by serial balloon dilations were implemented to successfully manage this stricture. The finalpatient sustained a caustic oropharyngeal injury resulting in a proximal esophageal stricturerefractory to reconstructive surgery and multiple attempts at stenting. By combining CARDwith APC and needle knife dissection, the patient's stricture was successfully recanalizedand patency was maintained. Conclusions: Occlusive esophageal strictures pose a difficultchallenge to gastroenterologists and little has been reported with regards to their management.Using the CARD technique, needle knife dissection and APC, individually or in combination,luminal patency of occlusive esophageal strictures can be accomplished.

Fluoroscopy of strictured esophagus.

Esophageal patency achieved after CARD. A view from the stomach.

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Contrast Enhanced Endoscopic Ultrasound is a Helpful Tool to DifferentiateGastrointestinal Stromatumors From Benign LesionsKlaus Kannengiesser, Reiner Mahlke, Frauke Petersen, Torsten F. Kucharzik, ChristianMaaser

Since its introduction endoscopic ultrasound (EUS) has shown to be a helpful tool inendoscopic diagnostics, allowing precise detection of not only pancreatic masses, but alsoevaluation of esophageal, gastric and biliary lesions, while differentiation of benign andmalignant lesions remains difficult. Gastric lesions with suspicion of gastrointestinal stromatu-mors (GIST) or benign lesions like lipoma or leiomyoma can often not be accurately differenti-ated by just using endoscopic ultrasound therefore requiring tissue sampling from thesubmucosal tissue after needle insertion with the risk of bleeding side effects especially inGIST. Contrast enhanced ultrasound has been used for several years in transabdominalultrasound and proofed to be effective in discriminating various lesions e.g. in the liverthrough their blood perfusion characteristics. As with the newest generation of endoscopicultrasound machines contrast enhanced harmonic endoscopic ultrasound (CEH-EUS) hasbecome a new option the aim of our study was to evaluate whether CEH-EUS may help todiscriminate various gastric/esophageal lesions. Methods: 10 patients with suspicious gastricor esophageal lesions where investigated with CEH-EUS after standard EUS procedures.Patients received 5 ml contrast agent (SonoVue, Bracco, Inc.) followed by a 10 ml salineflush. Ultrasound sequences were documented as a video file and perfusion characteristicsdetermined immediately after investigation. Samples from EUS-fine needle aspirates, biopsysamples from the submucosal tissue after needle cut or surgical specimen, where applicable,served as gold standard. Results: CEH-EUS showed 5 lesions with reduced contrast enhance-ment (maximum intensity 6 ± 4db) and 5 lesions with hyperenhancement (maximumintensity 50 ± 20db). The latter 5 lesions where all histological identified as GIST andsurgically removed, while the 5 hypoenhanced lesions emerged to be 1 lipoma and 4leiomyoma. In 2 out of 5 patients presenting with a GIST a bleeding complication appearedfollowing submucosal tissue sampling requiring endoscopic treatment. Conclusion: CEH-EUS in our hands could discriminate GIST from benign lesions with good accuracy in thissmall set of patients. If these results can be confirmed in a larger patient population thefollowing treatment algorithm might be applied: Gastric wall lesion with hyperenhancementcan be send directly for resection without prior biopsy sampling, hypoenhanced solid lesionscan either be further classified by tissue sampling or just controlled by endosonographyduring follow-up.

S-753 AGA Abstracts

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Contrast Enhanced Endoscopic Ultrasound Helps Distinguish PancreaticAdenocarcinoma From Other Malignant Pancreatic LesionsKlaus Kannengiesser, Reiner Mahlke, Frauke Petersen, Torsten F. Kucharzik, ChristianMaaser

