Thermal effects of laparoscopic saline-enhanced radiofrequency cautery on renal parenchyma in a porcine model

Purpose: Advances in the field of surgery have recently developed a number of devices and materials to improve surgical hemostasis. The effects of one such device, saline-cooled monopolar radiofrequency electrocautery, has been well scrutinized in splenic and hepatic applications. Despite the utilization of this device in urologic surgery, the classification of the thermal effects has been poorly characterized to date. The purpose of this study was to discern the thermal characteristics of the device in the laparoscopic environment when used on renal parenchyma. Materials and Methods: After institutional approval, four domestic swine were randomized to receive laparoscopic renal lesions randomly generated by either saline-cooled (25 W with saline flow rate of 4 mL/min) or standard monopolar radiofrequency electrocautery. The energy source was applied for between 1 and 11 seconds for each device in order to create a total of 64 renal lesions. Each kidney was harvested and examined by a genitourinary pathologist blinded to the treatment interval. Results: The saline-cooled device provided a greater depth of coagulation effect compared to standard monopolar electrocautery at all points in time (P < 0.05). The diameter of the lesions created using saline-cooled monopolar electrocautery was greater than those created with standard electrocautery (P < 0.05). Conclusions: The saline-cooled monopolar electrocautery provided an improved coagulation effect compared to standard electrocautery in the laparoscopic setting. Recognition of the time and resultant thermal consequences can help the laparoscopic surgeon plan surgical approaches for renal lesions and improve hemostasis.