In the literature, various theories concerning the cause of Zenker's diverticulum have been propounded. I believe that an anatomic predisposition plays a prominent role in the pathogenesis. This conclusion will be discussed in light of a study of the literature and characteristics of a series of 646 patients with Zenker's diverticulum. The current methods of treatment by an external surgical approach, as well as the (micro)endoscopic procedures, are described.

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.

Whether the occlusion between hypopharynx and esophagus is established by anatomical relations and tissue elasticity or by a functional resting tone of the muscle fibers is not quite clear. This study describes simultaneous electromyography (EMG) and electromanometry in the pharyngoesophageal segment to solve this problem and investigate the complex mechanism of deglutition. To register the EMG from the hypopharyngeal constrictor muscle and the upper esophageal sphincter (UES), two copper wire electrode pairs with hooked bare ends were used. These electrodes were introduced into the muscles through a rigid esophagoscope. It is demonstrated that at rest muscle activity is present in the UES. This activity disappears during the relaxation period. Simultaneous manometry and EMG is a valuable supplement to diagnostic procedures in dysphagia patients.

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.

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.