‘ Short ’ double-balloon enteroscope for endoscopic retrograde cholangiopancreatography in patients with a surgically altered upper gastrointestinal tract

The Centre for Therapeutic Endoscopy and Endoscopic Oncology, Division of Gastroenterology, St Michael’s Hospital, University of Toronto, Toronto, Ontario Correspondence: Dr Sarah Cho, Department of Gastroenterology, Royal North Shore Hospital, St Leonards 2065, Australia. Telephone 612-99068973, fax 612-94383220, e-mail scho74@hotmail.com Received for publication January 7, 2010. Accepted March 21, 2011 original article

E ndoscopic retrograde cholangiopancreatography (ERCP) remains a challenge for endoscopists in patients with surgically altered anatomy of the upper gastrointestinal tract.Because the main problem with access to the papilla of Vater or enteral anastomosis of the biliary or pancreatic duct is the length of bowel that needs to be traversed, variable approaches including the use of endoscopic instruments other than a standard duodenoscope (ie, pediatric colonoscope or push enteroscope), have been used in the past with limited success, frequently leading to percutaneous transhepatic cholangiography (PTC) or operative intervention (1)(2)(3)(4)(5).
The double-balloon enteroscope (DBE) has revolutionized the ability to access the small bowel, and is now widely used in the diagnosis and treatment of obscure gastrointestinal bleeding (6)(7).The indication for its therapeutic use has recently expanded, and its use in balloon dilation of small bowel strictures, polypectomy and endoscopic submucosal resection has been described (7)(8)(9)(10)(11).The DBE can also be used to facilitate ERCP in patients who have undergone a variety of small bowel reconstruction procedures.However, the use of ERCP accessories is limited for a conventional DBE due to its length.We evaluated the use of 'short' DBE, which allows the use of standard ERCP accessories, for ERCP in patients with a surgically altered upper gastrointestinal tract.

METHODS
A retrospective review of the patients with previous small bowel reconstruction who underwent ERCP with a short DBE at The Centre for Therapeutic Endoscopy and Endoscopic Oncology at St Michael's Hospital (Toronto, Ontario) between February 2007 and November 2008, was performed.All procedures were performed with a DBE (working length 152 cm, distal-end diameter 9.4 mm, channel diameter 2.8 mm [Fujinon EC-450BI5, Fuji Photo Optical Co Ltd, Japan]).A standard transparent straight viewing cap (Olympus Co Ltd, Japan) was taped onto the end of the DBE to enhance visibility.All procedures were performed in patients who were under conscious sedation with intravenous midazolam, fentanyl and diazepam, except in one patient in whom general anesthesia was administered.All procedures were performed at St Michael's Hospital (Toronto, Ontario).Once the papilla or bilioenteric anastomosis was reached, standard ERCP accessories were used for cannulation and therapeutic interventions.

RESULTS
A total of 20 patients (10 men), with a mean age of 58 years (range 26 to 85 years), underwent ERCP with a DBE.Six patients had undergone Billroth II gastroenterostomy, seven patients Roux-en-Y hepaticojejunostomy, five patients Roux-en-Y gastrojejunostomy, one patient esophagojejunostomy and one patient a Whipple resection with choledochojejunostomy.Twelve patients (60%) underwent previous attempts at ERCP in which the papilla of Vater or bilioenteric anastomosis could not be reached with either a duodenoscope or pediatric colonoscope.Five patients required one or more repeat ERCP procedures for repeat intervention or follow-up; therefore, a total of 29 'short' DBE-assisted ERCP procedures were performed in these 20 patients.The indications for ERCP are listed in Table 1.
Either the papilla of Vater or bilioenteric anastomosis was reached in a mean duration of 20.8 min (range 5 min to 82 min) in 25 of 29 cases (86.2%).In four patients, the papilla of Vater or bilioenteric anastomosis could not be reached due to either a long Roux limb in one patient (previous gastric bypass) or acute angulation of the afferent limb in three patients (one patient with esophagojejunostomy, one patient with hepaticojejunostomy and one patient with a previous Whipple resection).Bile duct cannulation was successful in 24 of 25 cases in which the papilla or bilioenteric anastomosis was reached.Therapeutic interventions were successful in 24 cases (15 patients) including sphincterotomy (n=7), balloon dilation of biliary sphincter (n=4), stone extraction (n=9), biliary stricture dilation (n=8), stent placement (n=9) and stent removal (n=8) (Table 2, Figures 1, 2 and 3).The mean total duration of the procedure was 70.7 min (range 30 min to 117 min).Although several patients experienced some abdominal discomfort immediately following the procedure, it resolved by the next day in all cases, with no biochemical evidence of pancreatitis or other procedure-related complications.

