T. Kraus et al., CONTINUOUS MEASUREMENT OF PORCINE RENAL-CORTEX MICROCIRCULATION WITH ENHANCED THERMAL-DIFFUSION TECHNOLOGY, The Journal of surgical research, 61(2), 1996, pp. 531-536
Continuous monitoring of renal cortical blood how (RCBF) in the periop
erative setting of aortic or renal vascular surgery could faciliate th
e early detection of vascular complications, possibly resulting in a r
eduction of postoperative renal failure. A new prototype system for me
asurement of parenchymous organ perfusion based on the principle of th
ermal diffusion (''TD''-Thermal Diffusion Electrode, Thermal Technolog
ies Inc., Cambridge, MA, USA) was used for RCBF measurements in the ou
ter cortex of the porcine kidney. We validated the sensitivity of the
device to detect renal blood flow impairment, comparing TD flow data w
ith renal artery blood flow values (RABF), measured by ultrasonic how
probes. The hypothesis was tested that acute disturbances of RCBF, ind
uced by a variable degree of renal artery stenosis, can be immediately
detected and continuously monitored by TD measurements in the porcine
renal cortex. Mean baseline RCBF measured by TD electrodes was 68.1 /- 25.0 ml/100 g/min. Mean baseline RABF was 102.1 +/- 26.6 ml/min. Co
ntrolled induction of a variable degree of renal arterial occlusion by
implanted vascular balloon occluders was always followed by an immedi
ate and proportional decline of RCBF, as measured by TD. Flow data obt
ained with both methods were significantly correlated by linear regres
sion (r = .82, r(2) = .68; P < 0.0001). Dynamic changes of RABF in the
time course of renal artery partial/total occlusion and arterial flow
release could be continuously followed by detection of corresponding
flow changes of RCBF. We conclude that the TD system investigated in t
he current study allows a continuous and sensitive determination of po
rcine renal cortex perfusion. A clinical evaluation of the method, e.g
., in the perioperative setting of aortic or renal transplantation sur
gery, now appears to be justified. (C) 1996 Academic Press, Inc.