used in a clinical setting for evaluating chronic venous disease due to inadequate reproducibility mainly caused by the angle dependency of the estimate. However, estimations of blood velocities are of importance in characterizing venous disease. Transverse Oscillation US (TOUS), a non-invasive angle independent method, has been implemented on a commercial scanner. TOUS's advantage compared to SDUS is a more elaborate visualization of complex flow. The aim of this study was to evaluate, whether TOUS perform equal to SDUS for recording velocities in the veins of the lower limbs. Four volunteers were recruited for the study. A standardized flow was provoked with a cuff compression-decompression system placed around the lower leg. The average peak velocity in the popliteal vein of the four volunteers was 151.5 cm/s for SDUS and 105.9 cm/s for TOUS (p <0.001). The average of the peak velocity standard deviations (SD) were 17.0 cm/s for SDUS and 13.1 cm/s for TOUS (p <0.005). The study indicates that TOUS estimates lower peak velocity with improved SD when compared to SDUS. TOUS may be a tool for evaluation of venous disease providing quantitative measures for the evaluation of venous blood flow.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miyayama, Shiro; Matsui, Osamu; Taki, Keiichi
2005-12-15
We retrospectively evaluated the usefulness of both arterial and venous access with the pull-through technique in endovascular treatment of totally occluded Brescia-Cimino fistulas. We treated 26 patients (17 men, 9 women; age range 43-82 years, mean age 66 years) with occluded Brescia-Cimino fistulas. First, the occluded segment was traversed from the antegrade brachial arterial access using a microcatheter-guidewire system. Second, the vein was retrogradely punctured after confirmation of all diseased segments, and a 0.014- or 0.016-inch guidewire was pulled through the venous access when the occluded segment was long. All interventions including thrombolysis, thromboaspiration, angioplasty, and stent placement were performedmore » via the venous access. The occlusion was successfully crossed via the brachial arterial access in 23 patients (88%). In 2 patients it was done from the venous approach. In the remaining patient it was not possible to traverse the occluded segment. The pull-through technique was successful in all 19 attempts. Clinical success was achieved in 96%, the primary patency rates at 6, 12, and 18 months were 83%, 78%, and 69%, the primary assisted patency rates were 92%, 92%, and 72%, and the secondary patency rates were 92%, 92%, and 92%, respectively. Minor complications in 5 patients included venous perforation in 2 (8%), venous rupture in 1 (4%), and regional hematoma in 2 (8%). Our study suggests that endovascular treatments with both arterial and venous access using the pull-through technique are highly effective in restoring function in totally occluded Brescia-Cimino fistulas.« less
Qureshi, Adnan I; Khan, Asif A; Capistrant, Rachel; Qureshi, Mushtaq H; Xie, Kevin; Suri, M Fareed K
2016-10-01
To report upon technique of concurrent placement of angioplasty balloon at the internal jugular vein and sigmoid venous sinus junction to facilitate stent delivery in two patients in whom stent delivery past the jugular bulb was not possible. A 21-year-old woman and a 41-year-old woman with worsening headaches, visual obscuration or diplopia were treated for pseudotumor cerebri associated with transverse venous stenosis. Both patients had undergone primary angioplasty, which resulted in improvement in clinical symptoms followed by the recurrence of symptoms with restenosis at the site of angioplasty. After multiple attempts at stent delivery through jugular venous bulb were unsuccessful, a second guide catheter was placed in the ipsilateral internal jugular vein through contralateral femoral venous approach. A 6 mm × 20 mm (left) or 5 × 15 mm (right) angioplasty balloon was placed across the internal jugular vein and sigmoid sinus junction and partially inflated until the inflation and relative straightening of the junction was observed. In both patients, the internal jugular vein and sigmoid sinus junction was successfully traversed by the stent delivery system in a parallel alignment to inflated balloon. Balloon mounted stent was deployed at the site of restenosis with near complete resolution of lumen narrowing delivery and improvement in clinical symptoms. We report a technique for realignment and diameter change with concurrent placement and partial inflation of angioplasty balloon at the jugular venous bulb to facilitate stent delivery into the sigmoid and transverse venous sinuses in circumstances where multiple attempts at stent delivery are unsuccessful.
International Meeting on Simulation in Healthcare 2007
2007-03-01
Research Abstract : 32 Simulationbased Training in Ultrasound Assisted Central Venous Catheterization . Pamela Andreatta 1 , Rajani Mangrulkar 2...vascular access skill training for central venous catheterization , and basic and difficult airway management skill training with infant/pediatric/adult task...Office of Clinical Affairs, University of Michigan Health System Background: More than 5 million central venous catheters (CVCs) are inserted in the
Suicide by Intentional Air embolism.
Simon, Gábor; Rácz, Evelin; Mayer, Mátyás; Heckmann, Veronika; Tóth, Dénes; Kozma, Zsolt
2017-05-01
Venous air embolism occurs when air enters the venous system. The main causes of venous air embolism include medical procedures, neck and head trauma, and injuries of the genitals. Self-induced suicidal (and intentional) air embolism is extremely rare. The authors report a rare case of a suicidal air embolism committed using a self-made tool composed of a plastic bottle and an infusion set, injecting nearly 2000 mL of air into the cubital vein. The toxicological analysis suggested that midazolam, together with air, was also injected into the circulation using the same bottle and infusion set. © 2016 American Academy of Forensic Sciences.
Clavijo-Alvarez, Julio A; Pannucci, Christopher J; Oppenheimer, Adam J; Wilkins, Edwin G; Rubin, J Peter
2011-03-01
Venous thromboembolism (VTE) has been identified as a major public health issue. Postbariatric body contouring surgery represents a major challenge for VTE prophylaxis due to the presence of multiple risk factors and broad areas of dissection that potentially increase the risk of postoperative bleeding. To define current VTE prophylaxis practices among surgeons of the American Society of Plastic Surgeons, performing postbariatric body contouring surgery in the United States. A total of 4081 surveys were sent to registered members of the American Society of Plastic Surgeons by e-mail. We received 596 (14.6%) responses. A total of 596 surgeons returned completed surveys, with 83% of respondents in private practice and 17% in academic practice. Deep venous thrombosis (DVT) was reported by 40% surgeons, pulmonary embolism (PE) by 34%, and 7% had at least 1 patient having died of a postoperative PE. About 39% to 48% participant surgeons reported providing no chemoprophylaxis to their postbariatric body contouring patients. The most common reason for not using routine prophylaxis was the concern for bleeding (84%), followed by lack of evidence specific to plastic surgery practice (50%). Academic surgeons were more likely to provide chemoprophylaxis when compared with those in nonacademic practice (P < 0.05). For postbariatric body contouring surgery, DVT has occurred in over one-third of plastic surgeons' practices with 7% of surgeons reporting a patient death from PE. A substantial proportion of surgeons performing postbariatric body contouring are not using chemoprophylaxis due to bleeding risk and perceived lack of evidence. VTE prophylaxis in postbariatric body contouring remains a topic that deserves further study.
Gender Differences in Bed Rest: Preliminary Analysis of Vascular Function
NASA Technical Reports Server (NTRS)
Platts, Steven H.; Stenger, Michael B.; Martin, David S.; Freeman-Perez, Sondra A.; Phillips, Tiffany; Ribeiro, L. Christine
2008-01-01
Orthostatic intolerance is a recognized consequence of spaceflight. Numerous studies have shown that women are more susceptible to orthostatic intolerance following spaceflight as well as bed rest, the most commonly used ground-based analog for spaceflight. One of the possible mechanisms proposed to account for this is a difference in vascular responsiveness between genders. We hypothesized that women and men would have differing vascular responses to 90 days of 6-degree head down tilt bed rest. Additionally, we hypothesized that vessels in the upper and lower body would respond differently, as has been shown in the animal literature. Thirteen subjects were placed in bedrest for 90 days (8 men, 5 women) at the Flight Analogs Unit, UTMB. Direct arterial and venous measurements were made with ultrasound to evaluate changes in vascular structure and function. Arterial function was assessed, in the arm and leg, during a reactive hyperemia protocol and during sublingual nitroglycerin administration to gauge the contributions of endothelial dependent and independent dilator function respectively. Venous function was assessed in dorsal hand and foot veins during the administration of pharmaceuticals to assess constrictor and dilator function. Both gender and day effects are seen in arterial dilator function to reactive hyperemia, but none are seen with nitroglycerin. There are also differences in the wall thickness in the arm vs the leg during bed rest, which return toward pre-bed rest levels by day 90. More subjects are required, especially females as there is not sufficient power to properly analyze venous function. Day 90 data are most underpowered.
Macartney, F J; Zuberbuhler, J R; Anderson, R H
1980-01-01
The atrial morphology and venous connections were assessed "blind" in 51 necropsy specimens from patients with visceral heterotaxy. This was compared with bronchial morphology as established by dissection. Six specimens were found to have both atria and bronchi in situs solitus or inversus, and were rejected. In the remainder, atrial isomerism was diagnosed, though this required minor revision of the atrial assessment in two patients. Thirty-four patients had isomeric right atria and bronchi, while 11 had isomeric left atria and bronchi. In seven cases, splenic status was unknown, but in seven of the remaining 38 (18.4%) atrial isomerism was not associated with either asplenia or polysplenia. Nevertheless, right isomerism was strongly associated with total anomalous pulmonary venous drainage (as is asplenia) and left isomerism was likewise associated with interruption of the inferior vena cava (as is polysplenia). Bilateral superior venae cavae and hepatic veins, and absence of the coronary sinus, were frequent in both forms of isomerism (as they are in asplenia and polysplenia). These findings suggest that atrial situs can be defined as solitus inversus, right isomerism, and left isomerism. This determination of atrial situs is quite independent of any other abnormalities of visceral situs. The high incidence of anomalies of both venous return and common atrium resulted in presumed complete mixing of blood at atrial level in all but one patient (97.8%), making the haemodynamic connection between atria and ventricles almost always ambiguous. To describe this anatomical connection as ambiguous when there are two ventricles present is therefore no more than recognition of anatomical and haemodynamic reality. Images PMID:7459148
Temperature monitoring during cardiopulmonary bypass--do we undercool or overheat the brain?
Kaukuntla, Hemanth; Harrington, Deborah; Bilkoo, Inderaj; Clutton-Brock, Tom; Jones, Timothy; Bonser, Robert S
2004-09-01
Brain cooling is an essential component of aortic surgery requiring circulatory arrest and inadequate cooling may lead to brain injury. Similarly, brain hyperthermia during the rewarming phase of cardiopulmonary bypass may also lead to neurological injury. Conventional temperature monitoring sites may not reflect the core brain temperature (Tdegrees). We compared jugular bulb venous temperatures (JB) during deep hypothermic circulatory arrest and normothermic bypass with Nasopharyngeal (NP), Arterial inflow (AI), Oesophageal (O), Venous return (VR), Bladder (B) and Orbital skin (OS) temperatures. 18 patients undergoing deep hypothermia (DH) and 8 patients undergoing normothermic bypass (mean bladder Tdegrees-36.29 degreesC) were studied. For DH, cooling was continued to 15 degreesC NP (mean cooling time-66 min). At pre-determined arterial inflow Tdegrees, NP, JB and O Tdegree's were measured. A 6-channel recorder continuously recorded all Tdegree's using calibrated thermocouples. During the cooling phase of DH, NP lagged behind AI and JB Tdegree's. All these equilibrated at 15 degreesC. During rewarming, JB and NP lagged behind AI and JB was higher than NP at any time point. During normothermic bypass, although NP was reflective of the AI and JB Tdegrees trends, it underestimated peak JB Tdegrees (P=0.001). Towards the end of bypass, peak JB was greater than the arterial inflow Tdegrees (P=0.023). If brain venous outflow Tdegrees (JB) accurately reflects brain Tdegrees, NP Tdegrees is a safe surrogate indicator of cooling. During rewarming, all peripheral sites underestimate brain temperature and caution is required to avoid hyperthermic arterial inflow, which may inadvertently, result in brain hyperthermia.
Mansilha, Armando; Sousa, Joel
2018-06-05
Chronic venous disease (CVD) is a common pathology, with significant physical and psychological impacts for patients and high economic costs for national healthcare systems. Throughout the last decades, several risk factors for this condition have been identified, but only recently, have the roles of inflammation and endothelial dysfunction been properly assessed. Although still incompletely understood, current knowledge of the pathophysiological mechanisms of CVD reveals several potential targets and strategies for therapeutic intervention, some of which are addressable by currently available venoactive drugs. The roles of these drugs in the clinical improvement of venous tone and contractility, reduction of edema and inflammation, as well as in improved microcirculation and venous ulcer healing have been studied extensively, with favorable results reported in the literature. Here, we aim to review these pathophysiological mechanisms and their implications regarding currently available venoactive drug therapies.
Shigemi, Kenji
2016-05-01
To maintain proper cardiac preload is one of the most effective procedures for the systemic circulation remaining stable. In particular, the balance between vascular capacity and total blood volume must be maintained within appropriate range by the administration of fluids, blood and/or vasoactive drugs with mean circulatory filling pressure (Pmcf), central venous pressure (CVP) or stroke volume variation (SVV). End-diastolic left ventricular volume (Ved) is theoretically the best index of cardiac preload; however, without transesophageal echocardbalanceiogram we cannot directly monitor Ved during anesthesia. The infused fluid volume remaining in intravascular space, the vascular capacity controlled by autonomic nervous system and/or vasoactive agents, and the unstressed blood volume properly mobilized to excess blood volume are the crucial factors to maintain cardiac output The knowledge of vascular physiology contribute the decision making to manipulate such factors to control blood circulation during general anesthesia. For example, CVP is usually maintained in the narrow range and seems to be stable; however, it must be changed just after the circulatory disturbances, such as acute bleeding, blood transfusion, and fluid infusion, and followed by gradual returning to initial value, because of the solid mechanism to preserve cardiac output
A new venous infusion path monitoring system utilizing electrostatic induced potential.
Ogawa, Hidekuni; Yonezawa, Yoshiharu; Maki, Hiromichi; Caldwell, W Morton
2008-01-01
A new venous infusion pathway monitoring system has been developed for hospital and home use. The system consists of linear and digital integrated circuits and a low-power 8-bit single chip microcomputer which constantly monitors the infusion pathway intactness. A 330 kHz AC voltage, which is induced on the patient's body by electrostatic coupling from a 330 kHz pulse oscillator, can be recorded by main and reference electrodes wrapped around the infusion polyvinyl chloride tube. If the injection needle or infusion tube becomes detached, then the system detects changes in the induced AC voltages and alerts the nursing station, via the nurse call system or PHS (personal handy phone system).
Eldeen, F Z; Lee, C-F; Lee, C-S; Chan, K-M; Lee, W-C
2013-03-01
The modified piggyback technique with side-to-side cavocavostomy decreases the risk of outflow obstruction compared with the standard piggyback method. However, this modification is not ideal for recipients who receive a graft that is voluminous or bears an enlarged caudate lobe. We modified the inferior vena cava (IVC) preservation technique against deleterious complications of compression by using a passing loop. A 49-year-old woman, who underwent orthotopic liver transplantation for hepatic failure, was allocated a large-size liver. In anticipation of serious caval compression due to the voluminous grafts, we kept the suprahepatic or infrahepatic donor caval cuffs open for an anastomosis. The first anastomosis was performed between suprahepatic donor IVC cuff and recipient middle-left hepatic vein common channel; the second anastomosis was a terminolateral cavocavostomy between infrahepatic donor IVC cuff and the anterior wall of the recipient's IVC. When the liver circulation was restored, the donor retrohepatic vena cava served as a passing loop for both hepatic venous outflow and infra-diaphragmatic venous return to bypass possible IVC compression. Our technique may solve a dilemna for patients receiving voluminous liver grafts. Copyright © 2013 Elsevier Inc. All rights reserved.
Ogilvie, R I; Zborowska-Sluis, D
1991-10-01
To determine whether changes in vascular capacitance induced by nitroglycerin (NTG) and nitroprusside were due to changes in compliance or unstressed vascular volume, doses producing similar reductions in arterial pressure (Psa) were studied on separate days in six dogs anesthetized and ventilated with pentobarbital after splenectomy during ganglion blockade with hexamethonium. Mean circulatory filling pressure (Pmcf) was determined during transient circulatory arrest induced by acetylcholine at baseline blood volumes and after increases of 5 and 10 ml/kg. Central blood volumes (CBVs, pulmonary artery to aortic root) were determined from transit times, and separately measured cardiac output (CO) was estimated by thermodilution (right atrium to pulmonary artery). NTG and nitroprusside produced similar reductions in Psa and Pmcf without significantly altering right atrial pressure (Pra), pressure gradient for venous return, or CO. Total vascular compliance was not altered, but total vascular capacitance was increased on an average of 4.0 +/- 1.4 ml/kg after NTG and 3.0 +/- 1.3 ml/kg after nitroprusside by increases in unstressed volume. Both drugs caused a variable reduction in CBV, averaging 2 ml/kg. Thus, both drugs produced a large increase in peripheral venous capacitance by increasing unstressed vascular volume without altering total vascular compliance.
Control of ventilation during intravenous CO2 loading in the awake dog.
Stremel, R W; Huntsman, D J; Casaburi, R; Whipp, B J; Wasserman, K
1978-02-01
The ventilatory response to venous CO2 loading and its effect on arterial CO2 tension was determined in five awake dogs. Blood, 200-500 ml/min, was diverted from a catheter in the right common carotid artery through a membrane gas exchanger and returned to the right jugular vein. CO2 loading was accomplished by changing the gas ventilating the gas exchanger from a mixture of 5% CO2 in air to 100% CO2. The ventilatory responses to this procedure were compared with those resulting from increased inspired CO2 concentrations (during which ventilation of the gas exchanger with the air and 5% CO2 mixture continued). The ventilatory response to each form of CO2 loading was computed as deltaVE/deltaPaco9. The mean ventilatory response to airway CO2 loading was 1.61 1/min per Torr PaCO2. The mean response for the venous CO2 loading was significantly higher and not significantly different from "infinite" CO2 sensitivity (i.e., isocapnic response). The results provide further evidence for a CO2-linked hyperpnea, not mediated by significant changes in mean arterial PCO2.
New treatment of vertigo caused by jugular bulb abnormalities.
Hitier, Martin; Barbier, Charlotte; Marie-Aude, Thenint; Moreau, Sylvain; Courtheoux, Patrick; Patron, Vincent
2014-08-01
Jugular bulb abnormalities can induce tinnitus, hearing loss, or vertigo. Vertigo can be very disabling and may need surgical treatments with risk of hearing loss, major bleeding or facial palsy. Hence, we have developed a new treatment for vertigo caused by jugular bulb anomalies, using an endovascular technique. Three patients presented with severe vertigos mostly induced by high venous pressure. One patient showed downbeat vertical nystagmus during the Valsalva maneuver. The temporal-bone computed tomography scan showed a high rising jugular bulb or a jugular bulb diverticulum with dehiscence and compression of the vestibular aqueduct in all cases. We plugged the upper part of the bulb with coils, and we used a stent to maintain the coils and preserving the venous permeability. After 12- to 24-month follow-up, those patients experienced no more vertigo, allowing return to work. The 3-month arteriographs showed good permeability of the sigmoid sinus and jugular bulb through the stent, with complete obstruction of the upper part of the bulb in all cases. Disabling vertigo induced by jugular bulb abnormalities can be effectively treated by an endovascular technique. This technique is minimally invasive with a probable greater benefit/risk ratio compare with surgery. © The Author(s) 2013.
Dabiri, Ganary; Hammerman, Scott; Falanga, Vincent
2014-01-01
Venous leg ulcers affect millions of patients worldwide and are a tremendous financial burden on our healthcare system. The hallmark of venous disease of the lower extremities is venous hypertension, and compression is the current mainstay of treatment. However, many patients are noncompliant, in part because of the complexity of the dressings and the difficulties with application and removal. The aim of our study was to determine an effective compression dressing regimen for patients with venous leg ulcers who require changing the ulcer primary dressing twice daily. We used two layers of a latex free tubular elastic bandage for compression. The primary endpoint of our study was increased wound healing rate and our secondary endpoint was complete wound closure. All active study subjects had positive healing rates at week 4 and week 8. Two subjects achieved complete wound closure by week 8. We conclude that compression with a latex-free tubular elastic bandage can be safely used in patients with venous leg ulcers requiring frequent dressing changes. This type of compression allows for daily inspection of wounds, dressing changes at home, flexibility in the context of clinical trials, and is a compromise for patients that are intolerant to compression dressings. PMID:24267477
Role of Catheter-directed Thrombolysis in Management of Iliofemoral Deep Venous Thrombosis.
Chen, James X; Sudheendra, Deepak; Stavropoulos, S William; Nadolski, Gregory J
2016-01-01
The treatment for iliofemoral deep venous thrombosis (DVT) is challenging, as the use of anticoagulation alone can be insufficient for restoring venous patency and thus lead to prolongation of acute symptoms and an increased risk of chronic complications, including venous insufficiency and postthrombotic syndrome (PTS). In these cases, earlier and more complete thrombus removal can ameliorate acute symptoms and reduce long-term sequelae. Endovascular therapies involving the use of pharmacologic, mechanical, and combined pharmacomechanical modalities have been developed to achieve these goals. The most frequently used of these techniques, catheter-directed thrombolysis (CDT), involves the infusion of a thrombolytic agent through a multiple-side-hole catheter placed within the thrombosed vein to achieve high local doses and thereby break down the clot while minimizing systemic thrombolytic agent exposure. Randomized controlled trial results have indicated decreased PTS rates and improved venous patency rates in patients treated with CDT compared with these rates in patients treated with anticoagulation. The use of newer pharmacomechanical techniques, as compared with conventional CDT, reduces procedural times and thrombolytic agent doses and is the subject of ongoing investigations. Endovascular thrombus removal techniques offer a means to improve venous valvular function and decrease the risk of debilitating long-term complications such as PTS and are a promising option for treating patients with iliofemoral DVT. (©)RSNA, 2016.
Ventilatory control in a primitive fish: signal conditioning via non-linear O2 affinity.
Katz, S L
1996-02-01
Gas exchange in the gills of the air-breathing fish Amia calva was modelled to determine how the gills modify fluctuations in venous P O2. These fluctuations form the physiological signal for aerial ventilation in these fish. This study was performed to examine the signal conditioning role that the gills may play in the control system that regulates P O2. The model incorporated a non-linear Hb-O2 affinity relationship. Fluctuations in venous P O2 were modelled as sinusoids, covering a range of frequencies and amplitudes. Mean venous P O2 ranged from normoxic to hypoxic values. Over a broad range of parameters the gills amplify fluctuations in venous P O2 during transit to the arterial side. It was also observed that aquatic hypoxia reduces the effectiveness of the gills in maximizing arterial P O2, while increases in venous P O2 increase the effectiveness of the gills in the face of similar blood-water P O2 gradients. Each of these performance features is a consequence of the sigmoid Hb-O2 affinity relationship.
Systemic Venous Inflow to the Liver Allograft to Overcome Diffuse Splanchnic Venous Thrombosis
Darius, Tom; Goffette, Pierre; Lerut, Jan
2015-01-01
Diffuse splanchnic venous thrombosis (DSVT), formerly defined as contraindication for liver transplantation (LT), is a serious challenge to the liver transplant surgeon. Portal vein arterialisation, cavoportal hemitransposition and renoportal anastomosis, and finally combined liver and small bowel transplantation are all possible alternatives to deal with this condition. Five patients with preoperatively confirmed extensive splanchnic venous thrombosis were transplanted using cavoportal hemitransposition (4x) and renoportal anastomosis (1x). Median follow-up was 58 months (range: 0,5 to 130 months). Two patients with previous radiation-induced peritoneal injury died, respectively, 18 days and 2 months after transplantation. The three other patients had excellent long-term survival, despite the fact that two of them needed a surgical reintervention for severe gastrointestinal bleeding. Extensive splanchnic venous thrombosis is no longer an absolute contraindication to liver transplantation. Although cavoportal hemitransposition and renoportal anastomosis undoubtedly are life-saving procedures allowing for ensuring adequate allograft portal flow, careful follow-up of these patients remains necessary as both methods are unable to completely eliminate the complications of (segmental) portal hypertension. PMID:26539214
Gianfaldoni, S; Wollina, U; Lotti, J; Gianfaldoni, R; Lotti, T; Fioranelli, M; Roccia, M G
To retrieve the history of venous ulcers and of skin lesions in general, we must go back to the appearance of human beings on earth. It is interesting to note that cutaneous injuries evolved parallel to human society. An essential first step in the pathogenesis of ulcers was represented by the transition of the quadruped man to Homo Erectus. This condition was characterized by a greater gravitational pressure on the lower limbs, with consequences on the peripheral venous system. Furthermore, human evolution was characterized by an increased risk of traumatic injuries, secondary to his natural need to create fire and hunt (e.g. stones, iron, fire, animal fighting). Humans then began to fight one another until they came to real wars, with increased frequency of wounds and infectious complications. The situation degraded with the introduction of horse riding, introduced by the Scites, who first tamed animals in the 7th century BC. This condition exhibited iliac veins at compression phenomena, favouring the venous stasis. With time, man continued to evolve until the modern age, which is characterized by increased risk factors for venous wounds such as poor physical activity and dietary errors (1, 2).
Ethanol-Gel Sclerotherapy of Venous Malformations: Effectiveness and Safety.
Teusch, Veronika I; Wohlgemuth, Walter A; Hammer, Simone; Piehler, Armin P; Müller-Wille, René; Goessmann, Holger; Uller, Wibke
2017-12-01
In the treatment of venous malformations, ethanol may be administered in a gelified form to increase local effects and reduce systemic ones. The purpose of this prospective study was to evaluate the efficacy and safety of a commercially available viscous ethanol gel in the treatment of venous malformations. Thirty-one patients (mean age, 23.4 years; age range, 6.6-46.5 years) with venous malformations were prospectively scheduled for two ethanol-gel sclerotherapy sessions. Venous malformations were located at the lower extremity (n = 18), the upper extremity (n = 9), and the face (n = 4). Questionnaires to assess pain, clinical examinations, professional photographs, and contrast-enhanced MRI of the venous malformations were performed before and after therapy to measure therapy-induced changes. Two experienced radiologists blinded to the examination date and clinical status compared photographs and MR images before and after treatment. A mean of 4.2 mL of ethanol gel were administered per session. The technical success rate was 100%. Clinical success, defined as improvement or resolution of symptoms, was noted in 81% of patients. Mean pain score decreased, and the difference was statistically significant (3.9 vs 3.1, p = 0.005). In 54 treatment sessions where follow-up was available, four minor complications occurred. Comparison of photographs and MR images before and after treatment showed improvement in 35% and 93% of patients, respectively. Ethanol gel is an effective and safe sclerosing agent in the treatment of venous malformations.
Development and testing of an artificial arterial and venous pulse oximeter.
Cloete, G; Fourie, P R; Scheffer, C
2013-01-01
The monitoring of patients healthcare is of a prime importance to ensure their efficient and effective treatment. Monitoring blood oxygen saturation is a field which has grown significantly in recent times and more specifically in tissues affected by diseases or conditions that may negatively affect the function of the tissue. This study involved the development and testing of a highly sensitive non-invasive blood oxygen saturation monitoring device. A device that can be used to continuously monitor the condition of tissue affected by diseases which affect the blood flow through the tissue, and the oxygen usage in tissue. The device's system was designed to specifically monitor occluded tissue which has low oxygen saturations and low perfusion. Although with limitted validation the system was unable to accurately measure the venous oxygenation specifically, but it was able to measure the mixed oxygen saturation. With further research it would be possible to validate the system for measuring both the arterial and venous oxygen saturations.
Cardiovascular Deconditioning and Venous Air Embolism in Simulated Microgravity in the Rat
NASA Technical Reports Server (NTRS)
Robinson, R. R.; Doursout, M.-F.; Chelly, J. E.; Powell, M. R.; Little, T. M.; Butler,B. D.
1996-01-01
Astronauts conducting extravehicular activities undergo decompression to a lower ambient pressure, potentially resulting in gas bubble formation within the tissues and venous circulation. Additionally, exposure to microgravity produces fluid shifts within the body leading to cardiovascular deconditioning. A lower incidence of decompression illness in actual spaceflight compared with that in ground-based altitude chamber flights suggests that there is a possible interaction between microgravity exposure and decompression illness. The purpose of this study was to evaluate the cardiovascular and pulmonary effects of simulated hypobaric decompression stress using a tail suspension (head-down tilt) model of microgravity to produce the fluid shifts associated with weightlessness in conscious, chronically instrumented rats. Venous bubble formation resulting from altitude decompression illness was simulated by a 3-h intravenous air infusion. Cardiovascular deconditioning was simulated by 96 h of head-down tilt. Heart rate, mean arterial blood pressure, central venous pressure, left ventricular wall thickening and cardiac output were continuously recorded. Lung studies were performed to evaluate edema formation and compliance measurement. Blood and pleural fluid were examined for changes in white cell counts and protein concentration. Our data demonstrated that in tail-suspended rats subjected to venous air infusions, there was a reduction in pulmonary edema formation and less of a decrease in cardiac output than occurred following venous air infusion alone. Mean arterial blood pressure and myocardial wall thickening fractions were unchanged with either tail-suspension or venous air infusion. Heart rate decreased in both conditions while systemic vascular resistance increased. These differences may be due in part to a change or redistribution of pulmonary blood flow or to a diminished cellular response to the microvascular insult of the venous air embolization.
[Effects of lidocaine on arterial and venous circulation of limbs in man].
Edouard, A; Probst, D; Duranteau, J; Tarot, J P; Pussard, E
1991-01-01
The effects of intravenous lidocaine on limb arteries and veins were investigated in a placebo-controlled study. Seven young healthy volunteers, 23 to 28-years-old, were included. Electrocardiogram, arterial pressure and arm and leg blood flows were recorded continuously. Systolic and diastolic blood pressures were measured in the left arm by finger photoplethysmography. Limb blood flow and the limb venous system were studied by venous occlusive plethysmography. The venous parameters studied were venous tone, lowest closing pressure, venous volume at 30 mmHg, and venous distensibility. After an initial bolus of 1.5 mg.kg-1 lidocaine had been given, 30, and then 60, micrograms.kg-1.min-1 were given for one hour each. Plasma noradrenaline and serum lidocaine titres were measured before giving the lidocaine, and at the end of each one hour period. Placebo consisted in a two hour infusion of 0.25 ml.min-1 normal saline. Lidocaine titres were 1.64 +/- 0.40 microgram.ml-1 after one hour, and 2.55 +/- 0.69 microgram.ml-1 after two hours. Lidocaine increased vascular resistances in both the forearm (+81% to +93%) and the calf (+38% to +57%). There was a concomitant increase in mean arterial blood pressure (+21% to +28%) without any change in heart rate. There was a significant dose-dependent increase in plasma noradrenaline levels during the second period of the lidocaine infusion with respect to the preinfusion period and the same period during the placebo infusion. Venous capacitance measured before any infusion had been started was greater in the leg than in the arm.(ABSTRACT TRUNCATED AT 250 WORDS)
Mid-term outcome of endovascular treatment for acute lower extremity deep venous thrombosis.
Jiang, Kun; Li, Xiao-Qiang; Sang, Hong-Fei; Qian, Ai-Min; Rong, Jian-Jie; Li, Cheng-Long
2017-04-01
Purposes of the study To evaluate the benefit of stenting the iliac vein in patients with residual iliac vein stenosis treated with catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis. Procedures In this randomized prospective study, patients with a first-time acute lower extremity deep venous thrombosis that had persisted <14 days were treated with catheter-directed thrombolysis. After catheter-directed thrombolysis, patients with >50% residual iliac vein stenosis were randomly divided into two groups: catheter-directed thrombolysis + Stent Group and catheter-directed thrombolysis Alone Group. Patients received urokinase thrombolysis and low-molecular-weight heparin/oral warfarin during the hospitalization period and were administrated oral warfarin after discharge. Cumulative deep vein patency, the Clinical Etiology Anatomic Pathophysiologic classification system, the Venous Clinical Severity Score and the Chronic Venous Insufficiency Questionnaire score were evaluated. Findings The cumulative deep vein patency rate was 74.07% in the catheter-directed thrombolysis + Stent Group and 46.59% in the catheter-directed thrombolysis Alone Group. The mean postoperative Clinical Etiology Anatomic Pathophysiologic classification and Venous Clinical Severity Score was significantly lower in the catheter-directed thrombolysis + Stent Group than in the catheter-directed thrombolysis Alone Group. The mean postoperative Chronic Venous Insufficiency Questionnaire score was significantly higher in the catheter-directed thrombolysis + Stent Group than the catheter-directed thrombolysis Alone Group. Conclusions Placement of an iliac vein stent in patients with residual iliac vein stenosis after catheter-directed thrombolysis for acute lower extremity deep venous thrombosis increases iliac vein patency and improves clinical symptoms and health-related quality of life at mid-term follow-up compared to patients treated with catheter-directed thrombolysis alone.
