Caval inflow to the graft: a successful way to overcome diffuse portal system thrombosis in liver transplantation

Portal vein thrombosis was considered to be a major contraindication to liver transplantation before the introduction of vessel grafts from the recipient's area of confluence of the splenic and superior mesenteric veins, behind the neck of the pancreas, to the graft's portal vein. Refinement in surgical technique has given rise to a large number of possibilities to overcome portal vein thrombosis in OLT recipients, ranging from portal vein thrombectomy to several different venous graft jump reconstructions. All these reconstructions require the presence of a patent vein of the portal system. When neither splanchnic veins nor sufficiently large venous collaterals are available, liver transplantation has been considered impossible. Salvage solutions include arterialization of the portal vein with the associated risk of liver damage in the longterm, a combined liver and bowel transplantation has been proposed but not yet reported (and in any case the results of combined liver and bowel transplants are not as good as those of liver transplantation alone) and finally the use of blood inflow from the inferior vena cava as first reported by Tzakis and coworkers. Portal flow from the inferior vena cava may be performed as a last resort. Although the consequences of severe pretransplantation portal hypertension remain and should be treated before, during, and after transplantation, liver function is normal in the short and midterm. With this new procedure, diffuse portal vein thrombosis is no longer an absolute contraindication to liver transplantation. But this needs to be confirmed in light of further experience and longterm followup.     

Clinical analysis of living donor liver transplantation in patients with portal vein thrombosis

Kim S‐J, Kim D‐G, Park J‐H, Moon I‐S, Lee M‐D, Kim J‐I, Yoon Y‐C, Yoo Y‐K. Clinical analysis of living donor liver transplantation in patients with portal vein thrombosis.
Clin Transplant 2011: 25: 111–118. © 2010 John Wiley & Sons A/S. Abstract: The aim of this study was to improve outcomes in living donor liver transplantation (LDLT) patients with portal vein thrombosis (PVT). Of 246 adult patients who underwent LDLT with a right lobe graft between January 2000 and May 2007, PVT was diagnosed in 50 patients (20.3%), who were further subdivided into partial (n = 39, 78%) and complete (n = 11, 22%) types. Patients with PVT, especially complete PVT, showed high incidences of variceal bleeding (p = 0.021), operative RBC transfusion (p < 0.046) and a post‐transplantation complications related to bleeding (p = 0.058). We also classified PVT according to its location and the presence of collaterals: type I (n = 41, 82%): PVT localized above the confluence of the splenic and superior mesenteric veins (SMV); type II (n = 7, 14%): PVT extending below the confluence with a patent distal SMV; type III (n = 2, 4%): complete portal vein and SMV thrombosis except for a coronary vein. LDLT could be safely undertaken in patients with PVT without increased mortality. In our type II and III PVT, when thrombectomy fails, jump grafting using a cryopreserved vessel may serve as a reliable alternative method to restore portal flow.     

Management of portal vein thrombosis in liver transplantation: influence on morbidity and mortality

BACKGROUND: Splanchnic thrombosis is a surgical challenge in liver transplantation (LT). The aim of this study was to analyze our experience in the management of portal vein thrombosis, and its influence on evolution. AIM: The aim of this study was to analyze our experience in the management of portal vein thrombosis, and its influence on evolution. PATIENTS AND METHODS: Between 1999 and 2004, 366 liver transplants were performed in 335 patients. Forty-two patients [12.5%: portal vein thrombosis (PVT) group] had portal thrombosis at the time of LT. We analyzed the technical aspects and compared their evolution with a group of patients without portal thrombosis (n = 293; no-PVT group). Retransplantations were excluded. RESULTS: Of the 42 patients with thrombosis, 18 had partial thrombosis and 16 complete thrombosis [six included the proximal superior mesenteric vein (SMV) and in two the whole splanchnic system]. In 12 cases, usual T-T anastomosis was performed and in 16 cases a thrombectomy was carried out; there were five cases of anastomosis at confluence of the SMV, five cases of anastomosis to a collateral vein, three cases of venous graft, and one case of cavoportal hemitransposition. The operative time was higher in PVT group (417 +/- 103 min vs. 363 +/- 83; p = 0.0005), as RBC transfusion (2.4 +/- 3.1 vs. 1.9 +/- 2.3; p = 0.04), and hospital stay (20.9 +/- 14.9 d vs. 15.1 +/- 10.6; p = 0.002). However, there were no differences in hospital mortality (4% vs. 7.8%; p = 0.98), primary dysfunction (4.8% vs. 7.8%; p = 0.44), or three-yr-actuarial survival (75% vs. 77%; p = 0.95). The incidence of post-transplant thrombosis was higher in the PVT group (15% vs. 2.4%; p = 0.0005). CONCLUSIONS: Portal thrombosis is associated with greater operative complexity and rethrombosis, but has no influence on overall morbidity and mortality.     

