[Modified posterior Dennis and Kashima cordectomy in treatment of bilateral recurrent nerve paralysis]

A number of different surgical methods are described in the literature to enlarge the glottic gap in patients with bilateral recurrent nerve paralysis with an excessively small glottic gap. The latest method is the posterior chordectomy described by Dennis and Kashima.

Twenty-three patients with bilateral recurrent nerve paralysis were treated between 1993 and 1997. In the first 5 patients, a muscular triangle as described by Dennis and Kashima from the posterior part of the muscular portion of the vocal fold was resected. Later on, the surgical procedure was extended by additional resection of muscular tissue from the anterior two-thirds of the vocal fold. Preoperative and postoperative data were carefully assessed in a prospective setting. Subjective data such as limitation of physical exertion and ability to communicate were documented. There was objective documentation by spirometry and phoniatric-logopedic assessment of voice quality parameters. Generally, it takes a number of months until the final permanent state is reached. The minimum follow-up was therefore at least 6 months with a mean of 16 months.

The follow-up of the 23 patients showed that the surgical technique as originally described by Dennis and Kashima does not always improve breathing sufficiently in the long run. A repeat chordectomy was required in three out of five patients with this technique. The modified technique with additional muscle resection of the anterior two-thirds of the vocal fold resulted in the desired long-term enlargement of the glottic gap in 16 out of 18 patients. Spirometric controls showed a significant improvement of respiration. However, some voice quality parameters showed a significant reduction as expected. Despite this, the overall communication ability was described as only slightly reduced by the patients themselves.

By the modified posterior laser chordectomy, the glottic gap is widened on a long term, though less than after an arytenoidectomy. The compromise between reduction of voice quality and dyspnoea is better than after arytenoidectomy. The preservation of the laryngeal sphincter is important in that it prevents the latent aspirations that are occasionally observed and achieves a certain adduction of the vocal folds with phonation. The surgical procedure is technically simple, may be repeated, and never needs a tracheostomy.