Risk Factors for Prolonged Hospital Stay after Endoscopy

Background/Aims@#The recovery room used after endoscopy has limited capacity, and an efficient flow of the endoscopy unit is desired. We investigated the duration of hospital stay after endoscopy and the risk factors for prolonged hospital stay among outpatients. @*Methods@#We retrospectively studied consecutive patients who underwent esophagogastroduodenoscopy or colonoscopy at the Toyoshima Endoscopy Clinic. We collected data on age, sex, body weight, midazolam and pethidine dosage, respiratory depression during endoscopy, and duration of hospital stay after endoscopy (scope out to check out). Risk factors for prolonged hospital stay (>100 minutes) were identified using multiple logistic regression analysis. @*Results@#We enrolled 3,898 patients, including 3,517 (90.2%) patients tested under sedation and 381 (9.8%) patients tested without sedation. Overall, 442 (11.3%) patients had prolonged stay (>100 min). The mean time difference between sedation group and non-sedation group was 44.2 minutes for esophagogastroduodenoscopy and 39.1 minutes for colonoscopy. Age (odds ratio [OR], 1.025; 95% confidence interval [CI], 1.014−1.036), female sex (OR, 1.657; 95% CI, 1.220−2.249), and midazolam dose (OR, 1.019; 95% CI, 1.013−1.026) were independently associated with prolonged hospital stay after esophagogastroduodenoscopy, with similar results for colonoscopy. @*Conclusions@#Old age, female sex, and midazolam dose were independent risk factors for prolonged hospital stay after endoscopy.

A Meta-Analysis of Slow Pull versus Suction for Endoscopic Ultrasound-Guided Tissue Acquisition

Background/Aims@#Endoscopic ultrasound (EUS)-guided tissue acquisition is widely utilized as a diagnostic modality for intra-abdominal masses, but there remains debate regarding which suction technique, slow pull (SP) or conventional suction (CS), is better. A meta-analysis of reported studies was conducted to compare the diagnostic yields of SP and CS during EUS-guided tissue acquisition. @*Methods@#We conducted a systematic electronic search using MEDLINE/PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials to identify clinical studies comparing SP and CS. We meta-analyzed accuracy, sensitivity, blood contamination and cellularity using the random-effects model. @*Results@#A total of 17 studies (seven randomized controlled trials, four prospective studies, and six retrospective studies) with 1,616 cases were included in the analysis. Compared to CS, there was a trend toward better accuracy (odds ratio [OR], 1.48; 95% confidence interval [CI], 0.97 to 2.27; p=0.07) and sensitivity (OR, 1.67; 95% CI, 0.95 to 2.93; p=0.08) with SP and a significantly lower rate of blood contamination (OR, 0.48; 95% CI, 0.33 to 0.69; p<0.01). However, there was no significant difference in cellularity between SP and CS, with an OR of 1.28 (95% CI, 0.68 to 2.40; p=0.45). When the use of a 25-gauge needle was analyzed, the accuracy and sensitivity of SP were significantly better than those of CS, with ORs of 4.81 (95% CI, 1.99 to 11.62; p<0.01) and 4.69 (95% CI, 1.93 to 11.40; p<0.01), respectively. @*Conclusions@#Compared to CS, SP appears to provide better accuracy and sensitivity in EUSguided tissue acquisition, especially when a 25-gauge needle is used.

A Prospective Multicenter Study of Partially Covered Metal Stents in Patients Receiving Neoadjuvant Chemotherapy for Resectable and Borderline Resectable Pancreatic Cancer: BTS-NAC Study

Background/Aims@#The aim of this study was to evaluate the safety and efficacy of partially covered self-expandable metallic stents (PCSEMS) in patients undergoing neoadjuvant chemo (radio) therapy (NAC) for pancreatic cancer (PC). @*Methods@#This was a prospective multicenter study to evaluate the safety and efficacy of PCSEMS in patients receiving NAC for resectable and borderline resectable PC. The primary endpoint was the rate of recurrent biliary obstruction (RBO). @*Results@#Twenty-six patients with PC (three with resectable PC and 23 with borderline resectable PC) who underwent NAC at seven Japanese centers were included in the analysis. Both the technical and functional success rates of PCSEMS placement were 100%. Early stent-related complications were observed in three patients (11.5%): mild pancreatitis (n=2) and mild liver abscess (n=1). The median time to surgery or palliation was 4.0 months. Surgical resection was eventually performed in 73.1% of patients, and stent removal during surgery was successful in all patients. RBO was observed in nine patients (34.6%): seven with stent occlusion, one with kinking and one with migration. The RBO rates in resected cases and nonresected cases were 36.8% and 28.6%, respectively. @*Conclusions@#Biliary drainage by PCSEMS was safe and feasible in patients undergoing NAC for resectable and borderline resectable PC.

