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.).

Learning Curve of Endoscopic Retrograde Cholangiopancreatography Using Single-Balloon Enteroscopy.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy is technically difficult. Extensive training is required to develop the ability to perform this procedure. AIMS: To investigate the learning curve of single-balloon-assisted enteroscopy ERCP (SBE-ERCP). METHODS: We conducted a retrospective, observational case series at a single center. We evaluated the SBE-ERCP procedures between April 2011 and February 2021. The main outcomes were the rate of reaching the target site and the success rate of the entire procedure. These parameters were additionally expressed as a learning curve. RESULTS: A total of 687 SBE-ERCP procedures were analyzed. The learning curve was analyzed in blocks of 10 cases. In this study, seven endoscopists, experts in conventional ERCP, were included. The overall SBE-ERCP procedural success rate was 92.2% (634/687 cases). Combining all data from individual endoscopists' evaluation periods, the insertion and success rates of the SBE-ERCP procedures gradually increased with increased experience performing SBE-ERCP. The insertion success rates for the number of SBE-ERCP cases (< 20, 21-30, > 30) were 82.9%, 92.9%, and 94.3%, respectively; the procedure success rates were 74.3%, 81.4%, and 92.9%, respectively. The endoscopists who had performed > 30 SBE-ERCP cases had a success rate of ≥ 90%. CONCLUSIONS: Our results suggest that performing > 30 cases is one of the targets for conventional ERCP experts to become competent in performing SBE-ERCP in patients with a surgically altered anatomy.

Severe acute respiratory syndrome coronavirus 2 prevalence in saliva and gastric and intestinal fluid in patients undergoing gastrointestinal endoscopy in coronavirus disease 2019 endemic areas: Prospective cross-sectional study in Japan.

OBJECTIVES: Gastrointestinal endoscopy (GIE) is useful for the early detection and treatment of many diseases; however, GIE is considered a high-risk procedure in the coronavirus disease 2019 (COVID-19) pandemic era. This study aimed to explore the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity in saliva and gastrointestinal fluids to which endoscopy medical staff are exposed. METHODS: The study was a single-center cross-sectional study. From June 1 to July 31, 2020, all patients who underwent GIE at Yokohama City University Hospital were registered. All patients provided 3 mL of saliva. For upper GIE, 10 mL of gastric fluid was collected through the endoscope. For lower GIE, 10 mL of intestinal fluid was collected through the endoscope. The primary outcome was the positive rate of SARS-CoV-2 in saliva and gastrointestinal fluids. We also analyzed serum-specific antibodies for SARS-CoV-2 and patients' background information. RESULTS: A total of 783 samples (560 upper GIE and 223 lower GIE samples) were analyzed. Polymerase chain reaction (PCR) on saliva samples did not show any positive results in either upper or lower GIE samples. However, 2.0% (16/783) of gastrointestinal fluid samples tested positive for SARS-CoV-2. No significant differences in age, sex, purpose of endoscopy, medication, or rate of antibody test positivity were found between PCR positive and PCR negative cases. CONCLUSIONS: Asymptomatic patients, even those with no detectable virus in their saliva, had SARS-CoV-2 in their gastrointestinal tract. Endoscopy medical staff should be aware of infection when performing procedures. The study was registered as UMIN000040587.

Effect of preventive closure of the frenulum after endoscopic papillectomy: A prospective pilot study.

BACKGROUND AND AIM: The usefulness of preventive closure of the frenulum after endoscopic papillectomy (EP) could reduce bleeding. The feasibility and safety of clipping were evaluated in this prospective pilot study. METHODS: This study involved 40 consecutive patients who underwent preventive closure of the frenulum by clipping just after EP. The outcome data were compared with those of the previous 40 patients in whom no preemptive closure had been performed (no-closure group) (UMIN000014783). Additionally, the bleeding sites were examined. RESULTS: The clipping procedure was successful in all patients. As compared to the no-closure group, the rate of bleeding (P = 0.026) and period of hospital stay (P < 0.001) were significantly reduced in the closure group. There was no difference in the procedure time between the two groups. Furthermore, the incidence rates of pancreatitis and perforation were comparable in the two groups. The bleeding was noted in the frenulum area rather than at any other site in 90.9% of cases. CONCLUSION: Preventive closure of the frenulum after EP is an effective, safe, rational, and economical method to reduce the incidence of delayed bleeding, without prolonging the procedure time or increasing the risk of post-procedure pancreatitis perforation.

