Sympathetic blocks: stellate, celiac, hypogastric and impar

Pick the sympathetic target by territory: stellate for head, neck and arm; celiac for upper abdominal viscera; superior hypogastric for pelvic viscera; ganglion impar for perineum and coccyx. Deep blocks are high bleeding risk.

1. Celiac plexus for upper abdominal viscera. It carries visceral afferent and sympathetic fibers from organs such as the pancreas; neurolysis, usually with alcohol, chemically destroys these fibers, reducing pancreatic and other upper abdominal cancer pain and lowering opioid requirements ¹.
2. Superior hypogastric plexus for pelvic viscera. It lies retroperitoneally in front of the lower L5 body and upper sacrum and supplies the bladder, uterus, vaginal fundus and rectum ²¹. In the original series, neurolysis gave satisfactory relief in 69% of patients with pelvic cancer pain ³.
3. Ganglion impar for perineum and coccyx. This solitary retroperitoneal ganglion supplies the perineum, distal rectum, anus and coccyx ¹⁴. For refractory coccydynia, ganglion impar block is used more often than coccygeal nerve block, with radiofrequency techniques as further options ⁴.
4. Expect sympathectomy side effects. After celiac neurolysis, unopposed parasympathetic activity commonly causes transient diarrhea, and splanchnic vasodilation can cause orthostatic hypotension ¹.
5. Stellate blocks are cervical, high-stakes procedures. In an iodinated contrast shortage, stellate blocks should be postponed unless done under ultrasound by physicians highly experienced in that technique ⁵.
6. Bleeding risk is high under ASIPP. The 2024 ASIPP guideline places deep sympathetic blocks and neurolysis (stellate, thoracic, splanchnic, celiac, lumbar sympathetic, hypogastric) in the high-risk category, alongside implants, vertebral augmentation and percutaneous decompression ⁶.

Bleeding-risk tiers differ by guideline: ASIPP 2024 rates deep sympathetic blocks high risk, so state which guideline you are applying when planning anticoagulant holds ⁶.

• Deep central pelvic visceral cancer pain points to the superior hypogastric plexus, not the celiac plexus ¹.
• Pancreatic and other upper abdominal cancer pain points to the celiac plexus ¹.
• Neurolytic celiac block reduces sympathetic, not parasympathetic, tone ¹.
• Ultrasound guidance is the advisory's contrast-free alternative for stellate blocks, by experienced operators ⁵.
• Spinal cord stimulator and intrathecal implants also sit in ASIPP's high-risk tier ⁶.
• Coccydynia is managed conservatively first with cushions, medications and pelvic floor therapy, with injections for persistent pain ⁷.
• Ultrasound shows vessels and soft tissue, letting the needle be directed away from arteries during a stellate block ⁵.
• The ganglion impar also supplies the distal urethra, vulva and distal third of the vagina ¹.

• Choosing a celiac block for deep pelvic visceral cancer pain ¹.
• Mistaking transient post-celiac diarrhea for a complication requiring reversal ¹.
• Proceeding with a stellate block without contrast or ultrasound expertise ⁵.
• Assuming every guideline rates sympathetic blocks the same bleeding risk ⁶.