Interventional Pain Procedures: A Narrative Review Focusing on Safety and Complications. Part 3 - Sympathetic and...

Interventional procedures that target the sympathetic nervous system and specific autonomic and sensory ganglia are widely used for refractory visceral, neuropathic, and cancer-related pain. They can provide substantial, often durable analgesia but carry a small yet clinically important risk of serious adverse events. This is the third part of our narrative-review series on the safety of interventional pain procedures, following Part 1 (spinal pain injections) and Part 2 (procedures for back pain), both published in the Journal of Pain Research. It is a structured but non-systematic narrative review (PubMed, Scopus, Embase, and the Cochrane Library; 1980-2026). We examine the complications of image-guided and neuroablative procedures directed at the trigeminal (Gasserian), sphenopalatine, stellate, thoracic sympathetic, celiac/splanchnic, lumbar sympathetic, superior and inferior hypogastric, and impar ganglia and plexuses; we outline the pharmacology of phenol and ethanol and compare them with conventional radiofrequency and cryoneurolysis. Most reported complications are mild, self-limiting, and physiologically predictable, such as hypotension, diarrhea, transient sensory change, and Horner syndrome. Serious events-paraplegia, spinal cord infarction, retropharyngeal hematoma, meningitis, visceral perforation, and anesthesia dolorosa-appear uncommon, but their true incidence remains uncertain and varies by procedure, and much of the evidence derives from isolated case reports. They reflect either anatomical proximity to critical neurovascular structures or unintended spread of the neurolytic agent. Across techniques, the determinants of safety comprise real-time image guidance, meticulous needle placement, incremental dosing, contrast confirmation, attention to anticoagulation status, and careful patient selection.