Clinical features of isolated proximal-type immunoglobulin G4-related sclerosing cholangitis.

BACKGROUND AND AIM: Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) presents as isolated proximal-type sclerosing cholangitis (i-SC). The present study sought to clarify the imaging differences between i-SC and Klatskin tumor. Differences between i-SC and IgG4-SC associated with autoimmune pancreatitis (AIP-SC) were also studied. METHODS: Differentiating factors between i-SC and Klatskin tumor were studied. Serum IgG4 level, CA19-9 level, computed tomography (CT) findings, cholangiography findings (symmetrical smooth long stricture extending into the upper bile duct [SSLS]), endosonographic features (continuous symmetrical mucosal lesion to the hilar part [CSML]), endoscopic biopsy results, treatment, relapse, and survival were also compared between patients with i-SC and those with AIP-SC. RESULTS: For a differential diagnosis between i-SC (N = 9) and Klatskin tumor (N = 47), the cut-off value of serum IgG4 level was 150 mg/dL (sensitivity, 0.857, specificity, 0.966). Logistic regression analysis indicated that serum IgG4 level, presence of SSLS, presence of CSML, and presence of swollen ampulla are independent factor for identifying i-SC. Relapse rate was significantly higher in the IgG4-SC with AIP group than in the i-SC group (log rank, P = 0.046). CONCLUSION: Isolated proximal-type sclerosing cholangitis presents as a nodular lesion with SSLS and/or CSML mimicking a Klatskin tumor. Those endoscopic features might provide a diagnostic clue for i-SC. i-SC is likely to have a more favorable prognosis than IgG4-SC with AIP.

Gastroduodenal stenting with Niti-S stent: long-term benefits and additional stent intervention.

BACKGROUND AND AIM: Self-expandable metallic stents have mainly been used for the palliation of malignant gastric outlet obstruction (GOO). However, their use in long-term survivors and the feasibility, safety and benefit of additional intervention for stent dysfunction remain controversial. The present study examined the long-term benefits of endoscopic gastroduodenal stenting. METHODS: We reviewed 61 patients treated with Niti-S stents at several hospitals and estimated the efficacy of stent intervention, stent patency, eating period and factors related to poor effectiveness. RESULTS: All 61 first stent interventions and 14 additional stent interventions (11 second interventions and 3 third interventions) were successfully carried out. Clinical success rates were 83.6% and 85.7%, and median stent patency was 214 days and 146 days (P = 0.47), respectively. Fifty patients could be treated with a first stent only, and 11 patients received additional stents. At the time of study termination or death, 70.0% of the former group and 63.6% of the latter group maintained oral intake (P = 0.71), and each 86% and 100% among the group could maintain oral intake for a period exceeding half of their remaining lives after first stent intervention. Karnofsky performance status ≤50 (P = 0.03), ascites (P = 0.009), and peritoneal dissemination (P = 0.001) appeared to be factors related to poor effectiveness. CONCLUSIONS: Despite the presence of factors related to poor effectiveness, endoscopic gastroduodenal stenting would be the first treatment of choice for GOO and provide long-term benefits. If stent dysfunction occurs, additional stent intervention enables continued oral intake safely.

Endoscopic treatment of postoperative benign bile duct stricture compared with malignant bile duct stricture.

