I failed to understand the grammatical structure in this pattern.
The result is shown as follows:
Is follow here a verb or something else? I don't know whether as do(es) is grammatically valid or not.
As stated in The Free Dictionary as follows is an idiom which is why you shouldn't bother about its grammar. Yet, most importantly, you must bear in mind that this idiom should always be used in its singular form :
The reason for its fixed form is that it was originally an impersonal construction = as it follows.
Also, Garner’s Modern American Usage (3rd ed.) has this to say:
As follows is always the correct form, even for an enumeration of many things. The expression is elliptical for as it follows—not as they follow.