Laparoscopic treatment of abdominal complications following ventriculoperitoneal shunt

PubMed Central

Grigorean, VT; Onose, G; Popescu, M; Strambu, V; Sandu, AM

2009-01-01

The aim of this study is the evaluation of laparoscopic treatment in abdominal complications following ventriculoperitoneal (VP) shunt. Methods: We report a retrospective study including 17 patients with abdominal complications secondary to VP shunt for hydrocephalus, laparoscopically treated in our department, between 2000 and 2007. Results: Patients' age ranged from 1 to 72 years old (mean age 25.8 years old). Male: female ratio was 1.4. Abdominal complications encountered were: shunt disconnection with intraperitoneal distal catheter migration 47.05% (8/17), infections 23.52% (4/17) such as abscesses and peritonitis, pseudocysts 11.76% (2/17), CSF ascites 5.88% (1/17), inguinal hernia 5.88% (1/17), and shunt malfunction due to excessive length of intraperitoneal tube 5.88% (1/17). Free–disease interval varies from 1 day to 21 years, depending on the type of complication, short in peritoneal irritation syndrome and abscesses (days) and long in ascites, pseudocysts(months– years). Laparoscopic treatment was: extraction of the foreign body in shunt disconnection with intraperitoneal distal catheter migration, evacuation, debridement, lavage and drainage for pseudocysts, abscess and peritonitis, shortening of the tube in shunt malfunction due to excessive length of intraperitoneal tube a nd hernioraphy. One diagnostic laparoscopy was performed in a peritoneal irritation syndrome, which found only CSF ascites. There were no conversions to open surgery. The overall mortality was of 5.88% and postoperative morbidity was of 11.76%. In 7 patients operated for abscesses, peritonitis, pseudocysts, and CSF ascites the shunting system was converted in to a ventriculocardiac shunt. Conclusions: Abdominal complication following VP shunt can be successfully performed laparoscopically. Abdominal surgery required, in selected cases, the repositioning of the distal catheter, frequently as a ventriculocardiac shunt. There are abdominal complications with no indication of surgery, like peritoneal irritation syndrome and CSF ascites. Free– disease interval varies from days (peritoneal irritation syndrome, abscesses) to month–years (pseudocyst, ascites), according to type of complication. PMID:20108757

Oculoplastic technique of connecting a glaucoma valve shunt to extraorbital locations in cases of severe glaucoma.

PubMed

Rubin, Peter A D; Chang, Eli; Bernardino, Carlo Roberto; Hatton, Mark P; Dohlman, Claes H

2004-09-01

To describe a technique for inserting glaucoma shunts to the sinuses or the lacrimal sac as a means of lowering intraocular pressure in patients with refractory glaucoma associated with severe ocular surface disease. Nineteen patients with severe ocular surface disease necessitating a keratoprosthesis and with intractable glaucoma underwent placement of a modified Ahmed shunt to direct aqueous in the maxillary or ethmoid sinus or lacrimal sac. Intraocular pressure is presently well controlled without glaucoma medications in two thirds of patients. None of the patients had endophthalmitis. Established oculoplastic surgery techniques may be used to redirect aqueous to extraorbital locations and effectively lower intraocular pressure in patients with severe ocular surface disease and refractory glaucoma. This procedure has not been associated with endophthalmitis.

Treatment of refractory chylothorax with externalized pleuroperitoneal shunts in children.

PubMed

Wolff, A B; Silen, M L; Kokoska, E R; Rodgers, B M

1999-09-01

Traditional therapy for refractory chylothorax in the pediatric population has included pleurodesis and thoracic duct ligation. These procedures are associated with high morbidity and questionable success rates. We retrospectively reviewed our experience with 15 patients who underwent treatment for chylous effusions using pleuroperitoneal shunts with exteriorized pump chambers. Mean patient age at time of shunt placement was 2.1 (0.1 to 11.5) years and the most common indication (7 of 15) was refractory chylothorax following surgical correction of congenital heart disease. Mean chylothorax duration before shunt placement was 76 (5 to 810) days and shunts were in place for an average of 104 (12 to 365) days. A total of 19 chylous effusions (pleural or pericardial) were treated with shunts. Nine of 11 right-sided chylothoraces, 5 of 6 left-sided chylothoraces, and 2 of 2 chylopericardia resolved with shunt therapy (84% total). Pleuroperitoneal shunting failed to clear the effusion in 3 children. There were six episodes of shunt malfunction that were repaired and two episodes of infection. Inguinal or umbilical hernia developed in 4 patients. Externalized pleuroperitoneal shunting is a safe, effective, and minimally invasive treatment for children with refractory chylous effusions.

Noninvasive Thermal Evaluation of Ventriculoperitoneal Shunt Patency and Cerebrospinal Fluid Flow Using a Flow Enhancing Device.

PubMed

Hameed, Mustafa Q; Zurakowski, David; Proctor, Mark R; Stone, Scellig S D; Warf, Benjamin C; Smith, Edward R; Goumnerova, Liliana C; Swoboda, Marek; Anor, Tomer; Madsen, Joseph R

2018-06-16

While a noninvasive flow determination would be desirable in the diagnosis of cerebrospinal fluid shunt malfunction, existing studies have not yet defined a role for thermal flow detection. To evaluate a revised test protocol using a micropumper designed to transiently enhance flow during thermal testing to determine whether thermal detection of flow is associated with progression to shunt revision surgery. Eighty-two unique tests were performed in 71 shunts. The primary outcome, need for revision within 7 d of testing, was compared with results of micropumper-augmented thermal flow detection. Statistical analysis was based on blind interpretation of test results and raw temperature data recorded during testing. The test was sensitive (73%) and specific (68%) in predicting need for revision, with 5.6-fold higher probability of revision when flow was not detected. Negative predictive value in our sample was 94.2%. The probability of not requiring revision increased with increasing total temperature drop. Analysis of various possible thresholds showed that the optimal temperature cutoff may be lower than suggested by the manufacturer (0.125°C vs 0.2°C). This is the first study to report a strong association between thermal flow evaluation and a clinical impression that a shunt is not malfunctioning. The current recommended threshold may increase the false positive rate unnecessarily, and as clinicians gain experience with the method, they may find value in examining the temperature curves themselves. Multicenter studies are suggested to further define a role for this diagnostic test.

Thinking outside the shunt-sterile CSF malabsorption in pilocytic astrocytomas: case series and review of the literature.

PubMed

Johnson, J A; O'Halloran, P J; Crimmins, D; Caird, J

2016-11-01

Ventriculoperitoneal (VP) shunt insertion is the most common cerebrospinal fluid (CSF) diversionary procedure used for the treatment of chronic hydrocephalus. Sterile CSF ascites is a rare complication of VP shunt insertion. This can arise from either an overproduction of CSF or inadequate filtration of CSF at the level of the peritoneum. By either mechanism, the development of CSF ascites requires an intact VP shunt. The authors discuss two paediatric cases diagnosed with suprasellar pilocytic astrocytomas treated with platinum-based chemotherapy, who subsequently developed sterile CSF ascites. We review the literature with regard to CSF malabsorption and discuss it as a contributing factor to shunt malfunction. CSF malabsorption with resultant ascites is a rare complication of VP shunting with many etiologies. Two common predisposing factors included the use of platinum-based chemotherapeutic agents, as well as the specific neuropathology. Further analysis of these two entities is needed in order to elucidate their role in contributing to the development of CSF ascites in this patient cohort.

Ventriculoperitoneal Shunt Fracture Following Application of Halo-Gravity Traction: A Case Report.

PubMed

Blakeney, William G; D'Amato, Charles

2015-09-01

Ventriculoperitoneal (VP) shunt malfunctions are very common, and shunt fracture is one of the most common causes. Shunt fractures are often a result of calcification and tethering, which predispose the tubing to fracture when mechanical stresses are applied. This case report describes a case of shunt fracture following application of halo-gravity traction for correction of spinal deformity. Chart and imaging data for a single case were reviewed and reported in this retrospective case study. A 10-year-old female, being treated for syndromic scoliosis, underwent posterior surgical release and application of halo-gravity traction. Increasing weight of traction was applied over a period of 6 weeks, for gradual deformity correction. It was noted on the 6-week cervical spine radiograph that the VP shunt had fractured at the base of the neck. The patient was taken to the operating room and intraoperative findings confirmed shunt fracture. This was repaired without complications. This case, to our best knowledge, is the first reported occurrence of shunt fracture following application of halo-gravity traction. It demonstrates the importance of careful monitoring of patients with VP shunts, when they are undergoing traction for correction of spinal deformity. Level IV.

Effect of bladder augmentation on VP shunt failure rates in spina bifida.

PubMed

Gonzalez, Dani O; Cooper, Jennifer N; McLeod, Daryl J

2017-12-11

Most patients with spina bifida require ventriculoperitoneal (VP) shunt placement. Some also require bladder augmentation, which may increase the risk of VP shunt malfunction and/or failure. The aim of this study was to assess whether bladder augmentation affects the rate of VP shunt failure in this population. Using the Pediatric Health Information System, we studied patients with spina bifida born between 1992 and 2014 who underwent VP shunt placement. Using conditional logistic regression, we compared age- and hospital-matched patients who did and did not undergo a bladder augmentation to determine their difference in rates of VP shunt failure. There were 4192 patients with spina bifida who underwent both surgical closure and VP shunt placement. Of these, 203 patients with bladder augmentation could be matched to 593 patients without bladder augmentation. VP shunt failure occurred within 2 years in 7.7% of patients, the majority of whom were in the group who underwent bladder augmentation (87%). After adjusting for confounders, undergoing bladder augmentation was independently associated with VP shunt failure (HR: 33.5, 95% CI: 13.15-85.44, p< 0.001). Bladder augmentation appears to be associated with VP shunt failure. Additional studies are necessary to better define this relationship and identify risk-reduction techniques.

Assessment of Cerebral Hemodynamics in Traumatic Brain Injury

DTIC Science & Technology

2006-11-01

be used in the diagnosis of patients with hydrocephalus symptoms or shunt malfunctions (Czosnyka et al. 2004). The frequency dependent aspects of...patients with normotensive hydrocephalus , are particularly important. Fig. 9. The values of wavelet gain and synchronization index, averaged over the

Reversible ventriculoperitoneal shunt dysfunction and chronic constipation: case report.

PubMed

Morais, Barbara A; Cardeal, Daniel D; Andrade, Fernanda G; Paiva, Wellingson S; Matushita, Hamilton; Teixeira, Manoel J

2018-05-11

Constipation can cause transient malfunction of the ventriculoperitoneal shunt (VPS). Patients with myelomeningocele or cerebral palsy are often diagnosed with hydrocephalus and constipation due to neurogenic bowel. These patients are more prone to VPS dysfunction, often requiring surgical revision. The authors report the case of a 6-year-old girl with a VPS that had been implanted due to hydrocephalus secondary to myelomeningocele. The patient was brought to the emergency department with intermittent headache, vomiting, constipation, and abdominal distension and pain. A CT scan revealed ventricular dilatation and radiography of the abdomen showed bowel loop distension. After a Fleet enema and digital maneuvers, her abdominal distension and symptoms improved. A CT scan obtained 24 hours later showed a reduction in ventricular size. The mechanism by which constipation can lead to VPS malfunction can be traced to indirect increases of intraabdominal pressure and direct obstruction of the catheter by distended intestinal loops. Treating constipation can restore the free circulation of the CSF and avoid surgical intervention. Careful neurological monitoring of these patients is essential, because some measures used to treat constipation can increase intracranial pressure. The objective of this report was to highlight constipation as a possible cause of transient VPS malfunction, thereby avoiding unnecessary surgical revisions, to which children with hydrocephalus are frequently submitted.

Anatomical considerations for the management of a left-sided superior caval vein draining to the roof of the left atrium.

PubMed

Saundankar, Jelena; Ho, Andrew B; Salmon, Anthony P; Anderson, Robert H; Magee, Alan G

2017-07-01

Aims The pathophysiological entity of a persisting left-sided superior caval vein draining into the roof of the left atrium represents an extreme form of coronary sinus de-roofing. This is an uncommon, but well-documented condition associated with systemic desaturation due to a right-to-left shunt. Depending on the size of the coronary ostium, the defect may also present with right-sided volume loading. We describe two patients, both of whom presented with desaturation, and highlight the important anatomical features underscoring management. Methods and Results Both patients were managed interventionally with previous assessment of the size of the coronary sinus ostium through cross-sectional imaging. This revealed a restrictive interatrial communication at the right atrial mouth of the coronary sinus in both patients, which permitted an interventional approach, as the residual left-to-right shunt subsequent to closure of the aberrant vessel would be negligible. At intervention, test occlusion of the left superior caval vein allowed assessment of decompressing vessels before successful occlusion using an Amplatzer Vascular Plug. Persistence of a left superior caval vein draining to the left atrium may be associated with an interatrial communication at the mouth of the unroofed coronary sinus. The ostium of the de-roofed coronary sinus can be atretic, restrictive, normally sized, or enlarged. Careful assessment of the size of this defect is required before treatment. In view of its importance, which has received little attention in the literature to date, we suggest an additional consideration to the classification of unroofed coronary sinus.

Predictive Factors for Response of Intracranial Dural Arteriovenous Fistulas to Transarterial Onyx Embolization: Angiographic Subgroup Analysis of Treatment Outcomes.

PubMed

Kim, Byungjun; Jeon, Pyoung; Kim, Keonha; Kim, Sungtae; Kim, Hyungjin; Byun, Hong Sik; Jo, Kyung-Il

2016-04-01

Endovascular treatment using Onyx has been increasingly used to treat intracranial dural arteriovenous fistulas (DAVFs). This study evaluated predictive factors for favorable treatment outcome in patients with intracranial noncavernous DAVFs treated by transarterial Onyx embolization. Between August 2008 and August 2014, 55 patients who underwent transarterial Onyx embolization for noncavernous DAVFs were retrospectively reviewed. Patients' demographic, clinical, and procedural data were analyzed to find statistically significant predictive factors for favorable treatment outcomes after Onyx embolization. Fistulas were classified angiographically according to the relationship between fistulas and dural venous sinuses and the presence of leptomeningeal venous reflux. Sixty-eight Onyx embolizations were performed in 55 patients. Immediate angiographic cure was achieved in 28 patients, and 14 of 27 patients with residual shunts showed progressive occlusion at follow-up imaging studies. Therefore, the overall favorable treatment outcome was 76.4% (42/55). The remaining 13 patients (23.6%) showed persistent residual shunts, and 3 (5.5%) of them showed aggravation of residual lesion on follow-up studies. Of 25 patients with non-sinus fistulas, 23 patients (92%) showed favorable treatment outcomes, and 19 of 30 patients (63.3%) with sinus fistulas showed favorable outcomes. Among the evaluated variables, non-sinus DAVFs was a statistically significant predictive factor for favorable response to transarterial Onyx embolization (P < 0.05). Transarterial Onyx embolization is a highly effective treatment method for non-sinus DAVFs. Careful consideration of angiographic features and multimodal embolization strategies are required for treatment of sinus DAVFs. Copyright © 2016 Elsevier Inc. All rights reserved.

Use of EOS Low-Dose Biplanar X-Ray for Shunt Series in Children with Hydrocephalus: A Preliminary Study.

PubMed

Ben-Sira, Liat; Shiran, Shelly I; Pratt, Li-Tal; Precel, Ronit; Ovadia, Dror; Constantini, Shlomi; Roth, Jonathan

2018-05-04

Shunt series (SS) are a common diagnostic tool used to verify shunt integrity. SS include X-ray films of the skull, chest, and abdomen and often are performed either when a shunted patient presents with suspected shunt malfunction or as a screening test to identify shunt disconnections or dislodgment. EOS low-dose biplanar X-rays are associated with significantly reduced radiation doses compared with ordinary X-rays and are used for various indications. This is the first publication on the use of EOS as a SS technique. Over a period of 6 months, EOS were performed at our center for various orthopedic indications, mostly for scoliosis evaluation. Nine children (<20 years of age) had a ventriculoperitoneal shunt and served as the study group. We retrospectively reviewed shunt visibility and integrity in the EOS scans as well as regular SS or plain spinal X-rays. Three patients had bilateral shunts, and 8 had previous X-rays for comparison. In all patients, the shunt integrity was easily demonstrated on the EOS images. Two patients had an identified shunt disconnection confirmed on the EOS images. No shunt-related information was missed on the EOS compared with the other X-ray images. These preliminary results suggest that EOS may be used as an alternative technology to demonstrate shunt integrity instead of regular X-ray SS. Favorable shunt visibility without the need for multiple radiation exposures and image processing (such as stitching) results in a significantly shorter examination time and significant less radiation. Copyright © 2018 Elsevier Inc. All rights reserved.

The baric probe: a novel long-term implantable intracranial pressure monitor with ultrasound-based interrogation.

PubMed

Limbrick, David D; Lake, Stephen; Talcott, Michael; Alexander, Benjamin; Wight, Samuel; Willie, Jon T; Richard, William D; Genin, Guy M; Leuthardt, Eric C

2012-12-01

Prompt diagnosis of shunt malfunction is critical in preventing neurological morbidity and death in individuals with hydrocephalus; however, diagnostic methods for this condition remain limited. For several decades, investigators have sought a long-term, implantable intracranial pressure (ICP) monitor to assist in the diagnosis of shunt malfunction, but efforts have been impeded by device complexity, marked measurement drift, and limited instrumentation lifespan. In the current report, the authors introduce an entirely novel, simple, compressible gas design that addresses each of these problems. The device described herein, termed the "baric probe," consists of a subdural fluid bladder and multichannel indicator that monitors the position of an air-fluid interface (AFI). A handheld ultrasound probe is used to interrogate the baric probe in vivo, permitting noninvasive ICP determination. To assess the function of device prototypes, ex vivo experiments were conducted using a water column, and short- and long-term in vivo experiments were performed using a porcine model with concurrent measurements of ICP via a fiberoptic monitor. Following a toe region of approximately 2 cm H(2)O, the baric probe's AFI demonstrated a predictable linear relationship to ICP in both ex vivo and in vivo models. After a 2-week implantation of the device, this linear relationship remained robust and reproducible. Further, changes in ICP were observed with the baric probe, on average, 3 seconds in advance of the fiberoptic ICP monitor reading. The authors demonstrate "proof-of-concept" and feasibility for the baric probe, a long-term implantable ICP monitor designed to facilitate the prompt and accurate diagnosis of shunt malfunction. The baric probe showed a consistent linear relationship between ICP and the device's AFI in ex vivo and short- and long-term in vivo models. With a low per-unit cost, a reduced need for radiography or CT, and an indicator that can be read with a handheld ultrasound probe that interfaces with any smart phone, the baric probe promises to simplify the care of patients with shunt-treated hydrocephalus throughout both the developed and the developing world.

A new shunt for obstructive hydrocephalus: ventricle-Sylvian fissure shunt A preliminary report.

PubMed

Patkar, Sushil

2017-06-01

Cerbrospinal fluid (CSF) pathway studies have revealed that after egressing from the fourth ventricle reaches the basal supra sellar cistern and ultimately the sylvian cisterns from where the CSF travels over the cerebral convexity subarachnoid space to reach the superior saggital sinus and enters the blood stream. Diverting CSF from the lateral ventricle with a shunt catheter to the sylvian cistern can be an option to treat obstructive hydrocephalus. 2 patients underwent this procedure of diverting CSF from the lateral ventricle with a shunt catheter (Chabbra, India) to the sylvian cistern successfully and had immediate relief of symptoms of raised intracranial pressure. Additional 4 patients had relief for 3mths to 6 mths and are under follow up. Though preliminary results seem logical and promising, more cases and longer follow-up is required to consider this shunt operation as an option in treatment of obstructive hydrocephalus.

Post ventriculoperitoneal shunt abdominal pseudocyst: Challenges posed in management.

PubMed

Hamid, Raashid; Baba, Aejaz A; Bhat, Nisar A; Mufti, Gowhar; Mir, Younis A; Sajad, Wani

2017-01-01

In patients with hydrocephalus, the abdominal cavity has been used for absorption of cerebrospinal fluid (CSF) since 1905. Ventriculoperitoneal (VP) shunt operation is followed by abdominal complications in about 5-47% cases. Abdominal CSF pseudo cyst is an uncommon, but well described complication. This survey was conducted to study the clinical profile and management of this entity. We present our experience with cases of CSF pseudo cyst in children. Retrospective analysis of 4 cases diagnosed to have abdominal pseudo cyst following VP shunt between 2008 and 2013. All the four cases were suspected clinically and diagnosis was confirmed by abdominal ultrasonography. In three patients, the cyst was multilocular and of varying size. Fourth one had a unilocular cyst at the lower end of VP shunt. All the four patients had features of varying degree raised intracranial pressure and a two patients had abdominal signs also. All the patients needed open exploration. Cyst fluid was drained and partial to complete excision of the cyst was done along with the repositioning of the shunt in abdominal cavity in three patients and exteriorization of shunt in one patient. Patients were followed for any further complication over a period of 1-year. Abdominal pseudo cyst is a rare complication after VP Shunt and could result in shunt malfunction or abdominal symptoms and signs. Whenever suspected it should be confirmed by imaging, followed by open exploration and repositioning of the shunt.

Triventricular hydrocephalus: review of 71 cases evaluated at the Istituto Neurologico "C. Besta" Milan over the last 10 years.

PubMed

Valentini, L; Solero, C L; Lasio, G; Giombini, S; Visintini, S; Balestrini, M R; Giordano, L; Grisoli, M

1995-03-01

The authors review 71 patients with triventricular hydrocephalus in whom a contrast-enhanced CT scan did not show any tumoral or vascular lesion that could have caused the hydrocephalus. The patients were subdivided into three age groups. The results of the neuroradiological examination, the surgical treatment, and the complications of the shunt procedure are analyzed, with special reference to the high number (13) of periaqueductal alterations of signal pattern found on MRI (interpreted as a "slow growing" neoplasm) and to the incidence and causes of shunt malfunction.

Slit ventricle syndrome and early-onset secondary craniosynostosis in an infant

PubMed Central

Ryoo, Hyun Gee; Kim, Seung-Ki; Cheon, Jung-Eun; Lee, Ji Yeoun; Wang, Kyu-Chang; Phi, Ji Hoon

2014-01-01

Patient: Female, 14 months Final Diagnosis: Slit ventricle syndrome Symptoms: Hydrocephalus • lethargy and seizure • vomiting Medication: — Clinical Procedure: — Specialty: Pediatrics and Neonatology Objective: Challenging differential diagnosis Background: Shunt surgery is a common solution for hydrocephalus in infancy. Slit ventricle syndrome and secondary craniosynostosis are late-onset complications after shunt placement; these 2 conditions occasionally occur together. Case Report: We report a case of early-onset secondary craniosynostosis with slit ventricle syndrome after shunt surgery in an infant, which led to a catastrophic increase in intracranial pressure (ICP). A 4-month-old girl with a Dandy-Walker malformation underwent a ventriculoperitoneal shunt procedure. Her head circumference (HC) gradually decreased to approximately the 5th percentile for her age group after shunt surgery. Seven months later, she developed increased ICP symptoms and underwent a shunt revision with a diagnosis of shunt malfunction. Her symptoms were temporarily relieved, but she repeatedly visited the emergency room (ER) for the same symptoms and finally collapsed, with an abrupt increase in ICP, 3 months later. Further evaluation revealed the emergence of sagittal synostosis at 7 months after initial shunt surgery. After reviewing all clinical data, slit ventricle syndrome combined with secondary craniosynostosis was diagnosed. Emergent cranial expansion surgery with shunt revision was performed, and the increased ICP signs subsided in the following days. Conclusions: Clinical suspicion and long-term HC monitoring are important in the diagnosis of slit ventricle syndrome and secondary craniosynostosis after shunt surgery, even in infants and young children. PMID:24944727

Management of the ventriculo-peritoneal shunt in pediatric patients during robot-assisted laparoscopic urologic procedures.

PubMed

Marchetti, Pablo; Razmaria, Aria; Zagaja, Greg P; Gundeti, Mohan S

2011-02-01

Infection or malfunction of ventriculo-peritoneal (VP) shunts is a severe complication during laparoscopic surgery involving the gastrointestinal or urinary tract. It has been recently suggested to externalize the shunt or convert into a ventriculo-atrial shunt to prevent this complication with laparoscopic approach. Herein, we present a novel technique for management of the VP shunt during robot-assisted laparoscopic (RAL) urologic procedures. After port placement and diagnostic peritoneoscopy, an Endopouch bag (Ethicon Endo-Surgery) was inserted into the peritoneal cavity and the distal end of the shunt was placed into the pouch. The Endopouch suture was synched around the shunt and the pouch was placed in the subhepatic space during the surgery. The intraperitoneal pressure was maintained at 12 mm Hg during the entire procedure. Metronidazole, gentamicin, and vancomycin were administered as prophylaxis. Following the completion of the surgery and profuse irrigation of the peritoneal cavity, the shunt was repositioned within the peritoneum. We evaluated perioperative shunt-related complications. We used this technique in four patients with VP shunt undergoing RAL cystoplasty and appendicovesicostomy and/or colonic enema channel formation. The average age of the patient at surgery was 10.8 (7-14) years. One patient was converted to open because of failure to progress due to multiple adhesions and the shunt was externalized temporarily. At a mean follow-up of 13 (3-20) months, no shunt-related complications were seen. In our preliminary experience, the use of an intracorporeal Endopouch bag with controlled pneumoperitoneal pressure to protect the VP shunt may be an effective alternative to prevent complications related to it during RAL urologic surgery involving the gastrointestinal or urinary tract. Further studies will be needed to confirm our results.

Post ventriculoperitoneal shunt abdominal pseudocyst: Challenges posed in management

PubMed Central

Hamid, Raashid; Baba, Aejaz A.; Bhat, Nisar A.; Mufti, Gowhar; Mir, Younis A.; Sajad, Wani

2017-01-01

Background: In patients with hydrocephalus, the abdominal cavity has been used for absorption of cerebrospinal fluid (CSF) since 1905. Ventriculoperitoneal (VP) shunt operation is followed by abdominal complications in about 5-47% cases. Abdominal CSF pseudo cyst is an uncommon, but well described complication. Aim: This survey was conducted to study the clinical profile and management of this entity. We present our experience with cases of CSF pseudo cyst in children. Materials and Methods: Retrospective analysis of 4 cases diagnosed to have abdominal pseudo cyst following VP shunt between 2008 and 2013. All the four cases were suspected clinically and diagnosis was confirmed by abdominal ultrasonography. Results: In three patients, the cyst was multilocular and of varying size. Fourth one had a unilocular cyst at the lower end of VP shunt. All the four patients had features of varying degree raised intracranial pressure and a two patients had abdominal signs also. All the patients needed open exploration. Cyst fluid was drained and partial to complete excision of the cyst was done along with the repositioning of the shunt in abdominal cavity in three patients and exteriorization of shunt in one patient. Patients were followed for any further complication over a period of 1-year. Conclusion: Abdominal pseudo cyst is a rare complication after VP Shunt and could result in shunt malfunction or abdominal symptoms and signs. Whenever suspected it should be confirmed by imaging, followed by open exploration and repositioning of the shunt. PMID:28413525

Dandy-Walker Malformation: A Clinical and Surgical Outcome Analysis.

PubMed

Bokhari, Iram; Rehman, Lal; Hassan, Sher; Hashim, M Sattar

2015-06-01

To determine the clinical presentations, complications and mortality in patients with Dandy-Walker Malformation (DWM) after surgery i.e., shunt with y-connector. Case series. Neurosurgery Ward, JPMC, Karachi, from January 2009 to December 2013. Cases of DWM, with associated hydrocephalus, further confirmed on CT scan of brain, were admitted through OPD. Those who were previously operated, those with other associated co-morbid or anomalies were excluded from this study. Combined drainage of the ventricular system and posterior fossa cyst, via dual shunt i.e. cystoperitoneal and ventriculoperitoneal shunt with y-connector was performed in all patients. Complications and mortality after surgical intervention in these patients were noted upto one month after surgery. The data analysis for descriptive statistics was done on SPSS version 20. In this study of 70 patients, majority of the patients were female aged between 1 - 2 years. Hydrocephalus was the predominant symptom as being present in all patients, followed by cerebellar signs in 60 (86%), and other in 5 (7.14%) patients. Complications of surgery were infection and shunt fracture dislocation in 7 (10%) each, malpositioning and shunt blockage in 6 (8.5%) each within one month of surgery, intracranial haemorrhage in 5 (7.14%) patients. Only one patient (1.42%) expired after surgical intervention. In DWM, the commonest presentation is that of hydrocephalus. Shunt malfunction and infection are the commonest complication after shunting. Dual shunt with y-connector has the lowest mortality when compared with other methods for treatment of shunt with y-connector.

Normal pressure hydrocephalus: long-term outcome after shunt surgery.

PubMed

Pujari, S; Kharkar, S; Metellus, P; Shuck, J; Williams, M A; Rigamonti, D

2008-11-01

Little is known about the long-term clinical course and management of patients with normal pressure hydrocephalus (NPH) treated by cerebrospinal fluid (CSF) shunting. We retrospectively reviewed records of 55 patients diagnosed with idiopathic NPH (INPH) and treated with CSF shunts, all of whom were followed for more than 3 years after the original shunt surgery. At each annual follow-up visit, the patient was assessed by Folstein Mini Mental State Examination, detailed clinical evaluation of gait and assessment of headache, cognition, gait or urination, as assessed by the patient and relatives. The mean duration of follow-up was 5.9+/-2.5 years. There was an overall sustained improvement among all symptoms. Gait showed the highest maintenance of improvement over baseline (83% at 3 years and 87% at the last analysed follow-up of 7 years), cognition showed intermediary improvement (84% and 86%, respectively), and urinary incontinence showed the least improvement (84% and 80%, respectively). Fifty-three percent of patients required shunt revisions. Indications for revision included shunt malfunction (87%), infection (10%) and change of shunt configuration (3%). Overall, 74% revisions resulted in clinical improvement. Clinical improvement of patients with NPH can be sustained for 5-7 years in some patients with NPH, even if shunt revision surgery is needed multiple times. With earlier diagnosis and treatment of NPH and the increasing lifespan of the ageing population, the need for long-term follow-up after shunt surgery for NPH may be greater than it was in the past. Monitoring, identification and treatment of shunt obstruction is a key management principle.

Development of a Cavum Septi Pellucidi after Ommaya Reservoir Placement: A Cause of Shunt Malfunction

DTIC Science & Technology

2005-09-01

pellucidi (Figure 1). After the first injection of intrathecal cytarabine (Ara-C) via the Ommaya reservoir the patient experienced a generalized tonic...methotrexate and cytarabine . Child’s Nerv Syst 1990; 6: 231-235. 3. Lishner M, Perrin RG, Feld R, Messner HA, Tuffnell PG, Elhakim T, Matlow A, Curtis JE

Parylene MEMS patency sensor for assessment of hydrocephalus shunt obstruction.

PubMed

Kim, Brian J; Jin, Willa; Baldwin, Alexander; Yu, Lawrence; Christian, Eisha; Krieger, Mark D; McComb, J Gordon; Meng, Ellis

2016-10-01

Neurosurgical ventricular shunts inserted to treat hydrocephalus experience a cumulative failure rate of 80 % over 12 years; obstruction is responsible for most failures with a majority occurring at the proximal catheter. Current diagnosis of shunt malfunction is imprecise and involves neuroimaging studies and shunt tapping, an invasive measurement of intracranial pressure and shunt patency. These patients often present emergently and a delay in care has dire consequences. A microelectromechanical systems (MEMS) patency sensor was developed to enable direct and quantitative tracking of shunt patency in order to detect proximal shunt occlusion prior to the development of clinical symptoms thereby avoiding delays in treatment. The sensor was fabricated on a flexible polymer substrate to eventually allow integration into a shunt. In this study, the sensor was packaged for use with external ventricular drainage systems for clinical validation. Insights into the transduction mechanism of the sensor were obtained. The impact of electrode size, clinically relevant temperatures and flows, and hydrogen peroxide (H2O2) plasma sterilization on sensor function were evaluated. Sensor performance in the presence of static and dynamic obstruction was demonstrated using 3 different models of obstruction. Electrode size was found to have a minimal effect on sensor performance and increased temperature and flow resulted in a slight decrease in the baseline impedance due to an increase in ionic mobility. However, sensor response did not vary within clinically relevant temperature and flow ranges. H2O2 plasma sterilization also had no effect on sensor performance. This low power and simple format sensor was developed with the intention of future integration into shunts for wireless monitoring of shunt state and more importantly, a more accurate and timely diagnosis of shunt failure.

Clinical assessment of cerebrospinal fluid dynamics in hydrocephalus. Guide to interpretation based on observational study.

PubMed

Weerakkody, R A; Czosnyka, M; Schuhmann, M U; Schmidt, E; Keong, N; Santarius, T; Pickard, J D; Czosnyka, Z

2011-08-01

The term hydrocephalus encompasses a range of disorders characterised by clinical symptoms, abnormal brain imaging and derangement of cerebrospinal fluid (CSF) dynamics. The ability to elucidate which patients would benefit from CSF diversion (a shunt or third ventriculostomy) is often unclear. Similar difficulties are often encountered in shunted patients to predict the scope for improvement by shunt re-adjustment or revision. In this study we aimed to update our knowledge of how key quantitative parameters describing CSF dynamics may be used in diagnosis of shunt-responsive hydrocephalus and in the assessment of shunt function. A number of quantitative parameters [including resistance to CSF outflow (Rcsf), pulse amplitude of intracranial pressure waveform (AMP), RAP index and slow vasogenic waves] were studies in 1423 patients with 2665 CSF infusion tests and 305 overnight intracranial pressure (ICP)-monitoring sessions over a 17 year period. We demonstrate our observations for typical values of Pb, Rcsf, AMP, slow vasogenic waves derived from infusion studies or overnight ICP monitoring in differentiating atrophy from shunt-responsive normal pressure hydrocephalus or acute hydrocephalus. From the same variables tested on shunted patients we demonstrate a standardised approach to help differentiate a properly-functioning shunt from underdrainage or overdrainage. Quantitative variables derived from CSF dynamics allow differentiation between clinically overlapping entities such as shunt-responsive normal pressure hydrocephalus and brain atrophy (not shunt responsive) as well as allowing the detection of shunt malfunction (partial or complete blockage) or overdrainage. This observational study is intended to serve as an update for our understanding of quantitative testing of CSF dynamics. © 2011 John Wiley & Sons A/S.

Can MR measurement of intracranial hydrodynamics and compliance differentiate which patient with idiopathic normal pressure hydrocephalus will improve following shunt insertion?

PubMed

Bateman, G A; Loiselle, A M

2007-01-01

Between 10 and 90% of patients with normal pressure hydrocephalus (NPH) treated with a shunt will improve but they risk significant morbidity/mortality from this procedure. NPH is treated hydrodynamically and it has been assumed that a hydrodynamic difference must exist to differentiate which patient will respond. The purpose of this study is to see whether MRI hydrodynamics can differentiate which patients will improve post shunting. Thirty-two patients with NPH underwent MRI with flow quantification measuring the degree of ventricular enlargement, sulcal compression, white matter disease, total blood inflow, sagittal sinus outflow, aqueduct stroke volume, relative compliance ratio and arteriovenous delay. Patients were followed up after shunt insertion to gauge the degree of improvement and were compared with 12 age-matched controls and 12 patients with Alzheimer's disease. 63% of patients improved with insertion. The responders were identical to the non-responders in all variables. The NPH patients were significantly different to the controls (e.g. Total blood inflow reduced 20%, sagittal sinus outflow reduced 35%, aqueduct stroke volume increased 210%, relative compliance ratio reduced 60% and arteriovenous delay reduced 57% with p = 0.007, 0.03, 0.04, 0.0002 and 0.0003 respectively. The patient's with Alzheimer's disease values were midway between the NPH and control patients. Significant hydrodynamic differences were noted between NPH and controls but these were unable to differentiate the responders from non-responders. The hydrodynamics of Alzheimer's disease makes exclusion of comorbidity from this disease difficult.

Incidence and predictors of dural venous sinus pressure gradient in idiopathic intracranial hypertension and non-idiopathic intracranial hypertension headache patients: results from 164 cerebral venograms.

PubMed

Levitt, Michael R; Hlubek, Randall J; Moon, Karam; Kalani, M Yashar S; Nakaji, Peter; Smith, Kris A; Little, Andrew S; Knievel, Kerry; Chan, Jane W; McDougall, Cameron G; Albuquerque, Felipe C

2017-02-01

OBJECTIVE Cerebral venous pressure gradient (CVPG) from dural venous sinus stenosis is implicated in headache syndromes such as idiopathic intracranial hypertension (IIH). The incidence of CVPG in headache patients has not been reported. METHODS The authors reviewed all cerebral venograms with manometry performed for headache between January 2008 and May 2015. Patient demographics, headache etiology, intracranial pressure (ICP) measurements, and radiographic and manometric results were recorded. CVPG was defined as a difference ≥ 8 mm Hg by venographic manometry. RESULTS One hundred sixty-four venograms were performed in 155 patients. There were no procedural complications. Ninety-six procedures (58.5%) were for patients with IIH. The overall incidence of CVPG was 25.6% (42 of 164 procedures): 35.4% (34 of 96 procedures) in IIH patients and 11.8% (8 of 68 procedures) in non-IIH patients. Sixty procedures (36.6%) were performed in patients with preexisting shunts. Seventy-seven patients (49.7%) had procedures preceded by an ICP measurement within 4 weeks of venography, and in 66 (85.7%) of these patients, the ICP had been found to be elevated. CVPG was seen in 8.3% (n = 5) of the procedures in the 60 patients with a preexisting shunt and in 0% (n = 0) of the 11 procedures in the 77 patients with normal ICP (p < 0.001 for both). Noninvasive imaging (MR venography, CT venography) was assessed prior to venography in 112 (68.3%) of 164 cases, and dural venous sinus abnormalities were demonstrated in 73 (65.2%) of these cases; there was a trend toward CVPG (p = 0.07). Multivariate analysis demonstrated an increased likelihood of CVPG in patients with IIH (OR 4.97, 95% CI 1.71-14.47) and a decreased likelihood in patients with a preexisting shunt (OR 0.09, 95% CI 0.02-0.44). CONCLUSIONS CVPG is uncommon in IIH patients, rare in those with preexisting shunts, and absent in those with normal ICP.

Failed Ventriculoperitoneal Shunt: Is Retrograde Ventriculosinus Shunt a Reliable Option?

PubMed

Oliveira, Matheus Fernandes de; Teixeira, Manoel Jacobsen; Reis, Rodolfo Casimiro; Petitto, Carlo Emanuel; Gomes Pinto, Fernando Campos

2016-08-01

Currently, the treatment of hydrocephalus is mainly carried out through a ventriculoperitoneal shunt (VPS) insertion. However, in some cases, there may be surgical revisions and requirement of an alternative distal site for shunting. There are several described distal sites, and secondary options after VPS include ventriculopleural and ventriculoatrial shunt, which have technical difficulties and harmful complications. In this preliminary report we describe our initial experience with retrograde ventriculosinus shunt (RVSS) after failed VPS. In 3 consecutive cases we applied RVSS to treat hydrocephalus in shunt-dependent patients who had previously undergone VPS revision and in which peritoneal space was full of adhesions and fibrosis. RVSS was performed as described by Shafei et al., with some modifications to each case. All 3 patients kept the same clinical profile after RVSS, with no perioperative or postoperative complications. However, revision surgery was performed in the first operative day in 1 out of 3 patients, in which the catheter was not positioned in the superior sagittal sinus. We propose that in cases where VPS is not feasible, RVSS may be a safe and applicable second option. Nevertheless, the long-term follow-up of patients and further learning curve must bring stronger evidence. Copyright © 2016 Elsevier Inc. All rights reserved.

Treatment options for Dandy-Walker malformation.

PubMed

Mohanty, Aaron; Biswas, Arundhati; Satish, Satyanarayana; Praharaj, Shanti Shankar; Sastry, Kolluri V R

2006-11-01

The aim of this study was to assess the efficacy of various treatment options available for children with Dandy-Walker malformation (DWM) and to evaluate the role of endoscopic procedures in the treatment of this disorder. The authors conducted a retrospective review of 72 children who underwent surgical treatment for DWM during a 16-year period. All patients underwent computed tomography scanning, and 26 underwent magnetic resonance (MR) imaging. The initial surgical treatment included ventriculoperitoneal (VP) shunt placement in 21 patients, cystoperitoneal (CP) shunt placement in 24, and combined VP and CP shunt insertion in three. Twenty-one patients underwent endoscopic procedures (endoscopic third ventriculostomy [ETV] alone in 16 patients, ETV with aqueductal stent placement in three, and ETV with fenestration of the occluding membrane in two). Three patients underwent membrane excision via a posterior fossa craniectomy. In the 26 patients who had undergone preoperative MR imaging, aqueductal patency was noted in 23 and aqueductal obstruction in three. These three patients underwent placement of a stent from the third ventricle to the posterior fossa cyst in addition to the ETV procedure. During the follow-up period, 12 patients with a CP shunt and four with a VP shunt experienced shunt malfunctions that required revision. Four patients with a CP shunt also required placement of a VP shunt. In addition, five of the 21 ETVs failed, requiring VP shunt insertion. A reduction in ventricle size noted on postoperative images occurred more frequently in patients with a VP shunt, whereas a reduction in cyst size was more appreciable in patients with a CP shunt. Successful ETV resulted in a slight decrease in ventricle size and varying degrees of reduction in cyst size. Endoscopic procedures may be considered an acceptable alternative in children with DWM. The authors propose a treatment protocol based on preoperative MR imaging findings of associated aqueductal stenosis.

The Neuroimaging Studies in Children with Ventriculoperitoneal Shunt Complications: A 10 Years Descriptive Sudy in Tehran.

PubMed

Shahi, Mohammad Vafaee; Noorbakhsh, Samileh; Zarrabi, Vida; Nourozi, Banafsheh; Tahernia, Leila

2018-01-01

Any mismatch between the production and absorption of CSF results in hydrocephalus. In most cases, the selected choice of treatment is the ventriculoperitoneal shunt insertion. Although, the surgery could have complications such as infection, shunt malfunction, subdural hematoma, seizure and Shunt immigration; so, the early and proper detection of these complications could result in better prognosis. The aim of this study was to evaluate and compare the efficacy of CT scan, CSF analysis and X-ray radiography in detection of shunt complications and problems in shunt placement and further follow-up in hospitalized children. The medical records of children in Rasul Akram hospital in Tehran were reviewed retrospectively in the last 10 years, from 2006 to 2016. All data were recorded in the prepared form including the age, sex, shunt complication, CT scan and CSF characteristics. The total number of 95 patients were interfered in this study including 56 males (58.9%) and 39 females (41.1%). The mean age at the onset of complications were 2.8±2.2 years-old. The shunt obstruction (60%) and infection (25.3%) were the most common complications. The CT scan was able to detect 36.5% of shunt complications. The CT scan had the sensitivity and specificity of 50 and 87%, respectively in detection of shunt obstruction. The all cases of brain hematoma and hemorrhage were revealed by CT scan. On the other hand, the CT scan had 20% of sensitivity and 60% of specificity in the detection of shunt infection. The CSF evaluation in shunt infection revealed 92% hypoglycemia, 87.5% pleocytosis, and 62.5% positive CSF culture. CSF had the sensitivity, specificity, positive predictive value and negative predictive value of 92, 82, 63 and 97%, respectively. The patient's symptoms and signs were helpful in obtaining higher test accuracy. The CT scan was not a good sensitive and specific study in the detection of shunt obstruction and infection, but it was very accurate in detection of hemorrhage and hematoma. On the other hand, CSF evaluation was a reliable test in shunt infection disclosure.

Comparative durability and costs analysis of ventricular shunts.

PubMed

Agarwal, Nitin; Kashkoush, Ahmed; McDowell, Michael M; Lariviere, William R; Ismail, Naveed; Friedlander, Robert M

2018-05-11

OBJECTIVE Ventricular shunt (VS) durability has been well studied in the pediatric population and in patients with normal pressure hydrocephalus; however, further evaluation in a more heterogeneous adult population is needed. This study aims to evaluate the effect of diagnosis and valve type-fixed versus programmable-on shunt durability and cost for placement of shunts in adult patients. METHODS The authors retrospectively reviewed the medical records of all patients who underwent implantation of a VS for hydrocephalus at their institution over a 3-year period between August 2013 and October 2016 with a minimum postoperative follow-up of 6 months. The primary outcome was shunt revision, which was defined as reoperation for any indication after the initial procedure. Supply costs, shunt durability, and hydrocephalus etiologies were compared between fixed and programmable valves. RESULTS A total of 417 patients underwent shunt placement during the index time frame, consisting of 62 fixed shunts (15%) and 355 programmable shunts (85%). The mean follow-up was 30 ± 12 (SD) months. The shunt revision rate was 22% for programmable pressure valves and 21% for fixed pressure valves (HR 1.1 [95% CI 0.6-1.8]). Shunt complications, such as valve failure, infection, and overdrainage, occurred with similar frequency across valve types. Kaplan-Meier survival curve analysis showed no difference in durability between fixed (mean 39 months) and programmable (mean 40 months) shunts (p = 0.980, log-rank test). The median shunt supply cost per index case and accounting for subsequent revisions was $3438 (interquartile range $2938-$3876) and $1504 (interquartile range $753-$1584) for programmable and fixed shunts, respectively (p < 0.001, Wilcoxon rank-sum test). Of all hydrocephalus etiologies, pseudotumor cerebri (HR 1.9 [95% CI 1.2-3.1]) and previous shunt malfunction (HR 1.8 [95% CI 1.2-2.7]) were found to significantly increase the risk of shunt revision. Within each diagnosis, there were no significant differences in revision rates between shunts with a fixed valve and shunts with a programmable valve. CONCLUSIONS Long-term shunt revision rates are similar for fixed and programmable shunt pressure valves in adult patients. Hydrocephalus etiology may play a significant role in predicting shunt revision, although programmable valves incur higher supply costs regardless of initial diagnosis. Utilization of fixed pressure valves versus programmable pressure valves may reduce supply costs while maintaining similar revision rates. Given the importance of developing cost-effective management protocols, this study highlights the critical need for large-scale prospective observational studies and randomized clinical trials of ventricular shunt valve revisions and additional patient-centered outcomes.

Dural Sinus Malformations (DSM) with Giant Lakes, in Neonates and Infants. Review of 30 Consecutive Cases.

PubMed

Barbosa, M; Mahadevan, J; Weon, Y C; Yoshida, Y; Ozanne, A; Rodesch, G; Alvarez, H; Lasjaunias, P

2003-12-20

Abstract: Background and Purpose. Dural Arteriovenous Shunt (DAVS) in children include Dural sinus malformation (DSM), infantile and adult types. They are rare and seldom reported. Our purpose was to highlight the angiographic features of the DSM sub group for prognosis of clinical evolution and outcome and to lay guidelines for management. From a dedicated neurovascular data bank, there were 52 cases of arteriovenous dural shunts in children from 1985 to 2003. Of these, there were 30 patients with DSM, which we analysed the various angioarchitecture, presentation and neurological outcome. Children clinical status was evaluated and scored at admission and follow up. Results. There was an overall male dominance of 2:1. Antenatal diagnosis was obtained in 8/30 (26.7%) cases. Mean age of diagnosis was 5 months. Mean age at first consultation was 8.7 months. No patient was diagnosed during childhood. The most common clinical presentations were macrocrania 76.7%, seizures 23.3% and mental retardation 23.3%. In 14/30 (35.7%) of the patients, the therapeutic decision was to manage conservatively; in 5/14 (30.7%) with predictable favourable evolution and in 9/14 (64.3%) with irreversible poor neurological outcome. In the remaining 16/30 (53.3%) patients, endovascular treatment was performed. In 12/16 (75.0%) patients the neurological outcome was good, 3/16 (18.8%) patients had unfavourable evolution despite embolization. There was no morbidity mortality related to the procedures themselves. 1/16 (6.3%) patient was lost to follow-up. Overall 12/29 (45.8%) patients had an unfavourable neurological outcome with 11 patients dead and 1 with severe neurological deficit. In the surviving group of children, 17/18 (94.4%) have a good neurological outcome; in 10/18 (55.5%) the lesion is morphologically excluded. Conclusion. DSM is rare disease with high mortality. They usually proceed to either total or partial spontaneous thrombosis before the age of 2 thus compromising normal cerebral venous drainage. DSM away from the torcular, good cavernous sinus, cavernous capture of sylvian veins, absence of pial veins, straight sinus or superior sagital sinus (SSS) reflux and absence of jugular bulb dysmaturation represent factors of good prognosis. Such patients will highly benefit for endovascular treatment. In partial endovascular approach the aim being is to separate the brain drainage from DSM drainage. This will be achieved by the transarterial approach to the associated mural arterio-venous shunts (AVS) and by disconnecting the pial reflux by transvenous route.

Anomalies of the systemic venous return: a review.

PubMed

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.

Dural arteriovenous fistulas as a cause of intracranial hypertension due to impairment of cranial venous outflow

PubMed Central

Cognard, C.; Casasco, A.; Toevi, M.; Houdart, E.; Chiras, J.; Merland, J.

1998-01-01

OBJECTIVES—A retrospective study was carried out on 13 patients with intracranial dural arteriovenous fistulas (DAVFs) who presented with isolated or associated signs of intracranial hypertension.
METHODS—Nine patients presented with symptoms of intracranial hypertension at the time of diagnosis. Ocular fundoscopy available in 12 patients showed bilateral papilloedema in eight and optic disk atrophy in four. Clinical evolution was particularly noticeable in five patients because of chronic (two patients) or acute (after lumbar shunting or puncture: three patients, one death) tonsillar herniation.
RESULTS—Two patients had a type I fistula (drainage into a sinus, with a normal antegrade flow direction). The remaining 11 had type II fistulas (drainage into a sinus, with abnormal retrograde venous drainage into sinuses or cortical veins). Stenosis or thrombosis of the sinus(es) distal to the fistula was present in five patients. The cerebral venous drainage was abnormal in all patients.
CONCLUSION—Type II (and some type I) DAVFs may present as isolated intracranial hypertension mimicking benign intracranial hypertension. Normal cerebral angiography should be added as a fifth criterion of benign intracranial hypertension. The cerebral venous drainage pattern must be carefully studied by contralateral carotid and vertebral artery injections to correctly evaluate the impairment of the cerebral venous outflow. Lumbar CSF diversion (puncture or shunting) may induce acute tonsillar herniation and should be avoided absolutely. DAVF may induce intracranial hypertension, which has a poor long term prognosis and may lead to an important loss of visual acuity and chronic tonsillar herniation. Consequently, patients with intracranial hypertension must be treated, even agressively, to obliterate the fistula or at least to reduce the arterial flow and to restore a normal cerebral venous drainage. The endovascular treatment may associate arterial or transvenous embolisation and /or surgery. Patients in whom the fistula is not obliterated after an endovascular therapeutic procedure, need continous clinical and angiographical follow up.

 PMID:9728941

Shunt diameter in agenesis of the ductus venosus with extrahepatic portosystemic shunt impacts on prognosis.

PubMed

Shen, O; Valsky, D V; Messing, B; Cohen, S M; Lipschuetz, M; Yagel, S

2011-02-01

Agenesis of the ductus venosus (ADV) is a rare condition in which there are two variants of umbilical vein drainage: intrahepatic shunt or extrahepatic (portosystemic) shunt. It has been posited that the extrahepatic variant carries a poorer prognosis. However, in the absence of associated anomalies there is still a wide variation in outcome. We evaluated the portal system in cases of ADV and aimed to identify parameters that might predict outcome. We conducted a retrospective study of cases of ADV with extrahepatic shunt that had been examined in two centers, and collected new cases prospectively. The route of the shunt was depicted using two-dimensional (2D) and three-dimensional (3D) ultrasound imaging. In an attempt to characterize portal system and shunt developmental variations and their possible impact on outcome, the diameter of the shunt was compared with the diameter of the umbilical vein and the entire portal vasculature was assessed. Poor outcome was defined as persistent morbidity or fetal or neonatal death. Twenty-two cases of ADV were identified: nine retrospectively and 13 prospectively. Aberrant shunts from the umbilical vein were identified to the right atrium, coronary sinus, inferior vena cava (IVC) and iliac vein. In seven of 22 cases (32%) a wide connection was observed. In six of these seven cases (86%) the outcome was poor, including four with severe associated anomalies and two with hepatic dysfunction. In five of these cases, cardiomegaly with tricuspid regurgitation was observed, as well as underdevelopment of the portal system. In only five of 15 cases with a narrow shunt (33%) was the outcome poor, and in all five cases the poor outcome was related to associated anomalies. In cases of ADV with extrahepatic shunt, portal system development is impacted by the diameter of the shunt. If the shunt is narrow, the portal system will have developed normally. A wide shunt is associated with underdevelopment or absence of the portal system. In cases of ADV with extrahepatic shunt, prognosis is determined by the severity of associated anomalies, the diameter of the shunt and development of the portal system. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.

Custom-made raster method for fistula and graft.

PubMed

Blokker, C

2005-01-01

Unfamiliarity with fistula and graft characteristics can lead to failed punctures, haematomas and sometimes access occlusion. The Custom-made Raster Method provides detailed shunt visualisation and angiographic images by using photo-editing software. Access veins of an individual shunt and an adapted raster are projected on a digital picture of the arm. During angiography the shunt arm is fixated and a digital picture is taken from a fixed vertical angle and distance. Reference points are marked on the shunt arm, which serves as a fixation to draw a raster with coordination points. In this way a picture is created similar to a roadmap with veins. There is complete integration of digital and radiological images by using software programmes Adobe Photoshop + Illustrator or Agfa Web 1000 under Windows XP. All illustrations fit 1:1 by scaling up or down without distortion. Editing with Photoshop gives a precise projection of shunt veins on the real coloured background of the digital photograph. In this projection the grey angiography background is made completely transparent. The system can contain more detailed information in combination with echo (duplex) images of depth and diameter. This visualisation method is a useful tool for multi disciplinary access meetings with intervention radiologists, access surgeons and nephrologists. Access malfunction, aneurysms and stenosis can be projected at the exact location. The system leads to clear and concrete puncture advice. Transfer of access information and communication to other dialysis centres is facilitated.

Current treatment of normal-pressure hydrocephalus: comparison of flow-regulated and differential-pressure shunt valves.

PubMed

Weiner, H L; Constantini, S; Cohen, H; Wisoff, J H

1995-11-01

FROM THE RECORDS of approximately 1500 shunt operations performed between 1987 and 1992, we identified 37 adults between ages 38 and 86 years (mean, 70 yr) with the normal-pressure hydrocephalus (NPH) syndrome who underwent surgery by a single surgeon. Since 1990, we have routinely used a flow-regulated shunt system (Orbis-Sigma valve [OSV]; Cordis Corporation, Miami, FL) in these patients. In this study, we compared the OSV system with conventional differential-pressure (DP) shunt systems uniformly used before 1990. This series (n = 37) consisted of 62% men (n = 23) and 38% women (n = 14). We excluded all patients with hydrocephalus associated with central nervous system neoplasms, intracerebral hemorrhage, or trauma as well those with radiographically documented late-onset aqueductal stenosis. All patients presented with the NPH clinical syndrome, chiefly with magnetic gait. In addition, 75% of patients experienced cognitive loss and 59% experienced urinary incontinence. The mean duration of preoperative symptoms was 35 months (range, 7-120 mo). Eight patients (22%) had undergone previous shunting procedures before referral to our service. A total of 89 shunt operations were performed in the 37 patients. Using actuarial methods and controlling for a history of prior shunt surgery, we found no significant difference in the time to initial malfunction (shunt survival) between the OSV and the DP shunts. There were three subdural hematomas and one infection in the OSV group compared with no complications in the DP valve group (P = 0.11). Thirty-six patients were available for follow-up, at a mean of 14 months after surgery. Nearly 90% of all patients experienced improvement in gait after shunting, regardless of the valve system that was used. There was one unrelated death. Realizing the limitations of a retrospective analysis and on the basis of the limited number of patients in this study, we conclude that using actuarial methods, we found no significant difference in shunt survival when comparing the OSV with the standard DP valve shunt systems with antisiphon devices in patients with NPH. Contrary to previous reports, the OSV is not free of overdrainage complications. Most patients (89%) with the NPH syndrome who primarily presented with gait disorder experienced significant improvement in gait after either OSV or DP shunting procedures when selected for surgery on the basis of the clinical syndrome and confirmatory radiographic data.

Brain Abscess Associated with Isolated Left Superior Vena Cava Draining into the Left Atrium in the Absence of Coronary Sinus and Atrial Septal Defect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erol, Ilknur; Cetin, I. Ilker; Alehan, Fuesun

A previously healthy 12-year-old girl presented with severe headache for 2 weeks. On physical examination, there was finger clubbing without apparent cyanosis. Neurological examination revealed only papiledema without focal neurologic signs. Cerebral magnetic resonance imaging showed the characteristic features of brain abscess in the left frontal lobe. Cardiologic workup to exclude a right-to-left shunt showed an abnormality of the systemic venous drainage: presence of isolated left superior vena cava draining into the left atrium in the absence of coronary sinus and atrial septal defect. This anomaly is rare, because only a few other cases have been reported.

The reversibility of reduced cortical vein compliance in normal-pressure hydrocephalus following shunt insertion.

PubMed

Bateman, G A

2003-02-01

Superficial cortical venous compression secondary to alterations in craniospinal compliance is implicated in the pathogenesis of normal pressure hydrocephalus (NPH). A reduction in the pulsation in the outflow of the cortical veins would be expected to occur following compression of these veins and this has been shown in NPH. If cortical vein compression is a causative factor in NPH, it would be expected that cortical vein compliance as measured by pulsatility would be significantly altered by a curative procedure i.e. shunt tube insertion. My purpose is to compare the blood flow pulsatility characteristics in a group of patients with NPH before and after shunt tube insertion. I initially studied 18 subjects without pathology with MRI flow quantification studies of the cerebral arteries and veins to define the range of normality. The main study involved 18 patients with idiopathic dementia and mild leukoaraiosis who served as controls and seven patients with NPH studied before and after shunt insertion. Arterial, superior sagittal and straight sinus pulsatility was not significantly different between the patients with idiopathic dementia and those NPH patients before or after shunting. Cortical vein pulsatility before shunting in the patients with NPH was 43% lower than in those with idiopathic dementia ( P=0.006). Following shunting, cortical vein pulsatility increased by 186% ( P=0.007). There is thus reduced compliance in cortical veins in NPH which is significantly increased in patients who respond to insertion of a shunt tube. These findings suggest that reversible elevation in cortical vein pressure and reversal of the normal absorption pathway for cerebrospinal fluid may be behind the pathophysiology of NPH.

Evaluation of the use of automatic exposure control and automatic tube potential selection in low-dose cerebrospinal fluid shunt head CT.

PubMed

Wallace, Adam N; Vyhmeister, Ross; Bagade, Swapnil; Chatterjee, Arindam; Hicks, Brandon; Ramirez-Giraldo, Juan Carlos; McKinstry, Robert C

2015-06-01

Cerebrospinal fluid shunts are primarily used for the treatment of hydrocephalus. Shunt complications may necessitate multiple non-contrast head CT scans resulting in potentially high levels of radiation dose starting at an early age. A new head CT protocol using automatic exposure control and automated tube potential selection has been implemented at our institution to reduce radiation exposure. The purpose of this study was to evaluate the reduction in radiation dose achieved by this protocol compared with a protocol with fixed parameters. A retrospective sample of 60 non-contrast head CT scans assessing for cerebrospinal fluid shunt malfunction was identified, 30 of which were performed with each protocol. The radiation doses of the two protocols were compared using the volume CT dose index and dose length product. The diagnostic acceptability and quality of each scan were evaluated by three independent readers. The new protocol lowered the average volume CT dose index from 15.2 to 9.2 mGy representing a 39 % reduction (P < 0.01; 95 % CI 35-44 %) and lowered the dose length product from 259.5 to 151.2 mGy/cm representing a 42 % reduction (P < 0.01; 95 % CI 34-50 %). The new protocol produced diagnostically acceptable scans with comparable image quality to the fixed parameter protocol. A pediatric shunt non-contrast head CT protocol using automatic exposure control and automated tube potential selection reduced patient radiation dose compared with a fixed parameter protocol while producing diagnostic images of comparable quality.

Adams-Oliver Syndrome with Unusual Central Nervous System Findings and an Extrahepatic Portosystemic Shunt

PubMed Central

Pérez-García, Carlos; Martín, Yolanda Ruíz; del Hoyo, Alejandra Aguado; Rodríguez, Carlos Marín; Domínguez, Minia Campos

2017-01-01

We report a case of a premature neonate girl with scalp and skull defects and brachydactyly of the feet consistent with an Adams-Oliver syndrome (AOS). The patient had central nervous system abnormalities, such as periventricular calcifications, hypoplastic corpus callosum, and bilateral hemispheric corticosubcortical hemorrhagic lesions. A muscular ventricular septal defect and a portosystemic shunt were diagnosed. To our knowledge, this is the first report of congenital supratentorial grey-white matter junction lesions without dural sinus thrombosis in association with AOS. Some of these lesions may be secondary to birth trauma (given the skull defect) whilst others have a watershed location, perhaps as further evidence of vascular disruption and decreased perfusion during critical periods of fetal brain development as the previously proposed pathogenesis of this syndrome. PMID:28706620

A tetrad of bicuspid aortic valve association: A single-stage repair

PubMed Central

Barik, Ramachandra; Patnaik, A. N.; Mishra, Ramesh C.; Kumari, N. Rama; Gulati, A. S.

