Deep learning analysis for differential diagnosis and risk classification of gastrointestinal tumors.

OBJECTIVES: Recently, artificial intelligence (AI) has been applied to clinical diagnosis. Although AI has already been developed for gastrointestinal (GI) tract endoscopy, few studies have applied AI to endoscopic ultrasound (EUS) images. In this study, we used a computer-assisted diagnosis (CAD) system with deep learning analysis of EUS images (EUS-CAD) and assessed its ability to differentiate GI stromal tumors (GISTs) from other mesenchymal tumors and their risk classification performance. MATERIALS AND METHODS: A total of 101 pathologically confirmed cases of subepithelial lesions (SELs) arising from the muscularis propria layer, including 69 GISTs, 17 leiomyomas and 15 schwannomas, were examined. A total of 3283 EUS images were used for training and five-fold-cross-validation, and 827 images were independently tested for diagnosing GISTs. For the risk classification of 69 GISTs, including very-low-, low-, intermediate- and high-risk GISTs, 2,784 EUS images were used for training and three-fold-cross-validation. RESULTS: For the differential diagnostic performance of GIST among all SELs, the accuracy, sensitivity, specificity and area under the receiver operating characteristic (ROC) curve were 80.4%, 82.9%, 75.3% and 0.865, respectively, whereas those for intermediate- and high-risk GISTs were 71.8%, 70.2%, 72.0% and 0.771, respectively. CONCLUSIONS: The EUS-CAD system showed a good diagnostic yield in differentiating GISTs from other mesenchymal tumors and successfully demonstrated the GIST risk classification feasibility. This system can determine whether treatment is necessary based on EUS imaging alone without the need for additional invasive examinations.

Efficacy of endoscopic ultrasound-guided tissue acquisition using stereo-microscopic on-site evaluation for possible comprehensive genome profile in patients with advanced pancreatic cancer.

BACKGROUND AND AIM: Stereomicroscopic on-site evaluation (SOSE) is a rapid evaluation method for endoscopic ultrasound-guided tissue acquisition (EUS-TA) with a high diagnostic sensitivity when the stereomicroscopically visible white core (SVWC) cut-off value (≥ 11 mm) is met. We prospectively examined the association between SVWCs and the adequacy of tissue specimens, assuming subsequent comprehensive genome profiling (CGP). METHODS: This study included 66 consecutive patients with suspected unresectable pancreatic cancer who underwent EUS-TA. The primary endpoint was the frequency of combined samples with ≥ 20% tumor cell content that met over twice the SVWC (T-SVWC) cut-off value, achieved through multiple punctures. The secondary endpoints were the number of punctures, the percentage of SVWC cut-off values, adverse events, the positive diagnosis rate, and the tissue section area. RESULTS: The median number of EUS-TA punctures for suspected unresectable pancreatic cancer was 3 (range, 3-4); SVWC and T-SVWC cut-off values were obtained in 171/206 specimens and 65/66 patients, respectively. There were no EUS-TA-related adverse events. The positive diagnosis rate of EUS-TA was 95.5%. Among the 63 patients meeting the T-SVWC cut-off value in pathological diagnoses, the median tumor cell content was 40% (range, 5-80%), with 57 patients having tumor cell content ≥ 20%. The median tissue section area was 15 (range, 3-40) mm2. CONCLUSIONS: When performing EUS-TA for unresectable pancreatic cancer with the intention of subsequent CGP, obtaining a high tumor cell content (≥ 20%) by assessing the T-SVWC cut-off value via SOSE may serve as a novel indicator for on-site estimation of CGP suitability for EUS-TA specimens.

Endoscopic Ultrasound-Guided Tissue Acquisition Using Fork-Tip Needle for Subepithelial Lesions: A Single-Center Validation Study.

