An atypical case of isolated immunoglobulin G4-related sclerosing cholangitis with a cholangiogram resembling primary sclerosing cholangitis.

An asymptomatic 77-year-old man with intrahepatic bile duct dilation was referred to our hospital. Cholangiography revealed alternations between strictures and dilated segments from the right and left hepatic ducts to the lower bile ducts, with findings of a pruned tree, beaded, shaggy appearance, and diverticulum-like outpouching. Histopathology revealed abundant immunoglobulin G4 (IgG4)-positive plasma cells (> 10 per high-power field) with an IgG4/IgG-positive cell ratio of 40-50%. After 2 weeks of steroid therapy, the cholangiography markedly improved. Because the cholangiographic findings resembled those of primary sclerosing cholangitis, steroid therapy proved useful in differentiating IgG4-related sclerosing cholangitis from primary sclerosing cholangitis.

Impact of sarcopenia on biliary drainage during neoadjuvant therapy for pancreatic cancer.

BACKGROUND/AIMS: Since the usefulness of neoadjuvant chemo(radiation) therapy (NAT) for pancreatic cancer has been demonstrated, recurrent biliary obstruction (RBO) in patients with pancreatic cancer with a fully covered self-expandable metal stent (FCSEMS) during NAT is expected to increase. This study investigated the impact of sarcopenia on RBO in this setting. METHODS: Patients were divided into normal and low skeletal muscle index (SMI) groups and retrospectively analyzed. Patient characteristics, overall survival, time to RBO (TRBO), stent-related adverse events, and postoperative complications were compared between the two groups. A Cox proportional hazard model was used to identify the risk factors for short TRBO. RESULTS: A few significant differences were observed in patient characteristics, overall survival, stent-related adverse events, and postoperative complications between 38 patients in the normal SMI group and 17 in the low SMI group. The median TRBO was not reached in the normal SMI group and was 112 days in the low SMI group (p=0.004). In multivariate analysis, low SMI was the only risk factor for short TRBO, with a hazard ratio of 5.707 (95% confidence interval, 1.148-28.381; p=0.033). CONCLUSION: Sarcopenia was identified as an independent risk factor for RBO in patients with pancreatic cancer with FCSEMS during NAT.

Outcomes of endoscopic papillectomy of ampullary carcinoma and factors affecting additional surgery.

BACKGROUND/PURPOSE: Data on the prognosis of endoscopic papillectomy (EP) for ampullary carcinoma (AC) is limited; therefore, we aimed to identify the factors associated with endoscopically controlled AC. METHODS: Between January 2003 and October 2022, 75 patients underwent EP for ampullary tumors and were diagnosed with AC based on the pathological features of the resected tissue. The factors associated with additional surgery after EP were also evaluated. RESULTS: A total of 67 patients had ACs ranging from carcinoma in situ to tumors limited to the mucosa (M group), and eight patients had ACs ranging from those limited to the sphincter of Oddi to those invading the duodenal muscularis propria (OD group). The 3-year endoscopic tumor control (condition not requiring additional surgery) rates in the M and OD groups were 90.8% and 84.6% (p = .033), respectively. In the M group, the presence of tumor components in the resection margins was the only significant factor associated with additional surgeries (p = .010) in the univariate analysis. The 3-year endoscopic tumor control rates were 100% for negative and uncertain resection margins and 76.6% for positive margins (p = .009). CONCLUSIONS: If the AC is confined to the mucosa and the resection margins are negative or uncertain, the tumor can be well-controlled endoscopically.

True diagnostic ability of EUS-guided fine-needle aspiration/biopsy sampling for small pancreatic lesions ≤10 mm and salvage diagnosis by pancreatic juice cytology: a multicenter study.

