Transvaginal pudendal nerve blocks in patients with pudendal neuralgia: 2-year follow-up results.

PURPOSE

Pudendal neuralgia (PN) is an extremely painful neuropathy of the pudendal nerve resulting in a negative impact on a patient's quality of life. The aim of this study is to evaluate the 2-year outcomes of repetitive doses of the transvaginal pudendal nerve injections (PNI), and to compare the success of the PNI concerning anatomical levels (endopelvic and extrapelvic portion) of the pudendal nerve pathology.

METHODS

This retrospective longitudinal cohort study consists of patients with PN diagnosed with the first four essential Nantes criteria. Diagnostic PNI was performed on 67 patients to fulfill the fifth criteria of Nantes. A total of 56 patients who responded to the initial diagnostic PNI underwent therapeutic repeated transvaginal PNIs twice for 3 weeks apart. Mean pain intensity scores were measured using a visual analog scale at the 1st, 3rd, 6th, 12th, and 24th months after the therapeutic blocks were completed. Effectiveness of the PNIs' was defined as ≥ 50% improvement of the initial pain, and relative improvement was defined as 30-50% improvement of the initial pain. Treatment failure was defined as the reduction of the initial pain by less than 30% or the return of the pain to its worst condition.

RESULTS

The efficacy of the PNIs significantly declined over time. Pudendal nerve blocks provided a significant decrease in pain scores; however, this decrease lost its strength significantly in the 24th month. The intervention was more effective in entrapments of the pudendal nerve between sacrospinous and sacrotuberous ligaments or below (Level-2) when compared to the injuries in the endopelvic part (Level-1). More than 50% pain reduction continued in five patients with pathology at Level-1 and 24 patients with pathology at Level-2.

CONCLUSION

Repeated PNIs could provide a significant decrease in pain scores for both short- and long-term periods. However, the efficacy of the PNIs declined over 2 years. The success of PNIs may be affected by the anatomical level of the nerve injury; therefore, interligamentous pudendal nerve entrapment cases have more benefits than the cases of pudendal nerve entrapment in the endopelvic part. However, it is recommended to perform therapeutic nerve blocks even in patients with suspected endopelvic pudendal nerve pathology before the referral to surgery.