A promising technique beset by challenges
Endoscopic retrograde cholangiopancreatography (ERCP) is primarily used to acquire access for pancreatic or biliary drainage in patients with obstructive jaundice. Although success rates for accessing the ducts are quite high, ERCP is likely to fail in patients who have altered anatomy from prior surgery, duodenal stenosis or tumors.
Traditional alternatives for these patients include percutaneous drainage and open surgery. But according to Michael J. Levy, M.D., and Mark D. Topazian, M.D., of Mayo Clinic in Minnesota, endoscopic ultrasound (EUS)-guided rendezvous drainage is a far better option.
"If we can't get the scope to the proper site or cannulate the bile or pancreatic ducts, we can thread a needle into the duct under EUS guidance and use it to advance a guidewire transhepatically into the duodenum," Dr. Levy explains. "We can then perform routine ERCP or place a stent."
Studies and clinical experience show EUS-guided rendezvous is safe and effective, yet only about 50 of the procedures are performed each year worldwide.
"There is a lot of pent-up need," Dr. Levy says. "It could easily be done 1,000 or 5,000 times if people took advantage of it instead of using other approaches."
Still, he acknowledges that a number of obstacles stand in the way of widespread adoption of the technique.
One is the high level of expertise required to maneuver the guidewire. "It's very operator-dependent, and there is a long learning curve," Dr. Levy says. "Ideally, it should be performed by someone trained in both EUS and ERCP, but even so, it's certainly the most technically difficult EUS procedure. So, few cases are done and as a result, fellows have no training. They might see it done, but they don't do it themselves."
Dr. Topazian adds that even experts continue to learn as the procedure evolves. "This is definitely up a notch from routine EUS and ERCP," he says.
Logistics are another problem, even at Mayo Clinic, which has performed 50 or 60 EUS-guided drainage procedures over the last seven years. "We're hampered by the difficulty of coordinating schedules between interventional radiologists and endoscopists," Dr. Topazian says. EUS-guided rendezvous can take three or more hours to perform, with a resulting loss of room and staff.
A lack of equipment designed specifically for the procedure also is an issue. So is cost. Charges for EUS-guided rendezvous can range from $5,000 to $10,000 with anesthesia, though pancreatectomy costs far more.
Pancreatitis flares are common after EUS-guided rendezvous, and most patients temporarily experience increased pain, which can sometimes be severe. Bleeding, infection and leaking from the punctured ducts also are potential complications.
But these are relatively minor problems compared with complications of pancreatectomy and percutaneous biliary drainage. Dr. Topazian says, "If we can provide drainage for patients with pancreatic duct obstruction and avoid surgery and the diabetes that follows surgery, then that would make a tremendous difference."
Mayo Clinic began experimenting with EUS-guided rendezvous because patients asked for it, he says. "When ERCP fails, the options are unpalatable. And then you have one patient who says, 'Let's do it, even if you've never done it before.' We'd also read the work others had published and knew their results. So we thought, 'Let's give it a try because the options are horrible.' So you do it and it works well and over time, it becomes easier to do."
Dr. Levy notes that easy doesn't mean simple. "Patients with failed ERCP benefit from having a multidisciplinary team that can sort out the best approach to the situation. That includes radiologists trained in ERCP and EUS as well as surgeons who have an interest in pancreatic and biliary procedures. "To do this, you really do need a strong team."