Hyperspectral Imaging Assesses Intra-Op Hemoglobin Saturation

Real-time, noninvasive method to assess renal hemoglobin saturation during kidney surgery

FRIDAY, Aug. 5 (HealthDay News) -- DLP Hyperspectral imaging (HSI) serves as a fast, noninvasive method to assess renal hemoglobin saturation parameters intraoperatively, according to a study published in the August issue of The Journal of Urology.

Michael S. Holzer, M.D., from the University of Texas Southwestern Medical Center in Dallas, and colleagues evaluated the use of HSI to assess renal hemoglobin saturation parameters in 21 patients (mean age, 56 years) undergoing open partial nephrectomy for renal cortical tumors. The hyperspectral camera illuminated the kidney using visible light consisting of a chemometrically predetermined spectrum (520 to 645 nm) for hemoglobin. A focal plane array captured the spectroscopic reflectance images. Digital processing of these images enabled the visualization of the percent of oxyhemoglobin at each image pixel.

The investigators found that the mean clamp time was 37.0 minutes and the median baseline percent of oxyhemoglobin in all patients was 74.6 percent. Compared to the normalized preocclusion baseline, HSI showed a median decrease of oxyhemoglobin of 20 percent at a median 10.3 minutes of hilar occlusion. This leveled off for the duration of renal ischemia and returned to baseline at a median of 5.8 minutes upon reperfusion.

"Hyperspectral imaging is a real-time noninvasive method to assess renal oxyhemoglobin saturation intraoperatively throughout the kidney. A nadir percent of oxyhemoglobin is attained within 10 minutes of hilar occlusion. This knowledge may allow future surgical or pharmacological interventions that titrate or minimize ischemic injury in real time," the authors write.

Several authors disclosed financial ties to the medical device industry, including Texas Instruments.

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