ERCP and EUS Procedures: ERCP and EUS Procedures: Altered Anatomy Access

0:00Welcome to Board Pearls. This is episode four of seven of the ERCP and EUS Procedures chapter, in the Endoscopic Procedures module. This episode is reaching the papilla, or a bile duct anastomosis, when surgery has moved it out of the duodenoscope's reach. The first patient is a woman with a duct stone years after gastric bypass, and her case shows why a standard endoscopic retrograde cholangiopancreatography, ERCP, can't reach her papilla, what the options are and why one of them is now preferred, and what that option costs her afterward and how that's prevented. A man with a stricture after a Whipple operation shows how a hepaticojejunostomy is reached. And an older woman with a Billroth two gastrectomy shows why that anatomy carries the highest perforation risk of the three.

0:45Here's the patient. A fifty-two-year-old woman had a Roux-en-Y gastric bypass six years ago and lost forty kilograms. She still has her gallbladder. She's had three episodes of biliary pain in a month. Her alanine aminotransferase and alkaline phosphatase are raised, her bilirubin is two point eight, and she has no fever. Her magnetic resonance cholangiopancreatography, MRCP, shows a nine-millimeter stone in a dilated common bile duct. She's well enough for an elective procedure, and she's very keen not to regain weight.

1:18She has choledocholithiasis with cholestasis after Roux-en-Y gastric bypass, and her stone needs removing, but her papilla is out of reach. In Roux-en-Y gastric bypass, a small gastric pouch drains into a Roux limb that bypasses the duodenum and proximal jejunum, leaving the gastric remnant, duodenum, and biliopancreatic limb as an excluded segment. Reaching her papilla from the mouth would mean going down the Roux limb to the jejunojejunostomy and then back up the biliopancreatic limb to the duodenum, a hundred to a hundred and fifty centimeters or more, which is beyond a standard duodenoscope. Length isn't the only problem. The side-viewing duodenoscope needs a face-on view of the papilla, so in altered anatomy, the technique chosen is whichever one restores that view.

2:08She has three ways in, and they differ in how well they restore that view. Laparoscopy-assisted ERCP, the historical approach, creates a laparoscopic gastrostomy in the gastric remnant and passes a duodenoscope through it into the duodenum, giving standard access to the papilla, but it needs general anesthesia, a surgeon, and a temporary or permanent gastrostomy. Single-balloon and double-balloon enteroscopy with a forward-viewing scope can sometimes reach the papilla through the Roux limb, but cannulation and therapy succeed in only sixty to seventy percent, because a forward-viewing instrument lacks the face-on view a side-viewing duodenoscope gives. The third is EUS-directed transgastric ERCP, known as EDGE. Under endoscopic ultrasound, EUS, guidance, a lumen-apposing metal stent, LAMS, creates a temporary fistula into the excluded stomach, either gastrogastric from the pouch or jejunogastric from the Roux limb. Once the fistula matures, a standard side-viewing duodenoscope passes through the LAMS into the remnant and through the pylorus to the papilla.

3:12EDGE suits her best, because it restores full access without an incision. Its advantages are no surgical incision, standard duodenoscope access, and a fistula that allows several ERCP sessions. Current best-practice guidance favors EDGE over laparoscopy-assisted ERCP in gastric bypass anatomy when local expertise is available. Repeat access matters most for a stone of a centimeter or more, because sphincterotomy alone fails in about ten to fifteen percent of large stones, which then need large-balloon dilation or cholangioscopic lithotripsy over more than one session. Without EDGE expertise, laparoscopy-assisted ERCP is reasonable, and enteroscopy is possible with lower success.

3:58Her wish not to regain weight shapes the aftercare, because EDGE has two drawbacks. The LAMS can dislodge during dilation and scope passage. And a persistent gastrogastric communication risks weight regain, undoing part of her operation. That's why the LAMS is removed and the fistula closed once her biliary therapy is complete. She has EDGE, a sphincterotomy, and stone removal, then LAMS removal and fistula closure. Because she still has her gallbladder, and residual gallbladder stones cause symptoms in about ten percent of patients a year after duct clearance, an interval cholecystectomy is discussed with her.

