Robotics and Laparoscopy
Lateral temperature spread of monopolar, bipolar and ultrasonic instruments for robot-assisted laparoscopic surgery
- To assess critical heat spread of cautery instruments used in robot-assisted laparoscopic (RAL) surgery.
Materials and Methods
- Thermal spread along bovine musculofascial tissues was examined by infrared camera, histology and enzyme assay.
- Currently used monopolar, bipolar and ultrasonic laparoscopic instruments were investigated at various power settings and application times.
- The efficacy of using an additional Maryland clamp as a heat sink was evaluated.
- A temperature of 45 °C was considered the threshold temperature for possible nerve damage.
- Monopolar instruments exhibited a mean (sem) critical thermal spread of 3.5 (2.3) mm when applied at 60 W for 1 s. After 2 s, the spread was >20 mm.
- For adjustable bipolar instruments the mean (sem) critical thermal spread was 2.2 (0.6) mm at 60 W and 1 s, and 3.6 (1.3) mm at 2 s.
- The PK and LigaSure forceps had mean (sem) critical thermal spreads of 3.9 (0.8) and 2.8 (0.6) mm respectively, whereas the ultrasonic instrument reached 2.9 (0.8) mm.
- Application of an additional Maryland clamp as a heat sink, significantly reduced the thermal spread.
- Histomorphometric analyses and enzyme assay supported these findings.
- All coagulation devices used in RAL surgery have distinct thermal spreads depending on power setting and application time.
- Cautery may be of concern due to lateral temperature spread, causing potential damage to sensitive structures including nerves.
- Our results provide surgeons with a resource for educated decision-making when using coagulation devices during robotic procedures.