Abstract 2348: Contrast Ultrasonography: A Novel Technique For The Assessment Of Graft Perfusion Following Maxillofacial Surgery
Introduction Reconstructive surgery for maxillofacial cancer uses free flap grafts with their vascular pedicles. Methods to detect graft success are crude. Myocardial contrast echocardiography is a novel technique that assesses myocardial perfusion at the bedside. Hypothesis We hypothesised that contrast ultrasonography (CU) detects graft perfusion and accurately predicts graft outcome.
Methods 22 patients (12 male) mean age 55 (range 30 – 82) years undergoing free flap surgery for maxillofacial cancer were recruited. Standard assessment of grafts with direct inspection (DI) and non-imaging spectral Doppler (NISD) were performed three times daily and CU performed 12, 24 and 48 hours after surgery. Tissue perfusion was assessed qualitatively by the presence or absence of microbubbles, and quantitatively by peak contrast intensity (α) and blood velocity (β).
Results Out of 22 grafts implanted, 3 (14%) failed (confirmed at rescue surgery). Qualitative CU predicted failure in all 3 grafts (100%) and success in the remaining (100%). All graft failures had complete contrast absence at 12, 24 and 48 hours. Quantitative CU (α) demonstrated a significant difference between healthy (4.4±2.2) and failed (0.22±0.14) grafts (p<0.05). Tissue blood flow (β) was significantly higher in healthy grafts compared to failed grafts (p<0.05). Whilst CU visualised all grafts, standard techniques could not assess 3 buried grafts. Of the 3 graft failures, DI did not detect impaired graft function until day 2 (1 graft) and day 5 (2 grafts). NISD did not detect any of the graft failures.
Conclusions CU is a simple bedside technique that accurately and rapidly assesses tissue perfusion following graft surgery and is superior to standard techniques.