Assessment of perfusion of free flaps used in head and neck reconstruction using pulsatility index

To detect venous or arterial obstruction in the pedicle of a free flap we can monitor resistance in the flap bed which is reflected in Pulsatility Index (PI) Therefore if we detect change in the values of the PI in these flaps then we can detect complications in flap due to vascular insufficiency early.

Seven patients of Free Fibular Flap Reconstruction and ten patients of Free Radial Forearm Flap reconstruction were evaluated over a period of 18 months. In the pre op we recorded PI of Radial and Peroneal artery using colour doppler study. In the Post Operative Period 2 readings of PI at the anastomotic site were taken on Day 1 and Day 7.

Both Free Radial Forearm and Free Fibula flaps which were healthy (n = 15) showed a significant decrease in PI values on first Post Op day as compared to Pre Op. Also there was a significant fall in PI on Post Op Day 7 as compared to post op Day 1 (P < 0.05) in these flaps. The flaps developing complications (n = 2) had significantly higher Day 1 Post op PI readings as compared to healthy flaps (P < 0.05).

PI is an objective index which can indicate changes in perfusion of free flaps used in Head and Neck reconstruction based on which we can predict if a flap is susceptible to circulatory compromise.