ERCP and EUS Procedures: ERCP and EUS Procedures: Pancreatic Duct Therapy

0:00Welcome to Board Pearls. This is episode five of seven of the ERCP and EUS Procedures chapter, in the Endoscopic Procedures module. This episode is when endoscopy can fix the pancreatic duct, and when the risk isn't worth it. The first patient is a woman with chronic pancreatitis, a duct stone, and a stricture, who doesn't want surgery, and her case shows who does well with endotherapy and who doesn't, how pancreatic duct stones are broken up, and how a dominant stricture is stented and for how long. A man with a new obstruction in his pancreatic head shows when a stricture in chronic pancreatitis may be cancer. The second patient is a woman with recurrent pancreatitis and no cause, and her case shows why the bar for endoscopic retrograde cholangiopancreatography, ERCP, is so high. And the episode ends with what a pancreatogram looks like in autoimmune pancreatitis.

0:51Here's the patient. A forty-four-year-old woman has alcohol-related chronic pancreatitis and stopped drinking and smoking two years ago. She has constant epigastric pain despite pregabalin and acetaminophen. Her computed tomography, CT, shows a main pancreatic duct dilated to eight millimeters, a seven-millimeter stone in the duct in the head, and a tight stricture just downstream. The rest of her gland has only scattered calcification. Her surgeon offered a lateral pancreaticojejunostomy, but she's declined surgery after a difficult operation years ago.

1:25She has painful chronic pancreatitis from an obstructed main duct, a stone with a stricture below it, and her choice is between endotherapy and surgery. In pancreatitis, the reason to act endoscopically is structural disease or stone burden, and the threshold reflects a modest expected benefit weighed against the risk of post-ERCP pancreatitis that any ERCP carries. For a fit patient with dilated-duct chronic pancreatitis and intractable pain, a randomized trial showed that early surgical drainage with a longitudinal pancreaticojejunostomy gives more lasting pain relief than an endoscopy-first approach, as chapter twenty-six covers. So endotherapy is reserved for patients who aren't surgical candidates, or for selected patients with discrete obstructive lesions that can be decompressed in a single session. She's declined surgery and has a discrete stone and stricture, so endotherapy is reasonable, with the explanation that surgery gives more durable relief and remains open to her.

2:24Her features predict a good result. The predictors of long-term endotherapy success are short disease duration, stopping smoking and alcohol, a limited stone burden, and complete clearance of the duct with resolution of the stricture. Diffuse calcification with severe damage to the gland responds less well and points toward surgical drainage, because stenting and dilation fix discrete obstructions that can be reached, while diffuse damage to the gland itself isn't relieved by decompressing the duct. She's abstinent, with a single stone and scattered calcification, so her predictors are good. Dense calcification with stones in every branch would send her back to the surgical conversation.

3:05Her endotherapy has four parts, each aimed at one piece of her obstruction. Pancreatic sphincterotomy opens the orifice so instruments can pass. Balloon dilation, at four to six millimeters, stretches a fibrotic dominant stricture. Stones are extracted or fragmented. And a stent keeps the duct open.

3:24Her stone has to be broken before it can come out, because of its size. Pancreatic duct stones larger than five millimeters need fragmentation, because the opening left after sphincterotomy is smaller than the stone. Extracorporeal shock-wave lithotripsy is first line, because it breaks stones with shock waves from outside the body without needing access to the duct. It clears the duct completely in roughly seventy percent of patients, with higher fragmentation rates, and the fragments are removed at a follow-up ERCP. Pancreatoscopy with electrohydraulic or laser lithotripsy is the alternative when shock-wave lithotripsy fails or the stone is impacted, but it's technically demanding in a small, tortuous duct. Mechanical lithotripsy with a basket is generally avoided, because a basket can become impacted in the narrow duct. She has shock-wave lithotripsy first, then ERCP with sphincterotomy to clear the fragments.

4:19Her stricture is treated next, because it would block the duct again even after the stone is gone. Current guidelines recommend a single plastic stent of the largest feasible caliber, typically ten French, kept in place for about twelve uninterrupted months, with exchanges driven by symptoms or stent dysfunction rather than a fixed schedule. Multiple side-by-side stents with stepwise upsizing are an option for refractory strictures that fail single-stent therapy, but they aren't first line, and they haven't been shown superior to a single stent in the pancreatic duct. Her stricture is dilated and a ten French stent placed for about a year, and her pain improves within weeks.

4:57One pattern of obstruction in chronic pancreatitis needs extra caution, because it can hide a cancer. A sixty-two-year-old man with long-standing calcific chronic pancreatitis develops a new obstruction confined to his pancreatic head. In an otherwise calcified gland, an isolated head obstruction can be a sentinel lesion for an underlying cancer. So ERCP is done both to sample the duct for malignancy and to relieve the obstruction, with a low threshold for cross-sectional imaging and endoscopic ultrasound, EUS, guided fine-needle biopsy when the head is the dominant obstructive lesion.

