Barrett's esophagus

Esophageal cancer staging is a widely accepted indication for endoscopic ultrasonography (EUS). The evaluation of Barrett's esophagus (BE) with EUS is indicated only when there is high-grade dysplasia or a concern for malignancy in an endoscopic lesion. Because the options for the management of BE and early adenocarcinoma are diverse, proper selection of patients by accurate staging with EUS is critical, particularly when nonoperative management is considered. For example, patients with BE with high-grade dysplasia may be offered esophagectomy in some medical centers, but nonoperative therapies such as endoscopic ablative therapy or mucosal resection may be the preferred treatment options in other gastroenterology practices. This article discusses the scientific evidence for the use of EUS in BE or early esophageal adenocarcinoma.     

Endoscopic ultrasound guided antitumor therapy

This paper will review the possibilities of EUS guided anti-tumor therapy. Ablative energy may be delivered to a tumor under EUS guidance to destruct tumor cells by ultrasound itself, radiofrequency or radiation. Pilot results of endoscopic high intensity focused ultrasound in a human trial have been reported. The feasibility of performing EUS guided radiofrequency ablation has been reported in a swine model. An EUS bases radiation target simulation method has been developed for anal cancer therapy. Targeted delivery of an anti-cancer agent into a tumor under EUS guidance is possible as reported in an early clinical trial of local immunotherapy (Cytoimplant) or modified viruses delivered by EUS guided fine needle injection in patients with advanced pancreatic carcinoma. Image guided injection of alcohol is another approach used for local tumor ablation. Application of other ablation therapies such as laser, microwave and cryo is also conceptually feasible. We will have to wait and see where these initial and ongoing attempts for applying EUS against cancer take us.     

Noninvasive competition for endoscopic ultrasound

Endoscopic ultrasonography (EUS) is one of the most significant developments in gastrointestinal (GI) imaging in recent years. EUS now plays a key role in the pretreatment staging of GI tract tumors and in the investigation of benign pancreaticobiliary pathology. It has not replaced conventional cross-sectional imaging (eg, ultrasound, CT, and MRI), but it has distinct properties and capabilities. EUS is most beneficial when used in a complementary fashion with cross-sectional and radionuclide imaging in the management of patients with GI tract disease. This article reviews the role of noninvasive imaging modalities in several clinical situations where EUS plays a prominent role.     

Impact of endoscopic ultrasound combined with fine-needle aspiration biopsy in the management of esophageal cancer

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound (EUS) in combination with fine-needle aspiration biopsy (FNA) is a highly accurate method for the preoperative staging of esophageal cancer. Its impact on medical decision-making and the cost of care is unknown. This prospective case series was undertaken in order to determine the impact of EUS in combination with FNA on patients' choice of therapy and on the cost of care. PATIENTS AND METHODS: Sixty consecutive patients with esophageal cancer, referred for preoperative EUS staging in a large tertiary-care academic medical center, were enrolled. The accuracy of EUS, the impact of EUS-based staging on the patients' choice of therapy, and costs were studied. RESULTS: The accuracy rates for EUS combined with FNA in tumor and lymph-node staging were 83 % and 89 %, respectively. Twenty-five patients (42 %) had EUS stage I and II and were candidates for curative surgery. Twenty-eight patients (47 %) had stage III, and seven (12 %) had stage IV. All patients with stage I had surgery, while all patients with stage IV had medical therapy. The majority (62 %) of patients with stage II had surgery, while only a minority (25 %) of patients with stage III had surgery. Thirty-six patients (60 %) underwent medical therapy. Patients' medical decisions in favor of surgical or medical therapy correlated strongly with the results of their EUS staging ( P = 0.005), but not with age, sex, or referring physicians (surgeons vs. nonsurgeons). EUS-guided therapy potentially decreased the cost of care by $ 740 424 ($ 12 340/patient) by reducing the number of thoracotomies. CONCLUSIONS: Patients' decisions regarding therapy correlated with their overall tumor staging, suggesting that the information provided by EUS played a significant role in patients' decision-making. The use of EUS in combination with FNA reduces the cost of managing patients with esophageal cancer.     

