Computed tomography derived body composition and risk of anastomotic leakage following rectal cancer surgery: A systematic review and meta-analysis.

Anastomotic leakage (AL) remains a severe postoperative complication following restorative rectal cancer surgery, adversely impacting morbidity, quality of life, and oncological outcomes. Computed tomography (CT)-derived body composition metrics have been proposed as more precise predictors of AL than conventional measures such as BMI

METHODS

A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines (PROSPERO: CRD42023471537). PubMed, EMBASE, Scopus, Web of Science, and Cochrane Library were searched for studies published between January 2010 and July 2025 assessing CT-derived body composition parameters and AL in rectal cancer patients undergoing restorative surgery. Meta-analyses were performed when ≥3 studies reported comparable metrics. Risk of bias was assessed using a modified MINORS tool

RESULTS

Twenty-seven studies comprising 5763 patients and 22 different CT-derived body parameters were identified. In prespecified sensitivity analyses, dichotomized visceral fat area (VFA > 100 cm2) was significantly associated with increased AL risk (OR 1.72, 95% CI: 1.26-2.36, p = 0.009). No consistent associations were observed for subcutaneous fat, skeletal muscle, or psoas muscle indices. Considerable heterogeneity in parameter definitions, cut-offs, and measurement protocols limited further pooling

CONCLUSION

Among various CT-derived body composition metrics, VFA > 100 cm2 was significantly associated with increased AL risk after restorative rectal cancer surgery, although this finding was sensitive to leave-one-out sensitivity analyses. Standardized methodologies for body composition assessment and AL definition are warranted to validate the role of CT-derived parameters within multifactorial risk prediction models.