Liver transplantation with calcific sclerosis of the portal vein

Thrombosis or phlebosclerosis of the portal vein is an infrequent finding during the preoperative evaluation of a potential liver transplant recipient. Occasionally the process extends proximally into the superior mesenteric vein. This precludes conventional methods of portal venous reconstruction, necessitating reconstitution of portal venous inflow during liver transplantation through a venous conduit. The authors present a case of calcific phlebosclerosis of the portal and distal superior mesenteric veins that was delineated during preoperative imaging. This case emphasizes the importance of visualizing both the portal and superior mesenteric veins during the preoperative assessment, when patency of the portal vein is questionable. When the obliterative process extends into the distal superior mesenteric vein the authors recommend construction of the venous conduit from the proximal superior mesenteric vein as a pre-emptive manoeuvre before dissection of the recipient's liver and hilar structures. The venous conduit is then ready for immediate use during engraftment, thereby maintaining the shortest possible anhepatic time.     

Outcome of extra-anatomic vascular reconstruction in orthotopic liver transplantation

BACKGROUND: Portal venous and hepatic arterial reconstruction are critical to successful outcomes in orthotopic liver transplantation (OLT). With portal vein thrombosis or inadequate hepatic arterial inflow, extra-anatomic vascular reconstruction is required. However, the clinical outcomes following extra-anatomic vascular reconstruction are largely unknown. METHODS: To determine the outcomes associated with extra-anatomic vascular reconstruction, we performed a retrospective review of 205 OLT recipients transplanted between 1995 and 2000. RESULTS: Extra-anatomic portal venous inflow was based upon the recipient superior mesenteric vein using donor iliac vein graft in a retrogastric position (n = 12). Extra-anatomic arterial inflow was based on recipient infrarenal aorta using donor iliac artery graft through the transverse mesocolon (n = 25). OLT with routine anatomic vascular construction served as control (n = 168). Extra-anatomic vascular reconstruction was not associated with increased morbidity, mortality, operating room time, length of stay, or thrombosis. CONCLUSION: We conclude that extra-anatomic vascular conduits are associated with excellent long-term outcomes and provide acceptable alternatives for vascular reconstruction in OLT.     

The risks of total pancreatectomy and splenic islet autotransplantation

The intraportal site is the most common site for islet transplantation. Many other sites have been tried experimentally, including the spleen, which has successfully lead to insulin independence in a number of animal models. Nevertheless, there are no detailed reports of total pancreatectomy and splenic islet autotransplantation in humans. Five patients underwent total pancreatectomy and splenic islet autotransplantation for chronic pancreatitis. Four patients had a pylorus-preserving total pancreatectomy and one patient a duodenal-preserving pancreatectomy. In three cases islets were embolized into both the portal vein and spleen. Two patients received splenic islet transplants alone. Islets were transplanted by retrograde venous infusion via the short gastric veins (n = 3), splenic vein stump (n = 1), and the left gastroepiploic vein (n = 1). The total volumes of transplanted pancreatic digest in those receiving combined intraportal and splenic autografts (n = 3) were 15.8, 13.0, and 13.5 ml. The volumes in those receiving a splenic-alone autograft (n = 2) were 12.0 and 5 ml. The mean rise in portal pressure was 18 cm of water. Complications related to the splenic autograft included a wedge splenic infarct, an emergency splenectomy, and a portal vein thrombosis in one patient having a combined intraportal and splenic autograft. Two patients developed insulin independence. two patients were still insulin independent at 1-year follow-up, and all had normal HbA1c levels (mean 5.6, range 5.2-6.3). Splenic islet autotransplantation, after total pancreatectomy, does lead to insulin independence. However, in our experience the combined procedure has a high morbidity because of splenic infarction and venous thrombosis.     

