A Paradigm Shift in Therapeutic Endoscopy
Therapeutic interventions to treat digestive tract strictures have traditionally relied on surgical or percutaneous approaches, or on endoscopically-inserted stents that re-establish luminal patency. But these approaches can be problematic. Surgery carries a higher risk of complications, and can expose patients to significant post-operative pain and recovery time. Endoscopic stenting is less invasive but still involves passing guidewires and stents through narrow, potentially occluded lumens.
The Therapeutic Endoscopy Center of Excellence is among a limited number of centers that have pioneered an alternative approach to luminal stent placement: a “purposeful perforation” technique that involves intentionally perforating the lumen of one organ to allow direct access to another.
The introduction of LAMS has allowed for a paradigm shift, where we can create transluminal anastomoses and effectively treat patients with a variety of complex gastrointestinal disorders.” — Shayan Irani, MD
Richard Kozarek, MD, first understood purposeful perforation in 1983 by fistulizing through the posterior stomach wall and inserting transgastric pigtail stents to drain pancreatic pseudocysts.
The technique took a leap forward with the advent of lumen-apposing metal stents (LAMS).
“LAMS opened up an entire field of therapeutic endoscopy by enabling us to do procedures via a natural orifice that had formerly been done via open or laparoscopic surgery, on the assumption that we could get adequate closure of the defects we leave,” Dr. Kozarek says.
Shayan Irani, MD, and his colleagues have used purposeful perforation and LAMS in over 300 procedures to drain pancreatic fluid collections. They were among the first to treat a broad variety of disorders including cholecystitis, gastric outlet obstruction, biliary occlusion, and the treatment of refractory esophageal anastomotic and pyloric channel strictures.
“The introduction of LAMS has allowed for a paradigm shift, where we can create transluminal anastomoses and effectively treat patients with a variety of complex gastrointestinal disorders,” Dr. Irani says.
Breakthrough Stent Design
The concept of intentionally perforating the gastrointestinal tract was developed more than 40 years ago with the advancement of percutaneous endoscopic gastrostomy and endoscopic transgastric drainage of pancreatic pseudocysts, but the latter was initially hindered by stent design. Small-caliber (2-3 mm diameter) pigtail stents led to infection in a subset of cases due to occlusion of the stent’s narrow bore. Biliary (10 mm diameter) covered self-expandable stents were also used, but tended to migrate because they had no flanges or tails to anchor them. As a result, patients had to potentially undergo subsequent procedures to drain pancreatic fluid collections and retrieve and replace the stents.
The solution came when LAMS were introduced in 2011. The innovative stents were developed for transluminal drainage of pancreatic fluid collections, with a dumbbell shape that provides an effective anchor, and a wide (10-15 mm diameter) center stem that allows for ample drainage.
“The LAMS design was truly a breakthrough — it reduced the risk of migration, occlusion and infection during transluminal approaches, which meant we had a much more viable alternative to conventional treatments,” Dr. Irani says.
The FDA approved LAMS for pancreatic fluid drainage in 2013, and the Therapeutic Endoscopy Center of Excellence quickly became one of the region’s highest-volume centers for pancreatic procedures involving LAMS. These procedures became even faster and safer when cautery-enhanced LAMS were introduced in 2017.
“After needle access, you can immediately deploy the cautery-enhanced stent and use its tip to cut through the lumen,” Dr. Irani says. “This allows access without prior balloon dilation and makes the whole process quicker and easier, reducing patient risk.”
Moving Beyond the Pancreas
As Dr. Irani and his therapeutic endoscopy colleagues built their expertise in using LAMS for pancreatic procedures, they started seeing opportunities to create transluminal anastomoses in other adjacent but non-adherent organs — especially in patients where the use of conventional luminal stenting may have not been the best treatment option. The team first focused on using LAMS as an alternative to percutaneous cholecystostomy in high-risk patients with acute cholecystitis. The experience was published in a 2015 paper in Gastrointestinal Endoscopy documenting contributions to the first case series in the United States using LAMS for transluminal endoscopic ultrasound-guided gallbladder drainage.
“Our initial patients were octogenarians whose only other option would have been a permanent external drain,” Dr. Irani says. “With LAMS, we were able to give them better outcomes and better quality of life.”
The team has completed more than 75 transluminal gallbladder procedures to date, and preliminary data indicates that LAMS are just as effective as a percutaneous drains for cholecystitis, with fewer complications and fewer re-interventions. The stent’s manufacturer has applied for an investigational device exemption (IDE) and Dr. Irani is heading a multicenter trial that could potentially pave the way for FDA approval of LAMS for cholecystitis in high risk surgical patients.
“The benefit to managing gallbladder infections with LAMS is probably even greater than for pancreatic fluid collections because there are few other good treatment options for internal gallbladder drainage,” he says.
Using LAMS to Break Up Gallstones
The team also presented a case at the annual Digestive Disease Week where they used LAMS combined with endoscopic laser lithotripsy to break up a very large gallstone (6-7 cm) in a patient who could not undergo surgery due to multiple comorbidities. In this particular case, all non-surgical methods to treat cholecystitis, including percutaneous drains and transcystic pigtail stents, had failed.
“We were able to use a LAMS to endoscopically access the gallbladder, perform cholecystoscopy, use laser lithotripsy to break up this very large stone, and then clear the gallbladder completely in this very high risk surgical patient. She has been free of symptoms, drains and stents for the last three years”
Applying LAMS in New Directions
Dr. Irani and his colleagues have also played a key role in pioneering additional transluminal applications for LAMS, including treatment of occluded biliary ducts, benign gastrointestinal strictures in the esophagus or pyloric channel, and malignant gastric outlet obstruction. Although deploying LAMS in the jejunum can be tricky during an endoscopic gastrojejunostomy due to the jejunum’s mobility when advancing the stent toward it, Dr. Irani and the team have achieved clinical success rates of over 90 percent — outcomes that are comparable to those reported with surgical gastrojejunostomy.
“The use of transluminal endoscopy to help patients avoid surgery is especially important for cancer patients. For example, an endoscopic gastrojejunostomy allows resumption of chemotherapy within a couple of days, while a surgical gastrojejunostomy might put that on hold for three to four weeks,” Dr. Irani says.
Dr. Kozarek attributes these innovations and progress to the culture of teamwork and collaboration that permeates Virginia Mason and the Therapeutic Endoscopy Center of Excellence.
“Our team is integrated with our surgical and interventional radiology colleagues at a level that is seen in very few centers in the world,” he says. “It allows us to work together to develop innovations and accomplish things together that none of us could do alone.”
Looking ahead, Dr. Irani and his colleagues intend to stay at the vanguard of transluminal procedures by developing new applications and investigating long-term outcomes and implications. Next, the team plans to collect data that could reveal whether transluminal cholecystitis treatment increases the risk of recurrent gallstone disease or other pancreaticobiliary conditions. They are also investigating whether it is more beneficial to remove LAMS or leave them in place long-term.
“It has been incredibly gratifying to be part of an effort that has improved treatment for so many patients,” Dr. Irani says, “We’re going to continue looking for ways to extend and improve these procedures, so we can hopefully help many more in the future.” See related publications.