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Journal of Digestive Diseases 2014; 15; 146–153

doi: 10.1111/1751-2980.12117

Original article

Management of benign biliary strictures with a novel retrievable self-expandable metal stent Bing HU,* Joseph W LEUNG,† Dao Jian GAO,* Tian Tian WANG* & Jun WU* *Department of Endoscopy, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai, China; and †Department of Gastroenterology and Hepatology, UC Davis Medical Center, Sacramento, California, USA

OBJECTIVE: Endoscopic placement of covered selfexpandable metal stent (SEMS) has gained popularity in the management of benign biliary strictures (BBS). The existing SEMS has been designed primarily to palliate malignant biliary obstruction and has a high frequency of stent migration, difficulty in retrieval and stricture recurrence after stent removal. This study aimed to design a novel retrievable SEMS dedicated to the treatment of extrahepatic BBS and evaluate its clinical efficacy and safety.

METHODS: A short fully covered SEMS (FCSEMS) with a retrieval lasso was designed for the specific treatment of BBS. A total of 45 patients with segmental extrahepatic BBS were included in this study. The stent was placed entirely inside the bile duct with only the retrieval lasso extending from the papilla. The stents

were recommended to be in situ for 6 to 12 months before removal. RESULTS: The FCSEMS was successfully placed in all 45 patients. In all, 33 patients had their FCSEMS successfully removed after a mean period of 8.6 ± 3.7 (range 2–15.5) months. Stent migration occurred in 9.1% of the patients. During a mean follow-up of 18.9 months after stent removal, recurrent stricture was found in 2 (6.1%) patients and was successfully treated with a second FCSEMS. Overall, the strictures resolved in 30/33 (90.9%) patients. CONCLUSIONS: Intraductal placement of a short FCSEMS is suitable for the treatment of segmental extrahepatic BBS. This new removable design offered prolonged stenting and drainage for BBS for up to one year with minimal complications.

KEY WORDS: benign biliary stricture, biliary injury, ERCP, liver transplantation, self-expandable metal stent (SEMS).

INTRODUCTION Correspondence to: Bing HU, Department of Endoscopy, Eastern Hepatobiliary Hospital, Second Military Medical University, 225 Changhai Road, Shanghai 200438, China. Email: [email protected] The paper was presented in part as a poster during the Digestive Disease Week in San Diego, CA, USA, 19–22 May 2012, and the abstract was published in Gastrointest Endosc 2012;75: AB375–6. Conflict of interest: None. © 2013 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd

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The etiologies of benign biliary strictures (BBS) differ among individuals, including postsurgical injury, anastomotic strictures following liver transplantation (LT) and chronic pancreatitis. Surgery has been the treatment of choice for extrahepatic BBS, usually involving a bilioenteric anastomosis between the bile duct and the small bowel. However, postoperative complications are common and occur in about 25% of patients with a recurrent stricture rate varying from 10% to 45%.1–4

Journal of Digestive Diseases 2014; 15; 146–153

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Endoscopic therapy, including gradual dilatation and the placement of multiple plastic stents, plays an increasing role in the management of BBS. Plastic stents are usually exchanged at regular intervals (at an average of 3 months) until the stricture is resolved. Although successful stricture resolution has been achieved in 64% to 97.5% of patients5–8 endoscopic therapy with multiple sessions is required, resulted in increased costs and risks for the patients. Covered self-expandable metal stent (SEMS) has been used to treat BSS.9–12 However, the currently available SEMS were designed primarily for the palliation of malignant biliary obstruction. Complications of SEMS therapy include stent migration occurring in up to 38% of patients, with difficulty or even failure in subsequent stent removal.13–18 In this study, we aimed to report an improved design of a new removable SEMS for the management of BBS in a prospective series of 45 patients. PATIENTS AND METHODS Design of a new SEMS A novel fully covered SEMS (FCSEMS) is made with braided nitinol wire and covered entirely with a silicon membrane (using an immersing technique). The stent is 12 mm at the proximal opening and 10 mm at the distal opening. The stent is relatively short, being only 4–6 cm in length, which allows it to be placed entirely within the bile duct. There are several visual markers on either end of the stent to assist with proper placement. A retrieval lasso (6 cm in length, made of nylon suture or nitinol wire) is attached to the distal end of the stent and is left outside the papilla in the duodenum after deployment. The distal end of the stent becomes tapered when the lasso is pulled, thus facilitating its removal (Fig. 1). The FCSEMS is mounted on a 9-Fr delivery system and its deployment is very similar to other SEMS. The stent shortens to about 40% of its collapsed length when fully expanded. Study population The clinical evaluation was performed at the Eastern Hepatobiliary Hospital (EHBH; Shanghai, China). The study protocol was approved by the Institutional Review Board for human research of the EHBH and written informed consent was obtained from each patients. Only patients with short (1.5 cm from the hepatic bifurcation and ampulla. Exclusion criteria were: strictures of unclear etiology or suspected underlying malignancy, being a living donor transplantation recipient, having undergone hepaticojejunostomy, stricture involving the liver hilum, clinical evidence of duodenal obstruction and patients who refused to give their consent. From July 2008 to April 2012, a total of 87 patients with BBS underwent endoscopic therapy. Among them, 38 patients with multiple strictures involving the hepatic hilum and four with distal long segment BBS due to chronic pancreatitis were treated with either multiple plastic stents (n = 40) or other type of SEMS (n = 2) placement. The remaining 45 patients were enrolled in the current study, including 36 men and 9 women with a mean age of 52.3 ± 12.2 years (range 30–85 years). The etiology of the bile duct strictures included anastomotic stricture following LT (n = 30), postoperative injury (n = 13) and chronic pancreatitis (n = 2). All patients had one single short stricture segment (5–10 mm >10–20 mm Pre-procedure bilirubin (μmol/L, mean ± SD) Previous endoscopic or percutaneous interventions (n)

