Persistent descending mesocolon (PDM) versus Non-PDM patients on postoperative outcomes after colorectal surgery

To compare the surgical outcomes between patients with and without Persistent Descending Mesocolon (PDM) undergoing colorectal resection. A systematic search of electronic databases (PubMed, Embase, Cochrane Library and Web of Science) was conducted for studies published from inception to October 13, 2025. Statistical heterogeneity was assessed using the I2 statistic and the Cochran’s Q test (with a significance level of P < 0.1). High heterogeneity was considered when I2 > 50%, in which case a random-effects model was applied. For studies with I2 ≤ 50%, a fixed-effects model was used, and a P-value < 0.05 was considered statistically significant. All analyses were performed using Stata software (version 18.0). The registration ID of this current meta-analysis on PROSPERO is CRD420251166710. Six observational studies, encompassing a total of 2437 patients (PDM: n=154; Non-PDM: n=2283), were included in the final analysis. Patients in the PDM group had a significantly longer operative time (MD: 28.43minutes, 95% CI: 2.71 to 54.16, p = 0.03). However, no significant difference was found in intraoperative blood loss and postoperative hospital stay between the PDM group and the Non-PDM group. Furthermore, no significance was found in overall complications (OR=1.14, 95% CI = 0.60 to 2.16, P = 0.69). The presence of PDM is associated with increased surgical complexity, evidenced by longer operative times. Surgeons should be aware of this anatomical variant during preoperative planning for colorectal procedures. No statistically significant differences were observed in postoperative outcomes between PDM and Non-PDM groups.