Pioneering Skin Treatments (Source: BBC News)
It is extraordinary that doctors were able to do anything for Todd Nelson.
The former US Army master sergeant’s injuries were so bad the medics thought he would not survive.
“I was on my 300th-plus convoy across Kabul, Afghanistan,” he recalls.
“We were headed home for the night when we passed next to a typical yellow and white sedan. When they saw us getting ready to pass, they flipped the switch.
“The blast came in my side of the truck; I was on the passenger side.
“It flipped the truck through a brick wall and put shrapnel through my right eye, into my sinus cavity.
“Both my upper and lower jawbones were crushed, as was my right orbital rim, and it crushed my forehead.
“It burned my right arm over the top of my head, [and] took my right ear off.”
Nelson went through more than 40 operations to reconstruct his face. The scars are evident but what is not so apparent to someone just talking to him is the pain he still feels over large portions of his body.
The veteran is now working with Colonel Robert Hale from the US Army Institute for Surgical Research, sitting on his advisory panel.
The pair came to speak to reporters here in Boston at the annual meeting of the American Association for the Advancement of Science (AAAS).
Col Hale is trying to develop new techniques that will give wounded soldiers better outcomes.
Nelson’s injuries destroyed all three main skin layers – the epidermis, dermis and hypodermis (the top, middle and bottom), in some places right down to the periosteum, the membrane overlying the bone.
“The way we treat Todd’s condition has been around for 30-some-odd years. It hasn’t evolved much,” said Col Hale.
“We basically removed the dead tissue, we conditioned the wound-bed as best we could, and then we covered it with split-thickness skin grafts taken from his thigh or somewhere that wasn’t burned on his body.
“It is a successful way to close the wound, but it leaves lots of fibrosis and scarring that the face simply cannot tolerate. If you have a lot of scarring and fibrosis, the face doesn’t work like it should – the eyelids can’t close, the nose won’t work, and the mouth won’t work.”
One of the great innovations in recent years has been negative pressure wound therapy. This involves sealing a foam deep in an open wound under suction to help condition the base tissues to get them ready to receive a graft. Patients greatly appreciate the therapy because it reduces the number of painful dressing changes.
“It has revolutionised our care of open wounds,” said Col Hale, “but we can’t use it on the face because there are too many areas of the face that will leak around the silicon seal – the eyelids, the nose, the mouth.”
The US Army doctor is therefore trying to develop a special mask that would do the same job.
Instead of using a foam, it would rely on microchannels in the mask to take away wound fluids. He then wants to take moulded sheets of artificial skin to build up the intermediate layer, the dermis, before adding the outer epithelium graft employing new approaches that lift thin, 20-cell-thick slices from elsewhere on the body.
For the deepest layer, the hypodermis, he is looking at taking fat from the abdomen and injecting under the healing wound.
“All the technologies I’m exploiting currently in my lab and what I’m funding in other research labs are things that are close at hand,” said Col Hale.
“In maybe five, six, and seven years, we should have products and strategies that we can apply to soldiers who have been injured in war, and all of this should be translatable to the general public.”