NCTH can potentially increase the risk of certain postoperative complications, especially infection, owing to its associated neutropenia (5). Nonetheless, the impact of NCTH on postoperative complications of BCS is still controversial. Although the Harmonic scalpel is a well-established tool in various surgeries, there is a controversy regarding its superiority over conventional methods in BCS. Moreover, no previous study has examined the superiority of the Harmonic scalpel in patients receiving NCTH. In this comparative study, the Harmonic Focus scalpel was associated with shorter operative time and less blood loss than conventional electrocautery. Moreover, patients in the Harmonic Focus group had a significantly lower drain volume and shorter time until drain removal than the monopolar electrocautery group and less pain on the third postoperative day. In contrast, patients in the Harmonic Focus scalpel group had comparable rates of postoperative complications to patients in the monopolar electrocautery group.
Previous reports demonstrated that drain volume and duration until drain removal are positively correlated with the risk of local infectious complications (12). This study showed that the Harmonic scalpel led to lower drain volume and shorter time until drain removal than monopolar electrocautery (13). These findings can be explained by induced lymphostasis, excessive thermal injury of the lymphatic system, and hematoma formation after electrocoagulation. In contrast, Harmonic Focus forms a coagulum that seals lymphatics and produces minimal damage to lymphatic tissue, which, in return, reduces drainage (14). These findings are also hypothesized to stem from the ability of the Harmonic scalpel to deal with lymphatic vessels without reopening again (15). This was in agreement with a previous meta-analysis of 12 studies, which demonstrated lower drain volume following Harmonic scalpel than conventional electrocautery (16). In another two reports from China and Germany, Harmonic Focus significantly reduced the drain volume and time until drain removal compared to monopolar electrocautery among women undergoing BCS (10).
Postoperative seroma, a term used to describe an accumulation of serious fluid beneath the flap or in the axially dead space, is a common complication after BC surgery, with a reported incidence of 2–80% according to the nature of the procedures (17). Although seroma is not associated with a significant increase in mortality, it can trouble the postoperative course of the affected patients by increasing the risk of prolonged draining, infection, and reoperation, which, in return, can significantly delay adjuvant CTH (17). Surgical techniques and devices are thought to impact the risk of postoperative seroma significantly. For example, electrocautery was found to be associated with the highest incidence of postoperative seroma among surgical devices for BC surgery (8). In contrast, the Harmonic scalpel is thought to reduce seroma incidence through minimal tissue damage, proper hemostasis, and lower risk of flap necrosis compared to other techniques. However, this study demonstrated that the rate of postoperative seroma was comparable between the Harmonic scalpel and monopolar electrocautery. In concordance with our findings, Archana et al. (15) and Selvendran et al. (18) reported no significant difference between the Harmonic scalpel and monopolar electrocautery regarding the incidence of post-BC surgery seroma. Similar findings were reported by others (19, 20). The similar rates of seroma formation in this study’s groups despite the significant difference in drain volume can be explained by the drain placement in all cases. The drain placement itself can significantly reduce the risk of seroma formation (21).
Nonetheless, current evidence shows conflicting results regarding the role of the Harmonic scalpel in reducing the incidence of seroma, as other reports demonstrated a significant reduction in seroma following Harmonic scalpel compared to monopolar electrocautery in patients undergoing BC surgery (14, 16). Such contradictory results can be explained by wide variations in patients’ characteristics, type of surgery, surgeon’s experience, the definition of seroma, and length of follow-up among published studies. Further, a well-designed trial with multinational collaboration is warranted to investigate the impact of the Harmonic scalpel on seroma prevention after BC surgery.
Proper hemostatic control is critical intraoperatively to reduce blood loss, time of surgery, and, subsequently, postoperative morbidity and operative expenses. As mentioned previously, conventional electrocautery is limited by excessive time for tissue dissection and wide thermal damage, which, in return, can result in excessive blood loss and prolonged operative time (22). The Harmonic scalpel works by dividing the tissues longitudinally through high-frequency ultrasonic waves, which potentially takes less time for tissue damage than conventional methods. Besides, the Harmonic scalpel produces lower temperature than electrocautery and hence less liability to excessive tissue damage and blood loss. Finally, coagulating shears lead to the development of a coagulum that effectively seals blood vessels (23). This comparative study demonstrated that the Harmonic scalpel had the advantage of less operative time and blood loss than monopolar electrocautery in BCS with lymphadenectomy. These findings are in line with recent systematic reviews indicating less blood loss following Harmonic scalpel than conventional methods (14, 16); however, no previous studies have assessed the Harmonic scalpel in NCTH.
Older age, large tumor size, advanced tumor stage, and history of anticoagulants or tamoxifen are common patient-related risk factors for postoperative seroma (24). Her-2-positive status was an independent predictor of seroma development in this cohort, whereas patients with seroma were more likely to have advanced TNM stages and shorter days to chest drain removal. These findings aligned with previous reports indicating significant associations between hormonal status and the risk of postoperative seroma.