MEASUREMENTS OF TISSUE OXYGEN-TENSION IN VASCULARIZED JEJUNAL AUTOGRAFTS IN PIGS

Tissue oxygen measurements were evaluated as a monitor of the jejunal flap in seven female landrace pigs. A small polarographic sensor (diam eter 0.55 mm) was used in which interstitial tissue oxygen tension was measured continuously in a jejunal flap and a muscle flap (rectus abd ominis) during arterial and venous occlusion. Mean (SEM) tissue oxygen tension in the two types of flap were 44(9) mmHg (jejunal flap) and 4 7(8) mmHg (rectus flap). After arterial occlusion for 30 minutes the v alues dropped to 17(4) mmHg for the jejunal flap and 12(2) mmHg for th e muscle flap. The decline became significant after five minutes. Duri ng venous occlusion (30 minutes) the values fell to 20(4) mmHg and 14( 1) mmHg. The arterial occlusion was undetectable by the naked eye, but the enteric tissue after venous occlusion became severely congested a nd blue-black in colour. The condition returned to normal after releas e of the clamp. We conclude that direct measurement of tissue oxygen t ension in a jejunal flap is a reliable method of detecting impaired pe rfusion. This method may in the future be used to monitor vascularised jejunal autografts.