Calcification of the Aorta-Iliac Trajectory as a Risk Factor for Anastomotic Leakage in Colorectal Surgery: Individual Patient Data Meta-Analysis and Systematic Review

OBJECTIVE: The purpose of this review is to evaluate the relevance of vascular calcification as a potential risk factor for anastomotic leakage in colorectal surgery. 

METHOD: The Embase, Medline, PubMed, and Cochrane databases and Google Scholar were systematically searched. Studies that assessed calcification of the aorta-iliac trajectory in patients who underwent colorectal surgery were included. An independent patient data meta-analysis was performed as follows: based on the heterogeneity of the study population, a "random-effects model" or "fixed-effects model" was used to perform a multivariable logistic regression and calculate pooled Odds Ratios (OR) and 95% confidence intervals (CI). Heterogeneity was assessed using the Q-test and I2-test. 

RESULTS: From a total of 457 articles retrieved, eight fell within the scope of the review, with a total of 2010 patients. Anastomotic leakage was found at a mean rate of 11.1% (SD 4.9%). In these eight studies, four different calcification scoring methods were used, which made a single structured meta-analysis not feasible. Therefore, an independent patient data meta-analysis on the most frequently used calcification scoring method was performed, including three studies with a total of 396 patients. After multivariable analyses, no significant association was found between anastomotic leakage and the amount of calcification in the aorta-iliac trajectory. The remaining three scoring methods were evaluated. In four of the five studies, vascular calcification was associated with anastomotic leakage after colorectal surgery. 

CONCLUSION: In contrast to previous studies, an individual patient data meta-analysis found no association between calcification and anastomotic leakage in colorectal surgery after multivariable analysis that considered a single calcification measurement method. In addition, this study demonstrated several scoring methods for arterial calcification and the need for a standardized technique. Therefore, the authors would recommend prospective studies using a calcification scoring method that includes grade of stenosis due to its potential to preoperatively improve perfusion by endovascular treatment.