How-I-do-it: laparoscopic intragastric submucosal dissection (LISD) for gastric and gastro-oesophageal junction early lesions

PURPOSE

Laparoscopic intragastric submucosal dissection (LISD) is a novel approach to the resection of gastric lesion that are not amenable to conventional endoscopic approaches. The technique permits favourable access to lesions situated at the cardia and angular notch of the stomach, enables en-bloc resection of large areas of tissue, and can prevent the need of formal gastrectomy or oesophagectomy in selected patients.

METHODS

All cases were deemed suitable for LISD by a multidisciplinary team panel following endoscopic assessment (using white light enhancement, chromoendoscopy and magnification endoscopy) that was integrated when needed with EUS, CT scan or PET scan. The surgical technique consisted in a 3-port laparoscopic approach; after establishment of pneumoperitoneum, three gastrotomies were performed to enable port insertion into the stomach. Following establishment of stable pneumogastrium, the area of interest was identified, submucosal hyaluronic acid injection performed to provide a cushion in the plane of dissection, and the excision area was circumferentially marked with cautery. Resection was completed using cautery hook, along a plane parallel to the muscolaris propria. After the specimen was extracted in a retrieval bag, intracorporeal single layer running suture closure of gastrotomies was performed. The abdominal wall closed by layers and tap block performed along with local anaesthetic injection on skin incision. Measures were taken to ensure correct orientation of resected specimens prior to fixation.

RESULTS

During the study period that spans from 2014 and 2022, a total of 11 patients underwent LISD for limited lesions of the stomach, 10 were located at gastro-oesophageal junction and one at the angular incisura. Four patients were female, seven males. The median age was 74 (46-79) years. R0 resection rate was 54.5%. Mean operative time was 109 min with very low blood loss (10 ml). Mortality rate was 0%, no immediate major complications (Grade II-V Clavien Dindo), including haemorrhage or perforation, occurred in these cases. Two patients developed dysphagia later that was successfully treated with endoscopic balloon dilatations. Median hospital stay was 3 days and median oral intake was on day 1 post-procedural.

CONCLUSIONS

Laparoscopic intragastric submucosal dissection is shown to be a safe and effective intervention for the treatment of early gastric cancers in selected patients having undergone deemed not amenable for endoscopic submucosal resection for their technically challenging location. Its application can serve as route to avoid formal surgery and the associated morbidity.

Ultrasound-Guided Interventions in the Biliary System

Ultrasound guidance in biliary interventions has become the standard tool to facilitate percutaneous biliary drainage as well as percutaneous gall bladder drainage. Monitoring of the needle tip whilst penetrating the tissue in real time using ultrasound allows precise manoeuvres and exact targeting without radiation exposure. Without the need for fluoroscopy, ultrasound-guided drainage procedures can be performed bedside as a sometimes life-saving procedure in patients with severe cholangitis/cholecystitis when they are critically ill in intensive care units and cannot be transported to a fluoroscopy suite. This article describes the current data background and guidelines and focuses on specific sonographic aspects of both the procedures of percutaneous biliary drainage and gallbladder drainage.

Mishaps with EUS-guided lumen-apposing metal stents in therapeutic pancreatic EUS: Management and prevention

EUS-guided interventions have become widely accepted therapeutic management options for drainage of peripancreatic fluid collections. Apart from endosonographic skills, EUS interventions require knowledge of the endoscopic stenting techniques and familiarity with the available stents and deployment systems. Although generally safe and effective, technical failure of correct stent positioning or serious adverse events can occur, even in experts' hands. In this article, we address common and rare adverse events in transmural EUS-guided stenting, ways to prevent them, and management options when they occur. Knowing the risks of what can go wrong combined with clinical expertise, high levels of technical skills, and adequate training allows for the safe performance of EUS-guided drainage procedures. Discussing the procedural risks and their likelihood with the patient is a fundamental part of the consenting process.

Comments on and Illustrations of the EFSUMB CEUS Guidelines: Transabdominal and Endoscopic Ultrasound Features of Intrapancreatic Metastases and the Role of Multiparametric Imaging and EUS-Guided Sampling in Rare Pancreatic Tumors

A definite pathologic diagnosis of intrapancreatic metastasis is crucial for the management decision, i.e., curative or palliative surgery versus chemotherapy or conservative/palliative therapy. This review focuses on the appearance of intrapancreatic metastases on native and contrast-enhanced transabdominal ultrasound and endoscopic ultrasound. Differences and similarities in relation to the primary tumor, and the differential diagnosis from pancreatic carcinoma and neuroendocrine neoplasms are described. The frequency of intrapancreatic metastases in autopsy studies and surgical resection studies will be discussed. Further emphasis is placed on endoscopic ultrasound-guided sampling to confirm the diagnosis.

Secondary sclerosing cholangitis and IgG4-sclerosing cholangitis - A review of cholangiographic and ultrasound imaging

Sclerosing cholangitis (SC) represents a spectrum of chronic progressive cholestatic diseases of the intrahepatic and/or extrahepatic biliary system characterized by patchy inflammation, fibrosis, and stricturing. Primary and secondary SC must be distinguished given the different treatment modalities, risks of malignancy, and progression to portal hypertension, cirrhosis, and hepatic failure. This review focuses on secondary SC and the pathogenic mechanisms, risk factors, clinical presentation, and novel imaging modalities that help to distinguish between these conditions. We explore the detailed use of cholangiography and ultrasound imaging techniques.

Pancreatic changes with lifestyle and age: What is normal and what is concerning?