BACKGROUND: The cutoff value for stereomicroscopic on-site evaluation (SOSE) in endoscopic ultrasound-guided tissue acquisition (EUS-TA) has high diagnostic sensitivity when a Franseen needle is employed for upper gastrointestinal subepithelial lesions (SELs) (stereomicroscopically visible white core [SVWC] ≥ 4 mm). AIM: We aimed to determine whether high diagnostic sensitivity could be obtained when EUS-TA was performed using a Fork-tip needle. METHODS: Twenty-one patients were prospectively registered. Patients underwent EUS-TA using a Fork-tip needle for upper gastrointestinal SELs at Kitasato University Hospital between January and November 2022. Punctures were made twice using the needle, and SOSE was conducted for each specimen. Blood and physical examination were performed to assess adverse events. Pathological diagnosis was made using hematoxylin and eosin-stained sections and immunohistochemical staining. Statistical comparisons were completed using Fisher's exact tests. RESULTS: The diagnostic rate of EUS-TA was 100% (21/21 cases). The final diagnosis was gastrointestinal stromal tumor in 17 (81.0%) and leiomyoma in 4 (19.0%) patients. SOSE was conducted on all 42 punctures, and the tissue sampling rate was 100% (42/42 punctures). Specimens with SVWC ≥ 4 mm were collected in 97.6% punctures (41/42 punctures) and the diagnostic sensitivity for these specimens was 100% (41/41 punctures), which is significantly higher (p < 0.0238) compared to the absence of cutoff value (diagnostic sensitivity of 0%). No EUS-TA-related adverse events occurred. CONCLUSIONS: EUS-TA combined with SOSE for upper gastrointestinal SEL using a fork-tip needle had a high diagnostic rate, and the cutoff value of SVWC ≥ 4 mm had high diagnostic sensitivity.

Multicenter prospective study of the efficacy of stereomicroscopic on-site evaluation in endoscopic ultrasound-guided tissue acquisition in patients with pancreatic cancer.

OBJECTIVE: In sample isolation processing by stereomicroscopy (SIPS), a technique used to assess the quality of specimens collected during endoscopic ultrasound (EUS)-guided tissue acquisition (EUS-TA), the cutoff value of stereomicroscopically visible white core (SVWC) (≥11 mm) indicates high diagnostic sensitivity. However, the procedure of SIPS is complicated and time-consuming. Therefore, we devised the stereomicroscopic on-site evaluation (SOSE), a new rapid assessment method that is simpler than SIPS and only determines if the SVWC cutoff value is attained. We aimed to examine the usefulness of SOSE in a multicenter, prospective setting. METHODS: Seventy patients from multiple institutions with solid pancreatic masses suspected to be pancreatic cancer were included. EUS-TA was performed using a 22-gauge Franseen needle. SVWCs were measured on-site using stereomicroscopy. The primary outcome was the sensitivity of SVWC cutoff value in EUS-TA with SOSE. RESULTS: The total number of punctures was 214 and SOSE was performed on 150 punctures. The SVWC cutoff value collection rate was 100% per lesion, with 80% in the first pass, 79% in the second pass, and 78% per puncture in all passes. The median time taken to determine the SVWC cutoff value for SOSE was 47 s. The sensitivity of the SVWC cutoff value was 93.2% for histology and 96.6% for cytology + histology. The per-lesion accuracy of pathological diagnosis reached the highest level (98.6%) at the second puncture. CONCLUSIONS: SOSE showed high diagnostic sensitivity and may be a new rapid assessment method for the diagnosis of malignant pancreatic cancer using EUS-TA.

Endoscopic re-intervention after stent-in-stent versus side-by-side bilateral self-expandable metallic stent deployment.

BACKGROUND AND AIM: Endoscopic bilateral self-expandable metallic stent (SEMS) placement for unresectable malignant hilar biliary obstruction (MHBO) is widely performed; however, re-intervention after recurrent biliary obstruction (RBO) is often challenging. We compared stent-in-stent (SIS) and side-by-side (SBS) SEMS placement for MHBO considering re-intervention for RBO. METHODS: One hundred five consecutive patients with MHBO who underwent endoscopic bilateral SEMS placement in our hospital and its affiliated institutions were enrolled in this study; 75 patients underwent partial SIS deployment between December 2005 and December 2012; and 30 underwent SBS deployment between January 2013 and March 2019. Initial treatments and re-interventions in each group were retrospectively evaluated. RESULTS: Technical success rate (92% vs 100%, P = 0.179), procedure duration (46 vs 35 min, P = 0.382), functional success rate (97.1% vs 100%, P = 1.00), complication rate (24.6% vs 20.0%, P = 0.797), time to RBO (260 vs 312 days; Gray test, P = 0.815), and rate of RBO (59.4% vs 70.0%, P = 0.371) were not significantly different between the SIS and SBS groups. However, bilateral re-stenting with plastic stents through SEMS was successful in 63.4% of patients in the SIS group compared with 100% of patients in the SBS group (P = 0.0013). Median time to RBO upon first re-stenting with a plastic stent was 75 days (range, 11-195 days). CONCLUSIONS: Endoscopic re-stenting after RBO was significantly more successful in the SBS group than in the SIS group. SBS method is suitable for MHBO considering revisionary stent placement.

