PlasmaKinetic Bipolar Vessel Sealing: Burst Pressures and Thermal Spread in an Animal Model

Abstract

Laparoscopic bipolar instruments are commonly employed to cauterize and divide tissue. A next-generation bipolar device has been developed that employs vapor pulse coagulation energy. We assessed the vessel-sealing capability of this device and quantified thermal spread during application. Bilateral laparoscopic nephrectomy was performed on six common swine >25 kg. Five-millimeter clips and surgical staplers (US Surgical, Norwalk, CT) were utilized to perform nephrectomy on one side, while the Gyrus PlasmaKinetic bipolar device (Minneapolis, MN) was employed for the contralateral nephrectomy. Vessel-sealing capabilities were assessed via burst-pressure studies. The extent of thermal spread was measured after tissue fixation and hematoxylin and eosin staining. Surgical clips/vascular staplers adequately controlled/sealed renal hilar vessels with burst pressures nearing 300 mm Hg. The Gyrus bipolar device reliably sealed and divided renal arteries <or=5 mm with burst pressures averaging 291 mm Hg. Renal arteries above this size were not consistently sealed, but, with the exception of one technical error, renal veins of all sizes (3-12 mm) were reliably controlled (average burst pressure 288 mm Hg). Histologic evidence of thermal spread extended an average of 3.6 mm from the cut edges of arteries and 3.4 mm from the edges of veins. The Gyrus PlasmaKinetic bipolar device is capable of reliably sealing/ dividing arteries as large as 6 mm, although we recommend restricting its use to vessels no larger than 5 mm in diameter to allow a safety margin. In addition, porcine renal veins of all sizes are adequately controlled. These sealed vessels are able to withstand pressures approaching 300 mm Hg. Thermal spread affects only the area surrounding the divided vessel. Further clinical studies are warranted.