Endoscopic ultrasound-guided fine-needle aspiration for gastrointestinal subepithelial lesions

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the first-choice procedure for obtaining pathological tissue samples from gastrointestinal (GI) subepithelial lesions (SELs). However, its diagnostic accuracy is lower than that for pancreatic masses owing to puncture difficulty and the need for immunostaining for definitive diagnosis. The advent of fine-needle biopsy needles, which have become well known in recent years, improves the diagnostic accuracy of EUS-FNA for GI SELs. The forward-viewing echoendoscope and rapid on-site evaluation (ROSE) have also helped to improve diagnostic accuracy. Furthermore, in facilities where ROSE is not available, endosonographers perform a macroscopic on-site evaluation. With these procedural innovations, EUS-FNA is now performed aggressively even for SELs smaller than 20 mm. The incidence of procedure-related adverse events such as bleeding and infection is low, and thus, EUS-FNA can be safely performed to diagnose SELs.

Artificial Intelligence in the Prediction of Gastrointestinal Stromal Tumors on Endoscopic Ultrasonography Images: Development, Validation and Comparison with Endosonographers

Background/Aims

The accuracy of endosonographers in diagnosing gastric subepithelial lesions (SELs) using endoscopic ultrasonography (EUS) is influenced by experience and subjectivity. Artificial intelligence (AI) has achieved remarkable development in this field. This study aimed to develop an AI-based EUS diagnostic model for the diagnosis of SELs, and evaluated its efficacy with external validation.

Methods

We developed the EUS-AI model with ResNeSt50 using EUS images from two hospitals to predict the histopathology of the gastric SELs originating from muscularis propria. The diagnostic performance of the model was also validated using EUS images obtained from four other hospitals.

Results

A total of 2,057 images from 367 patients (375 SELs) were chosen to build the models, and 914 images from 106 patients (108 SELs) were chosen for external validation. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the model for differentiating gastrointestinal stromal tumors (GISTs) and non-GISTs in the external validation sets by images were 82.01%, 68.22%, 86.77%, 59.86%, and 78.12%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the external validation set by tumors were 83.75%, 71.43%, 89.33%, 60.61%, and 80.56%, respectively. The EUS-AI model showed better performance (especially specificity) than some endosonographers. The model helped improve the sensitivity, specificity, and accuracy of certain endosonographers.

Conclusions

We developed an EUS-AI model to classify gastric SELs originating from muscularis propria into GISTs and non-GISTs with good accuracy. The model may help improve the diagnostic performance of endosonographers. Further work is required to develop a multi-modal EUS-AI system.

Prevalence, natural progression, and clinical practices of upper gastrointestinal subepithelial lesions in Korea: a multicenter study

BACKGROUND/AIMS

This study aimed to evaluate the prevalence and natural progression of subepithelial lesions (SELs) in the upper gastrointestinal (UGI) tract.

METHODS

The medical records of patients with UGI SELs who underwent endoscopic screening at eight university hospitals between January and December 2010 were retrospectively investigated. The follow-up evaluations were performed until December 2016.

RESULTS

UGI SELs were found in 1,044 of the 65,233 participants screened (endoscopic prevalence, 1.60%; the total number of lesions, 1,062; mean age, 55.1±11.2 years; men, 53.6%). The median follow-up period was 48 (range, 8-74) months. SELs were most frequently found in the stomach (63.8%) and had a mean size of 9.9±6.1 mm. Endoscopic ultrasonography (EUS) was performed in 293 patients (28.1%). The most common lesions were leiomyomas, followed by gastrointestinal stromal tumors (GISTs), and ectopic pancreas. The proportions of SELs with malignant potential according to size were 3% (<1 cm), 22% (1-2 cm), 27% (2-3 cm), and 38% (≥3 cm). In gastric SELs larger than 1 cm, resections were performed in 20 patients because of an increase in size, of which 12 were found to be GISTs.

