Michael B. Wallace

3892 How many supervised procedures does it take to become competent in eus?-results of a multicenter three year study.

Background: The amount of experience required to train new endosonographers is unknown. Competency in technical performance is likely to precede interpretive competence. Methods: Over a 3 year period, recognized experts in EUS provided one on one proctorship; evaluated the performance of new trainees in the specific categories listed below; and rated each procedure category as 0=Failed; 1=Unsatisfactory; 2=Satisfactory; 3=Excellent. Competency was defined as achieving a consistent score of 2. Results:10 third tier fellowship trainees and 2 PGY 6 trainees were evaluated. All were male. Only one had performed EUS prior to beginning his training. None had prior abdominal US experience. 10/12 were trained in ERCP. Mean number of ERCPs performed before EUS training was 229 ( SD 167). The median (range) of the number of EUS procedures required for competency is listed for the following categories: Esophageal Intubation 1(1-21), Pylorus Intubation 2(1-14), Duodenal Intubation 2(1-23), Esophageal wall visualization 10(1-36), Gastric wall 15(1-47), Mediastinum 10(1-33), Celiac axis 25(8-36), Pancreas body and tail 26(1-34), Pancreas head 34(15-74), CBD/PD 55(13-135), Ampulla 54(13-134) , Normal anatomy interpretation 54(9-92), and Pathology interpretation 60(16-134). The number of procedures needed to successfully visualize the head, tail and body of the pancreas was not different among the trainees who had performed more than 100 ERCPs compared to those who had performed less (p>0.05). In addition, the number of procedures needed to adequately interpret normal anatomy or EUS related pathology was not different among the two groups. Conclusions: With intensive hands-on experience and tutelage by an expert in a facility performing a high volume of EUS procedures, a trainee may become competent to perform EUS within a relatively short time-period. There is, however, a broad range in the ability to interpret normal anatomy and pathology. This information may alter the current pattern of advanced training and also be of importance to private practitioners wishing to develop skills in EUS. This study was support by a grant from the American Digestive Health Foundation.

4533 The detection of celiac lymphadenopathy in esopahgeal cancer by endosonography is synonymous with malignant involvement.

Background: EUS-guided FNA is the most accurate method of confirming loco-regional malignant lymphadenopathy. The additional yield of FNA beyond endosonographic characteristic is unknown. Aims: 1) To determine if the detection of a CLN by EUS, independent of FNA, indicates malignant involvement. 2) To evaluate the accuracy of EUS in detecting CLN metastasis. Methods:We reviewed all cases of esophageal cancer that underwent EUS at our institution from 1/26/94 to 11/1/99. All staging was performed with a radial scanning echoendoscope (UM-20 or UM-130). FNA was performed of all accessible CLN with a linear scanning echoendoscope (UC-30 P, UCT-30, UM-30P). Patients were included in this study if they underwent surgery (n= 59), or if they had FNA of a celiac LN (n=44). The accuracy of EUS compared to cytology or histology was subsequently determined. Results: 103 patients with esophageal cancer met inclusion criteria. Seventy eight percent were male and 76% were Caucasian. Fifty five percent had adenocarcinoma of the esophagus and 79% of the tumors were confined to the distal esophagus or GE junction. Twenty five percent underwent dilation to 45 Fr to complete the examination. No complications were encountered. EUS imaging identified 48 true positive patients with CLN, 6 false positive, 14 false negative and 35 true negative. Therefore, the sensitivity of EUS in detecting CLN was 77% (95% CI, 67-88), the specificity 85% (95% CI, 75-96), the negative predictive value 71%, and the positive predictive value 89%. The overall accuracy of EUS was 81%. EUS FNA confirmed the nature of a CLN in 88% of the cases. Seventy eight percent (21/27) of EUS-detected CLN ≤ 1cm were malignant while 100% (25/25) of EUS-detected CLN >1 cm were malignant (p=0.02). Conclusions: Approximately ninety percent of CLN detected by EUS in patients with esophageal cancer are ultimately proven to be malignant. Since cytological proof of malignant involvement is critical in clinical decision making, all visible CLN should undergo FNA. IF a CLN (>1 cm) is imaged by EUS and FNA is not technically feasible, this study suggests that the patient should be considered to have CLN malignant involvement and should be managed accordingly.

