Persistent descending mesocolon and its impact on the short-term outcomes of minimally invasive colorectal surgery: a systematic review and meta-analysis.

PURPOSE: Persistent descending mesocolon (PDM) is a rare congenital anomaly that may complicate minimally invasive surgery (MIS) for colorectal cancer (CRC). This systematic review and meta-analysis evaluated the perioperative impact of PDM on MIS for CRC.

METHODS

This study followed the PRISMA guidelines and was registered in PROSPERO (CRD420251055757). A systematic search was performed in PubMed, Cochrane, and Scopus (January, 2000 to April, 2025). Observational studies (OBSs) compared MIS for CRC in patients with and patients without PDM. The primary outcome was operative time and the secondary outcomes included intraoperative blood loss, open conversion rate, complications, and vascular anatomy. Meta-analyses used a random-effects model.

RESULTS

Seven OBSs (4,255 patients) were included in the analysis. PDM patients had significantly longer operative times (Mean difference [MD]:26.4; 95%CI:11.3-41.4) and greater intraoperative blood loss (MD:15.9; 95%CI:3.3-28.4). The rates of conversion to open surgery (Odds rate [OR]:9.6; 95%CI: 3.3-27.8) and anastomotic leakage (OR:2.49; 95%CI:1.2-5.1) were higher in PDM patients. The IMV-colon distance was significantly shorter in PDM patients, potentially increasing the marginal vessel injury risk.

CONCLUSION

PDM increases the intraoperative complexity of MIS for CRC. Thus, preoperative recognition of vascular variations is critical and such procedures should be performed at expert centers.