Uncovered Self-expandable Metal Stents Research Articles

Role of advanced endoscopy in the management of inflammatory digestive diseases (pancreas and biliary tract).

The progress of endoscopic diagnosis and treatment for inflammatory diseases of the biliary tract and pancreas have been remarkable. Endoscopic ultrasonography (EUS) and EUS-elastography are used for the diagnosis of early chronic pancreatitis and evaluation of endocrine and exocrine function in chronic pancreatitis. Notably, extracorporeal shock wave lithotripsy and electrohydraulic shock wave lithotripsy have improved the endoscopic stone removal rate in patients for whom pancreatic stone removal is difficult. Studies have reported the use of self-expanding metal stents for stent placement for pancreatic duct stenosis and EUS-guided pancreatic drainage for refractory pancreatic duct strictures. Furthermore, EUS-guided drainage using a double-pigtailed plastic stent has been performed for the management of symptomatic pancreatic fluid collection after acute pancreatitis. Recently, lumen-apposing metal stents have led to advances in the treatment of walled-off necrosis after acute pancreatitis. EUS-guided biliary drainage is an alternative to refractory endoscopic biliary drainage and percutaneous transhepatic biliary drainage for the treatment of acute cholangitis. The placement of an inside stent followed by switching to uncovered self-expanding metal stents in difficult-to-treat cases has been proposed for acute cholangitis by malignant biliary obstruction. Endoscopic transpapillary gallbladder drainage is an alternative to percutaneous transhepatic gallbladder drainage for severe and some cases of moderate acute cholecystitis. EUS-guided gallbladder drainage has been reported as an alternative to percutaneous transhepatic gallbladder drainage and endoscopic transpapillary gallbladder drainage. However, it is important to understand the advantages and disadvantages of each drainage method and select the optimal drainage method for each case.

Same-session endoscopic diagnosis and symptom palliation in pancreato-biliary malignancies: Clinical impact of rapid on-site evaluation (ROSE).

Background and study aims Besides increasing adequacy, rapid on-site evaluation (ROSE) during endoscopic ultrasound (EUS) or endoscopic retrograde cholangiopancreatography (ERCP) may impact choices and timing of subsequent therapeutic procedures, yet has been unexplored. Patients and methods This was a retrospective evaluation of a prospectively maintained database of a tertiary, academic centre with availability of ROSE and hybrid EUS-ERCP suites. All consecutive patients referred for pathological confirmation of suspected malignancy and jaundice or gastric outlet obstruction (GOO) between Jan-2020 and Sep-2022 were included. Results Of 541 patients with underlying malignancy, 323 (59.7%) required same-session pathological diagnosis (male: 54.8%; age 70 [interquartile range 63-78]; pancreatic cancer: 76.8%, biliary tract adenocarcinoma 16.1%). ROSE adequacy was 96.6%, higher for EUS versus ERCP. Among 302 patients with jaundice, ERCP-guided stenting was successful in 83.1%, but final drainage was completed in 97.4% thanks to 43 EUS-guided biliary drainage procedures. Twenty-one patients with GOO were treated with 15 EUS-gastroenterostomies and six duodenal stents. All 58 therapeutic EUS procedures occurred after adequate ROSE. With ERCP-guided placement of stents, the use of plastic stents was significantly higher among patients with inadequate ROSE (10/11; 90.9%) versus adequate sampling (14/240; 5.8%) P <0.0001; OR 161; 95%CI 19-1352). Median hospital stay for diagnosis and palliation was 3 days (range, 2-7) and median time to chemotherapy was 33 days (range, 24-47). Conclusions Nearly two-thirds of oncological candidates for endoscopic palliation require contemporary pathological diagnosis. ROSE adequacy allows, since the index procedure, state-of-the-art therapeutics standardly restricted to pathologically confirmed malignancies (e.g. uncovered SEMS or therapeutic EUS), potentially reducing hospitalization and time to oncological treatments.