Risk Factors for Perforation During Endoscopic Papillary Large Balloon Dilation and Bile Duct Stone Removal.

BACKGROUND: Stone removal using endoscopic papillary large balloon dilation (EPLBD) is extremely effective. However, limited research exists regarding the risk factors for perforation of the duodenal papilla and bile duct, which may be fatal. AIMS: We aimed to investigate the risk factors for perforation during EPLBD + stone removal. METHODS: We included patients who underwent EPLBD + stone removal at four medical facilities between January 2008 and December 2018. We retrospectively analyzed the risk factors for perforation and their relationship between overdilation and adverse events. Overdilation was defined as a ratio of the balloon diameter to the diameter of the bile duct that exceeded 100%. The diameter of the distal bile duct was measured using the diameter of the intrapancreatic bile duct at a point 10 mm toward the liver from the narrow distal segment on a cholangiogram. RESULTS: We included 310 patients (177 males; median age: 79 years [range: 46-102 years]). Perforation occurred in five patients (1.6%). Multivariate analysis indicated that no surrounding-pancreas (half or less of the circumference of the intrapancreatic bile duct was surrounded by the pancreatic parenchyma) was a significant risk factor (perforation rate: 8.3%, p = 0.011, odds ratio: 12.7 [95% confidence interval: 1.8-90.5]). No significant difference was found between the overdilation and non-overdilation groups regarding the occurrence of pancreatitis, bleeding, and cholangitis. Perforation rate in patients with no surrounding pancreas + overdilation was 16.7% (2/12). Patients with perforation underwent conservative therapy, which improved their conditions. CONCLUSIONS: EPLBD + stone removal should be avoided in patients with no surrounding pancreas. Overdilation is not a risk factor for adverse procedural events; however, it should be limited in patients with surrounding pancreas.

Nafamostat Mesylate is Not Effective in Preventing Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is associated with complications such as post-ERCP pancreatitis (PEP). Protease inhibitors, including nafamostat mesylate (NM), have been evaluated for prophylaxis against PEP. AIM: We describe the first multicenter randomized controlled trial assessing the prophylactic efficacy of NM against PEP. METHODS: In this multicenter prospective study, we aimed to enroll 800 patients aged ≥ 20 years with a planned ERCP between December 2012 and March 2019. The primary outcome was the incidence and severity of PEP in patients who did not receive NM (non-NM) versus those who did (NM; 20 mg). Secondary outcomes included the incidence of PEP by NM initiation (pre- and post-ERCP), risk factors for PEP, and NM-related adverse events. RESULTS: Only 441 of the planned 800 patients were enrolled (non-NM: n = 149; NM: n = 292 [pre-ERCP NM: n = 144; post-ERCP NM: n = 148]). Patient characteristics were balanced at baseline with no significant differences between groups. PEP occurred in 40/441 (9%) patients (non-NM: n = 15 [10%]; NM: n = 25 [9%]), including 17 (12%) and eight (8%) in the pre-ERCP and post-ERCP NM groups, respectively. In the NM group, the incidence of PEP was lower in the low-risk group than in the high-risk group. Pancreatic injection and double-guidewire technique were independent risk factors for PEP. NM-related adverse events of hyperkalemia occurred in two (0.7%) patients. CONCLUSIONS: We found no evidence for the prophylactic effect of NM against PEP, regardless of the timing of administration; however, further studies are needed.

Stent-induced symptomatic pancreatic duct stricture after endoscopic prophylactic pancreatic duct stent placement for the normal pancreas.