2012-01-01

We report a 27 years old male who presented with a combination of both congenital and acquired cardiac defects. This syndrome complex includes congenital bicuspid aortic valve, Seller's grade II aortic regurgitation, juxta- subclavian coarctation, stenosis of ostium of left subclavian artery and ruptured sinus of Valsalva aneurysm without any evidence of infective endocarditis. This type of constellation is extremely rare. Neither coarctation of aorta with left subclavian artery stenosis nor the rupture of sinus Valsalva had a favorable pathology for percutaneus intervention. Taking account into morbidity associated with repeated surgery and anesthesia patient underwent a single stage surgical repair of both the defects by two surgical incisions. The approaches include median sternotomy for rupture of sinus of Valsalva and lateral thoracotomy for coarctation with left subclavian artery stenosis. The surgery was uneventful. After three months follow up echocardiography showed mild residual gradient across the repaired coarctation segment, mild aortic regurgitation and no residual left to right shunt. This patient is under follow up. This is an extremely rare case of single stage successful repair of coarctation and rupture of sinus of Valsalva associated with congenital bicuspid aortic valve. PMID:22629035

A tetrad of bicuspid aortic valve association: A single-stage repair.

PubMed

Barik, Ramachandra; Patnaik, A N; Mishra, Ramesh C; Kumari, N Rama; Gulati, A S

2012-04-01

We report a 27 years old male who presented with a combination of both congenital and acquired cardiac defects. This syndrome complex includes congenital bicuspid aortic valve, Seller's grade II aortic regurgitation, juxta- subclavian coarctation, stenosis of ostium of left subclavian artery and ruptured sinus of Valsalva aneurysm without any evidence of infective endocarditis. This type of constellation is extremely rare. Neither coarctation of aorta with left subclavian artery stenosis nor the rupture of sinus Valsalva had a favorable pathology for percutaneus intervention. Taking account into morbidity associated with repeated surgery and anesthesia patient underwent a single stage surgical repair of both the defects by two surgical incisions. The approaches include median sternotomy for rupture of sinus of Valsalva and lateral thoracotomy for coarctation with left subclavian artery stenosis. The surgery was uneventful. After three months follow up echocardiography showed mild residual gradient across the repaired coarctation segment, mild aortic regurgitation and no residual left to right shunt. This patient is under follow up. This is an extremely rare case of single stage successful repair of coarctation and rupture of sinus of Valsalva associated with congenital bicuspid aortic valve.

Cranial dural arteriovenous shunts. Part 4. Clinical presentation of the shunts with leptomeningeal venous drainage.

PubMed

Baltsavias, Gerasimos; Spiessberger, Alex; Hothorn, Torsten; Valavanis, Anton

2015-04-01

Cranial dural arteriovenous fistulae have been classified into high- and low-risk lesions mainly based on the pattern of venous drainage. Those with leptomeningeal venous drainage carry a higher risk of an aggressive clinical presentation. Recently, it has been proposed that the clinical presentation should be considered as an additional independent factor determining the clinical course of these lesions. However, dural shunts with leptomeningeal venous drainage include a very wide spectrum of inhomogeneous lesions. In the current study, we correlated the clinical presentation of 107 consecutive patients harboring cranial dural arteriovenous shunts with leptomeningeal venous drainage, with their distinct anatomic and angiographic features categorized into eight groups based on the "DES" (Directness and Exclusivity of leptomeningeal venous drainage and features of venous Strain) concept. We found that among these groups, there are significant angioarchitectural differences, which are reflected by considerable differences in clinical presentation. Leptomeningeal venous drainage of dural sinus shunts that is neither direct nor exclusive and without venous strain manifested only benign symptoms (aggressive presentation 0%). On the other end of the spectrum, the bridging vein shunts with direct and exclusive leptomeningeal venous drainage and venous strain are expected to present aggressive symptoms almost always and most likely with bleeding (aggressive presentation 91.5%). Important aspects of the above correlations are discussed. Therefore, the consideration of leptomeningeal venous drainage alone, for prediction of the clinical presentation of these shunts appears insufficient. Angiographic analysis based on the above concept, offers the possibility to distinguish the higher- from the lower-risk types of leptomeningeal venous drainage. In this context, consideration of the clinical presentation as an additional independent factor for the prediction of their clinical course seems superfluous and possibly misleading. Topography is connected to the clinical presentation of the dural shunts inasmuch as the former determines the venous anatomy and the angioarchitectural features of the lesions.

Abnormalities of the umbilico-portal venous system in Down syndrome: a report of two new patients.

PubMed

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.

First report of atretic coronary sinus stenting in a 5-kg infant resulting in dramatic improvement of ventricular function in functional single ventricle.

PubMed

El-Said, Howaida; Hegde, Sanjeet; Moore, John

2014-01-01

The patient was a male infant with L-transposition of great arteries (L-TGA), Ebstein's anomaly of the tricuspid valve, subvalvar aortic stenosis, ventricular septal defect (VSD), hypoplastic right ventricle, arch hypoplasia, and congenital complete heart block. He underwent a Norwood procedure, aortic arch repair, permanent pacemaker implantation, and a 3.5-mm aortopulmonary shunt at 4 days of age. At the time of his surgery, left ventricular function was in the normal range (ejection fraction [EF] = 67%). However by 3 months of age, he was noted to have developed moderate-severe biventricular dysfunction (left ventricular ejection fraction [LVEF] = 34%). Atresia of the coronary sinus with a small left superior venacava (LSVC) and a bridging vein was discovered during cardiac catheterization at this time. The coronary sinus mean pressure was 17 mm Hg, and the common atrial mean pressure was 6 mmHg. We opened the atretic coronary sinus ostium using radiofrequency ablation and stent placement. There was dramatic improvement in ventricular function observed over a 2-month period. Follow-up cardiac catheterization 5 months later revealed the stent in the coronary sinus to be widely patent with no intimal buildup, and the ventricular function was normal (LVEF = 58%). The patient had a bidirectional Glenn procedure with an uncomplicated postoperative course and is currently awaiting Fontan completion. © 2013 Wiley Periodicals, Inc.

Platelets contribute to postnatal occlusion of the ductus arteriosus.

PubMed

Echtler, Katrin; Stark, Konstantin; Lorenz, Michael; Kerstan, Sandra; Walch, Axel; Jennen, Luise; Rudelius, Martina; Seidl, Stefan; Kremmer, Elisabeth; Emambokus, Nikla R; von Bruehl, Marie-Luise; Frampton, Jon; Isermann, Berend; Genzel-Boroviczény, Orsolya; Schreiber, Christian; Mehilli, Julinda; Kastrati, Adnan; Schwaiger, Markus; Shivdasani, Ramesh A; Massberg, Steffen

2010-01-01

The ductus arteriosus (DA) is a fetal shunt vessel between the pulmonary artery and the aorta that closes promptly after birth. Failure of postnatal DA closure is a major cause of morbidity and mortality particularly in preterm neonates. The events leading to DA closure are incompletely understood. Here we show that platelets have an essential role in DA closure. Using intravital microscopy of neonatal mice, we observed that platelets are recruited to the luminal aspect of the DA during closure. DA closure is impaired in neonates with malfunctioning platelet adhesion or aggregation or with defective platelet biogenesis. Defective DA closure resulted in a left-to-right shunt with increased pulmonary perfusion, pulmonary vascular remodeling and right ventricular hypertrophy. Our findings indicate that platelets are crucial for DA closure by promoting thrombotic sealing of the constricted DA and by supporting luminal remodeling. A retrospective clinical study revealed that thrombocytopenia is an independent predictor for failure of DA closure in preterm human newborns, indicating that platelets are likely to contribute to DA closure in humans.

A case of residual inferior sinus venosus defect after ineffective surgical closure.

PubMed

Uga, Sayuri; Hidaka, Takayuki; Takasaki, Taiichi; Kihara, Yasuki

2014-10-03

A 38-year-old woman presented with cyanosis and heart failure 34 years after patch closure of an atrial septal defect and partial anomalous pulmonary venous connection. CT and cardiac catheterisation showed a residual defect that caused right-to-left shunting. The patch almost blocked the inferior vena cava from the right atrium, resulting in uncommon drainage of the inferior vena cava into the left atrium. Other anomalies included the coronary-to-pulmonary artery fistula and duplicate inferior vena cava with dilated azygos venous system. A second surgery was performed, and we confirmed an inferior sinus venosus defect, which is rare and can be misdiagnosed. The ineffective patch closure had caused a haemodynamic status that rarely occurs. We describe the diagnostic process and emphasise the importance of correctly understanding the entity. 2014 BMJ Publishing Group Ltd.

Implantability, Complications, and Follow-Up After Transjugular Intrahepatic Portosystemic Stent-Shunt Creation With the 6F Self-Expanding Sinus-SuperFlex-Visual Stent.

PubMed

Spira, Daniel; Wiskirchen, Jakub; Lauer, Ulrich; Ketelsen, Dominik; Nikolaou, Konstantin; Wiesinger, Benjamin

2016-07-01

The transjugular intrahepatic portosystemic stent-shunt (TIPSS) builds a shortcut between the portal vein and a liver vein, and represents a sophisticated alternative to open surgery in the management of portal hypertension or its complications. To describe clinical experiences with a low-profile nitinol stent system in TIPSS creation, and to assess primary and long-term success. Twenty-six patients (5 females, 21 males; mean age 54.6 years) were treated using a low-profile 6F self-expanding sinus-SuperFlex-Visual stent system. The indication for TIPSS creation was refractory bleeding in 9 of the 26 patients, refractory ascites in 18 patients, and acute thrombosis of the portal vein confluence in one patient. Portosystemic pressure gradients before and after TIPSS, periprocedural and long-term complications, and the time to orthotopic liver transplantation (OLT) or death were recorded. The portosystemic pressure gradient was significantly reduced, from 20.9 ± 6.3 mmHg before to 8.2 ± 2.3 mmHg after TIPSS creation (P < 0.001). Procedure-related complications included acute tract occlusion (n = 2), liver hematoma (n = 1), hepatic encephalopathy (n = 1), and cardiac failure (n = 1). Three of the 26 patients had late-onset TIPSS occlusion (at 12, 12, and 39 months after TIPSS creation). Three patients died within one week after the procedure due to their poor general condition (multiorgan failure, acute respiratory distress syndrome, necrotizing pancreatitis, and aspiration pneumonia). Another four patients succumbed to their underlying advanced liver disease within one year after TIPSS insertion. Seven patients underwent OLT at a mean time of 9.4 months after TIPSS creation. The sinus-SuperFlex-Visual stent system can be safely deployed as a TIPSS device. The pressure gradient reduction was clinically sufficient to treat the patients' symptoms, and periprocedural complications were due to the TIPSS procedure per se rather than to the particular stent system employed in this study.

Rapid sequence magnetic resonance imaging in the assessment of children with hydrocephalus.

PubMed

O'Neill, Brent R; Pruthi, Sumit; Bains, Harmanjeet; Robison, Ryan; Weir, Keiko; Ojemann, Jeff; Ellenbogen, Richard; Avellino, Anthony; Browd, Samuel R

2013-12-01

Recent reports have shown the utility of rapid-acquisition magnetic resonance imaging (MRI) in the evaluation of children with hydrocephalus. Rapid sequence MRI (RS-MRI) acquires clinically useful images in seconds without exposing children to the risks of ionizing radiation or sedation. We review our experience with RS-MRI in children with shunts. Overall image quality, cost, catheter visualization, motion artifact, and ventricular size were reviewed for all RS-MRI studies obtained at Seattle Children's Hospital during a 2-year period. Image acquisition time was 12-19 seconds, with sessions usually lasting less than 3 minutes. Image quality was very good or excellent in 94% of studies, whereas only one was graded as poor. Significant motion artifact was noted in 7%, whereas 77% had little or no motion artifact. Catheter visualization was good or excellent in 57%, poor in 36%, and misleading in 7%. Small ventricular size was correlated with poor catheter visualization (Spearman's ρ = 0.586; P < 0.00001). RS-MRI imaging cost ∼$650 more than conventional computed tomography (CT). Our study supports that RS-MRI is an adequate substitute that allows reduced use of CT imaging and resultant exposure to ionizing radiation. Catheter position visualization remains suboptimal when ventricles are small, but shunt malfunction can be adequately determined in most cases. The cost is significantly more than CT, but the potential for lifetime reduction in radiation exposure may justify this expense in children. Limitations include the risk of valve malfunction after repeated exposure to high magnetic fields and the need for reprogramming with many types of adjustable valves. Copyright © 2013 Elsevier Inc. All rights reserved.

Theoretical considerations on the pathophysiology of normal pressure hydrocephalus (NPH) and NPH-related dementia.

PubMed

Hamlat, Abderrahmane; Adn, Mahmoudreza; Sid-ahmed, Seddik; Askar, Brahim; Pasqualini, Edouardo

2006-01-01

Normal pressure hydrocephalus (NPH) is considered to be an example of reversible dementia although clinical improvement after shunting varies from subject to subject, and recent studies have pointed to a possible link with other dementia. The authors consider that the craniospinal compartment is a partially closed sphere with control device systems represented by the spinal axis and the sagittal sinus-arachnoid villi complex which interact with each other in the clinical patient setting. We hypothesise that changing spinal compliance by altering the flow process and CSF dynamics lead to hydrocephalus. Therefore four NPH types have been distinguished according to the alterations in spinal compliance, decrease in CSF absorption at the sagittal sinus or both occurrences. The authors consider that NPH and NPH-related diseases (NPH-RD) are initiated by the same common final pathway and demonstrate that NPH could represent an initial stage of NPH-RD. Progression of clinical signs can be explained as damage to the cerebral tissue by both intermittent increased intracranial pressure and pulse pressure waves leading to periventricular ischaemia. In addition, they believe that both volume equilibrium and spinal compliance are restored in patients who improve after CSF shunt, whereas in patients whose condition does not improve, only volume equilibrium is restored and not spinal compliance, which was the underlying cause of hydrocephalus in such cases. They therefore wonder whether cervical decompression should not be indicated in patients who show no improvement. Although attractive, this analysis warrants confirmation from clinical, radiological, and hydrodynamic studies.

Multidetector-Row Computed Tomography in the Evaluation of Transjugular Intrahepatic Portosystemic Shunt Performed with Expanded-Polytetrafluoroethylene-Covered Stent-Graft

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fanelli, Fabrizio, E-mail: fabrizio.fanelli@uniroma1.it; Bezzi, Mario; Bruni, Antonio

2011-02-15

We assessed, in a prospective study, the efficacy of multidetector spiral computed tomography (MDCT) in the evaluation of transjugular intrahepatic portosystemic shunt (TIPS) patency in patients treated with the Viatorr (Gore, Flagstaff, AZ) expanded-polytetrafluoroethylene (e-PTFE)-covered stent-graft. Eighty patients who underwent TIPS procedure using the Viatorr self-expanding e-PTFE stent-graft were evaluated at follow-up of 1, 3, 6, and 12 months with clinical and laboratory tests as well as ultrasound-color Doppler (USCD) imaging. In case of varices, upper gastrointestinal endoscopy was also performed. In addition, the shunt was evaluated using MDCT at 6 and 12 months. In all cases of abnormal findingsmore » and discrepancy between MDCT and USCD, invasive control venography was performed. MDCT images were acquired before and after injection of intravenous contrast media on the axial plane and after three-dimensional reconstruction using different algorithms. MDCT was successfully performed in all patients. No artefacts correlated to the Viatorr stent-graft were observed. A missing correlation between UCSD and MDCT was noticed in 20 of 80 (25%) patients. Invasive control venography confirmed shunt patency in 16 (80%) cases and shunt malfunction in 4 (20%) cases. According to these data, MDCT sensitivity was 95.2%; specificity was 96.6%; and positive (PPV) and negative predictive values (NPV) were 90.9 and 98.2%, respectively. USCD sensitivity was 90%; specificity was 75%; and PPV and NPV were 54.5 and 95.7%, respectively. A high correlation (K value = 0.85) between MDCT and invasive control venography was observed. On the basis of these results, MDCT shows superior sensitivity and specificity compared with USCD in those patients in whom TIPS was performed with the Viatorr stent-graft. MDCT can be considered a valid tool in the follow-up of these patients.« less

Adjustable valves in normal-pressure hydrocephalus: a retrospective study of 218 patients.

PubMed

Zemack, Göran; Romner, Bertil

2002-12-01

We sought to assess the value of adjusting shunt valve opening pressure, complications, and outcomes with the use of an adjustable shunt valve in the treatment of patients with normal-pressure hydrocephalus (NPH). In a single-center retrospective study, 231 adjustable valves (range, 30-200 mm H(2)O) were the first shunt implantations in 147 patients with idiopathic NPH (INPH) and 71 patients with secondary NPH (SNPH). The effect of adjustment on gait disturbance, cognitive impairment, urinary incontinence and other symptoms were evaluated, and an improvement index was created. In the INPH group, 138 adjustments were performed in 49.0% of the patients (average, 0.94 adjustments/patient). For the SNPH group, 49 adjustments were performed in 32.4% of the patients (average, 0.69 adjustments/patient). The reasons for adjustment were overdrainage in 48 patients (25.7%), underdrainage in 98 patients (52.4%), subdural hematoma in 37 patients (19.8%), and other reasons in 2 patients (2.1%). Clinical status improved after 56 (49.1%) of all 114 adjustments, whereas 23 (42.6%) of 54 minor (< or =20 mm H2O) and 33 (66.0%) of 50 larger adjustments improved the patient's clinical status. The correlation of the improvement index with the size of the individual adjustments was not significant. Complications occurred in 43 (19.7%) of 218 patients, valve malfunction occurred in 3 patients (1.3%), infection occurred in 14 patients (6.4%), and nontraumatic subdural effusion occurred in 15 patients (6.9%; 8 were treated by adjustment alone). The 5-year shunt survival rate was 80.2%. Outcomes were excellent or good in 71 (78.9%) of 90 patients with INPH and in 30 (69.8%) of 43 patients with SNPH. Noninvasive, particularly consecutive, minor or single larger adjustments to the valve opening pressure can further improve outcome in patients with NPH who undergo shunting.

Alarm!!! A UFO inside the heart.

PubMed

Santoro, Giuseppe; Castaldi, Biagio; Iacono, Carola; Giugno, Luca; Gaio, Gianpiero; Russo, Maria G

2012-10-01

An 8-year-old asymptomatic child was referred for surgical repair of coronary sinus atrial septal defect resulting in significant left-to-right shunt and right chamber volume overload. The septal fenestration was located near to its drainage site into the right atrium. Due to this seemingly favourable anatomy, transcatheter closure of the septal defect was performed using an Amplatzer Septal Occluder device. The echocardiographic postprocedural evaluation imaged the occluding device almost perpendicular to the atrial septum, seemingly floating above the mitral valve orifice, like an alien spaceship inside the heart.

Normal pressure hydrocephalus: Diagnostic and predictive evaluationon

PubMed Central

Damasceno, Benito Pereira

2009-01-01

In typical cases, normal pressure hydrocephalus (NPH) manifests itself with the triad of gait disturbance, which begins first, followed by mental deterioration and urinary incontinence associated with ventriculomegaly (on CT or MRI) and normal cerebrospinal fluid (CSF) pressure. These cases present minor diagnostic difficulties and are the most likely to improve after shunting. Problems arise when NPH shows atypical or incomplete clinical manifestations (25–50% of cases) or is mimicked by other diseases. In this scenario, other complementary tests have to be used, preferentially those that can best predict surgical outcome. Radionuclide cisternography, intracranial pressure monitoring (ICP) and lumbar infusion tests can show CSF dynamics malfunction, but none are able to confirm whether the patient will benefit from surgery. The CSF tap test (CSF-TT) is the only procedure that can temporarily simulate the effect of definitive shunt. Since the one tap CSF-TT has low sensitivity, it cannot be used to exclude patients from surgery. In such cases, we have to resort to a repeated CSF-TT (RTT) or continuous lumbar external drainage (LED). The most reliable prediction would be achieved if RTT or LED proved positive, in addition to the occurrence of B-waves during more than 50% of ICP recording time. This review was based on a PubMed literature search from 1966 to date. It focuses on clinical presentation, neuroimaging, complementary prognostic tests, and differential diagnosis of NPH, particularly on the problem of selecting appropriate candidates for shunt. PMID:29213603

Cranial dural arteriovenous shunts. Part 1. Anatomy and embryology of the bridging and emissary veins.

PubMed

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.

Coronary artery to pulmonary artery fistula.

PubMed

Dadkhah-Tirani, Heidar; Salari, Arsalan; Shafighnia, Shora; Hosseini, Seyed Fazel; Naghdipoor, Misa

2013-01-01

Male, 69 FINAL DIAGNOSIS: Coronary artery to pulmonary artery fistula Symptoms: Chest pain Medication: - Clinical Procedure: Echocardiography • angiography • surgical intervention Specialty: Cardiology • Cardiac Surgery. Rare disease. A coronary artery fistula is an abnormal communication between a coronary artery and one of the cardiac chambers or a great vessel, so bypassing the myocardial capillary network. They are usually discovered incidentally upon coronary angiography. Clinical manifestations are variable depending on the type of fistula, the severity of shunt, site of shunt, and presence of other cardiac condition. We report a 69-year-old man without any previous medical history, who was admitted to our hospital with chest pain. The electrocardiogram (ECG) showed a sinus rhythm with ST depression in V2 to V6 precordial leads. Coronary angiography revealed a coronary artery fistula from left anterior descending coronary artery (LAD) to the main pulmonary artery, right coronary artery blockage and significant stenoses on the LAD and left circumflex artery (LCX). Surgical treatment was chosen because of the total occlusion of the right coronary artery and to relieve of pain to improve quality of life.

Telemetric Intracranial Pressure Monitoring with the Raumedic Neurovent P-tel.

PubMed

Antes, Sebastian; Tschan, Christoph A; Heckelmann, Michael; Breuskin, David; Oertel, Joachim

2016-07-01

Devices enabling long-term intracranial pressure monitoring have been demanded for some time. The first solutions using telemetry were proposed in 1967. Since then, many other wireless systems have followed but some technical restrictions have led to unacceptable measurement uncertainties. In 2009, a completely revised telemetric pressure device called Neurovent P-tel was introduced to the market. This report reviews technical aspects, handling, possibilities of data analysis, and the efficiency of the probe in clinical routine. The telemetric device consists of 3 main parts: the passive implant, the active antenna, and the storage monitor. The implant with its parenchymal pressure transducer is inserted via a frontal burr hole. Pressure values can be registered with a frequency of 1 Hz or 5 Hz. Telemetrically gathered data can be viewed on the storage monitor or saved on a computer for detailed analyses. A total of 247 patients with suspected (n = 123) or known (n = 124) intracranial pressure disorders underwent insertion of the telemetric pressure probe. A detailed analysis of the long-term intracranial pressure profile including mean values, maximum and negative peaks, pathologic slow waves, and pulse pressure amplitudes is feasible using the detection rate of 5 Hz. This enables the verification of suspected diagnoses as normal-pressure hydrocephalus, benign intracranial hypertension, shunt malfunction, or shunt overdrainage. Long-term application also facilitates postoperative surveillance and supports valve adjustments of shunt-treated patients. The presented telemetric measurement system is a valuable and effective diagnostic tool in selected cases. Copyright © 2016 Elsevier Inc. All rights reserved.

Cardioscopic tricuspid valve repair in a beating ovine heart.

PubMed

Umakanthan, Ramanan; Ghanta, Ravi K; Rangaraj, Aravind T; Lee, Lawrence S; Laurence, Rita G; Fox, John A; Mihaljevic, Tomislav; Bolman, Ralph M; Cohn, Lawrence H; Chen, Frederick Y

2009-04-01

Open heart surgery is commonly associated with cardiopulmonary bypass and cardioplegic arrest. The attendant risks of cardiopulmonary bypass may be prohibitive in high-risk patients. We present a novel endoscopic technique of performing tricuspid valve repair without cardiopulmonary bypass in a beating ovine heart. Six sheep underwent sternotomy and creation of a right heart shunt to eliminate right atrial and right ventricular blood for clear visualization. The superior vena cava, inferior vena cava, pulmonary artery, and coronary sinus were cannulated, and the blood flow from these vessels was shunted into the pulmonary artery via a roller pump. The posterior leaflet of the tricuspid valve was partially excised to create tricuspid regurgitation, which was confirmed by Doppler echocardiography. A 7.0-mm fiberoptic videoscope was inserted into the right atrium to visualize the tricuspid valve. Under cardioscopic vision, an endoscopic needle driver was inserted into the right atrium, and a concentric stitch was placed along the posterior annulus to bicuspidize the tricuspid valve. Doppler echocardiography confirmed reduction of tricuspid regurgitation. All animals successfully underwent and tolerated the surgical procedure. The right heart shunt generated a bloodless field, facilitating cardioscopic tricuspid valve visualization. The endoscopic stitch resulted in annular plication and functional tricuspid valve bicuspidization, significantly reducing the degree of tricuspid regurgitation. Cardioscopy enables less invasive, beating-heart tricuspid valve surgery in an ovine model. This technique may be useful in performing right heart surgery without cardiopulmonary bypass in high-risk patients.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bilbao, Jose Ignacio; Quiroga, Jorge; Herrero, Jose Ignacio

Since the insertion of the first TIPS in 1989 much has been learned about this therapeutic procedure. It has an established role for the treatment of some complications of portal hypertension: prevention of recurrent variceal bleeding and rescue of patients with acute uncontrollable variceal bleeding. In addition TIPS is useful for Budd-Chiari syndrome, refractory ascites and hepatorenal syndrome, although its specific role in these indications remains to be definitively established. However, the decrease in sinusoidal blood flow induced by TIPS can lead to the patient developing hepatic encephalopathy and liver failure in some cases. Therefore, TIPS should be used withmore » caution in patients with very poor liver function. From a technical point of view, successful placement of TIPS is achieved in more than 98% of cases by experienced groups. At present, evaluation of TIPS dysfunction based on morphology probably leads to an overdiagnosis of this complication since most of these cases are not associated with clinical manifestations (recurrent bleeding or refractory ascites). The major disadvantage of TIPS remains its poor long-term patency requiring a mandatory surveillance program. The indicator for shunt function/malfunction should be the portosystemic pressure gradient, which is best assessed by intravascular measurements. Shunt obstructions may be prevented or reduced by the use of stent-grafts in the future.« less

Influence of family environment on language outcomes in children with myelomeningocele.

PubMed

Vachha, B; Adams, R

2005-09-01

Previously, our studies demonstrated language differences impacting academic performance among children with myelomeningocele and shunted hydrocephalus (MMSH). This follow-up study considers the environmental facilitators within families (achievement orientation, intellectual-cultural orientation, active recreational orientation, independence) among a cohort of children with MMSH and their relationship to language performance. Fifty-eight monolingual, English-speaking children (36 females; mean age: 10.1 years; age range: 7-16 years) with MMSH were evaluated. Exclusionary criteria were prior shunt infection; seizure or shunt malfunction within the previous 3 months; uncorrected visual or auditory impairments; prior diagnoses of mental retardation or attention deficit disorder. The Comprehensive Assessment of Spoken Language (CASL) and the Wechsler Abbreviated Scale of Intelligence (WASI) were administered individually to all participants. The CASL Measures four subsystems: lexical, syntactic, supralinguistic and pragmatic. Parents completed the Family Environment Scale (FES) questionnaire and provided background demographic information. Spearman correlation analyses and partial correlation analyses were performed. Mean intelligence scores for the MMSH group: full scale IQ 92.2 (SD = 11.9). The CASL revealed statistically significant difficulty for supralinguistic and pragmatic (or social) language tasks. FES scores fell within the average range for the group. Spearman correlation and partial correlation analyses revealed statistically significant positive relationships for the FES 'intellectual-cultural orientation' variable and performance within the four language subsystems. Socio-economic status (SES) characteristics were analyzed and did not discriminate language performance when the intellectual-cultural orientation factor was taken into account. The role of family facilitators on language skills in children with MMSH has not previously been described. The relationship between language performance and the families' value on intellectual/cultural activities seems both statistically and intuitively sound. Focused interest in the integration of family values and practices should assist developmental specialists in supporting families and children within their most natural environment.

Surgical options for treatment of traumatic subdural hematomas in children younger than 2 years of age.

PubMed

Melo, José Roberto Tude; Di Rocco, Federico; Bourgeois, Marie; Puget, Stephanie; Blauwblomme, Thomas; Sainte-Rose, Christian; Meyer, Philippe G; Zerah, Michel

2014-04-01

Subdural hematoma (SDH) is the most common finding on cranial CT in pediatric victims of abusive head trauma (AHT). The hematomas are commonly bilateral and sometimes associated with interhemispheric hyperdensity and/or convexity hemorrhages. There is no consensus regarding the best surgical treatment in such cases nor are there standardized surgical protocols. The authors report their experience and discuss the routine surgical options in the management of traumatic SDH at a Level 1 Pediatric Trauma Center. In this paper, the authors describe a cross-sectional study with consecutive revision of data described in the medical records of Hôpital Universitaire Necker-Enfants Malades between January 2008 and January 2013. During this period, all children younger than 2 years of age who were admitted with a traumatic SDH identified on CT scans were included in this study. One hundred eighty-four children who had SDH and were younger than 2 years of age were included. Their median age was 5.8 months (range 5 days-23 months), and 70% of the children were male. On admission CT scans, the SDH was bilateral in 52% of cases and homogeneously hypodense in 77%. Neurosurgical treatment was undertaken in 111 children (60%) with an admission Glasgow Coma Scale score of 12 or less, bulging fontanels, or other signs suggestive of intracranial hypertension. The first surgical option was craniotomy in 1.8% (2) of these 111 cases, decompressive craniectomy in 1.8% (2), transcutaneous subdural puncture in 15% (17), external subdural drainage in 16% (18), subdural-subgaleal shunt placement in 17% (19), and subdural-peritoneal shunt placement in 48% (53). In 82% of the children initially treated with transcutaneous subdural puncture and in 50% of those treated with external subdural drainage, increase or persistence of the SDH, CSF or skin infection, or shunt system malfunction was observed and further surgical intervention was required. There was a 26% rate of complications in patients initially treated with a subdural-peritoneal shunt. Although 52% of the patients had bilateral SDH, bilateral drainage was only required in 9.4%. The choice of treatment should be determined by the clinical and radiological characteristics of the individual case. Although effective on an emergency basis, subdural puncture and external subdural drainage are frequently insufficient to obtain complete resolution of SDH, and temporary placement of a subdural-peritoneal shunt is needed in most cases.

Cyanosis and Stroke due to Functional Cor Triatriatum Dexter in a Neonate.

PubMed

León, Rachel L; Zaban, Nicholas B; Schamberger, Marcus S; Ho, Chang Y; Mietzsch, Ulrike

2018-01-01

Small remnants of the right valve of the sinus venosus are commonly found in adults, but the incidence and risk associated with these embryonic remnants in neonates are not well studied. The following report describes a cyanotic neonate with a large Eustachian valve remnant creating a functional cor triatriatum dexter who was initially diagnosed with persistent pulmonary hypertension of the newborn. The cyanosis in this infant improved over the first postnatal week with conservative management, but she suffered multifocal subcortical stroke, likely related to her intracardiac shunt. The clinical presentation and questions regarding long-term management of this rare diagnosis are explored. © 2018 S. Karger AG, Basel.

Atrial septal defect in a Korean wild raccoon dog

PubMed Central

YIM, Soomi; CHOI, Sooyoung; KIM, Jongtaek; CHUNG, Jin-Young; PARK, Inchul

2017-01-01

An approximately two-year-old, male 6.1 kg body weight, Korean wild raccoon dog (Nyctereutes procyonoides koreensis) was captured by the wildlife medical rescue center of Kangwon National University. Upon physical examination, the heart rate was 87 beats per min and there were no clinical signs. The hematological, and blood biochemical profiles revealed no remarkable findings; however, thoracic radiographs showed cardiac enlargement, especially in the right atrium. On electrocardiogram, sinus node dysfunction and bradyarrhythmia were revealed. Echocardiography showed a left-to-right shunting atrial septal defect. Based on these findings, this Korean wild raccoon dog was diagnosed with atrial septal defect. This is the rare case report of atrial septal defect in wildlife. PMID:28804099

Atrial septal defect in a Korean wild raccoon dog.

PubMed

Yim, Soomi; Choi, Sooyoung; Kim, Jongtaek; Chung, Jin-Young; Park, Inchul

2017-10-07

An approximately two-year-old, male 6.1 kg body weight, Korean wild raccoon dog (Nyctereutes procyonoides koreensis) was captured by the wildlife medical rescue center of Kangwon National University. Upon physical examination, the heart rate was 87 beats per min and there were no clinical signs. The hematological, and blood biochemical profiles revealed no remarkable findings; however, thoracic radiographs showed cardiac enlargement, especially in the right atrium. On electrocardiogram, sinus node dysfunction and bradyarrhythmia were revealed. Echocardiography showed a left-to-right shunting atrial septal defect. Based on these findings, this Korean wild raccoon dog was diagnosed with atrial septal defect. This is the rare case report of atrial septal defect in wildlife.

Following the canyon to reach and remove olfactory groove meningiomas.

PubMed

Stefini, Roberto; Zenga, Francesco; Giacomo, Esposito; Bolzoni, Andrea; Tartara, Fulvio; Spena, Giannantonio; Ambrosi, Claudia; Fontanella, Marco M

2017-04-01

Olfactory groove meningiomas (OGMs) represent approximately 10% of all intracranial meningiomas. They arise in the olfactory fossa, a variable depression delimited by the lateral lamella and perpendicular plate. The cribriform plate with the lateral lamella and ethmoidal and orbital roof could be viewed as a 'canyon' with the frontal sinus as the main entrance. Between January 2000 and December 2013, 32 consecutive patients underwent removal of OGMs through this 'canyon' at the Department of Neurosurgery of Brescia and Turin. Complete removal was achieved in all patients with this trans-frontal sinus subcranial approach (Simpson grade I; mean lesion volume, 46.6 cm3). Five patients (15.6%) experienced nasal CSF leakage, treated with external lumbar drain positioning for 4 days and resolved in all cases but one, which was re-operated. Two patients (6.2%) during the CSF leakage experienced meningitis at day 7 after surgery, both successfully treated by intravenous antibiotic therapy. After one month, one patient developed hydrocephalus, treated with a ventricular peritoneal shunt. In one patient, traction on the OGM caused bleeding of the callosomarginal artery, which was coagulated with superior frontal gyrus ischemia without neurological consequences. Glasgow Outcome Scale Score at 6 months was V in 29 patients, IV in one patient, and I in two patients. Advantages with this approach may include easy and early control of blood supply from its insertion in the skull base, minimal frontal lobe retraction, preservation of the frontal veins draining to the sagittal sinus, and a satisfactory aesthetic outcome.

Bilateral meningoencephaloceles with cerebrospinal fluid rhinorrhea after facial advancement in the Crouzon syndrome.

PubMed

Panuganti, Bharat A; Leach, Matthew; Antisdel, Jastin

2015-01-01

Cerebrospinal fluid (CSF) rhinorrhea and encephaloceles are rare complications of craniofacial advancement procedures performed in patients with craniofacial dysostoses (CD) to address the ramifications of their midface hypoplasia including obstructed nasal airway, exorbitism, and impaired mastication. Surgical repair of this CSF rhinorrhea is complicated by occult elevations in intracranial pressure (ICP), potentially necessitating open, transcranial repair. We report the first case in otolaryngology literature of a patient with Crouzon syndrome with late CSF rhinorrhea and encephalocele formation after previous LeFort III facial advancement surgery. Describe the case of a patient with Crouzon syndrome who presented with CSF rhinorrhea and encephaloceles as complications of Le Fort III facial advancement surgery. Review the literature pertaining to the incidence and management of post-operative CSF rhinorrhea and encephaloceles. Analyze issues related to repair of these complications, including occult elevations in ICP, the utility of perioperative CSF shunts, and the importance of considering alternative repair schemes to the traditional endonasal, endoscopic approach. Review of the literature describing CSF rhinorrhea and encephalocele formation following facial advancement in CD, focusing on management strategies. CSF rhinorrhea and encephalocele formation are rare complications of craniofacial advancement procedures. Occult elevations in ICP complicate the prospect of permanent surgical repair, potentially necessitating transcranial repair and the use of CSF shunts. Though no consensus exists regarding the utility of perioperative CSF drains, strong associations exist between elevated ICP and failed surgical repair. Additionally, the anatomic changes in the frontal and ethmoid sinuses after facial advancement present a challenge to endoscopic repair. Otolaryngologists should be aware of the possibility of occult elevations in ICP and sinonasal anatomic abnormalities when repairing CSF rhinorrhea in patients with CD. Clinicians should consider CSF shunt placement and carefully weigh the advantages of the transcranial approach versus endonasal, endoscopic techniques.

Normal pressure hydrocephalus in patients with myelomeningocele.

PubMed

Hammock, M K; Milhorat, T H; Baron, I S

1976-01-01

Although the syndrome of normal pressure hydrocephalus (NPH) was described in the adult as early as 1964, it has only recently been recognized in the child. In this preliminary report, eight myelomeningocele patients with presumed NPH were evaluated before and after ventricular shunting procedures. Cranial computed tomography and serial psychological testing have proved to be particularly valuable both in the pre-operative and post-operative assessment of these patients and have the distinct advantage of being simple, non-invasive diagnostic measures. Continuous intra-ventricular pressure monitoring has shown what promises to be characteristic elevated pressure plateaux imposed on normal baseline cerebrospinal fluid (CSF) pressures in so-called NPH but is a more difficult clinical procedure, necessarily associated with potential complications. Although decreasing response to growth-stimulating hormone can be demonstrated in patients with long-standing hydrocephalus, this endocrine malfunction cannot be considered an early indicator of intracranial pathology. Single IQ scores are inadequate measures of intellectural function in children with NPH and serial examinations should be carried out. Detailed neuropsychological testing will document performance IQ scores well below verbal IQ scores and will generally show failure of psychomotor development to keep pace with chronological ageing. Initial studies indicate that improved performance scores can be expected within 1 1/2 to 3 months following successful ventricular shunting operations, and that any downward trend in pre-operative test scoring can at least be reversed. Statistically significant improvements in full-scale IQ scores have not been seen, however, before the end of the first post-operative year. Clinically, improved attentiveness and sociability, and decreased spasticity (if present prior to surgery) can be expected following shunting. Over-all, ventriculomegaly, normal CSF pressure, stable head size, and non-progressive neurological symptoms cannot be regarded as sufficient criteria for the diagnosis of an arrested state of hydrocephalus, and should suggest NPH, especially in those children who demonstrate a discrepancy between performance and verbal IQ scores and who fail to exhibit continuing psychomotor development with advancing age.

Identifying diversion of inferior vena cava after repair of atrial septal defect.

PubMed

Lee, Yi Wei; Lee, Wei Chieh; Chua, Sarah

2015-10-01

Inadvertent IVC diversion into left atrium is a rare morbidity following ASD repair. Reported risk factors included a large secundum, or low-lying ASD, or inferior sinus venosus defect, and anomalous pulmonary connection into the RA. In our case, transesophageal echocardiogram showed abnormal connection of IVC to LA, but could not be identified owing to limited window. Cardiac CT could offer better anatomic clarification. On contrast transesophageal echocardiogram with agitated saline injected via right femoral vein, an abnormal right-to-left shunt was demonstrated by transit of microbubbles from IVC into LA, while majority of rest entered into the RA. Therefore, we confirm the IVC diversion into LA. Detection of such unusual condition is a challenge due to the fact that special echocardiographic windows are often needed.

Array automated assembly. Phase 2: quarterly report for the quarter ending September 30, 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, W.E.; Kimberly, W.; Mardesich, N.

Problems with excessive junction shunting previously reported were found to be associated with a malfunction discovered in one of the printers. Aluminum contamination of the front surface and junction edge were also identified as sources of shunting, as was damage to the tetrahedral peaks during handling of diffused wafers. Additional compositional variations of titania precipitated and baria--magnesia borosilicate glasses were prepared to improve fusion and maturation characteristics. An intensive effort was made to integrate the diffusion mask process into the process sequence. This attempt has been unsuccessful. All cells fabricated have had very low output attributable primarily to low shuntmore » resistance. Alcoa 1401 and AMPAL (Atomized Metal Powder, Inc.) aluminum powders were tested as the base for making screen printing pastes for back surface P+ contacts. Time--temperature firing matrix experiments showed that optimum conditions were different for the two different pastes: 850/sup 0/C and 20 seconds for the paste based on Alcoa 1401 powder and 825/sup 0/C for 30 seconds for the paste based on the AMPAL powder. Additional peel strength data on protective coating materials were gathered. The effect of exposure to a swelling solvent on coating layers was added as a test of adhesive bonding to the substrate and the effectiveness of primer coupling agents. The preliminary tests indicate ability to discriminate between different primers used with RTV-type silicon coatings.« less

Coexistance of cerebral sinovenous thrombosis and Dandy Walker malformation in newborn.

PubMed

Gverić-Ahmetasević, Snjezana; Colić, Ana; Gverić, Tugomir; Gasparović, Vesna Elvedi; Pavlisa, Goran; Ozretić, David

2011-01-01

Cerebral sinovenous thrombosis in neonatal period may cause neurological impairment, epilepsy, and lead to stroke. It is caused primarily by coagulopathy of numerous reasons, occasionally perinatal asphyxia, traumatic delivery and hyperhomocysteinemia. Dandy-Walker malformation is characterized by agenesis or hypoplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle, and enlargement of the posterior fossa. Dandy-Walker malformation, variant, and mega cisterna magna represent a spectrum of developmental anomalies. Insults to developing cerebellar hemispheres and the fourth ventricle are believed to be the cause of malformation. Our patient was born from noncomplicated pregnancy, noncomplicated nontraumatic vaginal delivery at term, excellent Apgar scores, without peculiarities in clinical status. She was brest-fed by the 42nd hour of life when she had rightsided seizures during sleep that repeated for five times in next 24 hours. Brain Ultrasound (US) revealed clot in left lateral ventricle, slight dilatation of left ventricle, both sided periventricular echodensity, ischemia, slight enlargement of forth ventricle and a bit smaller cerebellum. There was no visible flow through left transverse, superior sagittal and straight sinus. Magnetic Resonance (MRI) confirmed the finding and showed thrombosis of left and right transverse venous sinuses and confluence of sinuses. Electroencephalogram (EEG) showed leftsided focal changes. The newborn was treated with phenobarbiton for 8 days and had no convulsions during that period. All coagulation parameters, homocistein, lipoproteins (a) and D-dimers were normal. There were no mutations on FV R506Q, PT 20210A, MTHFR 677C/T. No antiphospholipides were found. Heart US showed no structural anomalies. No other patology or risk factors were present at the time. Before discharge, US showed hydrocephalus. Flow in affected sinuses was visible with color Doppler. MRI showed recanalization of affected sinuses, also hydrocephalus and presentation of Dandy Walker On EEG there was borderline finding. Due to progression of hydrocephalus ventriculo-peritoneal shunt was placed. In age of 1 year EEG was slower for age but without focus. Neurological development was normal for age. The question is whether this child had intrauterine insult and inception of Dandy Walker with further postnatal progress of thrombosis and evolution to full picture of Dandy Walker with hydrocephalus OR thrombosis that led to development of hydrocephalus and Dandy Walker malformation in this child were accidental coexistance.

[Assessment of the characteristics of echocardiography in pediatric patients with total anomalous pulmonary venous connection].

PubMed

Jiang, Guo-ping; Ye, Jing-jing; He, Jin; Zhao, Lei; Peng, Xue-hui; He, Yu; Yang, Xiu-zhen

2006-07-01

To assess the accuracy of echocardiography in diagnosis of total anomalous pulmonary venous connection (TAPVC). A combination of suprasternal, parasternal, subcostal and apical views were employed to diagnose TAPVC and to trace the course of the anomalous pulmonary venous connection, the direction of the inter-atrial shunt, enlargement of right atrium (RA) and right ventricle (RV), superior and inferior vena cava. All pediatric patients underwent surgical repair. The results of echocardiography were compared with surgical findings. A total of 28 consecutive pediatric patients with suspected TAPVC were included in this study. The TAPVC diagnosis was confirmed in 26 cases after surgery, partial anomalous pulmonary venous connection (PAPVC) in one case, and Cor Triatriatum and possible TAPVC in another. The diagnostic accuracy of TAPVC by echocardiography in the study was 92.86%. There were 17 supracardiac TAPVC, 11 intracardiac TAPVC. In all patients, enlargement of the RA and RV, inter-atrial right-to-left shunt via atrial septal defects were documented in parasternal and subcostal views. Common pulmonary vein or four pulmonary vein direct to RA or via coronary sinus to RA were the draining sites of intracardiac TAPVC. The enlargement of left innominate vein-right superior vena cava draining to RA was seen in supracardiac TAPVC. A combination of suprasternal and subcostal multi-views in echocardiography can increase the diagnostic accuracy of TAPVC in pediatric patients.

Gene- and cell-based bio-artificial pacemaker: what basic and translational lessons have we learned?

PubMed Central

Li, RA

2012-01-01

Normal rhythms originate in the sino-atrial node, a specialized cardiac tissue consisting of only a few thousands of pacemaker cells. Malfunction of pacemaker cells due to diseases or aging leads to rhythm generation disorders (for example, bradycardias and sick-sinus syndrome (SSS)), which often necessitate the implantation of electronic pacemakers. Although effective, electronic devices are associated with such shortcomings as limited battery life, permanent implantation of leads, lead dislodging, the lack of autonomic responses and so on. Here, various gene- and cell-based approaches, with a particular emphasis placed on the use of pluripotent stem cells and the hyperpolarization-activated cyclic nucleotide-gated-encoded pacemaker gene family, that have been pursued in the past decade to reconstruct bio-artificial pacemakers as alternatives will be discussed in relation to the basic biological insights and translational regenerative potential. PMID:22673497

Gene- and cell-based bio-artificial pacemaker: what basic and translational lessons have we learned?

PubMed

Li, R A

2012-06-01

Normal rhythms originate in the sino-atrial node, a specialized cardiac tissue consisting of only a few thousands of nodal pacemaker cells. Malfunction of pacemaker cells due to diseases or aging leads to rhythm generation disorders (for example, bradycardias and sick-sinus syndrome (SSS)), which often necessitate the implantation of electronic pacemakers. Although effective, electronic devices are associated with such shortcomings as limited battery life, permanent implantation of leads, lead dislodging, the lack of autonomic responses and so on. Here, various gene- and cell-based approaches, with a particular emphasis placed on the use of pluripotent stem cells and the hyperpolarization-activated cyclic nucleotide-gated-encoded pacemaker gene family, that have been pursued in the past decade to reconstruct bio-artificial pacemakers as alternatives will be discussed in relation to the basic biological insights and translational regenerative potential.

Endoscopic Third Ventriculostomy for the Treatment of Hydrocephalus in a Pediatric Population with Myelomeningocele.

PubMed

Rei, Joana; Pereira, Josué; Reis, Carina; Salvador, Sérgio; Vaz, Rui

2017-09-01

Hydrocephalus develops in up to 90% of patients born with myelomeningocele. Although endoscopic third ventriculostomy (ETV) is currently considered the preferred treatment for obstructive hydrocephalus, its results have been inconsistent in patients with myelomeningocele. This study focuses on clinical and radiologic outcomes of ETV in children with hydrocephalus related to myelomeningocele. Medical records of 18 pediatric patients with myelomeningocele treated with ETV from 1998 to 2015 at the Centro Hospitalar São João (Porto, Portugal) were reviewed retrospectively. Patients' caregivers were contacted to evaluate their clinical manifestations before and after surgery regarding signs and symptoms of hydrocephalus and Chiari malformation. Control neuroradiologic imaging of 9 patients was obtained and analyzed. Success of ETV was defined by clinical resolution and radiologic confirmation. ETV was successful in 8 of 18 cases (44.4%). Groups of patients were compared according to age at the time of surgery, with a 40% (2/5) success rate in newborns and a 50% success rate (3/6) in children older than 1 year. Eight patients underwent ETV as a first option, with a 37.5% success rate. Ten patients underwent the procedure after previous ventriculoperitoneal shunt (VPS), 5 for malfunction and 5 for VPS infection with 60% and 40% success rates, respectively. Early postoperative complications occurred in 2 patients. ETV can be performed in patients with myelomeningocele and hydrocephalus with success rates of almost 50%. Prior VPS or VPS malfunction or infection do not contraindicate ETV. If possible, the procedure should be delayed until the patient is at least 1 month old. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-term follow-up of DDD pacing mode.

PubMed

Ulman, Mateusz; Dębski, Maciej; Ząbek, Andrzej; Haberka, Kazimierz; Lelakowski, Jacek; Małecka, Barbara

2014-01-01

The aim of this study was to determine the long-term survival of DDD pacing and identify the main reasons for its loss. The study group consisted of 496 patients in whom a DDD pacing system was implanted between October 1984 and March 2002 and who were followed up until July 2010. The follow-up period was 152.1 ± 35.5 months. The patients' mean age at the time of implantation was 59.5 ± 12.5 years, and 53.5% were male; 58% had sick sinus syndrome (SSS), 26% had atrioventricular block (AVB), 15% had both of these indications simultaneously, and 1% had other indications. The incidence of lead malfunction, progression to chronic atrial fibrillation (AF), and the rate of infective complications was analysed. During the follow-up, 369 patients remained in DDD mode stimulation. DDD mode survival rate at one, five, ten and 15 years was, respectively, 96%, 86%, 77% and 72%. The most common reason for reprogramming out of DDD mode was the development of permanent AF in 65 (13.1%) patients. The occurrence of chronic AF was associated with a prior history of paroxysmal AF (p = 0.0001), SSS (p = 0.0215), and older age at time of implantation (p = 0.0068) compared to patients who remained in sinus rhythm. Lead malfunction caused loss of DDD mode pacing in 56 (11.3%) patients. Atrial leads were damaged in 37 patients, ventricular in 12 patients, and both leads in seven patients. The subclavian vein puncture was correlated with the mechanical damage of the atrial lead (p = 0.02935) compared to cephalic vein access. At the moment of complication, the patients with a dysfunctional lead were significantly younger than those who progressed to chronic AF(p = 0.0019). Infective complications which caused temporary loss of DDD pacing were observed in six patients: five had pocket infection and one had lead-dependent infective endocarditis. 1. Effective DDD pacing from the originally implanted system was noted in a high percentage (72%) of patients in long-term observation (15 years). 2. Progression to permanent AF is the most common reason for loss of DDD pacing;a history of paroxysmal AF and old age are the risk factors. 3. Subclavian vein puncture is associated with a higher rate of atrial lead damage.

Noninvasive measurement of cerebrospinal fluid flow using an ultrasonic transit time flow sensor: a preliminary study.

PubMed

Pennell, Thomas; Yi, Juneyoung L; Kaufman, Bruce A; Krishnamurthy, Satish

2016-03-01

OBJECT Mechanical failure-which is the primary cause of CSF shunt malfunction-is not readily diagnosed, and the specific reasons for mechanical failure are not easily discerned. Prior attempts to measure CSF flow noninvasively have lacked the ability to either quantitatively or qualitatively obtain data. To address these needs, this preliminary study evaluates an ultrasonic transit time flow sensor in pediatric and adult patients with external ventricular drains (EVDs). One goal was to confirm the stated accuracy of the sensor in a clinical setting. A second goal was to observe the sensor's capability to record real-time continuous CSF flow. The final goal was to observe recordings during instances of flow blockage or lack of flow in order to determine the sensor's ability to identify these changes. METHODS A total of 5 pediatric and 11 adult patients who had received EVDs for the treatment of hydrocephalus were studied in a hospital setting. The primary EVD was connected to a secondary study EVD that contained a fluid-filled pressure transducer and an in-line transit time flow sensor. Comparisons were made between the weight of the drainage bag and the flow measured via the sensor in order to confirm its accuracy. Data from the pressure transducer and the flow sensor were recorded continuously at 100 Hz for a period of 24 hours by a data acquisition system, while the hourly CSF flow into the drip chamber was recorded manually. Changes in the patient's neurological status and their time points were noted. RESULTS The flow sensor demonstrated a proven accuracy of ± 15% or ± 2 ml/hr. The flow sensor allowed real-time continuous flow waveform data recordings. Dynamic analysis of CSF flow waveforms allowed the calculation of the pressure-volume index. Lastly, the sensor was able to diagnose a blocked catheter and distinguish between the blockage and lack of flow. CONCLUSIONS The Transonic flow sensor accurately measures CSF output within ± 15% or ± 2 ml/hr, diagnoses the blockage or lack of flow, and records real-time continuous flow data in patients with EVDs. Calculations of a wide variety of diagnostic parameters can be made from the waveform recordings, including resistance and compliance of the ventricular catheters and the compliance of the brain. The sensor's clinical applications may be of particular importance to the noninvasive diagnosis of shunt malfunctions with the development of an implantable device.

The matching of ventilation and perfusion in the lung of the Tegu lizard, Tupinambis nigropunctatus.

PubMed

Hlastala, M P; Standaert, T A; Pierson, D J; Luchtel, D L

1985-06-01

Ventilation-perfusion (VA/Q) distribution was evaluated in the Tegu lizard, Tupinambis nigropunctatus, using the multiple inert gas elimination technique (MIGET) in order to define the limitations to gas exchange in the large chambered unicameral lung. The lizards (0.52-1.1 kg) were anesthetized with halothane and ventilated. Body temperature was maintained at 35 degrees C. Arterial and sinus venosus PO2 averaged 79.4 +/- 5.9 and 47.3 +/- 6.4 torr while breathing air and 232.1 +/- 31 and 64.8 +/- 11.5 torr while breathing oxygen. VA/Q distributions were broad and right-to-left shunt averaged 21% while breathing air and 27% while breathing oxygen. Gas exchange was significantly impaired due to the presence of both shunt and VA/Q heterogeneity. The walls of the lung enclose a large axial air chamber. Microscopic examination revealed approximately three generations of septa which subdivided the wall into tubular-shaped gas-exchange chambers. Wall thickness averages 2.8 mm at the anterior end of the lung, 2.1 mm in the middle portion of the lung and 1.4 mm at the posterior end. The thickness of the blood-air barrier (epithelial-basal lamina-endothelial cell layer) ranged from 0.35 to 0.90 micron. Although this barrier is slightly thicker than in the mammalian lung (0.1-0.5 micron), it is unlikely to be a source of diffusion limitation in gas exchange at rest.

[Malfunction simulation by spaceflight training simulator].

PubMed

Chang, Tian-chun; Zhang, Lian-hua; Xue, Liang; Lian, Shun-guo

2005-04-01

To implement malfunction simulation in spaceflight training simulator. The principle of malfunction simulation was defined according to spacecraft malfunction predict and its countermeasures. The malfunction patterns were classified, and malfunction type was confirmed. A malfunction simulation model was established, and the malfunction simulation was realized by math simulation. According to the requirement of astronaut training, a spacecraft subsystem malfunction simulation model was established and realized, such as environment control and life support, GNC, push, power supply, heat control, data management, measure control and communication, structure and so on. The malfunction simulation function implemented in the spaceflight training simulator satisfied the requirements for astronaut training.

Programming jammed Codman Hakim programmable valves: study of an explanted valve and successful programming in a patient.

PubMed

Wong, Sui-To; Wen, Eleanor; Fong, Dawson

2013-08-01

Malfunction of a Codman Hakim programmable valve due to jamming of its programmable component may necessitate shunt revision. The authors report a method for programming jammed Codman Hakim programmable valves by using a Strata II magnet and additional neodymium magnets. The programming method was derived after studying a jammed valve in the laboratory that was explanted from an 10-year-old boy with a history of fourth ventricle ependymoma. Programming the explanted valve with a Codman programmer failed, but rotating a Strata II magnet above the valve resulted in rotation of the spiral cam in the valve. It was found that the Strata II magnet could be used to program the jammed valve by rotating the magnet 90° or multiples of 90° above the valve. The strength of the magnetic field of the Strata II magnet was able to be increased by putting neodymium magnets on it. The programming method was then successfully used in a patient with a jammed Codman Hakim programmable valve. After successful programming using this method, clinical and radiological follow-up of the patient was advised.

Ten years of clinical experience in the use of fixed-pressure versus programmable valves: a retrospective study of 159 patients.

PubMed

Mpakopoulou, Maria; Brotis, Alexandros G; Gatos, Haralampos; Paterakis, Konstantinos; Fountas, Kostas N

2012-01-01

The aim of this study was to present our 10-year experience with the use of fixed-pressure and programmable valves in the treatment of adult patients requiring cerebrospinal fluid (CSF) diversion. Patients (n = 159; 89 male and 70 female) suffering from hydrocephalus of various causes underwent CSF shunt implantation. Forty fixed-pressure and 119 programmable valves were initially implanted. The observed revision rate was 40% in patients with fixed-pressure valves. In 20% of these patients, a revision due to valve mechanism malfunction was undertaken, and the initial valve was replaced with a programmable one. The revision rate in the adjustable-pressure valve subgroup was 20%. The infection rate for the fixed-pressure and programmable valve subgroups were 3%, and 1.7%, respectively. Similarly, subdural fluid collections were noticed in 17% and 4% of patients with fixed-pressure valves and programmable valves, respectively. The revision and over-drainage rates were significantly lower when using programmable valves, and thus, this type of valve is preferred whenever CSF has to be diverted.

Priapism - etiology, pathophysiology and management.

PubMed

Van der Horst, C; Stuebinger, Henrik; Seif, Christoph; Melchior, Diethild; Martínez-Portillo, F J; Juenemann, K P

2003-01-01

The understanding of erectile physiology has improved the prompt diagnosis and treatment of priapism. Priapism is defined as prolonged and persistent erection of the penis without sexual stimulation and failure to subside despite orgasm. Numerous etiologies of this condition are considered. Among others a disturbed detumescence mechanism, which may due to excess release of contractile neurotransmitters, obstruction of draining venules, malfunction of the intrinsic detumescence mechanism or prolonged relaxation of intracavernosal smooth muscle are postulated. Treatment of priapism varies from a conservative medical to a drastic surgical approach. Two main types of priapism; veno-occlusive low flow (ischemic) and arterial high flow (non-ischemic), must be distinguished to choose the correct treatment option for each type. Patient history, physical examination, penile hemodynamics and corporeal metabolic blood quality provides distinction between a static or dynamic pathology. Priapism can be treated effectively with intracavernous vasoconstrictive agents or surgical shunting. Alternative options, such as intracavernous injection of methylene blue (MB) or selective penile arterial embolization (SPEA), for the management of high and low flow priapism are described and a survey on current treatment modalities is given.

Analysis of clinical decision support system malfunctions: a case series and survey

PubMed Central

Wright, Adam; Hickman, Thu-Trang T; McEvoy, Dustin; Aaron, Skye; Ai, Angela; Andersen, Jan Marie; Hussain, Salman; Ramoni, Rachel; Fiskio, Julie; Sittig, Dean F; Bates, David W

2016-01-01

Objective To illustrate ways in which clinical decision support systems (CDSSs) malfunction and identify patterns of such malfunctions. Materials and Methods We identified and investigated several CDSS malfunctions at Brigham and Women’s Hospital and present them as a case series. We also conducted a preliminary survey of Chief Medical Information Officers to assess the frequency of such malfunctions. Results We identified four CDSS malfunctions at Brigham and Women’s Hospital: (1) an alert for monitoring thyroid function in patients receiving amiodarone stopped working when an internal identifier for amiodarone was changed in another system; (2) an alert for lead screening for children stopped working when the rule was inadvertently edited; (3) a software upgrade of the electronic health record software caused numerous spurious alerts to fire; and (4) a malfunction in an external drug classification system caused an alert to inappropriately suggest antiplatelet drugs, such as aspirin, for patients already taking one. We found that 93% of the Chief Medical Information Officers who responded to our survey had experienced at least one CDSS malfunction, and two-thirds experienced malfunctions at least annually. Discussion CDSS malfunctions are widespread and often persist for long periods. The failure of alerts to fire is particularly difficult to detect. A range of causes, including changes in codes and fields, software upgrades, inadvertent disabling or editing of rules, and malfunctions of external systems commonly contribute to CDSS malfunctions, and current approaches for preventing and detecting such malfunctions are inadequate. Conclusion CDSS malfunctions occur commonly and often go undetected. Better methods are needed to prevent and detect these malfunctions. PMID:27026616

Use of programmable versus nonprogrammable shunts in the management of hydrocephalus secondary to aneurysmal subarachnoid hemorrhage: a retrospective study with cost-benefit analysis.

PubMed

Lee, Lester; King, Nicolas K K; Kumar, Dinesh; Ng, Yew Poh; Rao, Jai; Ng, Huiyu; Lee, Kah Keow; Wang, Ernest; Ng, Ivan

2014-10-01

The choice of programmable or nonprogrammable shunts for the management of hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH) remains undefined. Variable intracranial pressures make optimal management difficult. Programmable shunts have been shown to reduce problems with drainage, but at 3 times the cost of nonprogrammable shunts. All patients who underwent insertion of a ventriculoperitoneal shunt for hydrocephalus after aneurysmal SAH between 2006 and 2012 were included. Patients were divided into those in whom nonprogrammable shunts and those in whom programmable shunts were inserted. The rates of shunt revisions, the reasons for adjustments of shunt settings in patients with programmable devices, and the effectiveness of the adjustments were analyzed. A cost-benefit analysis was also conducted to determine if the overall cost for programmable shunts was more than for nonprogrammable shunts. Ninety-four patients underwent insertion of shunts for hydrocephalus secondary to SAH. In 37 of these patients, nonprogrammable shunts were inserted, whereas in 57 programmable shunts were inserted. Four (7%) of 57 patients with programmable devices underwent shunt revision, whereas 8 (21.6%) of 37 patients with nonprogrammable shunts underwent shunt revision (p = 0.0413), and 4 of these patients had programmable shunts inserted during shunt revision. In 33 of 57 patients with programmable shunts, adjustments were made. The adjustments were for a trial of functional improvement (n = 21), overdrainage (n = 5), underdrainage (n = 6), or overly sunken skull defect (n = 1). Of these 33 patients, 24 showed neurological improvements (p = 0.012). Cost-benefit analysis showed $646.60 savings (US dollars) per patient if programmable shunts were used, because the cost of shunt revision is a lot higher than the cost of the shunt. The rate of shunt revision is lower in patients with programmable devices, and these are therefore more cost-effective. In addition, the shunt adjustments made for patients with programmable devices also resulted in better neurological outcomes.

