Refinement of eDNA as an early monitoring tool at the landscape-level: study design considerations.

Natural resource managers use data on the spatial range of species to guide management decisions. These data come from survey or monitoring efforts that use a wide variety of tools. Environmental DNA (eDNA) is a surveillance tool that uses genetic markers for detecting species and holds potential as a tool for large-scale monitoring programs. Two challenges of eDNA-based studies are uncertainties created by imperfect capture of eDNA in collection samples (e.g., water field samples) and imperfect detection of eDNA using molecular methods (e.g., quantitative PCR). Occurrence models can be used to address these challenges, thus we use an occurrence model to address two objectives: first, to determine how many samples were required to detect species using eDNA; second, to examine when and where to take samples. We collected water samples from three different habitat types in the Upper Mississippi River when both Bighead Carp and Silver Carp were known to be present based on telemetry detections. Each habitat type (backwater, tributary, and impoundment) was sampled during April, May, and November. Detections of eDNA for both species varied across sites and months, but were generally low, 0-19.3% of samples were positive for eDNA. Overall, we found that eDNA-based sampling holds promise to be a powerful monitoring tool for resource managers; however, limitations of eDNA-based sampling include different biological and ecological characteristics of target species such as seasonal habitat usage patterns as well as aspects of different physical environments that impact the implementation of these methods such as water temperature.

The No Endosonographic Detection of Tumor (NEST) Study: a case series of pancreatic cancers missed on endoscopic ultrasonography.

BACKGROUND AND STUDY AIMS: The purpose of this study was to identify possible associated factors that may have contributed to failure to detect a pancreatic neoplasm during endoscopic ultrasound (EUS) examinations by experienced endosonographers. PATIENTS AND METHODS: A multicenter retrospective study was organized, and 20 cases of pancreatic neoplasms missed by nine experienced endosonographers were identified. Careful analysis of each case was carried out to identify the factors that might have led to the missed diagnosis on EUS. RESULTS: Twelve patients with a missed pancreatic neoplasm had EUS features of chronic pancreatitis. Other factors that might have increased the likelihood of a false-negative EUS examination included a diffusely infiltrating carcinoma (n = 3), a prominent ventral/dorsal split (n = 2), and a recent episode (within the previous 4 weeks) of acute pancreatitis (n = 1). Five patients with a negative initial EUS underwent a follow-up EUS after 2-3 months, with a pancreatic mass being found in all cases. Three patients had a diffusely infiltrating pancreatic adenocarcinoma. CONCLUSIONS: EUS is not a foolproof method of detecting a pancreatic neoplasm. Possible associated factors that may increase the likelihood of a false-negative EUS examination include chronic pancreatitis, a diffusely infiltrating carcinoma, a prominent ventral/dorsal split and a recent episode (< 4 weeks) of acute pancreatitis. If there is a high clinical suspicion of pancreatic neoplasm, if EUS and other imaging methods are negative, and if the patient does not undergo surgery, this study suggests that a repeat EUS after 2-3 months may be useful for detecting an occult pancreatic neoplasm.

Plexosarcoma: endoscopic ultrasound and electron-microscopic characteristics of a stromal tumor.

Endoscopic ultrasound is useful for managing submucosal masses; however, some of these lesions can be difficult to classify except with full histological and electron microscopic evaluation. A 72-yr-old woman was seen with upper GI bleeding. Endoscopy showed a 1.7-cm sessile ulcerated submucosal mass in the duodenal bulb. Endoscopic ultrasound revealed an echolucent submucosal mass arising from the fourth echolayer, the muscularis propria of the duodenal wall. These findings suggested that the lesion was a leiomyoma. The patient eventually had the lesion resected because of recurrent bleeding. Histologically it was a spindle cell tumor that on electron microscopy showed neuronal elements consistent with a plexosarcoma, or gastrointestinal autonomic nerve tumor. These lesions account for some one third of all gastrointestinal stromal tumors. Despite their low grade malignant histologic appearance, local recurrence or hepatic metastases occur in about 70% of patients.

EUS with EUS-guided fine-needle aspiration as the first endoscopic test for the evaluation of obstructive jaundice.