Dickmann, Boris; Ahlbrecht, Jonas; Ay, Cihan; Dunkler, Daniela; Thaler, Johannes; Scheithauer, Werner; Quehenberger, Peter; Zielinski, Christoph; Pabinger, Ingrid
2013-01-01
Advanced cancer is a risk factor for venous thromboembolism. However, lymph node metastases are usually not considered an established risk factor. In the framework of the prospective, observational Vienna Cancer and Thrombosis Study we investigated the association between local (N0), regional (N1–3), and distant (M1) cancer stages and the occurrence of venous thromboembolism. Furthermore, we were specifically interested in the relationship between stage and biomarkers that have been reported to be associated with venous thromboembolism. We followed 832 patients with solid tumors for a median of 527 days. The study end-point was symptomatic venous thromboembolism. At study inclusion, 241 patients had local, 138 regional, and 453 distant stage cancer. The cumulative probability of venous thromboembolism after 6 months in patients with local, regional and distant stage cancer was 2.1%, 6.5% and 6.0%, respectively (P=0.002). Compared to patients with local stage disease, patients with regional and distant stage disease had a significantly higher risk of venous thromboembolism in multivariable Cox-regression analysis including age, newly diagnosed cancer (versus progression of disease), surgery, radiotherapy, and chemotherapy (regional: HR=3.7, 95% CI: 1.5–9.6; distant: HR=5.4, 95% CI: 2.3–12.9). Furthermore, patients with regional or distant stage disease had significantly higher levels of D-dimer, factor VIII, and platelets, and lower hemoglobin levels than those with local stage disease. These results demonstrate an increased risk of venous thromboembolism in patients with regional disease. Elevated levels of predictive biomarkers in patients with regional disease underpin the results and are in line with the activation of the hemostatic system in the early phase of metastatic dissemination. PMID:23585523
Bermo, Mohammed; Matesan, Manuela C; Itani, Malak; Behnia, Fatemeh; Vesselle, Hubert J
2018-04-09
The purpose of the study was to correlate lung shunt fraction (LSF) calculated by intra-arterial injection of Technetium-99m (Tc-99m)-labeled macroaggregated albumin (MAA) in a hepatic artery branch with the presence of certain patterns of vascular shunts on dynamic CT or MRI of the liver. This retrospective study was approved by the institutional review board and informed consent was waived. We reviewed 523 MAA scans in 453 patients (301 men, 152 women) performed from July 2007 to June 2015 and their correlative cross-sectional imaging. Patterns of vascular shunts on dynamic CT or MRI performed within 3 months of the MAA study and that potentially divert hepatic arterial inflow to the systemic venous return were defined as "target shunts." Dynamic CT or MRI was classified into three groups with target shunt present, absent, or indeterminate. The mean LSF was compared across the first and second groups using paired t test. 342 CT and MRI studies met inclusion criteria: target shunts were present in 63 studies, absent in 271 studies, and 8 studies were indeterminate. When target shunts were visualized, the mean LSF on corresponding MAA scans was 12.9 ± 10.36% (95% CI 10.29-15.15%) compared to 4.3 ± 3.17% (95% CI 3.93-4.68%) when no target shunt was visualized. The difference was statistically significant (p value < 0.001). Identified target shunts were either direct (arteriohepatic venous shunt) or indirect (arterioportal shunt combined with a portosystemic shunt). Visualizing certain patterns of vascular shunting on a dynamic CT or MRI scan is associated with high LSF.
Formation of edema and fluid shifts during a long-haul flight.
Mittermayr, Markus; Fries, Dietmar; Innerhofer, Petra; Schobersberger, Beatrix; Klingler, Anton; Partsch, Hugo; Fischbach, Uwe; Gunga, Hanns-Christian; Koralewski, Eberhard; Kirsch, Karl; Schobersberger, Wolfgang
2003-01-01
More than 1.5 billion passengers travel by aircraft every year. Leg edema, as a sign of venous stasis, is a well-known problem among passengers during and after long-haul flights. Until now, no studies have been done on the development of leg edema and fluid shifts under real flight conditions. The aim of our study was to evaluate edema formation in the leg and to investigate possible fluid shifts to the interstitial space under real flight conditions. Twenty participants, 10 without risk and 10 with moderate risk for venous thrombosis, were selected. They flew from Vienna to Washington, flight time 9 h, and returned 2 days later. Investigations were done 48 h before the flight, between the fifth and eighth flight hour on board to Washington and back to Vienna, immediately after arrival in Vienna, and 1 and 3 days after arrival. Plethysmographic measurements were carried out using an optoelectronic scanner system (Perometer). Thickness of the skin was measured at the forehead and in front of the tibia. There were no differences in all measurements between both groups. The volume of the leg increased from 8242 +/- 1420 mL to 8496 +/- 1474 mL after the flight (p <.001). Volume accumulation was distributed to the lower leg as well as to the thigh. Skin thickness in front of the tibia increased significantly during the flight (p <.05), and remained elevated 1 day after arrival. We have demonstrated that long-haul flights induce significant fluid accumulation in the lower extremity, involving the lower leg and thigh. This increase in tissue thickness was maintained for some days after the flights.
Licker, Marc; Ellenberger, Christoph; Sierra, Jorge; Christenson, Jan; Diaper, John; Morel, Denis
2005-03-01
Preoperative acute normovolemic hemodilution induces an increase in circulatory output that is thought to be limited in patients with cardiac diseases. Using multiple-plane transesophageal echocardiography, we investigated the mechanisms of cardiovascular adaptation during acute normovolemic hemodilution in patients with severe coronary artery disease. Prospective case-control study. Operating theater in a university hospital. Consecutive patients treated with beta-blockers, scheduled to undergo coronary artery bypass (n = 50). After anesthesia induction, blood withdrawal and isovolemic exchange with iso-oncotic starch (1:1.15 ratio) to achieve a hematocrit value of 28%. In addition to heart rate and intravascular pressures, echocardiographic recordings were obtained before and after acute normovolemic hemodilution to assess cardiac preload, afterload, and contractility. In a control group, not subjected to acute normovolemic hemodilution, hemodynamic variables remained stable during a 20-min anesthesia period. Following acute normovolemic hemodilution, increases in cardiac stroke volume (+28 +/- 4%; mean +/- sd) were correlated with increases in central venous pressure (+2.0 +/- 1.3 mm Hg; R = .56) and in left ventricular end-diastolic area (+18 +/- 5%, R = .39). The unchanged left ventricular end-systolic wall stress and preload-adjusted maximal power indicated that neither left ventricular afterload nor contractility was affected by acute normovolemic hemodilution. Diastolic left ventricular filling abnormalities (15 of 22 cases) improved in 11 patients and were stable in the remaining four patients. Despite reduction in systemic oxygen delivery (-20.5 +/- 7%, p < .05), there was no evidence for myocardial ischemia (electrocardiogram, left ventricular wall motion abnormalities). In anesthetized patients with coronary artery disease, moderate acute normovolemic hemodilution did not compromise left ventricular systolic and diastolic function. Lowering blood viscosity resulted in increased stroke volume that was mainly related to increased venous return and higher cardiac preload.
Gatzoulis, M A; Shinebourne, E A; Redington, A N; Rigby, M L; Ho, S Y; Shore, D F
1995-02-01
To show that abnormal systemic venous channels in patients who undergo cavopulmonary anastomoses can become manifest and haemodynamically important only after surgery despite detailed preoperative investigation. Descriptive study of patients fulfilling the above criteria selected from hospital records over the past three years. A tertiary referral centre. Of the three cases identified, two were isomeric, one with left atrial isomerism and hemiazygos continuation of the inferior vena cava who underwent bilateral bidirectional Glenn anastomoses and one with right isomerism who underwent total cavopulmonary anastomosis. Case 3 had absent left atrioventricular connection with a hypoplastic left lung and underwent a classic right Glenn procedure. All three cases presented with progressive cyanosis in the early postoperative period. Postoperative angiography in case 1 showed a remnant of a left inferior vena cava draining to the atrium to have become grossly dilated causing cyanosis, which resolved after redirection of this vessel and of the hepatic veins into the right pulmonary artery with an intra-atrial baffle. Cyanosis in case 2 was caused by intra-hepatic shunting to a hepatic vein draining to the left of the intra-atrial baffle. The diagnosis was made at necropsy, being overlooked on postoperative angiography. Repeat angiography in case 3 showed progressive dilatation of a small left superior vena cava to coronary sinus. Test occlusion with a view to embolisation revealed hitherto an undemonstrated hemiazygos continuation of inferior caval to brachiocephalic vein. The patient underwent surgical ligation of these two venous channels. Despite appropriate investigation some "abnormal" venous pathways manifest themselves, dilate, and become haemodynamically important only after surgical cavopulmonary anastomoses. In the presence of early postoperative cyanosis "new" systemic venous collateral channels should be considered as a possible cause, which may require reintervention.
Lee, Jong-Myung; Jung, Shin; Moon, Kyung-Sub; Seo, Jeong-Jin; Kim, In-Young; Jung, Tae-Young; Lee, Jung-Kil; Kang, Sam-Suk
2005-08-01
Recent developments in magnetic resonance (MR) technology now enable the use of MR venography, providing 3-dimensional (3D) images of intracranial venous structures. The purpose of this study was to assess the usefulness of 3D contrast-enhanced MR venography (CE MRV) in the evaluation of intracranial venous system for surgical planning of brain tumors. Forty patients underwent 3D CE MRV, as well as 25 patients, 2-dimensional (2D) time-of-flight (TOF) MR venography in axial and sagittal planes; and 10 patients, digital subtraction angiography. We determined the number of visualized sinuses and cortical veins. Degree of visualization of the intracranial venous system on 3D CE MRV was compared with that of 2D TOF MR venography and digital subtraction angiography as a standard. We also assessed the value of 3D CE MRV in the investigation of sinus occlusion or localization of cortical draining veins preoperatively. Superficial cortical veins and the dural sinus were better visualized on 3D CE MRV than on 2D TOF MR venography. Both MR venographic techniques visualized superior sagittal sinus, lateral sinus, sigmoid sinus, straight sinus, and internal cerebral vein and provided more detailed information by showing obstructed sinuses in brain tumors. Only 3D CE MRV showed superficial cortical draining veins. However, it was difficult to accurately evaluate the presence of cortical collateral venous drainage. Although we do not yet advocate MR venography to replace conventional angiography as the imaging standard for brain tumors, 3D CE MRV can be regarded as a valuable diagnostic method just in evaluating the status of major sinuses and localization of the cortical draining veins.
Infection in Venous Leg Ulcers: Considerations for Optimal Management in the Elderly.
Pugliese, Douglas J
2016-02-01
Venous leg ulcers are the most common cause of chronic leg wounds, accounting for up to 70 % of all chronic leg ulcers and carrying with them a significant morbidity, especially for elderly patients. Among people aged 65 years and older, the annual prevalence is 1.7 %. Billions of dollars per year are spent caring for patients with these often difficult-to-heal and sometimes recurrent chronic wounds. Chronic non-healing wounds of the lower extremities are susceptible to microbial invasion and can lead to serious complications, such as delayed healing, cellulitis, enlargement of wound size, debilitating pain, and deeper wound infections causing systemic illness. Recognition and treatment of the infected venous leg ulcer is an essential skill set for any physician caring for geriatric patients. Most physicians rely on subjective clinical signs and patient-reported symptoms in the evaluation of infected chronic wounds. The conventional bacterial culture is a widely available tool for the diagnosis of bacterial infection but can have limitations. Systemic antibiotics, as well as topical antiseptics and antibiotics, can be employed to treat and control infection and critical colonization. Better understanding of microbial biofilms in the wound environment have caused them to emerge as an important reason for non-healing and infection due to their increased resistance to antimicrobial, immunological, and chemical attack. A sound understanding of the microbial-host environment and its complexities, as well as the pathophysiology of venous hypertension, must be appreciated to understand the need for a multimodality approach to treating an infected venous leg ulcer. Other treatment measures are often required, in addition to systemic and topical antibiotics, such as the application of wound bandages, compression therapy, and wound debridement, which can hasten clearance of the infection and help to promote healing.
Abnormalities of the umbilico-portal venous system in Down syndrome: a report of two new patients.
Pipitone, Salvatore; Garofalo, Caterina; Corsello, Giovanni; Mongiovì, Maurizio; Piccione, Maria; Maresi, Emiliano; Sperandeo, Velio
2003-08-01
Congenital anomalies of the umbilical and portal venous system are rare vascular malformations which are often associated with anomalies of the heart and gastrointestinal tract. Association with chromosomal disorders has been sporadically reported. We now report on two patients with trisomy 21 and congenital anomalies of the umbilico-portal system. A male fetus showed absence of the intrahepatic portal vein (PV) and ductus venosus with a direct communication between portal sinus and inferior vena cava exhibiting an umbilicosystemic total shunt during the fetal life and a portosystemic total shunt after birth. A female infant showed absence of the intrahepatic PV and a total portocaval shunt. Both patients also had heart defects. As previously documented in other reports, our cases demonstrated that this association may be causally-related to the chromosomal aberration. In addition, the umbilico-portal venous system abnormalities seems to be the most frequent congenital vascular malformation in Down syndrome. A presumptive pathogenetic mechanism could be a trisomy 21-related altered angiogenesis of the vitelloumbilical plexus. Copyright 2003 Wiley-Liss, Inc.
Massive Air Embolism in a Fontan Patient
Matte, Gregory S.; Kussman, Barry D.; Wagner, Joseph W.; Boyle, Sharon L.; Howe, Robert J.; Pigula, Frank A.; Emani, Sitaram M.
2011-01-01
Abstract: Most institutions performing cardiopulmonary bypass for congenital heart disease patients use an integrated hard shell cardiotomy and venous reservoir attached to an oxygenator. It is of paramount importance that the integrated reservoir be vented so as not to cause pressurization. A pressurized sealed cardiotomy has been reported to occur secondary to issues with vacuum assisted venous drainage systems as well as improper venting in general. We report a case of air embolus caused by retrograde propulsion of air through the venous line secondary to a pressurized cardiotomy reservoir in a patient with Fontan circulation. The mechanism of cardiotomy pressurization is described, and the scenario simulated in a mock circuit. PMID:21848177
Massive air embolism in a Fontan patient.
Matte, Gregory S; Kussman, Barry D; Wagner, Joseph W; Boyle, Sharon L; Howe, Robert J; Pigula, Frank A; Emani, Sitaram M
2011-06-01
Most institutions performing cardiopulmonary bypass for congenital heart disease patients use an integrated hard shell cardiotomy and venous reservoir attached to an oxygenator. It is of paramount importance that the integrated reservoir be vented so as not to cause pressurization. A pressurized sealed cardiotomy has been reported to occur secondary to issues with vacuum assisted venous drainage systems as well as improper venting in general. We report a case of air embolus caused by retrograde propulsion of air through the venous line secondary to a pressurized cardiotomy reservoir in a patient with Fontan circulation. The mechanism of cardiotomy pressurization is described, and the scenario simulated in a mock circuit.
Flanigan, Robert C; Polcari, Anthony J; Shore, Neil D; Price, Thomas H; Sims, Robert B; Maher, Johnathan C; Whitmore, James B; Corman, John M
2013-02-01
Sipuleucel-T is an autologous cellular immunotherapy. We review the safety of the leukapheresis procedure required for sipuleucel-T preparation and complications related to venous catheter use in the randomized, placebo controlled phase 3 IMPACT (IMmunotherapy for ProstAte Cancer Trial) study (NCT 00065442). A total of 512 patients with asymptomatic or minimally symptomatic metastatic castrate resistant prostate cancer were enrolled in the study. All patients were scheduled to undergo 3 standard 1.5 to 2.0 blood volume leukapheresis procedures at 2-week intervals. Leukapheresis related adverse events and those related to venous catheter use were reviewed. Immune cell counts were examined throughout the treatment course. Of 512 enrolled patients 506 underwent 1 or more leukapheresis procedures and were included in this analysis. Adverse events were comparable between the sipuleucel-T and control arms. Leukapheresis related adverse events were primarily associated with transient hypocalcemia (39.3%). Most leukapheresis related adverse events (97%) were of mild/moderate intensity. Median white blood cell count and absolute monocyte and lymphocyte counts were stable and within normal ranges throughout the treatment course. Of all patients 23.3% had a central venous catheter placed primarily for leukapheresis. Patients with vs without a central venous catheter had a higher risk of infection potentially related to catheter use (11.9% vs 1.3%, p <0.0001) and a trend toward a higher incidence of venous vascular events potentially related to catheter use, excluding the central nervous system (5.9% vs 2.1%, p = 0.06). Adverse events related to leukapheresis are manageable and quickly reversible. The majority of patients can undergo leukapheresis without a central venous catheter. Central venous catheters are associated with an increased risk of infections and venous vascular events. Peripheral intravenous access should be used when feasible. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
[An update on the treatment of venous insufficiency in pregnancy].
Rodríguez-Nora, B; Álvarez-Silvares, E
Chronic venous insufficiency is a long-term pathological condition resulting from anatomical or functional alterations of the venous system. This leads to the appearance of symptoms and physical signs that affect a large part of the population and particularly pregnant women, due to the physiology of pregnancy. The few published studies on the use of pharmacological treatments of venous insufficiency in this group of the population, often makes the management of this condition difficult in routine clinical practice. A review is presented in this article, with all the latest updates in the treatment of this condition during pregnancy. There are numerous general, and some pharmacological, recommendations, that we can safely offer the pregnant patient. Copyright © 2017 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.
Young, Carlton J
2009-02-01
Controversy remains regarding the best methodology of handling exocrine pancreatic fluid and pancreatic venous effluent. Bladder drainage has given way to enteric drainage. However, is there an instance in which bladder drainage is preferable? Also, hyperinsulinemia, as a result of systemic venous drainage (SVD), is claimed to be proatherosclerotic, whereas portal venous drainage (PVD) is more physiologic and less atherosclerotic. Bladder drainage remains a viable method of exocrine pancreas drainage, but evidence is sparse that measuring urinary amylase has a substantial benefit in the early detection of acute rejection in all types of pancreas transplants. Currently, there is no incontrovertible evidence that systemic hyperinsulinemia is proatherosclerotic, whereas recent metabolic studies on SVD and PVD showed that there was no benefit to PVD. Given the advent of newer immunosuppressive agents and overall lower acute rejection rates, the perceived benefit of bladder drainage as a means to measure urinary amylase as an early marker of rejection has not been substantiated. However, there may be a selective role for bladder drainage in 'high risk' pancreases. Also, without a clear-cut metabolic benefit to PVD over SVD, it remains the surgeon's choice as to which method to use.
Reduction of oxidative stress by compression stockings in standing workers.
Flore, Roberto; Gerardino, Laura; Santoliquido, Angelo; Catananti, Cesare; Pola, Paolo; Tondi, Paolo
2007-08-01
Healthy workers who stand for prolonged periods show enhanced production of reactive oxygen species (ROS) in their systemic circulation. Oxidative stress is thought to be a risk factor for chronic venous insufficiency and other systemic diseases. To evaluate the effectiveness of compression stockings in the prevention of oxidative stress at work. ROS and venous pressure of the lower limbs were measured in 55 theatre nurses who stood in the operating theatre for >6 h, 23 industrial ironers who stood for up to 5 h during their shift and 65 outpatient department nurses and 35 laundry workers who acted as controls. Subjects and controls were examined on two consecutive days before and after work and with and without compression stockings. Without compression stockings, lower limb venous pressure increased significantly after work in all subjects and controls (P < 0.001), while only operating theatre nurses showed significantly higher mean levels of ROS (P < 0.001). There was no significant difference in venous pressures and ROS levels after work in subjects or controls when wearing compression stockings. Our data suggest a preventive role of compression stockings against oxidative stress in healthy workers with a standing occupation.
Koziorowski, M; Stefańczyk-Krzymowska, S; Tabecka-Lonczyńska, A; Gilun, P; Kamiński, M
2012-01-01
Circadian and seasonal rhythms in daylight affect many physiological processes. In the eye, energy of intense visible light not only initiates a well-studied neural reaction in the retina that modulates the secretory function of the hypothalamus and pineal gland, but also activates the heme oxygenase (HO) to produce carbon monoxide (CO). This study was designed to determine whether the concentration of carbon monoxide (CO) in the ophthalmic venous blood changes depending on the phase of the day and differing extremely light intensity seasons: summer and winter. The concentration of CO in the venous blood flowing out from the nasal cavity, where heme oxygenase (HO) is expressed, but no photoreceptors, was used as a control. Sixteen mature males of a wild boar and pig crossbreed were used for this study. Samples of ophthalmic and nasal venous blood and systemic arterial and venous blood were collected repeatedly for two consecutive days during the longest days of the summer and the shortest days of the winter. The concentrations of CO in blood samples was measured using a standard addition method. During the longest days of the summer the concentration of CO in ophthalmic venous blood averaged 3.32 ± 0.71 and 3.43 ± 0.8 nmol/ml in the morning and afternoon, respectively, and was significantly higher than in the night averaging 0.89 ± 0.12 nmol/ml (p<0.001). During the shortest day of the winter CO concentration in ophthalmic venous blood was 1.11 ± 0.10 and 1.13 ± 0.14 nmol/ml during the light and nocturnal phase, respectively, and did not differ between phases, but was lower than in the light phase of the summer (p<0.01). The CO concentration in the control nasal venous blood did not differ between seasons and day phases and was lower than in ophthalmic venous blood during the summer (p<0.01) and winter (p<0.05). The results indicate that the gaseous messenger carbon monoxide is released from the eye into the ophthalmic venous blood depending on the intensity of sunlight.
Lymphatic regulation in nonmammalian vertebrates.
Hedrick, Michael S; Hillman, Stanley S; Drewes, Robert C; Withers, Philip C
2013-08-01
All vertebrate animals share in common the production of lymph through net capillary filtration from their closed circulatory system into their tissues. The balance of forces responsible for net capillary filtration and lymph formation is described by the Starling equation, but additional factors such as vascular and interstitial compliance, which vary markedly among vertebrates, also have a significant impact on rates of lymph formation. Why vertebrates show extreme variability in rates of lymph formation and how nonmammalian vertebrates maintain plasma volume homeostasis is unclear. This gap hampers our understanding of the evolution of the lymphatic system and its interaction with the cardiovascular system. The evolutionary origin of the vertebrate lymphatic system is not clear, but recent advances suggest common developmental factors for lymphangiogenesis in teleost fishes, amphibians, and mammals with some significant changes in the water-land transition. The lymphatic system of anuran amphibians is characterized by large lymphatic sacs and two pairs of lymph hearts that return lymph into the venous circulation but no lymph vessels per se. The lymphatic systems of reptiles and some birds have lymph hearts, and both groups have extensive lymph vessels, but their functional role in both lymph movement and plasma volume homeostasis is almost completely unknown. The purpose of this review is to present an evolutionary perspective in how different vertebrates have solved the common problem of the inevitable formation of lymph from their closed circulatory systems and to point out the many gaps in our knowledge of this evolutionary progression.
Clinical Evaluation of the BD FACSPresto™ Near-Patient CD4 Counter in Kenya
Angira, Francis; Akoth, Benta; Omolo, Paul; Opollo, Valarie; Bornheimer, Scott; Judge, Kevin; Tilahun, Henok; Lu, Beverly; Omana-Zapata, Imelda; Zeh, Clement
2016-01-01
Background The BD FACSPresto™ Near-Patient CD4 Counter was developed to expand HIV/AIDS management in resource-limited settings. It measures absolute CD4 counts (AbsCD4), percent CD4 (%CD4), and hemoglobin (Hb) from a single drop of capillary or venous blood in approximately 23 minutes, with throughput of 10 samples per hour. We assessed the performance of the BD FACSPresto system, evaluating accuracy, stability, linearity, precision, and reference intervals using capillary and venous blood at KEMRI/CDC HIV-research laboratory, Kisumu, Kenya, and precision and linearity at BD Biosciences, California, USA. Methods For accuracy, venous samples were tested using the BD FACSCalibur™ instrument with BD Tritest™ CD3/CD4/CD45 reagent, BD Trucount™ tubes, and BD Multiset™ software for AbsCD4 and %CD4, and the Sysmex™ KX-21N for Hb. Stability studies evaluated duration of staining (18–120-minute incubation), and effects of venous blood storage <6–24 hours post-draw. A normal cohort was tested for reference intervals. Precision covered multiple days, operators, and instruments. Linearity required mixing two pools of samples, to obtain evenly spaced concentrations for AbsCD4, total lymphocytes, and Hb. Results AbsCD4 and %CD4 venous/capillary (N = 189/ N = 162) accuracy results gave Deming regression slopes within 0.97–1.03 and R2 ≥0.96. For Hb, Deming regression results were R2 ≥0.94 and slope ≥0.94 for both venous and capillary samples. Stability varied within 10% 2 hours after staining and for venous blood stored less than 24 hours. Reference intervals results showed that gender—but not age—differences were statistically significant (p<0.05). Precision results had <3.5% coefficient of variation for AbsCD4, %CD4, and Hb, except for low AbsCD4 samples (<6.8%). Linearity was 42–4,897 cells/μL for AbsCD4, 182–11,704 cells/μL for total lymphocytes, and 2–24 g/dL for Hb. Conclusions The BD FACSPresto system provides accurate, precise clinical results for capillary or venous blood samples and is suitable for near-patient CD4 testing. Trial Registration ClinicalTrials.gov NCT02396355 PMID:27483008
Clinical Aspects of the Control of Plasma Volume at Microgravity and During Return to One Gravity
NASA Technical Reports Server (NTRS)
Convertino, Victor A.
1995-01-01
Plasma volume is reduced by 10%-20% within 24 to 48 h of exposure to simulated or actual microgravity. The clinical importance of microgravity-induced hypovolemia is manifested by its relationship with orthostatic intolerance and reduced VO2max after return to one gravity (1G). Since there is no evidence to suggest plasma volume reduction during microgravity is associated with thirst or renal dysfunctions, a diuresis induced by an immediate blood volume shift to the central circulation appears responsible for microgravity-induced hypovolemia. Since most astronauts choose to restrict their fluid intake before a space mission, absence of increased urine output during actual spaceflight may be explained by low central venous pressure (CVP) which accompanies dehydration. Compelling evidence suggests that prolonged reduction in CVP during exposure to microgravity reflects a 'resetting' to a lower operating point which acts to limit plasma volume expansion during attempts to increase fluid intake. In groudbase and spaceflight experiments, successful restoration and maintenance of plasma volume prior to returning to an upright posture may depend upon development of treatments that can return CVP to its baseline 10 operating point. Fluid-loading and LBNP have not proved completely effective in restoring plasma volume, suggesting that they may not provide the stimulus to elevate the CVP operating point. On the other, exercise, which can chronically increase CVP, has been effective in expanding plasma volume when combined with adequate dietary intake of fluid and electrolytes. The success of designing experiments to understand the physiological mechanisms of and development of effective countermeasures for the control of plasma volume in microgravity and during return to one gravity will depend upon testing that can be conducted under standardized controlled baseline condi
Pancreas Transplant Venous Thrombosis: Role of Endovascular Interventions for Graft Salvage
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stockland, Andrew H.; Willingham, Darrin L.; Paz-Fumagalli, Ricardo
2009-03-15
Venous thrombosis of pancreas transplant allografts often leads to graft loss. We evaluated the efficacy of emergent endovascular techniques to salvage thrombosed pancreatic allografts in a series of six patients. Of the 76 pancreas transplants performed between 2002 and 2006, six patients were diagnosed with venous thrombosis on MRI between 2 and 28 days posttransplant (mean, 9 days). Five patients were systemic-enteric (donor portal vein anastomosis to recipient iliac vein) and one patient was portal-enteric (donor portal vein anastomosis to recipient superior mesenteric vein). Conventional venography confirmed the diagnosis of venous thrombosis in all patients. One patient was treated withmore » catheter-directed venous thrombolysis and balloon thrombectomy. Another patient was treated with rheolytic thrombectomy alone. The remaining four patients were treated with a combination of these mechanical and thrombolytic techniques. Completion venography revealed >50% clot reduction and resumption of venous drainage in all patients. One patient required additional intervention 16 days later for recurrent thrombosis. Two patients required metal stent placement for anastomotic stenoses or kinks. One patient required pancreatectomy 36 h after attempted salvage secondary to a major hemorrhage and graft necrosis. Two patients recovered pancreatic function initially but lost graft function at 8 and 14 months, respectively, from severe chronic rejection. Patient survival was 100%, long-term graft survival was 50%, rethrombosis rate was 16.6%, and graft loss from rejection was 33%. In conclusion, early recognition and treatment of venous thrombosis after pancreas transplantation has acceptable morbidity and no mortality using short-term endovascular pharmacomechanical therapy.« less
The cardiovascular system in the ageing patient
Moore, A; Mangoni, A A; Lyons, D; Jackson, S H D
2003-01-01
The ageing process is associated with important changes in the responses of the cardiovascular system to pharmacological stimuli. They are not limited to the arterial system, involved in the modulation of cardiac afterload and vascular resistance, but they also involve the low-resistance capacitance venous system and the heart. The main changes include loss of large artery compliance, dysfunction of some of the systems modulating resistance vessel tone, increased activity of the sympathetic nervous system, and reduced haemodynamic responses to inotropic agents. This review focuses on the effects of ageing on arterial and venous reactivity to drugs and hormones, the autonomic nervous system, and the cardiovascular responses to inotropic agents. Some of the age-related changes might be at least partially reversible. This may have important therapeutic implications. PMID:12919173
Schleich, Jean-Marc; Dillenseger, Jean-Louis; Houyel, Lucile; Almange, Claude; Anderson, Robert H
2009-01-01
Learning embryology remains difficult, since it requires understanding of many complex phenomena. The temporal evolution of developmental events has classically been illustrated using cartoons, which create difficulty in linking spatial and temporal aspects, such correlation being the keystone of descriptive embryology. We synthesized the bibliographic data from recent studies of atrial septal development. On the basis of this synthesis, consensus on the stages of atrial septation as seen in the human heart has been reached by a group of experts in cardiac embryology and pediatric cardiology. This has permitted the preparation of three-dimensional (3D) computer graphic objects for the anatomical components involved in the different stages of normal human atrial septation. We have provided a virtual guide to the process of normal atrial septation, the animation providing an appreciation of the temporal and morphologic events necessary to separate the systemic and pulmonary venous returns. We have shown that our animations of normal human atrial septation increase significantly the teaching of the complex developmental processes involved, and provide a new dynamic for the process of learning.
Surgical approach to left ventricular inflow obstruction due to dilated coronary sinus.
Vargas, Florentino J; Rozenbaum, Jorge; Lopez, Ricardo; Granja, Miguel; De Dios, Ana; Zarlenga, Beatriz; Flores, Enrique; Fischman, Enrique; Kreutzer, Eduardo
2006-07-01
Left superior vena cava draining to a dilated coronary sinus can cause left ventricular inflow obstruction. Our purpose is to report 4 severely ill patients with this malformation who were operated upon and in whom repair was accomplished using an original surgical approach. An operative procedure was designed, which included complete resection of the wall of the coronary sinus along its entire extension in the left atrium; division of the left superior vena cava; and establishment of the left superior vena cava-right atrial continuity by a wide left superior vena cava-right atrial appendage anastomosis. The series included 1 patient with interrupted inferior vena cava-hemiazygous continuation to left superior vena cava. There were no deaths. Absence of residual left ventricular inflow obstruction was demonstrated at follow-up in all cases, together with an unobstructed left superior vena cava-right atrial appendage-right atrial connection. A predictable relief of the left ventricular inflow obstruction, together with preservation of an adequate drainage for the systemic venous return, were both achieved with this repair.
