Feasibility and safety of a novel plastic stent designed specifically for endoscopic ultrasound-guided pancreatic duct drainage.

Background and study aims Endoscopic ultrasound-guided pancreatic duct drainage (EUS-PD) is emerging as an effective alternative treatment for obstructive pancreatitis after unsuccessful endoscopic retrograde pancreatography (ERP). However, the high incidence of adverse events associated with EUS-PD (approximately 20%) remains an issue. Recently, we developed a novel plastic stent for EUS-PD, with a radiopaque marker positioned at approximately one-third of the length from the distal end of the stent and side holes positioned exclusively distal to the marker. This study aimed to evaluate the feasibility and safety of using this stent in EUS-PD. Patients and methods We retrospectively reviewed data from 10 patients who underwent EUS-PD with the novel plastic stent at the National Cancer Center Hospital between March 2021 and October 2023. Technical and clinical success, procedure times, adverse events (AEs), recurrent pancreatic duct obstruction (RPO), and time to RPO were assessed. Results Of the 10 patients, five had postoperative benign pancreaticojejunal anastomotic strictures and five had malignant pancreatic duct obstruction. The technical and clinical success rates were both 100% (10/10). An AE (self-limited abdominal pain) occurred in one patient (10.0%). Two patients (20.0%) died of their primary disease during the follow-up period (median, 44 days; range, 25-272 days). The incidence of RPO was 10.0% (1/10), and the 3-month non-RPO rate was 83.3%. Conclusions The novel plastic stent shows potential as a useful and safe tool in EUS-PD.

Efficacy of endoscopic ultrasound-guided gastroenterostomy using self-expandable metallic stent for afferent loop syndrome: A single-center retrospective study.

BACKGROUND AND AIM: Endoscopic ultrasound-guided gastroenterostomy is a procedure used to connect the stomach and dilated afferent loop using a stent under endoscopic ultrasound for afferent loop syndrome. However, the actual efficacy and safety of this procedure remain unclear. Therefore, this retrospective study aimed to evaluate the efficacy and safety of endoscopic ultrasound-guided gastroenterostomy using a laser-cut-type fully covered self-expandable metallic stent and an anchoring plastic stent for afferent loop syndrome. METHODS: Technical and clinical success rates, adverse events, recurrent intestinal obstruction rates, time to recurrent intestinal obstruction, and technical and clinical success rates of re-intervention were evaluated in intended patients who underwent endoscopic ultrasound-guided gastroenterostomy for afferent loop syndrome from October 2018 to August 2022. RESULTS: In 25 intended patients with afferent loop syndrome who intended endoscopic ultrasound-guided gastroenterostomy, the technical success rate was 100% (25/25), whereas the clinical success rate was 96% (24/25). Two patients experienced grade ≥ 3 early adverse events, including one with intra-abdominal abscess and one with hypotension. Both events were attributed to intestinal fluid leakage. No late adverse events were observed. The recurrent intestinal obstruction rate was 32% (8/25), and the median time to recurrent intestinal obstruction was 6.5 months (95% confidence interval: 2.8-not available). The technical and clinical success rates of re-intervention were both 100% (8/8). CONCLUSIONS: Endoscopic ultrasound-guided gastroenterostomy using a fully covered self-expandable metallic stent and an anchoring plastic stent is effective and safe as a treatment procedure for afferent loop syndrome.

Incidence and factors associated with stent dysfunction and pancreatitis after gastroduodenal stenting for malignant gastric outlet obstruction.

Background and study aims Endoscopic gastroduodenal stent (GDS) deployment is currently a standard treatment for malignant gastric outlet obstruction (mGOO) in patients with limited life expectancy; however, stent dysfunction (SD) and complicated pancreatitis often occur after GDS deployment. We investigated incidence and contributing factors of SD and complicated pancreatitis. Patients and methods We retrospectively reviewed 203 patients who underwent initial GDS deployment for palliation of mGOO symptoms between October 2017 and July 2022, including 109 who underwent GDS deployment across the duodenal papilla (sub-cohort). Results SDs, including tumor ingrowth (n = 26), kinking (n = 14), and migration (n = 13), occurred in 68 patients (33.5%). Cumulative SD incidence was 41.1% (95% confidence interval, 32.6-49.4%). SD incidence increased to 0.4%, 0.16%, and 0.06% per day at < 8, 8-16, and>16 weeks, respectively. On multivariate analysis, Niti-S pyloric/duodenal stent deployment (sub-distribution hazard ratio [sHR] 0.26, P = 0.01) and survival length ≥ 90 days (sHR 2.5, P = 0.01) were respectively identified as favorable and risk factors significantly associated with SD. Pancreatitis developed in 14 patients (12.8%) in the sub-cohort, which had significantly higher parenchymal diameter ( P < 0.01) and lower main pancreatic duct (MPD) caliber ( P < 0.01) than the non-pancreatitis cohort. On multivariate analysis, MPD caliber < 3 mm independently predicted pancreatitis (odds ratio 6.8, P = 0.03). Conclusions Deployment of the Niti-S pyloric/duodenal stent, with conformability even for angulated strictures, significantly reduced the incidence of SD. Stent selection, life expectancy, and MPD caliber should be taken into consideration during decision-making for GDS deployment for mGOO.

