Stent selection for both biliary and pancreatic strictures caused by chronic pancreatitis: multiple plastic stents or metallic stents?

The utility of self-expanding metal stents in benign biliary strictures- a retrospective case series

BACKGROUND

Benign biliary strictures can have a significant negative impact on patient quality of life. There are several modalities which can be utilized with the goal of stricture resolution. These techniques include balloon dilatation, placement of multiple plastic stents and more recently, the use of metal stents. The aim of this study was to evaluate the local success of self-expanding metal stents in successfully resolving benign biliary strictures.

METHODS

This was a single institution, retrospective case series. Patients included in our study were patients who underwent endoscopic retrograde cholangiopancreatography with placement of self expanding metal stents for benign biliary strictures at our institution between 2016-2022. Patients were excluded for the following: malignant stricture, and inability to successfully place metal stent. Data was evaluated using two-sided t-test with 95% confidence interval.

RESULTS

A total of 31 patients underwent placement of 43 self-expanding metal stents and met inclusion criteria. Mean age of patients was 59 ± 10 years, and were largely male (74.2% vs. 25.8%). Most strictures were anastomotic stricture post liver transplant (87.1%), while the remainder were secondary to chronic pancreatitis (12.9%). Complications of stent placement included cholangitis (18.6%), pancreatitis (2.3%), stent migration (20.9%), and inability to retrieve stent (4.7%). There was successful stricture resolution in 73.5% of patients with anastomotic stricture and 33.3% of patients with stricture secondary to pancreatitis. Resolution was more likely if stent duration was > / = 180 days (73.3% vs. 44.4%, p < 0.05). There was no demonstrated added benefit when stent duration was > / = 365 days (75% vs. 60.9%, p = 0.64).

CONCLUSIONS

This study demonstrates that self expanding metal stents are a safe and effective treatment for benign biliary strictures, with outcomes comparable to plastic stents with fewer interventions. This study indicates that the optimal duration to allow for stricture resolution is 180-365 days.

Feasibility of in vivo swine models using guide wire-assisted intraductal radiofrequency ablation for benign biliary stricture

Several in vivo swine models of benign biliary stenosis (BBS) have been recently reported for preclinical studies of novel endoscopic techniques and devices. The aim of this study was to evaluate the efficacy and feasibility of large animal models of BBS by using intraductal radiofrequency ablation (RFA) assisted by guide wire. Six in vivo swine models were made by using an intraductal RFA for cauterization at 10 W, 80 °C, 90 s in the common bile duct (CBD). Endoscopic retrograde cholangiopancreatography (ERCP) was performed with cholangiography and histologic evaluation was done for the common bile duct. Blood tests were examined before, after, and at the final follow-up. Guide wire assisted RFA electrode produced BBS in all (6/6, 100%) animal models without severe complications. Fluoroscopy findings at 2 weeks after intraductal RFA in every model revealed BBS in the common bile duct. In histologic evaluations, fibrosis and chronic inflammatory changes were noted. After the procedure, ALP, GGT, and CRP were elevated and decreased after an appropriate drain. A swine model of BBS is developed by inducing intraductal thermal injury using intraductal RFA assisted by guide wire. This novel technique for inducing BBS in swine is effective and feasible.

Fully Covered Self-Expanding Metal Stent vs Multiple Plastic Stents to Treat Benign Biliary Strictures Secondary to Chronic Pancreatitis: A Multicenter Randomized Trial

BACKGROUND & AIMS

Benign biliary strictures (BBS) are complications of chronic pancreatitis (CP). Endotherapy using multiple plastic stents (MPS) or a fully covered self-expanding metal stent (FCSEMS) are acceptable treatment options for biliary obstructive symptoms in these patients.

METHODS

Patients with symptomatic CP-associated BBS enrolled in a multicenter randomized noninferiority trial comparing 12-month treatment with MPS vs FCSEMS. Primary outcome was stricture resolution status at 24 months, defined as absence of restenting and 24-month serum alkaline phosphatase not exceeding twice the level at stenting completion. Secondary outcomes included crossover rate, numbers of endoscopic retrograde cholangiopancreatography (ERCPs) and stents, and stent- or procedure-related serious adverse events.

