Efficacy and safety of a novel polytetrafluoroethylene-coated self-expandable metal stent for distal malignant biliary obstruction.

Background: Stent migration and sludge formation remain significant problems associated with covered self-expandable metal stents (CSEMSs). The EGIS biliary stent fully covered flare type (EGIS biliary stent), a new type of polytetrafluoroethylene-coated self-expandable metal stent with low axial force and an anti-migration system, was developed to overcome these disadvantages. We conducted this study to evaluate the efficacy and safety of this stent in comparison with conventional CSEMS (c-CSEMS). Methods: We retrospectively analyzed consecutive patients with unresectable pancreatic cancer who received initial CSEMS for distal malignant biliary obstruction. The primary outcome was time to recurrent biliary obstruction (RBO). Secondary outcomes included technical success rate, functional success rate, stent-related adverse events, causes of RBO, and re-intervention. Results: A total of 40 patients were included (EGIS group: 20; c-CSEMS group: 20). The technical and functional success rates were similar between the two groups. Stent-related adverse event rates (20% vs. 15%, p > 0.99) and overall RBO rates (56% vs. 50%, p > 0.99) were not significantly different between the two groups. Stent migration was the most common cause of RBO in the EGIS group, while stent occlusion was in the c-CSEMS group. The median time to RBO (102 vs. 434 days, p = 0.10) was not significantly different between the two groups. Endoscopic transpapillary re-intervention was successful in most patients in both groups. Conclusions: The EGIS biliary stent was not associated with a longer time to RBO compared to c-CSEMS. Further improvements, especially against stent migration, are needed to improve its efficacy.

Liver Oligometastasis in Biliary Tract Cancer and Impact on Survival Outcomes.

PURPOSE: Outcomes of unresectable biliary tract cancer (BTC) with varying extents of liver involvement remain unclear. We evaluated characteristics and outcomes of BTC patients with liver metastases who underwent chemotherapy. METHODS: We retrospectively reviewed consecutive BTC patients with synchronous or metachronous intrahepatic metastases who started first-line chemotherapy at our institution between January 2016 and December 2021. RESULTS: Ninety-six patients were included, of which 57 only had liver metastases and 39 had multiorgan involvement. The liver only group had longer median overall survival (OS) (11.8 vs. 7.4 months, P = 0.006) and median progression-free survival (PFS) (4.1 vs. 2.7 months, P = 0.035) than the multiorgan group. Patients with oligometastases (defined as no more than three liver metastases) achieved longer OS than those with polymetastases (four or more liver metastases) in the entire cohort. Within the liver only group, there were no significant differences in OS or PFS between the oligometastasis and polymetastasis groups. Patients who underwent subsequent surgery had significantly longer median OS than those who did not (44.4 vs. 7.7 months, P < 0.001). Age ≥ 75 years, liver-only metastasis, modified Glasgow prognostic score ≥ 1 carcinoembryonic antigen ≥ 5 µg/L, and subsequent surgery were independent predictors of OS. Liver oligometastasis was only a significant predictor of longer OS in univariate Cox analysis. CONCLUSIONS: Outcomes in BTC patients with metastases limited to the liver, particularly those with oligometastasis, were more favorable than those with multiorgan metastases. Selected cases, generally with liver oligometastases, may achieve prolonged OS through subsequent surgery.

Efficacy of Amamorelin in Advanced Pancreatic Cancer Patients with a Poor Performance Status.

Objective The efficacy of anamorelin in pancreatic cancer (PC) patients with a poor performance status (PS) is uncertain, as previous trials have excluded such patients. This study evaluated the efficacy of anamorelin in PC patients with a poor PS (2) compared with those with a good PS (0-1). Methods We retrospectively reviewed consecutive PC patients with cachexia who received anamorelin at our institution. The primary outcome was the proportion of responders, defined as those who maintained or gained body weight and appetite over 12 weeks. The secondary outcomes included anamorelin treatment duration, proportion of patients who discontinued anamorelin within 4 weeks (early discontinuation), and the overall survival. Results Forty-five patients (35/10) were included in this study. The proportion of responders was significantly lower in patients with a poor PS than in those with a good PS (0% vs. 37%, p=0.042). Moderate weight loss (5%-10%) and administration of pancreatic enzyme replacement therapy were associated with a response to anamorelin. A poor PS was significantly associated with a shorter treatment duration of anamorelin (14 vs. 93 days, p <0.001), a higher proportion of patients who discontinued anamorelin within 4 weeks (70% vs. 17%, p=0.003), and a reduced survival (62 vs. 188 days, p <0.001). A poor PS was associated with early discontinuation of anamorelin. Conclusions The efficacy of anamorelin is extremely limited in PC patients with a poor PS. Patients with PC with a poor PS may not be good candidates for anamorelin compared to those with a good PS.

