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Surgeons Weld Wounds Shut With Surgical Laser
Ruach writes "The promise of medical lasers goes beyond clean incisions and eye surgery: Many believe that lasers should be used not just to create wounds but to mend them too. Abraham Katzir, a physicist at Tel Aviv University, has a system that may just do the trick and is proving successful in its first human trials."
As usual, the summary misses the interesting bit. Using lasers to seal wounds is old news - I first read about it in the Readers Digest about a decade ago. What's new here is a mechanism to prevent overheating.
No, TFA shows two sample pictures, and TFA didn't do any comparison at all, especially not any based on these particular pictures. The *doctors* compared wounds on ten patients and decided that the laser-bonded scars were healing better, which is what the article reports.
The point of the pictures isn't so *you* can second guess the doctors (who believe it or not know an awful lot more about this than you do). They are there to give a quick visual impression of what's going on, to complement the real detail contained in the text of the article.
If you really want to double check the results, go find the original research paper. However I think you'll find it's rather longer and not quite so interesting to read.
From TFA:
"All a surgeon has to do is move the pen's tip along the cut, strengthening and sealing the weld with a solder of water-soluble protein."
It looks a lot like very controlled cooking and I suspect the protein used to connect the tissue denatures in the process. It's not welding, it's hot-melt glue.
Still very cool.
Second, since when does a skin melt?
Skin isn't just the rigid layer of dead cells covered in keratin that you're used to seeing. Lots of interesting things happen under the basement membrane in the "extra-cellular matrix". Cells aren't just glued to each other but rather they produce and surround themselves with different proteins - some for rigidity and others to allow flexibility and elasticity.
This matrix becomes more fluid at higher temperatures as the proteins unwind and change shape with the heat. The theory is that if you have two pieces of matrix close enough to each other and increase the temperature, some of the proteins from either side of the wound will entangle with the opposite side, and remain entangled when the temperature is lowered again, kind of like velcro on a molecular level. The trick is to provide just enough temperature to get the proteins to entangle with each other, without putting so much temperature that they end up destroyed.
Anyway surgeons have known about cauterization for a long time. It helps fix all those little mistakes (oops who put that artery there...). There's nothing more fun than watching a bleeder turn into a brown and black bubbling mess of protein goo - but goo that no longer bleeds.
It would be interesting to know how this "new" technique holds up under different conditions - sepsis, metabolic disorders like diabetes, etc. And of course how much trouble is the patient in if ever there's a dehiscence? At least with sutures, the other sutures are there to keep the wound reasonably closed...
Seven puppies were harmed during the making of this post.