Use of fully covered self-expanding metal stents in benign biliary diseases

Biliary fully covered self-expanding metal stents (FCSEMS) are now being used to treat several benign biliary conditions. Advantages include small predeployment and large postexpansion diameters in addition to an easy insertion technique. Lack of imbedding of the metal into the bile duct wall enables removability. In benign biliary strictures that usually require multiple procedures, despite the substantially higher cost of FCSEMS compared with plastic stents, the use of FCSEMS is offset by the reduced number of endoscopic retrograde cholangiopancreatography interventions required to achieve stricture resolution. In the same way, FCSEMS have also been employed to treat complex bile leaks, perforation and bleeding after endoscopic biliary sphincterotomy and as an aid to maintain permanent drainage tracts obtained by means of Endoscopic Ultrasound-guided biliary drainage. Good success rates have been achieved in all these conditions with an acceptable number of complications. FCSEMS were successfully removed in all patients. Comparative studies of FCSEMS and plastic stents are needed to demonstrate effi cacy and cost-effectiveness     

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 metal biliary stents: A review of the literature

Fully covered self-expandable metal stents (FCSEMS) represent the latest advancement of metal biliary stents used to endoscopically treat a variety of obstructive biliary pathology. A large stent diameter and synthetic covering over the tubular mesh prolong stent patency and reduce risk for tissue hyperplasia and tumor ingrowth. Additionally, FCSEMS can be easily removed. All these features address issues faced by plastic and uncovered metal stents. The purpose of this paper is to comprehensively review the application of FCSEMS in benign and malignant biliary strictures, biliary leak, and post-sphincterotomy bleeding.     

全覆膜金属支架与塑料支架在不可切除的远端胆道 恶性梗阻中的应用对比研究

目的探讨经内镜逆行胆胰管造影术（endoscopic retrograde cholangiopancreatography,ERCP）下胆道全覆膜金属支架及塑料支架置入治疗远端胆道恶性梗阻性黄疸的有效性及安全性。方法回顾性分析并总结2012年11月—2018年12月收治的52例接受ERCP下全覆膜金属支架（WallFlex）置入和40例胆道塑料支架置入治疗不可切除的恶性梗阻性黄疸患者的操作成功率、临床成功率、通畅时间、堵塞率、再干预次数、总费用等临床资料。结果ERCP 操作成功率两组均为100.0%（92/92）,金属支架组和塑料支架组临床成功率分别为94.2%（49/52）和75.0%（30/40）（χ2 =6.89,P<0.01）。两组生存时间比较,差异无统计学意义（6.5个月比7.2个月, χ2=0.25,P>0.05）。金属支架组中位通畅时间较塑料支架组明显延长（182.0 d 比 84.0 d,P<0.01）。两组胰腺炎（χ2 =0.2,P>0.05）及胆管炎发生率(χ2 =0.2,P>0.05）比较差异无统计学意义。金属支架组发生堵塞的概率要明显少于塑料支架组 [7.8%（4/51）比 25.0%（10/40）, χ2 =5.25,P<0.05],在再次干预次数方面,金属支架组要明显少于塑料支架组（0.06 次比 0.38次,t=2.91,P<0.01）。塑料支架组和金属支架组在总费用上比较差异无统计学意义（42 956.1元比 44 851.5元,t=1.84,P=0.07）。结论ERCP下全覆膜金属支架置入对于不可切除的远端胆道恶性梗阻患者是一种安全、有效、经济的治疗方法,在通畅时间及再次干预次数等方面要明显优于塑料支架。     

全覆膜金属支架治疗良性胆道狭窄的初步研究

目的探讨全覆膜胆道金属支架治疗良性胆道狭窄的安全性及其疗效。方法36例良性胆道狭窄患者行全覆膜胆道金属支架置入术治疗,术后每1～2个月接受1次门诊随访,观察并发症发生及胆道狭窄改变情况。结果36例均一次性成功置入全覆膜胆道金属支架,未出现与操作相关的严重并发症,支架放置3～6个月后全部成功拔除,其中28例（77．8％）良性胆道狭窄消失。结论置入全覆膜胆道金属支架治疗良性胆道狭窄是安全的,近期疗效显著。     

