Myocutaneous flap failure: early detection with Gd-DTPA-enhanced MR imaging

Magnetic resonance (MR) imaging was used to evaluate myocutaneous flap viability in an animal model. Bilateral myocutaneous panniculus carnosus groin flaps were created in 14 piglets. Eight of the piglets underwent early occlusion of the vascular pedicle to one flap that resulted in flap failure in all cases. Six piglets underwent late occlusion of the vascular pedicle to one flap that resulted in flap survival in all cases. Spin-echo T1- and T2-weighted MR images were obtained from all piglets 2 and 24 hours after occlusion. Additional gadolinium diethylene-triaminepentaacetic acid (DTPA)-enhanced serial T1-weighted images were obtained in four piglets who underwent early occlusion and in four piglets who underwent late occlusion of the pedicle. The T2-weighted images showed increased signal intensity in both occluded and control flaps and thus did not help predict flap viability. Gd-DTPA-enhanced images enabled accurate prediction of flap viability. The images of early-occluded (non-viable) flaps demonstrated no contrast material enhancement, while both the late-occluded (viable) flaps and the control flaps were contrast enhanced. The authors conclude that Gd-DTPA-enhanced MR imaging can help predict myocutaneous flap viability in piglets.