[Lemon:] How did Congresswoman Gabrielle Giffords survive a gunshot to the head? Our chief medical correspondent Dr. Sanjay Gupta explained to me earlier.
[Dr. Sanjay Gupta, Cnn Chief Medical Correspondent:] In this case, as you know, Don, she had what's known as a through-and-through injury. So the bullet actually came in and left the skull, and so, you know, there may be some remnants, but the vast majority of the bullet actually left.
[Lemon:] And that's because this bullet this is a smaller bullet so it can go through. But if it's a bigger bullet, it kind of explodes.
[Gupta:] Sometimes explodes or has an explosive effect.
[Lemon:] OK.
[Gupta:] But what we know now even as compared to yesterday when you and I last spoke is that this she was actually the bullet entered the back the left side of the head over here, it was the back, and exited on the same side, left side near the front. It did not cross from left to right. Very important point. They mentioned that a couple of times. It's important because the likelihood of someone doing well or having a more optimistic recovery, that means a lot. If the bullet or the missile crosses over here, it really changes everything here. Also, I just want to show you, Don, real quick, if I can. You know, when you talk about this type of injury, you know, you had the bullet enter, the bones in here as well sort of start to act like little missiles. You know, they get pushed into the brain and then in this case the bullet exited. But as part of the operation, you have to remove a lot of those bone fragments, stop the bleeding and some of the tissues, some of the brain tissues that have been damaged by this bullet, you have to remove that as well. The surgeon also mentioned that because of the concern about swelling. Other parts of the bone were actually taken off. That bone is gone right now for her. It's saved. And so, she will have a depression on that side of her head until that bone is placed back at some point in the future.
[Lemon:] Just what you explained here, can you bring that a little bit. Does this make a difference when you when someone comes in, if you have this sort of shrapnel or whatever, if the bullet is intact, does it make a big difference as to what's left in there?
[Gupta:] You know what's interesting is if it's a through-and-through injury, it does make a difference. In part, if you think it like think of it like this. You have you a significant amount of energy that's coming from this bullet. If that energy passes through the brain and comes out the front, some of the energy is going to dissipate in air as opposed to within the skull cavity. If all of that energy from that bullet is being sort of distributed in the brain, that's a much worse injury. So the fact that it goes through and through in this case is a better sign for her.
[Lemon:] Dr. Sanjay Gupta. The mass shooting in Tucson is not the first incident that's given the state of Arizona negative headlines. Some recent controversies next.