Post-operative assessment of perfusion of Deep Inferior Epigastric Perforator (DIEP) free flaps via Pulsatility Index (PI) using a portable colour Doppler sonogram device

Introduction PI as an independent indicator of resistance to flow is a widely-accepted alternative index to measurement of flow volume in vessels. This study aimed to determine the normal values and chronological trend of PI of abdominal wall free flaps in breast reconstruction and to revalidate its clinical relevance in post-operative monitoring of these flaps. Materials and methods 47 patients with breast reconstruction using DIEP, MS-TRAM and bi-pedicled DIEP flaps were assessed for PI of the supplying perforator vessels using a hand-held colour Doppler ultrasound device over 6 post-operative days. Triplicate measurements were obtained by one operator once daily concurrently with haemodynamic parameters. Results DIEP flaps demonstrate a descending trend of PI and resistance to blood flow post-operatively (p = 0.005) similar to non-perforator free flaps. MS-TRAM flaps show higher initial PI values and vascular resistance compared to DIEP flaps (p = 0.038). PI values show no correlation with haemodynamic parameters (r = 0.2, n = 38). Flaps with venous insufficiency demonstrate significantly higher values of PI (p = 0.03). Conclusions PI is an objective, non-invasive, efficient, easy-to-measure, reproducible and quickly-responsive indicator of perfusion of DIEP flaps.