BACKGROUND/AIMS: Endoscopic treatment for postoperative benign bile duct stricture (BBS) is a therapeutic challenge. No previous studies have compared endoscopic treatments for BBS and malignant bile duct stricture (MBS). The aim of this study was to compare endoscopic treatments for postoperative BBS and MBS. METHODOLOGY: This study enrolled 22 consecutive patients with a diagnosis of postoperative BBS and 110 patients diagnosed with MBS. Cases involving digestive tract reconstruction were excluded. We compared the length of the bile duct strictures, the success rate of endoscopic treatment, and the incidence of complications. RESULTS: The following results were obtained for the postoperative BBS and MBS groups, respectively: length of bile duct stricture, 6.50 mm vs. 24.3 mm (P<0.0001); success rate of endoscopic treatment, 90.9% vs. 93.6% (P=0.6551). Post-ERCP pancreatitis occurred after 11 sessions (10.7%) vs. 7 sessions (1.83%) (P=0.0002), and post-ERCP cholangitis occurred after 7 sessions (6.80%) vs. 4 sessions (1.04%) (P=0.0021). BBS was a significant risk factor for post-ERCP pancreatitis and cholangitis based on a multivariate analysis (OR, 10.732; P=0.0022; OR, 6.443; P=0.0260). CONCLUSIONS: Post-ERCP-related complications were more frequent after postoperative BBS than after MBS. The need for careful endoscopic treatment may be greater for postoperative BBS cases than for MBS cases.

Covered self-expandable metal stent deployment promises safe neoadjuvant chemoradiation therapy in patients with borderline resectable pancreatic head cancer.

BACKGROUND: Patients with borderline resectable pancreatic head cancer (BRPHC) have been treated with neoadjuvant chemoradiation therapy (NACRT) using metallic stents. The aim of the present study was to evaluate the efficacy and complications of covered self-expanding metallic stents (CSEMS) during the NACRT and surgical period. PATIENTS AND METHODS: We reviewed the outcomes of patients with BRPHC, then divided them chronologically into three groups as follows. Group A: upfront surgery with plastic stent (PS) deployment; group B: PS deployment plus neoadjuvant chemotherapy (NAC) and/or NACRT; group C: CSEMS deployment plus NAC/NACRT. Patients were categorized as borderline resectable based on National Comprehensive Cancer Network Guidelines, 2010. Days to reintervention (DR), reintervention rate, and the rate of R0 and complications were studied. Safe margin-negative resection (R0) surgery was defined as R0 surgery without reintervention during the NACRT period and no postoperative complications. RESULTS: DR were as follows. Groups A, B and C were 32, 55 and 97 days, respectively (P < 0.05). R0 surgery obtained in groups A, B and C was 53% (9/17), 100% (17/17) and 93% (14/15), respectively. CSEMS did not interfere with surgery. Safe R0 surgery obtained in groups B and C was 11% (2/19) and 67% (10/15), respectively (P < 0.05). Multivariate analysis showed that the odds ratio for safe R0 surgery was 16.210 (95% CI 2.457-106.962, P = 0.003) for CSEMS placement. CONCLUSION: CSEMS should be considered to relieve symptomatic biliary obstruction in patients with BRPHC receiving NACRT in view of the high attainability rate of safe R0 surgery compared to that with PS deployment.

Endoscopic papillectomy could be rewarding to patients with early stage duodenal ampullary carcinoma?

BACKGROUND/PURPOSE: There is currently no consensus on the use of endoscopic papillectomy (EP) for early stage duodenal ampullary adenocarcinoma. This study aimed to evaluate the feasibility of EP for patients with early stage duodenal ampullary adenocarcinoma. METHODS: Patients who underwent EP for ampullary adenocarcinomas were investigated. Complete and clinical complete resection rates were evaluated. Clinical complete resection was defined as either complete resection or resection with positive or unknown margins but no cancer in the surgically resected specimen, or no recurrence on endoscopy after at least a 1-year follow-up. RESULTS: Adenocarcinoma developed in 30 patients (carcinoma in situ [Tis]: 21, mucosal tumors [T1a(M)]: 4, tumors in the sphincter of Oddi [T1a(OD)]: 5). The complete resection rate was 60.0% (18/30) (Tis: 66.7% [14/21], T1a[M]: 50.0% [2/4], and T1a[OD]: 40.0% [2/5]). The mean follow-up period was 46.8 months. The recurrence rate for all patients was 6.7% (2/30). The clinical complete resection rates of adenocarcinoma were 89.2% (25/28); rates for Tis, T1a(M), and T1a(OD) were 89.4% (17/19), 100% (4/4), and 80% (4/5), respectively. CONCLUSIONS: EP may potentially achieve clinical complete resection of early stage (Tis and T1a) duodenal ampullary adenocarcinomas.

