Transsacrococcygeal Ganglion Impar Block for Postherpetic Neuralgia

Predictive factors affecting treatment success in ganglion impar block applied in chronic coccygodynia

BACKGROUND

This study aimed to determine the predictive factors affecting the success of ganglion impar block applied in chronic coccygodynia.

METHODS

Patients who received ganglion impar block to treat coccygodynia between January 1, 2018 and January 1, 2021 were retrospectively screened. Of the 195 patients, 102 met the final analysis criteria and were included in the study. Demographic data, coccygodynia etiology, coccygodynia symptom duration, history of coccyx fracture, regular opioid use, and presence of other musculoskeletal chronic pain conditions accompanying coccygodynia were obtained from patient records. In addition, coccyx radiography was examined, and coccyx curvature type, permanent subluxation, and posterior spicule presence were evaluated. The criterion for treatment success was set as ≥50% reduction in Numerical Rating Scale pain scores in the third month after treatment.

RESULTS

Treatment was successful of the patients in 69.6% (95% CI 60.4% to 78.7%). A significant cut-off value (24.5 months) was determined for coccygodynia symptom duration using receiver operating characteristic analysis. Symptom duration above the cut-off value was defined as prolonged symptom duration. Multivariable logistic regression analysis was performed to determine the predictive factors affecting treatment success in the third month after injection. In the final model, the presence of permanent subluxation (yes vs no), and the prolonged symptom duration (yes vs no) were found to have significant effects on treatment success (OR 9.56, 95% CI 1.44 to 63.40, p=0.02; OR 137.00, 95% CI 19.59 to 958.03, p<0.001).

CONCLUSION

Treatment success of ganglion impar block for coccygodynia is high. However, longer preprocedure symptom duration and the presence of permanent subluxation were associated with a decrease likelihood of treatment success.

Comparative evaluation of transsacrococcygeal and transcoccygeal approach of ganglion impar block for management of coccygodynia

BACKGROUND AND AIMS

Coccygodynia or Coccydynia is pain in the area of coccyx and ganglion impar block is commonly used technique for treatment of coccygodynia.

MATERIAL AND METHODS

Forty patients of either sex in the age group of 20-70 years suffering from coccygodynia, who failed to respond to six weeks of conservative treatment were enrolled in the study. All patients were subjected to detailed clinical history, examination in the Pain Management Centre (Pain Clinic) of our Institute and imaging studies were reviewed. The patients were randomly divided into two groups of 20 each by a computer generated randomization number table: Group-TS (n = 20): Patients were administered ganglion Impar block by trans-sacrococcygeal approach Group-TC (n = 20): Patients were administered ganglion Impar block by trans-coccygeal approach with 8 ml of 0.5% bupivacaine plus 2 ml of 40mg/ml methylprednisolone acetate under fluoroscopic guidance.

RESULTS

Both the techniques of ganglion Impar block were effective and provided good pain relief to the patients with coccygodynia. There was a 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). The mean pain score after ganglion Impar block was <2 at all time intervals throughout the three month study period in all patients in the two groups. All patients in both the groups had excellent satisfaction immediately after ganglion Impar block. Five patients each in both groups required second ganglion Impar block during the three months study period.

CONCLUSION

Both trans-sacrococcygeal and trans-coccygeal approaches of ganglion Impar block with a combination of local anaesthetic and steroid are safe and effective for management of coccygodynia. Trans-coccygeal ganglion Impar block through the first intra-coccygeal joint is better in terms of improvement in pain score, functional disability, patient satisfaction and ease of administration.