The sympathetic nervous system is involved in the pathophysiology that leads to a number of different chronic pain conditions, including pain arising from the bladder, uterus, rectum, vagina, and prostate. The relevant anatomy and technique for superior hypogastric block has been well described, but only limited observational data point to the usefulness of this technique for treating chronic pain arising from the pelvic viscera.

The superior hypogastric plexus is composed of a flattened band of intercommunicating nerve fibers that descend over the aortic bifurcation. The plexus carries sympathetic afferents and postganglionic efferent fibers from the lumbar sympathetic chain, as well as parasympathetic fibers that arise from S2 to S4. The plexus is retroperitoneal in location and lies over the anterior surface of the fourth and fifth lumbar and the first sacral vertebrae (Figs. 13-1 and 13-2). Sympathetic nerves passing through the plexus innervate the pelvic viscera, including the bladder, uterus, rectum, vagina, and prostate.

Superior hypogastric plexus block is used in the treatment of pain arising from the pelvic viscera. In patients with pain of nonmalignant origin, temporary block may be useful in better defining the source of the pain. More often, superior hypogastric neurolysis is used to treat intractable pelvic visceral pain associated with malignancy. Patients with locally invasive cancer involving the proximal vagina, uterus, ovaries, prostate, and rectum that are associated with pelvic pain may gain significant pain relief from this approach.

The use of sympathetic blocks in the diagnosis and management of a number of chronic pain conditions, including complex regional pain syndrome (CRPS), has been common for decades despite the lack of scientific validation for this approach. Yet, the usefulness of sympathetic blocks in either the diagnostic evaluation or the long-term management of pain syndromes remains in question. Superior hypogastric block was first popularized by Plancarte and colleagues in the late 1980s for treating pain associated with pelvic malignancies. Like other sympathetic blocks, there has been no rigorous testing of the safety and efficacy of this treatment approach and we can rely only on small, uncontrolled observational trials for hints at usefulness.

The American Society of Anesthesiologists (ASA) Task Force on Chronic Pain Management published a 2010 Practice Guideline offering the following recommendation regarding the use of sympathetic blocks for the diagnosis of pain: “The use of sympathetic blocks may be considered to support the diagnosis of sympathetically maintained pain. They should not be used to predict the outcome of surgical, chemical, or radiofrequency sympathectomy.” The ASA Guideline made the following recommendations regarding the use of sympathetic blocks as a component of pain treatment: “Lumbar sympathetic blocks or stellate ganglion blocks may be used as components of the multimodal treatment of CRPS if used in the presence of consistent improvement and increasing duration of pain relief. Sympathetic nerve blocks should not be used for long-term treatment of non-CRPS neuropathic pain.” Because of the dearth of available scientific evidence regarding superior hypogastric block, there is no current practice guideline that makes specific recommendations regarding the use of this block.