During the aging process, typical morphological changes occur in the pancreas, which leads to a specific "patchy lobular fibrosis in the elderly." The aging process in the pancreas is associated with changes in volume, dimensions, contour, and increasing intrapancreatic fat deposition. Typical changes are seen in ultrasonography, computed tomography, endosonography, and magnetic resonance imaging. Typical age-related changes must be distinguished from lifestyle-related changes. Obesity, high body mass index, and metabolic syndrome also lead to fatty infiltration of the pancreas. In the present article, age-related changes in morphology and imaging are discussed. Particular attention is given to the sonographic verification of fatty infiltration of the pancreas. Ultrasonography is a widely used screening examination method. It is important to acknowledge the features of the normal aging processes and not to interpret them as pathological findings. Reference is made to the uneven fatty infiltration of the pancreas. The differential diagnostic and the differentiation from other processes and diseases leading to fatty infiltration of the pancreas are discussed.

Controversies in EUS-guided treatment of walled-off necrosis

This review gives an overview of different techniques in the treatment of post-acute complications of acute pancreatitis. The endoscopic treatment of those complications is currently standard of care. EUS opened up the broad implementation of internal drainage methods to make them safe and effective. Due to different endoscopic approaches worldwide, controversies have arisen that are pointed out in this paper. The main focus was placed on weighing up evidence to find the optimal approach. However, if no evidence can be provided, the authors, experienced in the field, give their personal advice.

How to perform EUS-guided biliary drainage

EUS-guided biliary drainage (EUS-BD) has recently gained widespread acceptance as a minimally invasive alternative method for biliary drainage. Even in experienced endoscopy centers, ERCP may fail due to inaccessibility of the papillary region, altered anatomy (particularly postsurgical alterations), papillary obstruction, or neoplastic gastric outlet obstruction. Biliary cannulation fails at first attempt in 5%-10% of cases even in the absence of these factors. In such cases, alternative options for biliary drainage must be provided since biliary obstruction is responsible for poor quality of life and even reduced survival, particularly due to septic cholangitis. The standard of care in many centers remains percutaneous transhepatic biliary drainage (PTBD). However, despite the high technical success rate with experienced operators, the percutaneous approach is more invasive and associated with poor quality of life. PTBD may result in long-term external catheters for biliary drainage and carry the risk of serious adverse events (SAEs) in up to 10% of patients, including bile leaks, hemorrhage, and sepsis. PTBD following a failed ERCP also requires scheduling a second procedure, resulting in prolonged hospital stay and additional costs. EUS-BD may overcome many of these limitations and offer some distinct advantages in accessing the biliary tree. Current data suggest that EUS-BD is safe and effective when performed by experts, although SAEs have been also reported. Despite the high number of clinical reports and case series, high-quality comparative studies are still lacking. The purpose of this article is to report on the current status of this procedure and to discuss the tools and techniques for EUS-BD in different clinical scenarios.

Controversies in ERCP: Technical aspects

The aim of the series of papers on controversies of biliopancreatic drainage procedures is to discuss pros and cons of the varying clinical practices and techniques in ERCP and EUS for drainage of biliary and pancreatic ducts. While the first part focuses on indications, clinical and imaging prerequisites prior to ERCP, sedation options, post-ERCP pancreatitis prophylaxis, and other related technical topics, the second part discusses specific procedural ERCP techniques including precut techniques and their timing as well as management algorithms. In addition, reviews on controversies in EUS-guided bile duct and pancreatic drainage procedures are under preparation.

Controversies in ERCP: Indications and preparation

The aim of the series of papers on controversies of biliopancreatic drainage procedures is to discuss the pros and cons of the varying clinical practices and techniques in ERCP and EUS for drainage of biliary and pancreatic ducts. The first part focuses on indications, clinical and imaging prerequisites before ERCP, sedation options, post-ERCP pancreatitis (PEP) prophylaxis, and other related technical topics. In the second part, specific procedural ERCP-techniques including precut techniques and its timing as well as management algorithms are discussed. In addition, controversies in EUS-guided bile duct and pancreatic drainage procedures are under preparation.

[Acute Cholecystitis in high-risk surgical patients: sonographic and endoscopic treatment options]

Cholecystectomy is the gold standard in the treatment of acute cholecystitis, but has a significantly increased risk in multimorbid patients or in the severe course of acute cholecystitis. In such cases, drainage of the damaged gallbladder in combination with antibiotic therapy may be superior to primary surgery. The drainage can either be performed as sonographically guided percutaneous transhepatic gallbladder drainage or as EUS-guided transmural stent placement or endoscopic-transpapillary gallbladder drainage. These minimally invasive alternatives to cholecystectomy can be used both as long-term therapy for permanently inoperable patients and temporarily for patients in whom the cholecystectomy is intended after improvement of the general condition. In this overview, the various drainage methods are discussed with regard to technical requirements, immediate and long-term clinical results and complications. With advances in stent design, EUS-guided transmural stent placement from the stomach or duodenum into the gallbladder is becoming the preferred method of gallbladder drainage in centers with the appropriate expertise.

Interventional endoscopic ultrasound

PURPOSE OF REVIEW

To update on recent advances in interventional endoscopic ultrasound (INVEUS) techniques.

RECENT FINDINGS

The introduction of linear echoendoscopes with larger instrument channels and the combined development of new tools and devices have enabled various new applications of minimally invasive endoscopic ultrasound (EUS)-guided transluminal interventions of the pancreas, biliary system and peri-gastrointestinal structures. In this review, EUS-guided interventions are discussed and evaluated: drainage of peripancreatic fluid collections, access and drainage of bile ducts, gallbladder and pancreatic duct, treatment of gastrointestinal haemorrhage, coeliac plexus block and coeliac plexus neurolysis, fiducial placement, solid and cystic tumour ablation, drug delivery and brachytherapy, gastroenterostomy, angiotherapy and other EUS-guided applications. The EUS-guided interventions are classified based on the available evidence as established or experimental, standardized or nonstandardized procedures in common or rare diseases with well or little known complications and their established or nonestablished treatment.