Clinical outcomes of different types of metallic stents in malignant distal duodenum stenosis: A retrospective study

Background/purposeEndoscopic stenting at malignant distal duodenum stenosis (MDDS) is challenging because of the duodenal C-loop configuration, the acute angle of the duodenojejunal junction, and the limited length of the endoscope. Few studies have investigated the clinical outcomes of stenting at the distal duodenum. Therefore, this study aimed to investigate the clinical outcomes of treating MDDS with different types of metallic stents. MethodsFrom January 2012 to December 2020, fifty-six patients with MDDS who underwent duodenal stenting were enrolled for analysis. Thirty-five patients received uncovered self-expandable metallic stents (UC-SEMS), and twenty-one patients received partially covered self-expandable metallic stents (PC-SEMS). All patients were followed up till death or for 18 months. The clinical success rate, stent dysfunction rate, and stent patency were compared between the groups. Multivariate analysis was conducted to identify factors related to stent dysfunction. ResultsThe clinical success rates were 85.7 % in both the UC-SEMS and PC-SEMS groups. Stent dysfunction rates (UC-SEMS: 34.3 %, PC-SEMS: 38.1 %, p = 0.773) and the average stent patency (UC-SEMS: 117.2 days, PC-SEMS: 100.0 days, p = 0.576) were not statistically different between the groups. Multivariate analysis disclosed the age ≥65 years was significantly related to stent dysfunction (odds ratio: 4.78, p = 0.031). ConclusionsBoth UC-SEMS and PC-SEMS are safe and effective treatment options for MDDS. However, stent dysfunction remains a significant issue to overcome, particularly in the elderly. Further research is needed to explore novel strategies that can improve the effectiveness of stent placement and reduce the risk of stent dysfunction.

Comparison of covered self-expandable metallic stents with 12-mm and 10-mm diameters for unresectable malignant distal biliary obstructions: a prospective randomized trial

Covered self-expandable metallic stents have longer patency than uncovered self-expandable metallic stents for unresectable malignant distal biliary obstruction because of the prevention of tumor ingrowth, and they are removable during reintervention. One main cause of recurrent biliary obstruction in covered self-expandable metallic stents is sludge formation, which can be prevented by using large-bore stents. We evaluated the treatment results of 12-mm and 10-mm covered self-expandable metallic stents for unresectable malignant distal biliary obstructions using a randomized controlled trial. This study was conducted between May 2016 and January 2019 and included 81 consecutive patients with unresectable malignant distal biliary obstruction. The primary endpoint was the rate of nonrecurrent biliary obstruction at 6 months after stent placement. The primary endpoint in the 12-mm group was significantly higher than that in the 10-mm group (P= .0369). Therefore, the median time to recurrent biliary obstruction was 172 days in the 12-mm group and 120 days in the 10-mm group. The median time to recurrent biliary obstruction in the 12-mm group was significantly longer than that in the 10-mm group (P= .0168). Using the 12-mm covered self-expandable metallic stents and receiving chemotherapy were factors affecting the rate of recurrent biliary obstruction in the multivariate analysis. The 12-mm covered self-expandable metallic stents provide a longer time to recurrent biliary obstruction than do 10-mm covered self-expandable metallic stents for managing unresectable malignant distal biliary obstruction. (Clinical trial registration number: UMIN000016911.).

Outcome of both-bare type nitinol metal stents in distal biliary malignant obstruction: A post-market clinical follow-up study

BACKGROUND&#x0D; Neoplastic stenosis of the distal biliary (DBS) tract is not rare and the most common treatment is an endoscopic stent placement. Partially covered self-expandable metal stents (PC-SEMS) have been recently introduced and preliminary data are controversial in terms of lower stent ingrowth compared to uncovered self-expandable metal stents (SEMS) at expense of higher risk of migration.&#x0D; &#x0D; AIM&#x0D; To confirm the safety and/or clinical performance of partially covered nitinol metal stents (Niti-S- Taewoong Medical Co. Ltd., Korea) in DBS management.&#x0D; &#x0D; METHODS&#x0D; This is a post-market clinical follow-up study which analyzed all consecutive patients from March 2021 to April 2022 who underwent PC-SEMSs [Niti-S Biliary Covered stent (Both Bare Type) - Taewoong Medical Co. Ltd., Korea] placement for drainage of malignant DBS. The follow-up time was 6 mo. The safety of the device was evaluated by occurrence of procedure-related and stent-related adverse events.&#x0D; &#x0D; RESULTS&#x0D; Thirty patients (21 males, median age 75 years) were enrolled: at the time of the procedure 24 patients had pancreatic cancer, 67% of patients had, at the time of the procedure, an advanced inoperable disease. Technical success rate was achieved in 96.7% of patients, while clinical success after 3-6 wk was achieved in 95% of patients and all surviving patients achieved normal bilirubin levels within 10 wk from the procedure. One patient had a mild procedure-related adverse event, and one experienced a moderate stent-related adverse event. Stent occlusion rate was 6.6%: 2 patients had recurrent biliary obstruction endoscopically treated, while stent migration was never recorded.&#x0D; &#x0D; CONCLUSION&#x0D; This PMCF study demonstrates that Niti-S SEMS (Both Bare Type – Taewoong) provides adequate palliation, no migration and fair duration of patency comparable with the best results in reported series of SEMS placement for DBS treatment.