BACKGROUND/OBJECTIVES: Stent-induced pancreatic duct stricture (SI-PDS) is a complication associated with pancreatic stent placement. However, symptomatic SI-PDS associated with prophylactic pancreatic duct stents has not been sufficiently investigated. METHODS: We examined the incidence and characteristics of symptomatic SI-PDS in patients who underwent pancreatic duct stent placement to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) between April 2007 and March 2017. RESULTS: We examined 124 patients with normal pancreases consisting of 75 men and 49 women with a median age of 67.5 years [interquartile range (IQR): 61-74 years]. The median main pancreatic duct (MPD) diameter was 3.3 mm (IQR: 2.6-4.1 mm). The median duration of stent placement was 7 days (IQR: 3-14 days). Spontaneous dislodgment stents were placed in 43.5% of cases (54/124). The diameter of the stent was 5 Fr in 93.5% of cases (116/124) and 7 Fr in 6.5% of cases (8/124). Symptomatic SI-PDS was observed in 2.4% (3/124) of patients overall: 6.5% of patients with an MPD diameter of <3 mm and 0% of patients with an MPD diameter of ≥3 mm. Univariate analysis revealed that an MPD diameter <3 mm was a significant factor for symptomatic SI-PDS (p = 0.048). All cases of symptomatic SI-PDS improved with endoscopic treatment. CONCLUSIONS: Symptomatic SI-PDS occurred in 2.4% of patients who underwent prophylactic pancreatic duct stent placement for normal pancreases. Patients with an MPD diameter of <3 mm may be susceptible to symptomatic SI-PDS.

Analysis of BRCAness with multiplex ligation-dependent probe amplification using formalin-fixed and paraffin-embedded pancreatic ductal adenocarcinoma tissue obtained via endoscopic ultrasound-guided fine-needle aspiration biopsy.

BACKGROUND/OBJECTIVES: A breakthrough in chemotherapy for pancreatic ductal adenocarcinoma (PDAC) may be achieved using precision medicine, which involves identifying cases that are highly likely to respond to a certain treatment and then performing that treatment. BRCAness has been receiving attention as a novel predictor of anticancer drug sensitivity in PDAC, making the screening of BRCAness paramount. METHODS: We conducted the first-ever examination of the feasibility of analyzing BRCAness using multiplex ligation-dependent probe amplification (MLPA). Formalin-fixed paraffin-embedded (FFPE) tissue samples obtained via endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) from 20 patients with the highest pancreatic carcinoma cell counts in tissue samples out of 40 consecutive PDAC patients who underwent EUS-FNAB at our hospital were analyzed by MLPA for BRCAness. RESULTS: We were able to accurately analyze BRCAness in 75% of the 20 cases of PDAC using FFPE tissue obtained by EUS-FNAB. BRCAness was observed in one of the 20 cases. CONCLUSIONS: In PDAC, analyzing BRCAness by MLPA using FFPE tissue obtained by EUS-FNAB offers the remarkable benefit of yielding results in a short period of time and at a low cost. In addition, this method of BRCAness analysis may prove to be a feasible and effective approach for performing precision medicine.

On-site stereomicroscope quality evaluations to estimate white core cutoff lengths using EUS-FNA biopsy sampling with 22-gauge needles.

BACKGROUND AND AIMS: Although rapid on-site cytologic evaluation (ROSE) during EUS-guided FNA biopsy (EUS-FNAB) sampling may improve accuracy of pathologic analyses, cytopathologists are not widely available. We calculated the cutoff lengths required for accurate pathologic diagnoses from stereomicroscopically visible white cores (SVWCs) sampled using 22-gauge needles. METHODS: Overall, 118 patients with mediastinal or upper abdominal solid masses requiring pathologic diagnoses were included. EUS-FNAB sampling was performed using 22-gauge needles. SVWCs were isolated and measured using stereomicroscopy, and the utility of calculated cutoff lengths in diagnosis was investigated. RESULTS: The procedure success and SVWC sampling rates were both 100%, and the median SVWC length was 10 mm. Pathologic examination identified 75, 31, and 12 patients with pancreatic neoplasms (PNs), subepithelial lesions (SELs), and other lesions, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for diagnosing malignancy using EUS-FNAB sampling were 93.1%, 100%, 100%, 69.6%, and 94%, respectively. The final diagnostic accuracy in the entire cohort, PNs, and SELs was 92.4%, 90.7%, and 93.5%, respectively. Receiver operating characteristic curves demonstrated the overall SVWC cutoff length to be 11 mm (11 mm for PNs, 3.5 mm for SELs). The overall sensitivity according to SVWC cutoff length was 91.4% (87.6% for PNs, 98.8% for SELs). Compared with cutoff length, multivariate analysis confirmed SVWC length to be a stronger independent factor for tissue diagnosis in both groups. CONCLUSIONS: Diagnosis improved significantly with SVWC cutoff lengths ≥11 mm. This may be a useful index for endoscopists, particularly where ROSE is unavailable. (Clinical trial registration number: UMIN000023013.).

