Endoscopic ultrasound and gastric lesions

Endoscopic ultrasound (EUS) is useful in assessing gastric lesions found on endoscopy. EUS can assess the 5 layers of the gastric wall and is the most useful modality for staging tumors of the stomach, including adenocarcinoma and lymphoma. For subepithelial gastric lesions, EUS can assess the echogenicity of a lesion, which layer of the gastric wall is involved, and assess for the presence of blood flow with Doppler ultrasound. These characteristics help to determine the likely etiology of the lesion. Fine needle aspiration may also provide additional information, especially when mucosal biopsies are nondiagnostic.     

超声内镜对上消化道黏膜下小病变的诊断价值

目的探讨超声内镜对上消化道直径〈3cm的黏膜下病变的诊断价值。方法回顾性分析2002年1月～2010年8月我院收治的上消化道直径〈3em的黏膜下小病变患者的临床资料。纳入标准：患者经黏膜下肿块剜出术切除病灶,手术后有确切病理诊断;患者在术前曾行超声内镜检查。结果共纳入54例患者,病灶平均大小为（1．06±0．58）cm。黏膜下肿块剜出术的治愈率达82．9％。超声内镜对此类病灶的诊断准确率为74．1％（40／54）;共有14例病例误诊,其中异位胰腺最常见。结论超声内镜对上消化道直径〈3cm的黏膜下病灶具有较高的诊断价值,异位胰腺是最易误诊的病变,黏膜下肿块剜出术可能是治疗上消化道黏膜下小病变的一种有效且安全的方法。     

环扫超声内镜术前评估对食管上皮下肿物内镜治疗的意义

目的探讨环扫超声内镜(EUS)术前评估对食管上皮下肿物内镜治疗的意义。方法选取内镜发现食管上皮下肿物并行内镜下或外科手术治疗的患者30例,麻醉状态下行环扫EUS术前评估。食管上皮下肿物内镜下治疗可选择不同内镜下手术方式,黏膜肌层病变非气管插管麻醉行内镜下黏膜切除术(endoscopic mucosal resection,EMR);黏膜下层、固有肌层病变气管插管麻醉行内镜黏膜下隧道肿瘤切除术(submucosal tunneling endoscopic resection,STER)或外科手术。结果20例术后诊断为黏膜肌层病变中,19例术前环扫EUS明确诊断,1例术前诊断为固有肌层病变;8例术后诊断为固有肌层病变及2例黏膜下层病变中,术前环扫EUS均明确诊断。Weighted Kappa评价显示,点估计0.92268,95%CI估计0.77431~1.00000,提示环扫EUS诊断与术后内镜下诊断一致性优秀。结论环扫EUS对食管上皮下肿物层次定位有较高的可靠性,对手术方式及麻醉方式的选择有指导意义。检查可在患者麻醉状态下完成,检查过程较舒适。     

Endoscopic ultrasound‐guided fine‐needle aspiration of solid lesions on clopidogrel may not be a high‐risk procedure for bleeding: A case series

The major gastrointestinal endoscopy society guidelines list endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) as a high‐risk procedure for bleeding. However, there are no studies evaluating the risk of bleeding for EUS‐FNA of solid organs while patients continue to take clopidogrel. The aim of the present case series was to evaluate the rate of bleeding in a cohort of patients who underwent EUS‐FNA for solid lesions while on clopidogrel. Bleeding was measured at the time of the procedure by bleeding seen on EUS, endoscopic visualization of blood, or drop in hemoglobin after the procedure. From 2013 to 2015, 10 patients were identified for this case series. Lesions that underwent EUS‐FNA included gastric and rectal subepithelial lesions, pancreas masses, and liver masses. No immediate or delayed bleeding was observed in any of the patients. EUS‐FNA of solid lesions on clopidogrel may not be a high‐risk procedure for bleeding. Larger studies are needed to confirm this finding.     