Mechanical versus humoral determinants of brain death-induced lung injury
Dewachter, Laurence; Rorive, Sandrine; Remmelink, Myriam; Weynand, Birgit; Melot, Christian; Hupkens, Emeline; Dewachter, Céline; Creteur, Jacques; Mc Entee, Kathleen; Naeije, Robert; Rondelet, Benoît
2017-01-01
Background The mechanisms of brain death (BD)-induced lung injury remain incompletely understood, as uncertainties persist about time-course and relative importance of mechanical and humoral perturbations. Methods Brain death was induced by slow intracranial blood infusion in anesthetized pigs after randomization to placebo (n = 11) or to methylprednisolone (n = 8) to inhibit the expression of pro-inflammatory mediators. Pulmonary artery pressure (PAP), wedged PAP (PAWP), pulmonary vascular resistance (PVR) and effective pulmonary capillary pressure (PCP) were measured 1 and 5 hours after Cushing reflex. Lung tissue was sampled to determine gene expressions of cytokines and oxidative stress molecules, and pathologically score lung injury. Results Intracranial hypertension caused a transient increase in blood pressure followed, after brain death was diagnosed, by persistent increases in PAP, PCP and the venous component of PVR, while PAWP did not change. Arterial PO2/fraction of inspired O2 (PaO2/FiO2) decreased. Brain death was associated with an accumulation of neutrophils and an increased apoptotic rate in lung tissue together with increased pro-inflammatory interleukin (IL)-6/IL-10 ratio and increased heme oxygenase(HO)-1 and hypoxia inducible factor(HIF)-1 alpha expression. Blood expressions of IL-6 and IL-1β were also increased. Methylprednisolone pre-treatment was associated with a blunting of increased PCP and PVR venous component, which returned to baseline 5 hours after BD, and partially corrected lung tissue biological perturbations. PaO2/FiO2 was inversely correlated to PCP and lung injury score. Conclusions Brain death-induced lung injury may be best explained by an initial excessive increase in pulmonary capillary pressure with increased pulmonary venous resistance, and was associated with lung activation of inflammatory apoptotic processes which were partially prevented by methylprednisolone. PMID:28753621
Luo, Bin; Zhang, Xin; Duan, Chuan-Zhi; He, Xu-Ying; Li, Xi-Feng; Karuna, Tamrakar; Gu, Da-Qun; Long, Xiao-Ao; Li, Tie-Lin; Zhang, Shi-Zhong; Ke, Yi-Quan; Jiang, Xiao-Dan
2013-04-01
The purpose of this study was to evaluate the safety and efficacy of transorbital puncture for the retreatment of previously embolized cavernous sinus dural arteriovenous fistulas (DAVFs) via a superior ophthalmic vein (SOV) approach. During a 12-year period, 9 consecutive patients with previously embolized cavernous sinus DAVFs underwent retreatment via the transorbital SOV approach. All of the nine cases of previously embolized cavernous sinus DAVFs were successfully embolized. Clinical follow-ups were conducted in all nine cases at the duration of 17-141 months (61.22 ± 39.13 months). No recanalization occurred during the follow-up period. A subtle ptosis appeared in two patients and disappeared in one of the two cases after a 4-year follow-up. One patient suffered from paroxysmal positional vertigo and bruit for nearly 2 years after the treatment, but the follow-up angiography demonstrated no recurrence. One patient had persistent visual impairment caused by the initial venous stasis retinopathy. One patient with a history of a procedure-related transient decrease in visual acuity had it return to the normal level. The remaining four cases had clear improvement in the ocular symptoms and became completely asymptomatic during the follow-up period. No patient worsened or developed new symptoms. The approach of surgical cannulation of the SOV for the retreatment of previously embolized cavernous sinus DAVFs was proved feasible and efficient, especially when the transarterial and transfemoral venous approaches were inaccessible. However, if the SOV is not dilated enough or is located deeply in the orbit, transorbital venous puncture access may not be possible.
The timing of umbilical cord clamping at birth: physiological considerations.
Hooper, Stuart B; Binder-Heschl, Corinna; Polglase, Graeme R; Gill, Andrew W; Kluckow, Martin; Wallace, Euan M; Blank, Douglas; Te Pas, Arjan B
2016-01-01
While it is now recognized that umbilical cord clamping (UCC) at birth is not necessarily an innocuous act, there is still much confusion concerning the potential benefits and harms of this common procedure. It is most commonly assumed that delaying UCC will automatically result in a time-dependent net placental-to-infant blood transfusion, irrespective of the infant's physiological state. Whether or not this occurs, will likely depend on the infant's physiological state and not on the amount of time that has elapsed between birth and umbilical cord clamping (UCC). However, we believe that this is an overly simplistic view of what can occur during delayed UCC and ignores the benefits associated with maintaining the infant's venous return and cardiac output during transition. Recent experimental evidence and observations in humans have provided compelling evidence to demonstrate that time is not a major factor influencing placental-to-infant blood transfusion after birth. Indeed, there are many factors that influence blood flow in the umbilical vessels after birth, which depending on the dominating factors could potentially result in infant-to-placental blood transfusion. The most dominant factors that influence umbilical artery and venous blood flows after birth are lung aeration, spontaneous inspirations, crying and uterine contractions. It is still not entirely clear whether gravity differentially alters umbilical artery and venous flows, although the available data suggests that its influence, if present, is minimal. While there is much support for delaying UCC at birth, much of the debate has focused on a time-based approach, which we believe is misguided. While a time-based approach is much easier and convenient for the caregiver, ignoring the infant's physiology during delayed UCC can potentially be counter-productive for the infant.
Posterior tibial vein aneurysm presenting as tarsal tunnel syndrome.
Ayad, Micheal; Whisenhunt, Anumeha; Hong, EnYaw; Heller, Josh; Salvatore, Dawn; Abai, Babak; DiMuzio, Paul J
2015-06-01
Tarsal tunnel syndrome is a compressive neuropathy of the posterior tibial nerve within the tarsal tunnel. Its etiology varies, including space occupying lesions, trauma, inflammation, anatomic deformity, iatrogenic injury, and idiopathic and systemic causes. Herein, we describe a 46-year-old man who presented with left foot pain. Work up revealed a venous aneurysm impinging on the posterior tibial nerve. Following resection of the aneurysm and lysis of the nerve, his symptoms were alleviated. Review of the literature reveals an association between venous disease and tarsal tunnel syndrome; however, this report represents the first case of venous aneurysm causing symptomatic compression of the nerve. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Hyperthyroidism as a reversible cause of right ventricular overload and congestive heart failure
Di Giovambattista, Raniero
2008-01-01
We describe a case of severe congestive heart failure and right ventricular overload associated with overt hyperthyroidism, completely reversed with antithyroid therapy in a few week. It represents a very unusual presentation of overt hyperthyroidism because of the severity of right heart failure. The impressive right ventricular volume overload made mandatory to perform transesophageal echo and angio-TC examination to exclude the coexistence of ASD or anomalous pulmonary venous return. Only a few cases of reversible right heart failure, with or without pulmonary hypertension, have been reported worldwide. In our case the most striking feature has been the normalization of the cardiovascular findings after six weeks of tiamazole therapy. PMID:18549503
Lansing, Allan M.
1963-01-01
Septic shock may be defined as hypotension caused by bacteremia and accompanied by decreased peripheral blood flow, evidenced by oliguria. Clinically, a shaking chill is the warning signal. The immediate cause of hypotension is pooling of blood in the periphery, leading to decreased venous return: later, peripheral resistance falls and cardiac failure may occur. Irreversible shock is comparable to massive reactive hyperemia. Reticuloendothelial failure, histamine release, and toxic hypersensitivity may be factors in the pathogenesis of septic shock. Adrenal failure does not usually occur, but large doses of corticosteroid are employed therapeutically to counteract the effect of histamine release or hypersensitivity to endotoxin. The keys to successful therapy are time, antibiotics, vasopressors, cortisone and correction of acidosis. PMID:14063936
DOE Office of Scientific and Technical Information (OSTI.GOV)
Erinjeri, Joseph P., E-mail: erinjerj@mskcc.org; Deodhar, Ajita; Thornton, Raymond H.
Hepatic encephalopathy is considered a contraindication to hepatic artery embolization. We describe a patient with a well-differentiated neuroendocrine tumor metastatic to the liver with refractory hepatic encephalopathy and normal liver function tests. The encephalopathy was refractory to standard medical therapy with lactulose. The patient's mental status returned to baseline after three hepatic artery embolization procedures. Arteriography and ultrasound imaging before and after embolization suggest that the encephalopathy was due to arterioportal shunting causing hepatofugal portal venous flow and portosystemic shunting. In patients with a primary or metastatic well-differentiated neuroendocrine tumor whose refractory hepatic encephalopathy is due to portosystemic shunting (rathermore » than global hepatic dysfunction secondary to tumor burden), hepatic artery embolization can be performed safely and effectively.« less
McDonald, R W; Rice, M J; Reller, M D; Marcella, C P; Sahn, D J
1996-01-01
Sinus venosus atrial septal defects are frequently missed and difficult to visualize with conventional two-dimensional echocardiographic views. Using modified subcostal and right parasternal longitudinal views, nine patients were found to have a sinus venosus atrial septal defect. The modified subcostal view showed a sinus venosus atrial septal defect in all nine patients; three patients had secundum atrial septal defects as well. The right parasternal view detected only six patients with sinus venosus atrial septal defect. Partial anomalous pulmonary venous return was diagnosed in seven patients using these views. The combination of subcostal and right parasternal longitudinal imaging views will improve the detection of sinus venosus atrial septal defects.
Rehabilitation in Guillian Barre syndrome.
Khan, Fary
2004-12-01
Guillian Barre syndrome (GBS) is the most common form of neuromuscular paralysis. It mostly affects young people and can cause long-term residual disability. This article outlines the rehabilitation treatment for patients recovering from GBS. Recovery from GBS can be prolonged. Early rehabilitation intervention ensures medical stability, appropriate treatment and preventive measures to minimise long term complications. Specific problems include deep venous thrombosis prevention, complications of immobility, dysautonomia, de-afferent pain syndromes, muscle pain and fatigue. Longer-term issues include psychosocial adjustment, return to work and driving, and resumption of the role within the family and community. Effective communication between the GP and rehabilitation physicians is imperative for improved functional outcomes and successful social reintegration.
Development of Needle Insertion Manipulator for Central Venous Catheterization
NASA Astrophysics Data System (ADS)
Kobayashi, Yo; Hong, Jaesung; Hamano, Ryutaro; Hashizume, Makoto; Okada, Kaoru; Fujie, Masakatsu G.
Central venous catheterization is a procedure, which a doctor insert a catheter into the patient’s vein for transfusion. Since there are risks of bleeding from arterial puncture or pneumothorax from pleural puncture. Physicians are strictly required to make needle reach up into the vein and to stop the needle in the middle of vein. We proposed a robot system for assisting the venous puncture, which can relieve the difficulties in conventional procedure, and the risks of complication. This paper reports the design structuring and experimental results of needle insertion manipulator. First, we investigated the relationship between insertion force and angle into the vein. The results indicated that the judgment of perforation using the reaction force is possible in case where the needling angle is from 10 to 20 degree. The experiment to evaluate accuracy of the robot also revealed that it has beyond 0.5 mm accuracy. We also evaluated the positioning accuracy in the ultrasound images. The results displays that the accuracy is beyond 1.0 mm and it has enough for venous puncture. We also carried out the venous puncture experiment to the phantom and confirm our manipulator realized to make needle reach up into the vein.
Edema: diagnosis and management.
Trayes, Kathryn P; Studdiford, James S; Pickle, Sarah; Tully, Amber S
2013-07-15
Edema is an accumulation of fluid in the interstitial space that occurs as the capillary filtration exceeds the limits of lymphatic drainage, producing noticeable clinical signs and symptoms. The rapid development of generalized pitting edema associated with systemic disease requires timely diagnosis and management. The chronic accumulation of edema in one or both lower extremities often indicates venous insufficiency, especially in the presence of dependent edema and hemosiderin deposition. Skin care is crucial in preventing skin breakdown and venous ulcers. Eczematous (stasis) dermatitis can be managed with emollients and topical steroid creams. Patients who have had deep venous thrombosis should wear compression stockings to prevent postthrombotic syndrome. If clinical suspicion for deep venous thrombosis remains high after negative results are noted on duplex ultrasonography, further investigation may include magnetic resonance venography to rule out pelvic or thigh proximal venous thrombosis or compression. Obstructive sleep apnea may cause bilateral leg edema even in the absence of pulmonary hypertension. Brawny, nonpitting skin with edema characterizes lymphedema, which can present in one or both lower extremities. Possible secondary causes of lymphedema include tumor, trauma, previous pelvic surgery, inguinal lymphadenectomy, and previous radiation therapy. Use of pneumatic compression devices or compression stockings may be helpful in these cases.
Commercial liquid bags as a potential source of venous air embolism in shoulder arthroscopy.
Austin, Luke; Zmistowski, Benjamin; Tucker, Bradford; Hetrick, Robin; Curry, Patrick; Williams, Gerald
2010-09-01
Venous air embolism is a rare but potentially fatal complication of arthroscopy. Fatal venous air embolism has been reported with as little as 100 mL of air entering the venous system. During liquid-only arthroscopy, avenues for air introduction into the joint are limited. Therefore, we hypothesized that commercially prepared 3-L saline-solution bags are a source of potentially fatal amounts of gas that can be introduced into the joint by arthroscopic pumps. Eight 3-L arthroscopic saline-solution bags were obtained and visually inspected for air. The air was aspirated from four bags, and the volume of the air was recorded. A closed-system pump was prepared, and two 3-L bags were connected to it. The pump emptied into an inverted graduated cylinder immersed in a water bath. Both bags were allowed to run dry. Two more bags were then connected and also allowed to run dry. The air was quantified by the downward displacement of water. The experiment was then repeated with the four bags after the air had been aspirated from them. This experiment was performed at three institutions, with utilization of three pump systems and two brands of 3-L saline-solution bags. Air was visualized in all bags, and the bags contained between 34 and 85 mL of air. Arthroscopic pumps can pump air efficiently through the tubing. The total volumes of gas ejected from the tubing after the four 3-L bags had been emptied were 75, 80, and 235 mL. When bags from which the air had been evacuated were used, no air exited the system. Because a saline-solution arthroscopic pump is theoretically a closed system, venous air embolism has not been a concern. However, this study shows that it is possible to pump a fatal amount of air from 3-L saline-solution bags into an environment susceptible to the creation of emboli. Evacuation of air from the 3-L bags prior to use may eliminate this risk.
Improved methods for venous access: the Port-A-Cath, a totally implanted catheter system.
Strum, S; McDermed, J; Korn, A; Joseph, C
1986-04-01
We prospectively evaluated the performance and rate of long-term complications with the Port-A-Cath (PAC), a totally implanted vascular access system. Two catheter styles were evaluated, a small-bore (SB) catheter (0.51-mm diameter) and a large-bore (LB) catheter (1.02-mm diameter), in conjunction with the use of a strict catheter care protocol. The PAC performed well, and with both SB and LB systems, no significant extravasation, skin necrosis, hematoma, septum damage or leakage, or subcutaneous portal infections occurred after 7,240 days of implantation and 1,435 days of use. Complications with the PAC system consisted of catheter occlusion (seven patients, 21.5%) and one instance of possible catheter infection (3.1%). Occlusions were limited to patients implanted with the SB catheter (seven of 16, 43.8%), and five of the seven (71.4%) occurred in patients receiving continuous infusion chemotherapy and/or total parenteral nutrition. Patency of the PAC system was maintained using a regular flushing schedule once every 30 days, a significant advantage compared with the daily maintenance schedule required with externally placed venous catheters. The results of this study suggest that the PAC system can provide a safe and reliable method for venous access in patients requiring intermittent or prolonged intravenous therapy.
Liu, Saifei; Newland, Richard F; Tully, Phillip J; Tuble, Sigrid C; Baker, Robert A
2011-09-01
The delivery of gaseous microemboli (GME) by the cardiopulmonary bypass circuit should be minimized whenever possible. Innovations in components, such as the integration of arterial line filter (ALF) and ALFs with reduced priming volumes, have provided clinicians with circuit design options. However, before adopting these components clinically, their GME handling ability should be assessed. This study aims to compare the GME handling ability of different oxygenator/ALF combinations with our currently utilized combination. Five commercially available oxygenator/ALF combinations were evaluated in vitro: Terumo Capiox SX25RX and Dideco D734 (SX/D734),Terumo Capiox RX25R and AF125 (RX/AF125), Terumo FX25R (FX), Sorin Synthesis with 102 microm reservoir filter (SYN102), and Sorin Synthesis with 40 microm reservoir filter (SYN40). GME handling was studied by introducing air into the venous return at 100 mL/min for 60 seconds under two flow/ pressure combinations: 3.5 L/min, 150 mmHg and 5 L/min, 200 mmHg. Emboli were measured at three positions in the circuit using the Emboli Detection and Classification (EDAC) Quantifier and analyzed with the General Linear Model. All circuits significantly reduced GME. The SX/D734 and SYN40 circuits were most efficient in GME removal whilst the SYN102 handled embolic load (count and volume) least efficiently (p < .001). A greater number of emboli <70 microm were observed for the SYN102, FX and RX/AF125 circuits (p < .001). An increase in embolic load occurred with higher flow/pressure in all circuits (p < .001). The venous reservoir significantly influences embolic load delivered to the oxygenator (p < .001). The majority of introduced venous air was removed; however, significant variation existed in the ability of the different circuits to handle GME. Venous reservoir design influenced the overall GME handling ability. GME removal was less efficient at higher flow and pressure, and for smaller sized emboli. The clinical significance of reducing GME requires further investigation.
Jawień, Arkadiusz; Cierzniakowska, Katarzyna; Cwajda-Białasik, Justyna; Mościcka, Paulina
2010-01-01
Introduction The aim of the research was to compare the dynamics of venous ulcer healing when treated with the use of compression stockings as well as original two- and four-layer bandage systems. Material and methods A group of 46 patients suffering from venous ulcers was studied. This group consisted of 36 (78.3%) women and 10 (21.70%) men aged between 41 and 88 years (the average age was 66.6 years and the median was 67). Patients were randomized into three groups, for treatment with the ProGuide two-layer system, Profore four-layer compression, and with the use of compression stockings class II. In the case of multi-layer compression, compression ensuring 40 mmHg blood pressure at ankle level was used. Results In all patients, independently of the type of compression therapy, a few significant statistical changes of ulceration area in time were observed (Student’s t test for matched pairs, p < 0.05). The largest loss of ulceration area in each of the successive measurements was observed in patients treated with the four-layer system – on average 0.63 cm2/per week. The smallest loss of ulceration area was observed in patients using compression stockings – on average 0.44 cm2/per week. However, the observed differences were not statistically significant (Kruskal-Wallis test H = 4.45, p > 0.05). Conclusions A systematic compression therapy, applied with preliminary blood pressure of 40 mmHg, is an effective method of conservative treatment of venous ulcers. Compression stockings and prepared systems of multi-layer compression were characterized by similar clinical effectiveness. PMID:22419941
The efficacy of the new SCD response compression system in the prevention of venous stasis.
Kakkos, S K; Szendro, G; Griffin, M; Daskalopoulou, S S; Nicolaides, A N
2000-11-01
The current commercially available sequential intermittent pneumatic compression device used for the prevention of deep venous thrombosis has a constant cycle of 11 seconds' compression and 60 seconds' deflation. This deflation period ensures that the veins are filled before the subsequent cycle begins. It has been suggested that in some positions (eg, semirecumbent or sitting) and with different patients (eg, those with venous reflux), refilling of the veins may occur much earlier than 60 seconds, and thus a more frequent cycle may be more effective in expelling blood proximally. The aim of the study was to test the effectiveness of a new sequential compression system (the SCD Response Compression System), which has the ability to detect the change in the venous volume and to respond by initiating the subsequent cycle when the veins are substantially full. In an open controlled trial at an academic vascular laboratory, the SCD Response Compression System was tested against the existing SCD Sequel Compression System in 12 healthy volunteers who were in supine, semirecumbent, and sitting positions. The refilling time sensed by the device was compared with that determined from recordings of femoral vein flow velocity by the use of duplex ultrasound scan. The total volume of blood expelled per hour during compression was compared with that produced by the existing SCD system in the same volunteers and positions. The refilling time determined automatically by the SCD Response Compression System varied from 24 to 60 seconds in the subjects tested, demonstrating individual patient variation. The refilling time (mean +/- SD) in the sitting position was 40.6 +/- 10. 0 seconds, which was significantly longer (P <.001) than that measured in the supine and semirecumbent positions, 33.8 +/- 4.1 and 35.6 +/- 4.9 seconds, respectively. There was a linear relationship between the duplex scan-derived refill time (mean of 6 readings per leg) and the SCD Response device-derived refill time (r = 0.85, P <. 001). The total volume of blood (mean +/- SD) expelled per hour by the existing SCD Sequel device in the supine, semirecumbent, and sitting positions was 2.23 +/- 0.90 L/h, 2.47 +/- 0.86 L/h, and 3.28 +/- 1.24 L/h, respectively. The SCD Response device increased the volume expelled to 3.92 +/- 1.60 L/h or a 76% increase (P =.001) in the supine position, to 3.93 +/- 1.55 L/h or a 59% increase (P =. 001) in the semirecumbent position, and to 3.97 +/- 1.42 L/h or a 21% increase (P =.026) in the sitting position. By achieving more appropriately timed compression cycles over time, the new SCD Response System is effective in preventing venous stasis by means of a new method that improves on the clinically documented effectiveness of the existing SCD system. Further studies testing its potential for improved efficacy in preventing deep venous thrombosis are justified.
Smodlaka, H; Henry, R W; Reed, R B
2009-06-01
The ringed seal [Pusa (Phoca) hispida], as well as other seals, exhibits unique anatomical properties when compared to its terrestrial counterparts. In the ringed seal, the most conspicuous marine adaptation is the aortic bulb. This large dilatation of the ascending aorta is comparable to that found in other seal species and marine mammals. The branches of the ascending aorta (brachiocephalic trunk, left common carotid artery and left subclavian artery) are similar to those of higher primates and man. The peculiarities of the venous system are: three pulmonary veins, a pericardial venous plexus, a caval sphincter, a hepatic sinus with paired caudal vena cavae and a large extradural venous plexus. Generally, three common pulmonary veins (right, left and caudal) empty into the left atrium. The pericardial venous plexus lies deep to the mediastinal pericardial pleura (pleura pericardica) on the auricular (ventral) surface of the heart. The caval sphincter surrounds the caudal vena cava as it passes through the diaphragm. Caudal to the diaphragm, the vena cava is dilated (the hepatic sinus), and near the cranial extremity of the kidneys, it becomes biphid. The azygos vein is formed from the union of the right and left azygos veins at the level of the 5th thoracic vertebra. Cardiovascular physiological studies show some of these anatomical variations, especially of the venous system and the ascending aorta, to be modifications for diving. This investigation documents the large blood vessels associated with the heart and related structures in the ringed seal.
Franco, O.S.; Paulitsch, F.S.; Pereira, A.P.C.; Teixeira, A.O.; Martins, C.N.; Silva, A.M.V.; Plentz, R.D.M.; Irigoyen, M.C.; Signori, L.U.
2014-01-01
Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia. PMID:24820225
Congenital portosystemic venous shunt.
Papamichail, M; Pizanias, M; Heaton, N
2018-03-01
Congenital portosystemic venous shunts are rare developmental anomalies resulting in diversion of portal flow to the systemic circulation and have been divided into extra- and intrahepatic shunts. They occur during liver and systemic venous vascular embryogenesis and are associated with other congenital abnormalities. They carry a higher risk of benign and malignant liver tumors and, if left untreated, can result in significant medical complications including systemic encephalopathy and pulmonary hypertension. This article reviews the various types of congenital portosystemic shunts and their anatomy, pathogenesis, symptomatology, and timing and options of treatment. What is Known: • The natural history and basic management of this rare congenital anomaly are presented. What is New: • This paper is a comprehensive review; highlights important topics in pathogenesis, clinical symptomatology, and treatment options; and proposes an algorithm in the management of congenital portosystemic shunt disease in order to provide a clear idea to a pediatrician. An effort has been made to emphasize the indications for treatment in the children population and link to the adult group by discussing the consequences of lack of treatment or delayed diagnosis.
Cariou, M P; Lipscomb, V J; Hughes, D; Brodbelt, D; Brockman, D J
2009-08-22
Plasma concentration of lactate and the values of pH, pO(2) and pCO(2) were measured in the portal, systemic venous and, when possible, systemic arterial blood of 31 dogs with a single congenital portosystemic shunt, before and shortly after the temporary complete occlusion of the shunt, and at the end of surgery. At completion of the surgery, the shunt in 16 of the dogs had been occluded completely whereas in the other 15 it had been occluded only partially. There were no significant differences between any of the measurements of these variables in the portal venous, systemic venous or arterial plasma of any of the dogs, or between the values measured in the groups in which the shunts had been occluded completely or partially. Furthermore, there were no significant differences between the two groups of dogs in the arteriovenous gradients calculated at any of the sampling sites or sampling times. None of the variables was associated with the development of postoperative complications.
Pacific Pediatric Advanced Care Initiative
2011-01-01
infusing into the patient via a central venous line 6. After you have made sure the patient is safe, remove air from system. 7. Identify and fix...site. Push blood. Take fluid out of bladder to create a more negative venous pressure History : Day 1 for a 2 month old who had a witnessed...operating room, central supply, pharmacy, respiratory care, Neonatal Intensive Care Unit (NICU) nursing, Pediatric Intensive Care Unit (PICU) nursing, Risk
Kara, Tomas; Leinveber, Pavel; Vlasin, Michal; Jurak, Pavel; Novak, Miroslav; Novak, Zdenek; Chrastina, Jan; Czechowicz, Krzysztof; Belehrad, Milos; Asirvatham, Samuel J
2014-06-01
Despite the substantial progress that has been achieved in interventional cardiology and cardiac electrophysiology, endovascular intervention for the diagnosis and treatment of central nervous system (CNS) disorders such as stroke, epilepsy and CNS malignancy is still limited, particularly due to highly tortuous nature of the cerebral arterial and venous system. Existing interventional devices and techniques enable only limited and complicated access especially into intra-cerebral vessels. The aim of this study was to develop a micro-catheter magnetically-guided technology specifically designed for endovascular intervention and mapping in deep CNS vascular structures. Mapping of electrical brain activity was performed via the venous system on an animal dog model with the support of the NIOBE II system. A novel micro-catheter specially designed for endovascular interventions in the CNS, with the support of the NIOBE II technology, was able to reach safely deep intra-cerebral venous structures and map the electrical activity there. Such structures are not currently accessible using standard catheters. This is the first study demonstrating successful use of a new micro-catheter in combination with NIOBE II technology for endovascular intervention in the brain.
Noritomi, Danilo Teixeira; Zigaib, Rogério; Ranzani, Otavio T; Teich, Vanessa
2016-01-01
To evaluate the cost-effectiveness, from the funding body's point of view, of real-time ultrasound-guided central venous catheter insertion compared to the traditional method, which is based on the external anatomical landmark technique. A theoretical simulation based on international literature data was applied to the Brazilian context, i.e., the Unified Health System (Sistema Único de Saúde - SUS). A decision tree was constructed that showed the two central venous catheter insertion techniques: real-time ultrasonography versus external anatomical landmarks. The probabilities of failure and complications were extracted from a search on the PubMed and Embase databases, and values associated with the procedure and with complications were taken from market research and the Department of Information Technology of the Unified Health System (DATASUS). Each central venous catheter insertion alternative had a cost that could be calculated by following each of the possible paths on the decision tree. The incremental cost-effectiveness ratio was calculated by dividing the mean incremental cost of real-time ultrasound compared to the external anatomical landmark technique by the mean incremental benefit, in terms of avoided complications. When considering the incorporation of real-time ultrasound and the concomitant lower cost due to the reduced number of complications, the decision tree revealed a final mean cost for the external anatomical landmark technique of 262.27 Brazilian reals (R$) and for real-time ultrasound of R$187.94. The final incremental cost of the real-time ultrasound-guided technique was -R$74.33 per central venous catheter. The incremental cost-effectiveness ratio was -R$2,494.34 due to the pneumothorax avoided. Real-time ultrasound-guided central venous catheter insertion was associated with decreased failure and complication rates and hypothetically reduced costs from the view of the funding body, which in this case was the SUS.
Central Vein Dilatation Prior to Concomitant Port Implantation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krombach, Gabriele A., E-mail: krombach@rad.rwth-aachen.de; Plumhans, Cedric; Goerg, Fabian
2010-04-15
Implantation of subcutaneous port systems is routinely performed in patients requiring repeated long-term infusion therapy. Ultrasound- and fluoroscopy-guided implantation under local anesthesia is broadly established in interventional radiology and has decreased the rate of complications compared to the surgical approach. In addition, interventional radiology offers the unique possibility of simultaneous management of venous occlusion. We present a technique for recanalization of central venous occlusion and angioplasty combined with port placement in a single intervention which we performed in two patients. Surgical port placement was impossible owing to occlusion of the superior vena cava following placement of a cardiac pacemaker andmore » occlusion of multiple central veins due to paraneoplastic coagulopathy, respectively. In both cases the affected vessel segments were dilated with balloon catheters and the port systems were placed thereafter. After successful dilatation, the venous access was secured with a 25-cm-long, 8-Fr introducer sheath, a subcutaneous pocket prepared, and the port catheter tunneled to the venipuncture site. The port catheter was introduced through the sheath with the proximal end connected to a 5-Fr catheter. This catheter was pulled through the tunnel in order to preserve the tunnel and, at the same time, allow safe removal of the long sheath over the wire. The port system functioned well in both cases. The combination of recanalization and port placement in a single intervention is a straightforward alternative for patients with central venous occlusion that can only be offered by interventional radiology.« less
Optoacoustic monitoring of central and peripheral venous oxygenation during simulated hemorrhage
NASA Astrophysics Data System (ADS)
Petrov, Andrey; Kinsky, Michael; Prough, Donald S.; Petrov, Yuriy; Petrov, Irene Y.; Henkel, S. Nan; Seeton, Roger; Salter, Michael G.; Khan, Muzna N.; Esenaliev, Rinat O.
2014-03-01
Circulatory shock may be fatal unless promptly recognized and treated. The most commonly used indicators of shock (hypotension and tachycardia) lack sensitivity and specificity. In the initial stages of shock, the body compensates by reducing blood flow to the peripheral (skin, muscle, etc.) circulation in order to preserve vital organ (brain, heart, liver) perfusion. Characteristically, this can be observed by a greater reduction in peripheral venous oxygenation (for instance, the axillary vein) compared to central venous oxygenation (the internal jugular vein). While invasive measurements of oxygenation are accurate, they lack practicality and are not without complications. We have developed a novel optoacoustic system that noninvasively determines oxygenation in specific veins. In order to test this application, we used lower body negative pressure (LBNP) system, which simulates hemorrhage by exerting a variable amount of suction on the lower body, thereby reducing the volume of blood available for central circulation. Restoration of normal blood flow occurs promptly upon cessation of LBNP. Using two optoacoustic probes, guided by ultrasound imaging, we simultaneously monitored oxygenation in the axillary and internal jugular veins (IJV). LBNP began at -20 mmHg, thereafter was reduced in a step-wise fashion (up to 30 min). The optoacoustically measured axillary oxygenation decreased with LBNP, whereas IJV oxygenation remained relatively constant. These results indicate that our optoacoustic system may provide safe and rapid measurement of peripheral and central venous oxygenation and diagnosis of shock with high specificity and sensitivity.
Venous pump of the calf: a study of venous and muscular pressures.