BACKGROUND: This study assesses the cost savings associated with using endoscopic ultrasound (EUS) before endoscopic retrograde cholangiopancreatography (ERCP) for evaluating patients with suspected obstructive jaundice. METHODS: One hundred forty-seven patients with obstructive jaundice of unknown or possibly neoplastic origin had EUS as their first endoscopic procedure. With knowledge of the final diagnosis and actual management for each patient, their probable evaluation and outcomes and their additional costs were reassessed assuming that ERCP would have been performed as the first endoscopic procedure. Also calculated were the additional costs incurred if EUS were unavailable for use after ERCP and had to be replaced by computed tomography or other procedures. RESULTS: The final diagnoses in these patients included malignancies (65%), choledocholithiasis or cholecystitis (18%), "medical jaundice" (11%), and miscellaneous benign conditions (6%). Fifty-four percent had EUS-guided fine-needle aspiration but only 53% required ERCP after EUS. An EUS-first approach saved an estimated $1007 to $1313/patient, but the cost was $2200 more if EUS was unavailable for use after ERCP. Significant savings persisted through sensitivity analysis. CONCLUSIONS: Performing EUS with EUS-guided fine-needle aspiration as the first endoscopic procedure in patients suspected to have obstructive jaundice can obviate the need for about 50% of ERCPs, helps direct subsequent therapeutic ERCP, and can substantially reduce costs in these patients.

Evaluation of mediastinal masses by endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration.

OBJECTIVE: Interest has been growing in using endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration in the evaluation of mediastinal masses. The purpose of this study was to review the spectrum of mediastinal masses encountered using endoscopic ultrasound. METHODS: We reviewed all cases of mediastinal masses examined by endoscopic ultrasound, with or without endoscopic ultrasound-guided fine needle aspiration, prospectively gathered from our electronic database from April 1995 to July 2000. RESULTS: Of 1447 upper endoscopic ultrasound examinations, 33 (2.3%) involved a mediastinal mass. Sixty-one percent of the patients were male and the average age was 65 yr. Fifty-five percent of patients had dysphagia, 48 percent experienced weight loss, and only 12 percent were totally asymptomatic. Seventy-three percent had masses by chest CT. Sixty-seven percent were ultimately found to be malignant, 21 percent were solid benign lesions, and four were cystic. Only two lesions were resected. Endoscopic ultrasound-guided fine needle aspiration was used in 76 percent of all patients. The median survival of patients with malignant lesions was only 87 days. CONCLUSIONS: Lesions of the deep mediastinum are often difficult to conclusively diagnose with nonendoscopic studies. Endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration can easily access this region to aid in the diagnosis and management of these lesions.

Impact of endoscopic ultrasound on the management and outcome of pancreatic carcinoma.

OBJECTIVE: Although endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration have been shown to aid in the diagnosis and staging of pancreatic carcinoma, whether the general use of these new techniques impacts the overall management and survival of pancreatic cancer, is less clear. METHODS: Clinical data on all patients diagnosed with pancreatic carcinoma were assessed for two equal time periods during which computerized tomography-guided fine needle aspiration and biopsy was used (1/93-5/95) and then during which endoscopic ultrasound-guided fine needle aspiration was used (8/95-12/97) for the primary diagnosis of these patients. RESULTS: Comparative data for the computerized tomography era versus the endosonography era showed that 1) pancreatic carcinomas diagnosed: 52 versus 84 patients (stage I-III at diagnosis: 33% vs 54%; p < 0.05); 2) diagnosis by aspiration or biopsy of a pancreatic mass, nodes, liver metastasis, or by operation: 46%, 0%, 19%, 29% versus 52%, 8% (p = 0.02 nodes plus pancreatic masses), 20%, 7% (p = 0.002); 3) pancreatic resections: 13% versus 14%; 4) median survival without liver metastases: 102 versus 205 days (p < 0.02, log-rank test). Endoscopic ultrasound detected carcinomas that were either not seen or only possibly seen by computed tomography in 34%. CONCLUSIONS: More patients (62%) were diagnosed with pancreatic carcinoma when using endoscopic ultrasound and 75% fewer required operations for diagnosis. The 3-month improvement in median survival is probably multifactorial but most likely represents lead bias because of the greater sensitivity of endoscopic ultrasound for pancreatic carcinoma. Using endoscopic ultrasound with endoscopic ultrasound-guided fine needle aspiration in patients with pancreatic carcinoma significantly affects their management and outcomes.

