Laser surgery is widely applied in a variety of human surgical specialities such as otolaryngology, gynaecology, neurosurgery, plastic surgery, dermatology and oral & maxillofacial surgery. Out of several laser types available, the CO2 laser is considered the “workhorse” of laser surgery due to its unique capabilities in performing precise, hemostatic incisions, excisions and ablations of tissue. The CO2 laser emits continuous or pulsed infrared radiation which is highly absorbed in water. Since any soft tissue is composed mainly of water, tissue at the focal point of the laser beam is instantaneously vaporized, leaving behind a thin necrotic layer of tissue which assures hemostasis.
How does it work?
The wavelength emitted by a CO2 laser is 10,600 nanometers (nm). This wavelength is in the far infrared spectrum and is invisible to the human eye. Water has extremely high absorption at this wavelength. A 30-micron thin layer of water will absorb 90% of CO2 laser radiation, and only 10% will pass through. Since 75-95% of soft tissue is composed of water, this wavelength is highly absorbed in soft tissue and therefore highly effective in vaporizing soft tissue, regardless of colour. Tissue vaporization is instantaneous with very minimal surrounding thermal necrosis which aids in hemostasis. The spectral absorption of water also provides the CO2 laser with the ability to coagulate, cut, or char, tissue depending on the power density and the energy level applied by the surgeon. When the laser beam is focused, the laser can cut like a scalpel, but when the laser is defocused the laser vaporizes the soft tissue. The surgeon can control the extent by which the laser beam is absorbed into surrounding tissue, resulting in an extremely precise tissue incision. To minimize heat transfer to surrounding tissue and reduce collateral heat damage, the duration of the laser beam on the tissue can be controlled (usually less than 1 millisecond). To allow precise positioning of the surgical laser beam, an additional red, low power laser beam is incorporated in the system so that both beams are coincident at the surgical site.
BENEFITS
1. Pain Reduction
Patients will experience considerably less postoperative pain in almost every instance. This reduction in pain is a result of the unique characteristics of the laser beam as it cuts nerve endings, preventing the raw ends typical to scalpel incisions.
2. Swelling Reduction
Whenever an incision is made in the tissue with either a scalpel blade or scissors, inflammation begins in the affected tissue. This inflammation is a result of interaction with the circulatory and lymphatic systems. Because the laser beam effectively cauterizes the lymphatic system, there is much less postoperative swelling. In addition, laser energy does not crush, tear, or bruise tissue since there is no physical contact with the tissue. Postoperative Recovery is faster and the patient experiences more comfortable.
3. Control of Infection
Since laser beam operates at a temperature of over 200 degrees Fahrenheit; it is highly effective at killing bacteria that have the potential to cause an infection. In fact, this is particularly important in areas in which it is difficult to prevent contamination of the surgical site. The CO2 laser sterilizes the infected area as it removes diseased tissue, leaving healthy tissue undamaged. Because the sterilization process is so effective, the use of antibiotics is substantially reduced.
4. Minimal Surgical Bleeding
When an incision is made with a scalpel blade, blood vessels in the area are severed and can ooze during and after the surgery. The laser seals small blood vessels as it cuts, reducing or eliminating the need for any other bleeding control measures.
5. Hospitalization and Healing Time
With laser surgery, healing is rapid and there is less postoperative discomfort. Laser procedures provide reduced trauma and less invasive surgeries for patients, improve recovery time, and shorten time spent in the hospital. No tissue reaction (edema) is usually noted. The laser allows the destruction of diseased tissue while preserving normal tissue. Post-surgical scarring is also reduced.
6. Greater Accuracy & Precision
The laser can remove diseased tissue without affecting surrounding healthy tissue. Not only does the blood-free cutting benefit the patient, but it also provides a clear, dry surgical field for the surgeon.
However, the used of the laser in the field of otorhinolaryngology is limited. The described indications for the use of laser in E.N.T surgery are:
Middle Ear Surgery : Stapedotomies and myringotomies
Nasal, Endonasal & Endoscopic Sinus Surgery: Turbinate reduction | removal of nasal obstructions/synechiae | rhinophyma | keloids and hypertrophic scars
Oral Surgery: Leukoplakia | Erythroplakia | Papilloma | Hemangioma | Tumours | Zenker’s diverticulum | | LAUP (Laser Assisted Uvulo Palatoplasty) | Tonsillotomy & tonsillectomy
Transoral Laryngeal Microsurgery: Cordectomies and cordotomies | polyps and laryngeal papilloma | Reinke’s edema | laryngocele | hyperkeratosis laryngitis | scar tissue | granulomas | congenital web | primary laryngeal tumours | laryngotracheal stenosis | laryngeal amyloidosis
Tracheobronchial Tree:Stenosis, nodules, polyps, tumour
Head & Neck: Resection of tumours