E393: Evaluation of the introduction of a colorectal bundle in left sided colorectal resections. The Swiss EvaCol multicenter study

Introduction: Complications such as anastomotic leakage or surgical site infections after colorectal surgery remain a major concern. Several individual perioperative quality improvement measures have been found to reduce postoperative complications. The aim of this Swiss multicenter study was to evaluate the introduction of a combination of nine perioperative interventions in a colorectal bundle (CB) for the reduction of postoperative complications.

Methods: This prospective, multicenter, observational study (ClinicalTrial.gov NCT04550156) was performed in nine Swiss cantonal and tertiary referral centers. Data on left sided colorectal resections was collected 6 months prior and 6 months after the implementation period of one month for the CB. The primary endpoint was the median comprehensive complication index (CCI) at 30 days.

Results: Between October 2020 and December 2022, 1142 patients were included of which 198 had to be censored due to pandemic related capacity reductions, leaving 944 for final analysis (n=552 controls, n= 392 CB). In this preliminary analysis median age was 66 years, gender distribution was equal (50/50%). Median ASA score was 2 in both groups while 16% of the cases were emergencies in the control and 7.7% during the CB phase. In the control group, 45% were teaching procedures and 35.7% oncological resections (42% and 45% in the CB phase, respectively).
The median CCI in the controls was 11.7 vs. 10.4 in the CB (p=0.33). Twelve patients (2.1% of the controls vs. 11 (2.8%) in the CB group developed an anastomotic leakage (p=0.53) while surgical site infections occurred in 45 (8.1%) of the controls  and 35 (8.9%) patients in the CB group (p=0.72). The mortality 1.6% vs. 0.8% (p=0.37) in the control and CB patients, respectively.

Conclusions: EvaCol is the first prospective Swiss, multicenter, cohort study in colorectal surgery in a decade. Considering the already low complication rates in the control group, this study failed to show a clinically relevant and statistically significant reduction of complications with the introduction of the CB.