A Systematic Review and Meta-analysis of Harmonic Technology Compared With Conventional Techniques in Mastectomy and Breast-conserving Surgery With Lymphadenectomy for Breast Cancer

Ecchymosis

Results demonstrated a reduction in ecchymosis events with Harmonic technology compared to conventional techniques (RR =0.67; 95% CI: 0.36–1.25; P=0.21; two studies; I²=0%) (Table 3); however, these results were not statistically significant. Results were only available for the mastectomy (with lymph node dissection) subgroup.

Secondary analyses

In a secondary analysis of dichotomous outcomes reporting on the OR as the effect measure, results remained in favor of Harmonic technology compared with conventional methods in breast surgery. Overall total complications were statistically significantly reduced with Harmonic technology compared with conventional methods with an OR of 0.34 (95% CI: 0.17–0.66; two studies; P=0.002; I²=0%) (Table S1). Similarly, overall seroma was significantly reduced with Harmonic technology (OR =0.39; 95% CI: 0.27–0.57; eleven studies; P<0.00001; I²=0%), as was the incidence of necrosis (OR =0.46; 95% CI: 0.23–0.91; eight studies; P=0.03; I²=0%) (Table S1).

Sensitivity analyses

Sensitivity analyses demonstrated results that were similar to the primary analysis and were relatively robust to variables tested (Table 3). When excluding studies not randomizing device use in breast surgery,²⁸ results minimally changed. Additionally, primary analysis results were relatively robust to the exclusion of studies not randomizing device use in lymph node dissection.^5,29 However, in this sensitivity analysis, the outcome of hematoma became statistically significant in favor of Harmonic technology, and the outcome of necrosis became nonsignificant but still trended in favor of Harmonic technology. When imputed studies were excluded for operating time,^5,7,26 this outcome was statistically significantly reduced with Harmonic technology. Results were relatively insensitive to change when imputed studies were excluded for the outcomes of intraoperative blood loss,^5,7 postoperative drainage volume of the chest wall,⁴ and postoperative hospital length of stay⁴ and remained statistically significant in favor of Harmonic technology. Results for intraoperative blood loss, postoperative drainage volume of the chest wall, postoperative hospital length of stay, and overall seroma remained statistically significantly lower with Harmonic technology when studies of higher risk of bias were excluded (Table 3). Additionally, operating time became statistically significant in favor of Harmonic technology with the exclusion of these “lower” quality studies, while the necrosis outcome remained in favor of Harmonic technology, but the difference was not statistically significant.