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Surgical techniques in right lobe liver transplantation
Surgical Techniques in Right Lobe Liver Transplantation C.M. Lo and S.T. Fan
T
HE PROPOSAL for using a right lobe graft to extend the benefit of living donor liver transplantation (LDLT) to adult recipients1 was based on a high pretransplantation mortality rate of over 90% in high-urgency patients in Hong Kong and the inadequacy of a left lobe liver graft for an adult recipient. Since the first series was reported in 1997,1 over the last 2 years, increasing numbers of transplant centers have started programs of right lobe transplantation. Because of the extreme shortage of cadaver grafts, Asian countries including Japan, Korea, and Taiwan have shown the greatest enthusiasm in starting this new procedure; Western countries such as the United States have been quick to follow. Despite a slow diffusion of this procedure into clinical use in different parts of the world, the surgical technique is still evolving and various technical problems remain to be solved. In particular, the necessity of the middle hepatic venous drainage and biliary complications are issues of controversy and major concern. Optimal hepatic venous drainage is a key element for success in right lobe transplantation. Although a right lobe constitutes about two-thirds of the donor’s total liver volume, such a graft would still be small for size when used in a large recipient. Without adequate venous drainage, the graft is prone to congestion and damage by the excessive portal blood flow, particularly in a recipient with preexisting portal hypertension. We have advocated the extended right lobe graft that includes both the right hepatic vein and the middle hepatic vein for venous drainage. By transecting the liver on the left side of the middle hepatic vein, the middle hepatic vein is isolated at its junction with the left hepatic vein, and reconstruction is performed by an end-to-end anastomosis to the stump of the middle hepatic vein or left hepatic vein of the recipient. In addition, any inferior hepatic vein of significant size (⬎5 mm) would also be preserved and reimplanted to the inferior vena cava of the recipient. To facilitate these multiple hepatic venous anastomoses and to minimize the length of hepatic veins after anastomosis, the retrohepatic vena cava should be isolated. Contrary to this, most of the other transplant centers are using a right lobe graft without middle hepatic vein drainage. Our experience with the development of severe swelling and congestion of our first extended right lobe graft2 when reperfusion was established initially with right hepatic vein drainage alone prompted us to continue to use the extended right lobe graft. Cases of congestion of segments
V and VIII resulting in graft dysfunction and ascites have also been reported from Seoul, and this is particularly likely to occur if a major venous branch drains segments V and VIII into the middle hepatic vein. Although we have not encountered any difficulty or complication related to the isolation of the middle hepatic vein from the donor, it remains for centers that do not do so to accumulate enough data to demonstrate the absence of any adverse effect in the recipient. The biliary reconstruction is the Achille’s heal of right lobe liver transplant. Anatomic variations are common in the right hepatic duct3 and separate biliary reconstruction is anticipated for two distinct right anterior and right posterior segment ducts in nearly 40% of cases (right duct anatomic variations types A2, A3, A4, and A5). A goodquality intraoperative cholangiogram in two planes is mandatory to delineate the detailed biliary tract anatomy and avoid inadvertent ligation of an aberrant segmental branch. In addition, because of the short course of the right hepatic duct, division of the right duct away from the junction with the left duct to safeguard the donor’s bile duct implies that the site of transection will frequently be made proximal to the junction of the right anterior and right posterior segment ducts. Two or more bilioenteric anastomoses would then be necessary. Thus, it is advisable to place a marker at the planned site of transection of the right duct during the intraoperative cholangiogram and to transect the right duct close to the junction with the left duct. The stump of the right duct on the donor side should then be sutured with a free hand technique without any clamping. As compared to a LDLT using a left lobe liver graft, the most obvious advantage of a right lobe transplant is that donor selection would now be based truly on voluntarism instead of body build. Without the restriction imposed by the donor-to-recipient size match, it is possible to perform transplants from small donors to large recipients, and from female donors to male recipients. In addition, because the right lobe fits into the right subphrenic space of the recipient, the microvascular surgeons would find it easier to
From the Liver Disease Center, University of Hong Kong Medical Center, Queen Mary Hospital, Hong Kong, China. Address reprint requests to Prof C.M. Lo, Rm L457, Department of Surgery, University of Hong Kong Medical Center, Queen Mary Hospital, Hong Kong, China.