Advantages and limitations of endoscopic ultrasonography in the evaluation and management of patients with gastrointestinal submucosal tumors: a review

Conventional endoscopy can assess the location, mucosal appearance, and consistency of a gastrointestinal submucosal tumor but cannot provide enough information to differentiate the tumor from extraluminal compression by an external structure or from a neoplastic lesion or to determine whether the tumor is malignant. Therefore, endoscopic ultrasonography (EUS) has emerged as the most reliable method for evaluating submucosal tumors. EUS is very accurate in determining whether a submucosal "bump" is the result of extrinsic compression and can clearly distinguish solid from cystic structure within the submucosa, differentiate the layers of the gut wall, and define the layer of origin of the tumor. Moreover, EUS is the best way to decide whether a lesion can be resected safely and provides an indication as to whether endoscopic or surgical resection should be performed. Although various advanced EUS methods have been introduced, they require more study to determine their role in the diagnosis and staging of gastrointestinal tumors.     

A prospective study comparing endoscopy and EUS in the evaluation of GI subepithelial masses

BACKGROUND: The purpose of this study is to prospectively evaluate the performance characteristics of endoscopy and EUS in the diagnosis of GI subepithelial masses. METHODS: A total of 100 consecutive patients referred for the evaluation of a suspected GI subepithelial lesion were prospectively studied with endoscopy followed by EUS. Size, color, mobility, location (intramural or extramural), consistency (solid, cystic, or vascular), and presumptive diagnosis were recorded at the time of endoscopy. EUS then was performed, and size, echogenicity, location, and presumptive diagnosis were determined. RESULTS: A total of 100 subepithelial lesions were evaluated. Endoscopy had 98% sensitivity and 64% specificity in identifying intramural lesions. Size measurement by endoscopy correlated with size measurement by EUS (r = 0.88). Histology was obtained in 23 cases, with the presumptive EUS diagnosis correct in only 48% of cases. Most incorrect EUS diagnoses occurred with hypoechoic 3rd and 4th layer masses. CONCLUSIONS: Endoscopy has high sensitivity but low specificity in identifying the location (intramural or extramural) of subepithelial lesions. In addition, EUS imaging alone is insufficient to accurately diagnose 3rd and 4th layer hypoechoic masses, and histologic confirmation should be obtained whenever possible.     

ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION BIOPSY FOR THE DIAGNOSIS OF GASTROINTESTINAL SUBMUCOSAL TUMORS

Gastrointestinal submucosal tumors (SMT) detected by barium meal study or endoscopy include various kinds of diseases and various degrees of malignancy. Endoscopic ultrasonography (EUS) can provide useful information about the differentiation of intra‐ and extra‐wall lesions, location and originating layer, presumption of their histological nature, measurement of the actual size of the lesion, and the possibility of differentiating between a benign and a malignant lesion. However, EUS alone does not reveal the complete pathology. EUS fine‐needle aspiration biopsy (EUS‐FNAB) has been reported to be a useful tissue sampling method for pancreatic mass lesions, lymph nodes swelling, posterior mediastinal masses and also gastrointestinal submucosal tumors. The EUS‐FNAB procedure is effective not only for the differential diagnosis of benignancy and malignancy, but also for the specific histopathological nature of gastrointestinal SMT using immunohistochemical staining. When used with MIB‐1 (Ki‐67) staining, and gene analysis in case of gastrointestinal stromal tumor, EUS‐FNAB may indicate its prognosis and influence decisions regarding therapeutic strategy. Thus, EUS‐FNAB is an indispensable procedure in the diagnosis of SMT.     

Subepithelial mass lesions in the upper gastrointestinal tract

The finding of a mass lesion in the upper gastrointestinal tract at endoscopy with apparent normal overlying mucosa is common. The differential diagnosis of such lesions is broad and includes those of intramural or extramural origin. Endoscopic ultrasound provides accurate imaging of subepithelial mass lesions and characterizes them according to size, echogenicity, and origin including the histologic layer if the lesion is intramural which narrows the differential diagnosis. Endoscopic ultrasound allows a guided tissue sample to be obtained for histologic confirmation which is especially important for hypoechoic lesions arising from the 3rd or 4th echogenic layers. The purpose of this article is to review the diagnosis of the more common subepithelial mass lesions with an emphasis on endoscopic ultrasound and the subsequent management or monitoring.     

