Ultrasonic versus monopolar energy-based surgical devices in terms of surgical smoke and lateral thermal damage (ULMOST): a randomized controlled trial

Chahien Choi, In-Gu Do, Taejong Song

The purpose of this study was to compare the degree of surgical smoke or vapor and lateral thermal damage caused by two different energy-based surgical devices (ESDs) used in colpotomy during total laparoscopic hysterectomy. Patients undergoing laparoscopic hysterectomy were randomly assigned to an ultrasonic ESD group (n = 20) or monopolar ESD group (n = 20). Colpotomy was performed using the assigned ESD. The degree of surgical smoke or vapor obstructing the laparoscopic view was assessed by two independent reviewers using a 5-point Likert scale, in which a higher score indicates worse visibility. The degree of the lateral thermal damage was measured as the width from the point of instrument application to the margins of the unchanged nearby tissue using a light microscope. The baseline characteristics did not statistically differ between the two groups. The degree of surgical smoke or vapor obstructing vision was 1.2 ± 0.8 points in the ultrasonic group and 3.9 ± 0.7 points in the monopolar groups (p < 0.001). The lateral thermal damage was significantly increased in the monopolar group compared to in the ultrasound group (1500 µm [1200-2500 µm] vs. 950 µm [650-1725 µm], p = 0.037). Ultrasonic ESD had better laparoscopic visibility and caused less lateral thermal damage during colpotomy compared to monopolar device.