Structural factors influencing the clinical performance of 0.025-inch guidewires for pancreatobiliary endoscopy: An experimental study.

Background and study aims To develop a pancreatobiliary endoscopic guidewire with good clinical performance, an understanding of its structure is necessary. This study aimed to investigate the structural factors influencing the clinical performance of pancreatobiliary endoscopic guidewires. Methods Eight types of 0.025-inch guidewires were evaluated. The following structural properties were measured: tip length, tip deflection height, tip weight (TW), ratio of tip core weight to TW, shaft coating type (flat or uneven), outer diameter, and core wire diameter (CWD). Four performance tests were conducted to evaluate shaft stiffness as bending force (BF), shaft lubricity as friction force (FF), torque response as torque response rate (TRR), and seeking ability as total insertion success (TIS) in a technical test using a 3D bile duct model. The correlation coefficients of each variable were analyzed. Results The BF and CWDs were strongly correlated, as well as the FF and CWDs and BF. Among the guidewires with similar CWDs, the guidewires with uneven coating had significantly lower FF than those with flat coating. The TRR was strongly correlated with the CWDs; furthermore, guidewires with lower FF had better TRR. TIS was strongly correlated with the TRR, TWs, and ratio of the tip core weight to TW. Conclusions CWD affects shaft stiffness; CWD and coating type affect shaft lubricity and torque response. Because TRR and TW are correlated with seeking ability, an appropriate combination of core wire thickness, TW, and coating design is required to develop a guidewire with good seeking ability.

Contrast-enhanced endoscopic ultrasound likely does not improve diagnostic adequacy during endoscopic ultrasound guided tissue acquisition: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Solid pancreatic masses are sampled through tissue acquisition by endoscopic ultrasound (EUS). Inadequate samples may significantly delay diagnosis, increasing costs and carrying risks to the patients. AIM: assess the diagnostic adequacy of tissue acquisition using contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) compared to conventional EUS. METHODS: Five databases (PubMed, Embase, CENTRAL, Scopus and Web of Science) were searched in November 2023. Studies comparing diagnostic adequacy, accuracy and safety using CEH-EUS versus conventional EUS for tissue acquisition of solid pancreatic masses were included. Risk of bias was assessed using the Risk of Bias tool for randomized controlled trials (RoB2) and the Risk Of Bias In Non-Randomized Studies - of Interventions (ROBINS-I) tool for non-randomized studies, level of evidence using the GRADE approach, Odds Ratios (RR) with 95 % Confidence Intervals (CI) calculated and pooled using a random-effects model. I2 quantified heterogeneity. RESULTS: The search identified 3858 records; nine studies (1160 patients) were included. OR for achieving an adequate sample was 1.467 (CI: 0.850-2.533), for randomized trials 0.902 (CI: 0.541-1.505), for non-randomized 2.396 (CI: 0.916-6.264), with significant subgroup difference. OR for diagnostic accuracy was 1.326 (CI: 0.890-1977), for randomized trials 0.997 (CI: 0.593-1.977) and for non-randomized studies 1.928 (CI: 1.096-3.393), significant subgroup difference (p = 0.0467). No differences were observed for technical failures or adverse events. Heterogeneity was low, risk of bias "low" to "some concerns" for most outcomes, mostly moderate for non-randomized studies. CONCLUSION: Non-randomized studies indicated differences in favor of contrast-enhanced EUS, randomized studies showed no difference in diagnostic adequacy, accuracy or sensitivity when using CEH-EUS.

Equivalent efficacy and safety of plastic stents and lumen-apposing metal stents in the treatment of peripancreatic fluid collections: a prospective cohort study.

Background: Endoscopic ultrasound (EUS)-guided transmural drainage using double pigtail plastic stents (DPPS) has been routine for the treatment of peripancreatic fluid collections (PFC). Lumen-apposing metal stents (LAMS) have since their introduction been the preferred choice; however, their superiority has not been proven. The aim of this study was to compare the efficacy and safety of DPPS and LAMS. Methods: This was a single-center, prospective study that included consecutive patients undergoing EUS-guided drainage between January 2010 and December 2020. The primary endpoints were technical success, clinical success and adverse event rate, while the secondary endpoints included symptomatic relief, length of hospital stay, and need for adjunct drainage. A subgroup analysis of walled-off necrosis (WON) was performed. Results: A total of 89 patients (median age 56 years) underwent EUS-guided transmural drainage (DPPS: n=53; LAMS: n=36) because of a pseudocyst (n=37) or a WON (n=52). Both DPPS and LAMS had a 100% technical success rate and a comparable adverse event rate (4% vs. 6%, P=0.24). An equivalent efficacy was recorded for the drainage of PFC comparing DPPS and LAMS, and no significant statistical difference was recorded in clinical success (DPPS 60% vs. LAMS 61%, P=0.94) or the need for reintervention (DPPS 11% vs. LAMS 13%, P=0.72). Conclusions: In this large, prospective study of EUS-guided drainage of peripancreatic fluid collections, LAMS and DPPS showed equivalent safety, technical success, clinical success and hospital stay. Both techniques were associated with a comparable need for complementary necrosectomy.