Role of endoscopic ultrasound in diagnosis and therapy of pancreatic adenocarcinoma

Since its advent more than 20 years ago, endoscopic ultrasound （EUS） has undergone evolution from an experimental to a diagnostic instrument and is now established as a therapeutic tool for endoscopists. Endoscopic ultrasound cannot accurately distinguish benign from malignant changes in the primary lesion or lymph node on imaging alone. With the introduction of the curved linear array echoendoscope in the 2990s, the indications for EUS have expanded. The curved linear array echoendoscope enables the visualization of a needle as it exits from the biopsy channel in the same plane of ultrasound imaging in real time. This allows the endoscopist to perform a whole range of interventional applications ranging from fine needle aspiration （FNA） of lesions surrounding the gastrointestinal tract to celiac plexus block and drainage of pancreatic pseudocyst. This article reviews the current role of EUS and EUS-FNA in diagnosis, staging and interventional application of solid pancreatic cancer.     

Endoscopic ultrasonograpy for choledocholithiasis and biliary malignancy

Opinion statement Endoscopic ultrasound (EUS) is a valuable tool in gastrointestinal endoscopy, with various applications such as diagnosis, staging, and evaluation of the pancreaticobiliary system. EUS has comparable sensitivity to magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography (ERCP) for detection of choledocholithiasis. EUS may be considered for evaluation for choledocholithiasis as prelude to ERCP when there is a low to intermediate suspicion for common bile duct stones or when there is an increased risk for complications from ERCP. Endosonography may also be useful in the evaluation of cholangiocarcinoma. Intraductal ultrasound within the bile duct may help differentiate malignant from benign strictures. EUS-guided fine needle aspiration can be helpful in the diagnosis of cholangiocarcinoma, especially in the region of the hilum.     

Approach to the endoscopic resection of duodenal lesions

Duodenal polyps or lesions are uncommonly found on upper endoscopy. Duodenal lesions can be categorized as subepithelial or mucosally-based, and the type of lesion often dictates the work-up and possible therapeutic options. Subepithelial lesions that can arise in the duodenum include lipomas, gastrointestinal stromal tumors, and carcinoids. Endoscopic ultrasonography with fine needle aspiration is useful in the characterization and diagnosis of subepithelial lesions. Duodenal gastrointestinal stromal tumors and large or multifocal carcinoids are best managed by surgical resection. Brunner's gland tumors, solitary Peutz-Jeghers polyps, and non-ampullary and ampullary adenomas are mucosally-based duodenal lesions, which can require removal and are typically amenable to endoscopic resection. Several anatomic characteristics of the duodenum make endoscopic resection of duodenal lesions challenging. However, advanced endoscopic techniques exist that enable the resection of large mucosally-based duodenal lesions. Endoscopic papillectomy is not without risk, but this procedure can effectively resect ampullary adenomas and allows patients to avoid surgery, which typically involves pancreaticoduodenectomy. Endoscopic mucosal resection and its variations(such as cap-assisted, cap-band-assisted, and underwater techniques) enable the safe and effective resection of most duodenal adenomas. Endoscopic submucosal dissection is possible but very difficult to safely perform in the duodenum.     