Analysis of clinical decision support system malfunctions: a case series and survey.

PubMed

Wright, Adam; Hickman, Thu-Trang T; McEvoy, Dustin; Aaron, Skye; Ai, Angela; Andersen, Jan Marie; Hussain, Salman; Ramoni, Rachel; Fiskio, Julie; Sittig, Dean F; Bates, David W

2016-11-01

To illustrate ways in which clinical decision support systems (CDSSs) malfunction and identify patterns of such malfunctions. We identified and investigated several CDSS malfunctions at Brigham and Women's Hospital and present them as a case series. We also conducted a preliminary survey of Chief Medical Information Officers to assess the frequency of such malfunctions. We identified four CDSS malfunctions at Brigham and Women's Hospital: (1) an alert for monitoring thyroid function in patients receiving amiodarone stopped working when an internal identifier for amiodarone was changed in another system; (2) an alert for lead screening for children stopped working when the rule was inadvertently edited; (3) a software upgrade of the electronic health record software caused numerous spurious alerts to fire; and (4) a malfunction in an external drug classification system caused an alert to inappropriately suggest antiplatelet drugs, such as aspirin, for patients already taking one. We found that 93% of the Chief Medical Information Officers who responded to our survey had experienced at least one CDSS malfunction, and two-thirds experienced malfunctions at least annually. CDSS malfunctions are widespread and often persist for long periods. The failure of alerts to fire is particularly difficult to detect. A range of causes, including changes in codes and fields, software upgrades, inadvertent disabling or editing of rules, and malfunctions of external systems commonly contribute to CDSS malfunctions, and current approaches for preventing and detecting such malfunctions are inadequate. CDSS malfunctions occur commonly and often go undetected. Better methods are needed to prevent and detect these malfunctions. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association.

Minilaparotomy salvage of malfunctioning catheters in peritoneal dialysis.

PubMed

Li, Jian-Ri; Cheng, Chi-Hung; Chiu, Kun-Yuan; Cheng, Chen-Li; Yang, Chi-Rei; Ho, Hao-Chung; Ko, Jiunn-Liang; Ou, Yen-Chuan

2013-01-01

Catheter malfunction is a common and significant complication during peritoneal dialysis (PD). We developed a minilaparotomy procedure to rescue malfunctioning catheters and to prevent recurrence of malfunction. From 2006 to 2011, 11 patients receiving PD had a malfunctioning catheter. In all patients, a 2-cm incision, 5 cm caudally to the previous peritoneal entry site was used to correct the malfunctioning catheter, with concomitant fixation of the catheter to the peritoneum. Catheter tip migration occurred in 7 patients, omental wrapping in 3, and blood clot obstruction in 1. The mean onset time to catheter malfunction was 197.5 days (range: 4 - 1270 days), and the mean operating time was 41 minutes (range: 35 - 56 minutes). There was no recurrence of catheter malfunction and no surgery-related peritonitis. Our minilaparotomy procedure is safe and feasible for the salvage of malfunctioning PD catheters.

A computational fluid dynamics simulation framework for ventricular catheter design optimization.

PubMed

Weisenberg, Sofy H; TerMaath, Stephanie C; Barbier, Charlotte N; Hill, Judith C; Killeffer, James A

2017-11-10

OBJECTIVE Cerebrospinal fluid (CSF) shunts are the primary treatment for patients suffering from hydrocephalus. While proven effective in symptom relief, these shunt systems are plagued by high failure rates and often require repeated revision surgeries to replace malfunctioning components. One of the leading causes of CSF shunt failure is obstruction of the ventricular catheter by aggregations of cells, proteins, blood clots, or fronds of choroid plexus that occlude the catheter's small inlet holes or even the full internal catheter lumen. Such obstructions can disrupt CSF diversion out of the ventricular system or impede it entirely. Previous studies have suggested that altering the catheter's fluid dynamics may help to reduce the likelihood of complete ventricular catheter failure caused by obstruction. However, systematic correlation between a ventricular catheter's design parameters and its performance, specifically its likelihood to become occluded, still remains unknown. Therefore, an automated, open-source computational fluid dynamics (CFD) simulation framework was developed for use in the medical community to determine optimized ventricular catheter designs and to rapidly explore parameter influence for a given flow objective. METHODS The computational framework was developed by coupling a 3D CFD solver and an iterative optimization algorithm and was implemented in a high-performance computing environment. The capabilities of the framework were demonstrated by computing an optimized ventricular catheter design that provides uniform flow rates through the catheter's inlet holes, a common design objective in the literature. The baseline computational model was validated using 3D nuclear imaging to provide flow velocities at the inlet holes and through the catheter. RESULTS The optimized catheter design achieved through use of the automated simulation framework improved significantly on previous attempts to reach a uniform inlet flow rate distribution using the standard catheter hole configuration as a baseline. While the standard ventricular catheter design featuring uniform inlet hole diameters and hole spacing has a standard deviation of 14.27% for the inlet flow rates, the optimized design has a standard deviation of 0.30%. CONCLUSIONS This customizable framework, paired with high-performance computing, provides a rapid method of design testing to solve complex flow problems. While a relatively simplified ventricular catheter model was used to demonstrate the framework, the computational approach is applicable to any baseline catheter model, and it is easily adapted to optimize catheters for the unique needs of different patients as well as for other fluid-based medical devices.

Congenital portosystemic shunts with and without gastrointestinal bleeding - case series.

PubMed

Gong, Ying; Zhu, Hui; Chen, Jun; Chen, Qi; Ji, Min; Pa, Mier; Zheng, Shan; Qiao, Zhongwei

2015-12-01

The clinical presentation of congenital portosystemic shunt is variable and gastrointestinal bleeding is an uncommon presentation. To describe the imaging features of congenital portosystemic shunt as it presented in 11 children with (n = 6) and without gastrointestinal bleeding (n = 5). We performed a retrospective study on a clinical and imaging dataset of 11 children diagnosed with congenital portosystemic shunt. A total of 11 children with congenital portosystemic shunt were included in this study, 7 with extrahepatic portosystemic shunts and 4 with intrahepatic portosystemic shunts. Six patients with gastrointestinal bleeding had an extrahepatic portosystemic shunt, and the imaging results showed that the shunts originated from the splenomesenteric junction (n = 5) or splenic vein (n = 1) and connected to the internal iliac vein. Among the five cases of congenital portosystemic shunt without gastrointestinal bleeding, one case was an extrahepatic portosystemic shunt and the other four were intrahepatic portosystemic shunts. Most congenital portosystemic shunt patients with gastrointestinal bleeding had a shunt that drained portal blood into the iliac vein via an inferior mesenteric vein. This type of shunt was uncommon, but the concomitant rate of gastrointestinal bleeding with this type of shunt was high.

14 CFR 417.209 - Malfunction turn analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

14 CFR 417.209 - Malfunction turn analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

14 CFR 417.209 - Malfunction turn analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

... turn behavior for each cause of a malfunction turn. For each malfunction turn envelope, the analysis... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Malfunction turn analysis. 417.209 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.209 Malfunction turn...

Cerebrospinal Fluid Shunting Complications in Children

PubMed Central

Hanak, Brian W.; Bonow, Robert H.; Harris, Carolyn A.; Browd, Samuel R.

2018-01-01

Although cerebrospinal fluid (CSF) shunt placement is the most common procedure performed by pediatric neurosurgeons, shunts remain among the most failure-prone life-sustaining medical devices implanted in modern medical practice. This article provides an overview of the mechanisms of CSF shunt failure for the 3 most commonly employed definitive CSF shunts in the practice of pediatric neurosurgery: ventriculoperitoneal, ventriculopleural, and ventriculoatrial. The text has been partitioned into the broad modes of shunt failure: obstruction, infection, mechanical shunt failure, overdrainage, and distal catheter site-specific failures. Clinical management strategies for the various modes of shunt failure are discussed as are research efforts directed towards reducing shunt complication rates. As it is unlikely that CSF shunting will become an obsolete procedure in the foreseeable future, it is incumbent on the pediatric neurosurgery community to maintain focused efforts to improve our understanding of and management strategies for shunt failure and shunt-related morbidity. PMID:28249297

Ultrasound guided placement of the distal catheter in paediatric ventriculoatrial shunts-an appraisal of efficacy and complications.

PubMed

Clark, David J; Chakraborty, Aabir; Roebuck, Derek J; Thompson, Dominic N P

2016-07-01

Ventriculoatrial (VA) shunts are commonly used as a second-line treatment of hydrocephalus when the peritoneum is an unsuitable site for the distal catheter. Many centres now utilise ultrasound and interventional radiology techniques to aid placement of the distal catheter. The purpose of this study was to conduct a contemporary audit of VA shunting in children using interventional radiology techniques for placement of the distal catheter. A retrospective analysis of all patients who had VA shunts inserted between June 2000 and June 2010 was conducted using a prospectively updated surgical database and case notes review. Ninety-four VA shunts were inserted in 38 patients. Thirty-seven patients had been treated initially with ventriculoperitoneal (VP) shunts. Twenty-two patients required at least 1 shunt revision (58 %). The 6-month, 1- and 2-year shunt survival rates were 53, 43 and 27 %, respectively. Blockage was the commonest reason for shunt failure (68 %). The site of failure was proximal (ventricular catheter +/- valve) in 32 % and distal (atrial catheter) in 21 % of cases. The overall infection rate was 6 % per procedure and 11 % per patient. There were 7 deaths, of which 3 were shunt related. VA shunting provides a viable second-line option for shunt placement in complex hydrocephalus. The causes of shunt failure (blockage, infection and equipment failure) are similar to VP shunting though shunt survival rates are inferior to VP shunts. Ultrasound guided VA shunt placement provides a relatively safe, second-line alternative to the placement of a ventriculoperitoneal shunt when this route is unsuitable.

Outcomes of systemic to pulmonary artery shunts in patients weighing less than 3 kg: analysis of shunt type, size, and surgical approach.

PubMed

Myers, John W; Ghanayem, Nancy S; Cao, Yumei; Simpson, Pippa; Trapp, Katie; Mitchell, Michael E; Tweddell, James S; Woods, Ronald K

2014-02-01

To evaluate outcomes of systemic to pulmonary artery shunts (SPS) in patients weighing less than 3 kg with regard to shunt type, shunt size, and surgical approach. Patients weighing less than 3 kg who underwent modified Blalock-Taussig or central shunts with polytetrafluoroethylene grafts at our institution from January 1, 2000, to May 31, 2011, were reviewed. Patients who had undergone other major concomitant procedures were excluded from the analysis. Primary outcomes included mortality (discharge mortality and mortality before next planned palliative procedure or definitive repair), cardiac arrest and/or extracorporeal membrane oxygenation (ECMO), and shunt reintervention. In this cohort of 80 patients, discharge survival was 96% (77/80). Postoperative cardiac arrest or ECMO occurred in 6/80 (7.5%), and shunt reintervention was required in 14/80 (17%). On univariate analysis, shunt reintervention was more common in patients with 3-mm shunts (11/30, 37%) compared with 3.5-mm (2/36, 6%) or 4-mm shunts (1/14, 7%) (P < .003). There were no statistically significant associations between shunt type, shunt size, or surgical approach and cardiac arrest/ECMO or mortality. Multiple logistic regression demonstrated that a shunt size of 3 mm (P = .019) and extracardiac anomaly (P = .047) were associated with shunt reintervention, whereas no variable was associated with cardiac arrest/ECMO or mortality. In this high-risk group of neonates weighing less than 3 kg at the time of SPS, survival to discharge and the next planned surgical procedure was high. Outcomes were good with the 3.5- and 4-mm shunts; however, shunt reintervention was common with 3-mm shunts. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

What ASRS incident data tell about flight crew performance during aircraft malfunctions

NASA Technical Reports Server (NTRS)

Sumwalt, Robert L.; Watson, Alan W.

1995-01-01

This research examined 230 reports in NASA's Aviation Safety Reporting System's (ASRS) database to develop a better understanding of factors that can affect flight crew performance when crew are faced with inflight aircraft malfunctions. Each report was placed into one of two categories, based on severity of the malfunction. Report analysis was then conducted to extract information regarding crew procedural issues, crew communications and situational awareness. A comparison of these crew factors across malfunction type was then performed. This comparison revealed a significant difference in ways that crews dealt with serious malfunctions compared to less serious malfunctions. The authors offer recommendations toward improving crew performance when faced with inflight aircraft malfunctions.

Clinical features of congenital portosystemic shunt in children.

PubMed

Kim, Myung Jin; Ko, Jae Sung; Seo, Jeong Kee; Yang, Hye Ran; Chang, Ju Young; Kim, Gi Beom; Cheon, Jung-Eun; Kim, Woo Sun

2012-02-01

Clinical features, images, complications, treatments, and prognosis of 10 children with congenital portosystemic shunt (CPSS) were reviewed. Nine children were diagnosed with intrahepatic shunts while one presented with extrahepatic shunt. CPSS was detected by prenatal ultrasonography in four infants. Three infants presented with galactosemia without an enzyme deficiency. Two children presented with mental retardation and attention deficit hyperactivity disorder. Pulmonary hypertension developed in two patients. Spontaneous closure occurred in four infants with intrahepatic shunts including patent ductus venosus. The shunts were closed using transcatheter embolizations in four patients with intrahepatic shunts. Intrahepatic shunts may close spontaneously. Transcatheter embolization is effective for the treatment of symptomatic intrahepatic shunts.

A prospective study of basal insulin concentrations in dogs with congenital portosystemic shunts.

PubMed

Collings, A J; Gow, A G; Marques, A; Yool, D; Furneaux, R; Mellanby, R; Watson, P J

2012-04-01

Hypoglycaemia is a common cause of morbidity in dogs with congenital portosystemic shunts but the aetiology is unknown. The hypothesis of this study was that dogs with congenital portosystemic shunts would have significantly higher insulin concentrations than dogs without congenital portosystemic shunts. The main objective of the study was to compare peripheral glucose and insulin concentrations between dogs with congenital portosystemic shunts and dogs without congenital portosystemic shunts. Peripheral serum insulin and plasma glucose concentrations were measured in dogs with congenital portosystemic shunts and without congenital portosystemic shunts and compared both between groups as well as to reference intervals derived from healthy dogs. Congenital portosystemic shunts were diagnosed in 41 dogs. Forty-eight dogs hospitalised with other conditions acted as controls. Serum insulin concentrations were mildly elevated (Ä40 μU/mL) in seven dogs and were markedly elevated in two dogs with congenital portosystemic shunts, yet mild hypoglycaemia (3·3 mmol/L) was detected in only one of these dogs. Four dogs with congenital portosystemic shunts showed fasting hypoglycaemia, yet insulin concentrations were within or below the reference interval in three. There was no difference between the median insulin concentration of dogs with congenital portosystemic shunts and without congenital portosystemic shunts. Hyperinsulinaemia is infrequently observed in dogs with congenital portosystemic shunts. The aetiology of hypoglycaemia in dogs with congenital portosystemic shunts merits further investigation. © 2012 British Small Animal Veterinary Association.

Free energy landscape remodeling of the cardiac pacemaker channel explains the molecular basis of familial sinus bradycardia

PubMed Central

Boulton, Stephen; Akimoto, Madoka; Akbarizadeh, Sam; Melacini, Giuseppe

2017-01-01

The hyperpolarization-activated and cyclic nucleotide-modulated ion channel (HCN) drives the pacemaker activity in the heart, and its malfunction can result in heart disorders. One such disorder, familial sinus bradycardia, is caused by the S672R mutation in HCN, whose electrophysiological phenotypes include a negative shift in the channel activation voltage and an accelerated HCN deactivation. The outcomes of these changes are abnormally low resting heart rates. However, the molecular mechanism underlying these electrophysiological changes is currently not fully understood. Crystallographic investigations indicate that the S672R mutation causes limited changes in the structure of the HCN intracellular gating tetramer, but its effects on protein dynamics are unknown. Here, we utilize comparative S672R versus WT NMR analyses to show that the S672R mutation results in extensive perturbations of the dynamics in both apo- and holo-forms of the HCN4 isoform, reflecting how S672R remodels the free energy landscape for the modulation of HCN4 by cAMP, i.e. the primary cyclic nucleotide modulator of HCN channels. We show that the S672R mutation results in a constitutive shift of the dynamic auto-inhibitory equilibrium toward inactive states of HCN4 and broadens the free-energy well of the apo-form, enhancing the millisecond to microsecond dynamics of the holo-form at sites critical for gating cAMP binding. These S672R-induced variations in dynamics provide a molecular basis for the electrophysiological phenotypes of this mutation and demonstrate that the pathogenic effects of the S672R mutation can be rationalized primarily in terms of modulations of protein dynamics. PMID:28174302

Role of MRI in Diagnosis of Ruptured Intracranial Dermoid Cyst

PubMed Central

Muçaj, Sefedin; Ugurel, Mehmet Sahin; Dedushi, Kreshnike; Ramadani, Naser; Jerliu, Naim

2017-01-01

Introduction: Intracranial dermoid cystic tumors account for <1% of all intracranial masses. Case report: A 52-year-old male, having headaches, nausea and is presented with a history of 2 episodes of new onset seizures. On presentation, the patient had a normal physical exam, including a complete neurological and cranial nerve exam. Methods: Precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D – HI-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W, Flash/T2W oblique coronal plane, GRE/T2W axial. Post-contrast TSE/T1W sequence in axial, coronal and sagittal planes. Diffusion weighted and ADC mapping, postcontrast: TSE/T1W sequence in axial, coronal and sagittal planes. Results: Subsequent MRI of the brain revealed an oval and lobulated 47x34x30mm (TRxAPxCC) non-enhancing T1-hyperintense mass in right cavernous sinus, with compression of surrounding mesial temporal lobe and right anterolateral aspect of mesencephalon. Findings are consistent with ruptured dermoid cyst, given the evacuated sebum content at its lower half. Sebum particles in millimetric sizes are seen within right Sylvian fissure, anterior horns of lateral ventricles and to a lesser extent within left Sylvian fissure, right parietal sulci, cerebral aqueduct, and basal cisterns. No restricted diffusion is seen, eliminating the possibility of epidermoid. A shunt catheter is evident traversing between right lateral ventricle and right parietal bone; besides, slit-like right lateral ventricle is noted (likely secondary to over-draining shunt catheter). Conclusion: Intracranial dermoid cysts are benign rare slow-growing tumors that upon rupture, however, widespread presence of T1 hyperintense droplets and leptomeningeal enhancement can be noted–making MRI the best imaging modality for diagnosis of this rare entity. PMID:28883682

Role of MRI in Diagnosis of Ruptured Intracranial Dermoid Cyst.

PubMed

Muçaj, Sefedin; Ugurel, Mehmet Sahin; Dedushi, Kreshnike; Ramadani, Naser; Jerliu, Naim

2017-06-01

Intracranial dermoid cystic tumors account for <1% of all intracranial masses. A 52-year-old male, having headaches, nausea and is presented with a history of 2 episodes of new onset seizures. On presentation, the patient had a normal physical exam, including a complete neurological and cranial nerve exam. Precontrast MRI; TSE/T2Wsequence in axial/coronal planes; 3D - HI-resolution T1W sagittal; FLAIR/T2W axial; FLAIR/T2W, Flash/T2W oblique coronal plane, GRE/T2W axial. Post-contrast TSE/T1W sequence in axial, coronal and sagittal planes. Diffusion weighted and ADC mapping, postcontrast: TSE/T1W sequence in axial, coronal and sagittal planes. Subsequent MRI of the brain revealed an oval and lobulated 47x34x30mm (TRxAPxCC) non-enhancing T1-hyperintense mass in right cavernous sinus, with compression of surrounding mesial temporal lobe and right anterolateral aspect of mesencephalon. Findings are consistent with ruptured dermoid cyst, given the evacuated sebum content at its lower half. Sebum particles in millimetric sizes are seen within right Sylvian fissure, anterior horns of lateral ventricles and to a lesser extent within left Sylvian fissure, right parietal sulci, cerebral aqueduct, and basal cisterns. No restricted diffusion is seen, eliminating the possibility of epidermoid. A shunt catheter is evident traversing between right lateral ventricle and right parietal bone; besides, slit-like right lateral ventricle is noted (likely secondary to over-draining shunt catheter). Intracranial dermoid cysts are benign rare slow-growing tumors that upon rupture, however, widespread presence of T1 hyperintense droplets and leptomeningeal enhancement can be noted-making MRI the best imaging modality for diagnosis of this rare entity.

Ventriculoperitoneal shunt - discharge

MedlinePlus

... ventriculoperitoneal - discharge; VP shunt - discharge; Shunt revision - discharge; Hydrocephalus shunt placement - discharge ... Your child has hydrocephalus and needed a shunt placed to drain excess fluid and relieve pressure in the brain. This buildup of brain ...

Should ventriculoatrial shunting be the procedure of choice for normal-pressure hydrocephalus?

PubMed

McGovern, Robert A; Kelly, Kathleen M; Chan, Andrew K; Morrissey, Nicholas J; McKhann, Guy M

2014-06-01

Ventriculoatrial (VA) shunting is rarely used for patients with normal-pressure hydrocephalus (NPH), likely due to surgeon technical preference and case reports indicating cardiopulmonary complications. However, these complications have typically been limited to adults in whom VA shunts had been placed when they were children. Few studies have directly compared VA shunting to ventriculoperitoneal (VP) shunting in cases of NPH. The authors retrospectively analyzed all NPH patients treated by a single surgeon at their center from January 2002 through December 2011. Thirty patients were treated with VA shunts (14 male) and 157 with VP shunts (86 male). The patients' mean age (± SD) at surgery was 73.7 ± 9.4 years for VA shunting and 76.0 ± 8.2 years for VP shunting; the median durations of follow-up were 42.0 months (IQR 19.2-63.6 months) and 34.2 months (IQR 15.8-67.5), respectively. Statistical analysis was performed using chi-square tests and Wilcoxon rank-sum tests. Perioperative and postoperative complications for VA and VP shunting cohorts, respectively, included distal revision (2.7% vs 6.6%, p = 0.45), proximal revision (2.7% vs 2.5%, p = 0.97), and postoperative seizure (2.7% vs 1.5%, p = 0.62). Shunt drainage-related subdural hematomas/hygromas developed in 8.1%/27.0% of VA shunt-treated patients versus 6.6%/26.4% of VP shunt-treated patients (p = 0.76/0.98) and were nearly always successfully managed with programmable-valve adjustment. Symptomatic intracerebral hemorrhage (1.5%) and shunt infection (2.0%) were only observed in those who underwent VP shunting. Of note, no cardiovascular complications were observed in any patient, and there were no cases of distal occlusion of the VA shunt. The authors found no significant differences in complication rates between VA and VP shunting, and VA shunting was not associated with any cardiopulmonary complications. Thus, in the authors' experience, VA shunting is at least as safe as VP shunting for treating NPH.

Temporary arterial shunts to maintain limb perfusion after arterial injury: an animal study

NASA Technical Reports Server (NTRS)

Dawson, D. L.; Putnam, A. T.; Light, J. T.; Ihnat, D. M.; Kissinger, D. P.; Rasmussen, T. E.; Bradley, D. V. Jr

1999-01-01

BACKGROUND: Temporary shunt placement can quickly restore perfusion after extremity arterial injury. This study examined the adequacy of limb blood flow with shunt use, non-heparin-bonded shunt patency over prolonged periods, and the safety of this technique. METHODS: Common iliac arteries were divided and 4.0-mm Silastic Sundt shunts placed in 16 anesthetized pigs. Eight (group I) had shunts placed immediately; eight others (group II) were shunted after an hour of limb ischemia and hemorrhagic shock. Physiologic parameters and femoral artery blood flow in both hindlimbs were continuously monitored. Limb lactic acid generation, oxygen utilization, and hematologic and metabolic effects were serially evaluated for 24 hours. RESULTS: Shunts remained patent in 13 of 16 pigs. Shunts thrombosed in two group I animals because of technical errors, but functioned well after thrombectomy and repositioning. Patency could not be maintained in one animal that died from shock. Flow in group I shunted limbs was 57 (+/-11 SD) % of control. For group II animals in shock, shunted limb flow initially averaged 46 +/- 15% of control, but 4 hours after shunt placement, the mean limb blood flow was the same as in group I. Increased oxygen extraction compensated for the lower flow. Lactic acid production was not increased in comparison to control limbs. CONCLUSION: Shunts provided adequate flow in this model of extremity trauma. Correctly placed shunts stayed patent for 24 hours, without anticoagulation, if shunt placement followed resuscitation.

Morphology of congenital portosystemic shunts emanating from the left gastric vein in dogs and cats.

PubMed

White, R N; Parry, A T

2013-09-01

To describe the anatomy of congenital portosystemic shunts emanating from the left gastric vein in dogs and cats. A retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. Forty-six dogs and 27 cats met the inclusion criteria of a congenital portosystemic shunt emanating from the left gastric vein. Of the 46 dogs, 28 (61%) had a shunt that entered the left phrenic vein, 10 (22%) had a shunt that entered the post hepatic caudal vena cava and in 8 (17%) the shunt entered the azygos vein. Of the 27 cats, 19 (70%) had a shunt that entered the left phrenic vein and 8 (30%) had a shunt that entered the post hepatic caudal vena cava. The systemic vein into which the shunt entered was consistent showing three common presentations: left gastro-phrenic, left gastro-caval and left gastro-azygos. This information may help with surgical planning in cases undergoing shunt closure surgery. © 2013 British Small Animal Veterinary Association.

Do antibiotic-impregnated shunts in hydrocephalus therapy reduce the risk of infection? An observational study in 258 patients

PubMed Central

Ritz, Rainer; Roser, Florian; Morgalla, Matthias; Dietz, Klaus; Tatagiba, Marcos; Will, Bernd E

2007-01-01

Background Shunt infection in hydrocephalus patients is a severe, even life-threatening complication. Antibiotic-impregnated shunts (AIS) have been developed in an attempt to reduce rate of shunt infection. The study was performed to analyze if AIS can diminish the rate of shunt infection. The pathogenic nature of shunt infection in patients with AIS systems and those without antibiotic impregnated shunts (non-AIS) was compared. Methods Over a period of 24 months in the Department of Neurosurgery at University Hospital of Tübingen shunt surgery was performed in 258 patients. In 86 patients AIS systems were implanted. Shunt catheters were commercially impregnated with clindamycin and rifampicin. Analysis of the clinical data included sex, age, classification of hydrocephalus, shunt types and risk factors for shunt infection [age (< 1 year and > 80 years), prematurely born patients, external ventricular drainage, former shunt infection, former systemic infection, disturbance of consciousness, former radiation-/chemotherapy]. Infection rates and underlying bacterial pathogens of patients with AIS were compared to patients with implanted non-AIS systems (172 patients). Results AIS and non-AIS patients did not differ in sex, etiology of hydrocephalus and the shunt type. In the AIS group 72 out of 86 patients had at least one risk factor (83.7 %), compared to 126 patients in the non-AIS group (73.3 %). There was no significant difference between the two groups (p = 0.0629; Fisher's exact test). In patients with no risk factors, only one patient with non-AIS suffered from shunt infection. In patients with one or more risk factors the rate for shunt infection was 7.14 % in patients with non-AIS and 6.94 % in patients with AIS. Former shunt infection (p = 0.0124) was related to higher risk for shunt infection. The use of AIS had therefore no significant advantage (p = 0.8611; multiple logistic regression). Significantly related to a shunt infection was the number of shunt surgeries. 190 interventions in the AIS group (2.21 interventions per patient) and 408 in the non-AIS group (2.37 interventions per patient) had been performed (p = 0.3063; Wilcoxon). There was no shunt infection in the group of patients on whom only one shunt surgery was performed. In patients with at least two shunt surgeries the infection rate was 9%. The infection rate in AIS patients was 5/52 (9.6 %) and in the non-AIS 10/114 (8.77 %), (p = 1.0; Fisher's exact test). Staphylococcus epidermidis was the most frequent pathogen for shunt infection. Fourteen out of 15 infections occurred within the first 6 months of surgery. The most frequent pathogen for shunt infection was S. epidermidis. No toxic or allergic complications were seen using the AIS shunt systems. The presented data show a remarkably low infection rate of 5.8 % in the non-AIS group compared to other studies which demonstrated a significant decrease in the infection rate by AIS. Conclusion AIS did not significantly reduce shunt infection in hydrocephalus patients in the presented study. In the AIS group three patients suffered from shunt infections caused by skin ulceration or neurosurgical procedures with exposure of the cerebrospinal liquor after shunt implantation. AIS was not developed to prevent infection in such cases, therefore an advantage of AIS can not be excluded. In view of the presented data and the small number of reported studies a prospective randomized multicenter study is required. PMID:17488498

Superconducting fault current-limiter with variable shunt impedance

DOEpatents

Llambes, Juan Carlos H; Xiong, Xuming

2013-11-19

A superconducting fault current-limiter is provided, including a superconducting element configured to resistively or inductively limit a fault current, and one or more variable-impedance shunts electrically coupled in parallel with the superconducting element. The variable-impedance shunt(s) is configured to present a first impedance during a superconducting state of the superconducting element and a second impedance during a normal resistive state of the superconducting element. The superconducting element transitions from the superconducting state to the normal resistive state responsive to the fault current, and responsive thereto, the variable-impedance shunt(s) transitions from the first to the second impedance. The second impedance of the variable-impedance shunt(s) is a lower impedance than the first impedance, which facilitates current flow through the variable-impedance shunt(s) during a recovery transition of the superconducting element from the normal resistive state to the superconducting state, and thus, facilitates recovery of the superconducting element under load.

40 CFR 63.1111 - Startup, shutdown, and malfunction.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 11 2013-07-01 2013-07-01 false Startup, shutdown, and malfunction. 63... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown, and... develop a written startup, shutdown, and malfunction plan that describes, in detail, procedures for...

40 CFR 63.1111 - Startup, shutdown, and malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Startup, shutdown, and malfunction. 63... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown, and... develop a written startup, shutdown, and malfunction plan that describes, in detail, procedures for...

40 CFR 63.1111 - Startup, shutdown, and malfunction.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 11 2012-07-01 2012-07-01 false Startup, shutdown, and malfunction. 63... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown, and... develop a written startup, shutdown, and malfunction plan that describes, in detail, procedures for...

40 CFR 63.1111 - Startup, shutdown, and malfunction.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 10 2011-07-01 2011-07-01 false Startup, shutdown, and malfunction. 63... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown, and... develop a written startup, shutdown, and malfunction plan that describes, in detail, procedures for...

The clinical anatomy of congenital portosystemic venous shunts.

PubMed

Stringer, Mark D

2008-03-01

Congenital portosystemic venous shunts are rare. Their gross anatomy has not been well defined. Four different varieties of congenital portosystemic venous shunts are described in six children seen during a 10-year period, focusing on the anatomy of the shunt as determined by imaging studies and surgery. A detailed review of the literature indicates that congenital portosystemic venous shunts are best classified as: extrahepatic or intrahepatic. Extrahepatic shunts may be further subdivided into portocaval shunts (type 1 end-to-side and type 2 side-to-side) and others. Intrahepatic shunts are due to an abnormal intrahepatic connection between the portal vein and hepatic vein/inferior vena cava or a persistent patent ductus venosus. Additional congenital anomalies, particularly cardiac malformations, may be associated with any type. Some congenital intrahepatic portosystemic venous shunts close spontaneously in infancy; all other congenital portosystemic venous shunts tend to remain patent. To a variable extent, depending largely on the volume and duration of the shunt, affected individuals are at risk of developing hepatic encephalopathy and/or an intrahepatic tumor. The key to understanding the pathogenesis of these shunts lies in the normal developmental mechanisms underlying the formation of the portal vein and inferior vena cava in the embryo. Copyright 2008 Wiley-Liss, Inc.

Critical care nurses' experiences when technology malfunctions.

PubMed

Haghenbeck, Karen Toby

2005-01-01

When caring for critically ill patients, critical care nurses work with technology every day. Technology and equipment malfunctions can have a profound effect on nurses' practice and self-image. In this article, a descriptive phenomenological methodology was chosen to explicate the experience of seven critical care nurses. While participants realized that machines might malfunction, they experienced surprise, shock, and feelings of being "let down" and inadequate when malfunctions occurred. They questioned their competence and felt malfunctioning technology jeopardized their credibility and professional image. These findings are useful when structuring educational sessions on technology and in facilitating a supportive environment for critical care nurses when technology malfunctions.

Risk factors and possible mechanisms of superior vena cava intravenous port malfunction.

PubMed

Wu, Ching-Yang; Hu, Han-Chung; Ko, Po-Jen; Fu, Jui-Ying; Wu, Ching-Feng; Liu, Yun-Hen; Li, Hao-Jui; Kao, Tsung-Chi; Kao, Kuo-Chin; Yu, Sheng-Yueh; Chang, Chee-Jen; Hsieh, Hong-Chang

2012-05-01

To identify the risk factors leading to catheter malfunction. Reliable venous access is crucial for cancer patients. Malfunction of intravenous ports may lead to discontinuation of treatment and repeated interventions. We retrospectively reviewed the independent risk factors for catheter malfunction among patients receiving intravenous port implantations. A total of 1508 procedures were included from the calendar year 2006, and clinical data and chest plain films were analyzed. The patients were followed-up until June 30, 2010. For patients still alive, the last outpatient follow-up date was considered as the end point. For the remaining patients, the date of death or discharge against advice was considered as the end points. The risk factors for catheter malfunction were then evaluated. The intervention-free periods of the malfunction group and nonmalfunction group were 317 and 413 days, respectively. Statistical analyses showed that the Nut-Catheter Angle was the only risk factor for catheter malfunction (P = 0.001). A logistic model also confirmed that the Nut-Catheter Angle was the only risk factor for catheter malfunction (P < 0.001). Valve tip catheters were not advantageous with regard to catheter malfunction prevention as compared to open tip catheters. A smaller Nut-Catheter Angle had a greater risk for catheter malfunction. Catheter impingement caused by inadequate pocket creation and port implantation lead to compromised catheter lumen and difficulty flushing. The possibility of retained blood and medications increased thin thrombotic biofilm formation and medication precipitation. Catheter malfunctions can be avoided by using proper surgical techniques and adequate maintenance.

Clinical decision support alert malfunctions: analysis and empirically derived taxonomy.

PubMed

Wright, Adam; Ai, Angela; Ash, Joan; Wiesen, Jane F; Hickman, Thu-Trang T; Aaron, Skye; McEvoy, Dustin; Borkowsky, Shane; Dissanayake, Pavithra I; Embi, Peter; Galanter, William; Harper, Jeremy; Kassakian, Steve Z; Ramoni, Rachel; Schreiber, Richard; Sirajuddin, Anwar; Bates, David W; Sittig, Dean F

2018-05-01

To develop an empirically derived taxonomy of clinical decision support (CDS) alert malfunctions. We identified CDS alert malfunctions using a mix of qualitative and quantitative methods: (1) site visits with interviews of chief medical informatics officers, CDS developers, clinical leaders, and CDS end users; (2) surveys of chief medical informatics officers; (3) analysis of CDS firing rates; and (4) analysis of CDS overrides. We used a multi-round, manual, iterative card sort to develop a multi-axial, empirically derived taxonomy of CDS malfunctions. We analyzed 68 CDS alert malfunction cases from 14 sites across the United States with diverse electronic health record systems. Four primary axes emerged: the cause of the malfunction, its mode of discovery, when it began, and how it affected rule firing. Build errors, conceptualization errors, and the introduction of new concepts or terms were the most frequent causes. User reports were the predominant mode of discovery. Many malfunctions within our database caused rules to fire for patients for whom they should not have (false positives), but the reverse (false negatives) was also common. Across organizations and electronic health record systems, similar malfunction patterns recurred. Challenges included updates to code sets and values, software issues at the time of system upgrades, difficulties with migration of CDS content between computing environments, and the challenge of correctly conceptualizing and building CDS. CDS alert malfunctions are frequent. The empirically derived taxonomy formalizes the common recurring issues that cause these malfunctions, helping CDS developers anticipate and prevent CDS malfunctions before they occur or detect and resolve them expediently.

Rate of shunt revision as a function of age in patients with shunted hydrocephalus due to myelomeningocele.

PubMed

Dupepe, Esther B; Hopson, Betsy; Johnston, James M; Rozzelle, Curtis J; Jerry Oakes, W; Blount, Jeffrey P; Rocque, Brandon G

2016-11-01

OBJECTIVE It is generally accepted that cerebrospinal fluid shunts fail most frequently in the first years of life. The purpose of this study was to describe the risk of shunt failure for a given patient age in a well-defined cohort with shunted hydrocephalus due to myelomeningocele (MMC). METHODS The authors analyzed data from their institutional spina bifida research database including all patients with MMC and shunted hydrocephalus. For the entire population, the number of shunt revisions in each year of life was determined. Then the number of patients at risk for shunt revision during each year of life was calculated, thus enabling them to calculate the rate of shunt revision per patient in each year of life. In this way, the timing of all shunt revision operations for the entire clinic population and the likelihood of having a shunt revision during each year of life were calculated. RESULTS A total of 655 patients were enrolled in the spina bifida research database, 519 of whom had a diagnosis of MMC and whose mean age was 17.48 ± 11.7 years (median 16 years, range 0-63 years). Four hundred seventeen patients had had a CSF shunt for the treatment of hydrocephalus and thus are included in this analysis. There were 94 shunt revisions in the 1st year of life, which represents a rate of 0.23 revisions per patient in that year. The rate of shunt revision per patient-year initially decreased as age increased, except for an increase in revision frequency in the early teen years. Shunt revisions continued to occur as late as 43 years of age. CONCLUSIONS These data substantiate the idea that shunt revision surgeries in patients with MMC are most common in the 1st year of life and decrease thereafter, except for an increase in the early teen years. A persistent risk of shunt failure was observed well into adult life. These findings underscore the importance of routine follow-up of all MMC patients with shunted hydrocephalus and will aid in counseling patients and families.

40 CFR 57.304 - Bypass, excess emissions and malfunctions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... malfunctions. 57.304 Section 57.304 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... limitation, as well as the operating data, documents, and calculations used in determining the magnitude of... malfunction (or an unavoidable start up and shut down resulting from a malfunction) and that: (1) The air...

40 CFR 57.304 - Bypass, excess emissions and malfunctions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... malfunctions. 57.304 Section 57.304 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... limitation, as well as the operating data, documents, and calculations used in determining the magnitude of... malfunction (or an unavoidable start up and shut down resulting from a malfunction) and that: (1) The air...

40 CFR 57.304 - Bypass, excess emissions and malfunctions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... malfunctions. 57.304 Section 57.304 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... limitation, as well as the operating data, documents, and calculations used in determining the magnitude of... malfunction (or an unavoidable start up and shut down resulting from a malfunction) and that: (1) The air...

40 CFR 57.304 - Bypass, excess emissions and malfunctions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... malfunctions. 57.304 Section 57.304 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... limitation, as well as the operating data, documents, and calculations used in determining the magnitude of... malfunction (or an unavoidable start up and shut down resulting from a malfunction) and that: (1) The air...

40 CFR 57.304 - Bypass, excess emissions and malfunctions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... malfunctions. 57.304 Section 57.304 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... limitation, as well as the operating data, documents, and calculations used in determining the magnitude of... malfunction (or an unavoidable start up and shut down resulting from a malfunction) and that: (1) The air...

Individualization and Needed Research.

ERIC Educational Resources Information Center

Ott, Jack M.; And Others

As has been the case in medicine, social work, and psychiatry, progress in education will follow closely the adequacy of our category system concerning pertinent functions of a child, our understanding of these functions, how children fail to function properly (malfunction), causes of malfunction, signs of malfunction, course of malfunction (time,…

40 CFR 63.762 - Startups, shutdowns, and malfunctions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 11 2012-07-01 2012-07-01 false Startups, shutdowns, and malfunctions... Facilities § 63.762 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of non...

40 CFR 63.762 - Startups, shutdowns, and malfunctions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Startups, shutdowns, and malfunctions... Facilities § 63.762 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of non...

40 CFR 63.1272 - Startups, shutdowns, and malfunctions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Startups, shutdowns, and malfunctions... Facilities § 63.1272 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of...

40 CFR 63.1272 - Startups, shutdowns, and malfunctions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Startups, shutdowns, and malfunctions... Facilities § 63.1272 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of...

40 CFR 63.762 - Startups, shutdowns, and malfunctions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 10 2011-07-01 2011-07-01 false Startups, shutdowns, and malfunctions... Facilities § 63.762 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of non...

40 CFR 63.1272 - Startups, shutdowns, and malfunctions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Startups, shutdowns, and malfunctions... Facilities § 63.1272 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of...

14 CFR 417.209 - Malfunction turn analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... nozzle burn-through. For each cause of a malfunction turn, the analysis must establish the launch vehicle... the launch vehicle's turning capability in the event of a malfunction during flight. A malfunction... launch vehicle is capable. (4) The time, as a single value or a probability time distribution, when each...

14 CFR 417.209 - Malfunction turn analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... nozzle burn-through. For each cause of a malfunction turn, the analysis must establish the launch vehicle... the launch vehicle's turning capability in the event of a malfunction during flight. A malfunction... launch vehicle is capable. (4) The time, as a single value or a probability time distribution, when each...

Hepatopulmonary shunting on Tc99m-MAA liver mapping: correlation with dynamic cross-sectional imaging and description of different shunting patterns.

PubMed

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.

Predicting ventriculoperitoneal shunt infection in children with hydrocephalus using artificial neural network.

PubMed

Habibi, Zohreh; Ertiaei, Abolhasan; Nikdad, Mohammad Sadegh; Mirmohseni, Atefeh Sadat; Afarideh, Mohsen; Heidari, Vahid; Saberi, Hooshang; Rezaei, Abdolreza Sheikh; Nejat, Farideh

2016-11-01

The relationships between shunt infection and predictive factors have not been previously investigated using Artificial Neural Network (ANN) model. The aim of this study was to develop an ANN model to predict shunt infection in a group of children with shunted hydrocephalus. Among more than 800 ventriculoperitoneal shunt procedures which had been performed between April 2000 and April 2011, 68 patients with shunt infection and 80 controls that fulfilled a set of meticulous inclusion/exclusion criteria were consecutively enrolled. Univariate analysis was performed for a long list of risk factors, and those with p value < 0.2 were used to create ANN and logistic regression (LR) models. Five variables including birth weight, age at the first shunting, shunt revision, prematurity, and myelomeningocele were significantly associated with shunt infection via univariate analysis, and two other variables (intraventricular hemorrhage and coincided infections) had a p value of less than 0.2. Using these seven input variables, ANN and LR models predicted shunt infection with an accuracy of 83.1 % (AUC; 91.98 %, 95 % CI) and 55.7 % (AUC; 76.5, 95 % CI), respectively. The contribution of the factors in the predictive performance of ANN in descending order was history of shunt revision, low birth weight (under 2000 g), history of prematurity, the age at the first shunt procedure, history of intraventricular hemorrhage, history of myelomeningocele, and coinfection. The findings show that artificial neural networks can predict shunt infection with a high level of accuracy in children with shunted hydrocephalus. Also, the contribution of different risk factors in the prediction of shunt infection can be determined using the trained network.

40 CFR 60.1710 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... during periods of startup, shutdown, and malfunction? 60.1710 Section 60.1710 Protection of Environment... during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or malfunction...

40 CFR 60.1220 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2014 CFR

2014-07-01

... during periods of startup, shutdown, and malfunction? 60.1220 Section 60.1220 Protection of Environment... Emission Limits § 60.1220 What happens to the emission limits during periods of startup, shutdown, and... waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or malfunction must...

40 CFR 60.1220 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... during periods of startup, shutdown, and malfunction? 60.1220 Section 60.1220 Protection of Environment... Emission Limits § 60.1220 What happens to the emission limits during periods of startup, shutdown, and... waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or malfunction must...

40 CFR 60.1220 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... during periods of startup, shutdown, and malfunction? 60.1220 Section 60.1220 Protection of Environment... Emission Limits § 60.1220 What happens to the emission limits during periods of startup, shutdown, and... waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or malfunction must...

40 CFR 60.1220 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2013 CFR

2013-07-01

... during periods of startup, shutdown, and malfunction? 60.1220 Section 60.1220 Protection of Environment... Emission Limits § 60.1220 What happens to the emission limits during periods of startup, shutdown, and... waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or malfunction must...

40 CFR 60.1220 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... during periods of startup, shutdown, and malfunction? 60.1220 Section 60.1220 Protection of Environment... Emission Limits § 60.1220 What happens to the emission limits during periods of startup, shutdown, and... waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or malfunction must...

40 CFR 60.1710 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2013 CFR

2013-07-01

... during periods of startup, shutdown, and malfunction? 60.1710 Section 60.1710 Protection of Environment... during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or malfunction...

40 CFR 60.1710 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... during periods of startup, shutdown, and malfunction? 60.1710 Section 60.1710 Protection of Environment... during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or malfunction...

40 CFR 60.1710 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2014 CFR

2014-07-01

... during periods of startup, shutdown, and malfunction? 60.1710 Section 60.1710 Protection of Environment... during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or malfunction...

40 CFR 60.1710 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... during periods of startup, shutdown, and malfunction? 60.1710 Section 60.1710 Protection of Environment... during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or malfunction...

Successful preemptive surgical division of type 2-congenital extrahepatic portosystemic shunt in children.

PubMed

Nii, Akira; Takehara, Hiro-o; Kuyama, Hisako; Shimada, Mitsuo

2009-02-01

A congenital extrahepatic portosystemic shunt (CEPS) is a rare abnormality. The shunts are classified into 2 types. Of these, a type 2-shunt is a side-to-side one, which may be treated by a simple shunt division. The aim of this retrospective study was to clarify the effects of a surgical shunt division on 4 children with type 2-CEPS. Between June 2002 and June 2008, 4 children with type 2-CEPS underwent a surgical shunt division. Various clinical factors of each patient, including shunt types, shut ratios evaluated by portal scintigraphy using (123)I-iodoamphetamine, serum levels of ammonia and total bile acids before and after surgery were evaluated. Two children had a conventional open surgery and the other two had a laparoscopic surgery. The serum levels of ammonia as well as total bile acids of these children decreased significantly to the normal levels within a month after the surgical shunt divisions. All the children had a better clinical course. A shunt division, especially by laparoscopic surgery, is an effective therapy for type 2-CEPS. To the best of our knowledge by reviewing literatures, our cases are the youngest ones treated by laparoscopic shunt division.

Distribution of extrahepatic congenital portosystemic shunt morphology in predisposed dog breeds

PubMed Central

2012-01-01

Background An inherited basis for congenital extrahepatic portosystemic shunts (EHPSS) has been demonstrated in several small dog breeds. If in general both portocaval and porto-azygous shunts occur in breeds predisposed to portosystemic shunts then this could indicate a common genetic background. This study was performed to determine the distribution of extrahepatic portocaval and porto-azygous shunts in purebred dog populations. Results Data of 135 client owned dogs diagnosed with EHPSS at the Faculty of Veterinary Medicine of Utrecht University from 2001 – 2010 were retrospectively analyzed. The correlation between shunt localization, sex, age, dog size and breed were studied. The study group consisted of 54 males and 81 females from 24 breeds. Twenty-five percent of dogs had porto-azygous shunts and 75% had portocaval shunts. Of the dogs with porto-azygous shunts only 27% was male (P = 0.006). No significant sex difference was detected in dogs with a portocaval shunt. Both phenotypes were present in almost all breeds represented with more than six cases. Small dogs are mostly diagnosed with portocaval shunts (79%) whereas both types are detected. The age at diagnosis in dogs with porto-azygous shunts was significantly higher than that of dogs with portocaval shunts (P < 0.001). Conclusion The remarkable similarity of phenotypic variation in many dog breeds may indicate common underlying genes responsible for EHPSS across breeds. The subtype of EHPSS could be determined by a minor genetic component or modulating factors during embryonic development. PMID:22784395

New and improved ways to treat hydrocephalus: Pursuit of a smart shunt.

PubMed

Lutz, Barry R; Venkataraman, Pranav; Browd, Samuel R

2013-01-01

The most common treatment for hydrocephalus is placement of a cerebrospinal fluid shunt to supplement or replace lost drainage capacity. Shunts are life-saving devices but are notorious for high failure rates, difficulty of diagnosing failure, and limited control options. Shunt designs have changed little since their introduction in 1950s, and the few changes introduced have had little to no impact on these long-standing problems. For decades, the community has envisioned a "smart shunt" that could provide advanced control, diagnostics, and communication based on implanted sensors, feedback control, and telemetry. The most emphasized contribution of smart shunts is the potential for advanced control algorithms, such as weaning from shunt dependency and personalized control. With sensor-based control comes the opportunity to provide data to the physician on patient condition and shunt function, perhaps even by a smart phone. An often ignored but highly valuable contribution would be designs that correct the high failure rates of existing shunts. Despite the long history and increasing development activity in the past decade, patients are yet to see a commercialized smart shunt. Most smart shunt development focuses on concepts or on isolated technical features, but successful smart shunt designs will be a balance between technical feasibility, economic viability, and acceptable regulatory risk. Here, we present the status of this effort and a framework for understanding the challenges and opportunities that will guide introduction of smart shunts into patient care.

Distribution of extrahepatic congenital portosystemic shunt morphology in predisposed dog breeds.

PubMed

Van den Bossche, Lindsay; van Steenbeek, Frank G; Favier, Robert P; Kummeling, Anne; Leegwater, Peter A J; Rothuizen, Jan

2012-07-11

An inherited basis for congenital extrahepatic portosystemic shunts (EHPSS) has been demonstrated in several small dog breeds. If in general both portocaval and porto-azygous shunts occur in breeds predisposed to portosystemic shunts then this could indicate a common genetic background. This study was performed to determine the distribution of extrahepatic portocaval and porto-azygous shunts in purebred dog populations. Data of 135 client owned dogs diagnosed with EHPSS at the Faculty of Veterinary Medicine of Utrecht University from 2001 - 2010 were retrospectively analyzed. The correlation between shunt localization, sex, age, dog size and breed were studied. The study group consisted of 54 males and 81 females from 24 breeds. Twenty-five percent of dogs had porto-azygous shunts and 75% had portocaval shunts. Of the dogs with porto-azygous shunts only 27% was male (P = 0.006). No significant sex difference was detected in dogs with a portocaval shunt. Both phenotypes were present in almost all breeds represented with more than six cases. Small dogs are mostly diagnosed with portocaval shunts (79%) whereas both types are detected. The age at diagnosis in dogs with porto-azygous shunts was significantly higher than that of dogs with portocaval shunts (P < 0.001). The remarkable similarity of phenotypic variation in many dog breeds may indicate common underlying genes responsible for EHPSS across breeds. The subtype of EHPSS could be determined by a minor genetic component or modulating factors during embryonic development.

Iatrogenic Diversion of Inferior Vena Cava into Left Atrium after Surgery for a Rare Combination of Congenital Heart Diseases

PubMed Central

Sabzi, Feridoun

2016-01-01

Atrial septal defect (ASD) is a common congenital anomaly that has low surgical mortality and morbidity. We report a very rare case of a low-lying ASD, combined with the drainage of the inferior vena cava and the left superior vena cava into the left atrium. This combination was associated with an unroofed coronary sinus. We also describe an iatrogenic surgical diversion of the inferior vena cava into the left atrium with its complication. The patient presented with moderate cyanosis and was referred for elective ASD repair. He underwent surgical repair of the ASD after transthoracic echocardiography. Early postoperative right-to-left shunting with cyanosis and hypoxia was associated with abdominal complications. Surgical re-exploration revealed the diversion of the inferior vena cava into the left atrium, which was repaired with a pericardial patch. Peptic ulcer perforation was repaired after abdominal laparotomy. The patient had an uneventful recovery and was discharged home on the 17th postoperative day. One-year follow-up revealed no recurrence of cyanosis or residual ASD on echocardiography. PMID:27928261

Over-drainage and persistent shunt-dependency in patients with idiopathic intracranial hypertension treated with shunts and bariatric surgery.

PubMed

Roth, Jonathan; Constantini, Shlomi; Kesler, Anat

2015-01-01

Idiopathic intracranial hypertension (IIH) may lead to visual impairment. Shunt surgery is indicated for refractory IIH-related symptoms that persist despite medical treatment, or those presenting with significant visual decline. Obesity is a risk factor for IIH; a reduction in weight has been shown to improve papilledema. Bariatric surgery (BS) has been suggested for treating IIH associated with morbid obesity. In this study, we describe a high rate of over-drainage (OD) seen in patients following shunts and BS. The study cohort includes 13 patients with IIH that underwent shunt surgery for treatment of the IIH-related symptoms. Six patients underwent BS in addition to the shunt surgery (but not concomitantly). Seven patients had only shunt surgeries with no BS. Data were collected retrospectively. BS effectively led to weight reduction (body mass index decreasing from 43 ± 4 to 28 ± 5). Patients undergoing BS had 1-6 (2.5 ± 1.9) shunt revisions for OD following BS, as opposed to 0-3 (1.4 ± 1.1) revisions prior to BS over similar time spans (statistically insignificant difference), and 0-6 (1.6 ± 2.5) revisions among the non-BS patients over a longer time span (statistically insignificant difference). Two patients in the BS group underwent shunt externalization and closure; however, they proved to be shunt-dependent. Patients with IIH that undergo shunt surgery and BS (not concomitantly) may suffer from OD symptoms, necessitating multiple shunt revisions, and valve upgrades. Despite BS being a valid primary treatment for some patients with IIH, among shunted patients, BS may not lead to resolution of IIH-related symptoms and patients may remain shunt-dependent.

Outcome of shunting in idiopathic normal-pressure hydrocephalus and the value of outcome assessment in shunted patients.

PubMed

Klinge, Petra; Marmarou, Anthony; Bergsneider, Marvin; Relkin, Norman; Black, Peter McL

2005-09-01

To develop guidelines for assessing shunt outcome in patients with idiopathic normal-pressure hydrocephalus (INPH). To date, the literature available on this topic has been marked by disparate definitions of clinical improvement, varying postoperative follow-up protocols and periods, and substantial differences in the postoperative management. Because specific criteria for defining clinical improvement are seldom reported, conclusions drawn about shunt outcome may be subjective. A MEDLINE search back to 1966 was undertaken using the query NPH, normal-pressure hydrocephalus, shunting, shunt treatment, shunt response, outcome, and clinical outcome. The criteria for selection were studies that included INPH from 1966 to the present in which the outcome of INPH was reported in patient groups of 20 or more. To date, there is no standard for outcome assessment of shunt treatment in INPH. The variable improvement rates reported are not only because of different criteria for selection of patients but also because of different postoperative assessment procedures and follow-up intervals. Studies that have established fixed protocols for follow-up have shown that short- and long-term periods after shunting are determined by many factors. Whereas short-term results were more likely to be influenced by shunt-associated risks, long-term results were independent of factors inherent to the shunt procedure and shunt complications, i.e., death and morbidity related to concomitant cerebrovascular and vascular diseases. Studies have shown that beyond 1 year after surgery, these factors definitely influence the clinical effect of shunting, making the 1-year postshunt period a potential determinant of the shunt outcome. Guidelines for outcome assessment were developed on the basis of the available evidence and consensus of expert opinion.

40 CFR 63.1344 - Affirmative defense for exceedance of emission limit during malfunction.

Code of Federal Regulations, 2012 CFR

2012-07-01

... in paragraph § 63.1343(b) you may assert an affirmative defense to a claim for civil penalties for... methods and engineering judgment, the amount of excess emissions that were the result of the malfunction... malfunction, if it wishes to avail itself of an affirmative defense to civil penalties for that malfunction...

40 CFR 63.1344 - Affirmative defense for exceedance of emission limit during malfunction.

Code of Federal Regulations, 2011 CFR

2011-07-01

... in paragraph § 63.1343(b) you may assert an affirmative defense to a claim for civil penalties for... methods and engineering judgment, the amount of excess emissions that were the result of the malfunction... malfunction, if it wishes to avail itself of an affirmative defense to civil penalties for that malfunction...

Evaluation of Mismatch Losses due to Shunts in industrial Silicon Photovoltaic Modules

NASA Astrophysics Data System (ADS)

Somasundaran, P.; Shilpi, M.; Gupta, R.

2017-05-01

In order to achieve higher efficiencies in photovoltaic module technology, it is important to characterize the shunts and other defects which degrade the performance of cells and modules as well as decrease their efficiency. These shunts also affect the reliability of cells and modules. It is important to understand how much fill factor and power loss is caused by the presence of shunts in the module. Shunts not only reduce the module power output, but also affect the I-V characteristics of the cell and hence the characteristics of the shunted cells are different from those of the shunt-free cells connected in the module leading to the mismatch effect. This is an interesting effect which has been systematically investigated in the present work. Moreover, the flow of increased shunt current will give rise to increased temperature in the region of shunt, which will affect the cell and hence module performance. In the present study, the distributed diode model has been extended to the module level and applied to evaluate the electrical mismatch losses and thermal mismatch losses due to shunts in industrial Silicon PV modules.

Measurements of left-to-right intracardiac shunting in adults: oximetric versus indicator dilution techniques.

PubMed

Hillis, L D; Winniford, M D; Jackson, J A; Firth, B G

1985-01-01

Of the various techniques that are available to assess the presence and magnitude of intracardiac shunting, oximetry and indicator dilution are used most frequently. This study was performed to compare these methods in adult patients with pure left-to-right intracardiac shunting. In 27 patients [12 men, 15 women, aged 32 +/- 12 (mean +/- SD) years], shunt magnitude was assessed in close temporal proximity by both techniques. The oximetric percentage left-to-right shunt averaged 55 +/- 16%, whereas the indocyanine green dye percentage shunt was significantly less (36 +/- 14%, p less than 0.001). The oximetric percentage shunt exceeded the indocyanine green dye percentage shunt in 26 and did so by greater than 20% in 23 patients. Thus, there is a substantial difference in shunt magnitude between the oximetric and the indicator dilution techniques. In infants, indicator dilution yields results that are larger than those obtained with the oximetric method. Conversely, in adults, the indicator dilution technique gives results that are consistently smaller than those obtained with oximetry. As a result, the decision regarding therapy of an intracardiac shunt should be made with this in mind.

Outcome of infants shunted for post-haemorrhagic ventricular dilatation.

PubMed

Hislop, J E; Dubowitz, L M; Kaiser, A M; Singh, M P; Whitelaw, A G

1988-08-01

Between April 1980 and March 1986, 19 infants underwent cerebrospinal fluid (CSF) shunting procedures for post-haemorrhagic ventricular dilatation at the Hammersmith Hospital, London. A total of 58 shunt-related procedures have been performed on these children. The major perioperative complication was seizure activity (eight children). Postoperative complications included infection (12 shunts) and blockage (29 shunts). Prophylactic antibiotics failed to prevent shunt infection. The likelihood of the first shunt failing was significantly reduced by greater weight of the infant and lower CSF protein at surgery. Long-term outcome was poor: three have died and another four are quadriplegic with severe mental retardation. Only four children are developmentally normal. These outcomes cannot be related to the shunt surgery or its complications, but correlate best with pre-operative parenchymal brain-lesions, as shown on ultrasound scans.

Passively Shunted Piezoelectric Damping of Centrifugally-Loaded Plates

NASA Technical Reports Server (NTRS)

Duffy, Kirsten P.; Provenza, Andrew J.; Trudell, Jeffrey J.; Min, James B.

2009-01-01

Researchers at NASA Glenn Research Center have been investigating shunted piezoelectric circuits as potential damping treatments for turbomachinery rotor blades. This effort seeks to determine the effects of centrifugal loading on passively-shunted piezoelectric - damped plates. Passive shunt circuit parameters are optimized for the plate's third bending mode. Tests are performed both non-spinning and in the Dynamic Spin Facility to verify the analysis, and to determine the effectiveness of the damping under centrifugal loading. Results show that a resistive shunt circuit will reduce resonant vibration for this configuration. However, a tuned shunt circuit will be required to achieve the desired damping level. The analysis and testing address several issues with passive shunt circuit implementation in a rotating system, including piezoelectric material integrity under centrifugal loading, shunt circuit implementation, and tip mode damping.

What is the risk of infecting a cerebrospinal fluid-diverting shunt with percutaneous tapping?

PubMed

Spiegelman, Lindsey; Asija, Richa; Da Silva, Stephanie L; Krieger, Mark D; McComb, J Gordon

2014-10-01

Most CSF-diverting shunt systems have an access port that can be percutaneously tapped. Tapping the shunt can yield valuable information as to its function and whether an infection is present. The fear of causing a shunt infection by tapping may limit the physician's willingness to do so. The authors of this study investigate the risk of infecting a shunt secondary to percutaneous tapping. Following institutional review board approval, CSF specimens obtained from tapping an indwelling CSF-diverting shunt during the 2011 and 2012 calendar years were identified and matched with clinical information. A culture-positive CSF sample was defined as an infection. If results were equivocal, such as a broth-only-positive culture, a repeat CSF specimen was examined. The CSF was obtained by tapping the shunt access port with a 25-gauge butterfly needle after prepping the unshaven skin with chlorhexidine. During the study period, 266 children underwent 542 shunt taps. With 541 taps, no clinical evidence of a subsequent shunt infection was found. One child's CSF went from sterile to infected 11 days later; however, this patient had redness along the shunt tract at the time of the initial sterile tap. The risk of infection from tapping a shunt is remote if the procedure is done correctly.

Robotic equipment malfunction during robotic prostatectomy: a multi-institutional study.