SUMMARY

Some EUS-guided interventions have sparse published evidence with only single-centre studies, case series or individual case reports, others like drainage of peripancreatic fluid collections have become widely accepted practice. INVEUS has been accepted as an alternative to several surgical approaches, EUS-guided techniques result in faster recovery times, shorter hospital stay and lower costs.

A Pilot Study on Automatic Three-Dimensional Quantification of Barrett's Esophagus for Risk Stratification and Therapy Monitoring

BACKGROUND & AIMS

Barrett's epithelium measurement using widely accepted Prague C&M classification is highly operator dependent. We propose a novel methodology for measuring this risk score automatically. The method also enables quantification of the area of Barrett's epithelium (BEA) and islands, which was not possible before. Furthermore, it allows 3-dimensional (3D) reconstruction of the esophageal surface, enabling interactive 3D visualization. We aimed to assess the accuracy of the proposed artificial intelligence system on both phantom and endoscopic patient data.

METHODS

Using advanced deep learning, a depth estimator network is used to predict endoscope camera distance from the gastric folds. By segmenting BEA and gastroesophageal junction and projecting them to the estimated mm distances, we measure C&M scores including the BEA. The derived endoscopy artificial intelligence system was tested on a purpose-built 3D printed esophagus phantom with varying BEAs and on 194 high-definition videos from 131 patients with C&M values scored by expert endoscopists.

RESULTS

Endoscopic phantom video data demonstrated a 97.2% accuracy with a marginal ± 0.9 mm average deviation for C&M and island measurements, while for BEA we achieved 98.4% accuracy with only ±0.4 cm2 average deviation compared with ground-truth. On patient data, the C&M measurements provided by our system concurred with expert scores with marginal overall relative error (mean difference) of 8% (3.6 mm) and 7% (2.8 mm) for C and M scores, respectively.

CONCLUSIONS

The proposed methodology automatically extracts Prague C&M scores with high accuracy. Quantification and 3D reconstruction of the entire Barrett's area provides new opportunities for risk stratification and assessment of therapy response.

Artificial intelligence in endoscopy: The challenges and future directions

Artificial intelligence based approaches, in particular deep learning, have achieved state-of-the-art performance in medical fields with increasing number of software systems being approved by both Europe and United States. This paper reviews their applications to early detection of oesophageal cancers with a focus on their advantages and pitfalls. The paper concludes with future recommendations towards the development of a real-time, clinical implementable, interpretable and robust diagnosis support systems.

Tunneled biopsy is an underutilised, simple, safe and efficient method for tissue acquisition from subepithelial tumours

BACKGROUND

Tissue acquisition from subepithelial lesions is often attempted by endoscopic ultrasound (EUS)-sampling as conventional endoscopic biopsy usually fails to reach deeper layers of the gastrointestinal wall.

AIM

To investigate the utilisation, safety and diagnostic yield of an intensified “bite-on-bite” tunnel biopsy technique.

METHODS

In this retrospective cohort study, all patients presenting with subepithelial masses in the upper gastrointestinal tract from March 2013 to July 2019 were included. Data were analysed for size and location of the subepithelial mass, use of intensified tunnel biopsy protocol (more than 10 double bite-on-bite biopsies) or superficial conventional biopsies, histology and imaging results, occurrence of readmission and adverse events after endoscopy.

RESULTS

Two hundred and twenty-nine patients with subepithelial lesions were included. Superficial conventional biopsies were taken in 117 patients and were diagnostic only in one lipoma (0.9 %). Tunnel biopsies taken in 112/229 (48.9%) patients were significantly more likely to provide histological diagnosis (53.6%; P < 0.001). For lesions ≥ 10mm the diagnostic yield of tunnel biopsies further increased to 41/67 (61.2%). No immediate or delayed complications were reported. Only 8 of the 51 endoscopists (15.7%) regularly attempted tunnel biopsies.

CONCLUSION

Tunnel biopsy is a simple, safe and efficient but underutilised diagnostic modality for tissue acquisition in subepithelial masses. It should be routinely attempted at the initial endoscopy.

Gastrointestinal Ultrasound in Functional Disorders of the Gastrointestinal Tract - EFSUMB Consensus Statement

Abdominal ultrasonography and intestinal ultrasonography are widely used as first diagnostic tools for investigating patients with abdominal symptoms, mainly for excluding organic diseases. However, gastrointestinal ultrasound (GIUS), as a real-time diagnostic imaging method, can also provide information on motility, flow, perfusion, peristalsis, and organ filling and emptying, with high temporal and spatial resolution. Thanks to its noninvasiveness and high repeatability, GIUS can investigate functional gastrointestinal processes and functional gastrointestinal diseases (FGID) by studying their behavior over time and their response to therapy and providing insight into their pathophysiologic mechanisms. The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) has established a Task Force Group consisting of GIUS experts, which developed clinical recommendations and guidelines on the role of GIUS in several acute and chronic gastrointestinal diseases. This review is dedicated to the role of GIUS in assisting the diagnosis of FGID and particularly in investigating patients with symptoms of functional disorders, such as dysphagia, reflux disorders, dyspepsia, abdominal pain, bloating, and altered bowel habits. The available scientific evidence of GIUS in detecting, assessing, and investigating FGID are reported here, while highlighting sonographic findings and its usefulness in a clinical setting, defining the actual and potential role of GIUS in the management of patients, and providing information regarding future applications and research.

