Ganglion Impar Blocks

A ganglion impar block is a nerve block used to target sympathetic and nociceptive pain of the pelvic structures and perineum. This block has broadened its use since its inception to be utilized for both malignant and nonmalignant causes. Literature has further suggested this block can provide between 50% and 100% improvement in pain symptoms, with success being reliant on the anatomic location of the ganglion impar in relation to the sacrococcygeal junction (SCJ). There are several approaches and techniques to do this block, both safely and successfully. The trans-sacrococcygeal approach is frequently used as it provides direct access to the ganglion, and a needle-inside-needle approach further provides control and avoids needle fractures. In recent years, ganglion impar blocks (GIBs) have been completed using both fluoroscopy and ultrasound with similar effectiveness.