Ganglion Impar Blockade

The Ganglion Impar represents the termination of the sympathetic chain. It rests anterior to the sacrococcygeal junction. Various techniques are described to block this ganglion, including a bent needle technique that enters at the level of the anococcygeal ligament. However, given the close proximity of the rectal canal to this entry site, the easiest and safest approach is to traverse the sacrococcygeal itself. Injection of contrast agent under fluoroscopy confirms proper needle placement. The technique can be performed with local anesthetic and steroid for nonmalignant pain conditions, such as coccygodynia, or perirectal pain from tumor involvement. Neurolytic blockade should probably only be performed for malignant pain conditions, and only after a diagnostic block is performed. The advantage of the Ganglion Impar block over other neurolytic procedures for rectal pain is that bowel and bladder function is generally unaffected. However, this should be confirmed first with the local anesthetic block.

Learn about our other Sympathetic Blocks.