4:34A Whipple operation changes the target itself, not just the distance. A sixty-six-year-old man had a Whipple two years ago for ampullary cancer and now has a rising alkaline phosphatase, episodes of fever, and a stricture at his hepaticojejunostomy with dilated ducts on MRCP. After a Whipple, or a hepaticojejunostomy for a benign stricture, the bile duct is joined directly to a Roux limb of jejunum, and the papilla is bypassed entirely. So the target is the anastomosis, reached by going back up the long Roux limb from the jejunojejunostomy with single-balloon or double-balloon enteroscopy, because of the limb's length. Through the enteroscope, an anastomotic stricture can be dilated, stones extracted, and stents placed, with success in sixty to eighty percent depending on the limb length and the operator's experience.

5:22His backups are planned before he starts, because he's febrile and can't be left undrained if enteroscopy fails. Percutaneous transhepatic cholangiography is the alternative when enteroscopic access fails, and EUS-guided hepaticogastrostomy, covered in episode three, is the modern alternative. His stricture is reached and dilated. Her papilla was present but distant, while his is out of the circuit altogether, leaving only the anastomosis.

5:48A Billroth two gastrectomy keeps the papilla in reach but turns it upside down, which is why it's the riskiest of the three. An eighty-year-old woman had a Billroth two gastrectomy decades ago and now has a bile duct stone. A Billroth two creates a gastrojejunostomy with an afferent limb, carrying bile and pancreatic juice from the duodenum, and an efferent limb, carrying food away from the stomach. ERCP means finding and entering the afferent limb and going backward to the duodenal stump and the papilla.

6:19Her perforation risk sets the technique. A standard duodenoscope can sometimes pass through the afferent limb, but the perforation risk is markedly higher than standard ERCP: sphincterotomy-related perforation runs about one and a half to five percent, and overall perforation, including injury to the afferent limb from forcing the scope backward, is reported as high as five to eight percent. So a forward-viewing endoscope is sometimes preferred for safer entry into the afferent limb, despite losing the side view, and a cap-assisted forward-viewing technique improves cannulation. Her papilla is inverted compared with standard ERCP, so the sphincterotomy has to be cut in the opposite direction, and a needle-knife over a biliary stent is sometimes safer than a standard pull-type sphincterotome. Her consent addresses the higher perforation risk.

7:08Here are the traps the boards set in these patients. A standard duodenoscope can't reach the papilla after Roux-en-Y gastric bypass. EDGE is preferred over enteroscopy or laparoscopy-assisted ERCP when the expertise exists. An EDGE fistula is closed after biliary therapy, because a persistent fistula causes weight regain. After a Whipple, the target is the hepaticojejunostomy, not a papilla. Percutaneous drainage or EUS-guided hepaticogastrostomy is the backup when enteroscopy fails. A duodenoscope isn't forced up a Billroth two afferent limb. And on an inverted papilla, the sphincterotomy isn't cut in the standard direction.

7:49So, start to finish. Restore side-viewing access in altered anatomy. After Roux-en-Y gastric bypass, the papilla is a hundred to a hundred and fifty centimeters away, and EDGE, a LAMS from the pouch or the Roux limb into the remnant stomach, is preferred where expertise exists, over laparoscopy-assisted ERCP or balloon enteroscopy, which succeeds in only sixty to seventy percent. Remove the LAMS and close the fistula afterward to prevent weight regain.

8:16Reach a hepaticojejunostomy with balloon enteroscopy, which succeeds in sixty to eighty percent, with percutaneous drainage or EUS-guided hepaticogastrostomy planned as the backup. In a Billroth two, use a forward-viewing, cap-assisted scope for the afferent limb, because perforation can reach five to eight percent, and reverse the direction of the sphincterotomy.

8:37Episode five is ERCP and EUS in pancreatitis: what endoscopy can do for the pancreatic duct.

8:45For the full chapter, the practice vignettes, and the topic-tagged question bank, head to board pearls dot com. You'll find the rest of the series on Apple Podcasts, Spotify, or wherever you listen to podcasts. That brings us to the end of episode four of seven of chapter twenty-nine, and I'll see you in the next one.