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Sample records for abdominal wall thickness

  1. Fluid-structure interaction in abdominal aortic aneurysms: effects of asymmetry and wall thickness

    PubMed Central

    Scotti, Christine M; Shkolnik, Alexander D; Muluk, Satish C; Finol, Ender A

    2005-01-01

    Background Abdominal aortic aneurysm (AAA) is a prevalent disease which is of significant concern because of the morbidity associated with the continuing expansion of the abdominal aorta and its ultimate rupture. The transient interaction between blood flow and the wall contributes to wall stress which, if it exceeds the failure strength of the dilated arterial wall, will lead to aneurysm rupture. Utilizing a computational approach, the biomechanical environment of virtual AAAs can be evaluated to study the affects of asymmetry and wall thickness on this stress, two parameters that contribute to increased risk of aneurysm rupture. Methods Ten virtual aneurysm models were created with five different asymmetry parameters ranging from β = 0.2 to 1.0 and either a uniform or variable wall thickness to study the flow and wall dynamics by means of fully coupled fluid-structure interaction (FSI) analyses. The AAA wall was designed to have a (i) uniform 1.5 mm thickness or (ii) variable thickness ranging from 0.5 – 1.5 mm extruded normally from the boundary surface of the lumen. These models were meshed with linear hexahedral elements, imported into a commercial finite element code and analyzed under transient flow conditions. The method proposed was then compared with traditional computational solid stress techniques on the basis of peak wall stress predictions and cost of computational effort. Results The results provide quantitative predictions of flow patterns and wall mechanics as well as the effects of aneurysm asymmetry and wall thickness heterogeneity on the estimation of peak wall stress. These parameters affect the magnitude and distribution of Von Mises stresses; varying wall thickness increases the maximum Von Mises stress by 4 times its uniform thickness counterpart. A pre-peak systole retrograde flow was observed in the AAA sac for all models, which is due to the elastic energy stored in the compliant arterial wall and the expansion force of the artery

  2. Semiautomatic vessel wall detection and quantification of wall thickness in computed tomography images of human abdominal aortic aneurysms

    SciTech Connect

    Shum, Judy; DiMartino, Elena S.; Goldhammer, Adam; Goldman, Daniel H.; Acker, Leah C.; Patel, Gopal; Ng, Julie H.; Martufi, Giampaolo; Finol, Ender A.

    2010-02-15

    Purpose: Quantitative measurements of wall thickness in human abdominal aortic aneurysms (AAAs) may lead to more accurate methods for the evaluation of their biomechanical environment. Methods: The authors describe an algorithm for estimating wall thickness in AAAs based on intensity histograms and neural networks involving segmentation of contrast enhanced abdominal computed tomography images. The algorithm was applied to ten ruptured and ten unruptured AAA image data sets. Two vascular surgeons manually segmented the lumen, inner wall, and outer wall of each data set and a reference standard was defined as the average of their segmentations. Reproducibility was determined by comparing the reference standard to lumen contours generated automatically by the algorithm and a commercially available software package. Repeatability was assessed by comparing the lumen, outer wall, and inner wall contours, as well as wall thickness, made by the two surgeons using the algorithm. Results: There was high correspondence between automatic and manual measurements for the lumen area (r=0.978 and r=0.996 for ruptured and unruptured aneurysms, respectively) and between vascular surgeons (r=0.987 and r=0.992 for ruptured and unruptured aneurysms, respectively). The authors' automatic algorithm showed better results when compared to the reference with an average lumen error of 3.69%, which is less than half the error between the commercially available application Simpleware and the reference (7.53%). Wall thickness measurements also showed good agreement between vascular surgeons with average coefficients of variation of 10.59% (ruptured aneurysms) and 13.02% (unruptured aneurysms). Ruptured aneurysms exhibit significantly thicker walls (1.78{+-}0.39 mm) than unruptured ones (1.48{+-}0.22 mm), p=0.044. Conclusions: While further refinement is needed to fully automate the outer wall segmentation algorithm, these preliminary results demonstrate the method's adequate reproducibility

  3. Patient-specific modelling of abdominal aortic aneurysms: The influence of wall thickness on predicted clinical outcomes.

    PubMed

    Conlisk, Noel; Geers, Arjan J; McBride, Olivia M B; Newby, David E; Hoskins, Peter R

    2016-06-01

    Rupture of abdominal aortic aneurysms (AAAs) is linked to aneurysm morphology. This study investigates the influence of patient-specific (PS) AAA wall thickness on predicted clinical outcomes. Eight patients under surveillance for AAAs were selected from the MA(3)RS clinical trial based on the complete absence of intraluminal thrombus. Two finite element (FE) models per patient were constructed; the first incorporated variable wall thickness from CT (PS_wall), and the second employed a 1.9mm uniform wall (Uni_wall). Mean PS wall thickness across all patients was 1.77±0.42mm. Peak wall stress (PWS) for PS_wall and Uni_wall models was 0.6761±0.3406N/mm(2) and 0.4905±0.0850N/mm(2), respectively. In 4 out of 8 patients the Uni_wall underestimated stress by as much as 55%; in the remaining cases it overestimated stress by up to 40%. Rupture risk more than doubled in 3 out of 8 patients when PS_wall was considered. Wall thickness influenced the location and magnitude of PWS as well as its correlation with curvature. Furthermore, the volume of the AAA under elevated stress increased significantly in AAAs with higher rupture risk indices. This highlights the sensitivity of standard rupture risk markers to the specific wall thickness strategy employed. PMID:27056256

  4. Metachronous carcinoma of rectum with reconstruction of a full-thickness abdominal wall defect using a pedicled anterolateral thigh flap

    PubMed Central

    Kok, Amy Siu Yan

    2016-01-01

    Reconstruction of large, complex defects of the abdominal wall after resection of malignant tumors can be challenging. The transfer of an anterolateral thigh (ALT) flap is a feasible and effective option. However, no report has been published on the use of ALT flap after metachronous colonic tumor resection so far. We present an original case of resection of metachronous carcinoma of rectum with reconstruction of the abdominal wall defect using an ALT flap harvested with its aponeurosis. The postoperative course was uncomplicated. Functional and esthetic results were satisfactory. There was no postoperative incisional hernia or tumor recurrence. We conclude that abdominal wall defects of large sizes can be successfully reconstructed using an appropriately designed ALT flap; a simple, single-stage effective reconstruction. PMID:27161142

  5. The in vivo evaluation of tissue-based biomaterials in a rat full-thickness abdominal wall defect model.

    PubMed

    Bryan, Nicholas; Ahswin, Helen; Smart, Neil; Bayon, Yves; Wohlert, Stephen; Hunt, John A

    2014-05-01

    Hernias are defects in which an anatomical fascia is breached resulting in ectopic positioning of an organ into an orifice which routinely does not contain it. Intervention often involves repositioning translocated organs and repair of damaged fascia using exogenous grafts. Despite hernia prevalence, repairs can still fail due to postoperative complications, such as chronic pain and decreased mobility. This study compared repair capacities and characterized the foreign body response elicited by a number of hernia repair grafts to deduce their bulk inflammatory properties while also concluding the point in their fabrication when these are inferred. Materials derived from human dermis (Alloderm(®) ), porcine dermis (Permacol™, patch A, patch D and Strattice(®) ), porcine small-intestinal submucosa (Surgisis™) and a synthetic (multifilament Surgipro™) were implanted into a rat full-thickness abdominal wall excision model, incubated for up to 2 years and characterized histopathologically. Surgisis™ resorbed the fastest of the materials tested (1-3 months) resulting in a mechanically stable parietal peritoneum. Decellularization using sodium dodecyl sulfate (patch A) stimulated a large early inflammatory response which ultimately may have contributed to increased resorption of porcine dermal matrix however the remaining materials typically persisted throughout the 2-year incubation. Cross-linking porcine dermis using 1,6-hexamethylene disocyanate (vs. an identical noncross-linked counterpart) showed no difference in cell recruitment or material integration over 2 years. Typically Strattice(®) and Alloderm(®) recruited larger early populations of cells than Permacol™; however, over extended periods of time in vivo this response normalized. PMID:24155173

  6. Successful treatment of burn and visceral injury combined with full-thickness loss of the abdominal wall after blast injury.

    PubMed

    Başaran, Ozgür; Karaarslan, Pelin; Sakalloğlu, A Ebru; Kesik, Emine; Karakayalý, Hamdi; Haberal, Mehmet

    2006-01-01

    A 29-year-old man was admitted to our institution 10 days after he had undergone an urgent exploratory laparotomy at a local army hospital after a terrorist bombing attack. On admission, deep second-degree and third-degree burns involving 25% of the upper and lower extremities were present, together with a 25 x 10-cm abdominal full-thickness blast injury defect on the left side, an infected eviscerated midline incision, and a colostomy on the right side of the abdomen. The patient underwent a second laparotomy, at which time the intraabdominal abscess was drained, and the abdominal cavity was irrigated with saline. A jejunal perforation was found and sutured. The abdominal cavity was left open and covered with a Bogota bag for temporary closure. On postburn day 18, the patient underwent débridment and grafting of the third-degree burns to the left and right arm and right lower extremities. After several débridment sessions (postburn days 16, 18, 20, 22, and 24), an abdominal skin release and reapproximation were performed (postburn day 26). On postburn day 36, split-thickness skin grafts were placed directly on the granulated tissue of the intestines and on a defect in the left flank and iliac regions. Postoperatively, the patient did well. He was discharged on postburn day 78 with all wounds well healed. In our opinion, temporary closure followed by direct application of meshed split-thickness skin grafts to exposed abdominal viscera represents a simple method of reconstruction that can be safely performed, with minimal risk, on critically ill patients. PMID:16998411

  7. Economics of abdominal wall reconstruction.

    PubMed

    Bower, Curtis; Roth, J Scott

    2013-10-01

    The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias. PMID:24035086

  8. Behaviour of a New Composite Mesh for the Repair of Full-Thickness Abdominal Wall Defects in a Rabbit Model

    PubMed Central

    Pascual, Gemma; Sotomayor, Sandra; Rodríguez, Marta; Bayon, Yves; Bellón, Juan M.

    2013-01-01

    Introduction Composite biomaterials designed for the repair of abdominal wall defects are composed of a mesh component and a laminar barrier in contact with the visceral peritoneum. This study assesses the behaviour of a new composite mesh by comparing it with two latest-generation composites currently used in clinical practice. Methods Defects (7x5cm) created in the anterior abdominal wall of New Zealand White rabbits were repaired using a polypropylene mesh and the composites: PhysiomeshTM; VentralightTM and a new composite mesh with a three-dimensional macroporous polyester structure and an oxidized collagen/chitosan barrier. Animals were sacrificed on days 14 and 90 postimplant. Specimens were processed to determine host tissue incorporation, gene/protein expression of neo-collagens (RT-PCR/immunofluorescence), macrophage response (RAM-11-immunolabelling) and biomechanical resistance. On postoperative days 7/14, each animal was examined laparoscopically to quantify adhesions between the visceral peritoneum and implant. Results The new composite mesh showed the lowest incidence of seroma in the short term. At each time point, the mesh surface covered with adhesions was greater in controls than composites. By day 14, the implants were fully infiltrated by a loose connective tissue that became denser over time. At 90 days, the peritoneal mesh surface was lined with a stable mesothelium. The new composite mesh induced more rapid tissue maturation than PhysiomeshTM, giving rise to a neoformed tissue containing more type I collagen. In VentralightTM the macrophage reaction was intense and significantly greater than the other composites at both follow-up times. Tensile strengths were similar for each biomaterial. Conclusions All composites showed optimal peritoneal behaviour, inducing good peritoneal regeneration and scarce postoperative adhesion formation. A greater foreign body reaction was observed for VentralightTM. All composites induced good collagen deposition

  9. A New Rat Model for Orthotopic Abdominal Wall Allotransplantation

    PubMed Central

    Lao, William W.; Wang, Yen-Ling; Ramirez, Alejandro E.; Cheng, Hui-Yun

    2014-01-01

    Background: Abdominal wall, one of the most commonly transplanted composite tissues, is less researched and lacking animal models. Its clinical necessities were emphasized in multiple case series to reconstruct large abdominal defects. Previous animal models have only studied components of the abdominal wall transplant. We describe findings from a new model that more likely reflect clinical transplantation. Methods: Full-thickness hemiabdominal wall flap was procured from Brown Norway (BN) rats and transplanted to an orthotopic defect on Lewis rats. Three groups were studied: group 1: Lewis to Lewis syngeneic; group 2: BN to Lewis control; and group 3: BN to Lewis with postoperative cyclosporine. Vascular imaging and cross vessel section were performed along with full-thickness abdominal wall. Immune cell profiling with flow cytometry at different time points was studied in all groups. Results: Syngeneic group had no rejection. Control group consistently showed rejection around postoperative day 6. With cyclosporine treatment, however, transplant and recipient tissue integration was observed. Flow cytometry revealed that innate immunity is responsible for the initial inflammatory events following abdominal wall engraftment. Adaptive immunity cells, specifically interferon-γ-producing T helper (Th) 1 and interleukin-17-producing Th17 cells, dramatically and positively correlate with rejection progression of abdominal wall transplants. Conclusions: Technical, histological, and immunological aspects of a new rat model are described. These results give clues to what occurs in human abdominal wall transplantation. In addition, Th1, a proinflammatory cell, was found to be a potential biomarker for allograft rejection. PMID:25289329

  10. [A case of abdominal wall actinomycosis].

    PubMed

    Kim, Kyung Hoon; Lee, Jin Soo; Cho, Hyeong Jun; Choi, Seung Bong; Cheung, Dae Young; Kim, Jin Il; Lee, In Kyu

    2015-04-01

    Actinomycosis is a chronic suppurative granulomatous infectious disease caused by actinomyces species that is characterized by formation of characteristic clumps called as sulfur granules. Abdominal actinomycosis is a rare disease and is often difficult to diagnose before operation. Abdominal actinomycosis infiltrating into the abdominal wall and adhering to the colon is even rarer. Most abdominal actinomycosis develops after operation, trauma or inflammatory bowel disease, and is also considered as an opportunistic infection in immunocompromised patient with underlying malignancy, diabetes mellitus, human immunodeficiency virus infection, etc. Actinomycosis is diagnosed based on histologic demonstration of sulfur granules in surgically resected specimen or pus, and treatment consists of long-term penicillin based antibiotics therapy with or without surgical resection. Herein, we report an unusual case of abdominal wall actinomycosis which developed in a patient after acupuncture and presented as abdominal wall mass that was first mistaken for abdominal wall invasion of diverticulum perforation. PMID:25896158

  11. Abdominal wall reconstruction with implantable meshes.

    PubMed

    Masden, Derek; Felder, John M; Iorio, Matthew L; Bhanot, Parag; Attinger, Christopher E

    2011-01-01

    Abdominal wall defects present a difficult problem for the reconstructive surgeon. Over the years, numerous implantable materials have becomes available to aid the surgeon in recreating the abdominal wall. This spectrum of implants includes permanent synthetic meshes, absorbable meshes, composite meshes and biomaterials. This review includes the pros and cons for the commercially available abdominal wall implants as well as a review of the literature regarding outcomes for each material. This review will provide the surgeon with current evidence-based information on implantable abdominal materials to be able to make a more informed decision about which implant to use. PMID:21663579

  12. Genetics Home Reference: abdominal wall defect

    MedlinePlus

    ... size and can usually be diagnosed early in fetal development, typically between the tenth and fourteenth weeks of ... organs at the abdominal wall opening late in fetal development may also contribute to organ injury. Intestinal damage ...

  13. Large Abdominal Wall Endometrioma Following Laparoscopic Hysterectomy

    PubMed Central

    Borncamp, Erik; Mehaffey, Philip; Rotman, Carlos

    2011-01-01

    Background: Endometriosis is a common condition in women that affects up to 45% of patients in the reproductive age group by causing pelvic pain. It is characterized by the presence of endometrial tissue outside the uterine cavity and is rarely found subcutaneously or in abdominal incisions, causing it to be overlooked in patients with abdominal pain. Methods: A 45-year-old woman presented with lower abdominal pain 2 years following a laparoscopic supracervical hysterectomy. She was found to have incidental cholelithiasis and a large abdominal mass suggestive of a significant ventral hernia on CT scan. Results: Due to the peculiar presentation, surgical intervention took place that revealed a large 9cm×7.6cm×6.2cm abdominal wall endometrioma. Conclusion: Although extrapelvic endometriosis is rare, it should be entertained in the differential diagnosis for the female patient who presents with an abdominal mass and pain and has a previous surgical history. PMID:21902990

  14. Bioprosthetic Mesh in Abdominal Wall Reconstruction

    PubMed Central

    Baumann, Donald P.; Butler, Charles E.

    2012-01-01

    Mesh materials have undergone a considerable evolution over the last several decades. There has been enhancement of biomechanical properties, improvement in manufacturing processes, and development of antiadhesive laminate synthetic meshes. The evolution of bioprosthetic mesh materials has markedly changed our indications and methods for complex abdominal wall reconstruction. The authors review the optimal properties of bioprosthetic mesh materials, their evolution over time, and their indications for use. The techniques to optimize outcomes are described using bioprosthetic mesh for complex abdominal wall reconstruction. Bioprosthetic mesh materials clearly have certain advantages over other implantable mesh materials in select indications. Appropriate patient selection and surgical technique are critical to the successful use of bioprosthetic materials for abdominal wall repair. PMID:23372454

  15. Flap Coverage of Anterior Abdominal Wall Defects

    PubMed Central

    Sacks, Justin M.; Broyles, Justin M.; Baumann, Donald P.

    2012-01-01

    Reconstruction of complex defects of the anterior abdomen is both challenging and technically demanding for reconstructive surgeons. Advancements in the use of pedicle and free tissue transfer along with the use of bioprosthetic and synthetic meshes have provided for novel approaches to these complex defects. Accordingly, detailed knowledge of abdominal wall and lower extremity anatomy in combination with insight into the design, implementation, and limitations of various flaps is essential to solve these complex clinical problems. Although these defects can be attributed to a myriad of etiologic factors, the objectives in abdominal wall reconstruction are consistent and include the restoration of abdominal wall integrity, protection of intraabdominal viscera, and the prevention of herniation. In this article, the authors review pertinent anatomy and the various local, regional, and distant flaps that can be utilized in the reconstruction of these complex clinical cases of the anterior abdomen. PMID:23372457

  16. Abdominal wall herniae and their underlying pathology

    PubMed Central

    Upchurch, Emma; Al-Akash, Musallam

    2016-01-01

    We describe a case of pseudomyxoma peritonei presenting as a strangulated inguinal hernia. We review the current literature regarding the incidence of underlying pathology in patients presenting with abdominal wall herniae and discuss the need for histological assessment of the hernia sac in selected patients. We highlight the importance of assessing for and being aware of significant underlying pathology in certain patients. PMID:26855074

  17. [Large abdominal wall reconstruction by free flap after recurrence of a dermatofibrosarcoma protuberans].

    PubMed

    Le Fourn, B; Lejeune, F; Sartre, J Y; Loirat, Y; Pannier, M

    1996-12-01

    Based on a case of recurrence of a dermatofibrosarcoma protuberans of the abdominal wall, the authors discuss the need for initial wide resection of this type of skin tumour and the possibilities of repair of extensive full thickness defects of the abdominal wall by means of a latissimus dorsi myocutaneous free flap. PMID:9768175

  18. Tube wall thickness measurement apparatus

    DOEpatents

    Lagasse, Paul R.

    1987-01-01

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  19. Tube wall thickness measurement apparatus

    DOEpatents

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  20. Laparoscopic excision of abdominal wall desmoid tumor.

    PubMed

    Meshikhes, Abdul-Wahed; Al-Zahrani, Hana; Ewies, Tarek

    2016-02-01

    Open surgical resection is the mainstay treatment for desmoid tumors. Laparoscopic resection is rarely used and not well described in the literature. We report a case of a single, 35-year-old woman who presented with palpable abdominal wall desmoid tumor. The patient had had laparoscopic cholecystectomy 2 years earlier, and the tumor was at the insertion site of the right upper quadrant trocar. The diagnosis was made by a Tru-Cut biopsy at another institution, after the lesion had increased in size and caused increased discomfort. The patient underwent successful laparoscopic resection of the tumor. This report aimed to promote laparoscopic resection of abdominal wall desmoid tumors, whenever feasible, and describe the laparoscopic technique. We believe this is the second case of laparoscopic excision of desmoid tumor reported in the English-language literature. PMID:26781534

  1. ADULT ABDOMINAL WALL HERNIA IN IBADAN

    PubMed Central

    Ayandipo, O.O; Afuwape, O.O; Irabor, D.O; Abdurrazzaaq, A.I.

    2015-01-01

    Background: Abdominal wall hernias are very common diseases encountered in surgical practice. Groin hernia is the commonest type of abdominal wall hernias. There are several methods of hernia repair but tension-free repair (usually with mesh) offers the least recurrent rate. Aim: To describe the clinical profile of anterior abdominal wall hernias and our experience in the surgical management of identified hernias Method: The project was a retrospective study of all patients with abdominal wall hernia presenting into surgical divisions of University College Hospital Ibadan during a 6 year period (January 2008 to December 2013). Relevant information was retrieved from their case notes and analysed. Results: The case records of 1215 (84.7%) patients out of 1435 were retrieved. Elective surgery was done in 981(80.7%) patients while 234 (19.3%) patients had emergency surgery. There were 922 (84.8%) groin hernias and post-operative incisional hernia accounted for 9.1% (111) of the patients. About half (49.1%) of those with incisional hernia were post obstetric and gynaecologic procedure followed by post laparotomy incisional hernias 16 (14%) and others (23.5%). The ratio of inguinal hernia to other types in this study is 3:1. Hollow viscus resection and emergency surgery were predictors of wound infection statistically significant in predicting wound infection (P < 0.001). Peri-operative morbidity/mortality at 28 days post operation was documented in 113 patients (12.1%). One year recurrence rate of groin hernia was 2.1%. Conclusion: The pattern of presentation and management of anterior wall hernias are still the same compared with the earlier study in this hospital. New modality of treatment should be adopted as the standard choice of care. Abdominal wall hernias are very common clinical presentation. Modified Bassini repair was the preferred method of repair due to its simplicity. Mesh repair is becoming more common in recent time but high cost and initial non

  2. Splenic trauma during abdominal wall liposuction: a case report

    PubMed Central

    Harnett, Paul; Koak, Yashwant; Baker, Daryl

    2008-01-01

    Summary A 35-year-old woman collapsed 18 hours after undergoing abdominal wall liposuction. Abdominal CT scan revealed a punctured spleen. She underwent an emergency splenectomy and made an uneventful recovery. PMID:18387911

  3. Turbine airfoil with outer wall thickness indicators

    DOEpatents

    Marra, John J; James, Allister W; Merrill, Gary B

    2013-08-06

    A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

  4. [Endometriosis in the abdominal wall (author's transl)].

    PubMed

    Caligaris, P; Masselot, R; Ducassou, M J; Le Treut, Y; Bricot, R

    1981-01-01

    The authors give 9 case histories of endometriosis localised to the abdominal wall : 3 of them in the umbilicus, 3 in laparotomy incisions (2 of those were Caesareans), 2 of them in the round ligaments at the external opening of the inguinal canal and 1 of them in the right rectus muscle sheath in the abdomen. The functional symptomatology is rhythmical according to menstruation; it is associated with a burning type of pain, a tumour and blood loss. Over and above the theories of aetiology that are now classical, namely tubal retrograde spill, and lymphatic or venous spread, it would seem that prostaglandins and in particular the ratio of P.G.E. divided by P.D.F2 alpha can play a big role. Although Danazol is an effective treatment for endometriosis, the treatment of choice is, in these lesions that are superficial in localisation and easily accessible, to cut them out surgically. This makes it possible on the one hand to look for other intra-abdominal lesions and also on the other hand to confirm the anatomy and pathology (this was done in 7 out of 9 of our cases). PMID:6459361

  5. Radiofrequency ablation of abdominal wall endometrioma.

    PubMed

    Carrafiello, Gianpaolo; Fontana, Federico; Pellegrino, Carlo; Mangini, Monica; Cabrini, Luca; Mariani, Davide; Piacentino, Filippo; Cuffari, Salvatore; Laganà, Domenico; Fugazzola, Carlo

    2009-11-01

    Extraperitoneal endometriosis is the presence of ectopic, functional endometrium outside the peritoneal cavity, and its occurrence is exceedingly rare. Diagnostic imaging--including ultrasound, duplex ultrasonography, and magnetic resonance imaging--in the preoperative assessment of patients with suspected abdominal wall endometriosis (AWE) is helpful for detection and accurate determination of the extent of disease. The treatment of choice for AWE is surgical excision. In addition, medical therapies can be used. We present one case of AWE treated with percutaneous radiofrequency ablation under ultrasound guidance. There were no major complications, and the patient's symptoms improved. In selected patients, radiofrequency ablation can be used safely for the treatment of AWE; however, further studies are needed to confirm this hypothesis. PMID:19184197

  6. [Laparoscopic repair of abdominal wall hernias].

    PubMed

    Bezsilla, János

    2010-10-01

    Repair of abdominal wall defects is a challenge for all general surgeons and a variety of methods have been described in the past. Traditionally, primary suture repair was shown to have a high recurrence rate in long-term follow-up studies. Herniorrhaphies that apply a large prosthetic mesh are appear to have a lower failure rate, but extensive dissection of soft tissue contributes to an increased incidence of wound infections and wound-related complications. The method of laparoscopic incisional hernia repair was developed in the early 1990s. This technique is based on the same physical and surgical principles as the open underlay procedure. The laparoscopic intraperitoneal onlay mesh (IPOM) technique and mesh materials were developed further in subsequent years, and there have been numerous reports on successful use of the IPOM technique even for extremely large hernia openings in obese and elderly patients. Reduced surgical trauma and lower infection and recurrence rates are key advantages of the minimally invasive repair. Therefore, this operation has increased in popularity promising shorter hospital stay, improved outcome, and fewer complications than traditional open procedures. PMID:20965866

  7. Practical Approaches to Definitive Reconstruction of Complex Abdominal Wall Defects.

    PubMed

    Latifi, Rifat

    2016-04-01

    With advances in abdominal surgery and the management of major trauma, complex abdominal wall defects have become the new surgical disease, and the need for abdominal wall reconstruction has increased dramatically. Subsequently, how to reconstruct these large defects has become a new surgical question. While most surgeons use native abdominal wall whenever possible, evidence suggests that synthetic or biologic mesh needs to be added to large ventral hernia repairs. One particular group of patients who exemplify "complex" are those with contaminated wounds, enterocutaneous fistulas, enteroatmospheric fistulas, and/or stoma(s), where synthetic mesh is to be avoided if at all possible. Most recently, biologic mesh has become the new standard in high-risk patients with contaminated and dirty-infected wounds. While biologic mesh is the most common tissue engineered used in this field of surgery, level I evidence is needed on its indication and long-term outcomes. Various techniques for reconstructing the abdominal wall have been described, however the long-term outcomes for most of these studies, are rarely reported. In this article, I outline current practical approaches to perioperative management and definitive abdominal reconstruction in patients with complex abdominal wall defects, with or without fistulas, as well as those who have lost abdominal domain. PMID:26585951

  8. Case report: Leiomyoma of the anterior abdominal wall.

    PubMed

    Ernest Ong, C W; Siow, S L

    2016-04-01

    Leiomyomas are benign soft tissue swellings of smooth muscle origin, most commonly found in the uterus. Extra uterine leiomyomas presenting as an abdominal mass is often a diagnostic challenge as such occurrence is rare. We present a rare case of primary abdominal wall leiomyoma, and highlight the importance of laparoscopic approach in the diagnosis and treatment of such tumour. PMID:27326950

  9. Prosthetics and Techniques in Repair of Animal's Abdominal Wall.

    PubMed

    Karrouf, Gamal; Zaghloul, Adel; Abou-Alsaud, Mohamed; Barbour, Elie; Abouelnasr, Khaled

    2016-01-01

    The management of abdominal wall repair continues to present a challenging problem, especially in the repair of major defects. Many abdominal wall defects can be repaired by primary closure; however, if the defect is large and there is a tension on the closure of the wound, the use of prosthetic materials becomes indispensable. Many studies have been performed with various materials and implant techniques, without the comparison of their degrees of success, based on sound meta-analysis and/or inclusive epidemiologic studies. This review covered the effectiveness of recent advances in prosthetic materials and implant procedures used in repair of abdominal wall, based on biomechanical properties and economic aspects of reconstructed large abdominal wall defects and hernias in animals. The presented results in this review helped to reach treatment algorithms that could maximize outcomes and minimize morbidity. PMID:27293982

  10. Prosthetics and Techniques in Repair of Animal's Abdominal Wall

    PubMed Central

    Karrouf, Gamal; Zaghloul, Adel; Abou-Alsaud, Mohamed; Barbour, Elie; Abouelnasr, Khaled

    2016-01-01

    The management of abdominal wall repair continues to present a challenging problem, especially in the repair of major defects. Many abdominal wall defects can be repaired by primary closure; however, if the defect is large and there is a tension on the closure of the wound, the use of prosthetic materials becomes indispensable. Many studies have been performed with various materials and implant techniques, without the comparison of their degrees of success, based on sound meta-analysis and/or inclusive epidemiologic studies. This review covered the effectiveness of recent advances in prosthetic materials and implant procedures used in repair of abdominal wall, based on biomechanical properties and economic aspects of reconstructed large abdominal wall defects and hernias in animals. The presented results in this review helped to reach treatment algorithms that could maximize outcomes and minimize morbidity. PMID:27293982

  11. Abdominal Wall Endometrioma after Laparoscopic Operation of Uterine Endometriosis.

    PubMed

    Vukšić, Tihomir; Rastović, Pejana; Dragišić, Vedran

    2016-01-01

    Endometriosis is presence of functional endometrium outside of uterine cavum. As a pluripotent tissue, endometrium has the possibility of implanting itself almost everywhere; even implantation in abdominal wall was described, but it is not common site. This case report presents implantation of functional endometrium in abdominal wall, inside scar tissue, and after insertion of a laparoscopic trocar port. Final diagnosis was confirmed by pathohistological examination. PMID:27340586

  12. Abdominal Wall Endometrioma after Laparoscopic Operation of Uterine Endometriosis

    PubMed Central

    Vukšić, Tihomir; Rastović, Pejana; Dragišić, Vedran

    2016-01-01

    Endometriosis is presence of functional endometrium outside of uterine cavum. As a pluripotent tissue, endometrium has the possibility of implanting itself almost everywhere; even implantation in abdominal wall was described, but it is not common site. This case report presents implantation of functional endometrium in abdominal wall, inside scar tissue, and after insertion of a laparoscopic trocar port. Final diagnosis was confirmed by pathohistological examination. PMID:27340586

  13. [Abdominal wall closure by incisional hernia and herniation after laparostoma].

    PubMed

    Mischinger, H-J; Kornprat, P; Werkgartner, G; El Shabrawi, A; Spendel, S

    2010-03-01

    As hernias and abdominal wall defects have a variety of etiologies each with its own complications and comorbidities in various constellations, efficient treatment requires patient-oriented management. There is no recommended standard treatment and the very different clinical pictures demand an individualized interdisciplinary approach. Particularly in the case of complicated hernias, the planning of the operation should focus on the problems posed by the individual patient. Treatment mainly depends on the etiology of the hernia, immediate or long-term complications and the efficiency of individual repair techniques. Abdominal wall repair for recurrent herniation requires direct closure of the fascia generally using the sublay technique with a lightweight mesh. It is still unclear whether persistent inflammation, mesh dislocation, fistula formation or other long-term complications are due to certain materials or to the surgical technique. With mesh infections it has been shown to be advantageous to remove a polytetrafluoroethylene (PTFE) mesh, while the combination of systemic and local treatment appears to suffice for a polypropylene or polyester mesh. Heavier meshes in the sublay position or plastic reconstruction with autologous tissue are indicated as substitutes for the abdominal wall for giant hernias, repeated recurrences and large abdominal wall defects. A laparostoma is increasingly more often created to treat septic intra-abdominal processes but is very often responsible for a complicated hernia. If primary repair of the abdominal wall is not an option, resorbable material or split skin is used for coverage under the auspices of a planned hernia repair. PMID:20145901

  14. A Traumatic Abdominal Wall Hernia Repair: A Laparoscopic Approach

    PubMed Central

    Wilson, Kenneth L.; Rosser, James C.

    2012-01-01

    Background: Traumatic abdominal wall hernias from blunt trauma usually occur as a consequence of motor vehicle collisions where the force is tangential, sudden, and severe. Although rare, these hernias can go undetected due to preservation of the skin overlying the hernia defect. Open repairs can be challenging and unsuccessful due to avulsion of muscle directly from the iliac crest, with or without bone loss. A laparoscopic approach to traumatic abdominal wall hernia can aid in the delineation of the hernia and allow for a safe and effective repair. Case Description: A 36-year-old female was admitted to our Level 1 trauma center with a traumatic abdominal wall hernia located in the right flank near the iliac crest after being involved in a high-impact motor vehicle collision. Computed tomography and magnetic resonance imaging of the abdomen revealed the presence of an abdominal wall defect that was unapparent on physical examination. The traumatic abdominal wall hernia in the right flank was successfully repaired laparoscopically. One-year follow-up has shown no sign of recurrence. Discussion: A traumatic abdominal wall hernia rarely presents following blunt trauma, but should be suspected following a high-impact motor vehicle collision. Frequently, repair is complicated by the need to have fixation of mesh to bony landmarks (eg, iliac crest). In spite of this challenge, the laparoscopic approach with tension-free mesh repair of a traumatic abdominal wall hernia can be accomplished successfully using an approach similar to that taken for laparoscopic inguinal hernia repair. PMID:23477181

  15. Early metastasis to anterior abdominal wall following radical cystectomy: A rare presentation

    PubMed Central

    Sawant, Ajit; Bansal, Sumit; Pawar, Prakash; Kasat, Gaurav

    2016-01-01

    Abdominal wall metastasis from urothelial cancer is extremely rare and very few such cases have been reported in the literature. As such the treatment protocols are not so well defined. We present an interesting case of a 65-year-old male patient, known case of chronic kidney disease, who presented with a large, fungating infraumbilical mass 8 months postradical cystectomy. The mass involved full thickness anterior abdominal wall and small bowel including the ileal conduit. Wide excision of the mass along with adhered bowel loops and partial excision of the ileal conduit with right ureteric reimplant was performed. The large defect in the anterior abdominal wall was closed using a mesh (permanent with a bioresorbable coating inside) and myocutaneous thigh flap. The histopathological examination of the excised mass was consistent with secondary from the urothelial tumor. PMID:27453672

  16. Living donor liver transplantation with abdominal wall reconstruction for hepatocellular carcinoma with needle track seeding

    PubMed Central

    Yang, Horng-Ren; Thorat, Ashok; Gesakis, Kanellos; Li, Ping-Chun; Kiranantawat, Kidakorn; Chen, Hung Chi; Jeng, Long-Bin

    2015-01-01

    Malignant cell seeding in subcutaneous tissues along the needle track and/or percutaneous biliary drainage catheters is rare complication, but pose various technical issues in planning surgical treatment of such patients. If underlying primary hepatic malignancy can be treated, an aggressive resection of subcutaneous tissue bearing cancer cell with subsequent abdominal wall reconstruction has been sporadically reported. But, when hepatic resection is not possible due to underlying advanced cirrhosis, liver transplantation along with abdominal wall resection and subsequent reconstruction remains only feasible option. Herein, we describe our successful experience of living donor liver transplantation for hepatocellular carcinoma with full-thickness abdominal wall resection bearing the tumor seeding followed by reconstruction in single stage surgery. PMID:26722665

  17. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, L.J.; Bergren, D.A.

    1987-10-06

    An apparatus for measuring the wall thickness of a nonmagnetic article having a housing supporting a magnet and a contiguous supporting surface. The tubular article and the housing are releasably secured to the supporting surface and a support member of an optical comparator, respectively. To determine the wall thickness of the article at a selected point, a magnetically responsive ball is positioned within the tubular article over said point and retained therein by means of a magnetic field produced by the magnet. Thereafter, an optical comparator is employed to project a magnified image of the ball on a screen and the wall thickness at the selected point is calculated by using a ball surface measurement taken with the comparator in conjunction with a previously determined base line measurement.

  18. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, Leander J.; Bergren, Donald A.

    1989-01-01

    An apparatus for measuring the wall thickness of a nonmagnetic article having a housing supporting a magnet and a contiguous supporting surface. The tubular article and the housing are releasably secured to the supporting surface and a support member of an optical comparator, respectively. To determine the wall thickness of the article at a selected point, a magnetically responsive ball is positioned within the tubular article over said point and retained therein by means of a magnetic field produced by the magnet. Thereafter, an optical comparator is employed to project a magnified image of the ball on a screen and the wall thickness at the selected point is calculated by using a ball surface measurement taken with the comparator in conjunction with a previously determined base line measurement.

  19. Personalized identification of abdominal wall hernia meshes on computed tomography.

    PubMed

    Pham, Tuan D; Le, Dinh T P; Xu, Jinwei; Nguyen, Duc T; Martindale, Robert G; Deveney, Clifford W

    2014-01-01

    An abdominal wall hernia is a protrusion of the intestine through an opening or area of weakness in the abdominal wall. Correct pre-operative identification of abdominal wall hernia meshes could help surgeons adjust the surgical plan to meet the expected difficulty and morbidity of operating through or removing the previous mesh. First, we present herein for the first time the application of image analysis for automated identification of hernia meshes. Second, we discuss the novel development of a new entropy-based image texture feature using geostatistics and indicator kriging. Third, we seek to enhance the hernia mesh identification by combining the new texture feature with the gray-level co-occurrence matrix feature of the image. The two features can characterize complementary information of anatomic details of the abdominal hernia wall and its mesh on computed tomography. Experimental results have demonstrated the effectiveness of the proposed study. The new computational tool has potential for personalized mesh identification which can assist surgeons in the diagnosis and repair of complex abdominal wall hernias. PMID:24184112

  20. WSES guidelines for emergency repair of complicated abdominal wall hernias

    PubMed Central

    2013-01-01

    Emergency repair of complicated abdominal hernias is associated with poor prognosis and a high rate of post-operative complications. A World Society of Emergency Surgery (WSES) Consensus Conference was held in Bergamo in July 2013, during the 2nd Congress of the World Society of Emergency Surgery with the goal of defining recommendations for emergency repair of abdominal wall hernias in adults. This document represents the executive summary of the consensus conference approved by a WSES expert panel. PMID:24289453

  1. Improving the Efficiency of Abdominal Aortic Aneurysm Wall Stress Computations

    PubMed Central

    Zelaya, Jaime E.; Goenezen, Sevan; Dargon, Phong T.; Azarbal, Amir-Farzin; Rugonyi, Sandra

    2014-01-01

    An abdominal aortic aneurysm is a pathological dilation of the abdominal aorta, which carries a high mortality rate if ruptured. The most commonly used surrogate marker of rupture risk is the maximal transverse diameter of the aneurysm. More recent studies suggest that wall stress from models of patient-specific aneurysm geometries extracted, for instance, from computed tomography images may be a more accurate predictor of rupture risk and an important factor in AAA size progression. However, quantification of wall stress is typically computationally intensive and time-consuming, mainly due to the nonlinear mechanical behavior of the abdominal aortic aneurysm walls. These difficulties have limited the potential of computational models in clinical practice. To facilitate computation of wall stresses, we propose to use a linear approach that ensures equilibrium of wall stresses in the aneurysms. This proposed linear model approach is easy to implement and eliminates the burden of nonlinear computations. To assess the accuracy of our proposed approach to compute wall stresses, results from idealized and patient-specific model simulations were compared to those obtained using conventional approaches and to those of a hypothetical, reference abdominal aortic aneurysm model. For the reference model, wall mechanical properties and the initial unloaded and unstressed configuration were assumed to be known, and the resulting wall stresses were used as reference for comparison. Our proposed linear approach accurately approximates wall stresses for varying model geometries and wall material properties. Our findings suggest that the proposed linear approach could be used as an effective, efficient, easy-to-use clinical tool to estimate patient-specific wall stresses. PMID:25007052

  2. Management of the Sequelae of Severe Congenital Abdominal Wall Defects

    PubMed Central

    Marti, Eunate; Delgado, Maria-Dolores; Gomez, Andres

    2016-01-01

    Background The survival rate of newborns with severe congenital abdominal wall defects has increased. After successfully addressing life-threatening complications, it is necessary to focus on the cosmetic and functional outcomes of the abdominal wall. Methods We performed a chart review of five cases treated in our institution. Results Five patients, ranging from seven to 18 years of age, underwent the following surgical approaches: simple approximation of the rectus abdominis fascia, the rectus abdominis sheath turnover flap, the placement of submuscular tissue expanders, mesh repair, or a combination of these techniques depending on the characteristics of each individual case. Conclusions Patients with severe congenital abdominal wall defects require individualized surgical treatment to address both the aesthetic and functional issues related to the sequelae of their defects. PMID:27218024

  3. [BIOLOGICAL IMPLANTS IN ABDOMINAL WALL HERNIA REPAIR (REVIEW)].

    PubMed

    Abatov, N; Badyrov, R; Abatova, A; Assamidanov, E; Kaukenov, B

    2016-02-01

    The use of synthetic meshes as a material for abdominal wall hernia repair does not always ensure a recurrence-free treatment outcome and full recovery of the abdominal wall functional activity. There are well-known disadvantages such as poor resistance to infection, the infiltrate formation in the place of implantation, expressed adhesive process in cases of introperitoneal fixation, to create certain restrictions on the using of these implants for abdominal wall reconstruction. The search for alternative materials that could minimize the risk of complications, has led to the study of biological grafts. It is known that various methods for the manufacturing biological implants determine endogenous properties for each material separately, and may be cause a variety of biological responses in vivo after implantation. The question has not been resolved, what the fresh raw material is better to use for derive biological implants. In this review we investigated the interaction of different types of biological implants between the abdominal wall and the organs of abdominal cavity of the recipient, their ability to resist infection and the development of relapses, as a leading indicator of the effectiveness of hernioplasty. PMID:27001778

  4. The Pilates Method increases respiratory muscle strength and performance as well as abdominal muscle thickness.

    PubMed

    Giacomini, Mateus Beltrame; da Silva, Antônio Marcos Vargas; Weber, Laura Menezes; Monteiro, Mariane Borba

    2016-04-01

    The aim of this study was to verify the effects of the Pilates Method (PM) training program on the thickness of the abdominal wall muscles, respiratory muscle strength and performance, and lung function. This uncontrolled clinical trial involved 16 sedentary women who were assessed before and after eight weeks of PM training. The thickness of the transversus abdominis (TrA), internal oblique (IO) and external oblique (EO) muscles was assessed. The respiratory muscle strength was assessed by measuring the maximum inspiratory (MIP) and expiratory (MEP) pressure. The lung function and respiratory muscle performance were assessed by spirometry. An increase was found in MIP (p = 0.001), MEP (p = 0.031), maximum voluntary ventilation (p = 0.020) and the TrA (p < 0.001), IO (p = 0.002) and EO (p < 0.001) thickness after the PM program. No alterations in lung function were found. These findings suggest that the PM program promotes abdominal wall muscle hypertrophy and an increase in respiratory muscle strength and performance, preventing weakness in abdominal muscles and dysfunction in ventilatory mechanics, which could favor the appearance of illnesses. PMID:27210841

  5. Reproducibility of airway wall thickness measurements

    NASA Astrophysics Data System (ADS)

    Schmidt, Michael; Kuhnigk, Jan-Martin; Krass, Stefan; Owsijewitsch, Michael; de Hoop, Bartjan; Peitgen, Heinz-Otto

    2010-03-01

    Airway remodeling and accompanying changes in wall thickness are known to be a major symptom of chronic obstructive pulmonary disease (COPD), associated with reduced lung function in diseased individuals. Further investigation of this disease as well as monitoring of disease progression and treatment effect demand for accurate and reproducible assessment of airway wall thickness in CT datasets. With wall thicknesses in the sub-millimeter range, this task remains challenging even with today's high resolution CT datasets. To provide accurate measurements, taking partial volume effects into account is mandatory. The Full-Width-at-Half-Maximum (FWHM) method has been shown to be inappropriate for small airways1,2 and several improved algorithms for objective quantification of airway wall thickness have been proposed.1-8 In this paper, we describe an algorithm based on a closed form solution proposed by Weinheimer et al.7 We locally estimate the lung density parameter required for the closed form solution to account for possible variations of parenchyma density between different lung regions, inspiration states and contrast agent concentrations. The general accuracy of the algorithm is evaluated using basic tubular software and hardware phantoms. Furthermore, we present results on the reproducibility of the algorithm with respect to clinical CT scans, varying reconstruction kernels, and repeated acquisitions, which is crucial for longitudinal observations.

  6. Ultrasonography and computed tomography of inflammatory abdominal wall lesions

    SciTech Connect

    Yeh, H.C.; Rabinowitz, J.G.

    1982-09-01

    Twenty-four patients with inflammatory lesions of the abdominal wall were examined by ultrasonography. Nine of these patients underwent computed tomographic (CT) scanning as well. Both ultrasonography and CT clearly delineated the exact location and extent of abdominal wall abscesses. Abscesses were easily differentiated from cellulitis or phlegmon with ultrasound. The peritoneal line was more clearly delineated on ultrasonograms than on CT scans; abscesses were also more distinct on the ultrasonograms because of their low echogenicity compared with the surrounding structures. Gas bubbles, fat density with specific low attenuation values, and underlying inflamed bowel loops in obese patients with Crohn's disease were better delineated by CT.

  7. On thick domain walls in general relativity

    NASA Technical Reports Server (NTRS)

    Goetz, Guenter; Noetzold, Dirk

    1989-01-01

    Planar scalar field configurations in general relativity differ considerably from those in flat space. It is shown that static domain walls of finite thickness in curved space-time do not possess a reflection symmetry. At infinity, the space-time tends to the Taub vacuum on one side of the wall and to the Minkowski vacuum (Rindler space-time) on the other. Massive test particles are always accelerated towards the Minkowski side, i.e., domain walls are attractive on the Taub side, but repulsive on the Minkowski side (Taub-vacuum cleaner). It is also proved that the pressure in all directions is always negative. Finally, a brief comment is made concerning the possibility of infinite, i.e., bigger than horizon size, domain walls in our universe. All of the results are independent of the form of the potential V(phi) greater than or equal to 0 of the scalar field phi.

  8. High accuracy wall thickness loss monitoring

    NASA Astrophysics Data System (ADS)

    Gajdacsi, Attila; Cegla, Frederic

    2014-02-01

    Ultrasonic inspection of wall thickness in pipes is a standard technique applied widely in the petrochemical industry. The potential precision of repeat measurements with permanently installed ultrasonic sensors however significantly surpasses that of handheld sensors as uncertainties associated with coupling fluids and positional offsets are eliminated. With permanently installed sensors the precise evaluation of very small wall loss rates becomes feasible in a matter of hours. The improved accuracy and speed of wall loss rate measurements can be used to evaluate and develop more effective mitigation strategies. This paper presents an overview of factors causing variability in the ultrasonic measurements which are then systematically addressed and an experimental setup with the best achievable stability based on these considerations is presented. In the experimental setup galvanic corrosion is used to induce predictable and very small wall thickness loss. Furthermore, it is shown that the experimental measurements can be used to assess the effect of reduced wall loss that is produced by the injection of corrosion inhibitor. The measurements show an estimated standard deviation of about 20nm, which in turn allows us to evaluate the effect and behaviour of corrosion inhibitors within less than an hour.

  9. [Extraskeletal mesenchymal chondrosarcoma of lateral abdominal wall (case report)].

    PubMed

    Akfirat, Murat; Kayaoğlu, Hüseyin Ayhan

    2004-12-01

    Mesenchymal chondrosarcomas are very rare in comparison to the conventional types. They can occur from any location containing mesenchymal cells, but most arise in the lower extremities, leptomeninges and in the orbits. Other sites are very uncommon. We present a case of mesenchymal chondrosarcoma of the lateral abdominal wall, and this is the first report of the tumor localized in this region. PMID:15611919

  10. Malignant Schwannoma of Anterior Abdominal Wall: Report of a Case

    PubMed Central

    Khorgami, Zhamak; Nasiri, Shirzad; Rezakhanlu, Freshteh; Sodagari, Nassim

    2009-01-01

    Malignant schwannoma of the anterior abdominal wall nerves is extremely rare. Malignant peripheral nerve sheath tumors (MPNST) represent approximately 10% of all soft tissue sarcomas and it is found in 4% of patients with neurofibromatosis 1. We present a case of malignant schwannoma in a 28-year-old female patient with neurofibromatosis 1. She presented with a painful mass in the right upper quadrant of her abdomen. The tumor location was in the abdominal wall in explorative laparatomy and malignant schwannoma was diagnosed in pathologic assessment. The tumor recurred in 3 months and computed tomography showed two masses in the right side of abdominopelvic cavity. Thereafter, second complete surgical resection was performed and pathologic finding was the same. In spite of administering chemotherapy after second surgery,the tumor recurred and magnetic resonance imaging finding showed a huge heterogeneously enhancing mass with adhesion to the inner side of the abdominal wall. The patient died because of acute respiratory failure due to multiple bilateral pulmonary metastases. Tumor location and rapid recurrence was unique in our patient. Keywords Malignant peripheral nerve sheath tumor; Malignant schwannoma; Abdominal wall PMID:22461875

  11. Which mesh or graft? Prosthetic devices for abdominal wall reconstruction.

    PubMed

    Abid, Shazia; El-Hayek, Kevin

    2016-03-01

    This article reviews the ever-increasing number of prosthetic devices--both synthetic mesh and biologic grafts--now in use for abdominal wall reconstruction. It also introduces a novel hybrid synthetic/biologic graft (Zenapro) and suture passer device (Novapass). PMID:26961445

  12. Gas turbine bucket wall thickness control

    DOEpatents

    Stathopoulos, Dimitrios; Xu, Liming; Lewis, Doyle C.

    2002-01-01

    A core for use in casting a turbine bucket including serpentine cooling passages is divided into two pieces including a leading edge core section and a trailing edge core section. Wall thicknesses at the leading edge and the trailing edge of the turbine bucket can be controlled independent of each other by separately positioning the leading edge core section and the trailing edge core section in the casting die. The controlled leading and trailing edge thicknesses can thus be optimized for efficient cooling, resulting in more efficient turbine operation.

  13. [Controversies in the current management of traumatic abdominal wall hernias].

    PubMed

    Moreno-Egea, Alfredo; Girela, Enrique; Parlorio, Elena; Aguayo-Albasini, José Luis

    2007-11-01

    The management of traumatic abdominal wall hernias is controversial. We performed a MEDLINE search and report a personal series of 10 patients. Cases were classified according to the cause of injury. Fifty-six percent were caused by car accidents and 14% by bicycle accidents. Diagnosis was clinical in 22% and surgical in 13% and intra-abdominal lesions were found in 67%. Treatment was delayed in 12%. In our series, 55% were lumbar hernias due to traffic accidents and all were associated with pelvic fracture. Treatment was delayed in 50%, including laparoscopic surgery with good results. In conclusion, traumatic hernias due to road traffic accidents are frequently associated with intra-abdominal lesions. The diagnostic technique of choice is computed tomography and delayed surgery (laparoscopy) is an effective option. PMID:18021624

  14. Quantitative anatomical labeling of the anterior abdominal wall

    NASA Astrophysics Data System (ADS)

    Allen, Wade M.; Xu, Zhoubing; Asman, Andrew J.; Poulose, Benjamin K.; Landman, Bennett A.

    2013-03-01

    Ventral hernias (VHs) are abnormal openings in the anterior abdominal wall that are common side effects of surgical intervention. Repair of VHs is the most commonly performed procedure by general surgeons worldwide, but VH repair outcomes are not particularly encouraging (with recurrence rates up to 43%). A variety of open and laparoscopic techniques are available for hernia repair, and the specific technique used is ultimately driven by surgeon preference and experience. Despite routine acquisition of computed tomography (CT) for VH patients, little quantitative information is available on which to guide selection of a particular approach and/or optimize patient-specific treatment. From anecdotal interviews, the success of VH repair procedures correlates with hernia size, location, and involvement of secondary structures. Herein, we propose an image labeling protocol to segment the anterior abdominal area to provide a geometric basis with which to derive biomarkers and evaluate treatment efficacy. Based on routine clinical CT data, we are able to identify inner and outer surfaces of the abdominal walls and the herniated volume. This is the first formal presentation of a protocol to quantify these structures on abdominal CT. The intra- and inter rater reproducibilities of this protocol are evaluated on 4 patients with suspected VH (3 patients were ultimately diagnosed with VH while 1 was not). Mean surfaces distances of less than 2mm were achieved for all structures.

  15. A numerical investigation of the healthy abdominal wall structures.

    PubMed

    Pachera, P; Pavan, P G; Todros, S; Cavinato, C; Fontanella, C G; Natali, A N

    2016-06-14

    The present work aims to assess, via numerical modeling, the global passive mechanical behavior of the healthy abdominal wall under the action of pressures that characterize different daily tasks and physiological functions. The evaluation of a normal range of intra-abdominal pressure (IAP) during activities of daily living is fundamental because pressure alterations can cause several adverse effects. At this purpose, a finite element model is developed from literature histomorphometric data and from diagnostic images of Computed Tomography (CT), detailing the different anatomical regions. Numerical simulations cover an IAP up to the physiological limit of 171 (0.0223MPa) mmHg reached while jumping. Numerical results are in agreement with evidences on physiological abdomens when evaluating the local deformations along the craniocaudal direction, the transversal load forces in different regions and the increase of the abdominal area at a IAP of 12mmHg. The developed model can be upgraded for the investigation of the abdominal hernia repair and the assessment of prostheses mechanical compatibility, correlating stiffness and tensile strength of the abdominal tissues with those of surgical meshes. PMID:27133659

  16. 49 CFR 178.33-7 - Wall thickness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Wall thickness. 178.33-7 Section 178.33-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Containers, and Linings § 178.33-7 Wall thickness. (a) The minimum wall thickness for any container shall...

  17. 49 CFR 178.33-7 - Wall thickness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Wall thickness. 178.33-7 Section 178.33-7 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Specifications for Inside Containers, and Linings § 178.33-7 Wall thickness. (a) The minimum wall thickness...

  18. 49 CFR 178.33-7 - Wall thickness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Wall thickness. 178.33-7 Section 178.33-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Containers, and Linings § 178.33-7 Wall thickness. (a) The minimum wall thickness for any container shall...

  19. 49 CFR 178.33a-7 - Wall thickness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Wall thickness. 178.33a-7 Section 178.33a-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Containers, and Linings § 178.33a-7 Wall thickness. (a) The minimum wall thickness for any container shall...

  20. 49 CFR 178.33a-7 - Wall thickness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Wall thickness. 178.33a-7 Section 178.33a-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Containers, and Linings § 178.33a-7 Wall thickness. (a) The minimum wall thickness for any container shall...

  1. 49 CFR 178.33-7 - Wall thickness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Wall thickness. 178.33-7 Section 178.33-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Containers, and Linings § 178.33-7 Wall thickness. (a) The minimum wall thickness for any container shall...

  2. 49 CFR 178.33-7 - Wall thickness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Wall thickness. 178.33-7 Section 178.33-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Containers, and Linings § 178.33-7 Wall thickness. (a) The minimum wall thickness for any container shall...

  3. 49 CFR 178.33a-7 - Wall thickness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Wall thickness. 178.33a-7 Section 178.33a-7 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Specifications for Inside Containers, and Linings § 178.33a-7 Wall thickness. (a) The minimum wall thickness...

  4. 49 CFR 178.33a-7 - Wall thickness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Wall thickness. 178.33a-7 Section 178.33a-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Containers, and Linings § 178.33a-7 Wall thickness. (a) The minimum wall thickness for any container shall...

  5. 49 CFR 178.33a-7 - Wall thickness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Wall thickness. 178.33a-7 Section 178.33a-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... Containers, and Linings § 178.33a-7 Wall thickness. (a) The minimum wall thickness for any container shall...

  6. Gastric Wall Thickness in Sleeve Gastrectomy Patients: Thickness Variation of the Gastric Wall.

    PubMed

    van Rutte, Pim W J; Naagen, Bertus J; Spek, Marinus; Jakimowicz, Jack J; Nienhuijs, Simon W

    2015-11-01

    The sleeve gastrectomy has been accepted as a primary bariatric procedure. One of the most feared complications is staple line leakage. It is important to use the right staple sizes to minimize the risk of leak. Knowledge of gastric thickness is important. The goal of this study was to measure the thickness of the gastric wall after elimination of the gastric folds in the mucosa. An electronic thickness gauge was developed that measured the anterior and posterior wall of the fresh stomach specimen together at 5 points at a pressure based on the finger pressure necessary to flatten the gastric folds. Thirty-three fresh specimens were measured. The mean compression pressure was 714 grams, and no difference was found between the 5 measure points. There was a significant difference in stomach wall thickness. The gastric antrum was more than 1 mm thicker than the fundus. No difference was found between BMI groups <40 Kg/m2, 40-50 Kg/m2, or >50 Kg/m2. No bleeding occurred, leakage occurred in 1 case. There is a significant difference in thickness of the stomach wall between the gastric fundus and the antrum. A pressure 2.5 times lower than applied in prior studies was necessary to achieve full tissue compression. Choosing thinner staple sizes for the gastric fundus might be the optimal technique for compression. However, there are several additional factors that influence the risk of staple line leaks. PMID:26680415

  7. Wall thickness effect on the resistive wall mode stability in toroidal plasmas

    SciTech Connect

    Zheng, L.-J.; Kotschenreuther, M.T.

    2005-07-15

    The effect of finite wall thickness on the stability of n=1 resistive wall modes in toroidal plasmas is investigated. A fusion reactor-relevant configuration is examined. The investigation employs a novel ideal-magnetohydrodynamics adaptive shooting code for axisymmetric plasmas, extended to take into account the wall thickness. Although finite wall thickness generally reduces the growth rate of the resistive wall modes, no contribution to stabilization is found to be made by the portion of the wall that is located beyond the critical position for perfectly conducting wall stabilization. Thus, when the inner side of the wall lies near the critical wall position, the scaling of the growth rate versus wall thickness in the realistic thick-wall calculation is significantly different from that of the usual thin-wall theory. The thin-wall estimate is relevant only when the wall is brought very close to the plasma and is not too thick.

  8. A comparison of prosthetic materials used to repair abdominal wall defects.

    PubMed

    Mori, N; Takano, K; Miyake, T; Nishio, T; Muto, S; Koshizuka, K; Nakagomi, H; Kubo, M; Tada, Y

    1998-09-01

    Large abdominal wall defects may require a prosthesis for closure. The aim of our study was to identify the best material for abdominoplasty in pediatric patients. One hundred twenty-eight Wistar KY strain male rats (3 weeks old) were used. All animals underwent celiotomy via a midline skin incision. They were divided into seven groups as follows: the animals in groups 1 through 6 underwent full-thickness abdominal wall excision 3 cm in diameter. The animals in group 1 underwent primary closure. In groups 2 through 6 the defect was closed with prosthetic material. In Group 7, a sham operation was performed. Daily weights were measured. The animals were killed after 3 and 9 weeks. Adhesion scores were assigned for each group. Vicryl mesh resulted in the fewest adhesions and had no effect on weight gain in the developing rats. PMID:9716675

  9. Complex abdominal wall defects: appearances at prenatal imaging.

    PubMed

    Pakdaman, Reza; Woodward, Paula J; Kennedy, Anne

    2015-01-01

    Abdominal wall defects are a complex group of anomalies, and many are incorrectly diagnosed. Evaluation of the defect relative to the umbilical cord insertion site is fundamentally important in differentiating among the various malformations. The two most common abdominal wall defects are gastroschisis, in which the defect is on the right side of the normally inserting cord and free-floating bowel loops are present, and omphalocele, in which the cord inserts on a membrane-covered midline defect. Omphalocele may also form a portion of a more complex defect that may remain undiagnosed without thorough evaluation. In cloacal exstrophy, the defect extends inferiorly and the bowel loops extrude between the two bladder halves. In pentalogy of Cantrell, the defect extends superiorly and is typically associated with ectopia cordis. Bladder exstrophy is a lower abdominal defect in which the hallmark finding is absence of a fluid-filled bladder. The cord insertion site is normal to low but does not form part of the defect. Both body stalk anomaly and abdominoschisis due to amniotic bands cause severe malformations, often involving extrusion of solid organs and the bowel. Although these two entities have many overlapping features, body stalk anomaly may be recognized on the basis of absence of a free-floating umbilical cord. With use of an algorithmic approach beginning with discovery of the location of the defect, a more precise diagnosis can be determined that may directly affect pre- and postnatal management decisions. PMID:25763744

  10. Outcome of abdominal wall hernia repair with Permacol™ biologic mesh.

    PubMed

    Cheng, Amy W; Abbas, Maher A; Tejirian, Talar

    2013-10-01

    The use of biologic mesh in abdominal wall operations has gained popularity despite a paucity of outcome data. We aimed to review the experience of a large healthcare organization with Permacol™. A retrospective study was conducted of patients who underwent abdominal hernia repair with Permacol™ in 14 Southern California hospitals. One hundred ninety-five patients were analyzed over a 4-year period. Operations included ventral/incisional hernia repairs, ostomy closures, parastomal hernia repairs, and inguinal hernia repairs. In 50 per cent of the patients, Permacol™ was used to reinforce a primary fascial repair and in 50 per cent as a fascial bridge. The overall complication rate was 39.5 per cent. The complication rate was higher in patients with infected versus clean wounds, body mass index (BMI) 40 kg/m(2) or greater versus BMI less than 40 kg/m(2), in patients with prior mesh repair, and when mesh was used as a fascial bridge. With a mean follow-up of 2.1 years, morbid obesity was associated with a higher recurrence. To date this is the largest study on the use of Permacol™ in abdominal wall hernia repair. In our patient population undergoing heterogeneous operations with a majority of wounds as Class II or higher, use of Permacol™ did not eliminate wound morbidity or prevent recurrence, especially in morbidly obese patients. PMID:24160785

  11. Automated Delineation of Vessel Wall and Thrombus Boundaries of Abdominal Aortic Aneurysms Using Multispectral MR Images

    PubMed Central

    Rodriguez-Vila, B.; Tarjuelo-Gutierrez, J.; Sánchez-González, P.; Verbrugghe, P.; Fourneau, I.; Maleux, G.; Herijgers, P.; Gomez, E. J.

    2015-01-01

    A correct patient-specific identification of the abdominal aortic aneurysm is useful for both diagnosis and treatment stages, as it locates the disease and represents its geometry. The actual thickness and shape of the arterial wall and the intraluminal thrombus are of great importance when predicting the rupture of the abdominal aortic aneurysms. The authors describe a novel method for delineating both the internal and external contours of the aortic wall, which allows distinguishing between vessel wall and intraluminal thrombus. The method is based on active shape model and texture statistical information. The method was validated with eight MR patient studies. There was high correspondence between automatic and manual measurements for the vessel wall area. Resulting segmented images presented a mean Dice coefficient with respect to manual segmentations of 0.88 and a mean modified Hausdorff distance of 1.14 mm for the internal face and 0.86 and 1.33 mm for the external face of the arterial wall. Preliminary results of the segmentation show high correspondence between automatic and manual measurements for the vessel wall and thrombus areas. However, since the dataset is small the conclusions cannot be generalized. PMID:26236390

  12. New portable pipe wall thickness measuring technique

    NASA Astrophysics Data System (ADS)

    Pascente, Joseph E.

    1998-03-01

    One of the biggest inspection challenges facing many of the process industries; namely the petrochemical, refining, fossil power, and pulp and paper industries is: How to effectively examine their insulated piping? While there are a number of failure mechanisms involved in various process piping systems, piping degradation through corrosion and erosion are by far the most prevalent. This degradation can be in the form of external corrosion under insulation, internal corrosion through a variety of mechanisms, and internal erosion caused by the flow of the product through the pipe. Refineries, chemical plants and electrical power plants have MANY thousands of miles of pipe that are insulated to prevent heat loss or heat absorption. This insulation is often made up of several materials, with calcium based material being the most dense. The insulating material is usually wrapped with an aluminum or stainless steel outer wrap. Verification of wall thickness of these pipes can be accomplished by removing the insulation and doing an ultrasound inspection or by taking x- rays at a tangent to the edge of the pipe through the insulation. Both of these processes are slow and expensive. The time required to obtain data is measured in hours per meter. The ultrasound method requires that the insulation be plugged after the inspection. The surface needs to be cleaned or the resulting data will not be accurate. The tangent x-ray only shows two thicknesses and requires that the area be roped off because of radiation safety.

  13. Wall thickness design and corrosion management

    SciTech Connect

    Gestel, W.M. van; Guijt, J.

    1994-12-31

    In 1995, Norske Shell will install two 36-in. sweet wet gas pipe lines in the Norwegian sector of the North Sea. The lines cross the Norwegian trench with water depths up to 350 meter. For the last 3.5 km. of the route the pipelines will be laid in a tunnel which will be flooded after construction. The two lines will transport largely untreated well fluids from the Troll field to an onshore processing plant at Kollsness, North of Bergen. From there sales gas will be transported to the continent via the Furopipe and Zeepipe systems. Gas contracts covering 30 years have been concluded with gas utilities on the continent. The maximum wall thickness that could be installed was limited by the capabilities of the present generation of lay barges and pipe mill capacities. The over-thickness, i.e. beyond that what is required for pressure containment and external collapse, is available as corrosion allowance. The paper discusses a novel probabilistic approach to define the corrosion control measures. The corrosion control system is based on the injection of glycol for corrosion mitigation and inspection by ultrasonic internal smart pigs, which in combination with identified fall back options, ensure a minimum 50 year service life.

  14. The relationship between wall shear stress distributions and intimal thickening in the human abdominal aorta

    PubMed Central

    Bonert, Michael; Leask, Richard L; Butany, Jagdish; Ethier, C Ross; Myers, Jerry G; Johnston, K Wayne; Ojha, Matadial

    2003-01-01

    Purpose The goal of this work was to determine wall shear stress (WSS) patterns in the human abdominal aorta and to compare these patterns to measurements of intimal thickness (IT) from autopsy samples. Methods The WSS was experimentally measured using the laser photochromic dye tracer technique in an anatomically faithful in vitro model based on CT scans of the abdominal aorta in a healthy 35-year-old subject. IT was quantified as a function of circumferential and axial position using light microscopy in ten human autopsy specimens. Results The histomorphometric analysis suggests that IT increases with age and that the distribution of intimal thickening changes with age. The lowest WSS in the flow model was found on the posterior wall inferior to the inferior mesenteric artery, and coincided with the region of most prominent IT in the autopsy samples. Local geometrical features in the flow model, such as the expansion at the inferior mesenteric artery (common in younger individuals), strongly influenced WSS patterns. The WSS was found to correlate negatively with IT (r2 = 0.3099; P = 0.0047). Conclusion Low WSS in the abdominal aorta is co-localized with IT and may be related to atherogenesis. Also, rates of IT in the abdominal aorta are possibly influenced by age-related geometrical changes. PMID:14641919

  15. Congenital Anaplastic Rhabdomyosarcoma Presenting As Abdominal Wall Mass

    PubMed Central

    Mondal, Krishnendu; Mandal, Rupali

    2016-01-01

    Rhabdomyosarcoma encompasses a group of malignant myogenic neoplasms expressing a multitude of clinical and pathological diversities. It is the commonest soft tissue sarcoma of childhood but neonates are rarely affected. Embryonal subtype is the most frequent. Head-neck and genitourinary tracts are predominant sites, while trunk is considered among the unusual sites of rhabdomyosarcoma. Herein we report a case of anaplastic rhabdomyosarcoma in a newborn girl presenting, at the Pediatric Surgery Outpatient Department of North Bengal Medical College and Hospital, India in 2013 with a large tumor mass in the left flank region, arising from abdominal wall muscles. PMID:26870149

  16. Colonic wall thickness measured by ultrasound: striking differences in patients with cystic fibrosis versus healthy controls.

    PubMed Central

    Haber, H P; Benda, N; Fitzke, G; Lang, A; Langenberg, M; Riethmüller, J; Stern, M

    1997-01-01

    BACKGROUND: Colonic strictures represent an advanced stage of fibrosing colonopathy in patients with cystic fibrosis. AIMS: To clarify whether ultrasonography can identify patients with an early stage of fibrosing colonopathy and to determine clinical factors that influence bowel wall thickening. PATIENTS: Ninety patients with cystic fibrosis, median age 10 years, and 46 healthy controls, median age 13 years, were investigated. METHODS: Bowel wall thickness was measured by ultrasound in a prospective study. RESULTS: In cystic fibrosis, wall thickness of both small intestine and colon was significantly (p < 0.0001) higher than in controls; 81% of patients with cystic fibrosis had a maximum colon wall thickness at any site of 2 mm or more, a value that was never reached by controls. The maximum colon wall thickness was 6.5 mm. Bowel wall thickness was unchanged at re-examination after one year. There was no progression even with high dose pancreatic supplements. There was no association between bowel wall thickness and clinical features such as previous meconium ileus, intestinal resection, distal intestinal obstruction syndrome, abdominal pain, or pancreatic enzyme dose. CONCLUSIONS: There is genuine intestinal involvement in cystic fibrosis; in a few cases this could lead to fibrosing colonopathy. Images PMID:9135533

  17. Necrotizing Fasciitis of the Abdominal Wall Caused by Serratia Marcescens.

    PubMed

    Lakhani, Naheed A; Narsinghani, Umesh; Kumar, Ritu

    2015-04-15

    In this article, we present the first case of necrotizing fasciitis affecting the abdominal wall caused by Serratia marcescens and share results of a focused review of S. marcescens induced necrotizing fasciitis. Our patient underwent aorto-femoral bypass grafting for advanced peripheral vascular disease and presented 3 weeks postoperatively with pain, erythema and discharge from the incision site in the left lower abdominal wall and underwent multiple debridement of the affected area. Pathology of debrided tissue indicated extensive necrosis involving the adipose tissue, fascia and skeletal muscle. Wound cultures were positive for Serratia marcescens. She was successfully treated with antibiotics and multiple surgical debridements. Since necrotizing fasciitis is a medical and surgical emergency, it is critical to examine infectivity trends, clinical characteristics in its causative spectrum. Using PubMed we found 17 published cases of necrotizing fasciitis caused by Serratia marcescens, and then analyzed patterns among those cases. Serratia marcescens is prominent in the community and hospital settings, and information on infection presentations, risk factors, characteristics, treatment, course, and complications as provided through this study can help identify cases earlier and mitigate poor outcomes. Patients with positive blood cultures and those patients where surgical intervention was not provided or delayed had a higher mortality. Surgical intervention is a definite way to establish the diagnosis of necrotizing infection and differentiate it from other entities. PMID:26294949

  18. [Gasless laparoscopic cholecystectomy using retractor of the abdominal wall].