7127 Can a 3.1 mm stand-alone battery powered esophagoscope (bpe) screen the esophagus for esophagitis and barrett's ? a prospective blinded comparison with a standard videoendoscope (sve).

Intro: There exist several indications (varices, Barretts, GERD) where an esophagoscopy alone would suffice rather than a complete endoscopy. Feasibility of esophagoscopy using a prototype battery powered flexible fiberoptic esophagoscope (Olympus XEF-DP) with an outer diameter of 3.1 mm has been reported (GI Endo 1999;49: AB157). Aim: In a prospective blinded study, compare esophageal visualization between the BPE & the SVE. Methods: 95 consecutive pts. underwent sedated esophagoscopy with the BPE foll. by SVE, done by 2 endoscopists, each blinded to the findings of the other. On a visual analogue scale, the 2 endoscopists rated pt. tolerance & instrument performance. Results: 89 (M 57) pts. (mean age 56 yr.) were analyzed. Mean duration of esophagoscopy was 4.4 mins (range 2-10). Sensitivity : specificity (%) with BPE was 94 : 96 (Barretts) & 87 : 94 (all lesions). Measures of pt. tolerance were (BPE : SVE, p value): intubation ease 96 : 93, 0.06; gagging 98 : 91, 0.0012; coughing 98 : 96, 0.08; belching 89 : 92, 0.02 (higher scores indicate better rating). Measures of scope performance were (BPE : SEV, p value): visibility 90 : 98, 0.0001; air insufflation 92 : 98, 0.001; maneuverability 87 : 99, 0.001. Concl: The esophagus can be accurately visualized in under 5 min with the BPE. Inter-observer variability may account for some of the disagreements. Being a standalone instrument, not needing a light source, processor or a monitor, it could facilitate esophagoscopy outside of the conventional GI lab setting. Its tolerance unsedated, use transnasally & potential in a true screening environment are being studied.

3895 Randomized controlled trial of eus guided fine needle aspiration technique for confirming malignant lymphadenopathy.

Background: The optimal method for performing EUS guided FNA of malignant appearing lymph nodes (LN) is unknown. Histological evidence suggests that malignant cells are preferentially located in the edge of LNs. Improved techniques may increased diagnostic accuracy, and reduce procedure time and costs. Objetives: To determine the impact of the number of FNA passes, FNA-suction, FNA-location (center or edge), and examination of needle effluent on diagnostic yield and specimen quality. Methods: Consecutive EUS-FNA of LN were randomized in a 2x2 factorial design to suction (10cc syringe) or no suction, and to aspiration from the center or edge of the LN. Individual LN were sampled with all four possible combinations of suction and location for 30 seconds each FNA pass. Each aspirate was examined by a blinded cytopathologist for cellularity, and malignancy after Papanicolaou staining. Five cc of needle effluent from each pass were pooled and compared to the cytological diagnosis. Results: One hundred forty five FNA passes were performed on 32 LN in 27 patients. Ten LN were confirmed by cytology to be malignant, 3 were suspicious, 6 were confirmed by cytology and surgery to be benign, and 13 had normal cytology. Eighty percent of malignant specimens were obtained on the first FNA pass, and 100% were obtained in the first 3 passes (mean number of passes 4.5, range 2-8) regardless of the bedside cellularity of the specimen. Sampling the edge of the LN (compared to the center) did not improve the identification of malignant cells (Relative Risk 0.98, p=0.8) nor did it improve the specimen cellularity (RR=0.93, p=0.8). The use of suction did not improve the diagnostic yield of malignant cells (RR=1.1, p=0.4) nor cellularity (RR=1.3, p=0.3). The use of suction worsened of the quality (bloodiness) of the specimen (p value for trend 1cm) LN. Conclusion: This study suggests that three FNA passes are sufficient to diagnose malignant lymphadenopathy. The current standard use of suction significantly worsens the quality of the aspirate due to excessive bloodiness and does not improve diagnostic yield of EUS-FNA. FNA can be performed from either the center or edge of LN with equal yield. Dr. Wallace was supported by the American Digestive Health Foundation, Wilson Cook Award

4589 How much experience is required to correctly interpret eus features of chronic pancreatitis? a multicenter prospective trial of third tier eus trainees compared to a consensus of experts.