36:9 52.3 ± 12.2 13 30 2 34 9 2 7 33 5 48.7 ± 45.4 3

CBD, common bile duct; F, female; LT, liver transplantation; M, male; SD, standard deviation.

Boston Scientific, Marlborough, MA, USA) was introduced through the stricture. If the stricture was considered suitable for FCSEMS placement, as stated above, small sphincterotomy was routinely performed and the stricture was dilated initially using an 8.5-Fr dilation catheter (Cook Medical, Winston-Salem, NC, USA), followed by a dilation balloon of 6–10 mm in diameter and 3 cm in length (Cook Medical) before FCSEMS placement. Under fluoroscopy guidance, the stent was deployed across the stricture and left completely inside the bile duct, with only the retrieval lasso left outside the papilla. The proximal end of the stent was placed below the bifurcation to ensure effective drainage of both intra-hepatic ducts before scope withdrawal. Clinical follow-up of the patients All patients were followed up clinically with repeat liver function tests within the first week of stent placement. Subsequent follow-ups were conducted at 1 to 2-monthly intervals at the Outpatient Center or by phone. The FCSEMS was kept in situ for at least 6 months. Any changes in symptoms or laboratory test results were recorded. Stent malfunction was suspected if the patient had worsening liver function or appeared with symptoms of cholangitis. An immediate endoscopic intervention was performed and the FCSEMS was removed if stent malfunction was confirmed; otherwise, a repeat endoscopy was performed

on schedule to remove the stent by pulling on the retrieval lasso with a pair of grasping forceps. The entire stent could be removed through the endoscope channel. The ease of stent removal was recorded. Bile duct clearance was confirmed using standard retrieval balloons or Dormia baskets. Occlusion cholangiogram was performed to document the resolution of the stricture, defined as an obvious opening up of the stenosis compared with the previous imaging and the easy passage of an inflated stone retrieval balloon. The patients were then followed up closely for any symptoms that suggested stricture recurrence. RESULTS Following stricture dilatation, the FCSEMS placement was successful in all 45 patients (4-cm stents in 43 patients and 6-cm stents in 2 patients) without remarkable difficulty. Two mild procedure-related complications occurred, among which one patient developed post-ERCP pancreatitis that responded to conservative treatment within 3 days while the other had cholangitis and required additional endoscopic removal of biliary sludge and nasobiliary drainage for 3 days. Most patients had successful jaundice control, with a mean serum bilirubin level decreased to 20.3 ± 23.4 μmol/L (range 5.8–78.0 μmol/L) one week after the placement of stent. During the follow-up, two patients required early removal of the FCSEMS. One patient with previous bile leakage and complex intra-abdominal infection had continuing fever and abnormal liver function. Imaging showed the formation of new abscesses in the donor liver. A repeat ERCP was performed 1.5 months after the stent placement to remove the FCSEMS and nasobiliary drainage was performed to control the infection. Another patient had no amelioration of jaundice and was found to have chronic rejection from the stent. His stent was removed after only one month. Two patients developed an anastomotic stricture following LT for hepatocellular carcinoma. Their tumor recurred in the donor liver and lungs and died 8 and 10 months, respectively, after FCSEMS insertion without removal. Another 85-year-old patient with a postoperative stricture had successful control of his biliary symptoms after FCSEMS placement and refused to have the stent removed. The remaining patients all showed a significant improvement in their symptoms and liver function after the placement of stent. They remained relatively asymptomatic during the follow-up and all patients returned for the scheduled stent removal.

