Myringotomy Made by CO₂Laser An Alternative to the Ventilation Tube?:An Experimental Study

Abstract

In order to examine whether a myringotomy made with a CO2-laser might be alternative to a ventilation tube, a perforation was made in the upper rear quadrant bilaterally, of 22 rats. The laser-made perforations showed a delayed healing pattern, about twice the closing time of a similar-sized perforation made with a myringotomy lancet. Serous effusion was constantly observed in the attic space during the first 9 days but only in one ear was there actual discharge through the perforation. The size of the perforation started to diminish when the hyperplastic keratinizing squamous epithelium reached the perforation border.

IR Lasers and Application Systems for Myringotomy

“…tissues such as the tympanic membrane have a water component of 70-80%. CO 2 laser radiation with a wavelength of 10 600 nm and erbium:YAG laser radiation with a wavelength of 2940 nm are strongly absorbed by the most superficial layers of the tympanic membrane [2][3][4][5]. The presence of fluid in the middle ear, as in secretory otitis media (SOM), is the most important indication for myringotomy.…”

“…Since the introduction of laser myringotomy, CO 2 laser radiation has been transmitted to the tympanic membrane by micromanipulators that di#er in terms of spot size and beam profile [4][5][6][7]. The new generation of micromanipulators can focus the laser beam to a spot size of 200 m or less generating a high power density and reducing the thermic side e#ects.…”

Das CO 2 -Laserotoskop

“…Auf das einzelne Trommelfell wurden mehrere Einzelpulse in ausreichendem Ab- [19] und 1982 erstmalig klinisch in den USA angewendet [5]. 1984 publizierten Soederberg et al histologisch-morphologische Untersuchungen der Lasergewebeinteraktion am Trommelfell [18]. 1994 stellte eine Arbeitsgruppe aus Israel den in vitro getesteten Prototypen eines CO 2 -Laserotoskops vor, bei dem die Laserstrahlung über optische Fasern durch ein leicht modifiziertes, handelsübliches Otoskop auf das Trommelfell übertragen wurde [4].…”

The effects of incisional myringotomy and CO2 laser myringotomy on rat tympanic membranes

“…In 10 of 11 patients, laser myringotomies healed within 6 weeks. Söderberg et al [7] performed CO 2 laser myringotomies in 22 rats. All perforations closed within 24 days.…”

“…The incisions were 2 mm in size on both ears. Examination was made with otoendoscope on days 1, 3,5,7,9,11,13, 15, 17, 19, 21, 25, 30, 35, 40, 45, 50 with videorecording. Two rats were sacrificed every 2 days for 25 days and every 5 days thereafter, randomly.…”