Comparison of radiofrequency thermocoagulation of ganglion Impar with block using a combination of local anaesthetic and steroid in chronic perineal pain.

Background and aims: Chronic perineal pain (CPP) is the anorectal and perineal pain without underlying organic disease. The prevalence of CPP is 6-18%. The etiology for CPP may be idiopathic, benign, or malignant. We compared radiofrequency thermocoagulation of ganglion Impar with block using a combination of local anaesthetic and steroid for management of chronic perineal pain, with respect to pain relief, patients' self-reported belief about the efficacy of treatment, and side effects or complications, if any.

Material and methods: Forty patients attending the Pain Management Centre of either sex in the age group of 20-70 years with history, physical examination, and pain patterns consistent with chronic perineal pain, who had been investigated to rule out malignancy and failed to respond to 6 weeks of conservative treatment with a combination of analgesics, anti-inflammatory drugs, neuromodulators, and physiotherapy, were enrolled in the study. The patients were randomly divided into two groups of 20 each using a computer-generated randomization number table. Group-I (n = 20): Patients were administered ganglion Impar block using a drug mixture comprising of 8 ml of 0.25% bupivacaine plus 80 mg of triamcinolone acetate under fluoroscopic guidance. Group II (n = 20): Patients received conventional radiofrequency thermocoagulation of ganglion Impar at 80 degree Celsius for 90 seconds under fluoroscopic guidance. Outcome assessment was done after minimally invasive pain and spine intervention (MIPSI) with evaluation of pain using the Numeric Rating Scale (0-10), patients' self-reported belief about the efficacy of treatment using Patient Global Impression of Change (PGI-C), and side effects or complications, if any.

Results: The majority of the patients in our study were in the age group of 40-50 years, and 80% of the patients were females and weighed 60-70 kg. The majority of the patients in our study had history of trauma, which led to coccygodynia. There was statistically and clinically significant improvement in pain score after ganglion Impar block in both the groups at all time intervals during the study period (P < 0.05). Patients' self-reported belief about efficacy as per PGI-C was clinically and statistically better in group II as compared to group I at all time intervals throughout the study period (P < 0.005). Four patients in group I required second ganglion Impar block during the 12 months study period. The most common side effect was temporary pain on injection.

Conclusions: Both the techniques of MIPSI, that is, fluoroscope-guided ganglion Impar block using corticosteroid and local anaesthetic and radiofrequency thermocoagulation, are effective and provide good pain relief to the symptomatic patients. With respect to improvement in pain relief and patients' self-reported belief about the efficacy of treatment and side effects or complications, fluoroscope-guided ganglion Impar radiofrequency thermocoagulation is better as compared to fluoroscope-guided ganglion Impar block using corticosteroids and local anesthetics.