© 2013 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd

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Distal stent migration was found in three asymptomatic patients, which should be considered a late complication.

cant improvement in the liver function. Overall stricture resolution was achieved in 90.9% (30/33) patients (Fig. 3).

At the time of writing only seven patients still had stents in situ awaiting scheduled removal. The other 33 patients had their FCSEMS successfully removed after a mean period of 8.6 ± 3.7 months (range 2–15.5 months). Most stents were removed using the retrieval lasso and through the scope channel. In five cases the retrieval lasso was broken and a pair of foreign–bodygrasping forceps was advanced into bile duct to capture and remove the stents. There was no failure in stent removal. Subsequent occlusion cholangiography demonstrated stricture resolution in 30 patients (Fig. 2). In three patients with LT, the stents had migrated distally because the strictures were too close to the bifurcation and thus failed to respond to stenting. They underwent subsequent placement of multiple plastic stents. At the time of analysis, the mean follow-up period was 18.9 ± 12.3 months (range 3–46 months) after stent removal. Two of the 30 patients with stricture resolution had stricture recurrence 3 months after the stent removal and were treated with a second FCSEMS which resulted in stricture resolution after 7.6 and 10.1 months, respectively. All other patients remained symptom free with signifi-

DISCUSSION

a

b

Management of BBS is technically difficult and traditional surgical treatment often requires complex bilioenteric anastomosis. Endoscopic treatment involves stricture dilatation and a placement of plastic stents with repeated changes and an increasing number of stents until the stricture can be fully resolved. Although endoscopic placement of plastic stents is considered the first-line treatment for post-LT and postoperative biliary strictures,5,6,8,19,20 stent occlusion and cholangitis occur frequently which adversely affect the clinical outcome and the quality of life of the patients’. 21–23 The SEMS has a strong radial expansion force and is potentially more effective for the dilatation of bile duct stricture or stenosis and also provides a longer stent patency for drainage. SEMS placement usually requires one session of endoscopic therapy at a relatively low cost and risk for the patient. Uncovered SEMS are not used for treating BBS because the open mesh design could induce tissue reaction, resulting in

c

d

Figure 2. (a) A dominant biliary stricture following laparoscopic cholecystectomy is found on endoscopic retrograde cholangiopancreatography. (b) A fully covered self-expandable metal stent is placed across the bile duct stricture. (c) Five months after the placement of stent, the stent expands fully with (d) complete resolution of the stricture.

© 2013 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd

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B Hu et al.

Journal of Digestive Diseases 2014; 15; 146–153 The unique design of our novel short FCSEMS caters for the relatively short length of BBS. A long SEMS is more likely to damage the remaining normal bile duct, leading to inflammation or tissue hyperplasia. Complete internal placement of a short stent is more suitable for segmental BBS, allowing the local expansion force to dilate the stricture, with limited involvement of the normal bile duct. Furthermore, an indwelling stent placed entirely above the papilla can preserve the sphincter function, thus preventing ascending reflux and reducing the risk of cholangitis. This is especially helpful in patients who are immunosuppressed for transplantation. The added feature of retrieval lasso left outside the papilla facilitates the collapse of the stent and its subsequent removal.16 However, such a short FCSEMS design is not suitable for the treatment of intrahepatic stricture, or stenosis too close to either the hilar bifurcation or papilla.

Figure 3. Overall outcomes of 45 benign biliary strictures (BBS) patients treated with a novel fully covered selfexpandable metal stent (FCSEMS). CP, chronic pancreatitis; LT, liver transplantation; PI, postoperative, injury.

tissue ingrowth and stent blockage. Tissue ingrowth could also prevent subsequent stent removal. Removable SEMS for the endoscopic treatment of BBS was first reported by Bruno et al.24 in 2005, describing the temporary use of covered SEMS in patients with distal bile duct stricture that is associated with chronic pancreatitis. All stents were successfully removed after 3–6 months with a resolution of the stricture in three of the four patients. Since then, different types of covered SEMS have been used in BBS for varying durations and have achieved successful stricture resolution in 40% to 90% of the patients (Table 2).9–18,24–27 The early covered SEMS were designed primarily for the palliation of biliary malignancies and it was technically feasible to remove such a stent if the distal tip was placed across the papilla. However, it was difficult to retrieve the stent if it was left in the bile duct for over 6 months or it had migrated proximally.9,12,14,25,26 The early design of FCSEMS was complicated by frequent stent migration, which occurred in 4.8–38% of the cases.9,12–14,25,27 Moreover, the relatively short duration (

Management of benign biliary strictures with a novel retrievable self-expandable metal stent.

Endoscopic placement of covered self-expandable metal stent (SEMS) has gained popularity in the management of benign biliary strictures (BBS). The exi...
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