Endoscopic ultrasound-guided drainage of perforated gallbladder in patients with hilar cholangiocarcinoma postbiliary uncovered self-expandable metal stent placement.

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Uncovered versus fully covered self-expandable metal stents for the management of distal malignant biliary obstruction

Self-expandable metal stents (SEMSs) are widely used for palliation of distal malignant biliary obstruction (dMBO). However, previous studies comparing the outcomes between uncovered SEMSs (UCSEMSs) and fully covered SEMSs (FCSEMSs) report conflicting results. This large cohort study aimed to compare the clinical outcomes between UCSEMSs and FCSEMSs for dMBO. A retrospective cohort study was performed in patients with dMBO who underwent either UCSEMS or FCSEMS placement between May 2017 and May 2021. Primary outcomes were rates of clinical success, adverse events (AEs), and unplanned endoscopic reintervention. Secondary outcomes were types of AEs, intervention-free stent patency, and management and outcomes of stent occlusion. The cohort included 454 patients (364 in the UCSEMS group and 90 in the FCSEMS group). Median follow-up duration was 9.6 months and was similar between the 2 groups. Use of UCSEMSs and FCSEMSs had comparable clinical success (P= .250). However, use of UCSEMSs had significantly higher rates of AEs (33.5% vs 21.1%; P= .023) and unplanned endoscopic reintervention (27.0% vs 11.1%; P= .002). UCSEMSs had a higher rate of stent occlusion (26.9% vs 8.9%; P< .001) and shorter median time to stent occlusion (4.4 months vs 10.7 months; P= .002). Stent reintervention-free survival was higher in the FCSEMS group. FCSEMSs had a significantly higher rate of stent migration (7.8% vs 1.1%; P< .001), but patients in the FCSEMS group had similar rates of cholecystitis (.3% vs 1.1%; P= .872) and post-ERCP pancreatitis (6.3% vs 6.6%; P= .90). When UCSEMSs did occlude, placement of a coaxial plastic stent had a higher rate of stent reocclusion compared with coaxial SEMS placement (46.7% vs 19.7%; P= .007). FCSEMSs should be considered for the palliation of dMBO because of lower rates of AEs, longer patency rates, and lower rates of unplanned endoscopic intervention.

Efficacy and safety of covered versus uncovered self‑expandable metal stents for the palliative treatment of malignant distal biliary stricture: A long‑term retrospective study.

Both covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (USEMSs) have been tried in the palliation of malignant distal biliary strictures by means of endoscopic retrograde cholangiopancreatography (ERCP); however, the comparison of efficacy and safety between them remains contested. To the best of our knowledge, no similar studies have assessed this in the Chinese population. In the present study, the clinical and endoscopic data of 238 patients (CSEMSs, n=55; USEMSs, n=183) with malignant distal biliary strictures from 2014 to 2019 were collected. The efficacy indicated by mean stent patency, stent patency rate, mean patient survival time and survival rate, and the safety indicated by adverse events after CSEMS or USEMS placement were retrospectively analyzed and compared. The mean stent patency time was significantly longer in the CSEMSs group than that in the USEMSs group (262.8±195.3 days vs. 169.5±155.7 days, P=0.002). The mean patient survival time was significantly longer in the CSEMSs group than that in the USEMSs group (273.9±197.6 days vs. 184.9±167.6 days, P=0.003). The stent patency rate and patient survival rate were significantly higher in the CSEMSs group than those in the USEMSs group at 6 and 12 months, but not at 1 and 3 months. There was no significant difference in stent dysfunction and adverse events between the two groups, although post-ERCP pancreatitis (PEP) occurred more frequently in the CSEMSs group than in the USEMSs group (18.1% vs. 8.8%, P=0.049). In conclusion, CSEMSs were better than USEMSs for malignant distal biliary strictures in terms of stent patency time and patient survival time as well as stent patency rate and patient survival rate in the long term (>6 months). Adverse events in the two groups occurred at a similar rate, although the incidence of PEP was higher in the CSEMSs group.

