Gynecologic surgery requires the clamping, cauterization, and transection of arteries that lie within mil- limeters of the ureter, posing significant potential risk for ureteral injury. By leveraging the optical absorption properties of hemoglobin and methylene blue (an FDA-approved contrast agent), we propose intraoperative pho- toacoustic imaging during hysterectomies to simultaneously visualize the uterine arteries and ureter, respectively. Three experiments were performed to test the feasibility of a spectroscopic system aimed at intraoperative visual- ization. At 690 nm, the contrast from blood and urine mixed with 200 uM methylene blue was 13.83 dB and 11.06 dB, respectively, representing a 2.77 dB contrast difference. Conversely, at 750 nm, the contrast from blood was similar (14.61 dB), and the contrast from urine mixed with 200 uM methylene blue decreased to 1.74 dB, which produced a greater contrast difference of 12.87 dB. When tissue was added, similar contrast differences were observed at these wavelengths. Finally, a laparoscopic tool was additionally visualized in real time in proximity to the ureter and uterine arteries, which supports the feasibility of a spectroscopic photoacoustic approach to differentiating the ureter from the uterine arteries in relationship to a laparoscopic tool during hysterectomies.

Date Published: 27 February 2019
PDF: 7 pages
Proc. SPIE 10878, Photons Plus Ultrasound: Imaging and Sensing 2019, 108785K (27 February 2019); doi: 10.1117/12.2510716

Published in SPIE Proceedings Vol. 10878:
Photons Plus Ultrasound: Imaging and Sensing 2019
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)