Alimi, Y S; Barthelemy, P; Juhan, C
1994-11-01
Little data are available concerning the relation between the muscular pumping mechanism and the variation of superficial and deep venous pressure during normal action of the calf pump; therefore we undertook this study to determine the pressure values in three compartments of the calf and in the deep and the superficial venous system and to establish correlation between muscular and venous pressure. Nine healthy young women with a mean age of 23 years (range 19 to 28 years) were examined. In the same calf, a muscular catheter was placed in the deep posterior compartment (DPC), in the superficial posterior compartment (SPC), and in the anterior tibial compartment (ATC), and a vascular catheter was placed in the popliteal vein and in the greater saphenous vein (GSV). The five lines of pressure were simultaneously recorded in the following situations: at rest, during Valsalva maneuver, foot flexion, and foot extension. The situation was studied with the patient in the following positions: decubitus, sitting, standing, and squatting. A final continuous recording was carried out after the patient had been walking for 5 minutes. Mean values with standard errors of muscular and venous pressure were established in each situation. At rest and during Valsalva maneuver, the muscular pressures did not vary, whereas venous pressures increased significantly when the patient was sitting and standing. On the other hand, squatting was associated with a rise in the muscular and vein pressures. Foot flexion entailed a significant increase in the ATC pressure and a rise in the GSV pressure, whereas foot extension caused the DPC pressure to rise without venous pressure modifications. Walking was associated with an alternating increase in the DPC, SPC, GSV and popliteal vein pressures when the foot was compressed to floor followed by a significant decrease when the foot pressure was released. The variations in the deep and superficial venous pressures when the patient is sitting and standing both at rest and during Valsalva maneuver are not associated with an increase in the muscular pressure. On the contrary, during foot movements, the ATC and the DPC are responsible for superficial vein pressure variations without modifications of the SPC pressure.
Kort, D; van Rein, N; van der Meer, F J M; Vermaas, H W; Wiersma, N; Cannegieter, S C; Lijfering, W M
2017-12-01
Essentials Literature on socioeconomic status (SES) and incidence of venous thromboembolism (VTE) is scarce. We assessed neighborhood SES with VTE risk in a population of over 1.4 million inhabitants. Higher neighborhood SES was associated with lower incidence of VTE. These findings are helpful to inform policy and resource allocation in health systems. Background The association between socioeconomic status and arterial cardiovascular disease is well established. However, despite its high burden of disability-adjusted life years, little research has been carried out to determine whether socioeconomic status is associated with venous thromboembolism. Objective To determine if neighborhood socioeconomic status is associated with venous thromboembolism in a population-based study from the Netherlands. Methods We identified all patients aged 15 years and older with a first event of venous thromboembolism from inhabitants who lived in the urban districts of The Hague, Leiden and Utrecht in the Netherlands in 2008-2012. Neighborhood socioeconomic status was based on the status score, which combines educational level, income and unemployment on a four-digit postal code level. Incidence rate ratios of venous thromboembolism were calculated for different levels of neighborhood socioeconomic status, with adjustments for age and sex. Results A total of 7373 patients with a first venous thromboembolism (median age 61 years; 50% deep vein thrombosis) were identified among more than 1.4 million inhabitants. Higher neighborhood SES was associated with lower incidence of VTE. In the two highest status score groups (i.e. the 95-99th and > 99th percentile), the adjusted incidence rate ratios were 0.91 (95% confidence interval [CI], 0.84-1.00) and 0.80 (95% CI, 0.69-0.93), respectively, compared with the reference status score group (i.e. 30-70th percentile). Conclusions High neighborhood socioeconomic status is associated with a lower risk of first venous thromboembolism. © 2017 International Society on Thrombosis and Haemostasis.
Fritsch, P; Grubauer, G; Hilty, N; Biedermann, H
1989-07-01
A hypervascularization syndrome following arterialization of the deep dorsal vein of the penis to amend venous erectile impotence is a rare cause of penile ulcers that has not previously been described in the dermatological literature. Arterialization is performed by installing a shunt from the inferior epigastric artery or a venous bypass from the femoral artery to the deep dorsal vein of the penis, resulting in a blockage of venous outflow and in retrograde inflow into the corpora cavernosa. Complications arise as a result of persistently elevated blood pressure in the deep venous system and the erectile tissue in 10-20% of cases and are most often linked to dilatation of the shunt: the consequences are enlargement and induration of the glans, hazard of phimosis and paraphimosis, pulsation of the penis, micturation difficulties and, ultimately, ulceration of the glans. Surgical reduction of the arterial inflow ("banding" of the shunt) is the only therapeutic procedure that reduces hypervascularization without compromising the newly gained erectile function.
Association of physical examination with pulmonary artery catheter parameters in acute lung injury.
Grissom, Colin K; Morris, Alan H; Lanken, Paul N; Ancukiewicz, Marek; Orme, James F; Schoenfeld, David A; Thompson, B Taylor
2009-10-01
To correlate physical examination findings, central venous pressure, fluid output, and central venous oxygen saturation with pulmonary artery catheter parameters. Retrospective study. Data from the multicenter Fluid and Catheter Treatment Trial of the National Institutes of Health Acute Respiratory Distress Syndrome Network. Five hundred thirteen patients with acute lung injury randomized to treatment with a pulmonary artery catheter. Correlation of physical examination findings (capillary refill time >2 secs, knee mottling, or cool extremities), central venous pressure, fluid output, and central venous oxygen saturation with parameters from a pulmonary artery catheter. We determined association of baseline physical examination findings and on-study parameters of central venous pressure and central venous oxygen saturation with cardiac index <2.5 L/min/m2 and mixed venous oxygen saturation <60%. We determined correlation of baseline central venous oxygen saturation and mixed venous oxygen saturation and predictive value of a low central venous oxygen saturation for a low mixed venous oxygen saturation. Prevalence of cardiac index <2.5 and mixed venous oxygen saturation <60% was 8.1% and 15.5%, respectively. Baseline presence of all three physical examination findings had low sensitivity (12% and 8%), high specificity (98% and 99%), low positive predictive value (40% and 56%), but high negative predictive value (93% and 86%) for cardiac index <2.5 and mixed venous oxygen saturation <60%, respectively. Central venous oxygen saturation <70% predicted a mixed venous oxygen saturation <60% with a sensitivity 84%,specificity 70%, positive predictive value 31%, and negative predictive value of 96%. Low cardiac index correlated with cool extremities, high central venous pressure, and low 24-hr fluid output; and low mixed venous oxygen saturation correlated with knee mottling and high central venous pressure, but these correlations were not found to be clinically useful. In this subset of patients with acute lung injury, there is a high prior probability that cardiac index and mixed venous oxygen saturation are normal and physical examination findings of ineffective circulation are not useful for predicting low cardiac index or mixed venous oxygen saturation. Central venous oxygen saturation <70% does not accurately predict mixed venous oxygen saturation <60%, but a central venous oxygen saturation >or=70% may be useful to exclude mixed venous oxygen saturation <60%.
Kurstjens, Ralph L M; de Wolf, Mark A F; Alsadah, Sarah A; Arnoldussen, Carsten W K P; Strijkers, Rob H W; Toonder, Irwin M; Wittens, Cees H A
2016-07-01
Air plethysmography (APG) is a functional, noninvasive test that can assess volumetric changes in the lower limb and might therefore be used as a diagnostic tool in chronic deep venous disease. However, use of APG in chronic deep venous obstructive disease remains debatable. This study assessed the clinical value of APG in identifying chronic deep venous obstruction. All patients referred to our tertiary, outpatient clinic between January 2011 and August 2013 with chronic venous complaints and suspected outflow obstruction underwent an outflow fraction (OF), ejection fraction (EF), and residual volume fraction (RVF) test using APG. Duplex ultrasound and magnetic resonance venography were used to establish whether and where obstruction was present. Diagnostic values of these tests were assessed for obstructions at different levels of the deep venous system. A total of 312 limbs in 248 patients were tested. Mean age was 45.5 ± 14.0 years, and 62.5% were female. In post-thrombotic disease, specificity and positive predictive value for OF were as high as 98.4% and 95.0%, respectively; however, sensitivity was 34.8% and negative predictive value was 29.6%, with no clinically relevant positive or negative likelihood ratios. No clinically relevant differences were observed in stratifying for level of obstruction. EF and RVF were as inconclusive. Neither could these parameters be used in diagnosing nonthrombotic iliac vein compression. We found a poor correlation between OF, EF, or RVF, determined by APG, and the presence of chronic deep venous obstruction. Therefore, use of its relative parameters is unwarranted in daily clinical practice. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Bown, L Sand; Ricksten, S-E; Houltz, E; Einarsson, H; Söndergaard, S; Rizell, M; Lundin, S
2016-05-01
To minimize blood loss during hepatic surgery, various methods are used to reduce pressure and flow within the hepato-splanchnic circulation. In this study, the effect of low- to moderate doses of vasopressin, a potent splanchnic vasoconstrictor, on changes in portal and hepatic venous pressures and splanchnic and hepato-splanchnic blood flows were assessed in elective liver resection surgery. Twelve patients were studied. Cardiac output (CO), stroke volume (SV), mean arterial (MAP), central venous (CVP), portal venous (PVP) and hepatic venous pressures (HVP) were measured, intraoperatively, at baseline and during vasopressin infusion at two infusion rates (2.4 and 4.8 U/h). From arterial and venous blood gases, the portal (splanchnic) and hepato-splanchnic blood flow changes were calculated, using Fick's equation. CO, SV, MAP and CVP increased slightly, but significantly, while systemic vascular resistance and heart rate remained unchanged at the highest infusion rate of vasopressin. PVP was not affected by vasopressin, while HVP increased slightly. Vasopressin infusion at 2.4 and 4.8 U/h reduced portal blood flow (-26% and -37%, respectively) and to a lesser extent hepato-splanchnic blood flow (-9% and -14%, respectively). The arterial-portal vein lactate gradient was not significantly affected by vasopressin. Postoperative serum creatinine was not affected by vasopressin. Short-term low to moderate infusion rates of vasopressin induced a splanchnic vasoconstriction without metabolic signs of splanchnic hypoperfusion or subsequent renal impairment. Vasopressin caused a centralization of blood volume and increased cardiac output. Vasopressin does not lower portal or hepatic venous pressures in this clinical setting. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.
Helyar, Vincent G; Gupta, Yuri; Blakeway, Lyndall; Charles-Edwards, Geoff; Katsanos, Konstantinos; Karunanithy, Narayan
2018-02-01
This study evaluates the use of balanced steady-state free precession MRI (bSSFP-MRI) in the diagnostic work-up of patients undergoing interventional deep venous reconstruction (I-DVR). Intravenous digital subtraction angiography (IVDSA) was used as the gold-standard for comparison to assess disease extent and severity. A retrospective comparison of bSSFP-MRI to IVDSA was performed in all patients undergoing both examinations for treatment planning prior to I-DVR. The severity of disease in each venous segment was graded by two board-certified radiologists working independently, according to a predetermined classification system. In total, 44 patients (225 venous segments) fulfilled the inclusion criteria. A total of 156 abnormal venous segments were diagnosed using bSSFP-MRI compared with 151 using IVDSA. The prevalence of disease was higher in the iliac and femoral segments (range, 79.6-88.6%). Overall sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and the diagnostic ratio for bSSFP-MRI were 99.3%, 91.9%, 12.3, 0.007 and 1700, respectively. This study supports the use of non-contrast balanced SSFP-MRI in the assessment of the deep veins of the lower limb prior to I-DVR. The technique offers an accurate, fast and non-invasive alternative to IVDSA. Advances in Knowledge: Although balanced SSFP-MRI is commonly used in cardiac imaging, its use elsewhere is limited and its use in evaluating the deep veins prior to interventional reconstruction is not described. Our study demonstrates the usefulness of this technique in the work-up of patients awaiting interventional venous reconstruction compared with the current gold standard.
Helder, Onno; Kornelisse, René; van der Starre, Cynthia; Tibboel, Dick; Looman, Caspar; Wijnen, René; Poley, Marten; Ista, Erwin
2013-10-14
Central venous catheter-associated bloodstream infections in children are an increasingly recognized serious safety problem worldwide, but are often preventable. Central venous catheter bundles have proved effective to prevent such infections. Successful implementation requires changes in the hospital system as well as in healthcare professionals' behaviour. The aim of the study is to evaluate process and outcome of implementation of a state-of-the-art central venous catheter insertion and maintenance bundle in a large university children's hospital. An interrupted time series design will be used; the study will encompass all children who need a central venous catheter. New state-of-the-art central venous catheter bundles will be developed. The Pronovost-model will guide the implementation process. We developed a tailored multifaceted implementation strategy consisting of reminders, feedback, management support, local opinion leaders, and education. Primary outcome measure is the number of catheter-associated infections per 1000 line-days. The process outcome is degree of adherence to use of these central venous catheter bundles is the secondary outcome. A cost-effectiveness analysis is part of the study. Outcomes will be monitored during three periods: baseline, pre-intervention, and post-intervention for over 48 months. This model-based implementation strategy will reveal the challenges of implementing a hospital-wide safety program. This work will add to the body of knowledge in the field of implementation. We postulate that healthcare workers' willingness to shift from providing habitual care to state-of-the-art care may reflect the need for consistent care improvement. Trial registration: Dutch trials registry, trial # 3635. Dutch trials registry (http://www.trialregister.nl), trial # 3635.
Cialoni, Danilo; Pieri, Massimo; Balestra, Costantino; Marroni, Alessandro
2015-03-01
Inert gas accumulated after multiple recreational dives can generate tissue supersaturation and bubble formation when ambient pressure decreases. We hypothesized that this could happen even if divers respected the currently recommended 24-hour pre-flight surface interval (PFSI). We performed transthoracic echocardiography (TTE) on a group of 56 healthy scuba divers (39 male, 17 female) as follows: first echo--during the outgoing flight, no recent dives; second echo--before boarding the return flight, after a multiday diving week in the tropics and a 24-hour PFSI; third echo--during the return flight at 30, 60 and 90 minutes after take-off. TTE was also done after every dive during the week's diving. Divers were divided into three groups according to their 'bubble-proneness': non-bubblers, occasional bubblers and consistent bubblers. During the diving, 23 subjects never developed bubbles, 17 only occasionally and 16 subjects produced bubbles every day and after every dive. Bubbles on the return flight were observed in eight of the 56 divers (all from the 'bubblers' group). Two subjects who had the highest bubble scores during the diving were advised not to make the last dive (increasing their PFSI to approximately 36 hours), and did not demonstrate bubbles on the return flight. Even though a 24-hour PFSI is recommended on the basis of clinical trials showing a low risk of decompression sickness (DCS), the presence of venous gas bubbles in-flight in eight of 56 divers leads us to suspect that in real-life situations DCS risk after such a PFSI is not zero.
Unusual presentation of total anomalous systemic venous connection.
Vaidyanathan, Swaminathan; Kothandam, Sivakumar; Kumar, Rajesh; Pradhan, Priya M; Agarwal, Ravi
2017-07-01
A 9-year-old girl who presented with dyspnea on exertion was diagnosed with total anomalous systemic venous connection to the left atrium (both venae cavae), no left superior vena cava, and a moderate-sized atrial septal defect with severe pulmonary arterial hypertension and ectopic atrial rhythm. She underwent septation of the common atrium using autologous pericardium, thereby rerouting the superior vena cava, inferior vena cava, and coronary sinus to the right atrium. Her postoperative course was uneventful. This case is reported for its rarity of presentation with severe pulmonary arterial hypertension and ectopic atrial rhythm.
Monsen, Karen A; Kelechi, Teresa J; McRae, Marion E; Mathiason, Michelle A; Martin, Karen S
The growth and diversification of nursing theory, nursing terminology, and nursing data enable a convergence of theory- and data-driven discovery in the era of big data research. Existing datasets can be viewed through theoretical and terminology perspectives using visualization techniques in order to reveal new patterns and generate hypotheses. The Omaha System is a standardized terminology and metamodel that makes explicit the theoretical perspective of the nursing discipline and enables terminology-theory testing research. The purpose of this paper is to illustrate the approach by exploring a large research dataset consisting of 95 variables (demographics, temperature measures, anthropometrics, and standardized instruments measuring quality of life and self-efficacy) from a theory-based perspective using the Omaha System. Aims were to (a) examine the Omaha System dataset to understand the sample at baseline relative to Omaha System problem terms and outcome measures, (b) examine relationships within the normalized Omaha System dataset at baseline in predicting adherence, and (c) examine relationships within the normalized Omaha System dataset at baseline in predicting incident venous ulcer. Variables from a randomized clinical trial of a cryotherapy intervention for the prevention of venous ulcers were mapped onto Omaha System terms and measures to derive a theoretical framework for the terminology-theory testing study. The original dataset was recoded using the mapping to create an Omaha System dataset, which was then examined using visualization to generate hypotheses. The hypotheses were tested using standard inferential statistics. Logistic regression was used to predict adherence and incident venous ulcer. Findings revealed novel patterns in the psychosocial characteristics of the sample that were discovered to be drivers of both adherence (Mental health Behavior: OR = 1.28, 95% CI [1.02, 1.60]; AUC = .56) and incident venous ulcer (Mental health Behavior: OR = 0.65, 95% CI [0.45, 0.93]; Neuro-musculo-skeletal function Status: OR = 0.69, 95% CI [0.47, 1.00]; male: OR = 3.08, 95% CI [1.15, 8.24]; not married: OR = 2.70, 95% CI [1.00, 7.26]; AUC = .76). The Omaha System was employed as ontology, nursing theory, and terminology to bridge data and theory and may be considered a data-driven theorizing methodology. Novel findings suggest a relationship between psychosocial factors and incident venous ulcer outcomes. There is potential to employ this method in further research, which is needed to generate and test hypotheses from other datasets to extend scientific investigations from existing data.
Glass, Todd F; Knapp, Jason; Amburn, Philip; Clay, Bruce A; Kabrisky, Matt; Rogers, Steven K; Garcia, Victor F
2004-02-01
To determine whether a prototype artificial intelligence system can identify volume of hemorrhage in a porcine model of controlled hemorrhagic shock. Prospective in vivo animal model of hemorrhagic shock. Research foundation animal surgical suite; computer laboratories of collaborating industry partner. Nineteen, juvenile, 25- to 35-kg, male and female swine. Anesthetized animals were instrumented for arterial and systemic venous pressure monitoring and blood sampling, and a splenectomy was performed. Following a 1-hr stabilization period, animals were hemorrhaged in aliquots to 10, 20, 30, 35, 40, 45, and 50% of total blood volume with a 10-min recovery between each aliquot. Data were downloaded directly from a commercial monitoring system into a proprietary PC-based software package for analysis. Arterial and venous blood gas values, glucose, and cardiac output were collected at specified intervals. Electrocardiogram, electroencephalogram, mixed venous oxygen saturation, temperature (core and blood), mean arterial pressure, pulmonary artery pressure, central venous pressure, pulse oximetry, and end-tidal CO(2) were continuously monitored and downloaded. Seventeen of 19 animals (89%) died as a direct result of hemorrhage. Stored data streams were analyzed by the prototype artificial intelligence system. For this project, the artificial intelligence system identified and compared three electrocardiographic features (R-R interval, QRS amplitude, and R-S interval) from each of nine unknown samples of the QRS complex. We found that the artificial intelligence system, trained on only three electrocardiographic features, identified hemorrhage volume with an average accuracy of 91% (95% confidence interval, 84-96%). These experiments demonstrate that an artificial intelligence system, based solely on the analysis of QRS amplitude, R-R interval, and R-S interval of an electrocardiogram, is able to accurately identify hemorrhage volume in a porcine model of lethal hemorrhagic shock. We suggest that this technology may represent a noninvasive means of assessing the physiologic state during and immediately following hemorrhage. Point of care application of this technology may improve outcomes with earlier diagnosis and better titration of therapy of shock.
Evaluation of surgical treatment for ruptured Achilles tendon in 31 athletes.
Jallageas, R; Bordes, J; Daviet, J-C; Mabit, C; Coste, C
2013-09-01
In the past few decades, the incidence of Achilles tendon rupture has increased in parallel with increased sports participation. Although the optimal treatment remains controversial, there is a trend towards surgical treatment in athletes. Surgical repair of ruptured Achilles tendon in athlete results in good functional and objective recovery, irrespective of the type of surgery performed. Subsidiarily, are the results different between percutaneous surgery (PS) and standard open surgery (OS)? This was a cross-sectional study of 31 patients who presented with a ruptured Achilles tendon that occurred during sports participation. Percutaneous surgery was performed in 16 patients and open surgery in 15 patients between 2005 and 2009. The objective recovery status was evaluated by open chain goniometry, measurement of leg muscle atrophy and assessment of isokinetic strength. The functional analysis was based on the delay, level of sports upon return, AOFAS and VAS for pain. Our series of Achilles tendon rupture patients consisted of 88% men and 12% women, with an average age of 38 years. In 71% of cases, the rupture occurred during eccentric loading. After a follow-up of 15 months, the muscle atrophy was 13 mm after PS and 24 mm after OS (P=0.01). A strength deficit of 19% in the plantar flexors was found in the two groups. No patient experienced a rerupture. The return to sports occurred at 130 days after PS and 178 days after OS (P=0.005). The average AOFAS score was 94 and the VAS was 0.5. There were no differences in ankle range of motion between the two groups. The majority (77%) of patients had returned to their preinjury level of sports activity. The return to activities of daily living was slower in our study than in studies based in Anglo-Saxon countries; this can be explained by the different sick leave coverage systems. Percutaneous surgery resulted in a faster return to sports (about 130 days) and less muscle atrophy than open surgery. Our results for return to sports and return to preinjury levels were similar to published results for athletes and were independent of the type of surgery performed. The AOFAS score was comparable to published studies. We found no difference in muscle strength between the two surgery groups 15 months after the procedure. Apart from venous thrombosis typically described after lower-limb immobilization, secondary postoperative complications mostly consisted of sural paresthesia, which had resolved at the 15-month postoperative follow-up evaluation. The results of surgical treatment for ruptured Achilles tendon are good overall. By combining the simplicity of conservative treatment and the reliability of standard surgical treatment, percutaneous surgery is the treatment of choice to achieve excellent results. The return to sports occurred earlier, the muscle atrophy was less and the functional score was better in our patients treated by percutaneous surgery. Level IV. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Neck length and mean arterial pressure in the sauropod dinosaurs.
Hughes, Stephen; Barry, John; Russell, Jeremy; Bell, Robert; Gurung, Som
2016-04-15
How blood was able to reach the heads of the long-necked sauropod dinosaurs has long been a matter of debate and several hypotheses have been presented. For example, it has been proposed that sauropods had exceptionally large hearts, multiple 'normal' sized hearts spaced at regular intervals up the neck or held their necks horizontal, or that the siphon effect was in operation. By means of an experimental model, we demonstrate that the siphon principle is able to explain how blood was able to adequately perfuse the sauropod brain. The return venous circulation may have been protected from complete collapse by a structure akin to the vertebral venous plexus. We derive an equation relating neck height and mean arterial pressure, which indicates that with a mean arterial pressure similar to that of the giraffe, the maximum safe vertical distance between heart and head would have been about 12 m. A hypothesis is presented that the maximum neck length in the fossil record is due to the siphon height limit. The equation indicates that to migrate over high ground, sauropods would have had to either significantly increase their mean arterial pressure or keep their necks below a certain height dependent on altitude. © 2016. Published by The Company of Biologists Ltd.
Effects of spaceflight on human calf hemodynamics
NASA Technical Reports Server (NTRS)
Watenpaugh, D. E.; Buckey, J. C.; Lane, L. D.; Gaffney, F. A.; Levine, B. D.; Moore, W. E.; Wright, S. J.; Blomqvist, C. G.
2001-01-01
Chronic microgravity may modify adaptations of the leg circulation to gravitational pressures. We measured resting calf compliance and blood flow with venous occlusion plethysmography, and arterial blood pressure with sphygmomanometry, in seven subjects before, during, and after spaceflight. Calf vascular resistance equaled mean arterial pressure divided by calf flow. Compliance equaled the slope of the calf volume change and venous occlusion pressure relationship for thigh cuff pressures of 20, 40, 60, and 80 mmHg held for 1, 2, 3, and 4 min, respectively, with 1-min breaks between occlusions. Calf blood flow decreased 41% in microgravity (to 1.15 +/- 0.16 ml x 100 ml(-1) x min(-1)) relative to 1-G supine conditions (1.94 +/- 0.19 ml x 100 ml(-1) x min(-1), P = 0.01), and arterial pressure tended to increase (P = 0.05), such that calf vascular resistance doubled in microgravity (preflight: 43 +/- 4 units; in-flight: 83 +/- 13 units; P < 0.001) yet returned to preflight levels after flight. Calf compliance remained unchanged in microgravity but tended to increase during the first week postflight (P > 0.2). Calf vasoconstriction in microgravity qualitatively agrees with the "upright set-point" hypothesis: the circulation seeks conditions approximating upright posture on Earth. No calf hemodynamic result exhibited obvious mechanistic implications for postflight orthostatic intolerance.
Cherpanath, Thomas G V; Hirsch, Alexander; Geerts, Bart F; Lagrand, Wim K; Leeflang, Mariska M; Schultz, Marcus J; Groeneveld, A B Johan
2016-05-01
Passive leg raising creates a reversible increase in venous return allowing for the prediction of fluid responsiveness. However, the amount of venous return may vary in various clinical settings potentially affecting the diagnostic performance of passive leg raising. Therefore we performed a systematic meta-analysis determining the diagnostic performance of passive leg raising in different clinical settings with exploration of patient characteristics, measurement techniques, and outcome variables. PubMed, EMBASE, the Cochrane Database of Systematic Reviews, and citation tracking of relevant articles. Clinical trials were selected when passive leg raising was performed in combination with a fluid challenge as gold standard to define fluid responders and non-responders. Trials were included if data were reported allowing the extraction of sensitivity, specificity, and area under the receiver operating characteristic curve. Twenty-three studies with a total of 1,013 patients and 1,034 fluid challenges were included. The analysis demonstrated a pooled sensitivity of 86% (95% CI, 79-92), pooled specificity of 92% (95% CI, 88-96), and a summary area under the receiver operating characteristic curve of 0.95 (95% CI, 0.92-0.98). Mode of ventilation, type of fluid used, passive leg raising starting position, and measurement technique did not affect the diagnostic performance of passive leg raising. The use of changes in pulse pressure on passive leg raising showed a lower diagnostic performance when compared with passive leg raising-induced changes in flow variables, such as cardiac output or its direct derivatives (sensitivity of 58% [95% CI, 44-70] and specificity of 83% [95% CI, 68-92] vs sensitivity of 85% [95% CI, 78-90] and specificity of 92% [95% CI, 87-94], respectively; p < 0.001). Passive leg raising retains a high diagnostic performance in various clinical settings and patient groups. The predictive value of a change in pulse pressure on passive leg raising is inferior to a passive leg raising-induced change in a flow variable.
Microemboli in our bypass circuits: a contemporary audit.
Willcox, Timothy W; Mitchell, Simon J
2009-12-01
Cardiopulmonary bypass (CPB) may introduce microemboli into the patient's arterial circulation. These may arise from the CPB circuit. Most relevant studies have been performed in vitro; there are relatively few clinical studies. We used the Emboli Detection and Classification quantifier (EDAC) (Luna Innovations, Roanoke, VA) in a prospective clinical audit of emboli in a contemporary CPB circuit. Following ethics approval, standard clinical CPB circuits in patients undergoing CPB were instrumented with three EDAC system probes placed on the venous line, outlet of the hard-shell venous reservoir (HSVR), and distal to the arterial line filter. This was synchronized with the perfusion data management system and emboli number and volume were recorded at 30-second intervals. Recorded observations and combined data from both the EDAC and data management system were analyzed. We report data from the first 12 patients (24.5 hours of CPB) of a larger series currently being performed. The mean total emboli count per minute was significantly greater downstream of the HSVR than in the venous line and significantly less downstream of the arterial line filter than either of the above. The total count downstream of both the HSVR and the arterial line filter was greater when the vent pump was on vs. off. Despite the significant increase in emboli count downstream of the reservoir during vent operation there was a significant reduction in the total volume of emboli in this position compared with the venous line. This was further reduced by the arterial line filter. Nevertheless, the total embolic volume was greater downstream of the HSVR and the arterial filter with the vent on vs. off. The two overwhelming sources of emboli emanating from our CPB circuit were the use of the left ventricular vent and air entrained from the venous line. Such audit enables refinement of CPB management and potential component redesign which may make CPB safer and improve patient outcome.
Nanda, Sunil Kumar; Ray, Lopamudra; Dinakaran, Asha
2015-02-01
Electrolyte abnormalities are one of the common causes of morbidity and mortality in critically ill patients. The turnaround time for electrolyte reporting should be as low as possible. Electrolytes are measured conventionally in serum obtained from venous blood by electrolyte analyser which takes 20 to 30 min. Point of care analysers are now available where in electrolytes can be measured in arterial blood within 5 min. This study was done to study the agreement of arterial sodium and arterial potassium with venous sodium and venous potassium levels. Venous sodium and venous potassium levels and arterial sodium and arterial potassium levels were analysed on 206 patient samples admitted to Intensive Care Unit (ICU). The venous values were compared with the arterial values for correlation. Venous sodium was compared with arterial sodium by spearman correlation. Venous potassium was compared with arterial potassium by pearson correlation. The mean value of arterial sodium was 134 and venous sodium was 137. The mean value of arterial potassium was 3.6 and venous potassium was 4.1. The correlation coefficient obtained for sodium was 0.787 and correlation coefficient obtained for potassium was 0.701. There was positive correlation of arterial sodium and arterial potassium with venous sodium and venous potassium indicating agreement between the parameters. Arterial sodium and arterial potassium can be used instead of venous sodium and venous potassium levels in management of critically ill patients.
Effect of tilting on blood pressure and interstitial fluid pressures of bluefish and smooth dogfish.
Ogilvy, C S; DuBois, A B
1982-01-01
Tolerance of the circulatory system of fish for gravitational stress has not been measured previously. We examined this in bluefish (Pomatomus saltatrix) and smooth dogfish (Mustelus canis) by placing them horizontally on a V-board in air while their gills were perfused with aerated seawater, then tilting them head up for 0.5 h, and finally returning them to horizontal. Meanwhile, we recorded the blood pressure, pulse pressure, and heart rate in the ventral aorta, and interstitial fluid pressure in the head and tail. All four bluefish tolerated a 30 degrees tilt or even a 60 degrees tilt with little change in blood pressure or interstitial pressure in the anterior and posterior regions. All recovered afterward. However, in the seven dogfish examined, the posterior interstitial fluid pressure increased from 2.8 +/- 1.0 cmH2O before tilting to 11.8 +/- 3.3 cmH2O toward the end of a 30 degrees tilt lasting 30 min. The blood pressure decreased as the pulse pressure approached zero, showing that circulatory insufficiency had developed due to insufficient venous return to the heart. Most of the dogfish died within a few hours after the experiment. These findings are in keeping with the conclusion that the vasculature of bluefish has more rigidity, less permeability, and perhaps more compensatory tone than that of smooth dogfish. We speculate that bluefish may have evolved their circulatory tolerance for gravity as a cross-adaptation to the stresses imposed on the circulation by forward acceleration and by regional differences of transcutaneous pressure occurring during fast carangiform swimming.
Respiration and the watershed of spinal CSF flow in humans.
Dreha-Kulaczewski, Steffi; Konopka, Mareen; Joseph, Arun A; Kollmeier, Jost; Merboldt, Klaus-Dietmar; Ludwig, Hans-Christoph; Gärtner, Jutta; Frahm, Jens
2018-04-04
The dynamics of human CSF in brain and upper spinal canal are regulated by inspiration and connected to the venous system through associated pressure changes. Upward CSF flow into the head during inspiration counterbalances venous flow out of the brain. Here, we investigated CSF motion along the spinal canal by real-time phase-contrast flow MRI at high spatial and temporal resolution. Results reveal a watershed of spinal CSF dynamics which divides flow behavior at about the level of the heart. While forced inspiration prompts upward surge of CSF flow volumes in the entire spinal canal, ensuing expiration leads to pronounced downward CSF flow, but only in the lower canal. The resulting pattern of net flow volumes during forced respiration yields upward CSF motion in the upper and downward flow in the lower spinal canal. These observations most likely reflect closely coupled CSF and venous systems as both large caval veins and their anastomosing vertebral plexus react to respiration-induced pressure changes.
