Assessment of renal oxygenation during partial nephrectomy using hyperspectral imaging

Area of Science:

• Nephrology
• Surgical Oncology
• Medical Imaging

Background:

• Renal perfusion and oxygenation monitoring is crucial during partial nephrectomy.
• Current methods for assessing intraoperative renal oxygenation are limited.

Purpose of the Study:

• To evaluate the utility of DLP® hyperspectral imaging (HSI) for real-time, noninvasive assessment of renal hemoglobin saturation during open partial nephrectomy.
• To establish HSI as a tool for monitoring kidney oxygenation during hilar occlusion and recovery.

Main Methods:

• Intraoperative hyperspectral images were acquired using visible light (520-645 nm) during open partial nephrectomy in 21 patients.
• Spectroscopic reflectance images were processed to create pixel-by-pixel maps of oxyhemoglobin percentage.
• The technique assessed renal hemoglobin saturation parameters during hilar occlusion and reperfusion.

Main Results:

• HSI was performed in 21 patients undergoing partial nephrectomy (mean age 56 years; mean clamp time 37.0 min).
• Median baseline oxyhemoglobin was 74.6%. A median 20.0% decrease was observed within 10.3 minutes of hilar occlusion, plateauing during ischemia.
• Oxyhemoglobin levels returned to baseline within a median of 5.8 minutes after reperfusion.

Conclusions:

• Hyperspectral imaging provides a real-time, noninvasive method for intraoperative assessment of renal oxyhemoglobin saturation.
• A nadir in renal oxyhemoglobin occurs within 10 minutes of hilar occlusion.
• This technology may enable real-time surgical or pharmacological interventions to minimize ischemic injury.