    PubMed

    D'Urbano, C; Fuertes Guiro, F; Sampietro, R

    1996-03-01

    The Authors present a new gasless laparoscopic cholecystectomy method using an abdominal wall elevator with subcutaneous traction ("laparotenser"). Fifty patients between May 1994 and March 1995 were operated by videolaparoscopy using this new gasless method. Twenty of them were operated with Nagai's method while the laparotenser was used in the remaining thirty. The results obtained are similar to those using pneumoperitoneum. It has been observed a global reduction of costs, less postoperative pain, no influence in cardiovascular and metabolic indexes. No complications were reported during the postoperative period but two cases of conversion to laparotomy not related to the method used were needed. Laparoscopic cholecystectomy without pneumoperitoneum using the subcutaneous elevator of the abdominal wall ("laparotenser") has demonstrated that it's possible to operate in a working space similar to that created by the pneumoperitoneum. After an initial period of distrust towards the laparoscopic methods without pneumoperitoneum it has been accepted that gasless methods multiply the indications to minimally invasive surgery in patients with cardiorespiratory problems considered no ideal candidates to laparoscopic cholecystectomy with pneumoperitoneum. PMID:8679422

  19. Abdominal Wall Transplantation: Skin as a Sentinel Marker for Rejection.

    PubMed

    Gerlach, U A; Vrakas, G; Sawitzki, B; Macedo, R; Reddy, S; Friend, P J; Giele, H; Vaidya, A

    2016-06-01

    Abdominal wall transplantation (AWTX) has revolutionized difficult abdominal closure after intestinal transplantation (ITX). More important, the skin of the transplanted abdominal wall (AW) may serve as an immunological tool for differential diagnosis of bowel dysfunction after transplant. Between August 2008 and October 2014, 29 small bowel transplantations were performed in 28 patients (16 male, 12 female; aged 41 ± 13 years). Two groups were identified: the solid organ transplant (SOT) group (n = 15; 12 ITX and 3 modified multivisceral transplantation [MMVTX]) and the SOT-AWTX group (n = 14; 12 ITX and 2 MMVTX), with the latter including one ITX-AWTX retransplantation. Two doses of alemtuzumab were used for induction (30 mg, 6 and 24 h after reperfusion), and tacrolimus (trough levels 8-12 ng/mL) was used for maintenance immunosuppression. Patient survival was similar in both groups (67% vs. 61%); however, the SOT-AWTX group showed faster posttransplant recovery, better intestinal graft survival (79% vs. 60%), a lower intestinal rejection rate (7% vs. 27%) and a lower rate of misdiagnoses in which viral infection was mistaken and treated as rejection (14% vs. 33%). The skin component of the AW may serve as an immune modulator and sentinel marker for immunological activity in the host. This can be a vital tool for timely prevention of intestinal graft rejection and, more important, avoidance of overimmunosuppression in cases of bowel dysfunction not related to graft rejection. PMID:26713513

  20. [Diagnostic difficulty of abdominal wall endometrioma: clinical case and literature review].

    PubMed

    Martínez, Denzil Garteiz; Romano, Rafael Carbo; Sánchez, Alejandro Weber; Horcasitas, Lourdes Molinar

    2008-02-01

    Abdominal wall endometrioma is a rare clinical condition with which the general surgeon is faced and usually presents a diagnostic challenge due to the similar signs and symptoms that this illness shares with other tumors of the abdominal wall. A clinical case which exemplifies this diagnostic challenge is presented, and a review is made about the physiopathology, diagnosis and treatment of abdominal wall endometriomas, emphasizing on the different diagnoses with which it can be confused. PMID:18798406

  1. Use of synthetic mesh for the entire abdominal wall after TRAM flap transfer.

    PubMed

    Moscona, R A; Ramon, Y; Toledano, H; Barzilay, G

    1998-03-01

    Abdominal wall competence is a major concern of all plastic surgeons using the TRAM flap for breast reconstruction. Low hernia rates and adequate abdominal stability are standard expectations in abdominal wall closure. Described here is this institution's experience with the use of a large piece of synthetic mesh as a supplementary reinforcement for the entire abdominal wall in an attempt to stabilize it and achieve a superior abdominal aesthetic result. Twenty-five consecutive patients had routine reinforcement with the extended mesh technique. Mean patient follow-up was 24 months with a minimum of 1 year. No hernia or mesh-related infection were encountered and only one patient had a lower abdominal bulge. We recommend the use of a large synthetic mesh for improved strength and aesthetic quality of the abdominal wall after TRAM flap breast reconstruction. PMID:9500387

  2. Athletic injuries of the lateral abdominal wall: review of anatomy and MR imaging appearance.

    PubMed

    Stensby, J Derek; Baker, Jonathan C; Fox, Michael G

    2016-02-01

    The lateral abdominal wall is comprised of three muscles, each with a different function and orientation. The transversus abdominus, internal oblique, and external oblique muscles span the abdominal cavity between the iliocostalis lumborum and quadratus lumborum posteriorly and the rectus abdominis anteriorly. The lateral abdominal wall is bound superiorly by the lower ribs and costal cartilages and inferiorly by the iliac crest and inguinal ligament. The lateral abdominal wall may be acutely or chronically injured in a variety of athletic endeavors, with occasional acute injuries in the setting of high-energy trauma such as motor vehicle collisions. Injuries to the lateral abdominal wall may result in lumbar hernia formation, unique for its high incarceration rate, and also Spigelian hernias. This article will review the anatomy, the magnetic resonance (MR) imaging approach, and the features and complications of lateral abdominal wall injuries. PMID:26450606

  3. Abdominal Wall Endometrioma: Ultrasonographic Features and Correlation with Clinical Findings

    PubMed Central

    Solak, Aynur; Genç, Berhan; Yalaz, Seyhan; Şahin, Neslin; Sezer, Taylan Özgür; Solak, İlhami

    2013-01-01

    Background: The diagnosis of abdominal wall endometrioma (AWE) is often confused with other surgical conditions. Certain factors relating to knowledge of the clinical history of the disease make correct diagnosis and treatment difficult. Aims: To present the clinical findings and ultrasonographic (US) features of AWE with special emphasis on size-related features. Study Design: This study reviewed abdominal wall endometriomas during a 2-year period in the Radiology Department of Sifa University Hospital, Izmir. Methods: Eleven women (mean age 32.6 years) with 12 scar endometriomas (mean diameter 29.2 mm) were consecutively evaluated by US and Colour Doppler examination (CDUS) prior to surgery. Lesions were grouped into large (≥3 cm) and small nodules. Vascularisation was classified as location (central, peripheral and mixed) and severity (absent, moderately vascular and hypervascular). In each patient, the nature of pain (absent, cyclic: associated with menstruation and continuous), historical and clinical data were documented. Four patients underwent Magnetic Resonance Imaging and their findings were presented. Fisher’s exact test, χ2 test for categorical data and the unpaired T-test for continuous variables were used for statistical analysis. Results: In all the women, US of the AWE showed the presence of a solid hypoechoic mass (less echogenic than the surrounding hyperechoic fat) within the abdominal wall. There was a significant correlation between AWE sizes with repeated caesareans and the mean time between the last operation and admission to hospital (p<0.05). Large endometriomas showed increased central vascularity (p<0.05). Cyclic pain was more frequent in small lesions, whereas continuous pain was more commonly found in patients with larger lesions (p<0.05). Conclusion: AWE is often misdiagnosed clinically because endometriosis may occur years after the caesarean section, the pain is often non-cyclic in nature, and there is not always a palpable

  4. Novel Technique for Innervated Abdominal Wall Vascularized Composite Allotransplantation: A Separation of Components Approach

    PubMed Central

    Mavrophilipos, Vasilios D.; Zapora, Jeffrey A.; Berli, Jens; Broyles, Justin; Chopra, Karan; Sabino, Jennifer; Matthews, Jamil; Buckingham, E. Bryan; Maddox, John S.; Bluebond-Langner, Rachel; Silverman, Ronald P.

    2014-01-01

    Objective: Applications for Abdominal Wall Vascularized Composite Allotransplantation may expand if a functional graft with decreased immunosuppressive requirements can be designed. We hypothesize that it is anatomically feasible to prepare a functional, innervated, and vascularized abdominal composite graft using a multilayered component separation technique. Including vascularized bone in the graft design may decrease the immunosuppressive requirements by inducing immunologic chimerism. Methods: Two cadaver torsos were used. Adipocutaneous flaps were elevated from the midaxillary lines, preserving deep inferior epigastric artery perforators. A 2-layered component separation through the external and internal oblique fasciae was carried out, exposing segmental intercostal thoracolumbar nerves. Superiorly directed muscle release over the subcostal margin provided for a 3-rib segment with attached rectus abdominis muscle. The remainder of the full-thickness allograft was harvested with its vasculature. Flap inset into the recipient cadaver abdomen, with osteosynthesis fixation between donor and recipient ribs, was achieved. Results: The harvested grafts had an average size of 845 ± 205 cm2 with a total procurement time of 110 minutes. On one cadaver, 4 thoracolumbar nerves were isolated bilaterally, while the other cadaver yielded 3 nerves. The nerves were transected with an average length of 5.7 ± 1.2 cm. The graft vasculature was transected with a length of 4.40 ± 0.10 cm. Conclusion: Using the principles of component separation technique, we demonstrated a novel approach to harvest and transfer a neurotized osteomyofasciocutaneous abdominal wall allotransplant as a multipedicled, single functional unit. PMID:25328567

  5. Local Quantification of Wall Thickness and Intraluminal Thrombus Offer Insight into the Mechanical Properties of the Aneurysmal Aorta.

    PubMed

    Martufi, Giampaolo; Satriano, Alessandro; Moore, Randy D; Vorp, David A; Di Martino, Elena S

    2015-08-01

    Wall stress is a powerful tool to assist clinical decisions in rupture risk assessment of abdominal aortic aneurysms. Key modeling assumptions that influence wall stress magnitude and distribution are the inclusion or exclusion of the intraluminal thrombus in the model and the assumption of a uniform wall thickness. We employed a combined numerical-experimental approach to test the hypothesis that abdominal aortic aneurysm (AAA) wall tissues with different thickness as well as wall tissues covered by different thrombus thickness, exhibit differences in the mechanical behavior. Ultimate tissue strength was measured from in vitro tensile testing of AAA specimens and material properties of the wall were estimated by fitting the results of the tensile tests to a histo-mechanical constitutive model. Results showed a decrease in tissue strength and collagen stiffness with increasing wall thickness, supporting the hypothesis of wall thickening being mediated by accumulation of non load-bearing components. Additionally, an increase in thrombus deposition resulted in a reduction of elastin content, collagen stiffness and tissue strength. Local wall thickness and thrombus coverage may be used as surrogate measures of local mechanical properties of the tissue, and therefore, are possible candidates to improve the specificity of AAA wall stress and rupture risk evaluations. PMID:25631202

  6. [Training of residents in abdominal wall surgery in Spain].

    PubMed

    Miguelena Bobadilla, J M; Morales García, D; Serra Aracil, X; Sanz Sánchez, M; Iturburu, I; Docobo Durántez, F; Jover Navalón, J M; López De Cenarruzabeitia, I; Lobo Martínez, E

    2013-02-01

    The training of residents in abdominal wall surgery is a fundamental aspect of surgical training, representing globally 20% of its activity. In this paper, we analyze the current state of resident training in this kind of surgery in Spain, taking into account the broad spectrum it covers: general services, specific functional units, ambulatory surgery programs. To do this, based on the specifications of the specialty program, specific data were used from several different sources of direct information and a review of the results obtained by residents in hernia surgery. In general, our residents agree with their training and the recorded results are in line with objectives outlined in the program. However, it would be important to structure their teaching schedules, a rotation period in any specific unit and their involvement in outpatient surgery programs. PMID:22074730

  7. A simple, effective and clinically applicable method to compute abdominal aortic aneurysm wall stress.

    PubMed

    Joldes, Grand Roman; Miller, Karol; Wittek, Adam; Doyle, Barry

    2016-05-01

    Abdominal aortic aneurysm (AAA) is a permanent and irreversible dilation of the lower region of the aorta. It is a symptomless condition that if left untreated can expand to the point of rupture. Mechanically-speaking, rupture of an artery occurs when the local wall stress exceeds the local wall strength. It is therefore desirable to be able to non-invasively estimate the AAA wall stress for a given patient, quickly and reliably. In this paper we present an entirely new approach to computing the wall tension (i.e. the stress resultant equal to the integral of the stresses tangent to the wall over the wall thickness) within an AAA that relies on trivial linear elastic finite element computations, which can be performed instantaneously in the clinical environment on the simplest computing hardware. As an input to our calculations we only use information readily available in the clinic: the shape of the aneurysm in-vivo, as seen on a computed tomography (CT) scan, and blood pressure. We demonstrate that tension fields computed with the proposed approach agree well with those obtained using very sophisticated, state-of-the-art non-linear inverse procedures. Using magnetic resonance (MR) images of the same patient, we can approximately measure the local wall thickness and calculate the local wall stress. What is truly exciting about this simple approach is that one does not need any information on material parameters; this supports the development and use of patient-specific modelling (PSM), where uncertainty in material data is recognised as a key limitation. The methods demonstrated in this paper are applicable to other areas of biomechanics where the loads and loaded geometry of the system are known. PMID:26282385

  8. Resection and Abdominal Wall Reconstruction of a Desmoid Tumor with Endometrioma Features

    PubMed Central

    Majors, Jaqueline; Stoikes, Nathaniel F.; Nejati, Reza

    2016-01-01

    Desmoid tumors are rare, musculoaponeurotic mesenchymal origin tumors arising from the proliferation of well-differentiated fibroblasts. Desmoid tumors may arise from any location with the abdominal cavity, abdominal wall and extremity locations being most frequent. We present the case of a 35-year-old female with a history of endometriosis who presented palpable abdominal mass and cyclic abdominal pain. Resection was performed for a presumed desmoid soft tissue tumor. Final pathology demonstrated desmoid histology admixed with abdominal wall endometriosis (endometrioma). This unique pathologic finding has only been rarely reported and is discussed with a brief review of the literature. PMID:27247824

  9. Resection and Abdominal Wall Reconstruction of a Desmoid Tumor with Endometrioma Features.

    PubMed

    Majors, Jaqueline; Stoikes, Nathaniel F; Nejati, Reza; Deneve, Jeremiah L

    2016-01-01

    Desmoid tumors are rare, musculoaponeurotic mesenchymal origin tumors arising from the proliferation of well-differentiated fibroblasts. Desmoid tumors may arise from any location with the abdominal cavity, abdominal wall and extremity locations being most frequent. We present the case of a 35-year-old female with a history of endometriosis who presented palpable abdominal mass and cyclic abdominal pain. Resection was performed for a presumed desmoid soft tissue tumor. Final pathology demonstrated desmoid histology admixed with abdominal wall endometriosis (endometrioma). This unique pathologic finding has only been rarely reported and is discussed with a brief review of the literature. PMID:27247824

  10. An Abdominal Aorta Wall Extraction for Liver Cirrhosis Classification Using Ultrasonic Images

    NASA Astrophysics Data System (ADS)

    Hayashi, Takaya; Fujita, Yusuke; Mitani, Yoshihiro; Hamamoto, Yoshihiko; Segawa, Makoto; Terai, Shuji; Sakaida, Isao

    2011-06-01

    We propose a method to extract an abdominal aorta wall from an M-mode image. Furthermore, we propose the use of a Gaussian filter in order to improve image quality. The experimental results show that the Gaussian filter is effective in the abdominal aorta wall extraction.

  11. Spontaneous intraamniotic hemorrhage in the second trimester mimicking an abdominal wall defect

    PubMed Central

    Üstüner, Işık; Güven, Emine Seda Güvendağ; Balık, Gülşah; Şentürk, Şenol; Üstüner, Evren; Atman, Ebru Düşünceli; Avşar, Ayşe Filiz

    2013-01-01

    We report here a case of spontaneous intraamniotic haemorrhage in the second trimester which mimicked an abdominal wall defect. The ultrasound and magnetic resonance imaging findings are discussed and a review of the literature regarding differential diagnosis of bleeding and abdominal wall defects is made. PMID:24592085

  12. [Mutual influence and development between Gastrointestinal surgery and hernia and abdominal wall surgery].

    PubMed

    Chen, Shuang

    2015-11-25

    The aim of this article is to expound on the crossing and influence each other of gastrointestinal surgery and abdominal wall hernia surgery. Although these two departments are independent respectively, but due to the existence of association among anatomy, physiology and pathology, so they are also overlapping. First of all, the abdominal wall and digestive tract are interdependent, and the abdominal wall provides "protection" for gut. In case of large abdominal wall defect, intra-abdominal viscera, breathing, circulation system and spine will change accordingly. In addition, when intra-abdominal pressure increases due to various reasons, laparotomy is an effective way. But laparotomy is not an easy case, but a crisis. One of the most difficult problems is "enteroatmospheric fistulae". Therefore, to avoid serious complications after laparotomy, the concept of planned ventral hernia is proposed. When life safety is threatened by inter-abdominal hypertension, planned abdominal wall hernia is the style to save life. This is a kind of concept of innovation, and is the concrete practice of the theory of damage control surgery. For a planned abdominal wall hernia patient, it is better to wait and watch, and after making a comprehensive assessment, multidisciplinary collaboration mode should be applied to ensure the safety of surgery. PMID:26616795

  13. Myocardium wall thickness transducer and measuring method

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Lewis, G. W.; Silver, R. H.; Culler, V. H. (Inventor)

    1976-01-01

    A miniature transducer for measuring changes of thickness of the myocardium is described. The device is easily implantable without traumatizing the subject, without affecting the normal muscle behavior, and is removable and implantable at a different muscle location. Operating features of the device are described.

  14. Blunt Abdominal Wall Disruption by Seatbelt Injury; A Case Report and Review of the Literature

    PubMed Central

    Cornelissen, Maarten Philip; van Buijtenen, Jesse; van den Heuvel, Baukje; Bloemers, Frank; Geeraedts Jr., Leo

    2016-01-01

    With the introduction of the use of seatbelts in cars, mortality following motor vehicle crashes has decreased significantly. However, two patterns of injuries, the ‘seatbelt sign’ and ‘seatbelt syndrome’ have emerged. Injuries may consist of traumatic abdominal wall disruption. We present two cases of severe abdominal wall disruption caused by a seatbelt injury and treated with primary repair. A review of the literature is provided. Two patients were brought in after a high velocity Motor Vehicle Collision. Both presented with an acute abdomen and a seatbelt sign upon which the decision was made to perform emergency laparotomies. Both patients had an abdominal wall disruption along the seatbelt sign. These disruptions were primarily closed and during six months of follow-up no complications occurred. A disruption of the abdominal wall is a rare complication. However, it is a diagnosis that may not be missed as patients have a higher risk of morbidity and mortality. CT-scanning is an accurate method to detect disruptions. Closure of blunt traumatic abdominal wall disruption can be done primarily with sutures or addition of a mesh. In both cases of the severe abdominal wall disruption, primary repair without mesh in the acute phase was successful. When a laparotomy is not indicated, the abdominal wall must be assessed for disruption. If there is a disruption primary repair is a good option. PMID:27331068

  15. Reconstruction of full thickness chest wall defects.

    PubMed Central

    Morgan, R F; Edgerton, M T; Wanebo, H J; Daniel, T M; Spotnitz, W D; Kron, I L

    1988-01-01

    Over the last 5 years, 14 patients were treated by wide en bloc resection of chest wall tumors with primary reconstruction. There were nine females and five male patients with an age range of 31-77 years. All patients had a skeletal resection of the chest wall. An average of 3.9 ribs were resected in the patients treated. In three patients a partial sternectomy was carried out in conjunction with the rib resections. Chest wall skeletal defects were reconstructed with Prolene mesh, which was placed under tension. Soft tissue reconstruction utilized selected portions of the latissimus dorsi musculocutaneous territory with fasciocutaneous extensions beyond the muscle itself. Primary healing was obtained in all patients and secondary procedures were not required. The average hospitalization was 23 days. All patients survived the resection and reconstruction and were alive 30 days after operation. In selected patients the preservation of a portion of the innervated muscle in situ or the transfer of the muscle with the preservation of its resting length has maintained the majority of the muscle function. Images Fig. 3A. Fig. 3C. Fig. 3D. Fig. 4A. Fig. 4C. Fig. 4D. Fig. 4E. Fig. 5A. Fig. 5B. Fig. 5D. Fig. 6A. Fig. 6C. Fig. 6D. Fig. 6E. Fig. 6F. Fig. 6G. Fig. 6H. PMID:3389939

  16. Reconstruction of full thickness chest wall defects.

    PubMed

    Morgan, R F; Edgerton, M T; Wanebo, H J; Daniel, T M; Spotnitz, W D; Kron, I L

    1988-06-01

    Over the last 5 years, 14 patients were treated by wide en bloc resection of chest wall tumors with primary reconstruction. There were nine females and five male patients with an age range of 31-77 years. All patients had a skeletal resection of the chest wall. An average of 3.9 ribs were resected in the patients treated. In three patients a partial sternectomy was carried out in conjunction with the rib resections. Chest wall skeletal defects were reconstructed with Prolene mesh, which was placed under tension. Soft tissue reconstruction utilized selected portions of the latissimus dorsi musculocutaneous territory with fasciocutaneous extensions beyond the muscle itself. Primary healing was obtained in all patients and secondary procedures were not required. The average hospitalization was 23 days. All patients survived the resection and reconstruction and were alive 30 days after operation. In selected patients the preservation of a portion of the innervated muscle in situ or the transfer of the muscle with the preservation of its resting length has maintained the majority of the muscle function. PMID:3389939

  17. Evaluation of Tube Wall Thickness of Feed Water Heater

    NASA Astrophysics Data System (ADS)

    Uchikura, Takahisa; Morisaki, Koichi; Hamada, Seiichi

    With regard to the high pressure (HP) feed water heater of thermal power plant at Tokyo Electric Power Company (TEPCO) sites, inspection of feed water (FW) tubes wall thickness are conducted whenever required such that frequent tube leak occurs. As a standard inspection methodology, FW heater is disassembled during planned outage, tube wall thickness is measured by the ultrasonic pulse techique (UT), then plugs are installed at the both ends of FW tube if its measured wall thickness is found below calculated threshold. However, the root causes of wall thinning of FW tube are various such as erosion and corrosion, based on wall thinning condition, the above threshold is not applied but utilizing the other technically well-grounded evaluation method is sometimes more rational. Therefore, TEPCO classified wall-thinning condition based on inspection data and established technically well-grounded and rational evaluation methodologies of FW tube wall thickness to suite each wall thinning condition. Moreover, with recent improvement of inspection technique, technology enabled faster, larger amount, and more accurate data acquisition, TEPCO has developed the systematized evaluation methodology that can transact data acquisition and evaluation simultaneously. This article introduces the logic of evaluation methods and examined algorithms to make them systematized.

  18. An analytic description of thick-wall bubbles

    SciTech Connect

    Hong, Jooyoo.

    1992-01-01

    A new approximation scheme to the false-vacuum decay is suggested. In this scheme the bounce solutions can be obtained in an explicit and analytic way even for thick-wall bubbles. The result is compared with Coleman's thin-wall description, which shows that is nicely comprises the result of the latter prescription. Some applications are also discussed.

  19. An analytic description of thick-wall bubbles

    SciTech Connect

    Hong, Jooyoo

    1992-08-01

    A new approximation scheme to the false-vacuum decay is suggested. In this scheme the bounce solutions can be obtained in an explicit and analytic way even for thick-wall bubbles. The result is compared with Coleman`s thin-wall description, which shows that is nicely comprises the result of the latter prescription. Some applications are also discussed.

  20. Comparison of novel synthetic materials with traditional methods to repair exposed abdominal wall fascial defects.

    PubMed

    Aliabadi-Wahle, S; Cnota, M; Choe, E; Jacob, J T; Flint, L M; Ferrara, J J

    1998-01-01

    Repair of large abdominal wall defects is a challenge, particularly when full-thickness tissue loss prohibits coverage of the fascial repair. Two novel synthetic materials (TMS-1 and TMS-2) have been shown to be better accepted than expanded polytetrafluoroethylene (Gore-Tex), and polypropylene (Marlex) in the closure of clean and contaminated fascial wounds that are immediately covered by skin/soft tissue. Therefore, 1-cm2 abdominal wall defects were created in each of the four quadrants of rat groups. Gore-Tex, Marlex, and TMS-1 or TMS-2 were used to repair three defects, the fourth being primarily closed. To ensure that each repair remained exposed, skin edges were sutured to underlying muscle. Additional animal groups underwent the same protocol; however, peritonitis was induced at surgery using a fecal inoculum technique. Animals were sacrificed 2 weeks later, at which time a blinded observer assessed the surface area and severity of adhesions. In clean wounds, the surface area of formed adhesions was less (p < .004) after primary closure than each synthetic material; among the synthetics, TMS-2 caused significantly (p < .01) less extensive adhesions than Marlex. In addition, the severity of adhesions to TMS-2 was comparable to that of defects closed primarily, and less severe (p < .02) than those formed to Gore-Tex and Marlex. In animals with peritonitis, primary closure caused less extensive (p < .03) adhesions than Marlex and Gore-Tex and significantly (p < .002) less severe adhesions than Marlex, Gore-Tex, and TMS-2. However, the severity of adhesions formed to TMS-1 repairs proved comparable to primarily closed wounds. These experiments reaffirm the tenet that, whenever possible, abdominal wounds should undergo primary fascial closure. When soft tissue coverage over the repair cannot be achieved, TMS-2 is well tolerated in clean wounds. However, the superiority of TMS-1 over the other synthetic materials in contaminated wounds suggests it may also

  1. Bladder wall thickness mapping for magnetic resonance cystography

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Liang, Zhengrong; Zhu, Hongbin; Han, Hao; Duan, Chaijie; Yan, Zengmin; Lu, Hongbing; Gu, Xianfeng

    2013-08-01

    Clinical studies have shown evidence that the bladder wall thickness is an effective biomarker for bladder abnormalities. Clinical optical cystoscopy, the current gold standard, cannot show the wall thickness. The use of ultrasound by experts may generate some local thickness information, but the information is limited in field-of-view and is user dependent. Recent advances in magnetic resonance (MR) imaging technologies lead MR-based virtual cystoscopy or MR cystography toward a potential alternative to map the wall thickness for the entire bladder. From a high-resolution structural MR volumetric image of the abdomen, a reasonable segmentation of the inner and outer borders of the bladder wall can be achievable. Starting from here, this paper reviews the limitation of a previous distance field-based approach of measuring the thickness between the two borders and then provides a solution to overcome the limitation by an electric field-based strategy. In addition, this paper further investigates a surface-fitting strategy to minimize the discretization errors on the voxel-like borders and facilitate the thickness mapping on the three-dimensional patient-specific bladder model. The presented thickness calculation and mapping were tested on both phantom and human subject datasets. The results are preliminary but very promising with a noticeable improvement over the previous distance field-based approach.

  2. The use of a biological graft for the closure of large abdominal wall defects following excision of soft tissue tumours

    PubMed Central

    Illingworth, Emma; Rooney, Paul S.; Heath, Richard; Chandrasekar, Coonoor R.

    2015-01-01

    Primary soft tissue tumours arising from the abdominal wall are uncommon and surgical excision of such tumours can result in large abdominal wall defects. There are many techniques available for abdominal wall repair following tumour excision, each having its own advantages and disadvantages. The options range from direct closure to the use of tissue flap reconstructions and/or prosthetic meshes. Currently, synthetic material such as polypropylene mesh is a common choice for closure of abdominal wall defects after tumour excision. Biological meshes are an alternative option for repair, and this report outlines two cases of abdominal wall repair using the porcine intestinal submucosa biological graft following excision of abdominal wall tumours. There was no evidence of infection, recurrence, seroma or hernias at 2-year follow-up. Following excision of soft tissue tumours of the abdominal wall, biological reconstructions can be successfully used to bridge the defect with minimal morbidity. PMID:26109681

  3. Combination of tissue expansion and porcine mesh for secondary abdominal wall closure after pediatric liver transplantation.

    PubMed

    Lafosse, Aurore; de Magnee, Catherine; Brunati, Andrea; Bayet, Bénédicte; Vanwijck, Romain; Manzanares, Javier; Reding, Raymond

    2012-08-01

    We report the case of a two and a half yr boy hospitalized in our Pediatric Transplantation Unit for portal vein thrombosis following liver transplantation. After performing a meso-Rex shunt, abdominal wall closure was impossible without compressing the portal flow. A combination of two techniques was used to perform the reconstruction of the muscular fasciae and skin layers. The association of tissue expanders and porcine mesh (Surgisis(®)) allowed complete abdominal wall closure with good functional and esthetic results. Use of both techniques is a useful alternative for difficult abdominal closure after liver pediatric transplantation. PMID:21848529

  4. The surface landmarks of the abdominal wall: a plea for standardization

    PubMed Central

    Cirocchi, Roberto; Boselli, Carlo; Renzi, Claudio; Cagini, Lucio; Boccolini, Andrea; Noya, Giuseppe; Fingerhut, Abe

    2014-01-01

    Despite centuries of anatomical studies, controversies and contradictions still exist in the literature regarding the definition, anatomical terminology and the limits of the abdominal wall. We conducted a systematic research of books published from 1901 until December 2012 in Google Books. After the index screening, 16 remaining books were further assessed for eligibility. We decided to exclude journals. The aim of the study was to focus on surface landmarks and borders of the abdominal cavity. After this revision of the literature, we propose that the surface landmarks of the abdominal wall should be standardized. PMID:25097589

  5. Gear-shift lever having variable thickness walls

    SciTech Connect

    Tanaka, T.

    1988-01-03

    A one-piece elongated tubular transmission gear shift lever, is described comprising a tubular connector part at a first end of the gear shift lever, whereby the tubular connector part is adapted to be secured to a pivot means; a spherical part extending from the connector part, the connector part and the spherical part having a first wall thickness; a cylindrical part extending from the spherical part in a direction opposite the tubular connector part, the cylindrical part having a second wall thickness less than the first wall thickness; a tapered part extending from the cylindrical part; and a threaded part extending from the tapered part, the threaded part formed at a second end of the gear shift lever opposite the first end, whereby a gear shift knob may be attached.

  6. Vesicular thick-walled swollen hyphae in pulmonary zygomycosis.

    PubMed

    Kimura, Masatomo; Ito, Hiroyuki

    2009-03-01

    An autopsy case of pulmonary zygomycosis in a patient with rheumatoid arthritis on immunosuppressive therapy is presented herein. There was a pulmonary cavitated infarct caused by mycotic thrombosis. Thin-walled narrow hyphae and vesicular thick-walled swollen hyphae were found on the pleural surface and in the necrotic tissue at the periphery of the cavity. Findings of such shaped fungal elements may cause erroneous histopathological diagnosis because pauciseptate broad thin-walled hyphae are usually the only detectable fungal elements in zygomycosis tissue. Although immunohistochemistry confirmed these unusual elements to be zygomycetous in the present case, it is important for the differential diagnosis to be aware that zygomycetes can form thin narrow hyphae and vesicular thick-walled swollen hyphae. PMID:19261095

  7. Reliability of ultrasound thickness measurement of the abdominal muscles during clinical isometric endurance tests.

    PubMed

    ShahAli, Shabnam; Arab, Amir Massoud; Talebian, Saeed; Ebrahimi, Esmaeil; Bahmani, Andia; Karimi, Noureddin; Nabavi, Hoda

    2015-07-01

    The study was designed to evaluate the intra-examiner reliability of ultrasound (US) thickness measurement of abdominal muscles activity when supine lying and during two isometric endurance tests in subjects with and without Low back pain (LBP). A total of 19 women (9 with LBP, 10 without LBP) participated in the study. Within-day reliability of the US thickness measurements at supine lying and the two isometric endurance tests were assessed in all subjects. The intra-class correlation coefficient (ICC) was used to assess the relative reliability of thickness measurement. The standard error of measurement (SEM), minimal detectable change (MDC) and the coefficient of variation (CV) were used to evaluate the absolute reliability. Results indicated high ICC scores (0.73-0.99) and also small SEM and MDC scores for within-day reliability assessment. The Bland-Altman plots of agreement in US measurement of the abdominal muscles during the two isometric endurance tests demonstrated that 95% of the observations fall between the limits of agreement for test and retest measurements. Together the results indicate high intra-tester reliability for the US measurement of the thickness of abdominal muscles in all the positions tested. According to the study's findings, US imaging can be used as a reliable method for assessment of abdominal muscles activity in supine lying and the two isometric endurance tests employed, in participants with and without LBP. PMID:26118508

  8. Evaluation of scoring accuracy for airway wall thickness

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Ko, Jane P.; Godoy, Myrna C. B.

    2009-02-01

    Bronchial wall thickening is commonly observed in airway diseases. One method often used to quantitatively evaluate wall thickening in CT images is to estimate the ratio of the bronchial wall to the accompanying artery, or BWA ratio, and then assign a severity score based on the ratio. Assessment by visual inspection is unfortunately limited to airways perpendicular or parallel to the scanning plane. With high-resolution images from multi-detector CT scanners, it becomes possible to assess airways in any orientation. We selected CT scans from 20 patients with mild to severe COPD. A computer system automatically segmented each bronchial tree and measured the bronchial wall thicknesses. Next, neighboring arteries were detected and measured to determine BWA ratios. A score characterizing the extent and severity of wall thickening within each lobe was computed according to recommendations by Sheehan et al [1]. Two experienced radiologists independently scored wall thickening using visual assessment. Spearman's rank correlation showed a non-significant negative correlation (r=-0.1) between the computer and the reader average (p=0.4), while the correlation between readers was significant at r=0.65 (p=0.001). We subsequently identified 24 lobes with high discrepancies between visual and automated scoring. The readers re-examined those lobes and measured wall thickness using electronic calipers on perpendicular cross sections, rather than visual assessment. Using this more objective standard of wall thickness, the reader estimates of wall thickening increased to reach a significant positive correlation with automated scoring of r=0.65 (p=0.001). These results indicate that subjectivity is an important problem with visual evaluation, and that visual inspection may frequently underestimate disease extent and severity. Given that a manual evaluation of all airways is infeasible in routine clinical practice, we argue that automated methods should be developed and utilized.

  9. Stability of resistive wall modes with plasma rotation and thick wall in ITER scenario

    NASA Astrophysics Data System (ADS)

    Zheng, L. J.; Kotschenreuther, M.; Chu, M.; Chance, M.; Turnbull, A.

    2004-11-01

    The rotation effect on resistive wall modes (RWMs) is examined for realistically shaped, high-beta tokamak equilibria, including reactor relevant cases with low mach number M and realistic thick walls. For low M, Stabilization of RWMs arises from unusually thin inertial layers. The investigation employs the newly developed adaptive eigenvalue code (AEGIS: Adaptive EiGenfunction Independent Solution), which describes both low and high n modes and is in good agreement with GATO in the benchmark studies. AEGIS is unique in using adaptive methods to resolve such inertial layers with low mach number rotation. This feature is even more desirable for transport barrier cases. Additionally, ITER and reactors have thick conducting walls ( ˜.5-1 m) which are not well modeled as a thin shell. Such thick walls are considered here, including semi-analytical approximations to account for the toroidally segmented nature of real walls.

  10. Combined Visualization of Wall Thickness and Wall Shear Stress for the Evaluation of Aneurysms.

    PubMed

    Glaßer, Sylvia; Lawonn, Kai; Hoffmann, Thomas; Skalej, Martin; Preim, Bernhard

    2014-12-01

    For an individual rupture risk assessment of aneurysms, the aneurysm's wall morphology and hemodynamics provide valuable information. Hemodynamic information is usually extracted via computational fluid dynamic (CFD) simulation on a previously extracted 3D aneurysm surface mesh or directly measured with 4D phase-contrast magnetic resonance imaging. In contrast, a noninvasive imaging technique that depicts the aneurysm wall in vivo is still not available. Our approach comprises an experiment, where intravascular ultrasound (IVUS) is employed to probe a dissected saccular aneurysm phantom, which we modeled from a porcine kidney artery. Then, we extracted a 3D surface mesh to gain the vessel wall thickness and hemodynamic information from a CFD simulation. Building on this, we developed a framework that depicts the inner and outer aneurysm wall with dedicated information about local thickness via distance ribbons. For both walls, a shading is adapted such that the inner wall as well as its distance to the outer wall is always perceivable. The exploration of the wall is further improved by combining it with hemodynamic information from the CFD simulation. Hence, the visual analysis comprises a brushing and linking concept for individual highlighting of pathologic areas. Also, a surface clustering is integrated to provide an automatic division of different aneurysm parts combined with a risk score depending on wall thickness and hemodynamic information. In general, our approach can be employed for vessel visualization purposes where an inner and outer wall has to be adequately represented. PMID:26356964

  11. Testicular Ectopia in the Anterior Abdominal Wall of a Neonate: A Rare Site of Ectopic Testis.

    PubMed

    Siddiqui, Salman Atiq; Marei, Tamer Ibrahim; Al-Makhaita, Ghada

    2016-01-01

    BACKGROUND Abnormal testicular descent can either be undescended or, less commonly, ectopic. Most undescended testes complete the course of descent by the first year of life only if these remain in the normal path of descent. The deviation of the testis may occur to an ectopic location during the transinguinal phase. Of the known ectopic sites, the anterior abdominal wall is the rarest site of testicular ectopia and to our knowledge only 3 cases of this nature have been reported in the available literature to date.  CASE REPORT This rare case of testicular ectopia occurred in a 3-day-old boy in whom the right scrotal sac was empty; on abdominal ultrasound, the right testis was found in the subcutaneous tissues of the right antero-lateral abdominal wall. These findings were confirmed on abdominal MRI, where the right testis was seen beneath the skin between the subcutaneous tissues and external oblique aponeurosis. No aponeurotic or muscular defect was appreciable under the abdominal wall. The neonate underwent orchiopexy at the age of 6 months and remained uneventful postoperatively. CONCLUSIONS Preoperative imaging is recommended to detect and confirm the ectopic site as well as the morphology of testis, thereby increasing the chance of surveillance and preservation of an ectopic testis. Imaging can serve as preoperative road mapping to localize the exact site for surgical exploration of an ectopic testis if there is no apparent or palpable swelling over the anterior abdominal wall. PMID:27411886

  12. [Case of a Plasmacytoid Urothelial Carcinoma Identified Due to the Hardening of the Abdominal Wall].

    PubMed

    Yanagisawa, Masahiro; Kawakami, Toshifumi; Suzuki, Kotaro; Nakayama, Takashi

    2016-02-01

    The patient was a 75 year-old male. Noticing areas of hardening in the lower abdomen, and consequently feelings of systemic fatigue and difficulty in walking, the patient visited a clinic and was diagnosed with kidney failure prior to the visit to our clinic. Computed tomography and magnetic resonance imaging showed thickness of the rectus abdominis muscle and the bladder wall, and bilateral hydronephrosis was also identified. As no explicit tumor was identified in the bladder, the patient underwent biopsies of the abdominal wall and bladder membrane mucous, and was diagnosed with a plasmacytoid urothelial carcinoma primarily developed in the bladder. The patient displayed a poor general state of health and died five months after the diagnosis. It is known that plasmacytoid urothelial carcinomas progress rapidly and the prognosis is poorer than for the micropapillary variant. It is important to obtain a tissue specimen in the early stage of this disease because there are cases in which no explicit tumor can be identified. Furthermore, the value of carbohydrate antigen (CA) 19-9 of the patient was much higher than would be expected as normal at the first visit. It kept rising during the follow-up and was useful as a marker to indicate the progress of the disease. PMID:27018411

  13. Paragonimiasis mimicking chest cancer and abdominal wall metastaisis: A case report

    PubMed Central

    ZHOU, RONGXING; ZHANG, MINJIA; CHENG, NANSHENG; ZHOU, YONG

    2016-01-01

    Typical human paragonimiasis demonstrates an elevated eosinophil count, positive immunoblot, nodular shadows of the lung and pleural thickening with pleural effusion, and these symptoms may be confused with chest cancer. In the present case, a rare case of human paragonimiasis mimicking chest cancer and abdominal wall metastasis is described, the 39-year-old male patient was admitted in our hospital for cough, weight loss 5 kg and a firm mass in right upper abdominal wall. The laboratory test showed unremarkable hematology and biochemistry results. Chest X-ray, Plain computed tomography of the chest and abdomen showed right pleural effusion, several nodules in right lower lung and a mass in the right upper abdominal wall. The initial diagnosis was lung or chest cancer with abdominal wall metastasis, and the abdominal wall mass was resected for the final diagnosis. The biopsy revealed eosinophilic granuloma with Charcot-Leyden crystal formation infiltrated in the muscular fibers. Subsequent to assessment of the antibodies against parasites, the final diagnosis of paragonimiasis was made. PMID:27313691

  14. Testicular Ectopia in the Anterior Abdominal Wall of a Neonate: A Rare Site of Ectopic Testis

    PubMed Central

    Siddiqui, Salman Atiq; Marei, Tamer Ibrahim; Al-Makhaita, Ghada

    2016-01-01

    Patient: Male, 3-day Final Diagnosis: Ectopic right testis in anterior abdominal wall Symptoms: — Medication: — Clinical Procedure: Testicular ultrasound and MRI abdomen Specialty: Radiology Objective: Unusual clinical course Background: Abnormal testicular descent can either be undescended or, less commonly, ectopic. Most undescended testes complete the course of descent by the first year of life only if these remain in the normal path of descent. The deviation of the testis may occur to an ectopic location during the transinguinal phase. Of the known ectopic sites, the anterior abdominal wall is the rarest site of testicular ectopia and to our knowledge only 3 cases of this nature have been reported in the available literature to date. Case Report: This rare case of testicular ectopia occurred in a 3-day-old boy in whom the right scrotal sac was empty; on abdominal ultrasound, the right testis was found in the subcutaneous tissues of the right antero-lateral abdominal wall. These findings were confirmed on abdominal MRI, where the right testis was seen beneath the skin between the subcutaneous tissues and external oblique aponeurosis. No aponeurotic or muscular defect was appreciable under the abdominal wall. The neonate underwent orchiopexy at the age of 6 months and remained uneventful postoperatively. Conclusions: Preoperative imaging is recommended to detect and confirm the ectopic site as well as the morphology of testis, thereby increasing the chance of surveillance and preservation of an ectopic testis. Imaging can serve as preoperative road mapping to localize the exact site for surgical exploration of an ectopic testis if there is no apparent or palpable swelling over the anterior abdominal wall. PMID:27411886

  15. Texture analysis improves level set segmentation of the anterior abdominal wall

    SciTech Connect

    Xu, Zhoubing; Allen, Wade M.; Baucom, Rebeccah B.; Poulose, Benjamin K.; Landman, Bennett A.

    2013-12-15

    Purpose: The treatment of ventral hernias (VH) has been a challenging problem for medical care. Repair of these hernias is fraught with failure; recurrence rates ranging from 24% to 43% have been reported, even with the use of biocompatible mesh. Currently, computed tomography (CT) is used to guide intervention through expert, but qualitative, clinical judgments, notably, quantitative metrics based on image-processing are not used. The authors propose that image segmentation methods to capture the three-dimensional structure of the abdominal wall and its abnormalities will provide a foundation on which to measure geometric properties of hernias and surrounding tissues and, therefore, to optimize intervention.Methods: In this study with 20 clinically acquired CT scans on postoperative patients, the authors demonstrated a novel approach to geometric classification of the abdominal. The authors’ approach uses a texture analysis based on Gabor filters to extract feature vectors and follows a fuzzy c-means clustering method to estimate voxelwise probability memberships for eight clusters. The memberships estimated from the texture analysis are helpful to identify anatomical structures with inhomogeneous intensities. The membership was used to guide the level set evolution, as well as to derive an initial start close to the abdominal wall.Results: Segmentation results on abdominal walls were both quantitatively and qualitatively validated with surface errors based on manually labeled ground truth. Using texture, mean surface errors for the outer surface of the abdominal wall were less than 2 mm, with 91% of the outer surface less than 5 mm away from the manual tracings; errors were significantly greater (2–5 mm) for methods that did not use the texture.Conclusions: The authors’ approach establishes a baseline for characterizing the abdominal wall for improving VH care. Inherent texture patterns in CT scans are helpful to the tissue classification, and texture

  16. Thick domain walls in AdS black hole spacetimes

    SciTech Connect

    Moderski, Rafal; Rogatko, Marek

    2006-08-15

    Equations of motion for a real self-gravitating scalar field in the background of a black hole with negative cosmological constant were solved numerically. We obtain a sequence of static axisymmetric solutions representing thick domain wall cosmological black hole systems, depending on the mass of black hole, cosmological parameter and the parameter binding black hole mass with the width of the domain wall. For the case of extremal cosmological black hole the expulsion of scalar field from the black hole strongly depends on it.

  17. Multilayer injection moulding of thick-walled optical plastics parts

    NASA Astrophysics Data System (ADS)

    Hopmann, Ch.; Neuss, A.; Weber, M.; Walach, P.

    2014-05-01

    Optical components are often thick-walled. The cycle time of precise polymer optics with a wall thickness of more than 20 mm exceeds several minutes. The multilayer injection moulding or compression moulding lowers the cycle time and increases the quality of the moulded parts. For the production of multilayer moulded lenses the mould design plays an important role. An innovative mould concept is presented with the possiblity to produce double or triple layer lenses. To ensure the quality and the endurance of multilayer moulded optical components in their applications, the cohesion in the interface is important. Tensile shear tests show the ability of multilayer moulded parts with high cohesion values for optical applications.

  18. Fungating carcinoma of the stomach: en bloc multiple organ resection and abdominal wall reconstruction.

    PubMed Central

    Chu, K. M.; Lai, D. T.; Stern, H. S.; Sheldon, D. M.

    1995-01-01

    A patient with carcinoma of the stomach invading multiple adjacent organs and fungating through the anterior abdominal wall was treated by en bloc multiple organ resection and abdominal wall reconstruction. The patient is alive and well at the time of writing, six months after the operation. The rationale for embarking on multiple organ resection for gastric cancer is discussed. However, such an aggressive surgical approach should only be applied to carefully selected patients who are medically fit and have no evidence of widespread systemic metastases. Images Figure PMID:7596940

  19. Unusual Presentations of Actinomycosis; Anterior Abdominal Wall and Appendix: Report of Three Cases

    PubMed Central

    Karateke, Faruk; Özyazıcı, Sefa; Menekşe, Ebru; Daş, Koray; Özdoğan, Mehmet

    2013-01-01

    Background: Primary actinomycosis of the anterior abdominal wall and appendix are very rare clinical entities. An accurate diagnosis is generally obtained by histological examination, and treatment often requires surgical resection. Case Report: In this study we presented two cases of primary actinomycosis involving the anterior abdominal wall and a third one located in the appendix. Conclusion: Actinomyces Israelii can involve all anatomic structures of the abdomen. Although preoperative diagnosis is difficult, the combination of surgery and antibiotic treatment results in complete treatment in the majority of cases. PMID:25207127

  20. Evaluation of UT Wall Thickness Measurements and Measurement Methodology

    SciTech Connect

    Weier, Dennis R.; Pardini, Allan F.

    2007-10-01

    CH2M HILL has requested that PNNL examine the ultrasonic methodology utilized in the inspection of the Hanford double shell waste tanks. Specifically, PNNL is to evaluate the UT process variability and capability to detect changes in wall thickness and to document the UT operator's techniques and methodology in the determination of the reported minimum and average UT data and how it compares to the raw (unanalyzed) UT data.

  1. Polymicrobial abdominal wall necrotizing fasciitis after cesarean section.

    PubMed

    DeMuro, Jp; Hanna, Af; Chalas, E; Cunha, Ba

    2012-01-01

    We report a case of a previously healthy woman after an uneventful caesarean section who developed polymicrobial necrotizing fasciitis. She was given a non-steroidal anti-inflamatory drug (NSAID) after her delivery. Her post-delivery course was complicated by septic shock, and required multiple debridements before abdominal reconstruction. This case describes the increased risk of necrotizing fasciitis with NSAID use. Unusual were the organisms causing the polymicrobial necrotizing fasciitis: Staphylococcus aureus, Enterobacter agglomerans, Acinetobacter baumannii, and two strains of Enterobacter cloacae. PMID:24960796

  2. Contraction of Abdominal Wall Muscles Influences Incisional Hernia Occurrence and Size

    PubMed Central

    Lien, Samuel C.; Hu, Yaxi; Wollstein, Adi; Franz, Michael G.; Patel, Shaun P.; Kuzon, William M.; Urbanchek, Melanie G.

    2015-01-01

    Background Incisional hernias are a complication in 10% of all open abdominal operations and can result in significant morbidity. The purpose of this study is to determine if inhibiting abdominal muscle contraction influences incisional hernia formation during laparotomy healing. We hypothesize that reducing abdominal musculature deformation reduces incisional hernia occurrence and size. Study Design Using an established rat model for incisional hernia, a laparotomy through the linea alba was closed with one mid-incision, fast-absorbing suture. Three groups were compared: a SHAM group (SHAM; n = 6) received no laparotomies while the Saline Hernia (SH; n = 6) and Botox Hernia (BH; n = 6) groups were treated once with equal volume saline or Botulinum Toxin (Botox®, Allergan) before the incomplete laparotomy closure. On post-operative day 14, the abdominal wall was examined for herniation and adhesions and contractile forces were measured for abdominal wall muscles. Results No hernias developed in SHAM rats. Rostral hernias developed in all SH and BH rats. Caudal hernias developed in all SH rats, but in only 50% of the BH rats. Rostral hernias in the BH group were 35% shorter and 43% narrower compared to those in the SH group (p < 0.05). The BH group had weaker abdominal muscles compared to the SHAM and SH groups (p < 0.05). Conclusions In our rat model, partial paralysis of abdominal muscles reduces the number and size of incisional hernias. These results confirm abdominal wall muscle contractions play a significant role in the pathophysiology of incisional hernia formation. PMID:25817097

  3. Thick-wall effects in the theory of resistive wall modes

    SciTech Connect

    Pustovitov, V. D.

    2012-06-15

    Magnetic interaction of the plasma perturbations with the nearby resistive wall is considered as a resistive wall mode (RWM) problem, but with two essential differences from the traditional thin-wall approach. First, the wall is treated as magnetically thick, which means that the skin depth is not assumed larger than the wall thickness. Second, the plasma is allowed to enter the region where the RWM must be deeply unstable without rotation. The latter corresponds to the plasma operation above the no-wall stability limit demonstrated in the DIII-D tokamak [E. J. Strait et al., Phys. Plasmas 11, 2505 (2004)]. It is shown that the rotational stabilization observed in these experiments can be reproduced in this model if the mode is forced to rotate with a frequency above a critical level. The analytical estimates show that this effect (absent in the model based on the thin-wall approximation) is strong at realistic parameters. The model also predicts that the locking of the rotationally stabilized mode gives rise to instability with a growth rate much larger than its thin-wall estimate.

  4. Abdominal wall muscle elasticity and abdomen local stiffness on healthy volunteers during various physiological activities.

    PubMed

    Tran, D; Podwojewski, F; Beillas, P; Ottenio, M; Voirin, D; Turquier, F; Mitton, D

    2016-07-01

    The performance of hernia treatment could benefit from more extensive knowledge of the mechanical behavior of the abdominal wall in a healthy state. To supply this knowledge, the antero-lateral abdominal wall was characterized in vivo on 11 healthy volunteers during 4 activities: rest, pullback loading, abdominal breathing and the "Valsalva maneuver". The elasticity of the abdominal muscles (rectus abdominis, obliquus externus, obliquus internus and transversus abdominis) was assessed using ultrasound shear wave elastography. In addition, the abdomen was subjected to a low external load at three locations: on the midline (linea alba), on the rectus abdominis region and on lateral muscles region in order to evaluate the local stiffness of the abdomen, at rest and during "Valsalva maneuver". The results showed that the "Valsalva maneuver" leads to a statistically significant increase of the muscle shear modulus compared to the other activities. This study also showed that the local stiffness of the abdomen was related to the activity. At rest, a significant difference has been observed between the anterior (0.5N/mm) and the lateral abdomen locations (1N/mm). Then, during the Valsalva maneuver, the local stiffness values were similar for all locations (ranging from 1.6 to 2.2N/mm). This work focuses on the in vivo characterization of the mechanical response of the human abdominal wall and abdomen during several activities. In the future, this protocol could be helpful for investigation on herniated patients. PMID:26994992

  5. Comparison of Abdominal Muscle Thickness with Vaginal Pressure Changes in Healthy Women

    PubMed Central

    Kim, Bo-In; Hwang-Bo, Gak; Kim, Ha-Roo

    2014-01-01

    [Purpose] The purpose of this study was to verify the efficacy of a pelvic floor muscle exercise program by comparing subjects’ muscle thickness with changes in vaginal pressure. [Subjects] Two groups of female participants without a medical history of pelvic floor muscle dysfunction were evaluated. The mean age of Group I was 33.5 years and that of Group II was 49.69 years. [Methods] The participants were instructed to perform a pelvic floor muscle contraction. While measuring the vaginal pressure of the pelvic floor muscle, biofeedback was given on five levels, and the thicknesses of the transversus abdominis, external oblique, and internal oblique muscles were measured with ultrasound. [Results] The thickness of the transversus abdominis muscle was significantly increased at 30 cmH2O in Group I, and at 20 cmH2O in Group II. The thickness of the internal oblique abdominal muscle significantly increased at maximum contraction in Group II. [Conclusion] Different abdominal muscles contracted depending on vaginal pressure. The result may be used to create and implement an exercise program that effectively strengthens the pelvic floor muscles. PMID:24707099

  6. Primary synovial sarcoma of the abdominal wall: a case report and literature review

    PubMed Central

    Kritsaneepaiboon, Supika; Sangkhathat, Surasak; Mitarnun, Winyou

    2015-01-01

    Synovial sarcoma (SS) is the fourth most common type of soft tissue sarcoma, following malignant fibrous histiocytoma, liposarcoma, and rhabdomyosarcoma. It usually occurs in the extremities near the large joints of middle-aged patients. We describe a case of synovial sarcoma of the anterior abdominal wall (SSAW) in an adolescent girl and undertake a review of the literature. PMID:26629297

  7. US and MRI features in venous vascular malformation of the abdominal wall. A case report

    PubMed Central

    Alessandrino, F.; Maira, A.; Tarantino, C.C.

    2012-01-01

    Vascular anomalies are classified as vascular tumors and vascular malformations. Venous vascular malformations are the most common type of vascular malformation. They may be isolated or multiple and they rarely affect the trunk. The authors report a rare case of isolated venous vascular malformation of the abdominal wall with an emphasis on the related MRI and ultrasound (US) features. PMID:23450707

  8. Microvascular Reconstructions of Full-Thickness Oncological Chest Wall Defects

    PubMed Central

    Tukiainen, Erkki; Popov, Pentscho; Asko-Seljavaara, Sirpa

    2003-01-01

    Objective: To evaluate the suitability of microvascular flaps for the reconstruction of extensive full-thickness defects of the chest wall. Summary Background Data: Chest wall defects are conventionally reconstructed with pedicular musculocutaneous flaps or the omentum. Sometimes, however, these flaps have already been used, are not reliable due to previous operations or radiotherapy, or are of inadequate size. In such cases, microvascular flaps offer the only option for reconstruction. Methods: From 1988 to 2001, 26 patients with full-thickness resections of the chest wall underwent reconstruction with microvascular flaps. There were 8 soft tissue sarcomas, 8 recurrent breast cancers, 5 chondrosarcomas, 2 desmoid tumors, 1 large cell pulmonary cancer metastasis, 1 renal cancer metastasis, and 1 bronchopleural fistula. The surgery comprised 5 extended forequarter amputations, 5 lateral resections, 8 thoracoabdominal resections, and 8 sternal resections. The mean diameter of a resection was 28 cm. The soft tissue defect was reconstructed with 16 tensor fasciae latae, 5 tensor fascia latae combined with rectus femoris, and 3 transversus rectus abdominis myocutaneous flaps. In 2 patients with a forequarter amputation, the remnant forearm was used as the osteomusculocutaneous free flap. Results: There were no flap losses or perioperative mortality. Four patients needed tracheostomy owing to prolonged respiratory difficulties. The mean survival time for patients with sarcomas was 39 months and for those with recurrent breast cancer 18 months. Conclusions: Extensive chest wall resections are possible with acceptable results. In patients with breast cancer, the surgery may offer valuable palliation and in those with sarcomas it can be curative. PMID:14631216

  9. Thick-walled composite tubes under mechanical and hygrothermal loading

    NASA Astrophysics Data System (ADS)

    Wuetrich, C.

    1992-11-01

    The stresses in long thick-walled composite tubes were determined analytically for loading by internal and external pressure, longitudinal forces and twisting moments. Effects of thermal and hygrothermal expansion were also treated. The solution is restricted to tubes built up from one or more layers with macroscopically orthotropic properties. Such layers may be produced, for example, by filament winding or winding of textile reinforcements. It was shown how the elastic and hygrothermal parameters of the macroscopically orthotropic materials may be calculated by homogenization of the properties of uniaxially reinforced materials.

  10. Terahertz inline wall thickness monitoring system for plastic pipe extrusion

    NASA Astrophysics Data System (ADS)

    Hauck, J.; Stich, D.; Heidemeyer, P.; Bastian, M.; Hochrein, T.

    2014-05-01

    Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

  11. Terahertz inline wall thickness monitoring system for plastic pipe extrusion

    SciTech Connect

    Hauck, J. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Stich, D. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Heidemeyer, P. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Bastian, M. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Hochrein, T. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de

    2014-05-15

    Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

  12. Thick-wall Kevlar 49/Epoxy pressure vessels

    SciTech Connect

    Guess, T.R.

    1984-01-01

    The feasibility of thick-wall composite vessels for very high pressure applications is demonstrated. Prototype vessels, in both spherical and cylindrical geometries, were designed, fabricated and burst tested. It is shown that experimental burst pressures are in excellent agreement with predicted values for burst pressures up to 60 ksi. Each unit consisted of a thin, seamless, copper liner with stainless steel fill stems and a filament-wound Kevlar 49/epoxy outer shell. Analysis of vessel performance accounted for liner thickness and yield strengths, composite thickness, mechanical properties and fiber volume fraction, and stress concentrations caused by the fill stem. Spherical vessels of three different sizes (inside diameters of 2.15 inches, 4.0 inches and 5.3 inches) with either 30 ksi or 60 ksi design burst pressure are discussed. Also, cylindrical vessels with identical liners but of two different composite thicknesses are described. These vessels achieved 50 ksi and 57 ksi burst pressures, respectively. In addition to the design considerations alluded to throughout the paper, the stress state in a thin metal liner during cyclic loading and the life prediction of composite vessels under sustained loading are discussed.

  13. Surgical approach to abdominal wall defects: history and new trends.

    PubMed

    Basile, Francesco; Biondi, Antonio; Donati, Marcello

    2013-01-01

    We briefly outline the history of hernia surgery development from the Ebers Papyrus to modern prosthetic repairs. The rapid evolution of anatomical, physiological and pathogenetic concepts has involved the rapid evolution of surgical treatments. From hernia sack cauterization to sack ligation, posterior wall repair (Bassini), and prosthetic reinforcement there has been an evident improvement in surgical treatment results that has stimulated surgeons to find new technical solutions over time. The introduction of prosthetic repair, the laparoscopic revolution, the impact of local anesthesia and the diffusion of day surgery have been the main advances of the last 50 years. Searching for new gold standards, the introduction of new devices has also led to new complications and problems. Research of the last 10 years has been directed to overcome prosthetic repair complications, introducing every year new meshes and materials. Lightweight meshes, composite meshes and biologic meshes are novelties of the last few years. We also take a look at future trends. PMID:24380545

  14. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  15. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  16. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  17. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  18. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  19. [Impact of abdominoplasty on quality of life in patients, suffering anterior abdominal wall deformity and obesity].

    PubMed

    Dronov, O I; Koval's'ka, I O; Roshchyna, L O; Fedoruk, V I; Burov, E Iu; Fedoruk, P V

    2011-12-01

    The modern tendencies of surgery development include not only the operative procedures improvement but guaranteeing also a maximally high level achievement in the patients quality of life in the early, as well as during remote, postoperative period. The quality of life analysis was done in 132 patients, operated on for the anterior abdominal wall defects, obesity and other surgical diseases, using special questionnaire SF-36. The patients have aged 23-65 years old, in all of them the excessive body mass or obesity of abdominal type was noted. PMID:22432186

  20. Massive Localized Lymphedema Arising from Abdominal Wall: A Case Report and Review of the Literature.

    PubMed

    Tóth, Teodóra; Chang Chien, Yi-Che; Kollár, Sándor; Kovács, Ilona

    2015-01-01

    Massive localized lymphedema (MLL) is a rare pseudosarcomatous lesion due to localized lymphatic obstruction from variable causes. It is most common on medial aspect of thigh and inguinal region. Abdominal localization is rare and may cause clinical diagnostic confusion with other malignant tumors due to its large size. We report a case of abdominal wall MLL of a 56-year-old male patient under clinical suspicion of well differentiated liposarcoma. The literature search and differential diagnosis will be addressed. In doubt cases, immunohistochemical stain or fluorescent in situ hybridization can help to separate this entity from the other mimickers. PMID:26417468

  1. Traumatic disruption of the abdominal wall: lap-belt injuries in children.

    PubMed

    Moremen, Jacob R; Nakayama, Don K; Ashley, Dennis W; Astin, Matthew; Nolan, Tracy L

    2013-04-01

    Traumatic abdominal wall hernia (TAWH) from high speed mechanism is a unique finding in adult trauma, and exceedingly rare in pediatrics. The majority of reports are of low-speed "handlebar" hernias associated with direct injury by bicycle handlebars. We report a series of three pediatric patients in motor vehicle collisions (MVC) who experienced TAWH by lap-belt and associated intra-abdominal injuries necessitating immediate operative intervention. Different operative approaches were used in each case to manage the varying types of disruptions. This adds to the pediatric literature the largest series of its kind. PMID:23583160

  2. Clinical Application of a Silk Fibroin Protein Biologic Scaffold for Abdominal Wall Fascial Reinforcement

    PubMed Central

    Downey, Susan; Agullo, Frank; Lehfeldt, Max R.; Kind, Gabriel M.; Palladino, Humberto; Marshall, Deirdre; Jewell, Mark L.; Mathur, Anshu B.; Bengtson, Bradley P.

    2014-01-01

    Background: Preclinical studies have demonstrated that macroporous silk fibroin protein scaffolds are capable of promoting physiologically durable supportive tissue, which favors application of these engineered tissues for clinical implantation. The safety and effectiveness of a long-lasting, transitory, 510(k)-cleared purified silk fibroin biologic scaffold (SBS) are investigated for soft-tissue support and repair of the abdominal wall. Methods: We conducted a multicenter retrospective review of all consecutive patients who underwent abdominal wall soft-tissue reinforcement with an SBS device between 2011 and 2013. Indications, comorbid conditions, surgical technique, complications, and outcomes were evaluated. Results: We reviewed the records of 172 consecutive patients who received an SBS for soft-tissue support. Of those, 77 patients underwent abdominal wall fascial repair, with a mean follow-up of 18.4 ± 7.5 months. Procedures using an SBS included reinforcement of an abdominal-based flap donor site (31.2%), ventral hernia repair (53.2%), and abdominoplasty (15.6%). The overall complication rate was 6.5%, consisting of 2 wound dehiscences, 1 with device exposure, 1 seroma, 1 infection with explantation, and a perioperative bulge requiring reoperation. There were no reports of hernia. Conclusions: Postoperative complication rates after 18 months were low, and most surgical complications were managed nonoperatively on an outpatient basis without mesh removal. To our knowledge, this is the only series to report on a long-lasting, transitory SBS for abdominal wall repair and reinforcement. Procedure-specific outcome studies are warranted to delineate optimal patient selection and define potential device characteristic advantages. PMID:25506529

  3. Deep abdominal muscle thickness measured under sitting conditions during different stability tasks

    PubMed Central

    Nagai, Hideyuki; Akasaka, Kiyokazu; Otsudo, Takahiro; Sawada, Yutaka; Okubo, Yu

    2016-01-01

    [Purpose] This study was conducted to investigate ultrasonically determined changes in the thickness of the transversus abdominis and internal oblique muscles during different sitting conditions. [Subjects and Methods] Twenty healthy men volunteered to participate in this study. Four different sitting conditions including (A) sitting, (B) sitting with left hip flexion, (C) sitting with an abdominal hollowing maneuver (AHM), and (D) sitting with an AHM and left hip flexion, were used. Subjective exercise difficulty was evaluated. [Results] Transversus abdominis and internal oblique muscle thicknesses significantly differed between conditions, with significantly greater thickness between positions from (A) to (D). Stability of the surface when sitting had no effect on the muscle thickness of the transversus abdominis. By contrast, sitting on an unstable surface caused an increase in muscle thickness of the internal oblique in each condition. The subjects reported progressively increasing difficulty in performing each exercise in a stable position from (A) to (D), while the difficulty in an unstable position was significantly different between (A) and (B), and between (C) and (D). [Conclusion] Our findings suggest that task (B) on a stable surface should be chosen for maximal activation of transversus abdominis without inducing overactivation of the internal oblique muscle. PMID:27134381

  4. Abdominal Wall Endometriosis Excision with Mesh Closure - Report of Two Cases.

    PubMed

    Vaz-de-Macedo, Carolina; Gomes-da-Costa, Ana; Mendes, Sofia; Barata, Sónia; Alho, Conceição; Jorge, Carlos Calhaz; Osório, Filipa

    2016-04-01

    Abdominal wall endometriosis (AWE) is a rare condition included in the differential diagnosis of an abdominal wall mass and/or pelvic pain in women of reproductive age. It usually occurs after pelvic surgery, most commonly caesarean section. Given the variable clinical presentation, diagnosis can be challenging if a high index of suspicion for AWE does not exist. Consequently, the correct diagnosis is often missed in the preoperative assessment. The presence of endometriosis in other locations can aid in the diagnosis, but other endometriotic lesions do not always exist. Image studies, particularly ultrasound and magnetic resonance imaging, can also be of help in the differential diagnosis. Even though new management techniques such as ultrasound-guided percutaneous cryoablation seem to be promising, surgical excision is still the mainstay of treatment. When the aponeurosis is involved, lesion excision might need to be followed by wall closure with the use of a mesh to lessen tissue tension. We present two typical cases of AWE after caesarean section, one of them recurrent, in patients with concurrent endometriosis of other locations. Total lesion excision followed by polypropylene mesh closure has been performed, with very good post-operative outcomes. We aim to raise awareness towards this diagnosis and to highlight the importance of complete lesion excision and adequate closure of the abdominal wall. PMID:27042795

  5. Histological characteristics of the abdominal aortic wall in patients with vascular chronic Q fever

    PubMed Central

    Hagenaars, Julia C J P; Koning, Olivier H J; van den Haak, Ronald F F; Verhoeven, Bart A N; Renders, Nicole H M; Hermans, Mirjam H A; Wever, Peter C; van Suylen, Robert Jan

    2014-01-01

    The aim of this study was to describe specific histological findings of the Coxiella burnetii-infected aneurysmal abdominal aortic wall. Tissue samples of the aneurysmal abdominal aortic wall from seven patients with chronic Q fever and 15 patients without evidence of Q fever infection were analysed and compared. Chronic Q fever was diagnosed using serology and tissue PCR analysis. Histological sections were stained using haematoxylin and eosin staining, Elastica van Gieson staining and immunohistochemical staining for macrophages (CD68), T lymphocytes (CD3), T lymphocyte subsets (CD4 and CD8) and B lymphocytes (CD20). Samples were scored by one pathologist, blinded for Q fever status, using a standard score form. Seven tissue samples from patients with chronic Q fever and 15 tissue samples from patients without Q fever were collected. Four of seven chronic Q fever samples showed a necrotizing granulomatous response of the vascular wall, which was characterized by necrotic core of the arteriosclerotic plaque (P = 0.005) and a presence of high numbers of macrophages in the adventitia (P = 0.007) distributed in typical palisading formation (P = 0.005) and surrounded by the presence of high numbers of T lymphocytes located diffusely in media and adventitia. Necrotizing granulomas are a histological finding in the C. burnetii-infected aneurysmal abdominal aortic wall. Chronic Q fever should be included in the list of infectious diseases with necrotizing granulomatous response, such as tuberculosis, cat scratch disease and syphilis. PMID:24953727

  6. Histological characteristics of the abdominal aortic wall in patients with vascular chronic Q fever.

    PubMed

    Hagenaars, Julia C J P; Koning, Olivier H J; van den Haak, Ronald F F; Verhoeven, Bart A N; Renders, Nicole H M; Hermans, Mirjam H A; Wever, Peter C; van Suylen, Robert Jan

    2014-08-01

    The aim of this study was to describe specific histological findings of the Coxiella burnetii-infected aneurysmal abdominal aortic wall. Tissue samples of the aneurysmal abdominal aortic wall from seven patients with chronic Q fever and 15 patients without evidence of Q fever infection were analysed and compared. Chronic Q fever was diagnosed using serology and tissue PCR analysis. Histological sections were stained using haematoxylin and eosin staining, Elastica van Gieson staining and immunohistochemical staining for macrophages (CD68), T lymphocytes (CD3), T lymphocyte subsets (CD4 and CD8) and B lymphocytes (CD20). Samples were scored by one pathologist, blinded for Q fever status, using a standard score form. Seven tissue samples from patients with chronic Q fever and 15 tissue samples from patients without Q fever were collected. Four of seven chronic Q fever samples showed a necrotizing granulomatous response of the vascular wall, which was characterized by necrotic core of the arteriosclerotic plaque (P = 0.005) and a presence of high numbers of macrophages in the adventitia (P = 0.007) distributed in typical palisading formation (P = 0.005) and surrounded by the presence of high numbers of T lymphocytes located diffusely in media and adventitia. Necrotizing granulomas are a histological finding in the C. burnetii-infected aneurysmal abdominal aortic wall. Chronic Q fever should be included in the list of infectious diseases with necrotizing granulomatous response, such as tuberculosis, cat scratch disease and syphilis. PMID:24953727

  7. A Large Single-Center Experience of Open Lateral Abdominal Wall Hernia Repairs.

    PubMed

    Patel, Puraj P; Warren, Jeremy A; Mansour, Roozbeh; Cobb, William S; Carbonell, Alfredo M

    2016-07-01

    Lateral abdominal wall hernias may occur after a variety of procedures, including anterior spine exposure, urologic procedures, ostomy closures, or after trauma. Anatomically, these hernias are challenging and require a complete understanding of abdominal wall, interparietal and retroperitoneal, anatomy for successful repair. Mesh placement requires extensive dissection of often unfamiliar planes, and its fixation is difficult. We report our experience with open mesh repair of lateral abdominal wall hernias. A retrospective review of a prospectively maintained database was performed to identify patients with a classification of lateral abdominal wall hernia who underwent an open repair. A total of 61 patients underwent open lateral hernia repairs. Mean patient age was 58 years (range 25-78), with a mean body mass index of 32 kg/m(2) (range 19.0-59.1). According to the European Hernia Society classification, defects were located subcostal (L1, 14 patients), flank (L2, 33 patients), iliac (L3, 11 patients), and lumber (L4, 3 patients). Mean defect size was 78.6 cm(2), with a mean greatest single dimension of 9.2 cm (range 2-25 cm). Retromuscular or interparietal repair was performed in 50.8 per cent, preperitoneal in 41.0 per cent, intraperitoneal in 6.6 per cent, and onlay in 1.6 per cent. The rate of surgical site occurrence was 49.2 per cent, primarily seroma and surgical site infection rate was 13.1 per cent. With a mean follow-up of 15.4 months, seven patients (11.5%) have documented recurrence. Synthetic mesh reconstruction of lateral wall hernias is challenging. Our experience demonstrates the safety and success of repair using synthetic mesh primarily in the retromuscular, interparietal, or preperitoneal planes. PMID:27457859

  8. Strain to failure of pressurized thick wall cylinders

    SciTech Connect

    Priddy, T.G.; Roach, D.P.

