Fully covered self-expandable metal stents for treatment of malignant and benign biliary strictures

AIM:To present a series of covered self-expandable metal stents(CSEMS) placed for different indications and to evaluate the effectiveness,complications and extractability of these devices.METHODS:We therefore retrospectively reviewed the courses of patients who received CSEMS due to malignant as well as benign biliary strictures and postsphincterotomy bleeding in our endoscopic unit between January 2010 and October 2011.RESULTS:Twenty-six patients received 28 stents due to different indications(20 stents due to malignant biliary strictures,six stents due to benign biliary strictures and two stents due to post-sphincterotomy bleeding).Biliary obstruction was relieved in all cases,regardless of the underlying cause.Hemostasis could be achieved in the two patients who received the stents for this purpose.Complications occurred in five patients(18%).Two patients(7%) developed cholecystitis,stents dislocated/migrated in other two patients(7%),and in one patient(3.6%) stent occlusion was documented during the study period.Seven stents were extracted endoscopically.Removal of stents was easily possible in all cases in which it was desired using standard forceps.Twelve patients underwent surgery with pylorus preserving duodenopancreatectomy.In all patients stents could be removed during the operation without difficulties.CONCLUSION:Despite the higher costs of these devices,fully covered self-expanding metal stents may be suitable to relief biliary obstruction due to bile duct stenosis,regardless of the underlying cause.CSEMS may also represent an effective treatment strategy of severe post-sphincterotomy bleeding,not controlled by other measures.     

Fully covered self-expanding metal stents for benign refractory pancreatic duct strictures in chronic pancreatitis

Background: Pancreatic duct (PD) stricture is a common adverse event in chronic pancreatitis (CP). Primary treatment for refractory PD strictures is endotherapy (ET), including the insertion of multiple plastic stents. In addition, fully covered self-expandable metal stents (FC-SEMSs) have also been successfully used. More long-term studies are necessary to clarify the complication rate and efficiency, however.

Methods: This retrospective study was comprised of 17 patients with symptomatic CP and refractory fibrotic main pancreatic duct (MPD) stricture treated with FC-SEMSs between 2010–2018 at the Helsinki University Hospital. Treated strictures were located in the pancreatic head. Technical success was defined as the accurate positioning of the stent and resolution of the MPD stricture. Clinical success was defined as pain relief at the end of the follow-up.

Results: In 12 patients (71%), stricture resolution was accomplished. Clinical success was achieved in 12 patients (71%). The median duration of stenting was 169 days (range 15–804). Ten patients (58.8%) underwent a follow-up of two years or more. Early complications (≤7 days) occurred in two patients (12%): one pancreatitis and one cholestasis. Late complications (≥7 days) included severe abdominal pain (n?=?2, 12%), pancreatitis (n?=?3, 18%), cholestasis (n?=?1, 6%) and stent migration (n?=?7, 35%). Significant differences in stricture resolution and pain improvement were evident in patients with stent migration compared to patients without stent migration [1(14.3%) vs. 11(84.6%), p?=?.004 and 2(28.6%) vs. 11(84.6%), p?=?.022].

Conclusion: FC-SEMS placement is a safe and potentially effective treatment for this challenging group of patients. However, stent migration appears to affect the clinical and technical outcome.     

Fully-covered, self-expandable metal stents (CSEMS) in malignant distal biliary strictures: mid-term evaluation

Background and Aims: Limited data exist regarding fully‐covered, self‐expandable metal stents (CSEMS) with anchoring fins for the management of malignant distal biliary strictures. The aim of this study is to evaluate their safety and patency. Methods: Over a period of 2 years, 70 patients (45 males, 66 ± 13 years) underwent endoscopic retrograde cholangiopancreatography (ERCP) with placement of a 10‐mm (67 patients) or 8‐mm diameter (3 patients) CSEMS for the palliation of distal malignant biliary obstruction (pancreatic [53] or other [17]). Data were collected prospectively for survival and stent patency; complications were evaluated retrospectively. Results: After CSEMS placement, 17 patients proceeded to surgery, and 53 patients were deemed unresectable. Mean survival for non‐surgical candidates was 180 days (range: 15–1091), and 170 days (range: 9–589) for patients who underwent surgical management. CSEMS were left in place and remained patent for a mean of 163 days (range: 15–1091) in non‐surgical candidates, and a mean of 55 days (range: 5–126) in surgical candidates. Complications during placement included wire perforations (4) and proximal deployment requiring repositioning (4), one of which was complicated by a bile leak. Post‐procedure complications were observed in 24 cases (34%) and included post‐ERCP pancreatitis (8, with 2 of them severe), post‐procedure pain (5, with 3 requiring admission), cholecystitis (3), stent occlusion (3), cholangitis (2), proximal migration (1), post‐sphincterotomy bleeding (1), and sepsis leading to death (1). Conclusion: CSEMS appear to provide acceptable short‐term patency rates; however, their limited long‐term patency and high complication rate might limit their widespread use. Further long‐term prospective data are required to confirm this observation.     