CONCLUSION

The prevalence of UGI SELs was 1.60%. Further, 23% of gastric SELs ≥1 cm were precancerous lesions, most followed by EUS and clinical decisions without initial pathological confirmation.

Endoscopic ultrasound artificial intelligence-assisted for prediction of gastrointestinal stromal tumors diagnosis: A systematic review and meta-analysis

BACKGROUND

Subepithelial lesions (SELs) are gastrointestinal tumors with heterogeneous malignant potential. Endoscopic ultrasonography (EUS) is the leading method for evaluation, but without histopathological analysis, precise differentiation of SEL risk is limited. Artificial intelligence (AI) is a promising aid for the diagnosis of gastrointestinal lesions in the absence of histopathology.

AIM

To determine the diagnostic accuracy of AI-assisted EUS in diagnosing SELs, especially lesions originating from the muscularis propria layer.

METHODS

Electronic databases including PubMed, EMBASE, and Cochrane Library were searched. Patients of any sex and > 18 years, with SELs assessed by EUS AI-assisted, with previous histopathological diagnosis, and presented sufficient data values which were extracted to construct a 2 × 2 table. The reference standard was histopathology. The primary outcome was the accuracy of AI for gastrointestinal stromal tumor (GIST). Secondary outcomes were AI-assisted EUS diagnosis for GIST vs gastrointestinal leiomyoma (GIL), the diagnostic performance of experienced endoscopists for GIST, and GIST vs GIL. Pooled sensitivity, specificity, positive, and negative predictive values were calculated. The corresponding summary receiver operating characteristic curve and post-test probability were also analyzed.

RESULTS

Eight retrospective studies with a total of 2355 patients and 44154 images were included in this meta-analysis. The AI-assisted EUS for GIST diagnosis showed a sensitivity of 92% [95% confidence interval (CI): 0.89-0.95; P < 0.01), specificity of 80% (95%CI: 0.75-0.85; P < 0.01), and area under the curve (AUC) of 0.949. For diagnosis of GIST vs GIL by AI-assisted EUS, specificity was 90% (95%CI: 0.88-0.95; P = 0.02) and AUC of 0.966. The experienced endoscopists' values were sensitivity of 72% (95%CI: 0.67-0.76; P < 0.01), specificity of 70% (95%CI: 0.64-0.76; P < 0.01), and AUC of 0.777 for GIST. Evaluating GIST vs GIL, the experts achieved a sensitivity of 73% (95%CI: 0.65-0.80; P < 0.01) and an AUC of 0.819.

CONCLUSION

AI-assisted EUS has high diagnostic accuracy for fourth-layer SELs, especially for GIST, demonstrating superiority compared to experienced endoscopists' and improving their diagnostic performance in the absence of invasive procedures.

Recent advances and current challenges in endoscopic resection with the full-thickness resection device

Endoscopic full-thickness resection (EFTR) has emerged as a viable technique in the management of mucosal and subepithelial lesions of the gastrointestinal tract (GIT) not amenable to conventional therapeutic approaches. While various devices and techniques have been described for EFTR, a single, combined full-thickness resection and closure device (full-thickness resection device, FTRD system, Ovesco Endoscopy AG, Tuebingen, Germany) has become commercially available in recent years. Initially, the FTRD system was limited to use in the colorectum only. Recently, a modified version of the FTRD has been released for EFTR in the upper GIT as well. This review provides a broad summary of the FTRD, highlighting recent advances and current challenges.

Management of gastrointestinal subepithelial lesions: an answer to the conflicting opinions

Subepithelial lesions, formerly known as subepithelial tumors, are incidentally discovered protrusions throughout the gastrointestinal tract with normal overlying mucosa. Studies related to the diagnosis and therapy methods are limited due to the low incidence and malignant potential of these lesions. They commonly originating from the second, third, and fourth layers (muscularis mucosa, submucosa, and muscularis propria) of the gastrointestinal wall. They are reported to be more prevalent in the stomach and esophagus than small intestine and colon. Subepithelial lesions in the stomach and duodenum are more prone to malignancy than the lesions in the esophagus. Despite different strategies in the management of subepithelial lesions based on their size and location, there is still not a unique consensus on the issue. In this review, we have attempted to introduce the most practical approach to managing gastrointestinal subepithelial lesions based on current guidelines.