DISCUSSION
Some patients who have undergone Roux-en-Y surgery have very long Roux limbs.Such procedures include Roux-en-Y gastric bypass, Roux-en-Y hepaticojejunostomy for orthotopic liver transplantation or major bile duct reconstruction.In some patients with Whipple resection or Billroth II partial gastrectomy, the afferent limb is long or tightly angulated.In these patients, it is often impossible to perform ERCP using a standard duodenoscope, pediatric colonoscope or push enteroscope, especially when coupled with underlying adhesions, which are often present as a consequence of the original surgery.To overcome the length of standard endoscopes, ERCP through gastrostomy or jejunostomy tracts has been reported following failed attempts at ERCP per oral anatomical route in these patients (12)(13)(14)(15).This technique, however, is more invasive than other purely endoscopic approaches, requires combined surgical and endoscopic expertise, and is associated with risks related to anesthesia and surgery.Furthermore, unless ERCP is performed intraoperatively, it may be impractical to wait for the stoma to mature if patients are acutely ill.PTC is less invasive than surgery and may be a good option for patients who are not fit to undergo surgery; however, it has technical limitations in patients without a dilated intrahepatic bile duct and/or those with ascites (16).In addition, PTC is not a practical procedure in patients with pancreatic disease (17).
The length and flexibility of the enteroscope, coupled with a double-balloon system, allows access through distorted small bowel anatomy to reach native papilla of Vater or biliopancreaticoenteric anastomoses.Following early case reports -including Haruta et al (18) who performed an endoscopic balloon dilation of bilioenteric anastomotic stricture in a patient after liver transplantation -in recent years, there has been increasing experience with DBE-assisted ERCP using a standard DBE 200 cm in length in patients who have undergone Roux-en-Y surgery; high success rates without immediate or short-term complications have been reported.The success rate to reach the papilla of Vater or the biliopancreaticoenteric anastomosis ranges from 64% to 100% in published reports (19)(20)(21)(22)(23)(24)(25).These figures are superior compared with the 33% to 67% success rates using standard endoscopic instruments of the pre-DBE era (26,27).DBE-assisted ERCP with a standard DBE 200 cm in length in patients with Billroth II reconstruction has also shown to be effective (25,28).The results of the published reports (with >10 patients) of DBE-assisted ERCP in altered surgical anatomy using the standard 200 cm DBE are summarized in Table 3.
There are three different types of DBE that are commercially available (Table 4).Although the standard 200 cm therapeutic DBE has been shown to be effective in gaining access to the targeted limb, entry into the native papilla, bilioenteric or pancreaticoenteric anastomosis is not always possible.Failures in intended therapy have also been reported in published studies (22,24,25).There are several possible explanations for this finding.First, a standard DBE has a long working length, making endoscopic manipulation difficult.Second, due to their inadequate length, most standard ERCP accessories cannot be used, thus making cannulation and subsequent manipulation of the targeted duct more technically difficult.Third, a DBE is a forward viewing instrument; hence, it is not designed for ERCP.
A 'short' therapeutic DBE, which is 152 cm in length, overcomes some of the problems associated with manipulation of a long instrument and allows ERCP accessories of standard length to be used.The ability of a short DBE to reach the papilla of Vater or biliopancreaticoenteric anastomosis is comparable with and even slightly superior with that of a 200 cm DBE (29,30).Our study demonstrated a high success rate (100%) for short DBEs in performing a wide range of endoscopic therapy during ERCP once the papilla or bilioenteric anastomosis was reached.Shimatani et al ( 29) recently reported similar success with short DBE-assisted ERCP.A review of 103 ERCP procedures performed in 68 patients demonstrated a 97% success rate in obtaining cholangiograms.Endoscopic treatment was achieved in all patients following cholangiograms (100%).The results of the two published studies of short DBE-assisted ERCP are summarized in Table 5.
Despite the mechanical advantages of both short and long DBEs in reaching the target limb (considering the significant distance away from the mouth and beyond the tight angulation of the anastomosis), technical challenges associated with performing ERCP with a forwardviewing instrument remain because it is usually not possible to achieve an 'en face' view of the native papilla.We were unable to achieve cannulation in one of 25 cases.Even if the end of the target limb is reached with a DBE, failure to locate either native papilla or bilioenteric anastomosis has been reported.This may be aided by the use of a transparent cap attached to the end of the DBE, which enhances visibility and aids in inspecting small bowel mucosa between folds.The transparent cap was used in all cases of our study.Shimatani et al (29) reported its use in cases for which cannulation was difficult.In seven of our cases that required sphincterotomy, needle-knife sphincterotomy over the stent following stent placement was performed to overcome the absence of an elevator.To minimize the risk of perforation, balloon dilation of up to 8 mm to 10 mm was performed after a partial sphincterotomy in four of seven patients for removal of larger stones.Although most ERCP accessories can be used for short therapeutic DBEs, adaptation of accessories for the standard 200 cm therapeutic DBE would further improve the utility of DBE ERCP, especially in patients with long Roux-en-Y limbs in which the anastomosis or papilla cannot be reached with a short DBE.
More recently, there has been an increasing number of reports describing the use of a single-balloon enteroscope (SBE) for ERCP in patients with altered small bowel anatomy.The largest case series to date was reported by Saleem et al (31).A total of 50 patients with a Roux-en-Y anastomosis underwent 56 ERCP procedures using an SBE.Overall diagnostic success was achieved in 39 of 56 cases (70%).

CONCLUSION
Experience with using DBEs to perform ERCP is increasing in patients with a surgically altered upper gastrointestinal tract.It is a safe, effective and less invasive diagnostic and therapeutic option for this group of patients than PTC or surgery.Standard long DBEs have limitations of long working length and the need for modified ERCP accessories.Short DBEs are equally as effective in reaching the target limb as standard long DBEs, and overcome some of its limitations to result in high success rates for endoscopic therapy.The present study adds to the growing literature on the utility of short DBEs for the diagnosis and treatment of pancreaticobiliary disorders in patients with surgically altered anatomy.

Figure 1 )
Figure 1) Endoscopic image of balloon dilation of a hepaticojejunostomy

Figure 2 )Figure 3 )
Figure 2) X-ray image of balloon dilation of a hepaticojejunostomy

Table 6 .
A randomized comparison of DBE with SBE in ERCP is not yet available.SBEs are 200 cm in length and, therefore, have same restrictions as DBEs that are 200 cm in length in terms of their inability to use standard ERCP accessories.

Table 5 Summary of reports of 'short' double-balloon enteroscope-assisted endoscopic retrograde cholangiopancreatography in altered small bowel anatomy
*One patient required combined percutaneous-endoscopic technique; † Four patients managed conservatively, and one patient required laparotomy