A Meta-Analysis of Slow Pull versus Suction for Endoscopic Ultrasound-Guided Tissue Acquisition

Background/Aims@#Endoscopic ultrasound (EUS)-guided tissue acquisition is widely utilized as a diagnostic modality for intra-abdominal masses, but there remains debate regarding which suction technique, slow pull (SP) or conventional suction (CS), is better. A meta-analysis of reported studies was conducted to compare the diagnostic yields of SP and CS during EUS-guided tissue acquisition. @*Methods@#We conducted a systematic electronic search using MEDLINE/PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials to identify clinical studies comparing SP and CS. We meta-analyzed accuracy, sensitivity, blood contamination and cellularity using the random-effects model. @*Results@#A total of 17 studies (seven randomized controlled trials, four prospective studies, and six retrospective studies) with 1,616 cases were included in the analysis. Compared to CS, there was a trend toward better accuracy (odds ratio [OR], 1.48; 95% confidence interval [CI], 0.97 to 2.27; p=0.07) and sensitivity (OR, 1.67; 95% CI, 0.95 to 2.93; p=0.08) with SP and a significantly lower rate of blood contamination (OR, 0.48; 95% CI, 0.33 to 0.69; p<0.01). However, there was no significant difference in cellularity between SP and CS, with an OR of 1.28 (95% CI, 0.68 to 2.40; p=0.45). When the use of a 25-gauge needle was analyzed, the accuracy and sensitivity of SP were significantly better than those of CS, with ORs of 4.81 (95% CI, 1.99 to 11.62; p<0.01) and 4.69 (95% CI, 1.93 to 11.40; p<0.01), respectively. @*Conclusions@#Compared to CS, SP appears to provide better accuracy and sensitivity in EUSguided tissue acquisition, especially when a 25-gauge needle is used.

Impact of the Sensitivity to Empiric Antibiotics on Clinical Outcomes after Biliary Drainage for Acute Cholangitis

Background/Aims@#Empiric antibiotics are given in combina-tion with biliary drainage for acute cholangitis but sometimes turn out to be insensitive to microorganisms in blood and bile. Clinical outcomes were compared according to sensitiv-ity to microorganisms detected in blood and bile culture to evaluate the impact of sensitivity to empiric antibiotics in cholangitis. @*Methods@#Consecutive patients who underwent biliary drainage for acute cholangitis were retrospectively studied. Clinical outcomes such as 30-day mortality, length of hospital stay and high care unit stay, organ dysfunction and duration of fever were compared in three groups: group A (sensitive to both blood and bile culture), group B (sensitive to blood culture alone) and group C (insensitive to both blood and bile culture). @*Results@#Eighty episodes of cholangitis were classified according to sensitivity results: 42, 32 and six in groups A, B and C. Escherichia coli and Klebsiella were two major pathogens. There were no significant differences in 30-day mortality rate (7%, 0%, and 0%, p=0.244), length of hospital stay (28.5, 21.0, and 20.5 days, p=0.369), organ dysfunc­tion rate (14%, 25%, and 17%, p=0.500), duration of fever (4.3, 3.2, and 3.5 days, p=0.921) and length of high care unit stay (1.4, 1.2, and 1.7 days, p=0.070) in groups A, B and C. Empiric antibiotics were changed in 11 episodes but clinical outcomes appeared to be non-inferior even in 31episodes of cholangitis who were on inadequate antibiotics throughout the course. @*Conclusions@#Sensitivity of empiric antibiotics was not associated with clinical outcomes in acute cholangitis.