The 10 Hz dynamic response of a fluid-filled pressure monitoring system is a novel alternative to the fast flush test and indicative of unacceptable systolic pressure overshoot.

The standard method for qualitatively evaluating the dynamic response is to see if the gain of the amplitude spectrum curve approaches 1 (input signal = output signal) over the frequency band of the blood pressure waveform. In a previous report, Watanabe reported that Gardner's natural frequency and damping coefficient, which are widely used as evaluation methods, do not reflect the dynamic response of the circuit. Therefore, new parameters for evaluating the dynamic response of pressure monitoring circuits were desired. In this study, arterial pressure catheters with length of 30, 60, 150, and 210 cm were prepared, and a blood pressure wave calibrator, two pressure monitors with analog output and a personal computer were used to analyze blood pressure monitoring circuits. All data collection and analytical processes were performed using step response analysis program. The gain at 10 Hz was close to 1 and the systolic blood pressure difference was small in the short circuits (30 cm, 60 cm), and the gain at 10 Hz was 1.3-1.5 in the 150 cm circuit and over 1.7 in the 210 cm circuit. The difference in systolic blood pressure increased in proportion to the length of the circuit. It could also be inferred that the gain at 10 Hz should be less than 1.2 to meet a clinically acceptable blood pressure difference. In conclusion, the gain at 10 Hz is sufficiently useful as an indicator to determine the correct systolic blood pressure.

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.

Study protocol for a prospective, multicentre, phase II trial on endoscopic treatment using two fully covered self-expandable metallic stents for benign strictures after hepaticojejunostomy.

INTRODUCTION: The current endoscopic treatment for postoperative benign hepaticojejunostomy anastomotic stricture (HJAS) has a high technical success rate and is highly effective in the short term. However, long-term results have shown a high rate of stenosis recurrence, which indicates an insufficient response to treatment. Three prospective studies on fully covered self-expandable metallic stent (FC-SEMS) treatment for benign HJAS used the stenosis resolution rate as the primary endpoint, and no study has yet used the long-term non-stenosis rate (at 12 months) as the primary endpoint. METHODS AND ANALYSIS: We launched the 'saddle-cross study', which will be conducted as a multicentre, prospective intervention of endoscopic treatment using two modified FC-SEMSs (BONASTENT️ M-Intraductal) that have been improved for benign stenosis in patients with benign HJAS, with the long-term non-restenosis rate (at 12 months) as the primary endpoint. This study aims to evaluate the long-term non-restenosis rate (at 12 months) and safety of the saddle-cross technique for benign HJAS. We plan to enrol 50 participants. ETHICS AND DISSEMINATION: This study has been approved by the Certified Review Board of the National Cancer Center, Japan (CRB3180009). The results will be reported at various conferences and published in international peer-reviewed journals.

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.).

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.

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.

Franseen Needles May Be Promising for Improving the Sampling Adequacy of EUS-FNA for Subepithelial Lesions.

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is useful in diagnosing subepithelial lesions (SELs), and adequate tissue sampling is necessary to differentiate between benign and malignant diseases to determine therapeutic strategies. This study aimed to evaluate sampling adequacy and diagnostic performance of EUS-FNA for SELs with Franseen needles. This retrospective study enrolled 130 patients who underwent EUS-FNA with a 22-gauge needle for SELs from January 2010 to March 2021. We compared sampling adequacy and predictive factors influencing the sampling adequacy of EUS-FNA for SELs between Franseen and conventional needles. The sampling adequacy rates were 95.0% (38/40) with Franseen needles and 76.7% (69/90) with conventional needles (p = 0.011). The mean number of punctures with Franseen needles (2.80) was significantly less than that with conventional needles (3.42) (p < 0.001). In the multivariate analysis, the use of Franseen needles (p = 0.029; odds ratio [OR], 5.37; 95% confidence interval [CI], 1.18−23.36) was an independent factor influencing the sampling adequacy. Compared to conventional needles, the Franseen needle could play a vital role in accurately diagnosing SELs by yielding better sampling adequacy and reducing the number of passes.

Detection rate of endoscopic ultrasound and computed tomography in diagnosing pancreatic neuroendocrine neoplasms including small lesions: A multicenter study.

BACKGROUND/PURPOSE: The detection ability and role of different imaging modalities to detect pancreatic neuroendocrine neoplasms (PNENs) including small lesions is unclear. This study aimed to compare the ability of endoscopic ultrasound (EUS) and computed tomography (CT) to detect PNENs. METHODS: Data of patients who underwent EUS and contrast-enhanced CT and were diagnosed with PNENs were analyzed. The detection rates of pancreatic lesions with EUS and CT based on tumor size and influencing factors were investigated. RESULTS: For 256 PNEN lesions, the detection rate of EUS was better than that of CT (94.5% vs 86.3%; P < .001). EUS was significantly superior to CT for PNENs ≤5 mm (58.3% vs 16.7%; P = .006) and 5-10 mm (97.7% vs 79.5%; P = .008). There was no significant difference in the detection rate between EUS and CT for PNENs >10 mm (98.4% vs 96.4%; P = .375). Size (≤5 mm) and insulinoma were independent factors associated with poor EUS and CT detection rates. CONCLUSIONS: Endoscopic ultrasound exhibited better detection ability than CT, with an excellent detection rate for PNENs >5 mm, except for insulinomas. CT could detect PNENs >10 mm, which are amenable to treatment.

