What's the plural form of Heller myotomy? Here's the word you're looking for.
Answer
The noun Heller myotomy can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be Heller myotomy.
However, in more specific contexts, the plural form can also be Heller myotomies e.g. in reference to various types of Heller myotomies
or a collection of Heller myotomies.