Evaluation of fully covered self-expanding metal stents in benign biliary strictures and bile leaks

AIM: To investigate the use of fully covered metal stents in benign biliary strictures (BBS) and bile leaks.METHODS: We studied 17 patients, at Harbor-UCLA Medical center (Los Angeles), with BBS (n = 12) and bile leaks (n = 5) from July 2007 to February 2012 that had received placement of fully covered self-expanding metal stents (FCSEMs). Fourteen patients had endoscopic placement of VIABIL^® (Conmed, Utica, New York, United States) stents and three had Wallflex^® (Boston Scientific, Mass) stents. FCSEMS were 8 mm or 10 mm in diameter and 4 cm to 10 cm in length. Patients were followed at regular intervals to evaluate for symptoms and liver function tests. FCSEMS were removed after 4 or more weeks. Resolution of BBS and leak was documented cholangiographically following stent removal. Stent patency can be defined as adequate bile and contrast flow from the stent and into the ampulla during endoscopic retrograde cholangiopancreatography (ERCP) without clinical signs and/or symptoms of biliary obstruction. Criterion for bile leak resolution at ERCP is defined as absence of contrast extravasation from the common bile duct, cystic duct remanent, or gall bladder fossa. Rate of complications such as migration, and in-stent occlusion were recorded. Failure of endoscopic therapy was defined as persistent biliary stenosis or continuous biliary leakage after 12 mo of stent placement.RESULTS: All 17 patients underwent successful FCSEMS placement and removal. Etiologies of BBS included: cholecystectomies (n = 8), cholelithiasis (n = 2), hepatic artery compression (n = 1), pancreatitis (n = 2), and Whipple procedure (n = 1). All bile leaks occurred following cholecystectomy. The anatomic location of BBS varied: distal common bile duct (n = 7), common hepatic duct (n = 1), hepaticojejunal anastomosis (n = 2), right intrahepatic duct (n = 1), and choledochoduodenal anastomatic junction (n = 1). All bile leaks were found to be at the cystic duct. Twelve of 17 patients had failed prior stent placement or exchange. Resolution of the biliary strictures and bile leaks was achieved in 16 of 17 patients (94%). The overall median stent time was 63 d (range 27-251 d). The median stent time for the BBS group and bile leak group was 62 ± 58 d (range 27-199 d) and 92 ± 81 d (range 48-251 d), respectively. All 17 patients underwent successful FCSEMS removal. Long term follow-up was obtained for a median of 575 d (range 28-1435 d). Complications occurred in 5 of 17 patients (29%) and included: migration (n = 2), stent clogging (n = 1), cholangitis (n = 1), and sepsis with hepatic abscess (n = 1).CONCLUSION: Placement of fully covered self-expanding metal stents may be used in the management of benign biliary strictures and bile leaks with a low rate of complications.     

自膨式金属支架治疗远端胆管恶性狭窄优于塑料支架

【据Clinical Gastroenterology and Hepatology 2020年12月报道】题:自膨式金属支架治疗远端胆管恶性狭窄优于塑料支架(作者Jang S等)经内镜逆行胰胆管造影(ERCP)引导下放置支架治疗胆管恶性狭窄是非常有效的。来自克利夫兰诊所的Jang等进行了一项队列研究,比较了塑料支架(PS)和自膨式金属支架(SEMS)的疗效及不良结局。     

Plastic or metal stents for benign extrahepatic biliary strictures: a systematic review

Background  

Benign biliary strictures may be a consequence of surgical procedures, chronic pancreatitis or iatrogenic injuries to the ampulla. Stents are increasingly being used for this indication, however it is not completely clear which stent type should be preferred.     

Covered versus uncovered self-expandable metal stents for malignant biliary strictures: A meta-analysis and systematic review

Self-expandable metal stents (SEMS) are used for palliating inoperable malignant biliary strictures. It is unclear if covered metal stents are superior to uncovered metal stents in these patients. We compared clinical outcomes in patients with covered and uncovered stents. Studies using covered and uncovered metallic stents for palliation in patients with malignant biliary stricture were reviewed. Articles were searched in MEDLINE, PubMed, and Ovid journals. Fixed and random effects models were used to calculate the pooled proportions. Initial search identified 1436 reference articles, of which 132 were selected and reviewed. Thirteen studies (n?=?2239) for covered and uncovered metallic stents which met the inclusion criteria were included in this analysis. Odds ratio for stent occlusion rates in covered vs. uncovered stents was 0.79 (95 % CI?=?0.65 to 0.96). Survival benefit in patients with covered vs. uncovered stents showed the odds ratio to be 1.29 (95 % CI?=?0.95 to 1.74). Pooled odds ratio for migration of covered vs. uncovered stents was 9.9 (95 % CI?=?4.5 to 22.3). Covered stents seemed to have significantly lesser occlusion rates, increased odds of migration, and increased odds of pancreatitis compared to uncovered stents. There was no statistically significant difference in the survival benefit, overall adverse event rate, and patency period of covered vs. uncovered metal stents in patients with malignant biliary strictures.     

