Thermal spread and heat absorbance differences between open and laparoscopic surgeries during energized dissections by electrosurgical instruments.

BACKGROUND

The reported literature suggests a higher incidence of collateral damage during energized dissections in laparoscopic surgery than in open surgery, probably because the ambient environment of the two approaches causes different heat absorbance and thermal spread during energized dissection.

METHODS

The experimental design involved randomized allocation of the surgical approach (4 open and 4 laparoscopic procedures) for eight adult pigs. A bipolar electrosurgery system (LigaSure) was used to perform 40 standardized regional dissections and procedures (5 per animal in randomized order). During these procedures, both white light and infrared thermographic imaging (3-5 mum) were recorded, and biopsy specimens were procured for histology.

RESULTS

The core body temperatures were significantly different between the two approaches. The laparoscopic group had a smaller temperature drop (3.08 +/- 0.98 degrees C vs 1.9 +/- 0.72 degrees C; p = 0.03). Differences also were observed in the thermal spread between the laparoscopic and open groups during portal vein dissection with the Advance (1.7 +/- 0.2 mm vs 2.3 +/- 1.7 mm; p = 0.07). Both thermography and histology confirmed the safety of the LigaSure system in limiting thermal spread and necrosis at the fusion line. Significant degradation of the instruments began after 10 activations. The deterioration was faster and more extensive in laparoscopic surgery.

CONCLUSIONS

Heat absorbance and thermal spread during bipolar electrosurgery are significantly different between open and laparoscopic surgery. Device performance degradation with repeat activations is more marked in laparoscopic surgery.