Strategies to optimize donor safety with smaller grafts for adult-to-adult living donor liver transplantation.

PURPOSE OF REVIEW: To describe our current understanding of adult-to-adult living donor liver transplantation (AA-LDLT) in terms of graft size. RECENT FINDINGS: Improved outcomes of small liver graft with the use of portal vein pressure (PVP) modulation. SUMMARY: AA-LDLT is viewed as a viable alternative to whole liver transplantation on the treatment of end-stage liver disease. Over the past two decades, right lobe AA-LDLT has been the standard because of concerns related to graft size. Small-for-size syndrome (SFSS) is an entity that presents in recipients of small grafts. It negatively affects patient and graft survival and recipients of grafts with a graft weight-to-recipient weight ratio (GW/RW) lower than 1.0 are at the highest risk. Over the last decade, our understanding of SFSS has identified PVP as a major determinant in the development of SFSS. Direct or indirect surgical PVP modulation has demonstrated a way to prevent the development of SFSS in recipients of small grafts and has improved the survival outcomes of small grafts. These improved outcomes coupled with concerns for donor safety have led to the renaissance of the use of left lobe grafts. Based on the current clinical data, the use of small grafts GW/RW greater than 0.6 is viewed as well tolerated when PVP is modulated to achieve a target PVP less than 15 mmHg after reperfusion and the left lobe is currently viewed as the ideal graft for AA-LDLT.

Left lobe adult-to-adult living donor liver transplantation: small grafts and hemiportocaval shunts in the prevention of small-for-size syndrome.

Adult-to-adult living donor liver transplantation (AA-LDLT) has better outcomes when a graft weight to recipient weight ratio (GW/RW) > 0.8 is selected. A smaller GW/RW may result in small-for-size syndrome (SFSS). Portal inflow modulation seems to effectively prevent SFSS. Donor right hepatectomy is associated with greater morbidity and mortality than left hepatectomy. In an attempt to shift the risk away from the donor, we postulated that left lobe grafts with a GW/RW < 0.8 could be safely used with the construction of a hemiportocaval shunt (HPCS). We combined data from 2 centers and selected suitable left lobe living donor/recipient pairs. Since January 2005, 21 patients underwent AA-LDLT with left lobe grafts. Sixteen patients underwent the creation of an HPCS between the right portal vein and the inferior vena cava. The portocaval gradient (portal pressure - central venous pressure) was measured before the unclamping of the shunt and 10 minutes after unclamping. The median actual graft weight was 413 g (range = 350-670 g), and the median GW/RW was 0.67 (range = 0.5-1.0). The portocaval gradient was reduced from a median of 18 to 5 mmHg. Patient survival and graft survival at 1 year were 87% and 81%, respectively. SFSS developed in 1 patient, who required retransplantation. Two patients died at 3 and 10 months from a bile leak and fungal sepsis, respectively. The median recipient bilirubin level and INR were 1.7 mg/dL and 1.1, respectively, at 4 weeks post-transplant. One donor had a bile leak (cut surface). This is the first US series of small left lobe AA-LDLT demonstrating that the transplantation of small grafts with modulation of the portal inflow by the creation of an HPCS may prevent the development of SFSS while at the same time providing adequate liver volume. As it matures, this technique has the potential for widespread application and could positively effect donor safety, the donor pool, and waiting list times.

Endovascular closure of a hemiportocaval shunt after small-for-size adult-to-adult left lobe living donor liver transplantation.

Adult-to-adult living donor liver transplantation is an accepted treatment option for patients with end-stage liver disease. It is generally acknowledged that a graft weight to recipient body weight ratio > 0.8 is required in order to prevent the development of small-for-size syndrome. Size mismatch, however, is not the only factor responsible for the syndrome; instead, it results from a combination of factors, including the size, recipient status, and degree of portal hypertension. The ability to modulate the portal venous inflow has sparked renewed interest in the left lobe graft. We have used the hemiportocaval shunt, as described by Troisi et al. (Am J Transplant 2005;5:1397-1404), in left lobe living donor liver transplants in order to prevent small-for-size syndrome while enhancing the safety of the donor operation. In this report, we describe a novel technique for occluding a hemiportocaval shunt in a patient who developed hepatic encephalopathy after receiving a small-for-size left lobe liver allograft from a living donor.

Portosystemic shunts in children: a 15-year experience.

BACKGROUND: The role of portosystemic shunt (PSS) in children with portal hypertension has changed because of acceptance of liver transplantation and endoscopic hemostasis. We report our experience with PSS, mainly the distal splenorenal shunt, to define its role in the management of variceal bleeding. STUDY DESIGN: From 1987 to 2002, 20 children with variceal bleeding after endoscopic therapy underwent PSS. Patient and database records were reviewed. RESULTS: There were 14 boys and 6 girls; mean age was 11 years (range 3 to 18 years). Seventeen distal splenorenal and three mesocaval venous interposition shunts were performed. There was no operative mortality, 19 patients were alive at a median followup of 31 months (range 4 to 168 months) without evidence of recurrent gastrointestinal bleeding. One patient underwent transplantation 2 years after PSS and 1 patient died of hepatic failure while awaiting transplantation. The cause of portal hypertension was portal vein thrombosis (n = 13), biliary atresia (n = 3), congenital hepatic fibrosis (n = 2), hepatitis C cirrhosis (n = 1), and Budd-Chiari syndrome (n = 1). Eighteen children were Child-Turcotte-Pugh class A and the remaining two were class B. One patient had two episodes of hematemesis after PSS. Two patients had worsening ascites. One patient had mild encephalopathy and one patient had shunt stenosis requiring angioplasty. CONCLUSIONS: PSS is a safe and durable therapy for pediatric patients with portal hypertension. Liver transplantation should be reserved for children with poor synthetic function associated with variceal bleeding. PSS may also serve as a bridge to transplantation in patients with preserved hepatic function. PSS, in particular the distal splenorenal shunt, has produced excellent results. This experience challenges the need for alternative forms of portal decompression.

Transplantation for hepatocellular carcinoma and cholangiocarcinoma.

Hepatocellular carcinoma (HCC) and cholangiocarcinoma represent more than 95% of primary hepatic malignancies in adults. The incidence of both seems to be rising. Any form of cirrhosis and primary sclerosing cholangitis represent independent risk factors for the development of HCC and cholangiocarcinoma, respectively. The surgical treatment of these malignancies has evolved significantly in the past decade, and liver transplantation (LT) has revolutionized the prognosis of these conditions. Provided both malignancies are diagnosed early in their natural history, LT offers a greater than 75% chance of survival at 4 years. This is a remarkable improvement in the treatment of primary hepatic malignancies and compares favorably with any other form of treatment, including partial liver resection. The application of specific pretransplantation staging criteria, along with the addition of neoadjuvant chemoradiation therapy for cholangiocarcinoma, has made these results possible. The development of living donor LT further expands the treatment horizon for both diseases. It also lessens the impact of the scarcity of available deceased donor organs available for transplantation. The future challenge is to better characterize biologic staging/prognostic indicators that could expand the understanding and success in treating both malignancies.