Endoscopic Ultrasound Examination Research Articles

Endoscopic ultrasound features of rectal melanoma: A case report and review of literature

BACKGROUND Rectal mucosal melanoma is a rare and highly aggressive disease. Common symptoms include anal pain, an anal mass, or bleeding. As such, the disease is usually detected on rectal examination of patients with other suspected anorectal diseases. However, due to its rarity and nonspecific symptoms, melanoma of the rectal mucosa is easily misdiagnosed. CASE SUMMARY This report describes the case of a 58-year-old female patient who presented with a history of blood in her stool for the prior one or two months, without any identifiable cause. During colonoscopy, a bulge of approximately 2.2 cm × 2.0 cm was identified. Subsequently, the patient underwent endoscopic ultrasound (EUS) to characterize the depth of invasion of the lesions. EUS suggested a hypoechoic mucosal mass with involvement of the submucosal layer and heterogeneity of the internal echoes. Following surgical intervention, the excised tissue samples were examined and confirmed to be rectal malignant melanoma. The patient recovered well with no evidence of recurrence during follow-up. CONCLUSION This case shows that colonoscopy with EUS and pathological examination can accurately diagnose rare cases of rectal mucosal melanoma.

Beyond boundaries: Feasibility of curved linear array echoendoscope in appendiceal neoplasm detection

We recently read with great interest a study by Zhang et al in the World Journal of Gastroenterology . In our practice, we focus specifically on examining appendiceal mucinous neoplasms (AMNs) with endoscopic ultrasound (EUS) using different scopes. AMNs are rare neoplastic lesions characterized by an accumulation of mucin inside a cystic dilatation of the appendix. Clinically, they can present as nonspecific acute appendicitis. AMNs can turn into a life-threatening condition, termed pseudomyxoma peritonei, in which the ruptured appendix causes accumulation of mucin in the abdomen. Therefore, accurate and rapid diagnosis of AMN is essential. EUS is able to confirm and stage AMNs; although, EUS examination was once limited to the rectal and anal regions due to the conventional oblique-view scopes. With the emergence of new forward-view linear echoendoscopes and instruments like EUS miniprobes and overtubes, the scope of examination is changing. Herein, we discuss the feasibility of using the curved linear array echoendoscopes to examine cecal and appendiceal orifice lesions.

Radiomics analysis for prediction and classification of submucosal tumors based on gastrointestinal endoscopic ultrasonography.

To identify and classify submucosal tumors by building and validating a radiomics model with gastrointestinal endoscopic ultrasonography (EUS) images. A total of 144 patients diagnosed with submucosal tumors through gastrointestinal EUS were collected between January 2019 and October 2020. There are 1952 radiomic features extracted from each patient's EUS images. The statistical test and the customized least absolute shrinkage and selection operator regression were used for feature selection. Subsequently, an extremely randomized trees algorithm was utilized to construct a robust radiomics classification model specifically tailored for gastrointestinal EUS images. The performance of the model was measured by evaluating the area under the receiver operating characteristic curve. The radiomics model comprised 30 selected features that showed good discrimination performance in the validation cohorts. During validation, the area under the receiver operating characteristic curve was calculated as 0.9203 and the mean value after 10-fold cross-validation was 0.9260, indicating excellent stability and calibration. These results confirm the clinical utility of the model. Utilizing the dataset provided curated from gastrointestinal EUS examinations at our collaborating hospital, we have developed a well-performing radiomics model. It can be used for personalized and non-invasive prediction of the type of submucosal tumors, providing physicians with aid for early treatment and management of tumor progression.

Feasibility and clinical value of linear endoscopic ultrasonography imaging in the lower gastrointestinal subepithelial lesions.