Background: The amount of experience required to train new endosongraphers is unknown. Interpretative and procedural skills are likely acquired at different rates. Methods: Forty five standardized examinations (Olympus UM-20 or UM-130 at 7.5 mHz) of the pancreas were videotaped including patients with and without suspected pancreatic disease. Eleven experienced (“experts”) endosongraphers who had performed more than 1000 EUS examinations each, independently rated all examinations for nine separate features of chronic pancreatitis (hyperechoic foci, strands, lobularity, cysts, stones, duct dilation, duct irregularity, hyperechoic duct margins, and visible side branches), as well as a global diagnosis of CP. Consensus diagnoses for each feature and global assessment was considered when >90% of the experts agreed on the presence or absence of a feature. Ten EUS trainees independently rated the same videotape and were compared to the consensus cases. An answer was considered correct when the trainee agreed with the consensus diagnosis. Results: Ten trainees from three separate third-tier EUS training programs had performed a median of 150 (range 50-1200) lifetime EUS examinations, and 40 (range 0-100) lifetime chronic pancreatitis EUS examinations. Out of 450 features (45 examinations x 10 features), there was consensus by the expert panel on 206. The trainees correctly scored a median of 190 (range 181-200) out of 206. The score was strongly and positively correlated with the number of chronic pancreatic EUS examinations (R = 0.62, p= 0.05), and weakly correlated with total pancreatic examinations (R= 0.42, p = 0.22), and total EUS examinations (R = 0.47, p = 0.17). After performing at least 15 examinations, all trainees correctly diagnosed more than 90% of features. Scores greater than 95% were reached after performing 40 examinations. Conclusions: Skill in interpreting EUS features of chronic pancreatitis is strongly correlated with experience. Interpretive competence, as measured by agreement with an expert panel, is reached after performing only 15-40 chronic pancreatitis examinations in a supervised, third tier training program. In evaluating chronic pancreatitis with EUS, procedural skills as opposed to interpretive skills, are more likely to be the limiting factor in EUS training. Dr.Wallace was supported by the American Digestive Health Foundation, Wilson Cook Award

4661 Do pancreatic features identified with endoscopic ultrasound correlate with sphincter of oddi manometry in patients with clinically suspected sphincter of oddi dysfunction? an evaluation of 462 patients.

SOM is the accepted method for diagnosing SOD. EUS can evaluate anatomical features of the pancreas. The role of EUS in the evaluation of patients with clinically suspected SOD particularly in predicting the findings of SOM, is undefined. AIM: Evaluate if EUS assessment of the pancreas correlates with SOM in patients with clinically suspected SOD. METHOD: Patients with clinically suspected SOD who underwent EUS prior to SOM between 2/94 and 11/99 at MUSC were included for analysis. Patients with pancreas divisum, prior therapy to the major papilla, or inadequate SOM or EUS were excluded. EUS features of pancreatitis ( parenchymal : foci, strands, lobularity, cysts, and ductal : hyperechoic and irregular duct margins, calcification/stones, visible side-branches and duct dilatation) were compared with the SOM diagnosis of the biliary (BSOM) and pancreatic (PSOM) orifices. All EUS examinations were blinded to the findings at SOM. SOM was performed using a standard 5 F aspirating catheter and SOD diagnosed if the mean sphincter pressure from two leads was >40 mmHg. EUS was performed using a radial echoendoscope (Olympus UM-20, UM-130) at 7.5 MHz. RESULTS: Of 462 patients (mean age 45 yrs. range16-85yrs., M/F 137/325), 372 and 370 underwent unequivocal PSOM and BSOM respectively after EUS. Of the 176 patients with abnormal PSOM, 54% (n=95) had a total >4 EUS features of pancreatitis; 46% (89/194) with normal PSOM had 3 or less features (p=1). Of patients with no EUS features, 48%(25/52) and 52% (27/52) had normal and abnormal PSOM respectively (p=0.55). Similarly there was no correlation between BSOM (148 abnormal) and the total number of EUS features. The number of parenchymal or ductal EUS features was unrelated to BSOM or PSOM. CONCLUSIONS 1] Neither the total number nor the number of parenchymal or ductal EUS features of pancreatitis predict the findings of SOM in patients with clinically suspected SOD. 2] A normal EUS examination (i.e. no features) does not exclude SOD.

