Wireless capsule colonoscopy

Wireless capsule colonoscopy

"3412 WIRELESS CAPSULE COLONOSCOPY Eitan Scapa, Gavriel Meron, Arkady Glukhovsky, Daniel Gat, Harold Jacob, Reuven Shreiber, Given Imaging LTD, Yoqnea...

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"3412 WIRELESS CAPSULE COLONOSCOPY Eitan Scapa, Gavriel Meron, Arkady Glukhovsky, Daniel Gat, Harold Jacob, Reuven Shreiber, Given Imaging LTD, Yoqneam Israel; Mark N. Appleyard, Paul Swain, Royal london Hosp, London United Kingdom Background: Wireless capsule endoscopy has the potential to deliver video images of the colon. Slow transit, intermittent rapid movements, larger diameter lumen and capsule transmission times are challenges requiring study. Aim: To study colonic images received from experimental, human volunteer and clinical cases. To improve wireless capsule technology to image the human colon. Methods: Studies of colonic images from canine capsule endoscopies were reviewed. Human volunteer studies with (n=5) and without (n=27) colonic preparation were examined to review oral to caecal transit times and views of the colon were studied carefully. Clinical studies in n=32 patients were reviewed. Improvements in the capsule design to allow longer transmission times were tested. Results: The Given@Capsule studies in dogs frequently gave good views of mucosa and the vascular anatomy of the right colon. Foreign bodies: hair and ingested plastic were clearly identified by the capsule: In 27 human volunteer studies performed without colonic preparation interpretable images of the human colon were acquired, faecal material and some mucosal detail was seen in all 27 cases, under illumination was a problem in some cases. Oralcecal transit times were mean 229 rain (range 135-382 min, SD +/- 76). Oro-anal transit times were 18-48 hr. In 5 volunteers who took colonic preparation views of the right side of the colon were obtained. A lipid containing preparation prolonged gastric emptying to 5 hours in 1 subject, water-soluble preparations did not alter mean transit time. In a 37yr old patient with Hereditary Haemorrhagic Telangiectasia and a short oral cecal transit time (42 min) excellent colonic views from cecum to descending colon showed three telangiectasia in the right colon which were missed on previous colonoscopy. These were treated with bipolar eleetrocautery with clinical improvement. In another patient aged 26 with chronic diarrhoea several apthous ulcers were seen indicating Crohn s disease. Technical improvements in the capsule have prolonged transmission time. Improved efficiency allows the current capsules to transmit for 7-8 hours using only two silver oxide batteries. Experimental capsules with more batteries have lasted for 18 hours. Light adaptive capsules are being developed to overcome illumination problems. Conclusion: Wireless capsule colonoscopy is feasible and has already delivered valuable information in human patient studies. Further study and technical development is required to extend the range of the device and improve the images of the colon in patients.

"3414 METHOD FOR CONSTRUCTING THREE-DIMENSIONAL D'LTRASONOGRAPHIC DATA SETS TO DOCUMENT PATHOLOGY OF THE ESOPHAGUS USING VIDEOTAPES OF E N D O S C O P I C ULTRASOUND EXAMINATIONS Rideout J. David, Bruce P. Brown, Johlin C. Frederick, Hailer John, Wang Ge, Univ of Iowa Hospitals and Clinics, Iowa City, IA BACKGROUND: Endoscopic ultrasound (EUS)has become the standard method for evaluating pathology of the esophageal wall. However, threedimensional visualization, quantification, and documentation of the pathology seen during EUS examinations still remains subjective, most commonly relying on free-hand drawings constructed from the endoscopist's memory and static films after the procedure is performed. To obtain an accurate global record of pathology of the esophagus observed at EUS, we have developed methods for extracting three-dimensional ultrasonographic data sets of esophageal pathology from real-time videotapes of EUS examinations. METHODS/RESULTS: Esophageal examinations were recorded on standard one-half inch videotape at approximately 36 frames per second. During these examinations, the endoscope was advanced into the stomach and notation of the distance from the incisors was made as the starting point for one of three pull-back maneuvers. As the scope was slowly pulled back into the esophagus through the esophageal pathology, the distance of the scope tip from the incisors and the time oftravel for each centimeter of pull back was embedded onto the videotape frames. The best of three such pull-throughs was selected for processing. Knowing the time taken to travel each centimeter along the esophageal lumen, still frames of the videotape could be accurately located in space along the long axis of the esophageal lumen which was assumed to be the center of the scope. These frames were digitized using a frame-grabbing program (Ulead Video Studio, Ulead Systems Inc.) and the pathology, along with adjacent normal esophagus and aorta, were delineated and segmented. The data set, consisting of stacked frames of the segmented structures, was then transferred to an image analysis and reconstruction program (Analyze, Biomedical Imaging Resource, Mayo Clinic,Rochester, Minnesota) and the segmented structures were reconstituted into a three-dimensional data set delineating the pathology and its relation to normal remaining esophagus and the aorta which could then be viewed from any angle in space. CONCLUSION: We have developed methods for creating, extracting, and viewing three-dimensional ultrasonographic data sets from videotapes of endoscopic ultrasound examinations. These will allow more objective measurement, characterization, staging, and follow up of pathology of the esophagus.

