Surgical effect of laser radiation on the larynx biological model

Surgical effect of laser radiation on the larynx biological model

A.A. Krivopalov^1,2, M.Yu. Korkmazov³, P.A. Shamkina¹, A.I. Glushchenko¹, P.I. Panchenko¹ 

¹St. Petersburg Research Institute of Ear, Throat, Nose and Speech, St. Petersburg

²I.I. Mechnikov North-Western State Medical University, St. Petersburg

³South Ural State Medical University, Chelyabinsk

Background: one of the most commonly used technologies in otorhinolaryngology is the highly coherent monochromatic laser system of various intensities. To date, there are isolated reports in the national and foreign medical literature describing the photobiological effects of high-energy radiation with different wavelengths on a biological model.

Aim: to increase the effectiveness of surgical aids for laryngeal disorders with high-energy lasers of 445 nm and 10600 nm wavelengths with the most optimal physical parameters selected in the study on a biological model.

Patients and Methods: as an experimental model, 9 laryngeal parts of small cattle (sheep) seized in the first hours after the killing were used. A CO₂ laser of 4.0 W to 5.0 W and a 445 nm blue laser of 6.0 W to 8.0 W and were used. During the study, a visual assessment of the damage was conducted, as well as a macroscopic and microscopic study concerning the high-energy radiation effects on the laryngeal tissue.

Results: when visually assessing tissue damage to macroscopic specimens, the following parameters were assessed: shape, extent, defect width and depth, cut uniformity, and the carbonizate presence. The studied lasers showed satisfactory results, with the exception of the blue laser in the mode: 6.0 W, 10–20 ms pulse, 150 ms pause. The formation of carbonizate was not observed during continuous exposure to the tissue for 10 seconds. It was noted that the tissue ischemia area decreased with an increase in the pulse pause and a decrease in the exposure depth. Thus, at a power of 4.0 W, the destruction zone was 337 microns, and at 5.0 W — 491 microns with the same pause and depth indicators. Histology has confirmed that when working with the 445 nm laser, a relatively short destruction zone is formed with a necrosis zone adjacent to it.

Conclusion: the use of the CO₂ laser of 4.0 W to 5.0 W and a 445 nm blue laser of 6.0 W to 8.0 W in the surgical treatment of laryngeal disorders can be a highly effective method.

Keywords: laser surgery, phonosurgery, laryngeal disorders, CO₂ laser, wavelength, blue laser, experiment, wound assessment.

For citation: Krivopalov A.A., Korkmazov M.Yu., Shamkina P.A., Glushchenko A.I., Panchenko P.I. Surgical effect of laser radiation on the larynx biological model. RMJ. 2024;1:57–62.