Risk of re‐operation after incision and drainage for acute, abscess‐forming pilonidal sinus disease: A Danish population‐based cohort study

Background Acute abscess‐forming pilonidal sinus disease (PSD) is treated surgically, with lateral incision and drainage (I&D) considered the gold standard; however, the risk of re‐operation is unknown. Aim To evaluate re‐operation rates following abscess‐forming PSD treatment with lateral I&D, and to identify factors influencing re‐operation rates. Methods Using data from nationwide Danish databases covering 2010–2021, we identified patients diagnosed with abscess‐forming PSD undergoing lateral I&D as the initial treatment for PSD. Patients were followed up until re‐operation, death, emigration, or the end of the study period. Stratified by sex, the risk of re‐operation was reported as a cumulative incidence function (CIF). To explore risks, we used Cox regression analysis to calculate crude and age‐adjusted hazard ratios (aHR). Results Of 8251 (62% male) patients included, 2455 underwent re‐operation for PSD. The overall five‐year CIF was 32% for males and 33% for females. In males, the five‐year CIF decreased from 47% among 0‐ to 16‐year‐olds to 14% among 50+ year‐olds. In females, the corresponding numbers were 37% and 13%, respectively. A family history of PSD was found to increase re‐operation risk, especially among female patients (aHR: 1.64 (95% confidence interval [95% CI]: 1.39–1.93)). The risk increases following the second and third consecutive I&D procedures to 52% and 69% in males, and to 57% and 64% in females, respectively. Conclusion As roughly two‐thirds of patients do not require additional surgery, our findings do not support mandatory follow‐up with definitive surgery for all PSD patients undergoing I&D. For certain high‐risk subgroups, however, subsequent definitive surgery may be appropriate.