Dear editor,

We thank Dr. Li for his constructive and thought-provoking observations, with whom we partly agree [1].

  1. 1.

    In our article, we indeed emphasized that seroma formation is a common occurrence and is considered to be a complication only in a fraction of cases [2]. The majority of seromas, often incidentally detected during the postoperative examination, does not cause any discomfort to the patient and resolves spontaneously. We feel that the risk of seroma formation is indeed related both to the extent of tissue dissection and to the dead space generated, and that the onlay technique is relatively easier to perform. Whether it can be concluded that patients will then be exposed to less severe mesh-related complications remains to be determined. Once a surgical site infection occurs, onlay mesh placement might in fact be more prone to get infected compared to a retromuscularly positioned mesh [3].

  2. 2.

    In the discussion of our review, we stated that a number of strategies can be adopted to prevent seroma formation after onlay surgery. Among these strategies, the application of preventive negative pressure (pNPWT) is increasingly applied and we thank Dr. Li for mentioning this technique and for providing the interesting review by Guo et al. [4] as a reference to his statements.

    However, since the meta-analysis by Guo and coworkers included a variety of studies using both onlay and sublay repair techniques (five sublay; three onlay; one underlay; and two not specified), we agree only in part with the remark by Li, describing pNPWT as a preferable seroma-preventing technique in the context of an onlay repair.

    In addition, we would like to point out that whereas the meta-analysis by Guo and coworkers showed that pNPWT can significantly prevent the incidence of surgical site infections, and it does not provide evidence about the advantage of pNPWT in preventing seromas following closed laparotomy incisions in the context of ventral hernia repair. The meta-analysis, comparing the application of pNPWT versus standard wound dressing, resulted in a non-statistically significant odds ratio of 0.7, with a 95% confidence interval ranging between 0.48 and 1.03 (P = 0.07). In fact, among the 11 studies included in this meta-analysis, 9 showed no significant differences between the two techniques. Only Seaman et al. showed significantly lower odds of seroma by applying pNPWT after retromuscular mesh repair (OR = 0.08; 95% CI 0.01–0.69). In contrast, Leuchter et al. showed a striking fourfold odds of seroma by application of pNPWT compared to standard dressing after retromuscular repair (OR = 4.35; 95% CI 1.14–16.60) [5, 6]. Thus, additional evidence is needed to recommend pNPWT as an effective technique to prevent seroma formation following ventral hernia repair.

Again, we thank the author for his interesting and valuable comments.