Ultrasonic dissection was found to be superior to monopolar electrosurgical dissection; however, the Harmonic dissecting unit was found to be more difficult to maneuver and cost more.
Laparoscopic cholecystectomy is the gold standard for management of symptomatic gallstones. Electrocautery remains the main energy form used during laparoscopic dissection. However, due to its risks, search is continuous for safer and more efficient forms of energy. This review assesses the effects of dissection using ultrasonic energy compared with monopolar electrocautery during laparoscopic cholecystectomy.
A literature search of the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE, and EMBASE was performed. Studies included were trials that prospectively randomized adult patients with symptomatic gallstone disease to either ultrasonic or monopolar electrocautery dissection during laparoscopic cholecystectomy. Data were collected regarding the characteristics and methodological quality of each trial. Outcome measures included operating time, gallbladder perforation rate, bleeding, bile leak, conversion rate, length of hospital stay and sick leave, postoperative pain and nausea scores, and influence on systemic immune and inflammatory responses. For metaanalysis, the statistical package RevMan version 4.2 was used. For continuous data, Weighted Mean Difference (WMD) was calculated with 95% confidence interval (CI) using the fixed effects model. For Categorical data, the Odds Ratio (OR) was calculated with 95% confidence interval using fixed effects model.
Seven trials were included in this review, with a total number of 695 patients randomized to 2 dissection methods: 340 in the electrocautery group and 355 in the ultrasonic group. No mortality was recorded in any of the trials. With ultrasonic dissection, operating time is significantly shorter in elective surgery (WMD −8.19, 95% CI −10.36 to −6.02, P>0.0001), acute cholecystitis (WMD −17, 95% CI −28.68 to −5.32, P=0.004), complicated cases (WMD −15, 95% CI −28.15 to −1.85, P=0.03), or if surgery was performed by trainee surgeons who had performed >10 procedures (P=0.043). Gallbladder perforation risk with bile leak or stone loss is lower (OR 0.27, 95% CI 0.17 to 0.42, P>0.0001 and OR 0.13, 95% CI 0.04 to 0.47, P=0.002 respectively), particularly in the subgroup of complicated cases (OR 0.24 95% CI 0.09 to 0.61, P=0.003). Mean durations of hospital stay and sick leave were shorter with ultrasonic dissection (WMD −0.3, 95% CI −0.51 to −0.09, P=0.005 and WMD −3.8, 95% CI −6.21 to −1.39, P=0.002 respectively), with a smaller mean number of patients who stayed overnight in the hospital (OR 0.18, 95% CI 0.03 to 0.89, P=0.04). Postoperative abdominal pain scores at 1, 4, and 24 hours were significantly lower with ultrasonic dissection as were postoperative nausea scores at 2, 4, and 24 hours.
Based on a few trials with relatively small patient samples, this review does not attempt to advocate the use of a single-dissection technology but rather to elucidate results that could be used in future trials and analyses. It demonstrates, with statistical significance, a shorter operating time, hospital stay and sick leave, lower gallbladder perforation risk especially in complicated cases, and lower pain and nausea scores at different postoperative time points. However, many of these potential benefits are subjective, and prone to selection, and expectation bias because most included trials are unblinded. Also the clinical significance of these statistical results has yet to be proved. The main disadvantages are the difficulty in Harmonic scalpel handling, and cost. Appropriate training programs may be implemented to overcome the first disadvantage. Cost remains the main universal issue with current ultrasonic devices, which outweighs the potential clinical benefits (if any), indicating the need for further cost-benefit analysis.