I have one from MedicalZ. They have an Amazon store front. My doctor wanted to me to use it both as a compression garment and sports bra once I was cleared for exercise.

Measurements are typical - underbust + measurement for your expected cup size after the surgery.

https://www.medicalz.com/en/produits/zbra-adjustable-shoulder-straps/

Sizing — https://www.medicalz.com/wp-content/uploads/2022/02/Tableaux_taille_ZBRA-1024x395.png

On Amazon - https://www.amazon.com/Medical-Adjustable-Shoulder-ZBRA-Black/dp/B07L5S252B?ref_=ast_sto_dp&th=1&psc=1