Seven RCTs were included in the review (n=695). Sample size calculation was performed in two RCTs. None of the trials described the method of randomisation. Five trials reported allocation concealment. Only one study described blinding of caregivers and patients. Length of follow-up was not stated or was unclear.
Ultrasonic dissection was associated with significantly shorter operating time (WMD -8.19 minutes, 95% CI -10.36 to -6.02; five RCTs), fewer gallbladder perforations with bile loss (OR 0.27, 95% CI 0.17 to 0.42; three RCTs), fewer gallbladder perforations with stone loss (OR 0.13, 95% CI 0.04 to 0.47; one RCT), shorter duration of sick leave (WMD -3.8 days, 95% CI -6.21 to -1.39; one RCT), shorter length of hospital stay (WMD -0.30 days, 95% CI -0.51 to -0.09; one RCT).
Ultrasonic dissection was associated with lower postoperative pain scores at 24 hours (WMD -0.94, 95% CI -1.06 to -0.82; two RCTs) and lower postoperative pain scores at the first and fourth hours of recovery (WMD -0.90, 95% CI -1.62 to -0.18 and WMD -1.20, 95% -2.02 to -0.38; one RCT). In one study, postoperative nausea scores were significantly lower at two hours (WMD -0.90, 95% CI -1.62 to -0.18), four hours (WMD -0.80, 95% CI -1.31 to -0.29) and 24 hours (WMD -1.20, 95% CI -2.02 to -0.38). There was no significant difference in the number of patients who experienced clinically significant postoperative nausea or vomiting. Analyses for gallbladder perforations (I2=48.6%) and postoperative pain scores (I2=97.6%) were associated with statistical heterogeneity.
There was no significant difference between ultrasonic dissection and monopolar electrocautery dissection for the outcomes of postoperative bile leakage (two RCTs), conversion to open surgery (two RCTs), need for subhepatic drains (two RCTs) and postoperative complications (two RCTs).
Further laboratory-related measures and subgroup results were reported in the paper.