Background: The ganglion impar is the first pelvic ganglion of the efferent sympathetic trunk
that relays pelvic and perineal nociceptive messages and therefore constitutes a therapeutic target.
Objective: The objective of this single-center study was to evaluate the effectiveness of 3 repeated
ganglion impar blocks in patients with chronic pelvic and perineal pain on intention-to-treat.
Study Design: Retrospective single-center study.
Setting: We reviewed the medical records of 83 patients with chronic refractory pelvic and
perineal pain. On intention-to-treat analysis, 62 (74.7%) of the patients received 3 ganglion impar
blocks.
Methods: Ganglion impar block was performed with 0.75% ropivacaine via a lateral approach
over the Co1-Co2 coccygeal joint with computed tomography (CT) guidance. The effectiveness of
ganglion impar blocks was evaluated by visual analogue scale (VAS) before and 30 minutes after
the blocks. Evaluation at least one month after the block was also performed by Patient Global
Impression of Change (PGI-C).
Results: A total of 220 blocks were performed, 193 (87.7%) of which were considered to be
positive with immediate but transient improvement of pain by more than 50% and complete but
transient pain relief after the procedure in 119 (54.1%) procedures. The variation of the VAS score
before and after each block was statistically significant (P < 0.001). Similarly, the VAS score before
repeated blocks was significantly improved with decreased pain intensity over time (P = 0.001).
Analysis of the PGI-C one month after the block demonstrated improvement in 41% of cases in
the overall population and in 43.6% of cases in the subgroup of 62 patients treated by 3 blocks.
Limitations: Retrospective study, short term follow-up.
Conclusions: Repeated ganglion impar blocks allowed short-term reduction of pain intensity
with a moderate intermediate-term effect. Ganglion impar appears to be a useful therapeutic
target to block the nociceptive message by acting on sensitization phenomena.
Efficacy of ganglion impar block on vulvodynia