Vascular Complications Following Adult Piggyback Liver Transplantation With End-to-Side Cavo-Cavostomy: A Single-Center Experience

Background

Vascular complications remain a significant cause of morbidity, graft loss, and mortality following orthotopic liver transplantation (OLT). These problems predominantly include hepatic artery and portal vein thrombosis or stenosis. Venous outflow obstruction may be specifically related to the technique of piggyback OLT.

Materials and Methods

Between February 2002 and February 2009, we performed 200 piggyback OLT in 190 recipients. A temporary portacaval shunt was created in 44 (22%) cases, whereas end-to-side cavo-cavostomy was routinely performed for graft implantation. Pre-existent partial portal or superior mesenteric vein thrombosis was present in 17 (12%) cirrhotics in whom we successfully performed eversion thrombectomy, which was followed by a typical end-to-end portal anastomosis. The donor hepatic artery was anastomosed to the recipient aorta via an iliac interposition graft in 31 (16%) patients.

Results

The 14 (7%) vascular complications included hepatic artery thrombosis (n = 5), hepatic artery stenosis (n = 3), aortic/celiac trunk rupture (n = 2), portal vein stenosis (n = 2), and isolated left and middle hepatic venous outflow obstruction (n = 1). There was also 1 case of arterial steal syndrome via the splenic artery. No patient experienced portal or mesenteric vein thrombosis. Therapeutic modalities included re-OLT, arterial/aortic reconstruction and splenic artery ligation. Vascular complications resulted in death of 5 (36%) patients.

Conclusion

Our experience indicated that piggyback OLT with an end-to-side cavo-cavostomy showed a low risk of venous outflow obstruction. Partial portal or mesenteric vein thrombosis is no longer an obstacle to OLT; it can be successfully managed with the eversion thrombectomy technique.     

Adult liver transplantation and abnormalities of splanchnic veins: experience in 53 patients

The aim of this study was to analyze the influence of technical problems resulting from splanchnic venous anomalies on the outcome of orthotopic liver transplantation. From February 1984 until December 1995, 53 (16.3 %) of 326 adults underwent consecutive transplantations whilst having acquired anomalies of the splanchnic veins. These consisted of portal vein thrombosis (n = 32, 9.8 %), thrombosis with inflammatory venous changes (phlebitis; n = 6, 1.8 %) and alterations related to portal hypertension surgery (n = 15, 4.6 %). Because of major changes in surgical technique, i. e., eversion instead of blind venous thrombectomy, immediate superior mesenteric vein approach in cases of extended thrombosis, and piggyback implantation with preservation instead of removal of the inferior vena cava, patients were divided into two groups: those who underwent transplantation during the period February 1984 to December 1990 (group 1) and those transplanted between January 1991 and December 1995 (group 2). Surgical procedures to overcome the anomalies consisted of venous thrombectomy (n = 26), implantation of the donor portal vein at the splenomesenteric confluence (n = 5) or onto a splenic (n = 1) or ileal varix (n = 1), interposition of a free iliac venous graft between recipient superior mesenteric vein and donor portal vein (n = 9,) and interruption of surgical portosystemic shunt (n = 13). All patients had a complete follow-up. The 1- and 5-year actuarial patient survival rates were similar in patients with (n = 53) and without (n = 273) splanchnic venous abnormalities (75.5 % vs 78.1 % and 64.3 % vs 66.9 %, respectively). Early ( < 3 months) post-transplant mortality was 24.5 % (13/53 patients). Mortality was highest in the portal vein thrombophlebitis group (5/6, 83.3 %), followed by the portal hypertension surgery group (5/15, 33.3 %) and the portal vein thrombosis group (3/32, 9.4 %). Technical modifications significantly reduced mortality in group 2 (10.3 %, 3/29 vs 41.7 %, 10/24 patients in group 1; P < 0.05) as well as the need for re-exploration for bleeding (13.8 %, 4/29 patients in group 2 vs 15/24, 62.5 % in group 1; P < 0.01). Mortality directly related to bleeding was also significantly lowered (1/29, 3.4 % in group 2 vs 9/24, 37.5 % in group 1; P < 0.01). We conclude that liver transplantation can be safely performed in the presence of splanchnic vein thrombosis and previous portal hypertension surgery. Received: 11 April 1996 Received after revision: 31 July 1996 Accepted: 23 September 1996     

