Efficacy and Safety of Neurolytic Splanchnic Nerve Block via Transintervertebral Disc Approach to Retrocrural Space: A Multicenter Retrospective Study

INTRODUCTION: Celiac plexus block is effective for treating intractable cancer pain and has been the focus of many studies. Several guiding techniques such as fluoroscopy, computed tomography, and endoscopy have been devised, and the target of the block has varied in previous studies as both the celiac plexus and splanchnic nerve, which is the main origin of the celiac plexus, have been targeted. At our affiliated institution, fluoroscopy-guided splanchnic nerve block with a single needle via transintervertebral disc approach is the first choice. However, there have been few reports on the use of this technique. This study investigated the efficacy and safety of this technique. METHODS: This multicenter retrospective observational study reviewed the medical records of patients who underwent neurolytic splanchnic nerve block (NSNB) via transintervertebral disc approach for intractable cancer pain at five tertiary hospitals in Japan from April 2005 to October 2020. The primary outcome was the clinical success ratio of NSNB, and the secondary outcome was the incidence ratio of NSNB-related adverse events. RESULTS: In total, 103 patients were included in the analysis. Of these, 77 patients met the definition of clinical success, with a ratio of 74.8%. The incidence ratio of NSNB-related adverse events was 40.8% (hypotension, 21.4%; alcohol intoxication, 13.6%; diarrhea, 11.7%; and vascular puncture, 3.9%; duplicates were present). All adverse events improved with observation and symptomatic treatment only. No patient had infection or serious adverse events such as organ or nerve damage. CONCLUSIONS: The clinical success ratio of this technique was 74.8%. Although the incidence of adverse events was 40.8%, all events were mild and no serious adverse events were observed. The findings demonstrate the efficacy and safety of our NSNB in patients with intractable cancer pain.