Congenital absence of the portal vein: clinical and radiologic findings.
Niwa, Tetsu; Aida, Noriko; Tachibana, Katsuhiko; Shinkai, Masato; Ohhama, Youkatsu; Fujita, Kazutoshi; Abe, Aya; Lee, Jin; Ozawa, Yukihiko; Inoue, Tomio
2002-01-01
Congenital absence of the portal vein (CAPV) is a rare anomaly in which the intestinal and splenic venous drainage bypasses the liver and drains into the systemic veins through various venous shunts. In patients with CAPV, the portosystemic shunting causes disruption of the enterohepatic circulation and leads to various clinical manifestations. CAPV can be diagnosed without invasive techniques. This article illustrates the clinical and radiologic findings (including ultrasound, CT, and MRI) of CAPV.
Kugelman, David N.; Qatu, Abdullah M.; Haglin, Jack M.; Konda, Sanjit R.; Egol, Kenneth A.
2017-01-01
Background: Tibial plateau fractures can be devastating traumatic injuries to the knee, particularly in active athletes. Purpose/Hypothesis: The purpose of this study was to report on the return to participation in recreational athletics after operatively managed tibial plateau fractures. In addition, this study assessed factors associated with the ability to return to participation in recreational athletics after tibial plateau fractures treated with open reduction internal fixation and compared final outcomes between patients who were able to return to recreational athletics and those who could not. The hypothesis was that returning to participation in recreational athletics would be dependent on the time from surgery after operative fixation of tibial plateau fractures. Less severe injuries would be associated with a quicker return to athletics. Study Design: Case-control study; Level of evidence, 3. Methods: All tibial plateau fractures treated by 1 of 3 surgeons at a single academic institution over an 11-year period were prospectively followed. Final outcomes were evaluated using the Short Musculoskeletal Function Assessment at latest follow-up. All complications were recorded at each follow-up. Differences between the groups were compared using Student t tests for continuous variables. Chi-square analysis was used to determine whether differences between categorical variables existed. Logistic regression was performed to assess independent variables associated with returning to participation in recreational athletics. Results: A total of 169 patients who underwent operative management of their tibial plateau fracture reported participation in recreational athletics before their injury. By the 6-month time point, 48 patients (31.6%) had returned to participation in recreational athletics, and at final follow-up (mean, 15 months), 89 patients (52.4%) had returned to participation in recreational athletics. Predictors of returning to recreational athletics included white race, female sex, social alcohol consumption, younger age, increased range of motion (ROM), low-energy Schatzker patterns (I-III), injuries not inclusive of orthopaedic polytrauma or open fractures, and no postoperative complications. White race, social alcohol consumption, and increased ROM were associated with returning to athletics at both 6-month and final follow-up. Lack of a venous thromboembolism was associated with returning to athletics at final follow-up. Patients who returned to recreational athletics had associations with better functional outcomes and emotional status than those who did not. Conclusion: The number of patients who returned to participation in recreational athletics gradually increased over time after operative fixation of tibial plateau fractures. Less severe injuries and a lack of postoperative complications were associated with a quicker return to athletics. Predictors of returning to participation in recreational athletics after operatively managed tibial plateau fractures can be used to target patients at risk of not returning to play to provide interventions aimed at improving their recovery, such as early knee range of motion, muscle strengthening, and participation in low-impact activities. PMID:29276713
Peripheral arteriovenous fistula as vascular access for long-term chemotherapy.
Kovalyov, Oleksiy O; Kostyuk, Oleksandr G; Tkachuk, Tetyana V
To provide long-term vascular access in clinical oncology peripheral forearm veins (up to 95% of patients in Ukraine), central venous access and "complete implanted vascular systems" are used most often. Many oncology patients have contraindications to catheterization of superior vena cava. Besides, exploitation of central veins is associated with potential technical and infectious complications. The aim - to study short-term and long-term results of arteriovenous fistula exploitation as vascular access for continuous anticancer therapy. Peripheral venous bed status in 41 oncology patients taking long-term chemotherapy treatment is analyzed in the article. Doppler sonography, morphologic and immune histochemical analyses were used in the study. Doppler sonography found qualitative and quantitative changes in forearm veins at different time periods after initiation of chemotherapy in the majority of patients. The major morphologic manifestations of venous wall damage were chemical phlebitis, local or extended hardening of venous wall, venous thrombosis and extravasations with necrosis and subsequent paravasal tissue sclerosis. Alternative vascular access created in 12 patients completely met the adequacy criteria (safety, multiple use, longevity, realization of the designed therapy program). The conclusion was made about inapplicability of forearm veins for long-term administration of cytostatic agents. If it is impossible to use central veins, arteriovenous fistula can become an alternative vascular access.
[Injuries to blood vessels near the heart caused by central venous catheters].
Abram, J; Klocker, J; Innerhofer-Pompernigg, N; Mittermayr, M; Freund, M C; Gravenstein, N; Wenzel, V
2016-11-01
Injuries to blood vessels near the heart can quickly become life-threatening and include arterial injuries during central venous puncture, which can lead to hemorrhagic shock. We report 6 patients in whom injury to the subclavian artery and vein led to life-threatening complications. Central venous catheters are associated with a multitude of risks, such as venous thrombosis, air embolism, systemic or local infections, paresthesia, hemothorax, pneumothorax, and cervical hematoma, which are not always immediately discernible. The subclavian catheter is at a somewhat lower risk of catheter-associated sepsis and symptomatic venous thrombosis than approaches via the internal jugular and femoral veins. Indeed, access via the subclavian vein carries a substantial risk of pneumo- and hemothorax. Damage to the subclavian vein or artery can also occur during deliberate and inadvertent punctures and result in life-threatening complications. Therefore, careful consideration of the access route is required in relation to the patient and the clinical situation, to keep the incidence of complications as low as possible. For catheterization of the subclavian vein, puncture of the axillary vein in the infraclavicular fossa is a good alternative, because ultrasound imaging of the target vessel is easier than in the subclavian vein and the puncture can be performed much further from the lung.
Filkor, Kata; Németh, Tibor; Nagy, István; Kondorosi, Éva; Urbán, Edit; Kemény, Lajos; Szolnoky, Győző
2016-08-01
The systemic host defence mechanisms, especially innate immunity, in venous leg ulcer patients are poorly investigated. The aim of the current study was to measure Candida albicans killing activity and gene expressions of pro- and anti-inflammatory cytokines and innate immune response regulators, TAM receptors and ligands of peripheral blood mononuclear cells separated from 69 venous leg ulcer patients and 42 control probands. Leg ulcer patients were stratified into responder and non-responder groups on the basis of wound healing properties. No statistical differences were found in Candida killing among controls, responders and non-responders. Circulating blood mononuclear cells of patients overexpress pro-inflammatory (IL-1α, TNFα, CXCL-8) and anti-inflammatory (IL-10) cytokines as well as TAM receptors (Tyro, Axl, MerTK) and their ligands Gas6 and Protein S compared with those of control individuals. IL-1α is notably overexpressed in venous leg ulcer treatment non-responders; in contrast, Axl gene expression is robustly stronger among responders. These markers may be considered as candidates for the prediction of treatment response among venous leg ulcer patients. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.
Development of the human infrahepatic inferior caval and azygos venous systems
Hikspoors, Jill P J M; Soffers, Jelly H M; Mekonen, Hayelom K; Cornillie, Pieter; Köhler, S Eleonore; Lamers, Wouter H
2015-01-01
Differences in opinion regarding the development of the infrahepatic inferior caval and azygos venous systems in mammals centre on the contributions of ‘caudal cardinal’, ‘subcardinal’, ‘supracardinal’, ‘medial and lateral sympathetic line’ and ‘sacrocardinal’ veins. The disagreements appear to arise from the use of topographical position rather than developmental origin as criterion to define separate venous systems. We reinvestigated the issue in a closely spaced series of human embryos between 4 and 10 weeks of development. Structures were visualized with the Amira® reconstruction and Cinema4D® remodelling software. The vertebral level and neighbouring structures were used as topographic landmarks. The main results were that the caudal cardinal veins extended caudally from the common cardinal vein between CS11 and CS15, followed by the development of the subcardinal veins as a plexus sprouting ventrally from the caudal cardinal veins. The caudal cardinal veins adapted their course from lateral to medial relative to the laterally expanding lungs, adrenal glands, definitive kidneys, sympathetic trunk and umbilical arteries between CS15 and CS18, and then became interrupted in the part overlaying the regressing mesonephroi (Th12-L3). The caudal part of the left caudal cardinal vein then also regressed. The infrarenal part of the inferior caval vein originated from the right caudal cardinal vein, while the renal part originated from subcardinal veins. The azygos veins developed from the remaining cranial part of the caudal cardinal veins. Our data show that all parts of the inferior caval and azygos venous systems developed directly from the caudal cardinal veins or from a plexus sprouting from these veins. PMID:25496171
Interventions to enhance patient compliance with leg ulcer treatment: a review of the literature.
Van Hecke, Ann; Grypdonck, Maria; Defloor, Tom
2008-01-01
Non-compliance with compression therapy and with leg exercises and leg elevation is a common problem, often reported in patients with venous leg ulceration. Studies on compliance-enhancing interventions and the effectiveness of these interventions in patients with venous leg ulceration were reviewed. MEDLINE, Cochrane, Embase and CINAHL were explored up to April 2005. Reference lists, wound care journals and conference proceedings were searched. Experts and manufacturers of compression systems were contacted. Studies were eligible if they included patients with venous or mixed leg ulcers and reported patient compliance outcome. Twenty studies were included. Most studies describe patient compliance as the extent to which the compression system was worn and/or the extent to which treatment regimen was followed. Self-reporting was the most commonly used method of compliance assessment. There are indications that class III stockings for patients with venous ulcers enhance compliance compared with short stretch compression bandages. No real evidence is found that intermittent pneumatic compression systems improved compliance. There is no well-documented evidence that healthcare system interventions increase compliance. Educational programmes combining cognitive, behavioural and affective components were shown to have a positive effect on leg elevation, but not on compliance with compression therapy. The included studies have a lack of consistency in defining the standard and operationalization of compliance. Patient compliance plays an ancillary role in research. No study has been able to offer an acceptable and well-documented solution to the non-compliance problem. Research might focus on the development of comprehensive compliance-enhancing strategies. A stronger commitment of healthcare providers and society is needed to make progress in this area. The scope of nursing must be expanded to also include the problems experienced by patients with leg ulcers and the improvement of patient compliance.
Duration and Adverse Events of Non-cuffed Catheter in Patients With Hemodialysis
2014-10-09
Renal Failure Chronic Requiring Hemodialysis; Central Venous Catheterization; Inadequate Hemodialysis Blood Flow; Venous Stenosis; Venous Thrombosis; Infection Due to Central Venous Catheter; Central Venous Catheter Thrombosis
Quan, Reagan W; Gillespie, David L; Stuart, Rory P; Chang, Audrey S; Whittaker, David R; Fox, Charles J
2008-03-01
The management of venous trauma remains controversial. Critics of venous repair have cited an increased incidence of associated venous thromboembolic events with this management. We analyzed the current treatment of wartime venous injuries in United States military personnel in an effort to answer this question. From December 1, 2001, to October 31, 2005, all United States casualties with named venous injuries were evaluated. A retrospective review of a clinical database was performed on demographics, mechanism of injury, associated injuries, treatment, outcomes, and venous thromboembolic events. Data were analyzed using the Fisher exact test, analysis of variance, and logarithmic transformation. During this 5-year period, 82 patients sustained 103 named venous injuries due to combat operations. All patients were male, with an average age of 27.9 years (range, 20.3-58.3 years). Blast injuries accounted for 54 venous injuries (65.9%), gunshot wounds for 25 (30.5%), and motor vehicle accidents for 3 (3.6%). The venous injury was isolated in 28 patients (34.1%), and 16 (19.5%) had multiple venous injuries. The venous injury in two patients was associated with acute phlegmasia, with fractures in 33 (40.2%), and 22 (28.1%) sustained neurologic deficits. Venous injuries were treated by ligation in 65 patients (63.1%) and by open surgical repair in 38 (36.9%). Postoperative extremity edema occurred in all patients irrespective of method of management. Thrombosis after venous repair occurred in six of the 38 cases (15.8%). Pulmonary emboli developed in three patients, one after open repair and two after ligation (P > .99). In the largest review of military venous trauma in more than three decades, we found no difference in the incidence of venous thromboembolic complications between venous injuries managed by open repair vs ligation. Blast injuries of the extremities have caused most of the venous injuries. Ligation is the most common modality of treatment in combat zones. Long-term morbidity associated with venous injuries and their management will be assessed in future follow-up studies.
Jacobsen, Katja Kemp; Brandt, Ida; Christensen, Anne Vindahl; Rimsø, Bjørk Anine; Krøier, Camilla Julie; Sørensen, Michelle; Smith, Julie; Jensen, Kathrine Overgaard Foss; Larsen, Jeppe Madura
2018-06-01
Deviation in blood collection procedures is a central source of preanalytical variation affecting overall analytical and diagnostic precision. The order of draw of venous sampling is suspected to affect analytical results, in particular for coagulation analysis. Here we compare the procedures in venous blood sampling among clinical biochemistry departments to assess the uniformity of order of blood draw and adherence to international guidelines in the Danish health care system. We collected venous order of draw procedures from 49 clinical biochemistry departments at 22 public hospitals in Denmark. Procedures were compared to the international guidelines fromthe Clinical Laboratory Standards Institute (CLSI) and World Health Organization (WHO), and assessed in relation to department ISO 15189:2012 accreditation. We observed seven different order of draw procedures related to citrate, serum, heparin, and EDTA tubes, and the use of discard tubes in relation to coagulation assays. 31 departments (63.3%) were found to adhere to CLSI and WHO guidelines. A majority of departments instructs the use of discard tubes before collection for coagulation assays in citrate tubes (44 departments; 89.8%). The citrate tube was the first sample tube to be drawn for most departments (35 departments; 75.5%); and the preferred order of non-citrate tubes was serum-heparin-EDTA (36 departments; 73.5%). Adherence to the CLSI and WHO guidelines was not associated with department ISO 15189:2012 accreditation (p = .57). Venous order of draw procedures is diverse at Danish clinical biochemistry departments and show moderate adherence to international guidelines. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
Cerebral venous thrombosis with nonhemorrhagic lesions: clinical correlates and prognosis.
Ferro, José M; Canhão, Patrícia; Bousser, Marie-Germaine; Stam, Jan; Barinagarrementeria, Fernando; Stolz, Erwin
2010-01-01
Brain imaging of patients with acute cerebral venous thrombosis often shows parenchymal hemorrhagic and nonhemorrhagic lesions. The clinical relevance of nonhemorrhagic lesions is poorly known. In the International Study on Cerebral Vein and Dural Sinus Thrombosis cohort, demographic, clinical, risk factor, prognosis and imaging findings were compared between patients with parenchymal nonhemorrhagic lesions and no hemorrhagic lesions (NHL) and (1) patients with parenchymal hemorrhagic lesions (HL) and (2) patients without brain lesions. Predictors of prognosis at the end of follow-up in the NHL group were analyzed by bivariate and Cox regression methods. We identified 147 patients (23.6%) with NHL. When compared to patients without brain lesions (n = 309), those with NHL more often presented mental status disturbances, aphasia, decreased alertness, motor deficits, seizures, occlusions of the straight sinus, deep venous system and cortical veins. Patients with NHL had a better prognosis in the acute phase and at the end of follow-up than those with HL, but a worse one than patients without brain lesions, as more NHL patients were dead or dependent (modified Rankin Scale score = 3-6) at discharge (19.7 vs. 6.5%, p < 0.001) and final follow-up (14.3 vs. 7.4%, p = 0.03). In Cox regression analysis, coma (HR = 13.7; 95% CI = 4.3-43.7) and thrombosis of the deep venous system (HR = 3.5; 95% CI = 1.4-8.7) were associated with death or dependency at the end of follow-up. Cerebral venous thrombosis patients with NHL are intermediate between patients without brain lesions and those with HL, both in initial clinical picture and prognosis. Copyright 2010 S. Karger AG, Basel.
Emmerechts, J; Alfaro-Moreno, E; Vanaudenaerde, B M; Nemery, B; Hoylaerts, M F
2010-12-01
Epidemiological findings suggest an association between exposure to particulate matter (PM) and venous thrombo-embolism. To investigate arterial vs. venous thrombosis, inflammation and coagulation in mice, (sub)acutely exposed to two types of PM. Various doses (25, 100 and 200 μg per animal) of urban particulate matter (UPM) or diesel exhaust particles (DEP) were intratracheally (i.t.) instilled in C57Bl6/n mice and several endpoints measured at 4, 10 and 24 h. Mice were also repeatedly exposed to 100 μg per animal on three consecutive days with endpoints measured 24 h after the last instillation. Exposure to 200 μg per mouse UPM enhanced arterial thrombosis, but neither UPM nor DEP significantly enhanced venous thrombosis. Both types of PM induced dose-dependent increases in broncho-alveolar lavage fluid (BALF) total cell numbers (mainly neutrophils) and cytokines (IL-6, KC, MCP-1, RANTES, MIP-1α), with peaks at 4 h and overall higher values for UPM than for DEP. Systemic inflammation was limited to increased serum IL-6 levels, 4 h after UPM. Both types of PM induced similar and dose-dependent but modest increases in factor (F)VII, FVIII and fibrinogen. Three repeated instillations did not or only modestly enhance the proinflammatory and procoagulant status. Compared with DEP, UPM induced more pronounced pulmonary inflammation, but both particle types triggered similar and mild short-term systemic effects. Hence, acute exposure to PM triggers activation of primary hemostasis in the mouse, but no substantial secondary hemostasis activation, resulting in arterial but not venous thrombogenicity. © 2010 International Society on Thrombosis and Haemostasis.
Microgravity Testing of a Surface Sampling System for Sample Return from Small Solar System Bodies
NASA Technical Reports Server (NTRS)
Franzen, M. A.; Preble, J.; Schoenoff, M.; Halona, K.; Long, T. E.; Park, T.; Sears, D. W. G.
2004-01-01
The return of samples from solar system bodies is becoming an essential element of solar system exploration. The recent National Research Council Solar System Exploration Decadal Survey identified six sample return missions as high priority missions: South-Aitken Basin Sample Return, Comet Surface Sample Return, Comet Surface Sample Return-sample from selected surface sites, Asteroid Lander/Rover/Sample Return, Comet Nucleus Sample Return-cold samples from depth, and Mars Sample Return [1] and the NASA Roadmap also includes sample return missions [2] . Sample collection methods that have been flown on robotic spacecraft to date return subgram quantities, but many scientific issues (like bulk composition, particle size distributions, petrology, chronology) require tens to hundreds of grams of sample. Many complex sample collection devices have been proposed, however, small robotic missions require simplicity. We present here the results of experiments done with a simple but innovative collection system for sample return from small solar system bodies.
Patterns and Rates of Supplementary Venous Drainage to the Internal Jugular Veins.
Qureshi, Adnan I; Ishfaq, Muhammad Fawad; Herial, Nabeel A; Khan, Asif A; Suri, M Fareed K
2016-07-01
Several studies have found supplemental venous drainage channels in addition to bilateral internal jugular veins for cerebral venous efflux. We performed this study to characterize the supplemental venous outflow patterns in a consecutive series of patients undergoing detailed cerebral angiography with venous phase imaging. The venographic phase of the arteriogram was reviewed to identify and classify supplemental cerebral venous drainage into anterior (cavernous venous sinus draining into pterygoid plexus and retromandibular vein) and posterior drainage pattern. The posterior drainage pattern was further divided into plexiform pattern (with sigmoid venous sinus draining into the paravertebral venous plexus), and solitary vein pattern (dominant single draining deep cervical vein) drainage. The posterior plexiform pattern was further divided into 2 groups: posterior plexiform with or without prominent solitary vein. Supplemental venous drainage was seen ipsilateral to internal jugular vein in 76 (43.7%) of 174 venous drainages (87 patients) analyzed. The patterns were anterior (n = 23, 13.2%), posterior plexiform without prominent solitary vein (n = 40, 23%), posterior plexiform with prominent solitary vein (n = 62, 35.6%), and posterior solitary vein alone (n = 3, 1.7%); occipital emissary veins and/or transosseous veins were seen in 1 supplemental venous drainage. Concurrent ipsilateral anterior and posterior supplemental drainage was seen in 6 of 174 venous drainages analyzed. We provide an assessment of patterns and rates of supplementary venous drainage to internal jugular veins to improve our understanding of anatomical and physiological aspects of cerebral venous drainage. Copyright © 2016 by the American Society of Neuroimaging.
2011-01-01
Introduction Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0/1000 people have active leg ulcers. Prevalence increases with age to about 20/1000 in people aged over 80 years. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of standard treatments, adjuvant treatments, and organisational interventions for venous leg ulcers? What are the effects of advice about self-help interventions in people receiving usual care for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 101 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression bandages and stockings, cultured allogenic (single or bilayer) skin replacement, debriding agents, dressings (cellulose, collagen, film, foam, hyaluronic acid-derived, semi-occlusive alginate), hydrocolloid (occlusive) dressings in the presence of compression, intermittent pneumatic compression, intravenous prostaglandin E1, larval therapy, laser treatment (low-level), leg ulcer clinics, multilayer elastic system, multilayer elastomeric (or non-elastomeric) high-compression regimens or bandages, oral treatments (aspirin, flavonoids, pentoxifylline, rutosides, stanozolol, sulodexide, thromboxane alpha2 antagonists, zinc), peri-ulcer injection of granulocyte-macrophage colony-stimulating factor, self-help (advice to elevate leg, to keep leg active, to modify diet, to stop smoking, to reduce weight), short-stretch bandages, single-layer non-elastic system, skin grafting, superficial vein surgery, systemic mesoglycan, therapeutic ultrasound, and topical treatments (antimicrobial agents, autologous platelet lysate, calcitonin gene-related peptide plus vasoactive intestinal polypeptide, freeze-dried keratinocyte lysate, mesoglycan, negative pressure, recombinant keratinocyte growth factor, platelet-derived growth factor). PMID:22189344
The possibility for use of venous flaps in plastic surgery
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baytinger, V. F., E-mail: baitinger@mail.tomsknet.ru; Kurochkina, O. S., E-mail: kurochkinaos@yandex.ru; Selianinov, K. V.
2015-11-17
The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were nomore » differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.« less
Phlebitis: treatment, care and prevention.
Higginson, Ray; Parry, Andrew
Peripheral venous catheter-associated phlebitis is caused by inflammation to the vein at a cannula access site. It can have a mechanical, chemical or infectious cause. Good practice when inserting a cannula, including appropriate choice of device and site, can help to prevent phlebitis. Good infection control techniques are also vital in preventing the condition. There are two phlebitis scoring systems, which should be used in routine practice to identify and treat early signs of the Peripheral venous cannulation
Cui, Jian; McQuillan, Patrick M; Blaha, Cheryl; Kunselman, Allen R; Sinoway, Lawrence I
2012-08-15
We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P < 0.01) and more sustained MSNA and blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects.
Czihal, M; Paul, S; Rademacher, A; Bernau, C; Hoffmann, U
2015-03-01
To explore the association of the postthrombotic syndrome with venous hemodynamics and morphological abnormalities after upper extremity deep venous thrombosis. Thirty-seven patients with a history of upper extremity deep venous thrombosis treated with anticoagulation alone underwent a single study visit (mean time after diagnosis: 44.4 ± 28.1 months). Presence and severity postthrombotic syndrome were classified according to the modified Villalta score. Venous volume and venous emptying were determined by strain-gauge plethysmography. The arm veins were assessed for postthrombotic abnormalities by ultrasonography. The relationship between postthrombotic syndrome and hemodynamic and morphological sequelae was evaluated using univariate significance tests and Spearman's correlation analysis. Fifteen of 37 patients (40.5%) developed postthrombotic syndrome. Venous volume and venous emptying of the arm affected by upper extremity deep venous thrombosis did not correlate with the Villalta score (rho = 0.17 and 0.19; p = 0.31 and 0.25, respectively). Residual morphological abnormalities, as assessed by ultrasonography, did not differ significantly between patients with and without postthrombotic syndrome (77.3% vs. 86.7%, p = 0.68). Postthrombotic syndrome after upper extremity deep venous thrombosis is not associated with venous hemodynamics or residual morphological abnormalities. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Fenn, Joe; Lam, Richard; Kenny, Patrick J
2013-01-01
Variations in intracranial dural venous sinus anatomy have been widely reported in humans, but there have been no studies reporting this in dogs. The purpose of this retrospective study was to describe variations in magnetic resonance (MR) venographic anatomy of the dorsal dural venous sinus system in a sample population of dogs with structurally normal brains. Medical records were searched for dogs with complete phase contrast, intracranial MR venograms and a diagnosis of idiopathic epilepsy. Magnetic resonance venograms were retrieved for each dog and characteristics of the dorsal dural sinuses, symmetry of the transverse sinuses and other anatomic variations were recorded. A total of 51 dogs were included. Transverse sinus asymmetry was present in 58.8% of the dogs, with transverse sinus hypoplasia seen in 39.2%, and aplasia in 23.5% of dogs. For 70.6% of dogs, at least one anatomic variation in the dorsal sagittal sinus was observed, including deviation from the midline (33.3%) and collateral branches from either the dorsal sagittal sinus or dorsal cerebral veins (54.9%). In 5 dogs (9.8%) a vessel was also identified running from the proximal transverse sinus to the distal sigmoid sinus, in a similar location to the occipital sinus previously reported in children. Findings from this study indicated that, as in humans, anatomic variations are common in the intracranial dural venous sinus system of dogs. These anatomic variations should be taken into consideration for surgical planning or diagnosis of cerebrovascular disease. © 2013 Veterinary Radiology & Ultrasound.
Gómez-Simón, Antonia; Navarro-Núñez, Leyre; Pérez-Ceballos, Elena; Lozano, María L; Candela, María J; Cascales, Almudena; Martínez, Constantino; Corral, Javier; Vicente, Vicente; Rivera, José
2007-06-01
Predonation hemoglobin measurement is a problematic requirement in mobile donation settings, where accurate determination of venous hemoglobin by hematology analyzers is not available. We have evaluated hemoglobin screening in prospective donors by the semiquantitative copper sulphate test and by capillary blood samples analyzed by three portable photometers, HemoCue, STAT-Site MHgb, and the CompoLab HB system. Capillary blood samples were obtained from 380 donors and tested by the copper sulphate test and by at least one of the named portable photometers. Predonation venous hemoglobin was also determined in all donors using a Coulter Max-M analyzer. The three photometers provided acceptable reproducibility (CV below 5%), and displayed a significant correlation between the capillary blood samples and the venous hemoglobin (R2 0.5-0.8). HemoCue showed the best agreement with venous hemoglobin determination, followed by STAT-Site MHgb, and the CompoLab HB system. The copper sulphate test provided the highest rate of donors acceptance (83%) despite unacceptable hemoglobin levels, and the lowest rate for donor deferral (1%) despite acceptable hemoglobin levels. The percentage of donors correctly categorized for blood donation by the portable hemoglobinometers was 85%, 82%, and 76% for CompoLab HB system, HemoCue and STAT-Site, respectively. Our data suggest that hemoglobin determination remains a conflictive issue in donor selection in the mobile setting. Without appropriate performance control, capillary hemoglobin screening by either the copper sulphate method or by the novel portable hemoglobinometers could be inaccurate, thus potentially affecting both donor safety and the blood supply.
Çildağ, Mehmet B; Ertuğrul, Mustafa B; Köseoğlu, Ömer Fk; Armstrong, David G
2018-01-01
The study aimed to evaluate the ratio of venous contamination in diabetic cases without foot lesion, with foot lesion and with Charcot neuroarthropathy (CN). Bolus-chase three-dimensional magnetic resonance (MR) of 396 extremities of patients with diabetes mellitus was analyzed, retrospectively. Extremities were divided into three groups as follows: diabetic patients without foot ulcer or Charcot arthropathy (Group A), patients with diabetic foot ulcers (Group B) and patients with CN accompanying diabetic foot ulcers (Group C). Furthermore, amount of venous contamination classified as no venous contamination, mild venous contamination, and severe venous contamination. The relationship between venous contamination and extremity groups was investigated. Severe venous contamination was seen in Group A, Group B, and Group C, 5.6%, 15.2%, and 34.1%, respectively. Statistically significant difference was seen between groups with regard to venous contamination. Venous contamination following bolus chase MR was higher in patients with CN.
Tapping but not massage enhances vasodilation and improves venous palpation of cutaneous veins.
Ichimura, Mika; Sasaki, Shinsuke; Mori, Masaharu; Ogino, Tetsuya
2015-01-01
This paper investigated whether tapping on the median cubital vein or massaging the forearm was more effective in obtaining better venous palpation for venipuncture. Forty healthy volunteers in their twenties were subjected to tapping (10 times in 5 sec) or massage (10 strokes in 20 sec from the wrist to the cubital fossa) under tourniquet inflation on the upper arm. Venous palpation was assessed using the venous palpation score (0-6, with 0 being impalpable). Three venous factors-venous depth, cross-sectional area, and elevation-were also measured using ultrasonography. The venous palpation score increased significantly by tapping but not by massage. Moreover, all 3 venous measurements changed significantly by tapping, while only the depth decreased significantly by massage. The three venous measurements correlated significantly with the venous palpation score, indicating that they are useful objective indicators for evaluating vasodilation. We suggest that tapping is an effective vasodilation technique.
Pulhorn, H; Hartley, J C; Shanmuganathan, M; Lee, C H; Harkness, W; Thompson, D N P
2014-09-01
Increasingly, Onyx is used for endovascular embolization of aneurysms and arterio-venous malformations. Although reports in the literature on the use of Onyx are favourable, there have been so far no reports on the central nervous system (CNS) infection rate after embolisation with Onyx and no recommendations as to the management of these infections. We present two cases of paediatric patients who acquired CNS infection with Pseudomonas aeruginosa after Onyx embolisation of AVMs and describe their subsequent management. Presence of established infection after Onyx embolisation should be dealt with by removal of infected material, administration of appropriate antibiotic therapy and supportive treatment.
The comparative anatomy of the forelimb veins of primates.
Thiranagama, R; Chamberlain, A T; Wood, B A
1989-01-01
One hundred and thirteen forelimbs taken from 62 individuals belonging to 17 primate genera were dissected to reveal the entire course of the superficial venous system. The course of the deep venous system was also documented in at least one forelimb of each primate genus, and the number and location of perforating veins was recorded in 18 human and 45 non-human primate limbs. In Pan, Gorilla and in about 25% of human specimens the lateral superficial vein was confined to the forearm, while in all other primates, and in the majority of humans, this vein extended from the carpus to the clavicular region. Only Pongo and humans exhibited a second main superficial vein on the medial side of the forearm. In all primates the deep veins of the forelimb usually accompanied the arteries. Thus variation in the deep venous system reflected the different arterial patterns exhibited by these primates. The number of perforating veins in the forelimb was related to the length of the limb. Primate genera with longer forelimbs had more perforators, though not as many as would be expected if the number of perforators scaled linearly with limb length. PMID:2514175
Mixing problems in using indicators for measuring regional blood flow
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ushioda, E.; Nuwayhid, B.; Tabsh, K.
A basic requirement for using indicators for measuring blood flow is adequate mixing of the indicator with blood prior to sampling the site. This requirement has been met by depositing the indicator in the heart and sampling from an artery. Recently, authors have injected microspheres into veins and sampled from venous sites. The present studies were designed to investigate the mixing problems in sheep and rabbits by means of Cardio-Green and labeled microspheres. The indicators were injected at different points in the circulatory system, and blood was sampled at different levels of the venous and arterial systems. Results show themore » following: (a) When an indicator of small molecular size (Cardio-Green) is allowed to pass through the heart chambers, adequate mixing is achieved, yielding accurate and reproducible results. (b) When any indicator (Cardio-Green or microspheres) is injected into veins, and sampling is done at any point in the venous system, mixing is inadequate, yielding flow results which are inconsistent and erratic. (c) For an indicator or large molecular size (microspheres), injecting into the left side of the heart and sampling from arterial sites yield accurate and reproducible results regardless of whether blood is sampled continuously or intermittently.« less
The biomechanics of leg ulceration.