    1989-01-01

    The determination of the fully plastic response and pressure limit of a highly pressurized vessel is of considerable importance in design. The plastic-strain response during and following autofrettage operations, in comparison with the limiting strain condition, is of special interest. This paper presents the results of an analysis method for thick wall, high pressure, cylinders where the effective plastic strain distribution through the thickness is the material response variable of primary interest. The limiting value of this effective plastic strain depends on the level of tensile-stress triaxiality which also varies through the thickness. This strain-to-failure criterion is used to predict the complete pressure versus strain response and the maximum pressure for test cylinders. A simple model of effective-stress versus effective plastic strain is employed. This model is quantified by data taken from uniaxial, tension, true-stress-strain curves and from the fracture zone of the tensile specimen. A sample calculation is included and, in a companion paper, a series of burst tubes having properties ranging from brittle to ductile are compared with this analytical method. 21 refs., 5 figs., 2 tabs.

  9. Abdominal Wall Endometriosis on the Right Port Site After Laparoscopy: Case Report and Literature Review

    PubMed Central

    Cozzolino, Mauro; Magnolfi, Stefania; Corioni, Serena; Moncini, Daniela; Mattei, Alberto

    2015-01-01

    Background Endometriosis can be intrapelvic or, rarely, extrapelvic. Endometriosis involving the rectus abdominis muscle on the trocar port site is a rare event; until now, only 16 cases have been reported in the literature. The majority of cases were associated with previous abdominal surgery such as diagnostic laparoscopy, cyst excision, appendectomy, myomectomy, or cholecystectomy. We review all the reported cases of this unusual form of extrapelvic endometriosis. Case Report We report a new case of abdominal wall endometriosis at the trocar port site in the rectus abdominis muscle in a woman who had undergone 2 laparoscopies for endometriosis in the 3 years before coming to our attention. The diagnosis was made by sonography. We performed a surgical resection of the lesion with a free macroscopic margin of 5-10 mm. Conclusion Endometriosis should be considered in the differential diagnosis of any abdominal swelling. In our experience, surgery is the treatment of choice. PMID:26412997

  10. Development of a novel synthetic material to close abdominal wall defects.

    PubMed

    Cnota, M A; Aliabadi-Wahle, S; Choe, E U; Jacob, J T; Flint, L M; Ferrara, J J

    1998-05-01

    To compare the efficacy of a novel synthetic material (TMS-2) with polytetrafluoroethylene, polypropylene (Marlex), and primary closure of experimentally fashioned clean and contaminated abdominal wounds, 1-cm2 abdominal wall defects were created in each of the four abdominal quadrants of rats (n = 10). Patches of each material were used to repair three of these defects, the fourth being primarily closed. A second group of rats (n = 7) underwent the same operative protocol; however, peritonitis was induced at the time of surgery using a fecal inoculation technique. Animals were killed 2 weeks later, and surface area and severity of formed adhesions were assessed by a "blinded" observer. All closure techniques were successful insofar as none demonstrated fascial dehiscence. Compared with each synthetic material, the surface area of formed adhesions was smaller after primary closure in clean and in contaminated conditions; however, the three synthetic materials were equally matched regarding surface area of adhesions under both conditions. In the face of fecal contamination, TMS-2 proved identical to primary closure, each generating significantly (P < 0.02) milder adhesions than the other prosthetic materials. It is concluded that the TMS-2 may prove of clinical benefit to repair abdominal wall defects. PMID:9585774

  11. Desmoid tumor of the anterior abdominal wall in female patients: comparison with endometriosis.

    PubMed

    Krentel, H; Tchartchian, G; De Wilde, R L

    2012-01-01

    In female patients presenting a tumor of the lower abdominal wall especially after cesarian section, an endometriotic tumor as well as an aggressive desmoid tumor should be considered. Symptoms in correlation with the monthly period can facilitate the presurgical differentiation between endometriosis and fibromatosis. Ultrasound reveals the typical location of both tumors and its remarkable sonographic appearance. In the clinical practice, the desmoid fibromatosis of the lower abdominal wall is a very rare disease. We present a case of a 25-year-old pregnant and discuss diagnostic and therapeutic options by a PubMed literature review. With the knowledge of the prognosis of the desmoid fibromatosis and the respective treatment options including wait and see, complete surgical resection with macroscopically free margins and adjuvant approaches is essential to avoid further interventions and progression of the locally destructive tumor. PMID:22778752

  12. Desmoid Tumor of the Anterior Abdominal Wall in Female Patients: Comparison with Endometriosis

    PubMed Central

    Krentel, H.; Tchartchian, G.; De Wilde, R. L.

    2012-01-01

    In female patients presenting a tumor of the lower abdominal wall especially after cesarian section, an endometriotic tumor as well as an aggressive desmoid tumor should be considered. Symptoms in correlation with the monthly period can facilitate the presurgical differentiation between endometriosis and fibromatosis. Ultrasound reveals the typical location of both tumors and its remarkable sonographic appearance. In the clinical practice, the desmoid fibromatosis of the lower abdominal wall is a very rare disease. We present a case of a 25-year-old pregnant and discuss diagnostic and therapeutic options by a PubMed literature review. With the knowledge of the prognosis of the desmoid fibromatosis and the respective treatment options including wait and see, complete surgical resection with macroscopically free margins and adjuvant approaches is essential to avoid further interventions and progression of the locally destructive tumor. PMID:22778752

  13. Laparoscopic drainage of abdominal wall abscess from spilled stones post-cholecystectomy

    PubMed Central

    Chong, Vincent; Ram, Rishi

    2015-01-01

    We present a case on abdominal wall abscess from spilled stones post-cholecystectomy and describe laparoscopic drainage as our choice of management. Mr M is a 75-year-old male who presented on multiple occasions to the hospital with right upper quadrant pain and fever post-laparoscopic cholecystectomy. He also required multiple courses of antibiotics. Subsequent computed tomography and magnetic resonance imaging scan confirmed a number of retained stone with signs of chronic inflammation. Hence, 6 months after his initial laparoscopic cholecystectomy, he proceeded to an exploratory laparoscopy. We found an abscess cavity measuring 3 × 4 cm over the anterior abdominal wall. The cavity was de-roofed, drained and washed out. The tissue culture grew Klebsiella pneumoniae. Laparoscopic approach is optimal as the abscess cavity can be clearly identified, stones visualized and removed under direct vision. Patient does not require a laparotomy. PMID:26183574

  14. The Use of an Anterior Abdominal Wall Peritoneal Flap in the Laparoscopic Repair of Vesicouterine Fistula

    PubMed Central

    Tasdemir, Nicel; Abali, Remzi; Celik, Cem; Yazici, Cenk Murat; Akkus, Didem

    2014-01-01

    Vesicouterine fistula (VUF) is a rare type of genitourinary fistula. Lower-segment cesarean section is the leading cause of VUF. Patients mostly present with the classical triad of menouria, amenorrhea, and urinary incontinence, with the history of a previous cesarean section. Conservative management with catheterization and open, laparoscopic, and robotic surgeries are the prescribed treatment options. We present the case of a 35-year-old woman who presented with cyclical menouria and urinary incontinence. After diagnosis of VUF by cystoscopy, the laparoscopic approach was chosen. During the procedure, we used anterior abdominal wall peritoneum and adjacent adipose tissue interposition for the first time, instead of omental interposition, because of the unavailability of omentum. The postoperative period was uneventful, and the procedure was successful. In conclusion, the laparoscopic approach is feasible and the anterior abdominal wall peritoneal flap can be used instead of omentum for tissue interposition when the omentum is not available. PMID:25216441

  15. Current practice of abdominal wall closure in elective surgery – Is there any consensus?

    PubMed Central

    Rahbari, Nuh N; Knebel, Phillip; Diener, Markus K; Seidlmayer, Christoph; Ridwelski, Karsten; Stöltzing, Hartmut; Seiler, Christoph M

    2009-01-01

    Background Development of incisional hernia after open abdominal surgery remains a major cause of post-operative morbidity. The aim of this study was to determine the current practice of surgeons in terms of access to and closure of the abdominal cavity in elective open surgery. Methods Twelve surgical departments of the INSECT-Trial group documented the following variables for 50 consecutive patients undergoing abdominal surgery: fascial closure techniques, applied suture materials, application of subcutaneous sutures, subcutaneous drains, methods for skin closure. Descriptive analysis was performed and consensus of treatment variables was categorized into four levels: Strong consensus >95%, consensus 75–95%, overall agreement 50–75%, no consensus <50%. Results 157 out of 599 patients were eligible for analysis (85 (54%) midline, 54 (35%) transverse incisions). After midline incisions the fascia was closed continuously in 55 patients (65%), using slowly absorbable (n = 47, 55%), braided (n = 32, 38%) sutures with a strength of 1 (n = 48, 57%). In the transverse setting the fascia was closed continuously in 39 patients (72%) with slowly absorbable (n = 22, 41%) braided sutures (n = 27, 50%) with a strength of 1 (n = 30, 56%). Conclusion In the present evaluation midline incision was the most frequently applied access in elective open abdominal surgery. None of the treatments for abdominal wall closure (except skin closure in the midline group) is performed on a consensus level. PMID:19442311

  16. Lateral Abdominal Wall Defects: The Importance of Anatomy and Technique for a Successful Repair

    PubMed Central

    Pulikkottil, Benson J.; Pezeshk, Ronnie A.; Daniali, Lily N.; Bailey, Steven H.; Mapula, Steven

    2015-01-01

    Summary: Flank and lateral abdominal wall defects can be an extremely challenging phenomenon for surgeons to undertake. Their rarity and specific idiosyncrasies in regard to embryologic and anatomical characteristics must be taken into consideration when formulating an operative plan. We will discuss these cardinal points including technical recommendations by notable experts in the field to gain a better understanding in the diagnosis and treatment of this infrequent but morbid occurrence. PMID:26495194

  17. Stress intensity factors in a reinforced thick-walled cylinder

    NASA Technical Reports Server (NTRS)

    Tang, R.; Erdogan, F.

    1984-01-01

    An elastic thick-walled cylinder containing a radial crack is considered. It is assumed that the cylinder is reinforced by an elastic membrane on its inner surface. The model is intended to simulate pressure vessels with cladding. The formulation of the problem is reduced to a singular integral equation. Various special cases including that of a crack terminating at the cylinder-reinforcement interface are investigated and numerical examples are given. Results indicate that in the case of the crack touching the interface the crack surface displacement derivative is finite and consequently the stress state around the corresponding crack tip is bounded; and generally, for realistic values of the stiffness parameter, the effect of the reinforcement is not very significant.

  18. The effects of bridge exercise with the abdominal drawing-in maneuver on an unstable surface on the abdominal muscle thickness of healthy adults

    PubMed Central

    Cho, Misuk

    2015-01-01

    [Purpose] The purpose of this study was to determine the impact of a bridge exercise with an abdominal drawing-in maneuver (ADIM) performed with different surface conditions on abdominal muscle thickness. [Subjects] Thirty subjects were randomly divided into an unstable bridge exercise group (UBE group, n=15) and a stable bridge exercise group (SBE group, n=15). [Methods] After 6 weeks of performing bridge exercises accompanied by ADIM, the change in the muscle thicknesses of the transverse abdominis (TrA) and internal oblique abdominis (IOA) muscles was assessed using ultrasonography. [Results] After 6 weeks of exercise, the TrA was significantly altered in the SBEG, and the TrA and IOA were both significantly changed in the UBEG. [Conclusion] When performing bridge exercises to increase the Tra and the IO muscle thicknesses, exercising on an unstable surface is recommended. PMID:25642086

  19. [Hematoma of the abdominal wall. A case report: pitfall of Seldinger method via femoral artery].

    PubMed

    Hiramatsu, Hisaya; Sugiura, Yasushi; Takeda, Ririko; Nanba, Hiroki

    2009-02-01

    We reported a case of an abdominal wall hematoma which caused by Seldinger method via the femoral artery. A 48-year-old female, suffered from direct carotid cavernous fistula, was treated by transfemoral transvenous embolization (TVE). The whole procedure was completed without difficulty except minor resistance of guide wire manipulation during left femoral artery catheterization. Four hours later, the patient became hypotensive and showed the sign of impending shock without definitive causes. Nine hours after the embolization a huge hematoma of the abdominal wall was found. It required the total 1200 m/ of blood transfusion before her blood pressure returned to normal. She recovered fully from this event and discharged uneventfully. There is a speculation that a deep circumflex iliac artery (DCIA) was injured with an angle-shaped guide wire and bled into the abdominal wall. And subsequent systemic heparinization prevented the coagulation process, resulting a large hematoma. Anatomically, an angle-shaped guide wire is easily able to migrate into DCIA. To prevent a vascular injury, it is very important to manipulate a guide wire under fluoroscopic control and to select a J-shaped guide wire instead of an angle-shaped one. PMID:19227158

  20. The management of abdominal wall hernias – in search of consensus

    PubMed Central

    Bury, Kamil; Śmietański, Maciej

    2015-01-01

    Introduction Laparoscopic repair is becoming an increasingly popular alternative in the treatment of abdominal wall hernias. In spite of numerous studies evaluating this technique, indications for laparoscopic surgery have not been established. Similarly, implant selection and fixation techniques have not been unified and are the subject of scientific discussion. Aim To assess whether there is a consensus on the management of the most common ventral abdominal wall hernias among recognised experts. Material and methods Fourteen specialists representing the boards of European surgical societies were surveyed to determine their choice of surgical technique for nine typical primary ventral and incisional hernias. The access method, type of operation, mesh prosthesis and fixation method were evaluated. In addition to the laparoscopic procedures, the number of tackers and their arrangement were assessed. Results In none of the cases presented was a consensus of experts obtained. Laparoscopic and open techniques were used equally often. Especially in the group of large hernias, decisions on repair methods were characterised by high variability. The technique of laparoscopic mesh fixation was a subject of great variability in terms of both method selection and the numbers of tackers and sutures used. Conclusions Recognised experts have not reached a consensus on the management of abdominal wall hernias. Our survey results indicate the need for further research and the inclusion of large cohorts of patients in the dedicated registries to evaluate the results of different surgical methods, which would help in the development of treatment algorithms for surgical education in the future. PMID:25960793

  1. Excision of the urachal remnant using the abdominal wall-lift laparoscopy: A case report

    PubMed Central

    Kobayashi, Kosuke; Sasaki, Kazuhito; Iijima, Tatsuo; Yoshimi, Fuyo; Nagai, Hideo

    2016-01-01

    Introduction Here, we report the surgical excision of the urachal remnant using the abdominal wall-lift laparoscopy with a camera port in the umbilicus, combined with a small Pfannenstiel incision to optimally treat the bladder apex. Presentation of case A 21-year-old woman presented with periumbilical discharge and pain on urination. Contrast enhanced CT and MRI showed an abscess in the umbilical region that was connected to the bladder via a long tube-like structure. It was diagnosed as an infected urachal sinus. Partial excision of the umbilical fossa followed by dissection of the urachal remnant was easily performed using the abdominal wall-lift laparoscopy from the umbilicus down to the bladder without pneumoperitoneum or additional trocar placement. A Pfannenstiel incision was made above the pubis to get access to the junction between the urachal remnant and the bladder. Under direct vision, we succeeded in accurately dividing the remnant tract, and we adequately closed the bladder opening with absorbable sutures. This method has the advantage of easily closing peritoneal defects after excision of the urachal remnant with direct sutures under a laparoscopic view from the umbilicus. Cosmetic satisfaction was obtained postoperatively. Discussion and conclusion Urachal sinus excision using the abdominal wall-lift laparoscopy seems to surpass the previously reported methods in term of safety, cosmetics, and adequacy of surgical procedures. PMID:27064744

  2. Expansion abdominoplasty for a pregnant woman with severe abdominal wall contracture due to a major burn during childhood: a case report.

    PubMed

    Takeda, Kohsuke; Sowa, Yoshihiro; Numajiri, Toshiaki; Nishino, Kenichi

    2013-06-01

    Normal abdominal expansion that occurs as a result of hormonal actions during pregnancy may be prevented by the presence of excessive scar tissue in individuals who have received severe burns. In these instances, the lack of abdominal expansion may cause maternal pain and put the infant at risk. A 23-year-old pregnant woman presented with severe abdominal wall contracture due to a major burn sustained during childhood. At 20 weeks of pregnancy, expansion abdominoplasty, consisting of zigzag incisions in the fascia to release the contracture and a split-thickness skin graft, was performed. The patient gave birth, via a planned cesarean operation at 36 weeks of pregnancy, to a baby girl in good condition; the postpartum course was uneventful. PMID:23673563

  3. Thick Liquid-Walled, Field-Reversed Configuration

    SciTech Connect

    Moir, R W; Bulmer, R H; Gulec, K; Fogarty, P; Nelson, B; Ohnishi, M; Rensink, M; Rognlien, T D; Santarious, J F; Sze, D K

    2000-09-22

    A thick flowing layer of liquid (e.g., flibe--a molten salt, or Sn{sub 80}Li{sub 20}--a liquid metal) protects the structural walls of the field-reversed configuration (FRC) so that they can last the life of the plant even with intense 14 MeV neutron bombardment from the D-T fusion reaction. The surface temperature of the liquid rises as it passes from the inlet nozzles to the exit or receiver nozzles due to absorption of line and bremsstrahlung radiation, and neutrons. The surface temperature can be reduced by enhancement of convection near the surface to transport hot surface liquid into the cooler interior. This surface temperature must be compatible with a practical heat transport and energy recovery system. The evaporative flux from the wall driven by the surface temperature must also result in an acceptable impurity level in the core plasma. The shielding of the core by the edge plasma is modeled with a 2D transport code for the resulting impurity ions; these ions are either swept out to the distant end tanks, or diffuse to the hot plasma core. An auxiliary plasma between the edge plasma and the liquid wall can further attenuate evaporating flux of atoms and molecules by ionization. The current in this auxiliary plasma might serve as the antenna for the current drive method, which produces a rotating magnetic field. Another method of current drive uses small spheromaks injected along the magnetic fields, which additionally provide fueling along with pellet fueling if necessary.

  4. Impact of poroelasticity of intraluminal thrombus on wall stress of abdominal aortic aneurysms

    PubMed Central

    2012-01-01

    Background The predictions of stress fields in Abdominal Aortic Aneurysm (AAA) depend on constitutive descriptions of the aneurysm wall and the Intra-luminal Thrombus (ILT). ILT is a porous diluted structure (biphasic solid–fluid material) and its impact on AAA biomechanics is controversially discussed in the literature. Specifically, pressure measurements showed that the ILT cannot protect the wall from the arterial pressure, while other (numerical and experimental) studies showed that at the same time it reduces the stress in the wall. Method To explore this phenomenon further a poroelastic description of the ILT was integrated in Finite Element (FE) Models of the AAA. The AAA model was loaded by a pressure step and a cyclic pressure wave and their transition into wall tension was investigated. To this end ILT’s permeability was varied within a microstructurally motivated range. Results The two-phase model verified that the ILT transmits the entire mean arterial pressure to the wall while, at the same time, it significantly reduces the stress in the wall. The predicted mean stress in the AAA wall was insensitive to the permeability of the ILT and coincided with the results of AAA models using a single-phase ILT description. Conclusion At steady state, the biphasic ILT behaves like a single-phase material in an AAA model. Consequently, computational efficient FE single-phase models, as they have been exclusively used in the past, accurately predict the wall stress in AAA models. PMID:22931215

  5. Changes in Bladder Wall Thickness and Detrusor Wall Thickness After Surgical Treatment of Benign Prostatic Enlargement in Patients With Lower Urinary Tract Symptoms: A Preliminary Report

    PubMed Central

    Lee, Hakmin; Choo, Minsoo; Kim, Myong; Cho, Sung Yong; Lee, Seung Bae; Jeong, Hyeon

    2014-01-01

    Purpose The purpose of the present study was to evaluate the perioperative changes in bladder wall thickness and detrusor wall thickness after transurethral prostatectomy. Materials and Methods Fifty-one men who were treated for benign prostatic hyperplasia/lower urinary tract symptoms with transurethral prostatectomy were prospectively analyzed from May 2012 to July 2013. Prostate size, detrusor wall thickness, and bladder wall thickness were assessed by transrectal and transabdominal ultrasonography perioperatively. All postoperative evaluations were performed 1 month after the surgery. Results The patients' mean age was 69.0 years, the mean prostate-specific antigen concentration was 8.1 ng/mL, and the mean prostate volume was 63.2 mL. The mean bladder wall thickness was 5.1 mm (standard deviation [SD], ±1.6), 5.1 mm (SD, ±1.6), and 5.0 mm (SD, ±1.4) preoperatively and 4.5 mm (SD, ±1.5), 4.5 mm (SD, ±1.3), and 4.6 mm (SD, ±1.2) postoperatively in the anterior wall, dome, and trigone, respectively (p=0.178, p=0.086, and p=0.339, respectively). The mean detrusor wall thickness was 0.9 mm (SD, ±0.4) preoperatively and 0.7 mm (SD, ±0.3) postoperatively (p=0.001). A subgroup analysis stratifying patients into a large prostate group (weight, ≥45 g) and a high Abrams-Griffiths number group (>30) showed a significant decrease in detrusor wall thickness (p=0.002, p=0.018). Conclusions There was a decrease in detrusor wall thickness after transurethral prostatectomy. The large prostate group and the high Abrams-Griffiths number group showed a significant decrease in detrusor wall thickness after surgery. PMID:24466397

  6. The quasi-static failure properties of the abdominal aortic aneurysm wall estimated by a mixed experimental-numerical approach.

    PubMed

    Forsell, Caroline; Swedenborg, Jesper; Roy, Joy; Gasser, T Christian

    2013-07-01

    Assessing the risk for abdominal aortic aneurysm (AAA) rupture is critical in the management of aneurysm patients and an individual assessment is possible with the biomechanical rupture risk assessment. Such an assessment could potentially be improved by a constitutive AAA wall model that accounts for irreversible damage-related deformations. Because of that the present study estimated the elastic and inelastic properties of the AAA wall through a mixed experimental-numerical approach. Specifically, finite element (FE) models of bone-shaped tensile specimens were used to merge data from failure testing of the AAA wall with their measured collagen orientation distribution. A histo-mechanical constitutive model for collagen fibers was employed, where plastic fibril sliding determined not only remaining deformations but also weakening of the fiber. The developed FE models were able to replicate the experimentally recorded load-displacement property of all 16 AAA wall specimens that were investigated in the study. Tensile testing in longitudinal direction of the AAA defined a Cauchy strength of 569(SD 411) kPa that was reached at a stretch of 1.436(SD 0.118). The stiffness and strength of specimens decreased with the wall thickness and were elevated (p = 0.018; p = 0.030) in patients with chronic obstructive pulmonary disease (COPD). Smoking affected the tissue parameters that were related to the irreversible deformation response, and no correlation with gender and age was found. The observed effects on the biomechanical properties of the AAA wall could have long-term consequences for the management of aneurysm patients, i.e., specifically they might influence future AAA rupture risk assessments. However, in order to design appropriate clinical validation studies our findings should firstly be verified in a larger patient cohort. PMID:23263935

  7. Adipocyte in vascular wall can induce the rupture of abdominal aortic aneurysm

    PubMed Central

    Kugo, Hirona; Zaima, Nobuhiro; Tanaka, Hiroki; Mouri, Youhei; Yanagimoto, Kenichi; Hayamizu, Kohsuke; Hashimoto, Keisuke; Sasaki, Takeshi; Sano, Masaki; Yata, Tatsuro; Urano, Tetsumei; Setou, Mitsutoshi; Unno, Naoki; Moriyama, Tatsuya

    2016-01-01

    Abdominal aortic aneurysm (AAA) is a vascular disease involving the gradual dilation of the abdominal aorta. It has been reported that development of AAA is associated with inflammation of the vascular wall; however, the mechanism of AAA rupture is not fully understood. In this study, we investigated the mechanism underlying AAA rupture using a hypoperfusion-induced animal model. We found that the administration of triolein increased the AAA rupture rate in the animal model and that the number of adipocytes was increased in ruptured vascular walls compared to non-ruptured walls. In the ruptured group, macrophage infiltration and the protein levels of matrix metalloproteinases 2 and 9 were increased in the areas around adipocytes, while collagen-positive areas were decreased in the areas with adipocytes compared to those without adipocytes. The administration of fish oil, which suppresses adipocyte hypertrophy, decreased the number and size of adipocytes, as well as decreased the risk of AAA rupture ratio by 0.23 compared to the triolein administered group. In human AAA samples, the amount of triglyceride in the adventitia was correlated with the diameter of the AAA. These results suggest that AAA rupture is related to the abnormal appearance of adipocytes in the vascular wall. PMID:27499372

  8. Adipocyte in vascular wall can induce the rupture of abdominal aortic aneurysm.

    PubMed

    Kugo, Hirona; Zaima, Nobuhiro; Tanaka, Hiroki; Mouri, Youhei; Yanagimoto, Kenichi; Hayamizu, Kohsuke; Hashimoto, Keisuke; Sasaki, Takeshi; Sano, Masaki; Yata, Tatsuro; Urano, Tetsumei; Setou, Mitsutoshi; Unno, Naoki; Moriyama, Tatsuya

    2016-01-01

    Abdominal aortic aneurysm (AAA) is a vascular disease involving the gradual dilation of the abdominal aorta. It has been reported that development of AAA is associated with inflammation of the vascular wall; however, the mechanism of AAA rupture is not fully understood. In this study, we investigated the mechanism underlying AAA rupture using a hypoperfusion-induced animal model. We found that the administration of triolein increased the AAA rupture rate in the animal model and that the number of adipocytes was increased in ruptured vascular walls compared to non-ruptured walls. In the ruptured group, macrophage infiltration and the protein levels of matrix metalloproteinases 2 and 9 were increased in the areas around adipocytes, while collagen-positive areas were decreased in the areas with adipocytes compared to those without adipocytes. The administration of fish oil, which suppresses adipocyte hypertrophy, decreased the number and size of adipocytes, as well as decreased the risk of AAA rupture ratio by 0.23 compared to the triolein administered group. In human AAA samples, the amount of triglyceride in the adventitia was correlated with the diameter of the AAA. These results suggest that AAA rupture is related to the abnormal appearance of adipocytes in the vascular wall. PMID:27499372

  9. The occurrence of an abdominal wall abscess 11 years after appendectomy: report of a case.

    PubMed

    Matsuda, K; Masaki, T; Toyoshima, O; Ono, M; Muto, T

    1999-01-01

    Most complications after appendectomy occur within 10 days; however, we report herein the unusual case of a patient in whom a wound abscess was detected more than 10 years after an appendectomy. A 26-year-old woman presented to our hospital with nausea and vomiting, pain, and a mass in the right lower abdominal wall. She had undergone an appendectomy 11 years previously. Physical examination revealed a tender mass, 5 cm in diameter, under the appendectomy scar. An abdominal ultrasonography demonstrated a low-echoic mass lesion measuring 9.0 x 5.0 x 2.0 cm. Incision of the connective tissue revealed about 3 ml of cream-colored and odorless fluid in the abscess cavity. Fistulography revealed an abscess cavity not communicating with the bowel lumen. Floss was discovered in the connective tissue and removed. Debridement of the abscess wall was performed and a piece of the wall was sent for histologic examination. Pathological examination revealed panniculitis of the subcutaneous tissue, and panniculitis with granulation and granuloma of the abscess wall. This case report demonstrates that a preoperative diagnosis should be based not on one finding, but on all findings collected, inclusively. PMID:10489140

  10. A simulation framework for estimating wall stress distribution of abdominal aortic aneurysm.

    PubMed

    Qin, Jing; Zhang, Jing; Chui, Chee-Kong; Huang, Wei-Min; Yang, Tao; Pang, Wai-Man; Sudhakar, Venkatesh; Chang, Stephen

    2011-01-01

    Abdominal aortic aneurysm (AAA) rupture is believed to occur when the mechanical stress acting on the wall exceeds the strength of the wall tissue. In endovascular aneurysm repair, a stent-graft in a catheter is released at the aneurysm site to form a new blood vessel and protect the weakened AAA wall from the pulsatile pressure and, hence, possible rupture. In this paper, we propose a framework to estimate the wall stress distribution of non-stented/stented AAA based on fluid-structure interaction, which is utilized in a surgical simulation system (IRAS). The 3D geometric model of AAA is reconstructed from computed tomography angiographic (CTA) images. Based on our experiments, a combined logarithm and polynomial strain energy equation is applied to model the elastic properties of arterial wall. The blood flow is modeled as laminar, incompressible, and non-Newtonian flow by applying Navier-Stokes equation. The obtained pressure of blood flow is applied as load on the AAA meshes with and without stent-graft and the wall stress distribution is calculated by fluid-structure interaction (FSI) solver equipped in ANSYS. Experiments demonstrate that our analytical results are consistent with clinical observations. PMID:22254456

  11. Observation of a Flowing Duct in the Abdominal Wall by Using Nanoparticles

    PubMed Central

    Jung, Sharon Jiyoon; Kim, Min-Suk; Lee, Jin-Kyu; Kim, Young-Jae; Soh, Kwang-Sup

    2016-01-01

    The primo vascular system (PVS) is being established as a circulatory system that corresponds to acupuncture meridians. There have been two critical questions in making the PVS accepted as a novel liquid flowing system. The first one was directly to show the flow of liquid in PVS and the second one was to explain why it was not observed in the conventional histological study of animal tissues. Flow in the PVS in the abdominal cavity was previously verified by injecting Alcian blue into a primo node. However, the tracing of the dye to other subsystems of the PVS has not been done. In the current work we injected fluorescent nanoparticles (FNPs) into a primo node and traced them along a primo vessel which was inside a fat tissue in the abdominal wall. Linea alba is a white middle line in the abdominal skin of a mammal and a band of fat tissue is located in parallel to the linea alba in the parietal side of the abdominal wall of a rat. In this fat band a primo vessel runs parallel to the prominent blood vessels in the fat band and is located just inside the parietal peritoneum. About the second question on the reason why the PVS was not in conventional histological study the current work provided the answer. Histological analysis with hematoxyline and eosine, Masson’s trichrome, and Toluidine blue could not discriminate the primo vessel even when we knew the location of the PVS by the trace of the FNPs. This clearly explains why the PVS is hard to observe in conventional histology: it is not a matter of resolution but the contrast. The PVS has very similar structure to the connective tissues that surround the PVS. In the current work we propose a method to find the PVS: Observation of mast cell distribution with toluidine blue staining and the PN has a high density of mast cells, while the lymph node has low density. PMID:26937963

  12. Observation of a Flowing Duct in the Abdominal Wall by Using Nanoparticles.

    PubMed

    Jang, HyunSuk; Yoon, Joohwan; Gil, HyunJi; Jung, Sharon Jiyoon; Kim, Min-Suk; Lee, Jin-Kyu; Kim, Young-Jae; Soh, Kwang-Sup

    2016-01-01

    The primo vascular system (PVS) is being established as a circulatory system that corresponds to acupuncture meridians. There have been two critical questions in making the PVS accepted as a novel liquid flowing system. The first one was directly to show the flow of liquid in PVS and the second one was to explain why it was not observed in the conventional histological study of animal tissues. Flow in the PVS in the abdominal cavity was previously verified by injecting Alcian blue into a primo node. However, the tracing of the dye to other subsystems of the PVS has not been done. In the current work we injected fluorescent nanoparticles (FNPs) into a primo node and traced them along a primo vessel which was inside a fat tissue in the abdominal wall. Linea alba is a white middle line in the abdominal skin of a mammal and a band of fat tissue is located in parallel to the linea alba in the parietal side of the abdominal wall of a rat. In this fat band a primo vessel runs parallel to the prominent blood vessels in the fat band and is located just inside the parietal peritoneum. About the second question on the reason why the PVS was not in conventional histological study the current work provided the answer. Histological analysis with hematoxyline and eosine, Masson's trichrome, and Toluidine blue could not discriminate the primo vessel even when we knew the location of the PVS by the trace of the FNPs. This clearly explains why the PVS is hard to observe in conventional histology: it is not a matter of resolution but the contrast. The PVS has very similar structure to the connective tissues that surround the PVS. In the current work we propose a method to find the PVS: Observation of mast cell distribution with toluidine blue staining and the PN has a high density of mast cells, while the lymph node has low density. PMID:26937963

  13. Layer-dependent wall properties of abdominal aortic aneurysms: Experimental study and material characterization.

    PubMed

    Sassani, Sophia G; Kakisis, John; Tsangaris, Sokrates; Sokolis, Dimitrios P

    2015-09-01

    Mechanical testing and in-depth characterization of the abdominal aortic aneurysm wall from fifteen patients undergoing open surgery was performed to establish the layer-dependent tissue properties that are non-available in the literature. Quantitative microscopic evaluation was performed to identify the spatial organization of collagen-fiber network. Among a number of candidate models, the four-fiber family (microstructure-motivated) model, especially that including dispersions of fiber angles about the main directions, was superior to the Fung- and Gasser-type models in the fitting quality allowed, though it presented a practical difficulty in parameter estimation, so that an analysis was conducted aiding the identification of a more specific diagonal- and circumferential-fiber family model for all three layers. The adventitia was stiffer and stronger than the other layers, owing to its increased collagen content, and its contribution to the response of the intact wall was augmented being under greater residual tension than the media, whereas the intima was under residual compression. All layers were stiffer circumferentially than longitudinally, due to preferential collagen arrangement along that axis. The histologically-guided material characterization of layered wall presented herein is expected to assist clinical decision, by developing reliable criteria to predict the rupture risk of abdominal aortic aneurysms, and optimize endovascular interventions. PMID:26011656

  14. The influence of mesh topology in the abdominal wall repair process.

    PubMed

    De Maria, Carmelo; Burchielli, Silvia; Salvadori, Claudia; Santoro, Vito; Montemurro, Francesca; Orsi, Gianni; Vozzi, Giovanni

    2016-08-01

    The tissue integration and the formation of adhesions in the repair of abdominal wall defects are principally led to the topology and the mechanical properties of implanted prosthesis. In this study we analyzed the influence of the topology of the meshes for abdominal wall repair, made of polypropylene (PP), evaluating its ability to prevent and to minimize the formation of adhesions, and to promote tissue ingrowth. Two series of in vivo studies were performed. In the first, two types of PP meshes, a lightweight macroporous mesh (LWM) and a heavyweight microporous mesh (HWM) were compared with determine the optimal porosity for tissue integration. In the second, a composite mesh, Clear Mesh Composite (CMC), made of a LWM sewn on a PP planar smooth film, was compared with a PP planar film, to demonstrate how two different topologies of same material are able to induce different tissue integration with the abdominal wall and different adhesion with internal organs. In both studies, the prostheses were implanted in Wistar rats and histological analysis and mechanical characterization of tissue coupled with the implants were performed. LWM showed better host tissue ingrowth in comparison to HWM. CMC prosthesis showed no adhesions to the viscera and no strong foreign body reaction, moreover its elasticity and anisotropy index were more similar to that of natural tissue. These results demonstrated that the surface morphology of PP surgical meshes allowed to modulate their repair ability. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1220-1228, 2016. PMID:26097153

  15. Intensity modulated radiation-therapy for preoperative posterior abdominal wall irradiation of retroperitoneal liposarcomas

    SciTech Connect

    Bossi, Alberto . E-mail: alberto.bossi@uz.kuleuven.ac.be; De Wever, Ivo; Van Limbergen, Erik; Vanstraelen, Bianca

    2007-01-01

    Purpose: Preoperative external-beam radiation therapy (preop RT) in the management of Retroperitoneal Liposarcomas (RPLS) typically involves the delivery of radiation to the entire tumor mass: yet this may not be necessary. The purpose of this study is to evaluate a new strategy of preop RT for RPLS in which the target volume is limited to the contact area between the tumoral mass and the posterior abdominal wall. Methods and Materials: Between June 2000 and Jan 2005, 18 patients with the diagnosis of RPLS have been treated following a pilot protocol of pre-op RT, 50 Gy in 25 fractions of 2 Gy/day. The Clinical Target Volume (CTV) has been limited to the posterior abdominal wall, region at higher risk for local relapse. A Three-Dimensional conformal (3D-CRT) and an Intensity Modulated (IMRT) plan were generated and compared; toxicity was reported following the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events v3.0. Results: All patients completed the planned treatment and the acute toxicity was tolerable: 2 patients experienced Grade 3 and 1 Grade 2 anorexia while 2 patients developed Grade 2 nausea. IMRT allows a better sparing of the ipsilateral and the contralateral kidney. All tumors were successfully resected without major complications. At a median follow-up of 27 months 2 patients developed a local relapse and 1 lung metastasis. Conclusions: Our strategy of preop RT is feasible and well tolerated: the rate of resectability is not compromised by limiting the preop CTV to the posterior abdominal wall and a better critical-structures sparing is obtained with IMRT.

  16. Abdominal Wall Hematoma as a Rare Complication following Percutaneous Coronary Intervention

    PubMed Central

    Moon, In Tae; Sohn, Young Seok; Lee, Ji Young; Park, Hwan Cheol; Choi, Sung Il; Kim, Soon Gil; Oh, Ji Young

    2016-01-01

    Abdominal wall hematoma is a rare but potentially serious vascular complication that may develop after coronary angiographic procedures. In particular, an oblique muscle hematoma caused by an injury of the circumflex iliac artery is very rare, yet can be managed by conservative treatment including hydration and transfusion. However, when active bleeding continues, angiographic embolization or surgery might be needed. In this study, we report an uncommon case of injury to the circumflex iliac artery by an inappropriate introduction of the hydrophilic guidewire during the performance of a percutaneous coronary intervention.

  17. Systemic juvenile xanthogranulomatosis imitating a malignant abdominal wall tumor with lung metastases.

    PubMed

    Matcham, Nicola J; Andronikou, Savvas; Sibson, Keith; Ramani, Pramila; Grier, David

    2007-01-01

    Juvenile xanthogranulomatosis (JXG) is a rare benign condition, which usually presents with characteristic skin lesions and can be diagnosed clinically. However, systemic JXG may involve a wide range of extracutaneous sites and may pose a diagnostic dilemma for the clinician, radiologist, and pathologist. In particular it may simulate malignancy. Here, we report a case of systemic JXG within the abdominal wall musculature and lungs, which imitated a sarcoma with pulmonary metastases on computerized tomography. To the best of our knowledge, this is the first such reported case. In particular, systemic disease presenting without skin lesions is unusual. PMID:17230073

  18. Intramedullary spinal cord ganglioglioma presenting with abnormal abdominal wall movement. Case report.

    PubMed

    Aslanabadi, Saeid; Azhough, Ramin; Motlagh, Parviz Samad; Hadidchi, Shahram; Tabrizi, Ali Dastranj; Zonouzy, Keivan Kashy

    2004-10-15

    The authors present a case of intramedullary ganglioglioma in a 6-year-old girl. Since the age of 4 months the patient had experienced a spontaneous wavy undulating movement of her anterior abdominal wall resembling a severe peristalsis. The movement was continuous even during sleep, and this symptom was named "belly dance." Magnetic resonance images revealed an intramedullary tumor with ill-defined borders, and the lesion was partially resected. The patient made a good recovery, although 4 years postsurgery her scoliosis had progressed. PMID:15633994

  19. Repair of Full-Thickness Defects in Alimentary Tract Wall With Patches of Expanded Polytetrafluoroethylene

    PubMed Central

    Oh, Daniel S.; Manning, Melanie M.; Emmanuel, Janson; Broyles, Stuart E.; Stone, H. Harlan

    2002-01-01

    Objectives To test the efficacy of patches of expanded polytetrafluoroethylene (ePTFE) for the repair of full-thickness defects in alimentary tract wall. Summary Background Data A recent report of successful replacement of duodenal wall with patches of ePTFE was met with skepticism and clearly warranted confirmation as well as evaluation in repair of other segments of the abdominal intestinal tract. Methods Defects of 4 cm2 were created in various segments of canine abdominal alimentary tract (stomach, duodenum, small bowel, and colon) as well as in bladder dome. For the duodenum in 13 dogs, three different ePTFE fabrications were used: CVX (cardiovascular), PDX (preclude dura membrane), and DLM (dual mesh plus). In repair of the other areas in six dogs, the PDX patch was used. When the animals were killed, both gross inspection of the parietes and tissue for histologic study became the basis for evaluation. Peritoneal and intraluminal cultures of the specific study viscera were also taken. Results There were no patch failures. Only six significant adhesions were noted in 3 of the 19 dogs. Serosal surface healing was complete without exception by 1 week in all animals. Patches of CVX and PDX had heaping mucosa at the margin of well-sealed patch edges in the study involving duodenum. However, the DLM patch had an undergrowth of mucosa with partial patch separation by 1 week, beginning patch extrusion into gut lumen at 3 weeks, and total separation of patch with complete mucosal repair at 6 weeks. The fate of the PDX patches at 6 weeks in stomach, small bowel, colon, and bladder was identical to what had been observed for the PDX patch in the duodenum. All peritoneal and bladder cultures had no growth, whereas the contents of the alimentary tract grew expected flora. Conclusions These observations suggest that ePTFE may well be an acceptable membrane for at least temporary replacement of full-thickness hollow viscus defects, even in the face of heavy bacterial

  20. Assessment of bladder wall thickness in women with overactive bladder

    PubMed Central

    Üçer, Oktay; Gümüş, Bilal; Albaz, Ali Can; Pekindil, Gökhan

    2016-01-01

    Objective To compare bladder wall thickness (BWT) between female patients with overactive bladder (OAB) and aged-matched healthy controls. Material and methods Thirty-six female patients with OAB and 31 healthy women were enrolled in the present prospective observational study. Qmax and Qave were measured by using uroflowmetry in all of the women in the patient and control groups, and also maximum bladder capacity (MBC), post- void residual urine (PVRU), prevoiding and postvoiding BWT were measured by using transabdominal ultrasound. Lower urinary tract symptoms of the participants were assessed by using Overactive Bladder Version-8 (OAB-V8) and International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). All of the data were statistically compared between the patient and control groups. In the patient group, the relationships between parameters were evaluated correlation analysis. Results The mean age of the patients and controls were similar (respectively, 45.58±12.35 and 44.21±11.60 years (p=0.68). The mean pre- and post-voiding BWT, OAB-V8 and ICIQ-SF scores of the patients were significantly higher than the controls. In the patient group, the moderate positive correlations between BWT with Qmax (p=0.02) and Qave (p=0.02) were found. Conclusion This study showed that the BWTs of the female patients with OAB are higher than those of healthy women. Further studies should investigate the changes in BWT of patients with OAB after treatment of OAB. PMID:27274895

  1. A pilot study on bladder wall thickness at different filling stages

    NASA Astrophysics Data System (ADS)

    Zhang, Xi; Liu, Yang; Li, Baojuan; Zhang, Guopeng; Liang, Zhengrong; Lu, Hongbing

    2015-03-01

    The ever-growing death rate and the high recurrence of bladder cancer make the early detection and appropriate followup procedure of bladder cancer attract more attention. Compare to optical cystoscopy, image-based studies have revealed its potentials in non-invasive observations of the abnormities of bladder recently, in which MR imaging turns out to be a better choice for bladder evaluation due to its non-ionizing and high contrast between urine and wall tissue. Recent studies indicate that bladder wall thickness tends to be a good indicator for detecting bladder wall abnormalities. However, it is difficult to quantitatively compare wall thickness of the same subject at different filling stages or among different subjects. In order to explore thickness variations at different bladder filling stages, in this study, we preliminarily investigate the relationship between bladder wall thickness and bladder volume based on a MRI database composed of 40 datasets acquired from 10 subjects at different filling stages, using a pipeline for thickness measurement and analysis proposed in our previous work. The Student's t-test indicated that there was no significant different on wall thickness between the male group and the female group. The Pearson correlation analysis result indicated that negative correlation with a correlation coefficient of -0.8517 existed between the wall thickness and bladder volume, and the correlation was significant(p <0.01). The corresponding linear regression equation was then estimated by the unary linear regression. Compared to the absolute value of wall thickness, the z-score of wall thickness would be more appropriate to reflect the thickness variations. For possible abnormality detection of a bladder based on wall thickness, the intra-subject and inter-subject thickness variation should be considered.

  2. An Abdominal Wall Desmoid Tumour Mimicking Cesarean Scar Endometriomas: A Case Report and Review of the Literature

    PubMed Central

    Vural, Fisun; Müezzinoglu, Bahar

    2015-01-01

    Abdominal wall desmoid tumours (DT) are rare, slow-growing benign muscular-aponeurotic fibrous tumours with the tendency to locally invade and recur. They constitute 0.03% of all neoplasms and high infiltration and recurrence rate, but there is no metastatic potential. Although surgery is the primary treatment modality, the optimal treatment remains unclear. Abdominal wall endometriosis is also an unusual disease, and preoperative clinical diagnosis is not always easy. The preoperative radiologic imaging modalities may not aid all the time. Herein, we report an abdominal mass presenting as cyclic pain. Forty-two years old woman who gave birth by cesarean section admitted the complaints of painful abdominal mass (78x45 mm in size) under her cesarean incision scar. She had severe pain, particularly during menstruation. The clinical and radiological imaging findings mimicking endometrioma. We performed wide surgical excision of mass with a 1 cm tumor-free margin with the diagnosis of a benign mesenchymal tumor in the frozen section. The postoperative course was uneventful and recovered without any complication and recurrence three years after surgery. This report presents a case of abdominal wall desmoid tumor mimicking endometrioma. In this paper, shortcomings in diagnosis, abdominal wall endometriomas, and DTs were discussed in the view of literature. PMID:26500967

  3. Laparoscopic Treatment of Ventral Abdominal Wall Hernias: Preliminary Results in 100 Patients

    PubMed Central

    Martín del Olmo, Juan Carlos; Blanco, Jose Ignacio; de la Cuesta, Carmen; Martín, Fernando; Toledano, Miguel; Perna, Christiam; Vaquero, Carlos

    2000-01-01

    Objective: The laparoscopic treatment of eventrations and ventral hernias has been little used, although these hernias are well suited to a laparoscopic approach. The objective of this study was to investigate the usefulness of a laparoscopic approach in the surgical treatment of ventral hernias. Methods: Between January 1994 and July 1998, a series of 100 patients suffering from major abdominal wall defects were operated on by means of laparoscopic techniques, with a mean postoperative follow-up of 30 months. The mean number of defects was 2.7 per patient, the wall defect was 93 cm2 on average. There were 10 minor hernias (<5 cm), 52 medium-size hernias (5-10 cm), and 38 large hernia (>10 cm). The origin of the wall defect was primary in 21 cases and postsurgical in 79. Three access ports were used, and the defects were covered with PTFE Dual Mesh measuring 19 × 15 cm in 54 cases, 10 x 15 cm in 36 cases, and 12 × 8 cm in 10 cases. An additional mesh had to be added in 21 cases. In the last 30 cases, PTFE Dual Mesh Plus with holes was employed. Results: Average surgery time was 62 minutes. One procedure was converted to open surgery, and only one patient required a second operation in the early postoperative period. Minor complications included 2 patients with abdominal wall edema, 10 seromas, and 3 subcutaneous hematomas. There were no trocar site infections. Two patients developed hernia relapse (2%) in the first month after surgery and were reoperated with a similar laparoscopic technique. Oral intake and mobilization began a few hours after surgery. The mean stay in hospital was 28 hours. Conclusions: Laparoscopic technique makes it possible to avoid large incisions, the placement of drains, and produces a lower number of seromas, infections and relapses. Laparoscopic access considerably shortens the time spent in the hospital. PMID:10917121

  4. Intramuscular abdominal wall endometriosis treated by ultrasound-guided ethanol injection.

    PubMed

    Bozkurt, Murat; Çil, A Said; Bozkurt, Duygu Kara

    2014-12-01

    Abdominal wall endometriosis (AWE) is a rare condition that usually develops in a surgical scar resulting from a Caesarean section. While commonly seen in the cutaneous and subcutaneous fat tissue at the Caesarean scar level, its intramuscular localization is quite rare. Its treatment options consist of the excision of the lesion and/or hormonal therapies, although wide surgical excision is the treatment of choice in the literature. Wide surgical excision may create a defect in the abdominal wall and may increase the risk of hernia formation and mesh complications. This case report describes the clinical and radiological findings and treatment modalities of endometriosis that have appeared in the rectus abdominis muscle of a 25-year-old patient at the Caesarean scar level. Sclerotherapy may be used for endometrioma. We present a new and alternative treatment method using ultrasound-guided intralesional ethanol injection for AWE. Compared with the complications of surgical excision, the complications of sclerotherapy by ethanol are at a more acceptable level. Sclerotherapy by ethanol injection may be an alternative treatment to surgery for AWE. PMID:24667221

  5. Intramuscular Abdominal Wall Endometriosis Treated by Ultrasound-Guided Ethanol Injection

    PubMed Central

    Bozkurt, Murat; Çil, A. Said; Bozkurt, Duygu Kara

    2014-01-01

    Abdominal wall endometriosis (AWE) is a rare condition that usually develops in a surgical scar resulting from a Caesarean section. While commonly seen in the cutaneous and subcutaneous fat tissue at the Caesarean scar level, its intramuscular localization is quite rare. Its treatment options consist of the excision of the lesion and/or hormonal therapies, although wide surgical excision is the treatment of choice in the literature. Wide surgical excision may create a defect in the abdominal wall and may increase the risk of hernia formation and mesh complications. This case report describes the clinical and radiological findings and treatment modalities of endometriosis that have appeared in the rectus abdominis muscle of a 25-year-old patient at the Caesarean scar level. Sclerotherapy may be used for endometrioma. We present a new and alternative treatment method using ultrasound-guided intralesional ethanol injection for AWE. Compared with the complications of surgical excision, the complications of sclerotherapy by ethanol are at a more acceptable level. Sclerotherapy by ethanol injection may be an alternative treatment to surgery for AWE. PMID:24667221

  6. Neuromuscular independence of abdominal wall muscles as demonstrated by middle-eastern style dancers.

    PubMed

    Moreside, Janice M; Vera-Garcia, Francisco J; McGill, Stuart M

    2008-08-01

    Previous studies analyzing neuromuscular independence of the abdominal wall have involved a participant population with no specific training in separating individual muscle segments. We chose to study nine women trained in the art of middle-eastern dance, anticipating they may have unique skills in motor control. Specifically, we were searching for evidence of separation of upper rectus abdominis (URA) from lower rectus abdominis (LRA), as well as understanding what role the oblique muscles play in abdominal wall synergies. EMG analysis was done on eight trunk muscles bilaterally as the dancers participated in 30 dance, planar, and curl-up activities. The filtered data were then cross-correlated to determine the time lag between pairs of signals. Only three dance movements demonstrated consistent evidence of an ability to separate URA/LRA activation timing. The external and internal oblique muscles tend to align themselves temporally with the LRA. However, these findings were only evident in these three specific "belly-roll" conditions, all with low levels of muscle activation, and no external torque. Evidence of significantly different activation levels (% MVC) between URA/LRA was demonstrated in eight conditions, all of which required various pelvis movements with minimal thorax motion. PMID:17329127

  7. Efficacy and safety of hyaluronate membrane in the rabbit cecum-abdominal wall adhesion model

    PubMed Central

    Kim, Jae Young; Cho, Wan Jin; Kim, Jun Ho; Lim, Sae Hwan; Kim, Hyun Jung; Lee, Young Woo

    2013-01-01

    Purpose Tissue adhesion is a well-known postsurgical phenomenon, causing pain, functional obstruction, and difficult reoperative surgery. To overcome these problems, various synthetic and natural polymer membranes have been developed as postoperative tissue adhesion barriers. However, limitation in their use has hindered its actual application. We prepared a hyaluronate membrane (HM) to evaluate its efficacy and safety as an adhesion barrier compared to a commercialized product (Interceed, Ethicon). Methods To evaluate the antiadhesion effect, a cecum-abdominal wall abrasion model was adopted in a rabbit. The denuded cecum was covered by Interceed or HM or neither and apposed to the abdominal wall (each, n = 10). Four weeks after surgery, the level of adhesion was graded. Acute and chronic toxicity of the three groups were also evaluated. Results Blood samples drawn to evaluate acute toxicity at postoperative day 3 and 7 showed no significant difference among the three groups. The grade and area of adhesion were significantly lower in the HM compared to those of the control and Interceed at four weeks after surgery. Histologic evaluations, which was carried out to estimate tissue reactions at the site of application, as well as to assess chronic toxicity for the major organs, were not significantly different in the three groups. Conclusion This study showed that the antiadhesion efficacy of HM was superior to commercialized antiadhesion membrane, Interceed. Low inflammatory response and nontoxicity were also demonstrated. From these results, we suggest that the HM is a good candidate as a tissue adhesion barrier. PMID:23908960

  8. Whole Abdominal Wall Segmentation using Augmented Active Shape Models (AASM) with Multi-Atlas Label Fusion and Level Set

    PubMed Central

    Xu, Zhoubing; Baucom, Rebeccah B.; Abramson, Richard G.; Poulose, Benjamin K.; Landman, Bennett A.

    2016-01-01

    The abdominal wall is an important structure differentiating subcutaneous and visceral compartments and intimately involved with maintaining abdominal structure. Segmentation of the whole abdominal wall on routinely acquired computed tomography (CT) scans remains challenging due to variations and complexities of the wall and surrounding tissues. In this study, we propose a slice-wise augmented active shape model (AASM) approach to robustly segment both the outer and inner surfaces of the abdominal wall. Multi-atlas label fusion (MALF) and level set (LS) techniques are integrated into the traditional ASM framework. The AASM approach globally optimizes the landmark updates in the presence of complicated underlying local anatomical contexts. The proposed approach was validated on 184 axial slices of 20 CT scans. The Hausdorff distance against the manual segmentation was significantly reduced using proposed approach compared to that using ASM, MALF, and LS individually. Our segmentation of the whole abdominal wall enables the subcutaneous and visceral fat measurement, with high correlation to the measurement derived from manual segmentation. This study presents the first generic algorithm that combines ASM, MALF, and LS, and demonstrates practical application for automatically capturing visceral and subcutaneous fat volumes. PMID:27127333

  9. The muscles of the infrapubic abdominal wall of a 6-month-old Crocodylus niloticus (Reptilia: Crocodylia).

    PubMed

    Fechner, R; Schwarz-Wings, D

    2013-06-01

    The muscles of the infrapubic abdominal wall of crocodilians play an important role in their ventilatory mechanism. Yet the anatomy and homology of these muscles is poorly understood. To gain new insights into the anatomy of the crocodilian infrapubic abdominal wall, we dissected a specimen of Crocodylus niloticus. Origin and insertion of the muscles, as well as their arrangement relative to each other was examined in great detail. The findings were compared with those of other crocodilian taxa to detect potential variability of the muscles of interest. The homology of the muscles was studied by comparing the muscles of the crocodilian infrapubic abdominal wall with those of other diapsids. In Crocodylus niloticus, the infrapubic abdominal wall consists of four muscles: Musculus truncocaudalis, M. ischiotruncus, and Mm. rectus abdominis externus and internus. The arrangement of the muscles of the infrapubic abdominal wall of Crocodylus niloticus is consistent with that found in most other crocodilian taxa. In some crocodilian taxa, an additional muscle, M. ischiopubis, is found. In the remaining diapsids, only M. rectus abdominis is present. The crocodilian M. truncocaudalis, M. ischiotruncus and, if present, M. ischiopubis appear to be derivates of M. rectus abdominis; the development of those might be related to the evolution of the unique crocodilian ventilatory mechanism. PMID:22909340

  10. Abdominal wall competence after free transverse rectus abdominis musculocutaneous flap harvest: a prospective study.

    PubMed

    Suominen, S; Asko-Seljavaara, S; Kinnunen, J; Sainio, P; Alaranta, H

    1997-09-01

    A prospective study was designed to evaluate the possible changes in abdominal wall strength following free transverse rectus abdominis musculocutaneous (TRAM) flap surgery for breast reconstruction. Twenty-two patients were examined 1 day before surgery, and at 3, 6, and 12 months postoperatively. Trunk muscle strength was measured by the same physiotherapist using an isokinetic dynamometer (Lido Multi Joint II, Loredan Biomedical Inc., Davies, CA). The peak torque and average torque for both flexion and extension at 60 degrees per second angular velocity were recorded from the curves obtained. There was a significant reduction in trunk flexion strength at 3 months postoperatively (peak torque mean, 92% of the preoperative value; p = 0.04), but this was corrected by 6 months (mean, 96%), and improved to 98% by 12 months. The patient's ability to do curled trunk sit-ups was evaluated by the same physiotherapist and graded on a scale from 1 to 6. In 9 of 19 patients the operation had no effect on sit-up performance during follow-up. In 10 of 19 patients there was a reduction of one or two grades at 3 months that did not improve by 12 months. Magnetic resonance imaging of the abdominal wall was performed on 9 patients. The mean area of the upper third of both rectus muscles was measured on the axial images. At 3 months postoperatively the mean area of the upper third of the donor muscle was significantly larger than the contralateral (p = 0.03). There was no difference in size at 6 months, and by 12 months the donor side was smaller. This prospective study shows that harvesting of a free TRAM flap can cause a subclinical reduction in abdominal strength, although this was not noticed by the patients themselves. PMID:9326701

  11. Effects of Antimony and Wall Thickness on Graphite Morphology in Ductile Iron Castings

    NASA Astrophysics Data System (ADS)

    Glavas, Zoran; Strkalj, Anita; Maldini, Kresimir

    2016-05-01

    Effects of Sb additions on the graphite morphology of ductile iron castings in different wall thicknesses (3, 12, 25, 38, 50, 75, and 100 mm) were analyzed in this paper. In the wall thicknesses of 3, 12, and 25 mm, low contents of rare earth (RE) elements showed a beneficial effect on nodule count and nodularity. Nodularity >80 pct and a high nodule count were achieved without the addition of Sb. In the wall thicknesses of 38, 50, 75, and 100 mm, nodularity >80 pct was not achieved without the use of the chill or proper content of Sb. Excess of RE elements was neutralized with the addition of proper amount of Sb to the wall thickness. Addition of 0.01 wt pct Sb (ratio of RE/Sb = 0.34, ratio of RE/SE = 0.105) was sufficient to achieve nodularity >80 pct in the wall thicknesses of 38, 50, 75, and 100 mm.

  12. Effects of Antimony and Wall Thickness on Graphite Morphology in Ductile Iron Castings

    NASA Astrophysics Data System (ADS)

    Glavas, Zoran; Strkalj, Anita; Maldini, Kresimir

    2016-08-01

    Effects of Sb additions on the graphite morphology of ductile iron castings in different wall thicknesses (3, 12, 25, 38, 50, 75, and 100 mm) were analyzed in this paper. In the wall thicknesses of 3, 12, and 25 mm, low contents of rare earth (RE) elements showed a beneficial effect on nodule count and nodularity. Nodularity >80 pct and a high nodule count were achieved without the addition of Sb. In the wall thicknesses of 38, 50, 75, and 100 mm, nodularity >80 pct was not achieved without the use of the chill or proper content of Sb. Excess of RE elements was neutralized with the addition of proper amount of Sb to the wall thickness. Addition of 0.01 wt pct Sb (ratio of RE/Sb = 0.34, ratio of RE/SE = 0.105) was sufficient to achieve nodularity >80 pct in the wall thicknesses of 38, 50, 75, and 100 mm.

  13. A Digital Stereomicroscopic Study of the Radicular Wall Thickness of Two-Canal Mandibular Incisors

    PubMed Central

    Khedmat, Sedigheh; Mohamadian, Sohayla; Kharrazifard, Mohamad Javad

    2015-01-01

    Objectives: This study aimed to assess the radicular wall thickness in mandibular incisors with two canals and find the maximum and minimum thickness to prevent root canal treatment (RCT) procedural errors. Materials and Methods: A total of 160 extracted mandibular incisors were selected and radiographed; out of which, 55 had two canals. Three parallel transverse sections were made in each tooth at 1mm below the cementoenamel junction (CEJ), mid-root and 1 millimeter to the apex. Specimens were evaluated under a stereomicroscope and the thickness of radicular walls in each section was determined for the buccal, lingual and proximal surfaces. Data were statistically analyzed using Pearson’s correlation coefficient test. Results: The thickness of radicular wall decreased from the cervical towards the apex. In all three sections (cervical, mid-root and apical), the thickness of lingual wall was significantly greater than the buccal wall. Also, the thickness of buccal and lingual walls was significantly higher than that of the proximal walls. Conclusion: The lingual radicular wall had the highest thickness in two-canal mandibular incisors. Therefore, in these teeth, the lingual canal is a better choice for post placement. PMID:26877738

  14. Abdominal Wall Metastasis of Uterine Papillary Serous Carcinoma in a Post-Menopausal Woman: A Case Report

    PubMed Central

    Park, Jung-Woo

    2014-01-01

    Uterine papillary serous carcinoma (UPSC) is an aggressive form of endometrial cancer characterized by a high recurrence rate and poor prognosis. We report a case of a 58-year-old post-menopausal woman with an abdominal wall metastasis in stage IA UPSC. After surgical staging, she did not receive additional adjuvant therapy. An egg sized palpable mass developed in the right lower abdomen after 8 months. Both Abdominopelvic computed tomography (CT) and positron emission tomography (PET)-CT revealed a metastatic lesion in the abdominal wall. Hence, surgical excision was performed. The pathological findings showed metastatic UPSC with clear resection margin. After the diagnosis of UPSC metastasis in the abdominal wall, she received chemotherapy utilizing paclitaxel and carboplatin. After 3 years, no evidence of recurrence was found. Therefore, we suggest that even when UPSC is confined to the endometrium without lymph node metastasis and without lymphovascular invasion, chemotherapy should be considered as a postoperative adjuvant therapy. PMID:25371890

  15. Abdominal wall metastasis of uterine papillary serous carcinoma in a post-menopausal woman: a case report.

    PubMed

    Park, Jung-Woo; Hwang, Sung-Ook

    2014-04-01

    Uterine papillary serous carcinoma (UPSC) is an aggressive form of endometrial cancer characterized by a high recurrence rate and poor prognosis. We report a case of a 58-year-old post-menopausal woman with an abdominal wall metastasis in stage IA UPSC. After surgical staging, she did not receive additional adjuvant therapy. An egg sized palpable mass developed in the right lower abdomen after 8 months. Both Abdominopelvic computed tomography (CT) and positron emission tomography (PET)-CT revealed a metastatic lesion in the abdominal wall. Hence, surgical excision was performed. The pathological findings showed metastatic UPSC with clear resection margin. After the diagnosis of UPSC metastasis in the abdominal wall, she received chemotherapy utilizing paclitaxel and carboplatin. After 3 years, no evidence of recurrence was found. Therefore, we suggest that even when UPSC is confined to the endometrium without lymph node metastasis and without lymphovascular invasion, chemotherapy should be considered as a postoperative adjuvant therapy. PMID:25371890

  16. New technical approach for the repair of an abdominal wall defect after a transverse rectus abdominis myocutaneous flap: a case report

    PubMed Central

    Kaemmer, Daniel A; Conze, Joachim; Otto, Jens; Schumpelick, Volker

    2008-01-01

    Introduction Breast reconstruction with autologous tissue transfer is now a standard operation, but abnormalities of the abdominal wall contour represent a complication which has led surgeons to invent techniques to minimize the morbidity of the donor site. Case presentation We report the case of a woman who had bilateral transverse rectus abdominis myocutaneous flap (TRAM-flap) breast reconstruction. The surgery led to the patient developing an enormous abdominal bulge that caused her disability in terms of abdominal wall and bowel function, pain and contour. In the absence of rectus muscle, the large defect was repaired using a combination of the abdominal wall component separation technique of Ramirez et al and additional mesh augmentation with a lightweight, large-pore polypropylene mesh (Ultrapro®). Conclusion The procedure of Ramirez et al is helpful in achieving a tension-free closure of large defects in the anterior abdominal wall. The additional mesh augmentation allows reinforcement of the thinned lateral abdominal wall. PMID:18416835

  17. Impact of exercise training on arterial wall thickness in humans

    PubMed Central

    Thijssen, Dick H. J.; Cable, N. Timothy; Green, Daniel J.

    2011-01-01

    Thickening of the carotid artery wall has been adopted as a surrogate marker of pre-clinical atherosclerosis, which is strongly related to increased cardiovascular risk. The cardioprotective effects of exercise training, including direct effects on vascular function and lumen dimension, have been consistently reported in asymptomatic subjects and those with cardiovascular risk factors and diseases. In the present review, we summarize evidence pertaining to the impact of exercise and physical activity on arterial wall remodelling of the carotid artery and peripheral arteries in the upper and lower limbs. We consider the potential role of exercise intensity, duration and modality in the context of putative mechanisms involved in wall remodelling, including haemodynamic forces. Finally, we discuss the impact of exercise training in terms of primary prevention of wall thickening in healthy subjects and remodelling of arteries in subjects with existing cardiovascular disease and risk factors. PMID:22150253

  18. Method of manufacturing hollow members having uniform wall thickness through use of ablation

    DOEpatents

    Anderson, Paul R.; Downs, Raymond L.; Henderson, Timothy M.

    1982-01-01

    A method of manufacturing a hollow structure of uniform wall thickness comprising the steps of selecting or forming a precursor having one wall surface of desired geometry, treating a portion of the precursor consisting of the one wall surface and a uniform depth of material beneath the wall surface to increase resistance to ablation, and then removing by ablation and discarding the remaining or untreated portion of the precursor.

  19. Obesity increases the odds of acquiring and incarcerating noninguinal abdominal wall hernias.

    PubMed

    Lau, Briana; Kim, Hanjoo; Haigh, Philip I; Tejirian, Talar

    2012-10-01

    The current data available describing the relationship of obesity and abdominal wall hernias is sparse. The objective of this study was to investigate the current prevalence of noninguinal abdominal wall hernias and their correlation with body mass index (BMI) and other demographic risk factors. Patients with umbilical, incisional, ventral, epigastric, or Spigelian hernias with or without incarceration were identified using the regional database for 14 hospitals over a 3-year period. Patients were stratified based on their BMI. Univariate and multivariate analyses were performed to distinguish other significant risk factors associated with the hernias. Of 2,807,414 patients, 26,268 (0.9%) had one of the specified diagnoses. Average age of the patients was 52 years and 61 per cent were male. The majority of patients had nonincarcerated umbilical hernias (74%). Average BMI was 32 kg/m2. Compared with patients with a normal BMI, the odds of having a hernia increased with BMI: BMI of 25 to 29.9 kg/m2 odds ratio (OR) 1.63, BMI of 30 to 39.9 kg/m2 OR 2.62, BMI 40 to 49.9 kg/m2 OR 3.91, BMI 50 to 59.9 kg/m2 OR 4.85, and BMI greater than 60 kg/m2 OR 5.17 (P<0.0001). Age older than 50 years was associated with a higher risk for having a hernia (OR, 2.12; 95% [CI], 2.07 to 2.17), whereas female gender was associated with a lower risk (OR, 0.53; 95% CI, 0.52 to 0.55). Those with incarcerated hernias had a higher average BMI (32 kg/m2 vs 35 kg/m2; P<0.0001). Overall, BMI greater than 40 kg/m2 showed an increased chance of incarceration, and a BMI greater than 60 kg/m2 had the highest chance of incarceration, OR 12.7 (P<0.0001). Age older than 50 years and female gender were also associated with a higher risk of incarceration (OR, 1.28; 95% CI, 1.02 to 1.59 and OR, 1.80; CI, 1.45 to 2.24). Increasing BMI and increasing age are associated with a higher prevalence and an increased risk of incarceration of noninguinal abdominal wall hernias. PMID:23025954

  20. Evaluation of porcine dermal collagen (Permacol) used in abdominal wall reconstruction.

    PubMed

    Hsu, Patrick W; Salgado, Christopher J; Kent, Kathryn; Finnegan, Matthew; Pello, Mark; Simons, Robert; Atabek, Umur; Kann, Brian

    2009-11-01

    Various methods have been employed to reconstruct complex abdominal wall defects. Structural prosthetic materials such as polypropylene mesh and ePTFE (expanded polytetrafluoroethylene) have been widely used to close these large fascial defects, however, complications with infection and adhesions have led to the recent use of more biocompatible implants. Permacol (acellular porcine dermis) is used as a dermal scaffold, which eventually becomes vascularised and remodelled to reconstruct the abdominal wall in these complex patients. A retrospective review was performed of all patients who underwent consecutive abdominal wall reconstruction with Permacol at our institution in the year 2006. Twenty-eight patients were identified and included in our study. Factors evaluated were: body mass index, relevant co-morbidities, aetiology of hernia, hernia defect size based on CT scan and intraoperative measurement, size of Permacol implant, length of hospital stay, and postoperative complications. Surgical technique was standardised among six surgeons and involved a single layer of acellular porcine dermis as a subfascial 'underlay' graft under moderate tension upon maximal hernia reduction. Tissue expanders were not required for skin closure. Out of 28 patients, 12 were male and 16 were female. Mean intraoperative hernia size was 150 cm(2) (range of 10 cm(2) to 600 cm(2)). Mean age was 55 years with an average body mass index (BMI) of 34 (largest BMI of 61.4). Defects were attributed to either a previous laparotomy incision or open abdomen. Mean hospital stay was 9.67 days. At a mean follow-up of sixteen months, there were three recurrent hernias (10.7%) based on physical examination and postoperative CT scan evaluation. One patient developed a superficial wound dehiscence which was successfully treated with local wound care and one patient developed a cellulitis which was successfully treated with antibiotic therapy. Four patients (14.3%) developed a chronic, non

  1. Expression of fibrinolytic genes in atherosclerotic abdominal aortic aneurysm wall. A possible mechanism for aneurysm expansion.