Clinical utility of endoscopic ultrasound and endscopic ultrasound-guided fine needle aspiration in retroperitoneal neoplasms.

OBJECTIVE: Nonpancreatic, retroperitoneal tumors are a relatively uncommon clinical problem. With the advent of endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration, gastroenterologists may be called upon to assist in the diagnosis and management of these lesions. This paper reviews the spectrum of upper retroperitoneal lesions encountered at a single institution using endoscopic ultrasound. METHODS: We reviewed all cases of nonpancreaticobiliary or nonadrenal retroperitoneal lesions prospectively gathered from our endoscopic ultrasound database from April 1995 to September 1999. RESULTS: Of 1120 upper endoscopic ultrasound examinations, 18 (1.6%) involved a retroperitoneal lesion; 16/18 lesions were neoplasms, nine were primary retroperitoneal tumors (four lymphomas, two leiomyosarcomas, two extraadrenal paraganglionomas, one leiomyoma), and seven were metastatic cancers. There was one fibrous mass and one mass-like abscess. Endoscopic ultrasound-guided fine needle aspiration was used in 15/18 cases. The management of 16 patients was significantly affected by the results of endoscopic ultrasound and biopsy. CONCLUSIONS: Although it is not a frequent indication, assessing upper retroperitoneal tumors with endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration can significantly affect the subsequent management of patients with these lesions.

Factors predicting the number of EUS-guided fine-needle passes for diagnosis of pancreatic malignancies.

BACKGROUND: The factors that affect the number of needle passes needed to diagnose pancreatic malignancies using endoscopic ultrasound (EUS) -guided fine-needle aspiration are unknown. METHODS: Patient and endosonographic data were prospectively recorded on 121 consecutive patients with pancreatic malignancy. Of these, 110 underwent EUS-guided fine-needle aspiration. A cytopathologist was in attendance for all aspiration procedures. RESULTS: Initial EUS detected a pancreatic mass in 96% of cases; 23% of these were not seen by computed tomography. EUS-guided fine-needle aspiration was performed in 109 of 110 (99%) patients, including 95 masses, 7 lymph nodes, and 7 hepatic metastases. EUS-guided fine-needle aspiration provided a cytologic diagnosis of malignancy in 104 of 110 (95%). Only tumor differentiation and the site of aspiration affected the number of passes. CONCLUSIONS: With the participation of a cytopathologist, EUS-guided fine-needle aspiration can diagnose pancreatic malignancies with a high degree of accuracy. Only the aspiration site (mass versus node/liver metastasis) can be used to direct the number of passes if a cytopathologist is not present. Without a cytopathologist in attendance, 5 to 6 passes should be made for pancreatic masses and 2 to 3 for liver metastases or lymph nodes; however, this approach will be associated with a 10% to 15% reduction in definitive cytologic diagnoses, extra procedure time, increased risk and additional needles.

Endoscopic ultrasound and fine needle aspiration for the evaluation of pancreatic masses.

HYPOTHESIS: Endoscopic ultrasound (EUS) and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) are accurate for the preoperative staging of pancreatic ductal carcinoma. DESIGN: Retrospective medical record review. PATIENTS: A prospective registry of 98 patients having EUS-FNA for peripancreatic masses from April 1994 to April 1998 was analyzed. MAIN OUTCOME MEASURE: The accuracy of EUS-FNA for preoperative diagnosis and staging of peripancreatic neoplasms. RESULTS: Ninety-eight patients, aged 41 to 91 years (mean age, 67 years) with peripancreatic masses were evaluated by EUS-FNA. All patients had initial computed tomography scanning with a mass seen in 49 patients, "fullness" to the pancreas in 28 patients, and no mass seen in 21 patients. Evaluation with EUS-FNA revealed 22 benign lesions, 18 T2 masses, 37 T3 masses, 1 T4 mass, and 20 masses representing nonpancreatic tumors. Results of EUS-FNA of adjacent lymph nodes were positive in 27 patients. Twenty-seven patients had surgical resection or palliation permitting operative and pathologic staging. On comparison of EUS-FNA staging with surgical staging, 12 patients were the same stage, 14 patients were upstaged, and 1 patient was downstaged. The remaining patients who did not have surgery have been followed up for a mean of 15 months. Overall accuracy of EUS-FNA for differentiating benign from malignant masses was 96%. CONCLUSIONS: Endoscopic ultrasound-guided fine needle aspiration is a useful technique for the evaluation of pancreatic masses. It is highly accurate for differentiating between benign and malignant lesions and for predicting T stage, but is limited for predicting nodal status.

