Real-time monitoring of spinal cord blood flow with a novel sensor mounted on a cerebrospinal fluid drainage catheter in an animal model.
OBJECTIVE
The aim of our study was to develop a novel monitoring system for spinal cord blood flow (SCBF) to test the efficacy of the SCBF sensor in an animal model.


METHODS
The sensor system consisted of 2 optical fibers, a pedestal for fiber fixation, and a mirror for the laser reflection and was incorporated into a cerebrospinal fluid drainage catheter. In vivo studies were performed in a swine model (n=10) to measure SCBF during spinal cord ischemia induced by clamping the descending thoracic aorta and supra-aortic neck vessels, when necessary. A temporary low cardiac output model was also created by inflow clamping of the inferior vena cava to analyze the quantitative changes in SCBF during this maneuver.


RESULTS
The developed SCBF monitoring catheter placed intrathecally could detect SCBF in all the swine. The SCBF after aortic crossclamping at the fourth intercostal level exhibited diverse changes reproducibly among the swine, with a >25% reduction in SCBF in 5 pigs, an increase in 3, and no significant changes in 2. Consistent reductions were recorded during inferior vena cava occlusion. The mean SCBF decreased by 32% after inferior vena cava occlusion when the cardiac output had decreased by 27%.


CONCLUSIONS
We have developed a novel SCBF sensor that could detect real-time changes in spinal cord perfusion in a swine model. The device holds promise to detect imminent ischemia or ensure acceptable blood perfusion in the spinal cord and could further enhance our understanding of spinal cord circulation.
Department of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Miyagi, Japan.
Yukihiro
Y
Hayatsu
Department of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Miyagi, Japan.
Shunsuke
S
Kawamoto
Micro System Integration Center, Tohoku University, Miyagi, Japan.
Tadao
T
Matsunaga
Tohoku University Graduate School of Biomedical Engineering, Miyagi, Japan.
Yoichi
Y
Haga
Department of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Miyagi, Japan. Electronic address: yoshisaiki@med.tohoku.ac.jp.
Yoshikatsu
Y
Saiki
D000818:Animals; D003250:Constriction; D004195:Disease Models, Animal; D004322:Drainage; D005336:Fiber Optic Technology; D006439:Hemodynamics; D017078:Laser-Doppler Flowmetry; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011183:Postoperative Complications / Q000517:prevention & control; D012039:Regional Blood Flow; D013116:Spinal Cord / Q000098:blood supply*; D020760:Spinal Cord Ischemia / Q000134:cerebrospinal fluid*; D013552:Swine