Role of endoscopic ultrasound in the diagnosis and staging of pancreatic cancer

Early diagnosis of pancreatic cancer remains a difficult task, and multiple imaging tests have been proposed over the years. The aim of this review is to describe the current role of endoscopic ultrasound (EUS) for the diagnosis and staging of patients with pancreatic cancer. A detailed search of MEDLINE between 1980 and 2007 was performed using the following keywords: pancreatic cancer, endoscopic ultrasound, diagnosis, and staging. References of the selected articles were also browsed and consulted. Despite progress made with other imaging methods, EUS is still considered to be superior for the detection of clinically suspected lesions, especially if the results of other cross-sectional imaging modalities are equivocal. The major advantage of EUS is the high negative predictive value that approaches 100%, indicating that the absence of a focal mass reliably excludes pancreatic cancer. The introduction of EUS-guided fine needle aspiration allows a preoperative diagnosis in patients with resectable cancer, as well as a confirmation of diagnosis before chemoradiotherapy for those that are not. This comprehensive review highlighted the diagnostic capabilities of EUS including the newest refinements such as contrast-enhanced EUS, EUS elastography, and 3-dimensional EUS. The place of EUS-guided biopsy is also emphasized, including the addition of molecular marker techniques.     

Endoscopic ultrasound techniques for pancreatic cystic neoplasms

The role of EUS and EUS FNA in the evaluation of cystic pancreatic lesions is evolving. The detailed imaging provided by EUS and hence the ability to target the biopsy at suspicious areas within the pancreatic cystic lesion may prove to be invaluable. Improvements in EUS equipment will further secure the role of this technology when evaluating these patients.     

Endoscopic ultrasound-guided celiac neurolysis

Intractable abdominal pain commonly develops in patients with pancreatic cancer. Oral pharmacologic therapy is ineffective for many patients and side effects commonly occur. Celiac neurolysis (CN) is sometimes performed to enhance pain relief. Percutaneous approaches were initially described, with endoscopic ultrasound (EUS)-guided CN more recently introduced. There is uncertainty regarding the efficacy and role of CN in managing pancreatic cancer pain, but CN should still be considered in this difficult-to-treat cohort of patients. EUS-guided approaches may be favored when EUS is otherwise indicated for diagnostic or staging purposes. When EUS is not otherwise indicated, percutaneous approaches are likely favored.     

超声内镜对上消化道隆起性病变的诊断和治疗价值

目的评价超声内镜在上消化道隆起性病变诊断和治疗中的价值。方法对236例上消化道隆起性病变患者,先行胃镜及超声内镜检查,将超声内镜对上消化道隆起性病变的总诊断符合率与胃镜检查结果进行比较。结果对上消化道隆起性病变的总诊断符合率,超声内镜为91.2%,明显高于胃镜的60.4%（P〈0.01）。结论超声内镜对上消化道隆起性病变的部位、大小及性质较胃镜能做出更准确判断,并对其治疗方案的选择具有重要的指导意义,超声内镜对间质瘤和平滑肌瘤的鉴别诊断及良、恶性的判断尚存在一定困难。     

Accuracy of linear endoscopic ultrasonography in the evaluation of patients with suspected common bile duct stones