IgG4-related pancreatobiliary diseases could be associated with onset of pancreatobiliary cancer: A multicenter cohort study.

BACKGROUND: The risk and prognosis of pancreatobiliary cancer and in patients with autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC) remain unclear. Therefore, we retrospectively investigated the risk of pancreatobiliary cancer and prognosis in patients with AIP and IgG4-SC. METHODS: Patients with AIP and IgG4-SC at seven centers between 1998 and 2022 were investigated. The following data were evaluated: (1) the number of cancers diagnosed and standardized incidence ratio (SIR) for pancreatobiliary and other cancers during the observational period and (2) prognosis after diagnosis of AIP and IgG4-SC using standardized mortality ratio (SMR). RESULTS: This study included 201 patients with AIP and IgG4-SC. The mean follow-up period was 5.7 years. Seven cases of pancreatic cancer were diagnosed, and the SIR was 8.11 (95% confidence interval [CI]: 7.29-9.13). Three cases of bile duct cancer were diagnosed, and the SIR was 6.89 (95% CI: 6.20-7.75). The SMR after the diagnosis of AIP and IgG4-SC in cases that developed pancreatobiliary cancer were 4.03 (95% CI: 2.83-6.99). CONCLUSIONS: Patients with autoimmune pancreatitis and IgG4-SC were associated with a high risk of pancreatic and bile duct cancer. Patients with AIP and IgG4-SC have a worse prognosis when they develop pancreatobiliary cancer.

A novel scoring system for arterial invasion of pancreatic body and tail cancer based on multidetector row computed tomography and biomarkers.

BACKGROUND/OBJECTIVES: The absence of major-vessel involvement is a crucial factor in the resectability and prognosis of pancreatic cancer. However, arterial invasion cannot be evaluated adequately using imaging findings alone. We therefore developed a scoring system to assess arterial invasion by pancreatic adenocarcinoma using multidetector row computed tomography (MDCT) and serum tumor markers. METHODS: Twenty patients who underwent distal pancreatectomy and splenectomy for pancreatic adenocarcinoma were examined retrospectively using 4-, 16- or 64-row MDCT and serum tumor markers. Splenic arterial invasion was evaluated in terms of length of tumor contact, circumferential involvement (<180° or ≥180°) and deformity of vascular diameter. Preoperative expression of carbohydrate antigen 19-9 (CA19-9), DUPAN-2 and S-Pancreas-1 antigen (SPan-1) were also evaluated. The presence or absence of arterial invasion was confirmed histopathologically in all 20 cases. RESULTS: In 11 of 20 cases invasion into splenic arteries was observed histopathologically, mostly involving the external elastic lamina and periarterial nerves. Sensitivity, specificity and accuracy were 100%, 88.9% and 95%, respectively, for length of tumor contact (<16 mm or ≥16 mm), 90.9%, 77.8% and 85% for circumferential involvement (<180° or ≥180°), and 100%, 66.7% and 85% for deformity of vascular diameter. Furthermore, the sensitivity, specificity and accuracy were all increased to 100% when tumor markers were included in the score. CONCLUSIONS: MDCT is a useful technique for diagnosing arterial invasion of pancreatic body and tail cancer, even in comparison with pathological examination; however, this new scoring system can be further complemented and made more reliable by measurements of serous tumor markers.

aPKCλ/ι is a beneficial prognostic marker for pancreatic neoplasms.

