Five RCTs (n=310 patients) were included in the review. Two trials were judged to be of high quality (Jadad score of 3 points or more) and three trials low quality.
Among perioperative outcomes, minimally invasive video-assisted thyroidectomy was associated with significantly greater operative time than open thyroidectomy (WMD 18.77 minutes, 95% CI 17.09 to 20.45; four RCTs), but involved significantly less pain (VAS measured on a 100-point scale) at six hours postoperatively (WMD -11.57, 95% CI -17.50 to -5.64; three RCTs). Reductions in blood loss and pain scores at 24 hours and 48 hour postoperatively with minimally invasive video-assisted thyroidectomy were not statistically significant using the random-effects model (necessary due to the heterogeneity present).
Among short-term outcomes, the cosmetic result (measured on a scale of 0 to 10) was significantly better with minimally invasive video-assisted thyroidectomy than open thyroidectomy (WMD 1.86, 95% CI 0.03 to 3.69; three RCTs), and there were no significant differences between the two methods in occurrence of transient palsy or transient hypoparathyroidism.
Heterogeneity in late postoperative pain and cosmetic results outcomes were investigated, and sensitivity analyses were performed involving the removal of one particularly influential trial. This led to the pain score at 24 hours becoming statistically significant in favour of minimally invasive video-assisted thyroidectomy, but the statistical significance of other outcomes were unaffected.
Evidence of possible publication bias was detected in results for VAS at 24 hours and 48 hours, and not for operative time, transient palsy or hypoparathyroidism, but the other outcomes involved too few trials to assess this bias.