Endoscopic Ultrasound-Guided Tissue Acquisition by 22-Gauge Franseen and Standard Needles for Solid Pancreatic Lesions

Background/Aims@#Recently, a three-plane symmetric nee-dle with Franseen geometry was developed for endoscopic ultrasound-guided fine needle biopsy (EUS-FNB). In this ret-rospective study, tissue acquisition per pass was compared between 22-gauge Franseen FNB and standard fine needle aspiration (FNA) needles in patients with solid pancreatic le-sions. @*Methods@#Consecutive patients who underwent EUSFNA or EUS-FNB for solid pancreatic lesions between Octo-ber 2014 and March 2018 were retrospectively studied. The tissue acquisition rate and the diagnostic performance per session, per pass, and at first pass were compared. @*Results@#A total of 663 passes (300 by the FNB needle and 363 by the standard FNA needle) were performed in 154 patients (71 FNB and 83 FNA). The tissue acquisition rate per session and at first pass in the FNB and FNA groups was 100% and 95% (p=0.13) and 87% and 69% (p=0.007), respectively. The multivariate analysis revealed that among the patients, EUS-FNB (odds ratio, 3.07; p=0.01) was associated with a higher first-pass tissue acquisition rate. While the tissue ac-quisition rate reached a plateau after the 4th pass with FNA, it reached a plateau after the 2nd pass with FNB. Among the 129 malignant cases, the histological tissue acquisition rate per session was similar (100% and 94%), but the sensitivity by histology alone per session was higher for FNB than for FNA (93% and 73%, p<0.01). @*Conclusions@#The results of our retrospective analysis indicated that compared with a standard FNA needle, a 22-gauge Franseen FNB needle was associated with a higher first-pass tissue acquisition rate.

Management of Difficult Bile Duct Stones by Large Balloon, Cholangioscopy, Enteroscopy and Endosonography

Endoscopic management of bile duct stones is now the standard of care, but challenges remain with difficult bile duct stones. There are some known factors associated with technically difficult bile duct stones, such as large size and surgically altered anatomy. Endoscopic mechanical lithotripsy is now the standard technique used to remove large bile duct stones, but the efficacy of endoscopic papillary large balloon dilatation (EPLBD) and cholangioscopy with intraductal lithotripsy has been increasingly reported. In patients with surgically altered anatomy, biliary access before stone removal can be technically difficult. Endotherapy using two new endoscopes is now utilized in clinical practice: enteroscopy-assisted endoscopic retrograde cholangiopancreatography and endoscopic ultrasound-guided antegrade treatment. These new approaches can be combined with EPLBD and/or cholangioscopy to remove large bile duct stones from patients with surgically altered anatomy. Since various endoscopic procedures are now available, endoscopists should learn the indications, advantages and disadvantages of each technique for better management of bile duct stones.

Current Status of Endoscopic Ultrasound Techniques for Pancreatic Neoplasms

Endoscopic ultrasound (EUS) now plays an important role in the management of pancreatic neoplasms. There are various types of pancreatic neoplasms, from benign to malignant lesions, and the role of EUS ranges from the imaging diagnosis to treatment. EUS is useful for the detection, characterization, and tissue acquisition of pancreatic lesions. Recent advancement of contrast-enhanced harmonic EUS and elastography enables better characterization of pancreatic lesions. In addition to these enhanced EUS imaging techniques, EUS-guided tissue acquisition is now the standard procedure to establish the pathological diagnosis of pancreatic neoplasms. While these diagnostic roles of EUS have been established, EUS-guided interventions such as ablation and drainage are also increasingly utilized in the management of pancreatic neoplasms. However, most of these EUS-guided interventions are not yet standardized in terms of techniques and devices and thus need further investigations.

Endoscopic Ultrasound-Guided Biliary Drainage for Benign Biliary Diseases

Although endoscopic retrograde cholangiopancreatography (ERCP) is the first-line treatment for benign biliary diseases, this procedure is technically difficult in some conditions such as a surgically altered anatomy and gastric outlet obstruction. After a failed ERCP, a surgical or a percutaneous approach is selected as a rescue procedure; however, various endoscopic ultrasound (EUS)-guided interventions are increasingly utilized in pancreatobiliary diseases, including EUS-guided rendezvous for failed biliary cannulation, EUS-guided antegrade treatment for stone management, and EUS-guided hepaticogastrostomy for anastomotic strictures in patients with a surgically altered anatomy. There are some technical hurdles in EUS-guided interventions for benign biliary diseases owing to the difficulty in puncturing a relatively small bile duct and in subsequent guidewire manipulation, as well as the lack of dedicated devices. A recent major advancement in this field is the introduction of a 2-step approach, in which EUS-guided drainage is placed in the first session and antegrade treatment is performed in subsequent sessions. This approach allows the use of various techniques such as mechanical lithotripsy and cholangioscopy without a risk of bile leak. In summary, EUS-guided interventions are among the treatment options for benign biliary diseases; however, standardization of the procedure and development of a treatment algorithm are needed.

