CRD summary

The authors concluded that the wire-guided technique increased the primary cannulation rate and reduced risk of post endoscopic retrograde cholangiopancreatography pancreatitis compared with the standard contrast injection method. Large well-performed randomised controlled trials were needed to confirm the findings. The authors' conclusions reflected the evidence presented and appear reliable.

Authors' objectives

To compare the rates of primary biliary cannulation and post-endoscopic retrograde cholangiopancreatography (post-ERCP) pancreatitis of wire guided cannulation technique to those of standard contrast assisted techniques.

Searching

PubMed, EMBASE, The Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL), meta Register of Controlled Trials and National Institutes of Health databases and Google Scholar were searched. There were no language or publication restrictions. Searches were performed up to March 2009. Search terms were reported. Abstracts presented at 2008 United European Gastroenterology Week and American Gastroenterological Association Digestive Disease Week meetings were handsearched.

Study selection

Prospective randomised controlled trials (RCTs) that compared wire-guided and standard contrast-assisted techniques were eligible for inclusion in the review. Studies needed to report intention-to-treat data on successful bile duct cannulation rate before crossover or precut and on post-ERCP pancreatitis identified with clinical and laboratory assessments.

All studies were randomised and used 0.035 inch guide wires. Three studies were parallel in design and two were crossover (in the event of failure patients were crossed over to the alternative technique). Most studies used a sphincterotome for cannulation. Where reported, the wire was advanced by an assistant or an assistant and endoscopist. All studies used different definitions and severity criteria for post-ERCP pancreatitis.

Two reviewers selected studies for inclusion in the review. Any disagreements were resolved by consensus.

Assessment of study quality

Study quality was assessed using criteria of randomisation, generation of allocation sequence, allocation concealment, blinding, description of follow-up including the number of drop outs and withdrawals, sample size calculation, intention-to-treat analysis and similarity of study groups at baseline. Criteria were rated as fulfilled, partially fulfilled, not fulfilled or not clear/reported.

Two reviewers independently performed the study quality assessment. Any disagreements were resolved by discussion.

Data extraction

Data were extracted in order to calculate odds ratios (OR) and 95% confidence intervals (CI) for cannulation rates and Peto odds ratios and 95% CI for post-ERCP pancreatitis rates.

Two reviewers independently performed data extraction. Any disagreements were resolved by discussion.

Methods of synthesis

Odds ratios or Peto odds ratios and their associated 95% CI were pooled in fixed-effect (Mantel-Haenszel) and random-effects models. Heterogeneity was assessed using a Galbraith plot, Cochran Q test and Higgins test (I² test). Funnel plots and Begg's and Eggers tests were used to assess publication bias. A sensitivity analysis was performed to assess the influence of individual studies on the pooled estimate.

Results of the review

Five RCTs (n=1,762 patients), two of which were cross over studies (n=762 patients), were included in the review. Four studies had adequate generation of allocation. Allocation concealment was reported in only two studies. No studies were blinded. Four studies conducted sample size calculations and reported adequate power for the outcomes measured.

Wired cannulation was associated with a statistically significant greater cannulation success rate compared to the standard method (OR 2.05, 95% CI 1.27 to 3.3; five studies). However, there was evidence of statistically significant heterogeneity (Cochran's Q test 12.65, p=0.01, I²=68.4%). Sensitivity analysis revealed that one study was the source of heterogeneity. Wire cannulation was still associated with a statistically significant greater cannulation success rate compared to standard method when this study was removed from the meta-analysis (OR 1.66, 95% CI 1.14 to 2.43). There was no evidence of statistically significant heterogeneity.

Wired cannulations was associated with statistically significantly lower post-ERCP pancreatic rates (defined as pancreatic pain for more than 24 hours and serum amylase more than three times the upper normal limit) compared to the standard method (OR 0.23, 95% CI 0.13 to 0.41; three parallel studies only). There was no evidence of statistically significant heterogeneity.

There was no evidence of publication bias although, as the authors stated, the number of trials was not large enough to analyse this properly.

Authors' conclusions

The wire-guided technique increased the primary cannulation rate and reduced risk of post-ERCP pancreatitis compared with standard contrast-injection method. Further large well-performed RCTs were needed to confirm the findings.

CRD commentary

This review addressed a clear research question and was supported by detailed inclusion criteria. The search strategy was appropriate and there were no language or publication restrictions , which reduced risk of language and publication biases. Study quality criteria were appropriate for the included study designs. Synthesis methods were appropriate and included assessment of statistical heterogeneity. The review processes were carried out with sufficient attempts to minimise reviewer error and bias. The authors' conclusions reflected the evidence presented and appear reliable.

Implications of the review for practice and research

Practice: The authors did not state any implications for practice.

Research: The authors stated that further large well-performed randomised controlled trials were needed to confirm the review findings,

Funding

None stated.

Bibliographic details

Cennamo V, Fuccio L, Zagari RM, Eusebi LH, Ceroni L, Laterza L, Fabbri C, Bazzoli F. Can a wire-guided cannulation technique increase bile duct cannulation rate and prevent post-ERCP pancreatitis? A meta-analysis of randomized controlled trials American Journal of Gastroenterology 2009; 104(9): 2343-2350. [PubMed: 19532133]

Original Paper URL

http://www.nature.com/ajg/journal/v104/n9/abs/ajg2009269a.html

Indexing Status

Subject indexing assigned by NLM

MeSH

Bile Ducts; Catheterization /methods; Cholangiopancreatography, Endoscopic Retrograde /adverse effects /methods; Humans; Pancreatitis /etiology /prevention & control; Randomized Controlled Trials as Topic

AccessionNumber

12009108858

Database entry date

09/06/2010

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.