3491 Preliminary experiences of three-dimensional endoscopic ultrasonography in the united states.

INTRODUCTION: The advent of low cost computer power has greatly impacted body imaging resulting in a proliferation of technologies incorporating 3-D reconstruction. AIM: To image a variety of UGI lesions with a prototype 3-D EUS catheter probe to determine its potential clinical applications. METHOD: The 3D-EUS imaging system (Olympus Optical, Tokyo) consists of a 12 and 20 MHz ultrasonic probe (UM-3D2R, UM-3D3R), a motor unit, an ultrasound processor (EU-M30), and a computer for image processing (EU-IP2). Scanning and storing time is 4 to 13 sec. The ultrasound probe is housed in a clear sheath filled with water. The motor moves the probe radially (360°) and linearly (4cm). Images are stored and processed later. In all cases, the radial and linear images were reviewed and judgment was rendered as to whether combined imaging provided clinical benefit. Esophageal cases were performed using a condom placed over the end of a two channel endoscope. RESULT: Between 5/99 and 11/99, 13 3-D EUS cases were performed (2 esophageal cancer, 3 Barretts esophagus, 4 esophageal SMT, 1 gastric SMT, 1 mucinous ductal ectasia, 1 common bile duct stricture). The simultaneous display of linear and radial images made imaging and interpretation of images of SMT easier but did not provide unique and significant advantages. Imaging and evaluation of Barretts esophagus and biliary strictures was significantly better with the 3-D system because of the volume of area that can be scannedfrom a single position. CONCLUSION:We suggest that the simultaneous linear and radial images produced by this instrument may improve diagnosis in some circumstances. Prospective trials based on this data are ongoing. Volume rendering will be possible in the near future which may further expand the application of 3-D EUS.

4531 Has spiral ct replaced the need for eus staging of esophageal carcinoma

Background: The advantage of EUS over CT in staging esophageal carcinoma is based on comparisons to conventional single-slice CT scanners. Conventional CT has largely been replaced by spiral CT. The comparative accuracy of spiral CT versus EUS is unknown. Method: Consecutive patients with esophageal carcinoma were staged with both EUS and contrast enhanced spiral CT. Spiral CT examinations were performed with a Picker PQ6000 helical scanner using a single breath-hold technique followed by the injection of intravenous contrast medium. CT were read by a single experienced gastrointestinal radiologist blinded to the EUS results. EUS staging was performed with a radial scanning echoendoscope (Olympus UM-20 or UM-130) with dilation of stenotic tumors, if necessary, to completely visualize the celiac artery to its bifurcation. EUS exams were performed by experienced (>1000 EUS cases) endosonographers who were not blinded to the clinical or CT information. EUS and CT staging could not be directly compared to surgical staging because of pre-operative chemo-radiotherapy in all operated patients. Results: Twenty eight patients have been evaluated to date. Of these 15 patients had celiac lymph nodes (CLN) detected by any staging modality. EUS detected 14/15 patients with CLN (sensitivity 93%). Spiral CT detected 12/15 patients with CLN (sensitivity 80%). The three patients with CLN detected by EUS but missed by CT were all confirmed positive for malignancy by FNA. One patient had CLN detected by CT but missed by EUS. This patient also had T4 disease detected by EUS and was treated non-surgically. Eight patients were found to have locally advanced (T4) disease by EUS. CT detected 3/8 (sensitivity 38%). Twenty patients were found to have locally nonadvanced disease (T1-T3) by EUS. CT correctly diagnosed 18/20 as nonadvanced (Specificity 90%) and overstaged 2/20 as T4. Conclusions: This study suggests that EUS is superior to spiral CT but the methods are also complimentary for the detection of celiac lymph node metastases and locally advanced disease in patients with esophageal cancer. Spiral CT has not replaced the need for EUS staging of patients with esophageal carcinoma. Dr.Wallace was supported by a the American Digestive Health Foundation, Wilson Cook Award

