Noninvasive in vivo assessment of the pancreatic microcirculation: orthogonal polarization spectral imaging.
BACKGROUND
Capillary perfusion failure of the pancreatic microcirculation is characteristic in the pathogenesis of acute pancreatitis and ischemia-reperfusion damage after pancreas transplantation. Up to now, no logistic suitable method for analyzing pancreatic capillary perfusion during operations in humans has been established without the use of fluorescent dyes.


OBJECTIVE
To compare the well-established technique of intravital epifluorescence microscopy with the novel noninvasive method of orthogonal polarization spectral (OPS) imaging for measurement of the pancreatic functional capillary density.


METHODS
In eight anesthetized rats, six identical capillary regions of interest per animal were measured by both methods, and the results were compared.


RESULTS
Absolute values from the capillary perfusion data were not significantly different between the two methods (fluorescence microscopy: 394 +/- 44 cm/cm2; OPS imaging: 385 +/- 45 cm/cm2). Correlation parameters were significant, and Bland-Altman analyses showed good agreement with a mean difference (bias) between the two methods of 6.9 cm/cm2, indicating that slightly smaller values are measured with OPS imaging.


CONCLUSIONS
OPS imaging is a valid noninvasive method that analyzes the pancreatic microcirculation as accurately as the established intravital microscopy technique and therefore could be useful for clinical research and diagnosis during transplantation and operations.
von Dobschuetz
E
E
Department of General and Visceral Surgery, Albert-Ludwigs-University, Freiburg, Germany. ernst@von-dobschuetz.de
Biberthaler
P
P
Mussack
T
T
Langer
S
S
Messmer
K
K
Hoffmann
T
T
D000818:Animals; D002196:Capillaries / Q000502:physiology; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016014:Linear Models; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008856:Microscopy, Fluorescence / Q000379:methods; D008859:Microscopy, Polarization / Q000379:methods; D010179:Pancreas / Q000098:blood supply*; D051381:Rats; D017207:Rats, Sprague-Dawley