Pressure induced tissue resection in the larynx: A preliminary canine study

Abstract

Objectives: The application of laser (light amplification by stimulated emission of radiation) energy in the larynx relies on thermal injury. The impact of this injury on adjacent tissue can be undesirable. Attempts have been made to limit the extent and range of injury to adjacent tissue. The O-Pel Surgical System (Precise Light Surgical, Inc., Campbell, CA), a new technology, utilizes kinetic energy through Pressure Induced Tissue Resection (PITR) (Precise Light Surgical, Inc.) to cut tissue, theoretically eliminating injury to adjacent tissue. The purpose of this study was to evaluate the PSL in canine vocal folds.Methods: Four dogs underwent PITR incisions (4 mJ pulses at 200 Hz) on their vocal folds, through mucosa into the muscle. The animals were sacrificed at days 0, 3, 7, and 21 days postsurgery. The larynges were harvested and histology was performed with hematoxylin and eosin, Masson trichrome, and Verhoeff-van Gieson.Results: At day 0, focal denudation of the epithelium and coagulation necrosis in the lamina propria and adjacent connective tissue are noted. On days 3 and 7, an inflammatory infiltrate of neutrophils is seen within the lamina propria and surrounding connective tissue with minimal edema and early deposition of collagen. At day 21, the mucosa is completely regenerated with the area of previous PITR into the muscle replaced with thick bundles of collagen.Conclusion: The unique PITR characteristics offer a potentially unique cutting technology for laryngeal microsurgery. The current canine study suggests appropriate and rapid healing. With refinements of the tip size of the probe and adjustment of energy, PITR will likely be an appropriate alternate to traditional lasers in laryngeal surgery.