Linear endoscopic ultrasonography (EUS) has been extensively utilized as a novel diagnostic and therapeutic modality across various fields. However, there have been relatively few studies focusing on lower gastrointestinal lesions. The aim of our study was to investigate the feasibility, safety and clinical value of linear EUS in the lower gastrointestinal subepithelial lesions. This was a retrospective study involving patients with lower gastrointestinal subepithelial lesions diagnosed by linear EUS from August 2019 to April 2023 at the Second Affiliated Hospital of Anhui Medical University. The data, including basic clinical information, linear EUS features, technical success rate, complications, and follow-up, were retrospectively collected and analyzed. A total of 69 patients with lower gastrointestinal subepithelial lesions underwent examination by linear EUS. Excluding the rectum, the technical success rate of linear EUS was 90.6% (29/32). Apart from the 7 patients whose diagnosis remained unknown, 3 patients with no abnormal EUS findings, and 3 patients failed the procedure, 56 patients were included in the final diagnostic performance analysis. The most common locations of the lesions were the rectum (37/56, 66.1%) and sigmoid colon (7/56, 12.5%). Based on endoscopy findings and pathological results, the most prevalent types of subepithelial lesions in the lower gastrointestinal tract were neuroendocrine tumor (NET) (12/56, 20.3%), lipoma (8/56, 13.6%) and extraluminal compression (8/56, 13.6%). The majority of lesions ranged in diameter from 1 to 3cm (χ2 = 18.750, p < 0.001). After undergoing linear EUS examination, 36 patients received EUS-FNA (3/36), biopsy (5/36), endoscopic resection (25/36), or surgical excision (3/36) respectively. The pathological results of 29 patients were entirely consistent with the diagnosis made using linear EUS, with an 80.6% (29/36) diagnostic accuracy rate. Follow-up indicated that the lesions remained unchanged within 6-36months. All patients tolerated the procedure well without any complications. In conclusion, linear EUS demonstrates technical feasibility, safety, and a high diagnostic accuracy for subepithelial lesions in the lower gastrointestinal tract.

Clinical Significance and Resource Burden of Double Duct Sign in Non-jaundiced Patients.

Aim The study aims to determine the incidence of malignancy at presentation and subsequent risk of malignancy (at 12 months follow-up) in a cohort of patients with double duct sign (DDS) on cross-sectional imaging but no visible stigmata of jaundice. The study also correlates malignancy with liver enzyme dysfunction and estimates the resource burden incurred during the investigation of these patients. Methods A search for the key term "double duct sign" was undertaken in the radiological database of a tertiary hepatopancreatobiliary (HPB) centre between March 2017 and March 2022. Radiological reports, clinic letters, blood results, and multidisciplinary team meeting (MDT) outcomes were reviewed during this period and at one year. The national tariff payment system was reviewed to identify tariffs for different investigations required for the cohortand to calculate the total cost incurred. Results Ninety-seven patients with DDS were identified. Sixty-four patients (66%) had a normal bilirubin (0-21 µmol/L) at presentation and were included in the analysis. Seven patients (10.9%) were diagnosed with malignant peri-ampullary tumours, and 21 (32.8%) were diagnosed with benign diseases. In 34 patients (53%) with DDS, the underlying cause remained uncharacterised. Most patients had mild abnormalities of liver enzymes, but two patients (4.3%) were diagnosed with malignant peri-ampullary tumours despite having normal serological values. Patients who had a benign diagnosis and/or who had cancer excluded without a definitive diagnosis did not go on to develop a malignancy at 12 months follow-up. However, in those patients where the underlying aetiology could not be characterised, extended surveillance was required with a total of 80 MDT discussions and multiple surveillance scans (103 CT and 65 MRI scans). Twenty-six patients underwent endoscopic ultrasound (EUS) with three patients requiring more than one EUS examination (29 investigations in total). The cost of these investigations was £38,926.89. Conclusion This study confirms that DDS even in patients without clinical jaundice or with normal liver enzymes requires careful investigation to exclude malignancy despite the resource burden this entails. This supports previously reported results in the literature, and despite the increased use of cross-sectional imaging, DDS remains a clinically significant finding. Large cohort risk stratification studies would be useful to determine clinical urgency and allow the appropriate allocation of resources.