Establishment and validation of a risk score model based on EUS: assessment of lymph node metastasis in early gastric cancer.

BACKGROUND AND AIMS: Lymph node metastasis significantly affects the prognosis of early gastric cancer patients. Endoscopic ultrasonography (EUS) plays a crucial role in the preoperative assessment of early gastric cancer. This study evaluated the efficacy of EUS in identifying lymph node metastasis in early gastric cancer patients and developed a risk score model to aid in choosing the best treatment options. METHODS: We retrospectively analyzed the effectiveness of EUS for detecting lymph node metastasis in early gastric cancer patients. A risk score model for predicting lymph node metastasis preoperatively was created using independent risk factors identified through binary logistic regression analysis and subsequently validated. Receiver operating characteristic (ROC) curves were generated for both the development and validation cohorts. RESULTS: The overall accuracy of EUS in identifying lymph node metastasis was 85.3%, although its sensitivity (29.2%) and positive predictive value (38.7%) were relatively low. Patients were categorized based on preoperative risk factors for lymph node metastasis, including tumor size ≥20 mm, lymph nodes ≥10 mm, BMI ≥24 kg/m2, and lymph node metastasis on CT scans. A 7-point risk score model was developed to assess the likelihood of lymph node metastasis. The areas under the ROC curve (AUCs) for the development and validation sets were 0.842 and 0.837, respectively, with sensitivities of 64% and 79%, respectively. CONCLUSION: We developed a practical risk score model based on preoperative factors to help EUS predict lymph node metastasis in early gastric cancer patients, guiding the selection of optimal treatment approaches for these patients.

Differential Diagnosis of Solid Pancreatic Lesions Using Detective Flow Imaging Endoscopic Ultrasonography.

The differential diagnosis of solid pancreatic lesions (SPLs) using B-mode endoscopic ultrasonography (EUS) is challenging. Detective flow imaging (DFI) offers the potential for detecting low-flow vessels in the pancreas, thus enhancing diagnostic accuracy. This retrospective study aimed to investigate DFI-EUS findings of SPLs and analyze their differential diagnostic accuracy for pancreatic cancer. We included 104 patients with pathologically confirmed SPLs who underwent EUS between April 2021 and June 2023. Expert endosonographers, blinded to the patients' clinical data, evaluated images obtained through B-mode, eFLOW, and DFI-EUS. The frame rate and vessel detection sensitivity were compared between eFLOW and DFI, and the diagnostic criteria for pancreatic cancer were established. The visualization rate for vessels in SPLs was significantly higher with DFI-EUS (96%) compared to eFLOW (27%). Additionally, DFI showed a superior frame rate, sensitivity (99%), and accuracy (88%) for detecting pancreatic cancer, although with a modest specificity (43%). On DFI-EUS, characteristics such as hypovascularity, peritumoral vessel distribution, or spotty vessel form were suggestive of pancreatic cancer. DFI-EUS significantly improved the visualization of vascular structures within the SPLs, highlighting its efficacy as a diagnostic modality for pancreatic cancer.

Contributions of endoscopic ultrasonography-guided tissue acquisition (EUS-TA) to the diagnostics of biliary stricture and gallbladder lesions.

