Robotic stray energy with constant-voltage versus constant-power regulating electrosurgical generators

Stray energy from surgical energy instruments can cause unintended thermal injuries. There are no published data regarding electrosurgical generators and their influence on stray energy transfer during robotic surgery. There are two approved generators for the DaVinci Xi robotic platform: a constant-voltage regulating generator (cVRG) and a constant-power regulating generator (cPRG). The purpose of this study was to quantify and compare stray energy transfer in the robotic Xi platform using a cVRG versus a cPRG.

An ex vivo bovine model was used to simulate a standard multiport robotic surgery. The DaVinci Xi (Intuitive Surgical, Sunnyvale, CA) robotic platform was attached to a trainer box using robotic ports. A 5 s, open-air activation of the monopolar scissors was done with commonly used electrosurgical settings using a cPRG (ForceTriad, Covidien-Medtronic, Boulder, CO) or cVRG (ERBE VIO 300 dV 2.0, ERBE USA, Marietta, GA). Stray energy transfer was quantified as the change in tissue temperature (°C) nearest the tip of the assistance grasper (which was not in direct contact with the active monopolar scissors).

Stray energy transfer occurred with both generators. Utilizing common, comparable settings for standard coagulation, significantly less stray energy was transferred with the cVRG versus cPRG (4.4 ± 1.6 °C vs. 41.1 ± 13.0 °C, p < 0.001). Similarly, less stray energy was transferred using cut modes with the cVRG compared to the cPRG (5.61 ± 1.79 °C vs. 33.9 ± 18.4 °C, p < 0.001).

Stray energy transfer increases tissue temperatures more than 45C in the DaVinci Xi robotic platform. Low voltage modalities, such as cut or blend; as well as a cVRG generator, significantly reduces stray energy. Robotic surgeons can minimize the risk of stray energy injuries by using these low risk modes and/or generator.