Objective: To compare photoplethysmography and Doppler ultrasonography in the prediction of the viability of experimental jejunoileal anastomoses in the presence of arterial (n = 11), venous (n = 11), and mixed arterial and venous (n = 9) segmental ischaemia.
Design: Experimental open study.
Material: 31 Mongrel dogs.
Interventions: Laparotomy, selective devascularisation, and anastomosis. In 20 of the experiments a bolus injection of papaverine was given into the superior mesenteric artery. Second laparotomy on day 15, or earlier if indicated.
Outcome measures: Correlation between photoplethysmography, Doppler ultrasonography, and macroscopic and histological findings.
Results: All non-viable anastomoses had photoplethysmographic wave amplitudes of less than 10% of the control value, with sensitivity and specificity of 100%. Venous volume and maximum venous outflow had a sensitivity of 72% and a specificity of 77%. Doppler ultrasonography had a sensitivity of 100%, but a specificity of only 67%. Papaverine had no effect on photoplethysmographic wave amplitude in these experiments.
Conclusion: Photoplethysmography is the preferred method of assessing intestinal viability in the presence of ischaemia.