Endoscopic ultrasound in diagnosis and treatment of choledocholithiasis in children

Aim. To evaluate the informativeness of endoscopic ultrasound examination in children with suspected choledocholithiasis. Materials and methods. The study enrolled 20 patients with suspected choledocholithiasis. All patients underwent endoscopic ultrasound. Patient follow-up ranged from 4 to 14 months. Results. Endoscopic ultrasound proved to be informative in all patients and determined the treatment tactics in 10 patients. In 1 observation, the results of endoscopic ultrasound allowed for omitting endoscopic retrograde cholangiopancreatography as well as surgery. No complications were reported during the diagnostic examination. Conclusion. Endoscopic ultrasound is considered to be an informative and safe method in adults as well as in children. High efficiency in detecting gallstones enabled unnecessary and traumatic surgical interventions to be avoided. Assessment of anatomic features of the ductal system during endoscopic ultrasound serves as a significant factor for safer transpapillary surgeries.

Evaluation of appendiceal mucinous neoplasms by curved linear-array echoendoscope: A preliminary study.

Preoperative diagnosis of appendiceal mucinous neoplasms is challenging, and there are few reports regarding the endosonographic characteristics of these neoplasms. To provide a retrospective assessment of the imaging features of appendiceal mucinous neoplasms using endoscopic ultrasound (EUS) by curved linear-array echoendoscope. A database of all patients with appendiceal mucinous neoplasms who had received EUS examination at our hospital between January 2018 and July 2023 was retrospectively analyzed. The EUS characteristics and patients' clinical data were reviewed. Twenty-two patients were included in the study. The linear-array echoendoscope successfully reached the ileocecal region in every patient. In the endoscopic view, we could observe the protrusion in the appendiceal orifice in all patients. A volcano sign was observed in two patients, and an atypical volcano sign was seen in two patients. EUS showed that all 22 lesions were submucosal cystic hypoechoic lesions with clear boundaries. No wall nodules were observed, but an onion-peeling sign was observed in 17 cases. Linear-array echoendoscope is safe to reach the ileocecal region under the guidance of EUS. Image features on endoscopic and echoendosonograhic views could be used to diagnose appendiceal mucinous neoplasms.

Performance of European and American Societies of Gastrointestinal Endoscopy Guidelines for Prediction of Choledocholithiasis in Patients with Acute Biliary Pancreatitis.

Background and Objectives: Up to one-third of patients with acute biliary pancreatitis also present with choledocholithiasis. Guidelines from the European Society of Gastrointestinal Endoscopy (ESGE) and the American Society for Gastrointestinal Endoscopy (ASGE) for investigating suspected choledocholithiasis suggest endoscopic retrograde cholangiopancreatography in patients with high-likelihood (ESGE)/high-probability (ASGE) predictors and endoscopic ultrasound in those with intermediate-likelihood (ESGE)/intermediate-probability (ASGE) predictors. Although both guidelines are similar, they are not identical. Furthermore, these algorithms were mainly developed from cohorts of patients without pancreatitis and are therefore poorly validated in a subset of patients with acute pancreatitis. We aimed to assess the performance of the ESGE and ASGE algorithms for the prediction of choledocholithiasis in patients with acute biliary pancreatitis. Materials and Methods: This was a retrospective analysis of 86 consecutive patients admitted to a tertiary referral centre in the year 2020 due to acute biliary pancreatitis. Results: Choledocholithiasis was confirmed in 29/86 (33.7%) of patients (13 with endoscopic retrograde cholangiopancreatography and 16 with endoscopic ultrasound). All 10/10 (100%) ESGE high-likelihood and 14/19 (73.7%) ASGE high-probability patients had choledocholithiasis. Only 19/71 (26.8%) patients with ESGE intermediate likelihood and 15/67 (22.4%) with ASGE intermediate probability had choledocholithiasis. Only 8/13 (61.5%) patients with the ASGE high-probability predictor of dilated common bile duct plus bilirubin > 68.4 µmol/mL had choledocholithiasis. Since this predictor is not considered high likelihood by ESGE, this resulted in a superior specificity of the European compared to the American guideline (100% vs. 91.2%). Following the American instead of the European guidelines would have resulted in five unnecessary endoscopic retrograde cholangiopancreatographies and five unnecessary endoscopic ultrasound examinations. Conclusions: This retrospective analysis suggests that the European guidelines may perform better than the American guidelines at predicting choledocholithiasis in the setting of acute pancreatitis. This was because dilated common bile duct plus bilirubin > 68.4 µmol/mL was not a reliable predictor for persistent bile duct stones.