Efficacy and Safety of Laparoscopic Endoscopic Cooperative Surgery in Upper Gastrointestinal Lesions: A Systematic Review and Meta-Analysis

Background and Aims

Laparoscopic and endoscopic cooperative surgery (LECS) combines advantages of endoscopy and laparoscopy in order to resect upper gastrointestinal lesions. Our aim was to evaluate the efficacy and safety of LECS in patients with EGJ (esophagogastric junction), gastric and duodenal lesions, as well as to compare LECS with pure endoscopic and pure laparoscopic procedures.

Methods

PubMed, Scopus, and ISI Web of Knowledge were searched. Efficacy (R0, recurrence) and safety (conversion rate, procedure and hospitalization time, adverse events, mortality) outcomes were extracted and pooled (odds ratio or mean difference) using a random-effects model. Study quality was assessed with Newcastle-Ottawa Scale and heterogeneity by Cochran's Q test and I² . Subgroup analysis according to location was performed.

Results

This meta-analysis included 24 studies/1,336 patients (all retrospective cohorts). No significant differences were found between LECS and preexisting techniques (endoscopic submucosal dissection (ESD)/laparoscopy) regarding any outcomes. However, there was a trend to shorter hospitalization time, longer procedure duration, and fewer adverse events in LECS versus Laparoscopy and ESD. R0 tended to be higher in the LECS group. Hospitalization time was significantly shorter in gastric versus EGJ lesions (mean 7.3 vs. 13.7 days, 95% CI: 6.6-7.9 vs. 8.9-19.3). There were no significant differences in conversion rate, adverse events, or mean procedural time according to location. There was a trend to higher conversion rate and longer procedure durations in EGJ and higher rate of adverse events in duodenal lesions.

Conclusion

LECS is a valid, safe, and effective treatment option in patients with EGJ, gastric, and duodenal lesions, although existing studies are retrospective and prone to selection bias. Prospective studies are needed to assess if LECS is superior to established techniques.

Key Messages

LECS is safe and effective in the treatment of upper gastrointestinal lesions, but there is no evidence of superiority over established techniques.

Gastric lymphangioma: a case report and review of literature

Background

Gastric lymphangioma is one of the highly rare benign tumors characterized by multilocular or unilocular lymphatic spaces. Herein, we report a case of lymphangioma in the gastric antrum.

Case presentation

A 77-year-old male patient who had been experiencing epigastric discomfort for a year was presented to our hospital. A gastric subepithelial lesion was diagnosed by upper endoscopy and was entirely excised via diatal subtotal gastrectomy. Endoscopic ultrasonography revealed an echoless homogenous echo pattern in the third wall layer. A lymphangioma was diagnosed by pathologic investigation of the resected specimen. The PubMed, Embase and Web of Science databases were reviewed for literature in English while using the keywords of “gastric lymphangioma” or “lymphangioma of stomach” or “gastric lymphatic cyst” or “lymphatic cyst of stomach” and the results were discussed.

Conclusion

Gastric lymphangioma is a rarely occurring submucosal tumor that should be considered when diagnosing subepithelial lesions in the stomach.

A Gastroenterologist's Approach to the Diagnosis and Management of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. These tumors have been shown to harbor oncogenic mutations of the c-kit tyrosine kinase receptor or platelet-derived growth factor receptor alpha (PDGFRA). Immunohistochemical analysis of GISTs allows for the differentiation of these tumors from other mesenchymal tumors of the GI tract such as leiomyomas and leiomyosarcomas. All GISTs have the potential to behave in a malignant fashion. Tumor location, size, and mitotic index are factors used to predict the risk of malignant behavior. Endoscopy and endoscopic ultrasound play a critical role in the diagnosis of GISTs and can yield important information to further risk-stratify tumors and determine management. This article provides a gastroenterologist's perspective on the diagnosis and management of GISTs.