Fully versus partially covered self‐expandable metal stents in benign esophageal strictures

Self‐expandable plastic stents are currently recommended for refractory benign esophageal strictures but they show disappointing results in terms of migration and long‐term efficacy. We report here our experience in the management of benign esophageal strictures with partially covered (PCSEMS) and fully covered self‐expandable metal stents (FCSEMS). We performed a retrospective analysis of self‐expandable metal stent (SEMS) placements for benign esophageal strictures from 1998 to 2011 in Rouen University Hospital. Twenty‐two patients (15 men, 7 women) attempted 40 esophageal SEMS placements (17 PCSEMS, 23 FCSEMS) during this period. All technical complications were migrations. Migration was noted after 3/17 PCSEMS (17.6%) and 4/23 FCSEMS placement (17.4%, P = ns). Clinical complications occurred after 6/17 PCSEMS and 2/23 FCSEMS placements (35.3% vs. 8.7%, P = 0.053). PCSEMS caused two major complications (fistulae) whereas FCSEMS did not cause any major complication (11.7% vs. 0%). Mean dysphagia score was significantly lower after SEMS placement (1.68 vs. 3.08, P < 0.001) with similar results for PCSEMS and FCSEMS. Stent placement resulted in long‐term clinical success for 23.5% of PCSEMS and 34.7% of FCSEMS (P = 0.0505). FCSEMS provide satisfying clinical success rate with an acceptable complication rate and they could constitute a relevant therapeutic option in the management of benign esophageal strictures.     

Novel biliary self-expanding metal stents: indications and applications

Endoscopic insertion of a self-expanding metal stent (SEMS) through a malignant common bile duct stricture is the first line of palliation for malignant jaundice. Patency of these stents remains a major concern. SEMS dysfunction can result from tumor ingrowth, overgrowth and/or clogging. Initial SEMS modifications involved covering the central part of the stent in order to reduce ingrowth and ultimately increase patency. Fully covered stents became available shortly after reports of their use in human patients. The potential removability and radial strength of SEMS have led to evaluation of their use in new indications including benign biliary strictures, post sphincterotomy bleeding and perforation. Other aspects of development include the addition of features such as anti-reflux valves, drug elution and spontaneous biodegradability. These aspects and their clinical implications are reviewed and discussed.     

Drug-eluting fully covered self-expanding metal stent for dissolution of bile duct stones in vitro

BACKGROUND The treatment of difficult common bile duct stones(CBDS)remains a big challenge around the world.Biliary stenting is a widely accepted rescue method in patients with failed stone extraction under endoscopic retrograde cholangiopancreatography.Fully covered self-expanding metal stent(FCSEMS)has gained increasing attention in the management of difficult CBDS.AIM To manufacture a drug-eluting FCSEMS,which can achieve controlled release of stone-dissolving agents and speed up the dissolution of CBDS.METHODS Customized covered nitinol stents were adopted.Sodium cholate(SC)and disodium ethylene diamine tetraacetic acid(EDTA disodium,EDTA for short)were used as stone-dissolving agents.Three different types of drug-eluting stents were manufactured by dip coating(Stent I),coaxial electrospinning(Stent II),and dip coating combined with electrospinning(Stent III),respectively.The drugrelease behavior and stone-dissolving efficacy of these stents were evaluated in vitro to sort out the best manufacturing method.And the selected stonedissolving stents were further put into porcine CBD to evaluate their biosecurity.RESULTS Stent I and Stent II had obvious burst release of drugs in the first 5 d while Stent III presented controlled and sustainable drug release for 30 d.In still buffer,the final stone mass-loss rate of each group was 5.19%±0.69%for naked FCSEMS,20.37%±2.13%for Stent I,24.57%±1.45%for Stent II,and 33.72%±0.67%for Stent III.In flowing bile,the final stone mass-loss rate of each group was 5.87%±0.25%for naked FCSEMS,6.36%±0.48%for Stent I,6.38%±0.37%for Stent II,and 8.15%±0.27%for Stent III.Stent III caused the most stone mass-loss no matter in still buffer or in flowing bile,which was significantly higher than those of other groups(P<0.05).In vivo,Stent III made no difference from naked FCSEMS in serological analysis(P>0.05)and histopathological examination(P>0.05).CONCLUSION The novel SC and EDTA-eluting FCSEMS is efficient in diminishing CBDS in vitro.When conventional endoscopic techniques fail to remove difficult CBDS,SC and EDTA-eluting FCSEMS implantation may be considered a promising alternative.     

