A surfer and his severed leg were airlifted to hospital after a shark attack earlier this week, sparking speculation that surgeons may be able to reattach the limb.
Kai McKenzie was surfing off the mid-north coast of New South Wales on Tuesday morning when a suspected three-metre great white shark bit him.
McKenzie was able to fight it off before catching a wave into shore, where he was treated with makeshift tourniquets to stem the bleeding.
His leg washed up on shore a short time after the attack and locals put it on ice before it was transported to hospital.
McKenzie was recovering in John Hunter hospital in Newcastle in a stable condition on Thursday, a family spokesperson said. It has not been revealed if reattachment surgery was attempted.
But how do surgeons decide whether to attempt limb reattachment and what happens if they do?
How soon do you have to get to hospital?
Severed limbs should be taken to hospital in less than six hours to avoid muscle death, the president of the Australian Society of Plastic Surgeons, David Morgan, says.
“Muscle starts dying as soon as you start removing it from a blood supply, so you often start to get irreversible muscle death within six hours,” he says.
“The sooner you can get it there and the sooner you can start to get a blood supply back into it, the better off you will be.”
How should the limb be stored?
It’s good to keep a severed limb moist and cold, but don’t put it directly on ice, Morgan says.
“Wrap the amputated piece in something moist, and then put that in a plastic bag, and then put that plastic bag on ice, in a small Esky or even in a bag of frozen vegetables,” he says.
“But you can’t just put the piece directly into the frozen vegetables, because it just freezes it, and that destroys the tissue.”
Storing and transporting the limb appropriately will improve the chance of the limb surviving and healing properly if reattached.
“If it has been 24 hours and carried out of the deep forest and not stored properly, then you wouldn’t even attempt it, because it’s just not going to work,” Morgan says.
Can all severed limbs be reattached?
Even if the patient gets straight to hospital and the limb has been stored appropriately, doctors may decide the limb is too damaged to be useful.
Surgeons can keep the limb alive and reattach it correctly, but it is not certain whether the limb is capable of recovering and functioning normally.
“That’s a very difficult thing to predict, because you can do a perfect nerve repair, but the nerve may not recover, so some of this is a bit of educated guesswork,” Morgan says.
“A leg with nerves completely severed may be completely numb forever, and that’s not really a functional limb if you can’t really feel your foot at all.”
If a limb is unlikely to become functional after the operation, a patient may be better off and find it easier to return to normal life with a prosthetic limb.
How do surgeons reattach limbs?
Once the patient gets to hospital, they’ll need to survive their injuries and blood loss.
Then, if the doctors decide to go ahead with the procedure, the first thing to do is remove the parts of the limb that are beyond saving.
After that, doctors would get blood supply back into the limb, connecting the major artery back to an artery in the patient’s body through a small pipe.
Then the reattachment begins. The surgeons would start by trimming back the damaged bones and reattaching them with metal plates and screws.
“Once that has been done, you would then work through rejoining the blood vessels, rejoining the nerves, putting the muscles back together, and then putting the skin back together,” Morgan says.
Blood vessels would be stapled or stitched around a small conduit, while veins, arteries, muscles and tendons would be stitched back together.
How complex is the reattachment procedure?
While all plastic surgeons are trained in the microsurgery skills required for reattachment, the procedure is “among the most challenging that we do,” Morgan says.
He estimates a reattachment operation could typically take 10 hours or as many as 24 hours, depending on the circumstances.
Surgeons from multiple specialities are needed to operate on the different parts of the limb, and the reattachment process is slow and difficult.
“There is no fancy laser that will blend things together,” Morgan says. “It’s all very much hand-eye coordination under operating microscope to put it all together, which is why it takes so long.”
The reattachment process can be made more difficult depending on the type of injury, Morgan says.
“A very clean, sharp cut will be much easier to put back together than something that’s got a lot more crush or a broader zone of tearing,” he says.
Furthermore, the process of trimming and cutting out the injured bone and tissue means the reattached limb could be shorter than it was before.
“You often end up shortening the limb a little bit because all of the tissue in that injury zone is not useful … so that limb ends up being shorter than the other one, even if it is successful,” Morgan says.
What happens after the reattachment procedure?
Limb reattachments need to be monitored closely at first to ensure their connection keeps working and they don’t develop any infections.
“Like any plumbing joint, it can leak or it can block and occasionally you need to take people back to the operating room to fix one of those problems,” Morgan says.
Once the wound has healed, patients will need to start rehabilitation, including moving the limb joints with their hands, as they won’t be able to actively move the limb itself until the nerves recover.
“You don’t want them to stiffen up, so they go through a process of passive rehabilitation, just to keep the things supple,” Morgan says.
That passive physiotherapy can continue for months as the nerves recover, depending on how far the amputation is from the major nerve collections in the hip or shoulder.
“A nerve will recover at 1mm a day once it starts to recover. So if you’ve got an amputation at the mid thigh, it might be six months before you’re getting something down in the foot.”
A finger or toe reattached at the knuckle will recover function more quickly.
Do reattached limbs work?
The vast majority of reattached limbs will stay alive and have some level of function, but they may not return to the way they worked before amputation.
Morgan points to increasing use of hand and arm transplants in recent years, “many of which are technically successful, and many of which give people improved function, but they’re not working like a normal hand”.
As with the pace of healing, amputations closer to the shoulder or hip will be less likely to recover completely.
“The closer to the shoulder or the hip you get, then the more significant the damage is, and the longer it will take to recover and the less likely it will be to recover,” Morgan says.
People with reattached limbs that don’t successfully recover may opt for elective amputation and the attachment of a prosthetic limb.
How common is limb reattachment?
Reattachment of fully amputated arms or legs is not common, Morgan says.
“You’re probably not doing more than a handful a year at a major trauma centre.”
Surgeons more regularly reattach or repair limbs that have been mangled but remain attached to the body.
“We do get a lot of pretty significantly injured lower legs in car accidents and motorbike accidents,” Morgan says.
“The whole thought process of ‘Can we save it? Should we save it?’ is practised in major trauma centres every week.”
