Depopulated vena caval homograft: a new venous conduit

OBJECTIVE: Completion of the Fontan procedure is frequently performed by using an extracardiac conduit between the inferior vena cava and the pulmonary artery. Most centers use a polytetrafluoroethylene graft for the extracardiac conduit, and because re-endothelialization is unlikely, anticoagulation is used for a variable period. This study explores the use of an alternate large-caliber venous conduit. METHODS: The superior vena cava was replaced in 8 minipigs with either a polytetrafluoroethylene interposition graft (2 pigs) or a depopulated (acellular), cryopreserved superior vena caval homograft (6 pigs). After 6 months, the animals were killed, and the grafts were examined for patency and histology, including immunostaining. No anticoagulation was used. RESULTS: Polytetrafluoroethylene grafts have a cross-sectional luminal narrowing, ranging from 16% to 40%. Histology showed only partial intimal ingrowth, with excessive subendothelial fibrosis and early calcification. In contrast, the depopulated venous homografts showed minimal luminal narrowing, ranging from 2% to 9%. These grafts were completely repopulated by the recipient with an endothelial lining, which stained positively for factor VIII, and a subendothelial region appropriately recellularized by myofibroblasts, which stained positively for smooth muscle actin and procollagen. There was no evidence of an immune response to the venous homografts, as judged by staining for T-cell surface antigen, CD4, and CD8. Thrombus was not seen in any of the grafts. CONCLUSION: Depopulated, cryopreserved vena caval homografts might be superior conduits for cavopulmonary connection during completion of the Fontan operation by using the extracardiac conduit technique.     

A new strategy for management of retroperitoneal tumors with supradiaphragmatic vena caval thrombi

A new surgical technique to treat retroperitoneal tumors with supradiaphragmatic vena caval invasion is described. In this technique, hepatic warm ischemia can be avoided with reversed hepatic outflow through the portal vein and neither hypothermic circulatory arrest nor cardiopulmonary bypass is necessary using centrifugal blood pump-driven bypass.     

Inferior vena caval resection with autogenous peritoneo-fascial patch graft caval repair: a new technique.

BACKGROUND: In the course of oncological surgery, resection of the inferior vena cava (IVC) may be required to obtain an adequate resection margin and to offer the best opportunity of cure. The remaining defect in the IVC may be managed by: (i) primary repair which may lead to subsequent narrowing of the lumen, possibly leading to turbulent flow and thrombus formation; (ii) patch grafting of the defect, which may prevent narrowing. Several synthetic and biosynthetic materials are available as patch grafts and autologous pericardium has also been used. METHODS: The harvesting and use of the autogenous peritoneo-fascial (APF) graft as an alternative caval patch graft material in the management of defects in the caval wall is proposed. Autogenous peritoneo-fascial caval patch graft repair in six patients was undertaken. RESULTS: One patient with leiomyosarcoma secondaries in the liver eventually succumbed to the disease. The other five patients are clinically well with no evidence of IVC obstruction or venous aneurysms. CONCLUSION: Preliminary results show that this new technique of utilizing an APF patch graft for caval repair is clinically a suitable alternative to current biosynthetic and synthetic materials and may in fact be superior in many aspects.     

The helix filter: a new vena caval filter for the prevention of pulmonary embolism

The helix caval filter is a continuous band spiral composed of a highly elastic metal alloy. A vertical double-helix coil fixes the filter in the infrarenal vena cava by elastic expansion while a watch spring type horizontal coil works as the filtering element. The diameter of the filter can be reduced by torsion from 32 to 7 mm. Transvenous implantation was performed under fluoroscopy using a newly developed instrument featuring intraoperative angiographic control, high flexibility, a guidance system, and a well-controlled release mechanism. The filter and the implantation technique were tested in a circulation system and in 10 dogs and 4 calves (follow-up 3-91 days). In addition, two filters were released intentionally into the right atrium of a dog and a calf. Flow resistance of the filter is negligible up to more than 10 1/min. Thrombi larger than 3.5 mm were filtered out reliably. Lethal complications, filter migrations or perforations did not occur in animal experiments. Filter coils which are in contact with the vessel wall become firmly incorporated within 3 to 4 weeks. The patency rate of the vena cava was 80% (8/10) for dogs and 100% (4/4) for calves. Implantations in the right atrium did not cause any symptoms. The filter's design allows fixation without hooks or spikes and consequently makes transvenous extraction possible up to 7-10 days after implantation. Comparable clinical results could extend the indications for caval filter implantation, and the decision which is still difficult today could be made easier.     

Radical nephrectomy with vena caval thrombectomy: a contemporary experience

Study Type – Therapy (case series)
Level of Evidence 4 What’s known on the subject? and What does the study add? Renal tumours with caval thrombus are relatively rare. Surgical management is the standard of care for lesions of this nature. Small series have been published by other groups, but our understanding of the optimal management continues to evolve. We present the Memorial Sloan‐Kettering Cancer Center series, with a discussion of techniques and complications. Of interest, we include several patients with high‐level caval thrombi which were managed without bypass, supporting previous publications by the group from University of Miami.