Deep learning for detection and segmentation of artefact and disease instances in gastrointestinal endoscopy

The Endoscopy Computer Vision Challenge (EndoCV) is a crowd-sourcing initiative to address eminent problems in developing reliable computer aided detection and diagnosis endoscopy systems and suggest a pathway for clinical translation of technologies. Whilst endoscopy is a widely used diagnostic and treatment tool for hollow-organs, there are several core challenges often faced by endoscopists, mainly: 1) presence of multi-class artefacts that hinder their visual interpretation, and 2) difficulty in identifying subtle precancerous precursors and cancer abnormalities. Artefacts often affect the robustness of deep learning methods applied to the gastrointestinal tract organs as they can be confused with tissue of interest. EndoCV2020 challenges are designed to address research questions in these remits. In this paper, we present a summary of methods developed by the top 17 teams and provide an objective comparison of state-of-the-art methods and methods designed by the participants for two sub-challenges: i) artefact detection and segmentation (EAD2020), and ii) disease detection and segmentation (EDD2020). Multi-center, multi-organ, multi-class, and multi-modal clinical endoscopy datasets were compiled for both EAD2020 and EDD2020 sub-challenges. The out-of-sample generalization ability of detection algorithms was also evaluated. Whilst most teams focused on accuracy improvements, only a few methods hold credibility for clinical usability. The best performing teams provided solutions to tackle class imbalance, and variabilities in size, origin, modality and occurrences by exploring data augmentation, data fusion, and optimal class thresholding techniques.

Salvage endoscopic resection after definitive chemoradiotherapy for esophageal cancer: a Western experience

BACKGROUND AND AIMS

Definitive chemoradiotherapy (CRT) is increasingly used as a nonsurgical treatment for esophageal cancer. In Japanese studies, salvage endoscopic resection (ER) has emerged as a promising strategy for local failure after definitive CRT. We aimed to evaluate the safety and efficacy of salvage ER in a Western setting.

METHODS

Gastroenterologists from Europe and the United States were invited to submit their experience with salvage endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR) after definitive CRT. Participating gastroenterologists completed an anonymized database, including patient demographics, clinicopathologic variables, and follow-up on survival and recurrence.

RESULTS

Gastroenterologists from 10 endoscopic units in 6 European countries submitted information on 25 patients. A total of 35 salvage ER procedures were performed, of which 69% were ESD and 31% EMR. Most patients had squamous cell carcinoma (64%) of the middle or lower esophagus (68%) staged as cT2-3 (68%) and cN+ (52%) before definitive CRT. The median time from end of definitive CRT to ER was 22 months (interquartile range, 6-47). The en-bloc resection rate was 92% for ESD and 46% for EMR. During a median of 24 months (interquartile range, 12-59) of follow-up after salvage ER, 52% developed a recurrence (11 locoregional, 2 distant). The 5-year recurrence-free survival, overall survival, and disease-specific survival were 36%, 52%, and 79%, respectively. No major intra- or postprocedural adverse events, such as bleeding or perforation, were reported.

CONCLUSIONS

In carefully selected esophageal cancer patients, salvage ER is technically feasible after definitive CRT. Further prospective research is recommended to validate the safety and effectivity of salvage ER for the management of local failure.

Medical Student Ultrasound Education, a WFUMB Position Paper, Part II. A consensus statement of ultrasound societies

Ultrasound is becoming a fundamental first-line diagnostic tool for most medical specialties and an innovative tool to teach anatomy, physiology and pathophysiology to undergraduate and graduate students. However, availability of structured training programs during medical school is lagging behind and many physicians still acquire all their ultrasound skills during postgraduate training.There is wide variation in medical student ultrasound education worldwide. Sharing successful educational strategies from early adopter medical schools and learning from leading education programs should advance the integration of ultrasound into the university medical school curricula. In this overview, we present current approaches and suggestions by ultrasound societies concerning medical student educa-tion throughout the world. Based on these examples, we formulate a consensus statement with suggestions on how to integrate ultrasound teaching into the preclinical and clinical medical curricula.

A deep learning framework for quality assessment and restoration in video endoscopy

Endoscopy is a routine imaging technique used for both diagnosis and minimally invasive surgical treatment. Artifacts such as motion blur, bubbles, specular reflections, floating objects and pixel saturation impede the visual interpretation and the automated analysis of endoscopy videos. Given the widespread use of endoscopy in different clinical applications, robust and reliable identification of such artifacts and the automated restoration of corrupted video frames is a fundamental medical imaging problem. Existing state-of-the-art methods only deal with the detection and restoration of selected artifacts. However, typically endoscopy videos contain numerous artifacts which motivates to establish a comprehensive solution. In this paper, a fully automatic framework is proposed that can: 1) detect and classify six different artifacts, 2) segment artifact instances that have indefinable shapes, 3) provide a quality score for each frame, and 4) restore partially corrupted frames. To detect and classify different artifacts, the proposed framework exploits fast, multi-scale and single stage convolution neural network detector. In addition, we use an encoder-decoder model for pixel-wise segmentation of irregular shaped artifacts. A quality score is introduced to assess video frame quality and to predict image restoration success. Generative adversarial networks with carefully chosen regularization and training strategies for discriminator-generator networks are finally used to restore corrupted frames. The detector yields the highest mean average precision (mAP) of 45.7 and 34.7, respectively for 25% and 50% IoU thresholds, and the lowest computational time of 88 ms allowing for near real-time processing. The restoration models for blind deblurring, saturation correction and inpainting demonstrate significant improvements over previous methods. On a set of 10 test videos, an average of 68.7% of video frames successfully passed the quality score (≥0.9) after applying the proposed restoration framework thereby retaining 25% more frames compared to the raw videos. The importance of artifacts detection and their restoration on improved robustness of image analysis methods is also demonstrated in this work.