Endoscopic ultrasonography (EUS) provides high spatial resolution and more detailed images than other diagnostic modalities. Furthermore, EUS-guided tissue acquisition (EUS-TA), such as EUS-guided fine needle aspiration or biopsy (EUS-FNA/FNB), is an indispensable tool in pancreaticobiliary disease diagnostics, supporting a conclusive pathological diagnosis. In this review, we evaluate the current status and the usefulness of EUS-TA for the diagnostics of the following biliary tract diseases: (A) biliary stricture diagnostics, (B) biliary tract cancer (BTC) itself, and (C) staging of advanced BTC. Previous reports have shown that EUS-FNA for biliary lesions is a safe procedure that is useful in differentiating biliary cancer from benign lesions and in the staging of BTC. On the other hand, the diagnostic performance of EUS-TA for bile duct lesions is reported to be similar to that of transpapillary biopsy. Overall, EUS-TA for biliary lesions may be a safe and effective method, but it should be performed with an understanding of the risk of serious adverse events such as bile leakage and peritoneal dissemination of cancer. It is recommended for distal biliary stricture lesions for which endoscopic retrograde cholangiopancreatography cannot confirm the diagnosis or gallbladder lesions if they do not require the needle to pass through the biliary lumen.

Efficacy and histologic frequencies of endoscopic ultrasonography-guided tissue acquisition using conventional fine-needle aspiration needles for gastric subepithelial hypoechoic mass.

Introduction/Purpose: For gastric subepithelial lesions (GSELs) showing a hypoechoic mass (HM) on endoscopic ultrasonography (EUS) imaging, the utility of EUS-guided tissue acquisition using conventional fine-needle aspiration needles (EUS-TA-CFNAN) and the frequency of histological types remain unclear. This study aimed to examine this issue. Methods: This prospective observational study enrolled 291 consecutive patients who underwent EUS-TA-CFNAN for GSELs showing an HM (GSELHM) on EUS imaging. Immunohistochemical analysis was performed for all EUS-TA-CFNAN and surgically resected specimens. The main outcome measures were the technical results of EUS-TA-CFNAN and the frequency of histological types in GSELHM. Results: The endoscopic ultrasound-guided tissue acquisition using conventional fine-needle aspiration needle diagnosis rate for GSELHM was 80.1% (95% confidence interval [CI]: 75.0-84.5, 233/291). It was significantly lower for antrum (P = 0.004) and lesions smaller than 2 cm (P = 0.003). There were no adverse events. The immunohistochemical diagnoses of EUS-TA-CFNAN included 149 cases of gastrointestinal stromal tumour (GIST) (51.2%), 48 cases of leiomyoma (16.5%), 11 cases of schwannoma (3.8%), 8 cases of the ectopic pancreas (2.7%), 5 cases of subepithelial lesion like cancer (1.7%), 12 cases of other lesions (4.1%), and 58 cases of undiagnosable lesions (19.9%). The frequency of malignant or potentially malignant tumour in GSELHM was 55.0% (95% CI: 49.1-60.8, 160/291). Surgery was performed in 149 patients according to the conclusive EUS-TA-CFNAN results, in which the diagnostic accuracy of EUS-TA-CFNAN was 97.3% (95% CI: 94.7-99.9, 145/149). Conclusion: The use of EUS-TA-CFNAN for GSELHMs is safe and accurate. Gastric subepithelial lesions showing a hypoechoic mass have a reasonably high possibility of containing malignant or potentially malignant tumours, including GISTs.

Comprehensive Echographic Evaluation of Insulinoma, From Bedside to Endoscopic Ultrasonography: A Case Report and Brief Review of the Literature.

Insulinoma is a neuroendocrine tumor of the pancreas, and its identification with bedside ultrasonography (US) is extremely rare. With the aim of providing a comprehensive description of the main US characteristics of this rare form of neuroendocrine neoplasm, we are here describing an interesting case of a young woman with insulinoma, identified by using both bedside and endoscopic ultrasounds.

A novel artificial intelligence-based endoscopic ultrasonography diagnostic system for diagnosing the invasion depth of early gastric cancer.

BACKGROUND: We developed an artificial intelligence (AI)-based endoscopic ultrasonography (EUS) system for diagnosing the invasion depth of early gastric cancer (EGC), and we evaluated the performance of this system. METHODS: A total of 8280 EUS images from 559 EGC cases were collected from 11 institutions. Within this dataset, 3451 images (285 cases) from one institution were used as a development dataset. The AI model consisted of segmentation and classification steps, followed by the CycleGAN method to bridge differences in EUS images captured by different equipment. AI model performance was evaluated using an internal validation dataset collected from the same institution as the development dataset (1726 images, 135 cases). External validation was conducted using images collected from the other 10 institutions (3103 images, 139 cases). RESULTS: The area under the curve (AUC) of the AI model in the internal validation dataset was 0.870 (95% CI: 0.796-0.944). Regarding diagnostic performance, the accuracy/sensitivity/specificity values of the AI model, experts (n = 6), and nonexperts (n = 8) were 82.2/63.4/90.4%, 81.9/66.3/88.7%, and 68.3/60.9/71.5%, respectively. The AUC of the AI model in the external validation dataset was 0.815 (95% CI: 0.743-0.886). The accuracy/sensitivity/specificity values of the AI model (74.1/73.1/75.0%) and the real-time diagnoses of experts (75.5/79.1/72.2%) in the external validation dataset were comparable. CONCLUSIONS: Our AI model demonstrated a diagnostic performance equivalent to that of experts.

