Efficacy of neurolytic celiac plexus block in varying locations of pancreatic cancer: Influence on pain relief

Review by: Alec Meleger, M.D.
UC Davis Fellow

Rykowski, Jan J., M.D., Ph.D.; Hilgier, Maciej, M.D., Ph.D.
Anesthesiology, Volume 92(2). February 2000.

The incidence of pancreatic cancer has been steadily on the rise. It commonly presents in an advanced stage when palliative treatment and the relief of pain are the main goals of therapy. There have been a limited number of studies that compare effectiveness of neurolytic celiac plexus block (NCPB) and drug therapy on pain relief. Previous studies have neglected the location of primary pancreatic tumor (head versus tail and body) on the effectiveness of NCPB.

The aim of this prospective study was to assess the effectiveness of NCPB in pancreatic cancer pain using the location of the primary tumor, the head or tail and body of the pancreas as the predictor variable.

Fifty consecutive patients with adenocarcinoma of the pancreas and severe pain were scheduled for palliative NCPB. The following symptoms were evaluated: nausea, vomiting, weight loss, jaundice, pain characteristics, location, pain severity based on visual analogue scale (VAS; 0-10), time from first symptoms to NCPB, analgesics and their dosage before neurolysis. Patients with VAS score equal to or greater than 4 were started on opioid medications. The criteria for NCPB was VAS greater than 3, no response to diclofenac, and utilization of opioid medication (second and third steps of the World Health Organization guidelines). The diagnosis of pancreatic tumor was based on ultrasonography or computed tomography when diffuse metastases were suspected. The diagnosis of adenocarcinoma of the pancreas was confirmed with ultrasound-guided biopsy-cytology of the pancreatic tumor. Tumor staging was based on interpretation of ultrasound-guided-CT examination according to the American Joint Committee for Cancer Classification, stages I-IV. Upon positive diagnosis patients were stratified into two groups: group I with cancer of the head of the pancreas and group II with cancer of the body and tail of the pancreas. Group I consisted of 36 patients with 16 of them presenting with local metastases to the surrounding lymph nodes and occasional invasion of pancreatic duct.

All patients experienced 6-10 hours of effective pain relief after NCPB, with VAS pain scores of less than 2. The effect of the block was assessed 48 hours after neurolysis by a blinded examiner. Thirty seven out of 50 patients had effective pain relief (VAS of 3 or less) during the first 3 months or until death. Of the 37 patients with effective pain control, 33 were from group 1 (33/36=92%), and 4 were from group 2 (4/14=29%). These patients were able to discontinue opioid medication and continue only with NSAIDS. The patients in group 1 had a mean pain relief of 119 days vs. 65 days in group 2 and mean survival of 203 days vs. 85 days. Post 3 month follow-up of the surviving patients who initially had satisfactory results, revealed VAS scores to gradually increase with survival time. Seven patients underwent subsequent retrocrural neurolytic block with moderate effect, VAS between 3.5 and 4.5. Thirteen patients without the initial satisfactory pain relief subsequently underwent a CT guided neurolysis using a retrocrural approach without significant effect. CT scans showed massive growth of the tumor around the celiac axis that distorted the anatomy with a shift of the aorta to the left. Adverse reactions consisted of self limiting back pain, short lasting diarrhea, transient urinary retention, mild hematuria, hypotension, aortic puncture.

This study studied the correlation between the effectiveness of NCPB and pancreatic tumor location. The results show that patients with the cancer of the head of the pancreas (group 1) had much more pronounced and longer lasting pain relief after NCPB with a mean of 119 days vs. 65 days in group 2 (cancer of the body and tail of the pancreas). The response rate was significantly different between the two groups: 92% in group 1 and 29% in group 2 had effective pain control defined as VAS of 3 or less. The mean survival of patients with cancer of the head of the pancreas was 203 days versus 85 days in patients with cancer in the body and tail of the pancreas. Treatment failure was attributed to more advanced disease altering local anatomy and possible involvement of non-visceral nociceptive pathways for which a celiac block would be ineffective. The authors also made an interesting comment that differences in the dye spread during fluoroscopy could not predict future NCPB failure.

The results of this study can be of significant help to the pain management clinician in predicting the efficacy of NCPB.