Comparison between Suprapapillary and Transpapillary Uncovered Self-Expandable Metallic Stent Placement for Perihilar Cholangiocarcinoma

PurposeTo compare the effectiveness, adverse events (AEs), stent patency, and patient survival with suprapapillary and transpapillary uncovered self-expandable metallic stent placement for perihilar cholangiocarcinoma. Materials and MethodsA single-center retrospective study of 54 patients with inoperable perihilar cholangiocarcinoma who underwent percutaneous transhepatic biliary stent placement between January 1, 2019, and August 31, 2021, was conducted. According to stent location, the patients were classified into 2 groups: suprapapillary (S) and transpapillary (T). Demographic data, Bismuth-Corlette classification, type and location of the stent, laboratory data, postprocedural AEs, procedural success, stent occlusion, reintervention rate, and mortality were compared between the groups. ResultsStent placement was suprapapillary in 13 (24.1%) patients and transpapillary in 41 (75.9%) patients. Mean age was higher in Group T (78 vs 70.5 years; P = .046). Stent occlusion rates were similar in the 2 groups (Group S, 23.8%; Group T, 19.5%), as were AE rates, the most common being cholangitis (Group S, 23.1%; Group T, 24.4%). There were no significant differences in revision rate (Group S, 7.7%; Group T, 12.2%) and 30-day mortality rate (Group S, 15.4%; Group T, 19.5%). Ninety-day mortality rate was statistically significantly higher in Group T (46.3% vs 15.4%; P = .046). Preprocedural bilirubin level was higher in Group T, as were postprocedural leukocyte and C-reactive protein (CRP) levels. ConclusionsSuprapapillary and transpapillary stent placement procedures were similar in terms of procedural success, occlusion rate, revision rate, postprocedural AEs, and 30-day mortality. Ninety-day mortality rate and postprocedural leukocyte and CRP levels were higher in Group T, although these patients were also older and had higher preprocedural bilirubin levels.

Double bare metal stent deployment combined with intraductal radiofrequency ablation for malignant distal biliary obstruction: a prospective pilot study

Although uncovered self-expandable metal stents (SEMSs) possess certain advantages such as averting cystic duct obstruction and stent migration, they are susceptible to ingrowth occlusion. The combination of the double bare stent (DBS) and endobiliary radiofrequency ablation (RFA) may reduce ingrowth. Hence, this study aimed to examine the utility of this method for the treatment of unresectable malignant distal biliary obstruction (MDBO). This prospective, single-center, pilot study enrolled 51 patients who met the eligibility criteria between February 2020 and January 2022. The study outcomes included technical success, clinical success, recurrent biliary obstruction (RBO), and other adverse events (AE) besides RBO associated with DBS placement with RFA for MDBO. The technical success rate was 98.0% (50/51). Clinical success was achieved in all patients in whom technical success was achieved. The rates of early and late AEs were 5.9% (3/51) and 8.0% (4/50), respectively. The incidence rate of RBO was 38.0% (19/50). Sludge occlusion, ingrowth occlusion, and overgrowth occlusion occurred in 26.0% (13/50), 8.0% (4/50), and 2.0% (1/50) of patients, respectively (the main cause of RBO was undeterminable in 1 patient). The median time to RBO was 241 days. DBS with RFA showed good technical feasibility, good long-term outcomes, acceptable AE rates, and most importantly, a low ingrowth occlusion rate when employed for the treatment of MDBO.

EUS-guided hepaticogastrostomy in multimetastatic liver disease - an effective approach for biliary drainage that may complement ERCP.