5:33The second patient shows the situation where ERCP does the least good. The thirty-three-year-old woman from chapter twenty-five has had two attacks of acute pancreatitis without a cause, has pancreas divisum on imaging, and carries a SPINK1 variant. She's been referred for ERCP with sphincter of Oddi manometry. She has idiopathic recurrent acute pancreatitis, recurrent attacks after a standard workup that finds no cause.

6:01Her workup has to be complete before any ERCP is considered, because the most common missed cause is found by EUS. The standard workup is the alcohol and tobacco history, serum calcium and triglycerides, magnetic resonance cholangiopancreatography, MRCP, for pancreas divisum and intraductal papillary mucinous neoplasm, autoimmune pancreatitis serology including immunoglobulin G4, and EUS for criteria of chronic pancreatitis, microlithiasis, or a hidden mass. Microlithiasis means gallbladder stones too small to see on transabdominal ultrasound that cause intermittent biliary obstruction, and EUS for microlithiasis is the highest-yield study after MRCP, because it's the identifiable cause transabdominal imaging keeps missing. She's had all of it, and no cause was found.

6:52Her referral for manometry and sphincterotomy is where the evidence is weakest. Even when baseline pancreatic pressures are raised, the chance of improvement after biliary sphincterotomy is at best fifty percent. Raised pressure reflects truly fixed sphincter dysfunction in some patients, where sphincterotomy helps, but functional pain or a different underlying problem in others, where it doesn't address the cause. So the threshold for ERCP in idiopathic recurrent pancreatitis is high, and the procedure is reserved for patients with documented multiple recurrences who have exhausted the non-invasive workup and understand both the modest expected benefit and the risk of pancreatitis from the procedure.

7:29Her divisum doesn't change that. Pancreas divisum is mostly incidental and rarely explains pancreatitis. A sham-controlled trial published in twenty twenty-five found that minor papilla sphincterotomy didn't reduce recurrent acute pancreatitis, so it isn't routine. If it's considered at all, it belongs at an expert center, with explicit counseling that the benefit is unproven and that minor papilla cannulation carries a higher pancreatitis risk than standard biliary sphincterotomy.

7:57Her own risk from ERCP would be high. Post-ERCP pancreatitis complicates fifteen to thirty percent of high-risk procedures, and a woman with a normal bilirubin who's suspected of sphincter dysfunction sits squarely in the high-risk group. So she isn't referred for ERCP. Her plan is avoiding alcohol and tobacco, given her SPINK1 variant, a discussion of cholecystectomy, which is considered after a second idiopathic episode, as she's now had, and follow-up.

8:27Autoimmune pancreatitis can also cause strictures, and its pancreatogram looks different from cancer's. On ERCP, autoimmune pancreatitis shows long, irregular pancreatic duct strictures with side-branch effacement, a narrowed, attenuated main duct, multiple skip strictures, and lost side branches. Pancreatic cancer, by contrast, typically shows an abrupt cutoff with upstream dilation. Type one autoimmune pancreatitis, the immunoglobulin G4-related form, often shows biliary strictures as well, immunoglobulin G4-related sclerosing cholangitis, which respond to corticosteroids along with the pancreatic disease. Long skip strictures without upstream dilation point toward the autoimmune workup and steroid response covered in chapter twenty-six.

9:14Here are the traps the boards set in these patients. A fit patient with a dilated duct and intractable pain is offered early surgery rather than endoscopy first. Diffusely calcified disease responds poorly to endotherapy. A pancreatic duct stone over five millimeters is fragmented with shock-wave lithotripsy first, not removed with a basket. A pancreatic duct stricture starts with a single large plastic stent, not multiple side-by-side stents. That stent stays for about a year, not a few weeks. A new isolated head obstruction in chronic pancreatitis may be cancer and needs sampling. EUS for microlithiasis is part of the workup for idiopathic recurrent pancreatitis. Manometry and sphincterotomy aren't offered before the workup is exhausted. Pancreas divisum alone doesn't justify minor papilla sphincterotomy. And long skip strictures without upstream dilation suggest autoimmune pancreatitis, not cancer.

10:07So, start to finish. Keep the threshold for ERCP in pancreatitis high. In painful chronic pancreatitis with a dilated duct, prefer early surgery in fit patients, and reserve endotherapy for those who aren't surgical candidates or who have discrete lesions, with success likelier after short disease duration, abstinence, limited stones, and complete clearance. Fragment stones over five millimeters with shock-wave lithotripsy first, which clears about seventy percent, and use pancreatoscopic lithotripsy if it fails. Stent a dominant stricture with a single large plastic stent for about a year, and sample a new isolated head obstruction.

10:45In idiopathic recurrent pancreatitis, do EUS for microlithiasis after MRCP. Manometry-guided sphincterotomy helps at most half, and minor papilla sphincterotomy for divisum failed against sham. And long skip strictures without upstream dilation suggest autoimmune pancreatitis rather than cancer.

11:05Episode six is draining pancreatic collections by EUS, and direct endoscopic necrosectomy.

11:12For 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 five of seven of chapter twenty-nine, and I'll see you in the next one.