This study demonstrates that reduction of the dead space after mastectomy using flap fixation reduces seroma formation and seroma aspirations. For many decades, breast surgeons have used closed suction drainage to reduce dead space. However, seroma formation and its sequelae continued to cause postoperative problems in these patients, proving that wound drainage is insufficient in combating seroma. Flap fixation combined with low suction drainage significantly reduces seroma formation and the need for seroma aspiration after mastectomy.
The key to reducing seroma formation seems to partly lie in the obliteration of dead space. However, the techniques used to achieve this goal are subject of much controversy and debate [6]. In a randomised controlled study, it was difficult to elucidate whether reducing the dead space or ligation of lymphatics or a combination of both were responsible for reduction of seroma formation [13]. The extent of the dissection plane seems to be an important factor in seroma formation, and therefore, obliteration of dead space in patients undergoing mastectomy or modified radical mastectomy seems to be pivotal. Pressure garments or compression bandages are not effective in combating seroma; however, quilting of the skin flaps or skin flap fixation seems to be much more effective [10, 14].
When analysing the effect of flap fixation on seroma formation stratified by operation type, no significant effect was seen in seroma formation or seroma aspiration in the group undergoing mastectomy alone (seroma formation p = 0.16, seroma aspiration p = 0.35). The low number of patients in this subgroup could explain the non-significance, as a clear trend is visible. If this group had been larger (n = 20), the difference possibly might have been statistically significant.
In the group undergoing MRM, flap fixation was less effective on seroma formation, although there were fewer seroma aspirations. In this group of patients, seroma formation could be more pronounced due to the axillary lymph node dissection, and therefore, there might be a relative under treatment of the axilla when evaluating seroma prophylaxis. Several studies have been performed to assess the effect of sealing devices on seroma formation in axillary dissection [7]. The use of the harmonic scalpel has been shown to reduce the magnitude of seromas in the axilla [15]. In another prospective randomised controlled trial performed by Cortadellas et al., the use of an electrothermal bipolar vessel sealing system (LigaSure) in axillary dissection was assessed. The mean number of postsurgical seroma aspirations and the amount of seroma fluid drained were lower in the LigaSure group; however, they were not statistically significant [16].
No significant differences in SSIs were seen in this study. This could be due to the fact that all patients were treated with prophylactic antibiotics and strict operating room discipline was in place. This entailed limiting door openings in theatre and thus limiting movements of theatre staff during procedures. A difference of 5 % in infection rates between both groups was too small to achieve statistical significance. The reported rates of SSIs after breast operations range dramatically from 0.8 to 26 % in the literature. One possible factor accounting for such wide-ranging SSI rates is the use of different definitions of SSIs [17].
Cosmesis and shoulder function on the ipsilateral side were not evaluated in this study. One patient in the flap fixation group suffered from a diminished shoulder function postoperatively. It was unclear whether there was full range of motion preoperatively. Another patient in the flap fixation group appeared to develop skin dimpling on the chest wall 6 months after surgery. No studies to date have been published regarding cosmesis, shoulder function and patient satisfaction with long-term follow up after flap fixation. This should be addressed in a prospective trial.
The main limitations of this study are related to the retrospective nature. Being a retrospective study, indications for seroma aspiration had not been defined beforehand. This might be a potential confounder in this study. However, this is the first study to evaluate seroma aspiration in mastectomy patients treated with flap fixation and low suction wound drainage. Assessing the presence of seroma is difficult due to the subjective nature of this procedure. How does one objectively measure the presence of seroma? Maybe the only true measure for seroma is seroma aspiration. There were no major policy changes in the treatment of seroma in both time intervals, but bias is of course possible. There does seem to be an increasing surgical tendency towards watchful waiting when treating postoperative wound seroma.
Seroma aspiration is clinically relevant to our group of patients, and it is an important cause of patient discomfort [2]. Seroma leads to prolonged hospital stay, a higher rate of infections and therefore delayed administration of adjuvant treatment [18]. Patients undergo more frequent outpatient clinic visits, a higher rate of surgical reinterventions and patients may have a worse cosmetic outcome [10]. Finally, the cost of medical care is higher in the group of patients suffering from seroma and its sequelae [19].
The strength of this study lies in the proven efficacy of flap fixation after mastectomy in 180 patients in two large teaching hospitals. The most important outcome is diminished seroma aspirations in the group having undergone flap fixation when compared to patients with only low suction drainage postoperatively. This in itself should lead to a further reduction of patient discomfort.