RESULTS

Eighty-four patients were randomized to MPS and 80 to FCSEMS. Baseline technical success was 97.6% for MPS and 98.6% for FCSEMS. Eleven patients crossed over from MPS to FCSEMS, and 10 from FCSEMS to MPS. For MPS vs FCSEMS, respectively, stricture resolution status at 24 months was 77.1% (54/70) vs 75.8% (47/62) (P = .008 for noninferiority intention-to-treat analysis), mean number of ERCPs was 3.9 ± 1.3 vs 2.6 ± 1.3 (P < .001, intention-to-treat), and mean number of stents placed was 7.0 ± 4.4 vs 1.3 ± .6 (P < .001, as-treated). Serious adverse events occurred in 16 (19.0%) MPS and 19 (23.8%) FCSEMS patients (P = .568), including cholangitis/fever/jaundice (9 vs 7 patients respectively), abdominal pain (5 vs 5), cholecystitis (1 vs 3) and post-ERCP pancreatitis (0 vs 2). No stent- or procedure-related deaths occurred.

CONCLUSIONS

Endotherapy of CP-associated BBS has similar efficacy and safety for 12-month treatment using MPS compared with a single FCSEMS, with FCSEMS requiring fewer ERCPs over 2 years. (ClinicalTrials.gov, Number: NCT01543256.).

Preliminary study of a modified, nonflared, short, fully covered metal stent for refractory benign pancreatic duct strictures (with videos)

BACKGROUND AND AIMS

Fully covered self-expanding metal stents (FCSEMSs) are considered to be more effective than plastic stents for the treatment of main pancreatic duct (MPD) strictures associated with chronic pancreatitis (CP) because of their larger diameter and exertion of a radial expansion force. However, the current FCSEMSs have several limitations. To overcome these, a novel modified nonflared FCSEMS was developed. In this study we conducted a prospective long-term follow-up evaluation of the efficacy of the novel FCSEMS for the treatment of refractory benign PD strictures in patients with CP.

METHODS

Consecutive patients with symptomatic CP associated with refractory MPD strictures were enrolled prospectively in this single-arm study. The nonflared FCSEMS was placed intraductally or transpapillary according to the location and length of the stricture. Stent removal was performed at 3 months after placement. The primary outcome was the resolution of the pancreatic ductal stricture.

RESULTS

Endoscopic placement of modified nonflared FCSEMSs was technically successful in all 25 patients. Intraductal FCSEMS placement was performed in 14 patients (56.0%). Stents of diameter 8 mm were used in 17 patients (68.0%). Stents of lengths 3 and 5 cm were inserted in 22 (88.0%) and 3 (12.0%) patients, respectively. In 1 patient (4.0%), stent migration developed. All other stents were removed successfully. After stent removal, resolution of the MPD stricture was confirmed in all patients, and no FCSEMS-related de novo stricture was observed. During the follow-up period (median, 34 months; interquartile range, 25-56) after the stents had been removed from the 25 patients, reintervention for recurrence of MPD stricture with abdominal pain was performed in 2 patients (8.0%).

CONCLUSIONS

Endoscopic placement of a novel modified nonflared FCSEMS resulted in long-term stricture resolution with pain relief and reduced the rate of stent-related adverse events, particularly stent migration and stent-induced de novo MPD stricture. (Clinical trial registration number: UMIN000035681.).