    PubMed Central

    Schneiderman, J; Bordin, G M; Engelberg, I; Adar, R; Seiffert, D; Thinnes, T; Bernstein, E F; Dilley, R B; Loskutoff, D J

    1995-01-01

    Expansion of atherosclerotic abdominal aortic aneurysm (AAA) has been attributed to remodeling of the extracellular matrix by active proteolysis. We used in situ hybridization to analyze the expression of fibrinolytic genes in aneurysm wall from eight AAA patients. All specimens exhibited specific areas of inflammatory infiltrates with macrophage-like cells expressing urokinase-type plasminogen activator (u-PA) and tissue-type PA (t-PA) mRNA. Type 1 PA inhibitor (PAI-1) mRNA was expressed at the base of the necrotic atheroma of all specimens and also within some of the inflammatory infiltrates where it frequently colocalized in regions containing u-PA and t-PA mRNA expressing cells. However, in these areas, the cellular distribution of the transcripts for t-PA and u-PA extended far beyond the areas of PAI-1 expression. These observations suggest a local ongoing proteolytic process, one which is only partially counteracted by the more restricted expression of PAI-1 mRNA. An abundance of capillaries was also obvious in all inflammatory infiltrates and may reflect local angiogenesis in response to active pericellular fibrinolysis. The increased fibrinolytic capacity in AAA wall may promote angiogenesis and contribute to local proteolytic degradation of the aortic wall leading to physical weakening and active expansion of the aneurysm. Images PMID:7615837

  2. Patient-specific left atrial wall-thickness measurement and visualization for radiofrequency ablation

    NASA Astrophysics Data System (ADS)

    Inoue, Jiro; Skanes, Allan C.; White, James A.; Rajchl, Martin; Drangova, Maria

    2014-03-01

    INTRODUCTION: For radiofrequency (RF) catheter ablation of the left atrium, safe and effective dosing of RF energy requires transmural left atrium ablation without injury to extra-cardiac structures. The thickness of the left atrial wall may be a key parameter in determining the appropriate amount of energy to deliver. While left atrial wall-thickness is known to exhibit inter- and intra-patient variation, this is not taken into account in the current clinical workflow. Our goal is to develop a tool for presenting patient-specific left atrial thickness information to the clinician in order to assist in the determination of the proper RF energy dose. METHODS: We use an interactive segmentation method with manual correction to segment the left atrial blood pool and heart wall from contrast-enhanced cardiac CT images. We then create a mesh from the segmented blood pool and determine the wall thickness, on a per-vertex basis, orthogonal to the mesh surface. The thickness measurement is visualized by assigning colors to the vertices of the blood pool mesh. We applied our method to 5 contrast-enhanced cardiac CT images. RESULTS: Left atrial wall-thickness measurements were generally consistent with published thickness ranges. Variations were found to exist between patients, and between regions within each patient. CONCLUSION: It is possible to visually determine areas of thick vs. thin heart wall with high resolution in a patient-specific manner.

  3. Unexpected Abscess Localization of the Anterior Abdominal Wall in an ADPKD Patient Undergoing Hemodialysis.

    PubMed

    Sabanis, Nikos; Paschou, Eleni; Gavriilaki, Eleni; Mourounoglou, Maria; Vasileiou, Sotirios

    2015-01-01

    Autosomal Dominant Polycystic Kidney Disease (ADPKD) is one of the most common monogenic disorders and the leading inheritable cause of end-stage renal disease worldwide. Cystic and noncystic extrarenal manifestations are correlated with variable clinical presentations so that an inherited disorder is now considered a systemic disease. Kidney and liver cystic infections are the most common infectious complications in ADPKD patients. Furthermore, it is well known that ADPKD is commonly associated with colonic diverticular disease which recently has been reported to be linked to increased risk of infection on hemodialysis patients. Herein, we present a case of anterior abdominal wall abscess caused by Enterococcus faecalis in a patient with ADPKD undergoing hemodialysis. Although the precise pathway of infection remains uncertain, the previous medical history as well as the clinical course of our patient led us to hypothesize an alternative route of infection from the gastrointestinal tract through an aberrant intestinal barrier into the bloodstream and eventually to an atypical location. PMID:26301109

  4. Spontaneous extraskeletal osteosarcoma with various histological growth patterns in the abdominal wall of an ICR mouse

    PubMed Central

    Ito, Tsuyoshi; Katoh, Yoshitaka; Shimada, Yuko; Ohnuma-Koyama, Aya; Takahashi, Naofumi; Kuwahara, Maki; Harada, Takanori

    2015-01-01

    Extraskeletal osteosarcoma is extremely rare in mice. This case report demonstrates a spontaneous murine extraskeletal osteosarcoma that exhibited various histological growth patterns in an ICR mouse. At necropsy, the tumor mass was located in the abdominal wall and was 45 × 30 × 25 mm in size. Histopathologically, the tumor showed the following four growth patterns: a solid pattern of polygonal cells embedded in an osteoid eosinophilic matrix with calcification, an irregular sheet pattern of short spindle cells accompanying some eosinophilic multinucleated cells, a fascicular pattern of spindle cells and a cystic pattern lined by short spindle cells. Immunohistochemically, most of the tumor cells were positive for vimentin, proliferating cell nuclear antigen and osterix. The multinucleated cells mentioned above were desmin positive and were regarded as regenerative striated muscles but not tumor cells. Since no clear continuity with normal bone tissues was observed, the tumor was diagnosed as an “extraskeletal osteosarcoma.” PMID:26989300

  5. Aesthetic aspects of abdominal wall and external genital reconstructive surgery in bladder exstrophy-epispadias complex.

    PubMed

    VanderBrink, Brian A; Stock, Jeffrey A; Hanna, Moneer K

    2006-03-01

    Long-term follow-up of patients born with classical bladder exstrophy-epispadias complex (EEC) reveals that many of them suffer from poor self-image, and the aesthetic aspects of the genitalia and lower abdomen acquire greater significance with age. In this article, we review the aesthetic outcomes in performing puboplasty, umbilicoplasty, and genitoplasty in patients born with EEC. Retrospective review of the cosmetic and functional outcomes in 116 patients born with EEC treated by puboplasty, umbilicoplasty, or genitoplasty was performed. Satisfaction with the cosmetic and functional outcomes of these three reconstructive surgeries was high following initial reconstructive efforts (> 90%). Attention to cosmesis during abdominal wall and genital reconstruction for EEC helps to improve a patient's perception of body image and self-esteem. Our experience with these procedures over the past 25 years demonstrated that the efforts directed toward aesthetics have been well worthwhile. PMID:16527001

  6. Control of domain wall thickness by spatial modulation of uniaxial anisotropy and exchange stiffness parameters

    NASA Astrophysics Data System (ADS)

    Arai, Hiroko; Imamura, Hiroshi

    2015-03-01

    The effect of spatial modulation of the uniaxial anisotropy (K) and exchange stiffness (A) parameters on the domain wall thickness was theoretically studied. We derived the Euler-Lagrange equation and the Landau-Lifshitz-Gilbert equation considering the modulation of K and A, and showed that the modulation of A gives rise to an additional term consisting of the first derivatives of A and the magnetization unit vector. Owing to this term, the modulation of A is more effective to modify the domain wall thickness than K. The condition for domain wall pinning by controlling its thickness through the modulation of K and A was also obtained.

  7. Method and apparatus for determining diameter and wall thickness of minute hollow spherical shells

    DOEpatents

    Steinman, David A.

    1982-01-01

    Method and apparatus for determining diameter and wall thickness of hollow microspheres or shells wherein terminal velocities of shells traveling in fluid-filled conduits of differing diameters are measured. A wall-effect factor is determined as a ratio of the terminal velocities, and shell outside diameter may then be ascertained as a predetermined empirical function of wall-effect factor. For shells of known outside diameter, wall thickness may then be ascertained as a predetermined empirical function of terminal velocity in either conduit.

  8. Method and apparatus for determining diameter and wall thickness of minute hollow spherical shells

    DOEpatents

    Steinman, D.A.

    1980-05-30

    Method and apparatus for determining diameter and wall thickness of hollow microspheres or shells wherein terminal velocities of shells traveling in fluid-filled conduits of differing diameters are measured. A wall-effect factor is determined as a ratio of the terminal velocities, and shell outside diameter may then be ascertained as a predetermined empirical function of wall-effect factor. For shells of known outside diameter, wall thickness may then be ascertained as a predetermined empirical function of terminal velocity in either conduit.

  9. Method of controlling the side wall thickness of a turbine nozzle segment for improved cooling

    DOEpatents

    Burdgick, Steven Sebastian

    2002-01-01

    A gas turbine nozzle segment has outer and inner bands and a vane extending therebetween. Each band has a side wall, a cover and an impingement plate between the cover and nozzle wall defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through apertures of the impingement plate to cool the nozzle wall. The side wall of the band has an inturned flange defining with the nozzle wall an undercut region. The outer surface of the side wall is provided with a step prior to welding the cover to the side wall. A thermal barrier coating is applied in the step and, after the cover is welded to the side wall, the side wall is finally machined to a controlled thickness removing all, some or none of the coating.

  10. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the marked test pressure of the tank, the calculated fiber stress in psi at inner wall of tank multiplied by 3.0 will not exceed the tensile strength of any specimen taken from the tank and tested as... maximum marked test pressure permitted to be marked on the tank shall be made by the formula: P = [10S(D...

  11. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... pressure equal to 7/10 of the marked test pressure of the tank, the calculated fiber stress in psi at inner wall of tank multiplied by 3.0 will not exceed the tensile strength of any specimen taken from the tank... to determine the maximum marked test pressure permitted to be marked on the tank shall be made by...

  12. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the marked test pressure of the tank, the calculated fiber stress in psi at inner wall of tank multiplied by 3.0 will not exceed the tensile strength of any specimen taken from the tank and tested as... maximum marked test pressure permitted to be marked on the tank shall be made by the formula: P = [10S(D...

  13. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the marked test pressure of the tank, the calculated fiber stress in psi at inner wall of tank multiplied by 3.0 will not exceed the tensile strength of any specimen taken from the tank and tested as... maximum marked test pressure permitted to be marked on the tank shall be made by the formula: P = [10S(D...

  14. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the marked test pressure of the tank, the calculated fiber stress in psi at inner wall of tank multiplied by 3.0 will not exceed the tensile strength of any specimen taken from the tank and tested as... maximum marked test pressure permitted to be marked on the tank shall be made by the formula: P = [10S(D...

  15. Architectural Analysis of Human Abdominal Wall Muscles: Implications for Mechanical Function

    PubMed Central

    Brown, Stephen H. M.; Ward, Samuel R.; Cook, Mark S.; Lieber, Richard L.

    2010-01-01

    Study Design Cadaveric analysis of human abdominal muscle architecture. Objective To quantify the architectural properties of rectus abdominis (RA), external oblique (EO), internal oblique (IO) and transverse abdominis (TrA), and model mechanical function in light of these new data. Summary of Background Data Knowledge of muscle architecture provides the structural basis for predicting muscle function. Abdominal muscles greatly affect spine loading, stability, injury prevention and rehabilitation; however, their architectural properties are unknown. Methods Abdominal muscles from eleven elderly human cadavers were removed intact, separated into regions and micro-dissected for quantification of physiological cross-sectional area (PCSA), fascicle length and sarcomere length. From these data, sarcomere operating length ranges were calculated. Results IO had the largest PCSA and RA the smallest, and would thus generate the largest and smallest isometric forces, respectively. RA had the longest fascicle length, followed by EO, and would thus be capable of generating force over the widest range of lengths. Measured sarcomere lengths, in the post-mortem neutral spine posture, were significantly longer in RA and EO (3.29±0.07 and 3.18±0.11 μm) compared to IO and TrA (2.61±0.06 and 2.58±0.05 μm) (p < 0.0001). Biomechanical modeling predicted that RA, EO and TrA act at optimal force-generating length in the mid-range of lumbar spine flexion, where IO can generate approximately 90% of its maximum force. Conclusions These data provide clinically relevant insights into the ability of the abdominal wall muscles to generate force and change length throughout the lumbar spine range of motion. This will impact the understanding of potential postures in which the force-generating and spine stabilizing ability of these muscles become compromised, which can guide exercise/rehabilitation development and prescription. Future work should explore the mechanical interactions among

  16. Real-time velocimetry for evaluation of change in thickness of arterial wall.

    PubMed

    Kanai, H; Koiwa, Y

    2000-03-01

    We previously developed a new method, namely, the phased tracking method, for accurately tracking the movement of the heart wall and arterial wall based on both the phase and magnitude of the demodulated signals to determine the instantaneous position of an object. By this method, the local change in wall thickness during one heartbeat can be determined. We have now developed a real-time system for measuring change in thickness of the myocardium and arterial wall. In this system, four high-speed digital signal processing (DSP) chips are employed for obtaining the initially developed method in real time. The tracking results for both sides of the wall are superimposed on the M (motion)-mode image in the workstation, and the thickness changes of the arterial wall are displayed in real time. Using this system, reported herein, velocity signals of the arterial wall with amplitudes less than several micrometers can be successfully detected in real time with sufficient reproducibility. The elasticity of the arterial wall is evaluated by referring to the blood pressure. In in vivo experiments, the rapid response of the change in wall thickness of the carotid artery to the dose of nitroglycerine (NTG) is evaluated for a young healthy subject and a young smoker. This new real-time system offers potential for quantitative diagnosis of early-stage atherosclerosis by the transient evaluation of the rapid response of the cardiovascular system to physiological stress. PMID:10829692

  17. Mitigating the effects of surface morphology changes during ultrasonic wall thickness monitoring

    NASA Astrophysics Data System (ADS)

    Cegla, Frederic; Gajdacsi, Attila

    2016-02-01

    Ultrasonic wall thickness monitoring using permanently installed sensors has become a tool to monitor pipe wall thicknesses online and during plant operation. The repeatability of measurements with permanently installed transducers is excellent and can be in the nanometer range. It has, however, also been shown that the measured wall thickness is dependent on surface morphology and that when there are changes in surface morphology the monitored thickness trends can be affected. With an adaptive cross correlation approach, this effect can be successfully muted. However, under some surface morphology change conditions, this can also lead to inaccuracies. Here, an approach to detect when surface morphology changes can influence trend accuracies is presented. This method requires the combination of measurements from several sensors that independently sample an area where the same wall loss mechanism is assumed to occur. Simulation results for the effectiveness of the technique are presented.

  18. Combined therapy of NPWT and bipedicled flap as an alternative approach for giant abdominal wall defect with significant visceral edema: report of a case

    PubMed Central

    Yasui, Go; Furukawa, Hiroshi; Warabi, Takehiro; Hayashi, Toshihiko; Oyama, Akihiko; Funayama, Emi; Yamamoto, Yuhei

    2015-01-01

    Abstract Open abdomen management is commonly used for the critically injured patients to avoid abdominal compartment syndrome. But it usually continues for days to weeks and finally results in abdominal wall defect that is too wide to close at once. This article presents an alternative approach to close the giant abdominal wall defect by using the combination of bipedicled flaps with the components separation technique and V.A.C.® system.

  19. A Novel Diagnostic Aid for Detection of Intra-Abdominal Adhesions to the Anterior Abdominal Wall Using Dynamic Magnetic Resonance Imaging

    PubMed Central

    Randall, David; Fenner, John; Gillott, Richard; ten Broek, Richard; Strik, Chema; Spencer, Paul; Bardhan, Karna Dev

    2016-01-01

    Introduction. Abdominal adhesions can cause serious morbidity and complicate subsequent operations. Their diagnosis is often one of exclusion due to a lack of a reliable, non-invasive diagnostic technique. Development and testing of a candidate technique are described below. Method. During respiration, smooth visceral sliding motion occurs between the abdominal contents and the walls of the abdominal cavity. We describe a technique involving image segmentation and registration to calculate shear as an analogue for visceral slide based on the tracking of structures throughout the respiratory cycle. The presence of an adhesion is attributed to a resistance to visceral slide resulting in a discernible reduction in shear. The abdominal movement due to respiration is captured in sagittal dynamic MR images. Results. Clinical images were selected for analysis, including a patient with a surgically confirmed adhesion. Discernible reduction in shear was observed at the location of the adhesion while a consistent, gradually changing shear was observed in the healthy volunteers. Conclusion. The technique and its validation show encouraging results for adhesion detection but a larger study is now required to confirm its potential. PMID:26880884

  20. Effects of arterial blood flow on walls of the abdominal aorta: distributions of wall shear stress and oscillatory shear index determined by phase-contrast magnetic resonance imaging.

    PubMed

    Sughimoto, Koichi; Shimamura, Yoshiaki; Tezuka, Chie; Tsubota, Ken'ichi; Liu, Hao; Okumura, Kenichiro; Masuda, Yoshitada; Haneishi, Hideaki

    2016-07-01

    Although abdominal aortic aneurysms (AAAs) occur mostly inferior to the renal artery, the mechanism of the development of AAA in relation to its specific location is not yet clearly understood. The objective of this study was to evaluate the hypothesis that even healthy volunteers may manifest specific flow characteristics of blood flow and alter wall shear or oscillatory shear stress in the areas where AAAs commonly develop. Eight healthy male volunteers were enrolled in this prospective study, aged from 24 to 27. Phase-contrast magnetic resonance imaging (MRI) was performed with electrocardiographic triggering. Flow-sensitive four-dimensional MR imaging of the abdominal aorta, with three-directional velocity encoding, including simple morphological image acquisition, was performed. Information on specific locations on the aortic wall was applied to the flow encodes to calculate wall shear stress (WSS) and oscillatory shear index (OSI). While time-framed WSS showed the highest peak of 1.14 ± 0.25 Pa in the juxtaposition of the renal artery, the WSS plateaued to 0.61 Pa at the anterior wall of the abdominal aorta. The OSI peaked distal to the renal arteries at the posterior wall of the abdominal aorta of 0.249 ± 0.148, and was constantly elevated in the whole abdominal aorta at more than 0.14. All subjects were found to have elevated OSI in regions where AAAs commonly occur. These findings indicate that areas of constant peaked oscillatory shear stress in the infra-renal aorta may be one of the factors that lead to morphological changes over time, even in healthy individuals. PMID:26481791

  1. Stochastic modelling of wall stresses in abdominal aortic aneurysms treated by a gene therapy.

    PubMed

    Mohand-Kaci, Faïza; Ouni, Anissa Eddhahak; Dai, Jianping; Allaire, Eric; Zidi, Mustapha

    2012-01-01

    A stochastic mechanical model using the membrane theory was used to simulate the in vivo mechanical behaviour of abdominal aortic aneurysms (AAAs) in order to compute the wall stresses after stabilisation by gene therapy. For that, both length and diameter of AAAs rats were measured during their expansion. Four groups of animals, control and treated by an endovascular gene therapy during 3 or 28 days were included. The mechanical problem was solved analytically using the geometric parameters and assuming the shape of aneurysms by a 'parabolic-exponential curve'. When compared to controls, stress variations in the wall of AAAs for treated arteries during 28 days decreased, while they were nearly constant at day 3. The measured geometric parameters of AAAs were then investigated using probability density functions (pdf) attributed to every random variable. Different trials were useful to define a reliable confidence region in which the probability to have a realisation is equal to 99%. The results demonstrated that the error in the estimation of the stresses can be greater than 28% when parameters uncertainties are not considered in the modelling. The relevance of the proposed approach for the study of AAA growth may be studied further and extended to other treatments aimed at stabilisation AAAs, using biotherapies and pharmacological approaches. PMID:21264784

  2. The study on ``load relief`` mechanism of multiple cracks in thick-wall cylinder

    SciTech Connect

    Zhang, Y.H.; Huang, Z.Z.; Tan, Y.; Chen, L.Y.; Pan, B.Z.

    1995-11-01

    In this paper, the stress field on a given cross section in a thick-wall cylinder with single or multiple cracks is analyzed by means of 3-D photoelastic. Based on the study of the effect of crack on stress field, the concept of ``Additional Bending Moment`` is presented and the expression for non-dimensional ABM, M, is derived. The ``load relief`` mechanism of multiple cracks in a thick-wall cylinder is studied.

  3. Optimization of Focal Position of Ultrasonic Beam in Measurement of Small Change in Arterial Wall Thickness

    NASA Astrophysics Data System (ADS)

    Watanabe, Masaru; Kanai, Hiroshi

    2001-05-01

    We have previously developed a method for measurement of a small change in thickness of the arterial wall during a single cardiac cycle [H. Kanai, M. Sato, Y. Koiwa and N. Chubachi: IEEE Trans. UFFC 43 (1996) 791]. The resultant change in thickness is shown to be useful for the in vivo assessment of the regional elasticity of the arterial wall. Although the accuracy of the measurement of the change in thickness is found to be within 1 μm, it is affected by the interference of ultrasonic pulses. In this study, we simulate the propagation of ultrasonic pulses transmitted and received by a linear probe. In the simulation experiments, the ultrasonic pulses generated by a computer are reflected by a tube, which has a small change in wall thickness of 10 μm. The optimum focal position of the ultrasonic beam is determined by evaluating the root-mean-square (rms) error in the measured change in thickness.

  4. Prevalence and histopathological finding of thin-walled and thick-walled Sarcocysts in slaughtered cattle of Karaj abattoir, Iran.

    PubMed

    Nourollahi-Fard, Saeid R; Kheirandish, Reza; Sattari, Saeid

    2015-06-01

    Sarcocystosis is a zoonotic disease caused by Sarcocystis spp. with obligatory two host life cycle generally alternating between an herbivorous intermediate host and a carnivorous definitive host. Some species of this coccidian parasite can cause considerable morbidity and mortality in cattle. The present study was set to investigate the prevalence of Sarcocystis spp. and type of cyst wall in slaughtered cattle of Karaj abattoir, Iran. For this purpose 125 cattle (88 males and 37 females) were investigated for the presence of macroscopic and microscopic Sarcocystis cysts in muscular tissues. No macroscopic Sarcocystis cysts were found in any of the samples. In light microscopy, 121 out of 125 cattle (96.8 %) had thin-walled cysts of Sarcocystis cruzi, while 43 out of them (34.4 %) had thick-walled Sarcocystis cyst. In this survey, the most infected tissue was esophagus and heart and the less was diaphragm. Thin-walled cysts (S. cruzi) mostly found in heart and skeletal muscle showed the less. However, thick-walled cyst (S. hominis or S. hirsuta) mostly were detected in diaphragm, heart muscle showed no thick-walled cyst. No significant relation was observed between age and sex and the rate of infection. The results showed that Sarcocystis cyst is prevalent in cattle in the North part of Iran and the evaluation of infection potential can be useful when considering control programs. PMID:26064016

  5. Post-cast EDM method for reducing the thickness of a turbine nozzle wall

    DOEpatents

    Jones, Raymond Joseph; Bojappa, Parvangada Ganapathy; Kirkpatrick, Francis Lawrence; Schotsch, Margaret Jones; Rajan, Rajiv; Wei, Bin

    2002-01-01

    A post-cast EDM process is used to remove material from the interior surface of a nozzle vane cavity of a turbine. A thin electrode is passed through the cavity between opposite ends of the nozzle vane and displaced along the interior nozzle wall to remove the material along a predetermined path, thus reducing the thickness of the wall between the cavity and the external surface of the nozzle. In another form, an EDM process employing a profile as an electrode is disposed in the cavity and advanced against the wall to remove material from the wall until the final wall thickness is achieved, with the interior wall surface being complementary to the profile surface.

  6. Biomechanical and morphological study of a new elastic mesh (Ciberlastic) to repair abdominal wall defects.

    PubMed

    Calvo, B; Pascual, G; Peña, E; Pérez-Khöler, B; Rodríguez, M; Bellón, J M

    2016-06-01

    The aim of this study was to conduct a preclinical evaluation of the behaviour of a new type of abdominal LW prosthesis (Ciberlastic), which was designed with a non-absorbable elastic polyurethane monofilament (Assuplus, Assut Europe, Italy) to allow greater adaptability to mechanical area requirements and higher bio-mimicking with the newly formed surrounding tissues. Our hypothesis was that an increase in the elasticity of the mesh filament could improve the benefits of LW prostheses. To verify our hypothesis, we compared the short- and long-term behaviour of Ciberlastic and Optilene(®) elastic commercial meshes by repairing the partially herniated abdomen in New Zealand White rabbits. The implanted meshes were mechanically and histologically assessed at 14 and 180 days post-implant. We mechanically characterized the partially herniated repaired muscle tissue and also determined mesh shrinkage at different post-implant times. This was followed by a histological study in which the tissue incorporation process was analysed over time. The new prosthesis designed by our group achieved good behaviour that was similar to that of Optilene(®), one of the most popular LW prostheses on the market, with the added advantage of its elastic property. The mechanical properties are significantly lower than those of the polypropylene Optilene(®) mesh, and the new elastic mesh meets the basic mechanical requirements for positioning in the abdominal wall, which was also demonstrated by the absence of recurrences after implantation in the experimental model. We found that the growth of a connective tissue rich in collagen over the hernial defect and the proper deposit of the collagen fibres in the regenerated tissue substantially modified the original properties of the mesh, thereby increasing its biomechanical strength and making the whole tissue/mesh stiffer. PMID:26905037

  7. 3-D segmentation and quantitative analysis of inner and outer walls of thrombotic abdominal aortic aneurysms

    NASA Astrophysics Data System (ADS)

    Lee, Kyungmoo; Yin, Yin; Wahle, Andreas; Olszewski, Mark E.; Sonka, Milan

    2008-03-01

    An abdominal aortic aneurysm (AAA) is an area of a localized widening of the abdominal aorta, with a frequent presence of thrombus. A ruptured aneurysm can cause death due to severe internal bleeding. AAA thrombus segmentation and quantitative analysis are of paramount importance for diagnosis, risk assessment, and determination of treatment options. Until now, only a small number of methods for thrombus segmentation and analysis have been presented in the literature, either requiring substantial user interaction or exhibiting insufficient performance. We report a novel method offering minimal user interaction and high accuracy. Our thrombus segmentation method is composed of an initial automated luminal surface segmentation, followed by a cost function-based optimal segmentation of the inner and outer surfaces of the aortic wall. The approach utilizes the power and flexibility of the optimal triangle mesh-based 3-D graph search method, in which cost functions for thrombus inner and outer surfaces are based on gradient magnitudes. Sometimes local failures caused by image ambiguity occur, in which case several control points are used to guide the computer segmentation without the need to trace borders manually. Our method was tested in 9 MDCT image datasets (951 image slices). With the exception of a case in which the thrombus was highly eccentric, visually acceptable aortic lumen and thrombus segmentation results were achieved. No user interaction was used in 3 out of 8 datasets, and 7.80 +/- 2.71 mouse clicks per case / 0.083 +/- 0.035 mouse clicks per image slice were required in the remaining 5 datasets.

  8. Assessment of the chest wall thickness of the lawrence livermore torso phantom using a voxel image.

    PubMed

    Ahmed, A S M Sabbir; Capello, Kevin; Kramer, Gary H

    2011-06-01

    This paper describes the methodology of measuring the chest wall thickness using the voxel image of the Lawrence Livermore National Lab (LLNL) torso phantom. The LLNL phantom is used as a standard to calibrate a lung counter consisting of a 2 × 2 array of germanium detectors. In general, an average thickness estimated from four counting positions is used as the chest wall thickness for a given overlay plate. For a given overlay, the outer chest surface differs from that of inner one, and the chest wall thickness varies from one position to other. The LLNL phantom with chest plate and C4 overlay plate installed was scanned with a CT (computed tomography) scanner. The image data, collected in DICOM (Digital Imaging and Communication) format, were converted to the MCNP input file by using the Scan2Mcnp program. The MCNP file was visualized and analyzed with the Moritz visual editor. An analytic expression was formulated and solved to calculate the chest wall thickness by using the point detector responses (F 5 tally of MCNP). To map the chest thickness, the entire chest wall was meshed into virtual grids of 1 cm width. A source and detector pair was moved along the inner and outer surface of the chest wall from right to left at different heights from neck to abdomen. For each height (z(k)), (x(i), y(j)) coordinates for the detector source pair were calculated from the visual editor and were scaled on-screen. For each (x(i), y(j), z(k)) position, a mesh thickness was measured from on-screen measurement and by solving the detector responses. The chest wall thicknesses at different positions on the outer surface of the chest were compared and verified using two methods. PMID:22004927

  9. Performance Evaluation of Several Types of Pulsed Eddy Current Probes for Detecting Wall Thickness Reduction

    NASA Astrophysics Data System (ADS)

    Shin, Young-Kil; Choi, Dong-Myung; Jung, Hee-Sung; Um, Tae-Gun

    2010-02-01

    In this paper, four different types of pulsed eddy current (PEC) probe are designed and their performance of detecting wall thickness reduction is compared. By using the backward difference method in time and the finite element method in space, PEC signals from various thickness and materials are numerically calculated and three features of the signal are selected. Since PEC signals and features are obtained by various types and sizes of probe, the comparison is made through the normalized features which reflect the sensitivity of the feature to thickness reduction. The normalized features indicate that the shielded reflection probe provides the best sensitivity to wall thickness reduction for all three signal features. Results show that the best sensitivity to thickness reduction is achieved by the peak value, but also suggest that the time to peak can be a good candidate because of its linear relationship with the thickness variation.

  10. Changes in muscle strength and pain in response to surgical repair of posterior abdominal wall disruption followed by rehabilitation

    PubMed Central

    Hemingway, A; Herrington, L; Blower, A

    2003-01-01

    Background: Posterior abdominal wall deficiency (PAWD) is a tear in the external oblique aponeurosis or the conjoint tendon causing a posterior wall defect at the medial end of the inguinal canal. It is often known as sportsman's hernia and is believed to be caused by repetitive stress. Objective: To assess lower limb and abdominal muscle strength of patients with PAWD before intervention compared with matched controls; to evaluate any changes following surgical repair and rehabilitation. Methods: Sixteen subjects were assessed using a questionnaire, isokinetic testing of the lower limb strength, and pressure biofeedback testing of the abdominals. After surgery and a six week rehabilitation programme, the subjects were re-evaluated. A control group were assessed using the same procedure. Results: Quadriceps and hamstrings strength was not affected by this condition. A deficit hip muscle strength was found on the affected limb before surgery, which was significant for the hip flexors (p = 0.05). Before surgery, 87% of the patients compared with 20% of the controls failed the abdominal obliques test. Both the injured and non-injured sides had improved significantly in strength after surgery and rehabilitation. The strength of the abdominal obliques showed the most significant improvement over the course of the rehabilitation programme. Conclusions: Lower limb muscle strength may have been reduced as the result of disuse atrophy or pain inhibition. Abdominal oblique strength was deficient in the injured patients and this compromises rotational control of the pelvis. More sensitive investigations (such as electromyography) are needed to assess the link between abdominal oblique function and groin injury. PMID:12547744

  11. A randomized controlled experimental study comparing chitosan coated polypropylene mesh and Proceed™ mesh for abdominal wall defect closure

    PubMed Central

    Jayanth, S.T.; Pulimood, Anna; Abraham, Deepak; Rajaram, A.; Paul, M.J.; Nair, Aravindan

    2015-01-01

    Background Abdominal wall defects and hernias are commonly repaired with synthetic or biological materials. Adhesions and recurrences are a common problem. A study was conducted to compare Chitosan coated polypropylene mesh and a polypropylene–polydioxanone composite with oxidized cellulose coating mesh (Proceed™) in repair of abdominal wall defect in a Rabbit hernia model. Methods A randomized controlled experimental study was done on twelve New Zealand white rabbits. A ventral abdominal defect was created in each of the rabbits. The rabbits were divided into two groups. In one group the defect was repaired with Chitosan coated polypropylene mesh and Proceed mesh™ in the other. The rabbits were operated in two phases. They were followed up at four weeks and twelve weeks respectively after which the rabbits were sacrificed. They were evaluated by open exploration and histopathological examination. Their efficacy in reducing adhesion and ability of remodeling and tissue integration were studied. Results There was no statistical significance in the area of adhesion, the force required to remove the adhesions, tissue integration and remodeling between Chitosan and Proceed™ group. Histological analysis revealed that the inflammatory response, fibrosis, material degradation and remodeling were similar in both the groups. There were no hernias, wound infection or dehiscence in any of the studied animals. Conclusion Chitosan coated polypropylene mesh was found to have similar efficacy to Proceed™ mesh. Chitosan coated polypropylene mesh, can act as an anti adhesive barrier when used in the repair of incisional hernias and abdominal wall defects. PMID:26594357

  12. Delay in diagnosis and lessons learnt from a case of abdominal wall abscess caused by fishbone perforation

    PubMed Central

    Shanmugam, V; Badrinath, K; Dube, M; Panto, P

    2015-01-01

    Complications following foreign body (FB) ingestion are an uncommon clinical problem. A 59-year-old man presented with a 4-week history of left iliac fossa pain and 1 episode of dark red blood mixed with stools. Inflammatory markers were elevated, and computed tomography (CT) of the abdomen and pelvis showed an ill defined abdominal wall inflammatory collection in close contact with the small bowel loops. He was treated with antibiotics, and follow-up CT, colonoscopy and small bowel enema were mostly unremarkable. The patient presented again ten months later with left iliac fossa cellulitis and fever. Multiplanar CT (the patient’s fourth scan) demonstrated a 10cm abdominal wall collection with a linear hyperdense structure in the collection. The radiologists suspected a FB and on close scrutiny of the previous scans, they noted it to have been present on all of them. A targeted incision led to the removal of a 3cm fishbone from the collection. This case highlights the need to consider the possibility of a FB being the underlying cause in any unexplained intra-abdominal or abdominal wall inflammatory process so that the diagnosis is made in a timely manner. PMID:26263825

  13. Thick Liquid-Walled Spheromak Magnetic Fusion Power Plant

    SciTech Connect

    Moir, R W; Bulmer, R H; Fowler, T K; Youssef, M Z

    2002-04-08

    We assume a spheromak configuration can be made and sustained by a steady gun current, which injects particles, current and magnetic field, i.e., helicity injection. The equilibrium is calculated with an MHD equilibrium code, where an average beta of 10% is found. The toroidal current of 40 MA is sustained by an injection current of 100 kA (125 MW of gun power). The flux linking the gun is 1/1000th that of the flux in the spheromak. The geometry allows a flow of liquid, either molten salt, (flibe-Li{sub 2}BeF{sub 4} or flinabe-LiNaBeF{sub 4}) or liquid metal such as SnLi which protects most of the walls and structures from neutron damage. The free surface between the liquid and the burning plasma is heated by bremsstrahlung and optical radiation and neutrons from the plasma. The temperature of the free surface of the liquid is calculated and then the evaporation rate is estimated. The impurity concentration in the burning plasma is estimated and limited to a 20% reduction in the fusion power. For a high radiating edge plasma, the divertor power density of 460 MW/m{sup 2} is handled by high-speed (20 m/s), liquid jets. For low radiating edge plasmas, the divertor-power density of 1860 MW/m{sup 2} is too high to handle for flibe but possibly acceptable for SnLi with jets of 100 m/s flow speed. Calculations show the tritium breeding is adequate with enriched Li and appropriate design of the walls not covered by flowing liquid 15% of the total. We have come up with a number of problem areas needing further study to make the design self consistent and workable.

  14. Simultaneous measurement of sound velocity and wall thickness of a tube.

    PubMed

    He, P

    2001-10-01

    A method for simultaneously measuring the sound propagation velocity and the thickness of each wall on the opposite sides of a tube is presented. The method uses a pair of ultrasound transducers to produce two reflected pulses from the outer and inner surfaces of the tube wall on the each side, and two transmitted pulses, one with and one without the tube sample between the two transducers. Using the time-domain analysis, sound velocity and wall thickness of the tube are determined from the time delays between the three pairs of ultrasound pulses, whereas using the frequency-domain analysis, phase velocity, group velocity, and wall thickness of the tube are determined from the phase differences between the three pairs of ultrasound pulses. Results of measurements on five tube samples are reported. PMID:11775655

  15. Refining the course of the thoracolumbar nerves: a new understanding of the innervation of the anterior abdominal wall.

    PubMed

    Rozen, W M; Tran, T M N; Ashton, M W; Barrington, M J; Ivanusic, J J; Taylor, G I

    2008-05-01

    Previous descriptions of the thoracolumbar spinal nerves innervating the anterior abdominal wall have been inconsistent. With modern surgical and anesthetic techniques that involve or may damage these nerves, an improved understanding of the precise course and variability of this anatomy has become increasingly important. The course of the nerves of the anterior abdominal is described based on a thorough cadaveric study and review of the literature. Twenty human cadaveric hemi-abdominal walls were dissected to map the course of the nerves of the anterior abdominal wall. Dissection included a comprehensive tracing of nerves and their branches from their origins in five specimens. The branching pattern and course of all nerves identified were described. All thoracolumbar nerves that innervate the anterior abdominal wall were found to travel as multiple mixed segmental nerves, which branch and communicate widely within the transversus abdominis plane (TAP). This communication may occur at multiple locations, including large branch communications anterolaterally (intercostal plexus), and in plexuses that run with the deep circumflex iliac artery (DCIA) (TAP plexus) and the deep inferior epigastric artery (DIEA) (rectus sheath plexus). Rectus abdominis muscle is innervated by segments T6-L1, with a constant branch from L1. The umbilicus is always innervated by a branch of T10. As such, identification or damage to individual nerves in the TAP or within rectus sheath is unlikely to involve single segmental nerves. An understanding of this anatomy may contribute to explaining clinical outcomes and preventing complications, following TAP blocks for anesthesia and DIEA perforator flaps for breast reconstruction. PMID:18428988

  16. Laser Ultrasonic Thickness Measurements of Very Thick Walls at High Temperatures

    SciTech Connect

    Kruger, S. E.; Lord, M.; Monchalin, J.-P.

    2006-03-06

    Laser-ultrasonics presents many advantages compared to conventional ultrasonics, but is, generally, considered as less sensitive. As a consequence, laser-ultrasonics should not be adequate for ultrasonic measurements in coarse microstructure materials or measurements of large thicknesses. However, since the generated waves extend to very low frequencies, measurements in such conditions can be successfully performed if a photorefractive interferometer sensitive also to these low frequencies and properly balanced is used for detection. This is demonstrated by measurements of thicknesses up to 100 mm (4'') for various steel grades and at temperatures up to 1250 deg. C.

  17. Cutaneous squamous cell carcinoma in the lateral abdominal wall of local Libyan ewes

    PubMed Central

    Tmumen, S.K.; Al-Azreg, S.A.; Abushhiwa, M.H.; Alkoly, M.A.; Bennour, E.M.; Al­Attar, S.R.

    2016-01-01

    Gross and histopathological features of surgically excised squamous cell carcinomas (SCC) observed in thirteen local Libyan ewes were reported. The age of the ewes enrolled in the current study ranged from 2 to 3 years. The cases were admitted to private veterinary clinics in south-western region of Tripoli, Libya, during the period between July 2014 and October 2015. All lesions were located in the right and left lateral abdominal wall (caudo-ventrally) with a size range of 8 to 11cm in diameter. The tumor masses have been removed by surgical excision. The histopathological examination of surgically excised masses has revealed the characteristic cell nests of SCC showing central keratinization and hyalinization with presence of apoptotic bodies, fattened keratinocytes, and a heavy interstitial infiltration of neutrophils and lymphocytes. The follow up of the cases showed no signs of tumor reoccurrence. In conclusion, SCC in Libyan sheep affects mainly the woolless areas and can be successfully removed by surgical excision. PMID:27622155

  18. Active behavior of abdominal wall muscles: Experimental results and numerical model formulation.

    PubMed

    Grasa, J; Sierra, M; Lauzeral, N; Muñoz, M J; Miana-Mena, F J; Calvo, B

    2016-08-01

    In the present study a computational finite element technique is proposed to simulate the mechanical response of muscles in the abdominal wall. This technique considers the active behavior of the tissue taking into account both collagen and muscle fiber directions. In an attempt to obtain the computational response as close as possible to real muscles, the parameters needed to adjust the mathematical formulation were determined from in vitro experimental tests. Experiments were conducted on male New Zealand White rabbits (2047±34g) and the active properties of three different muscles: Rectus Abdominis, External Oblique and multi-layered samples formed by three muscles (External Oblique, Internal Oblique, and Transversus Abdominis) were characterized. The parameters obtained for each muscle were incorporated into a finite strain formulation to simulate active behavior of muscles incorporating the anisotropy of the tissue. The results show the potential of the model to predict the anisotropic behavior of the tissue associated to fibers and how this influences on the strain, stress and generated force during an isometric contraction. PMID:27111629

  19. Cutaneous squamous cell carcinoma in the lateral abdominal wall of local Libyan ewes.

    PubMed

    Tmumen, S K; Al-Azreg, S A; Abushhiwa, M H; Alkoly, M A; Bennour, E M; Al Attar, S R

    2016-01-01

    Gross and histopathological features of surgically excised squamous cell carcinomas (SCC) observed in thirteen local Libyan ewes were reported. The age of the ewes enrolled in the current study ranged from 2 to 3 years. The cases were admitted to private veterinary clinics in south-western region of Tripoli, Libya, during the period between July 2014 and October 2015. All lesions were located in the right and left lateral abdominal wall (caudo-ventrally) with a size range of 8 to 11cm in diameter. The tumor masses have been removed by surgical excision. The histopathological examination of surgically excised masses has revealed the characteristic cell nests of SCC showing central keratinization and hyalinization with presence of apoptotic bodies, fattened keratinocytes, and a heavy interstitial infiltration of neutrophils and lymphocytes. The follow up of the cases showed no signs of tumor reoccurrence. In conclusion, SCC in Libyan sheep affects mainly the woolless areas and can be successfully removed by surgical excision. PMID:27622155

  20. Long-term anisotropic mechanical response of surgical meshes used to repair abdominal wall defects.

    PubMed

    Hernández-Gascón, B; Peña, E; Pascual, G; Rodríguez, M; Bellón, J M; Calvo, B

    2012-01-01

    Routine hernia repair surgery involves the implant of synthetic mesh. However, this type of procedure may give rise to pain and bowel incarceration and strangulation, causing considerable patient disability. The purpose of this study was to compare the long-term behaviour of three commercial meshes used to repair the partially herniated abdomen in New Zealand White rabbits: the heavyweight (HW) mesh, Surgipro(®) and lightweight (LW) mesh, Optilene(®), both made of polypropylene (PP), and a mediumweight (MW) mesh, Infinit(®), made of polytetrafluoroethylene (PTFE). The implanted meshes were mechanical and histological assessed at 14, 90 and 180 days post-implant. This behaviour was compared to the anisotropic mechanical behaviour of the unrepaired abdominal wall in control non-operated rabbits. Both uniaxial mechanical tests conducted in craneo-caudal and perpendicular directions and histological findings revealed substantial collagen growth over the repaired hernial defects causing stiffness in the repair zone, and thus a change in the original properties of the meshes. The mechanical behaviour of the healthy tissue in the craneo-caudal direction was not reproduced by any of the implanted meshes after 14 days or 90 days of implant, whereas in the perpendicular direction, SUR and OPT achieved similar behaviour. From a mechanical standpoint, the anisotropic PP-lightweight meshes may be considered a good choice in the long run, which correlates with the structure of the regenerated tissue. PMID:22100101

  1. Urinary Bladder Adenocarcinoma Metastatic to the Abdominal Wall: Report of a Case with Cytohistologic Correlation.

    PubMed

    Nath, Vikas; Baliga, Mithra

    2016-01-01

    We report a case of adenocarcinoma metastatic to the abdominal wall in a 71-year-old man with a history of primary bladder adenocarcinoma. CT-guided core biopsy was performed; imprints and histologic sections showed malignant glands lined by tumor cells with hyperchromatic nuclei and prominent nucleoli, infiltrating through skeletal muscle. Immunohistochemistry revealed positivity for CK7, membranous/cytoplasmic β-catenin, caudal-type homeobox transcription factor 2 (CDX2), and α-methylacyl coenzyme A racemase and negativity for CK20, p63, prostate-specific antigen (PSA), and prostate-specific acid phosphatase (PSAP). These findings were interpreted as metastatic adenocarcinoma, consistent with bladder primary. Primary bladder adenocarcinoma is a rare malignancy arising within glandular metaplasia and is associated with cystitis cystica and cystitis glandularis. Predisposing factors include bladder exstrophy, schistosomiasis, and other causes of chronic bladder irritation. This tumor is divided into intestinal, clear cell, and signet ring cell subtypes. Treatment involves radical cystectomy with pelvic lymph node dissection, and prognosis is unfavorable. Primary bladder adenocarcinoma should be differentiated from urachal adenocarcinoma, which arises from urachal remnants near the bladder dome, and secondary adenocarcinoma, or vesical involvement by adenocarcinoma from a different primary. CK7, CK20, CDX2, thrombomodulin, and β-catenin can help distinguish primary bladder adenocarcinoma from colonic adenocarcinoma; PSA and PSAP can help distinguish primary bladder adenocarcinoma from prostate adenocarcinoma. PMID:27006847

  2. [A Case of Abdominal Wall Desmoid Tumor after Radical Nephrectomy for Renal Cancer].

    PubMed

    Ohtake, Shinji; Namura, Kazuhiro; Fujikawa, Atsushi; Sawada, Takuto; Ohta, Junichi; Moriyama, Masatoshi; Hayashi, Hiroyuki

    2015-09-01

    A 71-year-old man with a right renal tumor underwent nephrectomy. The procedure was converted from laparoscopy to open surgery due to profound bleeding from the renal vein. Pathological diagnosis was clear cell carcinoma G2pT3b v1 ly1 INFα. Three years after surgery, a 5 cm tumor in the abdominal wall was found on computed tomography (CT). A mild uptake was shown on positron emission tomography/CT and as the tumor was located near the surgical wound, recurrence of the renal cell carcinoma was suspected. However, desmoid tumor was suggested by the pathological examination of the tumor biopsy. En-bloc resection of the mass was carried out and the pathological examination showed an array of proliferating and tangling atypical spindle-shaped tumor cells. Immunohistochemical staining of the tumor cells was positive for vimentin, but negative for CD34, c-kit, and s100. Pathological diagnosis was desmoid tumor. There has been no recurrence so far. Desmoid tumor, despite its extremely low incidence, should be considered in a postoperative neoplasm. PMID:26497861

  3. Urinary Bladder Adenocarcinoma Metastatic to the Abdominal Wall: Report of a Case with Cytohistologic Correlation

    PubMed Central

    Baliga, Mithra

    2016-01-01

    We report a case of adenocarcinoma metastatic to the abdominal wall in a 71-year-old man with a history of primary bladder adenocarcinoma. CT-guided core biopsy was performed; imprints and histologic sections showed malignant glands lined by tumor cells with hyperchromatic nuclei and prominent nucleoli, infiltrating through skeletal muscle. Immunohistochemistry revealed positivity for CK7, membranous/cytoplasmic β-catenin, caudal-type homeobox transcription factor 2 (CDX2), and α-methylacyl coenzyme A racemase and negativity for CK20, p63, prostate-specific antigen (PSA), and prostate-specific acid phosphatase (PSAP). These findings were interpreted as metastatic adenocarcinoma, consistent with bladder primary. Primary bladder adenocarcinoma is a rare malignancy arising within glandular metaplasia and is associated with cystitis cystica and cystitis glandularis. Predisposing factors include bladder exstrophy, schistosomiasis, and other causes of chronic bladder irritation. This tumor is divided into intestinal, clear cell, and signet ring cell subtypes. Treatment involves radical cystectomy with pelvic lymph node dissection, and prognosis is unfavorable. Primary bladder adenocarcinoma should be differentiated from urachal adenocarcinoma, which arises from urachal remnants near the bladder dome, and secondary adenocarcinoma, or vesical involvement by adenocarcinoma from a different primary. CK7, CK20, CDX2, thrombomodulin, and β-catenin can help distinguish primary bladder adenocarcinoma from colonic adenocarcinoma; PSA and PSAP can help distinguish primary bladder adenocarcinoma from prostate adenocarcinoma. PMID:27006847

  4. Non-traumatic hernia of the lateral abdominal wall in a patient infected with the human immunodeficiency virus.

    PubMed

    Fan, Z; Pan, J; Liu, X; Zhuang, C; Ren, J; Yu, H; Tang, S; Wang, S

    2016-07-01

    Introduction There are several classifications for abdominal hernias, and a non-traumatic lateral wall hernia (LAWH) is a rare type. We report the first case of a patient with LAWH infected with the human immunodeficiency virus (HIV). Case History A 53-year-old HIV-infected male presented with an abdominal mass. The patient had a history of treatment with combination antiretroviral therapy. A LAWH was diagnosed based on physical examination and findings of computed tomography. Open mesh repair was undertaken successfully. The patient had no evidence of a recurrent hernia during 11 months of follow-up. Conclusions High intra-abdominal pressure and weak connective tissue can lead to LAWHs. Antiretroviral therapy and lipodystrophy can cause LAWHs in HIV-infected patients. PMID:27241599

  5. Colonic wall thickness using level sets for CT virtual colonoscopy visual assessment and polyp detection

    NASA Astrophysics Data System (ADS)

    Van Uitert, Robert L.; Summers, Ronald M.

    2007-03-01

    The detection of polyps in virtual colonoscopy is an active area of research. One of the critical elements in detecting cancerous polyps using virtual colonoscopy, especially in conjunction with computer-aided detection, is the accurate segmentation of the colon wall. The large CT attenuation difference between the lumen and inner, mucosal layer of the colon wall makes the segmentation of the lumen easily performed by traditional threshold segmentation techniques. However, determining the location of the colon outer wall is often difficult due to the low contrast difference between the colon wall's outer serosal layer and the fat surrounding the colon. We have developed an automatic, level set based method to determine from a CT colonography scan the location of the colon inner boundary and the colon outer wall boundary. From the location of the inner and outer colon wall boundaries, the wall thickness throughout the colon can be computed. Color mapping of the wall thickness on the colon surface allows for easy visual determination of potential regions of interest. Since the colon wall tends to be thicker at polyp locations, potential polyps also can be detected automatically at sites of increased colon wall thickness. This method was validated on several CT colonography scans containing optical colonoscopy-proven polyps. The method accurately determined thicker colonic wall regions in areas where polyps are present in the ground truth datasets and detected the polyps at a false positive rate between 44.4% and 82.8% lower than a state-of-the-art curvature-based method for initial polyp detection.

  6. Eddy current technique applied to the nondestructive evaluation of turbine blade wall thickness

    NASA Astrophysics Data System (ADS)

    Le Bihan, Yann; Joubert, Pierre-Yves; Placko, Dominique

    2000-05-01

    The high pressure turbine blades of jet engines show internal channels designed for air cooling. These recesses define the internal walls (partitions) and external walls of the blade. The external wall thickness is a critical parameter which has to be systematically checked in order to ensure the blade strength. The thickness evaluation is usually lead by ultrasonic technique or by X-ray tomography. Nevertheless, both techniques present some drawbacks related to measurement speed and automation capability. These drawbacks are bypassed by the eddy current (EC) technique, well known for its robustness and reliability. However, the wall thickness evaluation is made difficult because of the complexity of the blade geometry. In particular, some disturbances appear in the thickness evaluation because of the partitions, which exclude the use of classical EC probes such as cup-core probe. In this paper, we show the main advantages of probes creating an uniformly oriented magnetic field in order to reduce the partition disturbances. Furthermore, we propose a measurement process allowing to separate the wall thickness parameter from the EC signals. Finally, we present some experimental results validating the proposed technique.

  7. Surface plasmon and photonic mode propagation in gold nanotubes with varying wall thickness

    SciTech Connect

    Kohl, Jesse; Fireman, Micha; O'Carroll, Deirdre M.

    2011-12-15

    Gold nanotube arrays are synthesized with a range of wall thicknesses (15 to >140 nm) and inner diameters of {approx}200 nm using a hard-template method. A red spectral shift (>0.39 eV) with decreasing wall thickness is observed in dark-field spectra of nanotube arrays and single nanowire/nanotube heterostructures. Finite-difference-time-domain simulations show that nanotubes in this size regime support propagating surface plasmon modes as well as surface plasmon ring resonances at visible wavelengths (the latter is observed only for excitation directions normal to the nanotube long axis with transverse polarization). The energy of the surface plasmon modes decreases with decreasing wall thickness and is attributed to an increase in mode coupling between propagating modes in the nanotube core and outer surface and the circumference dependence of ring resonances. Surface plasmon mode propagation lengths for thicker-walled tubes increase by a factor of {approx}2 at longer wavelengths (>700 nm), where ohmic losses in the metal are low, but thinner-walled tubes (30 nm) exhibit a more significant increase in surface plasmon propagation length (by a factor of more than four) at longer wavelengths. Additionally, nanotubes in this size regime support a photonic mode in their core, which does not change in energy with changing wall thickness. However, photonic mode propagation length is found to decrease for optically thin walls. Finally, correlations are made between the experimentally observed changes in dark-field spectra and the changes in surface plasmon mode properties observed in simulations for the various gold nanotube wall thicknesses and excitation conditions.

  8. Increased Coronary Vessel Wall Thickness in HIV-Infected Young Adults

    PubMed Central

    Abd-Elmoniem, Khaled Z.; Unsal, Aylin B.; Eshera, Sarah; Matta, Jatin R.; Muldoon, Nancy; McAreavey, Dorothea; Purdy, Julia B.; Hazra, Rohan; Hadigan, Colleen; Gharib, Ahmed M.

    2014-01-01

    Background. Individuals with long-term human immunodeficiency virus (HIV) infection are at risk for premature vasculopathy and cardiovascular disease (CVD). We evaluated coronary vessel wall thickening, coronary plaque, and epicardial fat in patients infected with HIV early in life compared with healthy controls. Methods. This is a prospective cross-sectional study of 35 young adults who acquired HIV in early life and 11 healthy controls, free of CVD. Time resolved phase-sensitive dual inversion recovery black-blood vessel wall magnetic resonance imaging (TRAPD) was used to measure proximal right coronary artery (RCA) wall thickness, and multidetector computed tomography (CT) angiography was used to quantify coronary plaque and epicardial fat. Results. RCA vessel wall thickness was significantly increased in HIV-infected patients compared with sex- and race-matched controls (1.32 ± 0.21 mm vs 1.09 ± 0.14 mm, P = .002). No subject had discrete plaque on CT sufficient to cause luminal narrowing, and plaque was not related to RCA wall thickness. In multivariate regression analyses, smoking pack-years (P = .004) and HIV infection (P = .007) were independently associated with thicker RCA vessel walls. Epicardial fat did not differ between groups. Among the HIV-infected group, duration of antiretroviral therapy (ART) (P = .02), duration of stavudine exposure (P < .01), low-density lipoprotein cholesterol (P = .04), and smoking pack-years (P < .01) were positively correlated with RCA wall thickness. Conclusions. This investigation provides evidence of subclinical coronary vascular disease among individuals infected with HIV in early life. Increased duration of ART, hyperlipidemia, and smoking contributed to proximal RCA thickening, independent of atherosclerotic plaque quantified by CT. These modifiable risk factors appear to influence early atherogenesis as measured by coronary wall thickness and may be important targets for CVD risk reduction. PMID:25159580

  9. Computed tomographic assessment of maxillary sinus wall thickness in edentulous patients.

    PubMed

    Yang, S-M; Park, S-I; Kye, S-B; Shin, S-Y

    2012-06-01

    Posterior maxillary region is considered to be the most challenging area for dental implant placement. Lateral window opening is the gold standard procedure for maxillary sinus augmentation in this area. The purpose of this study is to evaluate lateral wall thickness of the maxillary sinus for sinus augmentation using computed tomography (CT) in edentulous patients. Computed tomography images of 302 patients were analysed. Using the maxillary sinus floor as the reference point in edentulous regions, lateral wall thickness was measured on CT scans. After drawing a tangent line at the lowest point of the sinus floor, another perpendicular line to the tangent line was drawn at the same point of the sinus floor. Thickness of the lateral wall of the maxillary sinus was measured using 10DR implant software at 3 (R1), 10 (R2) and 15 mm (R3) from the sinus floor. The mean thickness of the lateral wall of the maxillary sinus from the first premolar to second molar was 1·69 ± 0·71, 1·50 ± 0·72, 1·77 ± 0·78 and 1·89 ± 0·85 mm, respectively. The thickness differed significantly at the R2 and R3 points. Women had thinner lateral walls at the R1 and R2 points at the premolars than did men. At the R2 and R3 points at the second premolar, the mean thickness of smokers was larger than that of non-smokers. There were no significant differences on age or reasons for tooth loss. The changes in the thickness of the lateral wall at different reference points were observed, and CT examinations may help make lateral window without membrane perforation. PMID:22471834

  10. Multimodal optical measurement in vitro of surface deformations and wall thickness of the pressurized aortic arch.

    PubMed

    Genovese, Katia; Humphrey, Jay D

    2015-04-01

    Computational modeling of arterial mechanics continues to progress, even to the point of allowing the study of complex regions such as the aortic arch. Nevertheless, most prior studies assign homogeneous and isotropic material properties and constant wall thickness even when implementing patient-specific luminal geometries obtained from medical imaging. These assumptions are not due to computational limitations, but rather to the lack of spatially dense sets of experimental data that describe regional variations in mechanical properties and wall thickness in such complex arterial regions. In this work, we addressed technical challenges associated with in vitro measurement of overall geometry, full-field surface deformations, and regional wall thickness of the porcine aortic arch in its native anatomical configuration. Specifically, we combined two digital image correlation-based approaches, standard and panoramic, to track surface geometry and finite deformations during pressurization, with a 360-deg fringe projection system to contour the outer and inner geometry. The latter provided, for the first time, information on heterogeneous distributions of wall thickness of the arch and associated branches in the unloaded state. Results showed that mechanical responses vary significantly with orientation and location (e.g., less extensible in the circumferential direction and with increasing distance from the heart) and that the arch exhibits a nearly linear increase in pressure-induced strain up to 40%, consistent with other findings on proximal porcine aortas. Thickness measurements revealed strong regional differences, thus emphasizing the need to include nonuniform thicknesses in theoretical and computational studies of complex arterial geometries. PMID:25867620

  11. Comparison of Two Methods of Finite Element Modeling for Elbows with Unequal Wall Thickness

    NASA Astrophysics Data System (ADS)

    Dong, Junhua; Bao, Xiangfu; Zheng, Xize

    In Finite Element Stress Analysis of elbow, its unequal wall thickness can be obtained by two methods: eccentric circle method and multi-spot spline curve drawed according to wall thickness of elbow. In this work, an elbow with constant inner diameter was taken as an illustration and its simulation results based on these two modeling methods were compared under different ratios of central line bend radius to mean diameter of pipe R/D. It is found that modeling method has no effect on the stress analysis results of elbows. But eccentric circle method has the virtue of being easier to implement and can be used without restriction of R/D, so it is an ideal method of finite element modeling for unequal wall thickness elbows. Because the FEA results of equal thickness elbows are recognizably higher than those of elbows with unequal wall thickness, considering non-uniform thickness of elbows is necessary to set up a reasonable safety evaluation for elbows.

  12. Dependence of Thermal Conductivity on Thickness in Single-Walled Carbon Nanotube Films.

    PubMed

    Lee, Kyung-Min; Shrestha, Ramesh; Dangol, Ashesh; Chang, Won Seok; Coker, Zachary; Choi, Tae-Youl

    2016-01-01

    Herein, we report experimentally dependence of thermal conductivity on thickness of single walled carbon nanotubes (SWNTs) thin films; the measurements are based on the micropipette thermal sensor technique. Accurate and well resolved measurements of thermal conductivity made by the micropipette sensor showed a correlated behavior of thickness and thermal conductivity of CNT films that thermal conductivity decreased as thickness increased. The thickness dependence is explained by reduction of mean free path (MFP), which is induced by more intertubular junctions in more dense-packed carbon nanotube (CNT) networks; the thicker SWCNT films were revealed to have higher density. PMID:27398564

  13. Airway wall thickness assessment: a new functionality in virtual bronchoscopy investigation

    NASA Astrophysics Data System (ADS)

    Saragaglia, A.; Fetita, C.; Brillet, P. Y.; Prêteux, F.; Grenier, P. A.

    2007-03-01

    While classic virtual bronchoscopy offers visualization facilities for investigating the shape of the inner airway wall surface, it provides no information regarding the local thickness of the wall. Such information may be crucial for evaluating the severity of remodeling of the bronchial wall in asthma and to guide bronchial biopsies for staging of lung cancers. This paper develops a new functionality with the virtual bronchoscopy, allowing to estimate and map the information of the bronchus wall thickness on the lumen wall surface, and to display it as coded colors during endoluminal navigation. The local bronchus wall thickness estimation relies on a new automated 3D segmentation approach using strong 3D morphological filtering and model-fitting. Such an approach reconstructs the inner/outer airway wall surfaces from multi-detector CT data as follows. First, the airway lumen is segmented and its surface geometry reconstructed using either a restricted Delaunay or a Marching Cubes based triangulation approach. The lumen mesh is then locally deformed in the surface normal direction under specific force constraints which stabilize the model evolution at the level of the outer bronchus wall surface. The developed segmentation approach was validated with respect to both 3D mathematicallysimulated image phantoms of bronchus-vessel subdivisions and to state-of-the-art cross-section area estimation techniques when applied to clinical data. The investigation in virtual bronchoscopy mode is further enhanced by encoding the local wall thickness at each vertex of the lumen surface mesh and displaying it during navigation, according to a specific color map.

  14. Optimization of Condition of Ultrasonic Beam for Measurement of Small Change in Thickness of Arterial Wall

    NASA Astrophysics Data System (ADS)

    Watanabe, Masaru; Hasegawa, Hideyuki; Kanai, Hiroshi

    2002-05-01

    We previously developed a method for measuring small changes in thickness of the arterial wall during one cardiac cycle. Knowledge of this change in thickness is useful for in vivo assessment of the regional elasticity of the arterial wall. In this study, from computer simulations, it is found that measurement error depends on the distance of the ultrasonic beam from the center of the artery and it can be reduced by optimally setting the focal position. In basic experiments using a silicone rubber tube and in in vivo experiments with a human carotid artery, it is found that by optimizing the focal position, measurement of the change in thickness becomes more robust against mispositioning of the ultrasonic beam. From these results, it is demonstrated that optimum focal positioning provides more robustness in measurement, even if there is arterial wall motion causing the position of the ultrasonic beam to deviate from the center of the artery.

  15. Theoretical quantification of the effects of plastic wall thickness on phantom measurements in electromagnetic hyperthermia.

    PubMed

    Ross, M P; Paulsen, K D

    1989-08-01

    Phantom experiments are a staple of research and development in electromagnetic hyperthermia. Phantom containers and compartments are typically constructed from plastics which are readily available in a wide variety of thicknesses and material compositions. The perturbation effects of these plastics on the electric fields to be measured may be important, especially if one is trying to obtain quantitative results such as when comparing with a numerical model. This communication presents a theoretical investigation into the effects of plastic wall thickness on the computed electric field. Design curves are reported which aid in the selecting of an acceptable wall thickness given a maximum degree of wall perturbation that can be tolerated. Many other materials such as rubbers and polystyrenes also have electrical properties within the ranges considered herein; hence, the results should apply to a variety of commonly used phantom construction materials. PMID:2759648

  16. [Influence of laser -- infrared irradiation on local complications of early postoperative period in hernias of anterior abdominal wall].

    PubMed

    Gasymov, E M

    2005-01-01

    Results of laser-infrared irradiation (LIRI) of postoperative wound after surgical treatment of recurrent hernias of anterior abdominal wall were analyzed. LIRI decreased number of local complications in early postoperative period in patients both with recurrent and primary hernias. The method was more effective for the treatment of local complication in patients with recurrent hernia that is confirmed by reduced of frequency of infiltrates, seromas and suppurations. PMID:16247383

  17. Successful Treatment of Mesenteric Varices After Living Donor Liver Transplantation with Retrograde Transvenous Obliteration Via an Abdominal Wall Vein

    SciTech Connect

    Ikeda, Osamu Tamura, Yoshitaka; Nakasone, Yutaka; Yamashita, Yasuyuki; Okajima, Hideaki; Asonuma, Katsuhiro; Inomata, Yukihiro

    2010-06-15

    Balloon-occluded retrograde transvenous obliteration is an established treatment for gastric varices; it has been used more rarely to treat mesenteric varices. We report a 12-year-old girl who had received a living donor liver transplant and suffered melena due to ruptured mesenteric varices. We addressed treatment of the mesenteric varices by retrograde transvenous obliteration of an abdominal wall collateral vein detected by superior mesenteric arteriography.

  18. General tube law for collapsible thin and thick-wall tubes.

    PubMed

    Kozlovsky, Pavel; Zaretsky, Uri; Jaffa, Ariel J; Elad, David

    2014-07-18

    Modeling the complex deformations of cylindrical tubes under external pressure is of interest in engineering and physiological applications. The highly non-linear post-buckling behavior of cross-section of the tube during collapse attracted researchers for years. Major efforts were concentrated on studying the behavior of thin-wall tubes. Unfortunately, the knowledge on post-buckling of thick-wall tubes is still incomplete, although many experimental and several theoretical studies have been performed. In this study we systematically studied the effect of the wall thickness on post-buckling behavior of the tube. For this purpose, we utilized a computational model for evaluation of the real geometry of the deformed cross-sectional area due to negative transmural (internal minus external) pressure. We also developed an experimental method to validate the computational results. Based on the computed cross-sections of tubes with different wall thicknesses, we developed a general tube law that accounts for thin or thick wall tubes and fits the numerical data of computed cross-sectional areas versus transmural pressures. PMID:24837222

  19. Enhancing cell-free layer thickness by bypass channels in a wall.

    PubMed

    Saadatmand, M; Shimogonya, Y; Yamaguchi, T; Ishikawa, T

    2016-07-26

    When blood flows near a wall, red blood cells (RBCs) drift away from the wall and a cell-free layer (CFL) is formed adjacent to the wall. Controlling the CFL thickness is important for preventing adhesion of cells in the design of biomedical devices. In this study, a novel wall configuration with stenoses and bypass channels is proposed to increase the CFL thickness. We found that the presence of bypass channels modified the spatial distribution of cells and substantially increased the CFL downstream of the stenosis. A single-bypass geometry with 5% hematocrit (Hct) blood flow showed a 1.7μm increase in CFL thickness compared to without the bypass. In the case of three bypass channels, a 3μm increase in CFL thickness was observed. The CFL enhancement was observed up to 10% Hct, but no significant enhancement of CFL was indicated for 20% Hct blood flow. The mechanism of the CFL enhancement was investigated using a numerical simulation of the flow field. The results showed that the distance between each streamline and the corner of the stenosis compared with size of RBC was important parameter in regulating CFL thickness. These results show the potential of the proposed mechanism to prevent adhesion of cells to biomedical devices. PMID:26803337

  20. Wall-thickness and midwall-radius variations in ventricular mechanics.

    PubMed

    Chadwick, R S; Ohayon, J; Lewkowicz, M

    1989-05-01

    A fluid-fiber-collagen stress tensor is used to describe the rheology of the left ventricle of the heart. Linear theory is used to find the equilibrium solutions for the end-diastolic and end-systolic states of general axisymmetric shapes that are small perturbations of a thick-walled finite cylinder. The general problem can be studied by superposing the effects of variable midwall radius but constant wall thickness with those of variable wall thickness but constant midwall radius. A Fourier series representation is used to describe the midwall radius and thickness functions. Numerical calculations are performed to determine the deformed geometry and spatial distributions of tissue pressure, stresses, and fiber strains. The calculations proved to be highly accurate when compared to an analytical solution obtained for the special case of no fibers. The results show significant longitudinal differences when compared to results for the cylindrical geometry, with more sensitivity to variation in wall thickness than to variation in midwall radius. PMID:2717607

  1. Abdominal CT scan

    MedlinePlus

    ... results may also be due to: Abdominal aortic aneurysm Abscesses Appendicitis Bowel wall thickening Retroperitoneal fibrosis Renal ... Livingstone; 2014:chap 4. Read More Abdominal aortic aneurysm Abdominal aortic aneurysm repair - open Abscess Acute cholecystitis ...

  2. Surgically placed abdominal wall catheters on postoperative analgesia and outcomes after living liver donation.

    PubMed

    Khan, James; Katz, Joel; Montbriand, Janice; Ladak, Salima; McCluskey, Stuart; Srinivas, Coimbatore; Ko, Raynauld; Grant, David; Bradbury, Ashleene; LeManach, Yannick; Clarke, Hance

    2015-04-01

    Living donor liver resections are associated with significant postoperative pain. Epidural analgesia is the gold standard for postoperative pain management, although it is often refused or contraindicated. Surgically placed abdominal wall catheters (AWCs) are a novel pain modality that can potentially provide pain relief for those patients who are unable to receive an epidural. A retrospective review was performed at a single center. Patients were categorized according to their postoperative pain modality: intravenous (IV) patient-controlled analgesia (PCA), AWCs with IV PCA, or patient-controlled epidural analgesia (PCEA). Pain scores, opioid consumption, and outcomes were compared for the first 3 postoperative days. Propensity score matches (PSMs) were performed to adjust for covariates and to confirm the primary analysis. The AWC group had significantly lower mean morphine-equivalent consumption on postoperative day 3 [18.1 mg, standard error (SE)=3.1 versus 28.2 mg, SE=3.0; P=0.02] and mean cumulative morphine-equivalent consumption (97.2 mg, SE=7.2 versus 121.0 mg, SE=9.1; P=0.04) in comparison with the IV PCA group; the difference in cumulative-morphine equivalent remained significant in the PSMs. AWC pain scores were higher than those in the PCEA group and were similar to the those in the IV PCA group. The AWC group had a lower incidence of pruritus and a shorter hospital stay in comparison with the PCEA group and had a lower incidence of sedation in comparison with both groups. Time to ambulation, nausea, and vomiting were comparable among all 3 groups. The PSMs confirmed all results except for a decrease in the length of stay in comparison with PCEA. AWCs may be an alternative to epidural analgesia after living donor liver resections. Randomized trials are needed to verify the benefits of AWCs, including the safety and adverse effects. PMID:25546011

  3. An exact solution for a thick domain wall in general relativity

    NASA Technical Reports Server (NTRS)

    Goetz, Guenter; Noetzold, Dirk

    1989-01-01

    An exact solution of the Einstein equations for a static, planar domain wall with finite thickness is presented. At infinity, density and pressure vanish and the space-time tends to the Minkowski vacuum on one side of the wall and to the Taub vacuum on the other side. A surprising feature of this solution is that the density and pressure distribution are symmetric about the central plane of the wall whereas the space-time metric and therefore also the gravitational field experienced by a test particle is asymmetric.

