Version May 2024
INTRODUCTION — Endoscopic interventions such as pancreatic duct stenting have been increasingly used for treating pancreatic disorders such as pancreatic duct obstruction and pancreatic duct leakage. This topic will review issues related to endoscopic retrograde cholangiopancreatography (ERCP)-guided pancreatic duct stenting including indications for therapeutic stenting, stent placement and removal techniques, and complications.
The use of pancreatic stents to prevent post-ERCP pancreatitis is discussed separately. (See "Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis".)
Endoscopic management of walled-off pancreatic fluid collections is discussed separately. (See "Endoscopic interventions for walled-off pancreatic fluid collections".)
The use of biliary stents for treating malignant pancreaticobiliary obstruction is discussed separately. (See "Endoscopic stenting for malignant biliary obstruction".)
The use of biliary stents for treating nonmalignant disease is discussed separately:
●Primary sclerosing cholangitis – (See "Primary sclerosing cholangitis in adults: Management".)
●Post-surgical biliary complications – (See "Liver transplantation in adults: Endoscopic management of biliary adverse events" and "Endoscopic management of postcholecystectomy biliary complications".)
INDICATIONS
Therapeutic stent placement
Pancreatic duct obstruction — Endoscopic therapy is indicated for patients with abdominal pain due to pancreatic ductal obstruction, most commonly caused by pancreatic duct stricture(s) and/or stone(s) [1]. Of note, endoscopic therapy alone is generally less feasible for stones or strictures in the body of the pancreas and is impossible if the obstruction is in the tail of the pancreas. The endoscopic interventions often involve a pancreatic sphincterotomy, removal of pancreatic stones (if present), and placement of a transpapillary pancreatic duct stent.
Chronic pancreatitis is often characterized by pain that may be related to increased pressure within the pancreatic ductal system secondary to outflow obstruction of the main pancreatic duct [2]. Pancreatic duct stenting has been associated with improvement in pain among patients with chronic pancreatitis with downstream duct strictures resulting in upstream (ie, closer to the tail of the pancreas) dilation [3,4]. The management of chronic pancreatitis is discussed in more detail separately. (See "Chronic pancreatitis: Management".)
Some patients with pancreatic duct strictures also develop pancreatic duct stone formation upstream from the stricture [4]. For patients with stones that cannot be completely cleared, stent placement assists in drainage of pancreatic juices. Risk factors for incomplete stone removal include >3 stones, stones in the pancreatic tail, stone size ≥10 mm, impacted stone(s), and downstream pancreatic duct stricture [5].
Pancreatic duct leakage — ERCP-guided placement of a transpapillary pancreatic stent is indicated for patients with pancreatic fistulas who are symptomatic or those with persistent or enlarging fluid collections on abdominal imaging despite supportive care. Pancreatic ductal disruptions may arise from acute or chronic pancreatitis, trauma, or surgical injury. Duct disruptions lead to leakage of pancreatic fluid that may result in chronic pancreatic fistula (table 1). Endoscopic therapy promotes internal drainage of pancreatic secretions, thereby reducing flow through the fistula tract. Findings suggestive of a pancreatic duct disruption include extravasation of contrast during injection of the pancreatic duct during ERCP, pancreatic ascites, pancreatic fistula, or a fluid collection that communicates directly with the main pancreatic duct [6]. (See "Endoscopic interventions for walled-off pancreatic fluid collections", section on 'ERCP-guided transpapillary drainage'.)
The management of walled-off pancreatic fluid collections is discussed in more detail separately. (See "Approach to walled-off pancreatic fluid collections in adults".)
Other interventions — Pancreatic stent placement is used in combination with extracorporeal shock wave lithotripsy (ESWL) for patients without clearance of pancreatic stones after fragmentation by ESWL [7]. (See "Extracorporeal shock wave lithotripsy for pancreatic stones".)
Stenting as a preventive strategy — Pancreatic duct stent placement has been used to prevent pancreatitis in the following settings:
●Post ERCP-pancreatitis – The role of pancreatic stenting to prevent post-ERCP pancreatitis is discussed separately. (See "Management of difficult biliary access during ERCP in adults", section on 'Pancreatic stenting'.)