Accuracy of endoscopic ultrasonography in upper gastrointestinal submucosal lesions: a prospective multicenter study

BACKGROUND: Endoscopic ultrasonography (EUS) is commonly agreed to be the best imaging method for diagnosing and differentiating between submucosal lesions in the gastrointestinal tract. However, most of the current evidence for this derives from retrospective multicenter studies. A prospective multicenter analysis of the performance of EUS in diagnosing submucosal lesions in everyday practice was therefore conducted. METHODS: Over a 2-year period, this study included 150 patients (52% men, mean age 59.8 years) from 23 centers who had a presumptive diagnosis of a submucosal lesion on upper gastrointestinal endoscopy. The patients' symptoms and EUS results were recorded. Endoscopic and endosonographic findings regarding lesion size, layer of origin, and the presumptive diagnosis (benign or malignant) were recorded. The reference methods used were surgery, biopsy, other imaging tests, and a follow-up period of 6 months. RESULTS: Of the 150 patients, 102 had an intramural lesion (84 tumors, 18 other lesions such as cysts, aberrant pancreas, etc.), and 48 had an extraluminal compression--in most cases (n = 35) by normal organs or structures. For differentiating between a submucosal and an extraluminal compression, the sensitivity and specificity of endoscopy were 87% and 29%, whereas those of EUS were 92% and 100%. However, the sensitivity and specificity of EUS for differentiating between malignant and benign submucosal tumors were only 64% and 80%, respectively. CONCLUSIONS: The accuracy of EUS in differentiating between submucosal tumors and extraluminal compressions is substantially superior to that of endoscopy, but EUS is still inadequate for differential diagnosis between benign and malignant submucosal tumors. However, EUS is still the best method of visualizing submucosal lesions precisely. The influence of EUS on the further management in these patients remains to be examined in subsequent studies.     

Advances in endoscopic ultrasound imaging of colorectal diseases

The development of endoscopic ultrasound(EUS) has had a significant impact for patients with digestive diseases, enabling enhanced diagnostic and therapeutic procedures, with most of the available evidence focusing on upper gastrointestinal(GI) and pancreaticobiliary diseases. For the lower GI tract the main application of EUS has been in staging rectal cancer, as a complementary technique to other cross-sectional imaging methods. EUS can provide highly accurate indepth assessments of tumour infiltration, performing best in the diagnosis of early rectal tumours. In the light of recent developments other EUS applications for colorectal diseases have been also envisaged and are currently under investigation, including beyond-rectum tumour staging by means of the newly developed forward-viewing radial array echoendoscope. Due to its high resolution, EUS might be also regarded as an ideal method for the evaluation of subepithelial lesions. Their differential diagnosis is possible by imaging the originating wall layer and the associated echostructure, and cytological and histological confirmation can be obtained through EUS-guided fine needle aspiration or trucut biopsy. However, reports on the use of EUS in colorectal subepithelial lesions are currently limited. EUS allows detailed examination of perirectal and perianal complications in Crohn’s disease and, as a safe and less expensive investigation, can be used to monitor therapeutic response of fistulae, which seems to improve outcomes and reduce the need for additional surgery. Furthermore, EUS image enhancement techniques, such as the use of contrast agents or elastography, have recently been evaluated for colorectal indications as well. Possible applications of contrast enhancement include the assessment of tumour angiogenesis in colorectal cancer, the monitoring of disease activity in inflammatory bowel disease based on quantification of bowel wall vascularization, and differentiating between benign and malignant subepithelial tumours. Recent reports suggest that EUS elastography enables highly accurate discrimination of colorectal adenocarcinomas from adenomas, while inflammatory bowel disease phenotypes can be distinguished based on the strain ratio calculation. Among EUS-guided therapies, the drainage of abdominal and pelvic collections has been regarded as a safe and effective procedure to be used as an alternative for the transcutaneous route, while the placing of fiducial markers under EUS guidance for targeted radiotherapy in rectal cancer or the use of contrast microbubbles as drug-delivery vehicles represent experimental therapeutic applications that could greatly impact the forthcoming management of patients with colorectal diseases, pending on further investigations.     

