“Rex Shunt” for the Treatment of Portal Vein Thrombosis After Pediatric Liver Transplantation: A Case Report

Location and extent of cavernous transformation of the portal vein dictates different visceral side revascularization in Meso-Rex bypass

BACKGROUND

As an emerging standard of care for portal vein cavernous transformation (PVCT), Meso-Rex bypass (MRB) has been complicated and variated. The study aim was to propose a new classification of PVCT to guide MRB operations.

METHODS

Demographic data, the extent of extrahepatic PVCT, surgical methods for visceral side revascularization, intraoperative blood loss, operating time, changes in visceral venous pressure before and after MRB, postoperative complications and the condition of bypass vessels after MRB were extracted retrospectively from the medical records of 19 patients.

RESULTS

The median age of the patients (13 males and 6 females) was 32.5 years, while two patients were underage. Causes of PVCT can be summarized as follows: thrombophilia such as dysfunction of antithrombin III or proteins C; secondary to abdominal surgeries; secondary to abdominal infection or traumatic intestinal obstruction, and unknown causes. Intraoperatively, the median operation time was 9.5 h (7-13 h), and the intraoperative blood loss was 300 mL (100-1,600 mL). Ten cases used autologous blood vessels while 10 used allogeneic blood vessels. The vascular anastomosis was divided into the following types according to the site and approach: Type (T) 1-PV pedicel type, T2-confluence type, T3-major visceral vascular type; and T4-collateral visceral vascular type. Furthermore, the visceral venous pressure before and after MRB dropped significantly from 36 cmH2O (28-44) to 24.5 cmH2O (15-31) (P < 0.01). Postoperatively, one patient had delayed wound healing, two developed biochemical pancreatic fistulae, one experienced lymphatic leakage, the former caused by heat damage of the pancreatic tissues, the latter by cutting lymphatic vessels in the mesentery or removing the local lymph nodes during the process of separating the superior mesenteric vein, and one was re-operated on for an intervening intestinal fistulae. Postoperative enhanced CT scans revealed a significant improvement in abdominal varix in the patients with patent bypass, and at the 1-year postoperative follow-up, enhanced CT scans of six patients showed that the long axis of the spleen was reduced by ≥ 2 cm.

CONCLUSIONS

MRB can effectively reduce visceral venous pressure in patients with PVCT. It is feasible to determine the PVCT type according to the extent of involvement and to choose individualized visceral side revascularization performances.

Technical Aspects and Considerations of Meso-Rex Bypass Following Liver Transplantation With Left Lateral Segment Grafts: Case Report and Review of the Literature

In pediatric patients with extrahepatic portal vein obstruction and complications of portal hypertension, but with normal liver function, a meso-Rex bypass (MRB) connecting the superior mesenteric vein to the intrahepatic left portal is the favored surgical management. Pediatric patients with a history of a partial liver transplant (LT), especially living donors, are at greater risk for portal vein complications. Hence, an adequate knowledge of this technique and its additional challenges in the post-LT patient setting is crucial. We provide an overview of the available literature on technical aspects for an MRB post-LT. Preoperative considerations are highlighted, along with intraoperative considerations and postoperative management. Special attention is given to the even-more-demanding aspect of performing an MRB post-liver transplantation with a left lateral segment. Surgical alternatives are also discussed. In addition, we report here a unique case in which this surgical technique was performed on a complex pediatric patient with a history of a living-donor LT with a left lateral segment graft over a decade ago.

Meso-Rex bypass as an alternative technique for portal vein reconstruction at or after liver transplantation in children: review and perspectives

Direct portal revascularization can be achieved by interposing a vascular graft between the SMV and the Rex recessus (left portal vein system): the MRB. To review indications and results of the procedure in the setting of pediatric liver transplantation, reports were selected from the English literature. Previously reported series were updated to analyze long-term outcome. A new series was added and analyzed as a complementary set of cases. A total of 51 cases were analyzed. With a 96% overall patient survival rate and a 100% long-term patency rate when the IJV is used for the bypass, MRB achieves a very successful physiologic cure of chronic portal hypertension and restores the portal flow into and through the liver graft. It also has been used successfully for primary revascularization of liver grafts, as well as for managing early acute portal vein thrombosis episodes. The use of this procedure in conjunction with other strategies and techniques might be of interest for transplant surgeons, particularly those caring for children.

Living donor liver transplantation in 43 children with biliary atresia: a single-center experience from the mainland of China

BACKGROUND

There is no large-cohort report on living donor liver transplantation (LDLT) for biliary atresia (BA) patients from the mainland of China. This single-center study describes our initial experience with 43 LDLTs for BA patients aged two years or younger.

METHODS

In this study, the eligibility criteria were BA as the primary diagnosis and two years of age or younger. From October 2006 to December 2010, the clinical data of 43 LDLTs, including pre-operative evaluations, surgical techniques, postoperative complications and outcomes of donors and recipients, were retrospectively analyzed.