Chant, A.
1999-01-01
Research performed in the late 1960s, using 24Na, suggested that the perfusion of skin and subcutaneous tissues is critically dependent on the relationship between capillary (Pc) and tissue pressures (Pt). Perfusion changes differed significantly between controls and patients with venous disease and the differences could be interpreted as evidence that Pt remained high in venous diseased patients. From this starting point, a biomechanical theory for the aetiology of venous ulceration was developed and tested by measuring skin elasticity, limb cross-sectional area and laser Doppler flux. The results confirm that, modelled as a two-compartment system (vascular and interstitial fluid), forces can be demonstrated sufficient to cause intermittent capillary closure and subsequent reperfusion injury. These forces are maximal in the gaiter area, the site of most leg ulcers. Images Figure 2 Figure 4 PMID:10364960
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thompson, J. F., E-mail: j.f.thompson@exeter.ac.uk; Winterborn, R. J.; Bays, S.
2011-10-15
Paget Schroetter syndrome, or effort thrombosis of the axillosubclavian venous system, is distinct from other forms of upper limb deep vein thrombosis. It occurs in younger patients and often is secondary to competitive sport, music, or strenuous occupation. If untreated, there is a higher incidence of disabling venous hypertension than was previously appreciated. Anticoagulation alone or in combination with thrombolysis leads to a high rate of rethrombosis. We have established a multidisciplinary protocol over 15 years, based on careful patient selection and a combination of lysis, decompressive surgery, and postoperative percutaneous venoplasty. During the past 10 years, a total ofmore » 232 decompression procedures have been performed. This article reviews the literature and presents the Exeter Protocol along with practical recommendations for management.« less
Aboud, Anas; Mederos-Dahms, Hendrikje; Liebing, Kai; Zittermann, Armin; Schubert, Harald; Murray, Edward; Renner, Andre; Gummert, Jan; Börgermann, Jochen
2015-05-29
Because of its low rate of clinical complications, miniaturized extracorporeal perfusion systems (MEPS) are frequently used in heart centers worldwide. However, many recent studies refer to the higher probability of gaseous microemboli formation by MEPS, caused by subzero pressure values. This is the main reason why various de-airing devices were developed for today's perfusion systems. In the present study, we investigated the potential benefits of a simple one-way-valve connected to a volume replacement reservoir (OVR) for volume and pressure compensation. In an experimental study on 26 pigs, we compared MEPS (n = 13) with MEPS plus OVR (n = 13). Except OVR, perfusion equipment was identical in both groups. Primary endpoints were pressure values in the venous line and the right atrium as well as the number and volume of air bubbles. Secondary endpoints were biochemical parameters of systemic inflammatory response, ischemia, hemodilution and hemolysis. One animal was lost in the MEPS + OVR group. In the MEPS + OVR group no pressure values below -150 mmHg in the venous line and no values under -100 mmHg in right atrium were noticed. On the contrary, nearly 20% of venous pressure values in the MEPS group were below -150 and approximately 10% of right atrial pressure values were below -100 mmHg. Compared with the MEPS group, the bubble counter device showed lower numbers of arterial air bubbles in the MEPS + OVR group (mean ± SD: 13444 ± 5709 vs. 1 ± 2, respectively; p < 0.001). In addition, bubble volume was significantly lower in the MEPS + OVR group than in the MEPS group (mean ± SD: 1522 ± 654 μl vs. 4 ± 6 μl, respectively; p < 0.001). The proinflammatory cytokine interleukin-6 and biochemical indices of cardiac ischemia (creatine kinase, and troponin I) were comparable between both groups. The use of a miniaturized perfusion system with a volume replacement reservoir is able to counteract excessive negative venous line pressures and to reduce the number and volume of arterial air bubbles. This approach may lead to a lower rate of neurological complications.
Jasiński, Ryszard; Socha, Małgorzata; Sitko, Ludmiła; Kubicka, Katarzyna; Woźniewski, Marek; Sobiech, Krzysztof A
2015-03-29
Nordic walking and water aerobics are very popular forms of physical activity in the elderly population. The aim of the study was to evaluate the influence of regular health training on the venous blood flow in lower extremities and body composition in women over 50 years old. Twenty-four women of mean age 57.9 (± 3.43) years, randomly divided into three groups (Nordic walking, water aerobics, and non-training), participated in the study. The training lasted 8 weeks, with one-hour sessions twice a week. Dietary habits were not changed. Before and after training vein refilling time and the function of the venous pump of the lower extremities were measured by photoplethysmography. Body composition was determined by bioelectrical impedance. Eight weeks of Nordic walking training improved the venous blood flow in lower extremities and normalized body composition in the direction of reducing chronic venous disorder risk factors. The average values of the refilling time variable (p = 0.04, p = 0.02, respectively) decreased in both the right and the left leg. After training a statistically significant increase in the venous pump function index was found only in the right leg (p = 0.04). A significant increase in fat-free mass, body cell mass and total body water was observed (p = 0.01), whereas body mass, the body mass index, and body fat decreased (p < 0.03). With regard to water aerobic training, no similar changes in the functions of the venous system or body composition were observed.
Instiaty, Insti; Lindegardh, Niklas; Jittmala, Podjanee; Hanpithakpong, Warunee; Blessborn, Daniel; Pukrittayakamee, Sasithon; White, Nicholas J.
2013-01-01
Oseltamivir and oseltamivir carboxylate concentrations were measured in venous plasma, venous blood, and capillary blood taken simultaneously from 24 healthy volunteers. Median (range) venous-blood-to-plasma ratios were 1.42 (0.920 to 1.97) for oseltamivir and 0.673 (0.564 to 0.814) for oseltamivir carboxylate. Capillary blood/venous plasma ratios were 1.32 (0.737 to 3.16) for oseltamivir and 0.685 (0.502 to 1.34) for oseltamivir carboxylate. Oseltamivir concentrations in venous and capillary blood were similar. Oseltamivir carboxylate showed a time-dependent distribution between venous and capillary blood. PMID:23507284
Risk factors associated with PICC-related upper extremity venous thrombosis in cancer patients.
Yi, Xiao-lei; Chen, Jie; Li, Jia; Feng, Liang; Wang, Yan; Zhu, Jia-An; Shen, E; Hu, Bing
2014-03-01
To investigate the incidence and risk factors for peripherally inserted central venous catheters-related upper extremity venous thrombosis in patients with cancer. With the widespread use of peripherally inserted central venous catheters, peripherally inserted central venous catheters-related upper extremity venous thrombosis in patients with cancer leads to increasing morbidity and mortality. It is very important to further explore the incidence and risk factors for peripherally inserted central venous catheters-related venous thrombosis. Consecutive patients with cancer who were scheduled to receive peripherally inserted central venous catheters, between September 2009 and May 2012, were prospectively studied in our centre. They were investigated for venous thrombosis by Doppler sonography three times a day within 30 days after catheter insertion. Univariable and multivariable logistic regressions' analyses were performed to identify the risk factors for peripherally inserted central venous catheters-related thrombosis. A total of 89 patients with cancer were studied in our research. Of these, 81 patients were followed up within one month. The mean interval between catheter insertion and the onset of thrombosis was 12.45 ± 6.17 days. The multivariable analyses showed that chemotherapy history, less activities and diabetes were the key risk factors for thrombosis. Peripherally inserted central venous catheters-related upper extremity venous thrombosis had high incidence rate, and most cases had no significant symptoms. The history of chemotherapy, less activities and diabetes were found to be the key risk factors. It should be routinely scanned in high-risk patients every 3-5 days after catheter insertion, which would then find blood clots in time and reduce the incidence of pulmonary embolism. Risk factors associated with peripherally inserted central venous catheters-related upper extremity venous thrombosis are of critical importance in improving the quality of patients' life. It is very important to grasp the indications to reduce the incidence rate of peripherally inserted central venous catheters-related upper extremity venous thrombosis. © 2013 John Wiley & Sons Ltd.
Chang, Yi-Fang; Lo, An-Chi; Tsai, Chung-Hsin; Lee, Pei-Yi; Sun, Shen; Chang, Te-Hsin; Chen, Chien-Chuan; Chang, Yuan-Shin; Chen, Jen-Ruei
2013-02-01
Totally implantable port systems are generally recommended for prolonged central venous access in diverse settings, but their risk of complications remains unclear for patients with advanced cancer. The aim of this study was to assess the risk of port system failure in patients with advanced cancer. We conducted a retrospective cohort study in a comprehensive cancer centre. A detailed chart review was conducted among 566 patients with 573 ports inserted during January-June, 2009 (average 345.3 catheter-days). Cox regression analysis was applied to evaluate factors during insertion and early maintenance that could lead to premature removal of the port systems due to infection or occlusion. Port system-related infection was significantly associated with receiving palliative care immediately after implantation (hazard ratio, HR = 7.3, 95% confidence interval, 95% CI = 1.2-46.0), after adjusting for probable confounders. Primary cancer site also impacted the occurrence of device-related infection. Receiving oncologic/palliative care (HR = 3.0, P = 0.064), advanced cancer stage (HR = 6.5, P = 0.077) and body surface area above 1.71 m(2) (HR = 3.4, P = 0.029) increased the risk of port system occlusion. Our study indicates that totally implantable port systems yield a higher risk of complications in terminally ill patients. Further investigation should be carefully conducted to compare outcomes of various central venous access devices in patients with advanced cancer and to develop preventive strategies against catheter failure.
Hybrid procedure for orbital venous malformation in the endovascular operation room.
Cheng, A C O; Li, E Y M; Chan, T C Y; Wong, A C W; Chan, P C M; Poon, W W L; Fung, D H S; Yuen, H K L
2015-08-01
To describe a hybrid procedure for orbital venous malformation in the endovascular operating room (EVOR). Five consecutive patients with venous malformation in the periocular and orbital region were included. All patients received a one-stage direct puncture venogram, image-guided glue injection, and surgical resection in the EVOR equipped with a biplane digital subtraction angiography system (BDSAS). The mean age at the time of operation was 37.4 years (range, 22-69 years). The mean operative time was 193 min (range, 138-324 min). No intraoperative complications were noted. The mean follow-up duration was 18.8 months (range, 10-24 months). Three patients had complete removal of the vascular lesions. At the latest follow-up, no recurrence of symptoms related to the lesions was noted. All patients had an uneventful recovery and satisfactory outcome. The hybrid procedure of orbital venous malformation in the EVOR is a novel application in ophthalmology. It is a safe and well-controlled procedure with real-time high-quality BDSAS surveillance to facilitate surgical resection. Its success requires collaboration between the interventional radiologist, the surgeon, and the ophthalmologist.
Studies of a new multi-layer compression bandage for the treatment of venous ulceration.
Scriven, J M; Bello, M; Taylor, L E; Wood, A J; London, N J
2000-03-01
This study aimed to develop an alternative graduated compression bandage for the treatment of venous leg ulcers. Alternative bandage components were identified and assessed for optimal performance as a graduated multi-layer compression bandage. Subsequently the physical characteristics and clinical efficacy of the optimal bandage combination was prospectively examined. Ten healthy limbs were used to develop the optimal combination and 20 limbs with venous ulceration to compare the physical properties of the two bandage types. Subsequently 42 consecutive ulcerated limbs were prospectively treated to examine the efficacy of the new bandage combination. The new combination produced graduated median (range) sub-bandage pressures (mmHg) as follows: ankle 59 (42-100), calf 36 (27-67) and knee 35 (16-67). Over a seven-day period this combination maintained a comparable level of compression with the Charing Cross system, and achieved an overall healing rate at one year of 88%. The described combination should be brought to the attention of healthcare professionals treating venous ulcers as a possible alternative to other forms of multi-layer graduated compression bandages pending prospective, randomised clinical trials.
Transpulmonary passage of venous air emboli
NASA Technical Reports Server (NTRS)
Butler, B. D.; Hills, B. A.
1985-01-01
Twenty-seven paralyzed anesthetized dogs were embolized with venous air to determine the effectiveness of the pulmonary vasculature for bubble filtration or trapping. Air doses ranged from 0.05 to 0.40 ml/kg min in 0.05-ml increments with ultrasonic Doppler monitors placed over arterial vessels to detect any microbubbles that crossed the lungs. Pulmonary vascular filtration of the venous air infusions was complete for the lower air doses ranging from 0.05 to 0.30 ml/kg min. When the air doses were increased to 0.35 ml/kg min, the filtration threshold was exceeded with arterial spillover of bubbles occurring in 50 percent of the animals and reaching 71 percent for 0.40 ml/kg min. Significant elevations were observed in pulmonary arterial pressure and pulmonary vascular resistance. Systemic blood pressure and cardiac output decreased, whereas left ventricular end-diastolic pressure remained unchanged. The results indicate that the filtration of venous bubbles by the pulmonary vasculature was complete when the air infusion rates were kept below a threshold value of 0.30 ml/kg min.
Loss of interface pressure in various compression bandage systems over seven days.
Protz, Kerstin; Heyer, Kristina; Verheyen-Cronau, Ida; Augustin, Matthias
2014-01-01
Manufacturers' instructions of multi-component compression bandage systems inform that these products can remain up to 7 days during the therapy of venous leg ulcer. This implies that the pressure needed will be sustained during this time. The present research investigated the persistence of pressure of compression systems over 7 days. All 6 compression systems available in Germany at the time of the trial were tested on 35 volunteering persons without signs of venous leg disease. Bandaging with short-stretch bandages was included for comparison. Pressure was measured by using PicoPress®. Initially, all products showed sufficient resting pressure of 40 mm Hg checked with a pressure monitor, except for one system in which the pressure fell by at least 23.8%, the maximum being 47.5% over a period of 7 days. The currently available compression systems are not fit to keep the required pressure. Optimized products need to be developed.
Stimulation of cardiovascular adaptability during prolonged space exposure
NASA Technical Reports Server (NTRS)
Gorman, H. A.
1971-01-01
The deconditioning effects of weightlessness on the cardiovascular system of astronauts are discussed. It is believed that man cannot tolerate indefinite exposure to weightlessness without considerable circulatory deterioration. Analyses of data collected from space flights to date substantiate these beliefs, and confirm the fact that some form of compensation must be provided to keep the cardiovascular system of space travelers properly conditioned. Sequential pulsatile devices were investigated to produce periodic hydrostatic pressure gradients in the venous system of eight subhuman primates. Intermittent venous pooling of blood in the extremities triggers and stimulates the vascular reflex mechanisms of the cardiovascular system that may have significant benefits in maintaining the circulatory system in proper tone under weightless conditions. Electrocardiograms, blood pressure measurements, cardiac output and stroke volume determinations were used to evaluate the efficiency of the described technique. Results were amazingly consistent to indicate an efficient system for intermittently exercising the heart within safe and medically acceptable limits.
Multidetector CT of blunt traumatic venous injuries in the chest, abdomen, and pelvis.
Holly, Brian P; Steenburg, Scott D
2011-01-01
Venous injuries as a result of blunt trauma are rare. Even though current protocols for multidetector computed tomography (CT) of patients with trauma are designed to evaluate primarily the solid organs and arteries, blunt venous injuries may nevertheless be identified, or at least suspected, on the basis of the multidetector CT findings. Venous injuries are associated with high morbidity and mortality rates. Diagnosis of a possible venous injury is crucial because the physical findings of a venous injury are nonspecific and may be absent. This article aims to make the radiologist aware of various venous injuries caused by blunt trauma and to provide helpful hints to aid in the identification of venous injuries. Multidetector CT technology, in combination with interactive manipulation of the raw dataset, can be useful in the creation of multiplanar reconstructed images and in the identification of a venous injury caused by blunt trauma. Familiarity with direct and indirect signs of venous injuries, as well as with examples of blunt traumatic venous injuries in the chest, abdomen, and pelvis, will help in the diagnosis of these injuries.
Stana, Jan; Stergar, Janja; Gradišnik, Lidija; Flis, Vojko; Kargl, Rupert; Fröhlich, Eleonore; Stana Kleinschek, Karin; Mohan, Tamilselvan; Maver, Uroš
2017-09-11
Local drug delivery systems made from nontoxic polysaccharide nanofilms have an enormous potential in wound care. A detailed understanding of the structural, surface, physicochemical, and cytotoxic properties of such systems is crucial to design clinically efficacious materials. Herein, we fabricated polysaccharide-based nanofilms onto either a 2D model (SiO 2 and Au sensors) or on nonwoven alginate 3D substrates using an alternating assembly of N,N,N-trimethylchitosan (TMC) and alginic acid (ALG) by a spin-assisted layer-by-layer (LbL) technique. These TMC/ALG multilayered nanofilms are used for a uniform encapsulation and controlled release of pentoxifylline (PTX), a potent anti-inflammatory drug for treatment of the chronic venous ulceration. We show a tailorable film growth and mass, morphology, as well as surface properties (charge, hydrophilicity, porosity) of the assembled nanofilms through control of the coating during the spin-assisted assembly. The uniform distribution of the encapsulated PTX in the TMC/ALG nanofilms is preserved even with when the amount of the incorporated PTX increases. The PTX release mechanism from the model and real systems is studied in detail and is very comparable for both systems. Finally, different cell-based assays illustrated the potential of the TMC/ALG multilayer system in wound care (e.g., treatment chronic venous ulceration) applications, including a decrease of TNF-α secretion, a common indicator of inflammation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ganguli, Suvranu, E-mail: sganguli@partners.org; Kalva, Sanjeeva; Oklu, Rahmi
Purpose: A rare but described risk factor for deep venous thrombosis (DVT), predominately in the young, is congenital agenesis or atresia of the inferior vena cava (IVC). The optimal management for DVT in this subset of patients is unknown. We evaluated the efficacy of pharmacomechanical catheter-directed thrombolysis (PCDT) followed by systemic anticoagulation in the treatment of acute lower-extremity DVT in the setting of congenital IVC agenesis or atresia. Materials and Methods: Between November of 2005 and May of 2010, six patients (three women [average age 21 years]) were referred to our department with acute lower-extremity DVT and subsequently found tomore » have IVC agenesis or atresia on magnetic resonance imaging. A standardized technique for PCDT (the Angiojet Rheolytic Thrombectomy System followed by the EKOS Microsonic Accelerated Thrombolysis System) was used for all subjects. Successful thrombolysis was followed by systemic heparinization with transition to Coumadin or low molecular-weight heparin and compression stockings. Subjects were followed-up at 1, 3, and then every 6 months after the procedure with clinical assessment and bilateral lower-extremity venous ultrasound. Results: All PCDT procedures were technically successful. No venous stenting or angioplasty was performed. The average thrombolysis time was 28.6 h (range 12-72). Two patients experienced heparin-induced thrombocytopenia, and one patient developed a self-limited knee hemarthrosis, No patients were lost to follow-up. The average length of follow-up was 25.8 {+-} 20.2 months (range 3.8-54.8). No incidence of recurrent DVT was identified. There were no manifestations of postthrombotic syndrome. Conclusions: PCDT followed by systemic anticoagulation and the use of compression stockings appears to be safe and effective in relatively long-term follow-up treatment of patients who present with acute DVT and IVC agenesis or atresia.« less
Upper Body Venous Compliance Exceeds Lower Body Venous Compliance in Humans
NASA Technical Reports Server (NTRS)
Watenpaugh, Donald E.
1996-01-01
Human venous compliance hypothetically decreases from upper to lower body as a mechanism for maintenance of the hydrostatic indifference level 'headward' in the body, near the heart. This maintains cardiac filling pressure, and thus cardiac output and cerebral perfusion, during orthostasis. This project entailed four steps. First, acute whole-body tilting was employed to alter human calf and neck venous volumes. Subjects were tilted on a tilt table equipped with a footplate as follows: 90 deg, 53 deg, 30 deg, 12 deg, O deg, -6 deg, -12 deg, -6 deg, O deg, 12 deg, 30 deg, 53 deg, and 90 deg. Tilt angles were held for 30 sec each, with 10 sec transitions between angles. Neck volume increased and calf volume decreased during head-down tilting, and the opposite occurred during head-up tilt. Second, I sought to cross-validate Katkov and Chestukhin's (1980) measurements of human leg and neck venous pressures during whole-body tilting, so that those data could be used with volume data from the present study to calculate calf and neck venous compliance (compliance = (Delta)volume/(Delta)pressure). Direct measurements of venous pressures during postural chances and whole-body tilting confirmed that the local changes in venous pressures seen by Katkov and Chestukhin (1980) are valid. The present data also confirmed that gravitational changes in calf venous pressure substantially exceed those changes in upper body venous pressure. Third, the volume and pressure data above were used to find that human neck venous compliance exceeds calf venous compliance by a factor of 6, thereby upholding the primary hypothesis. Also, calf and neck venous compliance correlated significantly with each other (r(exp 2) = 0.56). Fourth, I wished to determine whether human calf muscle activation during head-up tilt reduces calf venous compliance. Findings from tilting and from supine assessments of relaxed calf venous compliance were similar, indicating that tilt-induced muscle activation is relatively unimportant. Low calf venous compliance probably results from stiffer venous, skeletal muscle, and connective tissues, and better-developed local and central neural controls of venous distensibility. This research establishes that upper-to-lower body reduction of venous compliance can explain headward positioning of the hydrostatic indifference level in humans.
Seyahi, Emire; Cakmak, Osman Serdal; Tutar, Burcin; Arslan, Caner; Dikici, Atilla Suleyman; Sut, Necdet; Kantarci, Fatih; Tuzun, Hasan; Melikoglu, Melike; Yazici, Hasan
2015-11-01
Vascular involvement can be seen in up to 40% of patients with Behcet syndrome (BS), the lower-extremity vein thrombosis (LEVT) being the most common type. The aim of the current study was to compare venous Doppler findings and clinical features between BS patients with LEVT and control patients diagnosed as having LEVT due to other causes.All consecutive 78 patients (71 men, 7 women; mean age 38.6 ± 10.3 years) with LEVT due to BS and 50 control patients (29 men, 21 women; mean age 42.0 ± 12.5 years) who had LEVT due to other causes, or idiopathic, were studied with the help of a Doppler ultrasonography after a detailed clinical examination. Patterns of venous disease were identified by cluster analyses. Clinical features of chronic venous disease were assessed using 2 classification systems. Venous claudication was also assessed.Patients with BS were more likely to be men, had significantly earlier age of onset of thrombosis, and were treated mainly with immunosuppressives and less frequently with anticoagulants. Furthermore, they had significantly more bilateral involvement, less complete recanalization, and more frequent collateral formation. While control patients had a disorganized pattern of venous involvement, BS patients had a contiguous and symmetric pattern, involving all deep and superficial veins of the lower extremities, with less affinity for crural veins. Clinical assessment, as measured by the 2 classification systems, also indicated a more severe disease among the BS patients. In line, 51% of the BS patients suffered from severe post-thrombotic syndrome (PTS) and 32% from venous claudication, whereas these were present in 8% and 12%, respectively, among the controls. Among BS patients, a longer duration of thrombosis, bilateral femoral vein involvement, and using no anticoagulation along with immunosuppressive treatment when first diagnosed were found to be associated independently with severe PTS.Lower-extremity vein thrombosis associated with BS, when compared to LEVT due to other causes, had distinctive demographic and ultrasonographic characteristics, and had clinically a more severe disease course.
Clinical and Ultrasonographic Evaluation of Lower-extremity Vein Thrombosis in Behcet Syndrome
Seyahi, Emire; Cakmak, Osman Serdal; Tutar, Burcin; Arslan, Caner; Dikici, Atilla Suleyman; Sut, Necdet; Kantarci, Fatih; Tuzun, Hasan; Melikoglu, Melike; Yazici, Hasan
2015-01-01
Abstract Vascular involvement can be seen in up to 40% of patients with Behcet syndrome (BS), the lower-extremity vein thrombosis (LEVT) being the most common type. The aim of the current study was to compare venous Doppler findings and clinical features between BS patients with LEVT and control patients diagnosed as having LEVT due to other causes. All consecutive 78 patients (71 men, 7 women; mean age 38.6 ± 10.3 years) with LEVT due to BS and 50 control patients (29 men, 21 women; mean age 42.0 ± 12.5 years) who had LEVT due to other causes, or idiopathic, were studied with the help of a Doppler ultrasonography after a detailed clinical examination. Patterns of venous disease were identified by cluster analyses. Clinical features of chronic venous disease were assessed using 2 classification systems. Venous claudication was also assessed. Patients with BS were more likely to be men, had significantly earlier age of onset of thrombosis, and were treated mainly with immunosuppressives and less frequently with anticoagulants. Furthermore, they had significantly more bilateral involvement, less complete recanalization, and more frequent collateral formation. While control patients had a disorganized pattern of venous involvement, BS patients had a contiguous and symmetric pattern, involving all deep and superficial veins of the lower extremities, with less affinity for crural veins. Clinical assessment, as measured by the 2 classification systems, also indicated a more severe disease among the BS patients. In line, 51% of the BS patients suffered from severe post-thrombotic syndrome (PTS) and 32% from venous claudication, whereas these were present in 8% and 12%, respectively, among the controls. Among BS patients, a longer duration of thrombosis, bilateral femoral vein involvement, and using no anticoagulation along with immunosuppressive treatment when first diagnosed were found to be associated independently with severe PTS. Lower-extremity vein thrombosis associated with BS, when compared to LEVT due to other causes, had distinctive demographic and ultrasonographic characteristics, and had clinically a more severe disease course. PMID:26554787
2015-03-01
statistically significant increase in systemic vascular resistance compared to control, but not whole blood, with a concomitant decrease in cardiac...increasing blood pressure as well as sys- temic vascular resistance in a hypovolemic hemorrhagic swine model.18 The primary hypothesis of this study is...output, sys- temic vascular resistance , mixed venous oxygen satura- tion, central venous pressure, pulmonary artery pressure, and core temperature. The
Matano, Fumihiro; Mizunari, Takayuki; Kominami, Shushi; Suzuki, Masanori; Fujiki, Yu; Kubota, Asami; Kobayashi, Shiro; Murai, Yasuo; Morita, Akio
2017-04-01
It is difficult to treat large internal carotid aneurysms with simple surgical clipping. Here, we present a retrograde suction decompression (RSD) procedure for large internal carotid aneurysms using a balloon guide catheter combined with a blood-returning circuit and a superficial temporal artery to middle cerebral artery (STA-MCA) bypass.All patients underwent an STA-MCA bypass before the temporary occlusion of the internal carotid artery (ICA). A 6-French sheath was inserted into the common carotid artery (CCA), and a 6-French Patrive balloon catheter was placed into the ICA 5 cm past the bifurcation. Aneurysm exposure was obtained; temporary clips were placed on the proximal M1, A1, and posterior communicating (Pcom) segments; and an extension tube was then connected to the balloon catheter. A three-way stopcock was placed, and aspiration was performed through the device to collapse the aneurysm. The aspirated blood was returned to a venous line with an added heparin to prevent anemia after aspiration. During the decompression, the blood flow to the cortical area was supplied through the STA-MCA bypass. After the aneurysm collapse, the surgeon carefully dissected the perforating artery from the aneurysm dome or neck, and permanent clips were then placed on the aneurysm neck. Our procedure has several advantages, such as STA-MCA bypass without external carotid artery occlusion for preventing ischemic complications of the cortical area, anemia may be avoided because of the return of the aspirated blood, and a hybrid operation room is not required to perform this method.
Patterns of anomalous pulmonary venous drainage.
Snellen, H A; van Ingen, H C; Hoefsmit, E C
1968-07-01
All of our cases of abnormal pulmonary venous connections collected to the middle of 1965 and verified at surgery or autopsy have been reviewed by means of diagrams and tabulations, using a specially devised code to facilitate the survey. The material consisted of 52 autopsy cases (half of them obtained after surgery) and the cases of 72 patients who survived operation. The postmortem group was much younger than the surgical group and differed also from the latter by showing male preponderance as well as relatively many instances of total abnormal pulmonary venous connection and frequently associated cardiac anomalies. Partial anomalous connection of right pulmonary veins was 10 times more frequent than that of the left pulmonary veins. This was caused by (1) the frequent drainage of some of the right pulmonary veins into the junctional area between right atrium and superior vena cava in the presence of normal left pulmonary veins, and (2) the complete absence of isolated left pulmonary venous connection to the right atrium. Abnormal connection of solitary pulmonary veins was always effected to the most proximal venous structure among the four possible ones which are derived from the main embryonic channels (superior vena cava and inferior vena cava on the right side, and left superior vena cava and coronary sinus on the left side). Common pulmonary veins from one lung also drained in accordance with this proximity rule, if this may be taken to apply also to the drainage of right pulmonary veins into the right atrium. The one exception in our material was the drainage of all right pulmonary veins into the portal venous system. Total abnormal pulmonary venous connection may be found with all structures mentioned, but most frequently with the left superior vena cava, or coronary sinus, or both, usually by way of a common pulmonary vein. In a few cases however, drainage into different sites, all of them abnormal, did occur. Then again the proximity rule seemed to apply. A tentative embryological explanation is given for the patterns described.
Herrera, Santiago; Comerota, Anthony J; Thakur, Subhash; Sunderji, Shiraz; DiSalle, Robert; Kazanjian, Sahira N; Assi, Zakaria
2014-02-01
Extensive deep venous thrombosis (DVT) during pregnancy is usually treated with anticoagulation alone, risking significant post-thrombotic syndrome (PTS) in young patients. Catheter-directed thrombolysis (CDT) and operative venous thrombectomy have been safely and effectively used in nonpregnant patients, demonstrating significant reduction in post-thrombotic morbidity. This report reviews short- and long-term outcomes of 13 patients with extensive DVT of pregnancy treated with a strategy of thrombus removal. From 1999 to 2013, 13 patients with iliofemoral DVT during pregnancy were offered CDT, pharmacomechanical thrombolysis (PMT), and/or venous thrombectomy. Gestational age ranged from 8 to 34 weeks. Fetal monitoring was performed throughout hospitalization. Radiation exposure was minimized with pelvic lead shields, focal fluoroscopy, and limited angiographic runs. Follow-up included objective vein evaluation using venous duplex and PTS assessment using the Villalta scale. CDT and/or PMT were used in 11 patients. Two patients underwent venous thrombectomy alone, and one patient had operative thrombectomy as an adjunct to CDT and PMT. Each patient had complete or near-complete thrombus resolution and rapid improvement in clinical symptoms. Eight of 11 having CDT or PMT underwent venoplasty and stenting of the involved iliac veins. Twelve of the 13 delivered healthy infants at term. One patient opted for termination of her pregnancy. Mean patient and gestational ages were 26 years and 26 weeks, respectively. Mean follow-up was 1.3 years, with only one recurrence. Duplex ultrasonography demonstrated patent veins in all but one patient and normal valve function in 10 patients. Eleven patients had Villalta scores <5 (considered normal), with a mean score of 0.7. Extensive DVT of pregnancy can be effectively and safely treated with a strategy of thrombus removal, resulting in a patent venous system, normal valve function in many, prevention of PTS, and reduction in recurrence. Copyright © 2014. Published by Mosby, Inc.
Ohno, Takuro; Muneuchi, Jun; Ihara, Kenji; Yuge, Tetsuji; Kanaya, Yoshiaki; Yamaki, Shigeo; Hara, Toshiro
2008-04-01
Pulmonary arterial hypertension has been reported to be observed in association with acquired portal hypertension. However, the contribution of congenital anomalies occurring in the portal system to the development of pulmonary arterial hypertension remains to be elucidated. Nine patients with congenital portosystemic venous shunt were studied from January 1990 through September 2005. Patent ductus venosus was detected in 5 patients, including 3 patients with an absence of the portal vein. The presence of either a gastrorenal or splenorenal shunt was evident in another 4 patients. Six patients had a history of hypergalactosemia with normal enzyme activities, as seen during neonatal screening. Six (66.7%) of the 9 patients were identified to have clinically significant pulmonary arterial hypertension (mean pulmonary artery pressure: 34-79 mm Hg; pulmonary vascular resistances: 5.12-38.07 U). The median age at the onset of pulmonary arterial hypertension was 12 years and 3 months. Histologic studies of lung specimens, which were available in 4 of the 9 patients with congenital portosystemic venous shunt, showed small arterial microthrombotic lesions in 3 patients. This characteristic finding was recognized even in the congenital portosystemic venous shunt patients without PAH. This study demonstrated thromboembolic pulmonary arterial hypertension to be a crucial complication in congenital portosystemic venous shunt, and this pathologic state may be latently present in patients with pulmonary arterial hypertension of unknown etiology.
