The Use of Technical Vessel Sealing Devices for Recipient Hepatectomy in Liver Transplantation

Overview

The surgical technique used in liver transplantation has undergone constant Evolution in an effort towards towards a safe, highly standardized procedure. Despite this, the initial step of the recipients' hepatectomy has not been in the focus of clinical research thus far. Due to usually advanced coagulopathy in liver transplantation recipients, this part of the operation still bares the risk of severe hemorrhage. This trial is designed to compare an electrothermic, bipolar vessel sealing device (LigaSureTM) and an ultrasound dissector (HARMONIC ACE®+7) to standard surgical techniques during the recipients' hepatectomy in liver transplantation. In a single center, prospective, randomized, controlled, parallel three armed, confirmatory, open trial, LigaSureTM and HARMONIC ACE®+7 will be compared to standard surgical techniques which, utilize titanium clips and conventional knot tying ligations during the recipients' hepatectomy in liver transplantation. Intraoperative total blood loss is the primary endpoint of the trial. Secondary endpoints include blood loss during the hepatectomy, the duration of both the hepatectomy and the entire surgical procedure, as well as blood transfusion requirements of the procedure. To generate reliable data, intraoperative blood loss will be recorded with respect to all rinse fluids during surgery, ascites and by weighing used swabs to generate reliable data. At 80% power and an alpha of 0.025 for both either of the experimental groups, twenty-three subjects will be analysed per protocol in each study arm in order to detect a clinically relevant reduction of intraoperative blood loss. The intention to treat analysis will include sixty-nine patients. The follow up period for each patient will be 90 days for safety reasons, whereas all clinical outcomes will be measured within the first ten postoperative days. This is the first prospective, randomized trial comparing two innovative, technical methods of vessel sealing and dissection against standard techniques for recipient hepatectomy. This will be done to detect a relevant reduction of intraoperative blood loss during liver transplantation.The results of the trial are expected to improve patients' outcome and safety after liver transplantation and to increase the general safety of this procedure.

Liver transplantation (LT) is a well-established procedure for the treatment of end stage liver disease. Many improvements in the surgical technique rendered this operation relatively safe. Most important operative innovations after the initial introduction of LT in the clinical Routine undertaken by Starzl include the use of veno-venous bypass in LT, the piggy-back technique with preservation of the recipients' caval vein and it's modification which was introduced by Belghiti with side-to-side cavo-caval anastomosis. Nevertheless very few improvements have been introduced in the surgical technique with regards to tissue preparation and sealing the blood vessels during recipient hepatectomy. Due to end stage liver disease and both the recipients' general and coagulatory condition, the hepatectomy carries the risk of severe blood loss which can impair the outcome after LT. Usually the recipient hepatectomy is carried out as a combination of sharp dissection of the hepatic adhesions to the abdominal wall and the diaphragm and clip or suture ligature of small retrohepatic caval vein branches. With advances in surgical procedures and equipment, modern technologies have been introduced, which have shortened operation time and improved surgical outcomes. Exquisite equipment for liver parenchyma transection, such as Cavitron ultrasonic surgical aspirator, ultrasonic dissector (USD), LigaSure (LS) and Tissue Link can also be used to reduce hemorrhage in liver resection. The ultrasonic scalpel (Ethicon) is a new USD that cuts and coagulates tissue using ultrasound at frequencies higher than those used by an ultrasonic aspirator. This device can also serve as a grasper and basically utilizes a blade which oscillates at 55 kHz, thus producing heat and enabling coagulation of vessels. Recently, its use and potential advantages in open liver resection have been demonstrated. The main technical advancement in this field relates to decreased intra-operative bleeding. Results of using USD (Harmonic Scalpel) during recipient hepatectomy showed that this method is safe compared with conventional knot tying ligation regarding intra- and postoperative bleeding rate. The electrothermal bipolar vessel sealing device LS is another alternative, which applies electrothermal bipolar coagulation and dissection in one step. The LS dissection device seals the tissue first before it is divided (both Tasks are performed with the same device). This may prevent severe bleeding. Furthermore, the sealing device is capable of coping with the small liver veins which can be sealed and divided safely without the need for sutures or clips. Especially the latter of which is known for interfering with sufficient "tangential" clamping of the inferior caval vein (IVC) for side to side cavo-cavostomy during piggy-back LT. It was reported that the use of LS devices for recipient hepatectomy in LT. It was concluded that, LS vessel sealing was an efficient method and that vessel sealing of the caval and Portal veins as well as other structures could be safely performed in the setting of end-stage liver disease. To our knowledge, no randomized clinical trial has been conducted to compare various innovative dissection methods against the standard techniques used for recipient hepatectomy. While LS and USD have been proven to be used safely in several major surgical procedures, including liver resection, their ability to reduce blood loss in liver transplant recipient hepatectomy has not yet been evaluated systematically.