Fully Covered Self-Expanding Metal Stent Does Not Reduce Chronic Pancreatitis Pain

Treatment with fully covered self-expanding metal stents (FCSEMS) does not reduce pain associated with dilated pancreatic ducts in patients with chronic pancreatitis, according to study findings in Gastrointestinal Endoscopy.

Researchers conducted a prospective multicenter single-arm trial (ClinicalTrials.gov Identifier: NCT02802020) to assess the pain reduction in patients with chronic pancreatitis after a 6-month indwell of a pancreatic FCSEMS.

The study population included patients aged 18 years and older who had chronic pancreatitis-induced Cremer Type IV stricture, upstream pancreatic ducts at least 5 mm in diameter, previous endoscopic sphincterotomy, and weekly pain occurrence rated a score of at least 20 on the Visual Analog Scale Pain Score (1-100 scale). 

Of the 93 patients screened for eligibility, 67 patients were included in the final analysis. The mean time (SD) from chronic pancreatitis diagnosis was 6.4[6.4] years. There were 34 patients with prior plastic stent placement within 90 days of study enrollment.

Researchers excluded patients who required extracorporeal shock wave lithotripsy therapy to clear pancreatic ductal stones before placement of FCSEMS.

Patients who had pancreatic duct dilation of 6 mm or less received 6 mm study stents, and patients with duct dilation of greater than 6 mm received 8 mm study stents.

Follow-up visits were scheduled at 1 month, 3 months, and 6 months. After stent removal at the 6-month appointment, patients received the option for placement of a nasopancreatic drain. Researchers performed a pancreatography of the pancreatic duct stricture from 24 to 72 hours after stent removal.

The primary efficacy endpoint was pain reduction 6 months following FCSEMS indwelling, and the safety endpoint was the rate of pancreatic duct stent-related adverse effects. This was measured using a self-reported pain score, calculated as the mean of the visual analog scale and the Izbicki Frequency of Pain subscore.

There were 21 patients excluded from the intention to treat (ITT) analysis due to insufficient pain levels after plastic stent placement, death, or loss to follow-up. Of the 46 patients left in the ITT population, 12 (26.1%) achieved partial or complete pain relief 6 months following FCSEMS removal or observation of complete distal migration, but these results did not meet the performance goal of 53% (P =.999).

The ITT analysis for the primary safety endpoint did not meet the safety performance goal of 32% (P =.513). Intervention-related adverse effects occurred in 21 (31.3%) patients, with pain being the most reported effect (14.9%). Other adverse effects were postendoscopic retrograde cholangiopancreatography pancreatitis (11.9%) and chronic pancreatitis exacerbation (4.5%).

Researchers observed stent migration in 31(47.7%) patients, 11 patients experienced restenting in the follow-up period, 5 patients reported secondary strictures, and 24 patients reported weight gain.

Study limitations include difficulty replicating the study, short follow-up time, and confounding factors for pain relief.

“Our results did not suggest a benefit for FCSEMS therapy in all patients with CP-associated pain,” the study authors wrote. “The two groups that appeared to benefit showed an early response after FCSEMS placement or plastic stent placement with subsequent exchange for a FCSEMS, with pain relief that was durable throughout the 6-month post-stent removal follow-up period.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.