The value of endoscopy and endosonography in the diagnosis of the dysphagic patient

The value of endoscopy in dysphagia is limited in the diagnosis of motility disorders and small structures, webs, and hiatal hernias. Endoscopy is of special use for the clarification of an organic cause of dysphagia. Intraluminal tumors can be seen and in a high percentage of cases be definitely diagnosed by taking biopsies; a malignant degeneration in Barrett's esophagus is detectable by endoscopy in 89.1% of cases. Gastroesophageal reflux disease can be diagnosed on endoscopy as it leads to an endoscopically visible inflammatory reaction; however, normal findings on endoscopy cannot exclude reflux disease. Endoscopy is the method of choice in the diagnosis of nonreflux esophagitis, especiallyCandida and viral esophagitis. A further advantage of endoscopy is the fact that a microscopic diagnosis can be obtained and endoscopic treatment can be performed simultaneously. Submucosal or extramural lesions can be missed by endoscopy.Endosonography, the combination of endoscopy and ultrasonography (EUS) yields additional information in diagnosing submucosal and extramural lesions of the esophagus which is missed by other imaging procedures. One of the main advantages of EUS is the detection of small and submucosal lesions. The most important indication is the local staging of esophageal carcinomas; the accuracy of endosonography in determining the depth of infiltration ranges between 79% and 92%. The detection of paraesophageal lymph nodes is successful in 60%–82%, although EUS cannot differentiate benign from malignant lymph nodes. Submucosal tumors can be visualized by endosonography and their size, echopattern, and the layers of origin can be determined with high accuracy. Further indications for EUS are the exclusion of focal lesions in achalasia or peptic strictures.     

直肠类癌的内镜超声诊断和内镜黏膜下切除

目的 研究内镜超声对直肠类癌的诊断价值，探讨内镜下黏膜切除术治疗直肠类癌的应用价值。方法 应用微超声探头对结肠镜发现的黏膜正常的大肠隆起性病灶进行超声检查，对诊断直肠类癌病例应用套扎器对准病灶负压吸引进行圈套结扎，再在皮圈根部连皮圈电切病灶。比较内镜超声诊断和病理检查结果，观察切除标本基底有无肿瘤累及。结果 126例黏膜正常的大肠隆起性病灶经内镜超声诊断，25例直肠类癌全部得到病理证实。直肠类癌表现为黏膜下层的边界清晰、回声欠均匀的低回声肿块。全部类癌病例无固有肌层和血管浸润，行内镜黏膜下切除无一例出现出血和穿孔，切除标本边缘和基底无肿瘤累及。结论 内镜超声可以明确直肠类癌的肠壁来源、大小、内部回声性质、边界、有无肌层和周围血管浸润，内镜下黏膜切除术治疗直肠类癌疗效确切。     

Forward‐viewing linear echoendoscope: a new option in the endoscopic ultrasound armamentarium (with video)

The forward‐viewing linear echoendoscope (FV‐EUS) has been developed with the aim of overcoming limitations of standard curved linear‐array echoendoscopes (CLA‐EUS) and to further expand interventional applications of EUS. The main characteristic of the FV‐EUS is a shifting in the orientation of both endoscopic and ultrasound views from oblique to forward, with the exit of the working channel at the tip of the instrument. This allows exit of the devices parallel to the longitudinal axis of the endoscope, thus resulting in a more direct and stable access to the lesion while increasing the precision and force applied to the target. Accumulating evidence has shown that the FV‐EUS can be used instead of the standard CLA‐EUS scope for routine fine needle aspiration, with extremely good performance for subepithelial lesions and for difficult to reach locations. Several areas of use of this echoendoscope are yet to be better defined, such as its potential for therapeutic and interventional procedures, as well as for natural orifice transluminal endoscopic surgery. The current report provides an updated overview of the available evidence for both diagnostic and interventional uses of the FV‐EUS.     