●Recurrent idiopathic acute pancreatitis – Prophylactic pancreatic duct stenting with or without pancreatic sphincterotomy has been reported for patients with recurrent bouts of idiopathic pancreatitis [8]. However, randomized trials are needed to clarify the role of this intervention in such patients. (See "Etiology of acute pancreatitis".)
CONTRAINDICATIONS — ERCP-guided pancreatic duct stenting is typically contraindicated in the following patients:
●Patients who cannot tolerate sedation, monitored anesthesia care or general anesthesia (see "Anesthesia for gastrointestinal endoscopy in adults")
●Patients with an untreated hemostatic disorder who are deemed to be at high risk for bleeding by the advanced endoscopist (see "Gastrointestinal endoscopy in patients with disorders of hemostasis")
●Patients who are hemodynamically unstable
●Patients with gastrointestinal (luminal) obstruction may undergo endoscopy, but the examination may be limited to an area proximal to the level of obstruction (see "Enteral stents for the palliation of malignant gastroduodenal obstruction")
PREPROCEDURE EVALUATION — The diagnosis of pancreatic duct obstruction or pancreatic duct leakage is often suspected based on presenting symptoms (eg, abdominal pain, weight loss) and cross-sectional imaging (computed tomography [CT] scan, magnetic resonance imaging [MRI] with magnetic resonance cholangiopancreatography [MRCP]). Thus, most patients will have had imaging, thereby mitigating the need for additional radiographic imaging before ERCP. Review of the radiographic imaging prior to ERCP will help to define the biliary and pancreatic ductal anatomy, exclude pancreas divisum, and identify pancreatic duct stones. (See "Chronic pancreatitis: Clinical manifestations and diagnosis in adults".)
During a single endoscopic session, endoscopic ultrasound (EUS) is often performed prior to ERCP because EUS may provide additional information such as defining pancreatic stone location (ie, intraductal or parenchymal) and excluding occult tumors and common bile duct stones.
STENT PLACEMENT
Patient preparation — The preprocedure preparation for patients undergoing ERCP with pancreatic duct stent placement is similar to that described for patients undergoing ERCP for other indications (see "Overview of endoscopic retrograde cholangiopancreatography (ERCP) in adults", section on 'Patient preparation'):
●Adjusting medications – Most patients do not need to discontinue aspirin or nonsteroidal anti-inflammatories when undergoing ERCP. Most patients who undergo ERCP with pancreatic stent placement only (ie, without pancreatic or biliary sphincterotomy) typically do not need to discontinue anticoagulant therapy. The management of antiplatelet and anticoagulant therapy is typically individualized, managed in conjunction with the prescribing specialist, and discussed separately. (See "Management of antiplatelet agents in patients undergoing endoscopic procedures" and "Management of anticoagulants in patients undergoing endoscopic procedures" and "Gastrointestinal endoscopy in patients with disorders of hemostasis".)
●Antibiotic prophylaxis – Prophylactic antibiotics are generally not indicated for patients undergoing ERCP with pancreatic duct stent placement in the absence of another indication (eg, biliary obstruction, risk for incomplete drainage, pancreatic fistula) (table 2). Thus, the use of antibiotic prophylaxis is individualized and based on patient- and procedure-related risk factors for infection, in addition to endoscopist preference. These issues are discussed separately. (See "Antibiotic prophylaxis for gastrointestinal endoscopic procedures".)
●Anesthesia – The procedure is typically performed using monitored anesthesia care or general anesthesia. Anesthetic management for endoscopic procedures including preprocedure fasting is discussed separately. (See "Anesthesia for gastrointestinal endoscopy in adults".)
Stents and other equipment
Types of stents — Pancreatic stents are available in varying lengths, diameters, and designs. Newer stents may be brought to market, and availability varies by geographic area. Features of pancreatic stents include [9,10]:
●Material – Most pancreatic stents are plastic stents composed of polyethylene materials.
●Size – Pancreatic stents are available in diameter sizes ranging from 3 to 10 French (Fr) and in lengths ranging from 2 to 15 cm. Larger stents (10 Fr) are rarely used and are reserved for patients with a markedly dilated, obstructed pancreatic duct (ie, duct diameter ≥4 mm) that requires drainage.
