Chapter 48: Superior and Inferior Hypogastric Plexus Blocks

INTRODUCTION

The hypogastric plexus is the extension of the aortic plexus in the retroperitoneal space, below the aortic bifurcation. The upper part, the superior hypogastric plexus, is located anterior to the L5 vertebral body and the sacral promontory, whereas the inferior hypogastric plexus lies within the bilateral presacral tissues on either side of the rectum at S2, S3, and S4 levels. Pain from the lower abdominal as well as the pelvic and perineal area is transmitted through the hypogastric plexus.

Chronic noncancer and cancer pain of the pelvic structures are often challenging to treat and interventional approaches may well be invaluable tools. Plancarte et al described the superior hypogastric block in 1990, and found that sympathetically mediated pain was significantly reduced or eliminated in all cases without serious complications. Although this injection was originally developed for the treatment of pelvic cancer pain, as with many procedures originally limited to the terminal cancer patient in pain, these techniques are now commonly used in the nonmalignant pain. Patients have frequently failed to respond to less invasive procedures, such as lumbar or caudal epidural injections.

INDICATIONS

The indications for performing the two types of blocks have some overlap. A diagnostic block of the hypogastric plexus with local anesthetic if positive can be followed by a neurolytic procedure, which could potentially provide long-term relief.

The superior hypogastric plexus block is indicated for chronic intractable lower abdominal and/or pelvic pain:

• Gynecologic disorders like endometriosis, pelvic inflammatory disease, and pelvic adhesions

• Nongynecologic disorders like interstitial cystitis, irritable bowel syndrome

• Sympathetically maintained pelvic pain (pelvic CRPS)

• Pain secondary to neoplasm in the pelvic area

The inferior hypogastric plexus block is indicated for chronic intractable lower abdominal and/or pelvic pain:

• Sacral or perineal pain

• Bladder conditions

• Penile pain

• Prostatitis

• Vaginal pain/vulvodynia

• Rectal/anal pain

• Irradiation-induced tenesmus

• Perineal, sacral, and lower pelvic pain caused by malignant causes

• Sympathetically maintained pelvic pain (pelvic CRPS)

• Lower pelvic endometriosis

• Acute herpes zoster

• Postherpetic neuralgia of the sacral area

CONTRAINDICATIONS

• Infection (systemic or localized)

• Coagulopathy

• Distorted or complicated anatomy

• Patient refusal

Other Considerations

The risks and potential contraindications need to be weighed carefully when performed in patients with cancer pain and noncancer pain.

• Although this injection is performed outside the neuroaxis, there are large blood vessels (iliac arteries and vein) in close proximity, and therefore an adequate coagulation status is warranted.

• In the same way, injections into or through an area of infection should be avoided.

• Psychological status in cancer pain patient appears to be less of an issue, as long as the patient or health care surrogate is capable of providing informed consent.

• However, for the nonmalignant pain patient, because of the dramatic psychological overlay often seen in patients who suffer from chronic ...