Linear Endoscopic Ultrasound Examination of the Biliary System and Its Clinical Applications

AbstractEndoscopic ultrasound (EUS) examination of the biliary system plays pivotal role in pancreatobiliary studies. EUS offers a safe and noninvasive method of the biliary tract disorder evaluation. Although radial EUS provides a straightforward orientation, practicing biliary system examination with a curvilinear echoendoscope is advisable because of its added therapeutic benefits. Linear EUS may pose challenge in understanding the orientation and tracing nondilated bile duct in the beginning. However, adopting a systematic station-wise approach can help in comprehending the orientation and effectively tracing the entire bile duct. In this review, we have discussed linear EUS examination of the bile duct and gallbladder from various stations and its clinical applications.

Impact of Slim Linear Echoendoscope on the Practice of EUS.

Standard linear echoendoscopes have a large distal tip and bending radius, which can preclude adequate examination in some patients. We examined the impact of having available slim linear echoendoscopes (SLE) on our endoscopic ultrasound (EUS) practice. As a quality improvement measure, data on the need for the use of SLE were documented in 2000 consecutive procedures performed over a 10-month period from February to November 2022. When examination using a standard size echoendoscope failed due to technical limitations, the procedure was reattempted in the same session using a SLE. The main outcome was the impact of SLE, which was defined as the establishment of a new diagnosis or if findings altered treatment plan. A complete EUS examination failed in 23 of 2000 procedures (1.15%, 95% CI, 0.73-1.72%) performed using standard size echoendoscope (14 male, median age 73y [IQR 66 to 79]). The examination was technically successful when using SLE in 22 of 23 (95.6%) patients. SLE impacted clinical management in all 22 patients (100%) by establishing tissue diagnosis in 19 and/or altering subsequent treatment plan in 5. Adverse event of transient hypoxia was observed in one patient (4.3%). A very experienced EUS team required SLE in 1.1% of consecutive examinations. Our findings suggest that when used, 95% of patients benefitted as it had a significant impact on their clinical management.

Endoscopic Ultrasonography-Derived Maximum Tumor Thickness and Tumor Shrinkage Rate as Independent Prognostic Factors in Locally Advanced Esophageal Squamous Cell Carcinoma after Neoadjuvant Chemoradiotherapy

Neoadjuvant chemoradiotherapy (NCRT) is increasingly used in patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC). Endoscopic ultrasonography (EUS)-derived maximum tumor thickness (MTT) before and after standard NCRT for LA-ESCC indicates treatment response. However, the accuracy of predicting long-term survival remains uncertain. This study aimed to investigate the association between EUS-derived MTT pre- and post-NCRT and tumor shrinkage rate as well as long-term survival in patients with LA-ESCC receiving NCRT. We retrospectively enrolled patients with LA-ESCC who underwent EUS examination pre- and post-NCRT from 2017 to 2021. MTT was measured using EUS. Tumor shrinkage rate was the ratio of the difference between pre- and post-MTT to pre-MTT. The most fitted cut-off value defining the EUS response was determined by the receiver operating characteristic curve. Univariate and multivariate Cox regression analyses and Kaplan-Meier (KM) curves were used to calculate overall survival (OS) and progression-free survival (PFS). Data from another center were also used for external validation testing. The median follow-up period was 30.6 months.230 patients with LA-ESCC who underwent EUS pre- or post-NCRT were enrolled. Of the patients, 178 completed the first EUS pre-NCRT and obtained pre-MTT, 200 completed the re-examined EUS post-NCRT and obtained post-MTT, and 148 completed both EUS and achieved tumor shrinkage. In the whole group the 1-year and 3-year OS rates were 93.9% and 67.9%, and PFS rates were 77.7% and 54.1%, respectively. Thinner post-MTT (≤8.8 mm) and EUS-responders (tumor shrinkage rate≥52%) were independently associated with better OS. The result of EUS-respond was an independent prognostic factor could be confirmed in the external validation group. Among LA-ESCC patients with initial ultrasonic T2-3 staging and T4 staging, no statistically differences were observed between the responder and non-responder groups (P = 0.082; P = 0.190). EUS-derived MTT and tumor shrinkage post-NCRT are independent prognostic factors for long-term survival and may be an alternative method for evaluating tumor response in patients with LA-ESCC after NCRT. Initial tumor infiltration beyond esophageal adventitial layer on ultrasound effect could not, however, predict the long-term prognosis.

