Evaluation of the Effect of Regional Anaesthesia on Microvascular Free Flaps.

Abstract

Multiple factors influence the success of microvascular free flap surgeries. Anaesthesia is an important factor to maximise the success rate of microvascular free flaps both by controlling haemodynamics and improving the perfusion of free vascularised tissue. The debate on the usefulness of regional and general anaesthesia for free tissue transfer is ongoing. This retrospective study was conducted to evaluate the effects of regional anaesthesia and other perioperative factors on outcomes of microvascular free flaps. This retrospective observational study was conducted on 165 patients undergoing microvascular free flap surgeries between January 2014 and December 2015 after obtaining approval from the Institutional Ethics Committee (Nizams Institute Ethics Committee, Nizams Institute of Medical Sciences, India). Perioperative variables analysed included the type of surgery, indication, ASA physical status, type of anaesthesia, perioperative haemodynamics, fluids used, duration of surgery, re-explorations, blood transfusion and duration of hospital stay. The primary outcome measure was to assess the effect of regional anaesthesia on the success of free flap. Multivariate analysis identified the type of anaesthesia and preoperative haemodynamics as independent risk factors for predicting the failure of flap with an odds ratio of 0.208 and 7.469, respectively. A subgroup analysis of 55 acute trauma patients revealed preoperative haemodynamic instability as an individual independent risk factor for graft failure with an odds ratio of 11.90. The results of this study emphasise the importance of the choice of anaesthesia and preoperative optimisation in improving the success of free flap surgeries.