●Design – Pancreatic stents are cylindrical in shape, and various designs are available. Pancreatic stents may be either straight, curved, or single pigtail. Most stents have features that help prevent internal migration (eg, distal flange, pigtail). Some stents have both proximal and distal flaring to help anchor the stent. In addition, some stents have radiopaque markers to improve visibility under fluoroscopy.
Some stents in development have features that mitigate the need for endoscopic stent removal (eg, biodegradable stent) [11-13]. Other types of pancreatic stents are being studied such as self-expandable stents (eg, removable, fully covered, metallic stents), but they are not used routinely in clinical practice [14].
Stent selection is individualized and informed by the duct length to be traversed, diameter of the duct lumen, indication for stenting (eg, obstruction, leakage), duct morphology (eg, disruption), and endoscopist preference [15].
Guidewires — Guidewires are used to facilitate stent deployment. Guidewires vary in diameter (eg, 0.018 inch, 0.021 inch, 0.025 inch, and 0.035 inch) and length, and may be hydrophilic, straight, have a "J" tip, or a loop tip. Guidewires are available with various radiopaque markings to aid in visualization and to minimize fluoroscopy time. Some guidewires are Teflon-coated, which provides stability for stent placement and accessory exchanges. "Glidewire" and "Roadrunner" are specialized wires that are used for patients with conditions resulting in difficult cannulation (eg, papillary stenosis).
It is important to keep in mind that guidewire caliber needs to be compatible with the catheter and stent size (eg, a 0.035 inch guidewire cannot be used to place a 3 Fr pancreatic stent or with a 4 Fr cannulation catheter).
Dilators — Two types of dilators are commonly used: balloon dilators and passage dilator catheters. Balloon dilators are inflation devices housed on a catheter, which are used to deliver a specific radial pressure to a stenotic area. They are available in several diameters and lengths. An inflation device is required to pressurize the balloon at a controlled rate.
Passage dilation catheters are available with a variety of tip sizes (ie, 3 to 11.5 Fr) or as graduated dilating catheters. The size of the tip of the catheter limits the size of the guidewire that can be used with it.
Stent deployment — Pancreatic duct stents are usually placed under endoscopic and fluoroscopic guidance.
Pancreatic ductal obstruction — The technique for stent placement for patients with ductal obstruction is summarized as follows [10]:
●Cannulate the ampulla and pancreatic duct.
●Place a guidewire across the location of the stricture and/or stone.
●Perform pancreatic sphincterotomy and stricture dilation, if needed (image 1A-B). As an example, patients with multiple or large pancreatic stones may require a combination of pancreatic sphincterotomy, stricture dilation, and/or other stone removal methods in addition to stent placement. Pancreatic sphincterotomy is used to facilitate access to the main pancreatic duct and passage of endoscopic accessories used for stricture dilation and stone removal. Patients being treated for a pancreatic leak or duct disruption may not always require a pancreatic sphincterotomy.
●Advance the stent over the guidewire and deploy it. Because of the small diameter of most pancreatic stents (eg, <10 Fr), they are usually deployed with only a guidewire and pushing catheter. To avoid placing the stent completely within the pancreatic duct, we maintain steady (but not increased) pressure on the pushing catheter, and we direct the endoscopy assistant to maintain steady wire traction.
●After stent deployment, document the stent position by obtaining endoscopic and fluoroscopic images.
Stent indwell time is individualized and is informed by the indication for stenting and symptomatic response. However, most stents typically remain in place for four to eight weeks prior to exchange or removal. (See 'Stent removal or replacement' below.)
Modifications to stent insertion technique can help minimize risks associated with pancreatic stenting [16]:
●Avoid placing the upstream portion of the stent at or around the genu of the pancreas. Transpapillary stents should either traverse the genu completely or remain entirely distal to the genu. Stents that terminate near the genu may be more likely to cause ductal injury or even perforation due to the sharp angulation at that site [17].
●Variations in pancreatic duct anatomy may inform the approach to stent placement. As an example, wire cannulation of the pancreatic duct may be limited in patients with ansa pancreatica, an anatomic variant consisting of a loop connecting the inferior branches of the dorsal and ventral ducts [18]. For patients with such ductal anatomy, a shorter transpapillary stent (eg, 2 to 3 cm in length) may be chosen because it reduces manipulation of the pancreatic duct at the level of the ansa loop [19].