Fully covered self-expanding metal stents for refractory pancreatic duct strictures in symptomatic chronic pancreatitis, US experience

Background and study aims  Fully covered self-expanding metal stents (FCSEMS) have been used to treat refractory pancreatic duct strictures. We aimed to evaluate the feasibility, safety, and efficacy of FCSEMS in chronic pancreatitis with refractory pancreatic duct strictures. Patients and methods  This was a retrospective multicenter cases series of patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) with FCSEMS placement in the main pancreatic duct (MPD) at five tertiary care centers between February 2010 and June 2016. Primary endpoints were technical success, clinical success, and procedure-related morbidity. Secondary endpoints were pain relief at the end of follow-up and resolution of the pancreatic stricture on ERCP. Results  Thirty-three patients with previously drained stents, 76 % of whom were male, underwent ERCP with FCSEMS placement. Mean duration of follow-up was 14 months. All of the patients had prior therapy. The technical success rate for FCSEMS placement was 100 % (n = 33) and the clinical success rate was 93 % (was n = 31). Stents were removed after a median duration of 14.4 weeks. After stent removal, the diameter of the narrowest MPD stricture had increased significantly from 1 mm to 4.5 mm ( P  < 0.001). There was a statistically significant improvement on the Visual Analogue Scale (VAS) from a median of 8.5 to 2.5. At the end of the study, (n = 27) 87.1 % of patients reported significant pain reduction with reduced narcotic use. Conclusion  FCSEMS appeared to be a feasible, safe, and potentially effective Intervention in patients who had not responded to endoscopic therapy with plastic stents.

Management of Benign and Malignant Pancreatic Duct Strictures

The diagnosis and management of pancreatic strictures, whether malignant or benign, remain challenging. The last 2 decades have seen dramatic progress in terms of both advanced imaging and endoscopic therapy. While plastic stents remain the cornerstone of the treatment of benign strictures, the advent of fully covered metal stents has initiated a new wave of interest in calibrating the pancreatic duct with fewer sessions. In malignant disease, palliation remains the priority and further data are necessary before offering systematic pancreatic stenting.

Outcome of stenting in biliary and pancreatic benign and malignant diseases: A comprehensive review

Endoscopic stenting has become a widely method for the management of various malignant and benign pancreatico-biliary disorders. Biliary and pancreatic stents are devices made of plastic or metal used primarily to establish patency of an obstructed bile or pancreatic duct and may also be used to treat biliary or pancreatic leaks, pancreatic fluid collections and to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis. In this review, relevant literature search and expert opinions have been used to evaluate the outcome of stenting in biliary and pancreatic benign and malignant diseases.

Palliation of pancreatic ductal obstruction in pancreatic cancer

Pancreatic stenting for patients with obstructive pain secondary to a malignant pancreatic duct stricture is safe and effective, and should be considered a therapeutic option. Although pancreatic stenting does not seem to be effective for patients with chronic pain, it may be beneficial in those with obstructive type pains, pancreatic duct disruption, or smoldering pancreatitis. Fully covered metal stents may be an option, but data on their use are limited. Further studies, including prospective randomized studies comparing plastic and metal stents in these indications, are needed to further validate and confirm these results.

Intraductal thermal injury using a heat probe and radiofrequency ablation electrode in a swine model of biliary stenosis

BACKGROUND AND OBJECTIVE

An animal model for bile duct stenosis using intraductal thermal injury has not yet been established. The aims of the current study were to develop biliary stenosis in a swine model by inducing intraductal thermal injury using a heat probe or radiofrequency ablation electrode and to investigate an effective and safe energy dose.

METHODS

Intraluminal thermal injury was applied to the common bile duct with a heat probe in three swines and a radiofrequency ablation electrode in the other three swines by either endoscopic retrograde cholangiography or open laparotomy. Cholangiography and histologic evaluation of common bile duct were taken 2 weeks after thermal injury.

RESULTS

Thermal injury with a heat probe at 25 J for 40 seconds produced a stricture in all three animals. Application of a radiofrequency ablation electrode produced a stricture in two of three animals. An energy dose of 40 W at 80°C for 30 seconds produced biliary stenosis without any complications initially and 2 weeks after thermal injury.

CONCLUSIONS

The application of a heat probe and a radiofrequency ablation electrode for intraductal thermal injury resulted in a reproducible animal model of biliary stenosis.

Antioxidant therapy does not reduce pain in patients with chronic pancreatitis: the ANTICIPATE study

BACKGROUND & AIMS

We investigated whether antioxidant therapy reduces pain and improves quality of life in patients with chronic pancreatitis.

