Comments on: Clinical Impacts of Minimally Invasive Transperineal Abdominoperineal Resection in Crohn's Disease

We read with great interest the recent article by Kondo et al. in which the authors present a valuable retrospective analysis comparing a novel minimally invasive approach (TpAPR) to conventional APR in Crohn's Disease patients [1]. We commend the authors for their research, and the reduction in intraoperative blood loss is a noteworthy finding that aligns with proposed minimally invasive techniques highlighted in studies on rectal cancer, such as those from Aroffo et al. and Yasukawa et al. [2, 3]. The study's primary limitation is its small sample size (n = 19), which limits the statistical power and generalizability of the findings. The notable trends towards surgical site infection (SSI) in the TpAPR group (36.4% vs. 75%) did not reach statistical significance (p = 0.07), likely due to being underpowered. In our opinion, the retrospective design that spans over a period of 15 years introduces potential biases, including evolving surgical techniques, improvement in perioperative care protocols, and the significant learning curve associated with complex procedures like TpAPR. We pose the following questions to contextualize the results and guide future research. First, given the extended study period (from 2008 to 2023), with the APR group predominantly treated in the earlier period (from 2008 to 2015), how did the authors account for potential confounders, such as advancements in biologics therapy for Crohn's disease, widespread use of Enhanced Recovery After Surgery (ERAS) protocols, or improved wound care—which themselves could influence outcomes like SSI and hospital stay? Second, operating in benign conditions like Crohn's disease, functional outcome is paramount as an outcome measure. In the study, the authors highlighted autonomic nerve preservation as a potential advantage in TpAPR, but did not provide structured data on urinary and sexual function. So we ask again: could the authors provide us with more detailed intra-operative or post-operative findings to substantiate the anatomical rationale for better nerve preservation with a transperineal approach? In conclusion, while this study introduces TpAPR as a promising technique, we think that this study would be strengthened by a large, multicenter, prospective cohort study that controls the confounders and rigorously evaluates both peri-operative and long-term functional outcomes in minimally invasive surgery in Crohn's disease, as reported by Zaman et al. [4]. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. The authors declare no conflicts of interest.