Complications of Long-Term Indwelling Transmural Double Pigtail Stent Placement for Symptomatic Peripancreatic Fluid Collections.

BACKGROUND: Endoscopic transmural drainage is performed for symptomatic peripancreatic fluid collections (PPFCs). Long-term transmural double-pigtail stent (DPS) placement is useful in preventing recurrences. There are few reports on the long-term safety of DPS placement. Thus, this study aimed to examine the complications of long-term indwelling DPS for PPFCs. METHODS: Among 53 patients who underwent endoscopic ultrasound-guided transmural drainage for symptomatic PPFCs between April 2006 and March 2017, those followed up for over one year were included. Complications of long-term indwelling DPS were examined retrospectively. RESULTS: This study enrolled 36 patients [30 men, median age 54 years (range 22-82)]. Walled-off necrosis was present in 22 cases (including 9 disconnected pancreatic duct syndrome cases) and pancreatic pseudocysts, in 14 cases. The median stenting period was 20.9 (range 0.8-142.3) months, and median observation period was 56.2 (range 12.4-147.1) months. Colon perforation due to DPS occurred in 3 cases (8.3%), at 5.8, 17.1, and 33.7 months after indwelling DPS placement; 2 cases developed perforation from the serosal side. In 1 case, the patient was treated surgically, and in 2 cases, the patients underwent endoscopic removal of the stent and showed improvement with conservative treatment. CONCLUSION: Long-term indwelling transmural DPS for symptomatic PPFCs poses a risk of intestinal perforation. Thus, if possible, it may be better to avoid long-term placement.

Endoscopic Balloon Dilation for Benign Bilioenteric Stricture: Outcomes and Factors Affecting Recurrence.

BACKGROUND: Balloon dilation (BD) is a simple, effective procedure for postoperative benign bilioenteric strictures (BBESs). Factors associated with BBES recurrence after endoscopic BD have not been studied adequately. This study examined the outcomes and 1-year recurrence factors in patients with BBES who underwent endoscopic BD. METHODS: Patients who underwent endoscopic BD as an initial treatment between April 2008 and March 2017 were retrospectively assessed. The median time to recurrence of BBES (RBBES) and recurrence factors were evaluated. RESULTS: The study group comprised 55 patients (median age 72 years). The rate of RBBES was 52.7% (29/55), and the median time to RBBES was 2.78 years (95% confidence interval [CI] 1.17-4.40). RBBES was observed in 32.7% (18/55) within 1 year after endoscopic BD. The significant factors associated with recurrence within 1 year, revealed by multivariate analysis, were: postoperative bile leak (p = 0.001; hazard ratio [HR] 10.94; 95% CI 2.47-48.39); BBES onset within 6 months, postoperatively (p = 0.013; HR 6.18; 95% CI 1.46-26.21); no intrahepatic stones (p = 0.049; HR 3.05; 95% CI 1.01-9.22); and remaining balloon waist (p = 0.005; HR 5.71; 95% CI 1.69-19.31). The median time to RBBES was significantly shorter in patients with these recurrence factors (0.88 years vs. not reached, p = 0.004). Patients exhibiting at least two recurrence factors were significantly more likely to experience recurrence (p < 0.001). CONCLUSION: Endoscopic BD is effective for BBES, especially for patients with no recurrence factors. Consideration of endoscopic BD and additional treatment may be necessary for patients with recurrence factors.

