Diverticulitis with abscess formation: Outcomes of non-operative management and nomogram for predicting emergency surgery

Background: To assess short- and long-term outcomes from non-surgical management of diverticulitis with abscess formation and to develop a nomogram to predict emergency surgery. Methods: This nationwide retrospective cohort study was performed in 29 Spanish referral centers, including patients with a first episode of a diverticular abscess (modified Hinchey Ib–II) from 2015 to 2019. Emergency surgery, complications, and recurrent episodes were analyzed. Regression analysis was used to assess risk factors, and a nomogram for emergency surgery was designed. Results: Overall, 1,395 patients were included (1,078 Hinchey Ib and 317 Hinchey II). Most (1,184, 84.9%) patients were treated with antibiotics without percutaneous drainage, and 194 (13.90%) patients required emergency surgery during admission. Percutaneous drainage (208 patients) was associated with a lower risk of emergency surgery in patients with abscesses of ≥5 cm (19.9% vs 29.3%, P =.035; odds ratio 0.59 [0.37–0.96]). The multivariate analysis showed that immunosuppression treatment, C-reactive protein (odds ratio: 1.003; 1.001–1.005), free pneumoperitoneum (odds ratio: 3.01; 2.04–4.44), Hinchey II (odds ratio: 2.15; 1.42–3.26), abscess size 3 to 4.9 cm (odds ratio: 1.87; 1.06–3.29), abscess size ≥5 cm (odds ratio: 3.62; 2.08–6.32), and use of morphine (odds ratio: 3.68; 2.29–5.92) were associated with emergency surgery. A nomogram was developed with an area under the receiver operating characteristic curve of 0.81 (95% confidence interval: 0.77–0.85). Conclusion: Percutaneous drainage must be considered in abscesses ≥5 cm to reduce emergency surgery rates; however, there are insufficient data to recommend it in smaller abscesses. The use of the nomogram could help the surgeon develop a targeted approach.