Lasers are widely used throughout surgical procedures. Whilst there are different types of lasers, the carbon dioxide (CO2) laser has shown to be the most used in surgery as a whole, especially in areas dealing with soft tissues. In this article, we look at the how the CO2 laser works as well as looking at some of the more prominent areas of surgery where lasers are used.
Carbon Dioxide Laser
The carbon dioxide (CO2) laser is one of the most widely used lasers for surgical procedures, especially when it is soft tissue that needs to be removed or altered. The carbon dioxide laser came into use in surgical procedures in 1980’s after two decades of development and replaced the older (harmful) techniques of phenol peel and mechanical abrasion.
CO2 lasers emit a wavelength of light at 10,600 nm, which is a wavelength that is strongly absorbed by water molecules. Given the amount of water present in the human body, CO2 lasers have become a great way of manipulating the cells within the body through these water absorption mechanisms.
Absorption of the laser light causes the temperature of the water within the tissues to increase to more than 100 °C, thus causing the water to vaporize. For lasers techniques that wish to remove something completely, the process will cause necrosis. However, for more reconstructive approaches, a pulsed laser approach is used so that the cells only undergo partial necrosis and can be reworked.
CO2 lasers are currently used to remove soft tissues in dermatology and plastic surgery, foot and ankle surgery, gastro-intestinal surgery, oral and dental surgery, gynaecology-related surgeries, genitourinary surgery, thoracic surgery, neurosurgery, orthopaedic surgery and otorhinolaryngologic surgery.
Dermatology and Plastic Surgery
Dermatology and plastic surgery are on the aesthetic end of the surgery spectrum. Nevertheless, lasers are used for a wide range of plastic surgery procedures, including in smoothing of the skin (laser resurfacing), removal of vascular lesions (adult and paediatric), in the treatment of acne vulgaris and for removing tattoos.
In these surgical approaches, there are three main types of lasers used – CO2 laser, erbium:yttrium-aluminium-garnet (Er:YAG) laser and a combined CO2/Er:YAG laser. Out of these, CO2 lasers are the most common kind used because they can selectively target and remove specific epidermis and dermis layers of the skin.
All lasers used in reconstructive-style surgery target the water molecules in the dermis layer, which then heat the collagen molecules in the skin and enables remodelling to occur. For the removal of unwanted surface features, the laser beam penetrates the skin where it is absorbed by a chromophore. The absorption causes an increased coagulation, induces tissue necrosis within the targeted area and causes removal of the targeted area.
Eye surgery is perhaps one of the most well-known types of laser surgery. Issues with eyes, be it either short or long-sighted, are also far more frequent than problems which require other types of surgery. Although, eye surgery can again be seen as a cosmetic procedure as it is not necessary to ensure normal eye function because other methods are available.
There are four common eye surgery methods that use lasers, these are laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), laser epithelial keratomileusis (LASEK) and epithelial laser in situ keratomileusis (Epi-LASIK), with the most common treatment being LASIK procedures.
All the procedures are simple, but as it’s the most common procedure, we’ll look at LASIK. In LASIK, a thin flap is created in the cornea and this can either be done by the surgeon’s hand or by using a laser. Once the flap has been created, an excimer (cool) laser fires ultraviolet (UV) light, which is then absorbed by the targeted corneal tissue. Upon absorption of the UV light, the molecular bonds of the cornea are broken down enabling the laser user to shape the cornea and correct the refractive error.
Using lasers is now one of the many methods available for treating and destroying cancer cells in various organ systems.
One area where lasers have been used a lot is in tackling tumours in the brain (neurosurgery), especially as other methods can cause too much damage to the surrounding brain matter. For neurosurgical tumour approaches, lasers have been employed to tackle gliomas, meniniomas, tumors of the deep skull base and tumors deep in the ventricles.
Another area is in the treatment of superficial gastrointestinal cancers using mucosal ablation techniques. Lasers have been used to treat early gastric cancer, superficial esophageal cancer, colorectal adenoma and high-grade Barrett’s esophagus. Direct laser ablation methods can also be used to destroy cancer cells using a combination of photochemical, photomechanical, and photothermal effects.
Light Scalpel: https://www.lightscalpel.com/laser-surgery/dermatology-plastic-surgery/
All about Vision: https://www.allaboutvision.com/visionsurgery/
“Lasers in Plastic Surgery”- Markus, F., Seminars in Plastic Surgery¸2007, DOI: 10.1055/s-2007-991181
“Laser applications in surgery”- Azadgoli B. and Baker R. Y., Annals of Translational Medicine, 2016, DOI: 10.21037/atm.2016.11.51
“Laser Resurfacing”- Janik J. P., et al, Seminars in Plastic Surgery, 2007, DOI: 10.1055/s-2007-991182