The role of spontaneous portosystemic shunts in the course of orthotopic liver transplantation

Abstract

Spontaneous portosystemic shunts are commonly found in cirrhotic patients. Not yet established is their role after orthotopic liver transplantation (OLTx), especially when an increase in portal pressure develops, as during early acute rejection. In this study, 34 cirrhotic patients in a series of 70 OLTx are considered. Each patient had preoperative angiographic assessment, and, in 21 (62%), large spontaneous portosystemic shunts were evident. In 12 cases the shunts were not affected by the surgical procedure and were present during the postoperative period; in 9 the hepatectomy itself involved interruption of the shunts. The patient population was divided into two groups: patients with postoperative shunts (n = 12) and those without (n = 22). The two groups were similar in age, sex, Child's stage, transplantation variables, and number and grade of rejection episodes. However, mean transaminases (AST) values in the first 2 weeks were significantly higher levels in shunt versus nonshunt patients (421 +/- 335 vs 183 +/- 126; P less than 0.025), and this was even more evident when rejection occurred (626 +/- 375 vs 195 +/- 129; P less than 0.001). Furthermore, during an acute rejection reaction, three cases showed a true "steal phenomenon" through the large reopened shunts with ischemic damage to the grafts. The data indicate a possible detrimental effect of the spontaneous shunts on graft perfusion and suggest the prophylactic surgical interruption of the residual shunts during the transplantation.

Triple-phase computed tomography and intraoperative flow measurements improve the management of portosystemic shunts during liver transplantation

“…Many authors have recommended occlusion of spontaneous shunts at the time of transplantation and reported on PV thrombosis in patients with preexisting surgical shunts left intact during liver transplantation. 1,[5][6][7][8] Competition between SRSs and the PV for blood flow has also been described in nontransplantation settings. [10][11][12] In a report from Rasmussen et al, 13 the importance of routine intraoperative measurement of graft portal flow is emphasized.…”

“…1 When large enough, these portosystemic collaterals can redistribute flow away from the main portal vein (PV) and be associated with secondary PV atrophy and/or thrombosis. [2][3][4] After successful liver transplantation, these large shunts tend to diminish, because the new liver serves as a low-resistance vascular bed that accepts much larger flows through the new PV.…”

“…Furthermore, under conditions of increased hepatic graft resistance (for example, fluid overload, rejection, ischemic damage, and portal hypertension), reopening of shunts has been described. 1,5 In patients undergoing liver transplantation, it has been recommended that large portosystemic shunts be ligated or in certain instances where there is complete PV thrombosis, used as primary portal inflow. [6][7][8][9] Duplex ultrasonography has been the accepted standard for pretransplantation evaluation of the portal venous system.…”

Liver transplantation in patients with splenorenal shunts: Intraoperative flow measurements to indicate shunt occlusion

“…[11][12][13] Steal of portal flow by the shunt in these circumstances could add further insult to the liver. Pretransplantation studies with Doppler ultrasound and angiography are mandatory in cases of portasystemic anastomosis to assess shunt and portal vein patencies.…”

Ligating coronary vein varices: An effective treatment of “coronary vein steal” to increase portal flow in liver transplantation

“…(5) Operative or endovascular ligation of splenorenal shunts has been reported to improve portal venous blood flow following living and deceased donor liver transplant. (1,2,4) The first patient had a large coronary varix, which we believe contributed to her complicated postoperative course. Preoperative imaging suggested PV thrombosis, which was later confirmed in the operating room during the transplant.…”