"3413 DIODE LASER THERAPY COMBINED WITH INDOCIANINE GREEN FOR THE TREATMENT OF ESOPHAGEAL VARICES Shoryoku Hino, Hiroshi Kakotani, Keiiehi Ikeda, Kazuki Sumiyama, Yujiro Uchiyama, Akira Kuramochi, Koji Matsuda, Hiroshi Arakawa, Muneo Kawamura, Katsunori Masuda, Hiroaki Suzuki, Dept Endoscopy Jikei Univ Sch of Medicine, Tokyo Japan; Takuya Hayashi, Dept of Medical Engineering, Saitama Japan Background: Although Endoscopic Variceal Ligation (EVL) is an easy alternative to sclerotherapy, it has been suggested that the recurrence of variceal bleeding is higher than scleretherapy. To minimize the risk of further bleeding after EVL, we have combined diode laser therapy with paravariceal injection of indocyanine green (ICG); this has a peak absorption wavelength around 805nm, similar to wavelength of light emitted by the diode laser. Low dose diode laser irradiation after submucosal injection of ICG enhances the tissue absorption of energy selectively around varices without vaporization of overlying tissue; it prevents deep penetration of the beam and minimize the risk of perforation. Alms: To investigate the efficacy and safety of this technique, a prospective study was carried out with prior informed consent. Patients and methods: Eight patients with esophageal varices were enrolled. All the patients had esophageal varices showing F2 (moderate) to F3(severe) in size. A diode laser (DIOMED25, Olympus) and a non-contact laser probe (DL6O60,Olympus) were used. At the first session, EVL was performed. A week later, ICG solution(1 mg/ml) was injected submucosally around the remaining varices. Diode laser was applied circumferentially to the mucosa for a distance of 5cm from esophagogastric junction, with the power of a 10watt (spot size 5mm in diameter). All patients were followed up after treatment for more than 12 months. Results: Laser irradiation was safely performed without acute variceal bleeding. There was no perforation. The number of sessions was 2 I1 for EVL, 1 for laser) in all the parients.1 month later, ensoscopy showed F0 in form in 7 patients and F1 in 1 patient; red color sign was absent in all the patients. Follow up period ranged from 12 to 46 (mean 32 ± 12) months. Recurrence of varices has net been observed during these period in any of patients. There were no significant complications. Transient pyrexia was observed a day after surgery in 2 patients and I patient developed mild dysphagea which resolved after two balloon dilatations. Conclusion: This technique may be a simple, safe and effective method of preventing a recurrence of esophageal varices after EVL.

"3415 FLOW CYTOMETRY (FACS) OF TISSUE OBTAINED BY E N D O S C O P I C ULTRASOUND-GUIDED FINE-NEEDLE BIOPSY (EUS-FNA) AID IN THE DIAGNOSIS OF LYMPH NODE TUMORS Stephan H. Hollerbach, Ulrich Graeven, Inga Wilhelms, Wolff H. Schmiegel, Ruhr Univ Bochum, Boehum Germany Background: Progress in the development of endoscopic ultrasound- guided fine-needle biopsy techniques (EUS-FNA) enabled the gastroenterologist/'or the first time to obtain tissue specimens from small periesophageal and perigastric tumors preoperatively such as lymphomas and metastases. Cytologic differentiation of lymphoid lesions obtained by fine-needle specimens, however, can be exceptionally difficult, while diagnosis of epithelial tumors is fasible and can be successfully performed in most cases, Thus, we investigated whether Flow- cytometry (FACS) techniques are helpful in this setting, particularly when lymphoma was suspected. Methods: In 40 patients with suspected Non-Hodgkin lymphoma (NHL) of mediastinal/abdominal lymph nodes or lymph node metastasis (lung cancer), EUS-FNA of mediastinal and perigastric tumors was performed by using the HITACHI FG34-UX echoendoscope and a 22 G needle. Tissue specimens were submitted for standard cytology and FACS analysis (n=40). FACS was analyzed for cellularity, light chain restriction (~ and k chains) and presence of cytokeratin. Surgically excised lymph nodes and/or large CT-guided tumor biopsies were used for reference. Results: Sufficient tissue specimens could be obtained in 37 out of 40 patients (93%). On average, 2.2 needle passes were necessary to obtain enough tissue material. Final diagnosis in all patients was NHL, lymph node metastasis of lung cancers, and benign lymphadenopathy. The sensitivity of EUS-FNA with FACS (light chain restriction) was 70% with a specificity of 91%, a positive predictive value (PPV) of 78%, and a negative predictive value (NPV) of 88%, while cytology alone reached a sensitivity of only 46% for lymphomas. In contrast, FACS analysis for cytokeratin markers in epithelial tumors was not helpful due to a relatively high rate of false positive findings, while cytology yielded a sensitivity of 80% for diagnosis of epithelial lymph node metastasis with a specificity of 100%. Conclusions: In patients with mediastinal or abdominal lymph node tumors, FACS analysis of light-chain restriction supports the tissue-based preoperative diagnosis in NonHodgkin lymphoma, whereas cytology alone has a low diagnostic yield for a definitive diagnosis in NHL. Further immunologic and molecular tumor markers should be evaluated to improve the diagnostic accuracy of EUSFNA.

VOLUME 53, NO. 5, 2001

GASTROINTESTINAL ENDOSCOPY

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