  4. Thermal Marangoni instability of a thin film flowing down a thick wall deformed in the backside

    NASA Astrophysics Data System (ADS)

    Dávalos-Orozco, L. A.

    2016-05-01

    The nonlinear instability of a thin liquid film flowing down a heated thick wall with deformations in the backside is investigated. Here it is assumed that the wall deformations are sinusoidal in space. Time dependent perturbations are imposed at the origin of the free surface of the film. It is found that the wall deformations have an important influence on the flow instability. Moreover, it is shown that the free surface has a large amplitude spatial response to the backside deformations of the wall. This response increases its amplitude considerably when decreasing the wall spatial wavelength down to the wavelength of the time dependent perturbations. At that point, numerical analysis reveals that the time dependent perturbations in some cases are almost impossible to observe on the free surface response. However, in other cases, their interaction produces large amplitude nonlinear wave modulations.

  5. Magnet Fall inside a Conductive Pipe: Motion and the Role of the Pipe Wall Thickness

    ERIC Educational Resources Information Center

    Donoso, G.; Ladera, C. L.; Martin, P.

    2009-01-01

    Theoretical models and experimental results are presented for the retarded fall of a strong magnet inside a vertical conductive non-magnetic tube. Predictions and experimental results are in good agreement modelling the magnet as a simple magnetic dipole. The effect of varying the pipe wall thickness on the retarding magnetic drag is studied for…

  6. Automatic Thickness and Volume Estimation of Sprayed Concrete on Anchored Retaining Walls from Terrestrial LIDAR Data

    NASA Astrophysics Data System (ADS)

    Martínez-Sánchez, J.; Puente, I.; GonzálezJorge, H.; Riveiro, B.; Arias, P.

    2016-06-01

    When ground conditions are weak, particularly in free formed tunnel linings or retaining walls, sprayed concrete can be applied on the exposed surfaces immediately after excavation for shotcreting rock outcrops. In these situations, shotcrete is normally applied conjointly with rock bolts and mesh, thereby supporting the loose material that causes many of the small ground falls. On the other hand, contractors want to determine the thickness and volume of sprayed concrete for both technical and economic reasons: to guarantee their structural strength but also, to not deliver excess material that they will not be paid for. In this paper, we first introduce a terrestrial LiDAR-based method for the automatic detection of rock bolts, as typically used in anchored retaining walls. These ground support elements are segmented based on their geometry and they will serve as control points for the co-registration of two successive scans, before and after shotcreting. Then we compare both point clouds to estimate the sprayed concrete thickness and the expending volume on the wall. This novel methodology is demonstrated on repeated scan data from a retaining wall in the city of Vigo (Spain), resulting in a rock bolts detection rate of 91%, that permits to obtain a detailed information of the thickness and calculate a total volume of 3597 litres of concrete. These results have verified the effectiveness of the developed approach by increasing productivity and improving previous empirical proposals for real time thickness estimation.

  7. Size Dependence in Hexagonal Mesoporous Germanium: Pore Wall Thickness versus Energy Gap and Photoluminescence

    SciTech Connect

    Armatas, G. S.; Kanatzidis, Mercouri G.

    2010-08-10

    A series of hexagonal mesoporous germanium semiconductors with tunable wall thickness is reported. These nanostructures possess uniform pores of 3.1-3.2 nm, wall thicknesses from 1.3 to 2.2 nm, and large internal BET surface area in the range of 404-451 m2/g. The porous Ge framework of these materials is assembled from the templated oxidative self-polymerization of (Ge9)4- Zintl clusters. Total X-ray scattering analysis supports a model of interconnected deltahedral (Ge9)-cluster forming the framework and X-ray photoelectron spectroscopy indicates nearly zero-valence Ge atoms. We show the controllable tuning of the pore wall thickness and its impact on the energy band gap which increases systematically with diminishing wall thickness. Furthermore, there is room temperature photoluminescence emission which shifts correspondingly from 672 to 640 nm. The emission signal can be quenched via energy transfer with organic molecules such as pyridine diffusing into the pores.

  8. Fatigue life improvement of an autofrettage thick-walled pressure vessel with an external groove

    NASA Astrophysics Data System (ADS)

    Koh, Seung K.; Stephens, Ralph I.

    1992-01-01

    This report presents an investigation into a fatigue life improvement of an autofrettaged thick-walled pressure vessel with an external groove subjected to pulsating internal pressure, along with mean strain and mean stress effects on strain-controlled low cycle fatigue behavior. Linear elastic stress analysis of an autofrettaged thick-walled pressure vessel with an external groove is done using a finite element method. Autofrettage loading is performed using a thermal loading analogy. Change of external groove geometry is made using a quasi-optimization technique and finite element method to achieve longer fatigue life by relieving the stress concentration at the groove root. Surface treatment using shot peening is employed to produce compressive residual stresses at the vulnerable surface of the groove root to counteract the high tensile stresses. An evaluation of the fatigue life of an autofrettaged thick-walled pressure vessel with an external groove is done through a series of simulation fatigue tests using C-shaped specimens taken from the thick-walled pressure vessel.

  9. A novel method for endoscopic perforation management by using abdominal exploration and full-thickness sutured closure

    PubMed Central

    Kumar, Nitin; Thompson, Christopher C.

    2016-01-01

    Background Perforation of the GI tract during endoscopy can result in significant morbidity and mortality. Early recognition and immediate management of endoscopic perforation are essential to optimize outcome. Larger perforations, defects with complex geometry, and those complicated by leakage of luminal contents have traditionally required surgical management. Objective To assess the feasibility of a new method for managing complex perforations that incorporates abdominal exploration and endoscopic sutured closure. Design Case series. Setting Tertiary care center. Patients Two patients with large, complicated perforations and peritoneal contamination. Interventions Endoscopic exploration of abdomen with angiocatheter placement under direct visualization, management of leaked luminal contents, and full-thickness sutured defect closure. Results Endoscopic abdominal exploration through the perforation site allowed safe placement of an angiocatheter for management of pneumoperitoneum, inspection for injury that may warrant surgical management, and removal of leaked luminal contents. Endoscopic sutured closure allowed safe and robust perforation management. Repair of gastrojejunal anastomotic perforation required 2 sutures and 63 minutes. Repair of gastric perforation required 4 sutures and 48 minutes. Patients had successful endoscopic defect closure confirmed by an upper GI series and were discharged 1 day later. Limitations Report of a new method in 2 patients performed at tertiary care center. Conclusions We demonstrate successful management of complex perforations with peritoneal contamination by incorporating endoscopic exploration and sutured closure with standard treatment measures. Traditional practice would have directed these patients to surgical management, which introduces additional morbidity and cost. A means for safe and broad implementation of these techniques should be evaluated. PMID:24721517

  10. Surgical resection of cerebellar hemangioblastoma with enhanced wall thickness: A report of two cases

    PubMed Central

    SUN, ZHENXING; YUAN, DAN; SUN, YAXING; YAN, PENGXIANG; ZUO, HUANCONG

    2015-01-01

    Hemangioblastomas are tumors of the central nervous system, and the cerebellum is the most common site of occurrence. Cerebellar hemangioblastoma with enhanced wall thickness is rare and often misdiagnosed preoperatively. At present, no unified radiological classification system based on magnetic resonance imaging (MRI) findings exists for cerebellar hemangioblastoma, and this tumor type can be solid or cystic mass, according to the MRI findings. The most common presentation of cerebellar hemangioblastoma observed radiologically is a large sac with small nodules, where the wall of the large cyst is not enhanced. A tumor with enhanced large cysts and tumor nodules is extremely rare. The most effective treatment is complete resection of the cyst and the solid growth. The present case reports the successful treatment of two cases of cerebellar hemangioblastoma with enhanced wall thickness, including the MRI findings for the differential diagnoses and the surgical experiences. PMID:25789007

  11. Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition

    PubMed Central

    Ionescu, Emanuel; Fu, Ganhua; Ensinger, Wolfgang

    2011-01-01

    Summary Conductive nanotubes consisting of indium tin oxide (ITO) were fabricated by electroless deposition using ion track etched polycarbonate templates. To produce nanotubes (NTs) with thin walls and small surface roughness, the tubes were generated by a multi-step procedure under aqueous conditions. The approach reported below yields open end nanotubes with well defined outer diameter and wall thickness. In the past, zinc oxide films were mostly preferred and were synthesized using electroless deposition based on aqueous solutions. All these methods previously developed, are not adaptable in the case of ITO nanotubes, even with modifications. In the present work, therefore, we investigated the necessary conditions for the growth of ITO-NTs to achieve a wall thickness of around 10 nm. In addition, the effects of pH and reductive concentrations for the formation of ITO-NTs are also discussed. PMID:21977422

  12. Real-time dielectric-film thickness measurement system for plasma processing chamber wall monitoring

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Yong; Chung, Chin-Wook

    2015-12-01

    An in-situ real-time processing chamber wall monitoring system was developed. In order to measure the thickness of the dielectric film, two frequencies of small sinusoidal voltage (˜1 V) signals were applied to an electrically floated planar type probe, which is positioned at chamber wall surface, and the amplitudes of the currents and the phase differences between the voltage and current were measured. By using an equivalent sheath circuit model including a sheath capacitance, the dielectric thickness can be obtained. Experiments were performed in various plasma condition, and reliable dielectric film thickness was obtained regardless of the plasma properties. In addition, availability in commercial chamber for plasma enhanced chemical vapor deposition was verified. This study is expected to contribute to the control of etching and deposition processes and optimization of periodic maintenance in semiconductor manufacturing process.

  13. Quantification of esophageal wall thickness in CT using atlas-based segmentation technique

    NASA Astrophysics Data System (ADS)

    Wang, Jiahui; Kang, Min Kyu; Kligerman, Seth; Lu, Wei

    2015-03-01

    Esophageal wall thickness is an important predictor of esophageal cancer response to therapy. In this study, we developed a computerized pipeline for quantification of esophageal wall thickness using computerized tomography (CT). We first segmented the esophagus using a multi-atlas-based segmentation scheme. The esophagus in each atlas CT was manually segmented to create a label map. Using image registration, all of the atlases were aligned to the imaging space of the target CT. The deformation field from the registration was applied to the label maps to warp them to the target space. A weighted majority-voting label fusion was employed to create the segmentation of esophagus. Finally, we excluded the lumen from the esophagus using a threshold of -600 HU and measured the esophageal wall thickness. The developed method was tested on a dataset of 30 CT scans, including 15 esophageal cancer patients and 15 normal controls. The mean Dice similarity coefficient (DSC) and mean absolute distance (MAD) between the segmented esophagus and the reference standard were employed to evaluate the segmentation results. Our method achieved a mean Dice coefficient of 65.55 ± 10.48% and mean MAD of 1.40 ± 1.31 mm for all the cases. The mean esophageal wall thickness of cancer patients and normal controls was 6.35 ± 1.19 mm and 6.03 ± 0.51 mm, respectively. We conclude that the proposed method can perform quantitative analysis of esophageal wall thickness and would be useful for tumor detection and tumor response evaluation of esophageal cancer.

  14. Distribution of ice thickness and subglacial topography of the "Chinese Wall" around Kunlun Station, East Antarctica

    NASA Astrophysics Data System (ADS)

    Cui, Xiang-Bin; Sun, Bo; Su, Xiao-Gang; Guo, Jing-Xue

    2016-03-01

    As fundamental parameters of the Antarctic Ice Sheet, ice thickness and subglacial topography are critical factors for studying the basal conditions and mass balance in Antarctica. During CHINARE 24 (the 24th Chinese National Antarctic Research Expedition, 2007/08), the research team used a deep ice-penetrating radar system to measure the ice thickness and subglacial topography of the "Chinese Wall" around Kunlun Station, East Antarctica. Preliminary results show that the ice thickness varies mostly from 1600 m to 2800 m along the "Chinese Wall", with the thickest ice being 3444 m, and the thinnest ice 1255 m. The average bedrock elevation is 1722 m, while the minimum is just 604 m. Compared with the northern side of the ice divide, the ice thickness is a little greater and the subglacial topography lower on the southern side, which is also characterized by four deep valleys. We found no basal freeze-on ice in the Gamburtsev Subglacial Mountains area, subglacial lakes, or water bodies along the "Chinese Wall". Ice thickness and subglacial topography data extracted from the Bedmap 2 database along the "Chinese Wall" are consistent with our results, but their resolution and accuracy are very limited in areas where the bedrock fluctuates intensely. The distribution of ice thickness and subglacial topography detected by ice-penetrating radar clarifies the features of the ice sheet in this "inaccessible" region. These results will help to advance the study of ice sheet dynamics and the determination of future locations of the GSM's geological and deep ice core drilling sites in the Dome A region.

  15. Increased Expression of Lamin A/C Correlate with Regions of High Wall Stress in Abdominal Aortic Aneurysms

    PubMed Central

    Malkawi, Amir; Pirianov, Grisha; Torsney, Evelyn; Chetter, Ian; Sakalihasan, Natzi; Loftus, Ian M.; Nordon, Ian; Huggins, Christopher; Charolidi, Nicoletta; Thompson, Matt; Xu, Xie Yun; Cockerill, Gillian W.

    2015-01-01

    Background Since aortic diameter is the most ­significant risk factor for rupture, we sought to identify stress-dependent changes in gene expression to illuminate novel molecular processes in aneurysm rupture. Materials and Methods We constructed finite element maps of abdominal computerized tomography scans (CTs) of seven abdominal aortic aneurysm (AAA) patients to map wall stress. Paired biopsies from high- and low-stress areas were collected at surgery using vascular landmarks as coordinates. Differential gene expression was evaluated by Illumina Array analysis, using the whole genome DNA-mediated, annealing, selection, extension, and ligation (DASL) gene chip (n = 3 paired samples). Results The sole significant candidate from this analysis, Lamin A/C, was validated at the protein level, using western blotting. Lamin A/C expression in the inferior mesenteric vein (IMV) of AAA patients was compared to a control group and in aortic smooth muscle cells in culture in response to physiological pulsatile stretch. ­Areas of high wall stress (n = 7) correlate to those ­regions which have the thinnest walls [778 µm (585–1120 µm)] in comparison to areas of lowest wall stress [1620 µm (962–2919 µm)]. Induced expression of Lamin A/C ­correlated with areas of high wall stress from AAAs but was not significantly induced in the IMV from AAA patients compared to controls (n = 16). Stress-induced expression of Lamin A/C was mimicked by exposing aortic smooth muscle cells to prolonged pulsatile stretch. Conclusion Lamin A/C protein is specifically increased in areas of high wall stress in AAA from patients, but is not increased on other vascular beds of aneurysm patients, suggesting that its elevation may be a compensatory response to the pathobiology leading to aneurysms. PMID:27175366

  16. Wall energy and wall thickness of exchange-coupled rare-earth transition-metal triple layer stacks

    SciTech Connect

    Raasch, D.; Mathieu, C.

    1997-08-01

    The room-temperature wall energy {sigma}{sub w}=4.0{times}10{sup {minus}3}J/m{sup 2} of an exchange-coupled Tb{sub 19.6}Fe{sub 74.7}Co{sub 5.7}/Dy{sub 28.5}Fe{sub 43.2}Co{sub 28.3} double layer stack can be reduced by introducing a soft magnetic intermediate layer in between both layers exhibiting a significantly smaller anisotropy compared to Tb{endash}FeCo and Dy{endash}FeCo. {sigma}{sub w} will decrease linearly with increasing intermediate layer thickness, d{sub IL}, until the wall is completely located within the intermediate layer for d{sub IL}{ge}d{sub w}, where d{sub w} denotes the wall thickness. Thus, d{sub w} can be obtained from the plot {sigma}{sub w} versus d{sub IL}. We determined {sigma}{sub w} and d{sub w} on Gd{endash}FeCo intermediate layers with different anisotropy behavior (perpendicular and in-plane easy axis) and compared the results with data obtained from Brillouin light-scattering measurements, where exchange stiffness, A, and uniaxial anisotropy, K{sub u}, could be determined. With the knowledge of A and K{sub u}, wall energy and thickness were calculated and showed an excellent agreement with the magnetic measurements. A ten times smaller perpendicular anisotropy of Gd{sub 28.1}Fe{sub 71.9} in comparison to Tb{endash}FeCo and Dy{endash}FeCo resulted in a much smaller {sigma}{sub w}=1.1{times}10{sup {minus}3}J/m{sup 2} and d{sub w}=24nm at 300 K. A Gd{sub 34.1}Fe{sub 61.4}Co{sub 4.5} with in-plane anisotropy at room temperature showed a further reduced {sigma}{sub w}=0.3{times}10{sup {minus}3}J/m{sup 2} and d{sub w}=17nm. The smaller wall energy was a result of a different wall structure compared to perpendicular layers. {copyright} {ital 1997 American Institute of Physics.}

  17. Bilateral photon deficient area along lateral abdominal wall in a Tc-99m DTPA renogram. A sign of massive ascites.

    PubMed

    Shih, W J; Marsano, L S

    1993-07-01

    A patient with congestive heart failure and hepatic and renal dysfunction underwent Tc-99m DTPA renal scintigraphic studies in which persistent cardiac blood pool activity, hepatic arterialization, and a longitudinal photon deficient area in each side of the abdominal wall were observed. The increase in hepatic artery inflow was believed to be due to a decrease in portal inflow of the liver. The elevation of portal pressure secondary to heart failure is attributable to the decrease in portal inflow of the liver; this phenomenon could account for the hepatic arterialization. Progressive renal dysfunction with high body background resulted in demonstrable ascites as photon deficient areas. Scintigraphic findings of hepatic arterialization plus an abdominal photon deficient area reflect severe heart failure and renal dysfunction. PMID:8344036

  18. Bladder wall thickness in the assessment of neurogenic bladder: a translational discussion of current clinical applications.

    PubMed

    Sturm, Renea M; Cheng, Earl Y

    2016-01-01

    The prospective trial by Kim et al. "Can Bladder Wall Thickness Predict Videourodynamic Findings in Children with Spina Bifida?" published in Journal of Urology investigated the measurement of bladder wall thickness (BWT) as a non-invasive assessment tool for lower urinary tract changes in neurogenic bladder (NGB). In this study, no significant association was observed between BWT and high-risk urodynamic parameters. This editorial discusses the basic science of bladder wall thickening as well as prior studies relating wall thickness to clinical parameters. Although Kim et al. provide a unique literature contribution in terms of assessment of BWT at defined percent cystometric capacity, specific aspects of study methodology and population may have contributed to a lack of correlation with high-risk urodynamic findings. The application of non-invasive modalities to lower urinary tract assessment of NGB remains a promising and relevant area of future research to prevent progression to end stage lower urinary tract changes for all individuals with spina bifida. PMID:26889485

  19. Bladder wall thickness in the assessment of neurogenic bladder: a translational discussion of current clinical applications

    PubMed Central

    Sturm, Renea M.

    2016-01-01

    The prospective trial by Kim et al. “Can Bladder Wall Thickness Predict Videourodynamic Findings in Children with Spina Bifida?” published in Journal of Urology investigated the measurement of bladder wall thickness (BWT) as a non-invasive assessment tool for lower urinary tract changes in neurogenic bladder (NGB). In this study, no significant association was observed between BWT and high-risk urodynamic parameters. This editorial discusses the basic science of bladder wall thickening as well as prior studies relating wall thickness to clinical parameters. Although Kim et al. provide a unique literature contribution in terms of assessment of BWT at defined percent cystometric capacity, specific aspects of study methodology and population may have contributed to a lack of correlation with high-risk urodynamic findings. The application of non-invasive modalities to lower urinary tract assessment of NGB remains a promising and relevant area of future research to prevent progression to end stage lower urinary tract changes for all individuals with spina bifida. PMID:26889485

  20. Venous malformations of the anterior abdominal wall in blue rubber bleb naevus syndrome: implications for antenatal and intrapartum management

    PubMed Central

    Cauldwell, Matthew; Kyle, Pippa; Treharne, Ian; Wong, Terry; Holden, Simon T; Nelson-Piercy, Catherine

    2011-01-01

    Blue rubber bleb naevus syndrome (BRBNS) is a rare vascular disorder characterized by rubbery blue–purple cutaneous nodules that are histologically thin-walled dilated vascular spaces. The exact inheritance of the disease in unknown but in cases of familial recurrence, there appears to be a pattern of autosomal dominant inheritance. The vascular lesions may manifest in any organ system but tend to predominate in the gastrointestinal tract (GI). There are only a handful of cases reported in the literature, but reported complications arising from the naevi include sponatenous GI bleeding requiring laparotomy and blood transfusion and the development of large naevi in the cervix thus preventing vaginal delivery. In this case we describe a patient with known BRBNS who developed symptomatic anaemia during her pregnancy which required antenatal admission and blood transfusion. She was managed expectantly in a multidisciplinary setting by obstetricians, gastroenterologists and an obstetric physician with the aim of a vaginal delivery. Nevertheless, she had an elective caesarean section at term for breech presentation. Surgery was complicated by the unexpected finding of venous malformations within the abdominal wall musculature and subcutaneous fat that resulted in a primary haemorrhage and required urgent blood transfusion. The patient made a good postoperative recovery and had a healthy male infant who at birth displayed no external features of BRBNS. This report demonstrates for the first time the appearance of naevi in the abdominal wall and the important considerations that need to be made regarding mode of delivery and future pregnancies.

  1. The effect of fig wall thickness in Ficus erecta var. beecheyana on parasitism

    NASA Astrophysics Data System (ADS)

    Tzeng, Hsy-Yu; Ou, Chern-Hsiung; Lu, Fu-Yuan; Bain, Anthony; Chou, Lien-Siang; Kjellberg, Finn

    2014-05-01

    Fig wasp communities constitute a model system to analyse determinants of community complexity and to investigate how biological interaction networks are maintained. It has been suggested for monoecious figs, that fig pollinating wasps avoid ovipositing in flowers located close to the fig wall because of strong parasitic pressure by wasps ovipositing through the fig wall. This behaviour could help explain why mainly seeds are produced in flowers located close to the fig wall, thus stabilizing the fig-pollinating wasp mutualism. In this contribution we explore, for dioecious figs, whether ovipositor length of parasitic species may really be limiting. In dioecious figs, functionally male figs produce pollinating wasps and pollen while female figs produce only seeds, facilitating selection of traits favouring pollinator reproduction in male figs. We show in Ficus erecta that fig walls are thicker in male figs than in female figs. Male figs presenting thick walls, thicker than the length of the parasites' ovipositors, went unparasitized while male figs presenting thinner walls were systematically parasitized. Hence, in F. erecta, ovipositor length of the parasites is limiting access to some figs. However, we also show that in another dioecious species, Ficus formosana, presenting thin walled male figs, no fig is protected against oviposition by its two parasites. Hence in dioecious as well as in monoecious figs, in some Ficus species, ovipositors of the parasites are limiting access to ovules, while in other Ficus species all ovules are exposed to parasitism.

  2. Chest wall thickness in military personnel: implications for needle thoracentesis in tension pneumothorax.

    PubMed

    Harcke, H Theodore; Pearse, Lisa A; Levy, Angela D; Getz, John M; Robinson, Stephen R

    2007-12-01

    Needle thoracentesis is an emergency procedure to relieve tension pneumothorax. Published recommendations suggest use of angiocatheters or needles in the 5-cm range for emergency treatment. Multidetector computed tomography scans from 100 virtual autopsy cases were used to determine chest wall thickness in deployed male military personnel. Measurement was made in the second right intercostal space at the midclavicular line. The mean horizontal thickness was 5.36 cm (SD = 1.19 cm) with angled (perpendicular) thickness slightly less with a mean of 4.86 cm (SD 1.10 cm). Thickness was generally greater than previously reported. An 8-cm angiocatheter would have reached the pleural space in 99% of subjects in this series. Recommended procedures for needle thoracentesis to relieve tension pneumothorax should be adapted to reflect use of an angiocatheter or needle of sufficient length. PMID:18274025

  3. Ultrasonic Wall Thickness Monitoring at High Temperatures (>500 °C)

    NASA Astrophysics Data System (ADS)

    Cegla, F. B.; Allin, J.; Davies, J. O.; Collins, P.; Cawley, P.

    2011-06-01

    Corrosion and erosion shorten the life of components that are used in the petrochemical industry. In order to mitigate the safety and financial risks posed by the degradation mechanisms, plant operators monitor wall thicknesses at regular inspection intervals. In high temperature locations inspections have to be carried out at plant shut downs because conventional ultrasonic sensors cannot withstand the high operating temperatures. The authors have developed a waveguide based high temperature thickness gauge for monitoring of wall thicknesses in high temperature areas. The waveguide allows the use of conventional transduction systems (max temp. 60 °C) at one end and guides ultrasonic waves into the high temperature region where the inspection is to be carried out. Slender stainless steel waveguides allow a temperature drop of ˜500-600 °C per 200 mm length to be sustained simply by natural convection cooling. This paper describes the technical challenges that had to be overcome (dispersion and source/receiver characteristics) in order to implement this "acoustic cable". A range of experimental results of thickness measurements on components of different thickness, and furnace tests at different temperatures are presented. An accelerated corrosion test that demonstrates the effectiveness of the monitoring for corrosion is also presented.

  4. Elastic analysis of heterogeneous thick-walled spherical pressure vessels with parabolic varying properties

    NASA Astrophysics Data System (ADS)

    Karami, Keyhan; Abedi, Majid; Zamani Nejad, Mohammad; Lotfian, Mohammad Hassan

    2012-12-01

    On the basis of plane elasticity theory (PET), the displacement and stress components in a thick-walled spherical pressure vessels made of heterogeneous materials subjected to internal and external pressure is developed. The mechanical properties except the Poisson's ratio are assumed to obey the parabolic variations throughout the thickness. Effect of material inhomogeneity on the elastic deformations and stresses is investigated. The analytical solutions and the solutions carried out through the FEM have a good agreement. The values used in this study are arbitrary chosen to demonstrate the effect of inhomogeneity on displacements, and stresses distributions.

  5. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

    PubMed

    Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

    2016-02-01

    Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output. PMID:26643090

  6. A thermoelastic transversely isotropic thick walled cylinder/disk application: An analytical solution and study

    NASA Technical Reports Server (NTRS)

    Arnold, S. M.

    1989-01-01

    A continuum theory is utilized to represent the thermoelastic behavior of a thick walled composite cylinder that can be idealized as transversely isotropic. A multiaxial statement of the constitutive theory employed is presented, as well as the out of the plane of isotropy, plane stress, and plane strain reductions. The derived analytical solution presented is valid for a cylindrical tube or thin disk with a concentric hole, subjected to internal and/or external pressure and a general radial temperature distribution. A specific problem examined is that of a thick walled cylinder subjected to an internal and external pressure loading and a linear radial temperature distribution. The results are expressed in nondimensional form and the effects on the response behavior are examined for various material properties, fiber orientation and types of loadings.

  7. Simulation on the Effect of Bottle Wall Thickness Distribution using Blow Moulding Technique

    NASA Astrophysics Data System (ADS)

    Suraya, S.; Azman, M. D.; Fatchurrohman, N.; Jaafar, A. A.; Yusoff, A. R.

    2016-02-01

    The aims of this study are to assess the deformation behavior of a polymeric material during a blow moulding process. Transient computations of two dimensional model of a PP bottle were performed using ANSYS Polyflow computer code to predict the wall thickness distribution at four different parison's diameter; 8mm, 10mm, 18mm, and 20mm. Effects on the final wall thickness diameter and time step are studied. The simulated data shows that the inflation performance degrades with increasing parison diameter. It is concluded that the blow moulding process using 10mm parison successfully meet the product processing requirements. Factors that contribute to the variation in deformation behaviour of the plastic during the manufacturing process are discussed.

  8. Increased wall thickness using ultrasonography is associated with inflammation in an animal model of experimental colitis

    PubMed Central

    Lied, Gülen Arslan; Milde, Anne Marita; Nylund, Kim; Mujic, Maja; Grimstad, Tore; Hausken, Trygve; Gilja, Odd Helge

    2012-01-01

    Experimentally induced colitis is used in animals to investigate pathophysiological mechanisms in inflammatory bowel disease. When following disease course and treatment effects, it should be possible to perform repeated measurements without harming the animals. This pilot study was performed to investigate whether transabdominal ultrasound using a clinical scanner could be used on rats to demonstrate bowel inflammation in an experimental colitis model. Colitis was induced by either 5% dextran sodium sulfate (DSS) in drinking water for 7 days or a single dose of intracolonic trinitrobenzene sulfonic acid (TNBS). Using ultrasonography, wall thickness of distal colon, cecum, and small bowel was recorded prior to and after DSS, and prior to, 2, and 7 days after TNBS. Blood (tumor necrosis factor [TNF]-alpha) and fecal samples (HemoFEC occult blood) were taken from each group on the same days as sonography. Thereafter, rats were killed and specimens for histology were taken. Wall thickness of distal colon, not of cecum or small bowel, increased significantly after 7 days of DSS, and wall thickness of both distal colon and small bowel increased on day 2 and 7 after TNBS. TNF-alpha increased after 7 days in the latter group only. There was a significant correlation between ultrasonographic measurements and combined histology score of distal colon in the DSS group. HemoFEC was also positive in accordance with sonographic and histological features. Increased intestinal wall thickness in response to both DSS- and TNBS-induced colitis was able to be visualized by transabdominal sonography. Moreover, ultrasound findings, occult blood sampling, and histological findings supported each other, indicating that ultrasonography can be used to assess inflammation in a rat experimental model. PMID:23055765

  9. Influence of slab thickness on responses of concrete walls under fire

    SciTech Connect

    Huang, C.L.D.; Ahmed, G.N. )

    1991-01-01

    Of considerable concern in safety assessments of high-temperature nuclear reactors and of tall buildings is the ability to determine the concrete response, and, in turn, its structural integrity after exposure, to a severe thermal environment. Under hostile environmental conditions, the concrete structure could be exposed to extremely high temperatures. The induced gradients of temperature, pressure, and moisture content in concrete provoke internal stresses that may cause microcracks, macrocracks, and explosive spalling of concrete. Thus the integrity of concrete may be questionable, and the prediction of coupled heat and mass transport in concrete under high temperature (fire, for instance) is becoming more and more important. For the purpose of fire safety, concrete walls with different thicknesses exposed to the fire course described by ASTM E119 and the following decay stage specified in ISO 834 standard are considered. A mathematical model, simulating the coupled heat and mass transfer in concrete walls under time-dependent boundary conditions, has been developed and numerically solved. The results predict the pore pressure, temperature, and moisture histories for different concrete wall thicknesses at various depth thickness ratios. The results show that, under fire, thinner slabs are more vulnerable to damages and ruptures than thicker ones.

  10. Carotid wall stress calculated with continuous intima-media thickness assessment using B-mode ultrasound

    NASA Astrophysics Data System (ADS)

    Pascaner, A. F.; Craiem, D.; Casciaro, M. E.; Danielo, R.; Graf, S.; Guevara, E.

    2016-04-01

    Cardiovascular risk is normally assessed using clinical risk factors but it can be refined using non-invasive infra-clinical markers. Intima-Media Thickness (IMT) is recognized as an early indicator of cardiovascular disease. Carotid Wall Stress (CWS) can be calculated using arterial pressure and carotid size (diameter and IMT). Generally, IMT is measured during diastole when it reaches its maximum value. However, it changes during the cardiac cycle and a time-dependant waveform can be obtained using B-mode ultrasound images. In this work we calculated CWS considering three different approaches for IMT assessment: (i) constant IMT (standard diastolic value), (ii) estimated IMT from diameter waveform (assuming a constant cross-sectional wall area) and (iii) continuously measured IMT. Our results showed that maximum wall stress depends on the IMT estimation method. Systolic CWS progressively increased using the three approaches (p<0.024). We conclude that maximum CWS is highly dependent on wall thickness and accurate IMT measures during systole should be encouraged.

  11. Detection of colonic polyp candidates with level set-based thickness mapping over the colon wall

    NASA Astrophysics Data System (ADS)

    Han, Hao; Li, Lihong; Duan, Chaijie; Zhao, Yang; Wang, Huafeng; Liang, Zhengrong

    2015-03-01

    Further improvement of computer-aided detection (CADe) of colonic polyps is vital to advance computed tomographic colonography (CTC) toward a screening modality, where the detection of flat polyps is especially challenging because limited image features can be extracted from flat polyps, and the traditional geometric features-based CADe methods usually fail to detect such polyps. In this paper, we present a novel pipeline to automatically detect initial polyp candidates (IPCs), especially flat polyps, from CTC images. First, the colon wall mucosa was extracted via a partial volume segmentation approach as a volumetric layer, where the inner border of colon wall can be obtained by shrinking the volumetric layer using level set based adaptive convolution. Then the outer border of colon wall (or the colon wall serosa) was segmented via a combined implementation of geodesic active contour and Mumford-Shah functional in a coarse-to-fine manner. Finally, the wall thickness was estimated along a unique path between the segmented inner and outer borders with consideration of the volumetric layers and was mapped onto a patient-specific three-dimensional (3D) colon wall model. The IPC detection results can usually be better visualized in a 2D image flattened from the 3D model, where abnormalities were detected by Z-score transformation of the thickness values. The proposed IPC detection approach was validated on 11 patients with 22 CTC scans, and each scan has at least one flat poly annotation. The above presented novel pipeline was effective to detect some flat polyps that were missed by our CADe system while keeping false detections in a relative low level. This preliminary study indicates that the presented pipeline can be incorporated into an existing CADe system to enhance the polyp detection power, especially for flat polyps.

  12. Harmonic amplitude distribution in a wideband ultrasonic wavefront after propagation through human abdominal wall and breast specimens.

    PubMed

    Liu, D L; Waag, R C

    1997-02-01

    The amplitude characteristics of ultrasonic wavefront distortion produced by transmission through the abdominal wall and breast is described. Ultrasonic pulses were recorded in a two-dimensional aperture after transmission through specimens of abdominal wall or breast. After the pulse arrival times were corrected for geometric path differences, the pulses were temporally Fourier transformed and two-dimensional maps of harmonic amplitudes in the measurement aperture were computed. The results indicate that, as the temporal frequency increases, the fluctuation in harmonic amplitudes increases but the spatial scale of the fluctuation decreases. The normalized second-order and third-order moments of the amplitude distribution also increase with temporal frequency. The wide range variation of these distribution characteristics could not be covered by the Rayleigh, Rician, or K-distribution because of their limited flexibility. However, the Weibull distribution and especially the generalized K-distribution provide better fits to the data. In the fit of the generalized K-distribution, a decrease of its parameter alpha with increasing temporal frequency was observed, as predicted by analysis based on a phase screen model. PMID:9035403

  13. [Pulse pressure and common carotid arterial wall thickness assessed by ultrasonography].

    PubMed

    Kawamoto, R; Doi, T

    2000-06-01

    This study was conducted on a total of 358 normotensive (mean blood pressure < 107 mmHg) inpatients (182 men and 176 women, mean age: 67.8 years) who had no cardiorenal or nutrition disorders that would affect blood pressure, lipid and glucose metabolism and who had not been given depressors or antilipidemic agents during the four years from September 1995 to August 1999. In addition to the known risk factors for atherosclerosis, the effects of pulse pressure and mean blood pressure on sclerotic changes of the carotid arteries were examined. These sclerotic changes were assessed by measuring the thickness of the combined intima-media of the common carotid artery (carotid arterial wall thickness) by ultrasonography (Hitachi EUB-565) and linear probe (7.5 MHz). When the patients were divided into three groups based on pulse pressure (PP1, lower than 51 mmHg: PP2, 51-65 mmHg; PP3, higher than 65 mmHg), the age of the group with higher pulse pressure was significantly higher (p = 0.0011), women more (p = 0.0315). However there were no differences in background factors such as body mass index, Brinkman index, lipid metabolism, uric acid, and glucose metabolism. There was observed a positive correlation between the mean blood pressure and the pulse pressure for both men and women (r = 0.31, p < 0.001, respectively). As for the relation between the pulse pressures and the blood pressure parameters, the systolic blood pressure, pulse pressure and the mean blood pressure were significantly higher in the group with higher pulse pressure (p < 0.001, respectively), but the diastolic blood pressure was significantly lower (p = 0.0275). As for the relation between the pulse pressure and the carotid wall thickness, the groups of both men and women with higher pulse pressures had significantly greater carotid arterial wall thickness (p < 0.001, p = 0.0042, respectively). Logistic regression analysis of the carotid arterial wall thickness (defined as hypertrophic if greater than 1

  14. Reproducibility of The Abdominal and Chest Wall Position by Voluntary Breath-Hold Technique Using a Laser-Based Monitoring and Visual Feedback System

    SciTech Connect

    Nakamura, Katsumasa . E-mail: nakam@radiol.med.kyushu-u.ac.jp; Shioyama, Yoshiyuki; Nomoto, Satoru; Ohga, Saiji; Toba, Takashi; Yoshitake, Tadamasa; Anai, Shigeo; Terashima, Hiromi; Honda, Hiroshi

    2007-05-01

    Purpose: The voluntary breath-hold (BH) technique is a simple method to control the respiration-related motion of a tumor during irradiation. However, the abdominal and chest wall position may not be accurately reproduced using the BH technique. The purpose of this study was to examine whether visual feedback can reduce the fluctuation in wall motion during BH using a new respiratory monitoring device. Methods and Materials: We developed a laser-based BH monitoring and visual feedback system. For this study, five healthy volunteers were enrolled. The volunteers, practicing abdominal breathing, performed shallow end-expiration BH (SEBH), shallow end-inspiration BH (SIBH), and deep end-inspiration BH (DIBH) with or without visual feedback. The abdominal and chest wall positions were measured at 80-ms intervals during BHs. Results: The fluctuation in the chest wall position was smaller than that of the abdominal wall position. The reproducibility of the wall position was improved by visual feedback. With a monitoring device, visual feedback reduced the mean deviation of the abdominal wall from 2.1 {+-} 1.3 mm to 1.5 {+-} 0.5 mm, 2.5 {+-} 1.9 mm to 1.1 {+-} 0.4 mm, and 6.6 {+-} 2.4 mm to 2.6 {+-} 1.4 mm in SEBH, SIBH, and DIBH, respectively. Conclusions: Volunteers can perform the BH maneuver in a highly reproducible fashion when informed about the position of the wall, although in the case of DIBH, the deviation in the wall position remained substantial.

  15. Accurate measurement of respiratory airway wall thickness in CT images using a signal restoration technique

    NASA Astrophysics Data System (ADS)

    Park, Sang Joon; Kim, Tae Jung; Kim, Kwang Gi; Lee, Sang Ho; Goo, Jin Mo; Kim, Jong Hyo

    2008-03-01

    Airway wall thickness (AWT) is an important bio-marker for evaluation of pulmonary diseases such as chronic bronchitis, bronchiectasis. While an image-based analysis of the airway tree can provide precise and valuable airway size information, quantitative measurement of AWT in Multidetector-Row Computed Tomography (MDCT) images involves various sources of error and uncertainty. So we have developed an accurate AWT measurement technique for small airways with three-dimensional (3-D) approach. To evaluate performance of these techniques, we used a set of acryl tube phantom was made to mimic small airways to have three different sizes of wall diameter (4.20, 1.79, 1.24 mm) and wall thickness (1.84, 1.22, 0.67 mm). The phantom was imaged with MDCT using standard reconstruction kernel (Sensation 16, Siemens, Erlangen). The pixel size was 0.488 mm × 0.488 mm × 0.75 mm in x, y, and z direction respectively. The images were magnified in 5 times using cubic B-spline interpolation, and line profiles were obtained for each tube. To recover faithful line profile from the blurred images, the line profiles were deconvolved with a point spread kernel of the MDCT which was estimated using the ideal tube profile and image line profile. The inner diameter, outer diameter, and wall thickness of each tube were obtained with full-width-half-maximum (FWHM) method for the line profiles before and after deconvolution processing. Results show that significant improvement was achieved over the conventional FWHM method in the measurement of AWT.

  16. Extensive Abdominal Wall Incisional Heterotopic Ossification Reconstructed with Component Separation and Strattice Inlay

    PubMed Central

    Suleiman, Nergis Nina

    2016-01-01

    Summary: Symptomatic heterotopic ossification of abdominal surgical incisions is a rare occurrence. We present a 67-year-old man with severe discomfort caused by heterotopic ossification extending from the xiphoid to the umbilicus. The patient underwent an abdominal aortic aneurysm repair 3 years before our treatment. A 13 × 3.5 cm ossified lesion was excised. The resulting midline defect was closed using component separation and inlay Strattice. Tension-free midline adaptation of the recti muscles was achieved. A computed tomography scan of the abdomen 6 months after the surgery showed no recurrence or hernias. Heterotopic ossification in symptomatic patients has previously been treated with excision and primary closure. We believe that tension-free repair is important to prevent recurrence. Acellular dermal matrix may add to this effect and also compartmentalize the process. PMID:27536495

  17. Extensive Abdominal Wall Incisional Heterotopic Ossification Reconstructed with Component Separation and Strattice Inlay.

    PubMed

    Suleiman, Nergis Nina; Sandberg, Lars Johan Marcus

    2016-07-01

    Symptomatic heterotopic ossification of abdominal surgical incisions is a rare occurrence. We present a 67-year-old man with severe discomfort caused by heterotopic ossification extending from the xiphoid to the umbilicus. The patient underwent an abdominal aortic aneurysm repair 3 years before our treatment. A 13 × 3.5 cm ossified lesion was excised. The resulting midline defect was closed using component separation and inlay Strattice. Tension-free midline adaptation of the recti muscles was achieved. A computed tomography scan of the abdomen 6 months after the surgery showed no recurrence or hernias. Heterotopic ossification in symptomatic patients has previously been treated with excision and primary closure. We believe that tension-free repair is important to prevent recurrence. Acellular dermal matrix may add to this effect and also compartmentalize the process. PMID:27536495

  18. Carotid Intima-media thickness in childhood and adolescent obesity relations to abdominal obesity, high triglyceride level and insulin resistance

    PubMed Central

    Fang, Jie; Zhang, Jian Ping; Luo, Cai Xia; Yu, Xiao Mei; Lv, Lan Qiu

    2010-01-01

    Aim: To investigate risk factors which impact on common carotid artery intima media thickness (IMT). Methods: A total of 86 obese children and adolescents and 22 healthy children and adolescents with normal weight were enrolled. Moreover, 23 of 86 obese children and adolescents were diagnosed with metabolic syndrome (MetS). The clinical, biochemical data and the IMT of the common carotid artery were measured in all subjects. Results: Obese and obese with MetS subjects demonstrated a significantly (p < 0.01) thicker intima media (0.69mm, 0.66mm) as compared to the control group (0.38mm), but there was no significant difference of IMT between obese and MetS group. IMT was correlated to body weight, body mass index, waist circumference, waist to hip ratio, systolic blood pressure, diastolic blood pressure, fasting insulin, homoeostasis model assessment-insulin resistance, triglyceride, high-density lipoprotein- cholesterol, low-density lipoprotein-cholesterol, alanine aminotransferase, aspartate aminotransferase and fatty liver. Waist circumference, waist to hip ratio, triglyceride and homoeostasis model assessment-insulin resistance were independent determinants of mean IMT level. Conclusion: Obesity especially abdominal obesity, high TG and insulin resistance may be the main risk predictors of increased IMT. PMID:20827427

  19. Avoiding Complications in Abdominal Wall Surgery: A Mathematical Model to Predict the Course of the Motor Innervation of the Rectus Abdominis.

    PubMed

    Tessone, Ariel; Nava, Maurizio; Blondeel, Phillip; Spano, Andrea

    2016-02-01

    Ever since its introduction, the transverse rectus abdominis myocutaneous flap has become the mainstay of autologous breast reconstruction. However, concerns regarding donor site morbidity due to the breach of abdominal wall musculature integrity soon followed. Muscle-sparing techniques, eventually eliminating the muscle from the flap all-together with the deep inferior epigastric artery perforator flap, did not eliminate the problem of abdominal wall weakness. This led to the conclusion that motor innervation might be at fault. Studies have shown that even in the presence of an intact rectus abdominis muscle, and an intact anterior rectus sheath, denervation of the rectus abdominis muscle results in significant abdominal wall weakness leading to superior and inferior abdominal bulges, and abdominal herniation. Our aim was to establish a mathematical model to predict the location of the motor innervation to the rectus abdominis muscle, and thus provide surgeons with a tool that will allow them to reduce abdominal morbidity during deep inferior epigastric artery perforator and free muscle-sparing transverse rectus abdominis myocutaneous surgery. We dissected 42 cadaveric hemiabdomens and mapped the course of the thoracolumbar nerves. We then standardized and analyzed our findings and presented them as a relative map which can be adjusted to body type and dimensions. Our dissections show that the motor innervation is closely related to the lateral vascular supply. Thus, when possible, we support the preferred utilization of the medial vascular supply, and the preservation of the lateral supply and motor innervation. PMID:26756600

  20. Growth and Remodeling in a Thick-Walled Artery Model: Effects of Spatial Variations in Wall Constituents

    PubMed Central

    Alford, Patrick W.; Humphrey, Jay D.; Taber, Larry A.

    2008-01-01

    A mathematical model is presented for growth and remodeling of arteries. The model is a thick-walled tube composed of a constrained mixture of smooth muscle cells, elastin and collagen. Material properties and radial and axial distributions of each constituent are prescribed according to previously published data. The analysis includes stress-dependent growth and contractility of the muscle and turnover of collagen fibers. Simulations were conducted for homeostatic conditions and for the temporal response following sudden hypertension. Numerical pressure-radius relations and opening angles (residual stress) show reasonable agreement with published experimental results. In particular, for realistic material and structural properties, the model predicts measured variations in opening angles along the length of the aorta with reasonable accuracy. These results provide a better understanding of the determinants of residual stress in arteries and could lend insight into the importance of constituent distributions in both natural and tissue-engineered blood vessels. PMID:17786493

  1. Continued research on the strain to failure of thick-walled cylinders subjected to internal pressure

    SciTech Connect

    Roach, D.P.; Priddy, T.G.

    1990-01-01

    The determination of the fully plastic response and pressure limit of a pressure vessel is of considerable importance in design. In-house experience in weapon development, new aerospace applications and autofrettage operations all require in-depth knowledge of the strength of high pressure containment structures. This paper presents additional results to support the strain-to-failure analysis of thick-walled cylindrical vessels. Both aluminum and steel, with material properties ranging from ductile to brittle, were tested at stress levels through plastic and strain hardening ranges to fracture. From these tests, the pressure-expansion and through thickness yielding characteristics were determined for these specimens. The critical effective plastic strain depends on the level of tensile stress triaxiality which varies through the wall thickness. It is shown that the proposed strain-to-failure criterion is based on this triaxiality of stress in the critical region and can be used to predict the complete pressure versus strain relations and maximum pressure for the test cylinders. 17 refs., 12 figs.

  2. A hybrid method for airway segmentation and automated measurement of bronchial wall thickness on CT.

    PubMed

    Xu, Ziyue; Bagci, Ulas; Foster, Brent; Mansoor, Awais; Udupa, Jayaram K; Mollura, Daniel J

    2015-08-01

    Inflammatory and infectious lung diseases commonly involve bronchial airway structures and morphology, and these abnormalities are often analyzed non-invasively through high resolution computed tomography (CT) scans. Assessing airway wall surfaces and the lumen are of great importance for diagnosing pulmonary diseases. However, obtaining high accuracy from a complete 3-D airway tree structure can be quite challenging. The airway tree structure has spiculated shapes with multiple branches and bifurcation points as opposed to solid single organ or tumor segmentation tasks in other applications, hence, it is complex for manual segmentation as compared with other tasks. For computerized methods, a fundamental challenge in airway tree segmentation is the highly variable intensity levels in the lumen area, which often causes a segmentation method to leak into adjacent lung parenchyma through blurred airway walls or soft boundaries. Moreover, outer wall definition can be difficult due to similar intensities of the airway walls and nearby structures such as vessels. In this paper, we propose a computational framework to accurately quantify airways through (i) a novel hybrid approach for precise segmentation of the lumen, and (ii) two novel methods (a spatially constrained Markov random walk method (pseudo 3-D) and a relative fuzzy connectedness method (3-D)) to estimate the airway wall thickness. We evaluate the performance of our proposed methods in comparison with mostly used algorithms using human chest CT images. Our results demonstrate that, on publicly available data sets and using standard evaluation criteria, the proposed airway segmentation method is accurate and efficient as compared with the state-of-the-art methods, and the airway wall estimation algorithms identified the inner and outer airway surfaces more accurately than the most widely applied methods, namely full width at half maximum and phase congruency. PMID:26026778

  3. Reduction of aneurysm pressure and wall stress after endovascular repair of abdominal aortic aneurysm in a canine model.

    PubMed

    Marston, W A; Criado, E; Baird, C A; Keagy, B A

    1996-03-01

    A canine model was designed to evaluate the changes in abdominal aortic aneurysm (AAA) pressure and wall stress after endovascular repair. Eight canines underwent laparotomy and creation of an AAA. The aneurysm was then excluded with a transluminally placed endovascular graft (TPEG) inserted through the right femoral artery and deployed across the AAA to exclude the infrarenal aortic branches from aortic perfusion. Blood pressure and flow data were recorded for 6 hours. The AAA blood pressure decreased from 135 +/- 9.3 mm Hg before exclusion to 45 +/- 17.6 mm Hg at 10 minutes after exclusion (p < 0.001). At 6 hours, AAA blood pressure had declined further to 26 +/- 12.5 mm Hg. Blood flow in the excluded iliac artery decreased from a baseline of 242 +/- 58 ml/min to 41 +/- 29 ml/min 10 minutes after TPEG placement (p < 0.001). At 6 hours, flow was reduced to 12 +/- 3.5 ml/min (p < 0.05 compared with that at 10 minutes). Aortic wall stress was significantly reduced by TPEG placement but was only slightly lower than baseline aortic wall stress before AAA creation. The lumbar arteries were patent with retrograde flow in all cases and were found to be the major contributors to postexclusion aneurysm pressure. Endovascular AAA exclusion results in an immediate decrease in blood pressure and wall stress within the excluded aneurysm, but the aneurysm remains perfused by retrograde flow through the lumbar arteries, which resulted in near-baseline levels of aneurysm wall stress in this canine model. Embolization of patient lumbar vessels at prosthesis placement may further reduce the risk of late rupture. PMID:8733869

  4. Influence of remaining dentin wall thickness on the fracture strength of endodontically treated tooth

    PubMed Central

    Haralur, Satheesh B.; Al-Qahtani, Ali Saad; Al-Qarni, Marie Mohammed; Al-Homrany, Rami Mohammed; Aboalkhair, Ayyob Ehsan

    2016-01-01

    Background: Remaining dentin wall thickness may influence the fracture resistance of tooth. Aims: To investigate the effect of various coronal dentin wall widths on the fracture strength of root canal treated teeth. Materials and Methods: Fifty recently extracted single canal mandibular premolars were used for the study. Ten unrestored teeth were used as control (Group 1); remaining teeth were root canal treated and divided into four groups (n = 10). The Groups 2a, 2b and 3a, 3b were having 2.5 mm, 1.5 mm remaining dentin with and without post, respectively. The samples fracture resistance was tested under the universal testing machine. The data were analyzed with one-way ANOVA and post-hoc Tukey test for comparative evaluation. Results: The mean fracture strength observed in Group 1 was (29.75 Mpa) followed by Group 2a (28.97 Mpa), Group 2b (27.70 Mpa), Group 3a (23.39 Mpa), and Group 3b (16.38 Mpa). There was no statistically significant difference between control and Groups 2a and 2b with P > 0.05. The post contributed significantly for fracture resistance in Group 3a. Conclusion: The endodontic post is not required in root canal treated teeth >2.5 mm coronal dentin wall width while the post is essential for a tooth with <1.5 mm dentin wall width to improve fracture resistance. PMID:26957796

  5. Adaptive ultrasonic measurement of blood vessel diameter and wall thickness: theory and experimental results.

    PubMed

    Rafii, K; Jaffe, J S

    1998-01-01

    An adaptive ultrasonic technique for measuring blood vessel diameter and wall thickness is presented. This technique allows one to use a target-specific transmitted waveform/receiver filter to obtain a larger signal-to-noise ratio (SNR) in the received signal than conventional techniques. Generally, SNR of a received wave increases as the intensity of the transmit wave increases; however, because of the FDA limitations placed on the amount of transmit energy, it is important to be able to make the most efficient use of the energy that is available to obtain the best possible SNR in the received signal. Adaptive ultrasonic measurement makes the most efficient use of the energy that is available by placing the maximum amount of energy in the largest target scattering mode. This results in more energy backscatter from a given target, which leads to a higher SNR in the received waveform. Computer simulations of adaptive ultrasonic measurement of blood vessel diameter show that for a SNR of 0 dB in the transmitted waveform, the standard deviation of the diameter measurements for a custom-designed transmitted waveform is about two orders of magnitude less than the standard deviation of the diameter measurements using more conventional waveforms. Diameter and wall thickness measurement experiments were performed on a latex tube and a bovine blood vessel using both custom-made and conventionally used transmitted waveforms. Results show that the adaptively designed waveform gives a smaller uncertainty in the measurements. The adaptive ultrasonic blood vessel diameter and wall thickness measuring technique has potential applications in examining vessels which are either too deep inside the body or too small for conventional techniques to be used, because of the low SNR in the received signal. PMID:18244211

  6. Failure prediction method for hydro forming simulation of thick walled tubes

    NASA Astrophysics Data System (ADS)

    Kolleck, Ralf; Auer, Peter; Auer, Gerfried

    2011-05-01

    The industrial production of thick walled hydro formed steel parts is a process difficult to control. In particular the prevention of cracks in the production of these parts is very important. It is of utmost importance to have a virtual tool to predict forming results. Standard methods for the simulation of hydro formed parts base upon processes using a shell element formulation and implement a forming limit curve (FLC) for crack prediction. But the forming limit curve is limited to the case of linear strain paths. The initial FLC is no longer valid in the case of nonlinear strain paths. Because of the geometric specifications of the investigated parts—thick walls, compact dimensions, high strains—and the known limitations of the forming limit curve—which don't accord to the hydro forming process— these standard simulation methods are not applicable for the present investigations. A new approach to simulate thick walled hydro formed parts is the use of a volume element formulation in combination with a more complex failure criterion, which gives information about the risk of ductile normal fracture and ductile shear fractures with nonlinear strain paths. The onset of necking must be predicted directly by the volume elements. The aim of this work is to implement the failure criteria in a hydroforming simulation and to compare the results of the simulation with real cracked test parts. The commercial FEM code PamStamp 2G is used as a solver and a comprehensive fracture model is applied. This fracture model distinguishes between two mechanisms responsible for ductile fracture. One is the void growth and coalescence (ductile normal fracture) and the other one is the shear failure model (ductile shear fracture).

  7. Impaired Gallbladder Motility and Increased Gallbladder Wall Thickness in Patients with Nonalcoholic Fatty Liver Disease

    PubMed Central

    Colak, Yasar; Bozbey, Gulcin; Erim, Tolga; Caklili, Ozge Telci; Ulasoglu, Celal; Senates, Ebubekir; Mutlu, Hasan Huseyin; Mesci, Banu; Doğan, Mehmet Sait; Tasan, Guralp; Enc, Feruze Yilmaz; Tuncer, Ilyas

    2016-01-01

    Background/Aims Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease worldwide. Along with the increase in the incidence of NAFLD and associated obesity, an increase in gallbladder disease (GD) has been noted. This has led to the identification of a new disease entity called fatty GD. There is a gap in the literature on the dynamics of gallbladder function in patients with NAFLD. Methods An observational case-control study, a total of 50 patients with biopsy proven NAFLD without gallbladder stone/sludge and 38 healthy comparison subjects were enrolled. Fasting, postprandial gallbladder volumes (PGV), gallbladder ejection fraction (GEF), and fasting gallbladder wall thickness (FGWT) were measured by real-time 2-dimensional ultrasonography. Results Fasting gallbladder wall thickness, fasting gallbladder volumes and PGV were significantly higher in patients with NAFLD than control subjects (P < 0.001, P = 0.006, and P < 0.001, respectively). Gallbladder ejection fraction was significantly lower in the NAFLD group than the controls (P = 0.008). The presence of NAFLD was an independent predictor for GEF, PGV, and FGWT. Also, steatosis grade was an independent predictor for GEF, and GEF was significantly lower in the nonalcoholic steatohepatitis (NASH) subgroup than the controls. Conclusions Gallbladder dysfunction and increase in gallbladder wall thickness exists in asymptomatic (without stone/sludge and related symptoms) patients with NAFLD and are useful in identifying fatty GD. Measurement of these variables in NAFLD patients may be useful in identifying those at higher risk for GD. PMID:26932908

  8. The importance of ultrasonographic measurement of peritoneal wall thickness in pediatric chronic peritoneal dialysis patients.

    PubMed

    Yavaşcan, Önder; Aksu, Nejat; Alparslan, Caner; Sarıtaş, Serdar; Elmas, Cengiz Han; Eraslan, Ali Nihat; Duman, Soner; Mir, Sevgi

    2015-04-01

    Loss of peritoneal function due to peritoneal fibrosing syndrome (PFS) is a major factor leading to treatment failure in chronic peritoneal dialysis (PD) patients. Although the precise biologic mechanisms responsible for these changes have not been defined, the general assumption is that alterations in peritoneal function are related to structural changes in the peritoneal membrane. Studies of the peritoneal membrane by non-invasive ultrasonography (US) in chronic PD patients are limited. The aim of the present study is to assess the relationship between functional parameters of peritoneum and peritoneal thickness measured by US in children treated by chronic PD. We recruited two groups of patients: 23 subjects (13 females, 10 males) on chronic PD (patient group) and 26 (7 females, 19 males) on predialysis out-patient follow-up (creatinine clearance: 20-60 mL/min/1.73 m(2)) (control group). Age, sex, weight, height, body mass index (BMI), chronic PD duration, episodes of peritonitis and the results of peritoneal equilibration test (PET) were recorded. Hemoglobin (Hb), blood pressure (BP), left ventricular mass index (LVMI) and renal osteodystrophy (ROD) parameters were also obtained. The thickness of the parietal peritoneum was measured by trans-abdominal US in all children. Statistical analyses were performed by using Student's t and Pearson's correlation tests. Mean peritoneal thickness in chronic PD patients (1028.26 ± 157.26 μm) was significantly higher than control patients (786.52 ± 132.33). Mean peritoneal thickness was significantly correlated with mean body height (R(2) = 0.93, p < 0.05), BMI (R(2) = 0.25, p < 0.05), chronic PD duration (R(2) = 0.64, p < 0.05), episodes of peritonitis (R(2) = 0.93, p < 0.05), D/Pcreatinine (R(2) = 0.76, p < 0.05) and D4/D0glucose (R(2) = 0.81, p < 0.05). No correlation was found between peritoneal thickness and Hb, BP, LVMI and ROD parameters. In conclusion

  9. IFE thick liquid wall chamber dynamics: Governing mechanisms andmodeling and experimental capabilities

    SciTech Connect

    Raffray, A.R.; Meier, W.; Abdel-Khalik, S.; Bonazza, R.; Calderoni, P.; Debonnel, C.S.; Dragojlovic, Z.; El-Guebaly, L.; Haynes,D.; Latkowski, J.; Olson, C.; Peterson, P.F.; Reyes, S.; Sharpe, P.; Tillack, M.S.; Zaghloul, M.

    2005-01-24

    For thick liquid wall concepts, it is important to understand the different mechanisms affecting the chamber dynamics and the state of the chamber prior to each shot a compared with requirements from the driver and target. These include ablation mechanisms, vapor transport and control, possible aerosol formation, as well as protective jet behavior. This paper was motivated by a town meeting on this subject which helped identify the major issues, assess the latest results, review the capabilities of existing modeling and experimental facilities with respect to addressing remaining issues, and helping guide future analysis and R&D efforts; the paper covers these exact points.

  10. Novel superhydrophilic poly(l-lactic acid-co-ε-caprolactone)/fibrinogen electrospun patch for rat abdominal wall reconstruction.

    PubMed

    Liu, Zhang; Li, Shaojie; Su, Ling; Sun, Kang; Wu, Xujun; Wu, Feng; Huang, Weihong; Yang, Li; Tang, Jianxiong; He, Hongbing

    2015-08-01

    A novel superhydrophilic hybrid scaffold was created by electrospinning a mixture of poly(l-lactic acid-co-ε-caprolactone) and formulated fibrinogen. The hybrid scaffolds possess the combined benefits of each individual component, such as moderate mechanical strength and excellent biocompatibility. In vitro studies also revealed that endothelial cells seeded on the hybrid scaffolds achieved a relatively high level of cell attachment after three days of culture and a significant increase in the proliferation rate after seven days of culture, compared with pure fibrinogen or poly(l-lactic acid-co-ε-caprolactone) scaffolds. A comparative study of hybrid and pure poly(l-lactic acid-co-ε-caprolactone) patches was performed in an abdominal wall defect model in rats. In both groups, implants degraded by six months, but muscle reconstruction was only observed in the hybrid patch group. PMID:25791683

  11. Effect of bladder wall thickness on miniature pneumatic artificial muscle performance.

    PubMed

    Pillsbury, Thomas E; Kothera, Curt S; Wereley, Norman M

    2015-10-01

    Pneumatic artificial muscles (PAMs) are actuators known for their high power to weight ratio, natural compliance and light weight. Due to these advantages, PAMs have been used for orthotic devices and robotic limbs. Small scale PAMs have the same advantages, as well as requiring greatly reduced volumes with potential application to prostheses and small scale robotics. The bladder of a PAM affects common actuator performance metrics, specifically: blocked force, free contraction, hysteresis, and dead-band pressure. This paper investigates the effect that bladder thickness has on static actuation performance of small scale PAMs. Miniature PAMs were fabricated with a range of bladder thicknesses to quantify the change in common actuator performance metrics specifically: blocked force, free contraction, and dead-band pressure. These PAMs were then experimentally characterized in quasi-static conditions, where results showed that increasing bladder wall thickness decreases blocked force and free contraction, while dead-band pressure increases. A nonlinear model was then applied to determine the structure of the stress-strain relationship that enables accurate modeling and the minimum number of terms. Two nonlinear models are compared and the identified parameters are analyzed to study the effect of the bladder thickness on the model. PMID:26414160

  12. Effect of subcooling and wall thickness on pool boiling from downward-facing curved surfaces in water

    SciTech Connect

    El-Genk, M.S.; Glebov, A.G.

    1995-09-01

    Quenching experiments were performed to investigate the effects of water subcooling and wall thickness on pool boiling from a downward-facing curved surface. Experiments used three copper sections of the same diameter (50.8 mm) and surface radius (148 mm), but different thickness (12.8, 20 and 30 mm). Local and average pool boiling curves were obtained at saturation and 5 K, 10 K, and 14 K subcooling. Water subcooling increased the maximum heat flux, but decreased the corresponding wall superheat. The minimum film boiling heat flux and the corresponding wall superheat, however, increased with increased subcooling. The maximum and minimum film boiling heat fluxes were independent of wall thickness above 20 mm and Biot Number > 0.8, indicating that boiling curves for the 20 and 30 thick sections were representative of quasi steady-state, but not those for the 12.8 mm thick section. When compared with that for a flat surface section of the same thickness, the data for the 12.8 mm thick section showed significant increases in both the maximum heat flux (from 0.21 to 0.41 MW/m{sup 2}) and the minimum film boiling heat flux (from 2 to 13 kW/m{sup 2}) and about 11.5 K and 60 K increase in the corresponding wall superheats, respectively.

  13. Electromagnetic acoustic transducers for wall thickness applications in the petrochemical industry

    NASA Astrophysics Data System (ADS)

    Edwards, C.; Dixon, S.; Widdowson, A.; Palmer, S. B.

    2000-05-01

    Electromagnetic acoustic transducers (EMATs) are now becoming widely used in the field, for example for boiler tube wall thickness surveys in Power Generation plant. In general EMATs work efficiently on steel components with a surface oxide layer, where the oxides can be residual mill scale from the steel manufacturing process due to in-service growth in boilers or chemical processing plant. Very often these oxides have rough surfaces and have to be removed prior to conventional ultrasonic inspection. This can be both time consuming and costly, in addition the removal of the protective oxide layer accelerates the future wall lose rate of the pipe or vessel. As well as the Power Generation application, EMATs can also be used for ultrasonic inspection of petrochemical tubulars without having to remove oxides giving the same associated benefits. This paper presents results obtained from laboratory trials of EMAT thickness monitoring of petrochemical plant pipe samples and real EMAT surveys carried out on-site on refinery plant. In parallel with the practical application of EMATs we are studying the underlying physics of operation with the aim of predicting the EMAT performance for steels with and without oxide layers.

  14. On what controls the spacing of spontaneous adiabatic shear bands in collapsing thick-walled cylinders

    NASA Astrophysics Data System (ADS)

    Lovinger, Zev; Rosenberg, Zvi; Rittel, Daniel

    2015-09-01

    Shear bands formation in collapsing thick walled cylinders occurs in a spontaneous manner. The advantage of examining spontaneous, as opposed to forced shear localization, is that it highlights the inherent susceptibility of the material to adiabatic shear banding without prescribed geometrical constraints. The Thick-Walled Cylinder technique (TWC) provides a controllable and repeatable technique to create and study multiple adiabatic shear bands. The technique, reported in the literature uses an explosive cylinder to create the driving force, collapsing the cylindrical sample. Recently, we developed an electro-magnetic set-up using a pulsed current generator to provide the collapsing force, replacing the use of explosives. Using this platform we examined the shear band evolution at different stages of formation in 7 metallic alloys, spanning a wide range of strength and failure properties. We examined the number of shear bands and spacing between them for the different materials to try and figure out what controls these parameters. The examination of the different materials enabled us to better comprehend the mechanisms which control the spatial distribution of multiple shear bands in this geometry. The results of these tests are discussed and compared to explosively driven collapsing TWC results in the literature and to existing analytical models for spontaneous adiabatic shear localization.

  15. Quantitative Analysis of Intraventricular Dyssynchrony Using Wall Thickness by Multidetector Computed Tomography

    PubMed Central

    Truong, Quynh A.; Singh, Jagmeet P.; Cannon, Christopher P.; Sarwar, Ammar; Nasir, Khurram; Auricchio, Angelo; Faletra, Francesco F.; Sorgente, Antonio; Conca, Cristina; Moccetti, Tiziano; Handschumacher, Mark; Brady, Thomas J.; Hoffmann, Udo

    2009-01-01

    OBJECTIVES We sought to determine the feasibility of cardiac computed tomography (CT) to detect significant differences in the extent of left ventricular dyssynchrony in heart failure (HF) patients with wide QRS, HF patients with narrow QRS, and age-matched controls. BACKGROUND The degree of mechanical dyssynchrony has been suggested as a predictor of response to cardiac resynchronization therapy. There have been no published reports of dyssynchrony assessment with the use of CT. METHODS Thirty-eight subjects underwent electrocardiogram-gated contrast-enhanced 64-slice multidetector CT. The left ventricular endocardial and epicardial boundaries were delineated from short-axis images reconstructed at 10% phase increments of the cardiac cycle. Global and segmental CT dyssynchrony metrics that used changes in wall thickness, wall motion, and volume over time were assessed for reproducibility. We defined a global metric using changes in wall thickness as the dyssynchrony index (DI). RESULTS The DI was the most reproducible metric (interobserver and intraobserver intraclass correlation coefficients ≥0.94, p < 0.0001) and was used to determine differences between the 3 groups: HF-wide QRS group (ejection fraction [EF] 22 ± 8%, QRS 163 ± 28 ms), HF-narrow QRS (EF 26 ± 7%, QRS 96 ± 11 ms), and age-matched control subjects (EF 64 ± 5%, QRS 87 ± 9 ms). Mean DI was significantly different between the 3 groups (HF-wide QRS: 152 ± 44 ms, HF-narrow QRS: 121 ± 58 ms, and control subjects: 65 ± 12 ms; p < 0.0001) and greater in the HF-wide QRS (p < 0.0001) and HF-narrow QRS (p = 0.005) groups compared with control subjects. We found that DI had a good correlation with 2-dimensional (r = 0.65, p = 0.012) and 3-dimensional (r = 0.68, p = 0.008) echocardiographic dyssynchrony. CONCLUSIONS Quantitative assessment of global CT-derived DI, based on changes in wall thickness over time, is highly reproducible and renders significant differences between subjects most likely to

  16. An approach for patient-specific multi-domain vascular mesh generation featuring spatially varying wall thickness modeling.

