The Evolution of ERCP

ERCP has evolved from diagnostic tool to therapeutic alternative. While technological advancements and new techniques have enhanced ease and speed, the procedure still carries risks.

Photo courtesy of Pentax

Endoscopic retrograde cholangiopancreatography (ERCP) is evolving into more of a therapeutic than diagnostic tool. The minimally invasive nature inherent to ERCP coupled with its ability to be performed under conscious sedation resulted in its rapid acceptance more than 20 years ago, becoming the gold standard in the evaluation of pancreaticobiliary disorders.¹

ERCP enables a diagnostic and therapeutic alternative where surgery might otherwise be required.² A catheter is advanced through the endoscope and inserted into the pancreatic or biliary ducts where a contrast agent is injected and X-rays are taken. Accessories may be passed through the endoscope into the ducts to remove stones, insert stents, or take tissue samples.

Conclusions derived from last year’s National Institutes of Health (NIH) Stateof- the-Science Conference on ERCP in Bethesda, Md. further cemented the fate of ERCP. The NIH reported, “Avoidance of unnecessary ERCP is the best way to reduce the number of complications. ERCP should be avoided if there is a low likelihood of biliary stone or stricture, especially in women with recurrent pain, a normal bilirubin, and no other objective sign of biliary disease.”

Advancements in other diagnostic modalities, however, have proven useful in the diagnosis and staging of pancreatic and hepatobiliary diseases.³ “With refinements and advances in technology of magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound (EUS), the ability to diagnose the diseases and disorders of the bile duct and the pancreas have improved dramatically,” says Adam Slivka, MD, PhD, associate chief of the Division of Gastroenterology, Hepatology and Nutrition at the University of Pittsburgh Medical Center. “Thus, the diagnostic role of ERCP is becoming extremely limited. The reason is that these other tests are much safer.”

The main complication of ERCP is pancreatitis, which occurs in approximately 5 percent to 7 percent of patients undergoing the procedure, whether for diagnosis or therapy. Other complications include hemorrhage, perforation, cholangitis, cholecystitis and cardiopulmonary complications.

Conversely, MRCP does not carry any risk of complications. Recent innovations in scanner hardware and software have made it possible for magnetic resonance imaging (MRI) machines to obtain highresolution images. MRCP relies on the strong T2 signal from stationary liquids, in this case bile, to generate images. No contrast agents are required.⁴ Complications of EUS are similar to those of standard upper gastrointestinal endoscopy because a fiberoptic endoscope is used.⁵ The endoscope is fitted with a miniature sonographic transducer that provides extraordinarily precise sonograms. Several researchers have noted MRCP, EUS and ERCP have comparable sensitivity and specificity.

Photo courtesy of Fujinon

“Approximately 10 years ago, expert centers were performing 40 percent to 50 percent diagnostic ERCP,” Slivka says. “Now, diagnostic cases are down to maybe 5 percent to 10 percent in our hospital. We are happy about this because we don’t want to be doing diagnostic studies and then having complications. We want to go in fully knowing what the diagnosis is and being prepared to treat it.”

This dramatic shift from ERCP to newer diagnostic modalities has not come without challenges. Many facilities have the equipment to perform MRCP, but do not have trained staff or the time to do effective studies. “If you don’t have a physician champion who is going to raise his or her hand and say ‘I’m going to be responsible for protocoling these studies and making sure we get good studies,’ then the studies don’t come out very well,” says Slivka.

The challenge with EUS is that there aren’t enough physicians trained in it. Learning EUS requires a significant amount of training that can’t be done on the job. Some physicians are taking four months’, six months’ or even a year’s sabbatical to develop their EUS skills, which obviously impacts their practice. The answer to increasing the number of skilled practitioners of EUS lies in the training of the next generation of doctors, Slivka says.

There are financial issues with EUS as well, which vary from state to state and from carrier to carrier. “It is a very time consuming study that is not reimbursed as well as it should be,” Slivka says. “But, thanks to the efforts of the societies — particularly the American Society for Gastrointestinal Endoscopy (ASGE) — they have been lobbying very heavily to improve reimbursements for the new technology. It has been improving slightly, but it’s still not where it needs to be.”

The Future of ERCP

Photo courtesy of Fujinon

With regard to ERCP as a therapeutic tool, experts say the indications are continuously expanding. “We are beginning to learn what factors are important in controlling complications, and that also has been an advance,” Slivka says. “Post-ERCP pancreatitis has been a nemesis of ours and we really have to learn more about why it happens. Looking at large numbers of patients in multicenter studies and trying to sort out what factors are important, patient selection is probably the most important. Other patient-related factors include gender and age. Young women with unexplained pancreatitis have the highest risk for post- ERCP pancreatitis.”

Slivka adds that “One of the most important things that we’ve learned based on a few randomized controlled trials and a lot of retrospective studies is that the placement of a pancreatic duct stent in a high-risk patient reduces both the incidence and severity of post-ERCP pancreatitis.”