Domestic violence: legal, practice, and educational issues.

Domestic violence is a recognized and growing public health concern in the United States. Health care professionals have a duty to improve the identification of victims of domestic violence, intervene effectively, and advocate for better education to break the cycle of abuse.

Endoscopic ultrasound for peripancreatic masses.

BACKGROUND: Pancreatic neoplasms can be difficult to diagnose and stage preoperatively. Accurate staging allows the surgeon to select which patients can benefit from resection versus palliative therapy. Endoscopic ultrasound (EUS) with endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a diagnostic modality that provides visualization of peripancreatic tumors and their relationship to the surrounding structures as well as enabling cytologic diagnosis of the tumor and adjacent lymphadenopathy. METHODS: To define the role of this technique, a retrospective study was performed on 20 patients in the past year with peripancreatic tumors. RESULTS: Twelve men and 8 women ranging in age from 28 to 84 years (mean 67) were included in the study. Each patient underwent computed tomography followed by EUS-FNA, and the results were compared with operative findings or clinical course. The EUS-FNA findings included 10 pancreatic ductal carcinomas (50%), 5 pancreatitis (25%), 2 spindle cell neoplasms (10%), 1 cholangiocarcinoma (5%), 1 cystadenoma (5%), and 1 metastatic breast carcinoma (5%). Overall, EUS-FNA led to a significant change in the management of 12 patients (60%) through either diagnosing benign pathology, upstaging of the carcinoma, or determination that the peripancreatic mass represented a metastatic lesion. Five patients underwent resection of their peripancreatic tumors, and 3 patients had palliative procedures. Operative findings corresponded with EUS-FNA in all 8 patients. The 5 patients diagnosed with pancreatitis continued to be followed up for the possibility of a false negative FNA, but to date none have developed malignancy. CONCLUSIONS: EUS-FNA is a useful tool for the imaging and staging of peripancreatic tumors and will aid in the proper preoperative selection of patients who will benefit from resectional therapy.

Clinical utility of endoscopic ultrasound-guided fine needle aspiration.

OBJECTIVE: To assess our institution's initial experience with the clinical utility of endoscopic ultrasound (EUS)-guided fine needle aspiration. STUDY DESIGN: Prospective analysis of the clinical utility of EUS-guided FNA. RESULTS: Fifty-three patients underwent EUS-guided FNA of 64 sites, 28 for pancreatic masses, 15 for lymph nodes, 10 for solid lesions, 7 for cystic masses, 2 for submucosal masses and 2 for perigastrointestinal fluid. A cytopathologist was present during all procedures. An average of four passes (range, one to nine) was required to make a diagnosis in the 22 patients with pancreatic malignancies. There was one possible complication among the 53 patients. In 36 of the 53 patients, the combination of diagnostic EUS findings and cytologic diagnosis made a major change in the patient's management. CONCLUSION: Because of its ability to affect patient management, EUS-guided FNA will become a more commonly used procedure, especially at oncologic centers. Since the number of fine needle passes needed for diagnosis is quite variable, it is important to have a cytopathologist participate in these procedures.

The clinical utility of endoscopic ultrasound-guided fine-needle aspiration in the diagnosis and staging of pancreatic carcinoma.