BACKGROUND AND AIMS: The diagnostic performance of EUS-guided fine-needle aspiration/biopsy sampling (EUS-FNAB) for pancreatic ductal adenocarcinoma (PDAC) ≤10 mm in diameter is relatively low. Pancreatic juice cytology (PJC) has gained attention because of its high sensitivity for small PDACs. We aimed to clarify the diagnostic ability of EUS-FNAB and the salvage ability of PJC for PDAC ≤10 mm. METHODS: Data obtained from attempted EUS-FNAB for patients with EUS-confirmed pancreatic tumors ≤10 mm (excluding pancreatic metastases/malignant lymphomas) were retrospectively analyzed. Patients who experienced technical failure or had a negative EUS-FNAB result and had a strong likelihood of PDAC based on imaging characteristics underwent PJC. PDAC was diagnosed using resected histologic specimens, EUS-FNAB-positive tumor growth on the imaging examination, or additional EUS-FNAB-positive results after increase in tumor size. The primary endpoint was the diagnostic ability of EUS-FNAB for PDAC ≤10 mm. The salvage ability of PJC was also assessed. RESULTS: Overall, 86 of 271 patients with pancreatic tumors ≤10 mm who underwent attempted EUS-FNAB were diagnosed with PDAC. The technical success rate, sensitivity, specificity, and accuracy of EUS-FNAB for PDAC ≤10 mm were 80.8%, 82.3%, 94.9%, and 91.3%, respectively. Among the 35 PDAC patients who experienced technical failure or false-negative results of EUS-FNAB, 26 (74.3%) were correctly diagnosed using salvage PJC. CONCLUSIONS: The true success rate and sensitivity of EUS-FNAB for PDAC ≤10 mm were relatively low. When EUS-FNAB for a pancreatic lesion ≤10 mm strongly suspected to be PDAC is unsuccessful or yields a negative result, PJC is recommended. (Clinical trial registration number: UMIN000049965.).

Current status of and future issues related to endoscopic papillectomy.

Endoscopic papillectomy is widely performed to treat duodenal papillary tumors, particularly at high-volume centers. It is indicated for adenomas without intraductal extension of the bile or pancreatic ducts. However, despite numerous reports of carcinomas that expand the indications to include well-differentiated adenocarcinomas that do not invade the sphincter of Oddi, the low agreement between biopsy and final pathological diagnosis, as well as the current inability of imaging modalities to diagnose sphincter of Oddi invasion, makes it difficult to consider expanding indications. Although complications can be prevented by certain methods, such as pancreatic duct stenting, and the frequency of severe complications has decreased, the safety of the procedure remains unconfirmed. In the future, this technology is expected to progress and enable wider applications, including those in tumors with extensive horizontal spread and those with intraductal extension of the bile and pancreatic ducts. Such technology may also improve the safety and accuracy of diagnosis.

Cutting edge of endoscopic ultrasound-guided fine-needle aspiration for solid pancreatic lesions.

This article provides an extensive review of the advancements and future perspectives related to endoscopic ultrasound-guided tissue acquisition (EUS-TA) for the diagnosis of solid pancreatic lesions (SPLs). EUS-TA, including fine-needle aspiration (EUS-FNA) and fine-needle biopsy (EUS-FNB), has revolutionized the collection of specimens from intra-abdominal organs, including the pancreas. Improvements in the design of needles, collection methods, and specimen processing techniques have improved the diagnostic performance. This review highlights the latest findings regarding needle evolution, actuation number, sampling methods, specimen evaluation techniques, application of artificial intelligence (AI) for diagnostic purposes, and use of comprehensive genomic profiling (CGP). It acknowledges the rising use of Franseen and fork-tip needles for EUS-FNB and emphasizes that the optimal number of actuations requires further study. Methods such as the door-knocking and fanning techniques have shown promise for increasing diagnostic performance. Macroscopic on-site evaluation (MOSE) is presented as a practical rapid specimen evaluation method, and the integration of AI is identified as a potentially impactful development. The study also underscores the importance of optimal sampling for CGP, which can enhance the precision of cancer treatment. Ongoing research and technological innovations will further improve the accuracy and efficacy of EUS-TA.