A 36-year-old male was diagnosed with a metastasized colon adenocarcinoma causing obstructive jaundice. Magnetic resonance cholangiography showed a dominant lesion causing hilar stenosis. The patient was submitted to endoscopic retrograde cholangiopancreatography (ERCP), nevertheless it was just possible to place a single uncovered self-expandable metallic stent (SEMS) in the right lobe. Although cholestasis significantly improved, safe levels for oncologic therapy were not reached. EUS-guided hepaticogastrostomy was proposed to complement ERCP biliary drainage. Using a forward-viewing echoendoscope and a transgastric approach, EUS-guided puncture of a dilated left intrahepatic duct at segment III was accomplished with a 19G needle (EchoTip ProCore®) that allowed passage of a 0.035 guidewire. A 6F cystotome and biliary dilators (5Fr+8.5Fr) were used for needle tract dilation. A partially-covered SEMS (GIOBOR™ 8x100mm) could be deployed under endoscopic and fluoroscopic control, being placed 3cm inside the gastric lumen. No associated complications were observed after the procedure.

HPB P07 A propensity matched retrospective study of metal vs plastic stents in the preoperative biliary drainage of patients with resectable perihilar cholangiocarcinoma

Abstract Background Preoperative biliary drainage is required in the majority of patients with resectable perihilar cholangiocarcinoma (pCCA). Most centres use plastic stents rather than uncovered self-expanding metal stents (uSEMS) because of the potential difficulties associated in removing uSEMS. In the palliative setting, however, uSEMS are associated with superior patency and even improved survival. The aim of this study is to compare the utility of uSEMS versus plastic stents in the pre-operative drainage of patients with resectable pCCA. Methods In this retrospective, multicentre, international cohort study, all consecutive patients with a high suspicion of resectable pCCA who underwent an initial endoscopic biliary drainage with uSEMS or plastic stent between 2010–2020 were included. Analyses were stratified by groups according to initial stent type. The primary outcome was stent failure, which was a composite endpoint of cholangitis and/or re-intervention due to biliary complications or inadequate biliary drainage. Propensity score matching (1:1) was performed to adjust for age, gender, primary sclerosing cholangitis, Bismuth classification, WHO performance status and ASA classification. Results A total of 474 patients with successful initial stent placement were included. Of these patients 61 received uSEMS and 413 plastic stents. Matching resulted in two groups of 59 patients. Stent failure occurred significantly less in the uncovered uSEMS group (31% vs 64%, P&amp;lt;0.001) and resulted in a significant reduction in the number of repeat ERCP procedures (14% vs 54%, P&amp;lt;0.001). Despite this the number of patients eventually required percutaneous transhepatic biliary drainage was similar (9% vs 7%, P=1). uSEMS placement was also associated with a reduction in episodes of cholangitis (15% vs 31%, P=0.012), although other ERCP and stent related complications did not differ. The number of patients ultimately undergoing surgical resection was not significantly different (81% vs 90%, P=0.19) between groups with uSEMS removal during surgery successful in all patients. The median overall survival after initial stent placement was 482 days [95% CI, 338–787] in the uSEMS group and 429 [95% CI, 263–881] in the plastic stent group (log-rank P=0.81). Survival after surgical resection was similar and post-operative outcomes also comparable: R1 resections (58% vs 59%, P=0.569), complications according to Clavien-Dindo (P=0.227), and hepatico-jejunostomy associated complications (leak: 4% vs 14%, P=0.393, stricture: 15% vs 21%, P=0.822). Conclusions Stent failure occurred significantly less often in uSEMS group resulting in fewer drainage procedures and reduced episodes of cholangitis. Removal of uSEMS during surgery was feasible and surgical outcomes were comparable. Although preoperative biliary drainage by uSEMS shows promising results further study is warranted and multicentre randomized controlled trials with a clear treatment strategy should be performed.

Efficacy of pancreatic duct stenting to prevent postendoscopic retrograde cholangiopancreatography pancreatitis after covered self-expandable metal stentdeployment.