⁎4588 Endoscopic ultrasound as a first-line diagnostic and staging test after ct in patients with suspected or proven lung cancer: yield in 122 consecutive patients.

Background: 50% of lung cancer patients have mediastinal lymph node metastases. Proof of ipsilateral node (N2) or contralateral node (N3) involvement contraindictates surgery as primary treatment, but usually requires mediastinoscopy. EUS-guided fine needle aspiration (FNA) provides access to posterior mediastinal nodes and may therefore prevent mediastinoscopy and document surgically incurable disease. Aim: To verify the yield of EUS as a first-line diagnostic and staging modality in patients with suspected or proven lung cancer by CT and/or bronchoscopy. Methods: EUS-FNA was used as a first-line diagnostic and/or staging test in consecutive patients with suspected or proven lung cancer in whom CT showed mediastinal disease accessable for EUS-FNA. Results: 122 consecutive patients had disease that appeared amenable to EUS-FNA: 70 with suspected and 52 with proven lung cancer. Overall, EUS was attempted in 118 (97%) cases: 10 masses and 108 nodes (47% level 7 [AP window]; 32% level 5 [subcarina]; 15% levels 5 & 7; and 6% other node levels). There were no complications. A cytological diagnosis of cancer was obtained in 46/70 (69%) of suspected cancers. The yield for nodal staging was calculated on an “intent to stage” basis. Mediastinal node involvement was documented cytologically in 73/112 (60%) cases where staging was the aim: 37/112 (33%) N2 and 36/112 (32%) N3 nodes. See Table. Conclusions: 1) EUS has a high yield in patients with suspected or proven lung cancer with mediastinal disease by CT. 2) A cytological diagnosis of cancer is obtained in 2/3 patients with suspected cancer. 3) Cytological proof of mediastinal ipsilateral or contralateral disease is obtained in 2/3 patients.

⁎4624 Is eus useful in predicting post-ercp pancreatitis? - an analysis of 509 patients.

BACKGROUND: EUS can provide detailed information regarding parenchymal and ductal changes in the pancreas. Other than prior history, there are no known pre-ERCP predictors of post-ERCP pancreatitis (PEP). The relationship between EUS features of pancreatitis and post- ERCP pancreatitis is unknown. AIM: Evaluate if the number or distribution (ie : ductal Vs. parenchymal ) of EUS features of pancreatitis ( parenchymal : foci, lobularity, stranding, cysts, and ductal : duct irregularity, hyperechoic margins, dilatation visible side-branches calcification/stone) are associated with the incidence of post-ERCP pancreatitis. METHOD: Consecutive patients who underwent EUS prior to ERCP at MUSC between 2/94 and 11/99 were evaluated. Patients who had an incomplete EUS, pancreatic cancer or prior pancreatic duct therapy (surgical or endoscopic), were excluded. Univariate analyses were performed to evaluate for any relationship between PEP and individual or groups of features seen on EUS. A multivariate analysis was also performed to include the influence of interventions performed during ERCP. RESULTS: Data from 509 patients (mean age 46 yrs. range 13-84 yrs., M/F: 153/356) were analyzed. PEP occurred in a total of 40 (8%) patients. The incidence of PEP in patients with >4 EUS features was 8% (22/275), and 8% (18/234) in those who had 5 EUS features compared to 7% (23/315) those with