Douglas M Overbey, MD, MPH, Thomas Robinson, Heather Carmichael, Brandon Chapman, Edward Jones. University of Colorado
Objective: Stray energy transfer from the monopolar “Bovie” instrument has been shown to cause unintended thermal injuries during laparoscopic surgery. Our prior work demonstrated increased stray energy transfer during single incision laparoscopic surgery in comparison to traditional laparoscopy. However, stray energy transfer during robotic single incision surgery has not been examined. The PURPOSE of this study was to quantify stray energy transfer with a standard (multiport) robotic surgery and compare this to single incision robotic surgery.
Methods: The DaVinci Si model (Intuitive Surgical, Sunnyvale, CA) was tested in standard and single-site configurations. A live porcine model was used to compare stray energy transfer in vivo. Temperature of small bowel tissue adjacent to the instrument expected to absorb stray energy (assistant grasper) was measured using a thermal camera after a 5 second open air activation in coagulation mode (ForceTriad Generator, Covidien, Boulder, CO). Select specimens from each trial were immediately resected and evaluated for histologic thermal injury. Experiments were repeated 20 times based to detect an expected difference of five degrees. Student t-tests were used for all comparisons with significance set at 0.05.
Results: Stray energy transfer was higher in the single incision setup compared to the traditional setup (Figure 1). Stray energy in the assistant grasper caused 8.4±1.6 °C of temperature change in the standard configuration, and 11.6±3.3 °C in the single incision configuration (p=0.015). Doubling energy output to 60W amplified the same finding, with 9.4±2.5 °C of temperature change in the standard configuration and 15.3±3.4 °C in the single incision configuration (p<0.001). Despite the changes in surface temperature, coagulation necrosis did not extend beyond the serosa on histologic examination.
Conclusions: More stray energy transfers to the assistant grasper during single incision robotic surgery than during multiport robotic surgery. This increases tissue temperatures by more than 15 degrees Celsius but does not result in full thickness bowel injury. Surgeons can decrease the risk of stray energy complications by avoiding single incision surgery and utilizing low power settings.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 88573
Program Number: P800
Presentation Session: iPoster Session (Non CME)
Presentation Type: Poster