Incidence and Risk Factors of Postoperative Urinary Retention After Thyroidectomy: A Retrospective Cohort Study.

Background Postoperative urinary retention (POUR) is a common complication, but its incidence and risk factors after thyroidectomy are not well‐defined. We investigated the incidence of POUR after thyroidectomy and its risk factors. Methods We conducted a retrospective review of 511 consecutive patients who underwent thyroidectomy by a single surgeon. POUR was defined as the inability to void within 6 h of the last preoperative void performed immediately prior to transfer to the operating room, with bladder volume > 500 mL requiring catheterization. Univariable and multivariable logistic regressions were performed separately for male and female. Results Among 511 patients (368 females, 143 males; mean age 49.6 years), 412 (80.6%) underwent lobectomy, 71 (13.9%) total thyroidectomy without lateral neck dissection, and 28 (5.5%) total thyroidectomy with lateral neck dissection. Surgical access was open in 333 (65.2%), transoral robotic in 158 (30.9%), and transoral endoscopic in 20 (3.9%). Overall, 68 patients (13.3%) developed POUR. In males, independent predictors were benign prostatic hyperplasia (BPH) (adjusted odds ratio [aOR] 7.890; 95% confidence interval [CI], 1.814–34.318; p = 0.006) and body mass index (BMI) < 25 kg/m 2 (≥ 25 kg/m 2 aOR 0.245; 95% CI, 0.066–0.909; p = 0.036; reference < 25 kg/m 2 ), BMI < 25 kg/m 2 (≥ 25 kg/m 2 aOR 0.465; 95% CI, 0.228–0.947; p = 0.035; reference < 25 kg/m 2 ), and operative time ≥ 60 min (aOR 1.939; 95% CI, 1.014–3.709; p = 0.045). Surgical approach, extent of surgery, pathology, and postoperative opioid use were not independently associated with POUR in either sex. Conclusions POUR occurred in 13.3% of thyroidectomy patients. Sex‐stratified analysis showed BPH and lower BMI as key risks in males, whereas older age, lower BMI, and longer operative time were significant in females. Recognizing these factors may support targeted perioperative screening and postoperative monitoring to reduce retention‐related delays and complications.