Karachi has big hospitals list. There are many big names where you can go for surgery. A health website "Marham.pk" has the list of virified hospitals. You can visit for the hospital reviews, timings services
I am listing some Hospital names:
"Civil Hospital" "Burhani Hospital" "Darul Sehat Hospital" "Indus Hospital" "Dr Zaiuddin Hospital" "Baqai Medical University"
I hope this answer will help you and guide others.
Thank You.