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.

IgG4-related sclerosing cholangitis may be a risk factor for cancer.

BACKGROUND/PURPOSE: The relationship between autoimmune pancreatitis (AIP) and malignancy has been reported. However, the potential risk for cancer in patients with immunoglobulin 4 (IgG4)-related sclerosing cholangitis (IgG4-SC) is unclear. The present study aimed to evaluate the incidence of cancer in IgG4-SC patients. METHODS: We retrospectively collected clinical data for 121 patients diagnosed with IgG4-SC from 7 hospitals. We calculated the standardized incidence ratio (SIR) of cancer in IgG4-SC patients based on the national cancer rates. The SIR of the period after the diagnosis of IgG4-SC were calculated. RESULTS: The mean follow-up period was 6.4 years, with 121 IgG4-SC patients. During the follow-up period, 26 patients had cancer, and 29 cancers were diagnosed. The SIR of cancer after the diagnosis of IgG4-SC was 1.90 (95% confidence interval [CI] 1.67-2.21). The SIR of pancreatic and bile duct cancer was 10.30 and 8.88, respectively. The SIR of cancer in <1 year, 1-5 years, and >5 years after diagnosis of IgG4-SC were 2.58, 1.01, and 2.44, respectively. CONCLUSIONS: IgG4-SC patients have a high risk of cancer including pancreatic and bile duct cancer. The risk of cancer was high less <1 year and >5 years after diagnosis of IgG4-SC. Therefore, IgG4-SC patients may require careful long-term follow-up.

Covered metallic stent placement for biliary drainage could be promising in the coming era of neoadjuvant chemo-radiation therapy for all pancreatic cancer.

BACKGROUND/PURPOSE: The role of endoscopic preoperative biliary drainage for pancreatic head cancer is controversial because of the high incidence of stent occlusion before surgery. We sought to validate a suitable stent for biliary drainage in patients with pancreatic cancer undergoing neoadjuvant chemotherapy (NAC)/neoadjuvant chemoradiotherapy (NAC-RT). METHODS: We evaluated patients who received preoperative neoadjuvant therapy for pancreatic head cancer between January 2013 and December 2019. A covered metal (CMS) or plastic stent (PS) was inserted in symptomatic patients for biliary drainage. Recurrent biliary obstruction (RBO), success rate of endoscopic drainage, adverse events, and surgical outcomes were compared between the CMS and PS groups. RESULTS: Occurrence rate of RBO was significantly higher with PS (97%) vs CMS (15%, P < .001), and time to RBO was significantly longer with CMS vs PS (not reached vs 40.5 days, P < .001). Delayed schedule associated with RBO for neoadjuvant chemotherapy was significantly lower in CMS vs PS (14% vs 50%, P < .05). There was no difference in postoperative bleeding, operation time, complications, and rate of a microscopically margin-negative resection between groups. CONCLUSIONS: Use of CMS during NAC/NAC-RT allows for safe chemotherapy without causing cholangitis or biliary obstruction and for surgery to be performed.

Why the natural frequency and the damping coefficient do not evaluate the dynamic response of clinically used pressure monitoring circuits correctly.

PURPOSE: The dynamic response of pressure monitoring circuits must be evaluated to obtain true invasive blood pressure values. Since Gardner's recommendations in 1981, the natural frequency and the damping coefficient have become standard parameters for anesthesiologists. In 2006, we published a new dynamic response evaluation method (step response analysis) that can plot frequency spectrum curves instantly in clinical situations. We also described the possibility of the defect of the standard parameters. However, the natural frequency and the damping coefficient are considered the gold standard and are even included in a major anesthesiology textbook. Therefore, we attempted to clarify the issues of these parameters with easy-to-understand pressure waves and basic numerical formulae. METHODS: A blood pressure wave calibrator, a single two-channel pressure amplifier, and personal computer were used to analyze blood pressure monitoring circuits. All data collection and analytical processes were performed using our step response analysis program. RESULTS: We compared two different circuits with almost the same natural frequency and damping coefficients. However, their amplitude spectrum curves and input/output pressure values were significantly different. CONCLUSIONS: The natural frequency and the damping coefficient are inadequate for the dynamic response evaluation. These parameters are primarily obtained from the phase spectrum curve and not from the amplitude spectrum curve. We strongly recommend an evaluation using the amplitude spectrum curve with our step response analysis method. It is crucial to maintain an amplitude gain of 1 (input amplitude = output amplitude) in the pressure wave frequency range of 0-20 Hz.