Portal vein reconstruction in pediatric liver transplantation from living donors.

OBJECTIVE: The authors analyze the surgical pattern and the underlying rationale for the use of different types of portal vein reconstruction in 110 pediatric patients who underwent partial liver transplantation from living parental donors. SUMMARY BACKGROUND DATA: In partial liver transplantation, standard end-to-end portal vein anastomosis is often difficult because of either size mismatch between the graft and the recipient portal vein or impaired vein quality of the recipient. Alternative surgical anastomosis techniques are necessary. METHODS: In 110 patients age 3 months to 17 years, four different types of portal vein reconstruction were performed. The portal vein of the liver graft was anastomosed end to end (type I); to the branch patch of the left and right portal vein of the recipient (type II); to the confluence of the recipient superior mesenteric vein and the splenic vein (type III); and to a vein graft interposed between the confluence and the liver graft (type IV). Reconstruction patterns were evaluated by their frequency of use among different age groups of recipients, postoperative portal vein blood flow, and postoperative complication rate. RESULTS: The portal vein of the liver graft was anastomosed by reconstruction type I in 32%, II in 24%, III in 14%, and IV 29% of the cases. In children <1 year of age, type I could be performed in only 17% of the cases, whereas 37% received type IV reconstruction. Postoperative Doppler ultrasound (mL/min/100 g liver) showed significantly (p < 0.05) lower portal blood flow after type II (76.6 +/- 8.4) versus type I (110 +/- 14.3), type III (88 +/- 18), and type IV (105 +/- 19.5). Portal vein thrombosis occurred in two cases after type II and in one case after type IV anastomosis. Portal stenosis was encountered in one case after type I reconstruction. Pathologic changes of the recipient native portal vein were found in 27 of 35 investigated cases. CONCLUSION: In living related partial liver transplantation, portal vein anastomosis to the confluence with or without the use of vein grafts is the optimal alternative to end-to-end reconstruction, especially in small children.     

肝移植术后门静脉狭窄-肠系膜上静脉血栓的影像诊断

Portal vein stricture complicated with superior mesenteric venous thrombosis is rarely seen in clinical practice. On December 26, 2009, a 51-year-old male patient who had a liver transplantation history was admitted to The General Hospital of Chinese People's Armed Police Forces with the chief complaint of intermittent abdominal pain and diarrhea.A plain and enhanced CT scan showed that the portal vein was constrictive and thrombosis had formed in the main trunk of the superior mesenteric vein, and varicose veins were seen in surrounding tissues of the esophagus. Edema was observed at the end of the ileum and cecum. The results of colonoscopy showed inflammatory changes and varicose veins of the colon. The patient received medical treatment. The thrombosis was dissolved 9 days later, and all symptoms disappeared 12 days later.     