    PubMed

    Raut, Samarth S; Liu, Peng; Finol, Ender A

    2015-07-16

    In this work, we present a computationally efficient image-derived volume mesh generation approach for vasculatures that implements spatially varying patient-specific wall thickness with a novel inward extrusion of the wall surface mesh. Multi-domain vascular meshes with arbitrary numbers, locations, and patterns of both iliac bifurcations and thrombi can be obtained without the need to specify features or landmark points as input. In addition, the mesh output is coordinate-frame independent and independent of the image grid resolution with high dimensional accuracy and mesh quality, devoid of errors typically found in off-the-shelf image-based model generation workflows. The absence of deformable template models or Cartesian grid-based methods enables the present approach to be sufficiently robust to handle aneurysmatic geometries with highly irregular shapes, arterial branches nearly parallel to the image plane, and variable wall thickness. The assessment of the methodology was based on i) estimation of the surface reconstruction accuracy, ii) validation of the output mesh using an aneurysm phantom, and iii) benchmarking the volume mesh quality against other frameworks. For the phantom image dataset (pixel size 0.105 mm; slice spacing 0.7 mm; and mean wall thickness 1.401±0.120 mm), the average wall thickness in the mesh was 1.459±0.123 mm. The absolute error in average wall thickness was 0.060±0.036 mm, or about 8.6% of the largest image grid spacing (0.7 mm) and 4.36% of the actual mean wall thickness. Mesh quality metrics and the ability to reproduce regional variations of wall thickness were found superior to similar alternative frameworks. PMID:25976018

  17. An Approach for Patient-Specific Multi-domain Vascular Mesh Generation Featuring Spatially Varying Wall Thickness Modeling

    PubMed Central

    Raut, Samarth S.; Liu, Peng; Finol, Ender A.

    2015-01-01

    In this work, we present a computationally efficient image-derived volume mesh generation approach for vasculatures that implements spatially varying patient-specific wall thickness with a novel inward extrusion of the wall surface mesh. Multi-domain vascular meshes with arbitrary numbers, locations, and patterns of both iliac bifurcations and thrombi can be obtained without the need to specify features or landmark points as input. In addition, the mesh output is coordinate-frame independent and independent of the image grid resolution with high dimensional accuracy and mesh quality, devoid of errors typically found in off-the-shelf image-based model generation workflows. The absence of deformable template models or Cartesian grid-based methods enables the present approach to be robust by handling aneurysmatic geometries with highly irregular shapes, arterial branches nearly parallel to the image plane, and variable wall thickness. The assessment of the methodology was based on i) estimation of the surface reconstruction accuracy, ii) validation of the output mesh using an aneurysm phantom, and iii) benchmarking the volume mesh quality against other frameworks. For the phantom image dataset (pixel size 0.105 mm; slice spacing 0.7 mm; mean wall thickness 1.401 ± 0.120 mm), the average wall thickness in the mesh was 1.459 ± 0.123 mm. The absolute error in average wall thickness was 0.060 ± 0.036 mm, or about 8.6% of the largest image grid spacing (0.7 mm) and 4.36% of the actual mean wall thickness. Mesh quality metrics and the ability to reproduce regional variations of wall thickness were found superior to similar alternative frameworks. PMID:25976018

  18. On the Opening of Thick Walled Elastic Tubes: A Fluid-Structure Model for Acid Reflux

    NASA Astrophysics Data System (ADS)

    Ghosh, Sudip; Kahrilas, Peter

    2005-11-01

    A coupled fluid-structure mathematical model was developed to quantify rapid opening of thick-walled elastic tubes, a phenomenon underlying biological flows such as gastroesophageal reflux disease (GERD). The wall was modeled using non-linear finite deformation theory to predict space-time radial distention of an axisymmetric tube with luminal fluid flow. Anisotropic azimuthal and longitudinal muscle-induced stresses were incorporated, and interstitial material properties were assumed isotropic and linearly elastic. Fluid flow was modeled using lubrication theory with inertial correction. Opening and flow were driven by a specified inflow pressure and zero pressure gradient was specified at outflow. No-slip and surface force balance were applied at the fluid-wall interface. Viscoelasticity was modeled with ad hoc damping and the evolution of the tube geometry was predicted at mid-layer. A potentially important discovery was made when applied to studies of initiation of opening with GERD: while material stiffness is of minor consequence, small changes in resting lumen distension (˜2 mm diameter) may be a sensitive distinguishing feature of the disease.

  19. Optimization of Cone Wall Thickness to Reduce High Energy Electron Generation for Fast-Ignition Scheme

    NASA Astrophysics Data System (ADS)

    Kojima, Sadaoki; Zhe, Zhang; Sawada, Hiroshi; Firex Team

    2015-11-01

    In Fast Ignition Inertial Confinement Fusion, optimization of relativistic electron beam (REB) accelerated by a high-intensity laser pulse is critical for the efficient core heating. The high-energy tail of the electron spectrum is generated by the laser interaction with a long-scale-length plasma and does not efficiently couple to a fuel core. In the cone-in-shell scheme, long-scale-length plasmas can be produced inside the cone by the pedestal of a high-intensity laser, radiation heating of the inner cone wall and shock wave from an implosion core. We have investigated a relation between the presence of pre-plasma inside the cone and the REB energy distribution using the Gekko XII and 2kJ-PW LFEX laser at the Institute of Laser Engineering. The condition of an inner cone wall was monitored using VISAR and SOP systems on a cone-in-shell implosion. The generation of the REB was measured with an electron energy analyzer and a hard x-ray spectrometer on a separate shot by injecting the LFEX laser in an imploded target. The result shows the strong correlation between the preheat and high-energy tail generation. Optimization of cone-wall thickness for the fast-ignition will be discussed. This work is supported by NIFS, MEXT/JSPS KAKENHI Grant and JSPS Fellows (Grant Number 14J06592).

  20. [The use of prosthetic materials placed intraperitoneally in the repair of large defects of the abdominal wall, reflections on a limited case series].

    PubMed

    Miro, A G; Auciello, I; Loffredo, D; Arenga, G; Lombardi, D

    1999-01-01

    To evaluate the best prosthetic material in direct contact with intestinal loops in the repair of large abdominal wall defects, four cases were reevaluated and an extensive review of the literature was undertake to point out the pathophysiology of prosthetic materials in abdominal wall surgery. For its intrinsic features, Gore-Tex represents the best prosthetic material to locate intraperitoneally, but the slow foreign body reaction is responsible for postoperative complications (e.g. hematoma, seroma, dehiscence). Marlex should not be used in direct contact with intestine because of the risk of multiple fistulas, very difficult to treat, while, the intense foreign body reaction rapidly integrate the mesh into the abdominal wall. To treat large abdominal wall defects are now been proposed mixed prostheses (Gore-Tex in intraperitoneal location, Marlex at the exterior) and dual mesh Gore-Tex (two textures at different microporosity on each side of the mesh). Preliminary studies have shown the safety and utility of these prostheses. PMID:10434463

  1. Relationship between intra-abdominal pressure and vaginal wall movements during Valsalva in women with and without pelvic organ prolapse: technique development and early observations

    PubMed Central

    Spahlinger, D. M.; Newcomb, L.; Ashton-Miller, J. A.; DeLancey, J. O. L.; Chen, Luyun

    2014-01-01

    Objectives To develop and test a method for measuring the relationship between the rise in intra-abdominal pressure and sagittal plane movements of the anterior and posterior vaginal walls during Valsalva in a pilot sample of women with and without prolapse. Methods Mid-sagittal MRI images were obtained during Valsalva while changes in intra-abdominal pressure were measured via a bladder catheter in 5 women with cystocele, 5 women with rectocele, and 5 controls. The regional compliance of the anterior and posterior vagina wall support systems were estimated from the ratio of displacement (mm) of equidistant points along the anterior and posterior vaginal walls to intra-abdominal pressure rise (mmHg). Results The compliance of both anterior and posterior vaginal wall support systems varied along different regions of vaginal wall for all three groups, with the highest compliance found near the vaginal apex and the lowest near the introitus. Women with cystocele had more compliant anterior and posterior vaginal wall support systems than women with rectocele. The movement direction differs between cystocele and rectocele. In cystocele, the anterior vaginal wall moves mostly toward the vaginal orifice in the upper vagina, but in a ventral direction in the lower vagina. In rectocele, the direction of the posterior vaginal wall movement is generally toward the vaginal orifice. Conclusions Movement of the vaginal wall and compliance of its support is quantifiable and was found to vary along the length of the vagina. Compliance was greatest in the upper vagina of all groups. Women with cystocele demonstrated the most compliant vaginal wall support. PMID:24474605

  2. Airway wall thickness is increased in COPD patients with bronchodilator responsiveness

    PubMed Central

    2014-01-01

    Rationale Bronchodilator responsiveness (BDR) is a common but variable phenomenon in COPD. The CT characteristics of airway dimensions that differentiate COPD subjects with BDR from those without BDR have not been well described. We aimed to assess airway dimensions in COPD subjects with and without BDR. Methods We analyzed subjects with GOLD 1–4 disease in the COPDGene® study who had CT airway analysis. We divided patients into two groups: BDR + (post bronchodilator ΔFEV1 ≥ 10%) and BDR-(post bronchodilator ΔFEV1 < 10%). The mean wall area percent (WA%) of six segmental bronchi in each subject was quantified using VIDA. Using 3D SLICER, airway wall thickness was also expressed as the square root wall area of an airway of 10 mm (Pi10) and 15 mm (Pi15) diameter. %Emphysema and %gas trapping were also calculated. Results 2355 subjects in the BDR-group and 1306 in the BDR + group formed our analysis. The BDR + group had a greater Pi10, Pi15, and mean segmental WA% compared to the BDR-group. In multivariate logistic regression using gender, race, current smoking, history of asthma, %emphysema, %gas trapping, %predicted FEV1, and %predicted FVC, airway wall measures remained independent predictors of BDR. Using a threshold change in FEV1 ≥ 15% and FEV1 ≥ 12% and 200 mL to divide patients into groups, the results were similar. Conclusion BDR in COPD is independently associated with CT evidence of airway pathology. This study provides us with greater evidence of changes in lung structure that correlate with physiologic manifestations of airflow obstruction in COPD. PMID:25248436

  3. Effects of Chitosan Coatings on Polypropylene Mesh for Implantation in a Rat Abdominal Wall Model

    PubMed Central

    Udpa, Natasha; Iyer, Shama R.; Rajoria, Rohit; Breyer, Kate E.; Valentine, Helen; Singh, Bhupinder; McDonough, Sean P.; Brown, Bryan N.; Bonassar, Lawrence J.

    2013-01-01

    Hernia repair and pelvic floor reconstruction are usually accompanied with the implantation of a surgical mesh, which frequently results in a foreign body response with associated complications. An ideal surgical mesh that allows force generation of muscle tissues without significant granulation tissue and/or fibrosis is of significant clinical interest. The objective of the present study was to evaluate the in vitro and in vivo responses of a chitosan coating on polypropylene mesh (Ch-PPM) in comparison with commercially available meshes. We found that application of a 0.5% (w/v) Ch-PPM elicited preferential attachment of myoblasts over fibroblast attachment in vitro. Therefore, we test the hypothesis that 0.5% Ch-PPM will encourage skeletal muscle tissue ingrowth and decrease fibrosis formation in vivo. We implanted 0.5% Ch-PPM, collagen-coated polypropylene mesh (Pelvitex™; C.R. Bard), and polypropylene (Avaulta Solo®; C.R. Bard) alone using a rat abdominal defect model. Force generation capacity and inflammatory response of each mesh were evaluated 2, 4, and 12 weeks postimplantation. We found that chitosan coating is associated with the restoration of functional skeletal muscle with histomorphologic characteristics that resemble native muscle and an early macrophage phenotypic response that has previously been shown to lead to more functional outcomes. PMID:23859182

  4. A method of computing the transient temperature of thick walls from arbitrary variation of adiabatic-wall temperature and heat-transfer coefficient

    NASA Technical Reports Server (NTRS)

    Hill, P R

    1958-01-01

    A method of calculating the temperature of thick walls has been developed in which the time series and the response to a unit triangle variation of surface temperature concepts are used, together with essentially standard formulas for transient temperature and heat flow into thick walls. The method can be used without knowledge of the mathematical tools of its development. The method is particularly suitable for determining the wall temperature in one-dimensional thermal problems in aeronautics where there is a continuous variation of the heat-transfer coefficient and adiabatic-wall temperature. The method also offers a convenient means for solving the inverse problem of determining the heat-flow history when temperature history is known.

  5. Pelvic and abdominal-wall actinomycotic infection by uterus gateway without genital lesions.

    PubMed

    Brezean, I; Aldoescu, S; Catrina, E; Vâlcu, M; Ionuţ, I; Predescu, G; Degeratu, D; Pantea, I

    2010-01-01

    We hereby aim to account on a case of actinomycotic infection occurred in a female patient with an intrauterine contraceptive device (IUCD). The infection occurred as a pseudo-tumour which raised differential diagnosis issues with a malignant tumour. The diagnosis has been eventually established following the pathologic examination of paraffin-embedded tissues. Although the infection's gateway was the uterus, the subsequent invasion of the parietal, urinary bladder and lateral rectal walls did not seem to affect the fallopian tubes or the ovaries. PMID:20405693

  6. Eccrine Porocarcinoma presenting as an abdominal wall mass in a patient with ulcerative colitis—A rare case report

    PubMed Central

    Parmar, Narendrasinh; Mohamed, Mohamed; Elmoghrabi, Adel; McCann, Michael

    2016-01-01

    Introduction Eccrine porocarcinoma (EPC) is a rare malignancy of eccrine sweat glands. It is often seen during the sixth to eighth decades of life. We report the first case of eccrine porocarcinoma arising on the abdomen of a 21-year-old patient with ulcerative colitis. Case presentation A 21-Year-old female presented to emergency department with a one month history of an enlarging mass over left lower abdomen. Abdominal examination revealed a slightly erythematous, nodular and non-mobile firm mass in left lower quadrant. There was superficial ulceration with slight serous discharge. CT scan of the abdomen and pelvis with contrast revealed a superficial cystic lesion over the anterior abdominal wall, provisionally diagnosed as sebaceous cyst. Incision and drainage were performed and on follow-up, no signs of healing were observed and the patient subsequently underwent surgical excision. Histopathological examination revealed an eccrine porocarcinoma. Discussion EPC is a rare and aggressive tumor. It may occur de novo or as a result of malignant transformation of an eccrine poroma. A long period of clinical history is often encountered. It usually occurs on the lower extremities followed by the, trunk, head and neck, and upper extremities. The clinical picture usually consists of a painless nodule or papule. Treatment is wide local excision. No strong evidence exists for adjuvant therapy. The risk of local recurrence is about 20%. Conclusion High index of suspicion is required for diagnosis of EPC. Early diagnosis is achieved by histopathological examination and early definitive surgical excision leads to excellent results. PMID:27085107

  7. Abdominal CT scan

    MedlinePlus

    ... tumors, including cancer Infections or injury Kidney stones Appendicitis ... also be due to: Abdominal aortic aneurysm Abscesses Appendicitis Bowel wall thickening Retroperitoneal fibrosis Renal artery stenosis ...

  8. Interventricular Septum and Posterior Wall Thickness Are Associated With Higher Systolic Blood Pressure.

    PubMed

    Eliakim-Raz, Noa; Prokupetz, Alex; Gordon, Barak; Shochat, Tzippy; Grossman, Alon

    2016-07-01

    Elevated blood pressure (BP) is a known factor that affects the structure of the left ventricle. The association between left ventricular hypertrophy (LVH) and BP in normotensive individuals is poorly understood. All individuals who underwent routine echocardiography and BP measurements as aircrew candidates for the Israeli Air Force in the years 2006 to 2012 were identified. Participants with normal values were included. Associations between echocardiographic characteristics and BP were studied. A total of 2386 participants were included. Mean systolic BP was 125.31±11.18 mm Hg and mean diastolic BP was 68.69±9.02 mm Hg. Interventricular septal (IVS) thickness was positively correlated with systolic BP (P<.001, correlation coefficient 0.121) and significantly inversely correlated with heart rate and hematocrit level (P<.001 for both). Men with evidence of IVS or posterior wall thickening on echocardiography, even within the normal range, may require a closer follow-up of BP. PMID:26607051

  9. Residual stress analysis in forming process of filament wound thick-walled CFRP pipes

    SciTech Connect

    Kondo, Toshimi; Sekine, Hideki; Nakano, Kunio

    1995-11-01

    Residual stress analysis for the cracking phenomenon of filament would thick-walled CFRP pipes, which frequently occurs in the forming process of curing and thermal cycling through the course of the wet filament winding, was made from both the experimental and theoretical points of view. A simple analytical model to study the cracking in the CFRP pipes was proposed. The pipes are multilayered and reinforced in the axial and circumferential directions alternatively by carbon fibers. Taking account of the anisotropy of mechanical and thermal properties including the shrinkage strain, which depend considerably on the temperature, the residual stresses in the CFRP pipes were elucidated in the forming process, particularly, in cooling of the cure process.

  10. Residual stress effect on fatigue crack growth in thick wall cylinders

    SciTech Connect

    Kiciak, A.; Glinka, G.; Burns, D.J.

    1995-11-01

    Recently derived weight functions for a single, semi-elliptical, longitudinal crack in a thick wall cylinder with the diameter ratio D{sub 0}/D{sub i} = 2, have been used to analyze fatigue crack propagation in autofrettaged and non-autofrettaged, pressurized cylinders. Two levels of autofrettage, 30 and 60%, have been considered. The influences of the level of autofrettage, surface crack closure, and different sets of parameters of crack closure, and different sets of parameters of crack propagation relation have been investigated. The development of cracks has been compared to the experimental results. The results of analyses confirm beneficial influence of autofrettage. It has been shown that the discrepancies between the observed and calculated crack developments cannot be ascribed to the influence of surface crack closure. The comparison of the experiments and predictions unveils the need for an additional series of experiments.

  11. Preferred propagation patterns of axial surface cracks in thick-walled cylinders

    SciTech Connect

    Perez, E.H.; Kendall, D.P.

    1996-12-01

    Semi-elliptical axial surface cracks, growing due to cyclic pressure loading in thick-walled cylinders undergo significant shape change during the propagation process. These growing cracks change their shapes such that they approach and follow preferred propagation patterns (PPPs). These PPPs depend on the diameter ratio of the cylinder and on the fatigue crack propagation constant, ``m`` in the Paris equation. The objective of this paper is to show the crack shape variation during fatigue crack growth using linear elastic fracture mechanics. It is shown that a crack whose initial shape does not agree with this preferred propagation pattern will grow such that its shape converges to the preferred pattern. The results of this study also show the effect of autofrettage on the PPPs and the final shape of the cracks at breakthrough.

  12. Facilitating protein crystal cryoprotection in thick-walled plastic capillaries by high-pressure cryocooling

    PubMed Central

    Chen, Yi-Fan; Tate, Mark W.; Gruner, Sol M.

    2009-01-01

    Many steps in the X-ray crystallographic solution of protein structures have been automated. However, the harvesting and cryocooling of crystals still rely primarily on manual handling, frequently with consequent mechanical damage. An attractive alternative is to grow crystals directly inside robust plastic capillaries that may be cryocooled and mounted on the beamline goniometer. In this case, it is still desirable to devise a way to cryoprotect the crystals, which is difficult owing to the poor thermal conductivity of thick plastic capillary walls and the large thermal mass of the capillary and internal mother liquor. A method is described to circumvent these difficulties. It is shown that high-pressure cryocooling substantially reduced the minimal concentrations of cryoprotectants required to cryocool water inside capillaries without formation of ice crystals. The minimal concentrations of PEG 200, PEG 400 and glycerol necessary for complete vitrification under pressure cryocooling were determined. PMID:19529790

  13. Left Ventricular Relative Wall Thickness Versus Left Ventricular Mass Index in Non-Cardioembolic Stroke Patients

    PubMed Central

    Hashem, M-Sherif; Kalashyan, Hayrapet; Choy, Jonathan; Chiew, Soon K.; Shawki, Abdel-Hakim; Dawood, Ahmed H.; Becher, Harald

    2015-01-01

    Abstract In non-cardioembolic stroke patients, the cardiac manifestations of high blood pressure are of particular interest. Emerging data suggest that echocardiographically determined left ventricular hypertrophy is independently associated with risk of ischemic stroke. The primary objective of this study was to evaluate the frequency of different patterns of left ventricular (LV) remodeling and hypertrophy in a group of consecutive patients admitted with non-cardioembolic stroke or transient ischemic attack (TIA). In particular, we were interested in how often the relative wall thickness (RWT) was abnormal in patients with normal LV mass index (LVMI). As both abnormal RWT and LVMI indicate altered LV remodeling, the secondary objective of this research was to study whether a significant number of patients would be missing the diagnosis of LV remodeling if the RWT is not measured. All patients were referred within 48 hours after a stroke or a TIA for a clinically indicated transthoracic echocardiogram. The echocardiographic findings of consecutive patients with non-cardioembolic stroke or TIA were analyzed. All necessary measurements were performed in 368 patients, who were enrolled in the study. Mean age was 63.7 ± 12.5 years, 64.4% men. Concentric remodeling carried the highest frequency, 49.2%, followed by concentric hypertrophy, 30.7%, normal pattern, 15.5%, and eccentric hypertrophy, 4.1%. The frequency of abnormal left ventricular RWT (80.4%) was significantly higher than that of abnormal LVMI (35.3%), (McNemar P < 0.05). In this group of non-cardioembolic stroke patients, abnormal LV remodeling as assessed by relative wall thickness is very frequent. As RWT was often found without increased LV mass, the abnormal left ventricular geometry may be missed if RWT is not measured or reported. PMID:25997067

  14. Superthin Abdominal Wall Glove-Like Flap Combined With Vacuum-Assisted Closure Therapy for Soft Tissue Reconstruction in Severely Burned Hands or With Infection.

    PubMed

    Wang, Fei; Liu, Sheng; Qiu, Le; Ma, Ben; Wang, Jian; Wang, Yong-Jie; Peszel, April; Chen, Xu-Lin

    2015-12-01

    Severe burn and infection to hands always involves the deep structures, such as tendons, joints, and bones. These wounds cannot be closed immediately and therefore creates a high risk for complication. We presented 9 cases with deep dermal burns to the dorsal of the hand (6 electrical burns and 3 thermal crush injuries) with wound infections in 2 cases. The vacuum-assisted closure system was used continuously until the flap reconstruction was performed. A random pattern and superthin abdominal wall skin flap-like glove was designed. The flap was transferred to the defected portion of the dorsum of the hand and resected from the abdominal wall about 3 weeks later. The flaps in 8 of the patients treated by this technique survived completely and partial necrosis of the distal flap occurred in 1 patient. The defect resolved after operative treatment and the function of the hands and fingers were successfully salvaged. All patients resulted in having a satisfactory aesthetic outcome with no or minor discomfort at the abdominal donor area. Integration of the vacuum-assisted closure system and the superthin abdominal wall glove-like flap reconstruction appeared to be successful and should be considered in patients with severely burned hands. PMID:26418768

  15. Cross-Sectional Elasticity Imaging of Arterial Wall by Comparing Measured Change in Thickness with Model Waveform

    NASA Astrophysics Data System (ADS)

    Tang, Jiang; Hasegawa, Hideyuki; Kanai, Hiroshi

    2005-06-01

    For the assessment of the elasticity of the arterial wall, we have developed the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791] for measuring the minute change in thickness due to heartbeats and the elasticity of the arterial wall with transcutaneous ultrasound. For various reasons, for example, an extremely small deformation of the wall, the minute change in wall thickness during one heartbeat is largely influenced by noise in these cases and the reliability of the elasticity distribution obtained from the maximum change in thickness deteriorates because the maximum value estimation is largely influenced by noise. To obtain a more reliable cross-sectional image of the elasticity of the arterial wall, in this paper, a matching method is proposed to evaluate the waveform of the measured change in wall thickness by comparing the measured waveform with a template waveform. The maximum deformation, which is used in the calculation of elasticity, was determined from the amplitude of the matched model waveform to reduce the influence of noise. The matched model waveform was obtained by minimizing the difference between the measured and template waveforms. Furthermore, a random error, which was obtained from the reproducibility among the heartbeats of the measured waveform, was considered useful for the evaluation of the reliability of the measured waveform.

  16. A more realistic thermal shock analysis of a radially multicracked thick-walled cylinder

    NASA Astrophysics Data System (ADS)

    Perl, M.; Ashkenazi, A.

    1992-07-01

    Presently available analyses of multicracking of thick-walled cylinders due to an internal thermal shock, model the shock by a temperature step-change at the cylinder bore, yielding a considerably overestimated temperature field through the cylinder's wall. In the present work a more realistic thermal shock model is employed assuming convection boundary conditions at both the inner and the outer cylinder surfaces. Transient mode I stress intensity factors (SIF), resulting from the thermal shock during the firing process in a typical gun barrel, are evaluated for large arrays of radial cracks emanating from the bore surface of the cylinder. The transient thermal analysis as well as the computation of the SIFs is performed via the finite element method. Once the thermal problem is solved, SIFs at various time steps are calculated for numerous crack arrays (2-1024) and for a wide range of relevant crack lengths. The present analysis emphasizes the importance of using the proper thermal shock model by showing that the previously available results are nonconservative, and exemplifies the favorable effect of the above thermal shock on the effective SIF prevailing at the tips of these cracks.

  17. Echocardiographic Manifestations of Glycogen Storage Disease III: Increase in Wall Thickness and Left Ventricular Mass over Time

    PubMed Central

    Vertilus, Shawyntee M.; Austin, Stephanie L.; Foster, Kimberly S.; Boyette, Keri E.; Bali, Deeksha; Li, Jennifer S.; Kishnani, Priya S.; Wechsler, Stephanie Burns

    2013-01-01

    Purpose Glycogen Storage Disease (GSD) type III, glycogen debranching enzyme deficiency, causes accumulation of glycogen in liver, skeletal, and cardiac muscle. Some patients develop increased left ventricular (LV) thickness by echocardiography, but the rate of increase and its significance remain unclear. Methods We evaluated 33 patients with GSD type III, 23 with IIIa and 10 with IIIb, ages 1 month – 55.5 yrs, by echocardiography for wall thickness, LV mass, shortening and ejection fractions, at 1 time point (n = 33) and at 2 time points in patients with more than 1 echocardiogram (13 of the 33). Results Of 23 cross-sectional patients with type IIIa, 12 had elevated LV mass, 11 had elevated wall thickness. One type IIIb patient had elevated LV mass but 4 had elevated wall thickness. For those with multiple observations, 9 of 10 with type IIIa developed increased LV mass over time, with 3 already increased at first measurement. Shortening and ejection fractions were generally normal. Conclusion Elevated LV mass and wall thickness is more common in patients with type IIIa but develops rarely in type IIIb, though ventricular systolic function is preserved. This suggests serial echocardiograms with attention to LV thickness and mass are important for care of these patients. PMID:20526204

  18. Lateral abdominal muscle size at rest and during abdominal drawing-in manoeuvre in healthy adolescents.

    PubMed

    Linek, Pawel; Saulicz, Edward; Wolny, Tomasz; Myśliwiec, Andrzej; Kokosz, Mirosław

    2015-02-01

    Lateral abdominal wall muscles in children and adolescents have not been characterised to date. In the present report, we examined the reliability of the ultrasound measurement and thickness of the oblique external muscle (OE), oblique internal muscle (OI) and transverse abdominal muscle (TrA) at rest and during abdominal drawing-in manoeuvre (ADIM) on both sides of the body in healthy adolescents. We also determined possible differences between boys and girls and defined any factors-such as body mass, height and BMI-that may affect the thickness of the abdominal muscles. B-mode ultrasound was used to assess OE, OI and TrA on both sides of the body in the supine position. Ultrasound measurements at rest and during ADIM were reliable in this age group (ICC3,3 > 0.92). OI was always the thickest and TrA the thinnest muscle on both sides of the body. In this group, an identical pattern of the contribution of the individual muscles to the structure of the lateral abdominal wall (OI > OE > TrA) was observed. At rest and during ADIM, no statistically significant side-to-side differences were demonstrated in either gender. The body mass constitutes between 30% and <50% of the thickness differences in all muscles under examination at rest and during ADIM. The structure of lateral abdominal wall in adolescents is similar to that of adults. During ADIM, the abdominal muscles in adolescents react similarly to those in adults. This study provided extensive information regarding the structure of the lateral abdominal wall in healthy adolescents. PMID:25088309

  19. Techniques for Abdominal Wall Closure after Damage Control Laparotomy: From Temporary Abdominal Closure to Early/Delayed Fascial Closure—A Review

    PubMed Central

    Huang, Qian; Li, Jieshou; Lau, Wan-yee

    2016-01-01

    Open abdomen (OA) has been an effective treatment for abdominal catastrophes in traumatic and general surgery. However, management of patients with OA remains a formidable task for surgeons. The central goal of OA is closure of fascial defect as early as is clinically feasible without precipitating abdominal compartment syndrome. Historically, techniques such as packing, mesh, and vacuum-assisted closure have been developed to assist temporary abdominal closure, and techniques such as components separation, mesh-mediated traction, bridging fascial defect with permanent synthetic mesh, or biologic mesh have also been attempted to achieve early primary fascial closure, either alone or in combined use. The objective of this review is to present the challenges of these techniques for OA with a goal of early primary fascial closure, when the patient's physiological condition allows. PMID:26819597

  20. Techniques for Abdominal Wall Closure after Damage Control Laparotomy: From Temporary Abdominal Closure to Early/Delayed Fascial Closure-A Review.

    PubMed

    Huang, Qian; Li, Jieshou; Lau, Wan-Yee

    2016-01-01

    Open abdomen (OA) has been an effective treatment for abdominal catastrophes in traumatic and general surgery. However, management of patients with OA remains a formidable task for surgeons. The central goal of OA is closure of fascial defect as early as is clinically feasible without precipitating abdominal compartment syndrome. Historically, techniques such as packing, mesh, and vacuum-assisted closure have been developed to assist temporary abdominal closure, and techniques such as components separation, mesh-mediated traction, bridging fascial defect with permanent synthetic mesh, or biologic mesh have also been attempted to achieve early primary fascial closure, either alone or in combined use. The objective of this review is to present the challenges of these techniques for OA with a goal of early primary fascial closure, when the patient's physiological condition allows. PMID:26819597

  1. Measurement of Change in Wall Thickness of Cylindrical Shell Due to Cyclic Remote Actuation for Assessment of Viscoelasticity of Arterial Wall

    NASA Astrophysics Data System (ADS)

    Hasegawa, Hideyuki; Kanai, Hiroshi; Koiwa, Yoshiro; Butler, James P.

    2003-05-01

    To characterize tissues in atherosclerotic plaques, we have developed a method, the phased tracking method, for measuring the strain (change in wall thickness) and elasticity of the arterial wall. However, some types of tissue, such as lipids and blood clots, cannot be discriminated from each other based only on elasticity because of the small difference in their elasticity. For more precise tissue characterization, we are attempting to measure the regional viscoelasticity. To determine viscoelastic properties, elastic moduli at multiple frequencies were obtained by generating the change in internal pressure due to remote cyclic actuation. From basic experiments using a silicone rubber tube, it was found that the change in internal pressure at the ultrasonic beam position (for measurement of the elastic modulus) can be generated by remotely applied actuation. Furthermore, from the resultant minute changes in wall thickness of less than 10 μm measured by the phased tracking method, elastic moduli were obtained at multiple actuation frequencies.

  2. Assessment of carotid diameter and wall thickness in ultrasound images using active contours improved by a multiresolution technique

    NASA Astrophysics Data System (ADS)

    Gutierrez, Marco A.; Pilon, Paulo E.; Lage, Silvia G.; Kopel, Liliane; Carvalho, Ricardo T.; Furuie, Sergio S.

    2002-04-01

    Carotid vessel ultrasound imaging is a reliable non-invasive technique to measure the arterial morphology. Vessel diameter, intima-media thickness (IMT) of the far wall and plaque presence can be reliably determined using B-mode ultrasound. In this paper we describe a semi-automatic approach to measure artery diameter and IMT based on an active contour technique improved by a multiresolution analysis. The operator selects a region-of-interest (ROI) in a series of carotid images obtained from B-mode ultrasound. This set of images is convolved with the corresponding partial derivatives of the Gaussian filter. The filter response is used to compute a 2D gradient magnitude image in order to refine the vessel's boundaries. Using an active contour technique the vessel's border is determined automatically. The near wall media-adventitia (NWMA), far wall media-adventitia (FWMA) and far wall lumen-intima (FWLI) borders are obtained by a least-square fitting of the active contours result. The distance between NWMA and FWLI (vessel diameter) and between FWLI and FWMA (far wall intima-media thickness) are obtained for all images and the mean value is computed during systole and diastole. The proposed method is a reliable and reproducible way of assessing the vessel diameter and far wall intima-media thickness of the carotid artery.

  3. CRITICAL ANALYSIS OF EXPERIMENTAL MODEL FOR STUDY OF ADHESIONS AFTER INCISIONAL HERNIAS INDUCED IN RATS’ AND REPAIR OF ABDOMINAL WALL WITH DIFFERENT BIOMATERIALS

    PubMed Central

    SERIGIOLLE, Leonardo Carvalho; BARBIERI, Renato Lamounier; GOMES, Helbert Minuncio Pereira; RODRIGUES, Daren Athiê Boy; STUDART, Sarah do Valle; LEME, Pedro Luiz Squilacci

    2015-01-01

    Background: Adhesions induced by biomaterials experimentally implanted in the abdominal cavity are basically studied by primary repair of different abdominal wall defects or by the correction of incisional hernias previously performed with no precise definition of the most appropriate model. Aim: To describe the adhesions which occur after the development of incisional hernias, before the prosthesis implantation, in an experimental model to study the changes induced by different meshes. Methods: Incisional hernias were performed in 10 rats with hernia orifices of standardized dimensions, obtained by the median incision of the abdominal wall and eversion of the defect edges. Ten days after the procedure adhesions of abdominal structures were found when hernias were repaired with different meshes. Results: The results showed hernia sac well defined in all rats ten days after the initial procedure. Adhesions of the greater omentum occurred in five animals of which two also showed adhesions of small bowel loops besides the omentum, and another two showed liver adhesions as well as the greater omentum, numbers with statistical significance by Student's t test (p<0.05). Conclusion: Although it reproduces the real clinical situation, the choice of experimental model of incisional hernia repair previously induced implies important adhesions, with possible repercussions in the evaluation of the second operation, when different implants of synthetic materials are used. PMID:26537141

  4. Reconstruction of full-thickness chest wall defects using rectus abdominis musculocutaneous flap: A report of fifteen cases

    SciTech Connect

    Miyamoto, Y.; Hattori, T.; Niimoto, M.; Toge, T. )

    1986-02-01

    In 15 patients chest walls were excised because of recurrent breast cancer, radiation ulcer, or rib tumor. In most cases the full-thickness defect of the chest wall was about 10 x 10 cm. Reconstruction was performed using only a rectus abdominis musculocutaneous flap. No patient developed circulation problems in the flap or severe flail chest, and we had successful results in all our cases. These results show that the rectus abdominis musculocutaneous flap is quite effective and safe to use in the reconstruction of chest wall defects.

  5. The preferential contraction ratios of transversus abdominis on the variations of knee angles during abdominal drawing-in maneuver in wall support standing

    PubMed Central

    Hwang, Young-In; Kim, Jwa-Jun; Park, Du-Jin

    2014-01-01

    The objective of this study was to determine appropriate knee angles for the abdominal drawing-in maneuver (ADIM) through evaluation of changes in contraction ratios of the abdominal muscles and activity of quadriceps muscle in relation to changes in knee angles occurring while the ADIM is performed in the wall support standing (WSS). 20 subjects performed the ADIM at different knee angles (0°, 20°, 40°, 60°) in random order, standing at a point 6 inches away from the wall with the spine maintained in the neutral position. The WSS with knee flexion at 20° showed significantly higher preferential contraction ratio (PCR) of transversus abdominis (TrA) compared to other positions (0°, 40°, 60°). Therefore, performing the ADIM in the WSS with knee flexion at 20° appears to be the most appropriate position for TrA PCR. PMID:24877045

  6. Reconstruction of the Abdominal Wall in Anatomical Plans. Pre- and Postoperative Keys in Repairing “Cold” Incisional Hernias

    PubMed Central

    POPA, FLORINA; ROSCA, OANA; GEORGESCU, ALEXANDRU; CANNISTRA, CLAUDIO

    2016-01-01

    Background and aims The clinical results of the vertical “vest-over-pants” Mayo repair were evaluated, and the risk factors for incisional hernia recurrence were studied. The purpose of this study is to point out the importance of reducing pre and post operative risk factors in the incisional hernia repair process in order to achieve a physiologically normal abdominal wall. Methods Twenty patients diagnosed with incisional hernia underwent an abdominal reconstruction procedure using the Mayo (Paletot) technique at Bichat Claude Bernard Hospital between 2005 and 2015. All procedures were performed by a single surgeon and all patients were pre-operatively prepared, identifying all coexisting conditions and treating them accordingly before undergoing surgery. Results All patients underwent at least one surgical operation before the hernia repair procedure and a quarter had experienced at least three, prior to this one. Nine patients had a body mass index of >30 kg/m2. Additional risk factors and comorbidities included obesity in 45%, diabetes mellitus in 10%, smoking in 55%, and high blood pressure in 40%. Hernia defect width was from 3 cm (25% F) to 15 cm (5% M) of which nine patients (45%) had a 10 cm defect. Most of the patients had an average hospitalization of 7 days. The patients were carefully monitored and were called on periodic consultations after 3, 6, and 12 months from the moment of the procedure. Patient feedback regarding hernia recurrence and complaints about the scar were noted. Physical examination is essential in determining the hernia recurrence therefore the scar was examined for any abnormalities that may have occurred, which was defined as any palpable or detected fascial defect located within seven centimeters of the hernia repair. Post-operative complications: seroma formation, wound hematoma, superficial and deep wound infection, recurrences and chronic pain were followed and no complications were registered during the follow-up period

  7. Utilization of a global data grid repository in CAD assessment of carotid wall thickness

    NASA Astrophysics Data System (ADS)

    Gutierrez, Marco A.; Lee, Jasper; Zhou, Zheng; Pilon, Paulo E.; Lage, Silvia G.

    2007-03-01

    A CAD method of calculating wall thickness of carotid vessels addresses the time-consuming issue of using B-mode ultrasound as well as inter- and intra-observer variability in results. Upon selection of a region-of-interest and filtering of a series of ultrasound carotid images, the CAD is able to measure the geometry of the lumen and plaque surfaces using a least-square fitting of the active contours during systole and diastole. To evaluate the approach, ultrasound image sequences from 30 patients were submitted to the procedure. The images were stored on an international data grid repository that consists of three international sites: Image Processing and Informatics (IPI) Laboratory at University of Southern California, USA; InCor (Heart Institute) at Sao Paulo, Brazil, and Hong Kong Polytechnic University, Hong Kong. The three chosen sites are connected with high speed international networks including the Internet2, and the Brazilian National Research and Education Network (RNP2). The Data Grid was used to store, backup, and share the ultrasound images and analysis results, which provided a large-scale and a virtual data system. In order to study the variability between the automatic and manual definition of artery boundaries, the pooled mean and the standard deviation for the difference between measurements of lumen diameter were computed. The coefficient of variation and correlation were also calculated. For the studied population the difference between manual and automatic measurement of the lumen diameter (LD) and intima-media-thickness (IMT) were 0.12 +/-0.10 and 0.09+/- 0.06, respectively.

  8. Successful treatment of mesenteric varices by retrograde transvenous obliteration by the delivery of N-butyl-2-cyanoacrylate via an abdominal wall vein.

    PubMed

    Ikeda, Osamu; Nakasone, Yutaka; Yokoyama, Koichi; Inoue, Seijiro; Takamori, Hiroshi; Baba, Hideo; Yamashita, Yasuyuki

    2014-04-01

    Bleeding from mesenteric varices associated with portal hypertension is occasionally life-threatening. A 53-year-old man who had undergone esophageal transection for esophageal varices and balloon-occluded retrograde transvenous obliteration for gastric varices presented with melena due to ruptured mesenteric varices. He was treated by injecting N-butyl-2-cyanoacrylate via an abdominal wall vein to obtain retrograde transvenous obliteration. PMID:23716126

  9. A new possibility of melt cooling in extrusion dies to prevent sagging-effects in thick-walled pipes

    NASA Astrophysics Data System (ADS)

    te Heesen, O.; Wortberg, J.

    2014-05-01

    One challenge in the extrusion process of thick-walled pipes is the cooling of the product. Besides the output of the extruder, the line speed is also limited by the efficiency of the cooling line. The cooling time increases according to the wall thickness of the pipe under otherwise equal process conditions. State of the art is the cooling of the outer surface in water tanks or spray-cool-tanks. In addition to that, it is possible to cool the inner surface by air that is sucked through the pipe. Despite these technologies it is problematic to cool down thick walled-products with the right speed. Especially thick-walled pipes show problems by cooling the layers in the middle of the wall. On the one hand an intensive cooling of the outer and inner surface of the pipe entail the formation of shrink holes in the middle of the pipe wall. On the other hand without a quick cooling the melt flow in circumferential direction because of the gravity takes place (sagging-effect). Because of this reason in the presented paper new possibilities of melt cooling in extrusion dies to prevent sagging-effects are given. An aimed cooling of the inbound melt layers inside the extrusion die could prevent the effect of melt flow in circumferential direction after the extrusion die, allows the specification of a specific temperature profile over the radius of the pipe wall and helps to reduce the melt temperature for rising mass throughputs and screw driving speeds of the extruder. It is also thinkable to influence the crystallization process and thereby the mechanical properties of the end-product by an aimed cooling of the inner pipe layers.

  10. Bobbin-Tool Friction-Stir Welding of Thick-Walled Aluminum Alloy Pressure Vessels

    SciTech Connect

    Dalder, E C; Pastrnak, J W; Engel, J; Forrest, R S; Kokko, E; Ternan, K M; Waldron, D

    2007-06-06

    It was desired to assemble thick-walled Al alloy 2219 pressure vessels by bobbin-tool friction-stir welding. To develop the welding-process, mechanical-property, and fitness-for-service information to support this effort, extensive friction-stir welding-parameter studies were conducted on 2.5 cm. and 3.8 cm. thick 2219 Al alloy plate. Starting conditions of the plate were the fully-heat-treated (-T62) and in the annealed (-O) conditions. The former condition was chosen with the intent of using the welds in either the 'as welded' condition or after a simple low-temperature aging treatment. Since preliminary stress-analyses showed that stresses in and near the welds would probably exceed the yield-strength of both 'as welded' and welded and aged weld-joints, a post-weld solution-treatment, quenching, and aging treatment was also examined. Once a suitable set of welding and post-weld heat-treatment parameters was established, the project divided into two parts. The first part concentrated on developing the necessary process information to be able to make defect-free friction-stir welds in 3.8 cm. thick Al alloy 2219 in the form of circumferential welds that would join two hemispherical forgings with a 102 cm. inside diameter. This necessitated going to a bobbin-tool welding-technique to simplify the tooling needed to react the large forces generated in friction-stir welding. The bobbin-tool technique was demonstrated on both flat-plates and plates that were bent to the curvature of the actual vessel. An additional issue was termination of the weld, i.e. closing out the hole left at the end of the weld by withdrawal of the friction-stir welding tool. This was accomplished by friction-plug welding a slightly-oversized Al alloy 2219 plug into the termination-hole, followed by machining the plug flush with both the inside and outside surfaces of the vessel. The second part of the project involved demonstrating that the welds were fit for the intended service. This

  11. The interaction of moderately strong shock waves with thick perforated walls of low porosity

    NASA Technical Reports Server (NTRS)

    Grant, D. J.

    1972-01-01

    A theoretical prediction is given of the flow through thick perforated walls of low porosity resulting from the impingement of a moderately strong traveling shock wave. The model was a flat plate positioned normal to the direction of the flow. Holes bored in the plate parallel to the direction of the flow provided nominal hole length-to-diameter ratios of 10:1 and an axial porosity of 25 percent of the flow channel cross section. The flow field behind the reflected shock wave was assumed to behave as a reservoir producing a quasi-steady duct flow through the model. Rayleigh and Fanno duct flow theoretical computations for each of three possible auxiliary wave patterns that can be associated with the transmitted shock (to satisfy contact surface compatibility) were used to provide bounding solutions as an alternative to the more complex influence coefficients method. Qualitative and quantitative behavior was verified in a 1.5- by 2.0-in. helium shock tube. High speed Schlieren photography, piezoelectric pressure-time histories, and electronic-counter wave speed measurements were used to assess the extent of correlation with the theoretical flow models. Reduced data indicated the adequacy of the bounding theory approach to predict wave phenomena and quantitative response.

  12. Modeling Periodic Adiabatic Shear Bands Evolution in a 304L Stainless Steel Thick-Walled Cylinder

    NASA Astrophysics Data System (ADS)

    Liu, Mingtao; Hu, Haibo; Fan, Cheng; Tang, Tiegang

    2015-06-01

    The self-organization of multiple shear bands in a 304L stainless steel thick-walled cylinder (TWC) was numerically studied. The microstructures of material lead to the non-uniform distribution of local yield stress, which plays a key role in the formation of spontaneous shear localization. We introduced a probability factor satisfied Gauss distribution into the macroscopic constitutive relationship to describe the non-uniformity of local yield stress. Using the probability factor, the initiation and propagation of multiple shear bands in TWC were numerically replicated in our 2D FEM simulation. Experimental results in the literature indicate that the machined surface at the internal boundary of a 304L stainless steel cylinder provides a work-hardened layer (about 20 μm) which has significantly different microstructures from base material. The work-hardened layer leads to the phenomenon that most shear bands are in clockwise or counterclockwise direction. In our simulation, periodic oriented perturbations were applied to describe the grain orientation in the work-hardened layer, and the spiral pattern of shear bands was successfully replicated.

  13. Computer-aided detection of bladder tumors based on the thickness mapping of bladder wall in MR images

    NASA Astrophysics Data System (ADS)

    Zhu, Hongbin; Duan, Chaijie; Jiang, Ruirui; Li, Lihong; Fan, Yi; Yu, Xiaokang; Zeng, Wei; Gu, Xianfeng; Liang, Zhengrong

    2010-03-01

    Bladder cancer is reported to be the fifth leading cause of cancer deaths in the United States. Recent advances in medical imaging technologies, such as magnetic resonance (MR) imaging, make virtual cystoscopy a potential alternative with advantages as being a safe and non-invasive method for evaluation of the entire bladder and detection of abnormalities. To help reducing the interpretation time and reading fatigue of the readers or radiologists, we introduce a computer-aided detection scheme based on the thickness mapping of the bladder wall since locally-thickened bladder wall often appears around tumors. In the thickness mapping method, the path used to measure the thickness can be determined without any ambiguity by tracing the gradient direction of the potential field between the inner and outer borders of the bladder wall. The thickness mapping of the three-dimensional inner border surface of the bladder is then flattened to a twodimensional (2D) gray image with conformal mapping method. In the 2D flattened image, a blob detector is applied to detect the abnormalities, which are actually the thickened bladder wall indicating bladder lesions. Such scheme was tested on two MR datasets, one from a healthy volunteer and the other from a patient with a tumor. The result is preliminary, but very promising with 100% detection sensitivity at 7 FPs per case.

  14. Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

    NASA Astrophysics Data System (ADS)

    Nishino, Hideo; Iwata, Kodai; Ishikawa, Masashi

    2016-07-01

    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

  15. Optimum heating of thick-walled pressure components assuming a quasi-steady state of temperature distribution

    NASA Astrophysics Data System (ADS)

    Dzierwa, Piotr; Trojan, Marcin; Taler, Dawid; Kamińska, Katarzyna; Taler, Jan

    2016-08-01

    As a result of the development of wind farms, the gas — steam blocks, which shall quickly ensure energy supply in case the wind velocity is too low, are introduced to the energy system. To shorten the start-up time of the gas — steam and conventional blocks, the structure of the basic components of the blocks are changed, e.g. by reducing the diameter of the boiler, the thickness of its wall is also reduced. The attempts were also made to revise the currently binding TRD 301 regulations, replacing them by the EN 12952-3 European Standard, to reduce the allowable heating and cooling rates of thick walled boiler components. The basic assumption, on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based, was the quasi — steady state of the temperature field in the simple shaped component, such as a slab, cylindrical or spherical wall.

  16. Image-guided intensity-modulated radiotherapy for refractory bilateral breast cancer in a patient with extensive cutaneous metastasis in the chest and abdominal walls

    PubMed Central

    Lu, Yueh-Feng; Lin, Yu-Chin; Chen, Kuo-Hsin; Shueng, Pei-Wei; Yeh, Hsin-Pei; Hsieh, Chen-Hsi

    2016-01-01

    Treatment for bilateral breast cancer with chest wall and abdominal skin invasion normally involves conventional radiotherapy (RT); however, conventional RT provides inadequate target volume coverage and excessive treatment of large volumes of normal tissue. Helical tomotherapy (HT) has the ability to deliver continuous craniocaudal irradiation that suppresses junction problems and provides good conformity of dose distribution. A 47-year-old female with stage IV bilateral breast cancer with chest wall and pectoralis major muscle invasion, lymphadenopathy, bilateral pleural effusion, and multiple bone metastases received chemotherapy and target therapy beginning in January 2014; 4 months after the initiation of chemotherapy, computed tomography revealed progression of chest and abdominal wall invasion. A total dose of 70.2 Gy was delivered to both breasts, the chest wall, the abdominal wall, and the bilateral supraclavicular nodal areas in 39 fractions via HT. The total planning target volume was 4,533.29 cm3. The percent of lung volume receiving at least 20 Gy (V20) was 28%, 22%, and 25% for the right lung, left lung, and whole lung, respectively. The mean dose to the heart was 8.6 Gy. Follow-up computed tomography revealed complete response after the RT course. Grade 1 dysphagia, weight loss, grade 2 neutropenia, and grade 3 dermatitis were noted during the RT course. Pain score decreased from 6 to 1. No cardiac, pulmonary, liver, or intestinal toxicity developed during treatment or follow-up. Concurrent HT with or without systemic treatment could be a safe salvage therapy for chemorefractory locally advanced breast cancer patients with extensive cutaneous metastasis. PMID:27284253

  17. Highly Fluorescent Nanotubes with Tunable Diameter and Wall Thickness Self-Assembled from Asymmetric Perylene Diimides.

    PubMed

    Peng, Cheng; Zhang, Yibin; Zhang, Yifan; Hu, Yanyong; Che, Yanke; Zhao, Jincai

    2016-08-01

    Highly fluorescent bilayer-walled and monolayer-walled nanotubes are assembled from elaborately designed asymmetric perylene diimide (PDI) molecules. The diameter of bilayer-walled nanotubes increases with the size of the branched substituents at the meta-position of the phenyl moiety of PDI molecules, whereas that of monolayer-walled nanotubes remains unchanged regardless of the size of branched substituents. PMID:27375155

  18. Abdominal wall surgery

    MedlinePlus

    ... Description Your surgery will be done in an operating room in a hospital. You will receive general ... are connected to a video monitor in the operating room that allows the surgeon to see the ...

  19. Abdominal wall surgery

    MedlinePlus

    ... skin. Abdominoplasty can be helpful when: Diet and exercise have not helped improve muscle tone, such as in women who have had more than one pregnancy. Skin and muscle cannot regain its normal tone. ...

  20. Evaluation of side effects of radiofrequency capacitive hyperthermia with magnetite on the blood vessel walls of tumor metastatic lesion surrounding the abdominal large vessels: an agar phantom study

    PubMed Central

    2014-01-01

    Background Magnetite used in an 8-MHz radiofrequency (RF) capacitive heating device can increase the temperature of a specific site up to 45°C. When treating a metastatic lesion around large abdominal vessels via hyperthermia with magnetite, heating-induced adverse effects on these vessels need to be considered. Therefore, this study examined hyperthermia-induced damage to blood vessel walls in vitro. Methods A large agar phantom with a circulatory system consisting of a swine artery and vein connected to a peristaltic pump was prepared. The blood vessels were placed on the magnetite-containing agar piece. Heating was continued for 30 min at 45°C. After heating, a histological study for injury to the blood vessels was performed. Results The inner membrane temperature did not reach 45°C due to the cooling effect of the blood flow. In the heated vessels, vascular wall collagen degenerated and smooth muscle cells were narrowed; however, no serious changes were noted in the vascular endothelial cells or vascular wall elastic fibers. The heated vessel wall was not severely damaged; this was attributed to cooling by the blood flow. Conclusions Our findings indicate that RF capacitive heating therapy with magnetite may be used for metastatic lesions without injuring the surrounding large abdominal vessels. PMID:25114787

  1. Reproducibility of Gadolinium Enhancement Patterns and Wall Thickness in Hypertrophic Cardiomyopathy

    PubMed Central

    Rodriguez-Granillo, Gaston A.; Deviggiano, Alejandro; Capunay, Carlos; Zan, Macarena C. De; Carrascosa, Patricia

    2016-01-01

    Background Reproducibility data of the extent and patterns of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is limited. Objective To explore the reproducibility of regional wall thickness (WT), LGE extent, and LGE patterns in patients with HCM assessed with cardiac magnetic resonance (CMR). Methods The extent of LGE was assessed by the number of segments with LGE, and by the total LV mass with LGE (% LGE); and the pattern of LGE-CMR was defined for each segment. Results A total of 42 patients (672 segments) with HCM constituted the study population. The mean WT measurements showed a mean difference between observers of -0.62 ± 1.0 mm (6.1%), with limits of agreement of 1.36 mm; -2.60 mm and intraclass correlation coefficient (ICC) of 0.95 (95% CI 0.93-0.96). Maximum WT measurements showed a mean difference between observers of -0.19 ± 0.8 mm (0.9%), with limits of agreement of 1.32 mm; -1.70 mm, and an ICC of 0.95 (95% CI 0.91-0.98). The % LGE showed a mean difference between observers of -1.17 ± 1.2 % (21%), with limits of agreement of 1.16%; -3.49%, and an ICC of 0.94 (95% CI 0.88-0.97). The mean difference between observers regarding the number of segments with LGE was -0.40 ± 0.45 segments (11%), with limits of agreement of 0.50 segments; -1.31 segments, and an ICC of 0.97 (95% CI 0.94-0.99). Conclusions The number of segments with LGE might be more reproducible than the percent of the LV mass with LGE. PMID:27305110

  2. Detection of myocardial viability by dobutamine stress echocardiography: incremental value of diastolic wall thickness measurement

    PubMed Central

    Zaglavara, T; Pillay, T; Karvounis, H; Haaverstad, R; Parharidis, G; Louridas, G; Kenny, A

    2005-01-01

    Objective: To assess the diagnostic accuracy of baseline diastolic wall thickness (DWT) alone and as an adjunct to dobutamine stress echocardiography (DSE) for prediction of myocardial viability in patients with ischaemic left ventricular (LV) dysfunction, with the recovery of resting function after revascularisation as the yardstick. Patients: 24 patients with ischaemic LV dysfunction (ejection fraction < 40%) scheduled for surgical revascularisation. Setting: Regional cardiothoracic centre. Methods: All patients underwent DSE before and resting echocardiography six months after revascularisation. DWT was measured in each of the 16 LV segments. A receiver operating characteristic (ROC) and a multi-ROC curve were generated to assess the ability of DWT alone and in combination with DSE to predict myocardial viability. Results: DWT > 0.6 cm provided a sensitivity of 80%, a specificity of 51%, and a negative predictive value of 80% for the prediction of viability in akinetic segments. DSE had an excellent specificity (92%) but a modest sensitivity (60%) in akinetic segments. A combination of improvement at DSE or DWT > 0.8 cm improved sensitivity (90% v 60%, p < 0.001) and negative predictive value (92% v 78%, p  =  0.03) in akinetic segments compared with DSE alone. This was achieved with some loss in specificity (75% v 92%, p  =  0.01) and positive predictive value (71% v 82%, p  =  0.79). Conclusions: DWT measurement may improve the sensitivity of DSE for the detection of myocardial viability. Akinetic segments with DWT > 0.8 cm have a good chance of recovery despite the absence of contractile reserve during DSE. Further testing may be required before excluding myocardial viability in these cases. PMID:15831644

  3. Sarcocystis sinensis is the most prevalent thick-walled Sarcocystis species in beef on sale for consumers in Germany.

    PubMed

    Moré, G; Pantchev, A; Skuballa, J; Langenmayer, M C; Maksimov, P; Conraths, F J; Venturini, M C; Schares, G

    2014-06-01

    Bovines are intermediate hosts of Sarcocystis cruzi, Sarcocystis hirsuta, and Sarcocystis hominis, which use canids, felids, or primates as definitive hosts, respectively. Cattle represent also intermediate hosts of Sarcocystis sinensis, but the definitive hosts of this parasite are not yet known. Sarcocystosis in cattle is frequently asymptomatic. The infection is characterized by the presence of thin-walled (S. cruzi) or thick-walled muscle cysts or sarcocysts (S. hominis, S. sinensis, and S. hirsuta). Recent reports suggest high prevalence of the zoonotic S. hominis in beef in Europe. We therefore aimed at differentiating Sarcocystis spp. in beef offered to consumers in Germany using molecular and microscopical methods, focusing on those species producing thick-walled sarcocysts. A total of 257 beef samples were obtained from different butcheries and supermarkets in Germany and processed by conventional and multiplex real-time PCR. In addition, 130 of these samples were processed by light microscopy and in 24.6% thick-walled cysts were detected. Transmission electron microscopical analysis of six of these samples revealed an ultrastructural cyst wall pattern compatible with S. sinensis in five samples and with S. hominis in one sample. PCR-amplified 18S ribosomal DNA (rDNA) fragments of 28 individual thick-walled cysts were sequenced, and sequence identities of ≥98% with S. sinensis (n = 22), S. hominis (n = 5) and S. hirsuta (n = 1) were observed. Moreover, nine Sarcocystis sp. 18S rDNA full length gene sequences were obtained, five of S. sinensis, three of S. hominis, and one of S. hirsuta. Out of all samples (n = 257), 174 (67.7%) tested positive by conventional PCR and 179 (69.6%) by multiplex real-time PCR for Sarcocystis spp. Regarding individual species, 134 (52%), 95 (37%), 17 (6.6%), and 16 (6.2%) were positive for S. cruzi, S. sinensis, S. hirsuta, and S. hominis, respectively. In conclusion, S. sinensis is the most prevalent thick-walled

  4. Biometric estimation of chest wall thickness of female radiation workers as an aid in in-vivo detection of the actinides

    SciTech Connect

    Lane, B.H.; Berger, C.D.

    1983-01-01

    An equation was derived to estimate female chest wall thickness from a series of biometric measurements. This technique will result in improved performance for actinide detection in females by accounting for variations in chest wall thickness in derivation of calibration factors.

  5. Finite-element modelling of low-temperature autofrettage of thick-walled tubes of the austenitic stainless steel AISI 304 L: Part II. Thick-walled tube with cross-bore

    NASA Astrophysics Data System (ADS)

    Feng, H.; Donth, B.; Mughrabi, H.

    1998-01-01

    In part I, the autofrettage of a smooth thick-walled tube of the austenitic stainless steel AISI 304 L was studied by finite-element (FE) modelling. It was shown that low- temperature autofrettage is more efficient than autofrettage at room temperature, since it produces a larger beneficial compressive residual tangential (hoop) stress at the inner bore of the tube and hence permits a more significant enhancement of the fatigue resistance against pulsating internal pressure. The objective of the present study (part II) was to investigate the technically more relevant case of a thick-walled tube with a cross-bore made of the same steel. For this purpose, three-dimensional FE calculations were performed in order to characterize the influences of the autofrettage pressure and temperature on the stress and strain changes, in particular at the site of the cross-bore, also taking into account the effects of work hardening and reverse yielding. The results indicate that low-temperature autofrettage can also be applied advantageously in the case of thick-walled tubes with a cross-bore by virtue of the significantly larger residual compressive stresses, compared to room temperature autofrettage. From the quantitative FE calculations, the optimal combination of autofrettage temperature and pressure were concluded to lie in the range of 0965-0393/6/1/007/img1 to 0965-0393/6/1/007/img2, respectively. The calculated results were found to be in fair agreement with the measured values.

  6. Recurrence of Brenner ovary borderline tumor in the abdominal wall postoperative scar--a case report and research of the literature.

    PubMed

    Klasa, Lukasz; Wydra, Dariusz; Biernat, Wojciech

    2014-11-01

    We report a case of a 74-year-old female, who underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy due to a solid-cystic tumor of the right ovary. The histopathological diagnosis revealed a borderline Brenner tumor (BBT). After 25 disease-free months the patient was admitted to a hospital because of a tumor in the postoperative scar of the abdominal wall, later diagnosed as infiltrating Brenner tumor consistent with ovarian borderline lesion. The tumor in the postoperative scar was therefore diagnosed as BBT. The article presents results of literature search on BBT in order to find characteristic features of this very rare ovarian tumor. To the best of our knowledge, this is the first report of subcutaneous recurrence of Brenner ovary tumor of low malignant potential. PMID:25675807

  7. Necrotizing fasciitis: literature review of contemporary strategies for diagnosing and management with three case reports: torso, abdominal wall, upper and lower limbs

    PubMed Central

    2011-01-01

    Necrotizing fasciitis (NF) is an uncommon soft tissue infection, usually caused by toxin-producing virulent bacteria. It is characterized by widespread fascial necrosis primarily caused by Streptococcus hemolyticus. Shortly after the onset of the disease, patients become colonized with their own aerobic and anaerobic microflora from the gastrointestinal and/or urogenital tracts. Early diagnosis with aggressive multidisciplinary treatment is mandatory. We describe three clinical cases with NF. The first is a 69 years old man with diabetes mellitus type II, who presented with NF on the posterior chest wall, shoulder and arm. He was admitted to the intensive care unit (ICU) with a clinical picture of severe sepsis. Outpatient treatment and early surgical debridement of the affected zones (inside 3 hours after admittance) and critical care therapy were performed. The second case is of a 63 years old paraplegic man with diabetes mellitus type I. Pressure sores and perineal abscesses progressed to Fournier's gangrene of the perineum and scrotum. He had NF of the anterior abdominal wall and the right thigh. Outpatient treatment and early surgical debridement of the affected zones (inside 6 hour after admittance) and critical care therapy were performed. The third patient was a 56 year old man who had NF of the anterior abdominal wall, flank and retroperitoneal space. He had an operation of the direct inguinal hernia, which was complicated with a bowel perforation and secondary peritonitis. After establishing the diagnosis of NF of the abdominal wall and retroperitoneal space (RS), he was transferred to the ICU. There he first received intensive care therapy, after which emergency surgical debridement of the abdominal wall, left colectomy, and extensive debridement of the RS were done (72 hours after operation of inquinal hernia). On average, 4 serial debridements were performed in each patient. The median of serial debridement in all three cases was four times. Other

  8. Necrotizing fasciitis: literature review of contemporary strategies for diagnosing and management with three case reports: torso, abdominal wall, upper and lower limbs.

    PubMed

    Roje, Zdravko; Roje, Zeljka; Matić, Dario; Librenjak, Davor; Dokuzović, Stjepan; Varvodić, Josip

    2011-01-01

    Necrotizing fasciitis (NF) is an uncommon soft tissue infection, usually caused by toxin-producing virulent bacteria. It is characterized by widespread fascial necrosis primarily caused by Streptococcus hemolyticus. Shortly after the onset of the disease, patients become colonized with their own aerobic and anaerobic microflora from the gastrointestinal and/or urogenital tracts. Early diagnosis with aggressive multidisciplinary treatment is mandatory. We describe three clinical cases with NF. The first is a 69 years old man with diabetes mellitus type II, who presented with NF on the posterior chest wall, shoulder and arm. He was admitted to the intensive care unit (ICU) with a clinical picture of severe sepsis. Outpatient treatment and early surgical debridement of the affected zones (inside 3 hours after admittance) and critical care therapy were performed. The second case is of a 63 years old paraplegic man with diabetes mellitus type I. Pressure sores and perineal abscesses progressed to Fournier's gangrene of the perineum and scrotum. He had NF of the anterior abdominal wall and the right thigh. Outpatient treatment and early surgical debridement of the affected zones (inside 6 hour after admittance) and critical care therapy were performed. The third patient was a 56 year old man who had NF of the anterior abdominal wall, flank and retroperitoneal space. He had an operation of the direct inguinal hernia, which was complicated with a bowel perforation and secondary peritonitis. After establishing the diagnosis of NF of the abdominal wall and retroperitoneal space (RS), he was transferred to the ICU. There he first received intensive care therapy, after which emergency surgical debridement of the abdominal wall, left colectomy, and extensive debridement of the RS were done (72 hours after operation of inquinal hernia). On average, 4 serial debridements were performed in each patient. The median of serial debridement in all three cases was four times. Other

  9. Does mechanical massage of the abdominal wall after colectomy reduce postoperative pain and shorten the duration of ileus? Results of a randomized study.

    PubMed

    Le Blanc-Louvry, Isabelle; Costaglioli, Bruno; Boulon, Catherine; Leroi, Anne-Marie; Ducrotte, Philippe

    2002-01-01

    The aim of this study was to determine the effectiveness of mechanical abdominal massage on postoperative pain and ileus after colectomy. We hypothesized that parietal abdominal stimulation could counteract induced pain and postoperative ileus, through common spinal-sensitive pathways, with nociceptive visceral messages. After preoperative randomization, 25 patients (age 52 +/- 5 years) underwent active mechanical massage by intermittent negative pressure on the abdominal wall resulting in aspiration (Cellu M50 device, LPG, Valence, France), and 25 patients (age 60 +/- 6 years) did not receive active mechanical massage (placebo group). Massage sessions began the first day after colectomy and were performed daily until the seventh postoperative day. In the active-massage group, amplitude and frequency were used, which have been shown to be effective in reducing muscular pain, whereas in the placebo group, ineffective parameters were used. Visual analogue scale (VAS) pain scores, doses of analgesics (propacetamol), and delay between surgery and the time to first passage of flatus were assessed. Types and dosages of the anesthetic drugs and the duration of the surgical procedure did not differ between groups. From the second and third postoperative days, respectively, VAS pain scores (P < 0.001) and doses of analgesics (P < 0.05) were significantly lower in patients receiving active massage compared to the placebo group. Time to first passage of flatus was also significantly shorter in the active-massage group (1.8 +/- 0.3 days vs. 3.6 +/- 0.4 days, P < 0.01). No adverse effects were observed. These results suggest that mechanical massage of the abdominal wall may decrease postoperative pain and ileus after colectomy. PMID:11986017

  10. Enhanced film thickness for Néel wall in soft magnetic film by introducing strong magnetocrystalline anisotropy.

    PubMed

    Xu, Fei; Wang, Tao; Ma, Tianyong; Wang, Ying; Zhu, Shimeng; Li, Fashen

    2016-01-01

    This study investigated the magnetic domain walls in a single-layer soft magnetic film with strong magnetocrystalline anisotropy energy. The soft magnetic film is composed of a highly c-axis-oriented hcp-Co81Ir19 alloy with strong negative magnetocrystalline anisotropy. The domain structure of the soft Co81Ir19 films with thickness ranging from 50-230 nm in a demagnetization state was observed through magnetic force microscopy and Lorentz transmission electron microscopy. Results reveal that the critical transition thickness at which the domain wall changes from Néel type to Bloch type is about 138 nm, which is much larger than the critical value of traditional Fe- and Co-based soft magnetic films with negligible magnetocrystalline anisotropy. Theoretical calculation was also performed and the calculated result agrees well with experimental data. PMID:26821614

  11. Enhanced film thickness for Néel wall in soft magnetic film by introducing strong magnetocrystalline anisotropy

    PubMed Central

    Xu, Fei; Wang, Tao; Ma, Tianyong; Wang, Ying; Zhu, Shimeng; Li, Fashen

    2016-01-01

    This study investigated the magnetic domain walls in a single-layer soft magnetic film with strong magnetocrystalline anisotropy energy. The soft magnetic film is composed of a highly c-axis-oriented hcp-Co81Ir19 alloy with strong negative magnetocrystalline anisotropy. The domain structure of the soft Co81Ir19 films with thickness ranging from 50–230 nm in a demagnetization state was observed through magnetic force microscopy and Lorentz transmission electron microscopy. Results reveal that the critical transition thickness at which the domain wall changes from Néel type to Bloch type is about 138 nm, which is much larger than the critical value of traditional Fe- and Co-based soft magnetic films with negligible magnetocrystalline anisotropy. Theoretical calculation was also performed and the calculated result agrees well with experimental data. PMID:26821614

  12. Using The Descending Aortic Wall Thickness Measured In Transesophageal Echocardiography As A Risk Marker For Aortic Dissection

    PubMed Central

    Fanari, Zaher; Hammami, Sumaya; Hammami, Muhammad Baraa; Hammami, Safa; Eze-Nliam, Chete; Weintraub, William S.

    2015-01-01

    Objective The aim of this study is to estimate whether aortic wall thickness is increased in patients with Aortic dissection (AD) compared to low risk control group and can be used in addition to aortic diameter as a risk marker of AD. Background AD occurs due to pathologies that may increase thickness of the aortic wall. Transesophageal echocardiography (TEE) has the ability to visualize both the thoracic aortic wall and lumen. Aortic diameter has been used to predict aortic dissection and timing of surgery, but it is not always predictive of that risk. Methods In 48 patients with AD who underwent TEE were examined retrospectively and compared to 48 control patients with patent foramen ovale (PFO). We measured aortic diameter at different levels, intimal/medial thickness (IMT) and complete wall thickness (CMT). Demographic data and cardiovascular risk factors were reviewed. The data was analyzed using ANOVA and student t test. Results (AD) patients were older [mean age 66 AD vs. 51 PFO], had more hypertension, diabetes, hyperlipidemia and Coronary artery disease. Both IMT and CMT in the descending aorta were increased in AD group [(1.85 vs. 1.43 mm; P=0.03 and 2.93 vs. 2.46 mm; p=0.01). As expected the diameter of ascending aorta was also greater in AD (4.61 vs. 2.92 cm; P=0.004). Conclusions CMT and IMT in the descending aorta detected by TEE is greater in patients with AD when compared to control and may add prognostic data to that of aortic diameter. PMID:25984293

  13. Investigation of Adiabatic Shear Bands in Thick-Walled Cylinders Collapsed by Electro-Magnetic Driving Forces

    NASA Astrophysics Data System (ADS)

    Lovinger, Z.; Rikanati, A.; Rittel, D.; Rosenberg, Z.

    2009-12-01

    The Thick-Walled Cylinder technique, reported in the literature, employs an explosive cylinder to create the driving force, collapsing the cylindrical sample. This experimental set-up has been established as a controlled and repeatable technique to create and study multiple adiabatic shear bands. Searching to establish a simpler experimental platform to perform large sets of experiments, we have designed an Electro-Magnetic (EM) set-up for the collapse of thick walled cylinders. The EM setup is based on a pulsed current generator using a capacitor bank system. The specimen is an assembly of coaxial cylinders, where the inner and outer cylinders, each attached to an opposite pole, are short-circuited. Upon discharge, a high current flows through the cylinders, in opposite directions, creating repulsive magnetic forces between them. This work presents the design procedure of the specimens using numerical simulations as well as some results for SS304L thick-walled specimens, using this setup. The spatial distribution of the multiple adiabatic shear bands in these experiments is in good agreement with that reported in the literature for the explosive driven experiments with SS304L specimens. Our numerical simulations show good agreement with the experimental results for both global behaviour and shear band distribution.