BACKGROUND AND STUDY AIMS: Endoscopic ultrasonography (EUS) with radial scanning is an efficient diagnostic tool where there is suspicion of common bile duct (CBD) stones. Little is known about the use of linear EUS in this condition. The aim of this study was to evaluate the diagnostic efficiency of linear EUS in a large group of patients suspected to have bile duct stones, using endoscopic retrograde cholangiopancreatography (ERCP) with endoscopic sphincterotomy and exploration of the CBD using a Dormia basket, or surgical choledochotomy with choledochoscopy, as diagnostic "gold standards." PATIENTS AND METHODS: 134 patients with clinical suspicion of CBD stones were included in the study and prospectively evaluated, using EUS, and ERCP with endoscopic sphincterotomy (127 patients), or choledochotomy with choledochoscopy where ERCP was unsuccessful (seven patients). EUS was done before ERCP using an echo endoscope (Pentax FG 32 UA; 5 - 7.5 MHz) and Hitachi EUB 405 ultrasound machine. ERCP was done using the TFJ 100 or TJ 20 Olympus duodenoscope. ERCP was carried out within a mean of 2 days after EUS. The longest time between EUS and ERCP was 3 days. The examiners were blinded to the results of the other method used. RESULTS: CBD stones were found in 91 (68 %) patients at ERCP with ES or at surgery. The correct diagnosis was established by EUS in 85 patients. The remaining 43 patients without CBD stones were correctly diagnosed in 41 cases by means of EUS, giving an accuracy of 94 %, sensitivity of 93 %, specificity of 93 %, a positive predictive value of 98 %, a negative predictive value of 87 %, and a Youden's index of 89 %. CONCLUSIONS: Linear EUS is a fairly reliable method for the evaluation of patients with high suspicion for CBD stones. The usefulness of linear EUS in the evaluation of patients with low or moderate suspicion for CBD stones warrants further study.     

Endoscopic ultrasonographic study of the azygos vein before and after endoscopic obliteration of esophagogastric varices by injection sclerotherapy

BACKGROUND AND STUDY AIMS: The azygos vein plays an important role as a drainage system for the superior portosystemic collateral circulation in portal hypertensive patients. Endoscopic ultrasonography (EUS) and Doppler EUS allow the performance of hemodynamic studies of the azygos vein. In this study, we observed the changes in the azygos vein which occur with variceal obliteration by endoscopic injection sclerotherapy (EIS). PATIENTS AND METHODS: We recruited patients with portal hypertension and bleeding varices who were not on portal pressure-lowering agents and who were scheduled for the EIS program. EUS was performed in these patients to study the azygos vein at the start of EIS. The azygos vein diameter, maximal velocity (Vmax), and blood flow volume index (BFVI) were measured. After variceal obliteration and within 1 week, another EUS study of the azygos vein was carried out. RESULTS: Out of 40 patients recruited into the study variceal obliteration and EUS assessment of the azygos vein, within 1 week of obliteration, was achieved in 33. We noticed a significant increase in azygos vein diameter (P<0.001) and BFVI (P=0.001) following variceal obliteration. No significant change was observed in Vmax (P>0.05). In one patient, marked caliber irregularities were observed in the azygos vein after variceal obliteration. CONCLUSIONS: Using EUS and Doppler EUS, hemodynamic studies of the azygos vein blood flow can be performed, allowing the monitoring of the effects of EIS and variceal obliteration on the superior portosystemic collateral circulation. The clinical significance of the observed changes in azygos blood flow that occur with variceal obliteration should be investigated in further studies and correlated with short-term and long-term outcome.     

EUS for portal hypertension: a comprehensive and critical appraisal of clinical and experimental indications

Endoscopic ultrasonography (EUS) has significantly improved our understanding of the complex vascular structural changes that occur in portal hypertension and their clinical and prognostic significance. EUS in combination with color Doppler technique enables us to study the hemodynamic changes in the portal venous system noninvasively, and to determine objectively the effect of different pharmacological agents on portal hypertension. EUS has also found some role in the treatment and follow up of esophageal and gastric varices. It may play a clinical role in the diagnosis of gastric, duodenal, and rectal varices. Recently reported EUS-based devices that measure variceal wall tension and intravariceal pressure noninvasively could have an impact on the identification of patients at high risk of variceal bleeding with the aim of initiating prophylactic treatment, and in the assessment of patients' responses to drug therapy of portal hypertension. EUS is occasionally very helpful in the clinical management of portal hypertension. It is an interesting and important research tool for many experimental indications that are not routinely applied in clinical practice at this time.     

