If you contact the clinic and explain they may be able to help if they have a transport scheme. I can't answer your question but I imagine it's best to go where they are familiar with the operation you have had and know how it should be progressing.
I had a Diep reconstruction last Tues 3/4 and the hospital wants to see me in the Dressing Clinic this Friday. It is far away and I can't arrange transport. Could a local GP/Nurse/Hospital see me instead or do they force you to go to the original hospital?
All seems to be progressing well at the mo with recovery.