  14. Shear flow over a plane wall with an axisymmetric cavity or a circular orifice of finite thickness

    NASA Astrophysics Data System (ADS)

    Pozrikidis, C.

    1994-01-01

    Shear flow over a plane wall that contains an axisymmetric depression or pore is studied using a new boundary integral method which is suitable for computing three-dimensional Stokes flow within axisymmetric domains. Numerical results are presented for cavities in the shape of a section of a sphere or a circular cylinder of finite length, and for a family of pores or orifices with finite thickness. The results illustrate the distribution of shear stresses over the plane wall and inside the cavities or pores. It is found that in most cases, the distribution of shear stresses over the plane wall, around the depressions, is well approximated with that for flow over an orifice of infinitesimal thickness for which an exact solution is available. The kinematic structure of the flow is discussed with reference to eddy formation and three-dimensional flow reversal. It is shown that the thickness of a circular orifice or depth of a pore play an important role in determining the kinematical structure of the flow underneath the orifice in the lower half-space.

  15. Recommendations for protecting against failure by brittle fracture: Category II and III ferritic steel shipping containers with wall thickness greater than four inches

    SciTech Connect

    Schwartz, M.W.; Fischer, L.E.

    1996-08-01

    This report provides criteria for selecting ferritic steels that would prevent brittle fracture in Category II and III shipping containers with wall thickness greater than 4 inches. These methods are extensions of those previously used for Category II and III containers less than 4 inches thick and Category I containers more than 4 inches thick.

  16. Riser Difference Evaluation from Ultrasonic Wall Thickness Inspection of Thirteen Double-Shell Tanks

    SciTech Connect

    Weier, Dennis R.; Pardini, Allan F.

    2010-03-15

    PNNL has performed an analysis of ultrasonic thickness measurements taken on Hanford's double-shell tanks (DSTs) approximately eight years apart. The analysis was performed to determine whether significant differences exist between ultrasonic thickness measurements made in two opposite risers in Hanford DSTs that have been examined twice.

  17. Diffusion capacity and CT measures of emphysema and airway wall thickness – relation to arterial oxygen tension in COPD patients

    PubMed Central

    Saure, Eirunn Waatevik; Bakke, Per Sigvald; Eagan, Tomas Mikal Lind; Aanerud, Marianne; Jensen, Robert Leroy; Grydeland, Thomas Blix; Johannessen, Ane; Nilsen, Roy Miodini; Thorsen, Einar; Hardie, Jon Andrew

    2016-01-01

    Background Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased arterial oxygen tension (PaO2), but there are limited data on associations between PaO2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective To examine whether CT measures of emphysema and airway wall thickness are associated with level of arterial oxygen tension beyond that provided by measurements of diffusion capacity and spirometry. Methods The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areas<−950 Hounsfield units (%LAA), and airway wall thickness as standardised measure at an internal perimeter of 10 mm (AWT-Pi10). Multiple linear regression models were fitted with PaO2 as the outcome variable, and %LAA, AWT-Pi10, DLCO and carbon monoxide transfer coefficient (KCO) as main explanatory variables. The models were adjusted for sex, age, smoking status, and haemoglobin concentration, as well as forced expiratory volume in one second (FEV1). Results Sixty two per cent of the subjects were men, mean (SD) age was 64 (7) years, mean (SD) FEV1 in percent predicted was 50 (15)%, and mean PaO2 (SD) was 9.3 (1.1) kPa. The adjusted regression coefficient (CI) for PaO2 was –0.32 (−0.04–(−0.019)) per 10% increase in %LAA (p<0.01). When diffusion capacity and FEV1 were added to the model, respectively, the association lost its statistical significance. No relationship between airway wall thickness and PaO2 was found. Conclusion CT assessment of airway wall thickness is not associated with arterial oxygen tension in COPD patients. Emphysema score measured by chest CT, is related to decreased PaO2, but cannot replace measurements of diffusion capacity in the clinical evaluation of hypoxaemia. PMID:27178139

  18. Ultrasound-Derived Abdominal Muscle Thickness Better Detects Metabolic Syndrome Risk in Obese Patients than Skeletal Muscle Index Measured by Dual-Energy X-Ray Absorptiometry.

    PubMed

    Ido, Ayumi; Nakayama, Yuki; Ishii, Kojiro; Iemitsu, Motoyuki; Sato, Koji; Fujimoto, Masahiro; Kurihara, Toshiyuki; Hamaoka, Takafumi; Satoh-Asahara, Noriko; Sanada, Kiyoshi

    2015-01-01

    Sarcopenia has never been diagnosed based on site-specific muscle loss, and little is known about the relationship between site-specific muscle loss and metabolic syndrome (MetS) risk factors. To this end, this cross-sectional study aimed to investigate the relationship between site-specific muscle size and MetS risk factors. Subjects were 38 obese men and women aged 40-82 years. Total body fat and lean body mass were assessed by whole-body dual-energy X-ray absorptiometry (DXA) scan. Muscle thickness (MTH) was measured using B-mode ultrasound scanning in six body regions. Subjects were classified into general obesity (GO) and sarcopenic obesity (SO) groups using the threshold values of one standard deviation below the sex-specific means of either MTH or skeletal muscle index (SMI) measured by DXA. MetS risk score was acquired by standardizing and summing the following continuously distributed variables: visceral fat area, mean blood pressure, HbA1c, and serum triglyceride / high density lipoprotein cholesterol, to obtain the Z-score. Multiple regression analysis revealed that the MetS risk score was independently associated with abdominal MTH in all subjects, but not with MTH in other muscle regions, including the thigh. Although HbA1c and the number of MetS risk factors in the SO group were significantly higher than those in the GO group, there were no significant differences between GO and SO groups as defined by SMI. Ultrasound-derived abdominal MTH would allow a better assessment of sarcopenia in obese patients and can be used as an alternative to the conventionally-used SMI measured by DXA. PMID:26700167

  19. Ultrasound-Derived Abdominal Muscle Thickness Better Detects Metabolic Syndrome Risk in Obese Patients than Skeletal Muscle Index Measured by Dual-Energy X-Ray Absorptiometry

    PubMed Central

    Ido, Ayumi; Nakayama, Yuki; Ishii, Kojiro; Iemitsu, Motoyuki; Sato, Koji; Fujimoto, Masahiro; Kurihara, Toshiyuki; Hamaoka, Takafumi; Satoh-Asahara, Noriko; Sanada, Kiyoshi

    2015-01-01

    Sarcopenia has never been diagnosed based on site-specific muscle loss, and little is known about the relationship between site-specific muscle loss and metabolic syndrome (MetS) risk factors. To this end, this cross-sectional study aimed to investigate the relationship between site-specific muscle size and MetS risk factors. Subjects were 38 obese men and women aged 40–82 years. Total body fat and lean body mass were assessed by whole-body dual-energy X-ray absorptiometry (DXA) scan. Muscle thickness (MTH) was measured using B-mode ultrasound scanning in six body regions. Subjects were classified into general obesity (GO) and sarcopenic obesity (SO) groups using the threshold values of one standard deviation below the sex-specific means of either MTH or skeletal muscle index (SMI) measured by DXA. MetS risk score was acquired by standardizing and summing the following continuously distributed variables: visceral fat area, mean blood pressure, HbA1c, and serum triglyceride / high density lipoprotein cholesterol, to obtain the Z-score. Multiple regression analysis revealed that the MetS risk score was independently associated with abdominal MTH in all subjects, but not with MTH in other muscle regions, including the thigh. Although HbA1c and the number of MetS risk factors in the SO group were significantly higher than those in the GO group, there were no significant differences between GO and SO groups as defined by SMI. Ultrasound-derived abdominal MTH would allow a better assessment of sarcopenia in obese patients and can be used as an alternative to the conventionally-used SMI measured by DXA. PMID:26700167

  20. Measure Guideline: Incorporating Thick Layers of Exterior Rigid Insulation on Walls

    SciTech Connect

    Lstiburek, Joseph; Baker, Peter

    2015-04-01

    This measure guideline provides information about the design and construction of wall assemblies that use layers of rigid exterior insulation thicker than 1-½ inches and that require a secondary cladding attachment location exterior to the insulation. The guideline is separated into several distinct sections that cover: fundamental building science principles relating to the use of exterior insulation on wall assemblies; design principles for tailoring this use to the specific project goals and requirements; and construction detailing to increase understanding about implementing the various design elements.

  1. Measure Guideline. Incorporating Thick Layers of Exterior Rigid Insulation on Walls

    SciTech Connect

    Lstiburek, Joseph; Baker, Peter

    2015-04-09

    This measure guideline, written by the U.S. Department of Energy’s Building America team Building Science Corporation, provides information about the design and construction of wall assemblies that use layers of rigid exterior insulation thicker than 1-½ in. and that require a secondary cladding attachment location exterior to the insulation. The guideline is separated into several distinct sections that cover: (1) fundamental building science principles relating to the use of exterior insulation on wall assemblies; (2) design principles for tailoring this use to the specific project goals and requirements; and (3) construction detailing to increase understanding about implementing the various design elements.

  2. Stress-intensity factors for a thick-walled cylinder containing an annular imbedded or external or internal surface crack

    NASA Technical Reports Server (NTRS)

    Erdol, R.; Erdogan, F.

    1976-01-01

    The elastostatic axisymmetric problem for a long thick-walled cylinder containing a ring-shaped internal or edge crack is considered. Using the standard transform technique the problem is formulated in terms of an integral equation which has a simple Cauchy kernel for the internal crack and a generalized Cauchy kernel for the edge crack as the dominant part. As examples the uniform axial load and the steady-state thermal stress problems have been solved and the related stress intensity factors have been calculated. Among other findings the results show that in the cylinder under uniform axial stress containing an internal crack the stress intensity factor at the inner tip is always greater than that at the outer tip for equal net ligament thicknesses and in the cylinder with an edge crack which is under a state of thermal stress the stress intensity factor is a decreasing function of the crack depth, tending to zero as the crack depth approaches the wall thickness.

  3. The gender-specific chest wall thickness prediction equations for routine measurements of 239Pu and 241Am within the lungs using HPGe detectors.

    PubMed

    Vickers, L R

    1996-03-01

    The current chest wall thickness prediction equation is not applicable to use in routine lung counting measurements for detection of low energy photons (17--60 keV) within the lungs of male and female subjects. The current chest wall thickness prediction equation was derived for the NaI-CsI "phoswich" detection system, which is not the routine detection system in use; the subject position was supine, which is not the routine position; the equation did not account for the intercostal tissue thicknesses of muscle and adipose which significantly attenuate low energy photons (17--60keV); it was derived from male subjects only and is used to predict the chest wall thickness of female subjects for whom it is not applicable. The current chest wall thickness prediction equation yields unacceptable percent errors in the HPGe detection efficiency calibration for 239Pu and 241Am (17- and 59.5-keV photons, respectively) relative to the gender-specific HPGe chest wall thickness prediction equations of this paper (+284% to --73% for 239Pu; (+)42% to --39% for 241Am). As a result, use of the current chest wall thickness prediction equation yields unacceptable percent errors (proportional in magnitude to the percent errors in the detection efficiency calibration) in the calculation of the minimum detectable activity (Bq) or in an initial assessment of a radioactive contamination exposure detected by a routine lung count measurement. PMID:8609026

  4. Oscillatory limited compressible fluid flow induced by the radial motion of a thick-walled piezoelectric tube

    NASA Astrophysics Data System (ADS)

    Shin, Dong-Youn; Grassia, Paul; Derby, Brian

    2003-09-01

    A simple oscillatory, slightly compressible, fluid flow model in a thick-walled piezoelectric tube used in a drop-on-demand inkjet print head is developed from the point of view of fluid-structure interaction to take account of pressure wave propagation and pressure loading opposing wall motion. A frequency sweep is performed computationally using the model revealing the first acoustic fluid-structure resonance frequency and the influence of fluid viscosity. The validity of the model, with given information on the speed of sound in a fluid, is evaluated by comparing the theoretically predicted resonance frequency to the experimentally measured resonance frequency. In addition, the intrinsic speed of sound can be easily computed using the measured acoustic resonance frequency and this computed speed of sound agrees closely with speeds of sound reported in the literature.

  5. Automatic airway wall segmentation and thickness measurement for long-range optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Qi, Li; Huang, Shenghai; Heidari, Andrew E.; Dai, Cuixia; Zhu, Jiang; Zhang, Xuping; Chen, Zhongping

    2016-03-01

    We present an automatic segmentation method for delineation and quantitative thickness measurement of multiple layers in endoscopic airway optical coherence tomography (OCT) images. The boundaries of the mucosa and the sub-mucosa layers were extracted using a graph-theory-based dynamic programming algorithm. The algorithm was tested with pig airway OCT images acquired with a custom built long range endoscopic OCT system. The performance of the algorithm was demonstrated by cross-validation between auto and manual segmentation experiments. Quantitative thicknesses changes in the mucosal layers are obtained automatically for smoke inhalation injury experiments.

  6. Safety Analysis Using Lebesgue Strain Measure of Thick-Walled Cylinder for Functionally Graded Material under Internal and External Pressure

    PubMed Central

    Aggarwal, A. K.; Sharma, Richa; Sharma, Sanjeev

    2013-01-01

    Safety analysis has been done for thick-walled circular cylinder under internal and external pressure using transition theory which is based on the concept of generalized principal Lebesgue strain measure. Results have been analyzed theoretically and discussed numerically. From the analysis, it can be concluded that circular cylinder made of functionally graded material is on the safer side of the design as compared to homogeneous cylinder with internal and external pressure, which leads to the idea of “stress saving” that minimizes the possibility of fracture of cylinder. PMID:24089605

  7. A comparative assessment of the wall thickness margin taking into account the initial flaws in steam line elements

    NASA Astrophysics Data System (ADS)

    Gladshtein, V. I.

    2011-02-01

    A procedure for estimating the wall thickness margin for operation during a specified design service life under creep conditions if the metal of articles contains initial flaws is presented. The analysis is carried out taking as an example parts of steam lines made of two different grades of steel: a cast elbow with the size d = 426 × 30 mm made of 15Kh1M1FL low-alloy steel and a pipe bend with the size d = 219 × 32 mm made of EI-756 12% chromium steel. The calculated assessments are compared with the results obtained from long-term operation.

  8. Modified hemi-double-stapling technique combined with the temporal abdominal-wall-lift method for performing Billroth I anastomosis after laparoscopically assisted distal gastrectomy.

    PubMed

    Fujii, Hidenori; Aotake, Toshiharu; Kawakami, Yoshiyuki; Okuda, Yukihiro; Doi, Koji; Hirose, Yuki; Matsushita, Toshio

    2008-12-01

    The authors have used a modified hemi-double-stapling (HDS) technique for reconstruction after laparoscopically assisted distal gastrectomy. The stomach is resected from the greater curvature side using a linear stapler inserted into the stomach from that side at a position vertical to the line of the greater curvature. Resection of the stomach is performed by extending the resection line to the lesser curvature using laparoscopic coagulating shears. The resected specimen is examined. After placement of a purse-string suture at the duodenal stump, an anvil is inserted into the stump, and an additional suture with 2-0 silk is placed over the purse-string suture. A curved intraluminal stapler (CDH25) is inserted into the stomach through the opening made on the lesser curvature side, and the center rod of the stapler is passed through the gastric wall on the corner of the resection line at the greater curvature. Ligation with 2-0 silk is added to the center rod by suturing the gastric tissue 5-8 mm from the center rod to encircle it. The authors call this the "one-knot setup HDS," and with this method, a large-caliber anastomosis is secured. In many cases, it is difficult to observe the anastomotic site through the small incisional opening. However, under laparoscopy with the temporal abdominal wall-lift method using the Multi Flap Gate, the anastomotic site can be easily and safely observed. One-knot setup HDS combined with the temporal abdominal wall-lift method is considered a safe and simple method for performing Billroth I anastomosis in laparoscopic distal gastrectomy. PMID:18324439

  9. Characteristics of colorectal cancer diagnosed with screening abdominal ultrasonography

    PubMed Central

    TOMIZAWA, MINORU; SHINOZAKI, FUMINOBU; HASEGAWA, RUMIKO; FUGO, KAZUNORI; SHIRAI, YOSHINORI; MOTOYOSHI, YASUFUMI; SUGIYAMA, TAKAO; YAMAMOTO, SHIGENORI; KISHIMOTO, TAKASHI; ISHIGE, NAOKI

    2016-01-01

    Patient records were retrospectively analyzed to elucidate the characteristics of patients with colorectal cancer (CRC) diagnosed with screening abdominal ultrasound (US). Patients diagnosed with CRC using abdominal US [localized irregular wall thickening (W) or a hypoechoic mass with a hyperechoic mass (M)] were enrolled. The patients were subjected to colonoscopy and treated surgically between March, 2010 and January, 2015. A total of 5 men (aged 74.0±0.8 years) and 10 women (aged 73.0±12.0 years) were analyzed. Stratification was analyzed with abdominal US. The threshold value of wall thickness to diagnose CRC was investigated with receiver operating characteristic (ROC) curve analysis. The average wall thickness was 2.8±0.4 mm in the surrounding normal tissue and 12.7±5.2 mm in CRC (one-way analysis of variance, P<0.0001). The wall was significantly thicker in CRC compared with the normal colonic wall. The calculated threshold value was 4.3 mm for the diagnosis of CRC. Stratification was preserved in W, while it was lost in M (Chi-squared test, P=0.0196). The hemoglobin concentration was lower, while the C-reactive protein, carcinoembryonic antigen and carbohydrate antigen 19-9 levels were elevated above normal values. The threshold value was 4.3 mm for the diagnosis of CRC with abdominal US. PMID:27330768

  10. Recurrent cystosarcoma phylloides of breast: extensive full-thickness excision of chest wall with immediate repair using steel mesh and a latissimus dorsi myocutaneous flap.

    PubMed

    Mindikoğlu, A N; Aktan, K

    1983-10-01

    The case of a young woman with a massive recurrent cystosarcoma phylloides of the breast is presented in whom a full thickness excision of the chest wall was carried out en bloc together with four ribs. The large full-thickness defect of the chest wall was reconstructed with stainless steel mesh and covered by a latissimus dorsi myocutaneous flap. The management of post-operative paradoxical movement is also described. PMID:6313105

  11. Abdominal Compartment Hypertension and Abdominal Compartment Syndrome.

    PubMed

    Maluso, Patrick; Olson, Jody; Sarani, Babak

    2016-04-01

    Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are rare but potentially morbid diagnoses. Clinical index of suspicion for these disorders should be raised following massive resuscitation, abdominal wall reconstruction/injury, and in those with space-occupying disorders in the abdomen. Gold standard for diagnosis involves measurement of bladder pressure, with a pressure greater than 12 mm Hg being consistent with IAH and greater than 25 mm Hg being consistent with ACS. Decompressive laparotomy is definitive therapy but paracentesis can be equally therapeutic in properly selected patients. Left untreated, ACS can lead to multisystem organ failure and death. PMID:27016163

  12. Analysis of abdominal wounds made by surgical trocars using functional luminal imaging probe (FLIP) technology.

    PubMed

    McMahon, Barry P; O'Donovan, Deidre; Liao, Donghua; Zhao, Jingbo; Schiretz, Rich; Heninrich, Russell; Gregersen, Hans

    2008-09-01

    The aim was to use a novel functional luminal imaging probe for evaluation of wound defects and tissue damage resulting from the use of trocars. Following general anesthesia of 4 adult pigs, 6 different trocars were randomly inserted at preselected locations in the porcine abdominal wall. The functional luminal imaging probe was used to profile the trocar holes during bag distension from 8 axial cross-sectional area measurements. The cross-sectional areas and pressure in the bag were recorded and exported to Matlab for analysis and data display. Geometric profiles were generated, and the minimum cross-sectional area and hole length (abdominal wall thickness) were used as endpoints. Successful distensions were made in all cases. The slope of the contours increased away from the narrowest point of the hole. The slope increased more rapidly toward the inner abdominal wall than toward the outer wall. The slope of the linear trend lines for the cross-sectional area-pressure relation represents the compliance at the narrowest point in the wall. The hole length (abdominal wall thickness) could be obtained at different cross-sectional area cutoff points. A cutoff point of 300 mm(2) gave good results when compared to the length of the hole measured after the tissue was excised. This technique represents a new and straightforward way to evaluate the effects of trocars on the abdominal wall. It may also prove useful in comparing techniques and technology from different manufacturers. PMID:18757380

  13. Thermoelastic Analysis of a Functionally Graded Rotating Thick-Walled Tube Subjected to Mechanical and Thermal Loads

    NASA Astrophysics Data System (ADS)

    Xin, Libiao; Yang, Shengyou; Ma, Baoyu; Dui, Guansuo

    2015-11-01

    A thermoelastic solution for the functionally graded rotating thick-walled tube subjected to axisymmetric mechanical and thermal loads is given in terms of volume fractions of constituents. We assume that the tube consists of two linear elastic constituents and the volume fraction of one phase is a power function varied in the radial direction. By using the assumption of a uniform strain field within the representative volume element, the theoretical solutions of the displacement and the stresses are presented. Based on the relation of the volume average stresses of constituents and the macroscopic stresses of the composite material in micromechanics, the present method can avoid the assumption of the distribution regularities of unknown overall material parameters appeared in existing papers, such as Young's modulus, thermal expansion coefficient, thermal conductivity, and density. The effects of the angular velocity, the volume fraction, the ratio of two thermal expansion coefficients, the ratio of two thermal conductivities, and the ratio of two densities on the displacement and stresses are systematically studied, which should help structural engineers and material scientists optimally design thick-walled tube comprised inhomogeneous materials.

  14. Collapse Pressure Analysis of Transversely Isotropic Thick-Walled Cylinder Using Lebesgue Strain Measure and Transition Theory

    PubMed Central

    Aggarwal, A. K.; Sharma, Richa; Sharma, Sanjeev

    2014-01-01

    The objective of this paper is to provide guidance for the design of the thick-walled cylinder made up of transversely isotropic material so that collapse of cylinder due to influence of internal and external pressure can be avoided. The concept of transition theory based on Lebesgue strain measure has been used to simplify the constitutive equations. Results have been analyzed theoretically and discussed numerically. From this analysis, it has been concluded that, under the influence of internal and external pressure, circular cylinder made up of transversely isotropic material (beryl) is on the safer side of the design as compared to the cylinders made up of isotropic material (steel). This is because of the reason that percentage increase in effective pressure required for initial yielding to become fully plastic is high for beryl as compared to steel which leads to the idea of “stress saving” that reduces the possibility of collapse of thick-walled cylinder due to internal and external pressure. PMID:24523632

  15. Instrumented thick-walled tube method for measuring thermal pressure in fluids and isotropic stresses in thermosetting resins

    NASA Astrophysics Data System (ADS)

    Merzlyakov, Mikhail; Simon, Sindee L.; McKenna, Gregory B.

    2005-06-01

    We have developed a method for measuring the thermal pressure coefficient and cure-induced and thermally induced stresses based on an instrumented thick-walled tube vessel. The device has been demonstrated at pressures up to 330 MPa and temperatures to 300 °C. The method uses a sealed stainless steel thick-walled tube to impose three-dimensional isotropic constraints. The tube is instrumented with strain gauges in hoop and in axial directions and can be used in open or closed configurations. By making measurements of the isotropic stresses as a function of temperature, the method allows determination of the thermal pressure coefficient in both the glassy and rubbery (or liquid) states. The method also can be used to measure isotropic stress development in thermosetting resins during cure and subsequent thermal cycling. Experimental results are presented for sucrose benzoate, di-2-ethylhexylsebacate, and an epoxy resin. The current report shows that the method provides reliable estimates for the thermal pressure coefficient. The thermal pressure coefficient is determined with resolution on the order of 10kPa/K. Among advantages of the method is that the tubes are reusable, even when measurements are made for cure response of thermosetting resins.

  16. The use of biomaterials in the repair of abdominal wall defects: a comparative study between polypropylene meshes (Marlex) and a new polytetrafluoroethylene prosthesis (Dual Mesh).

    PubMed

    Bellón, J M; Contreras, L A; Buján, J; Carrera-San Martín, A

    1997-10-01

    In this study we compared the behaviour of the non-porous on one side ePTFE Dual Mesh prosthesis and the macroporous polypropylene mesh Marlex in the repair of abdominal wall defects in rabbits. We evaluated the degree of integration with recipient tissue, biological tolerance, adhesion formation with viscera and the biomechanical resistance of the repair zone. Our results showed good biological tolerance of both prostheses and a high degree of adhesion formation in Marlex implants. In animals with Dual Mesh implants, only loose adhesions were seen. Marlex implants induced the presence of disorganized scar tissue, while the Dual Mesh prostheses were encapsulated by organized tissue. The macrophage response was similar in both decreasing with time. The resistance to traction was higher when the reparation was done with polypropylene. We concluded that the structure of the prosthesis determines its degree of integration and the resistance to traction of the repaired zone. PMID:9399138

  17. SU-C-BRA-04: Use of Esophageal Wall Thickness in Evaluation of the Response to Chemoradiation Therapy for Esophageal Cancer

    SciTech Connect

    Wang, J; Kligerman, S; Lu, W; Kang, M

    2015-06-15

    Purpose: To quantitatively evaluate the esophageal cancer response to chemoradiation therapy (CRT) by measuring the esophageal wall thickness in CT. Method: Two datasets were used in this study. The first dataset is composed of CT scans of 15 esophageal cancer patients and 15 normal controls. The second dataset is composed of 20 esophageal cancer patients who underwent PET/CT scans before (Pre-CRT) and after CRT (Post-CRT). We first segmented the esophagus using a multi-atlas-based algorithm. The esophageal wall thickness was then computed, on each slice, as the equivalent circle radius of the segmented esophagus excluding the lumen. To evaluate the changes of wall thickness, we computed the standard deviation (SD), coefficient of variation (COV, SD/Mean), and flatness [(Max–Min)/Mean] of wall thickness along the entire esophagus. Results: For the first dataset, the mean wall thickness of cancer patients and normal controls were 6.35 mm and 6.03 mm, respectively. The mean SD, COV, and flatness of the wall thickness were 2.59, 0.21, and 1.27 for the cancer patients and 1.99, 0.16, and 1.13 for normal controls. Statistically significant differences (p < 0.05) were identified in SD and flatness. For the second dataset, the mean wall thickness of pre-CRT and post-CRT patients was 7.13 mm and 6.84 mm, respectively. The mean SD, COV, and flatness were 1.81, 0.26, and 1.06 for pre-CRT and 1.69, 0.26, and 1.06 for post-CRT. Statistically significant difference was not identified for these measurements. Current results are based on the entire esophagus. We believe significant differences between pre- and post-CRT scans could be obtained, if we conduct the measurements at tumor sites. Conclusion: Results show thicker wall thickness in pre-CRT scans and differences in wall thickness changes between normal and abnormal esophagus. This demonstrated the potential of esophageal wall thickness as a marker in the tumor CRT response evaluation. This work was supported in part by

  18. Thick growing multilayer nanobrick wall thin films: super gas barrier with very few layers.

    PubMed

    Guin, Tyler; Krecker, Michelle; Hagen, David Austin; Grunlan, Jaime C

    2014-06-24

    Recent work with multilayer nanocoatings composed of polyelectrolytes and clay has demonstrated the ability to prepare super gas barrier layers from water that rival inorganic CVD-based films (e.g., SiOx). In an effort to reduce the number of layers required to achieve a very low oxygen transmission rate (OTR (<0.01 cc/m(2)·day·atm)) in these nanocoatings, buffered cationic chitosan (CH) and vermiculite clay (VMT) were deposited using layer-by-layer (LbL) assembly. Buffering the chitosan solution and its rinse with 50 mM Trizma base increased the thickness of these films by an order of magnitude. The OTR of a 1.6-μm-thick, six-bilayer film was 0.009 cc/m(2)·day·atm, making this the best gas barrier reported for such a small number of layers. This simple modification to the LbL process could likely be applied more universally to produce films with the desired properties much more quickly. PMID:24914613

  19. Strength-toughness requirements for thick-walled high pressure vessels

    NASA Astrophysics Data System (ADS)

    Kapp, Joseph A.

    1992-05-01

    The strength and toughness requirements of materials used in high pressure vessels has been the subject of some discussion in the meetings of the Materials Task Group of the Special Working Group - High Pressure Vessels. A fracture mechanics analysis has been performed to theoretically establish the required toughness for a high pressure vessel. The analysis is based on the validity requirement for plane-strain fracture of fracture toughness test specimens. This means that at fracture, the crack length, uncracked ligament, and vessel length must each be greater than fifty times the crack tip plastic zone since for brittle fracture to occur. For high pressure piping applications, the limiting physical dimension is the uncracked ligament, since it can be assumed that the other dimensions are always greater than fifty times the crack tip plastic zone. To perform the fracture mechanics analysis, several parameters must be known, including vessel dimensions, material strength, degree of autofrettage, and design pressure. Remarkably, the results of the analysis show that the effects of radius ratio, pressure, and degree of autofrettage can be ignored when establishing strength and toughness requirements for design code purposes. The only parameters that enter into the calculation are yield strength, toughness and vessel thickness. The final results can easily be represented as a graph of yield strength against toughness on which several curves, one for each vessel thickness, are plotted.

  20. Thermoacoustic Oscillations (He-4 Taconis Modes) inside a Thick-Walled Tube.

    NASA Astrophysics Data System (ADS)

    Williamson, J. J.; Toshida, S.; Ravikumar, R. V.; Frederking, T. H. K.

    The equations describing thermoacoustic (Taconis) oscillations inside a liquid-level finder do not have a gravitational dependence term. Therefore, examining these oscillatory modes has potential applications for low boiling cryoliquids in micro-gravity environments, particularly in covered, wall-adjacent domains, like cryoliquids in storage containers aboard spacecraft. Because of capillary action, these liquids tend to cling to the walls of the container. We have continued proceeding work (ICEC 16) using a heavy-walled liquid-level finder for cryogenic helium-4 in 1-g experiments. The apparatus used to observe Taconis oscillations is described by Gaffney and Clement, where a long, hollow tube is immersed, open end down, into a tank of liquid helium-4. The oscillations were measured by fitting the closed end of the tube with a rubber membrane having a small permanent magnet attached. Acoustic oscillations in the tube cause vibrations in the membrane-magnet system which were sensed by a pick-up coil, converting the oscillations into an electrical voltage. The oscillations were measured as a function of voltage (i.e., magnet displacement) versus time, i.e., a time series. The immersion length of the Taconis tube in liquid helium was varied from a finite length to "zero" (tube end touching liquid) and beyond "zero" in the gas phase. The purpose was to characterize the dynamics of the Taconis oscillations and examine usage of the Taconis tube as a liquid-level finder for liquid helium in storage tanks in microgravity environments. In order to characterize the underlying dynamics causing the oscillations, Nonlinear Dynamical Analysis (i.e., "Chaos" analysis) of the oscillations was performed. "Chaotic" behavior is summarized as: an erratic-looking system is in fact deterministic and governed by a set of nonlinear differential equations which are highly sensitive to the system's initial conditions. From the time series, a number of characterizations of the underlying

  1. Application of Internal Fusible Chills in Thick-Walled Castings Made of EN-GJS with an Optimized Microstructure

    NASA Astrophysics Data System (ADS)

    Krupa, Wojciech; Tonn, Babette

    2011-01-01

    The degeneration of graphite in thick-walled components made of ductile iron due to slower solidification affects the mechanical properties and is unacceptable for all safety-relevant components. The inoculation of the melt no longer leads to a fine microstructure. After exceeding the critical solidification time, degenerated shapes of graphite are to be expected. The external cooling with a chill-mould does not eliminate graphite degeneration in the thermal centres. The positive effect of these chills is also limited by the wall thickness. The aim of this study was to increase the heat dissipation of the melt by positioning the internal fusible chills in the thermal centre of the mould cavity. This should lead to accelerated solidification. The plate-shaped chills were placed in the middle of rectangular samples. The solidification processes were first simulated with Magmasoft in order to optimize the size and shape of the fusible chills and to thus guarantee a complete dissolving of the chills. A reduction in the solidification time of approximately 15% was achieved. In the experiments thick-walled samples were cast with and without internal fusible chills and compared. Areas with degenerated graphite, including chunky graphite, were found in the centres of the cast samples without internal cooling. Placing fusible chills in castings increased the number of graphite spheroids in the microstructure and exhibited no graphite degeneration. A homogenous microstructure was developed—no residues of the chills were found. Differences in microstructure and mechanical properties between the edges and centres of the casting could be nullified. The optimized graphite morphology of the casting with internal cooling led to an increase in tensile strength in the thermal centre of about 30 MPa (8%). This process was successfully implemented in an industrial environment. Blocks out of EN-GJS-400 for use in hydraulic engineering with a total weight of eight tonnes were cast in

  2. The impact of transcatheter aortic valve implantation on left ventricular performance and wall thickness – single-centre experience

    PubMed Central

    Szymański, Piotr; Dąbrowski, Maciej; Zakrzewski, Dariusz; Michałek, Piotr; Orłowska-Baranowska, Ewa; El-Hassan, Kamal; Chmielak, Zbigniew; Witkowski, Adam; Hryniewiecki, Tomasz

    2015-01-01

    Introduction Transcatheter aortic valve implantation (TAVI) is a treatment alternative for the elderly population with severe symptomatic aortic stenosis (AS) at high risk for surgical aortic valve replacement (SAVR). Aim To assess the impact of TAVI on echocardiographic parameters of left ventricular (LV) performance and wall thickness in patients subjected to the procedure in a single-centre between 2009 and 2013. Material and methods The initial group consisted of 170 consecutive patients with severe AS unsuitable for SAVR. Logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 21.73 ±12.42% and mean age was 79.9 ±7.5 years. Results The TAVI was performed in 167 (98.2%) patients. Mean aortic gradient decreased significantly more rapidly after the procedure (from 58.6 ±16.7 mm Hg to 11.9 ±4.9 mm Hg, p < 0.001). The LV ejection fraction (LVEF) significantly increased in both short-term and long-term follow-up (57 ±14% vs. 59 ±13%, p < 0.001 and 56 ±14% vs. 60 ±12%, p < 0.001, respectively). Significant regression of interventricular septum diameter at end-diastole (IVSDD) and end-diastolic posterior wall thickness (EDPWth) was noted in early (15.0 ±2.4 mm vs. 14.5 ±2.3 mm, p < 0.001 and 12.7 ±2.1 mm vs. 12.4 ±1.9 mm, p < 0.028, respectively) and late post-TAVI period (15.1 ±2.5 mm to 14.3 ±2.5 mm, p < 0.001 and 12.8 ±2.0 mm to 12.4 ±1.9 mm, p < 0.007, respectively). Significant paravalvular leak (PL) was noted in 21 (13.1%) patients immediately after TAVI and in 13 (9.6%) patients in follow-up (p < 0.001). Moderate or severe mitral regurgitation (msMR) was seen in 24 (14.9%) patients from the initial group and in 19 (11.8%) patients after TAVI (p < 0.001). Conclusions The TAVI had an immediate beneficial effect on LVEF, LV walls thickness, and the incidence of msMR. The results of the procedure are comparable with those described in other centres. PMID:25848369

  3. In a dynamic lifting task, the relationship between cross-sectional abdominal muscle thickness and the corresponding muscle activity is affected by the combined use of a weightlifting belt and the Valsalva maneuver.

    PubMed

    Blanchard, Trevor W; Smith, Camille; Grenier, Sylvain G

    2016-06-01

    It has been shown that under isometric conditions, as the activity of the abdominal muscles increases, the thicknesses of the muscles also increase. The purpose of this experiment was to determine whether change in muscle thickness could be used as a measure of muscle activity during a deadlift as well as determining the effect of a weightlifting belt and/or the Valsalva maneuver on the muscle thicknesses. The Transversus Abdominis (TrA) and Internal Obliques (IO) muscles were analyzed at rest and during a deadlift. Muscle thickness was measured using ultrasound imaging and muscle activity was simultaneously recorded using electromyography. Each subject performed deadlift under normal conditions, while performing the Valsalva maneuver, while wearing a weightlifting belt and while both utilizing the belt and the Valsalva maneuver. There was no relationship between change in muscle thickness and muscle activity for both the TrA and IO (R(2)<0.13 for all conditions). However it was found that the Valsalva maneuver increased abdominal muscle thickness whereas the belt limited muscle expansion; each with an increase in activity. These results indicate that ultrasound cannot be used to measure muscle activity for a deadlift and that the belt affects how the IO and TrA function together. PMID:27093137

  4. Environmentally-controlled fracture of an overstrained A723 steel thick-walled cylinder

    NASA Astrophysics Data System (ADS)

    Underwood, J. H.; Olmstead, V. J.; Askew, J. C.; Kapusta, A. A.; Young, G. A.

    1992-08-01

    A through-wall, 1.7 m long crack grew suddenly from a notch in a 285 mm outer diameter (OD) of an A723 steel overstrained tube that was undergoing plating operations with no externally applied loads. The fracture mechanics tests and analyses and the fractography performed to characterize the cracking are described. The tube had a yield strength of 1200 MPa, fracture toughness of 150 MPavm, and a tensile residual stress at the OD of about 600 MPa. The composition was typical of an air-melt A723 steel, and the electropolishing bath, consisting of sulfuric and phosphoric acids, was held at 54 C. The bolt-loaded test for the threshold stress intensity factor for environmentally controlled cracking described by Wei and Novak was used here with two significant modifications. Some tests included only a notch with the radius matching that of the tube, and a new expression for K in terms of crack-mouth displacement was developed and used. Scanning electron microscope fractography and energy dispersive x ray spectra were used to identify crack mechanisms. Results of the study include: (1) a measured threshold of hydrogen stress cracking for the material/environment below 20 MPavm; (2) da/dt versus K behavior typical of classic environmental control; and (3) an improved K/v expression for the bolt-loaded specimen and associated criteria for determining plane-strain test conditions in relation to the Irwin plastic zone.

  5. Quantum confinement effect in Bi anti-dot thin films with tailored pore wall widths and thicknesses

    SciTech Connect

    Park, Y.; Hirose, Y.; Fukumura, T.; Hasegawa, T.; Nakao, S.; Xu, J.

    2014-01-13

    We investigated quantum confinement effects in Bi anti-dot thin films grown on anodized aluminium oxide templates. The pore wall widths (w{sub Bi}) and thickness (t) of the films were tailored to have values longer or shorter than Fermi wavelength of Bi (λ{sub F} = ∼40 nm). Magnetoresistance measurements revealed a well-defined weak antilocalization effect below 10 K. Coherence lengths (L{sub ϕ}) as functions of temperature were derived from the magnetoresistance vs field curves by assuming the Hikami-Larkin-Nagaoka model. The anti-dot thin film with w{sub Bi} and t smaller than λ{sub F} showed low dimensional electronic behavior at low temperatures where L{sub ϕ}(T) exceed w{sub Bi} or t.

  6. The use of thick-walled hollow cylinder creep tests for evaluating flow criteria for rock salt

    SciTech Connect

    Morgan, H.S.; Wawersik, W.R.

    1990-01-01

    Finite element simulations of two laboratory creep tests on thick-walled hollow cylinders of rock salt are evaluated to determine if such bench-scale experiments can be used to establish applicability of either von Mises or Tresca stress measures and associated flow conditions. In the tests, the cylinders were loaded axially and pressurized both internally and externally to produce stress fields similar to those found around underground excavations in rock salt. Several different loading stages were used in each test. The simulations show that for each of two creep models studied, quite different deformations of the cylinders are predicted with the Mises and Tresca flow criteria, especially if friction between the cylinders and axial loading platens is ignored. When friction is included in the simulations, the differences in deformation are changed but are sill clearly distinguishable. 10 refs., 10 figs.

  7. Examination of Cell Shape in Wall Thickness Direction for Foamed Polyurethane Resin

    NASA Astrophysics Data System (ADS)

    Kono, Tsutomu; Matsuoka, Shin-Ichi; Araki, Kuninari; Iseki, Takashi

    The foaming flow process of polyurethane resin is difficult because temperature, density and thermal conductivity are changed greatly by heat generation resulting from the mixing reaction of polyol and polyisocyanate resin. It is thought that thermal conductivity and strength are influenced by cell shape after the foaming process. In this study, we evaluate three-dimensional cell shapes by quantitatively observation of the ratio of the diameter of the parallel and the perpendicular section to flow direction, the ratio of the major axis and the minor axis, and direction of the major axis of cells for closed cell shapes in foamed polyurethane resin. It is thought that cell shapes are mainly deformed by shear stress and pressure of adjacent cells. It becomes obvious by cell shape evaluation that cells in the skin layer are compressed in the thickness direction by pressure of adjacent cells, cells between the skin layer and the core layer are stretched perpendicular to the flow direction by shear stress, and cells in the core layer are similar to the sphere shape.

  8. Fracture behavior of shallow cracks in full-thickness clad beams from an RPV wall section

    SciTech Connect

    Keeney, J.A.; Bass, B.R.; McAfee, W.J.

    1995-04-01

    A testing program is described that utilizes full-thickness clad beam specimens to quantify fracture toughness for shallow cracks in weld material for which metallurgical conditions are prototypic of those found in reactor pressure vessels (RPVs). The beam specimens are fabricated from an RPV shell segment that includes weld, plate and clad material. Metallurgical factors potentially influencing fracture toughness for shallow cracks in the beam specimens include material gradients and material inhomogeneities in welded regions. The shallow-crack clad beam specimens showed a significant loss of constraint similar to that of other shallow-crack single-edge notch bend (SENB) specimens. The stress-based Dodds-Anderson scaling model appears to be effective in adjusting the test data to account for in-plane loss of constraint for uniaxially tested beams, but cannot predict the observed effects of out-of-plane biaxial loading on shallow-crack fracture toughness. A strain-based dual-parameter fracture toughness correlation (based on plastic zone width) performed acceptably when applied to the uniaxial and biaxial shallow-crack fracture toughness data.

  9. Application of the new Section XI, A-3000 method for stress intensity factor calculation to thick-walled pressure vessels

    SciTech Connect

    Kendall, D.P.

    1996-12-01

    The ASME Boiler and Pressure Vessel Code, Section XI, Appendix A, Article A-3000 has been recently revised to include a more accurate method for calculating stress intensity factors. It is based on fitting the distribution of the stress normal to the plane of the crack in the uncracked body, over the depth of the crack, with a cubic equation. The coefficients of this equation are used with correction factors given in the code to calculate the stress intensity factors at the deepest point of the crack and near the free surface. Correction factors are given for a range of values of relative crack depth and crack shape. In a pressurized thick-walled cylinder the stresses of interest are the tangential stresses due to internal pressure as given by the Lame Equations, plus the effect of the pressure in the crack. This paper shows that the Lame stresses, as a function of distance from the inner surface, can be accurately fitted with a simple set of cubic equations over the full wall thickness for a wide range of diameter ratios. The coefficients of these equations, combined with the correction factors, are used to calculate stress intensity factors for a range of diameter ratios and at both the deepest point of the crack and near the free surface. The results are compared with stress intensity factors calculated using the linearized stress method proposed by Kendall and Perez. The effect of the plastic zone correction given in the new method is reported. The stress intensity factors due to autofrettage residual stresses calculated by the new method are also reported.

  10. Uncertainty induced by chest wall thickness assessment methods on lung activity estimation for plutonium and americium: a large population-based study.

    PubMed

    Broggio, D; Lechaftois, X; Franck, D

    2015-03-01

    In vivo lung counting aims at assessing the retained activity in the lungs. The calibration factor relating the measured counts to the worker's specific retained lung activity can be obtained by several means and strongly depends on the chest wall thickness. Here we compare, for 374 male nuclear workers, the activity assessed with a reference protocol, where the material equivalent chest wall thickness is known from ultrasound measurements, with two other protocols. The counting system is an array of four germanium detectors.It is found that non site-specific equations for the assessment of the chest wall thickness induce large biases in the assessment of activity. For plutonium isotopes or (241)Am the proportion of workers for whom the retained activity is within ± 10% of the reference one is smaller than 10%.The use of site-specific equations raises this proportion to 20% and 58% for plutonium and (241)Am, respectively.Finally, for the studied population, when site-specific equations are used for the chest wall thickness, the standard uncertainties for the lung activity are 42% and 12.5%, for plutonium and (241)Am, respectively. Due to the relatively large size of the studied population, these values are a relatively robust estimate of the uncertainties due to the assessment of the chest wall thickness for the current practice at this site. PMID:25517347

  11. Wall irregularity rather than intima-media thickness is associated with nearby atherosclerosis.

    PubMed

    Graf, Iulia M; Schreuder, Floris H B M; Hameleers, Jeroen M; Mess, Werner H; Reneman, Robert S; Hoeks, Arnold P G

    2009-06-01

    In addition to intima-media thickness (IMT), IMT inhomogeneity may carry information about atherosclerosis progression. In 147 vascular diseased patients (mean 66 y, 48% male), we determined the carotid bulb stenosis degree based on local Doppler blood flow velocities. Common carotid artery (CCA) morphologic characteristics, i.e. IMT, IMT-inhomogeneity (intraregistration variation) and IMT uni- and bilateral intrasubject variation (DeltaIMT), were measured using multiple M-mode. Associations of morphologic characteristics, stenosis degree and Framingham score were evaluated with Pearson correlation (r) and multiple regression analysis. The IMT distributions for subjects without and with stenosis were not similar. The stenosis degree score correlated significantly to unilateral (r=0.68) and bilateral DeltaIMT (r=0.62), IMT (r=0.41) and IMT-inhomogeneity (r=0.45). The averaged IMT and IMT-inhomogeneity increased slightly for singular stenosis and abruptly for multiple stenoses. Mean uni- and bilateral DeltaIMT per stenosis degree increased linearly with this degree, reaching a correlation close to 1 (r=0.98 and r=0.97). Interestingly, the majority of the subjects with a moderate to severe bulb stenosis exhibited a carotid IMT lower than the considered critical threshold of 0.9 mm. In conclusion, although CCA is not prone to plaques, its morphologic characteristics are positively correlated with stenosis degree score and other risk scores. DeltaIMT can be more reliable derived from inter-registration rather than from intra-registration variation. In the CCA, DeltaIMT substantiates vascular alteration better than IMT. PMID:19251354

  12. Effect of material properties on the strain to failure of thick-walled cylinders subjected to internal pressure

    SciTech Connect

    Roach, D.P.; Priddy, T.G. )

    1994-05-01

    The determination of the fully plastic response and pressure limit of a pressure vessel is of considerable importance in design, especially in autofrettage considerations. This paper presents the results of an experimental study which measured the maximum internal pressure which can be applied to thick-walled cylindrical vessels. Both aluminum and steel, with material properties ranging from ductile to brittle, were tested at stress levels through plastic and strain hardening ranges to fracture. From these tests, the pressure-expansion and through-thickness yielding characteristics were determined for these specimens. It is shown that a strain-to-failure criterion, based on the triaxiality of stress in the critical region, can be used to predict the complete pressure versus strain relations and maximum pressure for these cylinders. A simple tension-true stress-strain relation of the material is employed to analytically predict the response of the cylinder into the plastic regime. Finally, simplified theoretical and empirical formulas for bursting pressures are checked against the experimental results.

  13. Abdominal Adhesions

    MedlinePlus

    ... Abdominal Adhesions 1 Ward BC, Panitch A. Abdominal adhesions: current and novel therapies. Journal of Surgical Research. 2011;165(1):91– ... are abdominal adhesions and intestinal obstructions ... generally do not require treatment. Surgery is the only way to treat abdominal ...

  14. Recurrent incisional hernia, enterocutaneous fistula and loss of the substance of the abdominal wall: plastic with organic prosthesis, skin graft and VAC therapy. Clinical case.

    PubMed

    Nicodemi, Sara; Corelli, Sergio; Sacchi, Marco; Ricciardi, Edoardo; Costantino, Annarita; Di Legge, Pietro; Ceci, Francesco; Cipriani, Benedetta; Martellucci, Annunziata; Santilli, Mario; Orsini, Silvia; Tudisco, Antonella; Stagnitti, Franco

    2015-01-01

    Surgical wounds dehiscence is a serious post-operatory complication, with an incidence between 0.4% and 3.5%. Mortality is more than 45%. Complex wounds treatment may require a multidisciplinary management. VAC Therapy could be an alternative treatment regarding complex wound. VAC therapy has been recently introduced on skin's graft tissue management reducing skin graft rejection. The use of biological prosthesis has been tested in a contaminated field, better than synthetic meshes, which often need to be removed. The Permacol is more resistant to degradation by proteases due to its cross-links. Surgery is still considered the best treatment for digestive fistula. A 58 years old obese woman come to our attention, she was operated for an abdominal hernia. She had a post-operatory entero-cutaneous fistula. She was submitted to bowel resection, the anastomosis has been tailored and the hernia of the abdominal wall has been repaired with biological mesh for managing such condition. She had a wound dehiscence with loss of substance and the exposure of the biological prosthesis, nearly 20 cm diameter. She was treated first with antibiotic therapy and simple medications. In addiction, antibiotic therapy was necessary late associated to 7 months with advanced medications allowed a small reduction's defect. Because of its, treatment went on for two more months using VAC therapy. Antibiotic's therapy was finally suspended. The VAC therapy allowed the reduction of the gap, between skin and subcutaneous tissue, and the defect's size preparing a suitable ground for the skin graft. The graft, managed with the vac therapy, was necessary to complete the healing process. PMID:25953007

  15. Open repair of large abdominal wall hernias with and without components separation; an analysis from the ACS-NSQIP database

    PubMed Central

    Desai, Nirav K.; Leitman, I. Michael; Mills, Christopher; Lavarias, Valentina; Lucido, David L.; Karpeh, Martin S.

    2016-01-01

    Background Components separation technique emerged several years ago as a novel procedure to improve durability of repair for ventral abdominal hernias. Almost twenty-five years since its initial description, little comprehensive risk adjusted data exists on the morbidity of this procedure. This study is the largest analysis to date of short-term outcomes for these cases. Methods The ACS-NSQIP database identified open ventral or incisional hernia repairs with components separation from 2005 to 2012. A data set of cohorts without this technique, matched for preoperative risk factors and operative characteristics, was developed for comparison. A comprehensive risk-adjusted analysis of outcomes and morbidity was performed. Results A total of 68,439 patients underwent open ventral hernia repair during the study period (2245 with components separation performed (3.3%) and 66,194 without). In comparison with risk-adjusted controls, use of components separation increased operative duration (additional 83 min), length of stay (6.4 days vs. 3.8 days, p < 0.001), return to the OR rate (5.9% vs. 3.6%, p < 0.001), and 30-day morbidity (10.1% vs. 7.6%, p < 0.001) with no increase in mortality (0.0% in each group). Conclusions Components separation technique for large incisional hernias significantly increases length of stay and postoperative morbidity. Novel strategies to improve short-term outcomes are needed with continued use of this technique. PMID:27158489

  16. The heart's fibre alignment assessed by comparing two digitizing systems. Methodological investigation into the inclination angle towards wall thickness.

    PubMed

    Lunkenheimer, P P; Redmann, K; Dietl, K H; Cryer, C; Richter, K D; Whimster, W F; Niederer, P

    1997-04-01

    Myocardial contractile pathways which are not aligned strictly parallel to the heart's epicardial surface, give rise to forces which also act in the ventricular dilating direction. We developed a method which allows us to assess any fibre orientation in the three-dimensional myocardial weave. Decollagenized hearts were prepared by peeling-off fibre strands, following their main fibre orientation down to near the endocardium. In the subepicardium the strands followed a course more or less parallel to the epicardium, whereas from the mid-wall on they tended to dive progressively deeper into the wall. The preparation displays more or less rugged surfaces rather than smooth layers. The grooves and crests on the exposed surfaces were sequentially digitized by two methods: (1) Using a magnet tablet (3 Draw Digitizer System, Polhemus, Cochester VTO 5446, USA) on a dilated pig heart we manually followed the crests using a stylus, handling each groove and crest as an individual contractile pathway. (2) A constricted cow heart was digitized using a contact-free optical system (opto TOP, Dr. Breuckmann, Meersburg, Germany), which is based on the principle of imaging triangulation. Using specially developed software the inclination angles of selected crests and grooves with respect to the epicardial surface were calculated. The two digitizing methods yield comparable results. We found a depth- and side-specific weave component inclined to the epi-endocardial direction. This oblique netting component was more pronounced in the inner 1/3 of the wall than in the subepicardium. The inclination angle probably increases with increasing wall thickness during the ejection period. Manual digitizing is an easy and fast method which delivers consistent results comparable with those obtained by the cumbersome high resolution optical method. The rationales for the assessment of transmural fibre inclination are (1) the putative existence of dilating forces inherent in the myocardial weave

  17. Component separation in abdominal trauma.

    PubMed

    Rawstorne, Edward; Smart, Christopher J; Fallis, Simon A; Suggett, Nigel

    2014-01-01

    Component separation is established for complex hernia repairs. This case presents early component separation and release of the anterior and posterior sheath to facilitate closure of the abdominal wall following emergency laparotomy, reinforcing the repair with a biological mesh. On Day 11 following an emergency laparotomy for penetrating trauma, this patient underwent component separation and release of the anterior and posterior sheath. An intra-abdominal biological mesh was secured, and the fascia and skin closed successfully. Primary abdominal closure can be achieved in patients with penetrating abdominal trauma with the use of component separation and insertion of intra-abdominal biological mesh, where standard closure is not possible. PMID:24876334

  18. Remodeling characteristics and collagen distribution in synthetic mesh materials explanted from human subjects after abdominal wall reconstruction: an analysis of remodeling characteristics by patient risk factors and surgical site classifications

    PubMed Central

    Cavallo, Jaime A.; Roma, Andres A.; Jasielec, Mateusz S.; Ousley, Jenny; Creamer, Jennifer; Pichert, Matthew D.; Baalman, Sara; Frisella, Margaret M.; Matthews, Brent D.

    2014-01-01

    Background The purpose of this study was to evaluate the associations between patient characteristics or surgical site classifications and the histologic remodeling scores of synthetic meshes biopsied from their abdominal wall repair sites in the first attempt to generate a multivariable risk prediction model of non-constructive remodeling. Methods Biopsies of the synthetic meshes were obtained from the abdominal wall repair sites of 51 patients during a subsequent abdominal re-exploration. Biopsies were stained with hematoxylin and eosin, and evaluated according to a semi-quantitative scoring system for remodeling characteristics (cell infiltration, cell types, extracellular matrix deposition, inflammation, fibrous encapsulation, and neovascularization) and a mean composite score (CR). Biopsies were also stained with Sirius Red and Fast Green, and analyzed to determine the collagen I:III ratio. Based on univariate analyses between subject clinical characteristics or surgical site classification and the histologic remodeling scores, cohort variables were selected for multivariable regression models using a threshold p value of ≤0.200. Results The model selection process for the extracellular matrix score yielded two variables: subject age at time of mesh implantation, and mesh classification (c-statistic = 0.842). For CR score, the model selection process yielded two variables: subject age at time of mesh implantation and mesh classification (r2 = 0.464). The model selection process for the collagen III area yielded a model with two variables: subject body mass index at time of mesh explantation and pack-year history (r2 = 0.244). Conclusion Host characteristics and surgical site assessments may predict degree of remodeling for synthetic meshes used to reinforce abdominal wall repair sites. These preliminary results constitute the first steps in generating a risk prediction model that predicts the patients and clinical circumstances for which non

  19. Numerical study of the coupling of two identification methods - thermal and electromagnetic - for the reconstruction of inclusions in thick walls

    NASA Astrophysics Data System (ADS)

    Le Touz, Nicolas; Dumoulin, Jean; Soldovieri, Francesco

    2016-04-01

    In this numerical study we present an approach allowing introducing a priori information in an identification method of internal thermal properties field for a thick wall using infrared thermography measurements. This method is based on a coupling with an electromagnetic reconstructing method which data are obtained from measurements of Ground Penetrating Radar (GPR) ([1], [2]). This new method aims at improving the accuracy of reconstructions performed by using only the thermal reconstruction method under quasi-periodic natural solicitation ([3], [4]). Indeed, these thermal reconstructions, without a priori information, have the disadvantage of being performed on the entire studied wall. Through the intake of information from GPR, it becomes possible to focus on the internal zones that may contain defects. These areas are obtained by defining subdomains around remarkable points identified with the GPR reconstruction and considered as belonging to a discontinuity. For thermal reconstruction without providing a priori information, we need to minimize a functional equal to a quadratic residue issued from the difference between the measurements and the results of the direct model. By defining search fields around these potential defects, and thus by forcing the thermal parameters further thereof, we provide information to the data to reconstruct. The minimization of the functional is then modified through the contribution of these constraints. We do not seek only to minimize a residue, but to minimize the overall residue and constraints, what changes the direction followed by the optimization algorithm in the space of thermal parameters to reconstruct. Providing a priori information may then allow to obtain reconstruction with higher residues but whose thermal parameters are better estimated, whether for locating potential defects or for the reconstructed values of these parameters. In particular, it is the case for air defects or more generally for defects having a

  20. Finite-element modelling of low-temperature autofrettage of thick-walled tubes of the austenitic stainless steel AISI 304 L: Part I. Smooth thick-walled tubes

    NASA Astrophysics Data System (ADS)

    Feng, H.; Mughrabi, H.; Donth, B.

    1998-01-01

    The stresses and strains introduced by low-temperature autofrettage of smooth thick-walled tubes made of the austenitic stainless steel AISI 304 L were modelled by the finite-element (FE) method. The objective was to show that low-temperature autofrettage is much more efficient than autofrettage at room temperature in enhancing the fatigue resistance by introducing a higher beneficial tangential (hoop) residual compressive stress at the inner part of the tube. Attention was paid to the influences of the autofrettage temperature and pressure, the work hardening and the reverse yielding on the residual stress components and on the total strain components of the tube. The FE calculations confirmed that more beneficial residual stress patterns can be attained by autofrettage at low rather than at room temperature. From the quantitative calculations, the optimal autofrettage temperature and pressure of the tube were concluded to be about 0965-0393/6/1/006/img1 and 4000 bar, respectively. The results of the calculations were shown to be in good agreement with recently measured data.

  1. Analysis of the Effect of Osteon Diameter on the Potential Relationship of Osteocyte Lacuna Density and Osteon Wall Thickness

    PubMed Central

    Skedros, John G.; Clark, Gunnar C.; Sorenson, Scott M.; Taylor, Kevin W.; Qiu, Shijing

    2011-01-01

    An important hypothesis is that the degree of infilling of secondary osteons (Haversian systems) is controlled by the inhibitory effect of osteocytes on osteoblasts, which might be mediated by sclerostin (a glycoprotein produced by osteocytes). Consequently, this inhibition could be proportional to cell number: relatively greater repression is exerted by progressively greater osteocyte density (increased osteocytes correlate with thinner osteon walls). This hypothesis has been examined, but only weakly supported, in sheep ulnae. We looked for this inverse relationship between osteon wall thickness (On.W.Th) and osteocyte lacuna density (Ot.Lc.N/B.Ar) in small and large osteons in human ribs, calcanei of sheep, deer, elk, and horses, and radii and third metacarpals of horses. Analyses involved: (1) all osteons, (2) smaller osteons, either ≤150μm diameter or ≤ the mean diameter, and (3) larger osteons (>mean diameter). Significant, but weak, correlations between Ot.Lc.N/B.Ar and On.W.Th/On.Dm (On.Dm = osteon diameter) were found when considering all osteons in limb bones (r values −0.16 to −0.40, p<0.01; resembling previous results in sheep ulnae: r= −0.39, p<0.0001). In larger osteons, these relationships were either not significant (five/seven bone types) or very weak (two/seven bone types). In ribs, a negative relationship was only found in smaller osteons (r= −0.228, p<0.01); this inverse relationship in smaller osteons did not occur in elk calcanei. These results do not provide clear or consistent support for the hypothesized inverse relationship. However, correlation analyses may fail to detect osteocyte-based repression of infilling if the signal is spatially non-uniform (e.g., increased near the central canal). PMID:21809466

  2. Left ventricular wall thickness in patients with hypertrophic cardiomyopathy: a comparison between cardiac magnetic resonance imaging and echocardiography.

    PubMed

    Corona-Villalobos, Celia P; Sorensen, Lars L; Pozios, Iraklis; Chu, Linda; Eng, John; Abraham, Maria Roselle; Abraham, Theodore P; Kamel, Ihab R; Zimmerman, Stefan L

    2016-06-01

    We assessed whether cardiac MRI (CMR) and echocardiography (echo) have significant differences measuring left ventricular (LV) wall thickness (WT) in hypertrophic cardiomyopathy (HCM) as performed in the clinical routine. Retrospectively identified, clinically diagnosed HCM patients with interventricular-septal (IVS) pattern hypertrophy who underwent CMR and echo within the same day were included. Left Ventricular WT was measured by CMR in two planes and compared to both echo and contrast echo (cecho). 72 subjects, mean age 50.7 ± 16.2 years, 68 % males. Interventricular septal WT by echo and CMR planes showed good to excellent correlation. However, measurements of the postero-lateral wall showed poor correlation. Bland-Altman plots showed greater maximal IVS WT by echo compared to CMR measurement [SAX = 1.7 mm (-5.8, 9.3); LVOT = 1.1 mm (-5.6, 7.8)]. Differences were smaller between cecho and CMR [SAX = 0.8 mm (-9.2, 10.8); LVOT = -0.2 mm (-10.0, 9.6)]. Severity of WT by quartiles showed greater differences between echo and SAX CMR WT compared to cecho. Echocardiography typically measures greater WT than CMR, with the largest differences in moderate to severe hypertrophy. Contrast echocardiography more closely approximates CMR measurements of WT. These findings have potential clinical implications for risk stratification of subjects with HCM. PMID:26896038

  3. Associations of Anger, Anxiety and Depressive symptoms with Carotid Arterial Wall Thickness: the Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Ohira, Tetsuya; Diez Roux, Ana V.; Polak, Joseph F.; Homma, Shunichi; Iso, Hiroyasu; Wasserman, Bruce A.

    2015-01-01

    Objective Carotid arterial wall thickness, measured as intima-media thickness (IMT), is an early subclinical indicator of cardiovascular disease. Few studies have investigated the association of psychological factors with IMT across multiple ethnic groups and by gender. Methods We included 6,561 men and women (2,541 whites, 1,790 African Americans, 1,436 Hispanics, and 794 Chinese) aged 45 to 84 years who took part in the first examination of the Multi-Ethnic Study of Atherosclerosis. Associations of trait anger, trait anxiety, and depressive symptoms with mean values of common carotid artery (CCA) and internal carotid artery (ICA) IMTs were investigated using multivariable regression and logistic models. Results In age, gender, race/ethnicity-adjusted analyses, the trait anger score was positively associated with CCA and ICA IMTs (mean differences per one SD increment of trait anger score were 0.014 (95% CI, 0.003–0.025, p=0.01) and 0.054 (0.017–0.090, p=0.004) for CCA and ICA IMTs respectively). Anger was also associated with the presence of carotid plaque (age, gender, and race/ethnicity-adjusted odds ratio per one SD increase in trait anger: 1.27 (95%CI, 1.06–1.52)). The associations of the trait anger score with thicker IMT was attenuated after adjustment for covariates, but remained statistically significant. Associations were stronger in men than in women and in whites than in other race/ethnic groups but heterogeneity was only marginally statistically significant by race/ethnicity. There was no association of depressive symptoms or trait anxiety with IMT. Conclusions Only one of the three measures examined was associated with IMT and the patterns appeared to be heterogeneous across race/ethnic groups. PMID:22511725

  4. Welding for testability: An approach aimed at improving the ultrasonic testing of thick-walled austenitic and dissimilar metal welds

    NASA Astrophysics Data System (ADS)

    Wagner, Sabine; Dugan, Sandra; Barth, Martin; Schubert, Frank; Köhler, Bernd

    2014-02-01

    Austenitic and dissimilar welds in thick walled components show a coarse grained, dendritic microstructure. Therefore, ultrasonic testing has to deal with beam refraction, scattering and mode conversion effects. As a result, the testing techniques typically applied for isotropic materials yield dissatisfying results. Most approaches for improvement of ultrasonic testing have been based on modeling and improved knowledge of the complex wave propagation phenomena. In this paper, we discuss an alternative approach: is it possible to use a modified welding technology which eliminates the cause of the UT complications, i.e. the large-grained structure of the weld seams? Various modification parameters were tested, including: TIG current pulsing, additional DC and AC magnetic fields, and also additional external vibrations during welding. For all welds produced under different conditions, the grain structure of the weld seam was characterized by optical and GIUM microstructure visualizations on cross sections, wave field propagation measurements, and ultrasonic tests of correct detectability of flaws. The mechanical properties of the welds were also tested.

  5. Welding for testability: An approach aimed at improving the ultrasonic testing of thick-walled austenitic and dissimilar metal welds

    SciTech Connect

    Wagner, Sabine; Dugan, Sandra; Barth, Martin; Schubert, Frank; Köhler, Bernd

    2014-02-18

    Austenitic and dissimilar welds in thick walled components show a coarse grained, dendritic microstructure. Therefore, ultrasonic testing has to deal with beam refraction, scattering and mode conversion effects. As a result, the testing techniques typically applied for isotropic materials yield dissatisfying results. Most approaches for improvement of ultrasonic testing have been based on modeling and improved knowledge of the complex wave propagation phenomena. In this paper, we discuss an alternative approach: is it possible to use a modified welding technology which eliminates the cause of the UT complications, i.e. the large-grained structure of the weld seams? Various modification parameters were tested, including: TIG current pulsing, additional DC and AC magnetic fields, and also additional external vibrations during welding. For all welds produced under different conditions, the grain structure of the weld seam was characterized by optical and GIUM microstructure visualizations on cross sections, wave field propagation measurements, and ultrasonic tests of correct detectability of flaws. The mechanical properties of the welds were also tested.

  6. Mechanical Performance and Failure Mechanism of Thick-walled Composite Connecting Rods Fabricated by Resin Transfer Molding Technique

    NASA Astrophysics Data System (ADS)

    Liu, Gang; Luo, Chuyang; Zhang, Daijun; Li, Xueqin; Qu, Peng; Sun, Xiaochen; Jia, Yuxi; Yi, Xiaosu

    2015-08-01

    A resin transfer molding technique was used to fabricate thick-walled composite connecting rods, and then the mechanical performance of the connecting rod was studied experimentally, at the same time the stress and failure index distributions were simulated numerically. The experimental results show that under a tensile load, the connecting rod first cracks near the vertex of the triangle areas at the two ends, and then the damage propagates along the interface between the main bearing beam and the triangle area as well as along the round angle of the triangle area. Whereas under a compressive load, the delamination primarily occurs at the corner of the U-shaped flange, and the final destruction is caused by the fracture of fibers in the main bearing beam. The simulated results reveal that the tensile failure is originated from the delamination at the round angle transition areas of the T-joints, and the failure strength is determined by the interlaminar strength. Whereas the compressive failure is caused by the fracture of fibers in the main bearing beam, and the failure strength of the structure is determined by the longitudinal compressive strength of the composite material. The simulated results are basically consistent with the experimental results. Hence the mechanical performance and failure mechanism of the complicated composite structure are revealed in great detail through the coupling of the two kinds of research methods, which is helpful for the optimal design of composite structures.

  7. Human coronary plaque wall thickness correlated positively with flow shear stress and negatively with plaque wall stress: an IVUS-based fluid-structure interaction multi-patient study

    PubMed Central

    2014-01-01

    Background Atherosclerotic plaque progression and rupture are believed to be associated with mechanical stress conditions. In this paper, patient-specific in vivo intravascular ultrasound (IVUS) coronary plaque image data were used to construct computational models with fluid-structure interaction (FSI) and cyclic bending to investigate correlations between plaque wall thickness and both flow shear stress and plaque wall stress conditions. Methods IVUS data were acquired from 10 patients after voluntary informed consent. The X-ray angiogram was obtained prior to the pullback of the IVUS catheter to determine the location of the coronary artery stenosis, vessel curvature and cardiac motion. Cyclic bending was specified in the model representing the effect by heart contraction. 3D anisotropic FSI models were constructed and solved to obtain flow shear stress (FSS) and plaque wall stress (PWS) values. FSS and PWS values were obtained for statistical analysis. Correlations with p < 0.05 were deemed significant. Results Nine out of the 10 patients showed positive correlation between wall thickness and flow shear stress. The mean Pearson correlation r-value was 0.278 ± 0.181. Similarly, 9 out of the 10 patients showed negative correlation between wall thickness and plaque wall stress. The mean Pearson correlation r-value was -0.530 ± 0.210. Conclusion Our results showed that plaque vessel wall thickness correlated positively with FSS and negatively with PWS. The patient-specific IVUS-based modeling approach has the potential to be used to investigate and identify possible mechanisms governing plaque progression and rupture and assist in diagnosis and intervention procedures. This represents a new direction of research. Further investigations using more patient follow-up data are warranted. PMID:24669780

  8. A tale of two neglected systems—structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves

    PubMed Central

    Botha, C. E. J.

    2013-01-01

    There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However, there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate, and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled) and late (thick-walled) sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma (VP) cells, whilst the late metaphloem, contains thick-walled sieve tubes (TSTs) that lack companion cells. TSTs are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube (ST) -companion cell complexes, TSTs are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the STs. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5–7 million years old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer. PMID:23964280

  9. Abdominal mass

    MedlinePlus

    Several conditions can cause an abdominal mass: Abdominal aortic aneurysm can cause a pulsating mass around the navel. ... This could be a sign of a ruptured aortic aneurysm, which is an emergency condition. Contact your health ...

  10. Abdominal mass

    MedlinePlus

    ... Several conditions can cause an abdominal mass: Abdominal aortic aneurysm can cause a pulsating mass around the navel. ... This could be a sign of a ruptured aortic aneurysm, which is an emergency condition. Contact your health ...