Primary anastomosis closure after endoscopic ultrasound-directed transgastric intervention.

Background and study aims Endoscopic ultrasound-directed transgastric intervention (EDGI) is a technique that creates an anastomosis between the gastric pouch or jejunum to the excluded stomach in Roux-en-Y gastric bypass (RYGB) anatomy to allow access to the pancreaticobiliary system. Thus far, management of anastomosis closure at the time of lumen-apposing metal stent (LAMS) removal has varied widely. This study aimed to assess the efficacy of primary closure at the time of LAMS removal using a through-the-scope (TTS) tack-based suture system.  Patients and methods This was a two-center retrospective study of RYGB patients who underwent single-stage EDGI using a 20-mm LAMS and subsequent primary anastomosis closure with the X-tack system at the time of stent removal. Patient demographics, procedure details, clinical outcomes, and imaging findings are reported. Results Nineteen patients (median age 63 years, 84% female) underwent single-stage EDGI with a median follow-up of 31.5 months. Adverse events occurred in two patients (11%) who had abdominal pain requiring hospitalization. The median LAMS dwell time was 32 days (range 16-86). All patients (100%) who underwent follow-up studies after LAMS removal had confirmed anastomosis closure (n = 18). Most patients had documented weight loss at the time of LAMS removal and at last follow-up (68%, n = 13). Conclusions Single-stage EDGI is an effective approach to managing RYGB patients with pancreaticobiliary pathology. Thus far, endoscopic TTS tack-based suturing appears to have a high success rate in anastomosis closure after LAMS removal and should be considered as a primary method for preventing chronic fistulae.

Colonoscopy in the diagnosis and management of appendiceal disease.

In this editorial, we comment on the article published in the recent issue of the World Journal of Gastrointestinal Endoscopy. We focused on the understanding of appendiceal disease, and the various options for diagnosis and treatment via endoscopy. Some factors affecting the diagnosis and management of appendiceal diseases are also discussed. The existence of any organ has its natural rationality, and the appendix is such a magical organ. A growing number of experts and scholars have gradually come to a consensus that the appendix is not a useless evolutionary relic. There are many lymphocytes and lymph nodes in the appendix wall, which has a strong immune function, and this function is particularly important for children and adolescents. Many intestinal probiotics in the appendix are very helpful for maintaining the balance of the intestinal flora. With the continuous progress of endoscopic technology, endoscopic treatment involving preservation of the appendix has shown great advantages over surgery. In the diagnosis of appendiceal inflammation and neoplasms, colonoscopy, endoscopic retrograde appendicography and choledochoscopy help assess conditions of the appendix. Endoscopic retrograde appendicitis therapy, abscess drainage under colonoscopy, fenestration of abscess under colonoscopy, and endoscopic or natural orifice transluminal endoscopic surgery resection of appendiceal neoplasms are safe and effective endoscopic treatments for appendiceal disease. New breakthroughs in the application of endoscopy in the appendix are expected to occur in the near future.

Using a customized GPT to provide guideline-based recommendations for management of pancreatic cystic lesions.

Background and study aims Rising prevalence of pancreatic cysts and inconsistent management guidelines necessitate innovative approaches. New features of large language models (LLMs), namely custom GPT creation, provided by ChatGPT can be utilized to integrate multiple guidelines and settle inconsistencies. Methods A custom GPT was developed to provide guideline-based management advice for pancreatic cysts. Sixty clinical scenarios were evaluated by both the custom GPT and gastroenterology experts. A consensus was reached between experts and review of guidelines and the accuracy of recommendations provided by the custom GPT was evaluated and compared with experts. Results The custom GPT aligned with expert recommendations in 87% of scenarios. Initial expert recommendations were correct in 97% and 87% of cases, respectively. No significant difference was observed between the accuracy of custom GPT and the experts. Agreement analysis using Cohen's and Fleiss' Kappa coefficients indicated consistency among experts and the custom GPT. Conclusions This proof-of-concept study shows the custom GPT's potential to provide accurate, guideline-based recommendations for pancreatic cyst management, comparable to expert opinions. The study highlights the role of advanced features of LLMs in enhancing clinical decision-making in fields with significant practice variability.