Role of endoscopic ultrasound and endoscopic ultrasound-guided tissue acquisition in diagnosing hepatic focal lesions.

Endoscopic ultrasonography (EUS) has become an established method in diagnostic and therapeutic procedures in gastroenterology; however, it has recently gained a growing role in hepatology. To evaluate the role of EUS features, strain elastography (SE), and EUS-tissue acquisition in diagnosing hepatic focal lesions (HFLs) that could affect further management. This cross-sectional study included 215 patients with pancreatic, biliary, or gastrointestinal malignancies referred for EUS examination. HFLs were identified in 43 patients (20%), and EUS-guided tissue acquisition was performed from these lesions. EUS features were highly sensitive (100%) but much less specific (57%) in diagnosing HFLs; the overall accuracy was 94%. Real-time elastography was also very sensitive (97%) but less specific (67%) in diagnosing HFLs; however, the overall accuracy was 92%. EUS tissue acquisition was extremely sensitive (100%) and specific (100%), with a 100% overall diagnostic accuracy. The diagnostic utility of EUS-guided tissue acquisition was extremely accurate in diagnosing HFLs. EUS characteristics and real-time SE accurately predicted the histological diagnosis of both benign and malignant HFLs.

Pictorial Essay of Linear Endoscopic Ultrasound Examination of Pancreas Anatomy

AbstractEndoscopic ultrasound (EUS) is a widely used imaging modality for both diagnostic and therapeutic purposes. Understanding the anatomy is crucial during a curved linear EUS examination. Compared with other advanced endoscopic techniques, the learning curve for EUS is longer, and the training facilities for EUS are also not widely available. The interest and enthusiasm for EUS among endoscopists is limited by the long learning curve and the scarcity of training programs. Imaging of the pancreas is the most common indication of EUS examination, and many endoscopist often face difficulty in understanding the anatomy and orientation of the pancreas on linear EUS examination. In this article, we will discuss the problems encountered during linear EUS examination and how to overcome each problem with a station-wise pancreas examination.

A comparative study between computed tomography and endoscopic ultrasound in the detection of a mural nodule in intraductal papillary mucinous neoplasm –Multicenter observational study in Japan

Background/objectivesThe detection of malignancy is a major concern in the management of intraductal papillary mucinous neoplasm (IPMN). The height of the mural nodule (MN), estimated using endoscopic ultrasound (EUS) and computed tomography (CT), has been considered crucial for predicting malignant IPMN. Currently, whether surveillance using CT or EUS alone is sufficient for detecting MNs remains unclear. This study aimed to compare the ability of CT and EUS to detect MNs in IPMN. MethodsThis multicenter, retrospective observational study was conducted in 11 Japanese tertiary institutions. Patients who underwent surgical resection of IPMN with MN after CT and EUS examinations were eligible to participate. The MN detection rates between CT and EUS were examined. ResultsTwo-hundred-and-forty patients who underwent preoperative EUS and CT had pathologically confirmed MNs. The MN detection rates of EUS and CT were 83% and 53%, respectively (p < 0.001). Additionally, the MN detection rate of EUS was significantly higher than that of CT regardless of morphological type (76% vs. 47% in branch-duct-type IPMN; 90% vs. 54% in mixed IPMN; 98% vs. 56% in main-duct-type IPMN; p < 0.001). Further, pathologically confirmed MNs ≥5 mm were more frequently observed on EUS than on CT (95% vs. 76%, p < 0.001). ConclusionsEUS was superior to CT for the detection of MN in IPMN. EUS surveillance is essential for the detection of MNs.