超声造影与增强CT评价肝癌射频消融疗效的研究

目的 比较动态灰阶超声造影和增强CT在评价肝癌射频消融（RFA）疗效中的作用。方法 对54例病理证实的69个肝癌病灶进行RFA治疗，并与增强CT检查结果进行比较。 结果 如果以RFA治疗后消融灶各期均无增强为肿瘤完全灭活的依据，则超声造影和增强CT诊断肝癌灭活的敏感性分别为96.8％、96.7％、特异性为85．7％、83．3％、准确性为95．7％、95．5％；2种方法比较差异无显著性意义（X^2检验，P〉0．05）。病灶最大直径测值超声造影与增强CT无差异。超声造影显示新病灶数增多。 结论 超声造影是评价RFA疗效的有效方法，具有与增强CT同样的敏感性。     

Preoperative evaluation of periampullary tumors by endoscopic sonography, transabdominal sonography, and computed tomography.

PURPOSE: The purpose of this retrospective study was to compare the sensitivity of endoscopic sonography (EUS), transabdominal sonography (US), and CT in the detection of, local staging of, and prediction of vascular involvement by or distant metastasis from periampullary tumors. METHODS: Seventy-four consecutive patients with presumed periampullary tumors were evaluated by EUS, US, and CT during a 3.25-year period. The local staging accuracy of the modalities was assessed in the 36 patients with solid tumors who underwent surgery. The sensitivity of the modalities in predicting vascular involvement and distant metastasis was assessed in the 56 patients with carcinomas. RESULTS: EUS was the most sensitive modality in the detection (EUS, 97%; US, 24%; and CT, 39%; p < 0.001 for EUS versus US or CT) and T classification (EUS, 72%; US, 11%; CT, 22%; p < 0.001 for EUS versus US or CT) of periampullary tumors. EUS also had better sensitivity than US in detecting lymph node metastasis from periampullary cancers (EUS, 47%; US, 7%; and CT, 33%; p = 0.02 for EUS versus US; p = 0.7 for EUS versus CT). The accuracy of EUS in determining the T classification (without stent, 81%; with stent, 65%) and N classification (without stent, 80%; with stent, 70%) tended to decrease in the presence of an endobiliary stent, but the differences were not significant. EUS was the most sensitive modality in demonstrating vascular involvement (EUS, 100%; US, 0%; and CT, 33%; p = 0.002 for EUS versus US; p = 0.03 for EUS versus CT) but was not significantly different in detecting distant metastasis (EUS, 11%; US, 44%; and CT, 44%). CONCLUSIONS: EUS is superior to US and CT in the local assessment of periampullary tumors. The staging accuracy of EUS is minimally but not significantly affected by the presence of an endobiliary stent.     

Is there a difference in diagnostic accuracy and clinical impact between endoscopic ultrasonography and magnetic resonance cholangiopancreatography?

BACKGROUND AND STUDY AIMS: It is still unknown whether there is a difference in diagnostic accuracy and clinical impact between endoscopic ultrasonography (EUS) and magnetic resonance cholangiopancreatography (MRCP). PATIENTS AND METHODS: The test performance and potential clinical impact of EUS and MRCP, had each investigation been performed as the first examination method, were compared prospectively in 163 patients admitted for and examined by endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: The accuracies of EUS and MRCP were 0.93 and 0.91, respectively (no significant difference, P > 0.05). Had EUS or MRCP been performed as the first investigation in the 75 patients who had a presumed high probability for needing therapeutic ERCP, only 15 and nine patients, respectively, would have avoided ERCP. In this group of patients, one patient needed other diagnostic investigations following EUS compared with 11 patients following MRCP ( P = 0.004). For the 57 patients with an intermediate probability of needing endoscopic therapy, EUS and MRCP would have spared 37 and 38 patients, respectively, from the need to have an ERCP. In 31 patients with a presumed low risk of needing endoscopic therapy, 30 and 29 patients would have been spared from ERCP had EUS and MRCP, respectively, been performed initially. CONCLUSIONS: There was no difference in the diagnostic accuracy and clinical impact between EUS and MRCP in the majority of the patients. The impact of EUS or MRCP on the ERCP workload was highly dependent on the presumed probability of needing endoscopic therapy.     