PubMed

Lavery, Hugh J; Thaly, Rahul; Albala, David; Ahlering, Thomas; Shalhav, Arieh; Lee, David; Fagin, Randy; Wiklund, Peter; Dasgupta, Prokar; Costello, Anthony J; Tewari, Ashutosh; Coughlin, Geoff; Patel, Vipul R

2008-09-01

Robotic-assisted laparoscopic prostatectomy (RALP) is growing in popularity as a treatment option for prostate cancer. As a new technology, little is known regarding the reliability of the da Vinci robotic system. Intraoperative robotic equipment malfunction may force the surgeon to convert the procedure to an open or pure laparoscopic procedure, or possibly even abort the procedure. We report the first large-scale, multi-institutional review of robotic equipment malfunction. A questionnaire was designed to evaluate the rate of perioperative robotic malfunction during RALP. High-volume, experienced surgeons were asked to complete this evaluation based on the analysis of their data. Questions included the overall number of RALPs performed, the number of equipment malfunctions, the number of procedures that had to be converted or aborted, and the part of the robotic system that malfunctioned. Eleven institutions participated in the study with a median surgeon volume of 700 cases, accounting for a total case volume of 8240. Critical failure occurred in 34 cases (0.4%) leading to the cancellation of 24 cases prior to the procedure, and the conversion to two laparoscopic and eight open procedures. The most common components of the robot to malfunction were the arms and optical system. Critical robotic equipment malfunction is extremely rare in institutions that perform high volumes of RALPs, with a nonrecoverable malfunction rate of only 0.4%.

Internal carotid artery rupture caused by carotid shunt insertion

PubMed Central

Illuminati, Giulio; Caliò, Francesco G.; Pizzardi, Giulia; Vietri, Francesco

2015-01-01

Introduction Shunting is a well-accepted method of maintaining cerebral perfusion during carotid endarterectomy (CEA). Nonetheless, shunt insertion may lead to complications including arterial dissection, embolization, and thrombosis. We present a complication of shunt insertion consisting of arterial wall rupture, not reported previously. Presentation of case A 78-year-old woman underwent CEA combined with coronary artery bypass grafting (CABG). At the time of shunt insertion an arterial rupture at the distal tip of the shunt was detected and was repaired via a small saphenous vein patch. Eversion CEA and subsequent CABG completed the procedure whose postoperative course was uneventful. Discussion Shunting during combined CEA-CABG may be advisable to assure cerebral protection from possible hypoperfusion due to potential hemodynamic instability of patients with severe coronary artery disease. Awareness and prompt management of possible shunt-related complications, including the newly reported one, may contribute to limiting their harmful effect. Conclusion Arterial wall rupture is a possible, previously not reported, shunt-related complication to be aware of when performing CEA. PMID:26255001

Simulation of Malfunctions for the ISS Double-Gimbal Control Moment Gyroscope

NASA Technical Reports Server (NTRS)

Inampudi, Ravi; Gordeuk, John

2016-01-01

This paper presents a simplified approach to simulation of malfunctions of the Control Moment Gyroscope (CMG) on board the International Space Station (ISS). These malfunctions will be used as part of flight training of CMG failure scenarios in the guidance navigation control (GNC) subsystem of the Training Systems for 21st Century (TS21) simulator. The CMG malfunctions are grouped under mechanical, thermal and electrical categories. A malfunction can be as simple as one which only affects the telemetry or a complex one that changes the state and behavior of the CMG model. In both cases, the ISS GNC flight software will read the telemetry and respond accordingly. The user executes these malfunctions by supplying conditional data which modify internal model states and then elicit a response as seen on the user displays. Ground operators and crew on board the ISS use CMG malfunction procedures to better understand and respond to anomalies observed within the CMG subsystem.

Shunting for normal pressure hydrocephalus (NPH).

PubMed

Esmonde, T; Cooke, S

2002-01-01

Since the condition was first described in 1965, the syndrome of normal pressure hydrocephalus (NPH) has conventionally been managed by placement of a cerebrospinal fluid (CSF) shunt. To determine the effectiveness of shunting procedures in promoting stability or improvement in the neurological symptoms and signs of NPH. The trials were identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 26 June 2001 using the terms 'shunt*' and 'normal pressure hydrocephalus'. Studies included for analysis were those involving the placement of a CSF shunt for the treatment of NPH as part of a randomized controlled trial. No data matching the selection criteria were found. No randomized controlled trials of shunt placement versus no shunt were found. There is no evidence to indicate whether placement of a shunt is effective in the management of NPH.

Investigating PID shunting in polycrystalline silicon modules via multiscale, multitechnique characterization

DOE PAGES

Harvey, Steven P.; Moseley, John; Norman, Andrew; ...

2018-02-27

We investigated the potential-induced degradation (PID) shunting mechanism in multicrystalline-silicon photovoltaic modules by using a multiscale, multitechnique characterization approach. Both field-stressed modules and laboratory-stressed mini modules were studied. We used photoluminescence, electroluminescence, and dark lock-in thermography imaging to identify degraded areas at the module scale. Small samples were then removed from degraded areas, laser marked, and imaged by scanning electron microscopy. We used simultaneous electron-beam induced current imaging and focused ion beam milling to mark around PID shunts for chemical analysis by time-of-flight secondary-ion mass spectrometry or to isolate individual shunt defects for transmission electron microscopy and atom-probe tomography analysis.more » By spanning a range of 10 orders of magnitude in size, this approach enabled us to investigate the root-cause mechanisms for PID shunting. We observed a direct correlation between recombination active shunts and sodium content. The sodium content in shunted areas peaks at the SiNX/Si interface and is consistently observed at a concentration of 0.1% to 2% in shunted areas. Analysis of samples subjected to PID recovery, either activated by electron beam or thermal effects only, reveals that recovery of isolated shunts correlates with diffusion of sodium out of the structural defects to the silicon surface. We observed the role of oxygen and chlorine in PID shunting and found that those species - although sometimes present in structural defects where PID shunting was observed - do not play a consistent role in PID shunting.« less

New and improved ways to treat hydrocephalus: Pursuit of a smart shunt

PubMed Central

Lutz, Barry R.; Venkataraman, Pranav; Browd, Samuel R.

2013-01-01

The most common treatment for hydrocephalus is placement of a cerebrospinal fluid shunt to supplement or replace lost drainage capacity. Shunts are life-saving devices but are notorious for high failure rates, difficulty of diagnosing failure, and limited control options. Shunt designs have changed little since their introduction in 1950s, and the few changes introduced have had little to no impact on these long-standing problems. For decades, the community has envisioned a “smart shunt” that could provide advanced control, diagnostics, and communication based on implanted sensors, feedback control, and telemetry. The most emphasized contribution of smart shunts is the potential for advanced control algorithms, such as weaning from shunt dependency and personalized control. With sensor-based control comes the opportunity to provide data to the physician on patient condition and shunt function, perhaps even by a smart phone. An often ignored but highly valuable contribution would be designs that correct the high failure rates of existing shunts. Despite the long history and increasing development activity in the past decade, patients are yet to see a commercialized smart shunt. Most smart shunt development focuses on concepts or on isolated technical features, but successful smart shunt designs will be a balance between technical feasibility, economic viability, and acceptable regulatory risk. Here, we present the status of this effort and a framework for understanding the challenges and opportunities that will guide introduction of smart shunts into patient care. PMID:23653889

Hepatic vascular shunts: embryology and imaging appearances

PubMed Central

Bhargava, P; Vaidya, S; Kolokythas, O; Katz, D S; Dighe, M

2011-01-01

The purpose of this pictorial review is to understand the embryological basis of the development of congenital hepatic vascular shunts and to review the multimodality imaging appearances of congenital and acquired hepatic vascular shunts. Hepatic vascular shunts are commonly seen in imaging. Familiarity with their characteristic appearances is important in order to accurately characterise these shunts and diagnose the underlying disorders. PMID:22101582

49 CFR 236.838 - Wire, shunt.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Wire, shunt. 236.838 Section 236.838 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Wire, shunt. A wire forming part of a shunt circuit. ...

49 CFR 236.838 - Wire, shunt.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Wire, shunt. 236.838 Section 236.838 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Wire, shunt. A wire forming part of a shunt circuit. ...

Ventriculosubgaleal shunts for posthemorrhagic hydrocephalus in premature infants.

PubMed

Willis, Brian K; Kumar, Cherukuri Ravi; Wylen, Esther L; Nanda, Anil

2005-01-01

The early management of posthemorrhagic hydrocephalus in premature infants is challenging and controversial. These infants need a temporary cerebrospinal fluid (CSF) diversion procedure until they gain adequate weight, and the blood and protein levels in CSF are reasonably low before permanent shunt can be placed. Various options are available with their associated advantages and disadvantages. Ventriculosubgaleal shunts have been recommended as a more physiologic and less invasive means of achieving this goal. We have performed this procedure in 6 premature infants to evaluate their effectiveness and complications. Six consecutive premature infants with posthemorrhagic hydrocephalus underwent placement of ventriculosubgaleal shunts over a 1-year period of time. We reviewed their clinical and imaging progress to assess the ability of the shunt to control hydrocephalus and the complication rates. In all 6 patients, the ventriculosubgaleal shunt controlled the progression of hydrocephalus as assessed by clinical and imaging parameters. A permanent shunt was avoided in 1 patient (16.6%). However, 4 patients developed shunt infections, 1 involving the ventriculosubgaleal shunt itself, and 3 immediately after conversion to ventriculoperitoneal shunt. The total infection rate of the series was 66.6%. All infections were caused by staphylococcus species. There was only a 1% shunt infection rate in our institution for all nonventriculosubgaleal shunts during the same period of time. Placement of ventriculosubgaleal shunts for interim CSF diversion in neonates with posthemorrhagic hydrocephalus is effective as a temporary method of CSF diversion. However, our experience has shown that it is associated with a unacceptably high CSF infection rate. A potential cause for infection is CSF stasis just beneath the extremely thin skin of the premature infants, promoting colonization by skin flora. CSF sampling before conversion to a permanent shunt and replacement of the proximal hardware, which has been in situ for a prolonged period, may decrease the infection rates. At present, the procedure is no longer performed at our institution.

Shunt Intervention for Possible Idiopathic Normal Pressure Hydrocephalus Improves Patient Outcomes: A Nationwide Hospital-Based Survey in Japan.

PubMed

Nakajima, Madoka; Miyajima, Masakazu; Ogino, Ikuko; Akiba, Chihiro; Kawamura, Kaito; Kurosawa, Michiko; Kuriyama, Nagato; Watanabe, Yoshiyuki; Fukushima, Wakaba; Mori, Etsuro; Kato, Takeo; Sugano, Hidenori; Karagiozov, Kostadin; Arai, Hajime

2018-01-01

Background and Purpose: This study aimed to investigate the efficacy of cerebrospinal fluid shunt intervention for idiopathic normal pressure hydrocephalus (iNPH) using data from a nationwide epidemiological survey in Japan. Methods: We conducted a cross-sectional study using data from a nationwide epidemiological survey performed in Japan. Propensity score matching was used to select 874 patients from 1,423 patients aged ≥60 years, who were diagnosed with iNPH based on clinical guidelines following a hospital visit in 2012. Patients who experienced an improvement of at least 1 modified Rankin Scale (mRS) grade after the intervention were classified as "improved," while the remaining patients were classified as "non-improved." In the shunt intervention ( n = 437) and non-shunt intervention ( n = 437) groups, the differences in mRS grade improvement were analyzed using the Mann-Whitney U -test. Finally, we examined subjects in the shunt intervention group ( n = 974) to compare the outcomes and complications of ventriculoperitoneal (VP) shunt (n = 417) with lumboperitoneal (LP) shunt ( n = 540). Results: We examined subjects with iNPH to compare the non-shunt intervention group to the shunt intervention group following adjustment for age and mRS grade at baseline by propensity score matching (0.31-0.901). The mRS grade (mean [SD]) was found to improve with non-shunt intervention (2.46 [0.88]) and shunt intervention (1.93 [0.93]) ( p < 0.001) in iNPH patients. The mRS outcome score and complications comparison between the VP and LP shunt groups did not show significant difference. Conclusions: In this study, analysis of the efficacy of shunts for possible iNPH conducted in Japan indicated a significant improvement in the mRS grade between baseline and outcome within 1 year, regardless of the surgical technique, and shunt intervention was found to be effective.

Intracardiac Shunting and Stroke in Children: A Systematic Review

PubMed Central

Dowling, Michael M.; Ikemba, Catherine M.

2017-01-01

In adults, patent foramen ovale or other potential intracardiac shunts are established risk factors for stroke via paradoxical embolization. Stroke is less common in children and risk factors differ. The authors examined the literature on intracardiac shunting and stroke in children, identifying the methods employed, the prevalence of detectible intracardiac shunts, associated conditions, and treatments. PubMed searches with keywords related to intracardiac shunting and stroke in children identified articles of interest. Additional articles were identified via citations in these articles or in reviews. The authors found that studies of intracardiac shunting in children with stroke are limited. No controlled studies were identified. Detection methods vary and the prevalence of echocardiographically detectible intracardiac shunting appears lower than reported in adults and autopsy studies. Defining the role of intracardiac shunting in pediatric stroke will require controlled studies with unified detection methods in populations stratified by additional risk factors for paradoxical embolization. Optimal treatment is unclear. PMID:21212453

Asymptomatic Congenital Intrahepatic Portosystemic Shunt.

PubMed

Brown, Karen M; Hal, Hassan

2009-01-01

Congenital (spontaneous) intrahepatic portosystemic shunt is rare in the English literature. Most cases of portosystemic shunt occur after trauma, surgery, liver biopsy or as a result of chronic portal hypertension. Chronic shunting may result in encephalopathy, bleeding or hyperinsulinism. We report a case of an asymptomatic adult female with a presumed congenital intrahepatic portosystemic shunt and discuss the pertinent imaging findings and important key concepts related to this condition.

Validated linear dynamic model of electrically-shunted magnetostrictive transducers with application to structural vibration control

NASA Astrophysics Data System (ADS)

Scheidler, Justin J.; Asnani, Vivake M.

2017-03-01

This paper presents a linear model of the fully-coupled electromechanical behavior of a generally-shunted magnetostrictive transducer. The impedance and admittance representations of the model are reported. The model is used to derive the effect of the shunt’s electrical impedance on the storage modulus and loss factor of the transducer without neglecting the inherent resistance of the transducer’s coil. The expressions are normalized and then shown to also represent generally-shunted piezoelectric materials that have a finite leakage resistance. The generalized expressions are simplified for three shunts: resistive, series resistive-capacitive, and inductive, which are considered for shunt damping, resonant shunt damping, and stiffness tuning, respectively. For each shunt, the storage modulus and loss factor are plotted for a wide range of the normalized parameters. Then, important trends and their impact on different applications are discussed. An experimental validation of the transducer model is presented for the case of resistive and resonant shunts. The model closely predicts the measured response for a variety of operating conditions. This paper also introduces a model for the dynamic compliance of a vibrating structure that is coupled to a magnetostrictive transducer for shunt damping and resonant shunt damping applications. This compliance is normalized and then shown to be analogous to that of a structure that is coupled to a piezoelectric material. The derived analogies allow for the observations and equations in the existing literature on structural vibration control using shunted piezoelectric materials to be directly applied to the case of shunted magnetostrictive transducers.

Crestal Sinus Augmentation in the Presence of Severe Sinus Mucosal Thickening: A Report of 3 Cases.

PubMed

Fang, Yiqin; An, Xueyin; Jeong, Seung-Mi; Choi, Byung-Ho

2018-06-01

In the presence of severe sinus mucosal thickening, the ostium can be blocked when the sinus membrane is lifted, causing drainage disturbances and sinusitis. Here, we present 3 cases in which maxillary sinus floor elevation was performed using a crestal approach in the presence of severe sinus mucosal thickening (>10 mm). The effects of maxillary sinus floor elevation using the crestal approach technique on sinus mucosal thickening and bone formation in the sinus were evaluated using cone beam computed tomography. None of the patients exhibited an increase in sinus membrane thickness. No complications were encountered during the follow-up periods, and bone formation was observed around the implants at the sinus floor. All implants were functioning successfully. Maxillary sinus floor elevation using the crestal approach technique in the presence of severe sinus mucosal thickening allows for minimally invasive sinus grafting and simultaneous implant placement and does not increase sinus membrane thickness.

Internal carotid artery rupture caused by carotid shunt insertion.

PubMed

Illuminati, Giulio; Caliò, Francesco G; Pizzardi, Giulia; Vietri, Francesco

2015-01-01

Shunting is a well-accepted method of maintaining cerebral perfusion during carotid endarterectomy (CEA). Nonetheless, shunt insertion may lead to complications including arterial dissection, embolization, and thrombosis. We present a complication of shunt insertion consisting of arterial wall rupture, not reported previously. A 78-year-old woman underwent CEA combined with coronary artery bypass grafting (CABG). At the time of shunt insertion an arterial rupture at the distal tip of the shunt was detected and was repaired via a small saphenous vein patch. Eversion CEA and subsequent CABG completed the procedure whose postoperative course was uneventful. Shunting during combined CEA-CABG may be advisable to assure cerebral protection from possible hypoperfusion due to potential hemodynamic instability of patients with severe coronary artery disease. Awareness and prompt management of possible shunt-related complications, including the newly reported one, may contribute to limiting their harmful effect. Arterial wall rupture is a possible, previously not reported, shunt-related complication to be aware of when performing CEA. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Multi-resonant electromagnetic shunt in base isolation for vibration damping and energy harvesting

NASA Astrophysics Data System (ADS)

Pei, Yalu; Liu, Yilun; Zuo, Lei

2018-06-01

This paper investigates multi-resonant electromagnetic shunts applied to base isolation for dual-function vibration damping and energy harvesting. Two multi-mode shunt circuit configurations, namely parallel and series, are proposed and optimized based on the H2 criteria. The root-mean-square (RMS) value of the relative displacement between the base and the primary structure is minimized. Practically, this will improve the safety of base-isolated buildings subjected the broad bandwidth ground acceleration. Case studies of a base-isolated building are conducted in both the frequency and time domains to investigate the effectiveness of multi-resonant electromagnetic shunts under recorded earthquake signals. It shows that both multi-mode shunt circuits outperform traditional single mode shunt circuits by suppressing the first and the second vibration modes simultaneously. Moreover, for the same stiffness ratio, the parallel shunt circuit is more effective at harvesting energy and suppressing vibration, and can more robustly handle parameter mistuning than the series shunt circuit. Furthermore, this paper discusses experimental validation of the effectiveness of multi-resonant electromagnetic shunts for vibration damping and energy harvesting on a scaled-down base isolation system.

Treatment of extrahepatic portal hypertension following a whipple procedure with a Rex shunt: report of a case.

PubMed

Reichman, Trevor W; Anthony, Tiffany; Testa, Giuliano

2011-02-01

The Rex shunt is a mesenteric vein to left portal vein decompressive shunt used for the treatment of portal vein thrombosis and portal hypertension. Its use has been reported primarily in the pediatric population where portal vein thrombosis occurs with some frequency. The shunt is thought to represent a more physiologic shunt, since it restores hepatopedal blood flow through the liver. This report describes the use of this shunt in an adult who had frequent gastrointestinal bleeding secondary to extrahepatic portal vein thrombosis, which occurred as a complication after a pancreaticoduodenectomy.

Reliability of robotic system during general surgical procedures in a university hospital.

PubMed

Buchs, Nicolas C; Pugin, François; Volonté, Francesco; Morel, Philippe

2014-01-01

Data concerning the reliability of robotic systems are scarce, especially for general surgery. The aim of this study was to assess the incidence and consequences of robotic malfunction in a teaching institution. From January 2006 to September 2012, 526 consecutive robotic general surgical procedures were performed. All failures were prospectively recorded in a computerized database and reviewed retrospectively. Robotic malfunctions occurred in 18 cases (3.4%). These dysfunctions concerned the robotic instruments in 9 cases, the robotic arms in 4 cases, the surgical console in 3 cases, and the optical system in 2 cases. Two malfunctions were considered critical, and 1 led to a laparoscopic conversion (conversion rate due to malfunction, .2%). Overall, there were more dysfunctions at the beginning of the study period (2006 to 2010) than more recently (2011 to 2012) (4.2% vs 2.6%, P = .35). The robotic system malfunction rate was low. Most malfunctions could be resolved during surgery, allowing the procedures to be completed safely. With increased experience, the system malfunction rate seems to be reduced. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of in vivo behavior of ameroid ring constrictors in dogs with congenital extrahepatic portosystemic shunts using computed tomography.

PubMed

Hunt, Geraldine B; Culp, William T N; Mayhew, Kelli N; Mayhew, Philipp; Steffey, Michele A; Zwingenberger, Allison

2014-10-01

To evaluate the in vivo pattern of ameroid constrictor closure of congenital extrahepatic portosystemic shunts in dogs. Prospective study. Dogs (n = 22) with congenital extrahepatic portosystemic shunts. Contrast-enhanced computed tomography was performed immediately before, and at least 8 weeks after placement of ameroid ring constrictors. Plastic-encased ameroid constrictors were used in 17 dogs and metal constrictors in 5 dogs. Presence of residual flow through the portosystemic shunt, additional anomalous vessels, acquired shunts and soft tissue associated with the ameroid constrictor was recorded. Postoperative internal diameter was recorded for the 17 plastic constrictors. Correlations between internal diameter and pre- and postoperative serum protein concentration were analyzed. No ameroid constrictor closed completely: shunt occlusion was always dependent on soft tissue within the ameroid ring. Residual flow through the shunt was present in 4 dogs (18%), although this caused persistent elevation of shunt fraction in only 1 dog (dog 8). The change in ameroid constrictor internal diameter was not significantly correlated with serum protein concentration. Complete shunt occlusion after AC placement is usually dependent on soft tissue reaction. Ameroid constrictors ≥5 mm diameter may not promote complete shunt occlusion. © Copyright 2014 by The American College of Veterinary Surgeons.

Serum hyaluronic acid in dogs with congenital portosystemic shunts.

PubMed

Seki, M; Asano, K; Sakai, M; Kanno, N; Teshima, K; Edamura, K; Tanaka, S

2010-05-01

To compare the serum level of hyaluronic acid in dogs with congenital portosystemic shunt with that in healthy dogs and to investigate the perioperative change in serum hyaluronic acid following shunt attenuation. Blood samples were obtained from 29 congenital portosystemic shunt dogs before the operation, and 2 and 4 weeks after the operation from 17 and 7 dogs, respectively. The serum hyaluronic acid level of these dogs was measured and compared with that of 10 healthy beagles. The median preoperative hyaluronic acid level in dogs with congenital portosystemic shunt was significantly elevated compared with that in healthy dogs. Furthermore, the median postoperative hyaluronic acid level significantly decreased compared with the median preoperative levels in congenital portosystemic shunt dogs. In the case of dogs with congenital portosystemic shunt, the reduction of intrahepatic portal blood flow might lower the clearance rate of hyaluronic acid in hepatic sinusoidal endothelial cells, so hyaluronic acid clearance could be improved by attenuation of a shunt vessel. Hence, serum hyaluronic acid levels might be useful to evaluate liver function and also have the potential to evaluate successful attenuation of a shunt vessel in dogs with congenital portosystemic shunt. Further investigations are required to clarify whether serum hyaluronic acid offers significant benefits over existing markers such as serum bile acid or ammonia concentrations.

Conversion of Low-Flow Priapism to High-Flow State Using T-Shunt with Tunneling.

PubMed

Mistry, Neil A; Tadros, Nicholas N; Hedges, Jason C

2017-01-01

Introduction . The three types of priapism are stuttering, arterial (high-flow, nonischemic), and venoocclusive (low-flow, ischemic). These are usually distinct entities and rarely occur in the same patient. T-shunts and other distal shunts are frequently combined with tunneling, but a seldom recognized potential complication is conversion to a high-flow state. Case Presentation . We describe 2 cases of men who presented with low-flow priapism episodes that were treated using T-shunts with tunneling that resulted with both men having recurrent erections shortly after surgery that were found to be consistent with high-flow states. Case 1 was a 33-year-old male with sickle cell anemia and case 2 was a 24-year-old male with idiopathic thrombocytopenic purpura. In both cases the men were observed over several weeks and both men returned to normal erectile function. Conclusions . Historically, proximal shunts were performed only in cases when distal shunts failed and carry a higher risk of serious complications. T-shunts and other distal shunts combined with tunneling are being used more frequently in place of proximal shunts. These cases illustrate how postoperative erections after T-shunts with tunneling can signify a conversion from low-flow to high-flow states and could potentially be misdiagnosed as an operative failure.

The relationship between CSF circulation and cerebrovascular pressure-reactivity in normal pressure hydrocephalus.

PubMed

Czosnyka, Z; van den Boogaard, F; Czosnyka, M; Momjian, S; Gelling, L; Pickard, J D

2005-01-01

Previously, we documented association between CSF circulation and transcranial-Doppler derived autoregulation in non-shunted patients suffering from hydrocephalus. In the present study we sought to investigate the relationship between the resistance to CSF outflow and pressure-reactivity both in shunted and non-shunted NPH patients. Sixty-eight patients (47 non-shunted and 21 shunted) with NPH have been examined as a part of routine diagnostic procedure. Resistance to CSF outflow (Rcsf) was measured using a ventricular constant rate infusion test. Cerebrovascular pressure-reactivity was assessed as a moving correlation coefficient (PRx) between coherent 'slow waves' of ICP and arterial blood pressure (ABP). This variable has previously been demonstrated to correlate with the autoregulation of CBF in patients following head injury. Results. In non-shunted patients cerebrovascular pressure-reactivity (PRx) was negatively correlated with Rcsf (R = -0.5; p < 0.0005). This relationship was inverted in shunted patients: a positive correlation between PRx and Rcsf was found (R = 0.51; p < 0.03). Cerebrovascular pressure-reactivity is disturbed in patients with normal resistance to CSF outflow, suggesting underlying cerebrovascular disease. This result confirms our previous finding where transcranial Doppler autoregulation was investigated. After shunting the pressure-reactivity strongly depends on shunt functioning and deteriorates when the shunt is blocked.

Complications of congenital portosystemic shunts in children: therapeutic options and outcomes.

PubMed

Franchi-Abella, Stéphanie; Branchereau, Sophie; Lambert, Virginie; Fabre, Monique; Steimberg, Clarisa; Losay, Jean; Riou, Jean-Yves; Pariente, Danièle; Gauthier, Frédéric; Jacquemin, Emmanuel; Bernard, Olivier

2010-09-01

Congenital portosystemic shunts are rare vascular malformations that lead to severe complications. Their management is controversial. The aim of this study was to propose a clear definition of the risks and management of congenital portosystemic shunts in children according to our experience and a review of the literature. Twenty-two children with a complicated congenital portosystemic shunt were studied in our institution. When necessary, management included portal pressure measurement and portal vein angiography during an occlusion test and closure of the shunt by surgical and/or endovascular methods. Five neonates with intrahepatic shunts presented with cholestasis that resolved spontaneously, and 17 older children presented with liver tumors (13) and/or hepatopulmonary syndrome (2), pulmonary artery hypertension (3), portosystemic encephalopathy (3), heart failure (1), and glomerulonephritis (1). The portosystemic shunt was extrahepatic (11) or intrahepatic (6). Portosystemic shunts were closed by endovascular methods in 5 children and surgically in 10, 4 of whom had portal pressure during occlusion above 35 mmHg and extremely hypoplastic or undetectable portal veins requiring banding of the fistula before closure. Shunt closure resulted in restoration of intrahepatic portal flow in all, with complete or partial regression of benign liver masses, and regression or stabilization of pulmonary, cardiac, neurological, and renal complications. Congenital portosystemic shunt carries risks of severe complications in children. Closure of a shunt persisting after age 2 years should be considered preventively. Intrahepatic portal flux restoration can be expected, even when intrahepatic portal veins are extremely hypoplastic or undetectable.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, Steven P.; Moseley, John; Norman, Andrew

We investigated the potential-induced degradation (PID) shunting mechanism in multicrystalline-silicon photovoltaic modules by using a multiscale, multitechnique characterization approach. Both field-stressed modules and laboratory-stressed mini modules were studied. We used photoluminescence, electroluminescence, and dark lock-in thermography imaging to identify degraded areas at the module scale. Small samples were then removed from degraded areas, laser marked, and imaged by scanning electron microscopy. We used simultaneous electron-beam induced current imaging and focused ion beam milling to mark around PID shunts for chemical analysis by time-of-flight secondary-ion mass spectrometry or to isolate individual shunt defects for transmission electron microscopy and atom-probe tomography analysis.more » By spanning a range of 10 orders of magnitude in size, this approach enabled us to investigate the root-cause mechanisms for PID shunting. We observed a direct correlation between recombination active shunts and sodium content. The sodium content in shunted areas peaks at the SiNX/Si interface and is consistently observed at a concentration of 0.1% to 2% in shunted areas. Analysis of samples subjected to PID recovery, either activated by electron beam or thermal effects only, reveals that recovery of isolated shunts correlates with diffusion of sodium out of the structural defects to the silicon surface. We observed the role of oxygen and chlorine in PID shunting and found that those species - although sometimes present in structural defects where PID shunting was observed - do not play a consistent role in PID shunting.« less

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

49 CFR 236.725 - Circuit, switch shunting.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, switch shunting. 236.725 Section 236.725 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, switch shunting. A shunting circuit which is closed through contacts of a switch circuit...

[Radiographic study of maxillary sinus associated with molars in adult].

PubMed

Hu, Zhi; Sun, Daming; Zhou, Quansheng; Wang, Yuli; Gu, Jingcheng; Han, Yaohua

2014-12-01

to explore the relationship between the maxillary sinus volume and the amount of alveolar bone, and the effect of molar loss upon the maxillary sinus was further analyzed,by measuring adult maxillary sinus volume, sinus ridge distance, and calculating the gasification coefficient of maxillary sinus. One hundred and ninety cases (361 maxillary sinus) with CT examinations were collected, they were divided into group A and group B, 121 cases (242 maxillary sinus) of normal subjects served as group A, 42 cases (65 maxillary sinus) with molar part off were B group, in which 31 maxillary sinus with a molar loss were group B1,22 maxillary sinus with two molar loss were B2 group,12 maxillary sinus with three molar loss (one molar remains) were B3 group, 27 cases (54 maxillary sinus) with upper teeth off were C group. Bymeasureing the maxillary sinus volume, sinus ridge distance and the size of the maxillary sinus, calculating the gasification coefficient, we analyzed the relationship between maxillary volume and sinus ridge distance, and comparatively analyzed the differences among the three groups in the size, gasification coefficient, volume of maxillary sinus and sinus ridge distance. In the normal group,the volume of maxillary sinus and sinus ridge distance had a correlation coefficient of -0. 63,(P< 0.05); Sinus ridge distance in group A was larger than the other two groups (P<0.05), and larger in B group than in C group (P<0. 05), anteroposterior maxillary sinus diameter and reft-right diameter in C group was greater than in A group and B group(P<0.05), group C gasification coeffiecent was less than A group and B group (P<0. 05). The volume of maxillary sinus is negatively correlated with the amont of alveolar bone; Upper teeth's shedding promotes maxillary sinus deformation; Maxiuary sinus volume has a tendency to decrease.

[Shunt and short circuit].

PubMed

Rangel-Abundis, Alberto

2006-01-01

Shunt and short circuit are antonyms. In French, the term shunt has been adopted to denote the alternative pathway of blood flow. However, in French, as well as in Spanish, the word short circuit (court-circuit and cortocircuito) is synonymous with shunt, giving rise to a linguistic and scientific inconsistency. Scientific because shunt and short circuit made reference to a phenomenon that occurs in the field of the physics. Because shunt and short circuit are antonyms, it is necessary to clarify that shunt is an alternative pathway of flow from a net of high resistance to a net of low resistance, maintaining the stream. Short circuit is the interruption of the flow, because a high resistance impeaches the flood. This concept is applied to electrical and cardiovascular physiology, as well as to the metabolic pathways.

A wireless monitoring system for Hydrocephalus shunts.

PubMed

Narayanaswamy, A; Nourani, M; Tamil, L; Bianco, S

2015-08-01

Patients with Hydrocephalus are usually treated by diverting the excess Cerebrospinal Fluid (CSF) to other parts of the body using shunts. More than 40 percentage of shunts implanted fail within the first two years. Obstruction in the shunts is one of the major causes of failure (45 percent) and the detection of obstruction reduces the complexity of the revision surgery. This paper describes a proposed wireless monitoring system for clog detection and flow measurement in shunts. A prototype was built using multiple pressure sensors along the shunt catheters for sensing the location of clog and flow rate. Regular monitoring of flow rates can be used to adjust the valve in the shunt to prevent over drainage or under drainage of CSF. The accuracy of the flow measurement is more than 90 percent.

Chemoembolic Hepatopulmonary Shunt Reduction to Allow Safe Yttrium-90 Radioembolization Lobectomy of Hepatocellular Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaba, Ron C., E-mail: rgaba@uic.edu; VanMiddlesworth, Kyle A.

2012-12-15

Yttrium-90 ({sup 90}Y) radioembolization represents an emerging transcatheter treatment option for the management of hepatocellular carcinoma (HCC). Elevation of the hepatopulmonary shunt fraction risks nontarget radiation to the lungs and may limit the use of {sup 90}Y therapy in patients with locally advanced disease with vascular invasion, who often demonstrate increased shunting. We present two cases in which patients with HCC and portal vein invasion resulting in elevated hepatopulmonary shunt fractions underwent chemoembolic shunt closure to allow safe {sup 90}Y radioembolization. Both patients demonstrated excellent tumor response and patient survival. On this basis, we propose a role for chemoembolic reductionmore » of the lung shunt fraction before {sup 90}Y radioembolization in patients with extensive tumor-related hepatopulmonary shunting.« less

Research of vibration control based on current mode piezoelectric shunt damping circuit

NASA Astrophysics Data System (ADS)

Liu, Weiwei; Mao, Qibo

2017-12-01

The piezoelectric shunt damping circuit using current mode approach is imposed to control the vibration of a cantilever beam. Firstly, the simulated inductance with large values are designed for the corresponding RL series shunt circuits. Moreover, with an example of cantilever beam, the second natural frequency of the beam is targeted to control for experiment. By adjusting the values of the equivalent inductance and equivalent resistance of the shunt circuit, the optimal damping of the shunt circuit is obtained. Meanwhile, the designed piezoelectric shunt damping circuit stability is experimental verified. Experimental results show that the proposed piezoelectric shunt damping circuit based on current mode circuit has good vibration control performance. However, the control performance will be reduced if equivalent inductance and equivalent resistance values deviate from optimal values.

Ascending transaqueductal cystoventriculoperitoneal shunting in Dandy-Walker malformation: technical note.

PubMed

Unal, Omer Faruk; Aras, Yavuz; Aydoseli, Aydin; Akcakaya, Mehmet Osman

2012-01-01

The optimal treatment for Dandy-Walker malformation is still controversial. Ventriculoperitoneal shunting, cystoperitoneal shunting or combinations are the most common surgical options in the management of this clinical entity. Endoscopic procedures like ventriculocystostomy, 3rd ventriculostomy or endoscopy-assisted shunt surgeries have become the focus of recent publications. We describe a new transcystic endoscopic technique, with the usage of a single ascending transaqueductal shunt catheter with additional holes, whereby both the posterior fossa cyst and supratentorial ventricular compartments are drained effectively. By using this new technique complications associated with combined shunting can be avoided. In addition, by equalizing the pressure within the supra- and infratentorial compartments, the upward or downward herniations associated with single-catheter shunting can be prevented. Copyright © 2013 S. Karger AG, Basel.

Persistent hydrocephalus due to postural activation of a ventricular shunt anti-gravity device.

PubMed

Craven, Claudia L; Toma, Ahmed K; Watkins, Laurence D

2017-03-01

The ever present need to balance over drainage with under drainage in hydrocephalus has required innovations including adjustable valves with antigravity devices. These are activated in the vertical position to prevent siphoning. We describe a group of bedridden patients who presented with unexplained under drainage caused by activation of antigravity shunt components produced by peculiar head/body position. Retrospective single centre case series of hydrocephalus patients, treated with ventriculo-peritoneal (VP) shunt insertion between April 2014 - February 2016. These patients presented with clinical and radiological under drainage syndrome. Medical notes were reviewed for clinical picture and outcome. Radiological studies were reviewed assessing shunt placement and ventricular size. Seven patients presented with clinical and radiological under drainage syndrome. A consistent posturing of long term hyper-flexion of the neck whilst lying supine was observed. All patients had similar shunt construct (adjustable Miethke ProGAV valve and shunt assistant anti-gravity component). In each of those patients a hypothesis was formulated that neck flexion was activating the shunt assistance anti-gravity component in supine position. Five patients underwent shunt revision surgery removing the shunt assistant device from the cranium and adding an anti-gravity component to the shunt system at the chest. One had the shunt assistant completely removed and one patient was managed conservatively with mobilisation. All patients had clinical and radiological improvement. Antigravity shunt components implanted cranially in bedridden hydrocephalus patients will produce underdrainage due to head flexion induced anti-gravity device activation. In these patients, anti-gravity devices should be placed at the chest. Alternatively, special nursing attention should be paid to head-trunk angle. Copyright © 2016 Elsevier Ltd. All rights reserved.

Two signs indicative of successful access in nuclear medicine cerebrospinal fluid diversionary shunt studies.

PubMed

Bermo, Mohammed S; Khalatbari, Hedieh; Parisi, Marguerite T

2018-05-08

Successful shunt access is the first step in a properly performed nuclear medicine cerebrospinal fluid (CSF) shunt study. To determine the significance of the radiotracer configuration at the injection site during initial nuclear medicine CSF shunt imaging and the lack of early systemic radiotracer activity as predictors of successful shunt access. With Institutional Review Board approval, three nuclear medicine physicians performed a retrospective review of all consecutive CSF shunt studies performed in children at our institution in 2015. Antecedent nuclear medicine CSF shunt studies in these patients were also assessed and included in the review. The appearance of the reservoir site immediately after radiotracer injection was classified as either figure-of-eight or round/ovoid configuration. The presence or absence of early systemic distribution of the tracer on the 5-min static images was noted and separately evaluated. A total of 98 nuclear medicine ventriculoperitoneal CSF shunt studies were evaluated. Figure-of-eight configuration was identified in 87% of studies and, when present, had 93% sensitivity, 78% specificity, 92% accuracy, 98% positive predictive value (PPV) and 54% negative predictive value (NPV) as a predictor of successful shunt access. Early systemic activity was absent in 89 of 98 studies. Lack of early systemic distribution of the radiotracer had 98% sensitivity, 78% specificity, 96% accuracy, 98% PPV and 78% NPV as a predictor of successful shunt access. Figure-of-eight configuration in conjunction with the absence of early systemic tracer activity had 99% PPV for successful shunt access. Figure-of-eight configuration at the injection site or lack of early systemic radiotracer activity had moderate specificity for successful shunt access. Specificity and PPV significantly improved when both signs were combined in assessment.

Emotion regulation and mania risk: Differential responses to implicit and explicit cues to regulate.

PubMed

Ajaya, Yatrika; Peckham, Andrew D; Johnson, Sheri L

2016-03-01

People prone to mania use emotion regulation (ER) strategies well when explicitly coached to do so in laboratory settings, but they find these strategies ineffective in daily life. We hypothesized that, compared with control participants, mania-prone people would show ER deficits when they received implicit, but not explicit, cues to use ER. Undergraduates (N = 66) completed the Hypomanic Personality Scale (HPS) and were randomly assigned to one of three experimental conditions: automatic ER (scrambled sentence primes), deliberate ER (verbal instructions), or control (no priming or instructions to use ER). Then, participants played a videogame designed to evoke anger. Emotion responses were measured with a multi-modal assessment of self-reported affect, psychophysiology, and facial expressions. Respiratory sinus arrhythmia (RSA) was used to index ER. The videogame effectively elicited subjective anger, angry facial expressions, and heart rate increases when keys malfunctioned. As hypothesized, persons who were more mania prone showed greater RSA increases in the deliberate ER condition than in the automatic or control conditions. One potential limitation is the use of an analog sample. Findings suggest that those at risk for mania require more explicit instruction to engage ER effectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Right-to-left shunt detection sensitivity with air-saline and air-succinil gelatin transcranial Doppler.

PubMed

Puledda, Francesca; Toscano, Massimiliano; Pieroni, Alessio; Veneroso, Gabriele; Di Piero, Vittorio; Vicenzini, Edoardo

2016-02-01

Air-saline transcranial Doppler is nowadays the first-choice examination to identify right-to-left shunt. To increase right-to-left shunt detection in echocardiography, cardiologists also use air-gelatin mixtures, which are more stable, more echogenic, and easier to be prepared. We assessed the sensitivity of air-gelatin compared with air-saline for transcranial Doppler right-to-left shunt detection. Air-saline transcranial Doppler, during unilateral middle cerebral artery monitoring at rest and after Valsalva maneuver, was performed in patients referred to our neurosonology laboratory for right-to-left shunt detection. The same transcranial Doppler protocol was repeated with air-gelatin. To consider transcranial Doppler positive for cardiac right-to-left shunt, at least one embolic signal had to be detected within 20″ from contrast injection. Later signals were interpreted of pulmonary origin. Trans-thoracic echocardiography was repeated with both air-saline and air-gelatin. A total of 97 patients were enrolled; 46 had negative transcranial Doppler for cardiac right-to-left shunt with both air-saline and air-gelatin; out of these, four patients with air-saline plus two more patients with air-gelatin presented late, isolated microemboli, slightly more numerous with air-gelatin: these were interpreted as pulmonary shunts and confirmed with trans-thoracic echocardiography. In 28 patients with already early positive air-saline transcranial Doppler at rest, air-gelatin induced a marked right-to-left shunt increase, facilitating its visualization at trans-thoracic echocardiography. In 23 patients in whom air-saline transcranial Doppler was negative at rest and positive for cardiac right-to-left shunt only after Valsalva maneuver, air-gelatin was able to reveal shunt also at rest. Air-gelatin increases right-to-left shunt detection sensitivity with transcranial Doppler in particular at rest, even in patients in whom air-saline mixture fails to identify the shunt. The choice of air-gelatin mixture should be considered for multicentric, clinical, and research trials. © 2016 World Stroke Organization.

A rare congenital extrahepatic portosystemic shunt affecting the inferior mesenteric vein, inferior vena cava, and left ovarian vein.

PubMed

Takeuchi, Hajime; Takeda, Yoko; Takahashi, Miyo; Hayashi, Shogo; Fukuzawa, Yoshitaka; Nakano, Takashi

2014-09-01

To observe a case of congenital extrahepatic portosystemic shunt and discuss it from the embryological and clinical viewpoints. An 85-year-old female cadaver was employed for a dissection course at Aichi Medical University in 2009. There was no evidence of liver cirrhosis macroscopically or microscopically. A portosystemic shunt was observed that involved communication between the inferior mesenteric vein, inferior vena cava (IVC), and left ovarian vein by a single Y-shaped shunt vessel. To the best of our knowledge, this is the first reported case of the above-mentioned three veins being connected by a single Y-shaped shunt vessel. Considering the other venous diameters, the shunt appeared to flow into the splenic vein and IVC. It cannot be denied that this shunt may have led to hepatic encephalopathy, although the shunt effect may have been minimal. Embryological development of IVC appears to occur close to the plexus of anastomosing vitelline veins, forming the portal vein.

[Selective portal-systemic shunts for bleeding portal hypertension].

PubMed

Orozco, H; Mercado, M A; Takahashi, T; García-Tsao, G; Guevara, L; Hernandez-Ortiz, J; Tielve, M

1990-07-01

At the beginning of the seventies, we began to perform regularly selective shunts for the treatment of portal hypertension. In a 15 year period, 177 patients (155 with liver cirrhosis) were operated with three kinds of selective shunts: 128 with a Warren shunt, 29 with an end to end renosplenic shunt and 20 with a splenocaval shunt. 167 cases were operated in an elective fashion. The 15 years global operative mortality, was 14.4%. Operative mortality of the Child A patients, was 11.6%. Survival for the Child A group was 74.6% at 1 year, 68.2% at 5 years and 64.6% at 15 years. Incapacitating encephalopathy was observed in 6.9%, rebleeding 6.2% and shunt thrombosis in 6.2%. Portal vein alterations in the postoperative period were observed: in 13.3% a reduction in diameter ocurred and in 20.5%, thrombosis was recorded. It is concluded that when feasible, the selective shunts are the treatment of choice for portal hypertension in those patients with good liver function.

40 CFR 63.1344 - Affirmative defense for violation of emission standards during malfunction.

Code of Federal Regulations, 2013 CFR

2013-07-01

... defense to a claim for civil penalties for violations of such standards that are caused by malfunction, as... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering...

40 CFR 63.1344 - Affirmative defense for violation of emission standards during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... defense to a claim for civil penalties for violations of such standards that are caused by malfunction, as... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering...

Successful embolization using interlocking detachable coils for a congenital extrahepatic portosystemic venous shunt in a child.

PubMed

Yamagami, Takuji; Yoshimatsu, Rika; Matsumoto, Tomohiro; Terayama, Koshi; Nishiumra, Akira; Maeda, Yousuke; Nishimura, Tsunehiko

2007-11-01

The authors report the case of a 6-year-old boy with a congenital extrahepatic portosystemic venous shunt. He had hyperammonemia. The shunt was 18 mm in diameter and located between the inferior mesenteric vein and the left internal iliac vein. The flow in the shunt was very rapid. After decreasing blood flow by inflating a balloon catheter inserted into the left internal iliac vein from the femoral vein, a microcatheter was coaxially advanced to the shunt to embolize the shunt. Embolization was successfully performed with interlocking detachable coils and microcoils without any complication. This patient's hyperammonemia resolved soon after the procedure.

Design and simulation of RF MEMS SPST shunt and SPDT shunt-shunt switches for X-band and Ku-band applications

NASA Astrophysics Data System (ADS)

Lenka, Manas K.; Sharma, Amit; Sharma, Jaibir; DasGupta, Amitava

2012-10-01

This paper describes the design and simulation of RF MEMS SPST shunt and SPDT shunt-shunt switches with modified coplanar waveguide (CPW) configuration for X-band and Ku-band applications exhibiting high isolation and low insertion loss. By modifying the basic CPW structure for a six-strip membrane having length 720 μm, the resonant frequency can be reduced from 33.5 GHz to 13.5 GHz with isolation as high as -30 dB(-63 dB at resonant frequency) in Ku-band. Similar results are also found in case SPST and SPDT switches with other membrane types.

Single-Session Percutaneous Endovascular Mesocaval Shunt Creation and Balloon-Occluded Retrograde Transvenous Obliteration for the Treatment of Gastric Varices.

PubMed

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.

Interventional embolization of congenital intrahepatic shunts in children.

PubMed

Wu, Lin; Zhao, Lu; Lu, Ying; He, Lan; Hu, Xihong

2016-04-01

Congenital intrahepatic shunts in children are rare and precise treatment strategies have not been established. The purpose of this study was to present our experience with transcatheter embolization in a descriptive case series of congenital intrahepatic shunts in children. We retrospectively studied 10 children with symptomatic congenital intrahepatic shunts who were treated with embolization at our institute between January 2008 and December 2014. Seven children had arteriovenous shunts in association with hepatic hemangiomas, two had arterioportal shunts and one had portosystemic shunts. The major presentations were congestive heart failure and severe anemia in the groups with arteriovenous and arterioportal shunts, respectively. Following embolization, two children died in the arteriovenous group, one from progressive liver dysfunction and the other from abdominal compartment syndrome. One child in the arterioportal group required liver transplantation after initial embolization. With mean post-procedure follow-up of 15 months (range 4-54 months), all the remaining children were well, with resolution of the symptoms. Interventional embolization provides an alternative to surgical ligation or hepatic resection in children with clinically significant intrahepatic shunts. For lesions with complex morphology, embolization may be inadequate and liver transplantation might be the only therapeutic option.

Prediction of Susceptibility to Acute Mountain Sickness Using Hypoxia-Induced Intrapulmonary Arteriovenous Shunt and Intracardiac Shunt Fractions

DTIC Science & Technology

2013-10-01

echocardiography to determine bubble/shunt scores. We will also use nuclear medicine imaging to determine shunt fractions following acute exposures to... echocardiography while breathing hypoxic gas mixtures. – TASK COMPLETED. For Task #1.3 “Quantify shunt during hypoxic exposure with SPECT CT – PFO...subjects.” 19 PFO+ subjects have completed saline contrast echocardiography while breathing hypoxic gas mixtures for 30 min. One PFO+ subject that had

Treatment of Portosystemic Shunt Myelopathy with a Stent Graft Deployed through a Transjugular Intrahepatic Route

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jain, Deepak, E-mail: deepakjain02@yahoo.com; Arora, Ankur, E-mail: aroradrankur@yahoo.com; Deka, Pranjal, E-mail: drpranjaldeka@gmail.com

2013-08-01

A case of surgically created splenorenal shunt complicated with shunt myelopathy was successfully managed by placement of a stent graft within the splenic vein to close the portosystemic shunt and alleviate myelopathy. To our knowledge, this is the first report of a case of shunt myelopathy in a patient with noncirrhotic portal fibrosis without cirrhosis treated by a novel technique wherein a transjugular intrahepatic route was adopted to deploy the stent graft.

Reduction of shunt obstructions by using a peel-away sheath technique? A multicenter prospective randomized trial.

PubMed

Kehler, Uwe; Langer, Niels; Gliemroth, Jan; Meier, Ullrich; Lemcke, Johannes; Sprung, Christian; Schlosser, Hans-Georg; Kiefer, Michael; Eymann, Regina; Heese, Oliver

2012-05-01

Shunt obstructions may partly be caused by brain debris, which intrude into the ventricular catheter during ventricle puncture. Avoiding contact between the catheter and brain tissue, by using a peel-away sheath, should reduce the number of shunt failures caused by obstruction. To test this hypothesis, we conducted a randomized, prospective multicenter study. 201 patients from 6 different neurosurgical centers in Germany receiving a ventriculo-peritoneal shunt were included in this study. Of these, 177 patients completed a 1-year follow-up period. Surgery was randomized in a 1 to 1 fashion, such that out of 177 procedures, 91 were performed using a peel-away sheath and 86 were performed without. The rate of surgical re-interventions and shunt obstructions within a 12-month period was recorded. Within 1 year post-surgery, 17 shunt obstructions (9.6%) leading to shunt revisions were recorded. However, no difference was found between surgeries performed using a peel-away sheath (9.9%) or not (9.3%). The overall shunt infection rate was 2.8% and the shunt revision rate for overdrainage was 3.9%. The theoretical advantages attributed to the use of a peel-away sheath to introduce a ventricular catheter could not be confirmed in this randomized study, suggesting that the proposed role of brain debris in shunt obstructions may be overestimated. Copyright © 2011 Elsevier B.V. All rights reserved.

Morphology of congenital portosystemic shunts involving the right gastric vein in dogs.

PubMed

White, R N; Parry, A T

2015-07-01

To describe the anatomy of congenital portosystemic shunts involving the right gastric vein in dogs. Retrospective review of a consecutive series of dogs managed for congenital portosystemic shunt. Twenty-two dogs met the inclusion criteria of a congenital portosystemic shunt involving the right gastric vein with recorded intraoperative mesenteric portovenography or computed tomography angiography and gross observations at the time of surgery. Of these, 20 (91%) had a shunt that entered the pre-hepatic caudal vena cava at the level of the epiploic foramen and two (9%) had a shunt that entered the post-hepatic caudal vena cava at the level of the diaphragm. Shunts entering the pre-hepatic caudal vena cava could be further classified into three consistent subdivisions. The morphology of each shunt type described appeared to be a result of an abnormal communication between the left gastric vein and the caudal vena cava, the presence or absence of an abnormal communication between the splenic, left gastric and portal veins and the subsequent development of preferential blood flow through essentially normal portal vessels within the portal venous system. The abnormal communication (shunt) was through the left gastric vein and not the right gastric vein, as might have been expected. This information may help with surgical planning in cases undergoing shunt closure surgery. © 2015 British Small Animal Veterinary Association.

Right-to-left shunt may be prone to affect the white matter integrity of posterior circulation in migraine without aura.

PubMed

Xie, Hui; Bian, Yitong; Jian, Zhijie; Huo, Kang; Liu, Rui; Zhu, Dan; Zhang, Lihui; Wu, Jun; Yang, Jian; Liu, Jixin; Luo, Guogang

2018-01-01

Numerous studies have indicated an association between migraine and right-to-left shunt. However, little is known about whether right-to-left shunt has an effect on the migraine brain. This observational study aims to explore the impact of right-to-left shunt on the brain of migraine without aura on microstructural level. Thirty-five patients with migraine without aura were enrolled in this study. Contrast-enhanced Transcranial Doppler was performed to evaluate the status of right-to-left shunt. Three-dimensional T1-weighted and diffusion tensor images were acquired for data analysis. We employed voxel-based morphometry and tract-based spatial statistical analyses to assess the differences of gray and white matter between migraineurs with and without right-to-left shunt, respectively. Among the 35 patients, 19 (54.3%) patients had right-to-left shunt. There were no significant differences in headache features between migraineurs with and without right-to-left shunt. There were significant increases of mean and radial diffusivity in migraineurs with right-to-left shunt compared with migraineurs without right-to-left shunt. The alterations were primarily located in the right posterior thalamic radiation, secondly in the body of corpus callosum and the right superior corona radiata. No significant differences were observed in values of fractional anisotropy and axial diffusivity. No significant between-group differences were found in gray matter volume. Right-to-left shunt may cause alterations of white matter integrity in migraine without aura, and the alterations are more likely to be located at the posterior circulation.

Congenital portosystemic shunts: prenatal manifestations with postnatal confirmation and follow-up.

PubMed

Han, Byoung Hee; Park, Sung Bin; Song, Mi Jin; Lee, Kyung Sang; Lee, Young-Ho; Ko, Sun Young; Lee, Yeon Kyung

2013-01-01

The purpose of this study was to evaluate prenatal sonographic findings that could be helpful for diagnosis of congenital intrahepatic portosystemic venous shunts and the follow-up results. Six neonates with congenital shunts between the portal vein and hepatic vein were enrolled in this study. Prenatal sonography was performed in 5 cases. We categorized the cases according to a previously published classification of intrahepatic portosystemic venous shunts and retrospectively reviewed the prenatal and postnatal sonographic examinations to identify findings that might be helpful for diagnosing shunts prenatally. Follow-up sonographic examinations were done until closure of the shunts. Clinical features were also determined. According to the original reports, intrahepatic portosystemic venous shunts were diagnosed by prenatal sonography in 2 of 5 cases. In the remaining 3 cases, there were suggestive abnormal findings on retrospective review, including an abnormal intrahepatic tubular structure, a prominent hepatic vein, and congestive heart failure. Postnatal sonography showed type 2 shunts in all 6 cases. In 1 case, there were 2 type 2 lesions between two branches of the left portal vein and the middle and left hepatic veins. On follow-up sonography, 5 of the 6 congenital shunts had spontaneously closed by 11 months of age. One case was treated with coil embolization during the neonatal period. Intrauterine growth restriction was the most commonly clinical feature prenatally. Findings such as an abnormal tubular structure, a prominent hepatic vein, and congestive heart failure can be important clues for identifying congenital intrahepatic portosystemic venous shunts on prenatal sonography. The use of prenatal and postnatal sonography is feasible for detection and evaluation of these shunts.

Use of intraoperative venography to guide the distal portion of a ventriculoatrial shunt past an obstruction in the central veins: technical case report.

PubMed

Momin, Eric N; Recinos, Pablo F; Coon, Alexander L; Rigamonti, Daniele

2010-06-01

Ventriculoatrial (VA) shunting is commonly used to treat hydrocephalus when ventriculoperitoneal shunting has failed. Placement of a VA shunt in patients with narrowing or occlusion of the central veins presents considerable difficulty because few imaging modalities exist to safely and reliably insert a guidewire or atrial catheter past the occlusion. We report the use of intraoperative venography to guide the placement of the distal portion of a VA shunt in a patient with a valve blocking the left brachiocephalic vein. A 42-year-old man with pseudotumor cerebri and a left ventriculoperitoneal shunt presented with severe headaches. He was diagnosed with partial distal shunt obstruction. Because of a history of failed attempts at ventriculoperitoneal shunting, conversion to a VA shunt via the left internal jugular vein was planned. Surgery was performed by using the standard technique until resistance was encountered when inserting a guidewire into the internal jugular vein. Intraoperative venography of the central veins was performed, which showed a large valve blocking progression of the guidewire in the left brachiocephalic vein. Using fluoroscopic guidance, a 0.035-inch guidewire was successfully directed through the vein past the obstruction and exchanged for a peel-away introducer. The distal shunt catheter was then inserted, and the correct position in the atrium was confirmed fluoroscopically. When obstruction of the central veins is found during a VA shunting procedure, intraoperative venography is a useful method to aid in the placement of the atrial catheter through the central veins.

The Electrophysiologic Effects of Acute Mitral Regurgitation in a Canine Model.

PubMed

Lawrance, Christopher P; Henn, Matthew C; Miller, Jacob R; Kopek, Michael A; Zhang, Andrew J; Schuessler, Richard B; Damiano, Ralph J

2017-04-01

Atrial fibrillation (AF) occurs in 30% of patients with mitral regurgitation referred for surgical intervention. However, the underlying mechanisms in this population are poorly understood. This study examined the effects of acute left atrial volume overload on atrial electrophysiology and the inducibility of AF. Ten canines underwent insertion of an atrioventricular shunt between the left ventricle and left atrium. Shunt and aortic flows were calculated, and the shunt was titrated to a shunt fraction to 40% to 50% of cardiac output. An epicardial plaque with 250 bipolar electrodes was used to determine activation and refractory periods. Biatrial pressures and volumes, conduction times, and atrial fibrillation inducibility were recorded. Data were collected at baseline and 20 minutes after shunt opening and closure. Mean shunt flow was 1.3 ± 0.5 L/min with a shunt fraction of 43% ± 6% simulating moderate to severe mitral regurgitation. Compared with baseline, left atrial volumes and maximum pressures increased by 27% and 29%, respectively, after shunt opening. Biatrial effective refractory periods did not change significantly after shunt opening or closure. Conduction times increased by 9% with shunt opening and returned to baseline after closure. AF duration or inducibility did not change with shunt opening. This canine model of mitral regurgitation demonstrated that acute left atrial volume overload did not increase the inducibility of atrial arrhythmias in contrast with experimental and clinical findings of chronic left atrial volume overload. This suggests that the substrates for AF in patients with mitral regurgitation are a result of chronic remodeling. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Diamox((R)) challenge test to decide indications for cerebrospinal fluid shunting in normal pressure hydrocephalus.

PubMed

Miyake, H; Ohta, T; Kajimoto, Y; Deguchi, J

1999-01-01

The indications for cerebrospinal fluid (CSF) shunting in patients with normal pressure hydrocephalus (NPH) have not been established. Establishment of clear-cut indications for this procedure is essential to ensure cost-effective, and safe treatment. We report the usefulness of the Diamox((R)) challenge test in evaluating indications for CSF shunting in patients with NPH. Pre- and post-operative responses in cerebral blood flow (CBF) and intracranial pressure (ICP) to intravenous administration of Diamox((R)) 1000mg (Diamox((R)) administration) were analysed in 41 patients with NPH who were treated by ventriculoperitoneal (VP) shunt with a programmable valve and an on-off valve. The preoperative response of ICP to Diamox((R)) administration was more than 10 mmHg in most patients in whom the shunt was effective (shunt effective group), however, it was less than 10 mmHg in most patients in whom the shunt was ineffective (shunt non-effective group). Furthermore, the postoperative response of ICP to Diamox((R)) administration decreased to less than 10 mmHg in most patients in the shunt effective group. The increases in CBF in response to Diamox((R)) administration were similar in the two groups both before and after placement of the VP shunt. Patients in whom ICP increased by more than 10 mmHg in response to Diamox((R)) administration were regarded to have poor CSF circulation and to thus be candidates for CSF shunting. The Diamox((R)) challenge test is a simple, safe procedure, useful in evaluating the response to treatment.

A rare and important case of Staphylococcus haemolyticus-associated ventricular atrial shunt nephritis.

PubMed

Suen, Kyle; Mashhadian, Ardavan; Figarsky, Ian; Payumo, Jeff; Liu, Antonio

2017-12-01

Shunt nephritis is a rare and relatively new diagnosis involving glomerular kidney damage following ventriculoperitoneal and ventriculoatrial shunt placement. Our case report summarizes the presentation, diagnostic workup, and management of a patient with shunt nephritis. We also review and discuss the current literature on the topic.

Effects of a malfunctional column on conventional and FeedCol-simulated moving bed chromatography performance.

PubMed

Song, Ji-Yeon; Oh, Donghoon; Lee, Chang-Ha

2015-07-17

The effects of a malfunctional column on the performance of a simulated moving bed (SMB) process were studied experimentally and theoretically. The experimental results of conventional four-zone SMB (2-2-2-2 configuration) and FeedCol operation (2-2-2-2 configuration with one feed column) with one malfunctional column were compared with simulation results of the corresponding SMB processes with a normal column configuration. The malfunctional column in SMB processes significantly deteriorated raffinate purity. However, the extract purity was equivalent or slightly improved compared with the corresponding normal SMB operation because the complete separation zone of the malfunctional column moved to a lower flow rate range in zones II and III. With the malfunctional column configuration, FeedCol operation gave better experimental performance (up to 7%) than conventional SMB operation because controlling product purity with FeedCol operation was more flexible through the use of two additional operating variables, injection time and injection length. Thus, compared with conventional SMB separation, extract with equivalent or slightly better purity could be produced from FeedCol operation even with a malfunctional column, while minimizing the decrease in raffinate purity (less than 2%). Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 63.1354 - Reporting requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... operator during a startup, shutdown, or malfunction of an affected source (including actions taken to correct a malfunction) are consistent with the procedures specified in the source's startup, shutdown, and... report. Reports shall only be required if a startup, shutdown, or malfunction occurred during the...

Gel-Sinuplasty for Chronic Rhinosinusitis With and Without Nasal Polyposis

ClinicalTrials.gov

2018-03-13

Chronic Sinusitis, Ethmoidal; Chronic Sinusitis - Ethmoidal Anterior; Chronic Sinusitis; Chronic Sinusitis - Ethmoidal, Posterior; Chronic Sinusitis, Sphenoidal; Chronic Sinusitis - Frontoethmoidal; Nasal Polyps; Nasal Polyp - Posterior

Haziness in X-Ray Paranasal Sinus Water's View in Sinusitis: A Fact or Fiction.

