A novel radiopaque biodegradable stent for pancreatobiliary applications – The first human phase I trial in the pancreas
Background/aims: During the recent years we have developed and experimentally tested a biodegradable stent for pancreatobiliary applications. Such stents may be used in benign strictures or when securing the flow of bile, pancreatic juice or a fluid collection after endoscopic or surgical procedures. The lack of suitable devices has so far prohibited clinical endoscopic or percutaneous tests whereas surgical application has become possible. Recently we described a modified binding (purse string) pancreaticojejunostomy, where a biodegradable stent is introduced to secure the lumen opening when tightening the bowel over the pancreas with a purse string. Although routine use of any stent in pancreaticojejunostomy has been under debate, we used this setting to run for the first phase I human clinical trial with a biodegradable stent in a pancreatobiliary application. Methods: After 29 pancreaticoduodenectomies, a braided gamma sterilized radiopaque 96L/4D polylactide stent was introduced into the duct of pancreas remnant, which was then sunk into the Roux-Y jejunal limb. Complications, stent disappearance and late anastomotic patency (MRI) were monitored. Results: Hospital mortality was zero. One patient developed Grade C fistula (overall fistula rate 3%). She also developed Grade C hemorrhage and Grade C delayed gastric emptying (DGE). One other patient developed Grade B hemorrhage (overall hemorrhage rate 7%) and B DGE. Three other patients developed clinically significant Grade B-C DGE (5/29=17%). In addition, 10 other patients were not on solid food only on post-operative day 8, and were classified as Grade A DGE (34%). Most of these patients were eating normally and could be discharged from hospital by day 10. Nine out of 26 patients (35%) with negative preoperative trypsinogen test, developed post-operative trypsinogen release suggesting pancreatitis. Within 12 months four patients died and one quitted the study. The stents disappeared in median 3 months. MRI interpretation of the anastomosis failed in one patient having ascites. Of the 23 patients, 13 (57%) had the anastomosis well open, three (13%) had some narrowing, while seven (30%) had the anastomosis obstructed. Conclusion: Compared with our previous experiences obtained in pancreaticoduodenectomy, a biodegradable stent is well tolerated in the human pancreatic duct, encouraging further development for future applications and tests in randomized trials.