Radiofrequency‐Assisted Liver Resection Does Not Induce Severe Liver Damage

Abstract

We read with interest the article by Mitsuo et al. [1] and were surprised by the conclusion that RF-assisted hepatectomy may induce severe postoperative liver damage and that the RF-assisted technique is not a safe procedure for liver transection in partial hepatectomy. We believe that to avoid misinterpretation and not to discredit an emerging and efficient procedure, certain issues need to be discussed. The authors used the original RF ‘‘CoolTip’’ precoagulation technique as it was described by Weber and Habib [2]. This technique implies that the noninsulated tip of the electrode is inserted through the entire liver mass until it reaches the undersurface, and when coagulation is completed, it is retracted upward to the liver surface in consecutive coagulation cycles. Precoagulation performed in this manner is maximal and complete for each cycle (cycle end is determined by change in current and impedance by generator) and requires more time and more RF energy than is really necessary. The liver surface is cut after the entire transection line has been precoagulated. Also, needlessly large coagulated and desiccated margins are achieved and, after transection, subsequently left on the remnant liver. The RF-assisted technique described by Mitsuo et al. used Pringle’s maneuver. It is unclear why Pringle’s maneuver was used, when this is a minimal blood-loss liver transection technique where only precoagulated, devitalized, liver tissue is cut. On the other hand, it is well established that hepatic blood flow occlusion is associated with a significant increase in the coagulation area which will lead to more extensive tissue necrosis and subsequently cause high levels of ALT [3–5]. The possibility of not using Pringle’s maneuver is one of the significant advantages of RF hepatectomy since ischemia– reperfusion hepatocellular injury is avoided. Furthermore, vascular occlusion abolishes the protective ‘‘heat sink’’ effect on vessels we do not intend to occlude. It is unclear why there was a 15% bile leak rate in the RF group compared with a 0% leak in the conventional group. RF energy induces desiccation and coagulation resulting in ‘‘welding’’ of the liver tissue, and it is equally effective for blood vessels and bile ducts. If there was no bleeding from the cut vessels, why should there be more bile leaks? In our series we have had no significant postoperative bleeding and no bile leaks. The authors did not specify the anatomic location of the resected segments. This is an important issue because the extent of liver mobilization and manipulation is an important cause of hepatocyte injury during liver surgery [6]. The degree of postcoagulation elevation of AST and ALT is noticeably higher in patients who have had preoperative chemotherapy and the incidence of these patients has not been described [7]. RF resection techniques in which Pringle’s maneuver is not used are not associated with high ALT levels. We base our observations on more than 250 RF ‘‘CoolTip’’-assisted hepatectomies using our own modification of the original Habib technique called the ‘‘sequential coagulate cut technique’’ [8, 9]. The electrode is advanced through liver tissue in the same way as the CUSA tip under optical guidance, the width of the coagulation rim is minimal, and Pringle’s maneuver is never used. In only five patients we had ALT levels close to 1000, while the majority had levels within the 100–200 range and all returned to normal within 7 days. There was no increase in the bilirubin level and postoperative bile fistulas were not observed. M. Milicevic (&) P. Bulajic The First Surgical Clinic, University of Belgrade School of Medicine, Koste Todorovica No. 6, Belgrade 11000, Serbia e-mail: machak@sbb.co.yu