Management of occluded self-expanding biliary metal stents in malignant biliary disease

Background: Occlusion of self-expanding metal stents(SEMS) in malignant biliary obstruction occurs in up to 40% of patients. This study aimed to compare the different techniques to resolve stent occlusion in our collective of patients.Methods: Patients with malignant biliary obstruction and occlusion of biliary metal stent at a tertiary referral endoscopic center were retrospectively identified between April 1, 1994 and May 31, 2014. The clinical records were further analyzed regarding the characteristics of patients, malignant strictures, SEMS,management strategies, stent patency, subsequent interventions, survival time and case charges.Results: A total of 108 patients with biliary metal stent occlusion were identified. Seventy-nine of these patients were eligible for further analysis. Favored management was plastic stent insertion in 73.4% patients. Second SEMS were inserted in 12.7% patients. Percutaneous transhepatic biliary drainage and mechanical cleansing were conducted in a minority of patients. Further analysis showed no statistically significant difference in median overall secondary stent patency(88 vs. 143 days, P = 0.069), median survival time(95 vs. 192 days, P = 0.116), median subsequent intervention rate(53.4% vs. 40.0%, P = 0.501)and median case charge(€5145 vs. €3473, P = 0.803) for the treatment with a second metal stent insertion compared to plastic stent insertion. In patients with survival time of more than three months,significantly more patients treated with plastic stents needed re-interventions than patients treated with second SEMS(93.3% vs. 57.1%, P = 0.037).Conclusions: In malignant biliary strictures, both plastic and metal stent insertions are feasible strategies for the treatment of occluded SEMS. Our data suggest that in palliative biliary stenting, patients especially those with longer expected survival might benefit from second SEMS insertion. Careful patient selection is important to ensure a proper decision for either management strategy.     

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.     

良性胆管狭窄的内镜治疗

随着腹腔镜下胆囊切除术的不断开展,良性胆管狭窄的发生率逐渐增多.而内镜附属设备及内镜技术的不断发展,使内镜下治疗良性胆管狭窄逐渐成为一种有效的方法.此文就良性胆管狭窄的病因、诊断、插管以及内镜下治疗作一综述.     

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.     

Biodegradable biliary stents have a different effect than covered metal stents on the expression of proteins associated with tissue healing in benign biliary strictures

Background: Benign biliary strictures (BBS) are primarily treated endoscopically with covered self-expandable metal stents (CSEMS). Biodegradable biliary stents (BDBS) may be the future of endoscopic therapy of BBS. The aim was to assess the expression of proteins related to tissue healing in BBS compared with the intact bile duct (BD), and to study the protein expression after therapy with CSEMS or BDBS.

Methods: Pigs with ischemic BBS were endoscopically treated either with BDBS or CSEMS. Samples were harvested from pigs with intact BD (n?=?5), untreated BBS (n?=?5), and after six months of therapy with BDBS (n?=?4) or CSEMS (n?=?5) with subsequent histologic analysis. Two-dimensional electrophoresis with protein identification was performed to evaluate protein expression patterns.

Results: In BBS, the expression of galectin-2 and annexin-A4 decreased, compared to intact BD. Treatment with biodegradable stents normalized galectin-2 level; with CSEMS therapy it remained low. Transgelin expression of intact BD and BBS remained low after BDBS treatment but increased after CSEMS therapy. Histologic analysis did not show unwanted foreign body reaction or hyperplasia in the BD in either group.

