Preoperative MRA for Patient Selection in Free Fibula Flap: Is a Venous Phase Indicated?

Abstract

Objectives:

We present our institutional experience with dynamic time-resolved magnetic resonance angiography (DTR MRA) with delayed venous imaging for free fibula flap (FFF) patient selection. We sought to (1) determine the sensitivity of the test for vascular anomalies predisposing to limb-threatening complications and (2) assess the impact of the venous phase findings in patient selection.

Methods:

Retrospective review of 46 patients considered for mandibular reconstruction with FFF in an academic tertiary setting from 2009-2012. A DTR MRA was performed preoperatively in all cases. Both imaging and physical examination findings were used to determine patient eligibility for the procedure.

Results:

Thirteen patients (28.2%) had findings on DTR MRA excluding flap harvesting from the preferred leg, with atherosclerosis (n = 8) and anatomic variations (n = 4) being the most common findings. Eight of these patients (61.5%) underwent harvesting from the opposite leg, while 5 underwent reconstruction with a different bony flap. Only 2 of these 13 patients (15.3%) had physical examination findings excluding reconstruction with FFF. DTR MRA was significantly more likely to detect potentially limb threatening vascular anomalies than physical examination (P = .004). There was 1 patient with an anomaly on delayed venous imaging (asymptomatic deep venous thrombosis–thrombophlebitis) which excluded flap harvesting from the affected leg. Both arterial phase imaging and physical examination were normal in this patient.

Conclusions:

DTR MRA is significantly more sensitive than physical examination in detecting limb-threatening anatomic variations and vascular pathology prior to FFF reconstruction. The venous phase allows identification of oligosymptomatic venous anomalies that, while uncommon, may predispose to significant morbidity. These findings justify routine use of this imaging modality.