BACKGROUND: Endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) of pancreatic lesions is being increasingly used. Our aim was to determine the safety, accuracy, and clinical utility of EUS-guided FNA in both the diagnosis and staging of pancreatic cancer. METHODS: Forty-four patients (24 men/20 women) had EUS-guided FNA of pancreatic lesions (39 head/neck, 5 body, 3 tail) and/or associated lymph nodes. The mean age was 61 (range, 28 to 88 years). The indication for EUS-guided FNA was a pancreatic lesion seen initially on CT (39%), ERCP (43%), or EUS (18%). Follow-up data were collected on all patients for mean of 14.5 months (range 1 to 33 months). RESULTS: CT detected only 15 of 61 (25%) focal lesions seen by EUS, Adequate specimens were obtained by EUS-guided FNA in 44 of 47 (94%) pancreatic lesions and 14 of 14 (100%) associated lymph nodes (overall adequacy was 95%). Of the 46 lesions in which specimens were adequate and a final diagnosis was available (32 malignant, 14 benign), EUS-guided FNA had a sensitivity of 92%, specificity of 100%, and diagnostic accuracy of 95% for pancreatic lesions and 83%, 100%, and 88% for lymph nodes, respectively. Six percent of pancreatic cases had inadequate specimens and, if included, lowered the sensitivity to 83%, specificity to 80%, and diagnostic accuracy to 88% for pancreatic lesions. In 3 patients with enlarged celiac nodes on EUS, EUS-guided FNA was able to make a tissue diagnosis of metastasis, which changed the preoperative staging and precluded surgery. EUS in combination with EUS-guided FNA precluded surgery in 12 of 44 (27%) and may have precluded surgery in an additional 6 of 44 (14%). EUS-guided FNA avoided the need for further diagnostic tests, thus expediting therapy in a total of 25 (57%) patients and influenced clinical decisions in 30 of 44 (68%) patients. The estimated cost savings based on surgeries avoided was approximately $3300 per patient. There was only one complication (2%), a post-FNA fever. CONCLUSION: EUS-guided FNA of the pancreas appears to be a safe and effective method that increases both the diagnostic and staging capability of EUS in pancreatic cancer. The clinical impact of EUS-guided FNA includes avoiding surgery and additional imaging studies with a substantial cost savings.

Endoscopic ultrasonography: a new diagnostic imaging modality.

Endoscopic ultrasonography uses high-frequency ultrasound to visualize the gut wall and the surrounding structures of the mediastinum, the abdomen and the pelvis. Echoendoscopes are available in two different designs. A radial scanning echoendoscope produces a 360 degree real-time view perpendicular to the shaft of the echoendoscope. A linear-array instrument produces a 100 degrees real-time view parallel to the shaft of the echoendoscope, permitting direct ultrasonographic guidance of fine needles exiting the biopsy channel. Endoscopic ultrasonography has been established as the preferred diagnostic tool for the evaluation of submucosal masses of the upper gastrointestinal tract and the rectosigmoid, for differentiating benign from pathologic thickened gastric folds and for locating pancreatic endocrine tumors. The widest application of endoscopic ultrasonography is in the diagnosis and staging of esophageal, gastric, rectal and pancreaticobiliary neoplasms. Endosonography is the most accurate modality available for determining the T and N stages of these tumors. The recent development of endoscopic ultrasound-guided fine-needle aspiration provides physicians with the ability to cytologically diagnose lesions visualized endosonographically and to confirm cancer staging with tissue.

Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration of the left adrenal gland.

BACKGROUND: We reported the application of endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (FNA) in the local staging of lung cancer. Up to 16% of patients with lung cancer may have adrenal masses. The role of EUS in the characterization of the adrenal gland, as well as EUS-guided FNA of the adrenal gland, has not been described. METHODS: The adrenal gland was characterized by EUS in 30 of 31 (97%) patients. EUS-guided FNA of an adrenal was performed in one patient. Anatomic correlation and ex vivo images were obtained. RESULTS: The average dimension was 2.5 cm (range 1.4 to 3.5) x 0.8 cm (range 0.3 to 1.4) with two morphologic types: "seagull" and "elliptical." One patient with lung cancer and a left adrenal mass with a nondiagnostic CT-guided FNA underwent EUS-guided FNA, which established the diagnosis of metastatic adenocarcinoma. Surgery was avoided. CONCLUSIONS: The left adrenal can be imaged by EUS in almost all patients. EUS-guided FNA may be useful when applied to left adrenal metastatic tumors for tissue diagnosis.

A primer on linear array endosonographic anatomy.

Linear array endosonography, with its capacity to perform EUS-guided FNA and EUS-guided injections, as well as color mapping and Doppler ultrasonography, is becoming an important instrument for the endosonographer. Familiarity with linear array anatomy, as introduced here, is the critical foundation on which these diagnostic and therapeutic procedures can be performed safely and effectively.

The role of endoscopic retrograde cholangiopancreatography in patients with laparoscopic cholecystectomies.