Kwon, Hyun-Jung; Jeong, Young-Il; Jun, In-Gu; Moon, Young-Jin; Lee, Yu-Mi
2018-01-01
Abstract Subclavian central venous catheterization is a common procedure for which misplacement of the central venous catheter (CVC) is a frequent complication that can potentially be fatal. The carina is located in the mid-zone of the superior vena cava (SVC) and is considered a reliable landmark for CVC placement in chest radiographs. The C-length, defined as the distance from the edge of the right transverse process of the first thoracic spine to the carina, can be measured in posteroanterior chest radiographs using a picture archiving and communication system. To evaluate the placement of the tip of the CVC in subclavian central venous catheterizations using the C-length, we reviewed the medical records and chest radiographs of 122 adult patients in whom CVC catheterization was performed (from January 2012 to December 2014) via the right subclavian vein using the C-length. The tips of all subclavian CVCs were placed in the SVC using the C-length. No subclavian CVC entered the right atrium. Tip placement was not affected by demographic characteristics such as age, sex, height, weight, and body mass index. The evidence indicates that the C-length on chest radiographs can be used to determine the available insertion length and place the right subclavian CVC tip into the SVC. PMID:29480861
Chandra, Dinesh; Gupta, Anubhav; Nath, Ranjit K.; kazmi, Aamir; Grover, Vijay; Gupta, Vijay K.
2013-01-01
Background The anatomical variability in patients with anomalous pulmonary venous connection to superior vena cava presents a surgical challenge. The problem is further compounded by the common occurrence of postoperative complications like arrhythmias and obstruction of the superior vena cava or pulmonary veins. We present our experience of managing this subset using the two patch and Warden's techniques. Patients and methods Between June 2011 and September 2012, 7 patients with APVC to the SVC were operated in our institute. After delineating the anatomy, five of them had a two patch repair and two were managed with Warden's technique. Results There was no in-hospital mortality or early mortality over a mean follow-up of 9.66 ± 3.88 months (range 6–15 months). All the patients on follow-up had unobstructed pulmonary venous and SVC drainage on echocardiography and all of them were in normal sinus rhythm. Conclusions Anomalous pulmonary venous connection to superior vena cava is a challenging subset of patients in whom the surgical management needs to be individualized. The detailed anatomy must be delineated using echocardiography with or without CT angiography before deciding the surgical plan. This entity can be repaired with excellent immediate and early results. However, these patients must be closely followed up for complications like systemic and pulmonary venous obstruction and sinus node dysfunction. PMID:24206880
Lin, Ming-Chih; Fu, Yun-Ching; Jan, Sheng-Ling; Chen, Ying-Tsung; Chi, Ching-Shiang
2005-01-01
To compare the right atrial pressure to the central venous pressures measured at different points in spontaneously breathing children and try to find a formula to estimate right atrial pressure by central venous pressure measurement. Fifty-one children, aged 5 +/- 4.7 years, who underwent right heart catheterization were studied. All patients were sedated and breathed naturally. The mean pressure was the electronic mean of nine heart beats calculated by Philips BC4000 digital angiographic system. Mean pressure of the right atrium was compared to those measured at the high superior vena cava (SVC), low SVC, high inferior vena cava (IVC) (T10-11), middle IVC (L1-2), low IVC (L3-4), and iliac vein (L5-S1). Mean pressures of central veins were significantly higher than that of the right atrium (all p<0.01). Adjusted central venous pressures of SVC-0.5, high IVC-1.5, middle IVC-2, low IVC-2.5, and iliac vein-3 (mmHg) had a good agreement with the right atrial pressure. Central venous pressures are significantly higher than the right atrial pressure in spontaneously breathing children. Adjusted pressures of SVC-0.5, high IVC-1.5, middle IVC-2, low IVC-2.5, and iliac vein-3 (mmHg) can accurately reflect the right atrial pressure.
NASA Astrophysics Data System (ADS)
Hickey, Michelle; Phillips, Justin P.; Kyriacou, Panayiotis
2015-03-01
The aim of the current work is to investigate the possibility of augmenting pulse oximetry algorithms to enable the estimation of venous parameters in peripheral tissues. In order to further understand the contribution of venous blood to the photoplethysmographic (PPG) signal, recordings were made from six healthy volunteer subjects during an exercise in which the right hand was placed in various positions above and below heart level. The left hand was kept at heart level as a control while the right hand was moved. A custom-made two-channel dual wavelength PPG instrumentation system was used to obtain the red and infrared plethysmographic signals from both the right and left index fingers simultaneously using identical sensors. Laser Doppler flowmetry signals were also recorded from an adjacent fingertip on the right hand. Analysis of all acquired PPG signals indicated changes in both ac and dc amplitude of the right hand when the position was changed, while those obtained from the left (control) hand remained relatively constant. Most clearly, in the change from heart level to 50cm below heart level there is a substantial decrease in both dc and ac amplitudes. This decrease in dc amplitude most likely corresponds to increased venous pooling, and hence increased absorption of light. It is speculated that the decrease in ac PPG amplitude is due to reduced arterial emptying during diastole due to increased downstream resistance due to venous pooling.
Stojanov, Petar; Vranes, Mile; Velimirovic, Dusan; Zivkovic, Mirjana; Kocica, Mladen J; Davidovic, Lazar; Neskovic, Voislava; Stajevic, Mila
2005-05-01
We examined the prevalence of venous obstruction in 12 newborns and infants with permanent endovenous ventricular pacing, clinically, and by ultrasonographic assessment of hemodynamics (spontaneity, phasicity, velocity, and turbulence of flow) and morphologic parameters (compressibility, wall thickness, and thrombus presence). All implantations of single ventricular unipolar endovenous steroid leads, were performed via cephalic vein, and pacemakers were placed in subcutaneous pocket in right prepectoral region. After the vascular surgeon has carefully examined all children for presence of venous collaterals in the chest wall, morphologic and hemodynamic parameters of the subclavian, axillary, and internal jugular veins, were assessed by linear-array color Doppler. Lead capacity (LC) was calculated for each patient. Mean age of patients at implant was 6.2 months (range 1 day-12 months), mean weight 6.5 kg (range 2.25-10 kg), and mean height 60.9 cm (range 48-78 cm). Mean LC was 1.99 (range 1.14-3.07). Total follow-up was 1023 and mean follow-up 85.2 pacing months (range 3-156). No clinical signs of venous obstruction were observed. Mild stenosis (20%) of subclavian vein was found by color Doppler in 2/12 patients. Both had adequate lead diameter for body surface. Permanent endovenous pacing is a feasible procedure, even in children of body weight less than 10 kg, with quite acceptable impact on venous system patency.
McLiesh, Paul; Wiechula, Rick
2012-01-01
BACKGROUND: The risk of venous thromboembolism for orthopaedic patients is often high due to the length of surgery, damage from trauma to bone and soft tissues and lengthy periods of immobility or reduced mobility. Although venous thromboembolism occurs mainly in inpatients a significant number of patients develop venous thromboembolism post discharge OBJECTIVES: To synthesise the best available evidence on strategies that effectively reduce post discharge venous thromboembolism in orthopaedic patients. INCLUSION CRITERIA: Patients regardless of age, gender or co-morbidities that have been admitted with an acute orthopaedic injury (unplanned) or a planned orthopaedic surgery/procedure and then followed up after discharge. Only papers describing the incidence and prophylaxis treatment used in non-Asian patients were considered for inclusion. Any interventions of combinations of chemoprophylaxis and/or mechanical prophylaxis to prevent venous thromboembolism incidence extending beyond hospital admission. Outcomes included diagnosis of venous thromboembolism following an orthopaedic admission/surgery for up to 6 months post discharge and the incidence of any significant bleeding or death related to venous thromboembolism or haemorrhage.The review considered any randomised controlled trials; in the absence of RCTs other research designs, such as non-randomised controlled trials and before and after studies, were considered SEARCH STRATEGY: Search strategy considered only papers in English from 2000 to March 2012. METHODOLOGICAL QUALITY: Papers selected for retrieval were assessed using standardised critical appraisal instruments from the Joanna Briggs Institute. DATA COLLECTION: Data was extracted from the studies using the standardised Johanna Briggs Institute data extraction form. DATA SYNTHESIS: Of the included studies none matched methodology, treatment or comparator that allowed meta-analysis. The results were therefore presented in a narrative form and were structured using patient population, then intervention and then analysis of results. RESULTS: 20 articles were included in the systematic review. The overall incidence of post discharge venous thromboembolism in orthopaedic patients is not possible to determine due to the variability in reporting criteria and poor follow-up. Use of Low Molecular Weight Heparins was generally shown to be effective in preventing venous thromboembolism. The new generation Factor Xa inhibitors were shown to improve venous thromboembolism prevention however had a slightly higher risk of bleeding. There was limited high level research presented to allow effective assessment of aspirin and/or mechanical compression devices. CONCLUSIONS: Prevention of post discharge venous thromboembolism is complex due to the number of variables that can influence its occurrence. The risk of post discharge venous thromboembolism varies among different patient populations so consideration must be given to matching the risk for each of those groups with available interventions.For higher risk orthopaedic patient groups such as those with large joint replacements and femoral fractures low molecular weight heparins should be considered and continued where possible post discharge for thirty days however the risk profile for venous thromboembolism and bleeding must be considered for both populations and individuals.Consideration in future research design must be given to factors such as: adequate follow-up time, and standardised criteria to measure the incidence of post discharge venous thromboembolism. • Save items Add to Favorites View more options Similar articles Effectiveness of nurse-led preoperative assessment services for elective surgery: a systematic review. [JBI Libr Syst Rev. 2010] The Effectiveness of Integrated Care Pathways for Adults and Children in Health Care Settings: A Systematic Review. [JBI Libr Syst Rev. 2009] Review The effect of insulin therapy algorithms on blood glucose levels in patients following cardiac surgery: A systematic review. [JBI Database System Rev Implem...] Continuous Subcutaneous Insulin Infusion (CSII) Pumps for Type 1 and Type 2 Adult Diabetic Populations: An Evidence-Based Analysis. [Ont Health Technol Assess Ser....] Review The effectiveness of ayurvedic oil-based nasal instillation (Nasya) medicines in the treatment of facial paralysis (Ardita): a systematic review. [JBI Database System Rev Implem...] See reviews... See all... Cited by 1 PubMed Central article A systematic scoping review on the consequences of stress-related hyperglycaemia. [PLoS One. 2018] Related information Cited in PMC Search details 27820532[uid] Search See more... Recent Activity ClearTurn Off Effectiveness of tight glycemic control in the medical Intensive Care Unit: a sy... PubMed 27820532[uid] (1) PubMed 27820349[uid] (1) PubMed Effectiveness of Tight Glycemic Control in the Medical Intensive Care Unit: A Sy... PubMed
Clinical aspects of the control of plasma volume at microgravity and during return to one gravity
NASA Technical Reports Server (NTRS)
Convertino, V. A.
1996-01-01
Plasma volume is reduced by 10-20% within 24-48 h of exposure to simulated or actual microgravity. The clinical importance of microgravity induced hypovolemia is manifested by its relationship with orthostatic intolerance and reduced maximal oxygen uptake (VO2max) after return to one gravity (1G). Since there is no evidence to suggest that plasma volume reduction during microgravity is associated with thirst or renal dysfunctions, a diuresis induced by an immediate blood volume shift to the central circulation appears responsible for microgravity-induced hypovolemia. Since most astronauts choose to restrict their fluid intake before a space mission, absence of increased urine output during actual space flight may be explained by low central venous pressure (CVP) which accompanies dehydration. Compelling evidence suggests that prolonged reduction in CVP during exposure to microgravity reflects a "resetting" to a lower operating point, which acts to limit plasma volume expansion during attempts to increase fluid intake. In ground based and space flight experiments, successful restoration and maintenance of plasma volume prior to returning to an upright posture may depend upon development of treatments that can return CVP to its baseline IG operating point. Fluid-loading and lower body negative pressure (LBNP) have not proved completely effective in restoring plasma volume, suggesting that they may not provide the stimulus to elevate the CVP operating point. On the other hand, exercise, which can chronically increase CVP, has been effective in expanding plasma volume when combined with adequate dietary intake of fluid and electrolytes. The success of designing experiments to understand the physiological mechanisms of and development of effective counter measures for the control of plasma volume in microgravity and during return to IG will depend upon testing that can be conducted under standardized controlled baseline conditions during both ground-based and space flight investigations.
21 CFR 870.1140 - Venous blood pressure manometer.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Venous blood pressure manometer. 870.1140 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1140 Venous blood pressure manometer. (a) Identification. A venous blood pressure manometer is a device attached to a venous...
21 CFR 870.1140 - Venous blood pressure manometer.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Venous blood pressure manometer. 870.1140 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1140 Venous blood pressure manometer. (a) Identification. A venous blood pressure manometer is a device attached to a venous...
21 CFR 870.1140 - Venous blood pressure manometer.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Venous blood pressure manometer. 870.1140 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1140 Venous blood pressure manometer. (a) Identification. A venous blood pressure manometer is a device attached to a venous...
21 CFR 870.1140 - Venous blood pressure manometer.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Venous blood pressure manometer. 870.1140 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1140 Venous blood pressure manometer. (a) Identification. A venous blood pressure manometer is a device attached to a venous...
Current Status of the Application of Intracranial Venous Sinus Stenting
Xu, Kan; Yu, Tiecheng; Yuan, Yongjie; Yu, Jinlu
2015-01-01
The intracranial venous sinus is an important component of vascular disease. Many diseases involve the venous sinus and are accompanied by venous sinus stenosis (VSS), which leads to increased venous pressure and high intracranial pressure. Recent research has focused on stenting as a treatment for VSS related to these diseases. However, a systematic understanding of venous sinus stenting (VS-Stenting) is lacking. Herein, the literature on idiopathic intracranial hypertension (IIH), venous pulsatile tinnitus, sinus thrombosis, high draining venous pressure in dural arteriovenous fistula (AVF) and arteriovenous malformation (AVM), and tumor-caused VSS was reviewed and analyzed to summarize experiences with VS-Stenting as a treatment. The literature review showed that satisfactory therapeutic effects can be achieved through stent angioplasty. Thus, the present study suggests that selective stent release in the venous sinus can effectively treat these diseases and provide new possibilities for treating intracranial vascular disease. PMID:26516306
Christianto, S; Lau, A; Li, K Y; Yang, W F; Su, Y X
2018-05-01
Venous compromise is still the most common cause of free flap failure. The use of two venous anastomoses has been advocated to reduce venous compromise. However, the effectiveness of this approach remains controversial. A systematic review and cumulative meta-analysis was performed to assess the effect of one versus two venous anastomoses on venous compromise and free flap failure in head and neck microsurgical reconstruction. A total of 27 articles reporting 7389 flaps were included in this study. On comparison of one versus two venous anastomoses, the odds ratio (OR) for flap failure was 1.66 (95% confidence interval 1.11-2.50; P=0.014) and for venous compromise was 1.50 (95% confidence interval 1.10-2.05; P=0.011), suggesting a significant increase in the flap failure rate and venous compromise rate in the single venous anastomosis group. These results show that the execution of two venous anastomoses has significant effects on reducing the vascular compromise and free flap failure rate in head and neck reconstruction. Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Richard, James A. (Inventor)
2012-01-01
A non-collinear valve actuator includes a primary actuating system and a return spring system with each applying forces to a linkage system in order to regulate the flow of a quarter-turn valve. The primary actuating system and return spring system are positioned non-collinearly, which simply means the primary actuating system and return spring system are not in line with each other. By positioning the primary actuating system and return spring system in this manner, the primary actuating system can undergo a larger stroke while the return spring system experiences significantly less displacement. This allows the length of the return spring to be reduced due to the minimization of displacement thereby reducing the weight of the return spring system. By allowing the primary actuating system to undergo longer strokes, the weight of the primary actuating system may also be reduced. Accordingly, the weight of the non-collinear valve actuator is reduced.
Klippel-Trenaunay syndrome in a Border collie.
de Cock, H; Mols, N; van Roy, M R; Ducatelle, R; Simoens, P
1996-10-01
A Border collie was presented at the age of 9 weeks with several lesions of the right forelimb, including a reddish-blue haemangiomatous macula in the medio-dorsal part of the elbow, multiple, scattered small cavernous haemangioma-like lesions at the plantar part of the foot and a general hypertrophy of the limb. X-rays of the limb showed osteolysis. On skin biopsy, telangiectatic veins were observed. The rest of the body did not show any skin lesions or hypertrophy. The dog was otherwise healthy. Due to the extension of the lesions and worsening of the limb swelling, it was decided to amputate the affected limb. The dog remained healthy for 2 weeks, but then passed through episodes of anaemia, and finally died suddenly with signs of shock. Dissection of the limb after amputation revealed hypoplasia and aplasia of the deep venous system in the lower part of the leg. No arterio-venous shunts were noticed. ln man, this syndrome, characterised by an insufficiently developed deep venous system associated with local overgrowth of the limb and cutaneous telangiectasia, is known as Klippel-Trenaunay syndrome.
Venous tree separation in the liver: graph partitioning using a non-ising model.
O'Donnell, Thomas; Kaftan, Jens N; Schuh, Andreas; Tietjen, Christian; Soza, Grzegorz; Aach, Til
2011-01-01
Entangled tree-like vascular systems are commonly found in the body (e.g., in the peripheries and lungs). Separation of these systems in medical images may be formulated as a graph partitioning problem given an imperfect segmentation and specification of the tree roots. In this work, we show that the ubiquitous Ising-model approaches (e.g., Graph Cuts, Random Walker) are not appropriate for tackling this problem and propose a novel method based on recursive minimal paths for doing so. To motivate our method, we focus on the intertwined portal and hepatic venous systems in the liver. Separation of these systems is critical for liver intervention planning, in particular when resection is involved. We apply our method to 34 clinical datasets, each containing well over a hundred vessel branches, demonstrating its effectiveness.
External cardiac compression may be harmful in some scenarios of pulseless electrical activity.
Hogan, T S
2012-10-01
Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient's cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless electrical activity. Investigation using a variety of animal models of pulseless electrical activity produced by different shock-inducing mechanisms is required to provide an evidence base for resuscitation guidelines. Copyright © 2012 Elsevier Ltd. All rights reserved.
... ulcers; Ulcers - venous; Venous ulcer; Venous insufficiency - stasis dermatitis; Vein - stasis dermatitis ... veins. Some people with venous insufficiency develop stasis dermatitis. Blood pools in the veins of the lower ...
Schleich, Jean-Marc; Dillenseger, Jean-Louis; Houyel, Lucile; Almange, Claude; Anderson, Robert H.
2009-01-01
Background Learning embryology remains difficult, since it requires understanding of many complex phenomena. The temporal evolution of developmental events has classically been illustrated using cartoons, which create difficulty in linking spatial and temporal aspects, such correlation being the keystone of descriptive embryology. Methods We synthesized the bibliographic data from recent studies of atrial septal development. On the basis of this synthesis, consensus on the stages of atrial septation as seen in the human heart has been reached by a group of experts in cardiac embryology and paediatric cardiology. This has permitted the preparation of three-dimensional (3-D) computer graphic objects for the anatomical components involved in the different stages of normal human atrial septation. Results We have provided a virtual guide to the process of normal atrial septation, the animation providing an appreciation of the temporal and morphologic events necessary to separate the systemic and pulmonary venous returns. Conclusion We have shown that our animations of normal human atrial septation increase significantly the teaching of the complex developmental processes involved, and provide a new dynamic for the process of learning. PMID:19363807
Cardiopulmonary physiology: why the heart and lungs are inextricably linked.
Verhoeff, Kevin; Mitchell, Jamie R
2017-09-01
Because the heart and lungs are confined within the thoracic cavity, understanding their interactions is integral for studying each system. Such interactions include changes in external constraint to the heart, blood volume redistribution (venous return), direct ventricular interaction (DVI), and left ventricular (LV) afterload. During mechanical ventilation, these interactions can be amplified and result in reduced cardiac output. For example, increased intrathoracic pressure associated with mechanical ventilation can increase external constraint and limit ventricular diastolic filling and, therefore, output. Similarly, high intrathoracic pressures can alter blood volume distribution and limit diastolic filling of both ventricles while concomitantly increasing pulmonary vascular resistance, leading to increased DVI, which may further limit LV filling. While LV afterload is generally considered to decrease with increased intrathoracic pressure, the question arises if the reduced LV afterload is primarily a consequence of a reduced LV preload. A thorough understanding of the interaction between the heart and lungs can be complicated but is essential for clinicians and health science students alike. In this teaching review, we have attempted to highlight the present understanding of certain salient aspects of cardiopulmonary physiology and pathophysiology, as well as provide a resource for multidisciplined health science educators and students. Copyright © 2017 the American Physiological Society.
Gluteal Compartment Syndrome following an Iliac Bone Marrow Aspiration
Vega-Najera, Carlos; Leal-Contreras, Carlos; Leal-Berumen, Irene
2013-01-01
The compartment syndrome is a condition characterized by a raised hydraulic pressure within a closed and non expandable anatomical space. It leads to a vascular insufficiency that becomes critical once the vascular flow cannot return the fluids back to the venous system. This causes a potential irreversible damage of the contents of the compartment, especially within the muscle tissues. Gluteal compartment syndrome (GCS) secondary to hematomas is seldom reported. Here we present a case of a 51-year-old patient with history of a non-Hodgkin lymphoma who underwent a bone marrow aspiration from the posterior iliac crest that had excessive bleeding at the puncture zone. The patient complained of increasing pain, tenderness, and buttock swelling. Intraoperative pressure validation of the gluteal compartment was performed, and a GCS was diagnosed. The patient was treated with a gluteal region fasciotomy. The patient recovered from pain and swelling and was discharged shortly after from the hospital. We believe clotting and hematologic disorders are a primary risk factor in patients who require bone marrow aspirations or biopsies. It is important to improve awareness of GCS in order to achieve early diagnosis, avoid complications, and have a better prognosis. PMID:24392235
NASA Astrophysics Data System (ADS)
Christensen, Nj; Heer, M.; Ivanova, K.; Norsk, P.
Sympathetic nervous system activity is closely related to gravitational stress in ground based experiments. Thus a high activity is present in the standing-up position and a very low activity is observed during acute head-out water immersion. Adjustments in sympathetic activity are necessary to maintain a constant blood pressure during variations in venous return. Head-down tilted bed rest is applied as a model to simulate changes observed during microgravity. The aim of the present study was to test the hypothesis that mean 24-hours sympathetic activity was low and similar during space flight and in ground based observation obtained during long-term head-down tilted bed rest. Forearm venous plasma noradrenaline was measured by a radioenzymatic technique as an index of muscle sympathetic activity and thrombocyte noradrenaline and adrenaline were measured as indices of mean 24-hours sympathoadrenal activity. Previous results have indicated that thrombocyte noradrenaline level has a half-time of 2 days. Thus to reflect sympathetic activity during a specific experiment the study period must last for at least 6 days and a sample must be obtained within 12 hours after the experiment has ended. Ten normal healthy subjects were studied before and during a 14 days head-down tilted bed rest as well as during an ambulatory study period of a similar length. The whole experiment was repeated while the subjects were on a low calorie diet. Thrombocyte noradrenaline levels were studied in 4 cosmonauts before and within 12 hours after landing after more than 7 days in flight. Thrombocyte noradrenaline decreased markedly during the head-down tilted bed rest (p<0.001), whereas there were no significant changes in the ambulatory study. Plasma noradrenaline decreased in the adaptation period but not during the intervention. During microgravity thrombocyte noradrenaline increased in four cosmonauts and the percentage changes were significantly different in cosmonauts and in subjects participating in the head down tilted bed rest study (170± 29% (Mean± SEM) vs. 57± 7%, respectively; p<0.001). The elevated sympathetic nervous system activity is most likely a regulatory response to combined effects of a reduced plasma volume and an increased vascular capacity in flight.
Liu, Ning; Vigod, Simone N; Farrugia, M Michèle; Urquia, Marcelo L; Ray, Joel G
2018-06-08
A woman's risk of venous thromboembolism during pregnancy is estimated to be two-to-six times higher than her risk when she is not pregnant. Such risk estimates are largely based on pregnancies that result in delivery of a newborn baby; no estimates exist for the risk of venous thromboembolism after induced abortion, another common pregnancy outcome. To fill this knowledge gap, we aimed to assess the risk of venous thromboembolism in women whose first pregnancy ended with induced abortion. We did this propensity score-matched cohort study using data from the universal health-care system of Ontario, Canada. We included primigravid women who had an induced abortion between Jan 1, 2003, and Dec 31, 2015, and used a propensity score to match them to primigravid women who had a livebirth (1:1) or nulligravid women who were not pregnant on the procedure date of their matched counterpart and who did not conceive within 1 year afterwards (5:1). We excluded from our analysis women younger than 15 years or older than 49 years and individuals who had missing or invalid information about their sex, area of residence, residential income, or world region of origin. The primary outcome was risk of any venous thromboembolism within 42 days of the index date (defined as the date of an induced abortion, delivery date for livebirth, or for non-pregnant women the induced abortion date of their matched counterpart). We compared the rate of venous thromboembolism in primigravid women who had an induced abortion with the rate of venous thromboembolism in propensity-score-matched non-pregnant women and propensity-score-matched primigravid women whose pregnancy ended with a livebirth. We generated hazard ratios (HRs) of 42-day risk of venous thromboembolism after induced abortion using Cox proportional hazard models. We identified 194 086 eligible women whose first pregnancy ended with induced abortion, of whom 176 001 (90·7%) could be matched with women whose first pregnancy ended in delivery of a newborn. These 176 001 women were also matched to 880 005 non-pregnant women. The rate of venous thromboembolism within 42 days of an induced abortion was 30·1 (95% CI 22·0-38·2) per 100 000 women compared with 13·5 (11·1-16·0) per 100 000 women in the non-pregnant group (HR 2·23, 95% CI 1·61-3·08). The HR was 0·16 (95% CI 0·12-0·22) when compared with the women in the livebirth cohort, whose venous thromboembolism rate within 42 days postpartum was 184·7 (95% CI 164·6-204·7) per 100 000 women. The 42-day risk of venous thromboembolism after an induced abortion is double that of a matched non-pregnant woman, and is significantly lower than after a livebirth. This novel information can inform estimates of peri-procedural risk of venous thromboembolism after induced abortion. Clinicians could consider a lower threshold for ordering a diagnostic test to rule out venous thromboembolism after induced abortion than they would in a non-pregnant woman. Institute for Clinical Evaluative Sciences. Copyright © 2018 Elsevier Ltd. All rights reserved.
Detection of emetic activity in the cat by monitoring venous pressure and audio signals
NASA Technical Reports Server (NTRS)
Nagahara, A.; Fox, Robert A.; Daunton, Nancy G.; Elfar, S.
1991-01-01
To investigate the use of audio signals as a simple, noninvasive measure of emetic activity, the relationship between the somatic events and sounds associated with retching and vomiting was studied. Thoracic venous pressure obtained from an implanted external jugular catheter was shown to provide a precise measure of the somatic events associated with retching and vomiting. Changes in thoracic venous pressure monitored through an indwelling external jugular catheter with audio signals, obtained from a microphone located above the animal in a test chamber, were compared. In addition, two independent observers visually monitored emetic episodes. Retching and vomiting were induced by injection of xylazine (0.66mg/kg s.c.), or by motion. A unique audio signal at a frequency of approximately 250 Hz is produced at the time of the negative thoracic venous pressure change associated with retching. Sounds with higher frequencies (around 2500 Hz) occur in conjunction with the positive pressure changes associated with vomiting. These specific signals could be discriminated reliably by individuals reviewing the audio recordings of the sessions. Retching and those emetic episodes associated with positive venous pressure changes were detected accurately by audio monitoring, with 90 percent of retches and 100 percent of emetic episodes correctly identified. Retching was detected more accurately (p is less than .05) by audio monitoring than by direct visual observation. However, with visual observation a few incidents in which stomach contents were expelled in the absence of positive pressure changes or detectable sounds were identified. These data suggest that in emetic situations, the expulsion of stomach contents may be accomplished by more than one neuromuscular system and that audio signals can be used to detect emetic episodes associated with thoracic venous pressure changes.
Yildiz, Cenk Eray; Conkbayir, Cenk; Huseynov, Eldeniz; Sayin, Omer Ali; Tok, Okan; Kaynak, Gokhan; Cebi, Deniz; Ugurlucan, Murat; Kantarci, Fatih; Inan, Muharrem
2017-04-01
Objective We aimed to evaluate the efficiency of O-(beta-Hydroxyethyl)-rutosides (Oxerutin) in reducing the incidence of venous system disease among patients with calf muscle pump dysfunction secondary to immobilization due to lower-limb fractures. Methods A total of 60 patients with lower-limb fractures and immobilized in plaster casts were included in this study randomized into control (n = 30; mean: 30.37 ± 6.03 years; 73.3% males; no treatment) and experiment (n = 30; mean: 31.67 ± 4.76 years; 66.6% males; Oxerutin, 500 mg po q12hr) treatment groups. Doppler ultrasound was performed to evaluate the effect of oxerutin on the alterations in the venous circulation. Results Patients in the control group were determined to be more commonly affected from the below-knee immobilization in terms of venous dysfunction in the great saphenous vein in the below-knee region when compared with the patients in the oxerutin treatment group (46.7 vs. 13.3%, respectively; p = 0.011). Incidence of reflux in the small saphenous vein was more common in the control group during the healing period when compared with the experiment group (40.0 vs. 10.0%, respectively; p = 0.017). None of the patients developed venous thrombosis. Conclusions In conclusion, the impairment of the lower extremity muscle pump should be considered as an important risk factor for venous disease, and should be evaluated. O-(beta-Hydroxyethyl)-rutosides during 6-8 week cast immobilization for a lower limb fracture may be an effective prophylactic regimen in reducing the incidence of reflux in the below-knee superficial veins.
