As we discussed in a previous post, liquid nitrogen is not only difficult to order online, but also has some unbelievably cool science behind it. We discussed how the cooling effect of liquid nitrogen is due to its very low boiling point (−196 °C), and for this reason it can quickly freeze human skin upon contact. This application is referred to in the scientific community as ‘cryotherapy’. The origin of the term comes from the Greek words for ‘cold’ and ‘cure’, and is essentially the use of low temperatures to help heal or cure certain conditions, such as removing benign lesions from the surface of the skin or preserving live tissue. As one can imagine, this means that cryotherapy likely has many applications, but today we will specifically discuss the use of liquid nitrogen sprayers in removing lesions and freezing tissue.
Cryosurgery is a type of cryotherapy that specifically applies to the delivery of liquid nitrogen to living or benign tissue via a liquid nitrogen sprayer in order to freeze and destroy the tissue. Often, cryosurgery is used for small cosmetic growths, such as skin tags, warts, moles, and more seriously, skin cancers. By rapidly cooling the tissue, the liquid nitrogen actually freezes the cytosol of the cells, causing them to fracture and rupture internally. Think of the cytosol as the plush, cozy swimming pool that all of the cellular machinery responsible for maintaining our cells swims around in. This is mostly made of water, and when water freezes, it expands. That’s the same reason you make sure to drain external plumbing on the outside of your house before the winter—just like the pipes will crack if the water inside them freezes, so too do your cells if they are rapidly frozen. For this reason, liquid nitrogen sprayers see most of their use in external application.
However, liquid nitrogen cryosurgery can also be performed internally in the case of many cancers, such as liver, lung, and prostate. Liquid nitrogen has also seen internal application in the treatment of hemorrhoids, although this can be painful for the patient due to the fact that other local damage may occur. For this reason, liquid nitrogen sprayers are often preferred due to their high precision, ability to be manipulated, and dependability. Although cryosurgery is often painless, since damage to healthy surrounding tissue can sometimes occur it is not uncommon for doctors to provide a little bit of analgesia with most procedures, such as a Tylenol or Aleve.