Pancreatic cancer is a lethal disease. Overall survival is typically 6 months from diagnosis. Determination of prognostic factors in pancreatic cancer that would allow identification of patients who could potentially benefit from aggressive treatment is important. However, until date, there are no established reliable prognostic factors for pancreatic cancer patients. Herein, we propose a beneficial biomarker which is significantly correlated with the prognosis in pancreatic cancer patients. Atypical protein kinase C λ/ι (aPKCλ/ι) is overexpressed and has been implicated in the progression of several cancers. We tested the expression levels of aPKCλ/ι in two types of pancreatic neoplasm, pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasms (IPMNs), by immunohistochemistry. Examination of the aPKCλ/ι expression levels in surgically resected specimens of PDCA (n = 115) demonstrated that the expression levels of aPKCλ/ιin PDAC had prognostic implications, independent of the Tumor-Node-Metastasis classification and World Health Organization tumor grade. In the case of IPMNs (n = 46) also, the expression levels of aPKCλ/ιin IPMN were found to be of prognostic importance, independent of the World Health Organization histological grade or morphological type. Interestingly, high expression levels of aPKCλ/ι were significantly correlated with a worse histological grade (p = 0.010) and advanced stage of the tumor (p = 0.0050) in IPMN patients. These findings suggest that high expression levels of aPKCλ/ι could be involved in the malignant transformation of IPMNs. Based on these observations, we propose the expression level of aPKCλ/ι as a prognostic marker common to different types of pancreatic neoplasms.

Positioning of nasobiliary tube using magnet-loaded catheters.

BACKGROUND AND STUDY AIMS: In endoscopic nasobiliary drainage (ENBD), repositioning the catheter from the mouth to the nose is complicated. We devised a method using catheters with magnets and verified its utility and safety. PATIENTS AND METHODS: We prospectively enrolled 20 patients undergoing ENBD at Yokohama City University Hospital. RESULTS: The procedures were successful in all 20 cases and no case required a change of operators to a senior doctor. The mean time for the procedure was 36.6 seconds. The emetic reflex was induced 0.5 times on average using the magnet method. The mean X-ray exposure time was 29.6 seconds. No complications occurred. CONCLUSIONS: The magnet-loaded catheter method for positioning the ENBD catheter before finally leading it through the nose took little time and was performed successfully and safely. Therefore, the magnet method could become the first choice among techniques for ENBD catheter placement.

Request for biliary drainage for IgG4-SC could be waived before steroid administration?

BACKGROUND: In IgG4-related sclerosing cholangitis (IgG4-SC), the necessity of biliary drainage (BD) is unclear. In this study, we aimed to retrospectively investigate the improvement of liver damage and jaundice in cases of IgG4-SC with and without BD, before starting steroids. METHODS: A total of 52 patients with IgG4-SC were investigated in the study. The study endpoints were the normalization rate of alkaline phosphatase (ALP)/total bilirubin (T-Bil) after 8 weeks of steroids, with and without BD. RESULTS: Propensity score matching was performed based on ALP and T-Bil, and 28 patients were included. There were 14 patients each in the BD and non-BD groups. Before initiation of steroids, the mean ALP in the BD group and the non-BD group was 378/461 (P = .541); the mean T-Bil was 2.5/1.8 (P = .401). Eight weeks after initiation of steroids, ALP improvement rate in the BD group/non-BD group was 69.2%/61.5% (P = 1.000), and T-Bil improvement rate was 100%/100% (P = Ns). CONCLUSIONS: Steroids for IgG4-SC could prove effective in improving liver damage and jaundice, regardless of the presence or absence of BD. BD for IgG4-SC aimed to improve jaundice may not be necessary.

Pre-emptive hydration with lactated Ringer's solution could reduce the incidence of post-endoscopic retrograde cholangiopancreatography pancreatitis in at-risk patients: Propensity score-matched analysis.