Outcomes of partially covered self-expandable metal stents with different uncovered lengths in endoscopic ultrasound-guided hepaticogastrostomy: a Japanese retrospective study.

BACKGROUND/AIMS: The optimal length of the uncovered portion of partially covered self-expandable metal stents (PCSEMSs) used in endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) remains unclear. This study investigated the safety and efficacy of PCSEMSs with different uncovered lengths, with a focus on stent migration and time to recurrent biliary obstruction (RBO). METHODS: Outcomes of patients undergoing EUS-HGS using PCSEMSs with 5-mm and 20-mm uncovered portions at our institution from January 2016 to December 2021 were compared. RESULTS: Sixty-two patients underwent EUS-HGS using PCSEMS (5/20-mm uncovered portions: 32/30). Stent migration occurred only in the 5-mm group. There were no differences in RBO rates (28.1% vs. 40.0%) or median time to RBO (6.8 vs. 7.1 months) between the two groups. Median overall survival (OS) was longer in the 20-mm group (3.1 vs. 4.9 months, p=0.037) due to the higher number of patients that resumed chemotherapy after EUS-HGS (56.7% vs. 28.1%, p=0.029). Good performance status, absence of hepatic metastases, and chemotherapy after EUS-HGS were independent predictors of longer OS. CONCLUSIONS: No migration was observed in patients treated with PCSEMS with 20-mm uncovered portions. Patients treated with PCSEMS with 20-mm uncovered portions performed at least as well as those treated with 5-mm uncovered portions in all material respects.

Outcomes of 6-mm diameter fully covered self-expandable metal stents for preoperative biliary drainage in pancreatic cancer.

Background: 10-mm self-expandable metal stents (SEMSs) are commonly used for preoperative biliary drainage in pancreatic cancer. However, smaller diameter SEMSs have attracted attention with the attempt to reduce stent-related adverse events (AEs). Methods: We retrospectively analyzed consecutive borderline resectable pancreatic cancer patients who underwent neoadjuvant therapy and fully covered SEMS (FCSEMS) placement from April 2015 to May 2023. The primary outcome was stent-related non-event rate (NER), which was defined as the rate of completion of surgery without developing any preoperative events (recurrent biliary obstruction [RBO] or stent-related AEs). Secondary outcomes included stent-related AEs, causes of RBO, and cumulative incidence of RBO. Risk factors for pancreatitis, RBO, and stent migration were also examined. Results: A total of 76 patients were included (6-mm group: 23; 10-mm group: 53). Stent-related NER (57% vs. 64%, p = 0.610), stent-related AEs (4% vs. 15%, p = 0.263), overall RBO rates (39% vs. 23%, p = 0.168), cumulative incidence of RBO (hazard ratio, 2.24; 95% confidence interval, 0.95-5.25; p = 0.065) were not significantly different between the two groups. Tumor involvement of the pancreatic duct was identified as a risk-reducing factor for pancreatitis, while an FCSEMS diameter of 6 mm was not identified as a risk factor for RBO and stent migration. Conclusions: Stent-related NER was not significantly affected by FCSEMS diameter. Further studies are needed to confirm the usefulness of 6-mm diameter FCSEMS for preoperative biliary drainage in patients with borderline resectable pancreatic cancer.

Bone loss over time and risk of osteoporosis in advanced pancreatic cancer.

