I have a string comprised of multiple substrings, separated by underscores. For example: `AbcdAEfd_hEgdgE_AbAAAAA`. I need to remove all vowels except the first from each substring. So:

* `AbcdAEfd` -> `Abcdfd`
* `hEgdgE` -> `hEgdg`
* `AbAAAAA` -> `Ab`

The resulting string should be `Abcdfd_hEgdg_Ab`