  We provide an exposition of a `horizontal' generalization of Goodman's
surgery operation on (pseudo-)Anosov flows. This operation is performed by
cutting along a specific kind of annulus that is transverse to the flow and
regluing with a Dehn twist of the appropriate sign. We then show that
performing horizontal Goodman surgery on a transitive pseudo-Anosov flow yields
an almost equivalent flow, i.e. the original flow and the surgered flow are
orbit equivalent after drilling out a finite collection of closed orbits. We
obtain some almost equivalence results by applying this theorem on examples of
the surgery operation. Along the way, we also show a structural stability
result for pseudo-Anosov flows.