BACKGROUND: Pancreatic cancer has a high risk of developing osteoporosis. However, the impact of osteoporosis has not been well-studied. This study aimed to evaluate bone loss over time and risk of osteoporosis in patients with advanced pancreatic cancer. METHODS: We retrospectively examined consecutive patients with unresectable pancreatic cancer who had evaluable computed tomography before treatment and at 1-year follow-up. Bone mineral density at the first lumbar vertebra was measured on computed tomography, and osteoporosis was defined as bone mineral density < 135 Hounsfield units. The prevalence and risk factors for osteoporosis, changes in bone mineral density over time and incidence of bone fractures were analyzed. RESULTS: Three hundred eighty patients were included. Osteoporosis was associated with older age, female sex, low body mass index and poor performance status at baseline. A consistent decrease in bone mineral density was observed over time regardless of age, sex or disease status, resulting in an increase in the prevalence of osteoporosis over time (47% at baseline, 79% at 1 year, 88% at 2 years, 89% at 3 years, 95% at 4 years and 100% at 5 years). Changes in bone mineral density from baseline were greater in patients with locally-advanced pancreatic cancer, in those who received modified FOLFIRINOX or S-IROX for more than 3 months, and in those who received radiation therapy. Incident fractures developed in 45 patients (12%) during follow-up. CONCLUSIONS: Osteoporosis and osteoporotic fractures were highly prevalent in patients with advanced pancreatic cancer. This study highlights the importance of screening for osteoporosis in such patients.

Current Status of Targeted Therapy for Biliary Tract Cancer in the Era of Precision Medicine.

First-line chemotherapy has been established for advanced biliary tract cancer (BTC). However, few treatment options are available as second-line treatment. Advances in comprehensive genomic analysis revealed that nearly half of patients with BTC harbor targetable genetic alterations such as fibroblast growth factor receptor (FGFR), isocitrate dehydrogenase (IDH), BRAF, human epidermal growth factor receptor 2 (HER2), microsatellite instability (MSI)-high, neurotrophic tropomyosin receptor kinase (NTRK), rearranged during transfection (RET), and poly (adenosine diphosphate-ribose) polymerase (PARP). This review summarizes currently available options in precision medicine and clinical trials for patients with advanced BTC.

Rotatable sphincterotome as a rescue device for endoscopic retrograde cholangiopancreatography cannulation: a single-center experience.

BACKGROUND/AIMS: Selective bile duct or pancreatic duct cannulation remains a significant initial hurdle in endoscopic retrograde cholangiopancreatography (ERCP) despite advances in endoscopy and accessories. This study evaluated our experience with a rotatable sphincterotome in cases of difficult cannulation. METHODS: We retrospectively reviewed ERCP cases using TRUEtome, a rotatable sphincterotome, as a rescue device for cannulation at a cancer institute in Japan from October 2014 to December 2021. RESULTS: TRUEtome was used in 88 patients. Duodenoscopes were used for 51 patients, while single-balloon enteroscopes (SBE) were used for 37 patients. TRUEtome was used for biliary and pancreatic duct cannulation (84.1%), intrahepatic bile duct selection (12.5%), and strictures of the afferent limb (3.4%). Cannulation success rates were similar in the duodenoscope and SBE groups (86.3% vs. 75.7%, p=0.213). TRUEtome was more commonly used in cases with steep cannulation angles in the duodenoscope group and in cases requiring cannulation in different directions in the SBE group. There were no significant differences in adverse events between the two groups. CONCLUSION: The cannulation sphincterotome was useful for difficult cannulations in both unaltered and surgically altered anatomies. It may be an option to consider before high-risk procedures such as precut and endoscopic ultrasound-guided rendezvous techniques.

Risk factors for recurrent stenosis after balloon dilation for benign hepaticojejunostomy anastomotic stricture.

BACKGROUND/AIMS: Hepaticojejunostomy anastomotic stricture (HJAS) is a feared adverse event associated with hepatopancreatobiliary surgery. Although balloon dilation for benign HJAS during endoscopic retrograde cholangiopancreatography with balloon-assisted enteroscopy has been reported to be useful, the treatment strategy remains controversial. Therefore, we evaluated the outcomes and risk factors of recurrent stenosis after balloon dilation alone for benign HJAS. METHODS: We retrospectively analyzed consecutive patients who underwent balloon-assisted enteroscopy-endoscopic retrograde cholangiopancreatography for benign HJAS at our institution between July 2014 and December 2020. RESULTS: Forty-six patients were included, 16 of whom had recurrent HJAS after balloon dilation. The patency rates at 1 and 2 years after balloon dilation were 76.8% and 64.2%, respectively. Presence of a residual balloon notch during balloon dilation was an independent predictor of recurrence (hazard ratio, 2.80; 95% confidence interval, 1.01-7.78; p=0.048), whereas HJAS within postoperative 1 year tended to be associated with recurrence (hazard ratio, 2.43; 95% confidence interval, 0.85-6.89; p=0.096). The patency rates in patients without a residual balloon notch were 82.1% and 73.1% after 1 and 2 years, respectively. CONCLUSION: Balloon dilation alone may be a viable option for patients with benign HJAS without residual balloon notches on fluoroscopy.

