[Studies on the prediction of intestinal recovery from ischemic injury by fluorescein fluorescence patterns]

Methods for the prediction of intestinal recovery from ischemic injury were evaluated in highly reproducible model of segmental intestinal strangulation in the rat. Systemic variables were minimized and survival was maximized by parenteral administration of antibiotics and nutrient solution, so that necrosis or recovery of the segment itself, not the rat, could be used as an endpoint of experiments. Recovery of ischemic intestine was assessed by two methods: Standard clinical criteria (color, peristalsis, pulsation.) Fluorescence after intravenous fluorescein injection. Findings were compared with ultimate viability assayed by histologic examination of each segment removed 48 hours after release of strangulation. Five distinctive patterns of fluorescein fluorescence were identified, two of which (normal pattern and fine granular pattern) reliably predicted survival of the segment, and two of which (perivascular pattern and no fluorescence) predicted subsequent necrosis. A fifth, coarse granular pattern usually, but not always, predicted non-recovery. Standard clinical criteria were relatively insensitive and could not be relied upon to detect nonviable segments. The fluorescein fluorescence method correctly identified all nonviable segments at the expense of an acceptably low overall false positive rate. This study suggests that the fluorescein methods is the method of choice for the prediction of small intestinal recovery following ischemic injury.