Although covered self-expandable metal stents (CSEMSs) are associated with the risk of postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis due to pancreatic duct (PD) orifice obstruction, they are often used for biliary drainage treatment in malignant biliary obstruction (MBO). This study aimed to investigate the efficacy of PD stenting in preventing post-ERCP pancreatitis after CSEMS implantation. This retrospective cohort study analyzed 554 patients with transpapillary CSEMS for MBO. Patients with noninitial deployment, benign disease, CSEMS deployment above the papilla, surgically altered anatomy, uncovered self-expandable metal stents, multiple thin self-expandable metal stents, and unavailable procedure videos were excluded. Logistic regression analysis estimated the association between PD stenting and post-ERCP pancreatitis incidence. We adjusted for age, sex, pancreatitis history, prophylactic rectal nonsteroidal anti-inflammatory drug use, naïve papilla, MBO etiology, and prolonged biliary cannulation time. Among 554 patients, 67 (12.1%) experienced post-ERCP pancreatitis. Post-ERCP pancreatitis was recorded in 13.7% of patients in the non-PD stenting and 4.3% in the PD stenting groups. Pancreatic duct stenting was associated with lower risks of post-ERCP pancreatitis (odds ratio [OR] 0.28; 95% confidence interval [CI] 0.099-0.79; P = 0.028). In multivariable analysis, the association between PD stenting and lower post-ERCP pancreatitis incidence was consistent (OR 0.19; 95% CI 0.062-0.58; P = 0.0034). Pancreatic duct stenting could reduce the risk of post-ERCP pancreatitis after CSEMSs.

Potential significance of uncovered self-expandable metal stents for distal malignant biliary obstruction: A propensity score-adjusted competing risk regression analysis.

ObjectivesSelection criteria for self‐expandable metal stents (SEMSs) with or without cover during palliative treatment of distal malignant biliary obstruction (DMBO) remain unclear. We evaluated factors associated with time to recurrent biliary obstruction (TRBO) in fully covered SEMSs (FCSEMSs) and uncovered SEMSs (UCSEMSs).MethodsWe retrospectively analyzed consecutive patients with DMBO who received a SEMS. TRBO was determined using the Kaplan–Meier analysis, and complications were compared between the FCSEMS and UCSEMS groups. After TRBO‐associated factors were extracted using multivariate competing‐risks regression (CRR), propensity score‐adjusted CRRs were performed to verify their robustness.ResultsThere were 180 patients (66 FCSEMSs and 114 UCSEMSs) enrolled in this study. There was no significant difference between median TRBO in the FCSEMS and UCSEMS groups (275 vs. 255 days, p = 0.67). Complications were more frequent in the FCSEMS than UCSEMS group (21.2% vs. 8.8%; p = 0.023). Multivariate CRR for TRBO‐associated factors revealed that “pancreatic ductal carcinoma (PDAC) treated with UCSEMS” was the only independent predictor of TRBO (p = 0.03). Similarly, the propensity score‐adjusted CRRs showed no significant difference in TRBO in “FCSEMS” vs “UCSEMS” (p = 0.96); however, there was a significant difference in “PDAC using UCSEMS” vs “other” (p = 0.043). In the palliative care group including any DMBO without chemotherapy, the first quartile of the TRBO of UCSEMS was 100 days.ConclusionsUCSEMSs are a possible option for both patients with DMBO arising from PDAC and for patients with any DMBO receiving palliative care who should avoid SEMS‐related complications.

Covered versus uncovered double bare self-expandable metal stent for palliation of unresectable extrahepatic malignant biliary obstruction: a randomized controlled multicenter trial

In a recent randomized controlled trial, a double bare metal stent (DBS) showed better stent patency than single-layer metal stents. However, clear evidence comparing the efficacy of uncovered (UCDBS) and partially covered (PCDBS) DBSs for distal malignant biliary obstruction (MBO) is lacking. Therefore, we compared the clinical outcomes including stent patency of UCDBSs versus PCDBSs. A multicenter, randomized study was performed in patients with distal MBO. The primary endpoint was stent patency. Secondary endpoints were the proportion of patients with patent stents at 6 months, risk factors for stent dysfunction, overall survival, technical and clinical success rates of stent placement, and other adverse events (AEs). Among 258 included patients, 130 were randomly assigned to the PCDBS group and 128 to the UCDBS group. The mean duration of stent patency of the PCDBS (421.2 days; 95% confidence interval [CI], 346.7-495.7) was longer than that of the UCDBS (377.4 days; 95% CI, 299.7-455.0), although total stent dysfunction and stent dysfunction within 6 months were not different between groups. Multivariate analysis indicated that chemotherapy after stent placement was a significant factor for overall survival (hazard ratio, .570; 95% CI, .408-.796) and had a marginal impact on stent patency (hazard ratio, 1.569; 95% CI, .923-2.667). There were no remarkable differences in AEs, including pancreatitis, cholecystitis, and stent migration, between the 2 groups. The use of PCDBSs compared with UCDBSs in patients with distal MBO has unclear benefits regarding stent patency and overall survival, although PCDBSs have a lower rate of tumor ingrowth. (Clinical trial registration number: NCT02937246.).

