Biomarkers in Urethral Stricture Disease and Benign Lower Urinary Tract Disease.

Increased understanding of molecular pathophysiology has led to the detection of clinically applicable biomarkers across medicine, which allow for minimally invasive detection, management, and monitoring of disease processes. Although biomarkers have traditionally played a more significant role in malignancy, these goals also pertain to benign disease. Herein, the authors review ongoing research into biomarker investigation and application in urethral stricture disease, benign prostatic hyperplasia, bladder outlet obstruction, and overactive bladder. No biomarkers for these entities are currently in clinical use; however, numerous physiologic pathways provide targets for current and future study.

Complex Lower Genitourinary Fistula Repair: Rectourethral Fistula and Puboprostatic Fistula.

Rectourethral fistula (RUF) and puboprostatic fistula (PPF) are potentially devastating complications that can develop after various pelvic insults, most notable treatment of prostate cancer. Both entities represent surgical challenges given the complex anatomy, risk of injury to adjacent structures, and poor tissue quality and wound healing. While extirpative surgery may be necessary for some patients, meticulous surgical dissection and interposition of healthy muscle allow for fistula repair in a high proportion of appropriately selected patients, especially in RUF. Herein the authors describe the nature, management, and outcomes of RUF and PPF with a full review of the literature.

Dosing Variability and Clinical Outcomes of Oxybutynin: A Pediatric Cohort of Patients With Neurogenic Bladder.

Background: Despite the therapeutic advancements of the last several decades, neurogenic bladder remains a significant source of morbidity for patients with a spinal pathology. Oxybutynin is a mainstay of treatment in pediatric populations despite significant side effects and highly variable bioavailability. Objectives: To characterize the use of oxybutynin in a cohort of pediatric patients with neurogenic bladder. Methods: Retrospective data were collected of dosing, drug interactions, and urodynamics parameters in the 100 consecutive patients in a spinal differences clinic who had an appointment between October 7, 2015, and December 30, 2015. In addition to descriptive statistics, a linear regression model of oxybutynin dose versus age and sex was developed to examine the impact of age on dosing variability. Results: One hundred patients (52% female) with a median age of 6.8 years were included. The median daily dose of oxybutynin was 0.36 mg/kg (interquartile range, 0.28-0.54 mg/kg). Of the 48 patients with a recent urodynamics study, 13 had a detrusor leak point pressure (DLPP) greater than the typical cutoff of 40 cm H2O, indicating a need for management escalation. However, of these 13 patients, 38% were already on or exceeding oxybutynin's maximum recommended dose. Conclusion: The wide dosing variability and high DLPPs despite maximal dosing indicate a need for further investigation of oxybutynin's bioavailability in this population compared to its side effects and clinical outcomes. If variability in response to the medication is due to differences in bioavailability, then a precision-dosing model based on patient genomics could be developed for oxybutynin.

Transurethral reconstruction of fossa navicularis strictures with dorsal inlay buccal mucosa graft urethroplasty.

PURPOSE: To describe a single stage, glans-sparing urethroplasty technique for fossa navicularis strictures using a transurethral dorsal inlay buccal mucosa graft. METHODS: We conducted a retrospective review of a prospectively maintained urethral stricture database to identify all fossa navicularis strictures reconstructed with a single stage, transurethral dorsal inlay buccal mucosa graft urethroplasty (5/2015-6/2020). Primary outcomes were anatomic success, defined as the ability to pass a 17 Fr flexible cystoscope, and functional success, defined as the lack of obstructive voiding symptoms and no need for further procedures. Secondary outcomes were postoperative complications and patient satisfaction. RESULTS: Sixteen patients were included. Mean age was 63.1 years (43.9-75.6) and mean stricture length was 1.7 cm (1.4-2.0). Stricture etiology included internal trauma (62.5%), idiopathic (25.0%), and lichen sclerosus (12.5%). Prior endoscopic procedures were done in 75% of patients. Over a median follow-up of 28.8 months (IQR 17.6-38.0), anatomic success was 15/16 (93.8%) and functional success was 16/16 (100%). The single anatomic recurrence was at 4.2 months postoperatively. No additional procedures were required. Urinary tract infection occurred in 25% (4/16). There were no instances of de novo erectile dysfunction, chordee, or wound infection. All patients would recommend urethroplasty to others and all patients were either very satisfied (83.3%) or satisfied (16.7%) with the procedure. Penile sensitivity was unchanged in 83.3%, increased in 8.3% and decreased in 8.3%. CONCLUSION: Transurethral dorsal inlay buccal mucosa graft urethroplasty is a viable option for reconstruction of fossa navicularis strictures that avoids splitting the glans and results in excellent cosmesis.