Endoscopic Stenting for Pancreatic Diseases Joseph Leung, MD., FRCP., FACP., MACG., FASGE., FHKCP., FHKAM Chief, Section of Gastroenterology, VA Northern California Health Care System, Mr. & Mrs. C.W. Law Professor of Medicine, University of California, Davis Medical Center

Pancreatic Stents Shape Size 3,5,7 or 10 Fr Length 3,5,7,9,12 cm Geenen - curve, multiple side holes/distal flaps Sherman - straight, multiple side holes, proximal flap/distal pigtail Modified Cotton-Leung stent – S-shaped with distal flap Size 3,5,7 or 10 Fr Length 3,5,7,9,12 cm

Pancreatic Stents – Design and Application Optimal design of stents Size (small) Material (soft) Less irritation to ductal epithelium Migrate out spontaneously Common Indications Acute pancreatitis Drainage to prevent post ERCP pancreatitis Assist endoscopic therapy Papillotomy Leaks Malignancy Drainage to relief pain Chronic pancreatitis Adjuvant therapy for stone and stricture

Technique of Pancreatic Stent Placement Deep cannulation with guide wire across papilla or stricture + Pancreatic papillotomy Stent inserted over wire and positioned with pusher

Pancreatic Stenting using Mechanical Simulator Stenting with Fusion system External wire lock anchors guide wire allowing minimal exchange over guide wire Stent deployment is easily coordinated

Post-ERCP Pancreatitis Incidence Most common complication of ERCP Incidence 5-10%, 1% severe, 0.1% fatal Significant medical/ social/economic and liability problem Possible causes Acinarization – overfilling Hyperosmolarity / contrast allergy Trauma – guide wire Coagulation injury Impaired drainage from pancreas Bacterial contamination Bile contamination

Mechanism of Post ERCP Pancreatitis Papillary manipulation results in edema and sphincter spasm obstructing PD flow, leading to intracellular activation of enzymes Improving drainage with PD stent may prevent post ERCP pancreatitis

PD Stenting Prevents PEP in SOD Pts 80 Pts with pancreatic SOD after biliary EST were randomized to PD stent or no stent Post ERCP pancreatitis occurred in 10/39 (26%) with “No stent” 1/41 (2.4%) with “Stent” 2 Pts (7%) developed PEP after stent removal Tarnasky Gastroenterol 1998

PD Stenting for High Risk Patients 76 high-risk pts: SOM or difficult cannulation + EST were randomized Post ERCP pancreatitis occurred in 10/36 (28%) with “No stent” (5 mild, 2 moderate, 3 severe) 2/38 (5%) with “Stent” (mild pancreatitis) PD cannulation failed in 2/40 pts (5%) Fazel GIE 2003

Is PD Stent Necessary for Every ERCP? Probably NOT Increased time and difficulty Increased risk Increased cost Risk of ductal changes from stent irritation Need follow–up to insure stent migration May need 2nd procedure for stent removal

Who Will Benefit from PD Stenting? Patient Factors Suspected SOD Young female Prior post-ERCP pancreatitis Normal serum bilirubin Technical Factors Difficult cannulation Pre-cut sphincterotomy Pancreatic sphincterotomy Ampullectomy Balloon sphincteroplasty

Potential Risks of Pancreatic Stenting Failed stent placement Proximal tip of stent damages PD Stent occlusion causing pancreatitis Chronic ductal changes Inward stent migration Dilemma To consider PD stent placement in a “high-risk” patient is a serious decision If successful, risk of PEP is reduced. However, failed attempt INCREASES the risks

Outcome of Failed PD Stenting 225 high-risk therapeutic ERCP’s PEP 32/222 (14%) with successful PD stents PEP in 2/3 (67%) with failed PD stent insertion Severe pancreatitis occurred only in failed stents Multivariate analysis: failed stent RR 16, SOD RR 3.2, prior PEP RR 3.2 Not significant: EST, NK precut, # PD injections or difficult cannulation Freeman GIE 2004

Balloon Sphincteroplasty & Double Stents Double wires Balloon sphincteroplasty Double stents for drainage PD stent for prophylactic drainage

Assisted Precut Biliary Sphincterotomy PD stent protects pancreas Needle knife precut along biliary axis

Pancreas Divisum Minor Papillotomy with PD Stenting

Chronic Pancreatitis - Stone & Stricture

EndoTherapy for Chronic Pancreatitis Less invasive than surgery Results comparable to surgery Surgery is still possible after failed endotherapy ? Predicts outcome after surgery

Dilation/Stenting of Pancreatic Stricture Guide wire (hydrophilic) across stricture Dilators Graded dilators Pneumatic balloons (4-6 mm) Short-term pancreatic stenting to insure drainage

Dilation of Tight PD Stricture with Soehendra Stent Retriever

Dilation of Pancreatic Stricture via Minor Papilla

Basket Stone Extraction

Pancreatic Stone Extraction Pancreatic sphincterotomy .035” guide wire Dilation of orifice/stricture Stone extraction with wire basket (e.g. 22Q) ? Mechanical lithotripsy limitations PD stent for drainage ESWL to fragment large (calcified) stone

Endoscopic Stenting for Chronic Pancreatitis Initial Technical Success N Stent Succ Comp Improv Surg Mean F/U (Fr) (%) (%) (%) (n) (months) Cremer (91) 76 10 99 16 94 11 37 Ponchon (95) 23 10 100 43 91 3 12 Smits (95) 51 5,7 96 22 82 4 34 Binmoeller (95) 93 5,7,10 100 6 74 24 3-12 Stent ex-change mean 2-6 months Complications included pancreatitis (15), cholangitis (3), bleeding (3), pain (4), fever (3), infection (8) and abscess (2)

Endoscopic Stenting for Chronic Pancreatitis Outcome after Stent Removal Author Continuous Mean F/U Stricture improvement (month) resolved Cremer (91) 7/64 (11%) 25 11% Ponchon (95) 12/21 (57%) 14 38% Smits (95) 23/33 (70%) 29 20% Binmoeller (95) 41/69 (59%) 33 ND Total 83/187(44%) 25.3 23%

ESWL for Pancreatic Stone Courtesy of Dr. N Reddy

Management of Pancreatic Stones ESWL + Endotherapy 405 29 primary extraction 20 stenting 356 (88%) Complete clearance 178 (50%) Partial clearance 135 (38%) Failure 43 (12%) Reddy DN, Rao GV, Trop Gastroenterol 2001

Management of Pancreatic Stones ESWL + Endotherapy MPD Pain clearance relief Complete 178 170 Partial 135 102 None 43 0 272/356 (76%) Reddy DN, Rao GV, Trop Gastroenterol 2001

Summary Successful pancreatic stenting and drainage prevents post ERCP pancreatitis Pancreatic stenting is a useful adjunct for assisted papillotomy Pancreatic stenting provides drainage in patients undergoing ESWL for stone obstruction Stenting helps to improve stricture post dilation and provides short term pancreatic drainage