A Comparison of Cellular Damage Using Electrocautery and CO 2 Laser in Transoral Robotic Glossectomy

Abstract

Objectives:

1) Compare the zone of cellular damage using monopolar electrocautery and CO₂ laser during transoral robotic glossectomy. 2) Examine the effect of tissue tension during glossectomy on the extent of cellular damage. 3) Highlight the choice of energy source during transoral robotic glossectomy with margin assessment.

Methods:

Setting: Memorial Hermann Robotics Institute, November 2012.. A live anesthetized porcine model placed supine with the ventral tongue exposed. Multiple robotic glossectomies were performed using monopolar cautery (15 watts delivered via a robotic arm) and CO₂ laser (8 watts delivered via FlexGuide Fiber Introducer carried by a Robotic needle driver). The study was then repeated with 4 lbs of weighted tension on each side of the tongue to simulate the concept of tension-countertension. Glossectomy specimens were harvested and evaluated in a blinded manner by a pathologist for the zone of cellular damage.

Results:

Unpaired t-test with unequal variance was conducted to compare the zone of cellular damage (mm) from the electrocautery and the CO₂ laser glossectomy. There was a significant difference in the damage zone for EC and CO₂; two-tailed P less than 0.0001; t(27) = 7.08; Standard Error of Difference = 0.062.

Conclusions:

The zone of cellular damage from the edge of the incision is significantly greater with electrocautery than CO₂ laser in this robotic porcine glossectomy model. The difference is further amplified when tension-countertension is applied to the tissues. These data suggest that robotic CO₂ laser glossectomy may preserve more normal tissue (margins) around a specimen than electrocautery.