Real-World Effectiveness and Risk Factors for Discontinuation of Ustekinumab in Ulcerative Colitis.

Introduction: Ustekinumab (UST) has been approved for the treatment of moderate-to-severe ulcerative colitis (UC). Real-world data showing the effectiveness and safety of UST are necessary to confirm the results of clinical trials for applicability in daily clinical practice. Although some studies have reported real-world evidence of UST, only few studies have confirmed its effectiveness in the real world. The aim of this study was to assess the short- and long-term effectiveness, durability, safety, and risk factors for discontinuation of UST in UC in clinical practice. Methods: This was a retrospective, single-center, observational study. From March 2020 to January 2023, all consecutive patients with active UC who were treated with UST at Nagoya University Hospital were included. The primary outcome was the clinical remission rate at weeks 2-8 and weeks 24-48. The secondary outcomes included clinical response, persistence of UST therapy, endoscopic changes during follow-up, risk factors for UST discontinuation, and occurrence of any adverse events. The clinical effectiveness was evaluated using the Lichtiger score. Results: A total of 31 patients were included in this study. The clinical remission rates were 9.7%, 29.0%, 54.8%, and 64.5% at weeks 2, 8, 24, and 48, respectively. Twelve (38.7%) patients discontinued UST during the follow-up period. The probability of continuing UST was 93.5%, 80.6%, 77%, and 70% at weeks 2, 8, 24, and 48, respectively. The major reason for discontinuation of UST was primary failure (75.0%). A high baseline C-reactive protein (CRP) level was a significant risk factor for the discontinuation of UST. No adverse events were observed in this study. Conclusion: UST is effective for patients with UC. High CRP levels were identified as a risk factor for UST discontinuation. The findings of this study would help clinicians to select appropriate treatment options for patients with UC by identifying the risk factors for treatment discontinuation.

Low-dose gemcitabine plus nab-paclitaxel versus standard-dose gemcitabine plus nab-paclitaxel in elderly patients with metastatic pancreatic cancer: A randomized Phase II trial.

Background and Aim: A multicenter, open-label randomized Phase II trial was conducted to determine whether low-dose gemcitabine plus nab-paclitaxel (GnP) could improve tolerability and show equivalent efficacy to the standard-dose GnP for elderly patients with metastatic pancreatic cancer. Methods: Consecutive patients aged ≥65 years with metastatic pancreatic cancer who presented at one of four Japanese referral centers between November 2016 and January 2021 were enrolled. The 60 patients were randomly assigned to low- or standard-dose groups with a 1:1 ratio. Patients in the low-dose GnP group received gemcitabine at a dose of 250 mg/m2 and nab-paclitaxel at 125 mg/m2. Results: Low-dose GnP significantly decreased the rate of cases requiring dose reduction (16.7% vs 63.3%). The response rate (36.7% vs 33.3%) and progression-free survival (7.3 vs 8 months) were comparable between the low- and standard-dose groups as determined by independent review. The difference in the median overall survival between the two groups was not significant (7.9 vs 12 months). The proportion of patients with hematologic and non-hematologic treatment-related adverse events was comparable between the two groups. Conclusion: Low-dose GnP had an equivalent efficacy to conventional therapy; however, it did not reduce adverse events.

Clinical characteristics of Dieulafoy's lesion in the small bowel diagnosed and treated by double-balloon endoscopy.