Conclusions: The expression of proteins related to tissue healing in BBS is different after treatment with biodegradable stents and CSEMS. Treatment with biodegradable stents may bring protein expression towards what is seen in intact BD. BDBS seem to have a good biocompatibility.     

Placement of a fully covered self-expandable metal stent in a young patient with chronic pancreatitis

Plastic stent insertion is a treatment option for pancreatic duct stricture with chronic pancreatitis. However, recurrent stricture is a limitation after removing the plastic stent. Self-expandable metal stents have long diameters and patency. A metal stent has become an established management option for pancreatic duct stricture caused by malignancy but its use in benign stricture is still controversial. We introduce a young patient who had chronic pancreatitis and underwent several plastic stent insertions due to recurrent pancreatic duct stricture. His symptoms improved after using a fully covered self-expandable metal covered stent and there was no recurrence found at follow-up at the outpatient department.     

内镜超声引导下经胃穿刺覆膜金属支架引流胰腺假性囊肿的初步临床研究

目的评价临床应用胆道覆膜自膨式金属支架引流胰腺假性囊肿的有效性、可行性和安全性。方法回顾分析2013年9月至2014年5月在长海医院接受内镜超声（EUS）引导下经胃胰腺假性囊肿全覆膜自膨式金属支架引流的11例患者病例和随访资料。引流方法采用EUS引导下经胃壁穿刺至囊腔,置入导丝,用囊肿切开刀进行针道扩张,置入金属覆膜支架引流。术后定期随访,囊肿消失后拔除支架。评价操作成功率、治愈成功率、并发症发生率。结果11例患者均完成囊肿穿刺、全覆膜金属支架置入引流术,手术成功率为100％,2例患者并发感染,1例患者发生支架移位,无出血、穿孔、死亡病例。其中7例已完成支架拔除术,囊肿均完全消失。结论EUS引导下经胃穿刺胆道覆膜金属支架引流胰腺假性囊肿手术成功率、治愈率高,并发症发生率较低。     

Endoscopic treatment for benign biliary strictures: Can placement of a covered metallic stent be an option in refractory cases?

Background: Recently, endoscopic treatment has been attempted to counter benign biliary strictures. It is expected to be an alternative to surgical operation because of its lower morbidity and its convenience, but the long‐term results have not yet been sufficiently elucidated. Here, we evaluate the short‐ and long‐term results of endoscopic stenting in patients with benign biliary strictures, and also describe a new technique using a covered metallic stent (CMS) in the refractory cases. Methods: The charts of 22 consecutive patients with benign biliary stricture treated endoscopically at our institutions between December 1995 and December 2002 were analyzed retrospectively. Results: Stricture etiology was as follows: postoperative, nine; chronic pancreatitis, seven; primary sclerosing cholangitis (PSC), three; and other, three. The stent initially placed was a 7 Fr in 11 patients and a 10 Fr in 11 patients. Eighteen of 22 patients (82%) were successfully treated by the initial treatment, and stents were removed after a mean duration of 3.1 months (range: 1–14 months). In the remaining four patients, stents were exchanged once to four times after that, and a CMS was placed as the second endoprosthesis in two patients with chronic pancreatitis. These stents, including CMS, were finally removed from these four patients after a mean duration of 14.8 months (range: 8–22 months). Over a median follow‐up period of 26 months (range: 6–78 months), one recurrence has been observed, in which case a CMS was placed in a patient with chronic pancreatitis. The CMS was removed successfully 6 months after the insertion, and no recurrence was observed during the 6‐month follow‐up period. Conclusions: Endoscopic stenting for benign biliary stricture is an alternative to surgery because it shows satisfactory results. Placement of a CMS would also be an option in refractory strictures, such as those due in chronic pancreatitis, if the certainty of removal is proven by cumulative experience with a large number of patients.     

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.