EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Objectives: Portal vein thrombosis is a common complication in end-stage liver diseases of candidates for liver transplant. Most portal vein thromboses can be removed with thrombectomy. However, if the thrombosis extends to the distal superior mesenteric vein, it is difficult to reconstruct the portal vein. We report herein a case of dilated gastric coronary vein to portal vein reconstruction in liver transplant.

Case Report: During the operation, the portal vein thrombosis was confirmed; it extended to the distal superior mesenteric vein. It could not be removed, and a jumping graft vein could not be used either. The dilated gastric coronary vein was dissected. After a piggy-back caval anastomosis, the recipient gastric coronary vein was anastomosed to donor portal vein using side-to-end anastomosis. Successive ultrasound studies demonstrated patent portal anastomosis. At postoperative day 30, computed tomography scans confirmed the patency of the portal anastomosis. The patient recovered fully and at the time of this writing, was doing well 1 year after transplant. Neither ascites nor upper gastrointestinal bleeding occurred.

Conclusions: If complete portal vein thrombosis extends to the distal superior mesenteric vein, and a jumping graft vein cannot be applied, the recipient gastric coronary vein or other collateral varix anastomosed to the donor portal vein is an alternative.

Key words : Liver transplant, Portal vein thrombosis, Portal vein reconstruction

Portal vein thrombosis (PVT) is a common complication in end-stage liver diseases arising in 2% to 16.5% of candidates for liver transplant.^1-4 With the development of surgical and medical strategies, PVT is no longer a contraindication in liver transplant. However, it remains a risk factor and is associated with posttransplant morbidity and mortality.⁵ Most PVTs can be managed with simple thrombectomy or a jumping graft. However, if the thrombosis extends to the distal superior mesenteric vein, it is difficult to reconstruct the portal vein. Given this situation, if a dilated gastric coronary vein can be found during the operation, one option is to use a gastric coronary vein to portal vein reconstruction.

Herein, we report a case of dilated gastric coronary vein to portal vein reconstruction in liver transplant. Based on related literature, we also discuss alternative portal vein reconstruction in liver transplant.

A 51-year-old man presented with hepatitis B liver cirrhosis associated with refractory ascites. The Model for End-stage Liver Disease score was 27. Before the transplant, Doppler ultrasound and spiral computed tomography (CT) imaging showed complete thrombosis in the portal, superior mesenteric, splenic vein and varices. The portal vein thrombosis (PVT) was confirmed during operation. Additionally, an operative ultrasound indicated the complete PVT extending to the distal superior mesenteric vein. The PVT could not be removed. And after low dissection of the portal vein, a jumping graft vein could not be applied either.

The dilated gastric coronary vein was dissected, and we performed an anastomosis between the dilated gastric coronary vein and graft portal vein. After a piggy-back caval anastomosis, the recipient gastric coronary vein was anastomosed to the donor portal vein, using side-to-end anastomosis with 6-0 Prolene (Figure 1). To ensure blood inflow to the graft, the distal gastric coronary vein was ligated with suture. A Doppler examination after reperfusion demonstrated a good signal in both portal branches. After the transplant, dextran 500 mL was administered intravenously and aspirin 81 mg/day was given orally. Successive ultrasound studies demonstrated a patent portal anastomosis. Thirty days after transplant, CT scans confirmed the patency of the portal anastomosis (Figure 2). At the time of this writing, the patient had recovered fully and was doing well 1 year after transplant. Neither ascites nor upper gastrointestinal bleeding occurred.

Most PVTs can be diagnosed with preoperative Doppler sonography, CT scan, or magnetic resonance imaging, based on an absence of a visible normal portal vein and its replacement with serpiginous veins. Before the liver transplant, one must evaluate and determine the extent of the thrombosis in cases with PTV. This allows one to predetermine alternative means of reconstructions.

According to extension and severity, PVT is classified as grade 1 to grade 4 (from partial to complete) by Yerdel and associates.⁶ Partial thrombosis (grade 1 or grade 2) can be removed with a thrombectomy/thromboendovenectomy and an end-to-end donor-recipient portal anastomosis. Some patients may need low dissection of the portal vein, thrombectomy, and then anastomosis without interposition of a vessel graft. However, managing a complete thrombosis (grade 3 or 4), especially a grade 4 PVT (ie, complete thrombosis of the portal vein and proximal and distal superior mesenteric vein) may challenge the surgeons’ skills. Based on the intraoperative characteristics of the thrombus and its extension, different surgical procedures and skills may be applied including a jumping graft vein, an anastomosis to collateral vessel, a portocaval hemitransposition, an extra-anatomic reconstruction, or portal vein arterializations.

If the PVT extends to the proximal superior mesenteric vein, but the distal part is a patent vessel, the preferred method is a mesoportal jumping graft using the donor iliac vein.⁵ However, if a complete PVT extends to the distal superior mesenteric vein, a jumping graft vein cannot be applied. In this situation, if a dilated coronary (> 1 cm in diameter) or other large collateral varix is found during the operation, the recipient gastric coronary vein or other collateral varix anastomosed to the donor portal vein is the alternative. This anastomosis is an easier reconstruction. However, because a varicose vessel wall is thin and fragile, it is easily torn. To prevent rethrombosis, anticoagulant therapy should be given postoperatively. Rodríguez-Castro and associates⁷ in reviewing the incidence of rethrombosis in patients with preventive therapy, found the incidence of rethrombosis was lower in patients with preventive therapy, compared to nontherapy (6.1% vs 10.3%; P = .019). Regarding preventive strategy, we give dextran and aspirin, whereas low-molecular weight or unfractionated heparin is most commonly suggested in the literature.⁷

A gastric coronary vein to portal vein reconstruction may not be available in all cases of PVT. If the PVT occludes completely the superior mesenteric vein without any adequate collateral veins, a portocaval hemitransposition, an extra-anatomic reconstruction, or a portal vein arterializations may be used for inflow to the graft. An anastomosis with the left renal vein or a cavoportal hemitransposition diverts caval blood to the liver, replacing portal inflow, but the problem of portal hypertension is not resolved absolutely. There remains the risk of portal hypertensive hemorrhage, ascites, and other complications. Ravaioli and associates⁵ reported after a cavoportal hemi-transposition, all patients develop some degree of renal failure and ascites, whereas patients managed with an anastomosis with a varix have excellent outcomes without complications. Multivisceral or liver and intestinal transplant may be an alternative for patients with diffuse portal mesenteric vein thromboses.

Another option for a complete PVT is a portal vein arterialization, which may offer a simple method of restoring portal blood flow into the graft. The donor portal vein can be anastomosed to the recipient gastroduodenal artery, donor splenic artery, or by using an iliac artery graft to the aorta.^8-10 However, because of the volume overload or high-pressure portal vein blood flow, some patients may experience right ventricular heart failure, aneurismal dilatation of the portal branches, or liver graft fibrosis. To limit the arterial blood flow to the liver, an artificial stenosis proximal to the anastomosis can be applied.

Volume: 12 Issue: 6 December 2014

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