BACKGROUND: Obscure gastrointestinal bleeding refers to bleeding for which the source cannot be ascertained even through balloon-assisted endoscopy. In certain instances, Dieulafoy's lesion in the small bowel is presumed to be the underlying cause. AIM: This retrospective study aimed to elucidate the clinical characteristics of Dieulafoy's lesion in the small bowel as diagnosed via double-balloon endoscopy while also exploring the feasibility of predicting bleeding from Dieulafoy's lesion prior to endoscopy in cases of obscure gastrointestinal bleeding. METHODS: A comprehensive analysis of our database was conducted, identifying 38 patients who received a diagnosis of Dieulafoy's lesion and subsequently underwent treatment via double-balloon endoscopy. The clinical background, diagnosis, and treatment details of patients with Dieulafoy's lesion were carefully examined. RESULTS: The median age of the 38 patients was 72 years, and 50% of the patients were male. A total of 26 (68%) patients exhibited a high comorbidity index. The upper jejunum and lower ileum were the most frequently reported locations for the occurrence of Dieulafoy's lesion in the small bowel. The detected Dieulafoy's lesions exhibited active bleeding (n = 33) and an exposed vessel with plaque on the surface (n = 5). Rebleeding after endoscopic treatment occurred in 8 patients (21%, median period: 7 days, range: 1-366 days). We conducted an analysis to determine the definitive nature of the initial double-balloon endoscopy diagnosis. Multivariate analysis revealed that hematochezia of ≥ 2 episodes constituted the independent factor associated with ≥ 2 double-balloon endoscopy diagnoses. Additionally, we explored factors associated with rebleeding following endoscopic treatment. Although the number of hemoclips utilized displayed a likely association, multivariate analysis did not identify any independent factor associated with rebleeding. CONCLUSION: If a patient encounters multiple instances of hematochezia, promptly scheduling balloon-assisted endoscopy, equipped with optional instruments without delay is advised, after standard endoscopic evaluation with esophagogastroduodenoscopy and colonoscopy is unrevealing.

Impact of Smad4 and p53 mutations on the prognosis of patients with pancreatic ductal adenocarcinoma undergoing chemotherapy.

BACKGROUND: This prospective cohort study evaluated the feasibility of using endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) samples for comprehensive mutational analysis of cancer-related genes using microtissues. METHODS: Fifty patients with suspected pancreatic cancer presenting consecutively at the Kindai University Hospital between January 2018 and January 2019 were enrolled. Cancerous tissues from EUS-FNB were obtained from each tumor and subjected to histological examination and mutational analysis. The primary endpoint was the collection rate of EUS-FNB specimens suitable for comprehensive cancer panels using deep sequencing. Clinical history and genetic variations between the disease control and progressive disease groups of patients on chemotherapy were evaluated as secondary endpoints. RESULTS: The collection rate of EUS-FNB specimens suitable for comprehensive cancer panels using deep sequencing was 93.6%. The cancer panel was sequenced for 25 patients with pancreatic cancer treated initially with systemic chemotherapy. Mutation in p53 and Smad4 were positively and negatively associated, respectively, with disease control at the initial evaluation. The median time to progression in 15 patients with p53 and without Smad4 mutations was 182.0 days; whereas, it was 92.5 days in other 10 patients; this difference was significant (p = 0.020). CONCLUSIONS: Tissue samples from EUS-FNB were suitable for mutational analysis. Pancreatic cancers with p53 and without Smad4 mutations responded better to chemotherapy and had a better prognosis than those others.

Artificial intelligence in a prediction model for postendoscopic retrograde cholangiopancreatography pancreatitis.

OBJECTIVES: In this study we aimed to develop an artificial intelligence-based model for predicting postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). METHODS: We retrospectively reviewed ERCP patients at Nagoya University Hospital (NUH) and Toyota Memorial Hospital (TMH). We constructed two prediction models, a random forest (RF), one of the machine-learning algorithms, and a logistic regression (LR) model. First, we selected features of each model from 40 possible features. Then the models were trained and validated using three fold cross-validation in the NUH cohort and tested in the TMH cohort. The area under the receiver operating characteristic curve (AUROC) was used to assess model performance. Finally, using the output parameters of the RF model, we classified the patients into low-, medium-, and high-risk groups. RESULTS: A total of 615 patients at NUH and 544 patients at TMH were enrolled. Ten features were selected for the RF model, including albumin, creatinine, biliary tract cancer, pancreatic cancer, bile duct stone, total procedure time, pancreatic duct injection, pancreatic guidewire-assisted technique without a pancreatic stent, intraductal ultrasonography, and bile duct biopsy. In the three fold cross-validation, the RF model showed better predictive ability than the LR model (AUROC 0.821 vs. 0.660). In the test, the RF model also showed better performance (AUROC 0.770 vs. 0.663, P = 0.002). Based on the RF model, we classified the patients according to the incidence of PEP (2.9%, 10.0%, and 23.9%). CONCLUSION: We developed an RF model. Machine-learning algorithms could be powerful tools to develop accurate prediction models.

