Celiac plexus block (CPB) in patients with unresectable pancreatic cancer-related pain

Abdominal pain is a major symptom in patients with inoperable pancreatic cancer and is often difficult to treat. Celiac plexus block (CPB) is a safe and effective method for reducing this pain. It involves the chemical destruction of the nerve fibres that convey pain from the abdomen to the brain. We searched for studies comparing CPB with standard analgesic therapy in patients with inoperable pancreatic cancer. We were interested in the primary outcome of pain, measured on a visual analogue scale (VAS). We also looked at the amount of opioid (morphine-like drugs) patients took (opioid consumption) and adverse effects of the treatment. Six studies (358 participants) comparing CPB with standard therapy (painkillers) met our inclusion criteria. At four weeks pain scores were significantly lower in the CPB group. Opioid consumption was also significantly lower than in the control group. The main adverse effects were diarrhoea or constipation (this symptom was significantly more likely in the control group, where opioid consumption was higher). Endoscopic ultrasonography (EUS)-guided CPB is becoming popular as a minimally invasive technique that has fewer risks, but we were not able to find any RCTs assessing this method (current medical literature on this subject is limited to studies without control groups). Although the data on EUS-guided CPB and pain control are promising, we await rigorously designed RCTs that may validate these findings. We conclude that, although statistical evidence is minimal for the superiority of pain relief over analgesic therapy, the fact that CPB causes fewer adverse effects than opioids is important for patients.

Authors' conclusions: 

Although statistical evidence is minimal for the superiority of pain relief over analgesic therapy, the fact that CPB causes fewer adverse effects than opioids is important for patients. Further studies and RCTs are recommended to demonstrate the potential efficacy of a less invasive technique under EUS guidance.

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Background: 

Pancreatic cancer causes severe pain in 50 to 70% of patients and is often difficult to treat. Celiac plexus block (CPB) is thought to be a safe and effective technique for reducing the severity of pain.

Objectives: 

To determine the efficacy and safety of celiac plexus neurolysis in reducing pancreatic cancer pain, and to identify adverse effects and differences in efficacy between the different techniques.

Search strategy: 

We searched Cochrane CENTRAL, MEDLINE, GATEWAY and EMBASE from 1990 to December 2010.

Selection criteria: 

Randomised controlled trials (RCTs) of CPB by the percutaneous approach or endoscopic ultrasonography (EUS)-guided neurolysis in adults with pancreatic cancer at any stage, with a minimum of four weeks follow-up.

Data collection and analysis: 

We recorded details of study design, participants, disease, setting, outcome assessors, pain intensity (visual analogue scale (VAS)) and methods of calculation.

Main results: 

The search identified 102 potentially eligible studies. Judged from the information in the title and abstract six of these concerning the percutaneous block, involving 358 participants, fulfilled the inclusion criteria and were included in the review. All were RCTs in which the participants were followed for at least four weeks. We excluded studies published only as abstracts. We identified one RCT comparing EUS-guided or computed tomography (CT) -guided CPB but its aim was to assess efficacy in controlling chronic abdominal pain associated with chronic pancreatitis rather than pancreatic cancer, so it was excluded.

For pain (VAS) at four weeks the mean difference was -0.42 in favour of CPB (95% confidence interval (CI) -0.70 to - 0.13, P = 0.004, fixed-effect model). At eight weeks the mean difference was -0.44 (95% CI -0.89 to - 0.01, random-effects model). At eight weeks there was significant heterogeneity (I2 = 89%).

Opioid consumption was significantly lower in the CPB group than the control group (P < 0.00001).