PubMed

Gujrathi, Aatish; Wakode, P T

2013-08-01

It is a clinical dilemma whether patients having no symptoms of sinusitis but sinus haziness in X-ray should be considered as sinusitis or not and patients clinically having sinusitis and do not have radiological evidence should be considered as case of sinusitis or not. This study is an attempt to discuss this issue in details. To study diagnostic efficacy of conventional X-ray para nasal sinus water's view in sinusitis. To study the proportion of asymptomatic individuals showing haziness in conventional X-ray para nasal sinus water's view. Sensitivity and specificity of sinus X-ray in combination (conventional + digital) is 95 and 44%, respectively. Proportion of asymptomatic individuals showing haziness in conventional X-ray and digital X-ray paranasal sinus water's view are 52.4 and 75%, respectively. X-ray paranasal sinus water's view undoubtedly yields valuable information regarding sinus pathology. However it should not be accepted as a diagnosis in itself, but considered in the light of patient's history and clinical findings.

Patient data system for monitoring shunts.

PubMed

Frank, E; Su, E; Smith, K

1988-01-01

Rapidly locating accurate data on a patient's shunt system is often extremely difficult. We have developed a simple system to fill a perceived need for recording current data on a patients shunt. This system employs an easily updated record in the patient's hospital or clinic chart as well as a wallet-sized data card for the patient or his family to carry. The data in the chart include the configuration of the patient's current shunt system and a graphic record of previous shunt problems. The small patient data card describes the age of the shunt system and its current configuration. We have found that this system provides assistance in the routine follow-up of patients with shunts and plays an extremely necessary role in the emergency evaluation of these patients, particularly when an emergency evaluation is undertaken in facilities distant from the location of regular treatment.

Sodium accumulation at potential-induced degradation shunted areas in polycrystalline silicon modules

DOE PAGES

Harvey, Steven P.; Aguiar, Jeffery A.; Hacke, Peter; ...

2016-09-19

Here, we investigated potential-induced degradation (PID) in silicon mini-modules that were subjected to accelerated stressing to induce PID conditions. Shunted areas on the cells were identified with photoluminescence and dark lock-in thermography (DLIT) imaging. The identical shunted areas were then analyzed via time-of-flight secondary-ion mass spectrometry (TOFSIMS) imaging, 3-D tomography, and high-resolution transmission electron microscopy. The TOF-SIMS imaging indicates a high concentration of sodium in the shunted areas, and 3-D tomography reveals that the sodium extends more than 2 um from the surface below shunted regions. Transmission electron microscopy investigation reveals that a stacking fault is present at an areamore » identified as shunted by DLIT imaging. After the removal of surface sodium, tomography reveals persistent sodium present around the junction depth of 300 nm and a drastic difference in sodium content at the junction when comparing shunted and nonshunted regions.« less

49 CFR 236.57 - Shunt and fouling wires.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Shunt and fouling wires. 236.57 Section 236.57...: All Systems Track Circuits § 236.57 Shunt and fouling wires. (a) Except as provided in paragraph (b) of this section, shunt wires and fouling wires hereafter installed or replaced shall consist of at...

49 CFR 236.57 - Shunt and fouling wires.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Shunt and fouling wires. 236.57 Section 236.57...: All Systems Track Circuits § 236.57 Shunt and fouling wires. (a) Except as provided in paragraph (b) of this section, shunt wires and fouling wires hereafter installed or replaced shall consist of at...

Portosystemic shunts for extrahepatic portal hypertension in children.

PubMed

Tocornal, J; Cruz, F

1981-07-01

Twenty-three children with prehepatic portal hypertension and hemorrhage due to ruptured esophagogastric varices had portosystemic shunts. Their ages ranged from two years and seven months to 15 years. Eleven were less than eight years of age. Twenty patients had portal vein cavernomatosis and three patients had double portal veins. In 21 patients, a mesocaval type of shunt was done. A splenorenal shunt was performed in two. There was no surgical mortality. Two shunts occluded, both in rather young infants--two years and seven months and three years of age. In all the others, there was no further bleeding, and the shunts remained patent, as shown by abdominal angiograms. Neuropsychiatric disorders, probably due to hepatic encephalopathy, occurred in only one patient. On the basis of this favorable experience, we believe that an elective portosystemic shunt should, in general, be performed upon children with prehepatic portal hypertension after one major variceal hemorrhage. We favor a mesocaval type of shunt in these children because of the larger diameter of the vessels involved in the anastomosis and because it preserves the spleen, maintaining defense against subsequent infection.

A novel method for passing cerebrospinal fluid shunt tubing: a proof of principle study.

PubMed

Tubbs, R Shane; Goodrich, Dylan; Tubbs, Isaiah; Loukas, Marios; Cohen-Gadol, Aaron A

2014-12-01

Few innovations in the method of tunneling shunt tubing for cerebrospinal fluid (CSF) shunt diversion have been made since this treatment of hydrocephalus was first developed. Therefore, this feasibility study was performed with the hope of identifying an improved technique that could potentially carry fewer complications. On 10 cadaver sides and when placed in the supine position, small skin incisions were made at the clavicle and ipsilateral subcostal region, and magnets were used to pass standard shunt tubing between the two incisions. Nickel-plated magnets were less effective in pulling the shunt tubing below the skin compared with ceramic magnets. Of these, magnets with pull strengths of 150-200 lbs were the most effective in dragging the subcutaneous tubing between the two incisions. No obvious damage to the skin from the overlying magnet was seen in any specimen. Few options exist for tunneling distal shunt tubing for CSF shunt procedures. Future patient studies are needed to determine if the technique described herein is superior to current methods, particularly when examining patient groups that are at a greater risk for injury during tunneling shunt catheters.

Are Shunt Revisions Associated with IQ in Congenital Hydrocephalus? A Meta -Analysis.

PubMed

Arrington, C Nikki; Ware, Ashley L; Ahmed, Yusra; Kulesz, Paulina A; Dennis, Maureen; Fletcher, Jack M

2016-12-01

Although it is generally acknowledged that shunt revisions are associated with reductions in cognitive functions in individuals with congenital hydrocephalus, the literature yields mixed results and is inconclusive. The current study used meta-analytic methods to empirically synthesize studies addressing the association of shunt revisions and IQ in individuals with congenital hydrocephalus. Six studies and three in-house datasets yielded 11 independent samples for meta-analysis. Groups representing lower and higher numbers of shunt revisions were coded to generate effect sizes for differences in IQ scores. Mean effect size across studies was statistically significant, but small (Hedges' g = 0.25, p < 0.001, 95 % CI [0.08, 0.43]) with more shunt revisions associated with lower IQ scores. Results show an association of lower IQ and more shunt revisions of about 3 IQ points, a small effect, but within the error of measurement associated with IQ tests. Although clinical significance of this effect is not clear, results suggest that repeated shunt revisions because of shunt failure is associated with a reduction in cognitive functions.

Ventriculoperitoneal shunt infection in Haji Adam Malik Hospital, Medan

NASA Astrophysics Data System (ADS)

Dharmajaya, R.

2018-03-01

Installation of ventriculoperitoneal shunts (VP) represented a substantial progress in the neurosurgical management of hydrocephalus in children. However, infection is the most commonpostoperative complication of aventriculoperitoneal shunt. It is important because it is related to substantial morbidity and mortality, and exerts a negative impact on the quality of life of patients. We retrospectively analyzed all 20 cases of shunt infection from 2013 to 2016. The types of infections found were exposed shunts15 cases (75%), and 5 cases of ventriculitis (25%). Length of infection time which calculated from the beginning of surgery was 350.20 days or 11 months. The most common pathogen types are S. epidermidis followed by P. aeruginosa, E. coli, and A. baumanii. There were many risk factors for shunt infection, but the interesting fact was the level of pre-operative albumin. There was a significant difference between low albumin levels (<3.0) and normal albumin (≥3.0) levels against the risk of exposure shunt, p = 0.015. It means there is asignificant difference between low pre-operative albumin and normal level for the risk of theexposed shunt.

Congenital portosystemic shunts: imaging findings and clinical presentations in 11 patients.

PubMed

Konstas, Angelos A; Digumarthy, Subba R; Avery, Laura L; Wallace, Karen L; Lisovsky, Mikhail; Misdraji, Joseph; Hahn, Peter F

2011-11-01

To evaluate the clinical anatomy and presentations of congenital portosystemic shunts, and determine features that promote recognition on imaging. Institutional review board approval was obtained for this HIPAA-compliant study. The requirement for written informed consent was waived. Radiology reports were retrospectively reviewed from non-cirrhotic patients who underwent imaging studies from January 1999 through February 2009. Clinical sources reviewed included electronic medical records, archived images and histopathological material. Eleven patients with congenital portosystemic shunts were identified (six male and five female; age range 20 days to 84 years). Seven patients had extrahepatic and four patients had intrahepatic shunts. All 11 patients had absent or hypoplastic intrahepatic portal veins, a feature detected by CT and MRI, but not by US. Seven patients presented with shunt complications and four with presentations unrelated to shunt pathophysiology. Three adult patients had four splenic artery aneurysms. Prospective radiological evaluation of five adult patients with cross-sectional imaging had failed prospectively to recognize the presence of congenital portosystemic shunts on one or more imaging examinations. Congenital portosystemic shunts are associated with splenic artery aneurysms, a previously unrecognized association. Portosystemic shunts were undetected during prospective radiologic evaluation in the majority of adult patients, highlighting the need to alert radiologists to this congenital anomaly. Copyright © 2010. Published by Elsevier Ireland Ltd.

40 CFR 63.1354 - Reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... owner or operator during a startup, shutdown, or malfunction of an affected source (including actions taken to correct a malfunction) are consistent with the procedures specified in the source's startup... information in a semiannual report. Reports shall only be required if a startup, shutdown, or malfunction...

40 CFR 52.1183 - Visibility protection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... excess emissions that occurs during startups, shutdowns, and malfunctions of the unit, the nature and... that occurs during startups, shutdowns, and malfunctions of the unit, the nature and cause of any... startup, shutdown, and malfunction. (viii) All CEMS required by this section must meet the minimum data...

40 CFR 63.1111 - Startup, shutdown, and malfunction.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Startup, shutdown, and malfunction. 63.1111 Section 63.1111 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown, and...

Congenital Shunts of the Portal Venous System: Case-series of Uncommon Shunts.

PubMed

Santos, Liliana; Nobre, Susana; Laezza, Nadia; Cunha, Catarina; Gonçalves, Isabel; Lopes, Maria F

Congenital shunts of the portal venous system are rare entities that can present in children with clinical heterogeneity. To evaluate the clinical course of children with uncommon shunts presenting to our institution and examine the available literature on this topic. Medical records of children with rare forms of congenital shunts were retrospectively reviewed for demographics, symptoms, management, and outcome between 2003 and 2016. Three female patients with congenital shunts, including a congenital mesenterico-portal Rex shunt (n = 1) and congenital portosystemic shunts (CPSS) (n = 2), were referred for surgical evaluation between ages 4 and 9. Median follow-up was 8 years (range, 6-13 years). One asymptomatic patient did not require treatment and remained disease-free during long-term follow-up. The other 2 patients with CPSS and unusual symptoms, including liver focal nodular hyperplasia (FNH) in infancy (n = 1) and bleeding from esophageal varices (n = 1), showed subsequent progression to liver nodules that were managed by endovascular shunt occlusion. One patient showed symptom resolution and the other showed stable lesions at last follow-up. Literature yielded descriptions of two cases of congenital mesenterico-portal Rex shunt, one case of coincident CPSS and FNH in infancy, but zero reports of bleeding from esophageal varices. This case series examines each distinct patient's presentation, discusses the diagnosis, management and outcome and compares findings while discussing literature on this topic. A high index of suspicion and familiarity with unusual forms and treatment options is required to allow timely diagnosis and appropriate treatment.

Predictors of Shunt Dysfunction and Overall Survival in Patients with Variceal Bleeding Treated with Transjugular Portosystemic Shunt Creation Using the Fluency Stent Graft.

PubMed

Wan, Yue-Meng; Li, Yu-Hua; Xu, Ying; Wu, Hua-Mei; Li, Ying-Chun; Wu, Xi-Nan; Yang, Jin-Hui

2018-01-16

Transjugular intrahepatic portosystemic shunt (TIPS) is an established method for portal hypertension. This study was to investigate the long-term safety, technical success, and patency of TIPS, and to determine the risk factors and clinical impacts of shunt dysfunction. A total of 154 consecutive patients undergoing embolotherapy of gastric coronary vein and/or short gastric vein and TIPS creation were prospectively studied. Follow-up data included technical success, patency and revision of TIPS, and overall survival of patients. During the study, the primary and secondary technical success rates were 98.7% and 100%, respectively. Sixty-three patients developed shunt dysfunction, 30 with shunt stenosis and 33 with shunt occlusion. The cumulative 60-month primary, primary assisted, and secondary patency rates were 19.6%, 43.0%, and 93.4%, respectively. The cumulative 60-month overall survival rates were similar between the TIPS dysfunction group and the TIPS non-dysfunction group (68.6% vs. 58.6%, P = .096). Baseline portal vein thrombosis (P < .001), use of bare stents (P = .018), and portal pressure gradient (PPG) (P = .020) were independent predictors for shunt dysfunction, hepatocellular carcinoma (P < .001), and ascites (P = .003) for overall survival. The accuracy of PPG for shunt dysfunction was statistically significant (P < .001), and a cutoff value of 8.5 had 77.8% sensitivity and 64.8% specificity. The long-term safety, technical success, and patency of TIPS were good; baseline portal vein thrombosis, use of bare stents, and PPG were significantly associated with shunt dysfunction; shunt dysfunction has little impact on patients' long-term survival because of high secondary patency rates. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Clinical and economic consequences of antibiotic-impregnated cerebrospinal fluid shunt catheters.

PubMed

Eymann, Regina; Chehab, Somar; Strowitzki, Martin; Steudel, Wolf-Ingo; Kiefer, Michael

2008-06-01

The authors evaluated the safety and efficacy of antibiotic-impregnated shunt catheters (AISCs) and determined the cost-benefit ratio related to the fact that AISCs increase the implant costs of a shunt procedure by approximately $400 per patient. The control group comprised 98 adults with chronic hydrocephalus and 22 children, who were treated without AISCs (non-AISCs). In the treatment group, AISCs (Bactiseal, Codman, Johnson & Johnson) were implanted in 171 adults and 26 children. The minimum follow-up period was 6 months. Important risk factors for shunt infections (such as age, comorbidity, cause of hydrocephalus, operating time, and duration of external cerebrospinal fluid drainage prior to shunt placement) did not differ between the study and control groups. In the pediatric AISC group, the frequency of premature, shunt-treated infants and the incidence of external ventricular drainage prior to shunt insertion were actually higher than those in the non-AISC group. When using AISCs, the shunt infection rate dropped from 4 to 0.6% and from 13.6 to 3.8% in the adult and the pediatric cohort, respectively. Overall the infection rate decreased from 5.8 to 1%, which was statistically significant (p = 0.0145). The average costs of a single shunt infection were $17,300 and $13,000 in children and adults, respectively. The cost-benefit calculation assumed to have saved shunt infection-related costs of approximately $50,000 in 197 AISC-treated patients due to the reduction in shunt infection rate in this group compared with costs in the control group. Despite the incremental implant costs associated with the use of AISCs, the overall reduction in infection-related costs made the use of AISCs cost beneficial in the authors' department. From clinical and economic perspectives, AISCs are seemingly a valuable addition in hydrocephalus therapy.

Use of mathematic modeling to compare and predict hemodynamic effects of the modified Blalock-Taussig and right ventricle-pulmonary artery shunts for hypoplastic left heart syndrome.

PubMed

Bove, Edward L; Migliavacca, Francesco; de Leval, Marc R; Balossino, Rossella; Pennati, Giancarlo; Lloyd, Thomas R; Khambadkone, Sachin; Hsia, Tain-Yen; Dubini, Gabriele

2008-08-01

Stage one reconstruction (Norwood operation) for hypoplastic left heart syndrome can be performed with either a modified Blalock-Taussig shunt or a right ventricle-pulmonary artery shunt. Both methods have certain inherent characteristics. It is postulated that mathematic modeling could help elucidate these differences. Three-dimensional computer models of the Blalock-Taussig shunt and right ventricle-pulmonary artery shunt modifications of the Norwood operation were developed by using the finite volume method. Conduits of 3, 3.5, and 4 mm were used in the Blalock-Taussig shunt model, whereas conduits of 4, 5, and 6 mm were used in the right ventricle-pulmonary artery shunt model. The hydraulic nets (lumped resistances, compliances, inertances, and elastances) were identical in the 2 models. A multiscale approach was adopted to couple the 3-dimensional models with the circulation net. Computer simulations were compared with postoperative catheterization data. Good correlation was found between predicted and observed data. For the right ventricle-pulmonary artery shunt modification, there was higher aortic diastolic pressure, decreased pulmonary artery pressure, lower Qp/Qs ratio, and higher coronary perfusion pressure. Mathematic modeling predicted minimal regurgitant flow in the right ventricle-pulmonary artery shunt model, which correlated with postoperative Doppler measurements. The right ventricle-pulmonary artery shunt demonstrated lower stroke work and a higher mechanical efficiency (stroke work/total mechanical energy). The close correlation between predicted and observed data supports the use of mathematic modeling in the design and assessment of surgical procedures. The potentially damaging effects of a systemic ventriculotomy in the right ventricle-pulmonary artery shunt modification of the Norwood operation have not been analyzed.

Patients with a Normal Pressure Hydrocephalus Shunt Have Fewer Complications than Do Patients with Other Shunts.

PubMed

Schenker, Pascale; Stieglitz, Lennart H; Sick, Beate; Stienen, Martin N; Regli, Luca; Sarnthein, Johannes

2018-02-01

Ventriculoperitoneal (VP) shunting is a well-established therapy for hydrocephalus. However, complications are frequent. The incidence of idiopathic normal pressure hydrocephalus (NPH) increases with the aging of the population. We evaluated the functional status of patients and the classification of complications associated with VP shunt procedures in our center. We recorded all VP shunt procedures in our prospective patient registry from January 2013 to December 2015. Functional outcome (Karnofsky Performance Status [KPS] and modified Rankin Scale) and complications were compiled from patient records. Any deviation from the normal postoperative course within 3 months after surgery was considered a complication. Complications were classified with the therapy-oriented Clavien-Dindo grading system. We evaluated potential risk factors with a logistic regression model. From 285 procedures in the reporting period, 90 were excluded, resulting in 195 patients. Among those patients, 174 (90%) were shunt implantations and 21 (11%) were shunt revisions. Forty-four shunts (23%) were implanted for NPH. Median KPS improved over the first year after surgery. Although some type of complication was observed in 114 patients (58%), 60 of those complications (31%) did not require surgical treatment (Clavien-Dindo grade <3). In 50 patients (26%), the complication concerned the shunt itself. A high KPS at admission and NPH as underlying indication significantly reduced the odds ratio for a complication. Although shunt surgery has a high general rate of complications, this rate is significantly lower for patients with NPH. The decision for shunting in patients with NPH should consider the low complication rate specific for the group of patients with NPH. Copyright © 2017 Elsevier Inc. All rights reserved.

Frontal and occipital horn ratio is associated with multifocal intraparenchymal hemorrhages in neonatal shunted hydrocephalus.

PubMed

Oushy, Soliman; Parker, Jonathon J; Campbell, Kristen; Palmer, Claire; Wilkinson, Corbett; Stence, Nicholas V; Handler, Michael H; Mirsky, David M

2017-11-01

OBJECTIVE Placement of a cerebrospinal fluid diversion device (i.e., shunt) is a routine pediatric neurosurgical procedure, often performed in the first weeks of life for treatment of congenital hydrocephalus. In the postoperative period, shunt placement may be complicated by subdural, catheter tract, parenchymal, and intraventricular hemorrhages. The authors observed a subset of infants and neonates who developed multifocal intraparenchymal hemorrhages (MIPH) following shunt placement and sought to determine any predisposing perioperative variables. METHODS A retrospective review of the electronic medical record at a tertiary-care children's hospital was performed for the period 1998-2015. Inclusion criteria consisted of shunt placement, age < 30 days, and available pre- and postoperative brain imaging. The following data were collected and analyzed for each case: ventricular size ratios, laboratory values, clinical presentation, shunt and valve type, and operative timing and approach. RESULTS A total of 121 neonates met the inclusion criteria for the study, and 11 patients (9.1%) had MIPH following shunt placement. The preoperative frontal and occipital horn ratio (FOR) was significantly higher in the patients with MIPH than in those without (0.65 vs 0.57, p < 0.001). The change in FOR (∆FOR) after shunt placement was significantly greater in the MIPH group (0.14 vs 0.08, p = 0.04). Among neonates who developed MIPH, aqueductal stenosis was the most common etiology (45%). The type of shunt valve was associated with incidence of MIPH (p < 0.001). Preoperative clinical parameters, including head circumference, bulging fontanelle, and coagulopathy, were not significantly associated with development of MIPH. CONCLUSIONS MIPH represents an underrecognized complication of neonatal shunted hydrocephalus. Markers of severity of ventriculomegaly (FOR) and ventricular response to CSF diversion (∆FOR) were significantly associated with occurrence of MIPH. Choice of shunt and etiology of hydrocephalus were also significantly associated with MIPH. After adjusting for corrected age, etiology of hydrocephalus, and shunt setting, the authors found that ∆FOR after shunting was still associated with MIPH. A prospective study of MIPH prevention strategies and assessment of possible implications for patient outcomes is needed.

Cerebral blood flow velocity and vasomotor reactivity before and after shunting surgery in patients with normal pressure hydrocephalus.

PubMed

Lee, E J; Hung, Y C; Chang, C H; Pai, M C; Chen, H H

1998-01-01

The purpose of this study was to evaluate pre- and post-shunting haemodynamic changes and their correlation with the clinical results in normal pressure hydrocephalus (NPH). Accordingly, eleven demented patients with clinical signs suggestive of NPH received examinations of cerebral blood flow velocity (BFV) and vasomotor reactivity (VMR) by transcranial Doppler sonography with carbogen testing before and after shunt treatment. Computerized tomography (CT), clinical assessment and neuropsychological grading were performed prior to and at 3 months following surgery. A control group consisting of 10 patients was included to establish baseline data. The pre-operative CBF studies in the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) revealed the NPH patients did not have significant decreases of BFVs, but had significant decreases of carbogen VMR (P < 0.05). After shunting, there were no significant changes of the BFVs as compared with the pre-shunting data. The post-shunting VMR of the ACA was significantly higher than the pre-shunting one (p < 0.05), but there was no variation in that of the MCA. Both the values of post-shunting VMR in ACA and the post-shunting increase in VMR in MCA of the 7 shunt-responsive patients who improved mentally and in other symptoms were significantly higher than those of patients without improvement (p < 0.05). In addition, the five patients with gait improvement showed significantly higher values of post-shunting VMR of ACA and the post-shunting increase of VMR for both ACA and MCA when compared with those patients without gait improvement (p < 0.05, respectively). Our study supports the view that patients with NPH had various degrees of impaired VMR in both the ACA and the MCA, but showed insignificant reduction in BFVs, indicating a compensatory mechanism of CBF over time to accommodate the subnormal state of cerebral perfusion pressure. Shunt placement would improve the VMR in responsive patients. Postoperatively, an increase of VMR tends to accompany improvement of the functional state: that in the MCA alone is associated with symptomatic improvement in mental function and that increase in VMR in both the ACA and the MCA with improvement in gait, respectively.

Insulin Pump Malfunction During Hospitalization: Two Case Reports.

PubMed

Faulds, Eileen R; Wyne, Kathleen L; Buschur, Elizabeth O; McDaniel, Jodi; Dungan, Kathleen

2016-06-01

Insulin pump malfunctions and failures continue to occur; however, more severe malfunctions such as the "runaway pump" phenomenon are rarely reported. This article describes two cases of pump malfunction in which pump users appear to have received an unsolicited bolus of insulin resulting in severe episodes of hypoglycemia during hospitalization. Both cases of insulin pump malfunction occurred in the inpatient setting at a large academic medical center in the United States. An analysis of the corresponding insulin pump downloads was performed. The Food and Drug Administration's (FDA's) Manufacturer and User Facility Device Experience (MAUDE) database was searched for similar cases involving Medtronic (Northridge, CA) insulin pumps using the terms "pump," "infusion," "insulin AND malfunction AND Medtronic." The two cases described show remarkable similarities, each demonstrating a severe hypoglycemic event preceded by an infusion site change followed by an alarm. In both cases a rapid spraying of insulin was reported. The insulin pump downloads validated much of the patients' and medical staff's descriptions of events. The FDA's MAUDE database search revealed 425 cases meeting our search term criteria. All cases were reviewed. Seven cases were identified involving independent movement of the reservoir piston. The cases detailed are the first to describe an insulin pump malfunction of this nature in the hospital setting involving unsolicited insulin boluses leading to severe hypoglycemia. The cases are particularly compelling in that they were witnessed by medical personnel. Providers and patients should receive instruction education on the recognition and management of insulin pump malfunction.

Cardiac Iodine-123-Meta-Iodo-Benzylguanidine Uptake in Carotid Sinus Hypersensitivity.

PubMed

Tan, Maw Pin; Murray, Alan; Hawkins, Terry; Chadwick, Thomas J; Kerr, Simon R J; Parry, Steve W

2015-01-01

Carotid sinus syndrome is the association of carotid sinus hypersensitivity with syncope, unexplained falls and drop attacks in generally older people. We evaluated cardiac sympathetic innervation in this disorder in individuals with carotid sinus syndrome, asymptomatic carotid sinus hypersensitivity and controls without carotid sinus hypersensitivity. Consecutive patients diagnosed with carotid sinus syndrome at a specialist falls and syncope unit were recruited. Asymptomatic carotid sinus hypersensitivity and non-carotid sinus hypersensitivity control participants recruited from a community-dwelling cohort. Cardiac sympathetic innervation was determined using Iodine-123-metaiodobenzylguanidine (123-I-MIBG) scanning. Heart to mediastinal uptake ratio (H:M) were determined for early and late uptake on planar scintigraphy at 20 minutes and 3 hours following intravenous injection of 123-I-MIBG. Forty-two subjects: carotid sinus syndrome (n = 21), asymptomatic carotid sinus hypersensitivity (n = 12) and no carotid sinus hypersensitivity (n = 9) were included. Compared to the non- carotid sinus hypersensitivity control group, the carotid sinus syndrome group had significantly higher early H:M (estimated mean difference, B = 0.40; 95% confidence interval, CI = 0.13 to 0.67, p = 0.005) and late H:M (B = 0.32; 95%CI = 0.03 to 0.62, p = 0.032). There was, however, no significant difference in early H:M (p = 0.326) or late H:M (p = 0.351) between the asymptomatic carotid sinus hypersensitivity group and non- carotid sinus hypersensitivity controls. Cardiac sympathetic neuronal activity is increased relative to age-matched controls in individuals with carotid sinus syndrome but not those with asymptomatic carotid sinus hypersensitivity. Blood pressure and heart rate measurements alone may therefore represent an over simplification in the assessment for carotid sinus syndrome and the relative increase in cardiac sympathetic innervation provides additional clues to understanding the mechanisms behind the symptomatic presentation of carotid sinus hypersensitivity.

To shunt or not to shunt? An experimental study comparing temporary vascular shunts and venous ligation as damage control techniques for vascular trauma.

PubMed

Marinho de Oliveira Góes Junior, Adenauer; de Campos Vieira Abib, Simone; de Seixas Alves, Maria Teresa; Venerando da Silva Ferreira, Paulo Sérgio; Carvalho de Andrade, Mariseth

2014-04-01

To evaluate vascular flow through temporary vascular shunts inserted into peripheral arteries and veins and the repercussion, on the arterial perfusion, of venous ligation and venous shunt insertion in an experimental model for damage control. Experimental study in pigs. Animals were distributed in 5 groups: group 1, right external iliac artery (EIA) shunting and right external iliac vein (EIV) ligation; group 2, right EIA shunting and right EIV shunting; group 3, right EIV ligation; group 4, right EIV shunting; group 5, no vascular shunting and no venous ligation. Flowmeters were used to measure vascular flow on right and left external iliac vessels, and blood samples were collected from the EIVs for biochemical analysis. A right anterior limb biopsy was performed before shock. Hemorrhagic shock was induced through the external right jugular vein, until the vascular flow through right iliac external artery shunt or right iliac external vein shunt (group 4) ceased or until the animal's death. After the end of the experiments, biopsies of bilateral hind limb were obtained for histologic analysis. For statistical analysis, Microsoft Office Excel 2007 and BioEstat 5.0 (2007) were used. In the absence of hemorrhagic shock, venous ligation (group 1) was associated with a 38.8% reduction (P < 0.05) and venous shunting with a 28.4% reduction on the vascular flow through the arterial shunt. When associated with hemorrhagic shock, the mean vascular flow on the right EIA was 13 mL/min and on the left EIA was 41.2 mL/min; on group 2, the right EIA flow was 8.5 mL/min and the left EIA flow was 8.1 mL/min. When associated with hemorrhagic shock, the pO2 was 25.8 mm Hg on right EIV and 33.8 mm Hg on the left EIV for group 1 (P < 0.05), whereas for group 2, the pO2 was 22.6 mm Hg on right EIV and 22.8 mm Hg on the left EIV. On group 1, serum potassium was 3.84 mEq/L on the right EIV and 3.96 mEq/L on the left EIV, whereas on group 2, it was 7.1 mEq/L on the right EIV and 5.88 mEq/L on the left EIV (P < 0.05). In the developed experimental model, venous shunting, when compared with venous ligation, offered less resistance to vascular flow through the arterial shunt and allowed a more efficient limb venous drainage than simple vein ligature. Copyright © 2014 Elsevier Inc. All rights reserved.

Sinuses / Sinusitis / Rhinosinusitis

MedlinePlus

... Primary Immunodeficiency Disease Related Conditions Drug Guide Conditions Dictionary Just for Kids Library School Tools Videos Virtual ... Search AAAAI Breadcrumb navigation Home ▸ Conditions & Treatments ▸ Conditions Dictionary ▸ Sinuses|Sinusitis|Rhinosinusitis Share | Sinuses | Sinusitis | Rhinosinusitis « Back ...

An electronic circuit for sensing malfunctions in test instrumentation

NASA Technical Reports Server (NTRS)

Miller, W. M., Jr.

1969-01-01

Monitoring device differentiates between malfunctions occurring in the system undergoing test and malfunctions within the test instrumentation itself. Electronic circuits in the monitor use transistors to commutate silicon controlled rectifiers by removing the drive voltage, display circuits are then used to monitor multiple discrete lines.

[Comparative analysis on data of nasal sinus between helicopter and(strike) fighter pilots under physical examination for change to new-type aircraft].

PubMed

Xu, Xianrong; Ma, Xiaoli; Zhang, Yang; Xiong, Wei

2012-01-01

To comparatively analyze the disease data of nasal sinus between helicopter and (strike) fighter pilots under flying qualification, and then to provide references for aeromedical support as a significant part of new logistics service union in army, The CT data of nasal sinus in 138 pilots who accepted physical examination for change to new-type aircraft, were collected included 46 cases of helicopter pilots and 92 cases of (strike)fighter pilots). The incidence of chronic sinusitis and cyst of nasal sinus were computed respectively in helicopter pilots and (strike)fighter pilots. (1) Fourteen cases suffered from chronic sinusitis (6 cases of maxillary sinusitis, 4 cases of ethmoiditis and 4 cases of maxillary sinusitis and ethmoiditis) in helicopter pilots whose incidence rate of chronic sinusitis was 30.4% (14/46). Of which, 3 cases of antracele were treated. Twelve cases suffered from chronic sinusitis (8 cases of maxillary sinusitis, 1 case of ethmoiditis, 3 cases of maxillary sinusitis and ethmoiditis) in (strike)fighter pilots whose incidence of chronic sinusitis was 13.0% (12/92). Of which, 1 case of antracele was treated. The incidence of chronic sinusitis was higher in helicopter pilots than (strike) fighters pilots (Chi2 = 6.07, P < 0.05). (2) Four cases suffered from unilateral mucosa cysts in maxillary sinus in helicopter pilots whose incidence of cyst of nasal sinus was 8.7% (4/46). Ten cases suffered from mucosa cysts in maxillary sinus (unilateral 8 cases and bilateral 2 cases) in (strike) fighters pilots whose incidence of cyst of nasal sinus was 10.87% (10/92). The difference of the incidence of cyst of nasal sinus was not statistically significant between the helicopter pilots and(strike)fighters pilots. The cysts of nasal sinus did not need treatment in 14 cases of this group data. The incidence of symptomless chronic sinusitis and cyst of nasal sinus are high in pilots. It is related with repeatedly changes of atmosphere pressure during flying. But most chronic sinusitis and cyst of nasal sinus do not need treatment. The incidence of chronic sinusitis is higher in helicopter pilots than(strike)fighter pilots. It may be related with the environment of helicopter which have unclosed cockpit and load other aircrew.

Importance of technical preparation of intraarterial shunts to prevent iatrogenic arterial injury during urgent procedures.

PubMed

Awad, Nadia; Choudry, Rashad; Durinka, Joel; Prabhu, Aparna; Dissin, Jonathan

2013-02-01

Although intraarterial shunting during carotid endarterectomy is a well-defined practice, its use remains controversial. Complication rates associated with shunt placement remain low, but may be underreported. When complications secondary to routine intraarterial shunting occur, they can cause significant morbidity or even mortality, emphasizing the importance of meticulous technique to prevent adverse outcomes. We report a case of internal carotid artery dissection and pseuedoaneurysm due to the technical failure of a safety device of an intraarterial shunt used during carotid endarterectomy.

Plain Language Summary: Adult Sinusitis (Sinus Infection).

PubMed

Caspersen, Leslie A; Walter, Lindsey M; Walsh, Sandra A; Rosenfeld, Richard M; Piccirillo, Jay F

2015-08-01

This plain language summary serves as an overview in explaining sinusitis (pronounced sign-you-side-tis). The purpose of this plain language summary is to provide patients with standard language explaining their condition in an easy-to-read format. This summary applies to those 18 years of age or older with sinusitis. The summary is featured as an FAQ (frequently asked question) format. The summary addresses how to manage and treat sinusitis symptoms. Adult sinusitis is often called a sinus infection. A healthcare provider may refer to a sinus infection as rhinosinusitis (pronounced rhi-no-sign-you-side-tis). This includes the nose as well as the sinuses in the name. A sinus infection is the swelling of the sinuses and nasal cavity.The summary is based on the published 2015 "Clinical Practice Guideline: Adult Sinusitis." The evidence-based guideline includes research to support more effective diagnosis and treatment of adult sinus infections. The guideline was developed as a quality improvement opportunity for managing sinus infections by creating clear recommendations to use in medical practice. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

Olfactory Training in Improving Sense of Smell After Radiation Therapy in Patients With Paranasal Sinus or Nasopharyngeal Cancer

ClinicalTrials.gov

2017-07-11

Stage 0 Nasopharyngeal Carcinoma; Stage 0 Paranasal Sinus Cancer; Stage I Nasopharyngeal Carcinoma; Stage I Paranasal Sinus Cancer; Stage II Nasopharyngeal Carcinoma; Stage II Paranasal Sinus Cancer; Stage IIA Nasopharyngeal Carcinoma; Stage IIB Nasopharyngeal Carcinoma; Stage III Nasopharyngeal Carcinoma; Stage III Paranasal Sinus Cancer; Stage IV Nasopharyngeal Carcinoma; Stage IV Paranasal Sinus Cancer; Stage IVA Nasopharyngeal Carcinoma; Stage IVA Paranasal Sinus Cancer; Stage IVB Nasopharyngeal Carcinoma; Stage IVB Paranasal Sinus Cancer; Stage IVC Nasopharyngeal Carcinoma; Stage IVC Paranasal Sinus Cancer

[The treatment principles of frontal sinus tract after the frontal approach craniotomy].

PubMed

Yu, Huanxin; Li, Haiyan; Liu, Gang

2015-12-01

To investigate the causes, clinical manifestation and treatment principles of frontal sinus tract after the frontal approach craniotomy. The clinic data of 13 patients with frontal skin sinus tract after the frontal approach craniotomy were retrospectively analyzed. All of them were described in the clinical record to have undergone frontal sinus mucosa pushing down or shaving and bone wax filling in the frontal sinus during the surgery, of whom 3 cases had history of frontal abscess incision drainage. All patients were performed endoscopic frontal sinus surgery and forehead skin sinus tract excision and suture. All of the patients successfully recovered after one-stage operation, and the frontal skin sinus tract was healed. The frontal approach craniotomy with postoperative frontal sinus tract was related with the improper use of bone wax tamponade and sealing of frontal sinus. The treatment principles were to remove bone wax, remove inflammatory granulation tissue around the sinus tract, and to open frontal sinus and promote frontal sinus drainage.

14 CFR 21.3 - Reporting of failures, malfunctions, and defects.

Code of Federal Regulations, 2014 CFR

2014-01-01

... crew compartment or passenger cabin. (4) A malfunction, failure, or defect of a propeller control... structural or flight control system malfunction, defect, or failure which causes an interference with normal control of the aircraft for which derogates the flying qualities. (12) A complete loss of more than one...

14 CFR 21.3 - Reporting of failures, malfunctions, and defects.

Code of Federal Regulations, 2013 CFR

2013-01-01

... crew compartment or passenger cabin. (4) A malfunction, failure, or defect of a propeller control... structural or flight control system malfunction, defect, or failure which causes an interference with normal control of the aircraft for which derogates the flying qualities. (12) A complete loss of more than one...

14 CFR 21.3 - Reporting of failures, malfunctions, and defects.

Code of Federal Regulations, 2012 CFR

2012-01-01

... crew compartment or passenger cabin. (4) A malfunction, failure, or defect of a propeller control... structural or flight control system malfunction, defect, or failure which causes an interference with normal control of the aircraft for which derogates the flying qualities. (12) A complete loss of more than one...

40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

Code of Federal Regulations, 2014 CFR

2014-07-01

... to minimize emissions from startup, shutdown, and malfunction events. 270.235 Section 270.235... from startup, shutdown, and malfunction events. (a) Facilities with existing permits—(1) Revisions to... from startup, shutdown, and malfunction events under any of the following options when requesting...

40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

Code of Federal Regulations, 2012 CFR

2012-07-01

... to minimize emissions from startup, shutdown, and malfunction events. 270.235 Section 270.235... from startup, shutdown, and malfunction events. (a) Facilities with existing permits—(1) Revisions to... from startup, shutdown, and malfunction events under any of the following options when requesting...

40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

Code of Federal Regulations, 2011 CFR

2011-07-01

... to minimize emissions from startup, shutdown, and malfunction events. 270.235 Section 270.235... from startup, shutdown, and malfunction events. (a) Facilities with existing permits—(1) Revisions to... from startup, shutdown, and malfunction events under any of the following options when requesting...

40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

Code of Federal Regulations, 2013 CFR

2013-07-01

... to minimize emissions from startup, shutdown, and malfunction events. 270.235 Section 270.235... from startup, shutdown, and malfunction events. (a) Facilities with existing permits—(1) Revisions to... from startup, shutdown, and malfunction events under any of the following options when requesting...

40 CFR 63.8615 - How do I monitor and collect data to demonstrate continuous compliance?

Code of Federal Regulations, 2010 CFR

2010-07-01

... monitoring malfunctions, associated repairs, out-of-control periods, or required quality assurance or control activities for purposes of calculating data averages. A monitoring malfunction is any sudden, infrequent, not... periods of monitor malfunctions, associated repairs, and required quality assurance or control activities...

40 CFR 52.271 - Malfunction, startup, and shutdown regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Malfunction, startup, and shutdown regulations. 52.271 Section 52.271 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.271 Malfunction, startup, and shutdown regulations. (a)...

40 CFR 52.271 - Malfunction, startup, and shutdown regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Malfunction, startup, and shutdown regulations. 52.271 Section 52.271 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.271 Malfunction, startup, and shutdown regulations. (a)...

40 CFR 52.271 - Malfunction, startup, and shutdown regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Malfunction, startup, and shutdown regulations. 52.271 Section 52.271 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.271 Malfunction, startup, and shutdown regulations. (a)...

40 CFR 52.271 - Malfunction, startup, and shutdown regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Malfunction, startup, and shutdown regulations. 52.271 Section 52.271 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.271 Malfunction, startup, and shutdown regulations. (a)...

40 CFR 52.271 - Malfunction, startup, and shutdown regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Malfunction, startup, and shutdown regulations. 52.271 Section 52.271 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.271 Malfunction, startup, and shutdown regulations. (a)...

75 FR 34192 - Self-Regulatory Organizations; NYSE Arca, Inc.; Notice of Filing and Immediate Effectiveness of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

... erroneous trades occurring from disruptions and/or malfunctions of Exchange systems. The changes described... disruptions and malfunctions. Specifically, the Exchange proposes to include ``verifiable systems disruptions... modification of transactions that resulted from verifiable disruptions and/or malfunctions of Exchanges systems...

40 CFR 65.6 - Startup, shutdown, and malfunction plan and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Startup, shutdown, and malfunction... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.6 Startup... Group 2A or Group 2B process vents. (b) Startup, shutdown, and malfunction plan—(1) Description and...

40 CFR 65.6 - Startup, shutdown, and malfunction plan and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Startup, shutdown, and malfunction... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.6 Startup... Group 2A or Group 2B process vents. (b) Startup, shutdown, and malfunction plan—(1) Description and...

40 CFR 65.6 - Startup, shutdown, and malfunction plan and procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 16 2014-07-01 2014-07-01 false Startup, shutdown, and malfunction... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.6 Startup... Group 2A or Group 2B process vents. (b) Startup, shutdown, and malfunction plan—(1) Description and...

40 CFR 60.3025 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... during periods of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Model Rule—Performance...

40 CFR 60.3025 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false What happens during periods of startup... during periods of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Model Rule—Performance...

40 CFR Table 15 to Subpart Xxxx of... - Requirements for Reports

Code of Federal Regulations, 2011 CFR

2011-07-01

... had a startup, shutdown or malfunction during the reporting period and you took actions consistent with your startup, shutdown, and malfunction plan, the compliance report must include the information... requirements for annual reporting in § 63.6010(f). 2. Immediate startup, shutdown, and malfunction report if...

40 CFR 65.6 - Startup, shutdown, and malfunction plan and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 16 2012-07-01 2012-07-01 false Startup, shutdown, and malfunction... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.6 Startup... Group 2A or Group 2B process vents. (b) Startup, shutdown, and malfunction plan—(1) Description and...

40 CFR 65.6 - Startup, shutdown, and malfunction plan and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 16 2013-07-01 2013-07-01 false Startup, shutdown, and malfunction... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.6 Startup... Group 2A or Group 2B process vents. (b) Startup, shutdown, and malfunction plan—(1) Description and...

40 CFR 60.2918 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What happens during periods of startup... of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Performance Testing ...

40 CFR 60.2918 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Performance Testing ...

40 CFR 60.2918 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What happens during periods of startup... of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Performance Testing ...

40 CFR 60.3025 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What happens during periods of startup... during periods of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Model Rule—Performance...

40 CFR 60.3025 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false What happens during periods of startup... during periods of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Model Rule—Performance...

40 CFR 60.3025 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What happens during periods of startup... during periods of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Model Rule—Performance...

40 CFR 63.1367 - Recordkeeping requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) of subpart A of this part. (3) Startup, shutdown, and malfunction plan. The owner or operator of an affected source shall develop a written startup, shutdown, and malfunction plan as specified in § 63.6(e)(3... during periods of startup, shutdown, and malfunction and a program for corrective action for a...

40 CFR 66.33 - De Minimis exemptions: malfunctions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 15 2011-07-01 2011-07-01 false De Minimis exemptions: malfunctions...; Revocation of Exemptions § 66.33 De Minimis exemptions: malfunctions. (a) The Administrator may, upon notice... respect to a particular instance of noncompliance, that such noncompliance was de minimis in nature and...

40 CFR 66.33 - De Minimis exemptions: malfunctions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false De Minimis exemptions: malfunctions...; Revocation of Exemptions § 66.33 De Minimis exemptions: malfunctions. (a) The Administrator may, upon notice... respect to a particular instance of noncompliance, that such noncompliance was de minimis in nature and...

40 CFR 63.1367 - Recordkeeping requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., and malfunction and a program for corrective action for a malfunctioning process, air pollution... duration of each malfunction of the process operations or of air pollution control equipment used to comply... explanation of the cause of the alarm and the corrective action taken. (6) The owner or operator of an...

40 CFR 63.102 - General standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

... in § 63.101 of this subpart), malfunction, or non-operation of the chemical manufacturing process... subpart G of this part apply. However, if a start-up, shutdown, malfunction or period of non-operation of... part during the start-up, shutdown, malfunction or period of non-operation. For example, if there is an...

The microbiology of ethmoid and maxillary sinuses in patients with chronic sinusitis.

PubMed

Aral, Murat; Keles, Erol; Kaygusuz, Irfan

2003-01-01

To investigate aerob-anaerob microorganisms growth in maxillary and ethmoid sinuses by evaluating aspiration materials from patients with chronic sinusitis. The study was performed prospectively, and there were 31 patients (23 men, 8 women; mean age, 31.4+/-14.15, between 18-65 years) who had endoscopic sinus surgery because of chronic sinusitis. During the operation, when the maxillary sinus ostium and ethmoid sinus were opened, readily aspirated materials from sinuses were evaluated regarding aerob and anaerob bacteria. Nose and throat swap samples were collected preoperatively to determine the upper respiratory tract flora and also to understand the relationship between the flora and the microorganisms aspirated from sinuses. Total aerob bacteria count, which was isolated from preoperative nasal swab cultures, was 36, and aerob-anaerob bacteria count that included cultures taken from maxillary and ethmoid sinuses during the functional endoscopic sinus surgery was 42. For each 2 samples, the most common isolated aerob bacteria were coagulase (-) staphylococci. Microorganisms were isolated in 87.0% of 27 patients, in which cultures taken from maxillary and ethmoid sinuses during the functional endoscopic sinus surgery were included. It is determined that the isolated aerob bacteria rate was 90.4%, and the isolated anaerob bacteria rate was 14.2%. All of the 6 samples in which anaerob bacteria isolated were all maxillary sinus aspiration materials. Microorganisms that isolated from the nose and the sinuses were similar with the rate of 25.8%, and microorganisms that isolated from the throat cultures and sinuses were similar with the rate of 22.5%. This study reveals the aerob and anaerob microbiology of the maxillary and ethmoid sinuses so the treatment of chronic sinusitis will be easier.

A review of the anatomy and clinical significance of adrenal veins.

PubMed

Cesmebasi, Alper; Du Plessis, Maira; Iannatuono, Mark; Shah, Sameer; Tubbs, R Shane; Loukas, Marios

2014-11-01

The adrenal veins may present with a multitude of anatomical variants, which surgeons must be aware of when performing adrenalectomies. The adrenal veins originate during the formation of the prerenal inferior vena cava (IVC) and are remnants of the caudal portion of the subcardinal veins, cranial to the subcardinal sinus in the embryo. The many communications between the posterior cardinal, supracardinal, and subcardinal veins of the primordial venous system provide an explanation for the variable anatomy. Most commonly, one central vein drains each adrenal gland. The long left adrenal vein joins the inferior phrenic vein and drains into the left renal vein, while the short right adrenal vein drains immediately into the IVC. Multiple variations exist bilaterally and may pose the risk of surgical complications. Due to the potential for collaterals and accessory adrenal vessels, great caution must be taken during an adrenalectomy. Adrenal venous sampling, the gold standard in diagnosing primary hyperaldosteronism, also requires the clinician to have a thorough knowledge of the adrenal vein anatomy to avoid iatrogenic injury. The adrenal vein acts as an important conduit in portosystemic shunts, thus the nature of the anatomy and hypercoagulable states pose the risk of thrombosis. © 2014 Wiley Periodicals, Inc.

The sinonasal communication in the horse: examinations using computerized three-dimensional reformatted renderings of computed-tomography datasets

PubMed Central

2014-01-01

Background Sinusitis is a common disease in the horse. In human medicine it is described, that obstruction of the sinonasal communication plays a major role in the development of sinusitis. To get spatial sense of the equine specific communication ways between the nasal cavity and the paranasal sinuses, heads of 19 horses, aged 2 to 26 years, were analyzed using three-dimensional (3D) reformatted renderings of CT-datasets. Three-dimensional models were generated following manual and semi-automated segmentation. Before segmentation, the two-dimensional (2D) CT-images were verified against corresponding frozen sections of cadaveric heads. Results Three-dimensional analysis of the paranasal sinuses showed the bilateral existence of seven sinus compartments: rostral maxillary sinus, ventral conchal sinus, caudal maxillary sinus, dorsal conchal sinus, frontal sinus, sphenopalatine sinus and middle conchal sinus. The maxillary septum divides these seven compartments into two sinus systems: a rostral paranasal sinus system composed of the rostral maxillary sinus and the ventral conchal sinus and a caudal paranasal sinus system which comprises all other sinuses. The generated 3D models revealed a typically configuration of the sinonasal communication ways. The sinonasal communication started within the middle nasal meatus at the nasomaxillary aperture (Apertura nasomaxillaris), which opens in a common sinonasal channel (Canalis sinunasalis communis). This common sinonasal channel ramifies into a rostral sinonasal channel (Canalis sinunasalis rostralis) and a caudo-lateral sinonasal channel (Canalis sinunasalis caudalis). The rostral sinonasal channel ventilated the rostral paranasal sinus system, the caudo-lateral sinonasal channel opened into the caudal paranasal sinus system. The rostral sinonasal channel was connected to the rostral paranasal sinuses in various ways. Whereas, the caudal channel showed less anatomical variations and was in all cases connected to the caudal maxillary sinus. Volumetric measurements of the sinonasal channels showed no statistically significant differences (P <0.05) between the right and left side of the head. Conclusions Under physiologic conditions both paranasal sinus systems are connected to the nasal cavity by equine specific sinonasal channels. To resolve sinus disease it is aimed to maintain or even reconstruct the normal anatomy of the sinonasal communication by surgical intervention. Therefore, the presented 3D analyses may provide a useful basis. PMID:24646003

Continuous monitoring of intracranial pressure after endoscopic third ventriculostomy in the management of CSF shunt failure.

PubMed

Elgamal, E A

2010-04-01

The effectiveness of continuous intracranial pressure (ICP) monitoring in the adaptation period, after endoscopic third ventriculostomy (ETV), and removal of the failed shunt in the management of CSF shunt failure is assessed. Nine patients with active hydrocephalus presenting with CSF shunt obstruction or infection were managed by ETV, removal of the shunt and insertion of an external ventricular drain (EVD) containing an ICP sensor for the purpose of postoperative monitoring of the ICP, and intermittent drainage of CSF. Patient ages ranged from 8 months to 24 years, and six of them were females. Hydrocephalus was obstructive in seven patients, and multiloculated in two. Six patients had an ventriculoperitoneal shunt (VPS), one with a bilateral VPS, one patient had a ventriculoatrial shunt, and one had a VPS and cystoperitoneal shunt (CPS). Shunt failure was caused by obstruction in six patients and infection in three. The post-operative ICP monitoring period ranged from 1-7 days. Intracranial hypertension was persistent in the first day after ETV in 3 patients, and up to 110 mL of CSF were drained to improve its symptoms. ETV was successful in six patients and 3 had permanent VPS. Post-operative continuous ICP monitoring and EVD insertion were very useful in the treatment of CSF shunt failure with ETV. This procedure allowed intermittent CSF drainage, relieving symptoms of elevated ICP, and provided accurate assessment of the success of the ETV and patency of the stoma in the early postoperative days by CT ventriculography and can also be used to install antibiotics in cases of infection.

Our initial experience with ventriculo-epiplooic shunt in treatment of hydrocephalus in two centers.

PubMed

Grigorean, Valentin Titus; Sandu, Aurelia Mihaela; Popescu, Mihai; Florian, Ioan Stefan; Lupascu, Cristian Dumitru; Ursulescu, Corina Lupascu

Hydrocephalus represents impairment in cerebrospinal fluid (CSF) dynamics. If the treatment of hydrocephalus is considered difficult, the repeated revisions of ventriculo-peritoneal (VP) shunts are even more challenging. The aim of this article is to evaluate the efficiency of ventriculo-epiplooic (VEp) shunt as a feasible alternative in hydrocephalic patients. A technical modification regarding the insertion of peritoneal catheter was imagined: midline laparotomy 8-10cm long was performed in order to open the peritoneal cavity; the great omentum was dissected between its two layers; we placed the distal end of the catheter between the two epiplooic layers; a fenestration of 4cm in diameter into the visceral layer was also performed. A retrospective study of medical records of 15 consecutive patients with hydrocephalus treated with VEp shunt is also presented. Between 2008 and 2014 we performed VEp shunt in 15 patients: 5 with congenital hydrocephalus, 8 with secondary hydrocephalus and 2 with normal pressure hydrocephalus. There were 7 men and 8 women. VEp shunt was performed in 13 patients with multiple distal shunt failures and in 2 patients, with history of abdominal surgery, as de novo extracranial drainage procedure. The outcome was favorable in all cases, with no significant postoperative complications. VEp shunt is a new, safe and efficient surgical technique for the treatment of hydrocephalus. VEp shunt is indicated in patients with history of recurrent distal shunt failures, and in patients with history of open abdominal surgery and high risk for developing abdominal complications. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Effect of accessory ostia on maxillary sinus ventilation: a computational fluid dynamics (CFD) study.

PubMed

Zhu, Jian Hua; Lee, Heow Pueh; Lim, Kian Meng; Gordon, Bruce R; Wang, De Yun

2012-08-15

We evaluated, by CFD simulation, effects of accessory ostium (AO) on maxillary sinus ventilation. A three-dimensional nasal model was constructed from an adult CT scan with two left maxillary AOs (sinus I) and one right AO (sinus II), then compared to an identical control model with all AOs sealed (sinuses III and IV). Transient simulations of quiet inspiration and expiration at 15 L/min, and nasal blow at 48 L/min, were calculated for both models using low-Reynolds-number turbulent analysis. At low flows, ventilation rates in sinuses with AOs (I ≈ 0.46 L/min, II ≈ 0.54 L/min), were both more than a magnitude higher than sinuses without AOs (II I ≈ 0.019 L/min, IV ≈ 0.020 L/min). Absence of AO almost completely prevented sinus ventilation. Increased ventilation of sinuses with AOs is complex. Under high flow conditions mimicking nose blowing, in sinuses II, III, and IV, the sinus flow rate increased. In contrast, the airflow direction through sinus I reversed between inspiration and expiration, while it remained almost constant throughout the respiration cycle in sinus II. CFD simulation demonstrated that AOs markedly increase maxillary sinus airflow rates and alter sinus air circulation patterns. Whether these airflow changes impact maxillary sinus physiology or pathophysiology is unknown. Copyright © 2012 Elsevier B.V. All rights reserved.

Auxiliary Components for Kilopixel Transition Edge Sensor Arrays

NASA Technical Reports Server (NTRS)

Brown, Ari-David; Chervenak, James A.; Chuss, David; Hilton Gene C.; Mikula, Vilem; Henry, ROss; Wollack, Edward; Zhao, Yue

2007-01-01

We have fabricated transition edge sensor bolometer focal plane arrays sensitive to mm-submillimeter (0.1-3 THz) radiation for the Atacama Cosmology Telescope (ACT), which will probe the cosmic microwave background at 0.147,0.215, and 0.279 GHz. Central to the performance of these bolometers is a set of auxiliary resistive components. Here we discuss shunt resistors, which allow for tight optimization of bolometer time constant and sensitivity. Our shunt resistors consist of AuPd strips grown atop of interdigitated superconducting MoN, wires. We can tailor the shunt resistance by altering the dimensions of the AuPd strips and the pitch and width of the MoN, wires and can fabricate over 1000 shunts on a single 4" wafer. By modeling the resistance dependence of these parameters, a variety of different 0.77 +I-0.13 mOhm shunt resistors have been fabricated. This variety includes different shunts possessing MoN, wires with wire width equal to 1.5 and 10 microns and pitch equal to 4.5 and 26 microns, respectively. Our ability to set the resistance of the shunts hints at the scalability of our design. We have also integrated a Si02 capping layer into our shunt resistor fabrication scheme, which inhibits metal corrosion and eventual degradation of the shunt. Consequently, their robustness coupled with their high packing density makes these resistive components attractive for future kilopixel detector arrays.

Universality of Non-Ohmic Shunt Leakage in Thin-Film Solar Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dongaonkar, S.; Servaites, J.D.; Ford, G.M.

2010-01-01

We compare the dark current-voltage (IV) characteristics of three different thin-film solar cell types: hydrogenated amorphous silicon (a-Si:H) p-i-n cells, organic bulk heterojunction (BHJ) cells, and Cu(In,Ga)Se 2 (CIGS) cells. All three device types exhibit a significant shunt leakage current at low forward bias (V<~0.4) and reverse bias, which cannot be explained by the classical solar cell diode model. This parasitic shunt current exhibits non-Ohmic behavior, as opposed to the traditional constant shunt resistance model for photovoltaics. We show here that this shunt leakage (I sh) , across all three solar cell types considered, is characterized by the following commonmore » phenomenological features: (a) voltage symmetry about V=0 , (b) nonlinear (power law) voltage dependence, and (c) extremely weak temperature dependence. Based on this analysis, we provide a simple method of subtracting this shunt current component from the measured data and discuss its implications on dark IV parameter extraction. We propose a space charge limited (SCL) current model for capturing all these features of the shunt leakage in a consistent framework and discuss possible physical origin of the parasitic paths responsible for this shunt current mechanism.« less

Difficulties of Distal Catheter Insertion of Ventriculoatrial Shunting in Infants and Little Children.

PubMed

Erdogan, Hakan; Altun, Adnan; Kuruoglu, Enis; Kaya, Ahmet Hilmi; Dagcinar, Adnan

2017-09-26

Ventriculoatrial (VA) shunting is a well-described cerebrospinal fluid diversion method for the treatment of hydrocephalus. However, it may be very challenging in infants and little children because of atrial catheter placement difficulties. This study aimed to create an algorithm to solve problems faced during open surgical procedures based on the present authors' experience. We conducted a retrospective analysis on 18 infants and children who underwent VA shunt insertion at the Department of Neurosurgery, Ondokuz Mayıs University School of Medicine Hospital between 2005 and 2012. Complications, clinical outcomes, revisions, and solutions for overcoming distal catheter placement difficulties were evaluated. Twenty-six VA shunt operations were performed in 18 patients. Six patients required eight VA shunt revisions. VA shunting was primarily performed from the internal jugular, facial, cephalic, and subclavian veins to the right atrium. In revision procedures, the internal jugular, cephalic, and subclavian veins were used. VA shunting in infants and little children requires careful surgical techniques. Neurosurgeons should necessarily have an appropriate strategy for VA shunting considering the complications and revisions. Our results suggest open surgical solutions to overcome distal catheter placement difficulties in this age group.

Morphology of splenocaval congenital portosystemic shunts in dogs and cats.

PubMed

White, R N; Parry, A T

2016-01-01

To describe the anatomy of congenital portosystemic shunts involving the splenic vein communicating with the caudal vena cava at the level of the epiploic foramen. A retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. Ninety-eight dogs and eight cats met the inclusion criteria of a congenital portosystemic shunt involving the splenic vein communicating with the prehepatic caudal vena cava plus recorded intra-operative mesenteric portovenography or computed tomography angiography and gross observations at surgery. All cases (both dogs and cats) had a highly consistent shunt that involved a distended gastrosplenic vein that communicated with the caudal vena cava at the level of the epiploic foramen via an anomalous left gastric vein. The morphology of the shunt type described appeared to be a result of an abnormal communication between the left gastric vein and the caudal vena cava and the subsequent development of preferential blood flow through an essentially normal portal venous system. The abnormal communication (shunt) was through the left gastric vein and not the splenic vein, as might have been expected. This information may help with surgical planning in cases undergoing shunt closure surgery. © 2015 British Small Animal Veterinary Association.

Measurement of Blood Flow in Arteriovenous Malformations before and after Embolization Using Arterial Spin Labeling

PubMed Central

Suazo, L.; Foerster, B.; Fermin, R.; Speckter, H.; Vilchez, C.; Oviedo, J.; Stoeter, P.

2012-01-01

Summary The assessment of shunt reduction after an embolization of an arteriovenous malformation (AVM) or fistula (AVF) from conventional angiography is often difficult and may be subjective. Here we present a completely non-invasive method using magnetic resonance imaging (MRI) to measure shunt reduction. Using pulsed arterial spin labeling (PASL), we determined the relative amount of signal attributed to the shunt over 1.75 s and 6 different slices covering the lesion. This amount of signal from the shunt was related to the total signal from all slices and measured before and after embolization. The method showed a fair agreement between the PASL results and the judgement from conventional angiography. In the case of a total or subtotal shunt occlusion, PASL showed a shunt reduction between 69% and 92%, whereas in minimal shunt reduction as judged by conventional angiography, the ASL result was –6% (indicating slightly increased flow) to 35% in a partially occluded vein of Galen aneurysm. The PASL method proved to be fairly reproducible (up to 2% deviation between three measurements without interventions). On conclusion, PASL is able to reliably measure the amount of shunt reduction achieved by embolization of AVMs and AVFs PMID:22440600

Effects of isradipine and other calcium antagonists on arteriovenous-shunt flow in anesthetized rabbits and cats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hof, R.P.

