Is it possible to add snippets with fixed width fields?

I have the following snippet definition to add a variable in C:

snippet av
${1:type} ${2:var_name }; ${3:/**< ${4:explanation} */}${0}
endsnippet

I would like to know if is possible to modify the snippet in such a way that the width of
each field if fixed.
What happens right now is something like this

int myvar1;
long int myvar2;

so the column where the variable name is depends on how big the variable type is.
I would like to know if there is a way of making the variable name start always in the same column.

Thanks.