Arterialization of the portal vein in pediatric liver transplantation. A report of two cases

Systemic Venous Inflow to the Liver Allograft to Overcome Diffuse Splanchnic Venous Thrombosis

Diffuse splanchnic venous thrombosis (DSVT), formerly defined as contraindication for liver transplantation (LT), is a serious challenge to the liver transplant surgeon. Portal vein arterialisation, cavoportal hemitransposition and renoportal anastomosis, and finally combined liver and small bowel transplantation are all possible alternatives to deal with this condition. Five patients with preoperatively confirmed extensive splanchnic venous thrombosis were transplanted using cavoportal hemitransposition (4x) and renoportal anastomosis (1x). Median follow-up was 58 months (range: 0,5 to 130 months). Two patients with previous radiation-induced peritoneal injury died, respectively, 18 days and 2 months after transplantation. The three other patients had excellent long-term survival, despite the fact that two of them needed a surgical reintervention for severe gastrointestinal bleeding. Extensive splanchnic venous thrombosis is no longer an absolute contraindication to liver transplantation. Although cavoportal hemitransposition and renoportal anastomosis undoubtedly are life-saving procedures allowing for ensuring adequate allograft portal flow, careful follow-up of these patients remains necessary as both methods are unable to completely eliminate the complications of (segmental) portal hypertension.

Portal vein arterialization promotes liver regeneration after extended partial hepatectomy in a rat model

In the current study, we sought to establish a novel rat model of portal vein arterialization (PVA) and evaluate its impact on liver regeneration after extended partial hepatectomy (PH). A total of 105 Sprague-Dawley rats were randomly assigned to three groups: 68% hepatectomy (the PH group), portal arterialization after 68% hepatectomy (the PVA group), and right nephrectomy only (the control group). Liver regeneration rate (LRR), 5-bromo-2-deoxyuridine (BrdU) labeling index, and liver functions were assessed on postoperative day 2, 7, 14 and 28. The 28-day survival rates were compared among the three groups. The 28-day survival rates were similar in all groups (P  =  0.331), and the anastomotic patency was 100%. The LRR in the PVA group was significantly higher than that of the PH group within postoperative 14 days (P < 0.05). The PVA and PH group had increased serum alanine aminotransferase levels (232 ± 61 U/L and 212 ± 53 U/L, respectively) compared with the control group (101 ± 13 U/L) on postoperative day 2, whereas from postoperative day 7 to day 28 there were no differences among the three groups. Serum albumin values were higher after the PVA procedure within postoperative day 14, which gradually became comparable on postoperative day 28 among the three groups. The peaks of BrdU labeling index appeared on postoperative day 2 in all rats, and the PVA procedure was associated with increased BrdU labeling index from postoperative day 7 to 28. The 28-day survival of the PVA rats was comparable. Our findings demonstrate that the PVA procedure utilizing portal vein trunk-renal artery microvascular reconstruction promotes remnant liver regeneration and confers beneficial effects on maintaining and even optimizing liver function after extended partial hepatectomy in rats.

Ten-year experience in porto-caval hemitransposition for liver transplantation in the presence of portal vein thrombosis

Porto-caval hemitransposition (PCH) in liver transplantation allows revascularization of the liver when the porto-mesenteric axis is thrombosed. We, here, review our experience over an 11-year period. A total of 23 patients underwent liver transplantation using PCH. Immunosuppression was based on tacrolimus, with sirolimus used in case of renal insufficiency. Most common diagnoses were hepatitis C, Laennec's, Budd-Chiari and cryptogenic cirrhosis. Six patients needed splenectomy prior to transplant, 5 during transplant, 1 post-transplant, 11 had no splenectomy. Overall survival was 60% at 1 year and 38% at 3 years, with 10 of 23 patients currently alive and the longest survivor at 9.3 years. Most common cause of death was sepsis/multisystem organ failure, followed by pulmonary embolism. A total of 7/23 patients experienced post-operative gastrointestinal bleeding episodes, 6/23 patients developed thrombosis of the vena cava (median 162 days post-op). Post-operative ascites was noted in almost all patients. Renal dysfunction was commonly seen even after the first month post-transplant. PCH offers a feasible option for liver transplantation in those patients with complex thrombosis of the mesenteric and portal circulation.

Surgical strategies for liver transplantation in the case of portal vein thrombosis--current role of cavoportal hemitransposition and renoportal anastomosis

Portal vein thrombosis (PVT), a common complication of end stage liver disease, is no longer considered a definite contraindication for liver transplantation (LTx). The clinical decision to perform an LTx in the case of PVT depends on the degree of PVT and the experience of the surgeon. Eversion thromboendovenectomy was suggested by most authors as the surgical technique of choice for PVT grade 1, 2, and 3. If PVT obstructs more extended parts of the porto-mesenteric venous circulation, surgical options would include different types of venous jump graft reconstructions or arterialization of the portal vein. Combined liver and small bowel transplantation is another possible alternative. Cavoportal hemitransposition (CPHT) and renoportal anastomosis (RPA) were recently particularly advocated as creative surgical strategies in case of diffuse PVT. In this work, we focus on CPHT and RPA surgical techniques during LTx, which attempts to secure the portal flow to the liver graft in case of pre-existent diffuse PVT. We provide a review of all reported clinical experience at international clinical centers using these techniques. According to our meta-analysis a total of 15 studies were published on this topic between 1996 and 2005. In summary, a total of 56 orthotopic LTx have been performed in 53 patients (28 men, 25 women) combined with either CPHT or RPA, for the purpose of providing the donor graft with adequate inflow. Mean age was 44 yr including two patients who were infants, with the youngest recipient being two yr old. Main indications for LTx were liver cirrhosis caused by viral hepatitis, alcoholic cirrhosis and cryptogenic cirrhosis. CPHT was performed in 46 cases, and RPA in 10 cases. Thirty-five of 53 patients (66%) had surgery previous to LTx. Of these, 13 patients (37%) [corrected] presented with a history of other previous surgical procedures for decompression of portal hypertension or treatment of associated complications (portocaval shunts, splenectomy, etc). Ascites, renal dysfunction, lower extremity and torso edema and variceal bleeding were dominant post-operative complications after CPHT or RPA noted in 22 cases (41.5%), 18 cases (34%), 17 cases (32%) and 13 cases (24.5%) respectively. Patients' follow-up ranged from two to 48 months. Thirty nine of 53 patients [corrected] (74%) survived [corrected] and 14 patients died (26%) [corrected] during the course of observation. Based on the literature, we conclude that the ideal technique to overcome PVT during LTx is still controversial. Short-term follow-up results of both methods are promising, however, long-term results are unknown at present. Furthermore, clinical follow-up and basic experimental work is required to evaluate the influence of systemic venous inflow to the liver graft with respect to long-term liver function and liver regeneration.