BACKGROUND/PURPOSE: This study aimed to investigate the efficacy of intensive fluid-loading therapy post-endoscopic retrograde cholangiopancreatography (ERCP) for the prevention of post-ERCP pancreatitis (PEP) in at-risk patients. METHODS: In this retrospective study, data of 1200 patients at risk for PEP were investigated. After propensity score matching, 404 patients were included in the normal (n = 202) and hydration (n = 202) groups. On the day of ERCP, patients in both groups were infused with 2000 ml/24 h of fluid before ERCP. Meanwhile, the hydration group received an additional 1000 ml/10 h of lactated Ringer's solution postoperatively. RESULTS: The incidence of PEP was lower in the hydration group (12.4%) than in the normal group (24.3%) (odds ratio [OR]: 0.44; 95% CI: 0.26-0.75, p = .003). The incidence of severe PEP was 2.0% and 6.9% in the hydration and normal groups (OR: 0.27; 95% CI: 0.09-0.84, p = .027), respectively. The incidence of fatal PEP was 0% and 2.0% in the hydration and normal groups (OR: N.A.: p = .123), respectively. CONCLUSIONS: Post-ERCP hydration may be an effective method of preventing PEP, including severe PEP, in at-risk patients.

Effectiveness and Prognostic Factors of Everolimus in Patients with Pancreatic Neuroendocrine Neoplasms.

Objective The effectiveness of everolimus for the management of pancreatic neuroendocrine neoplasms (PNENs), including the G3/NEC types, remains unclear. We therefore investigated the effectiveness of the drug for the management of PNENs. Methods We analyzed the progression-free survival (PFS) and overall survival (OS) associated with everolimus and factors influencing the PFS and OS. Results One hundred patients were evaluated. The PFS associated with the G1/G2 types tended to be significantly longer than that associated with the G3/NEC types [hazard ratio (HR), 0.45; p=0.005]. A multivariate analysis showed that the significant factors influencing the PFS were age (<65 years old; HR, 0.44; p=0.002), grade (G1/G2; HR, 0.42; p=0.006), everolimus treatment line (≤2nd; HR, 0.55; p=0.031), and presence of treatment with metformin (yes; HR, 0.29; p=0.044). The median OS was 63.8 months. In the multivariate analysis, the significant factors influencing the OS were grade (G1/G2; HR, 0.21; p<0.001), volume of liver metastasis (≤25%; HR, 0.27; p<0.001), everolimus treatment line (≤2nd; HR, 0.27; p<0.001), and presence of primary tumor resection (yes; HR, 0.33; p=0.005). Conclusion The effectiveness of everolimus in the management of G3/NEC types and prognoses tended to be poorer than those associated with the G1/G2 types. Everolimus combined with metformin and early-line treatment with everolimus may be effective for managing advanced PNENs.

Utility of Fine-Gauge Balloon Catheter for EUS-Guided Hepaticogastrostomy.

BACKGROUND AND PURPOSE: During endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS), tract dilation is one of the most important steps, and the placement of conventional metal stents with 8.5 Fr delivery devices is difficult due to the large outer shape of the device. Fine-gauge balloon catheters have become popular because of their stricture penetration ability and ease of dilation. This study aimed to evaluate the utility of fine-gauge balloon catheters. PATIENTS AND METHODS: This retrospective study involved 38 patients who underwent conventional metal stent placement. The patients were classified into two groups: those who underwent dilation with a fine-gauge balloon catheter before initial metal stenting (balloon dilation group) and those who underwent bougie dilation only (non-balloon dilation group). We evaluated the stenting success rate after initial dilation and adverse events. RESULTS: Seventeen and twenty-one patients were included in the balloon dilation and non-balloon dilation groups, respectively. The stenting success rate after initial dilation was 100% (17/17) in the balloon dilation group and 71.4% (15/21) in the non-balloon dilation group (p = 0.024). As adverse events, peritonitis was observed in one case (4.8%) in the balloon dilation group, and in three cases (14.3%) in the non-balloon dilation group (p = 0.613). CONCLUSIONS: Dilation using a fine-gauge balloon catheter before conventional metal stent with 8.5 Fr delivery device placement is considered effective in EUS-HGS.