What are Pelvic Plexus Blocks?
Pelvic plexus blocks are a type of nerve block used primarily to manage chronic pelvic pain or pain arising from pelvic organs such as the bladder, prostate, uterus, vagina, or rectum. The pelvic plexus, also called the inferior hypogastric plexus, is a network of nerves located deep in the pelvis that transmits pain and other signals from the pelvic organs. A pelvic plexus block involves the injection of a local anesthetic, often combined with a steroid, near the inferior hypogastric plexus to disrupt pain signal transmission.
Indications for Pelvic Plexus Block
Pelvic plexus blocks can be used to treat:
- Chronic pelvic pain (CPP)
- Pelvic cancer pain (prostate, bladder, rectum, uterus, cervix)
- Pain after pelvic surgery or radiation
- Interstitial cystitis/bladder pain syndrome
- Endometriosis-related pain
- Prostatitis-related pelvic pain
- As part of neurolytic blocks for palliative care
Procedure for Pelvic Plexus Block
During a pelvic plexus block procedure, the goal is to target the nerve fibers in the pelvic plexus to relieve pain from pelvic organs. The procedure is typically done under image guidance (CT or fluoroscopy) in a sterile environment by a pain specialist or interventional radiologist and generally involves the following steps:
- You are usually placed in the prone position (face down) or lateral decubitus (on your side), depending on the approach.
- A pillow may be used to support the pelvis for better access.
- The skin over the lower back or sacral area is cleaned and sterilized.
- A local anesthetic is injected to numb the skin and deeper tissues at the needle insertion site.
- A thin needle is inserted through the buttock or sacral area and guided to the pelvic plexus, typically near the rectum or prostate area (depending on the target).
- Imaging helps confirm the correct placement of the needle.
- A small amount of contrast dye may be used first to confirm correct needle placement on imaging.
- Then one of the following is injected:
- Local anesthetic (e.g., bupivacaine or lidocaine) – for short-term diagnostic or therapeutic relief
- Steroid (e.g., triamcinolone or dexamethasone) – to reduce inflammation
- Neurolytic agent (e.g., alcohol or phenol) – for long-term or cancer-related pain relief
Post-Procedure Care
After a pelvic plexus block procedure, the patient is monitored for a short period - usually 30 to 60 minutes - to ensure there are no immediate side effects, such as changes in blood pressure, dizziness, or allergic reactions. Mild soreness at the injection site or a temporary tingling or numbness in the pelvic area may occur. Pain relief can begin within minutes to a few hours, depending on the medication used, and may last from days to several months. Most patients can resume normal activities within a day, although it is recommended to rest for the remainder of the procedure day. A follow-up appointment is often scheduled to assess the effectiveness of the block and determine whether additional treatments are needed.
Risks and Complications
Pelvic plexus block is generally safe, but like any procedure, it carries some risks. Common minor risks include temporary pain at the injection site, bruising, mild numbness or tingling in the pelvic area, and low blood pressure. Less common but more serious complications can include infection, bleeding, nerve damage, or accidental puncture of nearby organs like the bladder or rectum. If a neurolytic agent like alcohol or phenol is used, there is a risk of longer-lasting numbness or unintended nerve damage. Most side effects are temporary and manageable with proper care.