Utility of C-reactive protein on the fourth postoperative day to detect complications beyond anastomotic dehiscence.

Purpose: Postoperative complications can affect recovery after colorectal cancer surgery. Elevated C-reactive protein (CRP) levels have been studied as a predictor of anastomotic dehiscence, but evidence regarding its association with overall complications is limited. This study aimed to explore the link between CRP levels on the fourth postoperative day and overall postoperative complications using the comprehensive complication index (CCI).

Methods: The observational study included 935 patients who underwent colorectal cancer surgery between 2015 and 2022. Patients were categorized into three groups: no complications, complications excluding dehiscence, and complications with dehiscence. The relationship between CRP levels and postoperative complications was analyzed, and the optimal CRP cutoff point was determined.

Results: The median CRP values were 34.3 (20.4-54.0) mg/L in the group with no complications, 69.9 (43.2-112.9) mg/L in the group with complications excluding dehiscence, and 167.6 (69.7-239.5) mg/L in patients with dehiscence. A significant correlation between CRP levels and postoperative complications was found (p < 0.001). Based on the identified cutoff points, CRP levels above 58 mg/L suggest the presence of any complication, including dehiscence. Levels between 42 and 58 mg/L suggest complications excluding dehiscence, and levels below 42 mg/L strongly exclude complications, with a negative predictive value of 82%.

Conclusions: Elevated CRP on postoperative day 4 is associated with overall postoperative complications, not just dehiscence. A positive correlation exists between CCI score and CRP levels. A CRP value < 42 mg/L on day 4 allows clinicians to reliably exclude the presence of any complication.