Myoelectric assessment of large bowel viability: an experiment in dogs

Objective: To design a device for myoelectric assessment of intestinal isch aemia and compare it with every day surgical experience and Doppler signals recorded on the bowel wall. Design: Experimental study. Setting: Thessaloniki university hospital, Greece. Material: 12 adult mongrel dogs. Interventions: On the first day the large intestine was devascularised fora length of 20 cm, 5 cm away from the ileocaecal valve, and the threshold of the electric stimulus (mA) required to produce a contraction of the normal large bowel was recorded. On the second day, measurements were made on the ischaemic segment of the large bowel at 0.5 cm intervals. Bowel resection and anastomoses were done at the stimulus level of 40 mA. Results: The mean (SD) stimulus threshold of the normal large intestine was 12.2 mA. The necrotic intestine demanded current stimulus of 100 mA or fai led to contract. On the eighth postoperative day the animals were killed to assess anastomotic healing. Of the 12 anastomoses made at the 40mA stimulu s point, only one ruptured. The 40mA limit of the stimulus level seems to b e of value in assessments of bowel viability in vivo. Conclusion: The use of a personal computer as a read out device makes myoel ectric analysis easier and more reliable in the assessment of intestinal vi ability. This method may have a clinical application.