Endoscopic ultrasound (EUS) has become a standard diagnostic tool for staging pancreaticlesions. As hypoechogenicity is not a soul sign of pancreatic adenocarcinoma but e.g. is alsoseen for neuroendocrine carcinoma as well as for metastasis one usually has to performEUS-guided fine needle aspiration with all its limitations in order to decide which form oftreatment to choose. Contrast enhanced ultrasound has been used for several years intransabdominal ultrasound and proofed to be effective in discriminating different lesionsespecially in the liver looking at the blood perfusion characteristics. As with the newestgeneration of endoscopic ultrasound machines contrast enhanced harmonic endoscopicultrasound (CEH-EUS) has become a new option the aim of our study was to evaluatewhether CEH-EUSmay help to discriminate pancreatic adenocarcinoma from other malignantand non-malignant pancreatic lesions. Methods: Twenty consecutive patients with suspiciouspancreatic lesions where investigated with CEH-EUS after standard EUS procedures. Patientsreceived intravenously 5 ml contrast agent (SonoVue, Bracco, Inc.) followed by a 10 ml salineflush. Ultrasound sequences were documented as a video file and perfusion characteristicsdetermined immediately after investigation. Time intensity curves were calculated and com-pared to areas of normal appearing pancreatic tissue in the same individual. Samples fromEUS-fine needle aspirates of the suspicious lesions or surgical resections, where applicable,served as gold standard. Results: CEH-EUS showed 12 lesions with reduced contrast enhance-ment (intensity 8±4db), 8 lesions showed up hyper- or isoenhanced. 8 pancreatic adenocarci-nomas, proven by histology, showed up hypoenhanced. Hyperenhanced lesions (n=5, intens-ity 48±7db) included 3 neuroendocrine carinomas, 1 metastasis of a renal cell carcinomaand 1 lymphoma. Sensitivity regarding pancreatic adenocarcinomas was 100%, specificity75%. In 4 patients with chronic pancreatitis, chronic inflammatory masses showed up withreduced contrast enhancement, while 3 showed up isoenhanced. No malignancies in patientswith chronic pancreatitis were detected in this set of patients. Conclusion: CE-EUS hasshown to be helpful in the evaluation of suspicious pancreatic masses clearly differentiatingbetween pancreatic adenocarcinoma versus neuroendocrine/metastatic lesions. We thereforesuggest the following algorithm: An endosonographic hypoenhanced hypoechogenic pancre-atic lesion in otherwise normal appearing pancreatic tissue without contraindication forsurgery can be send for surgical therapy without prior histological evaluation while lesionsshowing hyperenhancement during CE-EUS should be further evaluated e.g. by EUS-fineneedle aspiration.

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I-Scan Technology is Useful to Improve the Rate of Gastric Varices Diagnosisin Patients With Portal HypertensionLucia Sparano, Gianluca Ianiro, Marialuisa Novi, Immacolata A. Cazzato, AntonioGasbarrini, Giovanni Cammarota

BACKGROUND Gastric varices (GVs) are common in patients with portal hypertension andgastric variceal bleeding is associated with high mortality and morbidity rates. GVs mayappear similar to enlarged gastric folds and submucosal lesions at standard endoscopy. Asimple endoscopic method to diagnose GVs could be clinically useful. I-scan technology (I-ST) from PENTAX is a newly developed endoscopic tool that utilizes a digital contrastmethod to enhance endoscopic image in real time. MATERIALS AND METHODS Forty-threepatients with documented history of portal hypertension, prospectively recruited, underwentupper endoscopy for evaluation of esophageal and gastric varices. All examinations wereperformed by a single endoscopist with high experience in the standard evaluation ofesophageal and gastric varices and in the use of I-ST for the assessment of esophageal varices.Each patient was evaluated, during endoscopy, by using standard view before switching toI-ST . RESULTS Standard endoscopy revealed the presence of GVs in 4 patients of 43 (9,3%).Using I-ST, GVs were detected in 12 patients of 43 (27,9%). The four cases of GVs diagnosisat standard endoscopy were confirmed by I-ST. CONCLUSIONS Our results demonstratethat I-ST is a simple and useful method able to significantly improve the rate of GVs diagnosisin patients with portal hypertension. However, more investigations are necessary in a largernumber of subjects to confirm these preliminary results and to determine the real clinicalutility of this technology.

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Colonic Darkness: Seeing in a New Light?James Cullis, Ramesh P. Arasaradnam, Nigel R. Williams, Karna D. Bardhan, AdrianWilson

Introduction We observed by chance that PET scans showed areas of darkness in thecolon, signifying uptake of the radiopharmaceutical 18F-fluoro-deoxy glucose (FDG). Thephenomenon is well recognised by radiologists who accept this as an occasional backgroundevent but it is regarded as without significance. This pilot investigation assessed how frequentFDG uptake is observed in the colon, and its anatomical distribution. Methods 30 patientsinvestigated by PET-CT for head and neck tumours were selected at random from patientsstudied over the past three years provided the reports referred to either “no abdominalabnormality” or “normal physiological uptake”. Five observers independently scored uptakeusing a visual analogue scale from 0-5, where in each patient 5 was assigned to the segmentwith the maximum uptake, i.e. the score was normalised to an individual rather than tothe whole cohort. Scores were generated for 4 segments: caecum (C) + ascending colon(AC); transverse colon (TC); descending colon (DC); sigmoid and rectum (SR). Where nouptake was apparent anywhere, all segments were scored 0. Quantitative analysis in a subsetof 10 was done to determine uptake in each segment. This was expressed as a percentageof total colonic uptake, both with and without normalisation to segmental length. Results1. Qualitative analysis showed differences in uptake scores between the segments, with DCand C+AC having the highest uptake. 2. All observers commented on the high incidence

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