Transpapillary Biliary Cannulation is Difficult in Cases with Large Oral Protrusion of the Duodenal Papilla.

BACKGROUND: Biliary cannulation failure is a major problem during endoscopic retrograde cholangiopancreatography. It remains unclear how duodenal papilla morphology affects biliary cannulation. Therefore, we proposed a new classification system for the duodenal papilla based on oral protrusion pattern (ratio of the length of the oral protrusion to the transverse diameter of the papilla) and papilla pattern. AIMS: To retrospectively compare biliary cannulation results with regard to classification and operator experience. METHODS: We analyzed 589 naïve major duodenal papillae. Our classification system comprised oral protrusion pattern, classified as small (Protrusion-S), regular (Protrusion-R), or large (Protrusion-L), and the papilla pattern, classified as annular (Papilla-A), unstructured (Papilla-U), longitudinal (Papilla-LO), isolated (Papilla-I), or gyrus (Papilla-G). Intra-evaluator concordance and the results of biliary cannulation were analyzed. RESULTS: The following oral protrusion pattern classifications were observed: Protrusion-S, 11.7%; Protrusion-R, 77.9%; and Protrusion-L, 10.4%. The following papilla patterns were observed: Papilla-A, 67.1%; Papilla-U, 7.0%; Papilla-LO, 7.5%; Papilla-I, 1.2%; Papilla-G, 15.6%; and unclassified, 1.7%. Intra-evaluator concordance value (Fleiss kappa) was 0.788 for oral protrusion pattern and 0.750 for papilla pattern. A logistic regression analysis of cannulations performed by an experienced endoscopist identified Protrusion-L as a significant risk factor for difficult cannulation (odds ratio 2.956; 95% confidence interval 1.115-7.84; p = 0.029). Multivariate analysis confirmed Protrusion-L as an independent risk factor for difficult biliary cannulation (odds ratio 3.772; 95% confidence interval 1.359-10.464; p = 0.011). CONCLUSIONS: We propose a new general classification system for the duodenal papilla. Protrusion-L is a significant risk factor for difficult biliary duct cannulation.

A clinical trial to assess the feasibility and efficacy of nab-paclitaxel plus gemcitabine for elderly patients with unresectable advanced pancreatic cancer.

BACKGROUND: The efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-PTX) plus gemcitabine (GEM) in elderly Japanese patients with pancreatic cancer remain unclear. Therefore, we prospectively investigated the tolerability and efficacy of nab-PTX + GEM in Japanese patients aged ≥ 75 years with non-curatively resectable pancreatic cancer. METHODS: We treated eligible patients (n = 27) with nab-PTX + GEM until disease progression, appearance of adverse events, or withdrawal of consent. The primary endpoints included adverse events as well as dosing- and survival-related parameters. RESULTS: The rates of 2-cycle completion were 48.1% for nab-PTX and 55.6% for GEM; the relative dose intensities for the 7th (median) treatment cycle were 65.1% and 74.1%, respectively, whereas the dose-reduction rates were 81.5% and 48.1%, respectively. Grade 3 or higher hemotoxicity was observed in 14 of 27 subjects (51.9%); moreover, 22% experienced grade ≥ 3 peripheral nerve disorder and 1 patient (3.7%) died owing to chemotherapy-related interstitial pneumonia. The disease control rate was 92.6% (25/27), while the median progression-free and overall survival times were 7 and 10.3 months, respectively. CONCLUSION: The nab-PTX + GEM regimen is as efficacious in elderly patients who meet certain criteria as it is in previously reported non-elderly patients. The regimen is feasible with appropriate dose adjustments and attention to adverse events. TRIAL REGISTRATION: Clinical trial registration number: UMIN000018907.

Efficacy and Long-Term Outcomes of Side-by-Side Self-Expandable Metal Stent Placement Using a 2-Channel Endoscope for Unresectable Malignant Hilar Biliary Obstruction Occurring After Billroth II Reconstruction (with Video).

