C-reactive Protein for Predicting Early Postoperative Complications in Patients Undergoing Laparoscopic Shaving for Deep Infiltrating Endometriosis

Abstract

Study objective: To assess the accuracy of C-reactive protein (CRP) in predicting early postoperative complications in patients undergoing elective laparoscopic shaving for rectosigmoid deep infiltrating endometriosis (DIE).

Design: A single-center observational retrospective cohort study.

Setting: Third-level referral center for endometriosis.

Patients: A total of 294 patients were included in the study. All of them underwent elective laparoscopic shaving for rectosigmoid DIE.

Interventions: Postoperative CRP levels (assessed from day 3 onward, every 48 hours, until hospital discharge) and early postoperative complications were reviewed to assess CRP as a predictive marker of postoperative complications.

Measurements and main results: The study outcomes were the association between early postoperative complications and CRP levels, the optimal CRP cutoff, and its predictive accuracy. Twenty-five patients (8.5%) experienced early postoperative complications. Five patients with postoperative complications within 2 days of surgery were excluded from the analysis. On postoperative day 3 the difference in the means of CRP levels between patients with and without complications was 2.5 mg/dL (95% CI, 1.0-4.1), whereas on day 5 the difference was 5.3 mg/dL (95% CI, 3.3-7.5), with a significant increase of 2.8 mg/dL (95% CI, 0.2-5.5). On postoperative day 7 the difference was 11.4 mg/dL (95% CI, 8.2-14.6), with an increase of 6.1 mg/dL (95% CI, 2.2-9.9) from day 5. The mean CRP level in the group with complications showed an increase of 1.2 mg/dL (95% CI, -1.3 to 3.8) from day 3 to day 5 and of 6.2 mg/dL (95% CI, 2.6-9.8) from day 5 to day 7. The optimal cutoff for the CRP level in predicting early postoperative complications was 3.1 mg/dL on postoperative day 3 and 5.2 mg/dL on postoperative day 5, with a sensitivity of 87.5% (95% CI, 52.9-97.8) and 80% (95% CI, 37.6-96.4), a specificity of 62.5% (95% CI, 52.1-71.9) and 91.2% (95% CI, 81.1-96.2), a positive predictive value of 17.5% (95% CI, 8.7-31.9) and 44.4% (95% CI, 18.9-73.3), a negative predictive value of 98.2% (95% CI, 90.6-99.7) and 98.1% (95% CI, 90.1-99.7), and an area under the receiver operating characteristic curve of 75.0% (95% CI, 61.9-80.1) and 85.6% (95% CI, 74.1-96.5), respectively.

Conclusion: CRP on postoperative day 5 seemed to be a moderately accurate predictive marker of early postoperative complications in the patients who had undergone elective laparoscopic shaving for rectosigmoid DIE.

Keywords: Inflammatory markers; Rectosigmoid endometriosis; Surgical complications.