INTRACAPILLARY HEMOGLOBIN OXYGENATION AND INTERSTITIAL PO(2) IN VENOUS FLAPS - AN EXPERIMENTAL-STUDY IN RATS

In order to be able to objectively evaluate capillary perfusion of ven ous flaps, we created arterialised venous flaps, venous flow-through f laps, and unilateral pedicled venous island flaps in the epigastric va scular system of Wistar rats and determined their oxygen supply with t wo different methods. Interstitial pO(2) was polarographically measure d with a probe placed in tracutaneously in the center of the 4 x 2.5 c m flaps and continuously recorded on a connected computer. Moreover, w e also noninvasively determined the oxygenation of the intracapillary haemoglobin with a micro-lightguide spectrophotometer. The statistical evaluation showed comparable results for both measurement methods: Ar terialised venous flaps had a better oxygen supply with a pO(2) of 16 mmHg and an Hb oxygenation of 23% than the other types of venous flaps , but they have a poorer oxygen supply than conventionally perfused fl aps (pO(2): 24 mmHg, Hb oxygenation: 30%). Venous flow-through flaps ( pO(2): 9 mmHg, Hb oxygenation: 17%) and unilateral pedicled venous isl and flaps had a significant better oxygen supply than skin flaps witho ut any vascular connection. The results show that the capillary system in all types of venous flaps is reached by some of the inflowing oxyg enated haemoglobin over the entire flap surface to different degrees. (C) 1998 Wiley-Liss, Inc.