Endoscopic Ultrasound-Guided Biliary Drainage for Unresectable Hilar Malignant Biliary Obstruction

Endoscopic transpapillary biliary drainage is the current standard of care for unresectable hilar malignant biliary obstruction (MBO) and bilateral metal stent placement is shown to have longer patency. However, technical and clinical failure is possible and percutaneous transhepatic biliary drainage (PTBD) is sometimes necessary. Endoscopic ultrasound-guided biliary drainage (EUS-BD) is increasingly being reported as an alternative rescue procedure to PTBD. EUS-BD has a potential advantage of not traversing the biliary stricture and internal drainage can be completed in a single session. Some approaches to bilateral biliary drainage for hilar MBO under EUS-guidance include a bridging method, hepaticoduodenostomy, and a combination of EUS-BD and transpapillary biliary drainage. The aim of this review is to summarize data on EUS-BD for hilar MBO and to clarify its advantages over the conventional approaches such as endoscopic transpapillary biliary drainage and PTBD.

Groove Pancreatitis: Endoscopic Treatment via the Minor Papilla and Duct of Santorini Morphology

BACKGROUND/AIMS: Groove pancreatitis (GP) is an uncommon disease involving the pancreaticoduodenal area. Possible pathogenesis includes obstructive pancreatitis in the duct of Santorini and impaired communication with the duct of Wirsung, minor papilla stenosis, and leakage causing inflammation. Limited data regarding endoscopic treatment have been published. METHODS: Seven patients with GP receiving endoscopic treatment were reviewed. The morphology of the pancreatic duct was evaluated by a pancreatogram. Endoscopic dilation of the minor papilla and drainage of the duct of Santorini were performed. RESULTS: There were two pancreatic divisum cases, one ansa pancreatica case and four impaired connections between the duct of Santorini and the main pancreatic duct. Three to 31 sessions of endoscopy, with 2 to 24 sessions of transpapillary stenting and dilation, were performed. Interventions through the minor papilla were successfully performed in six of seven cases. The pancreatic stenting duration ranged from 2 to 87 months. Five patients with evidence of chronic pancreatitis (CP) tended to receive more endoscopic interventions than did the two patients without CP (2–24 vs 2, respectively) for GP and other complications associated with CP. CONCLUSIONS: Disconnection or impairment of communication between the ducts of Santorini and Wirsung was observed in all cases of GP. No surgery was required, and endoscopic minor papilla dilation and drainage of the duct of Santorini were feasible for the treatment of GP.

A Novel Partially Covered Self-Expandable Metallic Stent with Proximal Flare in Patients with Malignant Gastric Outlet Obstruction

BACKGROUND/AIMS: Endoscopic placement of self-expandable metal stents (SEMSs) has emerged as a palliative treatment for malignant gastric outlet obstruction (GOO). Although covered SEMSs can prevent tumor ingrowth, frequent migration of covered SEMSs may offset their advantages in preventing tumor ingrowth. METHODS: We conducted this multicenter, single-arm, retrospective study at six tertiary referral centers to evaluate the safety and efficacy of a partially covered SEMS with an uncovered large-bore flare at the proximal end as an antimigration system in 41 patients with symptomatic malignant GOO. The primary outcome was clinical success, and the secondary outcomes were technical success, stent dysfunction, adverse events, and survival after stent placement. RESULTS: The technical and clinical success rates were 100% and 95%, respectively. Stent dysfunctions occurred in 17 patients (41%), including stent migration in nine (23%), tumor ingrowth in one (2%), and tumor overgrowth in four (10%). Two patients (5%) developed adverse events: one pancreatitis and one perforation. No procedure-related death was observed. CONCLUSIONS: A novel partially covered SEMS with a large-bore flare proximal end was safe and effective for malignant GOO but failed to prevent stent migration. Further research is warranted to develop a covered SEMS with an optimal antimigration system.