Advances in endoscopic resection: a review of endoscopic submucosal dissection (ESD), endoscopic full thickness resection (EFTR) and submucosal tunneling endoscopic resection (STER)

Subepithelial lesions are often detected incidentally in patients undergoing an endoscopy. They are common tumors of the gastrointestinal (GI) tract which can originate from different layers of the GI tract wall. These lesions can be further classified based on GI layer of origin and unique histochemical staining. While most are benign and asymptomatic, some of these lesions have malignant potential with distant metastases. However, current diagnostic modalities including endoscopy with biopsy or endoscopic ultrasound with fine needle aspiration are not always reliable. In addition, management of these lesions has historically involved surgical resection via open or laparoscopic approaches. In recent years, with advancement in endoscopic techniques and improvement in endoscopists' skills, less invasive procedures such as endoscopic submucosal dissection (ESD), endoscopic full thickness resection (EFTR) and submucosal tunneling endoscopic resection (STER) have been developed and now are being used by endoscopists worldwide. Upon reviewing the literature, multiple studies have shown the advantages of these endoscopic techniques when compared with surgical treatment. As a result, there has been a dramatic shift towards minimally invasive endoscopic procedures for the management of these subepithelial lesions. In this review article, we will discuss these endoscopic resection techniques in detail, their safety and efficacy, as well as comparison studies to other therapeutic modalities.

Endoscopic ultrasound fine needle aspiration vs fine needle biopsy for pancreatic masses, subepithelial lesions, and lymph nodes

Endoscopic ultrasound tissue acquisition, in the form of both fine needle aspiration (EUS-FNA) and fine needle biopsy (EUS-FNB), is utilized for pancreatic mass lesions, subepithelial lesions, and lymph node biopsy. Both procedures are safe and yield high diagnostic value. Despite its high diagnostic yield, EUS-FNA has potential limitations associated with cytological aspirations, including inability to determine histologic architecture, and a small quantitative sample for further immunohistochemical staining. EUS-FNB, with its larger core biopsy needle, was designed to overcome these potential limitations. However, it remains unclear which technique should be used and for which lesions. Comparative trials are plagued by heterogeneity at every stage of comparison; including variable needles used, and different definitions of endpoints, which therefore limit generalizability. Thus, we present a review of prospective trials, systematic reviews, and meta-analyses on studies examining EUS-FNA vs EUS-FNB. Prospective comparative trials of EUS-FNA vs EUS-FNB primarily focus on pancreatic mass lesions, and yield conflicting results in terms of demonstrating the superiority of one method. However, consistent among trials is the potential for diagnosis with fewer passes, and a larger quantity of sample achieved for next generation sequencing. With regard to subepithelial lesions and lymph node biopsy, fewer prospective trials exist, and larger prospective studies are necessary. Based on the available literature, we would recommend EUS-FNB for peri-hepatic lymph nodes.

Utility of endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) for diagnosing small subepithelial lesions (< 20 mm)

AIM

Subepithelial lesions (SELs) are defined as being located under the mucosa. Presently, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is commonly performed to diagnose SELs. With the development of new puncture needles, endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB), which allows for the acquisition of large tissue samples, has been proposed. However, studies on EUS-FNB of SELs measuring < 20 mm have not yielded satisfactory results. Therefore, we aimed to assess the performance and usefulness of EUS-FNB of SELs measuring less than < 20 mm.

METHODS

The present study included 62 patients who underwent EUS-FNA or EUS-FNB for SELs at our hospital between January 2015 and March 2019. EUS-FNA was performed using fine-needle aspiration needles, and EUS-FNB was performed using fine-needle biopsy needles. These needles, which come in different shapes and diameters, were compared in terms of their usefulness in performing procedures for SELs measuring ≥ 20 mm and those measuring < 20 mm.

