Transvaginal Versus Fluoroscopy-guided Trans Gluteal Pudendal Nerve Block for Pudendal Neuralgia

Transvaginal Versus Fluoroscopy-guided Trans Gluteal Pudendal Nerve Block for Pudendal Neuralgia and Chronic Pelvic Pain: a Prospective, Noninferiority, Randomized Controlled Trial

Chronic pain affecting the pelvic and urogenital area is a major clinical problem and can have a profound impact on quality of life and health care costs. Pelvic pain arising from entrapment or neuropathy of the pudendal nerve is known as pudendal neuralgia, which results in chronic perineal pain. This pain syndrome is difficult to diagnose and patients with pudendal neuralgia may present to providers with refractory chronic pelvic pain. Pudendal nerve infiltration or pudendal nerve block (PNB) serves as a diagnostic tool and treatment modality for patients with this condition. To date, there are no published randomized controlled trials comparing imaging-guided PNB to transvaginal finger-guided PNB. While one can assume that image-guided nerve blocks will provide better accuracy for injection and potentially better efficacy in pain relief as a result, no published data exists comparing the outcomes and efficacy between modalities.

The purpose of this prospective, non-inferiority, randomized controlled trial is to compare the efficacy of pain relief from bilateral transvaginal finger-guided pudendal nerve block versus bilateral fluoroscopy-guided trans gluteal pudendal nerve block for patients with pudendal neuralgia.

Primary objective:

Determine the efficacy of pain relief comparing the change in Visual Analog Scale (VAS) from baseline to 6 weeks in women randomized to Transvaginal PNB (without imaging) versus Trans gluteal fluoroscopy-guided PNB.

Upon completion of 6-week follow-up, participants will be given the option to crossover to the alternative treatment arm

Secondary Objectives:

Characterize the effect of either pudendal nerve block approach using the following validated questionnaires

• PROMIS-29 (degree of pain intensity and bother across health domains)
• Pain catastrophizing scale (emotional and cognitive impact of pain)
• Short-form McGill (qualitative pain)
• Patient satisfaction with medical care
• Baseline demographics
• Baseline VAS
• Adverse events
• Determine the time to peak pain relief and duration of injection pain relief

Inclusion Criteria:

• women >18 years
• English speaking/reading
• Diagnosis of pudendal neuralgia OR chronic pelvic pain with pain in the distribution of the pudendal nerve for 3 months or longer
• Minimum pain/bother score of 4/10
• Desire for pudendal nerve block

Exclusion Criteria:

• Contraindication to pudendal nerve block (examples: skin or vaginal infection, bupivacaine allergy, uncorrected coagulopathy)
• Pregnant or intending to become pregnant during the study
• Pudendal nerve block from any route within the last 3 months
• Major pelvic surgery within the last 3 months (examples: hysterectomy, prolapse repair, midurethral sling)
• Neurologic disease affecting the perineum (examples: spinal cord injury, multiple sclerosis)