Controversies in EUS: Do we need miniprobes?

This is the fifth in a series of papers entitled "Controversies in EUS." In the current paper, we deal with high-resolution catheter probes, otherwise known as EUS miniprobes (EUS-MPs). The application of miniprobes for early carcinomas in the entire intestinal tract, for subepithelial lesions, and for findings in the bile duct and pancreatic duct as well as endobronchial use is critically discussed. Submucous lesions, especially in the colon, but also early carcinomas in special cases are considered the most important indications. The argument is illustrated by numerous examples.

An objective comparison of detection and segmentation algorithms for artefacts in clinical endoscopy

We present a comprehensive analysis of the submissions to the first edition of the Endoscopy Artefact Detection challenge (EAD). Using crowd-sourcing, this initiative is a step towards understanding the limitations of existing state-of-the-art computer vision methods applied to endoscopy and promoting the development of new approaches suitable for clinical translation. Endoscopy is a routine imaging technique for the detection, diagnosis and treatment of diseases in hollow-organs; the esophagus, stomach, colon, uterus and the bladder. However the nature of these organs prevent imaged tissues to be free of imaging artefacts such as bubbles, pixel saturation, organ specularity and debris, all of which pose substantial challenges for any quantitative analysis. Consequently, the potential for improved clinical outcomes through quantitative assessment of abnormal mucosal surface observed in endoscopy videos is presently not realized accurately. The EAD challenge promotes awareness of and addresses this key bottleneck problem by investigating methods that can accurately classify, localize and segment artefacts in endoscopy frames as critical prerequisite tasks. Using a diverse curated multi-institutional, multi-modality, multi-organ dataset of video frames, the accuracy and performance of 23 algorithms were objectively ranked for artefact detection and segmentation. The ability of methods to generalize to unseen datasets was also evaluated. The best performing methods (top 15%) propose deep learning strategies to reconcile variabilities in artefact appearance with respect to size, modality, occurrence and organ type. However, no single method outperformed across all tasks. Detailed analyses reveal the shortcomings of current training strategies and highlight the need for developing new optimal metrics to accurately quantify the clinical applicability of methods.

Do we need contrast agents for EUS?

We recently introduced a series of articles that dealt with controversies in EUS. In Part I, the authors discussed which clinical information is necessary prior to EUS and whether other imaging modalities are required before embarking on EUS examinations. Part II focuses on technical details and controversies about the use of EUS in special situations. In this article, important practical issues regarding the application of contrast-enhanced EUS in various clinical settings are raised and controversially discussed from different points of view.

Do we need elastography for EUS?

We recently introduced a series of papers “What should be known prior to performing EUS exams.” In Part I, the authors discussed which clinical information and whether other imaging modalities are needed before embarking EUS examinations. In Part II, technical controversies on how EUS is performed were discussed from different points of view. In this article, important practical issues regarding EUS elastography will be raised and controversially discussed from very different points of view.

How to perform EUS-guided tattooing?

Recently, we introduced a series of papers describing on how to perform certain techniques and controversies in EUS. In the first paper, "What should be known before performing EUS examinations, Part I," the authors discussed clinical information and whether other imaging modalities should be needed before embarking in EUS examination. In Part II, some technical controversies on how EUS is performed are discussed from different points of view by providing the relevant available evidence. Herewith, we describe on how to perform EUS-guided fine needle tattooing (FNT) in daily practice. The aim of this paper is to discuss pros and cons for several issues including historical remarks, injecting material, technical approach, and how to perform EUS-FNT including argues in favor and against.

What should be known prior to performing EUS?

Direct referral of patients for EUS – instead of preprocedural consultation with the endosonographer – has become standard practice (like for other endoscopic procedures) as it is time- and cost-effective. To ensure appropriate indications and safe examinations, the endosonographer should carefully consider what information is needed before accepting the referral. This includes important clinical data regarding relevant comorbidities, the fitness of the patient to consent and undergo the procedure, and the anticoagulation status. In addition, relevant findings from other imaging methods to clarify the clinical question may be necessary. Appropriate knowledge and management of the patients’ anticoagulation and antiplatelet therapy, antibiotic prophylaxis, and sedation issues can avoid unnecessary delays and unsafe procedures. Insisting on optimal preparation, appropriate indications, and clear clinical referral questions will increase the quality of the outcomes of EUS. In this paper, important practical issues regarding EUS preparations are raised and discussed from different points of view.

Therapeutic EUS: New tools, new devices, new applications

Linear echoendoscopes with large instrument channels enable EUS-guided interventions in organs and anatomical spaces in proximity to the gastrointestinal tract. Novel devices and tools designed for EUS-guided transluminal interventions allow various new applications and improve the efficacy and safety of these procedures. New-generation biopsy needles provide higher histology rates and require less passes. Specially designed stents and stent insertion devices enable intra- and extra-hepatic bile and pancreatic duct stenting as well as gallbladder drainage. Currently, EUS-guided biliary drainage in obstructive jaundice due to malignant distal bile duct obstruction is feasible and safe when ERCP has failed. It might replace ERCP as first choice intervention in future. EUS-guided transmural stenting is regarded as the preferred intervention in the management of symptomatic peripancreatic fluid collections. Creating a new anastomosis between different organs such as gastrojejunostomy has also become possible with lumen-apposing stents. EUS-guided creation of a gastrogastrostomy is a promising novel technique to access the excluded stomach to facilitate conventional ERCP in patients with Roux-en-Y gastric bypass anatomy. The role of EUS in tumor ablation and targeted angiotherapy is also constantly expanding. In this review, we report on the newest developments of therapeutic EUS within the past 4 years.

