Benign prostatic hyperplasia is one of the most prevalent diseases in older men. The enlarged prostate blocks the bladder outflow orifice, leading to a series of lower urinary tract symptoms including voiding, storage, and postmicturition. Storage symptoms may occur either secondary to or independent from benign prostatic hyperplasia. Surgical management with transurethral resection of the prostate may be indicated in some benign prostatic hyperplasia patients. Pharmacotherapy for storage symptoms may be warranted for those who have storage symptoms not effectively treated by surgery or develop de novo storage symptoms. Few studies have reported the clinical characteristics of patients who have persistent storage symptoms after surgery for benign prostatic hyperplasia. This study analyzed the risk factors of the use of antimuscarinics or beta-3 adrenergic agonist after transurethral resection of the prostate in benign prostatic hyperplasia patients.

We retrospectively reviewed medical records of benign prostatic hyperplasia patients who underwent transurethral resection of the prostate between January 2015 and December 2016 and were followed up for more than six months after surgery. Patients with urinary tract infection, bladder tumors, bladder stones, prostate cancer or overt neurological disorders (e.g., spinal cord pathology) were excluded. International Prostate Symptom Score was used to evaluate lower urinary tract symptoms prior to surgery. All patients received preoperative assessment with prostate-specific antigen, uroflowmetry and trans-abdominal ultrasound which provided the information of intravesical prostatic protrusion and prostate volume. intravesical prostatic protrusion was measured under the bladder volume of 150-200ml. The weight of resected specimens in transurethral resection of the prostate was measured. Postoperative pharmacotherapy for storage symptoms was defined as the prescription of antimuscarinics or beta-3 adrenergic agonist three month after transurethral resection of the prostate for more than three months. We evaluated the effects of comorbidities, symptoms severity, results of preoperative evaluation, and transurethral resection of the prostate-related variables for postoperative prescription of antimuscarinics or beta-3 adrenergic agonist.

Of 376 patients included in this study, 45 (12.0%) received postoperative pharmacotherapy for storage symptoms after transurethral resection of the prostate. Patients with postoperative pharmacotherapy were significantly older than those without (77.4 ± 7.92 vs 74.2 ± 9.76 years, p = 0.017).   Preoperative acute urinary retention and preoperative medications for storage symptoms did not correlate with postoperative pharmacotherapy. There were no significant differences in cormorbidities and body mass index between the two groups. More patients with preoperative intravesical prostatic protrusion >1cm used postoperative pharmacotherapy than those with preoperative intravesical prostatic protrusion <= 1cm (14.4% vs 5.2%, p= 0.015). There were no significant differences in total International Prostate Symptom Score, prostate-specific antigen level, prostate size and parameters of uroflowmetry between the two groups. Patients underwent bipolar transurethral resection of the prostate tended to use postoperative pharmacotherapy compared with those underwent unipolar transurethral resection of the prostate (15.7% vs 6.9%, p = 0.009). There were no significant differences in the weight of resected specimens in transurethral resection of the prostate and weight of resected specimens /prostate volume between the two groups. Multivariate logistic regression analysis revealed that age >75 years (OR, 2.84; 95% CI 1.21-6.62; p=0.016), intravesical prostatic protrusion> 1cm (OR, 3.61; 95% CI 1.00-13.07; p=0.050) and bipolar transurethral resection of the prostate (OR, 4.25; 95% CI 1.53-11.80; p=0.005) were the significant risk factors for postoperative pharmacotherapy.

The present study evaluated the effects of demographic and clinical characteristics, and transurethral resection of the prostate-related parameters for postoperative prescription of antimuscarinics or beta-3 agonist. We noted that 12% of benign prostatic hyperplasia patients who underwent transurethral resection of the prostate received postoperative pharmacotherapy for storage symptoms. Furthermore, age > 75 years, intravesical prostatic protrusion > 1cm and bipolar transurethral resection of the prostate were significant independent risk factors of postoperative pharmacotherapy for storage symptoms

Advanced patient age, intravesical prostatic protrusion and bipolar transurethral resection of the prostate correlated significantly with the postoperative pharmacotherapy for storage symptoms after transurethral resection of the prostate