RESULTS

Donor graft type was the left lateral segment with compatible ABO blood groups. Forty-three recipients were selected in this study. The median patient age at operation was 9 months (range 6-24), and the median body weight was 8 kg (range 5.7-12.5). Fourteen (32.6%) recipients received Kasai operations before liver transplantation. The overall one- and two-year cumulative survival rates for grafts and recipients were 81%, 81% and 76%, 76%, respectively. No donor mortality was encountered, with a minimal morbidity and no long-term sequelae. Nine out of 43 recipients died. Postoperative complications of recipients were biliary leakage and refluxing cholangitis (11/43, 25.6%), hepatic artery thrombosis (4, 9.3%), pulmonary infections (4, 9.3%), portal vein thrombosis (3, 7.0%), wound disruption (3, 7.0%), acute rejection (3, 7.0%), cytomegalovirus infection (2, 4.7%), and intra-abdominal bleeding (1, 2.3%).

CONCLUSION

Despite the relatively low survival rates due to lack of experience initially, LDLT still provides encouraging outcomes for pediatric recipients with BA, even small children under two years old.

Imaging the Rex vein preoperatively using wedged hepatic venous portography

BACKGROUND

Mesentericoportal bypass, the Rex shunt, restores the physiological hepatic portal flow and reduces the clinical sequelae of portal hypertension in children with extrahepatic portal vein obstruction (EHPVO). The preoperative evaluation includes an accurate assessment of the portal venous inflow and outflow. The former is readily assessed by ultrasound and MRI, while the outflow intrahepatic portal vein is harder to assess.

PURPOSE

To assess the efficacy of wedged hepatic venous portography (WHVP) at detecting a patent Rex vein preoperatively in children with EHPVO who were considered for mesenterico-portal bypass.

MATERIALS AND METHODS

A single-institution retrospective chart review was undertaken for children with EHPVO who had been considered for a mesoportal bypass between January 2001 and January 2010.

RESULTS

Sixteen children were considered for mesoportal bypass, including four post reduced-size liver transplant patients. Ten children (63%) underwent WHVP. The Rex vein was clearly identified in 8/10 (80%). One Rex vein was seen at surgery but not demonstrated at WHVP. Six mesoportal bypasses were performed without WHVP, of which three (50%) were successful.

CONCLUSION

WHVP had a sensitivity of more than 80% and specificity of 100% in the preoperative patency assessment of the Rex vein.

Transjugular intrahepatic porto-systemic shunt placement in a patient with left-lateral split-liver transplant and mesenterico-left portal vein by pass placement

This is a report of a successful placement of a transjugular intrahepatic porto-systemic shunt in a young patient with previous left-lateral, split-liver transplant and mesenterico-left portal vein by pass placement after posttransplant extrahepatic portal vein thrombosis.

Rex shunt for acute portal vein thrombosis after pediatric liver transplantation in children with biliary atresia

BACKGROUND/PURPOSE

Posttransplantation portal vein thrombosis (PVT) can have severe health consequences, and portal hypertension and other consequences of the long-term privation of portal inflow to the graft may be hazardous, especially in young children. The Rex shunt has been used successfully to treat PVT patients since 1998. In 2007, we started to perform this surgery in patients with idiopathic PVT and late posttransplantation PVT. Herein we have reported our experience with this technique in acute posttransplantation PVT.

METHODS

Three patients of ages 12, 15, and 18 months underwent cadaveric (n = 1) or living donor (n = 2) orthotopic liver transplantation (OLT). All patients had biliary atresia with portal vein hypoplasia; they developed acute PVT on the first postoperative day. They underwent a mesenteric-portal surgical shunt (Rex shunt) using a left internal jugular vein autograft (n = 2) or cadaveric iliac vein graft (n = 1) on the first postoperative day.

RESULTS

The 8-month follow-up has confirmed shunt patency by postoperative Doppler ultrasound. There have been no biliary complications to date.

CONCLUSIONS

The mesenteric-portal shunt (Rex shunt) using an autograft of the left internal jugular or a cadaveric vein graft should be considered for children with acute PVT after OLT. These children usually have small portal veins; reanastomosis is often unsuccessful. In addition, this technique has the advantage to avoid manipulation of the hepatic hilum and biliary anastomosis. Although this study was based on a limited experience, we concluded that this technique is feasible, with great benefits to and low risks for these patients.

Unusual portal reconstructions after liver transplantation — Case report and review of literature

Portal vein reconstruction might be a challenge in certain cases of liver transplantation. The problem usually arises due to small vessels in pediatric transplantation and/or living related donor and split liver transplantation, or as a result of extensive PVT in adult recipients. Authors report a case of a 60-year-old alcoholic cirrhotic patient with reverse portal flow. The standard end to end portal anastomosis did not work well, so a mesoportal shunt with a donor iliac vein conduit was performed first, followed by a cavoportal hemitransposition. After unsuccessful attempts of providing good portal flow, the donor umbilical vein and the iliac conduit was used for portal flow reconstruction as meso-Rex graft. The patient has been doing fine for eight months after her liver transplantation. Unusual types of portal reconstructions consist of meso-portal, umbilico-portal, renoportal anastomoses that are primarily used as rescue techniques. However, it is rare that one has to use them sequentially in the same patient.