Endoscopic therapy with dilation and stenting for pancreatic duct strictures with or without intraductal stones has been effective in reducing abdominal pain in 65 to 84 percent of patients [3,20,21]. In a study including over 1000 patients with chronic pancreatitis with mean follow-up of five years (range two to 12 years), pancreatic endotherapy for strictures, stones, or both was associated with improvement in pain in 65 percent of patients [3].
Pancreatic duct leakage — For patients with pancreatic duct leakage, the technique for stent placement is generally similar to placing a transpapillary stent for ductal obstruction. (See 'Pancreatic ductal obstruction' above.)
For patients with pancreatic duct leakage, stents are usually removed after four to six weeks and are not replaced if the ductal disruption has resolved. (See 'Stent removal or replacement' below.)
Bridging the region of the disruption with the stent is often accomplished, while nonbridging transpapillary stent placement also promotes healing by reducing resistance to pancreatic juice flow [22]. In a study of 43 patients with pancreatic duct disruption treated with pancreatic duct stenting, 25 patients (58 percent) had resolution of the disruption [23]. Factors associated with resolved ductal leakage after stenting included bridging of the ductal disruption and longer duration of stenting (ie, six weeks).
Post-procedure care — Routine post-procedure care following ERCP is discussed separately. (See "Overview of endoscopic retrograde cholangiopancreatography (ERCP) in adults".)
STENT REMOVAL OR REPLACEMENT
Timing — The duration of stenting is informed by the indications for stenting and the clinical response to stenting (eg, symptomatic improvement). As an example, for patients with pancreatic duct leakage, stents are usually removed after four to six weeks and are not replaced if the ductal disruption has resolved. For patients who require stent replacement (also referred to as stent exchange), stents are generally replaced every four to eight weeks until symptoms are relieved. However, there is no clear consensus on the optimal time interval between stent exchanges, and clinical practice is also guided by endoscopist preference. (See 'Stent deployment' above.)
Factors contributing to the uncertainty regarding timing of stent removal and replacement are the low reported rates of symptomatic stent occlusion and the risk, burden, and cost associated with therapeutic ERCP. In a study examining outcomes after 146 pancreatic duct stent placements in 115 patients, six percent of patients with occluded stents required hospitalization for pancreatitis or increased pain [24]. The low rates of symptomatic stent occlusion may be related to the observation that occluded stents may function as a "wick" around which pancreatic juices continue to drain [25].
Technique — The technique for removing a stent from the pancreatic duct is summarized as follows (picture 1):
●Use a duodenoscope to visualize the ampulla and the intraluminal portion of the stent.
●Grasp the stent close to the tip, distal to the flaps (or flanges). Avoid excessive tightening of the snare around the stent to prevent stent fracture. Alternatively, a biopsy forceps may be used to grasp the stent for removal.
●Extract the stent smoothly from the duct by grasping the catheter at the accessory channel and applying traction.
●After the stent is removed from the pancreatic duct, pull the snare and stent through the duodenoscope. The removed stent is inspected to confirm that it is intact and without any fracture.
Patients with conditions that require multiple stent exchanges (eg, stricture related to chronic pancreatitis) may benefit from using varying stent lengths at subsequent exchanges, since most stent-induced ductal changes occur at the upstream end of the stent within the pancreatic duct [4]. Whenever possible, shorter stents are preferred over longer stents to limit the area of the pancreatic duct that comes in contact with the foreign stent material, provided that the ductal obstruction (or disruption) has been traversed. (See 'Stent-related morphologic changes' below.)
ADVERSE EVENTS — Adverse events associated with ERCP-guided pancreatic duct stent placement may be related to the ERCP or to stent placement.
ERCP-related — Complications associated with ERCP may be due to the endoscopy itself (eg, acute pancreatitis, perforation) or due to anesthesia (eg, hypotension). These complications are discussed in more detail separately. (See "Overview of endoscopic retrograde cholangiopancreatography (ERCP) in adults", section on 'Adverse events' and "Anesthesia for gastrointestinal endoscopy in adults", section on 'Complications'.)