Randomized trial comparing 15 vs 5 actuations per pass during endoscopic ultrasound-guided fine-needle biopsy for specimen acquisition of solid pancreatic lesions.

BACKGROUND AND AIM: There is currently no established number of actuations (to-and-fro movements) per pass during endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB). This study aimed to compare 15 vs 5 actuations in terms of adequate specimen acquisition of solid pancreatic lesions. METHODS: In this prospective, randomized, crossover, noninferiority, single-center study, eligible patients underwent EUS-FNB using a 22-G Franseen needle with both 15 and 5 actuations per pass, performed in a randomized order, from October 2020 to December 2021. The acquired specimens from each pass were separately evaluated. The primary outcome was the accuracy of the histological diagnosis per pass. The noninferiority margin was set as 15%. RESULTS: Data from 85 patients were analyzed, revealing pancreatic cancer in 73 patients. The accuracy of the histological diagnosis in the 15 and 5 actuations groups was 83.5% (71/85) and 77.7% (66/85), respectively. The difference was -5.8% (95% confidence interval -15.6-3.4), which does not indicate noninferiority of the five actuations group. Among the secondary outcomes, the 15 actuations group was significantly superior to the five actuations group in terms of the obtained core tissues (1.88 [interquartile range 0.89-3.64] mm2 vs 1.66 [0.83-2.71] mm2 [P = 0.031]) and subjective evaluation of cytology specimens for pancreatic cancer (69.0% vs. 31.0%, P = 0.005). CONCLUSIONS: The noninferiority of five actuations in the accuracy of the histological diagnosis was not confirmed, and 15 actuations are preferred during EUS-FNB for solid pancreatic lesions.

Endoscopic Ultrasound Can Differentiate High-Grade Pancreatic Intraepithelial Neoplasia, Small Pancreatic Ductal Adenocarcinoma, and Benign Stenosis.

Background/Aims: High-grade pancreatic intraepithelial neoplasia and invasive pancreatic ductal adenocarcinoma ≤10 mm are targets for early detection of pancreatic cancer. However, their imaging characteristics are unknown. We aimed to identify endoscopic ultrasound findings for the detection of these lesions. Methods: Patients diagnosed with high-grade pancreatic intraepithelial neoplasia (n=29), pancreatic ductal adenocarcinoma ≤10 mm (n=11) (who underwent surgical resection), or benign main pancreatic duct stenosis (n=20) between January 2014 and January 2021 were retrospectively included. Six features differentiating these lesions were examined by endoscopic ultrasonography: main pancreatic duct stenosis, upstream main pancreatic duct dilation, hypoechoic areas surrounding the main pancreatic duct irregularities (mottled areas without demarcation or round areas with demarcation), branch duct dilation, prominent lobular segmentation, and atrophy. Interobserver agreement was assessed by two independent observers. Results: Hypoechoic areas surrounding the main pancreatic duct irregularities were observed more frequently in high-grade pancreatic intraepithelial neoplasia (82.8%) and pancreatic ductal adenocarcinoma ≤10 mm (90.9%) than in benign stenosis (15.0%) (p<0.001). High-grade pancreatic intraepithelial neoplasia exhibited mottled hypoechoic areas more frequently (79.3% vs 18.9%, p<0.001), and round hypoechoic areas less frequently (3.4% vs 72.7%, p<0.001), than pancreatic ductal adenocarcinoma ≤10 mm. The sensitivity and specificity of hypoechoic areas for differentiating high-grade pancreatic intraepithelial neoplasia, pancreatic ductal adenocarcinoma ≤10 mm, and benign stenosis were both 85.0%, with moderate interobserver agreement. Conclusions: The hypoechoic areas surrounding main pancreatic duct irregularities on endoscopic ultrasound may differentiate between high-grade pancreatic intraepithelial neoplasia, pancreatic ductal adenocarcinoma ≤10 mm, and benign stenosis (Trial Registration: UMIN Clinical Trials Registry (UMIN000044789).