Splenic Hilar Involvement and Sinistral Portal Hypertension in Unresectable Pancreatic Tail Cancer.

BACKGROUND: Pancreatic tail cancer (PTC) frequently displays splenic hilar involvement (SHI), but its impact on clinical outcomes remains unclear. We investigated the clinical impact of SHI in patients with unresectable PTC. METHODS: We retrospectively reviewed all patients with unresectable PTC who received first-line therapy at our institution from 2016 to 2020. RESULTS: Of the 111 included patients, 48 had SHI at diagnosis. SHI was significantly associated with younger age, liver metastasis, peritoneal dissemination, larger tumor size, modified Glasgow prognostic score of 1 or more, splenic artery involvement, gastric varices, and splenomegaly. Shorter median overall survival (OS; 9.3 vs. 11.6 months, p = 0.003) and progression-free survival (PFS; 4.3 vs. 6.3 months, p = 0.013) were observed in SHI patients. Poor performance status of 1 or 2, tumor size > 50 mm, hepatic metastasis, mGPS of 1 or 2, and SHI (hazard ratio: 1.65, 95% confidence interval: 1.08-2.52, p = 0.020) were independent predictors of shorter OS. Splenic artery pseudoaneurysm rupture and variceal rupture were rare and only observed in cases with SHI. CONCLUSIONS: Splenic hilar involvement is associated with worse outcomes in pancreatic tail cancer.

The impact of osteosarcopenia in patients with unresectable or recurrent biliary tract cancer receiving palliative chemotherapy.

BACKGROUND: Osteosarcopenia is a newly described syndrome that has been reported to be associated with worse outcomes in various types of cancer. However, its impact on survival in biliary tract cancer remains unclear. This study evaluated the impact of osteosarcopenia on survival in patients with unresectable or recurrent biliary tract cancer. METHODS: A total of 306 patients with unresectable or recurrent biliary tract cancer who initiated chemotherapy at our institution between 2015 and 2021 were retrospectively investigated. Skeletal muscle index and bone mineral density were measured using pretreatment cross-sectional computed tomography images. Baseline characteristics and survival outcomes were compared between patients with osteosarcopenia and those without. The Cox proportional hazards regression model was used to identify factors associated with survival. RESULTS: Osteosarcopenia was present in 66 patients (22%) and was associated with older age (74 vs. 69 years, P < 0.001) and female sex (58 vs. 37%, P = 0.003). Patients with osteosarcopenia tended to have worse performance status (P = 0.098), higher modified Glasgow prognostic score (P = 0.082), higher neutrophil to lymphocyte ratio (P = 0.058) and were significantly less likely to receive combination chemotherapy (68 vs. 80%, P = 0.044) than those without. Osteosarcopenia was associated with reduced survival (8.9 vs. 14.0 months, P < 0.001) and was identified as an independent factor predicting shorter survival in multivariate analysis. CONCLUSIONS: Osteosarcopenia was associated with poor survival in unresectable or recurrent biliary tract cancer treated with chemotherapy. This study highlights the potential importance of screening for osteosarcopenia in patients with biliary tract cancer.

Safety and Effectiveness of Chemotherapy in Elderly Biliary Tract Cancer Patients.

The safety and effectiveness of chemotherapy in elderly patients with biliary tract cancer (BTC) remain unclear. Therefore, we retrospectively reviewed patients who underwent chemotherapy for locally advanced, metastatic, or recurrent BTC at our institution from January 2016 to December 2021. Of the 283 included patients, 91 (32.5%) were aged 75 years or older when initiating chemotherapy. Elderly patients were more likely than non-elderly patients to receive monotherapy with gemcitabine or S-1 (58.7% vs. 9.4%, p < 0.001) and were less likely to experience grade 3-4 toxicities (55.4% vs. 70.2%, p = 0.015). The rates of termination due to intolerance (6.5% vs. 5.8%, p = 0.800) and transition to second-line chemotherapy (39.1% vs. 40.3%, p = 0.849) were similar between groups. In the overall cohort, age was not an independent predictor of overall survival (OS). Within the elderly cohort, there were no differences in severe adverse events between patients receiving monotherapy and combination therapy (50.0% vs. 63.2%, p = 0.211). Median OS was longer in the combination therapy group (10.4 vs. 14.1 months; p = 0.010); however, choice of monotherapy was not an independent predictor of overall survival. Monotherapy appears to be a viable alternative in selected elderly BTC patients.