Endoscopic resection of gastric glomus tumor: a case report and literature review

Abstract Objectives Gastric glomus tumor (GGT) is a rare mesenchymal tumor, mostly located in the gastric antrum region, and occasionally displays malignant behavior. Due to the lack of typical endoscopic or clinical features that distinguish GGT from other gastric submucosal tumors, the diagnosis is based primarily on postoperative histopathological and immunohistochemical findings. The first-line treatment is either local laparoscopic resection or open surgical intervention. Endoscopic resection techniques can also be used to successfully treat such lesions. Case presentation This case report presented a 39-year-old woman suffering from anorexia for the past 15 days. Barium upper gastrointestinal radiography suggested a benign space-occupying lesion in the antrum region. Endoscopically, a non-ulcerative, smooth submucosal lesion was observed in the greater curvature of the antrum. Endoscopic ultrasound (EUS) examination revealed a hypoechoic lesion with an anechoic zone in the center, originating from the muscularis propria layer of the stomach wall, which could be a gastrointestinal stromal tumor (GIST). Conclusions The lesion was successfully removed via submucosal tunneling endoscopic resection (STER). Based on histopathological and immunohistochemical findings, the patient was diagnosed with GGT.

Analysis of efficacy and safety of a new endoscopic anastomosis clip in the treatment of defects after endoscopic full-thickness resection

Objective: To investigate the efficacy and safety of a new endoscopic anastomosis clip in the treatment of defects after endoscopic full-thickness resection (EFTR). Methods: Retrospective cohort study. Fourteen patients [4 males and 10 females, aged (55.9±8.2) years (45-69 years)] with gastric submucosal tumors underwent EFTR at the First Affiliated Hospital of Soochow University were included from December 2018 to January 2021. Patients were divided into new anastomotic clamp group (n=6) and nylon ring combined with metal clips group (n=8). Preoperative endoscopic ultrasound examinations were required to all patients to evaluate the wound condition. The size of the defect, operation time required for wound closure, success rate of closure, postoperative gastric tube placement time, postoperative hospital stay, incidence of complications, preoperative and postoperative serological indexes were compared between the two groups. All patients were followed up after the operation, among which the general endoscopy was reviewed in the first month after the operation, and the telephone and questionnaire follow-up were used in the second, third, sixth month and one year after the operation to evaluate the therapeutic effect of the new endoscopic anastomosis clip and nylon rope combined with metal clip after the EFTR operation. Results: Both groups successfully completed EFTR and were successfully closed. There was no significant difference between the age, tumor diameter and defect diameter of the two groups (all P>0.05). Compared with the nylon ring combined with metal clip group, the operation time of the new anastomotic clip group was shortened [(5.0±1.8) minutes vs (35.6±10.2) minutes, P<0.001]. The operation time was shortened [(62.2±12.5) minutes vs (92.5±0.2) minutes, P=0.007]. Postoperative fasting time decreased [(2.8±0.8) days vs (4.9±1.1) days, P=0.002]. The hospital stay after operation was also shortened [(5.2±0.8) days vs (6.9±1.5) days, P=0.023]. The total intraoperative bleeding volume decreased [(20.00±5.48) ml vs (35.63±14.75) ml, P=0.031]. The patients in both groups received endoscopic examination 1 month after operation, and there was no delayed perforation and bleeding after operation. There was no obvious symptoms of discomfort. Conclusion: The new anastomotic clamp is suitable for the treatment of full-thickness gastric wall defects after EFTR, and shows advantages of shorter operation, less bleeding, and fewer postoperative complications.

Abdominal Pain—An Ambiguous Pancreatic Cyst

Question: A 74-year-old man presented with vague abdominal pain. There was no personal history of malignancy or weight loss. Serum laboratory tests were significant for a total bilirubin of 3.4 mg/dL but direct bilirubin of 0.20 mg/dL. Liver enzymes, lactate dehydrogenase, carcino-embryonic antigen, and cancer antigen 19-9 were all within normal range. Computed tomographic (CT) imaging (Figure A and B) revealed a 6 × 2.9 × 2.7 cm pancreatic mass in the body of the pancreas with associated mesenteric and left-side retro-peritoneal para-aortic lymphadenopathy without significant ductal dilation. Endoscopic ultrasound (EUS) examination (Figure C and D) demonstrated a nearly completely cystic mass measuring 2.5 × 2.2 cm. A plane appeared to separate the cystic mass from the pancreatic body itself. Multiple abnormal, oval, hypo-echoic lymph nodes were visualized in the peri-gastric region as well. EUS-guided core biopsies were obtained from the cyst wall.

