Can the laser-cut covered self-expandable metallic stent be the first choice for patients with unresectable distal malignant biliary obstruction? (with video)

Braided-type stent versus laser-cut-type stent for patients with unresectable distal malignant biliary obstruction: a randomized controlled trial

BACKGROUND AND AIMS

Fully covered self-expandable metallic stents (SEMSs) are laser-cut (L) or braided (B); however, it remains unclear which approach is more effective for distal malignant biliary obstruction (DMBO). This study compared the clinical outcomes of using L-type and B-type stents because we believe that recurrent biliary obstruction (RBO) is less likely to occur with L-type stents.

METHODS

Patients diagnosed with unresectable DMBO were randomly assigned to groups L and B in a stratified block fashion, and outcomes were compared. The primary outcome was the rate of RBO within 1 year; secondary outcomes were adverse events, clinical success rate, time to RBO (TRBO), and overall survival.

RESULTS

Of the 60 enrolled participants, 56 (group L, n = 27; group B, n = 29) were included. The rates of RBO within 1 year were 44.4% and 17.2% in groups L and B, respectively (odds ratio, 2.57; 95% confidence interval [CI], 1.045-6.353). Early adverse events, which improved with conservative treatment, included pancreatitis (n = 4) in group L and pancreatitis (n = 3) and cholecystitis (n = 1) in group B (P = .913). The median TRBO (220 days [95% CI, 56-272] vs 418 days [95% CI, 232-454]) was significantly longer in group B than in group L (log-rank test, P = .0118). The median overall survival (group L, 158 days; group B, 204 days) after stenting was not significantly different between groups (P = .8544).

CONCLUSIONS

In the setting of DMBO, B-type stents are associated with less recurrent obstruction than L-type stents, although there was no difference in safety. (UMIN Clinical Trials Registry number: UMIN000027239.).

Fully covered versus partially covered self-expandable metal stents for palliation of distal malignant biliary obstruction: a systematic review and meta-analysis

BACKGROUND AND AIMS

Self-expandable metal stents (SEMSs) are standardly used for distal malignant biliary obstruction (dMBO). Although data suggest that covered versus uncovered SEMSs increase the time to recurrent biliary obstruction (TRBO), no data are available for fully covered (FC) versus partially covered (PC) designs.

METHODS

PubMed, Scopus, and Cochrane databases were screened up to January 2023 for studies concerning dMBO treated by an FC- or PC-SEMS and describing adverse events (AEs), recurrences, or TRBO for specific design subpopulations. Pooled proportions or means were calculated using a random-effects model. Several subanalyses were preplanned, including a subanalysis restricted to prospective studies and unresectable diseases. Heterogeneity and publication bias were explored. Standardized differences (d-values) were calculated between groups.

RESULTS

From 1290 records, 62 studies (3327 using FC-SEMSs and 2322 using PC-SEMSs) were included. FC- versus PC-SEMSs showed negligible differences in the rate of total AEs (12% vs 9.9%) and all specific AEs, including cholecystitis (2.5% vs 2.6%). In a subanalysis restricted to prospective studies and unresectable diseases, the rate of RBO was comparable between FC-SEMSs (27.3% [95% confidence interval {CI}, 23.7-31.2], I2 = 35.34%) and PC-SEMSs (25.3% [95% CI, 20.2-30.7], I2 = 85.09%), despite small differences (d-values between .186 and .216) in the rate of ingrowth (.5% vs 2.9%) favoring FC-SEMSs and migration (9.8% vs 4.3%) favoring PC-SEMSs. TRBO was shorter for FC-SEMSs (238 days [95% CI, 191-286], I2 = 63.1%) versus PC-SEMSs (369 days [95% CI, 290-449], I2 = 71.9%; d-value = .116).

CONCLUSIONS

Despite considerable heterogeneity and small standardized differences, PC-SEMSs consistently exhibited longer TRBO than FC-SEMSs across analyses, without any other differences in AE rates, potentially proposing PC-SEMSs as the standard comparator and TRBO as the primary outcome for future randomized studies on dMBO. (Clinical trial registration number: CRD42023393965.).

Comparable Efficacy of Laser-Cut and Braided Self Expanding Metallic Biliary Stent: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

In patients with unresectable malignant biliary obstruction (MBO), endoscopic biliary drainage is the treatment of choice. Self-expanding metallic stents (SEMS) are mainly used for this purpose, and data is limited on the comparative outcomes of laser-cut versus braided SEMS. Herein, we performed the first systematic review and meta-analysis to study the effectiveness and safety of braided and laser-cut SEMS in MBO.

METHODS

Multiple databases, including Medline, Scopus, and Embase, were searched (in May 2022) using specific terms for studies evaluating the outcomes of braided and laser-cut SEMS in MBO. Outcomes of interest were technical and clinical success, recurrent biliary obstruction, and adverse events. Standard meta-analysis methods were employed using the random-effects model. I2% heterogeneity was used to assess the heterogeneity.

RESULTS

Seven studies were included in the final analysis. (Laser-cut: 271 patients, 46% females, mean age 70 years; and braided: 282 patients, 47% females, mean age 72 years). The pooled rate of technical success and clinical success with laser-cut SEMS was 99% (95% CI [95-99; I2 = 0%]), 86% [60-96; I2 = 74%], and 98% [96-99; I2 = 0%], 89% [74-95; I2 = 78%] with braided. The pooled rate of recurrent biliary obstruction with laser-cut SEMS was 26% [14-43; I2 = 88%] and 12% [5-27; I2 = 56%) with braided. Pooled total adverse events were 11% [5-21; I2 = 77%] in laser-cut and 12% [6-24; I2 = 63%] in braided.