Wrede, Karsten H.; Johst, Sören; Dammann, Philipp; Özkan, Neriman; Mönninghoff, Christoph; Kraemer, Markus; Maderwald, Stefan; Ladd, Mark E.; Sure, Ulrich; Umutlu, Lale; Schlamann, Marc
2014-01-01
Purpose Conventional saturation pulses cannot be used for 7 Tesla ultra-high-resolution time-of-flight magnetic resonance angiography (TOF MRA) due to specific absorption rate (SAR) limitations. We overcome these limitations by utilizing low flip angle, variable rate selective excitation (VERSE) algorithm saturation pulses. Material and Methods Twenty-five neurosurgical patients (male n = 8, female n = 17; average age 49.64 years; range 26–70 years) with different intracranial vascular pathologies were enrolled in this trial. All patients were examined with a 7 Tesla (Magnetom 7 T, Siemens) whole body scanner system utilizing a dedicated 32-channel head coil. For venous saturation pulses a 35° flip angle was applied. Two neuroradiologists evaluated the delineation of arterial vessels in the Circle of Willis, delineation of vascular pathologies, presence of artifacts, vessel-tissue contrast and overall image quality of TOF MRA scans in consensus on a five-point scale. Normalized signal intensities in the confluence of venous sinuses, M1 segment of left middle cerebral artery and adjacent gray matter were measured and vessel-tissue contrasts were calculated. Results Ratings for the majority of patients ranged between good and excellent for most of the evaluated features. Venous saturation was sufficient for all cases with minor artifacts in arteriovenous malformations and arteriovenous fistulas. Quantitative signal intensity measurements showed high vessel-tissue contrast for confluence of venous sinuses, M1 segment of left middle cerebral artery and adjacent gray matter. Conclusion The use of novel low flip angle VERSE algorithm pulses for saturation of venous vessels can overcome SAR limitations in 7 Tesla ultra-high-resolution TOF MRA. Our protocol is suitable for clinical application with excellent image quality for delineation of various intracranial vascular pathologies. PMID:25232868
2014-01-01
Background Subcutaneous veins localization is usually performed manually by medical staff to find suitable vein to insert catheter for medication delivery or blood sample function. The rule of thumb is to find large and straight enough vein for the medication to flow inside of the selected blood vessel without any obstruction. The problem of peripheral difficult venous access arises when patient’s veins are not visible due to any reason like dark skin tone, presence of hair, high body fat or dehydrated condition, etc. Methods To enhance the visibility of veins, near infrared imaging systems is used to assist medical staff in veins localization process. Optimum illumination is crucial to obtain a better image contrast and quality, taking into consideration the limited power and space on portable imaging systems. In this work a hyperspectral image quality assessment is done to get the optimum range of illumination for venous imaging system. A database of hyperspectral images from 80 subjects has been created and subjects were divided in to four different classes on the basis of their skin tone. In this paper the results of hyper spectral image analyses are presented in function of the skin tone of patients. For each patient, four mean images were constructed by taking mean with a spectral span of 50 nm within near infrared range, i.e. 750–950 nm. Statistical quality measures were used to analyse these images. Conclusion It is concluded that the wavelength range of 800 to 850 nm serve as the optimum illumination range to get best near infrared venous image quality for each type of skin tone. PMID:25087016
Anselmetti, Giovanni Carlo; Zoarski, Gregg; Manca, Antonio; Masala, Salvatore; Eminefendic, Haris; Russo, Filippo; Regge, Daniele
2008-01-01
The aim of this study was to assess the feasibility of and venous leakage reduction in percutaneous vertebroplasty (PV) using a new high-viscosity bone cement (PMMA). PV has been used effectively for pain relief in osteoporotic and malignant vertebral fractures. Cement extrusion is a common problem and can lead to complications. Sixty patients (52 female; mean age, 72.2 +/- 7.2) suffering from osteoporosis (46), malignancy (12), and angiomas (2), divided into two groups (A and B), underwent PV on 190 vertebrae (86 dorsal, 104 lumbar). In Group A, PV with high-viscosity PMMA (Confidence, Disc-O-Tech, Israel) was used. This PMMA was injected by a proprietary delivery system, a hydraulic saline-filled screw injector. In Group B, a standard low-viscosity PMMA was used. Postprocedural CT was carried out to detect PMMA leakages and complications. Fisher's exact test and Wilcoxon rank test were used to assess significant differences (p < 0.05) in leakages and to evaluate the clinical outcome. PV was feasible, achieving good clinical outcome (p < 0.0001) without major complications. In Group A, postprocedural CT showed an asymptomatic leak in the venous structures of 8 of 98 (8.2%) treated vertebrae; a discoidal leak occurred in 6 of 98 (6.1%). In Group B, a venous leak was seen in 38 of 92 (41.3%) and a discoidal leak in 12 of 92 (13.0%). Reduction of venous leak obtained by high-viscosity PMMA was highly significant (p < 0.0001), whereas this result was not significant (p = 0.14) related to the disc. The high-viscosity PMMA system is safe and effective for clinical use, allowing a significant reduction of extravasation rate and, thus, leakage-related complications.
Suprascarpal fat pad thickness may predict venous drainage patterns in abdominal wall flaps.
Bast, John; Pitcher, Austin A; Small, Kevin; Otterburn, David M
2016-02-01
Abdominal wall flaps are routinely used in reconstructive procedures. In some patients inadequate venous drainage from the deep vein may cause fat necrosis or flap failure. Occasionally the superficial inferior epigastric vessels (SIEV) are of sufficient size to allow for microvascular revascularization. This study looked at the ratio of the sub- and suprascarpal fat layers, the number of deep system perforators, and SIEV diameter to determine any correlation of the fat topography and SIEV. 50 abdominal/pelvic CT angiograms (100 hemiabdomens) were examined in women aged 34-70 years for number of perforators, SIEV diameter, and fat pad thickness above and below Scarpa's fascia. Data was analyzed using multivariate model. The average suprascarpal and subscarpal layers were 18.6 ± 11.5 mm and 6.2 ± 7.2 mm thick, respectively. The average SIEV diameter was 2.06 ± 0.81 mm and the average number of perforators was 2.09 ± 1.03 per hemiabdomen. Hemiabdomens with suprascarpal thickness>23 mm had greater SIEV diameter [2.69 mm vs. 1.8 mm (P < 0.0001)] The fat layer thickness did not correlate with the number of perforators. Neither subscarpal fat thickness nor suprascarpal-to-subscarpal fat layer thickness correlated significantly with SIEV caliber or number of perforators in multivariate model. Suprascarpal fat pad thicker than 23 mm had larger SIEVs irrespective of the number of deep system perforators. This may indicate a cohort of patients at risk of venous congestion from poor venous drainage if only the deep system is revascularized. We recommend harvesting the SIEV in patients with suprascarpal fat pad >23 mm to aid in superficial drainage. © 2015 Wiley Periodicals, Inc.
Franzoso, Francesca D; Wohlmuth, Christoph; Greutmann, Matthias; Kellenberger, Christian J; Oxenius, Angela; Voser, Eva M; Valsangiacomo Buechel, Emanuela R
2016-09-01
The atria serve as reservoir, conduit, and active pump for ventricular filling. The performance of the atrial baffles after atrial switch repair for transposition of the great arteries may be abnormal and impact the function of the systemic right ventricle. We sought to assess atrial function in patients after atrial repair in comparison to patients after arterial switch repair (ASO) and to controls. Using magnetic resonance imaging, atrial volumes and functional parameters were measured in 17 patients after atrial switch repair, 9 patients after ASO and 10 healthy subjects. After the atrial switch operation, the maximum volume of the pulmonary venous atrium was significantly enlarged, but not of the systemic venous atrium. In both patients groups, independently from the surgical technique used, the minimum atrial volumes were elevated, which resulted in a decreased total empting fraction compared with controls (P < .01). The passive empting volume was diminished for right atrium, but elevated for left atrium after atrial switch and normal for left atrium after ASO; however, the passive empting fraction was diminished for both right atrium and left atrium after both operations (P < .01). The active empting volume was the most affected parameter in both atria and both groups and active empting fractions were highly significantly reduced compared with controls. Atrial function is abnormal in all patients, after atrial switch and ASO repair. The cyclic volume changes, that is, atrial filling and empting, are reduced when compared with normal subjects. Thus, the atria have lost part of their capacity to convert continuous venous flow into a pulsatile ventricular filling. The function of the pulmonary venous atrium, acting as preload for the systemic right ventricle, after atrial switch is altered the most. © 2015 Wiley Periodicals, Inc.
Skopets, A A; Lomivorotov, V V; Karakhalis, N B; Makarov, A A; Duman'ian, E S; Lomivorotova, L V
2009-01-01
The purpose of the study was to evaluate the efficiency of oxygen-transporting function of the circulatory system under sevoflurane anesthesia during myocardial revascularization operations under extracorporeal circulation. Twenty-five patients with coronary heart disease were examined. Mean blood pressure, heart rate, cardiac index, total peripheral vascular resistance index, pulmonary pressure, pulmonary wedge pressure, and central venous pressure were measured. Arterial and mixed venous blood oxygen levels, oxygen delivery and consumption index, arteriovenous oxygen difference, and glucose and lactate concentrations were calculated. The study has demonstrated that sevoflurane is an effective and safe anesthetic for myocardial revascularization operations in patients with coronary heart disease. The use of sevoflurane contributes to steady-state oxygen-transporting function of the circulatory system at all surgical stages.
Dielectric coagulometry: a new approach to estimate venous thrombosis risk.
Hayashi, Yoshihito; Katsumoto, Yoichi; Omori, Shinji; Yasuda, Akio; Asami, Koji; Kaibara, Makoto; Uchimura, Isao
2010-12-01
We present dielectric coagulometry as a new technique to estimate the risk of venous thrombosis by measuring the permittivity change associated with the blood coagulation process. The method was first tested for a simple system of animal erythrocytes suspended in fibrinogen solution, where the coagulation rate was controlled by changing the amount of thrombin added to the suspension. Second, the method was applied to a more realistic system of human whole blood, and the inherent coagulation process was monitored without artificial acceleration by a coagulation initiator. The time dependence of the permittivity at a frequency around 1 MHz showed a distinct peak at a time that corresponds to the clotting time. Our theoretical modeling revealed that the evolution of heterogeneity and the sedimentation in the system cause the peak of the permittivity.
Energy demands during a judo match and recovery.
Degoutte, F; Jouanel, P; Filaire, E
2003-06-01
To assess energy demand during a judo match and the kinetics of recovery by measuring the metabolites of the oxypurine cascade, lipolytic activity, and glycolytic pathway. Venous blood samples were taken from 16 national judoists (mean (SEM) age 18.4 (1.6) years), before (T(1)) and three minutes (T(2)), one hour (T(3)), and 24 hours (T(4)) after a match. A seven day diet record was used to evaluate nutrient intake. Nutrient analysis indicated that these athletes followed a low carbohydrate diet. Plasma lactate concentration had increased to 12.3 (1.8) mmol/l at the end of the match. An increase in the levels of extracellular markers of muscle adenine nucleotide catabolism, urea, and creatinine was observed at T(2), while uric acid levels remained unchanged. High concentrations of urea persisted for 24 hours during the recovery period. Ammonia, hypoxanthine, xanthine, and creatinine returned to control levels within the 24 hour recovery period. Uric acid concentrations rose from T(3) and had not returned to baseline 24 hours after the match. The levels of triglycerides, glycerol, and free fatty acids had increased significantly (p<0.05) after the match (T(2)) but returned to baseline values within 24 hours. Concentrations of high density lipoprotein cholesterol and total cholesterol were significantly increased after the match. These results show that a judo match induces both protein and lipid metabolism. Carbohydrate availability, training adaptation, and metabolic stress may explain the requirement for these types of metabolism.
2008-01-01
Introduction Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0/1000 people have active leg ulcers. Prevalence increases with age to about 20/1000 in people aged over 80 years. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of standard treatments, adjuvant treatments, and organisational interventions for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 80 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression bandages and stockings, cultured allogenic (single or bilayer) skin replacement, debriding agents, dressings (cellulose, collagen, film, foam, hyaluronic acid-derived, semi-occlusive alginate), hydrocolloid (occlusive) dressings in the presence of compression, intermittent pneumatic compression, intravenous prostaglandin E1, larval therapy, laser treatment (low-level), leg ulcer clinics, multilayer elastic system, multilayer elastomeric (or non-elastomeric) high-compression regimens or bandages, oral treatments (aspirin, flavonoids, pentoxifylline, rutosides, stanozolol, sulodexide, thromboxane alpha2 antagonists, zinc), peri-ulcer injection of granulocyte-macrophage colony-stimulating factor, short-stretch bandages, single-layer non-elastic system, skin grafting, superficial vein surgery, systemic mesoglycan, therapeutic ultrasound, self-help (advice to elevate leg, advice to keep leg active, advice to modify diet, advice to stop smoking, advice to reduce weight), and topical treatments (antimicrobial agents, autologous platelet lysate, calcitonin gene-related peptide plus vasoactive intestinal polypeptide, freeze-dried keratinocyte lysate, mesoglycan, negative-pressure recombinant keratinocyte growth factor, platelet-derived growth factor). PMID:19445798
Chmielak, Zbigniew; Dębski, Artur; Kępka, Cezary; Rudziński, Piotr N.; Bujak, Sebastian; Skwarek, Mirosław; Kurowski, Andrzej; Dzielińska, Zofia; Demkow, Marcin
2016-01-01
Introduction Totally implantable venous access systems (TIVAS), Swan-Ganz (SG) and central venous catheters (CVC) allow easy and repetitive entry to the central cardiovascular system. Fragments of them may be released inadvertently into the cardiovascular system during their insertion or as a result of mechanical complications encountered during long-term utilization. Aim To present results of percutaneous retrieval of embolized fragments of central venous devices or knotted SG and review the procedural aspects with a series of detailed angiographies. Material and methods Between January 2003 and December 2012 there were 14 (~0.025%) successful retrievals in 13 patients (44 ±16 years, 15% females) of embolized fragments of TIVAS (n = 10) or CVC (n = 1) or of dislodged guide-wires (n = 2) or knotted SG (n = 1). Results Foreign bodies with the forward end located in the right ventricle (RV), as well as those found in the pulmonary artery (PA), often required repositioning with a pigtail catheter as compared to those catheter fragments which were located in the right atrium (RA) and/or great vein and possessed an accessible free end allowing their direct ensnarement with the loop snare (57.0% (4/7) vs. 66.7% (2/3) vs. 0.0% (0/3); p = 0.074 respectively). Procedure duration was 2–3 times longer among catheters retrieved from the PA than among those with the forward edge located in the RV or RA (30 (18–68) vs. 13.5 (11–37) vs. 8 min (8–13); p = 0.054 respectively). The SG catheter knotted in the vena cava superior (VCS) was encircled with the loop snare introduced transfemorally, subsequently cut at its skin entrance and then pulled down inside the 14 Fr vascular sheath. Conclusions By using the pigtail catheter and the loop snare, it is feasible to retrieve centrally embolized fragments or knotted central venous access devices. PMID:27279874
Catecholaminergic effects of prolonged head-down bed rest
NASA Technical Reports Server (NTRS)
Goldstein, D. S.; Vernikos, J.; Holmes, C.; Convertino, V. A.
1995-01-01
Prolonged head-down bed rest (HDBR) provides a model for examining responses to chronic weightlessness in humans. Eight healthy volunteers underwent HDBR for 2 wk. Antecubital venous blood was sampled for plasma levels of catechols [norepinephrine (NE), epinephrine, dopamine, dihydroxyphenylalanine, dihydroxyphenylglycol, and dihydroxyphenylacetic acid] after supine rest on a control (C) day and after 4 h and 7 and 14 days of HDBR. Urine was collected after 2 h of supine rest during day C, 2 h before HDBR, and during the intervals 1-4, 4-24, 144-168 (day 7), and 312-336 h (day 14) of HDBR. All subjects had decreased plasma and blood volumes (mean 16%), atriopeptin levels (31%), and peripheral venous pressure (26%) after HDBR. NE excretion on day 14 of HDBR was decreased by 35% from that on day C, without further trends as HDBR continued, whereas plasma levels were only variably and nonsignificantly decreased. Excretion rates of dihydroxyphenylglycol and dihydroxyphenylalanine decreased slightly during HDBR; excretion rates of epinephrine, dopamine, and dihydroxyphenylacetic acid and plasma levels of catechols were unchanged. The results suggest that HDBR produces sustained inhibition of sympathoneural release, turnover, and synthesis of NE without affecting adrenomedullary secretion or renal dopamine production. Concurrent hypovolemia probably interferes with detection of sympathoinhibition by plasma levels of NE and other catechols in this setting. Sympathoinhibition, despite decreased blood volume, may help to explain orthostatic intolerance in astronauts returning from spaceflights.
The effects of cross-linked thermo-responsive PNIPAAm-based hydrogel injection on retinal function.
Turturro, Sanja B; Guthrie, Micah J; Appel, Alyssa A; Drapala, Pawel W; Brey, Eric M; Pérez-Luna, Victor H; Mieler, William F; Kang-Mieler, Jennifer J
2011-05-01
There is significant interest in biomaterials that provide sustained release of therapeutic molecules to the retina. Poly(N-isopropylacrylamide) (PNIPAAm)-based materials have received significant attention as injectable drug delivery platforms due to PNIPAAm's thermo-responsive properties at approximately 32 °C. While the drug delivery properties of PNIPAAm materials have been studied extensively, there is a need to evaluate the safety effects of hydrogel injection on retinal function. The purpose of this study was to examine the effect of poly(ethylene glycol) diacrylate (PEG-DA) crosslinked PNIPAAm hydrogel injection on retinal function. Utilizing scanning laser ophthalmoscopy (SLO), optical coherent tomography (OCT), and electroretinography (ERG), retinal function was assessed following hydrogel injection. In region near the hydrogel, there was a significant decrease in arterial and venous diameters (∼4%) and an increase in venous blood velocity (∼8%) 1 week post-injection. Retinal thickness decreased (∼6%) at 1 week and the maximum a- and b-wave amplitudes of ERG decreased (∼15%). All data returned to baseline values after week 1. These data suggest that the injection of PEG-DA crosslinked PNIPAAm hydrogel results in a small transient effect on retinal function without any long-term effects. These results further support the potential of PNIPAAm-based materials as an ocular drug delivery platform. Copyright © 2011 Elsevier Ltd. All rights reserved.
Badham, George E; Dos Santos, Scott J; Lloyd, Lucinda Ba; Holdstock, Judy M; Whiteley, Mark S
2018-06-01
Background In previous in vitro and ex vivo studies, we have shown increased thermal spread can be achieved with radiofrequency-induced thermotherapy when using a low power and slower, discontinuous pullback. We aimed to determine the clinical success rate of radiofrequency-induced thermotherapy using this optimised protocol for the treatment of superficial venous reflux in truncal veins. Methods Sixty-three patients were treated with radiofrequency-induced thermotherapy using the optimised protocol and were followed up after one year (mean 16.3 months). Thirty-five patients returned for audit, giving a response rate of 56%. Duplex ultrasonography was employed to check for truncal reflux and compared to initial scans. Results In the 35 patients studied, there were 48 legs, with 64 truncal veins treated by radiofrequency-induced thermotherapy (34 great saphenous, 15 small saphenous and 15 anterior accessory saphenous veins). One year post-treatment, complete closure of all previously refluxing truncal veins was demonstrated on ultrasound, giving a success rate of 100%. Conclusions Using a previously reported optimised, low power/slow pullback radiofrequency-induced thermotherapy protocol, we have shown it is possible to achieve a 100% ablation at one year. This compares favourably with results reported at one year post-procedure using the high power/fast pullback protocols that are currently recommended for this device.
Determinants of systemic zero-flow arterial pressure.
Brunner, M J; Greene, A S; Sagawa, K; Shoukas, A A
1983-09-01
Thirteen pentobarbital-anesthetized dogs whose carotid sinuses were isolated and perfused at a constant pressure were placed on total cardiac bypass. With systemic venous pressure held at 0 mmHg (condition 1), arterial inflow was stopped for 20 s at intrasinus pressures of 50, 125, and 200 mmHg. Zero-flow arterial pressures under condition 1 were 16.2 +/- 1.3 (SE), 13.8 +/- 1.1, and 12.5 +/- 0.8 mmHg, respectively. In condition 2, the venous outflow tube was clamped at the instant of stopping the inflow, causing venous pressure to rise. The zero-flow arterial pressures were 19.7 +/- 1.3, 18.5 +/- 1.4, and 16.4 +/- 1.2 mmHg for intrasinus pressures of 50, 125, and 200 mmHg, respectively. At all levels of intrasinus pressure, the zero-flow arterial pressure in condition 2 was higher (P less than 0.005) than in condition 1. In seven dogs, at an intrasinus pressure of 125 mmHg, epinephrine increased the zero-flow arterial pressure by 3.0 mmHg, whereas hexamethonium and papaverine decreased the zero-flow arterial pressure by 2 mmHg. Reductions in the hematocrit from 52 to 11% resulted in statistically significant changes (P less than 0.01) in zero-flow arterial pressures. Thus zero-flow arterial pressure was found to be affected by changes in venous pressure, hematocrit, and vasomotor tone. The evidence does not support the literally interpreted concept of the vascular waterfall as the model for the finite arteriovenous pressure difference at zero flow.
Cardiovascular consequences of bed rest: effect on maximal oxygen uptake
NASA Technical Reports Server (NTRS)
Convertino, V. A.
1997-01-01
Maximal oxygen uptake (VO2max) is reduced in healthy individuals confined to bed rest, suggesting it is independent of any disease state. The magnitude of reduction in VO2max is dependent on duration of bed rest and the initial level of aerobic fitness (VO2max), but it appears to be independent of age or gender. Bed rest induces an elevated maximal heart rate which, in turn, is associated with decreased cardiac vagal tone, increased sympathetic catecholamine secretion, and greater cardiac beta-receptor sensitivity. Despite the elevation in heart rate, VO2max is reduced primarily from decreased maximal stroke volume and cardiac output. An elevated ejection fraction during exercise following bed rest suggests that the lower stroke volume is not caused by ventricular dysfunction but is primarily the result of decreased venous return associated with lower circulating blood volume, reduced central venous pressure, and higher venous compliance in the lower extremities. VO2max, stroke volume, and cardiac output are further compromised by exercise in the upright posture. The contribution of hypovolemia to reduced cardiac output during exercise following bed rest is supported by the close relationship between the relative magnitude (% delta) and time course of change in blood volume and VO2max during bed rest, and also by the fact that retention of plasma volume is associated with maintenance of VO2max after bed rest. Arteriovenous oxygen difference during maximal exercise is not altered by bed rest, suggesting that peripheral mechanisms may not contribute significantly to the decreased VO2max. However reduction in baseline and maximal muscle blood flow, red blood cell volume, and capillarization in working muscles represent peripheral mechanisms that may contribute to limited oxygen delivery and, subsequently, lowered VO2max. Thus, alterations in cardiac and vascular functions induced by prolonged confinement to bed rest contribute to diminution of maximal oxygen uptake and reserve capacity to perform physical work.
Improving results of the modified Fontan operation in patients with heterotaxy syndrome.
Stamm, Christof; Friehs, Ingeborg; Duebener, Lennart F; Zurakowski, David; Mayer, John E; Jonas, Richard A; del Nido, Pedro J
2002-12-01
Historically the Fontan operation in patients with single ventricle heterotaxy syndrome and atrial isomerism has been associated with high mortality. We studied whether recent modifications of the surgical technique have improved outcome. A retrospective review of 135 patients with heterotaxy syndrome who underwent a Fontan operation between 1981 and 2000 was performed. There were 93 patients with right isomerism and 42 with left isomerism. Anomalies of venous return included 25 patients with extracardiac pulmonary venous connection (19%) and 37 patients with an interrupted inferior vena cava (27%). Thirty-six patients (27%) had at least moderate atrioventricular valve regurgitation. The type of Fontan procedure included 17 patients with an atriopulmonary Fontan connection, 67 with a lateral tunnel modification, 19 with an intraatrial tube graft, 25 with an extracardiac tubegraft, and 7 with an intra-extra atrial tube graft. A fenestration was placed in 93 patients (78%). Early mortality was 19% before 1991, 3% since 1991, and no patient has died early since 1993. Ten-year survivals were 70% for Fontan operations before 1990 and 93% for Fontan operations after 1990. Thirty-two patients (23%) had prolonged pleural effusions. Risk factors for death included anomalous pulmonary venous connection (p = 0.02) and higher preoperative pulmonary vascular resistance (p = 0.002). Sixty-two patients (47%) had some form of early postoperative arrhythmia. At 10 years, freedom from late bradyarrhythmia and late tachyarrhythmia were 78% and 70%, respectively. Preoperative arrhythmias, older age at operation, and anatomic features were each independent predictors of late arrhythmia. The Fontan operation can now be performed in patients with heterotaxy syndrome with excellent survival. However, morbidity in terms of postoperative arrhythmias and prolonged pleural effusions remains significant. Fontan staging, appropriate choice of Fontan modification, aggressive treatment of concomitant malformations, and use of a baffle fenestration contribute to improved outcome.
Lucas, Rebekah A. I.; Pearson, James; Schlader, Zachary J.; Crandall, Craig G.
2016-01-01
This study tested the hypothesis that baroreceptor unloading during passive hyperthermia contributes to increases in ventilation and decreases in end-tidal partial pressure of carbon dioxide (PET,CO2) during that exposure. Two protocols were performed, in which healthy subjects underwent passive hyperthermia (increasing intestinal temperature by ~1.8°C) to cause a sustained increase in ventilation and reduction in PET,CO2. Upon attaining hyperthermic hyperventilation, in protocol 1 (n = 10; three females) a bolus (19 ± 2 ml kg−1) of warm (~38°C) isotonic saline was rapidly (5–10 min) infused intravenously to restore reductions in central venous pressure, whereas in protocol 2 (n = 11; five females) phenylephrine was infused intravenously (60–120 μg min−1) to return mean arterial pressure to normothermic levels. In protocol 1, hyperthermia increased ventilation (by 2.2 ± 1.7 l min−1, P < 0.01), while reducing PET,CO2 (by 4 ± 3 mmHg, P = 0.04) and central venous pressure (by 5 ± 1 mmHg, P <0.01). Saline infusion increased central venous pressure by 5 ± 1 mmHg (P < 0.01), restoring it to normothermic values, but did not change ventilation or PET,CO2 (P > 0.05). In protocol 2, hyperthermia increased ventilation (by 5.0 ± 2.7l min−1, P <0.01) and reduced PET ,CO2 (by 5 ± 2 mmHg, P < 0.01) and mean arterial pressure (by 9 ± 7 mmHg, P <0.01). Phenylephrine infusion increased mean arterial pressure by 12 ± 3 mmHg (P < 0.01), restoring it to normothermic values, but did not change ventilation or PET,CO2 (P > 0.05). The absence of a reduction in ventilation upon reloading the cardiopulmonary and arterial baroreceptors to pre-hyperthermic levels indicates that baroreceptor unloading with hyperthermia is unlikely to contribute to hyperthermic hyperventilation in humans. PMID:26299270
Wemmelund, K B; Lie, R H; Juhl-Olsen, P; Frederiksen, C A; Hermansen, J F; Sloth, E
2012-08-01
Although pleural effusion is a common complication in critically ill patients, detailed knowledge is missing about the haemodynamic impact and the underlining mechanisms. The aim of this study was to evaluate the haemodynamic effect of incremental pleural effusion by means of invasive haemodynamic parameters and transthoracic echocardiography. This experimental interventional study was conducted using 22 female piglets (17.5-21.5 kg) randomized for right-side (n = 9) and left-side (n = 9) pleural effusion, or sham operation (n = 4). Pleural effusion was induced by infusing incremental volumes of saline into the pleural cavity. Invasive haemodynamic measurements and echocardiographical images were obtained at baseline, a volume of 45 ml/kg, a volume of 75 ml/kg and 45 min after drainage. No difference (all P > 0.147) was found between right- and left-side pleural effusion, and the groups were thus pooled. At 45 ml/kg cardiac output, mean arterial pressure, stroke volume and mixed venous saturation decreased (all P < 0.003); central venous pressure and pulmonary arterial pressure increased (both P > 0.003) at this point. The changes accelerated at 75 ml/kg. At 45 ml/kg left ventricular pre-load in terms of end-diastolic area decreased significantly (P < 0.001). The effect on haemodynamics and cardiac dimensions changed dramatically at 75 ml/kg. Cardiac output, mean arterial pressure, central venous pressure and left ventricular end-diastolic area returned to normal during a recovery period of 45 min (all P > 0.061). Incremental volumes of unilateral pleural effusion induced a significant haemodynamic impact fully reversible after drainage. Pleural effusion causes a significant decrease of left ventricular pre-load in a diverse picture of haemodynamic compromise. © 2012 The Authors. Acta Anaesthesiologica Scandinavica © 2012 The Acta Anaesthesiologica Scandinavica Foundation.
Ramirez, Ana; Abril, Juan Carlos; Touza, Alberto
2012-11-01
The aim of this study was to determine the benefits of cystography in the management of a simple bone cyst, its implication in the final result of the treatment after corticoid intracystic injections, and the presence of secondary effects. We retrospectively reviewed 42 patients diagnosed with a simple bone cyst. Cystography was performed before the corticoid injection. The presence or absence of loculation intracyst and the existence and number of venous outflows were determined. According to the venous drainage, cysts were classified as type 0 when a venous outflow did not exist and as type 1 when there was a rapid venous outflow (<3 min). The treatment protocol included a maximum of three corticoid injections at an interval of 6 months. Healing of the cyst was determined on the basis of Neer's criteria. Secondary effects and surgical complications were assessed. Cystography studies showed a unicameral bone cyst with absent loculation in 16 cases (37.3%), whereas the lesion showed multiloculation in 26 cases (62.7%). There was no statistical difference between loculation intracyst (present or absent) and the final outcomes of the 42 cysts treated with a steroid injection (P=0.9). Cystography showed a negative venogram in 10 cases (23.8%), whereas the cysts showed a rapid venous outflow in 32 cases (76.2%). On the basis of Neer's classification, all patients with a negative venogram achieved complete healing of the cyst. Patients with a rapid venous outflow achieved complete healing in 14 cases (Neer I). In two patients, the healing was incomplete at the end of the follow-up period (Neer IV). In most cases (21 cysts), healing was partial (Neer II). Five patients showed a recurrence after initial healing of the cyst (Neer III) (P<0.05). The number or the size of veins did not affect healing of a bone cyst (P=0.6). Two patients with a rapid venous outflow showed a generalized hypertrichosis after the first injection of corticosteroids. Sex and age at the initiation of the first injection were not significant factors of healing (P=0.4). The average follow-up time was 59 months (24-60 months). Cystography provides morphological and functional information of simple bone cyst. It is a useful test before the administration of percutaneous injections of sclerosing substances. It facilitates the differentiation of cysts that may achieve complete healing (negative venogram) from those that tend to show recurrence (rapid venous outflow). Therapeutic material should be introduced slowly and a second trocar should always be placed to decrease the risk of migration in cysts with communication with the venous system. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Donovan, Michael S; Kassop, David; Liotta, Robert A; Hulten, Edward A
2015-01-01
Sinus venosus atrial septal defects (SV-ASD) have nonspecific clinical presentations and represent a diagnostic imaging challenge. Transthoracic echocardiography (TTE) remains the initial diagnostic imaging modality. However, detection rates have been as low as 12%. Transesophageal echocardiography (TEE) improves diagnostic accuracy though it may not detect commonly associated partial anomalous pulmonary venous return (PAPVR). Cardiac magnetic resonance (CMR) imaging provides a noninvasive, highly sensitive and specific imaging modality of SV-ASD. We describe a case of an adult male with exercise-induced, paroxysmal supraventricular tachycardia who presented with palpitations and dyspnea. Despite nondiagnostic imaging results on TTE, CMR proved to be instrumental in visualizing a hemodynamically significant SV-ASD with PAPVR that ultimately led to surgical correction.
Donovan, Michael S.; Kassop, David; Liotta, Robert A.; Hulten, Edward A.
2015-01-01
Sinus venosus atrial septal defects (SV-ASD) have nonspecific clinical presentations and represent a diagnostic imaging challenge. Transthoracic echocardiography (TTE) remains the initial diagnostic imaging modality. However, detection rates have been as low as 12%. Transesophageal echocardiography (TEE) improves diagnostic accuracy though it may not detect commonly associated partial anomalous pulmonary venous return (PAPVR). Cardiac magnetic resonance (CMR) imaging provides a noninvasive, highly sensitive and specific imaging modality of SV-ASD. We describe a case of an adult male with exercise-induced, paroxysmal supraventricular tachycardia who presented with palpitations and dyspnea. Despite nondiagnostic imaging results on TTE, CMR proved to be instrumental in visualizing a hemodynamically significant SV-ASD with PAPVR that ultimately led to surgical correction. PMID:25705227
Abdullah, Mohamed Hussein; Soliman, Hossam El Deen; Morad, Wessam Saber
2011-12-01
Many centers have adopted central vein cannulation both for central venous pressure monitoring and fluid administration for right hepatectomy in living-liver donors. However, use of central venous catheters is associated with adverse events that are hazardous to patients and expensive to treat. This study sought to examine the use of external jugular venous pressure as an alternative to conventional central venous pressure in right lobe donor hepatectomies Forty ASA grade I adult living liver-donors without a known history of significant cardiac or pulmonary diseases were enrolled in this prospective observational study. Paired measurement of venous pressures (external jugular venous pressure and internal jugular venous pressure) were taken at the following times: after induction of anesthesia, 30 minutes after skin incision, during right lobe mobilization (every 15 minutes), during hepatic transaction (every 15 minutes), after right lobe resection (every 15 minutes), and after abdominal closure. Paired measurements were equal in 47.5%, 53.5%, 61.5%, 46.3%, and 52.5% for after induction, after skin incision, right lobe mobilization, right lobe transection, after resection, and before abdominal closure periods. However, all measurements were within acceptable limits of bias measurements (± 2 mm Hg). Central venous pressure catheter placement can be avoided and replaced by a less-invasive method such as external jugular venous pressure (which gave an acceptable estimate of central venous pressure in all phases of right lobe resection) in living-donor liver transplant and allowed equivalent monitor even during fluid restriction phases.