Impact of endobiliary radiofrequency ablation on biliary drainage in patients with malignant biliary strictures treated with uncovered self-expandable metal stents: a randomized controlled multicenter trial

Endobiliary radiofrequency ablation (RFA), usually combined with endoscopic stent insertion, is a simple procedure with the potential to improve stent patency and patient survival for malignant biliary obstruction. We conducted this randomized multicenter trial to evaluate the impact of RFA on stent patency. Eighty-six patients with malignant biliary obstruction and nonresectable tumors (pancreatic carcinoma, cholangiocarcinoma, or metastases) were included and randomly assigned to receive a self-expandable metal stent (SEMS) only (n= 44) or RFA followed by SEMS insertion (RFA+SEMS, n= 42). The primary outcome measure was stent patency after 3 and 6 months; secondary outcome measures were patient survival and early adverse events within 30 days. Technical success rates for RFA and stent insertion were 100% and 98.8%, respectively. Stent patency after 3 and 6 months did not differ significantly between groups (RFA+SEMS group, 73.1% and 33.3%, respectively; SEMS-only group, 81.8% and 52.4%, respectively; P= .6). Similarly, the addition of RFA did not impact overall survival (hazard ratio, .72; P= .389 for RFA+SEMS). The adverse event rate in the RFA+SEMS group was 10.5% compared with 2.3% in the SEMS-only group, without a statistically significant difference (P= .18). RFA as an addition to SEMS implantation had no positive impact on patency rate or survival. (Clinical trial registration number: DRKS00018993.).

Endoscopic management of perihilar cholangiocarcinoma.

Endoscopic management for perihilar cholangiocarcinoma (PHCC) is evolving toward more accurate diagnosis and safer drainage. In imaging, it is important to diagnose the entire lesion using multidetector-row computed tomography to determine resectability and optimal surgical planning, followed by local diagnosis using endoscopic retrograde cholangiopancreatography. Video peroral cholangioscopy and probe-based confocal laser endomicroscopy have been newly introduced as diagnostic imaging methods and are being applied clinically. In transpapillary forceps biopsy for PHCC diagnosis, the location in the bile duct (for mapping biopsy) and the number of biopsy samples should be determined depending on resectability, the morphological type, and future surgical planning. Preoperative drainage has shifted from percutaneous transhepatic biliary drainage to endoscopic nasobiliary drainage given the possibility of seeding metastasis. In addition, considering potential patient discomfort from a nasal tube, the usefulness of the placement of a plastic stent above the papilla (inside stent) as a bridging therapy for surgery has been reported. For drainage of unresectable PHCC, the improved prognosis due to advances in chemotherapy has necessitated a strategy that accounts for reintervention. Thus, in addition to uncovered self-expandable metallic stents (SEMS), exchangeable slim fully covered SEMS and inside stents have started to be used. In addition to the conventional transpapillary approach, an endoscopic ultrasonography-guided approach has been introduced, and a combination of both methods has also been proposed. To improve the quality of life and prognosis of PHCC patients, endoscopists need to understand and be able to use the various methods of endoscopic management for PHCC.

PARTIALLY COVERED VERSUS UNCOVERED SELF-EXPANDIBLE METAL STENTS IN THE PALLIATIVE TREATMENT OF MALIGNANT DISTAL BILIARY OBSTRUCTION

Kyo-Sang Yoo: NO financial relationship with a commercial interest Background/Aims: Self-expandable metal stents (SEMSs) are commonly used to relieve malignant biliary obstruction. Covered self-expandable metal stents (CSEMSs) were introduced to improve the patency of SEMSs by preventing tissue ingrowth. Unlike uncovered self-expandable metal stents (USEMSs), which are integrated into the tumor or duct wall, CSEMSs do not embed, but has an increased risk of migration. Although several retrospective studies comparing these two types of stents for malignant biliary obstruction have shown longer patency with CSEMSs, prospective, randomized trials have not been able to confirm these results.