Antireflux Metal Stent as a First-Line Metal Stent for Distal Malignant Biliary Obstruction: A Pilot Study

BACKGROUND/AIMS: In distal malignant biliary obstruction, an antireflux metal stent (ARMS) with a funnel-shaped valve is effective as a reintervention for metal stent occlusion caused by reflux. This study sought to evaluate the feasibility of this ARMS as a first-line metal stent. METHODS: Patients with nonresectable distal malignant biliary obstruction were identified between April and December 2014 at three Japanese tertiary centers. We retrospectively evaluated recurrent biliary obstruction and adverse events after ARMS placement. RESULTS: In total, 20 consecutive patients were included. The most common cause of biliary obstruction was pancreatic cancer (75%). Overall, recurrent biliary obstruction was observed in seven patients (35%), with a median time to recurrent biliary obstruction of 246 days (range, 11 to 246 days). Stent occlusion occurred in five patients (25%), the causes of which were sludge and food impaction in three and two patients, respectively. Stent migration occurred in two patients (10%). The rate of adverse events associated with ARMS was 25%: pancreatitis occurred in three patients, cholecystitis in one and liver abscess in one. No patients experienced non-occlusion cholangitis. CONCLUSIONS: The ARMS as a first-line biliary drainage procedure was feasible. Because the ARMS did not fully prevent stent dysfunction due to reflux, further investigation is warranted.

Recent Development of Techniques and Devices in Colorectal Endoscopic Submucosal Dissection

Colorectal endoscopic submucosal dissection (ESD) is now a well-established endoscopic treatment for early-stage colorectal neoplasms, especially in Asian countries, including Japan. Despite the spread of colorectal ESD, there are still situations in which achieving successful submucosal dissection is difficult. Various novel techniques and devices have been developed to overcome these difficulties, and past reports have shown that some of these strategies can be applied to colorectal ESD. We review several recent developments in the field. The techniques reviewed include the pocket creation method and traction methods and the devices reviewed include the overtube with balloon and electrosurgical knives with water-jet function. These improved techniques and devices can facilitate safer, more reliable ESDs and expand its applicability and acceptability all over the world.

Endoscopic ultrasound-guided biliary drainage: Complications and their management

Endoscopic ultrasound-guided biliary drainage (EUS-BD), EUS-guided choledochoduodenostomy (EUS-CDS), and EUS-guided hepaticogastrostomy (EUS-HGS) can effectively palliate obstructive jaundice, but have not been well established yet. The incidence of complications is about 30% in EUSBD and higher for EUS-HGS. Several complications have been reported such as bleeding, perforation and peritonitis. Bleeding occurs due to puncture of portal vein, hepatic vein and artery, and we should use color Doppler. When a cautery dilator is used for fistula dilation, burn effects may cause delayed bleeding. Endoscopic hemostasis is only effective for anastomotic bleeding and embolization with interventional radiology technique is required for pseudo aneurysm. There are some types of perforation: failed stent placement after puncture or fistula dilation, double puncture during CDS procedure, and stent migration. Peritonitis with perforation requires surgery and can be fatal. Stent migration before mature fistula formation causes severe peritonitis because EUS-BD makes fistula between two unattached organs. Stents with flaps or long covered self-expandable metallic stents (cSEMSs) are effective to prevent migration. Recent development of lumen apposing stents may reduce early migration in EUS-CDS. Peritonitis without migration can be due to 1) leakage of bile juice or gastric/duodenal contents during EUS-BD or 2) leakage along the placed stent. We should make procedure time as short as possible, and cSEMSs reduce bile leak along the stent by occluding the dilated fistula. In summary, we should understand the mechanism of complications and the technique to prevent and manage complications. Development of dedicated devices to increase the success rate and reduce complications is required.

Placement of multiple metal stents for malignant intrahepatic biliary obstruction via an endoscopic ultrasound-guided choledochoduodenostomy fistula

Endoscopic ultrasound-guided choledochoduodenostomy [EUS-CDS] using a fully-covered self-expandable metal stent [SEMS] is increasingly used as an alternative to failed endoscopic retrograde cholangiopancreatography. An EUS-CDS fistula can provide endoscopists with a new approach route for intrahepatic bile ducts. Here, we present successful placement of multiple SEMS for intrahepatic biliary obstruction via an EUS-CDS fistula

Complications Related to Gastric Endoscopic Submucosal Dissection and Their Managements

Endoscopic submucosal dissection (ESD) for early gastric cancer is a well-established procedure with the advantage of resection in an en bloc fashion, regardless of the size, shape, coexisting ulcer, and location of the lesion. However, gastric ESD is a more difficult and meticulous technique, and also requires a longer procedure time, than conventional endoscopic mucosal resection. These factors naturally increase the risk of various complications. The two most common complications accompanying gastric ESD are bleeding and perforation. These complications are known to occur both intraoperatively and postoperatively. However, there are other rare but serious complications related to gastric ESD, including aspiration pneumonia, stenosis, venous thromboembolism, and air embolism. Endoscopists should have sufficient knowledge about such complications and be prepared to deal with them appropriately, as successful management of complications is necessary for the successful completion of the entire ESD procedure.

