[verb (dictionary form)] + ことなしに [verb (dictionary form)] + ことなしには + [negative clause]
ことなしに means "without doing". It follows the dictionary form of a verb, and it most often sets up a negative second half: without X, Y cannot happen.
With は added, ことなしには makes the condition sharper: "unless you do X".
It can also simply report that something was not done, as ことなく does.
ことなしに is literary, at home in essays and speeches. In conversation the same idea comes out with ないで, ずに, or きごう〜なければば〜ない.