C-reactive protein can predict anastomotic leak in colorectal surgery: a systematic review and meta-analysis.

Background: Anastomotic leakage (AL) is one of the most significant complications after colorectal surgery, affecting length of stay, patient morbidity, mortality, and long-term oncological outcome. Serum C-reactive protein (CRP) level rises in infective and inflammatory states. Elevated CRP has been shown to be associated with anastomotic leak.

Objective: Perform a meta-analysis of current CRP data in AL after colorectal surgery.

Data Sources: MEDLINE, EMBASE, CINAHL, CENTRAL databases STUDY SELECTION: Comparative studies studying serum CRP levels in adult patients with and without AL after colorectal surgery.

Intervention(s): Elective and emergency open, laparoscopic or robotic colorectal excisions for cancer and benign pathology.

Main Outcome Measures: Mean serum CRP measurements between post-operative days (POD) 1 through 7 in patients with and without AL. Perform ROC analysis to determine cut-off CRP values to indicate AL.

Results: Twenty-three studies with 6647 patients (482 AL). Pooled mean time to diagnosis of AL was 7.70 days. AL associated with higher CRP on POD1 (mean difference (MD) 15.19, 95% CI 5.88-24.50, p = 0.001), POD2 (MD 51.98, 05% CI 37.36-66.60, p < 0.00001), POD3 (MD 96.92, 95% CI 67.96-125.89, p < 0.00001), POD4 (MD 93.15, 95% CI 69.47-116.84, p < 0.00001), POD5 (MD 112.10, 95% CI 89.74-134.45, p < 0.00001), POD6 (MD 98.38, 95% CI 80.29-116.46, p < 0.00001), and POD7 (MD 106.41, 95% CI 75.48-137.35, p < 0.00001) compared with no AL. ROC analysis identified a cut-off CRP of 148 mg/l on POD3 with sensitivity and specificity of 95%. On POD4 through POD7, cut-off levels were 123 mg/l, 115 mg/l, 105 mg/l, and 96 mg/l, respectively, with sensitivity and specificity of 100%.

Limitations: Study heterogeneity, some characteristics unreported, no RCT CONCLUSIONS: AL is associated with higher CRP levels on each post-operative day compared to no AL after colorectal surgery. The cut-off CRP values can be used to predict AL to expedite investigation and treatment.