RT Book, Section A1 Hunter, Corey W. A1 Diwan, Sudhir A2 Diwan, Sudhir A2 Staats, Peter S. SR Print(0) ID 1107198500 T1 Ganglion Impar Block T2 Atlas of Pain Medicine Procedures YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071738767 LK accessanesthesiology.mhmedical.com/content.aspx?aid=1107198500 RD 2024/03/28 AB The ganglion impar, also known as the ganglion of Walther or sacrococcygeal ganglion is a singular retroperitoneal structure located at the level of the sacrococcygeal junction (SCJ). It is of particular importance when considering patients who suffer from pain in the pelvic and perineal structures as it provides nociceptive and sympathetic supply to those regions. It receives afferent innervation from the perineum, distal rectum, anus, distal urethra, and distal vagina. Plancarte et al first reported the successful relief of perineal pain through the blockade of the ganglion impar in 1990.1 The initial approach as offered by Plancarte involved a bent spinal needle. Through the years, techniques have evolved with the use of fluoroscopy, computed tomography (CT), and ultrasound, and the utility for its potential relief of patient remains relatively unquestioned.