ReSharper offers a few different ways to employ a advanced, or structural, search. One of the key features is it's "Find Usages Advanced". More than just finding usages of a method, it also searches for relevant code. This includes overridden/overloaded methods, occurrences in text (like comments), and dynamic references.
Also, the Structural Search features are great. It allows you to search for things like entire if-else statements that follow a certain pattern.