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

Breast cancer surgery, such as modified radical mastectomy, may involve widespread surgical tissue trauma increasing the risk of complications and postoperative morbidity.¹² Therefore, effective dissection and hemostasis surgical tools are needed to help minimize ensuing risks to the patient. In breast cancer surgeries, our study demonstrated that Harmonic technology significantly reduced the risk of complications, such as intraoperative blood loss, overall seroma, and necrosis compared with conventional methods. In addition, postoperative chest wall drainage and hospital length of stay were both significantly reduced with Harmonic technology compared with conventional methods.

Our study specifically demonstrated that overall risk of complications was reduced by ∼50% with Harmonic technology compared with conventional methods in breast cancer surgery patients. Electrosurgery was a prevalent comparator used in the included studies and is associated with an important risk of surgical morbidity, ranging from 35% to 50%.¹² When assessing complication types, the risk of overall seroma (ie, chest, axillary, or both) was significantly reduced by 46% with Harmonic technology compared with conventional methods. It has been noted that the incidence of seroma can vary widely from 3% to 85%³⁴ and is more common in mastectomy than BCS procedures. One important cause of seroma is the inadequate sealing of the lymphatics with electrosurgery. It is speculated that Harmonic technology may reduce the risk of seroma with more precise sealing mechanisms and its ability to induce less of an acute inflammatory response relative to electrosurgery.^23,29 Furthermore, this study demonstrated that the risk of necrosis was also significantly reduced by ∼50% with Harmonic technology. During electrosurgery, direct, high thermal energy is used that can result in the devitalization of tissues.²⁹ Harmonic technology reduces the risk of thermal damage, as it operates at lower temperatures, whereby less energy is dispersed to surrounding tissues.^19,35 For other less common complication types evaluated in this study, including hematoma, wound infection, and ecchymosis, Harmonic technology demonstrated numerical reductions in event rates, although not statistically significant. Given the rarity of some of these events, the possibility of results being underpowered cannot be ruled out. In summary, a reduction in breast cancer surgical complications, as demonstrated with Harmonic technology, may importantly help to prevent delays with adjuvant breast cancer treatments.

Our study can be compared to a recent meta-analysis by Huang et al,²³ conducted in mastectomy patients with breast cancer. Huang et al²³ reported significant reductions in blood loss, seroma, postoperative drainage volume, and wound complications with Harmonic technology, without a change in operating time. However, there are some important differences between this study and the study by Huang et al.²³ It is reassuring to note that for outcomes compared across both meta-analyses, results are generally similar despite inclusion of different study designs and surgery types. Our study included mastectomy and BCS, whereas Huang et al²³ only included mastectomy patients. Furthermore, our study focused on randomized trials only, whereas Huang et al²³ included both randomized and nonrandomized comparative studies. When considering the four nonrandomized studies^36–39 included by Huang et al,^23,36–39 results often favored Harmonic technology, although were sometimes not statistically significant. For example, the rate of local complications was statistically significantly lower in the Harmonic technology group compared to conventional techniques, while complications including seroma, necrosis, hematoma, and infection were not statistically significantly reduced but remained in favor of Harmonic technology.

Subgroup analyses in our study were performed based on the types of surgeries (mastectomy, BCS, or both). Generally, results appeared more favorable for Harmonic technology compared with conventional methods in studies that focused on mastectomy patients. For example, intraoperative blood loss was statistically significantly reduced by Harmonic technology in mastectomy (with lymph node dissection) patients (MD: −102.91 mL, 95% CI: −143.7 to −62.07; P<0.00001) and nonstatistically significantly reduced for Harmonic technology in combined mastectomy and BCS (with lymph node dissection) patients (MD: −66.62 mL, 95% CI: −159.5 to 26.27; P=0.16). Similarly, for postoperative chest wall drainage volume, the size of the reduction was greater for Harmonic technology in mastectomy (with lymph node dissection) patients (MD: −110.5 mL; 95% CI: −177.97 to −43.03; P=0.001) compared with BCS (with lymph node dissection) patients (MD: −37.50 mL; 95% CI: −59.2 to −15.79; P=0.0007). Furthermore, for the outcome of hospital length of stay, Harmonic technology significantly reduced the duration of hospital stay by 1.74 days in studies including both mastectomy and BCS (with lymph node dissection) patients, compared with 0.5 days in studies only reporting on BCS (with lymph node dissection). Overall, although data were limited in exclusive BCS populations, the data that are available in BCS suggest significant benefits with Harmonic technology compared to conventional methods for a reduction in postoperative chest wall drainage volume, hospital length of stay, and overall seroma.

Harmonic technology is more costly upfront than standard techniques (eg, traditional scalpel, sutures, electrosurgery); however, downstream cost savings through averted resource use are essential to consider in total cost calculations. In a recent publication involving thyroidectomy procedures,⁴⁰ a meta-analysis of seven studies demonstrated that Harmonic technology significantly reduced total hospital costs, considering the reduced operating time and/or length of hospital stay compared with conventional methods. Considering the results of our breast surgery meta-analysis, it may be predicted that the reduction in surgical complications with Harmonic technology may lead to less complication-related treatments and associated costs. Furthermore, our study demonstrated that hospital stay is significantly reduced with Harmonic technology by close to 1.5 days. This reduction in hospital stay is likely attributed to the lower complication risk observed with Harmonic technology in our study, as data demonstrate that postmastectomy complications are associated with prolonged hospital stay.^14,32,41,42 Given this potential health resource savings, future studies should comprehensively assess the cost-effectiveness of Harmonic technology in breast cancer surgeries.