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Myocutaneous flap failure: early detection with Gd-DTPA-enhanced MR imaging
R M Varnell1, P W Flint, R W Dalley
1Department of Radiology, University of Washington, Seattle.
Abstract:
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.
Insights
Gadolinium DTPA-enhanced Magnetic Resonance (MR) imaging accurately predicts myocutaneous flap viability in piglets. Non-viable flaps showed no contrast enhancement, while viable flaps did, unlike standard T2-weighted MR imaging.
Area of Science:
- Biomedical Imaging
- Surgical Research
- Animal Models
Background:
- Myocutaneous flaps are crucial in reconstructive surgery.
- Assessing flap viability is critical to prevent complications.
- Current methods for flap viability assessment have limitations.
Purpose of the Study:
- To evaluate the efficacy of Magnetic Resonance (MR) imaging in predicting myocutaneous flap viability.
- To compare T2-weighted and Gadolinium DTPA-enhanced T1-weighted MR imaging for flap viability assessment.
- To establish a reliable imaging technique for flap viability in an animal model.
Main Methods:
- Created bilateral myocutaneous groin flaps in 14 piglets.
- Induced early vascular pedicle occlusion (resulting in failure) in 8 piglets.
- Induced late vascular pedicle occlusion (resulting in survival) in 6 piglets.
- Acquired spin-echo T1- and T2-weighted MR images at 2 and 24 hours post-occlusion.
- Obtained serial Gadolinium DTPA-enhanced T1-weighted MR images in a subset of piglets.
Main Results:
- T2-weighted MR images showed increased signal intensity in both occluded and control flaps, failing to predict viability.
- Gadolinium DTPA-enhanced T1-weighted MR images accurately predicted flap viability.
- Early-occluded (non-viable) flaps demonstrated no contrast enhancement.
- Late-occluded (viable) and control flaps showed contrast enhancement.
Conclusions:
- Gadolinium DTPA-enhanced MR imaging is a reliable method for predicting myocutaneous flap viability.
- This technique offers a significant advantage over standard T2-weighted MR imaging for flap assessment.
- The findings support the use of Gd-DTPA-enhanced MR imaging in preclinical and potentially clinical settings for flap monitoring.