Efficacy and Safety of Low Energy Shock Wave Plus BotulinumToxin A in Treating Patients With Interstitial Cystitis

Overview

Low energy shock wave (LESW) is known to facilitate tissue regeneration with analgesic and anti-inflammatory effects. LESW treatment has been demonstrated effective in treatment of nonbacterial prostatitis and chronic pelvic pain syndrome. LESW reduced pain behavior and down-regulated the NGF expression, suppressed bladder overactivity by decreasing inflammation, IL-6 and COX2 expression and NGF expression. Previous rat interstitial cystitis (IC) models have shown LESW could increase urothelial permeability, facilitate intravesical botulinum toxin A (BoNT-A) delivery and block acetic acid induced hyperactive bladder, suggesting LESW might be a potential therapeutic candidate for relieving bladder inflammatory conditions and overactivity. A double-blind, randomized, placebo-controlled physician-initiated study revealed LESW treatment was associated with a statistically significant decrease in O'Leary-Saint Symptom Score and visual analog scale of pain in patients with interstitial cystitis/bladder pain syndrome (IC/BPS), but the improvement was not superior to the sham LESW treatment. Previous studies found the urothelial dysfunction and deficits of cell differentiation are fundamental pathophysiology of IC/BPS. Through intravesical platelet-rich plasma injections, the chronic inflammation in IC/BPS bladders could be reduced and improved cell differentiation of urothelium. Botox injection or liposome encapsulated Botox could also inhibit inflammation and improve IC/BPS symptoms. However, the Botox injection needs anesthesia and certain complications might occur. There is no study to test if LESW plus Botox intravesical instillation could improve bladder inflammation and relieve IC/BPS symptoms. This study aims to investigate the therapeutic efficacy and safety of concomitant LESW plus intravesical BoNT-A instillation for IC/BPS refractory to conventional treatments.

Interstitial cystitis/ bladder pain syndrome (IC/BPS) is a bladder disorder with unknown etiology and difficult treatment. Novel treatments have been searched to adequately improved symptoms. Low energy shock wave (LESW) increased urothelial permeability, facilitated intravesical botulinum toxin A (BoNT-A) delivery and blocked acetic acid induced hyperactive bladder. Rats that received BoNT-A plus LESW showed a significantly reduced response (48.6% decreased intercontractile interval) to acetic acid instillation without compromising voiding function. Rats pre-treated with BoNT-A plus LESW showed a decreased inflammatory reaction (p \<0.05), and decreased expressions of SNAP-23 (p \< 0.05), SNAP-25 (p = 0.061) and COX-2 (p \< 0.05) compared with the control group. These results support LESW as a promising method to deliver BoNT-A across urothelium without the need for injection. LESW is known to facilitate tissue regeneration with analgesic and anti-inflammatory effects. LESW treatment reduced pain behavior and down-regulated the NGF expression (33.3%, P \< 0.05) on day 4 and IL-6 (40.9%, P \< 0.05). LESW treatment suppressed bladder overactivity (intercontractile interval 77.8% increase, P \< 0.05) by decreasing inflammation and COX2 (38.6%, P \< 0.05) expression and NGF expression (25.2%, P = 0.0812). Previous study revealed that LESW might be a potential candidate for relieving bladder inflammatory conditions and overactivity. Recent clinical trial also revealed that Intravesical instillation of BoNT-A and LESW is a safe and effective method for the treatment of refractory overactive bladder with a durable response for 2 months. A double-blind, randomized, placebo-controlled physician-initiated study enrolled 54 patients with IC/BPS. The patients were assigned to LESW or placebo. At 4 weeks post-treatment, both groups were associated with a statistically significant decrease in OSS and VAS pain scale. A significantly higher proportion of patients on LESW responded as improved in the VAS ≥ 3 vs placebo (P = 0.035). At 12 weeks post-treatment, improvement in the VAS ≥ 3 was 57.1% vs 19.0% (LESW vs placebo; P = 0.011). No significant adverse events were found in either group. This study aims to investigate the therapeutic efficacy and safety of concomitant LESW plus intravesical BoNT-A instillation for IC/BPS patients refractory to conventional treatments. Materials and Methods Eligible participants of either gender with IC/BPS refractory to at least two treatments will be enrolled to this study. Participants are randomly allocated to receive either treatment in 1:1 ratio according to the permuted block randomization code as the following: (A) LESW treatment with 3000 shocks, and followed by intravesical instillation of 30ml normal saline. (placebo group) (B) LESW with 3000 shocks, and followed by intravesical BoNT-A 100U instillation. (treatment group) Urine samples will be collected for urinary protein and biomarkers analysis.