Steven M. Shaw, MD, a physician at Seattle Gastroenterology Associates, explains that the placement of a very small stent, usually 3 French to 5 French, reduces the risk of pancreatitis by preventing the obstruction of the ductal orifice by edema or trauma to the area. “Pancreatic duct stents must be removed within one to two weeks in most cases, however, because of the increased risk for ductal injury from longer periods of stenting, I typically remove the internal flanges from the stent (with a scalpel or scissors) before placement,” he says. “This often allows it to pass from the duct spontaneously within a few days, obviating the need for a second procedure to remove it.”

Gerald Chiappone, BSN, RN, CGRN, a technical specialist at the Medical University of South Carolina Digestive Disease Center in Charleston, says the use of stents at his facility has lowered their incidence of post- ERCP pacreatitis from 5 percent to less than 3 percent.

Repeated attempts to cannulate the duct increase the risk for post-ERCP pancreatitis as well. “Techniques that facilitate cannulation are likely to improve success in achieving treatment objectives, and in reducing pancreatitis and other potential complications from prolonged instrumentation, sedation and radiation exposure,” Shaw says. “The latest technique that has impacted most on my ERCP practice is an endoscopist-controlled wire cannulation technique. This involves use of a rotatable papillotome and guidewire. A thin groove in the papillotome allows the wire to be ‘stripped down’ from the catheter, giving the endoscopist separate control of the wire and papillotome. I have found this to significantly decrease the time of cannulation. Maintaining access to the duct is made simple by securing the wire to a locking device affixed to the endoscope, just above the cap on the working channel. Also, accessory exchanges over the wire are limited to a very short length, ensuring stable access within the duct.”

These newer ERCP techniques may seem intimidating; however, Chiappone says, “As I look back at this course that I teach, GI nurses in particular are nervous about working in ERCP. The take-home message is GI nurses who work in the general GI rooms need to understand that ERCP is just another piece for them to build on. They have pre-existing knowledge when they come into the ERCP suite. All they’re doing is taking new knowledge and building on top of that.”

Chiappone adds, “You just need to understand the concepts of where you’re working and the devices you’re working with. It is important for nurses to understand what they’re using — that is why courses and vendor education is important. To be comfortable with this equipment, you need to use it, play with it and work with it.”

Tomorrow’s Technology

Besides technology for endoscopist-controlled wire cannulation, there are a variety of other technologies targeted at complex or difficult problems which hold great promise and continue to evolve for ERCP. Shaw says, “The development of ultrathin fiberoptic endoscopes has allowed direct visualization within the lumen of the bile duct or pancreatic duct, helpful in the treatment of large stones and evaluation of intraductal tumors. These instruments are passed through the channel of a therapeutic duodenoscope in a “mother-baby” system.

“Similarly, intraductal ultrasound imaging can be performed using tiny ultrasound probes passed through the instrument channel of the ERCP scope into the duct. Treatment of tumors involving the ducts can now be treated in some instances by photodynamic therapy, using a laser light catheter placed into the duct during ERCP. Stent technology also continues to evolve. Self-expanding bioabsorbable stents are currently under development, and many applications could stem from these devices. At this stage, the more complex technologies are likely to be encountered only in advanced tertiary care centers, often in the setting of clinical research protocols.”

David Northcutt, product manager at World of Medicine, says, “One of the advances that World of Medicine is involved in is the use of lasers in breaking stones during ERCP. While this has been available to physicians in the past, it hasn’t been widely available. This will greatly increase the speed at which they can accomplish stone cases during ERCP.”

Northcutt mentions further that manufacturers are “continuing to strive for the development of much smaller, versatile scope systems and further refining the instruments that the physicians are using to enable them to do this quicker and easier, without exposing the patient to any additional harm or danger.”

Fujinon Inc. manufactures such a smaller scope. “Right now, Fujinon makes a therapeutic ERCP scope that is 11.8 millimeters on the outside with a 4.2 millimeter channel, which previously would have been closer to 12.8 millimeters on the outside with that same channel inside,” says Kurt Cannon, director of marketing at Fujinon. “We’ve managed to reduce the size of the scope, which makes it more comfortable for the patient, easier for the physician to intubate and drive through the pylorus into the duodenum and allow him to pass through all the necessary therapeutic accessories.”

Bob Enerson, ultrasound product manager at Pentax Precision Instrument Corp., says that different technologies are becoming very similar. “Ultrasound scopes are becoming like ERCP scopes,” he says. “Perhaps it is foreseeable that there will be scopes that will do both. You’ll have a scope that will be able to do ERCP procedures and be able to offer ultrasound, called EUS/ERCP. There is some hope from physicians for this type of technology.”

“The one other technology which Pentax is invested in that is coming down the pipeline is called OCT (optical cohesive tomography). It is a way of getting very high-resolution images using small light fibers through the channels of the scope. In the future, we’ll be doing things like OCT probes into the bile ducts through an ERCP scope. That technology is in the animal labs now.”

Why the great strides in endoscopy? “Endoscopes can deliver new modalities and new technologies,” says Tai Shimada, director of market and product development strategy at Pentax. “There is unlimited potential because endoscopes provide accessibility to a variety of organs.”

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