Giant Brunner's gland hamartoma: diagnosis and endoscopic treatment

Brunner's gland hamartoma is a polypoid lesion typically composed of an increased quantity of normal-appearing Brunner's glands, accompanied by a variable proportion of smooth muscle. Most of these masses are asymptomatic and behave as benign tumors. Occasionally tumoral growth can provoke gastrointestinal problems which, together with the possibility of malignant transformation, will require resection after a broad differential diagnosis has been made with solitary duodenal mass. Both clinical and radiographic studies are nonspecific and often do not allow diagnosis of these tumors. Basic endoscopic studies (upper endoscopy) with adequate characterization of the lesion by endoscopic ultrasound (EUS) can establish a high diagnostic suspicion and determine the best therapeutic option (endoscopy or surgery).We present a case of giant Brunner's gland hamartoma. The initial manifestation was iron-deficiency anemia with no evidence of bleeding. After adequate characterization of the lesion, EUS allowed complete and safe endoscopic resection, avoiding more invasive surgical treatment.     

Opinion: How to manage subepithelial lesions of the upper gastrointestinal tract?

Subepithelial lesions (SELs) in the upper gastrointestinal (GI) tract are relatively frequent findings in patients undergoing an upper GI endoscopy. These tumors, which are located below the epithelium and out of reach of conventional biopsy forceps, may pose a diagnostic challenge for the gastroenterologist, especially when SELs are indeterminate after endoscopy and endoscopic ultrasound (EUS). The decision to proceed with further investigation should take into consideration the size, location in the GI tract, and EUS features of SELs. Gastrointestinal stromal tumor (GIST) is an example of an SEL that has a well-recognized malignant potential. Unfortunately, EUS is not able to absolutely differentiate GISTs from other benign hypoechoic lesions from the fourth layer, such as leiomyomas. Therefore, EUS-guided fine needle aspiration (EUS-FNA) is an important tool for correct diagnosis of SELs. However, small lesions (size < 2 cm) have a poor diagnostic yield with EUS-FNA. Moreover, studies with EUS-core biopsy needles did not report higher rates of histologic and diagnostic yields when compared with EUS-FNA. The limited diagnostic yield of EUS-FNA and EUS-core biopsies of SELs has led to the development of more invasive endoscopic techniques for tissue acquisition. There are initial studies showing good results for tissue biopsy or resection of SELs with endoscopic submucosal dissection, suck-ligate-unroof-biopsy, and submucosal tunneling endoscopic resection.     

Diagnosis of an accessory spleen mimicking a gastric submucosal tumor using endoscopic ultrasonography-guided fine-needle aspiration

Accessory spleen can be mistaken as a gastric subepithelial mass, and may not be differentiated in CT or endoscopic ultrasonography (EUS). A gastric subepithelial mass was detected on routine endoscopy in a 39-year old woman with history of splenectomy. In subsequent CT and EUS, the subepithelial mass was located on the fourth layer of the stomach. To make a definite diagnosis, EUS-guided fine needle aspiration (FNA) was performed, and a splenic tissue was demonstrated in histologic examination. EUS-guided FNA can be beneficial in the diagnosis of accessory spleen which mimics a gastric subepithelial mass.     

Interventional endoscopic ultrasonography

Endoscopic ultrasonography (EUS) is the combination of endoscopy and intraluminal ultrasonography. This allows use of a high frequency transducer, which, due to the short distance to the target lesion, enables ultrasonographic images of high resolution to be obtained. Endoscopic ultrasonography is now a widely accepted modality for the diagnosis of pancreatobiliary diseases. It can be used to determine the depth of invasion of gastrointestinal malignancies, and often for visualizing lesions more precisely than other imaging modalities. The most important early limitation of EUS was the lack of specificity in the differentiation between benign and malignant changes. In 1992, EUS‐guided fine needle aspiration (EUS‐FNA) of lesions in the pancreas head has been made possible using a curved linear array echoendoscope. Since then, many researchers have expanded the indication of EUS‐FNA to various kinds of lesions and also for a variety of therapeutic purposes. In this review, we particularly focus on the present and future roles of interventional EUS, including EUS‐FNA and therapeutic EUS.