Celiac artery mesenteric fat measurement with endosonography (CAMEUS) reliably correlates with obesity and related comorbidities.

Background: Visceral fat represents a metabolically active entity linked to adverse metabolic sequelae of obesity. We aimed to determine if celiac artery mesenteric fat thickness can be reliably measured during endoscopic ultrasound (EUS), and if these measurements correlate with metabolic disease burden. Methods: This was a retrospective analysis of patients who underwent celiac artery mesenteric fat measurement with endosonography (CAMEUS) measurement at a tertiary referral center, and a validation prospective trial of patients with obesity and nonalcoholic steatohepatitis who received paired EUS exams with CAMEUS measurement before and after six months of treatment with an intragastric balloon. Results: CAMEUS was measured in 154 patients [56.5% females, mean age 56.5 ± 18.0 years, body mass index (BMI) 29.8 ± 8.0 kg/m2] and was estimated at 14.7 ± 6.5 mm. CAMEUS better correlated with the presence of non-alcoholic fatty liver disease (NAFLD) (R2 = 0.248, P < 0.001) than BMI (R2 = 0.153, P < 0.001), and significantly correlated with metabolic parameters and diseases. After six months of intragastric balloon placement, the prospective cohort experienced 11.7% total body weight loss, 1.3 points improvement in hemoglobin A1c (P = 0.001), and a 29.4% average decrease in CAMEUS (-6.4 ± 5.2 mm, P < 0.001). CAMEUS correlated with improvements in weight (R2 = 0.368), aspartate aminotransferase to platelet ratio index (R2 = 0.138), and NAFLD activity score (R2 = 0.156) (all P < 0.05). Conclusions: CAMEUS is a novel measure that is significantly correlated with critical metabolic indices and can be easily captured during routine EUS to risk-stratify susceptible patients. This station could allow for EUS access to sampling and therapeutics of this metabolic region.

Novel treatment with double scope technique for disconnected pancreatic duct syndrome with external pancreatic fistula.

Background and study aims External pancreatic fistula in association with disconnected pancreatic duct syndrome is a common sequelae of the percutaneous step-up approach for infected pancreatic necrosis and is associated with significant morbidity. The present study aimed to report the initial outcome of a novel technique of two-scope guided tractogastrostomy for management of this condition. Patients and methods The present study was a retrospective analysis of data from patients with external pancreatic fistula and disconnected pancreatic duct syndrome, who underwent two-scope-guided tractogastrostomy. All the patients had a 24F or larger drain placed in the left retroperitoneum. Transgastric echo endoscopy and sinus tract endoscopy were performed simultaneously to place a stent between the gastric lumen and the sinus tract. Technical success was defined as placement of the stent between the tract and the stomach. Clinical success was defined as successful removal of the percutaneous drain without the occurrence of pancreatic fluid collection, ascites, external fistula, or another intervention 12 weeks after the procedure. Results Three patients underwent two scope-guided tractogastrostomy. Technical and clinical success were achieved in all the patients. No procedure-related side effects or recurrence occurred in any of the patients. Conclusions Two-scope-guided tractogastrostomy for treatment of external pancreatic fistula due to disconnected pancreatic duct syndrome is a feasible technique and can be further evaluated.

Value of quantitative microsurface structure analysis for evaluating the invasion depth of type 0-II early gastric cancer.

