Strap muscle neurovascular supply.

Abstract

Knowledge and preservation of the neurovascular supply to strap muscles, such as the sternohyoid (SH) muscle, used in laryngotracheal reconstruction are important in preventing loss of tissue and bulk from ischemia and/or denervation. Arteriovenous and neural supply variations to the strap muscles were examined in cadaver specimens. Strap muscle neurovascular supply was studied in 16 cadavers, including one transparent corrosion cast specimen with injected vessels. For the upper SH and upper belly of the omohyoid (OMO), the arterial supply consistently arose from a branch of the superior thyroid artery (STA) most commonly terminating at the cricothyroid membrane. The inferior SH was supplied by the inferior thyroid artery. The ansa cervicalis innervated the SH inferiorly with a branch below the loop. Each arterial branch to the muscles had an accompanying venous tributary. The corrosion cast specimen demonstrated that the arterial lumen diameters were almost threefold larger in branches entering the upper SH, compared with the lower SH or OMO. Small intramuscular arteries without axial supply were found within the middle third of the upper SH, the lower SH, and the upper OMO. It is possible to preserve neurovascular integrity in an inferiorly based SH flap. The superior and medial borders are released, with dissection of vascular supply laterally and deep to the muscle, and preservation of the inferior terminal ansa branch.