The effects of vasodilators on arteriovenous (AV)-shunt flow was investigated in anesthetized cats and rabbits, using the tracer microsphere method. In cats, the calcium antagonist isradipine reduced AV-shunt flow; verapamil showed a similar tendency and nicardipine was without effect. Dihydralazine strongly increased, but nitroglycerin and dipyridamole decreased AV-shunt flow. In rabbits, the effects of isradipine and verapamil were similar to those seen in cats. Sodium nitroprusside had no effect, whereas prazosin, minoxidil, and the potassium-channel activator cromakalim increased AV-shunt flow. The contrasting effects of drugs sharing the same mechanism of action suggest that target-tissue selectivity is more important than themore » mechanism of action. An increase of AV-shunt flow is unlikely to be beneficial but could be associated with a number of undesirable side effects. It might negatively affect migraine sufferers and, if AV-shunt dilatation shows no tolerance development, it represents an unnecessary hemodynamic burden for the heart.« less

Hydrostatic and hydrodynamic considerations in shunted normal pressure hydrocephalus.

PubMed

de Jong, D A; Delwel, E J; Avezaat, C J

2000-01-01

Symptoms of overdrainage, a frequent complication following shunting procedures especially in patients with normal-pressure hydrocephalus (NPH), are presumed to be caused by siphoning: gravity-enhanced flow of cerebro spinal fluid (CSF) through shunts in upright position. A critical reappraisal of siphoning and overdrainage (OD) is presented considering the occurrence of subdural hygromas (SDH) encountered in a group of patients shunted for NPH. The patients participated in the multicentre Dutch NPH study: 101 NPH patients were randomised for treatment with shunts with low or medium-high working pressure. Treatment with shunts with low working pressure resulted in an increased incidence of SDH (iSDH). Current physiological concepts of overdrainage are discussed and criticised. A new theory is presented on the basis of general physiological considerations. The theoretical model proposed yields a revised explanation for the origin of extremely low ventricular pressure in the upright position found with overdrainage. The efficacy of siphoning-preventing shunts and subtemporal decompression is explored in the light of the proposed theory.

Sigmoid Sinus Diverticulum, Dehiscence, and Venous Sinus Stenosis: Potential Causes of Pulsatile Tinnitus in Patients with Idiopathic Intracranial Hypertension?

PubMed

Lansley, J A; Tucker, W; Eriksen, M R; Riordan-Eva, P; Connor, S E J

2017-09-01

Pulsatile tinnitus is experienced by most patients with idiopathic intracranial hypertension. The pathophysiology remains uncertain; however, transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence have been proposed as potential etiologies. We aimed to determine whether the prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence was increased in patients with idiopathic intracranial hypertension and pulsatile tinnitus relative to those without pulsatile tinnitus and a control group. CT vascular studies of patients with idiopathic intracranial hypertension with pulsatile tinnitus ( n = 42), without pulsatile tinnitus ( n = 37), and controls ( n = 75) were independently reviewed for the presence of severe transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence according to published criteria. The prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence in patients with idiopathic intracranial hypertension with pulsatile tinnitus was compared with that in the nonpulsatile tinnitus idiopathic intracranial hypertension group and the control group. Further comparisons included differing degrees of transverse sinus stenosis (50% and 75%), laterality of transverse sinus stenosis/sigmoid sinus diverticulum/dehiscence, and ipsilateral transverse sinus stenosis combined with sigmoid sinus diverticulum/dehiscence. Severe bilateral transverse sinus stenoses were more frequent in patients with idiopathic intracranial hypertension than in controls ( P < .001), but there was no significant association between transverse sinus stenosis and pulsatile tinnitus within the idiopathic intracranial hypertension group. Sigmoid sinus dehiscence (right- or left-sided) was also more common in patients with idiopathic intracranial hypertension compared with controls ( P = .01), but there was no significant association with pulsatile tinnitus within the idiopathic intracranial hypertension group. While our data corroborate previous studies demonstrating increased prevalence of sigmoid sinus diverticulum/dehiscence and transverse sinus stenosis in idiopathic intracranial hypertension, we did not establish an increased prevalence in patients with idiopathic intracranial hypertension with pulsatile tinnitus compared with those without. It is therefore unlikely that these entities represent a direct structural correlate of pulsatile tinnitus in patients with idiopathic intracranial hypertension. © 2017 by American Journal of Neuroradiology.

Cardiac Iodine-123-Meta-Iodo-Benzylguanidine Uptake in Carotid Sinus Hypersensitivity

PubMed Central

Tan, Maw Pin; Murray, Alan; Hawkins, Terry; Chadwick, Thomas J.; Kerr, Simon R. J.; Parry, Steve W.

2015-01-01

Background Carotid sinus syndrome is the association of carotid sinus hypersensitivity with syncope, unexplained falls and drop attacks in generally older people. We evaluated cardiac sympathetic innervation in this disorder in individuals with carotid sinus syndrome, asymptomatic carotid sinus hypersensitivity and controls without carotid sinus hypersensitivity. Methods Consecutive patients diagnosed with carotid sinus syndrome at a specialist falls and syncope unit were recruited. Asymptomatic carotid sinus hypersensitivity and non-carotid sinus hypersensitivity control participants recruited from a community-dwelling cohort. Cardiac sympathetic innervation was determined using Iodine-123-metaiodobenzylguanidine (123-I-MIBG) scanning. Heart to mediastinal uptake ratio (H:M) were determined for early and late uptake on planar scintigraphy at 20 minutes and 3 hours following intravenous injection of 123-I-MIBG. Results Forty-two subjects: carotid sinus syndrome (n = 21), asymptomatic carotid sinus hypersensitivity (n = 12) and no carotid sinus hypersensitivity (n = 9) were included. Compared to the non- carotid sinus hypersensitivity control group, the carotid sinus syndrome group had significantly higher early H:M (estimated mean difference, B = 0.40; 95% confidence interval, CI = 0.13 to 0.67, p = 0.005) and late H:M (B = 0.32; 95%CI = 0.03 to 0.62, p = 0.032). There was, however, no significant difference in early H:M (p = 0.326) or late H:M (p = 0.351) between the asymptomatic carotid sinus hypersensitivity group and non- carotid sinus hypersensitivity controls. Conclusions Cardiac sympathetic neuronal activity is increased relative to age-matched controls in individuals with carotid sinus syndrome but not those with asymptomatic carotid sinus hypersensitivity. Blood pressure and heart rate measurements alone may therefore represent an over simplification in the assessment for carotid sinus syndrome and the relative increase in cardiac sympathetic innervation provides additional clues to understanding the mechanisms behind the symptomatic presentation of carotid sinus hypersensitivity. PMID:26057525

Laparoscopic correction of congenital portosystemic shunt in children.

PubMed

Kimura, Takuya; Soh, Hideki; Hasegawa, Toshimichi; Sasaki, Takashi; Kuroda, Seika; Yuri, Etani; Tomoda, Kaname; Fukuzawa, Masahiro

2004-10-01

Congenital portosystemic shunt is a rare clinical entity that may progress to jaundice, severe encephalopathy, and pulmonary hypertension and require surgical correction or coil embolization. We present a novel approach to the management of children with congenital portosystemic shunt by means of a minimally invasive surgical technique. Congenital portosystemic shunts were identified between the superior mesenteric vein and inferior vena cava in case 1 and between the splenic vein and left renal vein in case 2. Both of them were successfully ligated by laparoscopic approach, and catheters were subsequently replaced to monitor portal venous pressure. The patients tolerated the procedure well, and short-term results were excellent. Laparoscopic ligation of congenital portosystemic shunt is technically feasible and less invasive to the management of patients with congenital portosystemic shunts, preventing late onset, life-threatening complications.

[Causes and management of frontal sinusitis after transfrontal craniotomy].

PubMed

Liu, T C; Yu, X F; Gu, Z W; Bai, W L; Wang, Z H; Cao, Z W

2018-02-01

Objective: The aim of this study is to investigate the causes and the strategy of frontal sinusitis after transfrontal craniotomy by endoscopic frontal sinus surgery and traditional surgery with facial incision. Method: A total of thirty-four patients with frontal sinusitis after transfrontal craniotomy were admitted, with the symptom of purulence stuff, headache and upper eyelid discharging. The onset time was 2.6 years on average. The frontal sinus CT and MRI images showed frontal sinusitis. Twenty-seven patients were treated with endoscopic frontal sinus surgery, and seven patient was treated with combined endoscopic and traditional frontal sinus surgery. In the revision surgery, the bone wax and inflammatory granulation tissue were cleaned out in both operational methods. The cure standard was that the postoperative frontal sinus inflammation disappeared and the drainage of the volume recess was unobstructed. Result: Thirty-four patients had a history of transfrontal craniotomy, and there was a record of bone wax packing in every operation. Among twenty-seven patients with endoscopic frontal sinus surgery, Twenty-five cases cured and two cases were operated twice. Seven patients were cured with combined endoscopic and traditional frontal sinus surgery. Conclusion: The frontal sinusitis after transfrontal craniotomy may be related to the inadequate sinus management, especially bone wax to be addressed to the frontal sinus ramming leading to frontal sinus mucosa secretion obstruction and poor drainage. Endoscopic frontal sinus surgery is a way of minimally invasive surgery. The satisfying curative effect can be obtained by endoscopic removal of bone wax, inflammatory granulation tissue, and the enlargement of frontal sinus aperture after exposure to the frontal sinus, and some cases was treated with both operation method.

Evaluation of Blalock-Taussig shunts in newborns: value of oblique MRI planes.

PubMed

Kastler, B; Livolsi, A; Germain, P; Zöllner, G; Dietemann, J L

1991-01-01

Eight infants with systemic-pulmonary Blalock-Taussig shunts were evaluated by spin-echo ECG-gated MRI. Contrary to Echocardiography, MRI using coronal oblique projections successfully visualized all palliative shunts entirely in one single plane (including one carried out on a right aberrant subclavian artery). MRI allowed assessment of size, course and patency of the shunt, including pulmonary and subclavian insertion. The proximal portion of the pulmonary and subclavian arteries were also visualized. We conclude that MRI with axial scans completed by coronal oblique planes is a promising, non invasive method for imaging the anatomical features of Blalock-Taussig shunts.

[The use of labelled albumin microspheres in the study of arteriovenous shunting in varicosities of the lower limbs (author's transl)].

PubMed

Serise, J M; Le Héron, D; Le Héron, G; Bonnet, A; Busquet, J; Basse-Cathalinat, B; Tingaud, R

1982-01-01

The greater proportion of oxygen in the blood circulating in veins of the lower limbs bought to attention the possibility of pre-capillary arteriovenous shunting. The intra-arteriel injection of Technetium labelled serum albumin microspheres enables one to quantify arteriovenous shunts greater than 25 microns. The authors made a comparative study of arterio-venous shunting by blood gases analysis and isotopic techniques in twenty patients. The results seem to deny the existence of arteriovenous shunts in the genesis of essential varicose veins in the lower limb.

40 CFR 63.1551 - Affirmative defense for exceedance of emission limit during malfunction.

Code of Federal Regulations, 2014 CFR

2014-07-01

... affirmative defense to a claim for civil penalties for exceedances of such standards that are caused by... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering... avail itself of an affirmative defense to civil penalties for that malfunction. The owner or operator...

40 CFR 63.1551 - Affirmative defense for exceedance of emission limit during malfunction.

Code of Federal Regulations, 2013 CFR

2013-07-01

... affirmative defense to a claim for civil penalties for exceedances of such standards that are caused by... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering... avail itself of an affirmative defense to civil penalties for that malfunction. The owner or operator...

30 CFR 75.1714-8 - Reporting SCSR inventory and malfunctions; retention of SCSRs.

Code of Federal Regulations, 2010 CFR

2010-07-01

... submit the inventory within 3 months of beginning operation. (1) The inventory shall include— (i) Mine... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Reporting SCSR inventory and malfunctions... Miscellaneous § 75.1714-8 Reporting SCSR inventory and malfunctions; retention of SCSRs. (a) SCSR inventory. A...

40 CFR 62.15150 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2013 CFR

2013-07-01

... requirements during periods of startup, shutdown, and malfunction? 62.15150 Section 62.15150 Protection of... § 62.15150 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR Table 7 to Subpart Aaaaa of... - Requirements for Reports

Code of Federal Regulations, 2011 CFR

2011-07-01

.... If you had a startup, shutdown or malfunction during the reporting period and you took actions...) Semiannually according to the requirements in § 63.7131(b). 2. An immediate startup, shutdown, and malfunction report if you had a startup, shutdown, or malfunction during the reporting period that is not consistent...

40 CFR Table 7 to Subpart Aaaaa of... - Requirements for Reports

Code of Federal Regulations, 2012 CFR

2012-07-01

.... If you had a startup, shutdown or malfunction during the reporting period and you took actions...) Semiannually according to the requirements in § 63.7131(b). 2. An immediate startup, shutdown, and malfunction report if you had a startup, shutdown, or malfunction during the reporting period that is not consistent...

40 CFR 62.15165 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2014 CFR

2014-07-01

... during periods of startup, shutdown, and malfunction? 62.15165 Section 62.15165 Protection of Environment... emission limits during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR Table 7 to Subpart Aaaaa of... - Requirements for Reports

Code of Federal Regulations, 2010 CFR

2010-07-01

.... If you had a startup, shutdown or malfunction during the reporting period and you took actions...) Semiannually according to the requirements in § 63.7131(b). 2. An immediate startup, shutdown, and malfunction report if you had a startup, shutdown, or malfunction during the reporting period that is not consistent...

40 CFR 60.2685 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... happens during periods of startup, shutdown, and malfunction? (a) The emission limitations and operating limits apply at all times except during CISWI unit startups, shutdowns, or malfunctions. (b) Each...

40 CFR 62.15150 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... requirements during periods of startup, shutdown, and malfunction? 62.15150 Section 62.15150 Protection of... § 62.15150 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 60.1695 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1695 Section 60.1695 Protection of... Requirements § 60.1695 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 63.1570 - What are my general requirements for complying with this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... control equipment. (d) You must develop a written startup, shutdown, and malfunction plan (SSMP) according... includes periods of startup, shutdown, and malfunction. You also must report each instance in which you did...), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 60.2685 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What happens during periods of startup... happens during periods of startup, shutdown, and malfunction? (a) The emission limitations and operating limits apply at all times except during CISWI unit startups, shutdowns, or malfunctions. (b) Each...

40 CFR 62.15150 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... requirements during periods of startup, shutdown, and malfunction? 62.15150 Section 62.15150 Protection of... § 62.15150 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 60.1205 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1205 Section 60.1205 Protection of... requirements during periods of startup, shutdown, and malfunction? (a) The operating requirements of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 63.5555 - How do I demonstrate continuous compliance with the emission limits, operating limits, and work...

Code of Federal Regulations, 2011 CFR

2011-07-01

... startup, shutdown, and malfunction. These instances are deviations from the emission limits, operating... during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the... determine whether deviations that occur during a period you identify as a startup, shutdown, or malfunction...

40 CFR 62.15165 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... during periods of startup, shutdown, and malfunction? 62.15165 Section 62.15165 Protection of Environment... emission limits during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 62.15150 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements during periods of startup, shutdown, and malfunction? 62.15150 Section 62.15150 Protection of... § 62.15150 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 60.1205 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1205 Section 60.1205 Protection of... requirements during periods of startup, shutdown, and malfunction? (a) The operating requirements of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 62.15165 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... during periods of startup, shutdown, and malfunction? 62.15165 Section 62.15165 Protection of Environment... emission limits during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 60.2120 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... 1, 2001 Emission Limitations and Operating Limits § 60.2120 What happens during periods of startup... during CISWI unit startups, shutdowns, or malfunctions. (b) Each malfunction must last no longer than 3...

40 CFR 63.9040 - How do I demonstrate continuous compliance with the emission limitations and work practice...

Code of Federal Regulations, 2011 CFR

2011-07-01

... to you. This includes periods of startup, shutdown, and malfunction. These instances are deviations... during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the... determine whether deviations that occur during a period of startup, shutdown, or malfunction are violations...

40 CFR Table 7 to Subpart Aaaaa of... - Requirements for Reports

Code of Federal Regulations, 2013 CFR

2013-07-01

.... If you had a startup, shutdown or malfunction during the reporting period and you took actions...) Semiannually according to the requirements in § 63.7131(b). 2. An immediate startup, shutdown, and malfunction report if you had a startup, shutdown, or malfunction during the reporting period that is not consistent...

40 CFR 63.5555 - How do I demonstrate continuous compliance with the emission limits, operating limits, and work...

Code of Federal Regulations, 2010 CFR

2010-07-01

... startup, shutdown, and malfunction. These instances are deviations from the emission limits, operating... during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the... determine whether deviations that occur during a period you identify as a startup, shutdown, or malfunction...

40 CFR 60.1695 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1695 Section 60.1695 Protection of... Requirements § 60.1695 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 63.1570 - What are my general requirements for complying with this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... control equipment. (d) You must develop a written startup, shutdown, and malfunction plan (SSMP) according... includes periods of startup, shutdown, and malfunction. You also must report each instance in which you did...), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 63.1570 - What are my general requirements for complying with this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... control equipment. (d) You must develop a written startup, shutdown, and malfunction plan (SSMP) according... includes periods of startup, shutdown, and malfunction. You also must report each instance in which you did...), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 60.2685 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What happens during periods of startup...-Emission Limitations and Operating Limits § 60.2685 What happens during periods of startup, shutdown, and... startups, shutdowns, or malfunctions. (b) Each malfunction must last no longer than 3 hours. Effective Date...

40 CFR 60.1205 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1205 Section 60.1205 Protection of... requirements during periods of startup, shutdown, and malfunction? (a) The operating requirements of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 60.2120 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What happens during periods of startup... 1, 2001 Emission Limitations and Operating Limits § 60.2120 What happens during periods of startup... during CISWI unit startups, shutdowns, or malfunctions. (b) Each malfunction must last no longer than 3...

40 CFR Table 7 to Subpart Aaaaa of... - Requirements for Reports

Code of Federal Regulations, 2014 CFR

2014-07-01

.... If you had a startup, shutdown or malfunction during the reporting period and you took actions...) Semiannually according to the requirements in § 63.7131(b). 2. An immediate startup, shutdown, and malfunction report if you had a startup, shutdown, or malfunction during the reporting period that is not consistent...

40 CFR 63.1570 - What are my general requirements for complying with this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... control equipment. (d) You must develop a written startup, shutdown, and malfunction plan (SSMP) according... includes periods of startup, shutdown, and malfunction. You also must report each instance in which you did...), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 60.2120 - What happens during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What happens during periods of startup... 1, 2001 Emission Limitations and Operating Limits § 60.2120 What happens during periods of startup... during CISWI unit startups, shutdowns, or malfunctions. (b) Each malfunction must last no longer than 3...

40 CFR 62.15165 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2013 CFR

2013-07-01

... during periods of startup, shutdown, and malfunction? 62.15165 Section 62.15165 Protection of Environment... emission limits during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 60.1205 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2014 CFR

2014-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1205 Section 60.1205 Protection of... requirements during periods of startup, shutdown, and malfunction? (a) The operating requirements of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 63.1570 - What are my general requirements for complying with this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... control equipment. (d) You must develop a written startup, shutdown, and malfunction plan (SSMP) according... includes periods of startup, shutdown, and malfunction. You also must report each instance in which you did...), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 60.1695 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2014 CFR

2014-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1695 Section 60.1695 Protection of... Requirements § 60.1695 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 60.1695 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1695 Section 60.1695 Protection of... Requirements § 60.1695 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 62.15165 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2010 CFR

2010-07-01

... during periods of startup, shutdown, and malfunction? 62.15165 Section 62.15165 Protection of Environment... emission limits during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 62.15150 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2014 CFR

2014-07-01

... requirements during periods of startup, shutdown, and malfunction? 62.15150 Section 62.15150 Protection of... § 62.15150 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 60.1205 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2013 CFR

2013-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1205 Section 60.1205 Protection of... requirements during periods of startup, shutdown, and malfunction? (a) The operating requirements of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

40 CFR 60.1695 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

Code of Federal Regulations, 2013 CFR

2013-07-01

... requirements during periods of startup, shutdown, and malfunction? 60.1695 Section 60.1695 Protection of... Requirements § 60.1695 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

40 CFR 63.9814 - What reports must I submit and when?

Code of Federal Regulations, 2011 CFR

2011-07-01

... beginning and ending dates of the reporting period. (4) If you had a startup, shutdown, or malfunction... (d)(1) and (2) of this section. This includes periods of startup, shutdown, and malfunction. (1) The... section. This includes periods of startup, shutdown, and malfunction. (1) The total operating time of each...

40 CFR 63.9814 - What reports must I submit and when?

Code of Federal Regulations, 2012 CFR

2012-07-01

... beginning and ending dates of the reporting period. (4) If you had a startup, shutdown, or malfunction... (d)(1) and (2) of this section. This includes periods of startup, shutdown, and malfunction. (1) The... section. This includes periods of startup, shutdown, and malfunction. (1) The total operating time of each...

40 CFR 63.9814 - What reports must I submit and when?

Code of Federal Regulations, 2014 CFR

2014-07-01

... beginning and ending dates of the reporting period. (4) If you had a startup, shutdown, or malfunction... (d)(1) and (2) of this section. This includes periods of startup, shutdown, and malfunction. (1) The... section. This includes periods of startup, shutdown, and malfunction. (1) The total operating time of each...

40 CFR 63.9814 - What reports must I submit and when?

Code of Federal Regulations, 2013 CFR

2013-07-01

... beginning and ending dates of the reporting period. (4) If you had a startup, shutdown, or malfunction... (d)(1) and (2) of this section. This includes periods of startup, shutdown, and malfunction. (1) The... section. This includes periods of startup, shutdown, and malfunction. (1) The total operating time of each...

Cerebrospinal fluid pulse pressure amplitude during lumbar infusion in idiopathic normal pressure hydrocephalus can predict response to shunting

PubMed Central

2010-01-01

Background We have previously seen that idiopathic normal pressure hydrocephalus (iNPH) patients having elevated intracranial pressure (ICP) pulse amplitude consistently respond to shunt surgery. In this study we explored how the cerebrospinal fluid pressure (CSFP) pulse amplitude determined during lumbar infusion testing, correlates with ICP pulse amplitude determined during over-night ICP monitoring and with response to shunt surgery. Our goal was to establish a more reliable screening procedure for selecting iNPH patients for shunt surgery using lumbar intrathecal infusion. Methods The study population consisted of all iNPH patients undergoing both diagnostic lumbar infusion testing and continuous over-night ICP monitoring during the period 2002-2007. The severity of iNPH was assessed using our NPH grading scale before surgery and 12 months after shunting. The CSFP pulse was characterized from the amplitude of single pressure waves. Results Totally 62 iNPH patients were included, 45 of them underwent shunt surgery, in whom 78% were shunt responders. Among the 45 shunted patients, resistance to CSF outflow (Rout) was elevated (≥ 12 mmHg/ml/min) in 44. The ICP pulse amplitude recorded over-night was elevated (i.e. mean ICP wave amplitude ≥ 4 mmHg) in 68% of patients; 92% of these were shunt responders. In those with elevated overnight ICP pulse amplitude, we found also elevated CSFP pulse amplitude recorded during lumbar infusion testing, both during the opening phase following lumbar puncture and during a standardized period of lumbar infusion (15 ml Ringer over 10 min). The clinical response to shunting after 1 year strongly associated with the over-night ICP pulse amplitude, and also with the pulsatile CSFP during the period of lumbar infusion. Elevated CSFP pulse amplitude during lumbar infusion thus predicted shunt response with sensitivity of 88 and specificity of 60 (positive and negative predictive values of 89 and 60, respectively). Conclusions In iNPH patients, shunt response can be anticipated in 9/10 patients with elevated overnight ICP pulse amplitude, while in only 1/10 with low ICP pulse amplitude. Additionally, the CSFP pulse amplitude during lumbar infusion testing was elevated in patients with elevated over-night ICP pulse amplitude. In particular, measurement of CSFP pulse amplitude during a standardized infusion of 15 ml Ringer over 10 min was useful in predicting response to shunt surgery and can be used as a screening procedure for selection of iNPH patients for shunting. PMID:20205911

Decreased head circumference in shunt-treated compared with healthy children.

PubMed

Nilsson, Daniel; Svensson, Johanna; Korkmaz, Betül A; Nelvig, Helena; Tisell, Magnus

2013-11-01

In this study, the authors' goal was to compare head circumference in hydrocephalic children during the first 4 years of ventriculoperitoneal (VP) shunt treatment with data on healthy children and to investigate predictors of skull growth in children with a VP shunt. Children from western Sweden treated for hydrocephalus with an initial VP shunt insertion performed between 2001 and 2006 who were younger than 12 months of age at the time of surgery were included. Children with major brain malformations, craniofacial syndromes, large cysts, and tumors were excluded. Head circumference, weight, and height at 9 defined ages up to 4 years were obtained and compared with data from a reference population of 3650 healthy children using the standard deviation score (SDS). Predictors (length, weight, etiology of hydrocephalus, valve type, number of revisions, valve setting, number of adjustments, and time of first surgery) for head circumference SDS and changes in head circumference SDS from shunt insertion at 1 year to last measurement were analyzed using bivariate and multiple linear regression analysis. Fifty children were included. The mean SDSs for head circumference in shunt-treated compared with healthy children were 1.95 ± 2.50 at shunt insertion (p < 0.001, n = 44), 0.38 ± 1.97 at 1 year (p = 0.27, n = 33), -0.96 ± 2.05 at 2 years (p = 0.046, n = 21), -1.39 ± 2.25 at 3 years (p = 0.026, n = 16), and 0.63 ± 3.34 at 4 years (p = 0.73, n = 4). Significant predictors for low head circumference SDS at 1 year of age were low weight (p = 0.002) and short height (p = 0.022) and at last measurement low weight (p < 0.0001), short height (p = 0.002), and 1-4 shunt revisions (p = 0.034). A significant predictor for change in head circumference SDS from shunt insertion to 1 year of age was the number of shunt valve revisions (p = 0.04) and at last measurement an etiology of intraventricular hemorrhage (p = 0.0058). Shunt-treated children have smaller head circumferences at 2 and 3 years of age than healthy children. Low weight, short height, etiology of intraventricular hemorrhage, and frequent shunt valve revisions are predictors for decreased head circumference. Prospective, randomized studies comparing skull growth using fixed and adjustable pressure-regulated shunt valves and flow-regulated valves are needed.

Predisposing Factors for Spontaneous Closure of Congenital Portosystemic Shunts.

PubMed

Paganelli, Massimiliano; Lipsich, José E; Sciveres, Marco; Alvarez, Fernando

2015-10-01

In a review of 382 cases of congenital portosystemic shunt, we found that presentation with neonatal cholestasis strongly predicts spontaneous closure of intrahepatic shunts (OR 8.3, 95% CI 3.4-20.2). Spontaneous closure before the 24th month of age is more likely for distal or multiple shunts, but rare for patent ductus venosus. Copyright © 2015 Elsevier Inc. All rights reserved.

Imaging of patent foramen ovale with 64-section multidetector CT.

PubMed

Saremi, Farhood; Channual, Stephanie; Raney, Aidan; Gurudevan, Swaminatha V; Narula, Jagat; Fowler, Steven; Abolhoda, Amir; Milliken, Jeffrey C

2008-11-01

To investigate the feasibility of 64-section multidetector computed tomography (CT) by using CT angiography (a) to demonstrate anatomic detail of the interatrial septum pertinent to the patent foramen ovale (PFO), and (b) to visually detect left-to-right PFO shunts and compare these findings in patients who also underwent transesophageal echocardiography (TEE). In this institutional review board-approved HIPAA-compliant study, electrocardiographically gated coronary CT angiograms in 264 patients (159 men, 105 women; mean age, 60 years) were reviewed for PFO morphologic features. The length and diameter of the opening of the PFO tunnel, presence of atrial septal aneurysm (ASA), and PFO shunts were evaluated. A left-to-right shunt was assigned a grade according to length of contrast agent jet (grade 1, 1 cm to 2 cm; grade 3, >2 cm). In addition, 23 patients who underwent both modalities were compared (Student t test and linear regression analysis). A difference with P < .05 was significant. A flap valve, seen in 101 (38.3%) patients, was patent at the entry into the right atrium (PFO) in 62 patients (61.4% of patients with flap valve, 23.5% of total patients). A left-to-right shunt was detected in 44 (16.7% of total) patients (grade 1, 61.4%; grade 2, 34.1%; grade 3, 4.5%). No shunt was seen in patients without a flap valve. Mean length of PFO tunnel was 7.1 mm in 44 patients with a shunt and 12.1 mm in 57 patients with a flap valve without a shunt (P < .0001). In patients with a tunnel length of 6 mm or shorter, 92.6% of the shunts were seen. ASA was seen in 11 (4.2%) patients; of these patients, a shunt was seen in seven (63.6%). In 23 patients who underwent CT angiography and TEE, both modalities showed a PFO shunt in seven. Multidetector CT provides detailed anatomic information about size, morphologic features, and shunt grade of the PFO. Shorter tunnel length and septal aneurysms are frequently associated with left-to-right shunts in patients with PFO. (c) RSNA, 2008.

Cavernous sinus thrombosis caused by contralateral sphenoid sinusitis: a case report

PubMed Central

2013-01-01

Objective To report a rare case of unilateral cavernous sinus thrombosis caused by contralateral sphenoid sinusitis. Case report A 33-year-old female visited our hospital for severe, right-sided, temporal headache, chemosis, periorbital edema, and proptosis. These signs were associated with congested erythematous nasal mucosa with purulent discharge from the right superior nasal meatus. Contrast enhanced CT showed dilated left superior ophthalmic vein, suggestive of thrombosis, contrast enhancement of the left cavernous sinuses, and dilation of cavernous sinus, indicating cavernous sinus inflammation. The right maxillary, ethmoid and sphenoid sinuses showed mucosal thickening and retention of purulent material. She was diagnosed with cavernous sinus thrombosis caused by contralateral sphenoid sinusitis. All clinical symptoms and signs improved after endoscopic sphenoidotomy and appropriate medical treatment. Conclusions Sphenoiditis can cause contralateral cavernous sinus thrombosis. Early surgical sphenoidotomy and aggressive medical treatment are the cornerstones of successful management of this life-threatening complication. PMID:23497466

Ventricular-subcutaneous shunt for the treatment of experimental hydrocephalus in young rats: technical note.

PubMed

Santos, Marcelo Volpon; Garcia, Camila Araujo Bernardino; Jardini, Evelise Oliveira; Romeiro, Thais Helena; da Silva Lopes, Luiza; Machado, Hélio Rubens; de Oliveira, Ricardo Santos

2016-08-01

Hydrocephalus is a complex disease that affects cerebrospinal fluid (CSF) dynamics and is very common in children. To this date, CSF shunting is still the standard treatment for childhood hydrocephalus, but, nevertheless, the effects of such an operation on the developing brain are widely unknown. To help overcome this, experimental models of CSF shunts are surely very useful tools. The objective of this study was to describe a feasible and reliable technique of an adapted ventricular-subcutaneous shunt for the treatment of kaolin-induced hydrocephalus in young rats. We developed a ventricular-subcutaneous shunt (VSCS) technique which was used in 31 Wistar young rats with kaolin-induced hydrocephalus. Hydrocephalus was induced at 7 days of age, and shunt implantation was performed 7 days later. Our technique used a 0.7-mm gauge polypropylene catheter tunneled to a subcutaneous pocket created over the animal's back and inserted into the right lateral ventricle. All animals were sacrificed 14 days after shunt insertion. Twenty-four rats survived and remained well until the study was ended. No major complications were seen. Their weight gain went back to normal. They all underwent ambulatory behavioral testing prior and after VSCS, which showed improvement in their motor skills. We have also obtained magnetic resonance (MR) scans of 16 pups confirming reduction of ventricular size after shunting and indicating effective treatment. Histopathological analysis of brain samples before and after shunting showed reversion of ependymal and corpus callosum disruption, as well as fewer reactive astrocytes in shunted animals. An experimental CSF shunt technique was devised. Excessive CSF of hydrocephalic rats is diverted into the subcutaneous space where it can be resorbed. This technique has a low complication rate and is effective. It might be applied to various types of experimental studies involving induction and treatment of hydrocephalus.

Exercise Physiology and Pulmonary Hemodynamic Abnormality in PH Patients with Exercise Induced Venous-To-Systemic Shunt.

PubMed

Guo, Jian; Shi, Xue; Yang, Wenlan; Gong, Sugang; Zhao, Qinhua; Wang, Lan; He, Jing; Shi, Xiaofang; Sun, Xingguo; Liu, Jinming

2014-01-01

To identify the pulmonary hypertension (PH) patients who develop an exercise induced venous-to-systemic shunt (EIS) by performing the cardiopulmonary exercise test (CPET), analyse the changes of CPET measurements during exercise and compare the exercise physiology and resting pulmonary hemodynamics between shunt-PH and no-shunt-PH patients. Retrospectively, resting pulmonary function test (PFT), right heart catheterization (RHC), and CPET for clinical evaluation of 104 PH patients were studied. Considering all 104 PH patients by three investigators, 37 were early EIS+, 61 were EIS-, 3 were late EIS+, and 3 others were placed in the discordant group. PeakVO2, AT and OUES were all reduced in the shunt-PH patients compared with the no-shunt-PH subjects, whereas VE/VCO2 slope and the lowest VE/VCO2 increased. Besides, the changes and the response characteristics of the key CPET parameters at the beginning of exercise in the shunt group were notably different from those of the no shunt one. At cardiac catheterization, the shunt patients had significantly increased mean pulmonary artery pressure (mPAP), mean right atrial pressure (mRAP) and pulmonary vascular resistance (PVR), reduced cardiac output (CO) and cardiac index (CI) compared with the no shunt ones (P<0.05). Resting CO was significantly correlated with exercise parameters of AT (r = 0.527, P<0.001), OUES (r = 0.410, P<0.001) and Peak VO2 (r = 0.405, P<0.001). PVR was significantly, but weakly, correlated with the above mentioned CPET parameters. CPET may allow a non-invasive method for detecting an EIS and assessing the severity of the disease in PH patients.

Turning crocodilian hearts into bird hearts: growth rates are similar for alligators with and without right-to-left cardiac shunt

PubMed Central

Eme, John; Gwalthney, June; Owerkowicz, Tomasz; Blank, Jason M.; Hicks, James W.

2010-01-01

The functional and possible adaptive significance of non-avian reptiles' dual aortic arch system and the ability of all non-avian reptiles to perform central vascular cardiac shunts have been of great interest to comparative physiologists. The unique cardiac anatomy of crocodilians – a four-chambered heart with the dual aortic arch system – allows for only right-to-left (R–L; pulmonary bypass) cardiac shunt and for surgical elimination of this shunt. Surgical removal of the R–L shunt, by occluding the left aorta (LAo) upstream and downstream of the foramen of Panizza, results in a crocodilian with an obligatory, avian/mammalian central circulation. In this study, R–L cardiac shunt was eliminated in age-matched, female American alligators (Alligator mississippiensis; 5–7 months of age). We tested the hypothesis that surgical elimination of R–L cardiac shunt would impair growth (a readily measured proxy for fitness) compared with sham-operated, age-matched controls, especially in animals subjected to exhaustive exercise. While regular exercise caused a decrease in size (snout-to-vent length, head length and body mass), elimination of the capacity for R–L cardiac shunt did not greatly reduce animal growth, despite a chronic ventricular enlargement in surgically altered juvenile alligators. We speculate that, despite being slightly smaller, alligators with an occluded LAo would have reached sexual maturity in the same breeding season as control alligators. This study suggests that crocodilian R–L cardiac shunt does not provide an adaptive advantage for juvenile alligator growth and supports the logic that cardiac shunts persist in crocodilians because they have not been selected against. PMID:20639429

Hydrogen sulfide upregulates heme oxygenase-1 expression in rats with volume overload-induced heart failure

PubMed Central

ZHANG, CHAO-YING; LI, XIAO-HUI; ZHANG, TING; FU, JIN; CUI, XIAO-DAI

2013-01-01

The present study investigated the role of hydrogen sulfide (H2S), a novel gaseous transmitter, in chronic heart failure (CHF) induced by left-to-right shunt, leading to volume overload. Thirty male Sprague-Dawley rats were randomly divided into four groups: the shunt group, the sham group, the shunt + sodium hydrosulfide (NaHS) group and the sham + NaHS group. CHF was induced in the rats by abdominal aorta-inferior vena cava shunt operation. Rats in the shunt + NaHS and sham + NaHS groups were injected intraperitoneally with NaHS (H2S donor). Haemodynamic parameters were measured 8 weeks after surgery. In addition, left ventricular heme oxygenase (HO)-1 mRNA expression was measured by real-time PCR. Protein expression of HO-1 was evaluated by western blot analysis. Eight weeks after surgery, compared to the sham group, the left ventricular systolic pressure (LVSP) and left ventricular peak rate of contraction and relaxation (LV±dp/dtmax) were significantly reduced; the left ventricular end-diastolic pressure (LVEDP) was significantly increased in the shunt group (all P<0.05). However, NaHS increased LVSP and LV±dp/dtmax (all P<0.05) and decreased LVEDP (P<0.05). Protein expression of HO-1 was significantly decreased in the shunt group compared to that in the sham group (P<0.05). NaHS increased protein expression of HO-1 compared to that in the shunt group (P<0.05). HO-1 mRNA expression was significantly increased in the shunt + NaHS group compared to that in the shunt group (P<0.01). The present study demonstrated that H2S may play a protective role in volume overload-induced CHF by upregulating protein and mRNA expression of HO-1. PMID:24648967

Staged Transcatheter Treatment of Portal Hypoplasia and Congenital Portosystemic Shunts in Children

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruckheimer, Elchanan, E-mail: elchananb@bezeqint.net; Dagan, Tamir; Atar, Eli

2013-12-15

Purpose: Congenital portosystemic shunts (CPSS) with portal venous hypoplasia cause hyperammonemia. Acute shunt closure results in portal hypertension. A transcatheter method of staged shunt reduction to afford growth of portal vessels followed by shunt closure is reported. Methods: Pressure measurements and angiography in the CPSS or superior mesenteric artery (SMA) during temporary occlusion of the shunt were performed. If vessels were diminutive and the pressure was above 18 mmHg, a staged approach was performed, which included implantation of a tailored reducing stent to reduce shunt diameter by {approx}50 %. Recatheterization was performed approximately 3 months later. If the portal pressuremore » was below 18 mmHg and vessels had developed, the shunt was closed with a device. Results: Six patients (5 boys, 1 girl) with a median age of 3.3 (range 0.5-13) years had CPSS portal venous hypoplasia and hyperammonemia. Five patients underwent staged closure. One patient tolerated acute closure. One patient required surgical shunt banding because a reducing stent could not be positioned. At median follow-up of 3.8 (range 2.2-8.4) years, a total of 21 procedures (20 transcatheter, 1 surgical) were performed. In all patients, the shunt was closed with a significant reduction in portal pressure (27.7 {+-} 11.3 to 10.8 {+-} 1.8 mmHg; p = 0.016), significant growth of the portal vessels (0.8 {+-} 0.5 to 4.0 {+-} 2.4 mm; p = 0.037), and normalization of ammonia levels (202.1 {+-} 53.6 to 65.7 {+-} 9.6 {mu}mol/L; p = 0.002) with no complications. Conclusion: Staged CPSS closure is effective in causing portal vessel growth and treating hyperammonemia.« less

Does hepatic steatosis have an impact on the short term hepatic response after complete attenuation of congenital extrahepatic portosystemic shunts? A prospective study of 20 dogs.

PubMed

Hunt, Geraldine B; Luff, Jennifer; Daniel, Leticia; Zwingenberger, Allison

2014-11-01

To evaluate the relationship between hepatic steatosis and increase in liver size and resolution of shunting after surgical attenuation of congenital extrahepatic portosystemic shunts in dogs. Prospective study. Dogs (n = 20) with congenital extrahepatic portosystemic shunts. Shunts were attenuated using ameroid ring constrictors. Portal blood flow and liver volume were evaluated using computed tomography before and ≥8 weeks after surgery. Hepatic steatosis was quantified by stereological point counting of lipid droplets and lipogranulomas (LG) in liver biopsies stained with Oil-red-O. Associations between steatosis and preoperative liver volume, liver growth after surgery, and development of acquired shunts were evaluated. Acquired shunts developed in 2 dogs (10%). Dogs with larger preoperative liver volumes relative to bodyweight had fewer lipid droplets per tissue point (P = .019). LG per tissue point were significantly associated with age: 0.019 ± 0.06 for dogs <12 months versus 0.25 ± 0.49 for dogs >12 months (P = .007). There was a significant positive association between liver growth after surgery and the number of LG/month of age in dogs >12 months (P = .003). There was no association between steatosis, presence of macrosteatosis, the number of LG or development of acquired shunts. This preliminary study suggests that the presence of hepatic lipidosis and LG has no demonstrable effect on development of acquired shunts or the magnitude of increase in liver volume after attenuation of congenital extrahepatic portosystemic shunts in dogs. © Copyright 2014 by The American College of Veterinary Surgeons.

Staged transcatheter treatment of portal hypoplasia and congenital portosystemic shunts in children.

PubMed

Bruckheimer, Elchanan; Dagan, Tamir; Atar, Eli; Schwartz, Michael; Kachko, Ludmila; Superina, Riccardo; Amir, Gabriel; Shapiro, Rivka; Birk, Einat

2013-12-01

Congenital portosystemic shunts (CPSS) with portal venous hypoplasia cause hyperammonemia. Acute shunt closure results in portal hypertension. A transcatheter method of staged shunt reduction to afford growth of portal vessels followed by shunt closure is reported. Pressure measurements and angiography in the CPSS or superior mesenteric artery (SMA) during temporary occlusion of the shunt were performed. If vessels were diminutive and the pressure was above 18 mmHg, a staged approach was performed, which included implantation of a tailored reducing stent to reduce shunt diameter by ~50 %. Recatheterization was performed approximately 3 months later. If the portal pressure was below 18 mmHg and vessels had developed, the shunt was closed with a device. Six patients (5 boys, 1 girl) with a median age of 3.3 (range 0.5-13) years had CPSS portal venous hypoplasia and hyperammonemia. Five patients underwent staged closure. One patient tolerated acute closure. One patient required surgical shunt banding because a reducing stent could not be positioned. At median follow-up of 3.8 (range 2.2-8.4) years, a total of 21 procedures (20 transcatheter, 1 surgical) were performed. In all patients, the shunt was closed with a significant reduction in portal pressure (27.7 ± 11.3 to 10.8 ± 1.8 mmHg; p = 0.016), significant growth of the portal vessels (0.8 ± 0.5 to 4.0 ± 2.4 mm; p = 0.037), and normalization of ammonia levels (202.1 ± 53.6 to 65.7 ± 9.6 μmol/L; p = 0.002) with no complications. Staged CPSS closure is effective in causing portal vessel growth and treating hyperammonemia.

Congenital portosystemic shunts in children: a new anatomical classification correlated with surgical strategy.

PubMed

Blanc, Thomas; Guerin, Florent; Franchi-Abella, Stéphanie; Jacquemin, Emmanuel; Pariente, Danièle; Soubrane, Olivier; Branchereau, Sophie; Gauthier, Frédéric

2014-07-01

To propose an anatomical classification of congenital portosystemic shunts (CPSs) correlating with conservative surgery. CPSs entail a risk of life-threatening complications because of poor portal inflow, which may be prevented or cured by their closure. Current classifications based on portal origin of the shunt are not helpful for planning conservative surgery. Twenty-three patients who underwent at least 1 surgical procedure to close the CPSs were included in this retrospective study (1997-2012). We designed a classification according to the ending of the shunt in the caval system. We analyzed the results and outcomes of surgery according to this classification. Two patients had an extrahepatic portosystemic shunt, 17 had a portacaval shunt [subdivided in 5 end-to-side-like portal-caval, 7 side-to-side-like portal-caval, and 5 H-shaped (H-type portal-caval)], 2 had portal-to-hepatic vein shunts (portohepatic), and 2 had a persistent ductus venosus. All extrahepatic portosystemic shunts, H-type portal-caval, portohepatic, and patent ductus venosus patients had a successful 1-stage ligation. All 5 end-to-side-like portal-caval patients had a threadlike intrahepatic portal venous system; a 2-stage complete closure was successfully achieved for 4 and a partial closure for 1. The first 2 side-to-side-like portal-caval patients had a successful 2-stage closure whereas the 5 others had a 1-stage longitudinal caval partition. All patients are alive and none needed a liver transplantation. Our classification correlates the anatomy of CPSs and the surgical strategy: outcomes are good provided end-to-side-like portal-caval shunts patients have a 2-stage closure, side-to-side portal-caval shunts patients have a 1-stage caval partition, and the others have a 1-stage ligation.

Short ORF-Dependent Ribosome Shunting Operates in an RNA Picorna-Like Virus and a DNA Pararetrovirus that Cause Rice Tungro Disease

PubMed Central

Pooggin, Mikhail M.; Rajeswaran, Rajendran; Schepetilnikov, Mikhail V.; Ryabova, Lyubov A.

2012-01-01

Rice tungro disease is caused by synergistic interaction of an RNA picorna-like virus Rice tungro spherical virus (RTSV) and a DNA pararetrovirus Rice tungro bacilliform virus (RTBV). It is spread by insects owing to an RTSV-encoded transmission factor. RTBV has evolved a ribosome shunt mechanism to initiate translation of its pregenomic RNA having a long and highly structured leader. We found that a long leader of RTSV genomic RNA remarkably resembles the RTBV leader: both contain several short ORFs (sORFs) and potentially fold into a large stem-loop structure with the first sORF terminating in front of the stem basal helix. Using translation assays in rice protoplasts and wheat germ extracts, we show that, like in RTBV, both initiation and proper termination of the first sORF translation in front of the stem are required for shunt-mediated translation of a reporter ORF placed downstream of the RTSV leader. The base pairing that forms the basal helix is required for shunting, but its sequence can be varied. Shunt efficiency in RTSV is lower than in RTBV. But in addition to shunting the RTSV leader sequence allows relatively efficient linear ribosome migration, which also contributes to translation initiation downstream of the leader. We conclude that RTSV and RTBV have developed a similar, sORF-dependent shunt mechanism possibly to adapt to the host translation system and/or coordinate their life cycles. Given that sORF-dependent shunting also operates in a pararetrovirus Cauliflower mosaic virus and likely in other pararetroviruses that possess a conserved shunt configuration in their leaders it is tempting to propose that RTSV may have acquired shunt cis-elements from RTBV during their co-existence. PMID:22396650

Surgical management of hydrocephalus secondary to intraventricular hemorrhage in the preterm infant.

PubMed

Christian, Eisha A; Melamed, Edward F; Peck, Edwin; Krieger, Mark D; McComb, J Gordon

2016-03-01

OBJECT Posthemorrhagic hydrocephalus (PHH) in the preterm infant remains a major neurological complication of prematurity. The authors first described insertion of a specially designed low-profile subcutaneous ventricular catheter reservoir for temporary management of hydrocephalus in 1983. This report presents the follow-up experience with the surgical management of PHH in this population and describes outcomes both in infants who were stable for permanent shunt insertion and those initially temporized with a ventricular reservoir (VR) prior to permanent ventriculoperitoneal (VP)/ventriculoatrial (VA) shunt placement. METHODS A retrospective review was undertaken of the medical records of all premature infants surgically treated for posthemorrhagic hydrocephalus (PHH) between 1997 and 2012 at Children's Hospital Los Angeles. RESULTS Over 14 years, 91 preterm infants with PHH were identified. Fifty neonates received temporizing measures via a VR that was serially tapped for varying time periods. For the remaining 41 premature infants, VP/VA shunt placement was the first procedure. Patients with a temporizing measure as their initial procedure had undergone CSF diversion significantly earlier in life than those who had permanent shunting as the initial procedure (29 vs 56 days after birth, p < 0.01). Of the infants with a VR as their initial procedure, 5/50 (10%) did not undergo subsequent VP/VA shunt placement. The number of shunt revisions and the rates of loculated hydrocephalus and shunt infection did not statistically differ between the 2 groups. CONCLUSIONS Patients with initial VR insertion as a temporizing measure received a CSF diversion procedure significantly earlier than those who received a permanent shunt as their initial procedure. Otherwise, the outcomes with regard to shunt revisions, loculated hydrocephalus, and shunt infection were not different for the 2 groups.

Measurement of peak CSF flow velocity at cerebral aqueduct, before and after lumbar CSF drainage, by use of phase-contrast MRI: utility in the management of idiopathic normal pressure hydrocephalus.

PubMed

Sharma, Ashwani Kumar; Gaikwad, Shailesh; Gupta, Vipul; Garg, Ajay; Mishra, Nalini K

2008-04-01

Since it was first described, normal pressure hydrocephalus (NPH) and its treatment by means of cerebrospinal fluid (CSF) shunting have been the focus of much investigation. Whatever be the cause of NPH, it has been hypothesized that in this disease there occurs decreased arterial expansion and an increased brain expansion leading to increased transmantle pressure. We cannot measure the latter, but fortunately the effect of these changes (increased peak flow velocity through the aqueduct) can be quantified with cine phase-contrast magnetic resonance imaging (MRI). This investigation was thus undertaken to characterize and measure CSF peak flow velocity at the level of the aqueduct, before and after lumbar CSF drainage, by means of a phase-contrast cine MRI and determine its role in selecting cases for shunt surgery. 37 patients with clinically suspected NPH were included in the study. Changes in the hyperdynamic peak CSF flow velocity with 50 ml lumbar CSF drainage (mimicking shunt) were evaluated in them for considering shunt surgery. 14 out of 15 patients who were recommended for shunt surgery, based on changes peak flow velocity after lumbar CSF drainage, improved after shunt surgery. None of the cases which were not recommended for shunt surgery, based on changes in CSF peak flow velocity after lumbar CSF drainage, improved after shunt surgery (2 out of 22 cases). The study concluded that the phase-contrast MR imaging, done before and after CSF drainage, is a sensitive method to support the clinical diagnosis of normal pressure hydrocephalus, selecting patients of NPH who are likely to benefit from shunt surgery, and to select patients of NPH who are not likely to benefit from shunt surgery.

Process management using component thermal-hydraulic function classes

DOEpatents

Morman, James A.; Wei, Thomas Y. C.; Reifman, Jaques

1999-01-01

A process management expert system where following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic function imbalance caused by the malfunctioning component. Each realignment to a new configuration produces the accompanying sequence of recommended operator actions. All possible new configurations are examined and a prioritized list of acceptable solutions is produced.

Process management using component thermal-hydraulic function classes

DOEpatents

Morman, J.A.; Wei, T.Y.C.; Reifman, J.

1999-07-27

A process management expert system where following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic function imbalance caused by the malfunctioning component. Each realignment to a new configuration produces the accompanying sequence of recommended operator actions. All possible new configurations are examined and a prioritized list of acceptable solutions is produced. 5 figs.

An Unusual Complication of Ventriculoperitoneal Shunt: Urinary Bladder Stone Case Report and Literature Review.

PubMed

Xu, Songtao; Sheng, Weixin; Qiu, Yufa; Wang, Jianguo

2016-01-01

Ventriculoperitoneal (V-P) shunt surgery is the most common technique used for the treatment of hydrocephalus. The migration of ventriculoperitoneal shunt to the bladder is rare. Only two cases have been previously reported in the literature. We report on a 38-year-old male who had hydrocephalus and V-P shunt for 12 years. Two years ago, he found himself with recurrent urinary tract infections, haematuria and urges incontinence, and then he was diagnosed with bladder perforation and merge stones. The patient had an abdominal operation to cut off and take out the shunt catheter, as well as a transurethral holmium laser lithotripsy. Bladder perforation and stones are rare examples of complications in V-P surgical procedures. Controlling the effective length of the terminal V-P shunt and modifying it appropriately can effectively reduce these complications.

Shunt attachment and method for interfacing current collection systems

DOEpatents

Denney, P.E.; Iyer, N.C.; Hannan, W.F. III.

1992-12-08

A composite brush to shunt attachment wherein a volatile component of a composite but mostly metallic brush, used for current collection purposes, does not upon welding or brazing, adversely affect the formation of the interfacial bond with a conductive shunt which carries the current from the zone of the brush. The brush to shunt attachment for a brush material of copper-graphite composite and a shunt of copper, or substituting silver for copper as an alternative, is made through a hot isostatic pressing (HIP). The HIP process includes applying high pressure and temperature simultaneously at the brush to shunt interface, after it has been isolated or canned in a metal casing in which the air adjacent to the interface has been evacuated and the interfacial area has been sealed before the application of pressure and temperature. 6 figs.

Shunt attachment and method for interfacing current collection systems

DOEpatents

Denney, Paul E.; Iyer, Natraj C.; Hannan, III, William F.

1992-01-01

A composite brush to shunt attachment wherein a volatile component of a composite but mostly metallic brush, used for current collection purposes, does not upon welding or brazing, adversely affect the formation of the interfacial bond with a conductive shunt which carries the current from the zone of the brush. The brush to shunt attachment for a brush material of copper-graphite composite and a shunt of copper, or substituting silver for copper as an alternative, is made through a hot isostatic pressing (HIP). The HIP process includes applying high pressure and temperature simultaneously at the brush to shunt interface, after it has been isolated or canned in a metal casing in which the air adjacent to the interface has been evacuated and the interfacial area has been sealed before the application of pressure and temperature.

Intrahepatic portosystemic venous shunt: diagnosis by color Doppler imaging.

PubMed

Kudo, M; Tomita, S; Tochio, H; Minowa, K; Todo, A

1993-05-01

Intrahepatic portosystemic venous shunt is a rare clinical entity; only 33 such cases have been reported. It may be congenital, or secondary to portal hypertension. Five patients with this disorder are presented, each of whom was diagnosed by color Doppler imaging, including waveform spectral analysis. One patient with clinical evidence of cirrhosis and portal hypertension had episodes of hepatic encephalopathy and elevated blood levels of ammonia. This patient had a large tubular shunt between the posterior branch of the portal vein and the inferior vena cava. Shunts of this type are considered to be collateral pathways which develop in the hepatic parenchyma as a result of portal hypertension. The other four patients had no evidence of liver disease, and all four evidenced an aneurysmal portohepatic venous shunt within the liver parenchyma. Shunts of this type are considered congenital. The diagnosis of intrahepatic portosystemic venous shunts was established by color Doppler imaging, which demonstrated a direct communication of color flow signals between the portal vein and hepatic vein, in addition to the characterization of the Doppler spectrum at each sampling point from a continuous waveform signal (portal vein) to a turbulent signal (aneurysmal cavity), and finally, to a biphasic waveform signal (hepatic vein). As demonstrated by the five patients, color Doppler imaging is useful in the diagnosis of an intrahepatic portosystemic hepatic venous shunt, and the measurement of shunt ratio may be useful in the follow-up and determining the therapeutic option.

A Comparative Result of Ventriculoperitoneal Shunt, Focusing Mainly on Gravity-Assisted Valve and Programmable Valve

PubMed Central

Lee, Won-Chul; Choe, Il-Seung; Park, Sung-Choon; Ha, Young-Soo; Lee, Kyu Chang

2010-01-01

Objective Despite rapid evolution of shunt devices, the complication rates remain high. The most common causes are turning from obstruction, infection, and overdrainage into mainly underdrainage. We investigated the incidence of complications in a consecutive series of hydrocephalic patients. Methods From January 2002 to December 2009, 111 patients underwent ventriculoperitoneal (VP) shunting at our hospital. We documented shunt failures and complications according to valve type, primary disease, and number of revisions. Results Overall shunt survival time was 268 weeks. Mean survival time of gravity-assisted valve (GAV) was 222 weeks versus 286 weeks for other shunts. Survival time of programmable valves (264 weeks) was longer than that of pressure-controlled valves (186 weeks). The most common cause for shunt revision was underdrainage (13 valves). The revision rate due to underdrainage in patients with GAV (7 of 10 patients) was higher than that for other valve types. Of 7 patients requiring revision for GAV underdrainage, 6 patients were bedridden. The overall infection rate was 3.6%, which was lower than reported series. Seven patients demonstrating overdrainage had cranial defects when operations were performed (41%), and overdrainage was improved in 5 patients after cranioplasty. Conclusion Although none of the differences was statistically significant, some of the observations were especially notable. If a candidate for VP shunting is bedridden, GAV may not be indicated because it could lead to underdrainage. Careful procedure and perioperative management can reduce infection rate. Cranioplasty performed prior to VP shunting may be beneficial. PMID:21082054

Shunt Devices for the Treatment of Adult Hydrocephalus: Recent Progress and Characteristics

PubMed Central

MIYAKE, Hiroji

2016-01-01

Various types of shunt valves have been developed during the past 50 years, most of which can be classified into the following categories: (1) fixed differential pressure valves; (2) fixed differential pressure (DP) valves with an antisiphon mechanism; (3) programmable DP valves; (4) programmable DP valves with an antisiphon mechanism; and (5) programmable antisiphon valves. When considering the myriad of possible postoperative condition changes, such as the onset of accidental non-related diseases or trauma in adults, and changes in normal physiological development or anticipation of future shunt removal in children, it has become standard to use the programmable valve as a first choice for cerebrospinal fluid shunting. However, it is still unclear what type of shunt valve is suitable for each individual case. Based on the results of SINPHONI and more recently SINPHONI 2 trials, the programmable DP valve is recommended as the first line shunt valve. The programmable DP valve with an antisiphon mechanism is thought to be beneficial for tall, slender patients, who have a tendency for easily developing complications of overdrainage, however, this type of valve must be used cautiously in obese patients because of the increased risk of underdrainage. Although the current evidence is still insufficient, the programmable antisiphon valve, which costs the same as the programmable DP valve, is also thought to be the first line shunt valve. The quick reference table is applicable for most shunt valves, and for patients with either the ventriculoperitoneal or the lumboperitoneal shunt. PMID:27041631

Shunt Devices for the Treatment of Adult Hydrocephalus: Recent Progress and Characteristics.

PubMed

Miyake, Hiroji

2016-05-15

Various types of shunt valves have been developed during the past 50 years, most of which can be classified into the following categories: (1) fixed differential pressure valves; (2) fixed differential pressure (DP) valves with an antisiphon mechanism; (3) programmable DP valves; (4) programmable DP valves with an antisiphon mechanism; and (5) programmable antisiphon valves. When considering the myriad of possible postoperative condition changes, such as the onset of accidental non-related diseases or trauma in adults, and changes in normal physiological development or anticipation of future shunt removal in children, it has become standard to use the programmable valve as a first choice for cerebrospinal fluid shunting. However, it is still unclear what type of shunt valve is suitable for each individual case. Based on the results of SINPHONI and more recently SINPHONI 2 trials, the programmable DP valve is recommended as the first line shunt valve. The programmable DP valve with an antisiphon mechanism is thought to be beneficial for tall, slender patients, who have a tendency for easily developing complications of overdrainage, however, this type of valve must be used cautiously in obese patients because of the increased risk of underdrainage. Although the current evidence is still insufficient, the programmable antisiphon valve, which costs the same as the programmable DP valve, is also thought to be the first line shunt valve. The quick reference table is applicable for most shunt valves, and for patients with either the ventriculoperitoneal or the lumboperitoneal shunt.

Paranasal sinus bony structures and sinus functioning during viral colds in subjects with and without a history of recurrent sinusitis.

PubMed

Alho, Olli-Pekka

2003-12-01

The objective was to assess the impact of ostial obstruction and anatomical variations on paranasal sinus functioning during viral colds with computed tomography (CT) in subjects with and without a history of sinusitis. Cross-sectional study. Twenty-three volunteers with a history of recurrent sinusitis and 25 subjects without such history who had an early (symptoms for 2-4 d) natural cold were examined by taking viral specimens and CT scans and recording symptoms. The pathological sinus changes in the CT scans were scored, and several paranasal bony anatomical variations recorded. Viral origin of the cold was identified in 32 (67%) subjects, similarly in the two groups. Ostiomeatal obstruction and anatomical variations were equally frequent in the subjects with and without a sinusitis history (17 of 23 vs. 17 of 25 for ostial obstruction and 17 of 23 vs. 20 of 25 for at least one variation, respectively). However, in the case of ostiomeatal obstruction the combined CT score of ethmoidal and maxillary sinuses was significantly higher in the subjects with a sinusitis history than in those without (mean +/- SD, 3.0 +/- 0.9 vs. 2.3 +/- 1.2 [P =.05, t test]). In the sinusitis-prone subjects, several variations were associated significantly with various pathological sinus CT changes (septal deviation, horizontally situated processus uncinatus, large concha bullosa, and laterally concave concha media), whereas in the control subjects, only the presence of Haller cells was related to sphenoidal sinus disease. Ostiomeatal complex obstruction and bony anatomical variations seem to have a greater impact on the functioning of paranasal sinuses during viral colds in sinusitis-prone subjects than in subjects without a sinusitis history. These differences may be associated with the increased risk of bacterial sinusitis.

The Bohr Effect Is Not a Likely Promoter of Renal Preglomerular Oxygen Shunting

PubMed Central

Olgac, Ufuk; Kurtcuoglu, Vartan

2016-01-01

The aim of this study was to evaluate whether possible preglomerular arterial-to-venous oxygen shunting is affected by the interaction between renal preglomerular carbon dioxide and oxygen transport. We hypothesized that a reverse (venous-to-arterial) shunting of carbon dioxide will increase partial pressure of carbon dioxide and decrease pH in the arteries and thereby lead to increased oxygen offloading and consequent oxygen shunting. To test this hypothesis, we employed a segment-wise three-dimensional computational model of coupled renal oxygen and carbon dioxide transport, wherein coupling is achieved by shifting the oxygen-hemoglobin dissociation curve in dependence of local changes in partial pressure of carbon dioxide and pH. The model suggests that primarily due to the high buffering capacity of blood, there is only marginally increased acidity in the preglomerular vasculature compared to systemic arterial blood caused by carbon dioxide shunting. Furthermore, effects of carbon dioxide transport do not promote but rather impair preglomerular oxygen shunting, as the increase in acidity is higher in the veins compared to that in the arteries. We conclude that while substantial arterial-to-venous oxygen shunting might take place in the postglomerular vasculature, the net amount of oxygen shunted at the preglomerular vasculature appears to be marginal. PMID:27833564

A physical framework for implementing virtual models of intracranial pressure and cerebrospinal fluid dynamics in hydrocephalus shunt testing.