Endoscopic Ultrasound Appearance of Jejunal Ectopic Pancreas Mimicking Metastatic Nodule in a Cancer Patient

The ectopic pancreas is a benign subepithelial tumor (SET) mostly found incidentally in the stomach and duodenum. Here, we present computed tomography (CT) scans and endoscopic ultrasound (EUS) images from a 71-year-old Taiwanese man newly diagnosed with colonic adenocarcinoma. CT examination revealed a mural nodule in the proximal jejunum, with good enhancement after IV contrast medium administration. Push enteroscopy was performed to localize the lesion and evaluate its nature, and a 1 cm subepithelial lesion was found. The lesion appeared hyperechoic within the submucosal layer of the bowel wall on endoscopic ultrasound examination. A tattoo was performed, and the lesion was removed during the resection of colon cancer. The histopathology confirmed the presence of pancreatic tissue inside. As far as we know, this is the first description in the literature of an endoscopic ultrasound finding of a jejunal ectopic pancreas.

EUS-guided cyanoacrylate injection into the perforating vein versus direct endoscopic injection in the treatment of gastric varices.

Background and study aims Endoscopic injection of gastric varices (GVs) using cyanoacrylate (CYA) is associated with significant adverse events (AEs). We aimed to compare the efficacy and safety of endoscopic ultrasound (EUS)-guided CYA injection into the perforating vein versus direct endoscopic injection (DEI) of CYA in treatment of high-risk GVs. Patients and methods This was a randomized controlled trial that included 52 patients with high-risk GVs. Group A underwent EUS-guided injection into the perforator vein and Group B underwent DEI of 1 mL CYA. Endoscopic examination and Doppler EUS were repeated after 3 months to confirm eradication. Obliteration by Doppler EUS was considered by absence of Doppler flow within the varix. Repeated injection was performed in the absence of obliteration. Doppler EUS examination was repeated at 3 and 6 months after each injection. Results Forty-three patients including 27 males and 16 females with mean age 57 years completed the study. Variceal obliteration was achieved during the index session after 3 months in eight of 21 (38.1 %) in group B compared to 17 of 22 (77.2 %) in group A ( P = 0.014). There was a significant difference in the amount of CYA needed to achieve obliteration in group B compared to group A (2 vs.1 mL, P = 0.027). There was no statistically significant difference in the overall AE rate between group A and group B (4.5 % vs. 14.3 %, P = 0.345). Conclusions EUS-guided CYA injection into the perforating veins achieved less amount of CYA, fewer number of sessions to obliteration, and similar overall AE rates in the treatment of high-risk GVs compared to DEI.

Electromagnetic tracking of endoscopic ultrasound probe for pancreas examination: accuracy assessment under realistic medical conditions

ABSTRACT Pancreatic cancer stands as the 3rdcause of death by cancer in 2021 and may become 2nd in a decade. In this context, early tumour diagnosis is primordial but unfortunately 3D medical imaging are not sensitive enough while Endoscopic ultrasound (EUS) allows early diagnosis. However it is not widely available due to its difficulty to master. We focus on developing a guidance system for low EUS expertise endoscopists . This would be enabled by providing a computer-assisted rendered scene showing patient’s 3D model with a real-time representation of the registered EUS probe. The corresponding accuracy is largely relying on the efficient registration of the patient-specific model to the real patient pose during EUS examination. For that purpose, we developed an electromagnetic tracking system attached to an EUS probe. We detail the used registration algorithm and our original experimental method for accuracy measurement based on Cone Beam Computed Tomography. We demonstrate an accuracy in position and angle of respectively mm and in pre-clinical conditions. We also demonstrate that efficient navigation can be proposed to clinicians during EUS even in complex and realistic anatomy of a swine model. This work is paving the way to a guided EUS navigation system for pancreas examination.