Introduction and Aim: A flawless technical performance of stapled anastomoses is crucial to prevent anastomotic leakage (AL) following colorectal resections. Here we aim to quantitatively investigate the morphology of anastomotic rings as an early available prognostic marker for AL and compare it to established inflammatory markers.
Methods: We performed a prospective single center cohort-study including patients undergoing stapled circular anastomosis formation at our tertiary center between 08/20 and 08/21. The configuration of anastomotic rings, including the minimal height, maximal height, minimal width and maximal width were measured intraoperatively; the Neutrophil-to-lymphocyte-ratio (NLR) was recorded perioperatively. The predictive value of anastomotic ring configuration and the NLR regarding anastomotic leakage was examined and compared by ROC analyses.

Results: Of the 204 included patients, 19 suffered from anastomotic leakage (LEAK group), while in 185 patients the anastomoses healed well (HEAL group). The rings’ minimal height was statistically lower in the LEAK group compared to the HEAL group (4.4mm vs. 5.2mm; p<0.001). The minimal height as binary classifier had a good ROC-AUC of 0.81 compared to the NLR at postoperative day (POD) 3 with an acceptable ROC-AUC of 0.74.

Conclusion: The minimal height of the anastomotic rings as indicator for a technically insufficient anastomosis is an equivalent predictor of AL, compared to the NLR at POD 3. Its real-time availability intraoperatively allows for early countermeasures as formation or revision of the anastomosis or at least careful postoperative surveillance of patients at risk.