METHODS

We performed a double-blind, randomized, controlled trial that compared the effects of antioxidant therapy with placebo in 70 patients with chronic pancreatitis. Patients provided 1 month of baseline data and were followed for 6 months while receiving either antioxidant therapy (Antox version 1.2, Pharma Nord, Morpeth, UK) or matched placebo (2 tablets, 3 times/day). The primary analysis was baseline-adjusted change in pain score at 6 months, assessed by an 11-point numeric rating scale. Secondary analyses included alternative assessments of clinical and diary pain scores, scores on quality-of-life tests (the European Organization for Research and Treatment of Cancer [EORTC-QLQ-C30], Quality of Life Questionnaire-Pancreatic modification [QLQ-PAN28], European Quality of Life questionnaire [EuroQOL EQ-5D], and European Quality of Life questionnaire - Visual Analog Score [EQ-VAS]), levels of antioxidants, use of opiates, and adverse events. Analyses, reported by intention to treat, were prospectively defined by protocol.

RESULTS

After 6 months, pain scores reported to the clinic were reduced by 1.97 from baseline in the placebo group and by 2.33 in the antioxidant group but were similar between groups (-0.36; 95% confidence interval [CI], -1.44 to 0.72; P = .509). Average daily pain scores from diaries were also similar (3.05 for the placebo group and 2.93 for the antioxidant group, a difference of 0.11; 95% CI, 1.05-0.82; P = .808). Measures of quality of life were similar between groups, as was opiate use and number of hospital admissions and outpatient visits. Blood levels of vitamin C and E, β-carotene, and selenium were increased significantly in the antioxidant group.

CONCLUSIONS

Administration of antioxidants to patients with painful chronic pancreatitis of predominantly alcoholic origin does not reduce pain or improve quality of life, despite causing a sustained increase in blood levels of antioxidants.

Endoscopic treatment for biliary stricture secondary to chronic pancreatitis

The causes of benign biliary stricture include chronic pancreatitis, primary/immunoglobulin G4-related sclerosing cholangitis and complications of surgical procedures. Biliary stricture due to fibrosis as a result of inflammation is sometimes encountered in patients with chronic pancreatitis. Frey's procedure, which can provide pancreatic duct drainage with decompression of biliary stricture, can be an initial treatment for chronic pancreatitis with pancreatic and bile duct strictures with upstream dilation. When patients are high-risk surgical candidates or hesitate to undergo surgery, endoscopic treatment appears to be a potential second-line therapy. Placement of multiple plastic stents is currently considered to be the best choice as endoscopic treatment for biliary stricture due to chronic pancreatitis. Temporary placement with a fully covered metal stent has become an attractive option due to the lesser number of endoscopic retrograde cholangiopancreatography (ERCP) sessions and its large diameter. Further clinical trials comparing multiple placement of plastic stents with placement of a covered metal stent for biliary stricture secondary to chronic pancreatitis are awaited.

Successful treatment of benign biliary stricture by a covered self-expandable metallic stent in a patient with chronic pancreatitis

The patient was a 73 year old man for whom surgery under general anesthesia was difficult to perform because of pulmonary emphysema. In April 2003, he visited our hospital complaining of epigastralgia and dorsal pain, and was admitted under a diagnosis of acute exacerbation of chronic pancreatitis. In 2005, acute cholangitis concomitantly developed with acute exacerbation of chronic pancreatitis, for which a plastic stent was placed in the common bile duct. Cholangitis repeatedly developed every 2-3 months thereafter, and admission was required each time to exchange the stent. Surgery was considered but not applicable because of his poor respiratory function, and a partially covered self-expandable metallic stent was inevitably placed in the bile duct. Ten months later, an aberration of the metallic stent in the bile duct occurred, but it was dealt with by placing an additional metallic stent, and no cholangitis or pancreatitis developed until the patient died of respiratory insufficiency 3 years later. Placement of a covered self-expandable metallic stent might be an option for the treatment of benign biliary stricture, especially in patients at high risk from surgery.