Douglas M Overbey, MD, MPH, Heather Carmichael, MD, Edward L Jones, Brandon Chapman, Luke Selby, Carlton Barnett, John T Moore, Thomas Robinson. University of Colorado
Objective: Stray energy transfer from surgical energy-based devices is a recognized mechanism for complications during laparoscopic operations. With the increasing use of the surgical robot for laparoscopic operations, characterizing stray energy transfer in robotic surgery is vital. The goal of this study was to quantify stray energy transfer within the robotic system by measuring energy transfer, heat transfer, and histologic cell damage in comparison to laparoscopic surgery.
Methods: A live porcine model was used with laparoscopic and robotic ports (DaVinci Si Robotic Surgery platform, Intuitive Surgical, Sunnyvale, CA) placed in standard cholecystectomy fashion. Energy transfer through the instrument was measured directly (milliamps) during activation with an oscilloscope. A thermal camera was used to measure surface temperature change nearest the tip of the instrument expected to absorb stray energy (inactive electrode: assistant grasper or camera). A standard L-hook was activated without touching tissue (open air activation) for five seconds on 30W coag mode (Force FX Generator, Covidien, Boulder, CO). The inactive electrode was placed touching small bowel to simulate accidental thermal injury. The bowel tissue at the site of temperature change was immediately resected and examined histologically for tissue injury. Student t-tests were used for all comparisons with a p-value less than 0.05 considered statistically significant.
Results: Comparison of the laparoscopic and robotic techniques are displayed in Table 1. Energy transfer was quantified using energy leak (per mA), which in these tests averaged 1.18 degree Celsius change (95% CI 1.05-1.31) at the inactive electrode. Surface temperature heated to a maximum of 5.5 degrees Celsius, more in the robotic system than laparoscopy but still clinically negligible. Pathology results from in vivo testing showed only thermal injury to the serosa without deeper mural injury.
Conclusions: Stray energy transfer occurs in both laparoscopic and robotic surgery in amounts that are measurable but without clinical relevance. The average change in tissue temperature is less than 2 degrees Celsius laparoscopically and less than 6 degrees robotically. While the robotic surgery appears to transfer more stray energy, no significant bowel injuries were caused in either group.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 88444
Program Number: P788
Presentation Session: iPoster Session (Non CME)
Presentation Type: Poster