The Collaborative International Dictionary of English v.0.48:
Myotomy \My*ot"o*my\, n. [Myo- + Gr. ? to cut: cf. F. myotomie.] The dissection, or that part of anatomy which treats of the dissection, of muscles. [1913 Webster]WordNet (r) 3.0 (2006):
myotomy n 1: surgical incision or division of a muscle