Operative assessment of intestinal viability

Acute intestinal ischemia and infarction remain serious clinical problems despite early operative intervention. Accurate intraoperative assessment of intestinal viability is essential in determining the limits of resection in patients with intestinal infarction. Clinical features of bowel viability such as color and peristalsis do not correlate uniformly with bowel survival, and as a result, several techniques have been developed to assess intestinal blood flow at the time of operation. The requirements of an ideal viability test are: 1. The technique must have ready availability, preferably in every operating theater dealing with abdominal emergencies. 2. The necessary equipment must not be cumbersome or require specialized personnel. 3. The method must be accurate with a minimum of false-negative results and, more importantly, few false positives. A false-negative results leaves in situ nonviable bowel, which may lead to early perforation and late stricturing. This situation may be recoverable with further surgical intervention, however. On the other hand, a false-positive assessment of bowel viability results in the resection of potentially recoverable intestine, which is lost forever and may represent a vital difference for morbidity-mortality and long-term nutrition. 4. The technique must be objective and be reproducible. 5. The method must be cost effective. To date, only two tests have found widespread acceptance and clinical applicability: fluorescein assessment and Doppler studies either with ultrasound or as refined in laser velocimetry. Although other techniques may be of some value today or in the future, the most practical approach would appear to be to use fluorescein assessment under a modified Wood's lamp as the initial method of evaluating intestinal viability and either Doppler ultrasound or perfusion fluorometry for any areas of particularly doubtful viability.