BACKGROUND & AIMS: The best clinical strategy for using endoscopic retrograde cholangiopancreatography (ERCP) with laparoscopic cholecystectomy is unknown. The aim of this study is to use decision analysis to assess four different approaches to using ERCP in patients undergoing laparoscopic cholecystectomy. METHODS: Decision trees were designed for four clinical strategies: (1) preoperative ERCP, with sphincterotomy for choledocholithiasis; (2) selective preoperative ERCP for patients at high risk for choledocholithiasis, choledocholithiasis found at surgery treated by postoperative ERCP; (3) no preoperative ERCP, choledocholithiasis detected intraoperatively treated by postoperative ERCP; and (4) no preoperative ERCP, choledocholithiasis detected intraoperatively treated with open common bile duct exploration. Using decision analysis with literature-derived data, the impact on outcome parameters was calculated. RESULTS: Postoperative ERCP resulted in the lowest cost, procedure numbers, and hospital and back-to-work days. With high preoperative likelihood of choledocholithiasis, selective preoperative ERCP was probably a clinically equivalent strategy. Sensitivity analysis supported these conclusions when the probabilities and utilities were varied over a wide range. The open operative approach to choledocholithiasis was only favored if ERCP had < 75% diagnostic and < 50% therapeutic success rates or lengthened hospitalization by > 7 days. CONCLUSIONS: This study suggests that performing ERCP after laparoscopic cholecystectomy minimizes costs and morbidity; however, when choledocholithiasis is likely, selective preoperative ERCP may be a clinically equivalent strategy.

Mechanism of colonic permeation of inulin: is rat colon more permeable than small intestine?

BACKGROUND/AIMS: Colonic epithelium is considered to be relatively tight. The colonic "pore" diameter is 6 A; therefore, colonic epithelium has generally been considered to be impermeable to hydrophilic probes with a cross-sectional diameter of > 6 A. This study examined whether rat colon is permeable to inulin, a large hydrophilic macromolecule having a molecular weight of 5000 g/mol and a cross-sectional diameter of 15 A (hydration diameter, 20 A). METHODS: The colonic permeation of inulin (10 mumol/L) in vivo was investigated by perfusion of rat colonic segments. RESULTS: There was significant colonic permeation of inulin, but tissue retention of inulin was low. The net colonic flux of inulin was strongly dependent on net water flux, showing a strong solvent drag effect. Addition of 16,16-dimethyl prostaglandin E2 decreased water flux with a corresponding decrease in inulin flux; this process seemed to be mediated by 5'-cyclic adenosine monophosphate because both the phosphodiesterase inhibitor aminophylline and dibutyryl adenosine 5'-cyclic adenosine monophosphate decreased water and inulin flux in a parallel manner. Chenodeoxycholic and taurocholic acids decreased net mucosal-to-serosal water flux but increased inulin flux. The net colonic permeation rate of inulin was higher than the small intestinal permeation rate. CONCLUSIONS: Rat colon is permeable to inulin. The higher net colonic permeability may be caused by differences in mucosal surface, permselectivity, solvent drag effect, and differences in net water fluxes of the colon and small intestine.

Endoscopic ultrasound-guided fine-needle aspiration.

Thirty-eight consecutive patients underwent endoscopic ultrasound-guided fine-needle aspiration. Of 46 lesions, 34 were extraluminal (12 pancreatic masses, 8 periesophageal nodes, 6 celiac nodes, 2 pericolonic masses, 1 mediastinal mass, 1 perigastric mass, 1 liver, 1 periduodenal node, 1 perirectal mass, 1 perirectal node) and 12 were submucosal (8 gastric, 3 duodenal, 1 esophageal). One hundred sixty-three passes were made, with an average of 3.5 passes per lesion and 4.3 passes per patient (range, 1 to 8). Adequate specimens were obtained from 91% of targeted lesions. The overall diagnostic accuracy was 87%. In patients with malignant lesions, sensitivity was 91% and specificity 100%. Celiac nodes were successfully sampled and diagnostic in 5 of 6 (83%) patients. No complications occurred. Using this technique, an initial tissue diagnosis of malignancy was made in 66% of cancer patients without a previous diagnosis and the preoperative stage was changed in 44% of cancer patients. The additional information gained by this modality directly influenced the decision not to perform surgery in 26% of patients with a primary malignancy. Endoscopic ultrasound-guided fine-needle aspiration is feasible and can be safely used to evaluate submucosal and extraluminal lesions in both the upper and lower gastrointestinal tract with a high degree of diagnostic accuracy.