ERCP and EUS Procedures: ERCP and EUS Procedures: Preventing Pancreatitis

0:00Welcome to Board Pearls. This is episode one of seven of the ERCP and EUS Procedures chapter, in the Endoscopic Procedures module. This episode is one endoscopic retrograde cholangiopancreatography, ERCP, built around the complication that shapes every step: post-ERCP pancreatitis. The first patient is a young woman with a stone in her bile duct, and her case shows why ERCP is a therapy and not a test, how the way the papilla is entered changes her pancreatitis risk, what to do when cannulation is difficult and in what order, who's at high risk, and which three preventive measures work and how they're dosed. A man with chronic pancreatitis shows why his scarred pancreas works in his favor.

0:45Here's the patient. A thirty-one-year-old woman had her gallbladder removed two years ago. She's had three episodes of right upper quadrant pain in the last month. Her liver tests rose briefly during the last episode and are now normal, including her bilirubin. Her magnetic resonance cholangiopancreatography, MRCP, shows a six-millimeter stone in her distal common bile duct. She's booked for ERCP with sphincterotomy and stone extraction. She weighs sixty kilograms.

1:16She has a retained common bile duct stone after cholecystectomy, confirmed by MRCP, and her ERCP is to remove it, not to find it. Diagnostic ERCP is largely obsolete, because MRCP and endoscopic ultrasound, EUS, image the pancreatic and biliary anatomy without instrumenting the ducts and carry no risk of post-ERCP pancreatitis. ERCP needs cannulation of the duct and injection of contrast, and both can cause pancreatitis through ductal hypertension and injury to acinar cells. So ERCP is reserved for therapy. The accepted indications are bile duct stones, for extraction with sphincterotomy; biliary strictures, for sampling and stenting; bile leaks, for decompression with a stent across the papilla; acute cholangitis, for drainage; ampullary lesions, for papillectomy; malignant biliary obstruction, for stenting; and pancreatic duct disease, for sphincterotomy, dilation, stenting, and stone extraction. Her MRCP answered the diagnostic question safely, and her ERCP will treat what it found.

2:24Her papilla is entered with a wire, because the way it's entered is the first chance to lower her risk. Wire-guided cannulation, in which a hydrophilic guidewire is passed through the papilla into the intended duct before any contrast is injected, reduces post-ERCP pancreatitis compared with injecting contrast first. Contrast-first cannulation can fill the pancreatic duct by accident and push contrast into the gland's tissue, called acinarization, which injures acinar cells by pressure and activates trypsinogen, the same cascade that drives acute pancreatitis. A wire finds the duct mechanically and avoids that pressure injury.

3:02Her cannulation turns difficult. Her papilla is small and mobile, and after several attempts the wire keeps entering her pancreatic duct. Difficult cannulation has a standard escalation, ordered from least to most added risk. The double-wire technique leaves a guidewire in the pancreatic duct to straighten and stabilize the papilla, so the biliary wire can be steered in a consistent direction. Transpancreatic septotomy uses cautery along the pancreatic septum to expose the biliary orifice, in patients with prominent transverse folds or papillary stenosis.

3:34The later steps carry more risk, which is why they come later. Precut needle-knife papillotomy makes a controlled incision over the bile duct when the anatomy resists standard cannulation. It carries more pancreatitis and perforation risk, so it's reserved for after standard wire-guided attempts have failed, and it's safest when done over a pancreatic duct stent that protects the pancreatic orifice from thermal injury. EUS-guided rendezvous, in which the bile duct is punctured under EUS, a wire is passed down through the papilla, and the wire is retrieved at ERCP, is the modern alternative to the older percutaneous rendezvous after failed cannulation, as episode three covers. With a wire already sitting in her pancreatic duct, the double-wire technique is her natural next step, and her bile duct is cannulated over the second wire.

4:24Her difficult cannulation adds to a pancreatitis risk that was already high. Post-ERCP pancreatitis complicates about four to nine percent of unselected ERCPs and fifteen to thirty percent of high-risk procedures. The high-risk features each have a reason. Suspected sphincter of Oddi dysfunction means repeated cannulation attempts and frequent pancreatic duct entry. A prior episode of post-ERCP pancreatitis marks a patient with constitutional susceptibility. Female sex is a risk factor. A normal bilirubin means there's no cholestasis to guide the wire, so biliary attempts more often enter the pancreatic duct. Difficult cannulation means more attempts, longer cannulation time, and more wire passes. And acinarization on injection injures the gland directly. She's a woman with a normal bilirubin and a difficult cannulation, which gives her three high-risk features.

