الفهرس 
Cover EnglishOnly 14 pages are availabe for public view
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Abstract
The most feared complication of laparoscopic cholecystectomy is injury of the axial bile ducts. Avoidance of this complication requires their adequate visualization at surgery. Though there are multiple methods that help surgeons localize these ducts, there is still need for more. This work aimed at the study of a new technology and device that were intended to augment duct visualization at surgery. This technique depends on ultraviolet A excitation of fluorescein sodium that reaches bile ducts either by excretion of the intravenously-administered or the directly injected material in the gallbladder to produce green fluorescent light.The theoretical bases behind the two components of the new technology were discussed. Physical properties, sources and potential dangers of ultraviolet light were reviewed, and so were those of fluorescein sodium and its biochemical features. The founding animal experiments upon which this technology rested and the steps of device development were presented.The clinical study involved 40 laparoscopic cholecystectomies where UV-A was cast on the area that was expected to contain the axial bile ducts. Neutral surgeons/observers were asked to comment on whether they were able to localize these ducts by virtue of their intense green fluorescence before they were displayed by dissection under white light, or not.Assessment of the accuracy of the technique in localizing bile ducts was carried out following the standard methods of evaluating new diagnostic procedures. Specificity was 100% and positive predictive value was 100%, which meant that if a fluorescent structure is detected in the field under UV-A, the surgeon would be confident that it is actually a bile duct. On the other hand, at seven operations fluorescence could not be seen by the observers producing a sensitivity of 82.5%, negative likelihood ratio of 0.18, and negative predictive value of 85.11%. The possible cause and solutions for negative results were discussed. Ultraviolet light A at the used dose and fluorescein are theoretically safe and recognized for use in humans. In fact, the use of the device produced no complications during the study. The cost of manufacturing the device on non-commercial basis and the running cost were estimated to be far below parallel methods. Its use was easy and without any cumbersome equipment or lengthy setup in the operating room.In conclusion, the new technology and device are highly reliable when fluorescent ducts are seen. The technique is safe, economical and easy to apply. It, however, requires refinements to improve its sensitivity, particularly at difficult cholecystectomies.