PubMed

Venkataraman, Pranav; Browd, Samuel R; Lutz, Barry R

2016-09-01

OBJECTIVE The surgical placement of a shunt designed to resolve the brain's impaired ability to drain excess CSF is one of the most common treatments for hydrocephalus. The use of a dynamic testing platform is an important part of shunt testing that can faithfully reproduce the physiological environment of the implanted shunts. METHODS A simulation-based framework that serves as a proof of concept for enabling the application of virtual intracranial pressure (ICP) and CSF models to a physical shunt-testing system was engineered. This was achieved by designing hardware and software that enabled the application of dynamic model-driven inlet and outlet pressures to a shunt and the subsequent measurement of the resulting drainage rate. RESULTS A set of common physiological scenarios was simulated, including oscillations in ICP due to respiratory and cardiac cycles, changes in baseline ICP due to changes in patient posture, and transient ICP spikes caused by activities such as exercise, coughing, sneezing, and the Valsalva maneuver. The behavior of the Strata valve under a few of these physiological conditions is also demonstrated. CONCLUSIONS Testing shunts with dynamic ICP and CSF simulations can facilitate the optimization of shunts to be more failure resistant and better suited to patient physiology.

Outcome of intrahepatic portosystemic shunt diagnosed prenatally.

PubMed

Francois, Bérengère; Gottrand, Fréderic; Lachaux, Alain; Boyer, Corinne; Benoit, Bernard; De Smet, Stéphanie

2017-12-01

We analyzed the characteristics of the population with congenital portosystemic shunt diagnosed during the antenatal period and the organization of their perinatal care. This multicentric retrospective study included all the patients with a prenatal diagnosis of congenital portosystemic shunt. Between 1999 and 2015, 12 patients were included. Prenatal diagnosis was done at a median 26.5 weeks of gestation (21-34). All the patients presented intrahepatic CPSS, three of them had associated congenital cardiopathy, and one a Bannayan-Zonana syndrome. Ten patients had simple outcome on conservative treatment, eight of them having a spontaneous closure of their portosystemic shunt within the first 2 years of life. One patient had surgical treatment which failed and he developed a focal nodular hyperplasia. Another patient had radiological interventional closure of his shunt which was complicated by a venal portal thrombosis. Outcome of intrahepatic portosystemic shunt diagnosed prenatally is good in the majority of cases. What is known: • Multiples studies exist on congenital porto systemic shunt but when the diagnosis is done after birth. • The evolution, management, and complication are well known. What is new: • There is very few studies with only patients diagnosed in antenatal and it is a large series of cases. • Outcome of intrahepatic portosystemic shunt diagnosed prenatally is good in the majority of cases.

Portal vascular anomalies in Down syndrome: spectrum of clinical presentation and management approach.

PubMed

Golewale, Nazar; Paltiel, Harriet J; Fishman, Steven J; Alomari, Ahmad I

2010-08-01

The occurrence of portal vascular anomalies in Down syndrome has been sporadically reported in the literature. These rare disorders have a wide spectrum of anatomical and clinical presentations. The aim of this communication was to describe the clinical course, imaging features, and management approaches in patients with this association. We conducted a comprehensive search of the databases of the Vascular Anomalies Center and the Department of Radiology at Children's Hospital Boston for patients with Down syndrome and portal vascular anomalies. Medical records and imaging studies of varying modalities were reviewed. Three children with Down syndrome and portal anomalies (portosystemic shunt, simple arterioportal shunt, complex arterioportal shunt) were managed at our institution. The portosystemic shunt was clinically insignificant and resolved without any intervention. The simple arterioportal shunt was successfully treated with embolization. The complex arterioportal shunt was associated with major congenital cardiac defects and the child ultimately expired despite a decrease in the arterioportal shunting after embolization. Three is a wide spectrum of clinical and anatomical features of portal vascular shunts in Down syndrome. The management approach should be tailored based on the severity of symptoms. Percutaneous embolization can offer a safe, effective, and minimally invasive alternative to the surgical approach in selective cases. Copyright 2010 Elsevier Inc. All rights reserved.

An in vitro lung model to assess true shunt fraction by multiple inert gas elimination.

PubMed

Varadarajan, Balamurugan; Vogt, Andreas; Hartwich, Volker; Vasireddy, Rakesh; Consiglio, Jolanda; Hugi-Mayr, Beate; Eberle, Balthasar

2017-01-01

The Multiple Inert Gas Elimination Technique, based on Micropore Membrane Inlet Mass Spectrometry, (MMIMS-MIGET) has been designed as a rapid and direct method to assess the full range of ventilation-to-perfusion (V/Q) ratios. MMIMS-MIGET distributions have not been assessed in an experimental setup with predefined V/Q-distributions. We aimed (I) to construct a novel in vitro lung model (IVLM) for the simulation of predefined V/Q distributions with five gas exchange compartments and (II) to correlate shunt fractions derived from MMIMS-MIGET with preset reference shunt values of the IVLM. Five hollow-fiber membrane oxygenators switched in parallel within a closed extracorporeal oxygenation circuit were ventilated with sweep gas (V) and perfused with human red cell suspension or saline (Q). Inert gas solution was infused into the perfusion circuit of the gas exchange assembly. Sweep gas flow (V) was kept constant and reference shunt fractions (IVLM-S) were established by bypassing one or more oxygenators with perfusate flow (Q). The derived shunt fractions (MM-S) were determined using MIGET by MMIMS from the retention data. Shunt derived by MMIMS-MIGET correlated well with preset reference shunt fractions. The in vitro lung model is a convenient system for the setup of predefined true shunt fractions in validation of MMIMS-MIGET.

Patent Foramen Ovale: Association between the Degree of Shunt by Contrast Transesophageal Echocardiography and the Risk of Future Ischemic Neurologic Events

NASA Technical Reports Server (NTRS)

Stone, David A.; Godard, Joel; Godard, Joel; Corretti, mary C.; Kittner, Steven J.; Sample, Cindy; Price, Thomas R.; Plotnick, Gary D.

1996-01-01

This study investigated whether there is an association between the degree of interatrial shunting across a patent foramen ovale, as determined by saline contrast transesophageal echocardiography, and the risk of subsequent systemic embolic events, including stroke. Thirty-four patients found to have patent foramen ovale during transesophageal echocardiography were divided into two groups on the basis of the maximum number of microbubbles in the left heart in any single frame after intravenous saline contrast injection: group 1 (n = 16) with a "large" degree of shunt (220 microbubbles) and group 2 (n = 18) with a "small" degree of shunt (23 but <20 microbubbles). Patients were followed up over a mean period of 21 months for subsequent systemic embolic events, including transient ischemic attack and stroke. Five (31%) of the patients with large shunts had subsequent ischemic neurologic events, whereas none of the patients with small shunts had embolic events (p= 0.03). These events occurred in spite of antiplatelet or anticoagulant therapy. We conclude that patients with a large degree of shunt across a patent foramen ovale, as determined by contrast transesophageal echocardiography, are at a significantly higher risk for subsequent adverse neurologic events compared with patients with a small degree of shunt.

Syringo-Subarachnoid-Peritoneal Shunt Using T-Tube for Treatment of Post-Traumatic Syringomyelia

PubMed Central

Kim, Seon-Hwan; Youm, Jin-Young; Kwon, Hyon-Jo

2012-01-01

Various surgical procedures for the treatment of post-traumatic syringomyelia have been introduced recently, but most surgical strategies have been unreliable. We introduce the concept and technique of a new shunting procedure, syringo-subarachnoid-peritoneal shunt. A 54-year-old patient presented to our hospital with a progressive impairment of motion and position sense on the right side. Sixteen years before this admission, he had been treated by decompressive laminectomy for a burst fracture of L1. On his recent admission, magnetic resonance (MR) imaging studies of the whole spine revealed the presence of a huge syrinx extending from the medulla to the L1 vertebral level. We performed a syringo-subarachnoid-peritoneal shunt, including insertion of a T-tube into the syrinx, subarachnoid space and peritoneal cavity. Clinical manifestations and radiological findings improved after the operation. The syringo-subarachnoid-peritoneal shunt has several advantages. First, fluid can communicate freely between the syrinx, the subarachnoid space, and the peritoneal cavity. Secondly, we can prevent shunt catheter from migrating because dural anchoring of the T-tube is easy. Finally, we can perform shunt revision easily, because only one arm of the T-tube is inserted into the intraspinal syringx cavity. We think that this procedure is the most beneficial method among the various shunting procedures. PMID:22993681

Shunting normal pressure hydrocephalus: the predictive value of combined clinical and CT data.

PubMed

Vanneste, J; Augustijn, P; Tan, W F; Dirven, C

1993-03-01

The value of an ordinal global scale derived from combined clinical and CT data (clin/CT scale) to predict the clinical outcome in 112 patients shunted for presumed normal pressure hydrocephalus (NPH) was analysed. The clinical data were retrospectively collected, all CT scans were re-evaluated, and the clin/CT scale was determined blind to the results of further ancillary tests and to the post-surgical outcome. The scale ranked three classes of prediction: on the basis of clinical and CT characteristics, improvement after shunting was probable, possible, or improbable. The predictive value of the clin/CT scale for the subgroup of communicating NPH was established for two different strategies, depending on the strictness of selection criteria for shunting. In the subgroup of patients with presumed communicating NPH, the prevalence of shunt responsiveness was 29%; the best strategy was to shunt only patients with probable shunt-responsive NPH: the sensitivity was 0.54, the specificity 0.84, and the predictive accuracy 0.75, with a limited number of ineffective shunts (11%) and missed improvements (13%). The study illustrates its need to assess the pre-test probability of NPH based on combined clinical and CT data, before establishing the clinical usefulness of an ancillary test.

Shunting normal pressure hydrocephalus: the predictive value of combined clinical and CT data.

PubMed Central

Vanneste, J; Augustijn, P; Tan, W F; Dirven, C

1993-01-01

The value of an ordinal global scale derived from combined clinical and CT data (clin/CT scale) to predict the clinical outcome in 112 patients shunted for presumed normal pressure hydrocephalus (NPH) was analysed. The clinical data were retrospectively collected, all CT scans were re-evaluated, and the clin/CT scale was determined blind to the results of further ancillary tests and to the post-surgical outcome. The scale ranked three classes of prediction: on the basis of clinical and CT characteristics, improvement after shunting was probable, possible, or improbable. The predictive value of the clin/CT scale for the subgroup of communicating NPH was established for two different strategies, depending on the strictness of selection criteria for shunting. In the subgroup of patients with presumed communicating NPH, the prevalence of shunt responsiveness was 29%; the best strategy was to shunt only patients with probable shunt-responsive NPH: the sensitivity was 0.54, the specificity 0.84, and the predictive accuracy 0.75, with a limited number of ineffective shunts (11%) and missed improvements (13%). The study illustrates its need to assess the pre-test probability of NPH based on combined clinical and CT data, before establishing the clinical usefulness of an ancillary test. PMID:8459240

40 CFR 63.11226 - How can I assert an affirmative defense if I exceed an emission limit during a malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... you may assert an affirmative defense to a claim for civil penalties for exceedances of numerical... malfunction event at issue. The analysis shall also specify, using best monitoring methods and engineering... avail itself of an affirmative defense to civil penalties for that malfunction. The owner or operator...

40 CFR Table 1 to Subpart Aaaa of... - Applicability of NESHAP General Provisions to Subpart AAAA

Code of Federal Regulations, 2010 CFR

2010-07-01

... reconstructed sources 63.6(e) Operation and maintenance requirements, startup, shutdown and malfunction plan...(b)(2)(i)-(b)(2)(v) General recordkeeping requirements 63.10(d)(5) If actions taken during a startup, shutdown and malfunction plan are consistent with the procedures in the startup, shutdown and malfunction...

40 CFR 63.7835 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2010 CFR

2010-07-01

... that applies to you. This includes periods of startup, shutdown, and malfunction. You also must report...) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the...

40 CFR 63.7835 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2012 CFR

2012-07-01

... that applies to you. This includes periods of startup, shutdown, and malfunction. You also must report...) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the...

40 CFR 63.7835 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2013 CFR

2013-07-01

... that applies to you. This includes periods of startup, shutdown, and malfunction. You also must report...) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the...

40 CFR Table 1 to Subpart Aaaa of... - Applicability of NESHAP General Provisions to Subpart AAAA

Code of Federal Regulations, 2011 CFR

2011-07-01

... reconstructed sources 63.6(e) Operation and maintenance requirements, startup, shutdown and malfunction plan...(b)(2)(i)-(b)(2)(v) General recordkeeping requirements 63.10(d)(5) If actions taken during a startup, shutdown and malfunction plan are consistent with the procedures in the startup, shutdown and malfunction...

40 CFR 63.7835 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2014 CFR

2014-07-01

... that applies to you. This includes periods of startup, shutdown, and malfunction. You also must report...) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the...

40 CFR 63.7835 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2011 CFR

2011-07-01

... that applies to you. This includes periods of startup, shutdown, and malfunction. You also must report...) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the...

Study on the Automatic Detection Method and System of Multifunctional Hydrocephalus Shunt

NASA Astrophysics Data System (ADS)

Sun, Xuan; Wang, Guangzhen; Dong, Quancheng; Li, Yuzhong

2017-07-01

Aiming to the difficulty of micro pressure detection and the difficulty of micro flow control in the testing process of hydrocephalus shunt, the principle of the shunt performance detection was analyzed.In this study, the author analyzed the principle of several items of shunt performance detection,and used advanced micro pressure sensor and micro flow peristaltic pump to overcome the micro pressure detection and micro flow control technology.At the same time,This study also puted many common experimental projects integrated, and successfully developed the automatic detection system for a shunt performance detection function, to achieve a test with high precision, high efficiency and automation.

Three-dimensional CAD/CAM imaging of the maxillary sinus in ageing process.

PubMed

Lovasova, Kvetuse; Kachlik, David; Rozpravkova, Mirela; Matusevska, Maria; Ferkova, Jana; Kluchova, Darina

2018-04-05

During the physiological ageing process atrophy of the alveolar bone appears in vertical direction. This bone resorption causes pushing the limits of the maxillary sinus at the expense of a degraded bone. The sinus volume increases due to the facial development in children and adolescents or during the ageing process due to the loss of teeth and bone mass. The main aim of this study is to determine the sinus shape and sinus floor morphology related to age. Human adult male and female cadaveric heads (aged 37 to 83 years) with different dental status were used. The three-dimensional CAD/CAM software was used to scan the solid impressions of the maxillary sinus to visualize the real sinus shape and sinus floor. Subsequently, other findings are shown in tables and evaluated graphically. The maxillary sinus morphology, its relationship to the nasal cavity, the sub sinus alveolar bone height, displacement of the lowest and highest points of sinus, and the sinus relationship to the roots of the upper teeth were studied and evaluated. Some septa, crests, and the prominent infraorbital canal were also found in the area of the sinus floor. This paper provides a unique view on the maxillary sinus and its changes during the ageing process with preserved topographical relations in a representative sample of the Slovak population. The visualization of the maxillary sinus anatomy is necessary in the diagnosis and treatment plans for dental implants and during current surgical procedures. Copyright © 2018 Elsevier GmbH. All rights reserved.

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

21 CFR 876.5955 - Peritoneo-venous shunt.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Identification. A peritoneo-venous shunt is an implanted device that consists of a catheter and a pressure...) Backflow specification and testing to prevent reflux of blood into the shunt. [48 FR 53023, Nov. 23, 1983...

Does wet hair in cold weather cause sinus headache and posterior eye pain? A possible mechanism through selective brain cooling system.

PubMed

Kaya, Abdullah; Calışkan, Halil

2012-12-01

As a general observation, wet hair in cold weather seems to be a predisposing factor for sinus headache and posterior eye pain. We offer a mechanism through selective brain cooling system for this observation. Selective brain cooling (SBC) is a mechanism to protect brain from hyperthermia. Components of SBC are head skin and upper respiratory tract (nose and paranasal sinuses). Cool venous blood from head skin and mucous membranes of nose and paranasal sinuses drains to intracranial dural sinuses and provide brain cooling. Brain will be cooled very much when head skin exposes to hypothermia such a condition like wet hair in cold weather. We suggest that, in order to reduce brain cooling activity, some alterations are being occurred within paranasal sinuses. For this purpose, sinus ostiums may close and mucus may accumulate to reduce air within sinuses. Also there may be some vasomotor changes to prevent heat loss. We hypothesize that this possible alterations may occur within paranasal sinuses as a control mechanism for brain temperature control during exposure of head skin to hypothermia. Paranasal sinuses may also cool brain directly by a very thin layer of bone separates the posterior ethmoid air sinus from the subarachnoid space and only thin plates of bone separate the sphenoidal sinuses from internal carotid artery and cavernous sinuses. Because of their critical role in the SBC, posterior ethmoid air sinus and sphenoidal sinuses may be affected from this alterations more than other paranasal sinuses. This situation may cause posterior eye pain. This mechanism can explain why a person who expose to hypothermia with wet hair or a person who don't use a beret or a hat during cold weather gets sinus headache and posterior eye pain. These symptoms could lead to an incorrect diagnosis of sinusitis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of static axial loads on the lateral vibration attenuation of a beam with piezo-elastic supports

NASA Astrophysics Data System (ADS)

Götz, Benedict; Platz, Roland; Melz, Tobias

2018-03-01

In this paper, vibration attenuation of a beam with circular cross-section by resonantly shunted piezo-elastic supports is experimentally investigated for varying axial tensile and compressive beam loads. The beam's first mode resonance frequency, the general electromechanical coupling coefficient and static transducer capacitance are analyzed for varying axial loads. All three parameter values are obtained from transducer impedance measurements on an experimental test setup. Varying axial beam loads manipulate the beam's lateral bending stiffness and, thus, lead to a detuning of the resonance frequencies. Furthermore, they affect the general electromechanical coupling coefficient of transducer and beam, an important modal quantity for shunt-damping, whereas the static transducer capacitance is nearly unaffected. Frequency transfer functions of the beam with one piezoe-elastic support either shunted to an RL-shunt or to an RL-shunt with negative capacitance, the RLC-shunt, are compared for varying axial loads. It is shown that the beam vibration attenuation with the RLC-shunt is less influenced by varying axial beam loads and, therefore, is more robust against detuning.

Calibration of piezoelectric RL shunts with explicit residual mode correction

NASA Astrophysics Data System (ADS)

Høgsberg, Jan; Krenk, Steen

2017-01-01

Piezoelectric RL (resistive-inductive) shunts are passive resonant devices used for damping of dominant vibration modes of a flexible structure and their efficiency relies on the precise calibration of the shunt components. In the present paper improved calibration accuracy is attained by an extension of the local piezoelectric transducer displacement by two additional terms, representing the flexibility and inertia contributions from the residual vibration modes not directly addressed by the shunt damping. This results in an augmented dynamic model for the targeted resonant vibration mode, in which the residual contributions, represented by two correction factors, modify both the apparent transducer capacitance and the shunt circuit impedance. Explicit expressions for the correction of the shunt circuit inductance and resistance are presented in a form that is generally applicable to calibration formulae derived on the basis of an assumed single-mode structure, where modal interaction has been neglected. A design procedure is devised and subsequently verified by a numerical example, which demonstrates that effective mitigation can be obtained for an arbitrary vibration mode when the residual mode correction is included in the calibration of the RL shunt.

Anesthesia equipment malfunction: origins and clinical recognition.

PubMed Central

McIntyre, J. W.

1979-01-01

Equipment malfunction is a problem of particular importance during anesthesia and resuscitation. A review of published reports shows that the most common clinical events involve endotracheal tubes, the inspired oxygen concentration, the volume of inspired anesthetic vapours and gases, and pressures in the breathing or ventilation system. It is concluded that protection of a patient from equipment malfunction depends on: (a) appropriate application of standards set by a national standards association; (b) careful evaluation of equipment prior to purchase; (c) comprehension of equipment function by the user; (d) conscientious routine servicing of all systems concerned with anesthesia and resuscitation, and checking after service and before clinical use; (e) preanesthesia testing of equipment, including the use of an oxygen analyser in the breathing circuit; (f) early inclusion of equipment malfunction in the differential diagnosis of events during anesthesia; and (g) rapid action that cannot present a new hazard to the patient to correct the results of apparatus malfunction. PMID:436069

Single-Blinded Prospective Implementation of a Preoperative Imaging Checklist for Endoscopic Sinus Surgery.

PubMed

Error, Marc; Ashby, Shaelene; Orlandi, Richard R; Alt, Jeremiah A

2018-01-01

Objective To determine if the introduction of a systematic preoperative sinus computed tomography (CT) checklist improves identification of critical anatomic variations in sinus anatomy among patients undergoing endoscopic sinus surgery. Study Design Single-blinded prospective cohort study. Setting Tertiary care hospital. Subjects and Methods Otolaryngology residents were asked to identify critical surgical sinus anatomy on preoperative CT scans before and after introduction of a systematic approach to reviewing sinus CT scans. The percentage of correctly identified structures was documented and compared with a 2-sample t test. Results A total of 57 scans were reviewed: 28 preimplementation and 29 postimplementation. Implementation of the sinus CT checklist improved identification of critical sinus anatomy from 24% to 84% correct ( P < .001). All residents, junior and senior, demonstrated significant improvement in identification of sinus anatomic variants, including those not directly included in the systematic review implemented. Conclusion The implementation of a preoperative endoscopic sinus surgery radiographic checklist improves identification of critical anatomic sinus variations in a training population.

Vascular Complications of Intercavernous Sinuses during Transsphenoidal Surgery: An Anatomical Analysis Based on Autopsy and Magnetic Resonance Venography.

PubMed

Deng, Xuefei; Chen, Shijun; Bai, Ya; Song, Wen; Chen, Yongchao; Li, Dongxue; Han, Hui; Liu, Bin

2015-01-01

Vascular complications induced by intercavernous sinus injury during dural opening in the transsphenoidal surgery may contribute to incomplete tumour resections. Preoperative neuro-imaging is of crucial importance in planning surgical approach. The aim of this study is to correlate the microanatomy of intercavernous sinuses with its contrast-enhanced magnetic resonance venography (CE-MRV). Eighteen human adult cadavers and 24 patients were examined based on autopsy and CE-MRV. Through dissection of the cadavers and CE-MRV, the location, shape, number, diameter and type of intercavernous sinuses were measured and compared. Different intercavernous sinuses were identified by their location and shape in all the cadavers and CE-MRV. Compared to the cadavers, CE-MRV revealed 37% of the anterior intercavernous sinus, 48% of the inferior intercavernous sinus, 30% of the posterior intercavernous sinus, 30% of the dorsum sellae sinus and 100% of the basilar sinus. The smaller intercavernous sinuses were not seen in the neuro-images. According to the presence of the anterior and inferior intercavernous sinus, four types of the intercavernous sinuses were identified in cadavers and CE-MRV, and the corresponding operative space in the transsphenoidal surgical approach was implemented. The morphology and classification of the cavernous sinus can be identified by CE-MRV, especially for the larger vessels, which cause bleeding more easily. Therefore, CE-MRV provides a reliable measure for individualized preoperative planning during transsphenoidal surgery.

Sinus CT scan

MedlinePlus

CAT scan - sinus; Computed axial tomography scan - sinus; Computed tomography scan - sinus; CT scan - sinus ... Risks for a CT scan includes: Being exposed to radiation Allergic reaction to contrast dye CT scans expose you to more radiation than regular ...

LED lamp power management system and method

DOEpatents

Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

2013-03-19

An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

Progressive Functional Underdrainage in Cerebrospinal Fluid Shunt-Dependent Women During Pregnancy: Case Report and Review of the Literature.

PubMed

Krauss, Philipp; Fritz-Naville, Marco; Regli, Luca; Stieglitz, Lennart Henning

2018-01-01

Since the 1950s cerebrospinal fluid (CSF) shunt dependency has no longer been a contradiction to normal life, including sexuality and pregnancy in women, because of advances in the understanding of hydrocephalus and shunt technology. Although pregnancy in shunt-dependent women is rare, it causes uncertainty among treating physicians. We report the case of a 34-year-old pregnant woman with a ventriculoperitoneal shunt. Throughout her pregnancy she experienced progressive symptoms of CSF underdrainage without any signs of other pregnancy-related complications. After the delivery of a healthy infant, shunt resistance had to be readjusted to prepregnancy levels. A comprehensive review of the literature reports in English, listed in PubMed, is provided. Conservative treatment of pregnancy-related functional underdrainage by consecutive valve pressure adjustment is possible, easy, and safe. Copyright © 2017 Elsevier Inc. All rights reserved.

Sound absorption of a finite micro-perforated panel backed by a shunted loudspeaker.

PubMed

Tao, Jiancheng; Jing, Ruixiang; Qiu, Xiaojun

2014-01-01

Deep back cavities are usually required for micro-perforated panel (MPP) constructions to achieve good low frequency absorption. To overcome the problem, a close-box loudspeaker with a shunted circuit is proposed to substitute the back wall of the cavity of the MPP constructions to constitute a composite absorber. Based on the equivalent circuit model, the acoustic impedance of the shunted loudspeaker is formulated first, then a prediction model of the sound absorption of the MPP backed by shunted loudspeaker is developed by employing the mode solution of a finite size MPP coupled by an air cavity with an impendence back wall. The MPP absorbs mid to high frequency sound, and with properly adjusted electrical parameters of its shunted circuit, the shunted loudspeaker absorbs low frequency sound, so the composite absorber provides a compact solution to broadband sound control. Numerical simulations and experiments are carried out to validate the model.

Congenital portosystemic shunts in children: recognition, evaluation, and management.

PubMed

Bernard, O; Franchi-Abella, S; Branchereau, S; Pariente, D; Gauthier, F; Jacquemin, E

2012-11-01

Congenital portosystemic shunts are present in one in 30,000 children. Among the associated risks of severe complications are neonatal cholestasis, benign and malignant liver tumors, hepatopulmonary syndrome, portopulmonary hypertension, and encephalopathy. They can be detected on prenatal ultrasonograms, during the investigation of a positive galactosemia screening test in neonates or of a complication, or be found fortuitously on an abdominal ultrasound. Small intrahepatic shunts may resolve spontaneously within one year of age, but other shunts such as extrahepatic, persistent ductus venosus or persisting intrahepatic shunts, must be closed in one or two steps, by interventional radiology techniques or surgically. The plasticity of the intrahepatic portal system allows revascularization of the liver after shunt closure, even when no intrahepatic portal structures can be detected on imaging studies. This leaves little or no place for liver transplantation in the management of these children. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Congenital intrahepatic portosystemic shunt diagnosed during intrauterine life

PubMed Central

Bellettini, Camila Vieira; Wagner, Rafaela; Balzanelo, Aleocídio Sette; Andretta, André Luis de Souza; de Moura, Arthur Nascimento; Fabris, Catia Carolina; Gubert, Eduardo Maranhão

2016-01-01

Abstract Objective: To report a patient with prenatal diagnosis of portosystemic shunt; a rare condition in humans. Case description: 17-Day-old female infant admitted for investigation of suspected diagnosis of portosystemic shunt, presumed in obstetric ultrasound. The hypothesis was confirmed after abdominal angiography and liver Doppler. Other tests such as echocardiography and electroencephalogram were performed to investigate possible co-morbidities or associated complications, and were normal. We chose conservative shunt treatment, as there were no disease-related complications and this was intrahepatic shunt, which could close spontaneously by the age of 2 years. Comments: Portosystemic shunt can lead to various complications such as hepatic encephalopathy, hypergalactosemia, liver tumors, and hepatopulmonary syndrome. Most diagnoses are done after one month of age, after such complications occur. The prenatal diagnosis of this patient provided greater security for the clinical picture management, as well as regular monitoring, which allows the anticipation of possible complications and perform interventional procedures when needed. PMID:27133713

Transient right-to-left shunt in massive pulmonary embolism.

PubMed

Panoutsopoulos, G; Ilias, L; Christakopoulou, I

2000-06-01

A 56-yr-old man, two months after an operation for an acoustic neurinoma, gradually developed dyspnea. Massive pulmonary embolism (MPE), with a significant right-to-left (R-L) shunt, was seen in a perfusion scan of the lungs with Tc-99m MAA. Radioactivity was noted in the thyroid, spleen, kidneys and brain. A cardiac ultrasound study did not reveal intracardiac shunting. A few days later, when the patient's condition improved, another perfusion scan of the lungs did not show the shunt, whereas a subsequent digital subtraction angiographic study confirmed the diagnosis of MPE but failed to reveal the cause of the shunt. In the absence of any possible pathophysiological mechanism, to explain the observed R-L shunt, we deduce that the particles of Tc-99m MAA might have passed through the precapillary pulmonary arteriovenous anastomoses and/or through dilated pulmonary capillaries, as a result of highly increased pulmonary vascular pressure due to MPE.

Shunting inhibition improves robustness of gamma oscillations in hippocampal interneuron networks by homogenizing firing rates.

PubMed

Vida, Imre; Bartos, Marlene; Jonas, Peter

2006-01-05

Networks of GABAergic neurons are key elements in the generation of gamma oscillations in the brain. Computational studies suggested that the emergence of coherent oscillations requires hyperpolarizing inhibition. Here, we show that GABA(A) receptor-mediated inhibition in mature interneurons of the hippocampal dentate gyrus is shunting rather than hyperpolarizing. Unexpectedly, when shunting inhibition is incorporated into a structured interneuron network model with fast and strong synapses, coherent oscillations emerge. In comparison to hyperpolarizing inhibition, networks with shunting inhibition show several advantages. First, oscillations are generated with smaller tonic excitatory drive. Second, network frequencies are tuned to the gamma band. Finally, robustness against heterogeneity in the excitatory drive is markedly improved. In single interneurons, shunting inhibition shortens the interspike interval for low levels of drive but prolongs it for high levels, leading to homogenization of neuronal firing rates. Thus, shunting inhibition may confer increased robustness to gamma oscillations in the brain.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, Steven P.; Aguiar, Jeffery A.; Hacke, Peter

Here, we investigated potential-induced degradation (PID) in silicon mini-modules that were subjected to accelerated stressing to induce PID conditions. Shunted areas on the cells were identified with photoluminescence and dark lock-in thermography (DLIT) imaging. The identical shunted areas were then analyzed via time-of-flight secondary-ion mass spectrometry (TOFSIMS) imaging, 3-D tomography, and high-resolution transmission electron microscopy. The TOF-SIMS imaging indicates a high concentration of sodium in the shunted areas, and 3-D tomography reveals that the sodium extends more than 2 um from the surface below shunted regions. Transmission electron microscopy investigation reveals that a stacking fault is present at an areamore » identified as shunted by DLIT imaging. After the removal of surface sodium, tomography reveals persistent sodium present around the junction depth of 300 nm and a drastic difference in sodium content at the junction when comparing shunted and nonshunted regions.« less

The application of frontal sinus index and frontal sinus area in sex estimation based on lateral cephalograms among Han nationality adults in Xinjiang.

PubMed

Luo, Huifang; Wang, Jierui; Zhang, Shuang; Mi, Congbo

2018-05-01

The frontal sinus, due to its unique anatomical features, has become an important element in research for individual identification. Previous studies have demonstrated the use of frontal sinus as an indicator for sex discrimination; however, the sex discrimination rate using frontal sinus was lower compared to that using the traditional morphological methods. In order to improve the sex discrimination percentage, we developed a new method involving the measurement of the frontal sinus index and frontal sinus area from lateral cephalogram radiographs. In this study, 475 digital lateral cephalograms of adult Han citizens from Xinjiang were included. The maximum height, depth, and area of the frontal sinus were calculated using the NemoCeph NX software. The frontal sinus index (ratio of the maximum height to the depth of frontal sinus) was also computed. Statistical analysis results showed significant differences in the frontal sinus index and area between males and females. Discriminant function equation derived from this study differentiated between sexes with 76.6% accuracy. The results demonstrated that the use of frontal sinus index and area for sex discrimination was more accurate than using the frontal sinus index alone. Copyright © 2017. Published by Elsevier Ltd.

75 FR 16022 - Airworthiness Directives; Turbomeca S.A. MAKILA 1A and 1A1 Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-31

... investigation by Turbom[eacute]ca are that these malfunctions are due to a lapse of quality control in the... Turbomeca are that these malfunctions are due to a lapse of quality control in the varnishing process... these malfunctions are due to a lapse of quality control in the varnishing process applied to the boards...

40 CFR 63.9925 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2010 CFR

2010-07-01

... includes periods of startup, shutdown, and malfunction. You must also report each instance in which you did... § 63.9931. (b) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 63.9925 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2013 CFR

2013-07-01

... includes periods of startup, shutdown, and malfunction. You must also report each instance in which you did... § 63.9931. (b) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 63.9925 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2012 CFR

2012-07-01

... includes periods of startup, shutdown, and malfunction. You must also report each instance in which you did... § 63.9931. (b) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 63.9925 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2011 CFR

2011-07-01

... includes periods of startup, shutdown, and malfunction. You must also report each instance in which you did... § 63.9931. (b) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

40 CFR 63.9925 - What other requirements must I meet to demonstrate continuous compliance?

Code of Federal Regulations, 2014 CFR

2014-07-01

... includes periods of startup, shutdown, and malfunction. You must also report each instance in which you did... § 63.9931. (b) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you...

Two- and Three-Dimensional Anatomy of Paranasal Sinuses in Arabian Foals

PubMed Central

BAHAR, Sadullah; BOLAT, Durmus; DAYAN, Mustafa Orhun; PAKSOY, Yahya

2013-01-01

ABSTRACT The 2- and 3-dimensional (3D) anatomy and the morphometric properties of the paranasal sinuses of the foal have received little or no attention in the literature. The aim of this study was to obtain details of the paranasal sinuses using multiplane CT imaging to create 3D models and to determine morphological and morphometric data for the sinuses using the 3D models. The heads of five female foals were used in this study. The heads were scanned using computed tomography (CT) in the rostrocaudal direction. After the heads had been frozen, anatomical sections were obtained in the scan position. The 3D models of sinuses and the skull were prepared using MIMICS®. These models were used to assess the surface area and volume of the sinuses, the width, height and orientation of the apertures connecting these sinuses and finally the planar relation of the sinuses with the skull. The right and left sides of all anatomical structures, except the sphenoid sinuses, had symmetric organization on CT images and anatomical sections. The total sinus surface area and volume on both sides were 214.4 cm2 and 72.9 ml, respectively. The largest and the smallest sinuses were the frontal sinus (41.5 ml) and the middle conchal sinus (0.2 ml), respectively. It was found that the planes bounding the sinuses passed through easily palpable points on the head. In conclusion, 3D modeling in combination with conventional sectional imaging of the paranasal sinuses of the foal may help anatomists, radiologists, clinicians and veterinary students. PMID:24004969

Two- and three-dimensional anatomy of paranasal sinuses in Arabian foals.

PubMed

Bahar, Sadullah; Bolat, Durmus; Dayan, Mustafa Orhun; Paksoy, Yahya

2014-01-01

The 2- and 3-dimensional (3D) anatomy and the morphometric properties of the paranasal sinuses of the foal have received little or no attention in the literature. The aim of this study was to obtain details of the paranasal sinuses using multiplane CT imaging to create 3D models and to determine morphological and morphometric data for the sinuses using the 3D models. The heads of five female foals were used in this study. The heads were scanned using computed tomography (CT) in the rostrocaudal direction. After the heads had been frozen, anatomical sections were obtained in the scan position. The 3D models of sinuses and the skull were prepared using MIMICS(®). These models were used to assess the surface area and volume of the sinuses, the width, height and orientation of the apertures connecting these sinuses and finally the planar relation of the sinuses with the skull. The right and left sides of all anatomical structures, except the sphenoid sinuses, had symmetric organization on CT images and anatomical sections. The total sinus surface area and volume on both sides were 214.4 cm(2) and 72.9 ml, respectively. The largest and the smallest sinuses were the frontal sinus (41.5 ml) and the middle conchal sinus (0.2 ml), respectively. It was found that the planes bounding the sinuses passed through easily palpable points on the head. In conclusion, 3D modeling in combination with conventional sectional imaging of the paranasal sinuses of the foal may help anatomists, radiologists, clinicians and veterinary students.

Root Cause Analysis: An Examination of Odontogenic Origins of Acute Maxillary Sinusitis in Both Immunocompetent & Immunocompromised Patients.

PubMed

McCarty, Jennifer L; David, Ryan M; Lensing, Shelly Y; Samant, Rohan S; Kumar, Manoj; Van Hemert, Rudy L; Angtuaco, Edgardo J C; Fitzgerald, Ryan T

Dental and periodontal diseases represent important but often overlooked causes of acute sinusitis. Our goal was to examine the prevalence of potential odontogenic sources of acute maxillary sinusitis according to immune status and their associations with sinusitis. A retrospective review of maxillofacial computed tomography studies from 2013 to 2014 was performed. Each maxillary sinus and its ipsilateral dentition were evaluated for findings of acute sinusitis and dental/periodontal disease. Eighty-four patients (24 immunocompetent, 60 immunocompromised) had 171 maxillary sinuses that met inclusion criteria for acute maxillary sinusitis. Inspection of dentition revealed oroantral fistula in 1%, periapical lucencies in 16%, and projecting tooth root(s) in 71% of cases. Immunocompromised patients were more likely to have bilateral sinusitis than immunocompetent patients (67% vs 33%, P = 0.005). A paired case-control analysis in a subset of patients with unilateral maxillary sinusitis (n = 39) showed a higher prevalence of periapical lucency in association with sinuses that had an air fluid level-29% of sinuses with a fluid level had periapical lucency compared with 12% without sinus fluid (P = 0.033). Potential odontogenic sources of acute maxillary sinusitis are highly prevalent in both immunocompetent and immunocompromised patients, although the 2 patient populations demonstrate no difference in the prevalence of these potential odontogenic sources. Periapical lucencies were found to be associated with an ipsilateral sinus fluid level. Increased awareness of the importance of dental and periodontal diseases as key components of maxillofacial computed tomography interpretation would facilitate a more appropriate and timely treatment.

Torcular Herophili classification and evaluation of dural venous sinus variations using digital subtraction angiography and magnetic resonance venographies.

PubMed

Gökçe, Erkan; Pınarbaşılı, Tansu; Acu, Berat; Fırat, M Murat; Erkorkmaz, Ünal

2014-08-01

The configurations of cerebral veins and dural venous sinuses differ not only between individuals, but also between the two brain hemispheres of an individual, making the anatomical classification of the cerebral veins difficult. We evaluated the superior dural venous sinuses and classified their types and variations using magnetic resonance venography (MRV) and digital substraction angiography (DSA). A total of 394 patients were studied retrospectively. Superior dural venous sinuses were evaluated and the confluence of the sinuses was classified on 2-dimensional time-of-flight MRV, contrast-enhanced 3-dimensional spoiled gradient recalled echo magnetic resonance imaging, and/or cerebral DSA. Confluens sinuum was divided into three types: true confluence, partial confluence, and non-confluence. Of the three types, partial confluence (type II) was most frequently seen. Co-dominance of the transverse sinuses was most frequently observed. An occipital sinus was observed in 15 % of the patients. There were statistically significant differences between the left transverse sinus agenesis and the presence of the occipital sinus (p < 0.001), between the co-presence of the partial confluence type torcular and the occipital sinus (p = 0.040), and between the co-presence of the fenestrated straight sinus and the occipital sinus (p = 0.010). Although anatomical variations of dural venous sinuses are seen frequently, classification of venous sinuses helps surgeons in preoperative evaluation and management, and prevention of possible complications. In this study, we think that a comprehensive evaluation and classification of dural venous sinuses is a significant contribution to the literature.

The CHESS score: a simple tool for early prediction of shunt dependency after aneurysmal subarachnoid hemorrhage.

PubMed

Jabbarli, R; Bohrer, A-M; Pierscianek, D; Müller, D; Wrede, K H; Dammann, P; El Hindy, N; Özkan, N; Sure, U; Müller, O

2016-05-01

Acute hydrocephalus is an early and common complication of aneurysmal subarachnoid hemorrhage (SAH). However, considerably fewer patients develop chronic hydrocephalus requiring shunt placement. Our aim was to develop a risk score for early identification of patients with shunt dependency after SAH. Two hundred and forty-two SAH individuals who were treated in our institution between January 2008 and December 2013 and survived the initial impact were retrospectively analyzed. Clinical parameters within 72 h after the ictus were correlated with shunt dependency. Independent predictors were summarized into a new risk score which was validated in a subsequent SAH cohort treated between January and December 2014. Seventy-five patients (31%) underwent shunt placement. Of 23 evaluated variables, only the following five showed independent associations with shunt dependency and were subsequently used to establish the Chronic Hydrocephalus Ensuing from SAH Score (CHESS, 0-8 points): Hunt and Hess grade ≥IV (1 point), location of the ruptured aneurysm in the posterior circulation (1 point), acute hydrocephalus (4 points), the presence of intraventricular hemorrhage (1 point) and early cerebral infarction on follow-up computed tomography scan (1 point). The CHESS showed strong correlation with shunt dependency (P = 0.0007) and could be successfully validated in both internal SAH cohorts tested. Patients scoring ≥6 CHESS points had significantly higher risk of shunt dependency (P < 0.0001) than other patients. The CHESS may become a valuable diagnostic tool for early estimation of shunt dependency after SAH. Further evaluation and external validation will be required in prospective studies. © 2016 EAN.

Deletion of Rbpj from postnatal endothelium leads to abnormal arteriovenous shunting in mice

PubMed Central

Nielsen, Corinne M.; Cuervo, Henar; Ding, Vivianne W.; Kong, Yupeng; Huang, Eric J.; Wang, Rong A.

2014-01-01

Arteriovenous malformations (AVMs) are tortuous vessels characterized by arteriovenous (AV) shunts, which displace capillaries and shunt blood directly from artery to vein. Notch signaling regulates embryonic AV specification by promoting arterial, as opposed to venous, endothelial cell (EC) fate. To understand the essential role of endothelial Notch signaling in postnatal AV organization, we used inducible Cre-loxP recombination to delete Rbpj, a mediator of canonical Notch signaling, from postnatal ECs in mice. Deletion of endothelial Rbpj from birth resulted in features of AVMs by P14, including abnormal AV shunting and tortuous vessels in the brain, intestine and heart. We further analyzed brain AVMs, as they pose particular health risks. Consistent with AVM pathology, we found cerebral hemorrhage, hypoxia and necrosis, and neurological deficits. AV shunts originated from capillaries (and possibly venules), with the earliest detectable morphological abnormalities in AV connections by P8. Prior to AV shunt formation, alterations in EC gene expression were detected, including decreased Efnb2 and increased Pai1, which encodes a downstream effector of TGFβ signaling. After AV shunts had formed, whole-mount immunostaining showed decreased Efnb2 and increased Ephb4 expression within AV shunts, suggesting that ECs were reprogrammed from arterial to venous identity. Deletion of Rbpj from adult ECs led to tortuosities in gastrointestinal, uterine and skin vascular beds, but had mild effects in the brain. Our results demonstrate a temporal requirement for Rbpj in postnatal ECs to maintain proper artery, capillary and vein organization and to prevent abnormal AV shunting and AVM pathogenesis. PMID:25209249

Transdiaphragmatic Approach to Attenuate Porto-Azygos Shunts Inserting in the Thorax.

PubMed

Or, Matan; Kitshoff, Adriaan; Devriendt, Nausikaa; De Ridder, Marianne; Quist-Rybachuk, Galena; de Rooster, Hilde

2016-11-01

To describe the surgical technique and document the application of a transdiaphragmatic approach to attenuate porto-azygos shunts inserting in the thoracic section of the azygos vein. Cadaveric study and prospective case series. Canine cadavers (n=6) and client-owned dogs with porto-azygos shunts inserting in the thoracic section of the azygos vein (n=9). In the cadavers, the azygos vein was filled with aqueous latex. Landmarks were established for creating a safe transdiaphragmatic approach to the caudal intrathoracic portion of the azygos vein. In the clinical cases, porto-azygos communication was diagnosed by trans-splenic portal scintigraphy. All shunts were attenuated close to their insertion site via ventral midline celiotomy and a transdiaphragmatic approach to the shunt. Perioperative complications were recorded. A 3-5 cm incision, 0.5-1 cm ventral and lateral to the level of the aortic hiatus, was made in the pars lumbalis part of the diaphragm. Stay sutures at both sides of the diaphragmatic incision were placed to open up the incision and a retractor was used to push the esophagus away from the aorta. Intrathoracic insertion of the shunt was confirmed intraoperative. Exposure of the shunt insertion site at the azygos vein was excellent in all clinical cases. No intraoperative or postoperative complications were encountered. If thoracic attenuation of a porto-azygos shunt is considered, a transdiaphragmatic approach exposes the insertion site for shunt attenuation. This approach is straightforward, without unnecessary abdominal organ manipulation, and since attenuates at the insertion, avoids missing additional contributing branches. © Copyright 2016 by The American College of Veterinary Surgeons.

Management of Hydrocephalus with Ventriculoperitoneal Shunts: Review of 109 Cases of Children.

PubMed

Dakurah, Thomas K; Adams, Fuseini; Iddrissu, Mutawakilu; Wepeba, George Kojo; Akoto, Harry; Bankah, Patrick; Ametefe, Mawuli; Kasu, Philip W

2016-12-01

Treatment of hydrocephalus by shunting procedure is associated with variable outcomes, depending on the setting. Results from some published series in sub-Saharan Africa are not so good and various reasons have been given. This study presents preliminary findings of 109 cases of shunted hydrocephalus in children in a 3-year period. The main aim of the study was to evaluate the complications of the procedure in a tertiary-care center. It also seeks to identify ways of reducing such complications where appropriate in subsequent shunt placement procedures. A single-institutional retrospective study was conducted by reviewing 124 patients who had ventriculoperitoneal shunting including revisions, and subgroup analysis was performed in 109 patients younger than 18 years classified as children who had first-time shunt placement between January 2011 and December 2013. Data analysis was performed using Microsoft Excel and SPSS (version 20.0). The mean age at shunt insertion of the subgroup was 5.35 years ± 1.264 standard deviations. Shunt-related complications were identified in 37 of the patients (33.9%). Infections were the most common form of complication, occurring in 16 patients (14.6%). The overall mortality of the 109 patients was 4.59%. The most common indications for shunt insertions were tumoral and congenital lesions, which may offer us benefit with the use of endoscopic third ventriculostomy. Comprehensive follow-up of these patients may give a better picture of the magnitude of the problem; hence the need for properly designed prospective studies to improve the current outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

3T magnetic resonance imaging testing of externally programmable shunt valves

PubMed Central

Zabramski, Joseph M.; Preul, Mark C.; Debbins, Josef; McCusker, Daniel J.

2012-01-01

Background: Exposure of externally programmable shunt-valves (EPS-valves) to magnetic resonance imaging (MRI) may lead to unexpected changes in shunt settings, or affect the ability to reprogram the valve. We undertook this study to examine the effect of exposure to a 3T MRI on a group of widely used EPS-valves. Methods: Evaluations were performed on first generation EPS-valves (those without a locking mechanism to prevent changes in shunt settings by external magnets other than the programmer) and second generation EPS-valves (those with a locking mechanisms). Fifteen new shunt-valves were divided into five groups of three identical valves each, and then exposed to a series of six simulated MRI scans. After each of the exposures, the valves were evaluated to determine if the valve settings had changed, and whether the valves could be reprogrammed. The study produced 18 evaluations for each line of shunt-valves. Results: Exposure of the first generation EPS-valves to a 3T magnetic field resulted in frequent changes in the valve settings; however, all valves retained their ability to be reprogrammed. Repeated exposure of the second generation EPS-valves has no effect on shunt valve settings, and all valves retained their ability to be interrogated and reprogrammed. Conclusions: Second generation EPS-valves with locking mechanisms can be safely exposed to repeated 3T MRI systems, without evidence that shunt settings will change. The exposure of the first generation EPS-valves to 3T MRI results in frequent changes in shunt settings that necessitate re-evaluation soon after MRI to avoid complications. PMID:22937481

Cross-Species Functionality of Pararetroviral Elements Driving Ribosome Shunting

PubMed Central

Pooggin, Mikhail M.; Fütterer, Johannes; Hohn, Thomas

2008-01-01

Background Cauliflower mosaic virus (CaMV) and Rice tungro bacilliform virus (RTBV) belong to distinct genera of pararetroviruses infecting dicot and monocot plants, respectively. In both viruses, polycistronic translation of pregenomic (pg) RNA is initiated by shunting ribosomes that bypass a large region of the pgRNA leader with several short (s)ORFs and a stable stem-loop structure. The shunt requires translation of a 5′-proximal sORF terminating near the stem. In CaMV, mutations knocking out this sORF nearly abolish shunting and virus viability. Methodology/Principal Findings Here we show that two distant regions of the CaMV leader that form a minimal shunt configuration comprising the sORF, a bottom part of the stem, and a shunt landing sequence can be replaced by heterologous sequences that form a structurally similar configuration in RTBV without any dramatic effect on shunt-mediated translation and CaMV infectivity. The CaMV-RTBV chimeric leader sequence was largely stable over five viral passages in turnip plants: a few alterations that did eventually occur in the virus progenies are indicative of fine tuning of the chimeric sequence during adaptation to a new host. Conclusions/Significance Our findings demonstrate cross-species functionality of pararetroviral cis-elements driving ribosome shunting and evolutionary conservation of the shunt mechanism. We are grateful to Matthias Müller and Sandra Pauli for technical assistance. This work was initiated at Friedrich Miescher Institute (Basel, Switzerland). We thank Prof. Thomas Boller for hosting the group at the Institute of Botany. PMID:18286203

Extended Endoscopic and Open Sinus Surgery for Refractory Chronic Rhinosinusitis.

PubMed

Eloy, Jean Anderson; Marchiano, Emily; Vázquez, Alejandro

2017-02-01

This review discusses extended endoscopic and open sinus surgery for refractory chronic rhinosinusitis. Extended maxillary sinus surgery including endoscopic maxillary mega-antrostomy, endoscopic modified medial maxillectomy, and inferior meatal antrostomy are described. Total/complete ethmoidectomy with mucosal stripping (nasalization) is discussed. Extended endoscopic sphenoid sinus procedures as well as their indications and potential risks are reviewed. Extended endoscopic frontal sinus procedures, such the modified Lothrop procedure, are described. Extended open sinus surgical procedures, such as the Caldwell-Luc approach, frontal sinus trephine procedure, external frontoethmoidectomy, frontal sinus osteoplastic flap with or without obliteration, and cranialization, are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

What are the implications of the spontaneous spleno-renal shunts in liver cirrhosis?

PubMed Central

2009-01-01

Background Although significant advances are expected to be made in the assessment of the portal hypertension-related complications, the prognostic role of spleno-renal shunts has not been fully explored so far. Clarifying this aspect could help tackle the life-treating events occurring in patients suffering from liver cirrhosis. The aim of the study was to analyze the relationships between the spleno-renal shunts presence at doppler ultrasound and the liver cirrhosis complications. Methods Design: eighty one patients out of 129 formed the study population (35 females). Chronic liver damage in these patients was caused by HCV (66), HBV (2), alcohol abuse (2) or unknown etiology, likely non-alcoholic steatohepatitis (11). Setting: two Liver Units of university/primary hospitals in Southern Italy. Main outcome measures: grading of esofageal varices; detection of ascites: assessment of hepatic encephalopathy; evaluation of liver cirrhosis severity; tracking hepatocellular carcinoma; doppler features of spleno-renal shunts and splenic flow velocity; spleen longitudinal diameter at sonography. Results The prevalence of spleno-renal shunts was 18.5%, without no difference concerning the etiology (HCV versus non-HCV, p = 0.870); the prevalence of hepatocellular carcinoma in patients with spleno-renal shunts was superior to that of patients without them (Pearson Chi-square, p = 0.006, power of sample size 74%), also after adjustment for liver decompensation (p = 0.024). The median score of hepatic encephalopathy in patients with and without spleno-renal shunts was similar, i.e., 0 (range, 0-2) versus 0 (0 - 3), p = 0.67. The median splenic vein flow velocity in patients with spleno-renal shunts was significantly inferior to that of patients without them, i.e., 13 cm/sec (95% confidence intervals, 6-18) versus 21 cm/sec (17-24), p < 0.0001. By far the largest percentage of large esophageal varices was in patients without spleno-renal shunts (p = 0.005). In contrast, the frequency of ascites and hepatic encephalopathy severity was overlapping in the two groups. BMI values but not Child-Pugh's classification predicted spleno-renal shunts (Ors = 1.84, 95% confidence intervals = 1.28-2.64, p = 0.001 and 1.145, 95% confidence intervals = 0.77-1.51, p = 0.66). Conclusion Taking into consideration the relatively small sample size, patients with spleno-renal shunts are burdened by an increased incidence of hepatocellular carcinoma. BMI predicted the spleno-renal shunts presence. PMID:19930687

Congenital intrahepatic portosystemic venous shunt presenting with paraparesis as the initial symptom.

PubMed

Torigoe, Masataka; Maeshima, Keisuke; Takeshita, Yasushi

2013-01-01

An 85-year-old woman was hospitalized with rapidly progressive paraparesis without altered consciousness, although she was not definitively diagnosed. She developed acute drowsiness and disorientation several days later. An intrahepatic portosystemic venous shunt (IPSVS) was observed on enhanced computed tomography, and hyperammonemia suggested leakage of neurotoxins from the shunt as the etiology of the patient's symptoms. Her neurological symptoms and hyperammonemia improved following transcatheter shunt embolization. We diagnosed her with hepatic myelopathy, which is a rare complication of liver cirrhosis and portosystemic venous shunts. Hepatic myelopathy resulting from a congenital IPSVS has not been previously reported. A diagnosis of hepatic myelopathy should be ruled out in diagnostically difficult cases of paraparesis.

Congenital intrahepatic portosystemic venous shunt and liver mass in a child patient: successful endovascular treatment with an amplatzer vascular plug (AVP).

PubMed

Lee, Sae Ah; Lee, Young Seok; Lee, Kun Song; Jeon, Gyeong Sik

2010-01-01

A congenital intrahepatic portosystemic shunt is a rare anomaly; but, the number of diagnosed cases has increased with advanced imaging tools. Symptomatic portosystemic shunts, especially those that include hyperammonemia, should be treated; and various endovascular treatment methods other than surgery have been reported. Hepatic masses with either an intra- or extrahepatic shunt also have been reported, and the mass is another reason for treatment. Authors report a case of a congenital intrahepatic portosystemic shunt with a hepatic mass that was successfully treated using a percutaneous endovascular approach with vascular plugs. By the time the first short-term follow-up was conducted, the hepatic mass had disappeared.

Simultaneous Umbilical Hernia Repair with Transumbilical Ventriculoperitoneal Shunt Placement.

PubMed

Montalbano, Michael J; Loukas, Marios; Oakes, W Jerry; Tubbs, R Shane

2017-01-01

Recently, placement of a ventriculoperitoneal shunt via a transumbilical approach has been reported. Herein, we report the repair of an umbilical hernia via the same incision and introduction of the distal end of a ventricultoperitoneal shunt into the peritoneal cavity in 3 patients. A case illustration is included. Both hernia repair and placement of the distal end of the ventriculoperitoneal shunt were uncomplicated in our small case series. To our knowledge, simultaneous repair of an umbilical hernia followed by transumbilical shunt placement has not been reported. As umbilical hernias are so common in infants, this finding, based on our experience, should not exclude placement of peritoneal tubing in the same setting. © 2017 S. Karger AG, Basel.

Safety and efficacy of Cardi-O-fix occluder for percutaneous closure of a patent foramen ovale

PubMed Central

Zhao, Enfa; Liu, Wenjuan; Zhang, Yushun; Cheng, Gesheng; Du, Yajuan; He, Lu; Wang, Xingye; He, Xumei

2017-01-01

Abstract Background: Amplatzer occluder and Cardio-O-fix occluder are currently used in percutaneous closure of patent foramen ovale. However, there is still a lack of relevant reports comparison the differences between them. The aim of this study was to evaluate the short-term and mid-term safety and efficacy of the Cardi-O-fix occluder in preventing recurrent cerebrovascular events in patients with a patent foramen ovale (PFO). Methods: We enrolled 246 patients (105 men) with a PFO from May 30, 2013 to March 30, 2015 in this single-center prospective study. All patients were treated by PFO interventional closure, with the Cardi-O-fix PFO occluder being used in 180 patients and the Amplatzer PFO occluder being utilized in the remaining 66 patients. After the procedure, we verified the safety and efficacy of different devices using contrast transthoracic echocardiography. Results: Neither recurrent stroke nor death was encountered during the follow-up of 12 months. Transient ischemic attack (TIA) was noted in 2 patients (1.1%) in the Cardi-O-fix PFO occluder group, and 1 patient suffered from TIA (1.5%) in the Amplatzer PFO occluder group. Among them, only 1 patient exhibited a small right to left shunt (RLS). There was no statistical difference in recurrent cerebral ischemic events. Three cases of paroxysmal atrial fibrillation were observed in the Cardi-O-fix PFO occluder group. One reverted spontaneously to sinus rhythm and the other 2 cases had pharmacologic conversion to sinus rhythm. One case of paroxysmal atrial fibrillation occurred in the Amplatzer group, which underwent pharmacologic conversion to sinus rhythm. There was no significant difference between the 2 groups regarding incidence of arrhythmia. No occluder translocation, erosion, pericardial effusion, and puncture site bleeding were observed in the 2 groups within 12 months of follow-up. The complete closure rates of the Cardi-O-fix and Amplatzer PFO occluder devices at the 12 months after the procedure were 73.9% and 63.6%, respectively, and the effective closure rates were 90.6% and 86.4%, respectively. There was no statistically significant difference in the complete closure rate and effective occlusion rate (P > 0.05) between the devices. Conclusions: There was no significant difference in the short- and mid-term efficacy and safety between the Cardi-O-fix PFO occluder and Amplatzer PFO occluder. The efficacy and safety of the Cardi-O-fix occluder were comparable to those of the Amplatzer PFO occluder. PMID:28383438

The unacknowledged incidence of laparoscopic stapler malfunction.

PubMed

Kwazneski, Douglas; Six, Cheryl; Stahlfeld, Kurt

2013-01-01

Laparoscopic instruments are being used with increasing frequency. Our surgeons recently experienced several independent adverse events involving the laparoscopic linear stapler. Although the Food and Drug Administration maintains a Manufacturer and User Facility Device Experience (MAUDE) database to track such voluntary reports, many events are not reported and the true incidence of adverse events is unknown. We attempted to determine how frequently minimally invasive surgeons have experienced technical problems with a laparoscopic stapler. Following IRB approval, we electronically distributed an anonymous 10-question survey to the 124 minimally invasive program directors listed in the Fellowship Council database. The questions focused on personal or peer experience with laparoscopic stapler malfunction, frequency and type of malfunction, device manufacturer, whether the operation was altered, and root cause analysis of the event. Forty-four of the 124 program directors (35%) completed the survey. The majority reported personal or peer experience (86%) with a linear stapler not releasing (66%) or not firing (73%) after application, with 27% of the respondents noting that this occurred three or more times. The malfunction was not related to type of load, straight (23%) or reticulating (32%) model, or manufacturer (Ethicon 30%, Covidien 36%). One quarter of the respondents noted that the malfunction caused them to significantly alter their operative procedure, and 30% reported that they received no helpful feedback from the manufacturer despite contacting it. Most minimally invasive surgeons have experienced laparoscopic linear stapler malfunction and 25% have had to significantly alter the planned operative procedure due to the malfunction.

The incidence of maxillary sinus membrane perforation during endoscopically assessed crestal sinus floor elevation: a pilot study.

PubMed

Garbacea, Antoanela; Lozada, Jaime L; Church, Christopher A; Al-Ardah, Aladdin J; Seiberling, Kristin A; Naylor, W Patrick; Chen, Jung-Wei

2012-08-01

Transcrestal sinus membrane elevation is a surgical procedure performed to increase the bone volume in the maxillary sinus cavity. Because of visual limitations, the potential for maxillary sinus membrane perforations may be greater than with the lateral approach technique. The aim of this study was to macroscopically investigate ex vivo the occurrence of sinus membrane perforation during surgery using 3 transcrestal sinus floor elevation methods. Twenty fresh human cadaver heads, with 40 intact sinuses, were used for simultaneous sinus membrane elevation, placement of graft material, and dental implants. Real-time sinus endoscopy, periapical digital radiographs, and cone-beam computerized tomography (CBCT) images were subsequently used to evaluate the outcome of each surgical procedure. Perforation rates for each of the 3 techniques were then compared using a significance level of P < .05. No statistically significant differences in the perforation rate (P = .79) were found among the 3 surgical techniques. Although the sinus endoscope noted a higher frequency of perforations at the time of implant placement as compared with instrumentation or graft insertion, the difference was not statistically significant (P = .04). The CBCT readings were judged to be more accurate for identifying evidence of sinus perforations than the periapical radiographs when compared with the direct visualization with the endoscope. This pilot study demonstrated that a sinus membrane perforation can occur at any time during the sinus lift procedure, independent of the surgical method used.

[Experimental evaluation of the role of the coronary sinus pressure in the regulation of coronary return volume via the coronary sinus. Surgical considerations in atrio-pulmonary diversion procedures].

PubMed

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.

Prediction of Susceptibility to Acute Mountain Sickness Using Hypoxia-Induced Intrapulmonary Arteriovenous Shunt and Intracardiac Shunt Fractions

DTIC Science & Technology

2012-10-31

intrapulmonary and intracardiac shunt using saline contrast echocardiography to determine bubble/shunt scores. We will also use nuclear medicine imaging to...subjects have completed saline contrast echocardiography while breathing hypoxic gas mixtures. For Task #2 “10 hr hypoxic exposure and AMS... echocardiography while breathing an FIO2=0.14, will be susceptible or resistant to developing AMS after 10 hr hypoxic exposure. For Task #3 “Hypoxia

Lower incidence of reoperation with longer shunt survival with adult ventriculoperitoneal shunts placed for hemorrhage-related hydrocephalus.