What should be known prior to performing EUS exams? (Part II)

In “What should be known prior to performing EUS exams, Part I,” the authors discussed the need for clinical information and whether other imaging modalities are required before embarking EUS examinations. Herewith, we present part II which addresses some (technical) controversies how EUS is performed and discuss from different points of view providing the relevant evidence as available. (1) Does equipment design influence the complication rate? (2) Should we have a standardized screen orientation? (3) Radial EUS versus longitudinal (linear) EUS. (4) Should we search for incidental findings using EUS?

Never seen before? Opisthorchiasis and Clonorchiasis

Parasitic diseases are relatively rarely diagnosed and treated in Europe. Therefore, European clinicians are not familiar with their clinical and imaging features. In an era of increased human migration, it is fundamental for clinicians to be able to identify such diseases. We have recently described the features of cystic echinococcosis, schistosomiasis, fascioliasis and ascariasis. Here, we report on the clinical and imaging features as well as on the current therapy options of infections by the small liver flukes: Clonorchis sinensis, Opisthorchis viverrini (Southeast Asian liver fluke) and Opisthorchis felineus (cat liver fluke) and other Opisthorchis species prevalent in South Asia.

Endoscopic ultrasound elastography of small solid pancreatic lesions: a multicenter study

BACKGROUND

The prevalence of malignancy in patients with small solid pancreatic lesions is low; however, early diagnosis is crucial for successful treatment of these cases. Therefore, a method to reliably distinguish between benign and malignant small solid pancreatic lesions would be highly desirable. We investigated the role of endoscopic ultrasound (EUS) elastography in this setting.

METHODS

Patients with solid pancreatic lesions ≤ 15 mm in size and a definite diagnosis were included. Lesion stiffness relative to the surrounding pancreatic parenchyma, as qualitatively assessed and documented at the time of EUS elastography, was retrospectively compared with the final diagnosis obtained by fine-needle aspiration/biopsy or surgical resection.

RESULTS

218 patients were analyzed. The average size of the lesions was 11 ± 3 mm; 23 % were ductal adenocarcinoma, 52 % neuroendocrine tumors, 8 % metastases, and 17 % other entities; 66 % of the lesions were benign. On elastography, 50 % of lesions were stiffer than the surrounding pancreatic parenchyma (stiff lesions) and 50 % were less stiff or of similar stiffness (soft lesions). High stiffness of the lesion had a sensitivity of 84 % (95 % confidence interval 73 % - 91 %), specificity of 67 % (58 % - 74 %), positive predictive value (PPV) of 56 % (50 % - 62 %), and negative predictive value (NPV) of 89 % (83 % - 93 %) for the diagnosis of malignancy. For the diagnosis of pancreatic ductal adenocarcinoma, the sensitivity, specificity, PPV, and NPV were 96 % (87 % - 100 %), 64 % (56 % - 71 %), 45 % (40 % - 50 %), and 98 % (93 % - 100 %), respectively.

CONCLUSIONS

In patients with small solid pancreatic lesions, EUS elastography can rule out malignancy with a high level of certainty if the lesion appears soft. A stiff lesion can be either benign or malignant.

Single cell RNA-seq reveals profound transcriptional similarity between Barrett's oesophagus and oesophageal submucosal glands

Barrett's oesophagus is a precursor of oesophageal adenocarcinoma. In this common condition, squamous epithelium in the oesophagus is replaced by columnar epithelium in response to acid reflux. Barrett's oesophagus is highly heterogeneous and its relationships to normal tissues are unclear. Here we investigate the cellular complexity of Barrett's oesophagus and the upper gastrointestinal tract using RNA-sequencing of single cells from multiple biopsies from six patients with Barrett's oesophagus and two patients without oesophageal pathology. We find that cell populations in Barrett's oesophagus, marked by LEFTY1 and OLFM4, exhibit a profound transcriptional overlap with oesophageal submucosal gland cells, but not with gastric or duodenal cells. Additionally, SPINK4 and ITLN1 mark cells that precede morphologically identifiable goblet cells in colon and Barrett's oesophagus, potentially aiding the identification of metaplasia. Our findings reveal striking transcriptional relationships between normal tissue populations and cells in a premalignant condition, with implications for clinical practice.

Ultrasound findings in extragenital endometriosis

We present a report on ultrasound findings in extragenital endometriosis and a literature review accompanied by illustrations. Intestinal endometriosis should be considered in female patients of reproductive age who present with constipation, gastrointestinal bleeding, nausea, vomiting, cramp-like abdominal pain, diarrhoea and pelvic pain. Although definitive preoperative diagnosis of endometriosis is difficult, clinical suspicion and appropriate imaging might prevent extensive surgical procedures with higher morbidity. Contrast-enhanced ultrasound is an efficient non-invasive imaging method without any radiation exposure that supports the early diagnosis of intestinal endometriosis and may help assess the vascularization of endometriotic lesions within the distinct layers of the intestinal wall.

How to get the most out of costly Barrett's oesophagus surveillance

Current endoscopic surveillance protocols for Barrett's oesophagus have several limitations, mainly the poor cost-effectiveness and high miss rate. However, there is sufficient evidence that patients enrolled in a surveillance program have better survival chances of oesophageal cancer due to earlier tumor stages at diagnosis compared to patients with de novo diagnosed oesophagus cancer. Risk stratifications aim to identify patients at highest risk of developing adenocarcinoma of the oesophagus; most of them base on the length of the Barrett's segment and the presence of dysplasia. This review discusses prognostic factors and provides practical guidance on how to improve the efficacy and outcome in Barrett's surveillance programs.