OBJECTIVE

• ? To report on the contemporary Memorial Sloan‐Kettering Cancer Center experience with radical nephrectomy and vena caval thrombectomy.

PATIENTS AND METHODS

• ? Patients who underwent radical nephrectomy and vena caval thrombectomy without the use of bypass techniques were retrospectively identified.
• ? Data were collected on intraoperative and pathological findings as well as postoperative complications and oncological outcomes.

RESULTS

• ? In all, 78 patients underwent radical nephrectomy with off‐bypass resection of vena caval thrombus between 1989 and 2009.
• ? The median (interquartile range, IQR) operation duration was 293 (226–370) min, and median (IQR) blood loss was 1300 (750–2500) mL. In all, 10 patients (13%) were confirmed to have intra‐ or supra‐hepatic tumour thrombus (level 3/4), eight of whom required supra‐hepatic control of the inferior vena cava (IVC).
• ? Major (grade 3–5) postoperative complications occurred in 14 (18%), with five postoperative deaths. Disease recurred in 27/62 patients who were considered completely resected at surgery and had adequate follow‐up.
• ? The overall 5‐year survival (95% confidence interval) probability was 48% (35–60%).

CONCLUSIONS

• ? Radical nephrectomy with vena caval thrombectomy is associated with acceptable postoperative morbidity and mortality, and long‐term survival is possible in some patients.
• ? Many level 3/4 thrombi could be safely approached without the use of bypass techniques.

     

Superior vena caval obstruction secondary to fibrosing mediastinitis

Eight patients with obstruction of the superior vena cava (SVC) secondary to fibrosing mediastinitis are presented. Four patients were managed without surgical reconstruction of the SVC. Of these, 2 are severely symptomatic from SVC obstruction, I is asymptomatic, and I is alive though his condition is unknown.Four patients were managed with surgical replacement of the SVC. Each is asymptomatic. One of 2 aortic homografts is occluded and the other is markedly stenosed at the cephalad suture line. A late occlusion occurred in the Teflon prosthesis. In the fourth patient, a bypass graft using composite autogenous veins was complemented with an arteriovenous fistula. Venography in this patient at one, six, and thirteen months revealed graft patency; he has no limitations in his physical activities.     

Autogenous vein graft to restore ureteric continuity in dogs

Free, autogenous vein segments were grafted to restore continuity of partially excised ureters in 12 mongrel dogs. Shortening and stricture formation of the vein graft occurred over the following four weeks. There was external adhesion around the graft but no urinary leakage, pooling or fistula. Intubation of the graft maintained patency but shortening occurred. Once the tube was removed, stricture formation and complete obliteration of the lumen of the graft occurred over the following few weeks. Prolonged splinting by biologically inert material may facilitate luminal patency and urothelial lining of the fibrous remnant of the venous graft. Gradual shortening of the graft eventually allows end-to-end anastomosis, without tension, as a second stage procedure.     

Abdominal vena caval injuries: outcomes remain dismal

BACKGROUND: The mortality rate for abdominal vena caval injuries remains high. We examined the experience of a level I trauma center to determine factors significant to the outcome in these injuries. METHODS: Forty-seven patients were identified in a retrospective review (1989 to 1999) of patients were identified with abdominal vena caval injury. Data were analyzed by uni- and multivariate methods, including logistic regression. RESULTS: Most of the individuals with abdominal vena caval injuries were young male patients who were injured by penetrating trauma and who were hypotensive on arrival. The severity of injury and the number of organs injured was high. The overall mortality rate was 55%. Nonsurvivors were more often hypotensive in the field with physiologic derangement consistent with hemorrhagic shock. Type and location of injury as well as method of repair were associated with death. Multiple regression analysis revealed that prehospital initial systolic blood pressure and intraoperative bicarbonate levels were independent predictors of survival. CONCLUSIONS: We identified factors related to poor outcome, including suprarenal and retrohepatic location of injury and variables that reflected the evolution of shock. Management should include appropriate resuscitation and ultimately may require novel operative techniques.     

Post-traumatic inferior vena caval thrombosis: case report

Thrombosis of the aorta and inferior vena cava is a rare sequela of blunt abdominal trauma. Inferior vena caval thrombosis developed in a 55-year-old man after blunt abdominal trauma. It was detected 18 days after injury through the use of computed tomography. The patient was treated with a Greenfield filter and anticoagulation.     

Superior vena caval stenosis: a complication of transvenous endocardial pacing.

Superior vena caval obstruction is a rare complication of transvenous endocardial pacing and is usually the result of thrombus formation round the pacing electrode (Kosowsky and Barr, 1972). We report a case of superior vena caval obstruction without thrombus formation secondary to localised stenosis at the site of the proximal cut end of a retracted endocardial electrode. This complication of transvenous pacing electrodes has not been described previously.