PubMed

Hoh, Brian L; Lang, Shih-Shan; Ortiz, Michael V; Chi, Yueh-Yun; Lewis, Stephen B; Pincus, David W

2008-07-01

The incidence of reoperation for ventriculoperitoneal shunts (VPS) in adults, although lower than in pediatric patients, is not insignificant. We hypothesize that adult VPS placed for hemorrhage-related hydrocephalus have a lower incidence of reoperation than those placed for other types of hydrocephalus. We retrospectively reviewed all adult (>/= 20 yr) VPS initially placed from February 2001 to August 2006 at the University of Florida. We determined the incidence and time interval to reoperation. Follow-up was conducted by telephone interview and review of medical records. A total of 286 adult VPS were initially placed: 96 (34%) hemorrhage and 190 (66%) nonhemorrhage. A total of 15 (16%) hemorrhage patients underwent 22 shunt reoperations, compared with 50 (27%) nonhemorrhage patients who underwent 82 shunt reoperations (P = 0.0316). A Poisson regression analysis of the number of reoperations, factoring hemorrhage, age, and sex, demonstrated a significantly lower incidence of reoperation in hemorrhage patients (P = 0.0900). A Cox proportional hazards model analysis of time to first reoperation, factoring hemorrhage, age, and sex, demonstrated a significantly longer shunt survival in hemorrhage patients (P = 0.0404). Adult VPS placed for hemorrhage-related hydrocephalus have a significantly lower incidence of reoperation and significantly longer shunt survival. This result may be related to an incidence of transient shunt dependency in patients with hemorrhage-related hydrocephalus. However, the precise mechanism remains unclear.

Parent ratings of executive functioning in children with shunted hydrocephalus.

PubMed

Lacy, Maureen; Baldassarre, Megan; Nader, Todd; Frim, David

2012-01-01

The present study examined the executive functioning of a group of children with a history of communicating hydrocephalus and how their level of functioning was correlated with parent ratings of executive functioning. The study examined the executive functioning of 39 shunted children with a history of hydrocephalus and 20 healthy peers. Additionally, parents of both groups of children completed the Behavior Rating Inventory of Executive Function (BRIEF) to assess the parents' perceptions of their children's executive functioning. Finally, the study investigated the relationship between the shunted hydrocephalus children's executive functioning and the parent ratings of their executive functioning. Overall, the children with a history of shunted hydrocephalus displayed more executive dysfunction than their healthy peers. These children were rated by their parents as having more executive dysfunction than their healthy peers and displaying working memory, initiation, mental flexibility and self-monitoring difficulties, which appear to increase with age among the shunted hydrocephalus group. While parent ratings as measured by the BRIEF indices did not correlate with all executive tasks within the shunted hydrocephalus group, the cognitive tests assessing mental flexibility may be sensitive to the problems noted by parents at home. The children with a history of shunted hydrocephalus displayed executive functioning deficits on formal examination. The parents of children with a history of shunted hydrocephalus report ongoing executive difficulties which may increase with age. Copyright © 2012 S. Karger AG, Basel.

Impact of Magnetic Field on Pressures of Programmable Cerebrospinal Fluid Shunts: An Experimental Study.

PubMed

Altun, Idiris; Yuksel, Kasim Zafer; Mert, Tufan

2017-01-01

To investigate whether programmable cerebrospinal fluid (CSF) shunts are influenced by exposure to the magnetic field and to compare the effects of magnetic field in 4 different brands of programmable CSF shunts. This experimental study was performed in the laboratory using a novel design of magnetic field. Four types of programmable CSF shunts (Miethke®, Medtronic®, Sophysa® and Codman®Hakim®) were exposed to the magnetic field generated by an apparatus consisting of Helmholtz coil for 5 minutes. In every CSF shunt, initial pressures were adjusted to 110 mm H2O and pressures after exposure to magnetic field were noted. These measurements were implemented at frequencies of 5 Hz, 20 Hz, 30 Hz, 40 Hz, 60 Hz and 80 Hz. In each type, three shunts were utilized and evaluations were made twice for every shunt. At 5, 30, 40 and 60 Hz, Groups 1, 2 and 3 had significantly higher average pressures than Group 4. At 20 and 80 Hz, Groups 1 and 2 had notably different pressure values than Groups 3 and 4. Group 3 displayed the highest pressure, while Group 4 demonstrated the lowest pressure. Exposure to magnetic fields may affect the pressures of programmable CSF shunts. However, further controlled, clinical trials are warranted to elucidate the in-vivo effects of magnetic field exposure.

Elective minimally invasive coronary artery bypass: Shunt or tournique occlusion? Assessment of a protective role of perioperative left anterior descending shunting on myocardial damage. A prospective randomized study

PubMed Central

2012-01-01

Background To determine impact of intraluminal-left anterior descending shunt to prevent myocardial damage in minimally invasive coronary artery bypass. Methods 38 patients were randomly assigned to external tournique occlusion (n = 19) or intraluminal-left anterior descending shunt group (n = 19). Blood samples for cardiac troponin T were collected at 30 minutes prior to, 6 and 24 hours after surgery. Results One patient in external tournique occlusion and two patients in intraluminal-left anterior descending shunt group were excluded from futher analysis due to preoperative cardiac troponin T level above the 99th-percentile. Postoperatively, each six patients in external tournique occlusion (33.3%) and intraluminal-left anterior descending shunt (35.3%) group were above the 99th-percentile. Two patients from each group (external tournique occlusion group 11.1% vs. intraluminal-left anterior descending shunt group 11.8%) had peak values above 10-% coeficient of variation cutoff (p = 1). There were no significant differences in between both groups at all studied timepoints. Conclusion There was no protective effect of intraluminal shunting on myocardial damage compared to short-term tournique occlusion. It is upon the surgeon's discretion which method may preferrably be used to achieve a bloodless field in grafting of the non-occluded left anterior descending in minimally invasive coronary artery bypass. PMID:22809563

Use of the proGAV shunt valve in normal-pressure hydrocephalus.

PubMed

Toma, Ahmed K; Tarnaris, Andrew; Kitchen, Neil D; Watkins, Laurence D

2011-06-01

Overdrainage is a common complication associated with shunt insertion in normal-pressure hydrocephalus (NPH) patients. Using adjustable valves with antigravity devices has been shown to reduce its incidence. The optimal starting setting of an adjustable shunt valve in NPH is debatable. To audit our single-center practice of setting adjustable valves. We performed a retrospective review of clinical records of all NPH patients treated in our unit between 2006 and 2009 by the insertion of shunts with a proGAV valve, recording demographic and clinical data, shunt complications, and revision rates. Radiological reports of postoperative follow-up computed tomography scans of the brain were reviewed for detected subdural hematomas. A proGAV adjustable valve was inserted in 50 probable NPH patients between July 2006 and November 2009. Mean ± SD age was 76 ± 7 years. Mean follow-up was 15 months. The initial shunt setting was 6 ± 3 cm H2O, and the final setting was 4.9 ± 1.9 cm H2O. Nineteen patients required 24 readjustment procedures (readjustment rate, 38%; readjustment number, 0.48 times per patient). One patient (2%) developed delayed bilateral subdural hematoma after readjustment of his shunt valve setting as an outpatient. Starting with a low opening pressure setting on a proGAV adjustable shunt valve does not increase the chances of overdrainage complications and reduces the need for repeated readjustments.

The use of abdominal binders to treat over-shunting headaches.

PubMed

Sklar, Frederick H; Nagy, Laszlo; Robertson, Brian D

2012-06-01

Headaches are common in children with shunts. Headaches associated with over-shunting are typically intermittent and tend to occur later in the day. Lying down frequently makes the headaches better. This paper examines the efficacy of using abdominal binders to treat over-shunting headaches. Over an 18-year period, the senior author monitored 1027 children with shunts. Office charts of 483 active patients were retrospectively reviewed to identify those children with headaches and, in particular, those children who were thought to have headaches as a result of over-shunting. Abdominal binders were frequently used to treat children with presumed over-shunting headaches, and these data were analyzed. Of the 483 patients undergoing chart review, 258 (53.4%) had headache. A clinical diagnosis of over-shunting was made in 103 patients (21.3% overall; 39.9% of patients with headache). In 14 patients, the headaches were very mild (1-2 on a 5-point scale) and infrequent (1 or 2 per month), and treatment with an abdominal binder was not thought indicated. Eighty-nine patients were treated with a binder, but 19 were excluded from this retrospective study for noncompliance, interruption of the binder trial, or lack of follow-up. The remaining 70 pediatric patients, who were diagnosed with over-shunting headaches and were treated with abdominal binders, were the subjects of a more detailed retrospective study. Significant headache improvement was observed in 85.8% of patients. On average, the patients wore the binders for approximately 1 month, and headache relief usually persisted even after the binders were discontinued. However, the headaches eventually did recur in many of the patients more than a year later. In these patients, reuse of the abdominal binder was successful in relieving headaches in 78.9%. The abdominal binder is an effective, noninvasive therapy to control over-shunting headaches in most children. This treatment should be tried before any surgery is considered. It is suggested that the abdominal binder may modulate abnormally increased intracranial pulse pressures associated with over-shunting. Interactions with the cerebrovascular bed are suspected to account for persistent headache relief after the binder is discontinued.

Prenatal surgery for myelomeningocele and the need for cerebrospinal fluid shunt placement

PubMed Central

Tulipan, Noel; Wellons, John C.; Thom, Elizabeth A.; Gupta, Nalin; Sutton, Leslie N.; Burrows, Pamela K.; Farmer, Diana; Walsh, William; Johnson, Mark P.; Rand, Larry; Tolivaisa, Susan; D’Alton, Mary E.; Adzick, N. Scott

2016-01-01

Object The Management of Myelomeningocele Study (MOMS) was a multicenter randomized trial comparing the safety and efficacy of prenatal and postnatal closure of myelomeningocele. The trial was stopped early because of the demonstrated efficacy of prenatal surgery, and outcomes on 158 of 183 pregnancies were reported. Here, the authors update the 1-year outcomes for the complete trial, analyze the primary and related outcomes, and evaluate whether specific prerandomization risk factors are associated with prenatal surgery benefit. Methods The primary outcome was a composite of fetal loss or any of the following: infant death, CSF shunt placement, or meeting the prespecified criteria for shunt placement. Primary outcome, actual shunt placement, and shunt revision rates for prenatal versus postnatal repair were compared. The shunt criteria were reassessed to determine which were most concordant with practice, and a new composite outcome was created from the primary outcome by replacing the original criteria for CSF shunt placement with the revised criteria. The authors used logistic regression to estimate whether there were interactions between the type of surgery and known prenatal risk factors (lesion level, gestational age, degree of hindbrain herniation, and ventricle size) for shunt placement, and to determine which factors were associated with shunting among those infants who underwent prenatal surgery. Results Ninety-one women were randomized to prenatal surgery and 92 to postnatal repair. The primary outcome occurred in 73% of infants in the prenatal surgery group and in 98% in the postnatal group (p < 0.0001). Actual rates of shunt placement were only 44% and 84% in the 2 groups, respectively (p < 0.0001). The authors revised the most commonly met criterion to require overt clinical signs of increased intracranial pressure, defined as split sutures, bulging fontanelle, or sunsetting eyes, in addition to increasing head circumference or hydrocephalus. Using these modified criteria, only 3 patients in each group met criteria but did not receive a shunt. For the revised composite outcome, there was a difference between the prenatal and postnatal surgery groups: 49.5% versus 87.0% (p < 0.0001). There was also a significant reduction in the number of children who had a shunt placed and then required a revision by 1 year of age in the prenatal group (15.4% vs 40.2%, relative risk 0.38 [95% CI 0.22–0.66]). In the prenatal surgery group, 20% of those with ventricle size < 10 mm at initial screening, 45.2% with ventricle size of 10 up to 15 mm, and 79.0% with ventricle size ≥ 15 mm received a shunt, whereas in the postnatal group, 79.4%, 86.0%, and 87.5%, respectively, received a shunt (p = 0.02). Lesion level and degree of hindbrain herniation appeared to have no effect on the eventual need for shunting (p = 0.19 and p = 0.13, respectively). Similar results were obtained for the revised outcome. Conclusions Larger ventricles at initial screening are associated with an increased need for shunting among those undergoing fetal surgery for myelomeningocele. During prenatal counseling, care should be exercised in recommending prenatal surgery when the ventricles are 15 mm or larger because prenatal surgery does not appear to improve outcome in this group. The revised criteria may be useful as guidelines for treating hydrocephalus in this group. PMID:26369371

The incidence and morphology of maxillary sinus septa in dentate and edentulous maxillae: a cadaveric study with a brief review of the literature

PubMed Central

Wabale, Rajendra Namdeo; Siddiqui, Abu Ubaida; Farooqui, Mujjebuddeen Samsudeen

2015-01-01

Objectives The aim of this study is to determine the incidence, location, and orientation of maxillary sinus septa in formalin embalmed cadavers. Materials and Methods The study was conducted on 210 cadaveric heads available in our department. After taking the mid-sagittal section the specimens were opened from the medial aspect and the sinus cavity was explored for the presence of maxillary sinus septa, their anatomical plane, location and dimensions. Results The mean linear distance between maxillary sinus floor and its anatomical ostium was 26.76±5.21 mm and 26.91±4.96 mm on right and left side, respectively. A total of 59 maxillary sinus septa (28.1%) were observed in 210 maxillary specimens. Septae were most common, 33 septa (55.9%), in the middle region (between first and second molar tooth) of the sinus cavity. The maxillary sinus membrane (Schneiderian membrane) adhered tightly to the maxillary sinus and over the septae. Significantly more maxillary sinus septa were observed in edentulous maxillae in comparison to the dentate upper jaw. Conclusion Knowledge of location of maxillary sinus ostium is mandatory for the rhinologist for drainage of secretions in maxillary sinusitis. The morphological details of maxillary sinus septa, particularly their location and anatomical planes, will guide dentists in performance of safe implant surgeries. The maxillary antrum septa of category I and II may complicate the procedure of inversion of bone plate and elevation of sinus membrane during maxillary augmentation surgeries. The category III septa observed in the sagittal plane were embedded by one of the branches of the infraorbital nerve in it, and if accidentally cut will lead to infraorbital nerve palsy in maxillary sinus surgeries. PMID:25741466

40 CFR 63.7501 - How can I assert an affirmative defense if I exceed an emission limitations during a malfunction?

Code of Federal Regulations, 2011 CFR

2011-07-01

... operating limits set forth in § 63.7500 you may assert an affirmative defense to a claim for civil penalties... monitoring methods and engineering judgment, the amount of excess emissions that were the result of the... malfunction, if it wishes to avail itself of an affirmative defense to civil penalties for that malfunction...

40 CFR 63.7501 - How can I assert an affirmative defense if I exceed an emission limitations during a malfunction?

Code of Federal Regulations, 2012 CFR

2012-07-01

... operating limits set forth in § 63.7500 you may assert an affirmative defense to a claim for civil penalties... monitoring methods and engineering judgment, the amount of excess emissions that were the result of the... malfunction, if it wishes to avail itself of an affirmative defense to civil penalties for that malfunction...

40 CFR Table 6 to Subpart Cccc of... - Applicability of General Provisions to Subpart CCCC

Code of Federal Regulations, 2013 CFR

2013-07-01

... Requirements 1. For § 63.6(e) and (f), requirements for startup, shutdown, and malfunctions apply only to.... 3. For § 63.8(c)(1), requirements for startup, shutdown, and malfunctions apply only to malfunctions, and no report pursuant to § 63.10(d)(5)(i) is required. 4. For § 63.8(d), requirements for startup...

40 CFR Table 6 to Subpart Cccc of... - Applicability of General Provisions to Subpart CCCC

Code of Federal Regulations, 2011 CFR

2011-07-01

... Requirements 1. For § 63.6(e) and (f), requirements for startup, shutdown, and malfunctions apply only to.... 3. For § 63.8(c)(1), requirements for startup, shutdown, and malfunctions apply only to malfunctions, and no report pursuant to § 63.10(d)(5)(i) is required. 4. For § 63.8(d), requirements for startup...

40 CFR Table 6 to Subpart Cccc of... - Applicability of General Provisions to Subpart CCCC

Code of Federal Regulations, 2014 CFR

2014-07-01

... Requirements 1. For § 63.6(e) and (f), requirements for startup, shutdown, and malfunctions apply only to.... 3. For § 63.8(c)(1), requirements for startup, shutdown, and malfunctions apply only to malfunctions, and no report pursuant to § 63.10(d)(5)(i) is required. 4. For § 63.8(d), requirements for startup...

40 CFR Table 6 to Subpart Cccc of... - Applicability of General Provisions to Subpart CCCC

Code of Federal Regulations, 2012 CFR

2012-07-01

... Requirements 1. For § 63.6(e) and (f), requirements for startup, shutdown, and malfunctions apply only to.... 3. For § 63.8(c)(1), requirements for startup, shutdown, and malfunctions apply only to malfunctions, and no report pursuant to § 63.10(d)(5)(i) is required. 4. For § 63.8(d), requirements for startup...

40 CFR Table 6 to Subpart Cccc of... - Applicability of General Provisions to Subpart CCCC

Code of Federal Regulations, 2010 CFR

2010-07-01

... Requirements 1. For § 63.6(e) and (f), requirements for startup, shutdown, and malfunctions apply only to.... 3. For § 63.8(c)(1), requirements for startup, shutdown, and malfunctions apply only to malfunctions, and no report pursuant to § 63.10(d)(5)(i) is required. 4. For § 63.8(d), requirements for startup...

Reproducibility of right-to-left shunt quantification using transthoracic contrast echocardiography in hereditary haemorrhagic telangiectasia.

PubMed

Vorselaars, V M M; Velthuis, S; Huitema, M P; Hosman, A E; Westermann, C J J; Snijder, R J; Mager, J J; Post, M C

2018-04-01

Transthoracic contrast echocardiography (TTCE) is recommended for screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia. Shunt quantification is used to find treatable PAVMs. So far, there has been no study investigating the reproducibility of this diagnostic test. Therefore, this study aimed to describe inter-observer and inter-injection variability of TTCE. We conducted a prospective single centre study. We included all consecutive persons screened for presence of PAVMs in association with hereditary haemorrhagic telangiectasia in 2015. The videos of two contrast injections per patient were divided and reviewed by two cardiologists blinded for patient data. Pulmonary right-to-left shunts were graded using a three-grade scale. Inter-observer and inter-injection agreement was calculated with κ statistics for the presence and grade of pulmonary right-to-left shunts. We included 107 persons (accounting for 214 injections) (49.5% male, mean age 45.0 ± 16.6 years). A pulmonary right-to-left shunt was present in 136 (63.6%) and 131 (61.2%) injections for observer 1 and 2, respectively. Inter-injection agreement for the presence of pulmonary right-to-left shunts was 0.96 (95% confidence interval (CI) 0.9-1.0) and 0.98 (95% CI 0.94-1.00) for observer 1 and 2, respectively. Inter-injection agreement for pulmonary right-to-left shunt grade was 0.96 (95% CI 0.93-0.99) and 0.95 (95% CI 0.92-0.98) respectively. There was disagreement in right-to-left shunt grade between the contrast injections in 11 patients (10.3%). Inter-observer variability for presence and grade of the pulmonary right-to-left shunt was 0.95 (95% CI 0.91-0.99) and 0.97 (95% CI 0.95-0.99) respectively. TTCE has an excellent inter-injection and inter-observer agreement for both the presence and grade of pulmonary right-to-left shunts.

Gravitational shunt units may cause under-drainage in bedridden patients.

PubMed

Kaestner, S; Kruschat, T; Nitzsche, N; Deinsberger, W

2009-03-01

Implantation of a shunt in a hydrocephalic patient still carries a risk of complications such as over-drainage and under-drainage. Gravitational shunt units are especially designed to minimize the problem of over-drainage. Nevertheless, these valves carry a risk of under-drainage. The best choice of valve for a patient is still challenging. The purpose of this survey was to identify in which patients a gravitational shunt valve is liable to lead to under-drainage. Patients with hydrocephalus entered prospectively into a data base were reviewed retrospectively. The patients were treated between January 2006 to the end of Feb 2007 and those experiencing under- or over-drainage were identified. Thirty-five ventriculo-peritoneal shunt systems were implanted in adult patients. The cause of the hydrocephalus was: normal pressure hydrocephalus in 18 patients, post-haemorrhagic following subarachnoid or intracerebral haemorrhage in 11, associated with a tumour in four and followed a head injury in two patients. Three different valves were used: an adjustable shunt valve with gravitational unit (Pro-GAV 0-20/25 in 21 patients), a gravitational shunt valve with fixed opening pressure (GAV 5/30 in nine patients) and an adjustable differential valve (Hakim medos in five patients). Four patients developed severe, valve-related under-drainage. Each had received a gravitational shunt valve and all were bedridden. In two of these patients it was necessary to change the valve. One patient who had received a differential valve, after regaining mobility developed severe over-drainage with bilateral subdural haematomas. Over-drainage was not seen in long-term bedridden patients with a differential shunt valve. If a bedridden patient with a gravitational shunt valve system lies with a slightly elevated head, this leads to activation of the gravitational unit and this may cause under drainage. As a result, we advise not using an anti-siphon devices in a patient who is bedridden for a long period.

[Hemodynamic study of the patient with hemorrhagic portal hypertension: importance of the left renal vein in patients with a distal splenorenal shunt (Warren)].

PubMed

Orozco, Héctor; Tielve, Manuel; Ramos, Guillermo; Mercado, Miguel Angel

2006-01-01

There is no information in the literature about surgical outcome of the distal splenorenal shunt (Warren shunt) in those patients with anomalous flow in the left renal vein to the inferior vena cava. The purpose of this manuscript was to evaluate the incidence of thrombosis in the Warren shunt in those patients with anomalous flow in the left renal vein to the inferior vena cava. We performed a prospective, descriptive and longitudinal study in those patients who performed a surgical procedure to the treatment of hemorrhagic portal hypertension in a tertiary referral center in Mexico City during a one year period (2002-2003). Before the surgical procedure an arterial and venous angiographic study was done including celiac axis, superior mesenteric artery and splenic artery. The patients were scheduled in the outpatient office the first, third, sixth month and the year after the surgical procedure. We looked in them for gastrointestinal bleeding secondary to portal hypertension. In those patients with Warren shunt an angiographic study was done during the first month after the surgical procedure. Twenty eight patients were included, 17 of them women (60.7%). Median patient age was 48 years old. In 20 patients a Warren shunt were done and in eigth patients a devascularization operation were done. The anomalous flow of the left renal vein was identified in nine patients (28.7%). In seven of them a Warren shunt were done and in two of them a devascularization operation were done. We didn't find gastrointestinal bleeding or thrombosis of the Warren shunt in any of these patients. In those cases of patients with anomalous flow in the left renal vein a Warren shunt can be performed. In this study we didn't find thrombosis of the shunt or gastrointestinal bleeding. In this way a surgical decompression of the portal system can be done preventing bleeding episodes.

Percutaneous Transjugular Direct Porto-caval Shunt in Patients with Budd-Chiari Syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quateen, A.; Pech, M.; Berg, T.

The purpose of the study was to evaluate the feasibility and effectiveness of direct porto-caval shunts in patients with Budd-Chiari syndrome (BCS) in whom there is no access to the hepatic veins during transjugular intrahepatic portosystemic shunt (TIPSS). We included six consecutive patients with fulminant/acute Budd-Chiari syndrome (mean age: 35 years) in whom a conventional TIPSS was not possible due to inaccessible hepatic veins. We performed a direct porto-caval shunt via a transhepatic approach. Patients were followed up by means of clinical examination, laboratory investigations, and Doppler ultrasound. TIPSS implantation from the inferior vena cava (IVC) was successful in allmore » six patients (100%). The median transhepatic shunt length was 9 cm (8-10 cm). No procedure-related complications were observed in our patients. Early shunt occlusion occurred in three out of six patients (50%). In all three of these patients, the stent used to stabilize the shunt ended 1-2 cm before reaching the IVC. All occlusions were successfully recanalized. One of these patients developed recurrent early shunt as well as mesenteric and splenic vein occlusions. She died 7 days after TIPSS placement due to an unmanageable coagulation disorder. The remaining five patients were followed up by planned clinical examination and laboratory investigations (mean follow-up time was 15 months; patient 1 was followed up for 13 months, patient 2 for 14 months, patient 3 for 15 months, and patients 4 and 5 for 16 months) and all displayed a complete and durable resolution of liver failure and ascites without reintervention. In patients with acute liver failure originating from BCS and inaccessible hepatic veins, a direct transhepatic porto-caval shunt can be performed safely and effectively under ultrasound guidance. Future studies in larger patient groups should investigate if the patency of transcaval TIPSS with long transhepatic shunt segments is similar compared to conventional TIPSS via the hepatic vein.« less

Contemporary survival of patients with pulmonary arterial hypertension and congenital systemic to pulmonary shunts

PubMed Central

Chungsomprasong, Paweena; Bositthipichet, Densiri; Ketsara, Salisa; Titaram, Yuttapon; Chanthong, Prakul; Kanjanauthai, Supaluck

2018-01-01

Objective To compare survival of patients with newly diagnosed pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) according to various clinical classifications with classifications of anatomical-pathophysiological systemic to pulmonary shunts in a single-center cohort. Methods All prevalent cases of PAH-CHD with hemodynamic confirmation by cardiac catheterization in 1995–2015 were retrospectively reviewed. Patients who were younger than three months of age, or with single ventricle following surgery were excluded. Baseline characteristics and clinical outcomes were retrieved from the database. The survival analysis was performed at the end of 2016. Prognostic factors were identified using multivariate analysis. Results A total of 366 consecutive patients (24.5 ± 17.6 years of age, 40% male) with PAH-CHD were analyzed. Most had simple shunts (85 pre-tricuspid, 105 post-tricuspid, 102 combined shunts). Patients with pre-tricuspid shunts were significantly older at diagnosis in comparison to post-tricuspid, combined, and complex shunts. Clinical classifications identified patients as having Eisenmenger syndrome (ES, 26.8%), prevalent left to right shunt (66.7%), PAH with small defect (3%), or PAH following defect correction (3.5%). At follow-up (median = 5.9 years; 0.1–20.7 years), no statistically significant differences in survival rate were seen among the anatomical-pathophysiological shunts (p = 0.1). Conversely, the clinical classifications revealed that patients with PAH-small defect had inferior survival compared to patients with ES, PAH post-corrective surgery, or PAH with prevalent left to right shunt (p = 0.01). Significant mortality risks were functional class III, age < 10 years, PAH-small defect, elevated right atrial pressure > 15 mmHg, and baseline PVR > 8 WU•m.2 Conclusion Patients with PAH-CHD had a modest long-term survival. Different anatomical-pathophysiological shunts affect the natural presentation, while clinical classifications indicate treatment strategies and survival. Contemporary therapy improves survival in deliberately selected patients. PMID:29664959

Five-year outcome of normal pressure hydrocephalus with or without a shunt: predictive value of the clinical signs, neuropsychological evaluation and infusion test.

PubMed

Savolainen, S; Hurskainen, H; Paljärvi, L; Alafuzoff, I; Vapalahti, M

2002-06-01

Between 1993-1995, 51 patients under 75 years of age with clinical symptoms and CT-based diagnosis of normal pressure hydrocephalus were investigated prospectively in order to clarify the value of neuropsychological tests, clinical symptoms and signs and infusion test in the differential diagnosis and prediction of outcome in normal pressure hydrocephalus. Patients had a thorough neurological examination, and neuropsychological evaluation. A 24-hour intraventricular ICP-measurement, infusion test, neurophysiological investigations and MRI study were performed, and a cortical biopsy was obtained. The ICP measurement defined the need for a shunt. All 51 patients were re-examined three and twelve months later. The final follow-up was accomplished five years postoperatively. 25 of the patients needed a shunt operation. One year after a shunt placement 72% of these patients had a good recovery concerning activities of daily living, 58% benefited in their urinary incontinence and 57% walked better. During the 5 years of follow-up 8 patients with shunt and 9 without shunt had died. Positive effect of shunting remained. Only one neuropsychological test, recognition of words test, distinguishes the patients with the need for a shunt. Simple mini mental examination test was not different in those who improved. In the postoperative follow-up patients with shunt showed no change in neuropsychological tests even if they were subjectively better. The infusion test was of no value in diagnosing NPH. The 16 patients with Alzheimer's disease did worse after one year than those without pathological changes, but the mortality was not increased. Specific neuropsychological tests are of little value in diagnosing NPH. Mini-Mental status examination was neither of value in diagnosing NPH nor in prediction of the outcome. In this study the infusion test did not improve diagnostic accuracy of NPH, but shunt placement relieves urinary incontinence and walking disability in patients with increased ICP. The patients with positive Alzheimer diagnosis on biopsy did not improve.

Association of Genetic Polymorphisms of Renin–Angiotensin–Aldosterone System-Related Genes with Arterio-Venous Fistula Malfunction in Hemodialysis Patients

PubMed Central

Chen, Yu-Wei; Wu, Yu-Te; Lin, Jhin-Shyaun; Yang, Wu-Chang; Hsu, Yung-Ho; Lee, Kuo-Hua; Ou, Shou-Ming; Chen, Yung-Tai; Shih, Chia-Jen; Lee, Pui-Ching; Chan, Chia-Hao; Chung, Ming-Yi; Lin, Chih-Ching

2016-01-01

Hemodialysis (HD) is the most commonly-used renal replacement therapy for patients with end-stage renal disease worldwide. Arterio-venous fistula (AVF) is the vascular access of choice for HD patients with lowest risk of infection and thrombosis. In addition to environmental factors, genetic factors may also contribute to malfunction of AVF. Previous studies have demonstrated the effect of genotype polymorphisms of angiotensin converting enzyme on vascular access malfunction. We conducted a multicenter, cross-sectional study to evaluate the association between genetic polymorphisms of renin-angiotensin-aldosterone system and AVF malfunction. Totally, 577 patients were enrolled. Their mean age was 60 years old and 53% were male. HD patients with AVF malfunction had longer duration of HD (92.5 ± 68.1 vs. 61.2 ± 51.9 months, p < 0.001), lower prevalence of hypertension (44.8% vs. 55.3%, p = 0.025), right-sided (31.8% vs. 18.4%, p = 0.002) and upper arm AVF (26.6% vs. 9.7%, p < 0.001), and higher mean dynamic venous pressure (DVP) (147.8 ± 28.3 vs. 139.8 ± 30.0, p = 0.021). In subgroup analysis of different genders, location of AVF and DVP remained significant clinical risk factors of AVF malfunction in univariate and multivariate binary logistic regression in female HD patients. Among male HD patients, univariate binary logistic regression analysis revealed that right-side AVF and upper arm location are two important clinical risk factors. In addition, two single nucleotide polymorphisms (SNPs), rs275653 (Odds ratio 1.90, p = 0.038) and rs1492099 (Odds ratio 2.29, p = 0.017) of angiotensin II receptor 1 (AGTR1), were associated with increased risk of AVF malfunction. After adjustment for age and other clinical factors, minor allele-containing genotype polymorphisms (AA and CA) of rs1492099 still remained to be a significant risk factor of AVF malfunction (Odds ratio 3.63, p = 0.005). In conclusion, we demonstrated that rs1492099, a SNP of AGTR1 gene, could be a potential genetic risk factor of AVF malfunction in male HD patients. PMID:27240348

International Space Station Solar Array Wing On-Orbit Electrical Performance Degradation Measured

NASA Technical Reports Server (NTRS)

Gustafson, Eric D.; Kerslake, Thomas W.

2004-01-01

The port-side photovoltaic power module (P6) was activated on the International Space Station in December 2000. P6 provides electrical power to channels 2B and 4B to operate ISS power loads. A P6 is shown in the preceding photograph. This article highlights the work done at the NASA Glenn Research Center to calculate the on-orbit degradation of the P6 solar array wings (SAWs) using on-orbit data from December 2000 to February 2003. During early ISS operations, the 82 strings of photovoltaic cells that make up a SAW can provide much more power than is necessary to meet the demand. To deal with excess power, a sequential shunt unit successively shunts the current from the strings. This shunt current was the parameter chosen for the SAW performance degradation study for the following reasons: (1) it is based on a direct shunt current measurement in the sequential shunt unit, (2) the shunt current has a low temperature dependence that reduces the data correction error from using a computationally derived array temperature, and (3) the SSU shunt current is essentially the same as the SAW short-circuit current on a per-string basis.

Vaginal Migration of Ventriculoperitoneal Shunt Catheter and Cerebrospinal Fluid Leak as a Complication of Hysterectomy.

PubMed

Houten, John K; Smith, Shiela; Schwartz, Amit Y

2017-08-01

Ventriculoperitoneal (VP) shunting is a common neurosurgical procedure to treat hydrocephalus that diverts cerebrospinal fluid from the cerebral ventricles to the peritoneal cavity for reabsorption. The distal catheter may potentially migrate through any potential or iatrogenic opening in the peritoneal cavity. Increasingly successfully management of childhood hydrocephalus and adult-onset conditions leading to hydrocephalus, such as subarachnoid hemorrhage, is leading many adult female patients harboring VP shunts needing to undergo hysterectomy. Hysterectomy creates a potential defect though which a VP shunt catheter may migrate. It is not known whether the hysterectomy cuff closure technique may affect the likelihood of distal catheter migration though the repair site. We report the case of a 38-year-old woman with a VP shunt who underwent laparoscopic hysterectomy via an open vaginal cuff technique who subsequently presented with vaginal cerebrospinal fluid leakage secondary to migration of the distal shunt catheter through the hysterectomy cuff. Vaginal migration of the distal VP shunt catheter is a possible complication of hysterectomy. The authors postulate that an open cuff hysterectomy closure technique may increase the risk of catheter migration, an issue that may be better understood with further investigation. Copyright © 2017 Elsevier Inc. All rights reserved.

Electron microscopic evaluation of a gold glaucoma micro shunt after explantation.

PubMed

Berk, Thomas A; Tam, Diamond Y; Werner, Liliana; Mamalis, Nick; Ahmed, Iqbal Ike K

2015-03-01

We present a case of an explanted gold glaucoma micro shunt (GMS Plus) and the subsequent light and electron microscopic analyses. The shunt was implanted in a patient with medically refractive glaucoma. The intraocular pressure (IOP) was stable at 12 mm Hg 6 months postoperatively but spiked to 26 mm Hg 6 months later; membranous growth was visible on the implant gonioscopically. A second gold micro shunt was placed 2 years after the first. The IOP was 7 mm Hg 1 week postoperatively but increased to 23 mm Hg 3 weeks later; similar membranous growth was visible on this implant. One of the shunts was explanted, and light and scanning electron microscopic analyses revealed encapsulation around the shunt exterior and connective tissue invasion of the microstructure. This represents the first electron microscopic analysis of an explanted gold glaucoma micro shunt and the first unequivocal images of the fibrotic pseudo-capsule traversing its microchannels and fenestrations. Dr. Ahmed is a consultant to and has received research grants from Solx, Inc. No other author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Morphology of congenital portosystemic shunts involving the left colic vein in dogs and cats.

PubMed

White, R N; Parry, A T

2016-05-01

To describe the anatomy of congenital portosystemic shunts involving the left colic vein in dogs and cats. Retrospective review of a consecutive series of dogs and cats managed for congenital portosystemic shunts. For inclusion a shunt involving the left colic vein with recorded intraoperative mesenteric portovenography or computed tomography angiography along with direct gross surgical observations at the time of surgery was required. Six dogs and three cats met the inclusion criteria. All cases had a shunt which involved a distended left colic vein. The final communication with a systemic vein was variable; in seven cases (five dogs, two cats) it was via the caudal vena cava, in one cat it was via the common iliac vein and in the remaining dog it was via the internal iliac vein. In addition, two cats showed caudal vena cava duplication. The morphology of this shunt type appeared to be a result of an abnormal communication between either the left colic vein or the cranial rectal vein and a pelvic systemic vein (caudal vena cava, common iliac vein or internal iliac vein). This information may help with surgical planning in cases undergoing shunt closure surgery. © 2016 British Small Animal Veterinary Association.

[Design of cross-sectional anatomical model focused on drainage pathways of paranasal sinuses].

PubMed

Zha, Y; Lv, W; Gao, Y L; Zhu, Z Z; Gao, Z Q

2018-05-01

Objective: To design and produce cross-sectional anatomical models of paranasal sinuses for the purpose of demonstrating drainage pathways of each nasal sinus for the young doctors. Method: We reconstructed the three-dimensional model of sinuses area based on CT scan data, and divided it into 5 thick cross-sectional anatomy models by 4 coronal plane，which cross middle points of agger nasi cell, ethmoid bulla, posterior ethmoid sinuses and sphenoid sinus respectively. Then a 3D printerwas used to make anatomical cross-sectional anatomical models. Result: Successfully produced a digital 3D printing cross-sectional models of paranasal sinuses. Sinus drainage pathways were observed on the models. Conclusion: The cross-sectional anatomical models made by us can exactly and intuitively demonstrate the ostia of each sinus cell and they can help the young doctors to understand and master the key anatomies and relationships which are important to the endoscopic sinus surgery. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

Pilot Comparisons of Temporary Open Revascularization Using Stent Grafts vs. Standard Shunts in a Sheep (Ovis aries) Model

DTIC Science & Technology

2016-03-14

using stent grafts vs. standard shunts in a sheep (Ovis aries) model." PRINCIPAL INVESTIGATOR (Pl) I TRAINING COORDINATOR (TC): Lt Col James Sampson...Objectives: Pilot study and development of an experimental model to test and compare the performance of endovascular stent -graft as an arterial shunt...FDG2015001 OA 2 Results: Exposure and placement of vascular stent -grafts and shunts into the common carotid artery was feasible. Stent -graft and

Successful transcatheter closure of a congenital high-flow portosystemic venous shunt with the Amplatzer vascular plug II.

PubMed

Guneyli, Serkan; Cinar, Celal; Bozkaya, Halil; Parildar, Mustafa; Oran, Ismail; Akin, Yigit

2012-12-01

Congenital portosystemic venous shunt is extremely rare and should be treated. Advances in treatment techniques allow for patients to be treated safely. We present a 9-year-old boy with a large congenital portosystemic venous shunt. The shunt was occluded interventionally with the Amplatzer vascular plug II. Our case was unique with its clinical manifestation, the use of a 22-mm Amplatzer vascular plug II, and the presence of the patient's 1-year follow-up.

Presentation of Preauricular Sinus and Preauricular Sinus Abscess in Southwest Nigeria

PubMed Central

Adegbiji, W. A.; Alabi, B. S.; Olajuyin, O. A.; Nwawolo, C. C.

2013-01-01

BACKGROUND AND AIM: Preauricular sinus abscess is a common congenital external ear disease. This abscess is usually misdiagnosed because it is commonly overlooked during physical examination. In Nigeria, the prevalence was 9.3% in Ilorin, north central Nigeria This study is to determine the distribution and clinical presentation of the preauricular sinus abscess in Ekiti, south west Nigeria. MATERIALS AND METHODS: This is a prospective hospital based study of all patients with diagnosis of preauricular sinus abscess seen in our clinic carried out between April 2008 to March 2010. Detailed clinical history, administered interviewer’s assisted questionnaires full examination and. Data obtained were collated and analysed. RESULTS: Preauricular sinus were noticed in 184 (4.4%) out of 4170 patients seen during the study period. Preauricular sinus abscess were noticed in 21 (11.4%) of the preauricular sinuses especially in children. Unilateral preauricular sinus abscess accounted for 90.5%. Common presenting complaints were preauricular swelling (81.0%), 90.5% with recurrent earaches, 76.2% with ear discharges. All patients had antibiotic / analgesic while 17 out of 21 (81.0%) had surgical excisions. CONCLUSION: Preauricular sinus abscess were noticed among 11.4% of the preauricular sinuses especially in children, unilateral preauricular sinus abscess accounted for 90.5%. Common complaints were otorrhoea, earaches, and swelling and they were mostly managed surgically. PMID:24711764

Radiographic, computed tomographic and surgical anatomy of the equine sphenopalatine sinus in normal and diseased horses.

PubMed

Tucker, R; Windley, Z E; Abernethy, A D; Witte, T H; Fiske-Jackson, A R; Turner, S; Smith, L J; Perkins, J D

2016-09-01

Knowledge of imaging anatomy, surgical anatomy and disorders affecting the sphenopalatine sinus are currently lacking. To describe the computed tomographic (CT) and surgical anatomy of the sphenopalatine sinus and diagnosis, treatment and outcome in clinical cases with sphenopalatine sinus disease. Cadaver observational study and retrospective case series. The sphenopalatine sinuses of 10 normal cadaver heads were examined with digital radiography, CT and sinoscopic examination prior to anatomical sectioning. Sphenopalatine sinus anatomy was described and compared between cadaver specimens across the imaging modalities. Medical records (January 2004-2014) of cases diagnosed with sphenopalatine sinus disease were reviewed. The anatomy of the sphenopalatine sinus was variable. The borders of the sphenopalatine sinus were not identifiable on plain radiographs, whereas CT provided useful anatomical information. The palatine portion of the sphenopalatine sinus was consistently accessible sinoscopically and the sphenoidal portion was accessible in 6/10 cadaver heads. Fourteen cases of sphenopalatine sinus disease were identified, presenting with one or more clinical signs of exophthalmos, blindness, unilateral epistaxis or unilateral nasal discharge. Diagnoses included neoplasia (7), progressive ethmoidal haematoma (4), sinus cyst (2) and empyema (1). Computed tomography provided diagnostic information but could not differentiate the nature of soft tissue masses. Standing sinoscopic access to the palatine portion of the sphenopalatine sinus was possible for evaluation, biopsy and resection of abnormal soft tissues. Surgical access to the sphenoidal portion was limited. Eight horses were alive at 1 year after diagnosis, with a worse outcome associated with CT evidence of bone loss and a diagnosis of neoplasia. Sphenopalatine sinus disease should be considered a rare cause of the clinical signs described. Knowledge of the anatomical variation of the sphenopalatine sinus is vital for interpreting CT images. A combination of CT and sinoscopy provides the most comprehensive approach for diagnosis and treatment of sphenopalatine sinus disease. © 2015 EVJ Ltd.

Management of acute maxillary sinusitis after sinus bone grafting procedures with simultaneous dental implants placement - a retrospective study.

PubMed

Chirilă, Lucian; Rotaru, Cristian; Filipov, Iulian; Săndulescu, Mihai

2016-03-08

The sinus lift was first described in 1974 and it has proven to be a predictable procedure ever since. The complications of this surgical procedure are reported in the literature to be low, and can include acute maxillary sinusitis, scattering of the grafting material into the sinus cavity, wound dehiscence and Schneiderian membrane perforations. We aimed to evaluate the rate of acute maxillary sinusitis after sinus lift procedures and the appropriate management strategies. Between 2013 and 2015, 245 dental implants were placed in 116 patients (76 males and 40 females) with concomitant bone augmentation of the maxillary sinus floor. The sinus lifting procedure was bilateral in 35 patients and unilateral in 81 patients (a total of 151 sinuses). Maxillary sinusitis occurred in 5 patients (4.3 %). The clinical signs of infection were: headache, locoregional pain, cacosmia, inflammation of the oral buccal mucosa and rhinorrhea or unilateral nasal discharge. A mucosal fistula was observed during inspection in one patient. The management included only the removal of the grafting material in 3 patients, in 1 patient the grafting material was removed together with all the implants, and in 1 patient only 2 implants and the grafting material were removed, 1 implant being left in place. The sinus cavity was irrigated with metronidazole solution and antibiotic therapy with clindamycin and metronidazole was prescribed for 10 days. Subsequently, all signs of infection disappeared within 5 to 7 days and normal sinus function and drainage were restored. Although sinus lift is regarded as a safe and reliable procedure, acute sinusitis is a possible complication which has to be managed immediately in order to reduce the risk of further complications like pansinusitis, osteomyelitis of the maxillary bone, and spreading of the infection in the infratemporal space or orbital cavity. To minimize risk, caution must be taken with all the steps of the procedure, in order not to obliterate the ostium, impairing maxillary sinus clearance.

Clopidogrel in infants with systemic-to-pulmonary-artery shunts.

PubMed

Wessel, David L; Berger, Felix; Li, Jennifer S; Dähnert, Ingo; Rakhit, Amit; Fontecave, Sylvie; Newburger, Jane W

2013-06-20

Infants with cyanotic congenital heart disease palliated with placement of a systemic-to-pulmonary-artery shunt are at risk for shunt thrombosis and death. We investigated whether the addition of clopidogrel to conventional therapy reduces mortality from any cause and morbidity related to the shunt. In a multicenter, double-blind, event-driven trial, we randomly assigned infants 92 days of age or younger with cyanotic congenital heart disease and a systemic-to-pulmonary-artery shunt to receive clopidogrel at a dose of 0.2 mg per kilogram of body weight per day (467 infants) or placebo (439 infants), in addition to conventional therapy (including aspirin in 87.9% of infants). The primary efficacy end point was a composite of death or heart transplantation, shunt thrombosis, or performance of a cardiac procedure due to an event considered to be thrombotic in nature before 120 days of age. The rate of the composite primary end point did not differ significantly between the clopidogrel group (19.1%) and the placebo group (20.5%) (absolute risk difference, 1.4 percentage points; relative risk reduction with clopidogrel, 11.1%; 95% confidence interval, -19.2 to 33.6; P=0.43), nor did the rates of the three components of the composite primary end point. There was no significant benefit of clopidogrel treatment in any subgroup, including subgroups defined by shunt type. Clopidogrel recipients and placebo recipients had similar rates of overall bleeding (18.8% and 20.2%, respectively) and severe bleeding (4.1% and 3.4%, respectively). Clopidogrel therapy in infants with cyanotic congenital heart disease palliated with a systemic-to-pulmonary-artery shunt, most of whom received concomitant aspirin therapy, did not reduce either mortality from any cause or shunt-related morbidity. (Funded by Sanofi-Aventis and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00396877.).

Deriving the Intrahepatic Arteriovenous Shunt Rate from CT Images and Biochemical Data Instead of from Arterial Perfusion Scintigraphy in Hepatic Arterial Infusion Chemotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozaki, Toshiro, E-mail: ganronbun@amail.plala.or.jp; Seki, Hiroshi; Shiina, Makoto

2009-09-15

The purpose of the present study was to elucidate a method for predicting the intrahepatic arteriovenous shunt rate from computed tomography (CT) images and biochemical data, instead of from arterial perfusion scintigraphy, because adverse exacerbated systemic effects may be induced in cases where a high shunt rate exists. CT and arterial perfusion scintigraphy were performed in patients with liver metastases from gastric or colorectal cancer. Biochemical data and tumor marker levels of 33 enrolled patients were measured. The results were statistically verified by multiple regression analysis. The total metastatic hepatic tumor volume (V{sub metastasized}), residual hepatic parenchyma volume (V{sub residual};more » calculated from CT images), and biochemical data were treated as independent variables; the intrahepatic arteriovenous (IHAV) shunt rate (calculated from scintigraphy) was treated as a dependent variable. The IHAV shunt rate was 15.1 {+-} 11.9%. Based on the correlation matrixes, the best correlation coefficient of 0.84 was established between the IHAV shunt rate and V{sub metastasized} (p < 0.01). In the multiple regression analysis with the IHAV shunt rate as the dependent variable, the coefficient of determination (R{sup 2}) was 0.75, which was significant at the 0.1% level with two significant independent variables (V{sub metastasized} and V{sub residual}). The standardized regression coefficients ({beta}) of V{sub metastasized} and V{sub residual} were significant at the 0.1 and 5% levels, respectively. Based on this result, we can obtain a predicted value of IHAV shunt rate (p < 0.001) using CT images. When a high shunt rate was predicted, beneficial and consistent clinical monitoring can be initiated in, for example, hepatic arterial infusion chemotherapy.« less

The classification based on intrahepatic portal system for congenital portosystemic shunts.

PubMed

Kanazawa, Hiroyuki; Nosaka, Shunsuke; Miyazaki, Osamu; Sakamoto, Seisuke; Fukuda, Akinari; Shigeta, Takanobu; Nakazawa, Atsuko; Kasahara, Mureo

2015-04-01

Liver transplantation was previously indicated as a curative operation for congenital absence of portal vein. Recent advances in radiological interventional techniques can precisely visualize the architecture of the intrahepatic portal system (IHPS). Therefore, the therapeutic approach for congenital portosystemic shunt (CPS) needs to be reevaluated from a viewpoint of radiological appearances. The aim of this study was to propose the IHPS classification which could explain the pathophysiological characteristics and play a complementary role of a therapeutic approach and management for CPS. Nineteen patients with CPS were retrospectively reviewed. The median age at diagnosis was 6.8 years old. Eighteen of these patients underwent angiography with a shunt occlusion test and were classified based of the severity of the hypoplasia of IHPS. The eighteen cases who could undergo the shunt occlusion test were classified into mild (n=7), moderate (n=6) and severe types (n=5) according to the IHPS classification. The IHPS classification correlated with the portal venous pressure under shunt occlusion, the histopathological findings, postoperative portal venous flow and liver regeneration. Shunt closure resulted in dramatic improvement in the laboratory data and subclinical encephalopathy. Two patients with the severe type suffered from sepsis associated with portal hypertension after treatment, and from the portal flow steal phenomenon because of the development of unexpected collateral vessels. The patients with the severe type had a high risk of postoperative complications after shunt closure in one step, even if the PVP was relatively low during the shunt occlusion test. The IHPS could be visualized by the shunt occlusion test. The IHPS classification reflected the clinicopathological features of CPS, and was useful to determine the therapeutic approach and management for CPS. Copyright © 2015 Elsevier Inc. All rights reserved.

Experimental Percutaneous Extrahepatic Portacaval Shunt Creation by Transjugular Approach in Swine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seong, Chang Kyu; Pavcnik, Dusan, E-mail: pavcnikd@ohsu.edu; Uchida, Barry T.

2005-06-15

The purpose of the study was to evaluate the feasibility of the creation of a percutaneous extrahepatic portacaval shunt (PEPS) in swine by a transjugular approach and to find a suitable stent-graft to use in PEPS. In 12 swine, the extrahepatic portal vein (PV) was entered from the inferior vena cava (IVC) by a needle system introduced from the transjugular approach. A catheter introduced through the transhepatic approach served as a target. Five types of stent-graft consisting of homemade Z stents and a polytetrafluoethylene cover were explored for PEPS creation. Eight animals had follow-up venograms up to 6 weeks ormore » until the shunt became severely stenotic. Gross and histologic examinations were performed after the final follow-up venography. The PV punctures and stent-graft placement were difficult, but the PEPS was established in all animals. In four animals, the stent-graft failed to adequately cover the tract, causing severe hemorrhage. Only two shunts remained patent up to 6 weeks. The other shunts exhibited severe stenosis or occlusion. At gross examination, all shunts traversed the liver parenchyma of the caudate lobe surrounding the IVC. The extravascular PEPS portion was 4 mm to 2 cm long. All shunts entered the PV close to the splenomesenteric junction and exhibited neointimal formation. Shunt stenoses were caused by neointimal hyperplasia and occlusions by a superimposed thrombus. PEPS can be created by the transjugular approach in swine, but only the PV shunt entrance is extrahepatic. None of the tested rigid stent-grafts were suitable for PEPS creation. A short flexible stent-graft with flanged ends is suggested for further exploration.« less

Clinical outcomes of temporary shunting for infants with cerebral pseudomeningocele.

PubMed

Mattei, Tobias A; Sambhara, Deepak; Bond, Brandon J; Lin, Julian

2014-02-01

Although in the case of subdural collections temporary shunting has been suggested as a viable alternative for definitive drainage of the accumulated fluid until restoration of the normal CSF dynamics, there is no agreement on the best management strategy for pseudomeningocele. The authors performed a retrospective chart review in order to evaluate the clinical outcomes of infants temporarily shunted for pseudomeningocele without encephalocele at our institution (The University of Illinois at Peoria/Illinois Neurological Institute) in the period from 2004 to 2012. The epidemiological characteristics, clinical management, and final outcomes of such subpopulation were compared with a control group which received temporary shunting for subdural hematomas (SDH) during the same period. Four patients (100% male) ranging in age from 8.9 to 27.1 months (mean = 13.88) with pseudomeningocele and 17 patients (64.7% male) ranging in age from 1.9 to 11.8 months (mean = 4.15) with SDH were identified. Although the initial management included sequential percutaneous subdural tapping in 82% of the patients, all children ultimately failed such strategy, requiring either subdural-peritoneal (81% of the cases) or subgaleal-peritoneal (19% of the cases) shunting. The mean implant duration was 201 days for the pseudomeningocele group and 384 days for the SDH one. Mean post-shunt hospitalization was 2 days for patients with pseudomeningocele and 4 days for patients with SDH. There was no statistical difference in terms of complications, length of hospitalization post-shunting, or clinical outcomes between the patients with pseudomeningocele and those with SDH. Temporary shunting of infants with pseudo-meningocele constitutes a viable therapeutic alternative with favorable clinical outcomes and a low risk of shunt dependency similar to those of children with SDH.

Baseline neuropsychological profile and cognitive response to cerebrospinal fluid shunting for idiopathic normal pressure hydrocephalus.

PubMed

Thomas, George; McGirt, Matthew J; Woodworth, Graeme; Heidler, Jennifer; Rigamonti, Daniele; Hillis, Argye E; Williams, Michael A

2005-01-01

To evaluate neurocognitive changes and predict neurocognitive outcome after ventriculoperitoneal shunting for idiopathic normal pressure hydrocephalus (INPH). Reports of neurocognitive response to shunting have been variable and studies that predict cognitive outcomes after shunting are limited. We reviewed our experience with cognitive outcomes for INPH patients who were selected for shunting based on abnormal cerebrospinal fluid (CSF) pressure monitoring and positive response in any of the NPH symptoms following large volume CSF drainage. Forty-two INPH patients underwent neurocognitive testing and Folstein Mini-Mental State Examination (MMSE) prior to shunting. Neurocognitive testing or MMSEwere performed at least 3 months after shunt insertion. Significant improvement in a neurocognitive subtest was defined as improvement by one standard deviation (1 SD) for the patient's age, sex and education level. Significant improvement in overall neurocognitive outcome was defined as a 4-point improvement in MMSE or improvement by 1 SD in 50% of the administered neurocognitive subtests. Nonparametric tests were used to assess changes. Predictors of outcome were assessed via logistic regression analysis. Twenty-two patients (52.3%) showed overall neurocognitive improvement, and significant improvement was seen in tests of verbal memory and psychomotor speed. Predictive analysis showed that patients scoring more than 1 SD below mean at baseline on verbal memory immediate recall were fourfold less likely to show overall cognitive improvement, and sixfold less likely if also associated with visuoconstructional deficit or executive dysfunction. Verbal memory scores at baseline were higher in patients who showed overall cognitive improvement. Shunting INPH patients on the basis of CSF pressure monitoring and drainage response shows a significant rate of cognitive improvement, and baseline neurocognitive test scores may distinguish patients likely to respond to shunt surgery from those who will not. Copyright (c) 2005 S. Karger AG, Basel.

Pulse amplitude of intracranial pressure waveform in hydrocephalus.

PubMed

Czosnyka, Z; Keong, N; Kim, D J; Radolovich, D; Smielewski, P; Lavinio, A; Schmidt, E A; Momjian, S; Owler, B; Pickard, J D; Czosnyka, M

2008-01-01

There is increasing interest in evaluation of the pulse amplitude of intracranial pressure (AMP) in explaining dynamic aspects of hydrocephalus. We reviewed a large number of ICP recordings in a group of hydrocephalic patients to assess utility of AMP. From a database including approximately 2,100 cases of infusion studies (either lumbar or intraventricular) and overnight ICP monitoring in patients suffering from hydrocephalus of various types (both communicating and non-communicating), etiology and stage of management (non-shunted or shunted) pressure recordings were evaluated. For subgroup analysis we selected 60 patients with idiopathic NPH with full follow-up after shunting. In 29 patients we compared pulse amplitude during an infusion study performed before and after shunting with a properly functioning shunt. Amplitude was calculated from ICP waveforms using spectral analysis methodology. A large amplitude was associated with good outcome after shunting (positive predictive value of clinical improvement for AMP above 2.5 mmHg was 95%). However, low amplitude did not predict poor outcome (for AMP below 2.5 mmHg 52% of patients improved). Correlations of AMP with ICP and Rcsf were positive and statistically significant (N = 131 with idiopathic NPH; R = 0.21 for correlation with mean ICP and 0.22 with Rcsf; p< 0.01). Correlation with the brain elastance coefficient (or PVI) was not significant. There was also no significant correlation between pulse amplitude and width of the ventricles. The pulse amplitude decreased (p < 0.005) after shunting. Interpretation of the ICP pulse waveform may be clinically useful in patients suffering from hydrocephalus. Elevated amplitude seems to be a positive predictor for clinical improvement after shunting. A properly functioning shunt reduces the pulse amplitude.

Hearing aid malfunction detection system

NASA Technical Reports Server (NTRS)

Kessinger, R. L. (Inventor)

1977-01-01

A malfunction detection system for detecting malfunctions in electrical signal processing circuits is disclosed. Malfunctions of a hearing aid in the form of frequency distortion and/or inadequate amplification by the hearing aid amplifier, as well as weakening of the hearing aid power supply are detectable. A test signal is generated and a timed switching circuit periodically applies the test signal to the input of the hearing aid amplifier in place of the input signal from the microphone. The resulting amplifier output is compared with the input test signal used as a reference signal. The hearing aid battery voltage is also periodically compared to a reference voltage. Deviations from the references beyond preset limits cause a warning system to operate.

Vibration attenuations induced by periodic arrays of piezoelectric patches connected by enhanced resonant shunting circuits

NASA Astrophysics Data System (ADS)

Wang, Gang; Wang, Jianwei; Chen, Shengbing; Wen, Jihong

2011-12-01

Periodic arrays of piezoelectric patches connected by enhanced resonant shunting circuits are attached to a slender beam to control the propagation of vibration. Numerical models based on the transfer matrix methodology are constructed to predict the band structure, attenuation factors and the transmission of vibration in the proposed smart structure. The vibration attenuations of the proposed smart structure and that with the passive resonant shunting circuits are compared in order to verify the efficiency of the enhanced resonant shunting circuits. Vibration experiments are conducted in order to validate the theoretical predictions. The specimen with a combination of different types of resonant shunting circuits is also studied in order to gain wider attenuation frequency ranges.

The internal mammary artery as a shunt in a noncyanotic infant with hemitruncus: surgical and anesthetic management.

PubMed

Mahan, Vicki L; Stevens, Randy M; Mesia, Cesar I; Schwartz, Roy E; Moulick, Achintya N

2016-08-01

The internal mammary artery (IMA) has been used as a systemic-to-pulmonary artery shunt in selected patients with congenital heart disease. Growth and development of hypoplastic pulmonary arteries have been described. We discuss the surgical and anesthetic management of an infant with an atretic-thrombosed right pulmonary artery originating from the ascending aorta in whom the IMA was used to create a systemic-to-pulmonary artery shunt after failure of a previous shunt and later successful pulmonary artery reconstruction. The IMA should be considered as an alternative conduit in patients requiring a systemic-to-pulmonary artery shunt for growth of pulmonary arteries. Copyright © 2016 Elsevier Inc. All rights reserved.

Congenital extrahepatic portosystemic shunt (Abernethy malformation) treated endovascularly with vascular plug shunt closure.

PubMed

Passalacqua, Matthew; Lie, Kevin T; Yarmohammadi, Hooman

2012-01-01

A 3-year-old boy, who presented with progressive cyanosis and hypoxia, was diagnosed with a large congenital extrahepatic portosystemic shunt, interrupted IVC with azygos continuation, and multiple congenital anomalies. Traditionally open and laparoscopic surgical techniques have been used to treat this malformation. Endovascular repair using a 16-mm Amplatzer vascular plug (AGA Medical Corporation, Golden Valley, Minnesota, USA) was used to occlude the shunt. Immediate post-placement venography demonstrated cessation of flow within the shunt and increased portal venous flow. The patient's hypoxia and cyanosis decreased significantly, and he was discharged on the 5th post-procedure day in stable clinical condition. Three months follow-up evaluation demonstrated the vascular plug in place, unchanged in position.

Congenital Intrahepatic Portosystemic Venous Shunt and Liver Mass in a Child Patient: Successful Endovascular Treatment with an Amplatzer Vascular Plug (AVP)

PubMed Central

Lee, Sae Ah; Lee, Young Seok; Lee, Kun Song

2010-01-01

A congenital intrahepatic portosystemic shunt is a rare anomaly; but, the number of diagnosed cases has increased with advanced imaging tools. Symptomatic portosystemic shunts, especially those that include hyperammonemia, should be treated; and various endovascular treatment methods other than surgery have been reported. Hepatic masses with either an intra- or extrahepatic shunt also have been reported, and the mass is another reason for treatment. Authors report a case of a congenital intrahepatic portosystemic shunt with a hepatic mass that was successfully treated using a percutaneous endovascular approach with vascular plugs. By the time the first short-term follow-up was conducted, the hepatic mass had disappeared. PMID:20808706

Two cases of esophageal cancer with portal hypertension: esophagectomy with venous shunt procedure.

PubMed

Kato, T; Motohara, T; Kaneko, Y; Shikishima, H; Okushiba, S; Kondo, S; Kato, H

2001-01-01

We performed venous shunt procedure in the reconstruction of the esophagus after esophagectomy using the gastric tube in two cases of esophageal cancer with portal hypertension due to liver cirrhosis. In both cases, the short-term postoperative course was uneventful, without congestion in the gastric tube. In Case 1 where the short gastric vein had been used as the shunt vein, the long-term postoperative course was also uneventful, without hepatic encephalopathy or hemorrhage from deterioration of the varices of the gastric tube. However, in Case 2 where the left gastroepiploic vein had been used, hepatic encephalopathy developed due to excessive shunt flow. These results suggested that appropriate shunt flow could be expected by using short gastric vein.