The Authors' Reply.

Abstract

We appreciate the insightful comments by Prieto and colleagues1 on our study that documented an association of biliary strictures and low hepatic artery flows in patients without arterial complications. We share their interest in hepatic flows in liver transplantation and applaud their great results in liver transplantation, especially their low biliary complication rates (12.8% and 8.3%). We recognize the difficulties with proving the relationship between a specific hepatic arterial flow (400 mL/min) and a specific outcome (eg, long-term biliary complications) after liver transplantation. It is true that there are multiple factors that are in play when trying to study the cause of biliary complications in liver transplantation. Because of this challenge, we recognize that it is important to have in-depth information and granularity of data when studying this topic. After documenting the relationship between ratio of hepatic arterial flow/body weight and overall biliary complications, we conducted this study to further understand the relationship.2,3 The details that are required to accurately study the topic include bile duct reconstruction technique (duct-to-duct vs hepaticojejunostomy), the contribution of arterial complications, distinction between leaks and strictures, and most importantly, comparison of the incidence of biliary complications in a Kaplan-Meier curve as a cumulative incidence instead of comparing absolute incidence. Just as the comparison of survival after transplantation is best reported as cumulative rates in a Kaplan-Meier curve, we feel that the incidence of biliary complication is most accurately reported as such. Only when our data were analyzed in depth with the necessary detail of the data, the relationship between low hepatic artery flow and cumulative biliary strictures in patients who had duct-to-duct anastomosis and without arterial complications was identified. Unfortunately, in the study by Pratschke et al,4 the relationship between the hepatic arterial flow and biliary strictures were not investigated in detail. This study also lacked details on bile duct reconstruction technique, etiology of liver disease, the definition of biliary complications, and the rate of hepatic artery complications. The biliary complication rates in this study were unusually high (33.9%); the biliary complications were not stratified into leaks or strictures, and the rates were not reported as cumulative incidence. Likewise, although we applaud the great results reported in their comments, data presented by Prieto and colleagues1 also lack the necessary details to conclude that there is no relationship between hepatic artery flows and biliary complications. We agree with our colleagues that there is a relationship between hepatic flows and outcomes after liver transplantation and that more thoughtful studies with granularity are needed to further our understanding on the topic.