Endoscopic ultrasound-guided drainage of pancreatic walled-off necrosis using self-expanding metal stents without fluoroscopy

AIM

To investigate whether endoscopic ultrasound (EUS)-guided insertion of fully covered self-expandable metal stents in walled-off pancreatic necrosis (WOPN) is feasible without fluoroscopy.

METHODS

Patients with symptomatic pancreatic WOPN undergoing EUS-guided transmural drainage using self-expandable and fully covered self expanding metal stents (FCSEMS) were included. The EUS visibility of each step involved in the transmural stent insertion was assessed by the operators as “visible” or “not visible”: (1) Access to the cyst by needle or cystotome; (2) insertion of a guide wire; (3) introducing of the diathermy and delivery system; (4) opening of the distal flange; and (5) slow withdrawal of the delivery system until contact of distal flange to cavity wall. Technical success was defined as correct positioning of the FCSEMS without the need of fluoroscopy.

RESULTS

In total, 27 consecutive patients with symptomatic WOPN referred for EUS-guided drainage were included. In 2 patients large traversing arteries within the cavity were detected by color Doppler, therefore the insertion of FCSEMS was not attempted. In all other patients (92.6%) EUS-guided transgastric stent insertion was technically successful without fluoroscopy. All steps of the procedure could be clearly visualized by EUS. Nine patients required endoscopic necrosectomy through the FCSEMS. Adverse events were two readmissions with fever and one self-limiting bleeding; there was no procedure-related mortality.

CONCLUSION

The good endosonographic visibility of the FCSEMS delivery system throughout the procedure allows safe EUS-guided insertion without fluoroscopy making it available as bedside intervention for critically ill patients.

Present status and perspectives of endosonography 2017 in gastroenterology

Endoscopic ultrasound has become an essential tool in modern gastroenterology and abdominal surgery. Compared with all other endoscopic methods, it has the most potential for innovation and its future looks bright. Thus, we compiled this summary of established and novel applications of endoscopic ultrasound methods to inform the reader about what is already possible and where future developments will lead in improving patient care further. This review is structured in four parts. The first section reports on developments in diagnostic endoscopic ultrasound, the second looks at semi-invasive endoscopic ultrasound, and the third discusses advances in therapeutic endoscopic ultrasound. An overview on the future prospects of endoscopic ultrasound methods concludes this article.

Contrast enhanced ultrasound features of hepatic cystadenoma and hepatic cystadenocarcinoma

OBJECTIVE

Hepatic (biliary) cystic tumor (HBCT) is a rare focal cystic liver lesion, which has been rarely described in the literature. In our current multicenter, retrospective study, we aimed to analyze contrast enhanced ultrasound (CEUS) features and its diagnostic performance in histologically proved HBCT.

MATERIAL AND METHODS

Twenty-three patients with single HBCT were retrospectively analyzed. Histologically, 17 (73.9%) were benign hepatic (biliary) cystadenoma (HBCA), 6 (26.1%) were hepatic (biliary) cystadenocarcinoma (HBCAC). All CEUS examinations were assessed by two independent radiologists in consensus. Criteria of CEUS imaging evaluation included the contrast enhancement pattern of lesion (hypoenhancing, hyperenhancing, isoenhancing in comparison to the surrounding liver parenchyma) during the arterial, portal venous and late phases.

RESULTS

After injection of ultrasound contrast agents, most of the HBCTs (78.3%, 18/23) had typical honeycomb enhancement pattern of the cystic wall, septa or mural nodules. Comparing between HBCA and HBCAC, hyperenhancement of the honeycomb septa during the arterial phase was more common in HBCA (p = .047). However, hypoenhancement during the portal venous and late phases was the characteristic of HBCAC (p = .041).

CONCLUSIONS

The EFSUMB algorithm for CEUS for characterization of solid focal liver lesions is also applicable to HBCT. CEUS evaluation can avoid further diagnostic investigations or invasive biopsy procedure.

"Clinical" cytology for endoscopists: A practical guide

Clinical cytology was originally used by clinicians to provide rapid diagnosis. However, with advancing medical subspecialization, few clinicians interpret cytology themselves these days, for example, gynecologists, hematologists, urologists, and occasional gastroenterologist (mainly in Asian countries). Cytological assessment enjoyed a renaissance with the development of endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA). Subsequently, pathologists, most of them more experienced in histology, had to take over. Recently, it has been shown that in-room cytology can be easily performed by the endoscopist themselves for initial evaluation of the quality of the EUS-FNA specimen and an initial diagnosis distinguishing benign or malignant cells. Bringing cytology back to the clinician has some advantages but does not substitute the professional cytopathologist. This report has written to lower the threshold for the clinician to find his way back to the microscope, which may improve both their diagnostic yield and assessment of EUS-FNA sample quality.

B-mode and contrast-enhancement characteristics of small nonincidental neuroendocrine pancreatic tumors

BACKGROUND AND OBJECTIVES

Imaging of the pancreas for detection of neuroendocrine tumors is indicated as surveillance in multiple endocrine neoplasia type 1 (MEN1) or if typical clinical symptoms combined with hormone production raise the suspicion of a neuroendocrine tumor. Endoscopic ultrasound (EUS) is considered the best imaging modality to detect small pancreatic tumors. However, little is known about how small pancreatic neuroendocrine tumors (pNETs) present on EUS.

PATIENTS AND METHODS

In this multicenter study, we retrospectively analyzed the endosonographic characteristics of small pNETs which had been detected due to typical biochemistry and clinical symptoms or during surveillance of MEN 1. Only small pancreatic tumors ≤15 mm with histological confirmation as pNET were included. B-mode and contrast-enhanced ultrasound- and EUS patterns were analyzed.