Efficacy of a novel large-cell Niti-S stent with a slim delivery system for hilar biliary obstruction: a preliminary study

Objectives The large-cell Niti-S stent is useful for multiple stenting in patients with malignant hilar biliary obstruction (MHBO). Recently, a novel uncovered self-expandable metallic stent (USEMS) (a Niti-S large-cell SR slim delivery system) was developed. In this study, we aimed to evaluate the efficacy of this USEMS slim delivery system in MHBO patients. Materials and methods Outcomes related to USEMS placement, the clinical course, and the period to recurrent biliary obstruction (RBO) were evaluated in MHBO patients who received multiple USEMSs with the Niti-S large-cell SR slim delivery system. Results Twenty-two MHBO patients underwent the placement of multiple USEMSs, including the novel slim-delivery stent. Six patients had a past history of upper gastrointestinal reconstruction (Billroth I: 1, Billroth II: 4, Roux-en-Y: 1). The number of USEMSs placed in each patient was 2-6. Three procedures were reinterventions. The new slim delivery system was placed as the first stent in ten patients and as an additional stent in the remaining patients. Seven patients were drained using only Niti-S large-cell SR slim delivery stents. The technical and clinical success rates were both 100%. Conclusions Placing multiple USEMSs in patients with a past history of abdominal surgery or in reintervention is difficult. Although difficult cases were included in this study, stent-in-stent placement with the novel Niti-S large-cell SR slim delivery system was useful in treating MHBO patients. In addition, this novel stent might be the first choice for MHBO patients. KEY MESSAGES Endoscopic multistenting for MHBO is challenging. In addition, reintervention or multistenting for MHBO patients with a past history of abdominal surgery becomes more difficult. The novel Niti-S large-cell SR slim delivery USEMS is useful as an additional stent because the delivery system is thin and suitable for a 0.025 guidewire. In addition, the novel stent is of the braided type and has a large mesh. Therefore, the novel stent is expected to have strong radial force and can be used as the first SEMS. The Niti-S large-cell SR slim delivery stent is long enough to be used in patients with upper gastrointestinal reconstruction. Although this study included patients with reintervention or a past history of upper gastrointestinal reconstruction, the technical success rate of multiple stenting for MHBO patients was 100%. The slim-delivery stent might overcome several difficulties of endoscopic multistenting.

Comparison of outcomes between secondary fully covered and uncovered self-expandable metal stents in the treatment of recurrent biliary obstruction of pancreatic cancer.

The overall survival (OS) of pancreatic cancer (PC) has been prolonged by advances in chemotherapy, and the number of cases of recurrent biliary obstruction (RBO) after self-expandable metal stent (SEMS) placement is expected to increase. We herein compared outcomes between secondary fully covered SEMS (FC) and uncovered SEMS (UC) for RBO of PC with FC placed as the 1st SEMS. Between May 2010 and March 2021, 62 PC patients who underwent SEMS exchange to FC (n = 34) or UC (n = 28) for RBO were retrospectively analyzed. Patient characteristics, OS, time to RBO (TRBO), and stent-related adverse events were compared between the FC and UC groups. Cox's proportional hazard model was used to identify risk factors for RBO with the 2nd SEMS. There was a significant difference between the FC and UC groups only in the 2nd SEMS diameter. Median OS and TRBO were 195 and 238days in FC patients and 306 and 455days in UC patients, respectively, with no significant differences between the two groups. No significant differences were observed in the stent-related adverse event rate. In multivariate analyses, only the 2nd SEMS diameter was significant (P = 0.009). Median TRBO were 455, 238, and 103days in 10-mm UC, 10-mm FC, and 8-mm UC patients, with 10-mm UC patients having significantly longer TRBO than 10-mm FC and 8-mm UC patients (P = 0.020 and 0.001). SEMS exchange to 10-mm UC may be appropriate for RBO of PC with FC as the 1st SEMS.