CONCLUSION

Our meta-analysis demonstrates similar clinical outcomes with laser-cut and braided SEMS in MBO. Given the comparable performance, a cost-effectiveness analysis might help in choosing one type versus another in patients with MBO.

Removal of Duckbill-type laser-cut anti-reflux metal stents: Clinical evaluation and in vitro study

Objectives

Duckbill-type metal stent (DMS) was the first laser-cut biliary metal stent with an anti-reflux valve. Removal of DMS is believed to be difficult and relevant reports are scarce. This study aims to investigate the feasibility of DMS removal.

Methods

We retrospectively analyzed patients who underwent DMS removal between June 2019 and March 2022 to evaluate success rates and factors affecting outcomes. In addition, six different methods of DMS removal were reproduced in vitro, varying removal devices, angle of applied force, and grasped location. Extraction resistance, the distance of forceps stroke, and stent length after removal were compared.

Results

Forty patients were enrolled, and DMS removal was successful in 31 cases (78%). No adverse events were observed. Tumor ingrowth was evident in 78% (7/9) of failed cases. Patients receiving biliary metal stents for the first time (naïve cases), long indwelling time, longer stent, and stent tearing during removal were associated with unsuccessful stent removal. In the in vitro study, a larger force was required to remove the stent at an extraction angle of 120° than at 0°. Among cases in which force was applied at 120°, the load tended to be lower when rat-tooth forceps were applied horizontally across the stent.

Conclusions

Stent removal was possible in a majority of cases. Deployment of additional stents inside DMS may be preferable to forceful removal in the presence of factors associated with difficult stent removals, such as tumor ingrowth, naïve cases, longer stents, long indwelling time, and stent tearing during removal.

The efficacy and safety of a duckbill-type anti-reflux metal stent as the initial metal stent for distal malignant biliary obstruction in unresectable pancreatic cancer

Background

The usefulness of duckbill-type anti-reflux metal stent (DMS) in self-expandable metal stent-naïve pancreatic cancer (PC) patients has not been well-studied. This study aimed to evaluate the efficacy and safety of DMS in such patients.

Methods

We analyzed consecutive patients with unresectable PC who received a covered metal stent (CMS) as the initial self-expandable metal stent at our institution. Technical success, functional success, causes of recurrent biliary obstruction (RBO), time to RBO (TRBO), adverse events (AEs), and reintervention rates were compared between DMS and conventional CMS (c-CMS).

Results

A total of 69 patients were included (DMS: 28, c-CMS: 41). Technical success, functional success, and AEs were similar between groups. Tumor ingrowth was more common in the DMS group (18% vs. 0%, p = 0.009), while non-occlusion cholangitis tended to be more common in the c-CMS group (0% vs. 15%, p = 0.074). Median time to RBO was similar between groups (276 vs. 273 days, p = 0.915). The anti-reflux valve of DMS was found torn in 56% of patients. Endoscopic reintervention was successful in all cases, despite failed stent removal in 88% of patients in the DMS group.

Conclusions

DMS was not associated with longer time to RBO compared to c-CMS in self-expandable metal stent-naïve patients.

Usefulness of duckbill‐type anti‐reflux self‐expandable metal stents for distal malignant biliary obstruction with duodenal invasion: A pilot study

Objectives

Early obstruction of a self‐expandable metal stent placed for distal malignant biliary obstruction is more likely to occur in the presence of duodenal invasion. An anti‐reflux self‐expandable metal stent (ARMS) has been developed for the purpose of preventing duodenal fluid reflux into the bile duct. In this study, we evaluated the usefulness and safety of a duckbill‐type ARMS (D‐ARMS) in the situation of duodenal invasion.

Methods

We retrospectively analyzed 10 consecutive patients who received D‐ARMS for distal malignant biliary obstruction with duodenal invasion. We evaluated non‐occlusion cholangitis, recurrent biliary obstruction (RBO), and adverse events after D‐ARMS placement.

Results

There were no cases of non‐occlusion cholangitis. RBO was observed in 2 patients (20%), and time to RBO was 236 days and 117 days, respectively. The causes of RBO were overgrowth and sludge formation. The median time to RBO was 382 days (range, 117–382 days). Only one adverse event was observed (cholecystitis).

Conclusions

D‐ARMS shows potential as an optimal ARMS.

Current Status of Endoscopic Biliary Drainage in Patients with Distal Malignant Biliary Obstruction

Distal malignant biliary obstruction is caused by various malignant diseases that require biliary drainage. In patients with operable situations, preoperative biliary drainage is required to control jaundice and cholangitis until surgery. In view of tract seeding, endoscopic biliary drainage is the first choice. Since neoadjuvant therapies are being developed, the time to surgery is increasing, especially in pancreatic cancer cases. Therefore, it requires long stent patency. Recently, preoperative biliary drainage using self-expandable metal stents has been reported as a useful modality to secure long stent patency. In patients with unresectable distal malignant biliary obstruction, self-expandable metal stent is the first choice for maintaining long stent patency. Although there are many comparison studies between a covered and an uncovered self-expandable metal stent, their use is still controversial. Recently, endoscopic ultrasound-guided biliary drainage has been performed as an alternative treatment. The clinical success and stent patency are favorable. We should take into consideration that both endoscopic retrograde cholangiopancreatography-guided biliary drainage and endoscopic ultrasound-guided biliary drainage have advantages and disadvantages and chose the drainage method depending on the patient’s situation or the expertise of the endoscopist. Here, we discuss the current status of endoscopic biliary drainage in patients with distal malignant biliary obstruction.