Good wishes your way for your DH's safe recovery.
My family has this problem; it's hereditary on our Dad's side. I'm the only one of my siblings that it has not happened to yet. The pulmonologist says that the probable reason that I've escaped so far is that I have never smoked a cigarette in my life, nor lived for an extended period with anyone who did. (It's not that smoking causes this, but if you have it, smoke aggravates it and makes it more likely for the blebs to rupture.)
There is also some theory that having this condition makes you more susceptible to lung cancer -- God knows that this family has a truly bad track record in that regard.
My sister almost died the last time hers decided to collapse. They both went at once, when she was home alone in the bathtub -- she couldn't get enough air, got weak, and just slid right down under the water. Luckily her roommate came home and saw water coming out from under the bathroom door. When she didn't get an answer, she broke in and dragged my sister out. My sister had the procedure you are speaking of after that incident, and she hasn't had another spontaneous collapse since -- 23 years now.