The recovery of intestine after ischaemic injury.

A reproducible model of reversible segmental ischaemia was used to evaluate methods of predicting intestinal viability after the release of strangulation. Visual assessment in the immediate period after reperfusion and at "second-look' 24 hours later was inaccurate in identifying recoverable bowel. A Doppler probe used to detect the return of pulsatile blood flow was overpredictive of necrosis. The pattern of surface fluorescence after injection of the supravital dye fluorescein increased the accuracy of predicting intestinal recovery. A series of silicone rubber injections was carried out to investigate whether the patency of the microvessels influenced the outcome. It was shown that as the ischaemic period increased there was progressive failure of the microcirculation. It was concluded that the fluorescein injection test correctly identifies recoverable bowel and that the outcome after ischaemic injury is related to microvascular patency.