Hypothesis / aims of study
Overactive bladder syndrome, without metabolic or local pathological factors that can explain the symptoms, is the feeling of "urgency" and may be accompanied by urinary incontinence. The symptoms negatively influence the daily activities and emotional well-being of the patients and have serious effects on the quality of life. Initial management of overactive bladder (OAB) syndrome involves behavioral therapy, which includes bladder training, pelvic floor rehabilitation, and fluid management strategies. If conservative approaches prove ineffective, antimuscarinics and beta-3 agonists serve as the second line of treatment. However, many patients discontinue oral therapies due to dissatisfaction with treatment outcomes or intolerance to side effects. For patients unresponsive to oral therapy, various third-line treatment options such as botulinum toxin A (BTA) injections, sacral neuromodulation, and percutaneous tibial nerve stimulation (PTNS) may be considered, each offering therapeutic benefits but also presenting distinct limitations. Consequently, there is a need for more effective, tolerable, and convenient therapeutic option for refractory OAB.
We aimed to investigate the efficacy and safety of selective bladder denervation (SBD) with radiofrequency ablation (RFA) in patients with refractory overactive bladder (rOAB) which is a new treatment option for refractory OAB patients by comparing the treatment outcomes with intravesical botulinum toxin injection (IBTI) which is a proven and used third line treatment therapy.
Study design, materials and methods
A prospective randomized comparative study was conducted. Patients diagnosed with refractory overactive bladder syndrome are included in this study. Between March 2023 and April 2024, a total number of 60 rOAB patients were enrolled in this study and grouped as 30 SBD patients and 30 IBTI patients according to the treatment arms with 3 months of follow-up. SBD was performed with a temperature-controlled 60-second RFA of the trigone in four regions. IBTI was performed with the intravesical injection of 100 units of Botulinum toxin A in 10 injection points. Treatment outcomes were obtained 2 weeks - 4 weeks and 12 weeks after the procedures and compared in both groups. This is a preliminary report with a total of 12 weeks of follow-up results of 25 patients with both groups. It is planned to evaluate 30 patients in 2 groups, with 3 months of follow-up.
Results
A total of 50 patients were included in the preliminary report and patients were followed up for 12 weeks after the treatments. Median symptom reduction based on a 3-day bladder diary in the SBD group is 32% (n:8) for urinary incontinence, urgency episodes 32% (n:8), and treatment benefit depending on International Consultation on Incontinence Questionnaire Female Lower Urinary Tract Symptoms Form (ICIQ-FLUTS) was reported in 28% (n:7) patients after 12 weeks of follow-up. Median symptom reduction based on a 3-day bladder diary in the IBTI group is 72% (n:18) for urinary incontinence, urgency episodes 80% (n:20), and treatment benefit depending on ICIQ-FLUTS form was reported in 84% (n:21) of patients. Device or procedure-related adverse events which include hematuria and dysuria were reported in %44 (n:11) of patients in the SBD group. Whereas %16 (n:4) of patients in the IBTI group had related adverse events including dysuria and hematuria. In the SBD group, there was no significant increase observed in post-void residual measurement, and no retention was observed in patients. However, in the IBTI group, an average increase of 82 cc in post-void residual measurement was observed. No patients in either group were catheterized during the postoperative period.
Interpretation of results
This study demonstrates the comparison of selective bladder denervation of trigone in relieving symptoms of refractory OAB with bladder intramuscular botulinum toxin injection. The preliminary findings of our study, which included 50 patients followed up for 12 weeks after treatment, revealed notable differences in outcomes between the two intervention groups. The IBTI group demonstrated substantially higher median symptom reductions of 72% for urinary incontinence and 80% for urgency episodes, with treatment benefits reported in 84% of patients according to the ICIQ-FLUTS form. Notably, no significant increase in post-void residual measurement or retention was observed in the SBD group, while the IBTI group exhibited an average increase in post-void residual measurement with symptoms of dysuria and hesitancy. These findings suggest a more favorable treatment response and lower incidence of adverse events associated with IBTI compared to SBD, highlighting the potential superiority of IBTI in managing urinary incontinence and urgency episodes.