Background: Bipolar electrosurgical and ultrasonic devices are routinely used in laparoscopic and open surgeries for hemostasis. Thermal spread and other device characteristics were evaluated for the Ligasure V (LV), Ligasure Advance (LA) (Valleylab, Boulder, Colorado), and Harmonic ACE (HS) (Ethicon).
Methods: Five millimeter laparoscopic instruments were tested within an in-vivo porcine model. Splenic, renal, uterine, and small bowel mesenteric vessels were tested. Each device was used to seal vessels less than 6-mm in diameter. Time to seal, device peak temperatures, time to peak temperatures, average jaw temperatures, and thermal spread were determined. Thermal imaging data was collected using the FLIR SC6000. SAS® software was used for statistical analysis. P-values <0.05 were considered statistically significant.
Results: The mean times to seal for the LV, LA, and HS were 3.29 (0.50 standard deviation), 3.26 (0.27), and 7.24 seconds (1.76). There was a difference in time to seal between the LV vs. HS (p<0.0001) and LA vs. HS (p<0.0003) but not between LV vs. LA (p=0.68). The mean peak temperatures for the LV (96.9°C, 6.64 SD), LA (83.0°C, 7.05 SD) and HS (297.7°C, 9.66) were significantly different (p<0.0001). When comparing LV vs. LA, significance was also achieved (p<0.0001). The time to peak temperature for each device (LV 2.63 seconds, 0.46 SD, LA 3.82, 0.93 SD, HS 6.83, 0.89 SD) was also significantly different (p<0.0001) as well as the average jaw temperatures of LV vs. LA (63.2°C, 5.14 SD vs. 68.3°C, 5.94 SD, p<0.02) when compared to HS (237.9°C, 9.37, p<0.001 and p<0.004). There was less thermal spread with the LV vs. LA (1.14mm, 0.53 SD vs. 1.25mm, 0.34 SD, p<0.0495) and significantly less thermal spread when both the LV and LA were compared to the HS (1.73mm, 0.50 SD, p<0.0001 and p<0.0001).
Conclusions: The LV and LA had significantly less thermal spread and peak temperatures when compared to HS, thus minimizing the risk of thermal damage to adjacent tissues. The LV had less thermal spread, lower average jaw temperatures, and quicker time to peak temperatures than the LA. Further investigations including burst pressure testing and histological analysis of sealed vessels will help elucidate differences between these electrosurgical devices.