BACKGROUND: Long-term studies evaluating self-expandable metal stents in patients who have unresectable malignant hilar biliary obstruction (UMHBO) after surgical reconstruction of the intestine remain inadequate. We developed a side-by-side (SBS) technique using a two-channel endoscope to place self-expandable metal stents in patients with UMHBO occurring after Billroth II reconstruction. AIMS: We validated the long-term outcomes obtained with this technique. METHODS: The study group comprised seven patients with UMHBO in whom we attempted to place metal stents by the SBS technique using a two-channel scope. The procedure was validated retrospectively. RESULTS: The technical success rate was 86% and functional success rate was 100%. The median time to recurrent biliary obstruction (RBO) was 222 days (95% CI 4.9-439.1). Besides RBO, there were no other complications. CONCLUSIONS: The SBS procedure performed using a two-channel scope is a safe and useful new technique for the treatment of UMHBO occurring after Billroth II reconstruction.

Therapeutic peroral direct cholangioscopy using a single balloon enteroscope in patients with Roux-en-Y anastomosis (with videos).

BACKGROUND: Peroral cholangioscopic lithotripsy is a useful procedure in patients with a normal gastrointestinal anatomy who have difficult-to-treat stones. We evaluated the usefulness of peroral direct cholangioscopy (PDCS) using single-balloon enteroscope (SBE) in patients with difficult-to-treat stones who had undergone Roux-en-Y reconstruction. METHODS: Among 118 patients (169 sessions) who underwent SBE-assisted endoscopic retrograde cholangiopancreatography to treat biliary stones after Roux-en-Y reconstruction, patients in whom it was difficult to remove biliary stones via a transpapillary or transanastomotic approach and difficult to switch to ultra-slim endoscope, were retrospectively enrolled. The biliary insertion success rate, procedure success rate, procedure time, and procedural complications were assessed. The SBE was inserted into the bile-duct, first using a free-hand technique, second using a guide wire, and third using the large balloon anchoring and deflation (LBAD) technique. RESULTS: A total of 11 patients (14 sessions) were enrolled in this study. The biliary insertion success rate was 100%. Bile-duct insertion was performed using a free-hand technique in 4 sessions, a guide wire in 3 sessions (rendezvous technique, 2 sessions), and the LBAD technique in 7 sessions. The procedure success rate was 86% in first session, and 100% in second session. The median procedure time was 81 min (range 49-137). The median procedure time in the bile-duct was 21.5 min (range 6-60). Mild pancreatitis occurred as a complication in one patient. The median follow-up was 528 days (range 282-764). No patient had stone recurrence. CONCLUSIONS: PDCS using SBE is a useful procedure in patients with Roux-en-Y reconstruction. The LBAD technique is an useful technique of inserting SBE into the bile-duct.

Influence of cholangitis after preoperative endoscopic biliary drainage on postoperative pancreatic fistula in patients with middle and lower malignant biliary strictures.

BACKGROUND AND AIM: Preoperative cholangitis after preoperative drainage has been reported to increase postoperative complications, particularly pancreatic fistula. We therefore examined the effects of cholangitis after preoperative endoscopic biliary drainage (EBD) on postoperative pancreatic fistula in patients with middle and lower malignant biliary strictures. METHODS: The study group comprised 102 patients who underwent EBD among patients who underwent surgery. RESULTS: Of the 102 patients, 33 (32%) had postoperative pancreatic fistulas, and 56 (55%) had preoperative cholangitis after preoperative drainage. Analysis of risk factors for preoperative cholangitis showed that a total bilirubin level of 2.9 mg/dL or higher (hazard ratio [HR], 2.95; 95% confidence interval [CI], 1.223-7.130; P = 0.016) and a surgical waiting time of 29 days or longer (HR, 4.23; 95% CI, 1.681-10.637; P = 0.02) were independent risk factors for cholangitis. Patients with preoperative cholangitis had a significantly higher incidence of pancreatic fistula than did patients without preoperative cholangitis (78.8 vs 21.2%; P = 0.001). Patients with biliary cancer had a significantly higher incidence of pancreatic fistula than did those with pancreatic cancer (72.7 vs 27.2%; P = 0.005). Multivariate analysis showed that preoperative cholangitis (HR, 4.8; 95% CI, 1.785-12.992; P = 0.001) and biliary cancer (HR, 3.5; 95% CI, 1.335-8.942; P = 0.006) were significant independent risk factors for postoperative pancreatic fistula. CONCLUSION: Prevention of preoperative cholangitis, a risk factor for postoperative pancreatic fistula, is likely to decrease the incidence of postoperative pancreatic fistula.