Outcomes of lung oligometastasis in pancreatic cancer.

OBJECTIVE: Pancreatic cancer with lung oligometastasis may have favourable overall survival. The aim of this study was to evaluate outcomes of pancreatic cancer with lung oligometastases including both synchronous and metachronous metastases. METHODS: Consecutive pancreatic cancer patients with lung metastasis treated at our institution between February 2015 and December 2021 were identified from our prospectively maintained database. Clinical characteristics and outcomes were compared and analysed according to the extent of lung metastases. Predictors for overall survival were analysed using the Cox proportional hazards model. RESULTS: A totoal of 171 patients were included (oligometastasis/polymetastasis/multi-organ metastasis: 34/50/87). Patients with oligometastases were more likely to undergo surgical resection (41% vs. 0% vs. 2%) and showed a longer median overall survival (41.3 vs. 17.6 vs. 13.1 months) compared with those with other types of metastases. Oligometastasis (hazard ratio, 0.43; 95% confidence interval, 0.24-0.76; P = 0.004) was identified as an independent factor predicting favourable overall survival in patients with lung-only metastasis. Disease status (synchronous vs. metachronous) was not associated with survival in patients with oligometastasis (29.4 vs. 41.3 months, P = 0.527) and polymetastasis (17.9 vs. 16.7 months, P = 0.545). Selected patients who underwent surgical resection showed a median overall survival of 52.7 months. CONCLUSIONS: Patients with lung oligometastases presented a favourable prognosis. Surgical resection in selected patients was associated with a long median overall survival.

Outcomes of Intraductal Placement of Covered Metal Stents for Unresectable Distal Malignant Biliary Obstruction.

Intraductal self-expandable metal stent (SEMS) placement may prolong stent patency by reducing duodenobiliary reflux. This study aimed to evaluate the efficacy and safety of this biliary drainage method in patients with unresectable distal malignant biliary obstruction (MBO). Consecutive patients with unresectable MBO who underwent initial covered SEMS placement between 2015 and 2022 were retrospectively reviewed. We compared the causes of recurrent biliary obstruction (RBO), time to RBO (TRBO), adverse events (AEs), and reintervention rates between two biliary drainage methods (SEMSs placed above and across the papilla). A total of 86 patients were included (above: 38 and across: 48). Overall RBO rates (24% vs. 44%, p = 0.069) and median TRBO (11.6 months vs. 9.8 months, p = 0.189) were not significantly different between the two groups. The frequency of overall AEs was similar between the two groups in the entire cohort, but was significantly lower in patients with non-pancreatic cancer (6% vs. 44%, p = 0.035). Reintervention was successfully performed in the majority of patients in both groups. Intraductal SEMS placement was not associated with a prolonged TRBO in this study. Larger studies are warranted to further evaluate the benefit of intraductal SEMS placement.

Prognostic impact of osteosarcopenia in patients with advanced pancreatic cancer receiving gemcitabine plus nab-paclitaxel.

