Nagels, W., Pease, N., Bekkering, G., Cools, F., & Dobbels, P. (2013). Celiac plexus neurolysis for abdominal cancer pain: A systematic review. Pain Medicine, 14, 1140–1163.

STUDY PURPOSE: To review the evidence for effects of neurolysis for abdominal cancer pain

TYPE OF STUDY:  Meta-analysis and systematic review

DATABASES USED: MEDLINE, EMBASE, AMED, Web of Science, CINAHL from 1980–2011

KEYWORDS: Broad neurolysis terms were used. Terms included pain, quality of life, and possible side effects.

INCLUSION CRITERIA: All study designs and case reports involving percutaneous and endoscopic ultrasound-guided celiac plexus neurolysis, abdominal pain due to intra-abdominal cancers, and adults; English language

EXCLUSION CRITERIA: Noncancer pain; other neurolysis techniques

TOTAL REFERENCES RETRIEVED = 2,303

EVALUATION METHOD AND COMMENTS ON LITERATURE USED: Critical Appraisal Skills Programme was used to evaluate strength of evidence. For case series, a checklist was developed from the Joanna Briggs Institute.

• FINAL NUMBER STUDIES INCLUDED = 66 publications—32 case series, 24 case reports, one survey, and nine RCTs. Five studies were included in meta-analysis that compared celiac plexus neurolysis (CPN) with analgesic therapy.
• TOTAL PATIENTS INCLUDED IN REVIEW = 469 patients in RCTs
• SAMPLE RANGE ACROSS STUDIES = 20–100 patients
• KEY SAMPLE CHARACTERISTICS: Most had pancreatic cancer, but additional abdominal cancers were reported in case series and case reports.

• PHASE OF CARE: Late effects and survivorship     
• APPLICATIONS: Palliative care

Meta-analysis showed a mean difference with CPN (versus analgesics) of -0.87 (95% CI -1.47, -0.28, p = .004) in favor of neurolysis after one to two weeks. After four weeks, the mean difference in pain scores was -0.47 (95% CI -0.71, -0.23, p = .0001). At eight weeks, from four studies, the mean difference with CPN was -0.46 (95% CI -0.68, -0.25, p < .0001). In the two studies that evaluated pain after three months, neither showed a benefit of CPN at that time point.  For endoscopic ultrasound-guided CPN, mean difference at one to two weeks was -4.26 (95% CI -5.53, -3.0, p < .00001), at four weeks was -4.21 (95% CI -5.29, -3.13, p < .00001), and at eight weeks was -4.13 (95% CI -4.84, -3.43, p < .00001). At 12 weeks, only 60 patients could be evaluated. These results in meta-analysis showed a mean difference of -4.28 (95% CI -5.63, -2.94, p < .00001). Analysis also showed significant reduction in opioid consumption from one to four weeks. Meta-analysis of data related to side effects showed higher risk of diarrhea with CPN (p + .0003) and risk of constipation with opioids (RR = 0.34, p < .00001). More nausea and vomiting occured in patients on analgesics (RR = 0.44, p < .0001). Information on side effects, mainly from case series, is provided. Hypotension was shown in four studies to be more prevalent with CPN (RR = 7.43, p = .0003). Across three studies, opioid consumption was reduced with CPN (mean difference = -70.02, p < .0001).

Evidence suggests that CPN reduces abdominal cancer-related pain and that it is a relatively safe procedure. Diarrhea and hypotension are more prevalent with CPN, and constipation is more prevalent with analgesics alone. Analysis was only possible up to two to three months after the procedure, so longer-term efficacy is unknown. It is noted that a significant number of patients with advanced abdominal cancers do not have a long survival time, so this duration is likely clinically meaningful. More evidence is needed to evaluate differences between endoscopic ultrasound-guided and percutaneous CPN.

• There was significant heterogeneity among studies. 
• Methodologic quality of studies was sometimes low, and specific quality data are not reported in the analysis.
• The number of trials included in meta-analyses was low.
• Authors point out a lack of differentiation between somatic and visceral pain, and peritoneal involvement with advanced malignancies can confuse findings because related pain is not transmitted via the celiac plexus.

CPN is shown to be effective for reduction of pain from advanced abdominal cancers, with relatively few side effects. Current evidence, however, only shows duration of effects over about two to three months, so any longer-term efficacy is not known. This procedure may reduce opioid needs, reducing opioid-related complications such as constipation. Nurses should be aware that, although of low prevalence, CPN can be associated with severe complications, so patients need to be observed for these. It needs to be recognized that CPN only can be effective for pain that originates in areas innervated by the celiac plexus.