Advisor isn't advising
My answer depends on how far along you are in your research and whether you are in PhD or MD?PhD program. 

If you are in a PhD program and you are less than a year in leave the lab. If you are more than a year in at you next Thesis Committee meeting, if it's scientifically reasonable, try to either set a date for graduating or ask for a co-PI.

If you are in the MD/PhD program, you will have to consider your PI's position and whether a lukewarm letter from someone in his position is worth your staying in the lab. If you plan to go into a competitive surgicial or medical subspecialty, it just might be. 

I, sadly, think that checked-out PIs- even those without the excuse of having to go see patients- are increasingly the norm. Getting to be a professor is a great way to age rapidly and burn out, especially in the biomedical sciences. Also, professors aren't selected for their mentoring skills so much as scientific productivity. Often scientific productivity means exploitation or disregard because of self-involvement rather than nurturing.