help please - perineal urethrostomy questions - LONG

My male cat Ashley (will be 5 yrs old in May) got blocked a little over
2 weeks ago. Took him to the vet, he was cathetherized (sp?) and
unblocked, but the vet said they couldn't get whatever was blocking him
to come out - they just flushed it back into the bladder. The vet said
they couldn't find any crystals in his urine. She suspected calcuim
oxalate stones, but couldn't be sure because she couldn't get a sample.
She said that it's very unlikely for it to be struvite (sp?) crystals,
because he eats only wet food (Medi-cal Hypoallergenic - he's got a
sensitive stomach).

Well, now 2 weeks later he's blocked again. I came home from work and
there were drops of blood everywhere, and he was straining in the
litterbox and leaving only some blood. He's back at the vet's again.

The first time he blocked, the vet mentioned a perineal urethrostomy. I
didn't want to do that at the time, but since he's blocked twice in 2-3
weeks, I'm beginning to change my mind. So I want to know more about
this procedure, and about what to expect afterwards. Could some of you
guys who have had this done to your cats please answer my questions?

1. Is this a complicated surgery? Should I trust my vet to do it (I
don't know if she's ever done it before). Or should I ask for a
recommendation to someone who specializes in this kind of procedure? I
want the best possible person to do it.
2. What are the chances that something could go wrong with the surgery?
And if it happens, would they be able to correct it?
3. After the surgery, how long will they keep him at the vet's?
4. How long does the recovery process take? What should I expect his
behaviour to be during that time? What should I watch out for? Should I
do anything special to keep him as healthy and as happy as possible
while he's recovering?
5. After your cat(s) had this done, did it really prevent future
blocking? I don't want to put my baby through this for nothing...

thanks,
Nadia (and Ashley)