Flowmetric Evaluation of Internal Mammary Artery Flap During Repair of Aortic Coarctation

Resection of the internal shelf through a longitudinal aortotomy and widening with the free end of the left in situ internal mammary artery (IMA) were steps in correction of aortic coarctation with isthmus hypoplasia in nine patients aged 9–14 (mean 10.5) years. Electromagnetic flowmetry was performed on the left IMA before and after the repair. The essential finding was considerably increased mean blood flow in the IMA flap during cross-clamping proximal to the completed repair, from 53 ± 48 to 430 ± 74 ml/min (378 ± 78%). The IMA thus is a powerful conduit with extraordinary flow capacity when runoff is appropriate. Integration of IMA as a viable flap in the repair of aortic coarctation implies that this artery increases its collateral flow contribution to the distal aorta.