CO2 enterography in endoscopic retrograde cholangiography using double-balloon endoscopy: A randomized clinical trial.

BACKGROUND AND AIM: Double-balloon endoscopic retrograde cholangiography (DBERC) is a valuable procedure for patients with altered gastrointestinal anatomy. Nonetheless, it is time-consuming and burdensome for both patients and endoscopists, partly because route selection in the reconstructed bowel with complicating loop is challenging. Carbon dioxide insufflation enterography is reportedly useful for route selection in the blind loop. This prospective randomized clinical trial investigated the usefulness of carbon dioxide insufflation enterography for route selection by comparing it with conventional observation. METHODS: Patients scheduled to undergo DBERC were consecutively registered. They were divided into carbon dioxide insufflation enterography and conventional groups via randomization according to stratification factors, type of reconstruction methods, and experience with DBERC. The primary endpoint was the correct rate of initial route selection. The secondary endpoints were the insertion time, examination time, amount of anesthesia drugs, and complications. RESULTS: The correct rate of route selection was significantly higher in the carbon dioxide insufflation enterography group (23/25, 92%) than in the visual method (15/25, 60%) (P = 0.018). The insertion time was significantly shorter in the carbon dioxide insufflation enterography group than in the visual group (10.8 ± 11.1 min vs 29.8 ± 15.7 min; P < 0.001). No significant differences in complications were noted between the two groups. The amounts of sedatives and analgesics used were significantly lower in the carbon dioxide insufflation enterography group (P < 0.001 and P < 0.001, respectively). CONCLUSIONS: Carbon dioxide insufflation enterography can reduce the burden of DBERC on patients and endoscopists by shortening the examination time and reducing the amount of medication.

Uncovered versus covered expandable metal stents for malignant gastric outlet obstruction caused by intrinsic and extrinsic tumors: meta-analysis and meta-regression analysis.

BACKGROUND AND AIMS: Malignant gastric outlet obstruction (GOO) can be palliated by endoscopic placement of self-expandable metal stents (SEMSs). Studies comparing uncovered (USEMSs) and covered (CSEMSs) SEMSs have yielded inconclusive results. This meta-analysis compared USEMSs with CSEMSs in patients with GOO caused by intrinsic and extrinsic tumors. METHODS: Potentially relevant articles were identified by searching PubMed, the Cochrane Library, and Medline. The primary outcome was stent dysfunction. Relationships between characteristics of tumors causing GOO and the stent dysfunction rate following USEMSs and CSEMS placement were assessed. RESULTS: Overall, six randomized controlled trials and 12 observational studies, including 2431 patients, were identified. Rate of stent dysfunction did not differ significantly between USEMSs and CSEMSs (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.73-1.25, I2 = 44%), but there was heterogeneity. Meta-regression analysis showed that heterogeneity of stent dysfunction was caused by a difference in the ratio of intrinsic-to-extrinsic tumors causing GOO between studies (coefficient, 0.944; 95% CI, 0.30-1.58). Studies were divided into intrinsic and extrinsic tumor groups. Subgroup analysis showed that the stent dysfunction rate did not differ between USEMSs and CSEMSs in the intrinsic tumor group (OR, 1.10; 95% CI, 0.85-1.41; I2 = 32%). In the extrinsic tumor group, USEMS was associated with a lower rate of stent dysfunction than CSEMS (OR, 0.64; 95% CI, 0.47-0.87; I2 = 25%). CONCLUSION: USEMS and CSEMS placement generally showed comparable outcomes among patients with GOO. USEMS was more effective than CSEMS for patients with GOO caused by extrinsic tumors.