Analysis of the diagnostic yield of endoscopic ultrasonography-guided fine-needle aspiration in patients with a suspected pancreatic malignancy.

OBJECTIVES: to determine the diagnostic yield of endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) for suspected pancreatic malignancy. As well as to identify factors that affect the incidence of false-negative cases and evaluate the value of repeated EUS-FNA in patients with inconclusive results. METHODS: we retrospectively evaluated the data of patients who underwent EUS-FNA due to a suspected pancreatic malignancy in our hospital from January 2015 to December 2016. RESULTS: a total of 194 EUS-FNA procedures performed and 175 cases were analyzed. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were 83.4% (151/181), 100% (13/13), 100% (151/151), 30.2% (13/43), and 84.5% (164/194), respectively. The combination of cytological and histological examination significantly increased the diagnostic performance compared to either method alone. The diagnostic sensitivity in metastatic tumors was significantly lower than that for adenocarcinoma. EUS-FNA performed using standard needles combined with the "slow-pull" technique had a lower sensitivity than other methods. According to the multivariate analysis, neither the combination of needle type and suction technique nor final diagnosis were independent factors that affected the diagnostic sensitivity. The sensitivity of repeated EUS-FNA was 50.0% (8/16). Definitive results after a repeated puncture were more likely for pancreatic body and tail masses, heterogeneous lesions and poorly demarcated lesions. However, the difference was not significant. CONCLUSIONS: EUS-FNA was accurate for the evaluation of a suspected pancreatic malignancy. Metastatic tumors and the use of a standard needle in combination with the slow-pull technique may increase the incidence of false-negative results. Repeated EUS-FNA has limited value but should be considered for selected cases where the suspicion of malignancy persists.

Endoscopic ultrasonography diagnosis of subepithelial lesions.

Using endoscopic ultrasonography (EUS), it is practicable to diagnose subepithelial lesions (SEL) with originating layer, echo level, and internal echo pattern etc. Lipoma, lymphangioma, and cyst have characteristic features; therefore, there is no need for endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Ectopic pancreas and glomus tumors, which originate from the third and fourth layers, are frequently seen in the antrum. However, ectopic pancreas located in the fundus or body is large and originates from the third and fourth layers (thickening of fourth layer). Each subepithelial lesion has characteristic findings. However, imaging differentiation of tumors originating from the fourth layer is very difficult, even if contrast echo is used. Therefore, EUS-FNA should be done in these tumors, but the diagnostic yield for small lesions is not sufficient for clinical demands. Generally, those tumors, including small ones, should be first followed up in 6 months, then yearly follow up in cases of no significant change in size and features. When those tumors become larger than 1-2 cm, EUS-FNA is recommended. Furthermore, unusual SEL and SEL with malignant findings such as nodular, heterogeneous, anechoic area, and ulceration indicate EUS-FNA. Cap-attached forward-viewing echoendoscope is very helpful for EUS-FNA of small SEL.

[Conversion Surgery for Initially Unresectable Locally Advanced Pancreatic Cancer Following Gemcitabine plus Nab-Paclitaxel - A Case Report].

We report a case of unresectable locally advanced pancreatic cancer successfully resected after gemcitabine(GEM)plus nab-paclitaxel(PTX)treatment. A 68-year-old man was referred to our institution with jaundice. We diagnosed pancreatic head cancer using computed tomography(CT)and endoscopic retrograde cholangiopancreatography. We initially diagnosed it as locally advanced unresectable pancreatic cancer because of extensive invasion to the portal vein. GEM plus nab- PTX was administered to the patient as systemic chemotherapy. After 9 courses of chemotherapy, a CT scan revealed that the tumor had significantly reduced in size and range of portal vein invasion. Therefore, we performed pancreaticoduodenectomy with resection of the portal vein and achieved R0 resection. Currently, the patient is alive without recurrence. Therefore, conversion surgery after treatment with GEM plus nab-PTX chemotherapy for unresectable pancreatic cancer should be considered.