[IMPACT OF MEMBRANOUS URETHRAL LENGTH IN DE NOVO STRESS URINARY INCONTINENCE FOLLOWING HOLMIUM LASER ENUCLEATION OF THE PROSTATE].

(Purpose) Holmium laser enucleation of the prostate (HoLEP) is widely performed in recent years; however, difficulties of surgical techniques and high frequency of postoperative stress urinary incontinence (SUI) remain as significant problems. We determined the predictive factors for de novo SUI after HoLEP. (Patients and methods) A total of 303 patients with benign prostatic hyperplasia who underwent HoLEP were retrospectively evaluated between July 2013 and April 2019. Of these, 109 patients underwent MRI preoperatively. Patients who were unable to answer the questionnaire regarding their SUI because of dementia, those who presented with SUI preoperatively, and those with placed Foley catheter at the time of MRI were excluded. Hence, a total of 83 patients were eligible for the present study. We recorded the MRI findings and clinical variables, including membranous urethral length (MUL), transitional zone (TZ) volume, serum prostate-specific antigen levels, operative time, and presence or absence of SUI. The predictive factors for de novo SUI were determined using multivariable logistic regression analysis. (Results)De novo SUI occurred in 19 (22.9%) patients but disappeared in 16 (84.2%) patients at a mean duration of 14 weeks. The mean MUL was 17.2 mm. Univariate analysis showed that MRI TZ volume >40 mL, MUL ≤17 mm, operative time >100 min, and enucleation time >50 min were associated with de novo SUI. In multivariable logistic regression analysis, MUL ≤17 mm (odds ratio [OR], 23.81; 95% confidence interval [CI], 4.34-447.19; P < 0.0001) and operative time >100 min (OR, 3.91; 95% CI, 1.20-14.01; P = 0.023) were significantly associated with de novo SUI. (Conclusions) Although de novo SUI occurred occasionally after HoLEP, most of them improved in about 3 months. The MRI measurement of MUL was shown to be a practical tool for predicting de novo SUI after HoLEP.