Laser surgery in lingual tonsil hyperplasia.

Modern techniques have reduced the long existing reluctance to perform lingual tonsillectomy. The results of treatment of hyperplasia of the lingual tonsil with the carbon dioxide laser in 32 patients are presented. After exposure with a special endoscope the lingual tonsil can be vaporized or excised under microscopic control with promising results, far superior to the results obtained with other surgical techniques. Since the success rate of the surgery depends on the diagnostic criteria for applying this therapy, a careful selection of patients is essential.

Microendoscopic surgery of the hypopharyngeal pouch with the CO2 laser.

In 1964 we started to treat hypopharyngeal (Zenker's) diverticula endoscopically, using the procedure described by Dohlman. With the increase in the number of patients (350), the technique and the instruments used have improved. This paper describes the technique, which involves exposure of the tissue bridge between esophagus and diverticulum with the aid of a specially designed scope and subsequent severance with the CO2 laser of this bridge under microscopic control. The use of an operating microscope and the laser is a great improvement in endoscopic treatment of hypopharyngeal diverticula.

CO2 laser in malignant lesions of the larynx.

The CO2 laser is being used in several otolaryngology departments around the world. Clinical experience has shown that it is a unique surgical tool in the management of benign and in some malignant lesions of the larynx. Until now, little has been written about its indications in patients with carcinomas of the larynx. The purpose of this paper is to present our experience with 58 patients with various premalignant and malignant lesions of the larynx in which the CO2 laser was employed as a curative or palliative debulking procedure.

Microendoscopic surgery of the hypopharyngeal diverticulum using electrocoagulation or carbon dioxide laser.

In 1964 we started to treat hypopharyngeal (Zenker's) diverticular endoscopically, using the procedure described by Dohlman. With the increase in the number of patients (274 patients up until 1982), the technique and the instruments used have improved. This paper describes the technique we have used since 1981, which involves exposure of the tissue bridge between esophagus and diverticulum with the aid of a specially designed scope and subsequent severance of this bridge under microscopic control. In 12 cases the bridge was severed by electrocoagulation, while the CO2 laser was used for this purpose in another 12 cases. Both techniques have given good results. Essential advantages or disadvantages of either of these methods could not be elicited. We regard the use of an operating microscope as a great improvement.

Endoscopic treatment of the hypopharyngeal diverticulum: 211 cases.

It is somewhat surprising that endoscopic treatment of hypopharyngeal diverticula has failed to become as widely known as the method merits in our opinion. In principle we use the Dohlman procedure. The septum between diverticulum and esophageal lumen is divided with a diathermic knife after electrocoagulation. In larger diverticula we prefer to divide the tissue bridge in several sessions. Endoscopic treatment (under local anesthesia, if necessary) can be carried out in patients whose general condition is poor. From 1964 until 1980 we have endoscopically treated 211 patients, including 6 patients with a recurrent diverticulum after transcutaneous surgery. The complication rate is low and the complications were successfully controlled except in 1 patient, who died from cardiac failure 2 days after operation. Ultimately 193 patients (91.5%) are very satisfied and 17 patients (8%) are fairly satisfied with the therapeutic result. We feel justified in maintaining that endoscopic treatment of hypopharyngeal diverticula can be regarded as a good method of treatment.

[The CO2 laser in laryngeal diseases]. / De CO2-laser bij larynxaandoeningen.

At present the CO2-laser is employed in almost every surgical specialism. If it is right to prefer laser treatment for special operations to conventional surgical methods, is not yet decided. However, the use of laser beam energy for laryngeal conditions offers undeniable advantages as: -- No direct instrumental contact. Involuntary movements which can occur when using long-reach instruments during conventional microlaryngeal surgery do not play a role. -- Little bleeding. The treating area stays all the time under good visual control. --Outmost precision by which an intended operation is to perform. Exact on the desired place with an adjust quantity of energy tissue can be vaporized as well with very limited amount as extensive, or be removed by cutting round. -- No postoperative edema. No or hardly any edema means that tracheotomy often needed for some conditions in another way of treatment usually is unnecessary. On account of experience during 4 years is shown which possibilities laser-microlarynx surgery offers.

Scanning electron microscopic study of the organ of Corti in normal and sound-damaged guinea pigs.

A method was evolved by which the organ of Corti could be examined in its entirety with the scanning electron microscope, the organ meanwhile retaining its spiral form. This made it possible to assess traumatic effects on the cochlea and qualify lesions in terms of extent, localization and pattern. It was also found possible eventually to cut the same specimen into sections for cellular and subcellular studies. The number of guinea pigs examined totalled 91, divided into three groups. The first group was used to study the anatomy of the organ of Corti with special reference to normal variations and artifacts. Unmistakable indications were found that the longest stereocilia of the inner hair cells are linked to the tectorial membrane. The animals of the second group were exposed to pure tones of high intensity, whereupon, lesions of the organ of Corti were described according to intensity, time, and frequency. Three different types of otologic drills were used to perform mastoidectomies on temporal bones and on the cadaver. The noise produced was analyzed as to intensity and frequency range. It was found that the drill with the lowest rpm (and highest torque) produced the highest noise intensities, at levels which can be traumatic to the human organ of hearing. The animals of the third group were exposed to the amplified noise produced by otologic drills of three different types. The resulting lesions in the organ of Corti were examined by the method described for scanning electron microscopy and compared. In spite of the wide variation in individual lesions, patterns of degeneration of three different types could be distinguished. The high-speed and the very-high-speed drill inflicted less damage on the organ of Corti than the low-speed drill. It is therefore advised to refrain from using the latter drill in prolonged operations.