ERCP with the overtube-assisted enteroscopy technique: a systematic review.BACKGROUND AND STUDY AIM
 Overtube-assisted enteroscopy (OAE) techniques have increased the ability to perform endoscopic retrograde cholangiopancreatography (ERCP) in patients with altered upper gastrointestinal anatomy, such as Roux-en-Y gastric bypass.  The aim of this study was to compare the efficacy and safety of OAE-ERCP in patients with different configurations of upper gastrointestinal anatomy.


 The following end points were analyzed: diagnostic and therapeutic success rates, cannulation success rate, ERCP success rate, type of enteroscopy, types of intervention, complications.


 Among patients who underwent Roux-en-Y with gastric bypass, endoscopic success was 80 % and ERCP success was 70 %.  In patients who had undergone a Roux-en-Y with either a pancreaticoduodenectomy, pylorus-preserving pancreaticoduodenectomy, or hepaticojejunostomy, endoscopic success was 85 % and ERCP success was 76 %.  In patients who had undergone a Billroth II procedure, endoscopic success was 96 % and ERCP success was 90 %.  Overall ERCP success for all attempts was approximately 74 %.  Both endoscopic and ERCP success rates were highest in patients with Billroth II anatomy, followed by those with pancreaticoduodenectomy and Roux-en-Y hepaticojejunostomy; the lowest success rates were in patients with Roux-en-Y gastric bypass.  The diagnostic and therapeutic potential of balloon-assisted ERCP were high and the adverse event rate was low.
ERCP
The aim of this study was to compare the efficacy and safety of OAE-ERCP in patients with different configurations of upper gastrointestinal anatomy.



OAE-ERCP
The following databases were searched: MEDLINE (via PubMed), Embase, Cochrane library, and Scopus. 
MEDLINE (via PubMed)
The following databases were searched: MEDLINE (via PubMed), Embase, Cochrane library, and Scopus. 
Embase
The following databases were searched: MEDLINE (via PubMed), Embase, Cochrane library, and Scopus. 
Cochrane library
The following databases were searched: MEDLINE (via PubMed), Embase, Cochrane library, and Scopus. 
Scopus