Duplex ultrasonography in portal vein thrombosis

Summary Duplex ultrasonography (US) was performed in 23 patients with portal vein thrombosis. In 7 children and 16 adults, duplex US demonstrated intraluminal thrombi (4 cases), thrombus and periportal collaterals (2 cases), and cavernomatous transformation of the portal vein (17 cases). Real-time US is a suitable means of demonstrating the anatomy of the portal venous system; pulsed Doppler provided information on the patency and direction of portal flow. In a few cases, Doppler color flow imaging was used, which was helpful in the examination of branches of the portal vein and the superior mesenteric and splenic veins. Portal duplex US is suggested in selected groups of patients before surgery to demonstrate the presence or absence of portal vein thrombosis.     

Portal revascularization in the setting of cavernous transformation through a paracholedocal vein: a case report

Diffuse thrombosis of the entire portal system (PVT) and cavernomatous transformation of the portal vein (CTPV) represents a demanding challenge in liver transplantation. We present the case of a patient with nodular regenerative hyperplasia and recurrent episodes of type B hepatic encephalopathy concomitant with PVT as well as CTPV, successfully treated with orthotopic liver transplantation. The portal inflow to the graft was carried out through the confluence of 2 thin paracholedochal varicose veins, obtaining good early graft function and recovery of the encephalopatic episodes. This alternative should be kept in mind as an option to assure hepatopetal splanchnic flow in those cases of diffuse thrombosis and cavernomatous transformation of portal vein.     

Improved technique of portal vein reconstruction in pediatric liver transplant recipients with portal vein hypoplasia

BACKGROUND: Children with small or hypoplastic portal veins represent a challenge for liver transplantation. Graft loss of up to 70% has been reported in these patients in the past. A variety of techniques has been used in both cadaveric and living related transplants in an effort to overcome this problem. Variability arises as to whether to use a vascular graft and where on the portal system to attach the graft. METHOD: We present our usage of a simple and straightforward interposition iliac vein allograft fashioned in a manner to achieve large anastomotic cross-sectional area on the confluence of the superior mesenteric/splenic veins. The procedure also overcomes problems of graft vein/portal vein size mismatch in the cases where liver and vein grafts are procured from much larger donors. RESULTS: A total of 14 children presented with hypoplastic portal vein (diameter<5 mm), of a total of 30 consecutive patients requiring cadaveric liver transplants, and benefited from this technique. Median recipient age was 10.5 months. Revascularization times ranged from 22 to 43 min with a mean of 33 min. All patients are alive and well at a mean follow-up of 329 days (10 months). All liver grafts are well and functioning. No portal vein problem was detected. CONCLUSION: Results from this technique are clearly encouraging. Because portal vein hypoplasia is a common problem in pediatric transplant candidates, we believe this alternative technique is of interest and should be added to the transplant surgeon's armamentarium.     

Percutaneous transhepatic treatment of symptomatic mesenteric venous thrombosis

Three patients were seen with acute mesenteric venous thrombosis. With a transhepatic access, percutaneous pharmacologic thrombolysis was performed in one patient with extensive thrombosis of the portal and mesenteric veins, resulting in complete thrombolysis of the portal vein and partial thrombolysis of the superior mesenteric vein. In two patients with focal thrombosis, the use of mechanical devices achieved complete thrombolysis. Percutaneous thrombolysis of portal and mesenteric veins with a transhepatic approach, followed by coil embolization, is a promising endovascular technique for treatment of symptomatic acute mesenteric venous thrombosis.     