Efficacy of multiple biliary stenting for refractory benign biliary strictures due to chronic calcifying pancreatitis

AIM To investigate endoscopic therapy efficacy for refractory benign biliary strictures(BBS) with multiple biliary stenting and clarify predictors.METHODS Ten consecutive patients with stones in the pancreatic head and BBS due to chronic pancreatitis who underwent endoscopic therapy were evaluated. Endoscopic insertion of a single stent failed in all patients. We used plastic stents(7F, 8.5F, and 10F) and increased stents at intervals of 2 or 3 mo. Stents were removed approximately 1 year after initial stenting. BBS and common bile duct(CBD) diameter were evaluated using cholangiography. Patients were followed for ≥ 6 mo after therapy, interviewed for cholestasis symptoms, and underwent liver function testing every visit. Patients with complete and incomplete stricture dilations were compared.RESULTS Endoscopic therapy was completed in 8(80%) patients, whereas 2(20%) patients could not continue therapy because of severe acute cholangitis and abdominal abscess, respectively. The mean number of stents was 4.1 ± 1.2. In two(20%) patients, BBS did not improve; thus, a biliary stent was inserted. BBS improved in six(60%) patients. CBD diameter improved more significantly in the complete group than in the incomplete group(6.1 ± 1.8 mm vs 13.7 ± 2.2 mm, respectively, P = 0.010). Stricture length was significantly associated with complete stricture dilation(complete group; 20.5 ± 3.0 mm, incomplete group; 29.0 ± 5.1 mm, P = 0.011). Acute cholangitis did not recur during the mean follow-up period of 20.6 ± 7.3 mo.CONCLUSION Sequential endoscopic insertion of multiple stents is effective for refractory BBS caused by chronic calcifying pancreatitis. BBS length calculation can improve patient selection procedure for therapy.     

Evaluation of anti-migration properties of biliary covered self-expandable metal stents

AIM: To assess anti-migration potential of six biliary covered self-expandable metal stents(C-SEMSs) by using a newly designed phantom model. METHODS: In the phantom model, the stent was placed in differently sized holes in a silicone wall and retracted with a retraction robot. Resistance force to migration(RFM) was measured by a force gauge on the stent end. Radial force(RF) was measured with a RF measurement machine. Measured flare structure variables were the outer diameter, height, and taper angle of the flare(ODF, HF, and TAF, respectively). Correlations between RFM and RF or flare variables were analyzed using a linear correlated model.RESULTS: Out of the six stents, five stents were braided, the other was laser-cut. The RF and RFM of each stent were expressed as the average of five replicate measurements. For all six stents, RFM and RF decreased as the hole diameter increased. For all six stents, RFM and RF correlated strongly when the stent had not fully expanded. This correlation was not observed in the five braided stents excluding the laser cut stent. For all six stents, there was a strong correlation between RFM and TAF when the stent fully expanded. For the five braided stents, RFM after full stent expansion correlated strongly with all three stent flare structure variables(ODF, HF, and TAF). The laser-cut C-SEMS had higher RFMs than the braided C-SEMSs regardless of expansion state.CONCLUSION: RF was an important anti-migration property when the C-SEMS did not fully expand. Once fully expanded, stent flare structure variables plays an important role in anti-migration.     

Benign biliary strictures related to chronic pancreatitis: Balloons,stents, or surgery

Opinion statement Benign biliary strictures are seen in a subset of patients with chronic pancreatitis. Most patients are asymptomatic and require no intervention. In some patients, benign strictures can become symptomatic. In these patients, the aim of biliary drainage is to prevent long-term complications such as recurrent cholangitis and secondary biliary cirrhosis. The possibility of a malignant stricture should always be excluded. Successful endoscopic drainage of biliary obstruction has no influence on pain pattern in patients with chronic pancreatitis. At the first diagnosis of a symptomatic biliary stricture due to chronic pancreatitis, a polyethylene stent can be inserted endoscopically. If the stricture is still present despite stent exchange with serial insertion of multiple stents every 3 months for 1 year, surgery is indicated as definitive treatment. The role of self-expandable metal stents in the management of benign biliary strictures due to chronic pancreatitis is unclear, but they may be useful for nonoperative candidates and a select group of patients in whom surgery is planned. The aim of surgical therapy is to definitively treat the benign biliary stricture, especially in younger patients, who presumably have a longer lifespan.     

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.     

Expandable metal stents in chronic pancreatitis

BackgroundBiliary obstruction in chronic pancreatitis may be relieved by the insertion of a biliary endoprosthesis. Stenting is usually achieved with a plastic device, but self-expandable metal stents may also be used.Case outlinesTwo patients are described with severe chronic pancreatitis complicated by biliary obstruction and portal vein thrombosis, who underwent insertion of metallic biliary endoprostheses. In both patients the endoprostheses became occluded, at 12 and 7 months respectively, which necessitated open operation. Both patients experienced surgical complications and one patient died postoperatively.DiscussionThe use of metal endoprostheses in chronic pancreatitis may result in occlusion, necessitating open operation. Such stents should be used with caution in these patients, who are likely to be high-risk surgical candidates.