超声内镜对结直肠黏膜下病变的诊断价值

目的探讨超声内镜(EUS)在结直肠黏膜下病变诊断和治疗中的作用。方法对结直肠黏膜下病变进行EUS检查。根据黏膜下病灶的起源层次,部分患者接受深挖活检、超声内镜引导下细针穿刺吸取活检术(EUS-FNA)、内镜下治疗或外科手术。回顾性分析EUS诊断结果与临床病理的相关性。结果 EUS检查的74例患者中,诊断神经内分泌肿瘤28例(均位于直肠);脂肪瘤15例(其中位于回盲部4例、横结肠1例、升结肠8例、乙状结肠2例);直肠间质瘤2例(固有肌层和黏膜肌层各1例);外压性改变14例(卵巢肿瘤9例,淋巴结2例,盆腔肿瘤3例);囊肿5例(横结肠4例、升结肠1例);气囊肿1例;乙状结肠子宫内膜异位3例;直肠周边恶性肿瘤侵犯4例;肠道淋巴瘤2例。所有病灶均接受深挖活检、EUS-FNA、内镜下治疗或外科手术。最终病理和EUS诊断符合率为68/74(91.9%),其中2例EUS考虑直肠类癌最后病理确诊为黏膜肌层来源的平滑肌瘤。1例考虑脂肪瘤最终确诊为肠道淋巴瘤。2例考虑直肠周边恶性肿瘤最终为炎性包块,1例考虑子宫内膜异位症最终诊断为直肠癌。结论 EUS能清晰地显示消化道各层结构,能清楚显示结直肠黏膜下病变的大小、起源及其与相邻结构的关系,并且能较精确地判断各种病变的性质,进而指导结直肠黏膜下病变的治疗。     

Endoscopic ultrasonography.

Over the past two decades, endoscopic ultrasonography (EUS) has undergone a transition from being a novel imaging technique to a clinical diagnostic test that is necessary for the optimal management of gastrointestinal diseases. EUS has established itself as an important diagnostic modality, mainly for the detection and staging of gastrointestinal cancers. As EUS has become more widespread, research has gradually shifted towards studies that explore the effect of EUS on patient management and outcome. These outcome studies have examined the primary clinical applications of EUS, such as esophageal, gastric, pancreatic, and colorectal cancer staging, as well as the role of EUS in the diagnosis of inflammatory pancreatic diseases. Widespread use of EUS has recently led to studies that examine complications associated with the performance of the procedure. Endosonographers have continued efforts to define a clinical role for EUS in other gastrointestinal diseases, such as portal hypertension. EUS-guided fine-needle aspiration (FNA) is continuing to develop into a powerful diagnostic tool for the management of lung cancer and other mediastinal diseases. New applications for EUS-FNA are also emerging. Finally, investigators are continuing to explore the remaining frontier of EUS-guided therapy.     

Endoscopic ultrasonography in the diagnosis and management of cancer

Since its development and introduction to clinical practice, endoscopic ultrasonography (EUS) has progressed rapidly from being a purely imaging modality with limited use in the detection of small pancreatic cancers to one that can provide a tissue diagnosis by fine-needle aspiration (FNA) and deliver therapy. EUS has now firmly established a place as the investigation of choice in the diagnosis, locoregional staging and management of a wide range of gastrointestinal cancers. With the increasing use of FNA, the accuracy of EUS has substantially improved and may become a stand-alone investigation in some situations. However, it is recommended that a combination of information obtained from other imaging modalities and EUS is needed to maximize the accuracy, in particular to complete staging beyond locoregional stage. In addition to well-established indications, newer applications of EUS are emerging and are no longer limited to the gastrointestinal system. In lung cancer, EUS combined with endobronchial ultrasonography is emerging as an accurate, minimally invasive, nonsurgical alternative to staging of the mediastinum. Furthermore, the ability of EUS to acquire tissue safely and conveniently results in a potential role of the molecular diagnostics to enhance the performance of EUS-guided FNA. Besides a diagnostic role of EUS, there continues to be technological advances in the field of interventional EUS, with many potential applications under investigation. This review focuses on the current and future roles of EUS in the diagnosis and management of cancers.     