Stent-related — Pancreatic duct stent placement has been associated with a range of potential complications. Some complications occur during or within several days of ERCP (ie, acute complications), while other complications are delayed [19,26-29]:
●Acute complications include abdominal pain, ductal rupture related to catheter/balloon dilation, gastrointestinal bleeding, intraprocedural inward stent migration, and post-ERCP pancreatitis [30]. Prevention and management of post-ERCP pancreatitis is discussed separately. (See "Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis".)
●Nonacute or delayed complications include stent malfunction (migration, occlusion), stent-related perforation, pancreatic ductal injury, and pancreatic stricture.
Stent-related morphologic changes — Pancreatic stents may induce morphologic changes that resemble chronic pancreatitis:
●Prevalence – The reported rates of stent-induced changes (eg, pancreatic strictures, ductal irregularities) have ranged from 18 to 80 percent [31-35]. Stent diameter size has been linked to risk of ductal changes [31,35]. In a study including 2283 patients who underwent ERCP and pancreatic stent placement, smaller diameter stents (3 to 4 Fr) were associated with lower rates of ductal changes compared with larger stents (5 to 6 Fr [24 versus 80 percent]) [35].
●Location – The morphologic changes induced by pancreatic stenting may affect the pancreatic parenchyma (eg, inflammatory response associated with the upstream end of the stent) and/or the pancreatic duct (eg, dilation of side branches, narrowing, and ductal irregularities) (image 2A-B) [31,36].
●Detection – During ERCP that is performed to remove a therapeutic pancreatic stent, the endoscopist may perform a pancreatogram to confirm resolution of the ductal pathology and to evaluate for morphologic changes. (See 'Therapeutic stent placement' above.)
Stent-related ductal changes may also be detected on magnetic resonance cholangiopancreatography (MRCP).
For patients with stent-induced changes such as ductal stricture, additional endoscopic therapy such as stricture dilation and stenting may be performed.
Issues related to morphologic changes in a previously normal pancreas in the setting of prophylactic stenting to prevent ERCP-related pancreatitis are discussed separately. (See "Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis".)
Stent occlusion — Most pancreatic duct stents occlude within 8 to 12 weeks after placement [24,25,37,38]. In a study including 68 patients with pancreatic duct stents, 42 patients (62 percent) had complete stent occlusion at the time of stent removal and the median time to occlusion was 35 days (95% CI, 30 to 40 days) [39]. Stents with >3 large side holes were less likely to be occluded at the time of stent removal (hazard ratio [HR] 0.46, 95% CI 0.23-0.93).
Serious complications after stent blockage are uncommon, possibly due to drainage of pancreatic juices alongside the occluded stent such that the stent acts as a wick [25]. However, some patients develop abdominal pain or acute pancreatitis in the setting of stent occlusion [27,33,37,40]. As a result, most advanced endoscopists perform stent exchanges electively before occlusion is expected to occur. (See 'Stent removal or replacement' above.)
Occluded pancreatic stents can be treated endoscopically by removing the occluded stent and replacing it with a new plastic stent.
The adherence of proteins to the inner surface of the stent seems to play a central role in stent occlusion [34]. The occluding material (biofilm) consists of a protein matrix laden with calcium carbonate crystals, mucopolysaccharides, and plant material [38].
Stent migration — Pancreatic duct stents may migrate in one of two directions:
●Downstream stent migration (ie, outside the duct) rarely results in symptoms such as worsening abdominal pain because the stent passes into the duodenum and is then excreted [41]. In one report including 589 stent placements, the rate of downstream stent migration was 8 percent [40].
●Upstream (or inward) stent migration (ie, into the duct) may lead to further complications because of stent-induced ductal damage and technical challenges associated with stent retrieval (small pancreatic duct diameter, bended duct course, presence of stricture) [42,43]. In one report including 589 stent placements, upstream migration developed in 5 percent of patients [40].
