Publications by authors named "John Fengler"

Background: Intraoperative ureteral injury, a serious complication of abdominopelvic surgeries, can be avoided through ureter visualization. Near-infrared fluorescence imaging offers real-time anatomical visualization of ureters during surgery. Pudexacianinium (ASP5354) chloride is an indocyanine green derivative under investigation for intraoperative ureter visualization during colorectal or gynecologic surgery in adult and pediatric patients.

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Considerable advances in cancer-specific optical imaging have improved the precision of tumor resection. In comparison to traditional imaging modalities, this technology is unique in its ability to provide real-time feedback to the operating surgeon. Given the significant clinical implications of optical imaging, there is an urgent need to standardize surgical navigation tools and contrast agents to facilitate swift regulatory approval.

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We evaluated diffuse reflectance spectroscopy implemented as a small field-of-view technique for discrimination of dysplasia from metaplasia in Barrett's esophagus as an adjuvant to autofluorescence endoscopy. Using linear discriminant analysis on 2579 spectra measured in 54 patients identified an optimum a 4-wavelength classifier (at 485, 513, 598 and 629 nm). Sensitivity and specificity for a test data set were 0.

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Background And Objectives: In autofluorescence endoscopy, the difference in the fluorescence of intrinsic fluorophores is imaged to help visualize pre-malignant lesions, as in the system evaluated here. In this, blue light is used for excitation and the green autofluorescence is normalized by the red diffuse reflectance and presented using a false color scale. The present study was designed to quantify the degree of fluorescence photobleaching induced by the excitation light during use in the colon, since significant photobleaching could lead to false interpretation of the images, particularly false-positive lesions.

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