RESULTS

Among 32 patients with histologically proven small pNETs, 7 patients had known MEN1. Among the pNETs, 20 were insulinoma, 2 gastrinoma, 3 glucagonoma, 6 nonfunctional in MEN1, and one PPoma. 94% of the pNET appeared hypoechogenic, only 1 isoechogenic and 1 hyperechogenic. After contrast injection, 90% of the pNETS showed hyperenhancement compared to the surrounding pancreatic parenchyma.

CONCLUSION

The high spatial resolution of EUS allows detection and even cytological confirmation of pNET <7 mm diameter. Hypoechogenicity in B-mode and hyperenhancement after injection of contrast agents are endosonographic characteristics of small pNET and present in >90% of pNETs.

Non-radical, stepwise complete endoscopic resection of Barrett's epithelium in short segment Barrett's esophagus has a low stricture rate

Background and aims: Radical endoscopic excision of Barrett's epithelium performing 4 - 6 endoscopic resections during the same endoscopic session results in complete Barrett's eradication but has a high stricture rate (40 - 80 %). Therefore radiofrequency ablation is preferred after endoscopic mucosal resection (EMR) of visible nodules. We investigated the clinical outcome of non-radical, stepwise endoscopic mucosal resection with a maximum of two endoscopic resections per endoscopic session. Methods: We analysed our prospectively maintained database of patients undergoing esophageal EMR for early neoplasia in Barrett's esophagus from 2009 to 2014. EMR was performed using a maximum of two band ligation mucosectomies per endoscopic session; thereafter, follow-up was 3-monthly and EMR was repeated as required for Barrett's eradication. Results: In total, 118 patients underwent staging EMR for early Barrett's neoplasia. Subsequently, 27 patients underwent surgery/chemotherapy due to deep submucosal or more advanced tumor stages or were managed conservatively. The remaining 91 patients with high grade dysplasia (48), intramucosal (38) or submucosal cancer (5) in the resected nodule underwent further endoscopic therapy with a mean follow-up of 24 months. Remission of dysplasia/neoplasia was achieved in 95.6 % after 12 months treatment. Stepwise endoscopic Barrett's resection resulted in complete Barrett's eradication in 36/91 patients (39.6 %) in a mean of four sessions; 40/91 patients (44.0 %) had a short circumferential Barrett's segment (< 3 cm). In this group, repeated EMR achieved complete Barrett's excision in 85.0 %. One patient developed a stricture (1.1 %), one a delayed bleeding, and there were no perforations. Conclusion: In patients with a short Barrett's segment, non-radical endoscopic Barrett's resection at the time of scheduled endoscopy follow-up allows complete Barrett's eradication with very low stricture rate.

Particularities of Crohn's disease in pediatric patients: current status and perspectives regarding imaging modalities

A consensus on the best imaging modality evaluating inflammatory bowel disease in the pediatric population is lacking and it is often unclear which modality to choose in specific clinical circumstances. Children with inflammatory bowel disease are exposed to ionizing radiation from multiple imaging studies performed at initial diagnosis, throughout treatment and during the follow-up period. This paper discusses the value of different imaging techniques in pediatric patients with inflammatory bowel disease and gives a review of the literature. In addition, particular features of inflammatory bowel disease in children including the predilection of affected segments in the gastrointestinal tract are highlighted. Based on current literature knowledge, we encourage an integrative approach to the interpretation of clinical and imaging data for diagnosis and follow-up in daily clinical settings.

Helicobacter Pylori Infection: Diagnostic Strategies in Primary Diagnosis and After Therapy

Accurate diagnosis of Helicobacter pylori infection pre- and post-treatment is mandatory in the current era of decreasing prevalence and increasing antibiotic resistance. The diagnostic performance of most tests is poorer in clinical situations with low bacterial density which is seen in conditions such as atrophic gastritis or intake of antisecretory and antibiotic medications. Noninvasive tests require less cost and resource but provide excellent accuracy; however, endoscopy with testing of gastric biopsy specimens is indicated where alarming symptoms are present or antibiotic susceptibility testing by culture is desired. Newer modalities such as polymerase chain reaction testing provide additional virulence and antibiotic sensitivity profiling. This article outlines new developments and the key parameters of each test, as careful selection of test modality within the clinical context is required for adequate management of infected symptomatic patients.

Advantages and Limitations of Focal Liver Lesion Assessment with Ultrasound Contrast Agents: Comments on the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines

Contrast-enhanced ultrasound (CEUS) represents a significant breakthrough in sonography. Due to US contrast agents (UCAs) and contrast-specific techniques, sonography offers the potential to show enhancement of liver lesions in a similar way as contrast-enhanced cross-sectional imaging techniques. The real-time assessment of liver perfusion throughout the vascular phases, without any risk of nephrotoxicity, represents one of the major advantages that this technique offers. CEUS has led to a dramatic improvement in the diagnostic accuracy of US and subsequently has been included in current guidelines as an important step in the diagnostic workup of focal liver lesions (FLLs), resulting in a better patient management and cost-effective therapy. The purpose of this review was to provide a detailed description of contrast agents used in different cross-sectional imaging procedures for the study of FLLs, focusing on characteristics, indications and advantages of UCAs in clinical practice.

[Echoscopy]

The clinical use of pocket size ultrasound devices is still at an early stage. Its performance has been studied and proven in cardiology, gynecology, and gastroenterology. It is expected that the image quality will improve and that more techniques for miniaturized devices will be available in the near future. The perspective will be that more and more clinicians will have “echoscopes” as a bedside tool, replacing or complementary to a “stethoscope”. The term “echoscopy” was defined by the European Federation of Societies of Ultrasound in Medicine and Biology (EFSUMB). Echoscopy is one form of point of care ultrasound (POCUS). Teaching material has been prepared by EFSUMB on how to use it (www.efsumb.org).