However, most migrated pancreatic stents can be retrieved endoscopically (image 3) [42,44]. Surgical extraction is infrequently needed but has been performed for patients with upstream migrated pancreatic stents in whom ERCP-guided retrieval attempts have failed [45,46]. Pancreatoscopy may facilitate extraction of migrated pancreatic stents that cannot be removed using retrieval techniques such as balloon catheter or grasping device methods [47,48]. (See "Cholangioscopy and pancreatoscopy".)
The risk of upstream stent migration can be decreased by initial positioning the stent such that it does not extend beyond the genu of the pancreas. In addition, modifications of stent design have been studied to reduce the risk of internal migration. One possible approach is eliminating internal stent flaring, which in one report, decreased risk of upstream migration but increased the risk of downstream migration [35,40,49,50].
Other complications — Other complications related to pancreatic duct stenting include ductal damage from the dilating catheter, cholangitis, and acute pancreatitis. While acute pancreatitis is a known complication associated with ERCP, data have suggested that unsuccessful pancreatic stent insertion was a risk factor for post-ERCP pancreatitis. In a study including 225 therapeutic ERCPs, failed stent insertion was associated with higher rates of acute pancreatitis compared with successful stent placement (67 versus 14 percent) [19]. (See "Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis".)
Evaluating for a suspected complication — For patients who had ERCP with pancreatic stent placement and then developed symptoms such as new or worsening abdominal pain, our initial evaluation for complications typically consists of laboratory testing (ie, liver biochemical tests, amylase) and abdominal imaging (ie, plain film of the abdomen or computed tomography scan if a walled-off pancreatic fluid collection is suspected). (See "Approach to walled-off pancreatic fluid collections in adults", section on 'Clinical features'.)
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Endoscopic retrograde cholangiopancreatography (ERCP)".)
SUMMARY AND RECOMMENDATIONS
●Indications for therapeutic stent placement – Endoscopic retrograde cholangiopancreatography (ERCP)-guided pancreatic duct stenting has been increasingly used for treating pancreatic disorders such as pancreatic duct obstruction (often related to pancreatic stricture and/or stones) and pancreatic duct leakage. (See 'Indications' above.)
●Preprocedure evaluation - Most patients will have had imaging prior to ERCP with pancreatic duct stent placement, thereby mitigating the need for additional imaging prior to the procedure. The diagnosis of pancreatic duct obstruction or pancreatic duct leakage is often suspected based on presenting symptoms (eg, abdominal pain, weight loss) and cross-sectional imaging (eg, computed tomography [CT] scan, magnetic resonance imaging [MRI] with magnetic resonance cholangiopancreatography [MRCP]). (See 'Preprocedure evaluation' above.)
●Patient preparation - Antibiotic prophylaxis prior to ERCP-guided pancreatic stent placement is generally not indicated in the absence of another indication (eg, biliary obstruction, risk for incomplete drainage) (table 2). Thus, the use of antibiotic prophylaxis is individualized and based on patient- and procedure-related risk factors for infection in addition to endoscopist preference. (See 'Patient preparation' above and "Antibiotic prophylaxis for gastrointestinal endoscopic procedures".)
●Types of pancreatic stents - Pancreatic stents are available in varying lengths, diameters, and designs and are primarily composed of polyethylene materials. Pancreatic stents are cylindrical in shape, and most stents have features that help prevent internal migration (eg, distal flange, pigtail). (See 'Types of stents' above.)
●Duration of pancreatic stent placement - The duration of stent placement is informed by the indications for and clinical response to stenting (eg, symptomatic improvement) (see 'Stent removal or replacement' above):
•For patients with pancreatic duct leakage, stents are usually removed after four to six weeks and are not replaced if the duct disruption has resolved.
•For patients with pancreatic duct obstruction, stents are generally replaced every four to eight weeks with the endpoint being resolution of symptoms.
●Adverse events - Adverse events reported with ERCP-guided pancreatic duct stent placement may be related to the ERCP or to stent placement:
•Complications associated with ERCP may be due to the endoscopy itself (eg, acute pancreatitis, perforation) or due to anesthesia (eg, hypotension). (See 'ERCP-related' above.)
•Complications related to pancreatic stenting include stent dysfunction (eg, occlusion, migration) and stent-related morphologic changes involving the pancreatic duct (eg, stricture, irregularities) or parenchyma (eg, inflammatory change). (See 'Stent-related' above.)
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