Background and Aim: The microsurface structure reflects the degree of damage to the glands, which is related to the invasion depth of early gastric cancer. To evaluate the diagnostic value of quantitative microsurface structure analysis for estimating the invasion depth of early gastric cancer. Methods: White-light imaging and narrow-band imaging (NBI) endoscopy were used to visualize the lesions of the included patients. The area ratio and depth-predicting score (DPS) of each patient were calculated; meanwhile, each lesion was examined by endoscopic ultrasonography (EUS). Results: Ninety-three patients were included between 2016 and 2019. Microsurface structure is related to the histological differentiation and progression of early gastric cancer. The receiver operating characteristic curve showed that when an area ratio of 80.3% was used as a cut-off value for distinguishing mucosal (M) and submucosal (SM) type 0-II gastric cancers, the sensitivity, specificity, and accuracy were 82.9%, 80.2%, and 91.6%, respectively. The accuracies for distinguishing M/SM differentiated and undifferentiated early gastric cancers were 87.4% and 84.8%, respectively. The accuracy of EUS for distinguishing M/SM early gastric cancer was 74.9%. DPS can only distinguish M-SM1 (SM infiltration <500 µm)/SM (SM infiltration ≥500 µm) with an accuracy of 83.8%. The accuracy of using area ratio for distinguishing 0-II early gastric cancers was better than those of using DPS and EUS (P < 0.05). Conclusion: Quantitative analysis of microsurface structure can be performed to assess M/SM type 0-II gastric cancer and is expected to be effective for judging the invasion depth of gastric cancer.

The advent of the first electric driven EUS-guided 17 gauge core needle biopsy - A pilot study on subepithelial lesions.

BACKGROUND AND AIMS: This pilot study aimed to evaluate safety and tissue sampling from subepithelial lesions (SEL) in the upper gastrointestinal tract with a novel electric motor driven endoscopic ultrasonography (EUS)-guided 17-gauge (G) size core needle biopsy (CNB) instrument. METHODS: An investigator-led prospective open label, performance and safety control study, including seven patients (female n = 4, median 71 y, range 28-75) with a determined SEL (median size 30 mm, range 17-150 mm) in the upper digestive tract (stomach n = 6, duodenum n = 1) were eligible and later followed up 14 days after index procedure. All investigations were completed according to protocol with three FNB 22-G passes with four fanning strokes and two EndoDrill® 17-G passes with three fanning strokes. RESULTS: Quality of samples as 'visible pieces' (>5 mm): FNB (n = 5/7) (fragmented/blood imbibed n = 1, poor tissue quantity n = 1) compared with 17-G CNB (n = 7/7). Histological result which led to final diagnosis (leiomyoma n = 2, adenocarcinoma n = 1, schwannoma n = 1, neuroendocrine tumour n = 1, desmoid tumour n = 1 and gastrointestinal stromal tumour (GIST) n = 1) could be obtained with the 17-G CNB instrument in all seven patients. FNB technique reached correct diagnosis in six patients. No serious adverse event were recorded. CONCLUSIONS: By using an electric driven 17-G biopsy device, a true cylinder of core tissue can be obtained in one single puncture from the area of interest reducing the need for a second sampling. The absolute benefit of EUS-guided CNB is that the sample can be handled and histologically prepared in the same manner as standard percutaneous core needle sample, e.g., breast and prostate cancer.

Establishing the optimal number of passes during EUS-FNB for diagnosis of pancreatic solid lesions: Prospective multicenter study.

Background and study aims The optimal number of needle passes during endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is not yet established. We aimed to perform a per-pass analysis of the diagnostic accuracy of EUS-FNB of solid pancreatic lesions using a 22G Franseen needle. Patients and methods Consecutive patients with solid pancreatic lesions referred to 11 Italian centers were prospectively enrolled. Three needle passes were performed; specimens were collected after each pass and processed individually as standard histology following macroscopic on-site evaluation (MOSE) by the endoscopist. The primary endpoint was diagnostic accuracy of each sequential pass. Final diagnosis was established based on surgical pathology or a clinical course of at least 6 months. Secondary endpoints were specimen adequacy, MOSE reliability, factors impacting diagnostic accuracy, and procedure-related adverse events. Results A total of 504 samples from 168 patients were evaluated. Diagnostic accuracy was 90.5% (85.0%-94.1%) after one pass and 97.6% (94.1%-99.3%) after two passes ( P =0.01). Similarly, diagnostic sensitivity and sample adequacy were significantly higher adding the second needle pass (90.2%, 84.6%-94.3% vs 97.5%, 93.8%-99.3%, P =0.009 and 91.1%, 85.7%-94.9% vs 98.2%, 95.8%-99.3%, P =0.009, one pass vs two passes, respectively). Accuracy, sensitivity, and adequacy remained the same after the third pass. The concordance between MOSE and histological evaluation was 89.9%. The number of passes was the only factor associated with accuracy. One case of mild acute pancreatitis (0.6%) was managed conservatively. Conclusions At least two passes should be performed for the diagnosis of solid pancreatic lesions. MOSE is a reliable tool to predict the histological adequacy of specimens.