Severe Bleeding and Perforation Are Rare Complications of Endoscopic Ultrasound-Guided Fine Needle Aspiration for Pancreatic Masses: An Analysis of 3,090 Patients from 212 Hospitals

BACKGROUND/AIMS: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is useful for the pathological diagnosis of pancreatic masses, but patients are susceptible to severe bleeding and perforation. Because the incidence and severity of these complications have not been fully evaluated. METHODS: We aimed to evaluate severe bleeding and perforation after EUS-FNA for pancreatic masses using large-scale data derived from a Japanese nationwide administrative database. RESULTS: In total, 3,090 consecutive patients from 212 low- to high-volume hospitals were analyzed. Severe bleeding requiring transfusion or endoscopic treatment occurred in seven patients (0.23%), and no perforation was observed. No patient mortality was recorded within 30 days of EUS-FNA. The rate of severe bleeding in low-volume hospitals was significantly higher than that in medium- and high-volume hospitals (0.48% vs 0.10%, p=0.045). CONCLUSIONS: Severe bleeding and perforation following EUS-FNA for pancreatic masses are rare, and the procedure is safe.

Total Cholesterol Level for Assessing Pancreatic Insufficiency Due to Chronic Pancreatitis

BACKGROUND/AIMS: To determine the nutritional markers important for assessing the degree of pancreatic insufficiency due to chronic pancreatitis in routine clinical practice. METHODS: A total of 137 patients with chronic pancreatitis were followed up for more than 1 year. They were divided into two groups: a pancreatic diabetes mellitus (DM) group, consisting of 47 patients undergoing medical treatment for DM of pancreatic origin, and a nonpancreatic DM group, consisting of 90 other patients (including 86 patients without DM). Serum albumin, prealbumin, total cholesterol, cholinesterase, magnesium, and hemoglobin were compared between the two groups. RESULTS: The total cholesterol was significantly lower in the pancreatic than the nonpancreatic DM group (164 mg/dL vs 183 mg/dL, respectively; p=0.0028). Cholinesterase was significantly lower in the former group (263 U/L vs 291 U/L, respectively; p=0.016). Among the 37 patients with nonalcoholic pancreatitis, there was no difference in the cholinesterase levels between the pancreatic and nonpancreatic (296 U/L vs 304 U/L, respectively; p=0.752) DM groups, although cholesterol levels remained lower in the former (165 mg/dL vs 187 mg/dL, respectively; p=0.052). CONCLUSIONS: Cholinesterase levels are possibly affected by concomitant alcoholic liver injury. The total cholesterol level should be considered when assessing pancreatic insufficiency due to chronic pancreatitis.

A Novel, Fully Covered Laser-Cut Nitinol Stent with Antimigration Properties for Nonresectable Distal Malignant Biliary Obstruction: A Multicenter Feasibility Study

BACKGROUND/AIMS: Stent migration occurs frequently, but the prevention of complications resulting from covered self-expandable metal stents (C-SEMSs) remains unresolved. We prospectively assessed a newly developed C-SEMS, a modified covered Zeo stent (m-CZS), in terms of its antimigration effect. METHODS: Between February 2010 and January 2011, an m-CZS was inserted into 42 patients (31 initial drainage cases and 11 reintervention cases) at a tertiary referral center and three affiliated hospitals. The laser-cut stent was flared for 1.5 cm at both ends, with a 1 cm raised bank located 1 cm in from each flared end. The main outcome of this study was the rate of stent migration, and secondary outcomes were the rate of recurrent biliary obstruction (RBO), the time to RBO, the frequencies of complications, and overall survival. RESULTS: Of the 31 patients with initial drainage, stent migration occurred in four (12.9%, 95% confidence interval, 5.1% to 29.0%), with a mean time of 131 days. RBO occurred in 18 (58%), with a median time to RBO of 107 days. Following previous C-SEMS migration, seven of 10 patients (70%) did not experience m-CZS migration until death. CONCLUSIONS: m-CZSs with antimigration properties effectively, although not completely, prevented stent migration after stent insertion.