Experimental model to estimate intestinal viability using charge-coupled device microscopy.

Abstract

Intraoperative assessment of intestinal viability following release of strangulation remains difficult. The aim of this study was to establish clinical standards for the evaluation of intestinal viability by charge-coupled device (CCD) microscopy. A rat ileus model with strangulation for between 15 and 120 min was used. The images obtained by CCD microscopy were used to calculate maximum velocity (V (max)) ratio (ratio of V (max) of blood cell transition in the experimental segment to that in the reference segment) and S ratio (the ratio of S-the effective area of the vascular bed against the total area of the vascular bed-in the experimental segment to that in the reference segment). Rats were divided into group 1, comprising animals that survived for 7 days or more, and group 2, which consisted of animals that died within 4 days. V (max) ratio and S ratio in group 1 were both significantly higher than those in group 2 (P < 0.01). No death occurred at a V (max) ratio of 0.76 or higher and an S ratio of 0.61 or more, while there were no survivors with a V (max) ratio of 0.54 or less and an S ratio of 0.51 or less. V (max) ratio and S ratio could be used as indices for evaluation of intestinal viability.