5:20So she gets every proven preventive measure. Three measures have randomized evidence. Octreotide, gabexate, and intravenous secretin, used in the past, lack supporting evidence in current American Society for Gastrointestinal Endoscopy guidance and aren't recommended. The first proven measure is rectal indomethacin, one hundred milligrams given immediately before the procedure, in every ERCP with a native papilla, under current European Society of Gastrointestinal Endoscopy and American guidance. A randomized trial in high-risk patients roughly halved post-ERCP pancreatitis, and later guidelines extended it to all ERCPs with a native papilla. Anti-inflammatory drugs of this class block phospholipase A2, cyclooxygenase, and lipoxygenase, damping the inflammatory cascade that follows acinar injury. Given rectally, indomethacin is absorbed quickly and bypasses gastric metabolism, and giving it immediately before the procedure means a therapeutic level is present during cannulation.

6:23Her high risk adds the second measure, a prophylactic pancreatic duct stent. A twenty twenty-four non-inferiority trial failed to show that indomethacin alone was non-inferior to indomethacin plus a stent, with more pancreatitis in patients who didn't get the stent, so combined prophylaxis remains standard in high-risk patients. Pancreatic duct cannulation causes transient swelling of the papilla that can block pancreatic outflow for hours after the procedure, and a small stent keeps the duct draining through it. It's placed at the ERCP and either falls out over days or is removed later. Her wire is already in her pancreatic duct, so a stent goes in over it.

7:05The third measure is aggressive lactated Ringer's solution around the procedure, which works through a separate mechanism. It maintains the pancreatic microcirculation during the inflammatory response, dilutes the inflammatory milieu, and prevents the dehydration that follows fasting and preparation. The protocol is three milliliters per kilogram per hour during the procedure, a twenty-milliliter-per-kilogram bolus immediately after, and three milliliters per kilogram per hour for the eight hours after. Lactated Ringer's is preferred over saline because its lactate, a bicarbonate precursor, counters the metabolic acidosis that large volumes of saline cause. At sixty kilograms, she gets one hundred eighty milliliters an hour during the procedure, twelve hundred milliliters immediately after, and one hundred eighty milliliters an hour for eight hours.

7:52That preventive regimen is different from the treatment of established acute pancreatitis, where a randomized trial found that aggressive fluids caused overload without benefit, so moderate, goal-directed fluids are used there instead. She gets all three preventive measures, which act on different steps of the injury. Her stone is extracted after sphincterotomy, and she goes home the next day without pancreatitis.

8:16Some patients are paradoxically protected, and the second patient shows why. A seventy-year-old man with long-standing calcific chronic pancreatitis needs ERCP for a distal bile duct stricture. Pre-existing chronic pancreatitis protects against post-ERCP pancreatitis, because the acinar tissue has already atrophied and can't mount the inflammatory cascade. He still gets rectal indomethacin, because his papilla is native, but not her high-risk plan. A woman with a prior episode of post-ERCP pancreatitis, by contrast, would have the full combination planned from the start.

8:51Here are the traps the boards set in these patients. ERCP isn't used for diagnosis when MRCP or EUS can answer the question. Cannulation starts with a wire, not contrast. Precut isn't the first move in a difficult cannulation, and it's done over a pancreatic stent. Rectal indomethacin is given immediately before every ERCP with a native papilla, not long after. A high-risk patient gets a pancreatic stent as well as indomethacin. Octreotide, gabexate, and secretin aren't used for prevention. The periprocedural fluid is lactated Ringer's, not saline. A young woman with a normal bilirubin is high risk. And chronic pancreatitis is protective.

9:35So, start to finish. Use ERCP only for therapy, because MRCP and EUS answer diagnostic questions without pancreatitis risk. Cannulate with a wire, not contrast, and escalate difficult cannulation through the double-wire technique, septotomy, precut over a pancreatic stent, and EUS rendezvous. Post-ERCP pancreatitis follows four to nine percent of all ERCPs and up to thirty percent of high-risk ones, and high risk means suspected sphincter dysfunction, prior post-ERCP pancreatitis, female sex, a normal bilirubin, difficult cannulation, and acinarization.

10:16Give rectal indomethacin, one hundred milligrams, immediately before every ERCP with a native papilla, and add a pancreatic duct stent in high-risk patients. Give lactated Ringer's at three milliliters per kilogram per hour during the procedure, a twenty-milliliter-per-kilogram bolus after, and three milliliters per kilogram per hour for eight hours. And remember that chronic pancreatitis is protective.

10:41Episode two is the indeterminate biliary stricture and how to get tissue, the sphincter of Oddi, and ampullectomy.

10:51For 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 one of seven of chapter twenty-nine, and I'll see you in the next one.