I had clexane during my last pg as I had my leg in plaster (broken foot) The ob who was pretty relaxed about everything else was adamant (sp?) that I must be off the clexane 4 weeks before the birth and that if I went into labour early I wouldn't be given an epidural if I was still on clexane. Luckily the plaster was off and I had finished the clexane before I had Riley. I can't believe your vascular surgeon and ob can't talk to each other, my ob and orthopedic surgeon were fantastic together and really shared the care for a while there!
Good luck with everything, I am sure it will be fine its just a bit confusing now.