Pancreatic neuroendocrine carcinoma with unique morphological features mimicking intraductal papillary mucinous carcinoma: A case report.

Background: Pancreatic neuroendocrine carcinoma (PanNEC) is a rare disease entity with rapid progression and poor prognosis. Here, we report a PanNEC case with unique morphological features mimicking intraductal papillary mucinous carcinoma. Case presentation: A 69-year-old Japanese man was referred to our hospital for further evaluation of weight loss and deterioration of diabetes mellitus. Contrast-enhanced computed tomography showed a solid and cystic mass with hypo-enhancement at the tail of the pancreas. The main pancreatic duct (MPD) was diffusely dilated without obstruction, accompanied by marked parenchymal atrophy. Multiple peritoneal and omental nodules were observed, suggesting tumor dissemination. Endoscopic retrograde cholangiopancreatography revealed that the mass correlated with the dilated MPD. During pancreatography, a large amount of mucus was extruded from the pancreatic orifice of the ampulla. Based on these imaging findings, intraductal papillary mucinous carcinoma was suspected. Per-oral pancreatoscopy (POPS)-guided tumor biopsies were conducted for the lesion's solid components. Histopathological examination of the biopsied material confirmed small-cell-type PanNEC with a Ki-67 labeling index of 90%. Due to his condition's rapid decline, the patient was given the best supportive care and died 28 days after diagnosis. Conclusion: Although rare, PanNEC, which correlates with the MPD and is accompanied by marked dilation of the MPD, does exist as one phenotype. In such cases, POPS-guided biopsy could be a useful diagnostic modality.

Comparison of an Inside Stent and a Fully Covered Self-Expandable Metallic Stent as Preoperative Biliary Drainage for Patients with Resectable Perihilar Cholangiocarcinoma.

Background: There is a need for a more tolerable preoperative biliary drainage (PBD) method for perihilar cholangiocarcinoma (PHCC). In recent years, inside stents (ISs) have attracted attention as a less suffering PBD method. Few studies have compared IS with a fully covered self-expandable metallic stent (FCSEMS) as PBD for resectable PHCC. The aim of this study is to compare them. Methods: This study involved 86 consecutive patients (IS: 51; FCSEMS: 35). The recurrent biliary obstruction (RBO) rate until undergoing surgery or being diagnosed as unresectable, time to RBO, factors related to RBO, incidence of adverse events related to endoscopic retrograde cholangiography, and postoperative complications associated with each stent were evaluated retrospectively. Results: There was no significant difference between the two groups in the incidence of adverse events after stent insertion. After propensity score matching, the mean (SD) time to RBO was 37.9 (30.2) days in the IS group and 45.1 (35.1) days in the FCSEMS group, with no significant difference (P=0.912, log-rank test). A total of 7/51 patients in the IS group and 3/35 patients in the FCSEMS group developed RBO. The only risk factor for RBO was bile duct obstruction of the future excisional liver lobe(s) due to stenting (HR 29.8, P=0.008) in the FCSEMS group, but risk factors could not be indicated in the IS group. There was no significant difference in the incidence of bile leakage or liver failure. In contrast, pancreatic fistula was significantly more common in the FCSEMS group (13/23 patients) than in the IS group (3/28 patients) (P < 0.001), especially in patients who did not undergo pancreatectomy (P=0.001). Conclusions: As PBD, both IS and FCSEMS achieved low RBO rates. Compared with FCSEMS, IS shows no difference in RBO rate, is associated with fewer postoperative complications, and is considered an appropriate means of PBD for resectable PHCC. This trail is registered with UMIN000025631.