The Benefits and Harms of Botulinum Toxin-A in the Treatment of Chronic Pelvic Pain Syndromes: A Systematic Review by the European Association of Urology Chronic Pelvic Pain Panel

CONTEXT: Patients with chronic pelvic pain syndrome (CPPS) may have pain refractory to conventional management strategies. Botulinum toxin A (BTX-A) is a potential therapeutic option. OBJECTIVE: To evaluate the benefits and harms of BTX-A injections in the treatment of CPPS. EVIDENCE ACQUISITION: A systematic review of the use of BTX-A in the treatment of CPPS was conducted (PROSPERO-ID: 162416). Comprehensive searches of EMBASE, PUBMED, Medline, and SCOPUS were performed for publications between January 1996 and May 2020. Identified studies were screened and selected studies assessed for quality prior to data extraction. The primary outcomes were improvement in pain and adverse events following treatment. Secondary outcomes included quality of life, global response assessment, sexual function, bowel function, and bladder function. EVIDENCE SYNTHESIS: After screening 1001 abstracts, 16 studies including 11 randomised controlled trials were identified, enrolling 858 patients and covering a range of CPPS subtypes. Most studies showed high risks of bias and confounding across all domains. A narrative synthesis was performed as heterogeneity of included studies precluded a meta-analysis and calculation of pooled effect estimates of measured outcomes. BTX-A reduced pain significantly in patients with bladder pain syndrome in two studies and in patients with prostate pain syndrome in one study, but no included studies showed benefit for patients with gynaecological pelvic pain. Adverse event reporting was variable and generally poor, but no serious adverse events were described. CONCLUSIONS: Beneficial effects of BTX-A on pain, quality of life, and functional symptoms were seen in patients with certain CPPS subtypes, but the current evidence level is too weak to allow recommendations about BTX-A use for treating CPPS. PATIENT SUMMARY: Botulinum toxin A is used to treat different pain disorders, but current studies are of insufficient quality to determine whether it reduces pain and improves quality of life in patients with chronic pelvic pain. Further research is needed.