RESULTS

For SELs measuring ≥ 20 mm, the use of needles with a large diameter, such as 19 or 20 G, resulted in significantly improved diagnostic rates. For SELs measuring < 20 mm, the use of FNB needles showed significantly improved diagnostic rates, regardless of the size of the puncture needles.

CONCLUSION

Even when SELs are less than 20 mm, they might have malignant potential, and histological diagnosis may be desirable in some cases. EUS-FNB has an advantage over EUS-FNA in the diagnosis of SELs measuring < 20 mm.

Submucosal Tunneling Endoscopic Resection

Minimally invasive endoscopic resection procedures continue to evolve, with submucosal tunneling endoscopic resection (STER) being a durable option for en bloc resection of submucosal tumors. Whether STER can be effectively used for larger (>3.5 cm) lesions remains to be seen. STER-ET is a novel approach for removal of extraluminal tumors, but data are currently limited to support its use.

Endoscopic ultrasound-guided fine-needle aspiration biopsy - Recent topics and technical tips

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is a useful procedure that enables reliable pathological diagnoses of pancreatobiliary diseases, subepithelial lesions, and swollen lymph nodes. In recent years, a pathological diagnosis based on EUS-FNA has made it possible to provide accurate treatment methods not only in these fields, but also in respiratory organs and otorhinolaryngology. This review discusses the latest topics pertaining to EUS-FNA as well as procedural tips.

Rectal Endoscopic Ultrasound in Clinical Practice

PURPOSE OF REVIEW

Endoscopic ultrasound (EUS) is routinely utilized for evaluation of disorders of the lower gastrointestinal tract. In this review, we summarize the current status of rectal EUS in clinical practice and describe recent developments in diagnostic and therapeutic rectal EUS.

RECENT FINDINGS

Recent guidelines recommend rectal EUS for rectal cancer staging as a second line modality in cases where MRI is contraindicated. Forward-viewing echoendoscopes and through the scope EUS miniprobes allow for EUS imaging of lesions through the entire colon and for evaluation beyond stenoses or luminal narrowings. EUS can be used to assess perianal disease and drain pelvic abscess associated with IBD, along with newer applications currently under investigation. For rectal varices, EUS can confirm the diagnosis, assess the optimal site for banding, guide therapy placement with sclerotherapy and/or coils, and assess response to treatment by confirming absence of flow. Therapeutic rectal EUS is emerging as a promising modality for drainage of pelvic fluid collection drainage and fiducial placement for rectal or prostatic cancer. Drug delivery mechanisms and substances that may increase the scope of therapy with rectal EUS are in varying stages of development. Rectal EUS continues to be an important modality for evaluation of benign and malignant disorders of the lower gastrointestinal tract, although its use as a cancer staging modality has declined due to improvements in MRI technology. Various technologies to enhance ultrasound imaging and for therapeutics have been developed that have or may contribute to expanded indications for rectal EUS.

Benign esophageal lesions: Endoscopic and pathologic features

Benign esophageal lesions have a wide spectrum of clinical and pathologic features. Understanding the endoscopic and pathologic features of esophageal lesions is essential for their detection, differential diagnosis, and management. The purpose of this review is to provide updated features that may help physicians to appropriately manage these esophageal lesions. The endoscopic features of 2997 patients are reviewed. In epithelial lesions, the frequency of occurrence was in the following order: glycogenic acanthosis, heterotopic gastric mucosa, squamous papilloma, hyperplastic polyp, ectopic sebaceous gland and xanthoma. In subepithelial lesions, the order was as follows: hemangioma, leiomyoma, dysphagia aortica and granular cell tumor. Most benign esophageal lesions can be diagnosed according to their endoscopic appearance and findings on routine biopsy, and submucosal lesions, by endoscopic resection. Management is generally based upon the confidence of diagnosis and whether the lesion causes symptoms. We suggest endoscopic resection of all granular cell tumors and squamous papillomas because, while rare, these lesions have malignant potential. Dysphagia aortica should be considered in the differential diagnosis of dysphagia in the elderly.