High incidence of thrombosis of the portal venous system after laparoscopic splenectomy: a prospective study with contrast-enhanced CT scan

OBJECTIVE: The aims of this prospective study were to investigate the true incidence of portal or splenic vein thrombosis (PSVT) after elective laparoscopic splenectomy using contrast-enhanced computed tomography (CT) scan, and outcome of anticoagulant therapy for PSVT. SUMMARY BACKGROUND DATA: Although rare, thrombosis of the portal venous system is considered a possible cause of death after splenectomy. The reported incidence of ultrasonographically detected PSVT after elective open splenectomy ranges from 6.3% to 10%. METHODS: Twenty-two patients underwent laparoscopic splenectomy (LS group), and 21 patients underwent open splenectomy (OS group). Preoperative and postoperative helical CT with contrast were obtained in all patients, and the extent of thrombosis was investigated. Prothrombotic disorder was also determined. RESULTS: PSVT occurred in 12 (55%) patients of the LS group, but in only 4 (19%) of the OS group. The difference was significant (P = 0.03). Clinical symptoms appeared in 4 of the 12 LS patients. Thrombosis occurred in the intrahepatic portal vein (n = 9), extrahepatic portal vein (n = 2), mesenteric veins (n = 1), proximal splenic vein (n = 4), and distal splenic vein (n = 8). Prothrombotic disorder was diagnosed in 1 patient. Anticoagulant therapy was initiated once the diagnosis was established, and complete recanalization, except for distal splenic vein, was observed without any adverse event. Patients with splenomegaly were at high risk of PSVT. CONCLUSIONS: PSVT is a more frequent complication of laparoscopic splenectomy than previously reported but can be treated safely following early detection by CT with contrast.     

Successful Treatment of a Patient With Diffuse Portosplenomesenteric Thrombosis Using a Pericholedochal Varix for Portal Flow Reconstruction During Deceased Donor Liver Transplantation: A Case Report

Portal vein thrombosis remains a challenging issue in liver transplantation. When thrombectomy is not feasible due to diffuse portosplenomesenteric thrombosis, other modalities are adapted such as the use of a jump graft or portal tributaries or even multivisceral transplantation. For patients with diffuse thrombosis of the splanchnic venous system, a large pericholedochal varix can be a useful vessel for providing splanchnic blood flow to the graft and for relieving portal hypertension. We report our experience of successfully treating a patient with diffuse portosplenomesenteric thrombosis using a pericholedochal varix for portal flow reconstruction during deceased donor liver transplantation and eventually preventing unnecessary multivisceral transplantation. A 56-year-old man diagnosed with liver cirrhosis due to hepatitis B underwent deceased donor liver transplantation due to refractory ascites. Preoperative imaging revealed diffuse portosplenomesenteric thrombosis with large amount of ascites. During the operation, dissection of the main portal vein was not possible due to the development of multiple large pericholedochal varices and cavernous change of the main portal vein. After outflow reconstruction, portal inflow was restored by anastomosing the graft portal vein to a large pericholedochal varix. Postoperatively, although abdominal computed tomography scan showed stenosis of portal vein anastomosis site, liver function tests improved, and Doppler sonogram revealed no flow disturbance. During follow-up, the patient repeatedly developed hydrothorax and ascites. In addition, stenosis of the portal vein anastomosis and thrombosis of the portomesenteric system still remained. The patient underwent transhepatic portal vein stent insertion. After portal vein stent insertion, hydrothorax and ascites improved and the extent of thrombosis of the portomesenteric system decreased without anticoagulation therapy. In conclusion, enlarged pericholedochal varix in patients with totally obliterated splanchnic veins can be a source of useful inflow to restore portal flow and decrease the extent of thrombosis, thereby preventing unnecessary multivisceral transplantation.     

Innovative techniques for and results of portal vein reconstruction in living-related liver transplantation