0041-1345/00/$–see front matter PII S0041-1345(00)01336-1
© 2000 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
1512
Transplantation Proceedings, 32, 1512–1513 (2000)
RIGHT LOBE LIVER TX
accomplish the hepatic artery anastomosis without any retraction and pressure on the graft. Similarly, during the bilioenteric anastomosis and on closure of the abdomen, damage to the graft from pressure will also be avoided. A right lobe liver transplant demands the highest degree of technical skill in hepatectomy and transplantation. Armed with the experience and technique that has driven us toward zero hospital death in hepatic resection,4 our previous analysis showed a higher risk for donors in right lobe liver transplant than those donating the left lobe5 even though blood loss can be minimized and homologous transfusion avoided. The justification for developing right lobe liver transplant depends on a balance of the recipient’s benefit that is largely reflected by the pretransplant mortality rate, and the donor’s cost as measured by the risk of the
1513
donor hepatectomy. Before considering offering this option to patients, a transplant center should honestly estimate these two parameters according to its own situation and experience. For any individual patient, it should be the potential donor and recipient who make the final decision as to whether this operation is worthwhile, based on such information. REFERENCES 1. Lo CM, Fan ST, Liu CL, et al: Ann Surg 226:261, 1997 2. Lo CM, Fan ST, Liu CL, et al: Transplantation 63:1524, 1997 3. Huang TL, Cheng YF, Chen CL, et al: Transplant Proc 28:1669, 1996 4. Fan ST, Lo CM, Liu CL, et al: Ann Surg 229:322, 1999 5. Lo CM, Fan ST, Liu CL, et al: Transplant Proc 31:533, 1999
T
HE PROPOSAL for using a right lobe graft to extend the benefit of living donor liver transplantation (LDLT) to adult recipients1 was based on a high pretransplantation mortality rate of over 90% in high-urgency patients in Hong Kong and the inadequacy of a left lobe liver graft for an adult recipient. Since the first series was reported in 1997,1 over the last 2 years, increasing numbers of transplant centers have started programs of right lobe transplantation. Because of the extreme shortage of cadaver grafts, Asian countries including Japan, Korea, and Taiwan have shown the greatest enthusiasm in starting this new procedure; Western countries such as the United States have been quick to follow. Despite a slow diffusion of this procedure into clinical use in different parts of the world, the surgical technique is still evolving and various technical problems remain to be solved. In particular, the necessity of the middle hepatic venous drainage and biliary complications are issues of controversy and major concern. Optimal hepatic venous drainage is a key element for success in right lobe transplantation. Although a right lobe constitutes about two-thirds of the donor’s total liver volume, such a graft would still be small for size when used in a large recipient. Without adequate venous drainage, the graft is prone to congestion and damage by the excessive portal blood flow, particularly in a recipient with preexisting portal hypertension. We have advocated the extended right lobe graft that includes both the right hepatic vein and the middle hepatic vein for venous drainage. By transecting the liver on the left side of the middle hepatic vein, the middle hepatic vein is isolated at its junction with the left hepatic vein, and reconstruction is performed by an end-to-end anastomosis to the stump of the middle hepatic vein or left hepatic vein of the recipient. In addition, any inferior hepatic vein of significant size (⬎5 mm) would also be preserved and reimplanted to the inferior vena cava of the recipient. To facilitate these multiple hepatic venous anastomoses and to minimize the length of hepatic veins after anastomosis, the retrohepatic vena cava should be isolated. Contrary to this, most of the other transplant centers are using a right lobe graft without middle hepatic vein drainage. Our experience with the development of severe swelling and congestion of our first extended right lobe graft2 when reperfusion was established initially with right hepatic vein drainage alone prompted us to continue to use the extended right lobe graft. Cases of congestion of segments
