Canadian PR: delayed application and extending current visa

[sppc42]

Hi,

My brother has done his studies from Ontario, Canada. After the education, he applied for the PR. His medical ran into a bit that it showed 'probable tuberclosis (TB)' in his chest X-Ray, which I read online that its very frequent and happens for three out of five applicants.

Now he is undergoing further medical tests to determine if it is inactive TB (most of the cases) or active. Meanwhile, his current visa is about to expire. I would like to ask:

1. Is there a way of extending his current visa? He has talked to his current employer but they have refused as its a lengthy process and they do it only for very senior level people.

2. Will asking the Canadian Immigration directly on this and asking them to extend his current visa till the medical tests conclude help? Is there any contact he can directly approach?

Basically, any route via which he can go about to get out of this situation that his current visa is expiring soon and the PR application will take time to complete now.

Any inputs will be greatly appreciated!

Thanks
Sandy