  11. Management of voluminous abdominal incisional hernia.

    PubMed

    Bouillot, J-L; Poghosyan, T; Pogoshian, T; Corigliano, N; Canard, G; Veyrie, N

    2012-10-01

    Incisional hernia is one of the classic complications after abdominal surgery. The chronic, gradual increase in size of some of these hernias is such that the hernia ring widens to a point where there is a loss of substance in the abdominal wall, herniated organs can become incarcerated or strangulated while poor abdominal motility can alter respiratory function. The surgical treatment of small (<5 cm) incisional hernias is safe and straightforward, by either laparotomy or laparoscopy. For large hernias, surgical repair is often difficult. After reintegration of herniated viscera into the abdominal cavity, the abdominal wall defect must be closed anatomically in order to restore the function to the abdominal wall. Prosthetic reinforcement of the abdominal wall is mandatory for long-term successful repair. There are multiple techniques for prosthetic hernia repair, but placement of Dacron mesh in the retromuscular plane is our preference. PMID:23137643

  12. Anterior vaginal wall repair

    MedlinePlus

    Lentz GM. Anatomic defects of the abdominal wall and pelvic floor: abdominal and inguinal hernias, cystocele, urethrocele, ... uterine and vaginal prolapse: diagnosis and management. In: Lentz GM, Lobo RA, Gershenson DM, Katz VL, eds. ...

  13. JAMA Patient Page: Abdominal Hernia

    MedlinePlus

    ... an operation. Umbilical hernia Abdominal wall Intestinal loop Peritoneum Skin Peritoneum Umbilical annulus SYMPTOMS The first symptom of a ... vomiting, or constipation. Inguinal hernia Indirect inguinal hernia Peritoneum Deep inguinal ring Inguinal canal Superficial inguinal ring ...

  14. Method and apparatus to produce and maintain a thick, flowing, liquid lithium first wall for toroidal magnetic confinement DT fusion reactors

    DOEpatents

    Woolley, Robert D.

    2002-01-01

    A system for forming a thick flowing liquid metal, in this case lithium, layer on the inside wall of a toroid containing the plasma of a deuterium-tritium fusion reactor. The presence of the liquid metal layer or first wall serves to prevent neutron damage to the walls of the toroid. A poloidal current in the liquid metal layer is oriented so that it flows in the same direction as the current in a series of external magnets used to confine the plasma. This current alignment results in the liquid metal being forced against the wall of the toroid. After the liquid metal exits the toroid it is pumped to a heat extraction and power conversion device prior to being reentering the toroid.

  15. Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

    SciTech Connect

    Gomez-Cardona, Daniel; Nagle, Scott K.; Li, Ke; Chen, Guang-Hong; Robinson, Terry E.

    2015-10-15

    Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo{sup TM}, GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose

  16. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness.

    PubMed

    Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

    2015-01-01

    The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010-2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate. PMID:26305893

  17. High vancomycin MICs within the susceptible range in Staphylococcus aureus bacteraemia isolates are associated with increased cell wall thickness and reduced intracellular killing by human phagocytes.

    PubMed

    Falcón, Rocío; Martínez, Alba; Albert, Eliseo; Madrid, Silvia; Oltra, Rosa; Giménez, Estela; Soriano, Mario; Vinuesa, Víctor; Gozalbo, Daniel; Gil, María Luisa; Navarro, David

    2016-05-01

    Vancomycin minimum inhibitory concentrations (MICs) at the upper end of the susceptible range for Staphylococcus aureus have been associated with poor clinical outcomes of bloodstream infections. We tested the hypothesis that high vancomycin MICs in S. aureus bacteraemia isolates are associated with increased cell wall thickness and suboptimal bacterial internalisation or lysis by human phagocytes. In total, 95 isolates were evaluated. Original vancomycin MICs were determined by Etest. The susceptibility of S. aureus isolates to killing by phagocytes was assessed in a human whole blood assay. Internalisation of bacterial cells by phagocytes was investigated by flow cytometry. Cell wall thickness was evaluated by transmission electron microscopy. Genotypic analysis of S. aureus isolates was performed using a DNA microarray system. Vancomycin MICs were significantly higher (P=0.006) in isolates that were killed suboptimally (killing index <60%) compared with those killed efficiently (killing index >70%) and tended to correlate inversely (P=0.08) with the killing indices. Isolates in both killing groups were internalised by human neutrophils and monocytes with comparable efficiency. The cell wall was significantly thicker (P=0.03) in isolates in the low killing group. No genotypic differences were found between the isolates in both killing groups. In summary, high vancomycin MICs in S. aureus bacteraemia isolates were associated with increased cell wall thickness and reduced intracellular killing by phagocytes. PMID:27056298

  18. Accurate method for measurement of pipe wall thickness using a circumferential guided wave generated and detected by a pair of noncontact transducers

    NASA Astrophysics Data System (ADS)

    Nishino, H.; Taniguchi, Y.; Yoshida, K.

    2012-05-01

    A noncontact method of an accurate estimation of a pipe wall thickness using a circumferential (C-) Lamb wave is presented. The C-Lamb waves circling along the circumference of pipes are transmitted and received by the critical angle method using a pair of noncontact air-coupled ultrasonic transducers. For the accurate estimation of a pipe wall thickness, the accurate measurement of the angular wave number that changes minutely owing to the thickness must be achieved. To achieve the accurate measurement, a large number of tone-burst cycles are used so as to superpose the C-Lamb wave on itself along its circumferential orbit. In this setting, the amplitude of the superposed region changes considerably with the angular wave number, from which the wall thickness can be estimated. This paper presents the principle of the method and experimental verifications. As results of the experimental verifications, it was confirmed that the maximum error between the estimates and the theoretical model was less than 10 micrometers.

  19. Application of elastic wave dispersion relations to estimate thermal properties of nanoscale wires and tubes of varying wall thickness and diameter.

    PubMed

    Bifano, Michael F P; Kaul, Pankaj B; Prakash, Vikas

    2010-06-11

    This paper reports dependency of specific heat and ballistic thermal conductance on cross-sectional geometry (tube versus rod) and size (i.e., diameter and wall thickness), in free-standing isotropic non-metallic crystalline nanostructures. The analysis is performed using dispersion relations found by numerically solving the Pochhammer-Chree frequency equation for a tube. Estimates for the allowable phonon dispersion relations within the crystal lattice are obtained by modifying the elastic acoustic dispersion relations so as to account for the discrete nature of the material's crystal lattice. These phonon dispersion relations are then used to evaluate the specific heat and ballistic thermal conductance in the nanostructures as a function of the nanostructure geometry and size. Two major results are revealed in the analysis: increasing the outer diameter of a nanotube while keeping the ratio of the inner to outer tube radius (gamma) fixed increases the total number of available phonon modes capable of thermal population. Secondly, decreasing the wall thickness of a nanotube (i.e., increasing gamma) while keeping its outer diameter fixed, results in a drastic decrease in the available phonon mode density and a reduction in the frequency of the longitudinal and flexural acoustic phonon modes in the nanostructure. The dependency of the nanostructure's specific heat on temperature indicates 1D, 2D, and 3D geometric phonon confinement regimes. Transition temperatures for each phonon confinement regime are shown to depend on both the nanostructure's wall thickness and outer radius. Compared to nanowires (gamma = 0), the frequency reduction of acoustic phonon modes in thinner walled nanotubes (gamma = 0.96) is shown to elevate the ballistic thermal conductance of the thin-walled nanotube between 0.2 and 150 K. At 20 K, the ballistic thermal conductance of the thin-walled nanotube (gamma = 0.96) becomes 300% greater than that of a solid nanowire. For temperatures above

  20. In the femoral artery bifurcation, differences in mean wall shear stress within subjects are associated with different intima-media thicknesses.

    PubMed

    Kornet, L; Hoeks, A P; Lambregts, J; Reneman, R S

    1999-12-01

    In elastic arteries, intima-media thickening is more pronounced in areas with low than with high mean and peak wall shear stress. These findings in elastic arteries are not necessarily representative of the situation in muscular arteries. The former arteries have to store volume energy, whereas the latter are mainly conductive vessels. It was the aim of the present study to investigate noninvasively whether differences in wall shear stress within a muscular artery bifurcation, if any, were associated with different intima-media thicknesses (IMTs). The effect of age on the possible differences was assessed as well. We determined IMT and mean, peak systolic, and the maximum cyclic change in shear stress near the posterior wall in the common (FC) and the superficial (FS) femoral artery 20 to 30 mm from the flow divider in 54 presumed healthy subjects between 21 and 74 years of age. Results were considered in terms of intrasubject differences. Before the study, the reliability of the ultrasonic system to assess wall shear rate and IMT was determined in terms of intrasubject variability. IMT at the posterior wall was significantly larger in the FC than in the FS, probably owing to the significantly lower mean wall shear stress at this site in the FC. The relative differences in IMT and mean wall shear stress between FC and FS were independent of age. The difference in wall shear stress between both arteries can likely be explained by a different influence of reflections. In both the FC and FS, mean, peak systolic, and maximum cyclic change in shear stress near the posterior wall did not change significantly with age, whereas IMT did increase significantly with age. PMID:10591672

  1. Abdominal wall fat pad biopsy

    MedlinePlus

    ... J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also ... URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  2. Precise Measurement of Pipe Wall Thickness in Noncontact Manner Using a Circumferential Lamb Wave Generated and Detected by a Pair of Air-Coupled Transducers

    NASA Astrophysics Data System (ADS)

    Nishino, Hideo; Asano, Tadashi; Taniguchi, Yuta; Yoshida, Kenichi; Ogawa, Hitoshi; Takahashi, Masakazu; Ogura, Yukio

    2011-07-01

    In this paper, we present a novel method of accurately estimating pipe wall thickness by detecting the minute difference in the angular wave number of a circumferential (C-) Lamb wave. A C-Lamb wave circling along a circumference of a pipe is transmitted and received by a pair of noncontact air-coupled ultrasonic transducers. For the accurate detection of the angular wave number, a large number of tone-burst cycles are used so as to superpose the C-Lamb wave on itself along its circumferential orbit. In this setting, the amplitude of the superposed region changes considerably with the angular wave number, from which the wall thickness can be estimated. This method is very useful to monitor the integrity of piping in high-temperature environments because of its noncontact nature. The principle of the method and experimental verification are shown.

  3. An experimental investigation of lead zirconate titanate--epoxy-multi-walled carbon nanotube bulk and flexible thick film composites

    NASA Astrophysics Data System (ADS)

    Banerjee, Sankha

    Piezoelectric sensors and actuators are needed for a wide range of applications from physiological measurement to industrial monitoring systems. Sensors that can be easily integrated with the host, while maintaining high sensitivity and reliability over a wide range of frequencies are not readily feasible and economical with homogenous piezoelectric materials. It is well known that two-phase piezoelectric-epoxy composites offer several benefits over their single phase counterparts, as the properties of the constituent phases combine to improve the range of applicability. However, the piezoelectric properties of these materials suffer from the electrically insulating properties of the epoxy matrix. The electrical properties of the matrix may be enhanced by including electrically conducting inclusions however, less is known about the mechanisms that drive the changes in these properties. Hence, this experimental investigation of sensor materials builds on the previous work in two-phase piezoelectric composites, where the aims are to understand the roles that specific fabrication parameters and inclusion composition play in determining the piezoelectric and dielectric performance the aforementioned composites. The materials under investigation will be comprised of Lead Zirconate Titanate, Epofix Cold-Setting Embedding Resin and multi-walled carbon nanotubes, i.e. the piezoelectric, epoxy and electrical inclusions respectively. Our work suggests that inclusion of MWCNTs enhances the piezoelectric and dielectric properties with increasing volume fraction below the percolation threshold. This work seeks to understand how the processing parameters: poling temperature, poling type and particle distribution influence the contact resistance, space charge double layer at the piezoelectric and conductor interfaces and electric field intensity at the piezoelectric boundary, which all ultimately dictate the piezoelectric and dielectric performance of the composite materials

  4. [Differential diagnosis of abdominal pain].

    PubMed

    Frei, Pascal

    2015-09-01

    Despite the frequency of functional abdominal pain, potentially dangerous causes of abdominal pain need to be excluded. Medical history and clinical examination must focus on red flags and signs for imflammatory or malignant diseases. See the patient twice in the case of severe and acute abdominal pain if lab parameters or radiological examinations are normal. Avoid repeated and useless X-ray exposure whenever possible. In the case of subacute or chronic abdominal pain, lab tests such as fecal calprotectin, helicobacter stool antigen and serological tests for celiac disease are very useful. Elderly patients may show atypical or missing clinical signs. Take care of red herrings and be skeptical whether your initial diagnosis is really correct. Abdominal pain can frequently be an abdominal wall pain. PMID:26331201

  5. [New echocardiographic para-apical technic for determining the size and thickness of the wall of the right ventricle in probands and patients with dilated cardiomyopathy].

    PubMed

    Dyczynski, J; Schweitzer, L

    1987-12-01

    To evaluate the right ventricular size and free wall thickness a new echocardiographic para-apical technique was developed. All cases were examined from the para-apical window in the extreme left lateral decubitus position, on a special mattress that allowed us to investigate the total apical region. The para-apical transducer position makes it possible to cut the right ventricle cross-sectionally in serial bread-loafing fashion from the apex to the base, like the left ventricle. In this way, using the M-mode technique, either diameters and/or right ventricular free wall thickness as well as shortening fraction could be estimated. To estimate the usefulness of the para-apical technique, a study was performed in 50 normal subjects as well as in 16 patients with dilated cardiomyopathy. In all patients, standard views and the new para-apical view were performed. In five cases, contrast echocardiography of the heart was performed to verify the right-heart anatomy. In five patients, computer-tomography of the heart was performed to see the position of the right-heart chambers in the chest and to evaluate the new para-apical ultrasound window. The standard values for the right ventricle in the control group were (in mean values): diastolic diameter, 28.61 +/- 3.19 mm; systolic diameter, 19.10 +/- 2.40 mm; free wall thickness, 4.46 +/- 1.06 mm and shortening fraction, 32.42% +/- 4.02%. The examined parameters in patients with dilated cardiomyopathy were: diastolic diameter, mean value 38.63 +/- 5.80 mm; systolic diameter, mean value 32.48 +/- 4.96 mm; free wall thickness, mean value 8.70 +/- 1.05 mm and shortening fraction, mean value 15.96 +/- 4.02%.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3439250

  6. A historically controlled, single-arm, multi-centre, prospective trial to evaluate the safety and efficacy of MonoMax® suture material for abdominal wall closure after primary midline laparotomy. ISSAAC-Trial [NCT005725079

    PubMed Central

    Fischer, Lars; Baumann, Petra; Hüsing, Johannes; Seidlmayer, Christoph; Albertsmeier, Markus; Franck, Annette; Luntz, Steffen; Seiler, Christoph M; Knaebel, Hanns-Peter

    2008-01-01

    Background Several randomized controlled trials have compared different suture materials and techniques for abdominal wall closure with respect to the incidence of incisional hernias after midline laparotomy and shown that it remains, irrespective of the methods used, considerably high, ranging from 9% to 20%. The development of improved suture materials which would reduce postoperative complications may help to lower its frequency. Design This is a historically controlled, single-arm, multi-centre, prospective trial to evaluate the safety of MonoMax® suture material for abdominal wall closure in 150 patients with primary elective midline incisions. INSECT patients who underwent abdominal closure using Monoplus® and PDS® will serve as historical control group. The incidences of wound infections and of burst abdomen are defined as composite primary endpoints. Secondary endpoints are the frequency of incisional hernias within one year after operation and safety. To ensure adequate comparability in surgical performance and recruitment, the 4 largest centres of the INSECT-Trial will participate. After hospital discharge, the investigators will examine the enrolled patients again at 30 days and at 12 ± 1 months after surgery. Conclusion This historically controlled, single-arm, multi-centre, prospective ISSAAC trial aims to assess whether the use of an ultra-long-lasting absorbable monofilament suture material is safe and efficient. Trial registration NCT005725079 PMID:18644124

  7. Ultrasonographic characteristics of the abdominal esophagus and cardia in dogs.

    PubMed

    Gory, Guillaume; Rault, Delphine N; Gatel, Laure; Dally, Claire; Belli, Patrick; Couturier, Laurent; Cauvin, Eddy

    2014-01-01

    Differential diagnoses for regurgitation and vomiting in dogs include diseases of the gastroesophageal junction. The purpose of this cross-sectional study was to describe ultrasonographic characteristics of the abdominal esophagus and gastric cardia in normal dogs and dogs with clinical disease involving this region. A total of 126 dogs with no clinical signs of gastrointestinal disease and six dogs with clinical diseases involving the gastroesophageal junction were included. For seven euthanized dogs, ultrasonographic features were also compared with gross pathology and histopathology. Cardial and abdominal esophageal wall thicknesses were measured ultrasonographically for all normal dogs and effects of weight, sex, age, and stomach filling were tested. Five layers could be identified in normal esophageal and cardial walls. The inner esophageal layer was echogenic, corresponding to the cornified mucosa and glandular portion of the submucosa. The cardia was characterized by a thick muscularis, and a transitional zone between echogenic esophageal and hypoechoic gastric mucosal layers. Mean (±SD) cardial wall thicknesses for normal dogs were 7.6 mm (±1.6), 9.7 mm (±1.8), 10.8 mm (±1.6), 13.3 mm (±2.5) for dogs in the <10 kg, 10-19.9 kg, 20-29.9 kg and ≥30 kg weight groups, respectively. Mean (±SD) esophageal wall thicknesses were: 4.1 mm (±0.6), 5.1 mm (±1.3), 5.6 mm (±1), and 6.4 mm (±1.1) for the same weight groups, respectively. Measurements of wall thickness were significantly correlated with dog weight group. Ultrasonography assisted diagnosis in all six clinically affected dogs. Findings supported the use of transabdominal ultrasonography as a diagnostic test for dogs with suspected gastroesophageal disease. PMID:24629089

  8. Fluid-structure interaction in abdominal aortic aneurysms: Structural and geometrical considerations

    NASA Astrophysics Data System (ADS)

    Mesri, Yaser; Niazmand, Hamid; Deyranlou, Amin; Sadeghi, Mahmood Reza

    2015-08-01

    Rupture of the abdominal aortic aneurysm (AAA) is the result of the relatively complex interaction of blood hemodynamics and material behavior of arterial walls. In the present study, the cumulative effects of physiological parameters such as the directional growth, arterial wall properties (isotropy and anisotropy), iliac bifurcation and arterial wall thickness on prediction of wall stress in fully coupled fluid-structure interaction (FSI) analysis of five idealized AAA models have been investigated. In particular, the numerical model considers the heterogeneity of arterial wall and the iliac bifurcation, which allows the study of the geometric asymmetry due to the growth of the aneurysm into different directions. Results demonstrate that the blood pulsatile nature is responsible for emerging a time-dependent recirculation zone inside the aneurysm, which directly affects the stress distribution in aneurismal wall. Therefore, aneurysm deviation from the arterial axis, especially, in the lateral direction increases the wall stress in a relatively nonlinear fashion. Among the models analyzed in this investigation, the anisotropic material model that considers the wall thickness variations, greatly affects the wall stress values, while the stress distributions are less affected as compared to the uniform wall thickness models. In this regard, it is confirmed that wall stress predictions are more influenced by the appropriate structural model than the geometrical considerations such as the level of asymmetry and its curvature, growth direction and its extent.

  9. Thickness estimation of the subcutaneous fat using coaxial probe.

    PubMed

    Ramezani, Mohammad Hossein; Nadimi, Esmaeil S

    2016-03-01

    In this Letter, a non-invasive method for thickness estimation of the subcutaneous fat layer of abdominal wall is presented by using a coaxial probe. Fat layer has the highest impact on the averaged attenuation parameter of the abdominal wall due to its high thickness and low permittivity. The abdominal wall is modelled as a multi-layer medium and an analytical model for the probe is derived by calculation of its aperture admittance facing to this multi-layer medium. The performance of this model is then validated by a numerical simulation using finite-difference-time-domain (FDTD) analysis. Simulation results show the high impact of the probe dimension and fat layer thickness on the sensitivity of the measured permittivity. The authors further investigate this sensitivity by statistical analysis of the permittivity variations. Finally, measuring in different locations relative to the body surface is presented as a solution to estimate the fat layer thickness in the presence of uncertainty of model parameters. PMID:27222737

  10. Interfacial heat transfer in squeeze casting of magnesium alloy AM60 with variation of applied pressures and casting wall-thicknesses

    NASA Astrophysics Data System (ADS)

    Zhang, Xuezhi; Fang, Li; Sun, Zhizhong; Hu, Henry; Nie, Xueyuan; Tjong, Jimi

    2015-12-01

    The heat transfer coefficient at the casting-die interface is the most important factor on the solidification process. With the 75-ton hydraulic press machine and P20 steel die mold, 5-step castings of magnesium alloy AM60 with different wall-thicknesses (3, 5, 8, 12, 20 mm) were poured under various hydraulic pressures (30, 60, and 90 MPa) using an indirect squeeze casting process. Thermal histories throughout the die wall and the casting surface have been recorded by fine type-K thermocouples. The in-cavity local pressures measured by pressure transducers were explored at the casting-die interfaces of 5 steps. The casting-die interfacial heat transfer coefficients (IHTC) initially reached a maximum peak value followed by a gradually decline to the lower level. Similar characteristics of IHTC peak values can be observed at the applied pressures of 30, 60 and 90 MPa. With the applied pressure of 90 MPa, the peak IHTC values from steps 1 to 5 varied from 5623 to 10,649 W/m2 K. As the applied hydraulic pressure increased, the IHTC peak value of each step was increased accordingly. The wall thickness also affected IHTC peak values significantly. The peak IHTC value and heat flux increased as the step became thicker. The empirical equations relating the IHTCs to the local pressures and the solidification temperature at the casting surface were developed based on the multivariate linear and polynomial regression.

  11. Reconstruction option of abdominal wounds with large tissue defects

    PubMed Central

    2014-01-01

    Background Abdominal wall defects result from trauma, abdominal wall tumors, necrotizing infections or complications of previous abdominal surgeries. Apart from cosmetics, abdominal wall defects have strong negative functional impact on the patients. Many different techniques exist for abdominal wall repair. Most problematic and troublesome are defects, where major part of abdominal wall had to be resected and tissue for transfer or reconstruction is absent. Case presentation Authors of the article present operative technique, in which reconstruction of abdominal wall was managed by composite polypropylene mesh with absorbable collagen film, creation of granulation tissue with use of NPWT (negative pressure wound therapy), and subsequent split skin grafting. Three patients with massive abdominal wall defect were successfully managed and abdominal wall reconstruction was performed by mentioned technique. Functional and cosmetic effect is acceptable and patients have good postoperative quality of life. Conclusions Patients with giant abdominal defects can benefit from described technique. It serves as the only option, with which abdominal wall is fully reconstructed without need for the secondary intervention. PMID:25103782

  12. Analysis of Round Robin Test for Ultrasonic Thickness Measurement of Wall Thinned Pipe in Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Hoon; Lee, Seung-Joon; Lee, Joon-Hyun; Lee, Sung-Ho

    2008-02-01

    It is well recognized that one of the most serious problems on the maintenance of piping system in Nuclear Power Plants (NPPs) is the wall thinning of carbon steel pipe components. The objective of this research is to verify confidence of wall thinning measurement system by conducting Round Robin Test (RRT). 23 specimens with different size and shape of pipe were used according to standard practice in RRT. The gage R&R analysis was introduced for each sigma quality level, so that repeatability and reproducibility can be estimated from RRT results.

  13. Abdominal sounds

    MedlinePlus

    ... during sleep. They also occur normally for a short time after the use of certain medicines and after abdominal surgery. Decreased or absent bowel sounds often indicate constipation. Increased ( hyperactive ) bowel sounds ...

  14. Abdominal MRI

    MedlinePlus

    ... provider if you have: Artificial heart valves Brain aneurysm clips Heart defibrillator or pacemaker Inner ear (cochlear) ... which the test may be performed: Abdominal aortic aneurysm Atheroembolic renal disease Carcinoma of the renal pelvis ...

  15. Abdominal pain

    MedlinePlus

    ... threatening conditions, such as colon cancer or early appendicitis , may only cause mild pain or no pain. ... Food poisoning Stomach flu Other possible causes include: Appendicitis Abdominal aortic aneurysm (bulging and weakening of the ...

  16. Abdominal Pain

    MedlinePlus

    ... can help the overall situation for the child. Teaching kids self-hypnosis [8] or guided imagery [8a] ... related topics? Functional Abdominal Pain (English, French or Spanish)—from The North American Society for Pediatric Gastroenterology, ...

  17. Development of a Versatile Laser-Ultrasonic System and Application to the Online Measurement for Process Control of Wall Thickness and Eccentricity of Seamless Tubes

    SciTech Connect

    Robert V. Kolarik II

    2002-10-23

    A system for the online, non-contact measurement of wall thickness in steel seamless mechanical tubing has been developed and demonstrated at a tubing production line at the Timken Company in Canton, Ohio. The system utilizes laser-generation of ultrasound and laser-detection of time of flight with interferometry, laser-doppler velocimetry and pyrometry, all with fiber coupling. Accuracy (<1% error) and precision (1.5%) are at targeted levels. Cost and energy savings have exceeded estimates. The system has shown good reliability in measuring over 200,000 tubes in its first six months of deployment.

  18. Measurements of core and compressed-shell temperature and density conditions in thick-wall target implosions at the OMEGA laser facility

    SciTech Connect

    Florido, R.; Mancini, R. C.; Nagayama, T.; Tommasini, R.; Delettrez, J. A.; Regan, S. P.; Yaakobi, B.

    2011-06-15

    A spectroscopic method is discussed to measure core and compressed-shell conditions in thick-wall plastic-shell implosions filled with deuterium and a tracer amount of argon. Simultaneous observation over a broad photon energy range of the argon line emission and the attenuation and self-emission effects of the compressed shell confining the core yields enough information to extract average temperature and density conditions in both core and compressed shell. The spectroscopic analysis also provides an estimate of the target areal density which is an important characteristic of inertial confinement fusion implosions.

  19. Acute incarcerated external abdominal hernia

    PubMed Central

    Yang, Xue-Fei

    2014-01-01

    External abdominal hernia occurs when abdominal organs or tissues leave their normal anatomic site and protrude outside the skin through the congenital or acquired weakness, defects or holes on the abdominal wall, including inguinal hernia, umbilical hernia, femoral hernia and so on. Acute incarcerated hernia is a common surgical emergency. With advances in minimally invasive devices and techniques, the diagnosis and treatment have witnessed major changes, such as the use of laparoscopic surgery in some cases to achieve minimally invasive treatment. However, strict adherence to the indications and contraindications is still required. PMID:25489584

  20. Coating of multi-walled carbon nanotube with SnO 2 films of controlled thickness and its application for Li-ion battery

    NASA Astrophysics Data System (ADS)

    Wang, Zhenyao; Chen, Ge; Xia, Dingguo

    Multi-walled carbon nanotubes (MWCNTs) coated with a smooth and uniform tin oxide (SnO 2) layers of different thickness were prepared by a novel thioglycolic acid assisted one-step wet chemical method. The coatings were characterized by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thickness of the SnO 2 coatings can be easily controlled by changing the synthesis conditions, such as pH value of the solution and hydrolysis time. The electrochemical properties of the SnO 2/MWCNTs composites as anode materials for lithium batteries were studied by galvanostatic method. The composites showed high charge capacities and good durability against decay. This could be ascribed to the good dispersion, thin layer and small particle size of SnO 2 on MWCNTs.

  1. Relationship between the thickness of bronchial wall layers, emphysema score, and markers of remodeling in bronchoalveolar lavage fluid in patients with chronic obstructive pulmonary disease.

    PubMed

    Górka, Karolina; Soja, Jerzy; Jakieła, Bogdan; Plutecka, Hanna; Gross-Sondej, Iwona; Ćmiel, Adam; Mikrut, Sławomir; Łoboda, Piotr; Andrychiewicz, Anna; Jurek, Paulina; Sładek, Krzysztof

    2016-06-30

    INTRODUCTION    Airway remodeling plays an important role in the development of chronic obstructive pulmonary disease (COPD). Imaging methods, such as computed tomography (CT) and endobronchial ultrasound (EBUS), may be useful in the assessment of structural alterations in the lungs. OBJECTIVES    The aim of this study was to evaluate a relationship between the severity of emphysema assessed by chest CT, the thickness of bronchial wall layers measured by EBUS, and the markers of remodeling in bronchoalveolar lavage fluid (BALF) in patients with COPD. PATIENTS AND METHODS    The study included 33 patients with COPD who underwent pulmonary function tests, emphysema score assessment by chest CT, as well as bronchofiberoscopy with EBUS in order to measure the total bronchial wall thickness and, separately, layers L1, L2, and L3-5. Selected remodeling (matrix metalloproteinase 9 [MMP-9], tissue inhibitor of metalloproteinase 1, transforming growth factor β1 [TGF-β1]) and inflammatory markers (neutrophil elastase, eosinophil cationic protein) were measured in BALF samples using an enzyme-linked immunosorbent assay. RESULTS    MMP-9 levels in BALF were significantly higher in patients with very severe bronchial obstruction than in those with moderate and mild bronchial obstruction (P = 0.02), and showed a negative correlation with forced expiratory volume in 1 second (r = -0.538, P = 0.002). The thickness of L1 and L2, which histologically correspond to the mucosa, submucosa, and smooth muscle, demonstrated a positive correlation with TGF-β1 levels in BALF (r = 0.366, P = 0.046 and r = 0.425, P = 0.02) and the thickness of L1 showed a negative association with neutrophil elastase levels (r = -0.508, P = 0.004). There was no significant correlation between the analyzed markers in BALF and the emphysema score. CONCLUSIONS    Significant correlations of TGF-β1 and elastase with the thickness of bronchial wall layers, and of MMP-9 with the severity of

  2. Analysis of transient heat flow to thick-walled plates and cylinders. [to determine gas heat transfer coefficient

    NASA Technical Reports Server (NTRS)

    Powell, W. B.

    1973-01-01

    A methodology is described for the analysis of a transient temperature measurement made in a flat or curved plate subjected to convective heat transfer, such that the surface heat flux, the hot-gas temperture, and the gas heat transfer coefficient can be determined. It is shown that if the transient temperature measurement is made at a particular point located nearly midway in the thickness of the plate there is an important simplification in the data analysis process, in that the factor relating the surface heat flux to the measured rate of rise of temperature becomes invariant for a Fourier Number above 0.60 and for all values of the Biot Number. Parameters are derived, tabulated, and plotted which enable straightforward determination of the surface heat flux, the hot-gas temperature, of the plate, the rate of rise of temperature, the plate thickness and curvature, and the mean thermal properties of the plate material at the test temperature.

  3. Postherpetic pseudohernia: delayed onset of paresis of abdominal muscles due to herpes zoster causing an ipsilateral abdominal bulge.

    PubMed

    Ohno, Shunsuke; Togawa, Yasuhiro; Chiku, Tsuyoshi; Sano, Wataru

    2016-01-01

    Postherpetic pseudohernia causes an abdominal bulge as well as an abdominal wall herniation. This disease is one of the neurological complications of herpes zoster and essentially consists of paresis of ipsilateral abdominal muscles. Postherpetic pseudohernia may be mistaken for abdominal wall herniation because it is not well known. We describe two cases presenting an abdominal bulge. The ipsilateral abdominal bulge appeared after recovery from abdominal zoster. Abdominal CT showed no evidence of a herniation or mass. We diagnosed a postherpetic pseudohernia. One of the patients recovered spontaneously 4 months after the onset, and the other partially recovered after 2 months. This disease can be expected to disappear spontaneously, unlike abdominal herniation requiring surgery. It has been reported that 79.3% of patients eventually recovered spontaneously. For surgeons and general practitioners, it is beneficial to keep this disease in mind when examining a patient presenting an abdominal bulge. PMID:27229900

  4. Gold-Based Cubic Nanoboxes with Well-Defined Openings at the Corners and Ultrathin Walls Less Than Two Nanometers Thick.

    PubMed

    Sun, Xiaojun; Kim, Junki; Gilroy, Kyle D; Liu, Jingyue; König, Tobias A F; Qin, Dong

    2016-08-23

    We report a facile synthesis of Au-based cubic nanoboxes as small as 20 nm for the outer edge length, together with well-defined openings at the corners and walls fewer than 10 atomic layers (or <2 nm) in thickness. The success relies on the selective formation of Ag2O at the corners of Ag nanocubes, followed by the conformal deposition of Au on the side faces in a layer-by-layer fashion. When six atomic layers of Au are formed on the side faces to generate Ag@Au6L core-shell nanocubes, we can selectively remove the Ag2O patches at the corner sites using a weak acid, making it possible to further remove the Ag core by H2O2 etching without breaking the ultrathin Au shell. This synthetic approach works well for Ag nanocubes of 38 and 18 nm in edge length, and the wall thickness of the nanoboxes can be controlled down to 2 nm. The resultant Au nanoboxes exhibit strong plasmonic absorption in the near-infrared region, consistent with computational simulations. PMID:27458731

  5. Novel technique for full-thickness resection of gastric malignancy: feasibility of nonexposed endoscopic wall-inversion surgery (news) in porcine models.

    PubMed

    Mitsui, Takashi; Goto, Osamu; Shimizu, Nobuyuki; Hatao, Fumihiko; Wada, Ikuo; Niimi, Keiko; Asada-Hirayama, Itsuko; Fujishiro, Mitsuihiro; Koike, Kazuhiko; Seto, Yasuyuki

    2013-12-01

    Full-thickness resection for gastric malignancy carries a risk of peritoneal dissemination due to opening of the gastric lumen. We evaluated the feasibility and safety a novel method of full-thickness resection without transmural communication, called nonexposed endoscopic wall-inversion surgery in ex vivo and in vivo porcine models. Six explanted porcine stomachs and 6 live pigs were used for this study. After marking and submucosal injection around 3 cm simulated lesions, the seromuscular layer was laparoscopically cut and sutured with the lesion inverted to the inside. Consecutively, a mucosubmucosal incision was made endoscopically. Three pigs used for the survival study were monitored for 7 days. All 12 lesions were successfully resected en bloc without perforation. The 3 pigs survived for 1 week without adverse events, and necropsy revealed neither leakage nor abscess formation related to the operation. We demonstrated nonexposed endoscopic wall-inversion surgery to be technically feasible and safe in both ex vivo and in vivo porcine studies. PMID:24300935

  6. Abdominal Sepsis.

    PubMed

    De Waele, Jan J

    2016-08-01

    Abdominal infections are an important challenge for the intensive care physician. In an era of increasing antimicrobial resistance, selecting the appropriate regimen is important and, with new drugs coming to the market, correct use is important more than ever before and abdominal infections are an excellent target for antimicrobial stewardship programs. Biomarkers may be helpful, but their exact role in managing abdominal infections remains incompletely understood. Source control also remains an ongoing conundrum, and evidence is increasing that its importance supersedes the impact of antibiotic therapy. New strategies such as open abdomen management may offer added benefit in severely ill patients, but more data are needed to identify its exact role. The role of fungi and the need for antifungal coverage, on the other hand, have been investigated extensively in recent years, but at this point, it remains unclear who requires empirical as well as directed therapy. PMID:27363829

  7. Ordered hexagonal mesoporous aluminosilicates synthesized using zeolite as precursor and the wall-thickness tuned by pH control

    NASA Astrophysics Data System (ADS)

    Wang, Chunlei; Zhu, Guangshang; Shang, Tiecun; Cai, Xiaohui; Liu, Chengzhan; Li, Nan; Wei, Yuhong; Li, Jian; Zhang, Weiwei; Qiu, Shilun

    2005-07-01

    High aluminium content mesoporous aluminosilicates MAS-X1 and MAS-X3 have been successfully synthesized using zeolite FAU-X as precursors and triblock copolymer pluronic P123 as structure directing agent. Samples have been characterized by XRD, TEM, nitrogen adsorption/desorption, 27Al MAS NMR, and ICP element analysis techniques. The salt, NaCl, which was introduced by dissolving the zeolite FAU-X, played an important role in the synthesis of high order sample. The secondary growth of the wall was considered to occur after the pH value had been increased up to five.

  8. Augmentation of Left Ventricular Wall Thickness With Alginate Hydrogel Implants Improves Left Ventricular Function and Prevents Progressive Remodeling in Dogs With Chronic Heart Failure

    PubMed Central

    Sabbah, Hani N.; Wang, Mengjun; Gupta, Ramesh C.; Rastogi, Sharad; Ilsar, Itamar; Sabbah, Michael S.; Kohli, Smita; Helgerson, Sam; Lee, Randall J.

    2013-01-01

    Objectives The study tested the hypothesis that augmentation of the left ventricular (LV) wall thickness with direct intramyocardial injections of alginate hydrogel implants (AHI) reduces LV cavity size, restores LV shape, and improves LV function in dogs with heart failure (HF). Background Progressive LV dysfunction, enlargement, and chamber sphericity are features of HF associated with increased mortality and morbidity. Methods Studies were performed in 14 dogs with HF produced by intracoronary microembolizations (LV ejection fraction [EF] <30%). Dogs were randomized to AHI treatment (n = 8) or to sham-operated control (n = 6). During an open-chest procedure, dogs received either intramyocardial injections of 0.25 to 0.35 ml of alginate hydrogel (Algisyl-LVR, LoneStar Heart, Inc., Laguna Hills, California) or saline. Seven injections were made ∼1.0 to 1.5 cm apart (total volume 1.8 to 2.1 ml) along the circumference of the LV free wall halfway between the apex and base starting from the anteroseptal groove and ending at the posteroseptal groove. Hemodynamic and ventriculographic measurements were made before treatment (PRE) and repeated post-surgery for up to 17 weeks (POST). Results Compared to control, AHI significantly reduced LV end-diastolic and end-systolic volumes and improved LV sphericity. AHI treatment significantly increased EF (26 ± 0.4% at PRE to 31 ± 0.4% at POST; p < 0.05) compared to the decreased EF seen in control dogs (27 ± 0.3% at PRE to 24 ± 1.3% at POST; p < 0.05). AHI treatment was well tolerated and was not associated with increased LV diastolic stiffness. Conclusions In HF dogs, circumferential augmentation of LV wall thickness with AHI improves LV structure and function. The results support continued development of AHI for the treatment of patients with advanced HF. PMID:23998003

  9. High-temperature (>500°c) wall thickness monitoring using dry-coupled ultrasonic waveguide transducers.

    PubMed

    Cegla, Frederic B; Cawley, Peter; Allin, Jonathan; Davies, Jacob

    2011-01-01

    Conventional ultrasonic transducers cannot withstand high temperatures for two main reasons: the piezoelectric elements within them depolarize, and differential thermal expansion of the different materials within a transducer causes them to fail. In this paper, the design of a high-temperature ultrasonic thickness gauge that bypasses these problems is described. The system uses a waveguide to isolate the vulnerable transducer and piezoelectric elements from the high-temperature measurement zone. Use of thin and long waveguides of rectangular cross section allows large temperature gradients to be sustained over short distances without the need for additional cooling equipment. The main problems that had to be addressed were the transmission and reception of ultrasonic waves into and from the testpiece that the waveguides are coupled to, and optimization of the wave propagation along the waveguide itself. It was found that anti-plane shear loading performs best at transmitting and receiving from the surface of a component that is to be inspected. Therefore, a nondispersive guided wave mode in large-aspect-ratio rectangular strips was employed to transmit the anti-plane shear loading from the transducer to the measurement zone. Different joining methods to attach the waveguides to the component were investigated and experiments showed that clamping the waveguides to the component surface gave the best results. The thickness of different plate samples was consistently measured to within less than 0.1 mm. Performance at high temperatures was tested in a furnace at 730°C for 4 weeks without signal degradation. Thicknesses in the range of 3 to 25 mm could be monitored using Hanning windowed tonebursts with 2 MHz center frequency. PMID:21244983

  10. A non-destructive experimental investigation of elastic plastic interfaces of autofrettaged thick-walled cylindrical aluminium high pressure vessels

    NASA Astrophysics Data System (ADS)

    Ma, Yanling; Zhang, Shu Yan; Goodway, Chris; Done, Robert; Evans, Beth; Kirichek, Oleg; Bowden, Zoë

    2012-09-01

    Positions of elastic plastic interfaces play a vital role in safe design and safe use of high pressure vessels. The ENGIN-X neutron diffractometer at the ISIS facility was used to measure the residual strain profiles in a series of aluminium vessels which had been subjected to different pressure levels. The positions of elastic plastic interfaces of the autofrettaged pressure vessels were identified. The results revealed that the residual strain magnitude and the depth of the plastic region will increase with increasing autofrettage pressure level. When autofrettage pressure produces an elastic-plastic boundary at a greater depth than the geometric mean position of the vessel wall, reverse yielding will occur, hence the loss of the vessels' elastic ability to its subsequent loading. The neutron experimental results agreed well with both the suggestions from existing literatures and the results from FE simulations.

  11. Abdominal thrusts

    MedlinePlus

    ... call 911 . If the person loses consciousness, start CPR . If you are not comfortable performing abdominal thrusts, ... American Red Cross. First Aid/CPR/AED Participant's Manual. 2nd ... Red Cross; 2014. Berg RA, Hemphill R, Abella BS, et al. Part 5: ...

  12. Abdominal Adhesions

    MedlinePlus

    ... Adhesions 1 Ward BC, Panitch A. Abdominal adhesions: current and novel therapies. Journal of Surgical Research. 2011;165(1):91–111. Seek Help for ... and how to participate, visit the NIH Clinical Research Trials and You website ... Foundation for Functional Gastrointestinal Disorders 700 West Virginia ...

  13. Estimation of PSD shifts for high-resolution metrology of thickness micro-changes with possible applications in vessel walls and biological membrane characterization.

    PubMed

    Ramos, Antonio; Bazán, Ivonne; Negreira, Carlos; Brum, Javier; Gómez, Tomás; Calás, Héctor; Ruiz, Abelardo; de la Rosa, José Manuel

    2012-01-01

    Achieving accurate measurements of inflammation levels in tissues or thickness changes in biological membranes (e.g., amniotic sac, parietal pleura) and thin biological walls (e.g., blood vessels) from outside the human body, is a promising research line in the medical area. It would provide a technical basis to study the options for early diagnosis of some serious diseases such as hypertension, atherosclerosis or tuberculosis. Nevertheless, achieving the aim of non-invasive measurement of those scarcely-accessible parameters on patient internal tissues, currently presents many difficulties. The use of high-frequency ultrasonic transducer systems appears to offer a possible solution. Previous studies using conventional ultrasonic imaging have shown this, but the spatial resolution was not sufficient so as to permit a thickness evaluation with clinical significance, which requires an accuracy of a few microns. In this paper a broadband ultrasonic technique, that was recently developed by the authors to address other non-invasive medical detection problems (by integrating a piezoelectric transducer into a spectral measuring system), is extended to our new objective; the aim is its application to the thickness measurement of sub-millimeter membranes or layers made of materials similar to some biological tissues (phantoms). The modeling and design rules of such a transducer system are described, and various methods of estimating overtones location in the power spectral density (PSD) are quantitatively assessed with transducer signals acquired using piezoelectric systems and also generated from a multi-echo model. Their effects on the potential resolution of the proposed thickness measuring tool, and their capability to provide accuracies around the micron are studied in detail. Comparisons are made with typical tools for extracting spatial parameters in laminar samples from echo-waveforms acquired with ultrasonic transducers. Results of this advanced measurement

  14. Estimation of PSD Shifts for High-Resolution Metrology of Thickness Micro-Changes with Possible Applications in Vessel Walls and Biological Membrane Characterization

    PubMed Central

    Ramos, Antonio; Bazán, Ivonne; Negreira, Carlos; Brum, Javier; Gómez, Tomás; Calás, Héctor; Ruiz, Abelardo; de la Rosa, José Manuel

    2012-01-01

    Achieving accurate measurements of inflammation levels in tissues or thickness changes in biological membranes (e.g., amniotic sac, parietal pleura) and thin biological walls (e.g., blood vessels) from outside the human body, is a promising research line in the medical area. It would provide a technical basis to study the options for early diagnosis of some serious diseases such as hypertension, atherosclerosis or tuberculosis. Nevertheless, achieving the aim of non-invasive measurement of those scarcely-accessible parameters on patient internal tissues, currently presents many difficulties. The use of high-frequency ultrasonic transducer systems appears to offer a possible solution. Previous studies using conventional ultrasonic imaging have shown this, but the spatial resolution was not sufficient so as to permit a thickness evaluation with clinical significance, which requires an accuracy of a few microns. In this paper a broadband ultrasonic technique, that was recently developed by the authors to address other non-invasive medical detection problems (by integrating a piezoelectric transducer into a spectral measuring system), is extended to our new objective; the aim is its application to the thickness measurement of sub-millimeter membranes or layers made of materials similar to some biological tissues (phantoms). The modeling and design rules of such a transducer system are described, and various methods of estimating overtones location in the power spectral density (PSD) are quantitatively assessed with transducer signals acquired using piezoelectric systems and also generated from a multi-echo model. Their effects on the potential resolution of the proposed thickness measuring tool, and their capability to provide accuracies around the micron are studied in detail. Comparisons are made with typical tools for extracting spatial parameters in laminar samples from echo-waveforms acquired with ultrasonic transducers. Results of this advanced measurement

  15. Abdominal Aortic Aneurysms: Treatments

    MedlinePlus

    ... information Membership Directory (SIR login) Interventional Radiology Abdominal Aortic Aneurysms Interventional Radiologists Treat Abdominal Aneurysms Nonsurgically Interventional radiologists ...

  16. Extremal states of energy of a double-layered thick-walled tube - application to residually stressed arteries.

    PubMed

    Waffenschmidt, Tobias; Menzel, Andreas

    2014-01-01

    Various biological tissues are designed to optimally support external loads for complex geometries and mechanobiological structures. This results in complex microstructures of such materials. The design of, for instance, (healthy) arteries, which are in the focus of this work, is characterised by a residually stressed fibre-reinforced multi-layered composite with highly non-linear elastic response. The complex interaction of material properties with the geometry and residual stress effects enables the optimal support under different blood pressures, respectively blood flow, within the vessel. The fibres reinforcing the arterial wall, as well as residual stresses present in the vessel, strongly influence its overall behaviour and performance. Turn-over and remodelling processes of the collagenous fibres occurring in the respective layers - either resulting from natural growth phenomena or from artificially induced changes in loading condition such as stent deployment - support the optimisation of the multi-layered composite structure of arteries for the particular loading conditions present in the artery. Within this contribution, the overall energetic properties of an artery are discussed by means of the inflation, bending and extension of a double-layered cylindrical tube. Different states of residual stresses and different fibre orientations are considered so that, for instance, representative fibre angles that result in extremal states of the total potential energy can be identified. In view of turn-over and remodelling processes, these orientations are considered to constitute preferred directions of fibre alignment. In summary, the main goal of this work is to calculate optimal material, structural and loading parameters by concepts of energy-minimisation. Several numerical studies show that the obtained values - such as the fibre orientations, the residual axial stretch and the opening angle - are in good agreement with respective physiological parameters

  17. Automated airway evaluation system for multi-slice computed tomography using airway lumen diameter, airway wall thickness and broncho-arterial ratio

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Lerallut, Jean-Francois

    2006-03-01

    Pulmonary diseases such as bronchiectasis, asthma, and emphysema are characterized by abnormalities in airway dimensions. Multi-slice computed tomography (MSCT) has become one of the primary means to depict these abnormalities, as the availability of high-resolution near-isotropic data makes it possible to evaluate airways at oblique angles to the scanner plane. However, currently, clinical evaluation of airways is typically limited to subjective visual inspection only: systematic evaluation of the airways to take advantage of high-resolution data has not proved practical without automation. We present an automated method to quantitatively evaluate airway lumen diameter, wall thickness and broncho-arterial ratios. In addition, our method provides 3D visualization of these values, graphically illustrating the location and extent of disease. Our algorithm begins by automatic airway segmentation to extract paths to the distal airways, and to create a map of airway diameters. Normally, airway diameters decrease as paths progress distally; failure to taper indicates abnormal dilatation. Our approach monitors airway lumen diameters along each airway path in order to detect abnormal profiles, allowing even subtle degrees of pathologic dilatation to be identified. Our method also systematically computes the broncho-arterial ratio at every terminal branch of the tree model, as a ratio above 1 indicates potentially abnormal bronchial dilatation. Finally, the airway wall thickness is computed at corresponding locations. These measurements are used to highlight abnormal branches for closer inspection, and can be summed to compute a quantitative global score for the entire airway tree, allowing reproducible longitudinal assessment of disease severity. Preliminary tests on patients diagnosed with bronchiectasis demonstrated rapid identification of lack of tapering, which also was confirmed by corresponding demonstration of elevated broncho-arterial ratios.

  18. Novel synthesis of thick wall coatings of titania supported Bi poisoned Pd catalysts and application in selective hydrogenation of acetylene alcohols in capillary microreactors.

    PubMed

    Cherkasov, Nikolay; Ibhadon, Alex O; Rebrov, Evgeny V

    2015-04-21

    Catalysis in microreactors allows reactions to be performed in a very small volume, reducing the environmental problems and greatly intensifying the processes through easy pressure control and the elimination of heat- and mass-transfer limitations. In this study, we report a novel method for the controlled synthesis of micrometre-thick mesoporous TiO2 catalytic coatings on the walls of long channels (>1 m) of capillary microreactors in a single deposition step. The method uses elevated temperature and introduces a convenient control parameter of the deposition rate (displacement speed controlled by a stepper motor), which allows deposition from concentrated and viscous sols without channel clogging. A capillary microreactor wall-coated with titania supported Bi-poisoned Pd catalyst was obtained using the method and used for the semihydrogenation of 2-methyl-3-butyn-2-ol providing 93 ± 1.5% alkene yield for 100 h without deactivation. Although the coating method was applied only for TiO2 deposition, it is nonetheless suitable for the deposition of volatile sols. PMID:25749619

  19. Differences in near-wall shear rate in the carotid artery within subjects are associated with different intima-media thicknesses.

    PubMed

    Kornet, L; Lambregts, J; Hoeks, A P; Reneman, R S

    1998-12-01

    In the common carotid artery, reflections originating from the periphery and the flow divider may affect the shape of the flow velocity profile and, hence, near-wall shear rate (WSR) differently just before the bifurcation (location B) than 20 to 30 mm farther upstream (location A). Recent developments in ultrasound technology allow the assessment of WSR and intima-media thickness (IMT) at the same site in the carotid artery in vivo. We therefore determined WSR at locations A and B and investigated whether the differences between both sites, if any, were associated with different IMTs and different mechanical properties of the arterial wall. The effect of age on the possible differences was assessed as well. The study was performed on presumably healthy volunteers (n=53). In all individuals, IMT was larger at location B than at location A. The relative difference in IMT between both locations was not affected by age. No significant differences in diameter and distension were found between locations. Near peak systolic and near mean WSR at the posterior wall (PWSRp and MWSRp, respectively) were significantly lower at location B than at location A. The relative differences in PWSRp and MWSRp between both locations within subjects were independent of age. The velocity profiles were more blunted at location A than at location B. PWSRp and MWSRp significantly decreased and IMT significantly increased with age at both locations. IMT was negatively correlated with PWSRP and MWSRP at location B, but this correlation was not significant at location A. In summary, in the common carotid artery, the lower WSR near the bifurcation, as compared with 20 to 30 mm upstream, is associated with a larger IMT than at the more proximal site. The relative difference between both locations within subjects is independent of age. PMID:9848879

  20. Unexpected multiple intra-abdominal injuries after projectile fragmentation: report of three cases.

    PubMed

    Unlü, Aytekin; Petrone, Patrizio; Karşıdağ, Tamer; Asensio, Juan A

    2012-11-01

    Explosives create and energize particles that act as projectiles prone to further fragmentation or create other secondary missiles in the body. These fragments may result in secondary injuries. This has been repeatedly described in the orthopedic and neurosurgical literature. We report the same process for abdominal injuries after fascial penetration in the military setting. This is an observational case series study. Local wound exploration as a standard approach was performed in conscious patients who sustained abdominal wall injuries. Patients with negative physical examination were excluded from the study. An intraperitoneal injury was assumed in those with a full-thickness fascial defect, and laparotomy was performed. Twenty patients met the study eligibility criteria. Of those 20 patients, 12 had negative wound exploration and were excluded from the study, while abdominal organ injuries were found in eight (40%) patients. During laparotomy, projectile-induced injuries in a sprayed distribution were found in three (38%) of these patients. These injuries were far from the predictable trajectory and in the absence of bone fragmentation. The overall mean number of peritoneal defects was 1.7, and a mean 6.8 intra-abdominal injuries for each peritoneal defect were found when through-and-through injuries were excluded.Despite a single peritoneal defect, there may be multiple intraperitoneal injuries due to further fragmentation of the projectile. Under mass casualties, wound exploration with a full-thickness fascial defect could serve as an indicator of possible intra-abdominal injuries, and consequently indicate exploratory laparotomy. PMID:23588915

  1. Abdominal trauma by ostrich

    PubMed Central

    Usurelu, Sergiu; Bettencourt, Vanessa; Melo, Gina

    2015-01-01

    Introduction Ostriches typically avoid humans in the wild, since they correctly assess humans as potential predators, and, if approached, often run away. However, ostriches may turn aggressive rather than run when threatened, especially when cornered, and may also attack when they feel the need to defend their offspring or territories. Presentation of case A 71-year-old male patient presented with intra abdominal injury sustained from being kicked in the abdominal wall by an ostrich. During laparotomy, were found free peritoneal effusion and perforation of the small intestine. Discussion The clinical history and physical examination are extremely important for diagnostic and therapeutic decision making. CT-scan is the most accurate exam for making diagnosis. Surgery is the treatment of choice, and is always indicated when there is injury to the hollow viscera. In general it is possible to suture the defect. Conclusion In cases of blunt abdominal trauma by animals is necessary to have a low threshold of suspicion for acute abdomen. PMID:25685344

  2. Abdominal rigidity

    MedlinePlus

    Causes can include: Abscess inside the abdomen Appendicitis Cholecystitis caused by gallstones Hole that develops through the entire wall of the stomach, small intestine, large bowel, or gallbladder ( gastrointestinal perforation ) Injury ...

  3. Ultrasonographic diagnosis in abdominal tuberculosis.

    PubMed

    Sheikh, M; Moosa, I; Hussein, F M; Qurttom, M A; Behbehani, A I

    1999-05-01

    Sonographic findings were retrospectively analysed in 39 patients with proven abdominal tuberculosis (TB). The patients were treated over 15 years at a major teaching hospital, Mubarak Al-Kabber Hospital, in Kuwait. The findings included clear or complex ascites with fine strands, loculations and debris. The other findings were lymphadenopathy, bowel wall thickening, omental mass, focal lesions in the liver and spleen and psoas abscess. The sonographic findings in abdominal TB are not specific but may give valuable information to prevent unnecessary laparotomy. PMID:10901897

  4. Retrospective analysis of a VACM (vacuum-assisted closure and mesh-mediated fascial traction) treatment manual for temporary abdominal wall closure – results of 58 consecutive patients

    PubMed Central

    Beltzer, Christian; Eisenächer, Alexander; Badendieck, Steffen; Doll, Dietrich; Küper, Markus; Lenz, Stefan; Krapohl, Björn Dirk

    2016-01-01

    Introduction: The optimal treatment concept for temporary abdominal closure (TAC) in critically ill visceral surgery patients with open abdomen (OA) continues to be unclear. The VACM (vacuum-assisted closure and mesh-mediated fascial traction) therapy seems to permit higher delayed primary fascial closure rates (FCR) than other TAC procedures. Material and methods: Patients of our clinic (n=58) who were treated by application of a VAC/VACM treatment manual in the period from 2005 to 2008 were retrospectively analysed. Results: The overall FCR of all patients was 48.3% (95% confidence interval: 34.95–61.78). An FCR of 61.3% was achieved in patients who had a vicryl mesh implanted at the fascial level (VACM therapy) in the course of treatment. Mortality among patients treated with VACM therapy was 45.2% (95% CI: 27.32–63.97). Conclusions: The results of our own study confirm the results of previous studies which showed an acceptable FCR among non-trauma patients who were treated with VACM therapy. VACM therapy currently appears to be the treatment regime of choice for patients with OA requiring TAC. PMID:27547691

  5. Wall thickness of gas- and marrow-filled avian long bones: measurements on humeri, femora and tibiotarsi in crows (Corvus corone cornix) and magpies (Pica pica).

    PubMed

    Suhai, Bence; Gasparik, Mihály; Csorba, Gábor; Gerics, Balázs; Horváth, Gábor

    2006-01-01

    We studied how the ratio K of the internal to external diameter of gas- and marrow-filled avian long bones follows the biomechanical optima derived for tubular bones with minimum mass designed to fulfil various mechanical requirements. We evaluated radiographs of numerous humeri, femora and tibiotarsi in Corvus corone cornix and Pica pica. The K-values of the gas-filled humerus (K=0.78+/-0.03) and the marrow-filled femur (K=0.79+/-0.02) in Corvus are practically the same, while K of the marrow-filled tibiotarsus (K=0.71+/-0.04) is significantly smaller. The same is true for the gas-filled humerus (K=0.78+/-0.02) and the marrow-filled femur (K=0.77+/-0.02) and tibiotarsus (K=0.67+/-0.05) in Pica. K in Corvus is slightly larger than K in Pica, but the differences are statistically not significant. The standard deviation DeltaK of the tibiotarsi (DeltaK=0.04-0.05) is approximately two times as large as that of the humeri (DeltaK=0.02-0.03) and femora (DeltaK=0.02) in both species. Accepting the assumption of earlier authors that the ratio Q of the marrow to bone density is 0.5, our data show that the marrow-filled tibiotarsi of Corvus and Pica are optimized for stiffness, while the marrow-filled femora are far from any optimum. The relative wall thickness W=1-K of the gas-filled avian humeri studied is much larger than the theoretical optimum W*=1-K*=0.07, and thus these bones are thicker-walled than the optimal gas-filled tubular bone with minimum mass. PMID:16084519

  6. Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index.

    PubMed

    Polzer, Stanislav; Gasser, T Christian

    2015-12-01

    A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach. PMID:26631334

  7. Abdominal Aortic Aneurysm (AAA)

    MedlinePlus

    ... Resources Professions Site Index A-Z Abdominal Aortic Aneurysm (AAA) Abdominal aortic aneurysm (AAA) occurs when atherosclerosis ... aortic aneurysm treated? What is an abdominal aortic aneurysm? The aorta, the largest artery in the body, ...

  8. Development of a Versatile Laser Ultrasonic System and Application to On-Line Measurement for Process Control of Wall Thickness and Eccentrictiy of Steel Seamless Mechanical Tubing

    SciTech Connect

    Kisner, R.A.; Kercel, S.W.; Damiano, B.; Bingham, P.R.; Gee, T.F.; Tucker, R.W.; Moore, M.R.; Hileman, M.; Emery, M.; Lenarduzzi, R.; Hardy, J.E.; Weaver, K.; Crutcher, R.; Kolarik, R.V., II; Vandervaart, R.H.

    2002-04-24

    Researchers at the Timken Company conceived a project to develop an on-line instrument for wall thickness measurement of steel seamless mechanical tubing based on laser ultrasonic technology. The instrument, which has been installed and tested at a piercing mill, provides data on tube eccentricity and concentricity. Such measurements permit fine-tuning of manufacturing processes to eliminate excess material in the tube wall and therefore provide a more precisely dimensioned product for their customers. The resulting process energy savings are substantial, as is lowered environmental burden. The expected savings are $85.8 million per year in seamless mechanical tube piercing alone. Applied across the industry, this measurement has a potential of reducing energy consumption by 6 x 10{sup 12} BTU per year, greenhouse gas emissions by 0.3 million metric tons carbon equivalent per year, and toxic waste by 0.255 million pounds per year. The principal technical contributors to the project were the Timken Company, Industrial Materials Institute (IMI, a contractor to Timken), and Oak Ridge National Laboratory (ORNL). Timken provided mill access as well as process and metallurgical understanding. Timken researchers had previously developed fundamental ultrasonic analysis methods on which this project is based. IMI developed and fabricated the laser ultrasonic generation and receiver systems. ORNL developed Bayesian and wavelet based real-time signal processing, spread-spectrum wireless communication, and explored feature extraction and pattern recognition methods. The resulting instrument has successfully measured production tubes at one of Timken's piercing mills. This report concentrates on ORNL's contribution through the CRADA mechanism. The three components of ORNL's contribution were met with mixed success. The real-time signal-processing task accomplished its goal of improvement in detecting time of flight information with a minimum of false data. The signal processing

  9. BIOMECHANICS OF ABDOMINAL AORTIC ANEURYSM

    PubMed Central

    Vorp, David A.

    2009-01-01

    Abdominal aortic aneurysm (AAA) is a condition whereby the terminal aorta permanently dilates to dangerous proportions, risking rupture. The biomechanics of AAA has been studied with great interest since aneurysm rupture is a mechanical failure of the degenerated aortic wall and is a significant cause of death in developed countries. In this review article, the importance of considering the biomechanics of AAA is discussed, and then the history and the state-of-the-art of this field is reviewed - including investigations into the biomechanical behavior of AAA tissues, modeling AAA wall stress and factors which influence it, and the potential clinical utility of these estimates in predicting AAA rupture. PMID:17254589

  10. Drought-induced increase in water-use efficiency reduces secondary tree growth and tracheid wall thickness in a Mediterranean conifer.

    PubMed

    Olano, José Miguel; Linares, Juan Carlos; García-Cervigón, Ana I; Arzac, Alberto; Delgado, Antonio; Rozas, Vicente

    2014-09-01

    In order to understand the impact of drought and intrinsic water-use efficiency (iWUE) on tree growth, we evaluated the relative importance of direct and indirect effects of water availability on secondary growth and xylem anatomy of Juniperus thurifera, a Mediterranean anisohydric conifer. Dendrochronological techniques, quantitative xylem anatomy, and (13)C/(12)C isotopic ratio were combined to develop standardized chronologies for iWUE, BAI (basal area increment), and anatomical variables on a 40-year-long annually resolved series for 20 trees. We tested the relationship between iWUE and secondary growth at short-term (annual) and long-term (decadal) temporal scales to evaluate whether gains in iWUE may lead to increases in secondary growth. We obtained a positive long-term correlation between iWUE and BAI, simultaneously with a negative short-term correlation between them. Furthermore, BAI and iWUE were correlated with anatomical traits related to carbon sink or storage (tracheid wall thickness and ray parenchyma amount), but no significant correlation with conductive traits (tracheid lumen) was found. Water availability during the growing season significantly modulated tree growth at the xylem level, where growth rates and wood anatomical traits were affected by June precipitation. Our results are consistent with a drought-induced limitation of tree growth response to rising CO2, despite the trend of rising iWUE being maintained. We also remark the usefulness of exploring this relationship at different temporal scales to fully understand the actual links between iWUE and secondary growth dynamics. PMID:24958369

  11. [Crepitant abdominal cellulitis: a rare clinical presentation of sigmoid tumor].

    PubMed

    Chaib, E; Leal, M C; Onofrio, P L; Nahas, P; de Mello, J B

    1990-01-01

    Unusual infections associated with colorectal tumors may, in some instances, be the sole clue to presence of malignancy. The infections are either related to invasion of tissues or organs in close proximity to the tumor or secondary to distant seeding by transient bacteremia arising from necrotic tumors. The authors present one case of spontaneous crepitant cellulitis in the lower abdominal wall, associated with sigmoid tumor. The patient had abdominal pain in the left iliaca fossa, fever and skin necrosis of the lower abdominal wall in the last 4 hours. At surgery they performed debridement and excision of necrotic tissue (lower abdominal wall) and partial sigmoidectomy with sigmoid colostomy. The patient died 9 months after initial surgery. A study of tumor mass revealed an adenocarcinoma. The presence of crepitant cellulitis in a lower abdominal wall should result in a search for bowel perforation. PMID:2151244

  12. Combined subcutaneous, intrathoracic and abdominal splenosis.

    PubMed

    Javadrashid, Reza; Paak, Neda; Salehi, Ahad

    2010-09-01

    We report a case of combined subcutaneous, intrathoracic, and abdominal splenosis who presented with attacks of flushing, tachycardia and vague abdominal pain. The patient's past medical history included a splenectomy due to abdominal trauma and years later, a lung lobectomy due to recurrent pneumonia. An enhancing solid mass adjacent to the upper pole of the left kidney and nodular pleural based lesions in the left hemi-thorax along with nodular lesions in subcutaneous tissue of the left chest wall suggested possible adrenal malignancy with multiple metastases. Histopathologic examination demonstrated benign lesions of ectopic splenic tissue. PMID:20804314

  13. Assessing abdominal aorta narrowing using computational fluid dynamics.

    PubMed

    Al-Rawi, Mohammad; Al-Jumaily, Ahmed M

    2016-05-01

    This paper investigates the effect of developing arterial blockage at the abdominal aorta on the blood pressure waves at an externally accessible location suitable for invasive measurements such as the brachial and the femoral arteries. Arterial blockages are created surgically within the abdominal aorta of healthy Wistar rats to create narrowing resemblance conditions. Blood pressure is measured using a catheter inserted into the right femoral artery. Measurements are taken at the baseline healthy condition as well as at four different severities (20, 50, 80 and 100 %) of arterial blockage. In vivo and in vitro measurements of the lumen diameter and wall thickness are taken using magnetic resonance imaging and microscopic techniques, respectively. These data are used to validate a 3D computational fluid dynamics model which is developed to generalize the outcomes of this work and to determine the arterial stress and strain under the blockage conditions. This work indicates that an arterial blockage in excess of 20 % of the lumen diameter significantly influences the pressure wave and reduces the systolic blood pressure at the right femoral artery. High wall shear stresses and low circumferential strains are also generated at the blockage site. PMID:26319006

  14. Abdominal Compartment Syndrome in a Pediatric Patient With Cloacal Exstrophy.

    PubMed

    Cooper, Caleb E; Kennedy, Alfred P; Smith, D Preston

    2016-07-01

    We present a rare complication of abdominal compartment syndrome (ACS) in a child undergoing complex urologic reconstruction. A 10-year-old female born with the abdominal wall defect cloacal exstrophy who had previously undergone multiple abdominal procedures then developed findings consistent with ACS following a complex Mitrofanoff procedure. Although intravesical pressures were not documented because of the nature of her reconstruction, her ACS-type findings were (1) abdominal pain, (2) melena, (3) pulmonary hypoinflation, (4) renal insufficiency, (5) tachycardia, and (6) segmental ischemic small bowel. Management consisted of abdominal decompression, segmental bowel resections, and wound vacuum-assisted-closure management. Patient was eventually discharged home. PMID:26921644

  15. Paediatric case of a large gastric rupture after a blunt abdominal trauma: Report of a case in a District General Hospital

    PubMed Central

    Pafitanis, Georgios; Koulas, Spiros; Bikos, Stavros; Tsimoyiannis, Evangelos

    2012-01-01

    INTRODUCTION Isolated gastric rupture after blunt abdominal trauma is rare. In current literature gastric rupture from blunt abdominal trauma ranges between 0.02% and 1.7%. This document reports the first non-motor-vehicle case of an isolated gastric rapture after blunt abdominal injury, which repaired after early diagnosis and aggressive surgical treatment. PRESENTATION OF CASE A 14-year-old boy attended our emergency surgical department after sustained a blunt abdominal trauma following a fall from his bicycle. He presented with pain and left para-umbilical abdominal ecchymoses. Examination revealed subcutaneous emphysema and a palpable abdominal wall dimple. DISCUSSION Radiological examination with CT scan determined the need for exploratory laparotomy. Operation revealed, extensive rupture of the left lateral border of the rectus abdominus muscle, free intra-peritoneal position of the nasogastric tube with gross spillage of gastric contents and pneumo-peritoneum observed with 7-8cm full thickness rupture of anterior stomach wall, from the lesser towards the greater curvature. Primary, two-layer closure was performed. On the 5th post-operative day he developed gastrorrhagia. He was discharged on the 15th postoperative day. CONCLUSION We present this case report focusing on the paediatric patient to illustrate isolated gastric injury in terms of mechanism of injury, clinical presentation, and immediate surgical management. PMID:23295382

  16. Transanal endoscopic microsurgery in the management of rectal wall endometriosis.

    PubMed

    Banky, Balazs; Saleki, Mahsa; Gill, Talvinder S

    2016-01-01

    A 29-year-old woman with known history of endometriosis was referred to colorectal outpatient clinic from gynaecology with a history of intermittent rectal bleeding and no associated bowel symptoms. Flexible sigmoidoscopy in concordance with pelvic MRI revealed a 3×2×2 cm sessile lesion in the anterior rectal wall. The lesion was also palpable as a firm mass on digital rectal examination. From the gynaecological point of view no intra-abdominal exploration was required; the sole rectal wall lesion was removed with the minimally invasive surgical technique of transanal endoscopic microsurgery. Full thickness rectal wall excision sample was reported to be histologically complete and confirmed endometriosis. No recurrence was detected at endoscopic follow-up at 6 months. The patient remained symptom free. Therefore, we demonstrated a case of minimally invasive removal of a rectal wall large endometriosis nodule in a fertile woman with a complete, symptomatic, uneventful recovery. PMID:27495176

  17. Merkel cell carcinoma of the abdominal wall

    PubMed Central

    Gaopande, Vandana L.; Joshi, Avinash R.; Khandeparkar, Siddhi G. S.; Deshmukh, Sanjay D.

    2015-01-01

    Merkel cell carcinoma also known as neuroendocrine carcinoma of the skin is a very rare skin tumor. It commonly presents in the old age and the common sites are head, neck and extremities. The diagnosis requires histopathological examination with immunohistochemical correlation. We report a case of Merkel cell carcinoma stage IIIB with bilateral inguinal lymphadenopathy that on FNAB showed metastatic deposits of the tumor. PMID:26225333

  18. Component Separation for Complex Abdominal Wall Reconstruction

    MedlinePlus Videos and Cool Tools

    ... to you from Albany Medical Center in Albany, New York. In just moments, you'll learn how ... what we'll do is we'll take new 2-0s, and if we can kind of ... reconstruction performed from Albany Medical Center in Albany, New York. OR-Live makes it easy for you ...

  19. Abdominal aortic aneurysm

    MedlinePlus

    ... to the abdomen, pelvis, and legs. An abdominal aortic aneurysm occurs when an area of the aorta becomes ... blood pressure Male gender Genetic factors An abdominal aortic aneurysm is most often seen in males over age ...

  20. Abdominal x-ray

    MedlinePlus

    ... More Abdominal aortic aneurysm Abdominal pain Acute cholecystitis Acute kidney failure Addison disease Adenomyosis Annular pancreas Aplastic anemia Appendicitis Ascariasis Atheroembolic renal disease Biliary atresia Blind loop syndrome Cholangitis Chronic ...