V and VIII resulting in graft dysfunction and ascites have also been reported from Seoul, and this is particularly likely to occur if a major venous branch drains segments V and VIII into the middle hepatic vein. Although we have not encountered any difficulty or complication related to the isolation of the middle hepatic vein from the donor, it remains for centers that do not do so to accumulate enough data to demonstrate the absence of any adverse effect in the recipient. The biliary reconstruction is the Achille’s heal of right lobe liver transplant. Anatomic variations are common in the right hepatic duct3 and separate biliary reconstruction is anticipated for two distinct right anterior and right posterior segment ducts in nearly 40% of cases (right duct anatomic variations types A2, A3, A4, and A5). A goodquality intraoperative cholangiogram in two planes is mandatory to delineate the detailed biliary tract anatomy and avoid inadvertent ligation of an aberrant segmental branch. In addition, because of the short course of the right hepatic duct, division of the right duct away from the junction with the left duct to safeguard the donor’s bile duct implies that the site of transection will frequently be made proximal to the junction of the right anterior and right posterior segment ducts. Two or more bilioenteric anastomoses would then be necessary. Thus, it is advisable to place a marker at the planned site of transection of the right duct during the intraoperative cholangiogram and to transect the right duct close to the junction with the left duct. The stump of the right duct on the donor side should then be sutured with a free hand technique without any clamping. As compared to a LDLT using a left lobe liver graft, the most obvious advantage of a right lobe transplant is that donor selection would now be based truly on voluntarism instead of body build. Without the restriction imposed by the donor-to-recipient size match, it is possible to perform transplants from small donors to large recipients, and from female donors to male recipients. In addition, because the right lobe fits into the right subphrenic space of the recipient, the microvascular surgeons would find it easier to
From the Liver Disease Center, University of Hong Kong Medical Center, Queen Mary Hospital, Hong Kong, China. Address reprint requests to Prof C.M. Lo, Rm L457, Department of Surgery, University of Hong Kong Medical Center, Queen Mary Hospital, Hong Kong, China.
0041-1345/00/$–see front matter PII S0041-1345(00)01336-1
© 2000 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
1512
Transplantation Proceedings, 32, 1512–1513 (2000)
RIGHT LOBE LIVER TX
accomplish the hepatic artery anastomosis without any retraction and pressure on the graft. Similarly, during the bilioenteric anastomosis and on closure of the abdomen, damage to the graft from pressure will also be avoided. A right lobe liver transplant demands the highest degree of technical skill in hepatectomy and transplantation. Armed with the experience and technique that has driven us toward zero hospital death in hepatic resection,4 our previous analysis showed a higher risk for donors in right lobe liver transplant than those donating the left lobe5 even though blood loss can be minimized and homologous transfusion avoided. The justification for developing right lobe liver transplant depends on a balance of the recipient’s benefit that is largely reflected by the pretransplant mortality rate, and the donor’s cost as measured by the risk of the
1513
donor hepatectomy. Before considering offering this option to patients, a transplant center should honestly estimate these two parameters according to its own situation and experience. For any individual patient, it should be the potential donor and recipient who make the final decision as to whether this operation is worthwhile, based on such information. REFERENCES 1. Lo CM, Fan ST, Liu CL, et al: Ann Surg 226:261, 1997 2. Lo CM, Fan ST, Liu CL, et al: Transplantation 63:1524, 1997 3. Huang TL, Cheng YF, Chen CL, et al: Transplant Proc 28:1669, 1996 4. Fan ST, Lo CM, Liu CL, et al: Ann Surg 229:322, 1999 5. Lo CM, Fan ST, Liu CL, et al: Transplant Proc 31:533, 1999