spondy atwood

I hope someone can put our minds to rest a little bit my wife is a nurse and we have recently undertaken our medicals.However whilst both my son and I had the A box ticked my wife due to an operation for tendinitis 9 years ago and a DVT in her left leg 3 years ago has had the B box ticked in other words Significant history that may affect health costs in the future. Although this has not been a major problem in the UK we are now extremely worried that this may deie us a visa.Can anybody please give info