I don't have actual knowledge or experience here, but I would think the hole left by a mere catheter would almost close up on its own, and then begin to heal like normal live tissue. The other defect would have a more gradual thinning and then a hole, perhaps as much as two-four mm in diameter, maybe even more in some cases. Think of what happens when you stick a wooden skewer into a loaf being baked and then remove it to see if any batter has stuck to the skewer indicating that more bake time is needed. When the skewer is withdrawn, the batter 'heals' itself quickly inside the loaf and you'll only see a hole where the outer portions had baked and the skewer leaves a permanent 'drill hole'. The defect, though, would have much wider margins.