BACKGROUND: Osteosarcopenia, defined as the combination of osteoporosis and sarcopenia, has recently gained attention as a novel prognostic factor for survival in patients with cancer. This study aimed to evaluate the prognostic impact of osteosarcopenia in metastatic pancreatic cancer (PC). METHODS: We retrospectively investigated consecutive metastatic PC patients receiving first-line gemcitabine plus nab-paclitaxel (GnP). Skeletal muscle index at the third lumbar vertebra and bone mineral density at the first lumbar vertebra were measured using pretreatment computed tomography. Treatment outcomes of osteosarcopenia and non-osteosarcopenia groups were compared and analyzed. Multivariate analysis was performed to identify variables associated with survival. RESULTS: Among 313 patients, osteosarcopenia was present in 59 patients (19%). The osteosarcopenia group was associated with older age, higher proportion of females, worse performance status, and higher modified Glasgow prognostic scores (mGPS). Response rates to chemotherapy, progression-free survival (3.5 months vs. 6.4 months, p < 0.001), and overall survival (5.6 months vs. 13.0 months, p < 0.001) were significantly better in the non-osteosarcopenia group. Osteosarcopenia, performance status of 1-2, mGPS score of 1-2, carcinoembryonic antigen ≥10 ng/mL, and carbohydrate antigen 19-9 ≥ 1000 IU/mL were identified as independent factors predicting shorter survival. Grade 3 or higher anemia and febrile neutropenia occurred more frequently in the osteosarcopenia group. CONCLUSIONS: Osteosarcopenia was associated with poor survival in metastatic PC treated with first-line GnP. Screening for osteosarcopenia may be helpful for better management of metastatic PC.

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.

Treatment Outcomes and Prognostic Factors of Gemcitabine Plus Nab-Paclitaxel as Second-Line Chemotherapy after Modified FOLFIRINOX in Unresectable Pancreatic Cancer.

Outcomes and prognostic factors of second-line gemcitabine plus nab-paclitaxel (GnP) after modified FOLFIRINOX (mFFX) for unresectable pancreatic cancer were unclear. We retrospectively analyzed consecutive patients with unresectable pancreatic cancer treated with GnP after first-line mFFX treatment between March 2015 and March 2022 at our hospital. A total of 103 patients were included. Median overall survival (OS) from the start of first-line and second-line treatments was 14.9 months and 7.2 months, respectively. Median progression-free survival (PFS) was 3.6 months. Performance status, modified Glasgow prognostic score, and neutrophil-to-lymphocyte ratio were independently associated with OS. Our prognostic model using these parameters classifies patients into good (n = 70) and poor (n = 33) prognosis groups. Median OS and PFS were longer in the good prognosis group than in the poor prognosis group (OS: 9.3 vs. 3.8 months, p < 0.01; PFS: 4.1 vs. 2.3 months, p < 0.01). Grade 3/4 adverse events were observed in 70.9% of patients, with neutropenia being the most frequent. While GnP as second-line treatment was well-tolerated, efficacy of second-line gemcitabine plus nab-paclitaxel was notably limited, particularly in the poor prognosis group.

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.

Long-term outcomes of duckbill-type anti-reflux metal stents versus conventional covered metal stents in reinterventions after covered biliary metal stent dysfunction in unresectable pancreatic cancer.

BACKGROUND: The use of duckbill-type anti-reflux metal stents (DMS) in reinterventions after covered metal stent (CMS) dysfunction has been reported in patients with distal malignant biliary obstruction (MBO). However, the superiority of DMS over conventional CMS (c-CMS) has not been established. Therefore, we conducted this retrospective study to evaluate the long-term efficacy and safety of DMS as a second stent in comparison with c-CMS. METHODS: We investigated consecutive patients with distal MBO due to unresectable pancreatic cancer who underwent reintervention after dysfunction of initial biliary CMS at our institution. We compared causes of recurrent biliary obstruction (RBO), time to RBO (TRBO), adverse events (AEs), and reintervention rates of DMS and c-CMS in this stenting. RESULTS: A total of 76 patients were included (DMS 41 and c-CMS 35). While overall RBO rates were similar between the two groups (46% vs. 63%, p = 0.172), RBO due to non-occlusion cholangitis tended to be less frequent in the DMS group than in the c-CMS group (2% vs. 14%, p = 0.089). Median TRBO was significantly longer in the DMS group (286 days vs. 112 days, p = 0.029). DMS was identified as the only significant risk factor for TRBO (hazard ratio, 0.52; p = 0.044). Overall AE rates were significantly lower in the DMS group (2% vs. 23%, p = 0.010), with non-occlusion cholangitis being the most common AE in the c-CMS group. Endoscopic reintervention was successfully performed in all patients in both groups, despite failed stent removal in 15% of patients in DMS group. CONCLUSIONS: DMS was associated with a significantly longer TRBO and lower rate of AEs compared with c-CMS in reinterventions after initial CMS dysfunction. DMS may be preferable to c-CMS as a second stent after biliary CMS dysfunction.