There have been many studies on DBE-assisted ERCP and the results vary widely. Success rates for deep insertion to the blind end range from 60 to 100%; the success rate of ERCP-related interventions is 60–100%,[30-48] which is probably because many studies have reported on a small number of cases. Regarding treatments such as stone extraction, balloon dilation of the ampulla or common bile duct, endoscopic sphincterotomy, placement of plastic and metallic stents, endoscopic nasobiliary drainage tubes and so on, almost all the treatments are carried out as frequently as conventional ERCP.
As a single center study, we have reported a large case study (103 procedures on 68 patients). In our report, we evaluated Roux-en-Y reconstruction and various other reconstruction methods. The overall success rate for ERCP was 95% (based on success rates for Roux-en-Y reconstruction, Billroth II reconstruction, and pancreatoduodenectomy of 91%, 100%, and 100%, respectively). In all successful ERCP cases, we were able to carry out endoscopic therapeutic interventions. Details of the treatments which are performed with DBE-assisted ERCP equivalent to those with conventional ERCP.
Recently, several multicenter studies have been reported in the USA. One report, which focused only on Roux-en-Y reconstruction using several enteroscopes, observed 180 procedures (129 patients). The success rate for reaching the blind end was 71%, and for cannulation, the success rate was 88%. The overall success rate for ERCP was 63%. ERCP success rates were similar between Roux-en-Y gastric bypass and other long-limb surgical bypasses for SBE and DBE. Regarding type of endoscope, the overall success rates for ERCP were: SBE 60%, DBE 63%, and SE 65%. Regarding reaching the blind end, the success rates were: SBE 69%, DBE 74%, SE 72%; and for cannulation, the success rates were: SBE 87%, DBE 85%, and SE 90%. Our success rate for ERCP was higher, which we assume is because our study was done in a single center. A second multicenter report, which focused on ERCP using the short-type DBE for various anatomical variations, observed 79 patients. The overall success rate for DBE-assisted ERCP was 90%. The success rate of reaching the blind end was 89% (based on success rates of 82% for Roux-en-Y gastric bypass, 95% for pancreatoduodenectomy, and 100% for Billroth II gastrectomy, hepaticojejunostomy, Roux-en-Y hepaticojejunostomy, Roux-en-Y gastrojejunostomy, choledochojejunostomy, and Roux-en-Y pancreaticojejunostomy). The overall success rate of biliary or pancreatic duct cannulation was 90% (based on success rates of 91% for Roux-en-Y gastric bypass, 84% for pancreatoduodenectomy, and 100% for Billroth II gastrectomy, hepaticojejunostomy, Roux-en-Y hepaticojejunostomy, Roux-en-Y gastrojejunostomy, choledochojejunostomy, and Roux-en-Y pancreaticojejunostomy). Similar to our study, DBE-assisted ERCP was successful in most of the cases in which reaching the blind end was successful and endoscopic therapeutic interventions could be carried out. Details of the treatment are equivalent to those of conventional ERCP cases. However, those reports are retrospective. To examine the efficacy and safety in the future, a prospective study with a large number of cases from multiple centers will be essential.