Our retrospective review of 93 consecutively imaged limbs over 32 months demonstrates a peronea arteria magna (PAM) prevalence of 5.3% in an urban population. Free fibula transfer is now a commonplace technique for long bone and mandibular reconstruction, but the utility of preoperative angiography continues to be debated. We present a case report and performed a cost-effectiveness analysis for pre-operative vascular imaging of the donor limb using MRA and traditional angiography (TA).

Case: A 42-year-old man with a shotgun blast to his forearm had a segmental bony defect of the radius of 10cm reconstructed with a free fibula osteocutaneous flap. Pre-operatively, the patient had a normal vascular exam of the donor leg including palpable DP and PT pulses. Intraoperatively, DP and PT signals were dopplerable, however in the PACU the foot appeared mottled with no arterial signal. Angiogram revealed absent PT, spasm of the AT, and surgically absent peroneal. Vascular bypass was required for salvage.

Donor site complications of fibula harvest range from 20-30%, but are rarely limb threatening. Limb loss is a dreaded complication of congenital PAM, which can be present with a normal vascular exam. The reported incidence of PAM from the plastic surgery and radiology literature ranges from 0.2% to 8.3%.

In our patient with unrecognized PAM, the excess direct medical cost of the complication was $140,000. We performed a cost-effectiveness analysis using the cost of arterial imaging at our institution, which suggests that TA is expected to either cost $1020 excess or save $6,100 per patient, depending on the actual prevalence. Similarly, MRA is expected to either cost $144 excess or save $6,900 per patient. This represents the direct medical costs and is an underestimate of the actual costs, which might include time lost from work, disability, pain, and medico-legal action.

Some microsurgery groups advocate using no preoperative imaging of the donor limb; they rely on intraoperative assessment of the vascular anatomy. An aborted harvest due to aberrant anatomy leads to both direct and indirect added costs. Our group feels that MRA imaging of the donor limb, being minimally invasive, is cost-effective and indicated for all free fibula transfers. For equivocal results, conversion to more-invasive and costly TA may be necessary.