BACKGROUND: Portal vein reconstruction is a crucial factor affecting the outcome of a successful living-related liver transplantation. We describe here our experience with portal vein reconstruction in 314 cases of living-related liver transplantation with use of novel surgical modalities to enable the transplant surgeons to deal with any size mismatch between the donor's and recipient's portal veins. METHODS: Portal vein reconstruction was classified into 2 major groups, anastomosis without and with a vein graft. When there was no stenosis of the recipient portal vein and the diameter was the same, the portal trunk was used for anastomosis. When the diameter mismatch was minimal, branch patch anastomosis was feasible. When the recipient portal vein was significantly stenotic and the portal vein of the graft was long enough, we removed the stenotic trunk and constructed an anastomosis between the graft portal vein and the confluence of the recipient portal vein. When the graft portal vein was short, a vein graft was interposed. The vein patch technique was preferable when the diameter of the graft vein was not large enough for the interposition technique. RESULTS: Anastomosis without vein graft included trunk anastomosis (n = 156), branch patch anastomosis (n = 39), and confluence anastomosis (n = 22). Anastomosis with vein graft used the interposition technique (n = 77) and vein patch technique (n = 27). The origin of the grafts was mostly from the maternal left ovarian vein (70%) or the paternal inferior mesenteric vein (27%). Complications related to portal vein reconstruction occurred in 16 (5%) patients: portal vein thrombosis in 8, stenosis in 7, and fatal rupture in 1 patient. The incidence of complications was similar for all techniques except for confluence anastomosis. CONCLUSION: Our innovative techniques should be helpful for overcoming diameter or length mismatches in portal vein reconstruction in pediatric liver transplantation.     

Intraoperative stent placement in the portal vein during or after liver transplantation.

The purpose of this research was to evaluate the intermediate effectiveness of intraoperative portal vein stent placement for portal venous stenosis in liver transplantation. We attempted intraoperative portal vein stent placement in 44 portal venous anastomotic stenoses in 36 patients. All patients underwent stent placement via either the inferior or superior mesenteric vein. A total of 22 patients underwent portal vein stent placement simultaneously with liver transplantation, and 14 patients underwent stent placement 1-25 days (mean 5.93 days) after liver transplantation. Of the 22 patients, there was portal vein occlusion in 3 patients and small portal vein (<6 mm) in 10 patients (2.5-5.7 mm; mean size 3.9 mm). Patient follow-up included clinical and laboratory data collection, Doppler ultrasonography (US), and computed tomography (CT). Intraoperative portal vein stent placement was technically successful in all of our study patients, even in 6 patients with total occlusion of the portal vein. A total of 10 study patients underwent thrombectomy of the portal vein, 1 underwent patient portosystemic shunt ligation, and 7 patients had both procedures simultaneously. Portal venous patency has been maintained for 0-56 months (mean 16 months) in 42 (95%) of the 44 stent placements. In conclusion, intraoperative portal vein stent placement is an effective and long lasting treatment modality for treat portal venous stenosis, especially in patients with portal vein occlusion or small sized portal vein.     

A new technique for venous anastomosis of pancreatic allografts

Venous thrombosis is still a frequent cause of graft loss after pancreas transplantation where the portal vein is used for revascularisation. It is known that an increase in velocity of venous flow decreases the incidence of thrombosis. According to the equation of continuity, the flow velocity in the portal vein should decrease to 25% as compared with that in the splenic vein. Based on the rheological considerations we started to use the superior mesenteric vein, the diameter of which is similar to that of the splenic vein, for revascularisation of pancreas transplants after sewing the portal vein closed at its origin. This technique has been applied in 12 consecutive pancreatic transplants. Two patients died of a cerebrovascular accident and myocardial infarction, respectively. The only single pancreatic graft was lost due to rejection. The remaining 9 patients are alive and well between 2 and 23 months with normally functioning grafts. Another advantage of this technique is that a full-length portal vein can be left with the liver graft in the event of simultaneous liver and pancreas procurement.     

Outcome with surgical repair of extrahepatic portal vein aneurysms

Extrahepatic portal vein aneurysm is a rare clinical entity. The two most common locations for aneurysmal formation are at the confluence of the superior mesenteric vein (SMV) and the splenic vein, and at main portal vein trunk, just above the SMV-splenic vein confluence. In this article, two cases of extrahepatic portal vein aneurysm and their surgical treatment are presented. One is a saccular aneurysm located at the truncus of the portal vein; the other is a fusiform aneurysm at the confluence of the superior mesenteric vein and the splenic vein.