Current techniques of liver transection.

The operative mortality rate of liver resection has decreased from 10% to 20% before the 1980s to <5% in most specialized hepatobiliary centers nowadays. The most important factor for better outcome is reduced blood loss due to improvement in surgical techniques. Liver transection is the most challenging part of liver resection, associated with a risk of massive hemorrhage. Understanding the segmental anatomy of the liver and delineation of the proper transection plane using intraoperative ultrasound are prerequisites to safe liver transection. Clamp crushing and ultrasonic dissection are the two most widely used transection techniques. In recent years, new instruments using different types of energy for coagulation or sealing of vessels have been developed for liver transection. These include radiofrequency devices, Harmonic Scalpel, Ligasure and TissueLink dissecting sealer. Whether these new instruments, used alone or in combination with clamp crushing or ultrasonic dissection, improve the safety of liver transection has not been clearly demonstrated. The use of the vascular stapler for transection of major intrahepatic vascular trunks is also gaining popularity. These new instruments are particularly useful in liver transection during laparoscopic liver resection. Adjunctive measures such as intermittent Pringle maneuver and low central venous pressure anesthesia are also useful measures to reduce the risk of hemorrhage. This article reviews the safety and efficacy of different techniques of liver transection, with particular attention to evidence from randomized controlled trials available in the literature.