Retrospective analysis of dual-phase MDCT and follow-up EUS/EUS-FNA in the diagnosis of pancreatic cancer

Background The optimal approach for detecting small pancreatic tumors is uncertain. We compared multidetector CT (MDCT) with follow-up endoscopic ultrasonography (EUS) without or with fine-needle aspiration (EUS-FNA) for diagnosing pancreatic cancer. Methods Patients with suspicion of pancreatic cancer who underwent dual-phase MDCT and follow-up EUS were retrospectively reviewed. This consisted of scoring MDCT scans independently by three radiologists on a 1–5 scale of certainty, determining whether a stent was present, scoring EUS reports regarding presence of a mass and analyzing EUS-FNA results. Results A total of 117 patients underwent MDCT and EUS. ROC values for MDCT were 0.85, 0.87, and 0.91. There was no significant difference in the accuracy of EUS and MDCT. Follow-up EUS (99%) was significantly more sensitive than MDCT (89% and 93%), as interpreted by two radiologists. Follow-up EUS was statistically significantly more sensitive than MDCT (96% vs. 70%) for one radiologist for tumors < 2 cm. Specificity of EUS was 50%, and sensitivity of EUS-FNA was 82%. Negative predictive value of EUS-FNA was significantly less in patients with (21%) than without (70%) biliary stents. Conclusions Follow-up EUS improves lesion detection over MDCT alone. Close follow-up/repeat biopsy should be considered if FNA is negative, but EUS is positive.     

Endoscopic ultrasonography in patients with gastro-esophageal cancer.

For patients with gastro-esophageal cancer ultrasonography (EUS) is superior to any other imaging modality in the assessment of local tumor infiltration and local lymph nodes status. EUS is especially important in the preoperative staging of patients with esophageal cancer and patients with proximal gastric cancer. Here it allows for the identification of those patients with advanced disease who are unlikely to benefit from surgery and in whom a conservative palliative treatment is indicated. In advanced gastric cancer the clinical implications of EUS less clear. Still preoperative EUS is indicated in every patient with cancer of the proximal stomach to assess tumor infiltration in the esophagus. Relatively new is the use of EUS in staging early cancers in order to select patients for local endoscopic treatment. High-frequency miniprobes are the instruments of choice for imaging these lesions. Strict criteria should be applied in the selection of patients for local endoscopic treatment of early gastro-esophageal cancers. EUS guided fine needle aspiration (EUS-FNA) is currently only indicated in patients with esophageal cancer and suspicious celiac lymph nodes. It may become more important if new treatment protocols demand more objective and reliable assessment of lymph node status.     

Endoscopic sonography in the diagnosis of gallbladder wall lesions in patients with gallstones

PURPOSE: The purpose of this study was to evaluate the diagnostic accuracy of endoscopic sonography (EUS) in the detection of gallbladder wall lesions in patients with and without gallstones. METHODS: We retrospectively reviewed the medical records, sonograms, and sonographic reports of 62 patients who underwent cholecystectomy for gallbladder wall lesions evaluated by EUS. We assessed the accuracy of EUS in diagnosing gallbladder wall lesions in the presence or absence of gallstones and on the basis of the size and number of stones and the size of the gallbladder wall lesions. We also evaluated the effect of acoustic shadowing. The EUS results were compared with the histopathologic results. RESULTS: EUS correctly diagnosed the gallbladder wall lesions in 17 (71%) of 24 patients with gallstones and in 34 (89%) of 38 patients without gallstones. The diagnostic accuracy of EUS was 86% in patients with gallbladder wall lesions smaller than 20 mm and 79% in patients with gallbladder wall lesions 20 mm or larger. The diagnostic accuracy was 75% in patients with gallstones smaller than 5 mm and 67% in patients with stones 5 mm or larger. The accuracy was 67% in patients with 1-5 stones and 83% in patients with 6 or more stones. None of these differences was statistically significant. Acoustic shadowing did not affect the diagnostic accuracy of EUS. CONCLUSIONS: The diagnostic accuracy of EUS for gallbladder wall lesions is not affected by the presence of gallstones. However, better diagnostic criteria must be established based on larger studies, and technical refinements of the equipment are needed to increase the accuracy of EUS in the diagnosis of gallbladder wall lesions.