Alternating unilateral botulinum toxin type A (BOTOX) injections for spasmodic dysphonia.

Injection of botulinum toxin type A (BOTOX) into both thyroarytenoid muscles is an accepted treatment for spasmodic dysphonia. The authors of this study identified patients who could not tolerate the interval of breathy voice that immediately follows bilateral injections. These patients were offered a protocol in which the injection side was alternated on subsequent treatments. Eighteen patients who received at least two bilateral injections and two unilateral injections were reviewed. Alternating unilateral injections yielded a shorter breathy interval by an average of 12.7 days (P=.0007) and a shorter duration of return of spasmodic symptoms by an average of 26.0 days (P=.0006). Compared with bilateral injections, alternating unilateral injections yielded an average (median) of 3.2 more days of strong voice per day of breathy voice (P=.001). However, unilateral injections had a shorter average interval of strong voice (27.4 days; P=.007), as well as a slightly higher failure rate (4.9% vs. 1.1%). The authors conclude that alternating unilateral botulinum toxin type A injections are useful in patients with spasmodic dysphonia who have difficulty with the breathy voice that follows bilateral injection.

Vocal fold paralysis following the anterior approach to the cervical spine.

The anterior cervical approach is commonly used for access to the cervical spine. Vocal fold paralysis (VFP), a complication of this approach, is underrepresented in the literature. A review of the database of the Vanderbilt Voice Center revealed 289 patients with VFP, including 16 patients who developed paralysis as a result of an anterior cervical approach. The paralysis was on the right side in all but 1 patient. Compared to patients who developed VFP after thyroidectomy and carotid endarterectomy, patients with VFP after an anterior cervical approach have a higher incidence of aspiration and dysphagia, suggesting the presence of trauma to the superior laryngeal and pharyngeal branches as well as the recurrent branch of the vagus nerve. Two patients had partial return and 1 patient had complete return of vocal fold movement within 10 months. Of the remaining 13 patients, 8 underwent vocal fold medialization with improvement of symptoms. Two patients are 6 and 7 months postinjury and await vocal fold medialization. Two patients are 27 months and 45 months postinjury and are considering vocal fold medialization. The remaining patient was lost to follow-up. An anatomic-geometric analysis of the right and left recurrent laryngeal nerves was performed by using measurements obtained from computed tomography scans of 8 patients with idiopathic unilateral VFP, as well as experience gained through surgical and cadaveric dissections. We conclude 1) the anterior cervical approach may place multiple branches of the vagus nerve at risk; 2) because of anatomic-geometric factors, the right-sided anterior cervical approach may carry a greater risk to the ipsilateral recurrent laryngeal nerve than does the left; and 3) an understanding of the anatomy and geometry presented herein allows relatively safe exposure from either side of the neck.

Open surgical techniques for laryngotracheal stenosis.

Adult subglottic and proximal tracheal stenoses are some of the most crippling complications of endotracheal intubation or other laryngotracheal trauma. Subglottic stenoses are a part of the broader category of laryngotracheal stenoses that comprises any lesion from supraglottic larynx to trachea. Patients with laryngotracheal or tracheal stenosis may present with stridor, shortness of breath, or exercise intolerance and may be tracheotomy dependent. The surgeon must have several choices of procedures available to correctly treat the variety of lesions that may occur. This article briefly outlines the pathophysiology of subglottic and tracheal stenosis and discusses in detail the open procedures available.

A tissue-culture model for the study of canine vocal fold fibroblasts.

A tissue-culture model has been developed for the study of fibroblasts from the canine vocal fold. Laryngeal tissue (lamina propria) obtained from euthanized dogs is rinsed, cut into 1-mm3 pieces, and incubated in 5% carbon dioxide at 37 degrees C. A confluent monolayer is established within several days. Detectable levels of elastin in the tissue culture supernatant are measured by an indirect enzyme-linked immunosorbent assay. Various external agents have been shown to affect elastin production. The effects of KTP laser irradiation, hydrocortisone (1.3 mumol/L), transforming growth factor-beta (10 ng/mL), and human leukocyte elastase have been measured. Thus the canine vocal fold fibroblast tissue culture is established as a model for further investigations to improve wound healing and to understand the wound-healing process following laryngeal microsurgery.

Difficulties in endoscopic removal of Teflon granulomas of the vocal fold.

The difficulties in treating granulomas resulting from Teflon injection into the vocal fold are underreported in the literature. We have reviewed our experience with nine patients undergoing 27 procedures for Teflon granuloma. Two patients required tracheotomy before undergoing endoscopic granuloma removal because of airway compromise, and a third required urgent tracheotomy following endoscopy. One of the patients requiring elective tracheotomy had a granuloma that extended across the midline to the contralateral arytenoid, causing its fixation. Arytenoidectomy was required for decannulation in this patient. In all but one patient the granuloma nearly completely replaced the thyroarytenoid muscle. This extensive involvement often precludes the adequate excision of the granuloma in a single procedure; however, the microflap technique allows mucosal preservation to facilitate future procedures. In some cases the granuloma destroys large amounts of mucosa, and a microflap cannot be elevated and saved. The difficulties of excision are related to the near-total replacement of the thyroarytenoid muscle by granuloma. This paper will help the otolaryngologist--head and neck surgeon understand this destructive process and the resulting difficulties in surgical rehabilitation.

A new endotracheal tube for carbon dioxide and KTP laser surgery of the aerodigestive tract.

We have tested the fire-resistance of a new endotracheal tube designed for use in laser surgery of the upper aerodigestive tract. This Teflon/metallic-wrapped silicone tube seems capable of withstanding occasional, accidental pulsed laser impact at power settings used clinically (1 to 10 watts) without fire. On rare occasions when continuous mode is used, the tube seems capable of withstanding at least several seconds of continuous irradiation at clinical power settings without igniting. When used with other recommended safety procedures, this tube should minimize the risk of endotracheal tube fire from accidental laser impact.

Characterization of clones of a human pancreatic adenocarcinoma cell line representing different stages of differentiation.

With a limiting dilution technique, clones have been established from the human pancreatic adenocarcinoma cell line, HPAF. Phenotypic analysis by a panel of murine monoclonal antibodies demonstrated distinct profiles of antigenic expression between the clones. However, identical isozyme patterns of different clones indicated their common origin from the parental HPAF cells. Two clones, CD11 and CD18, appeared to be arrested at different stages of secretory epithelial cell differentiation. CD11 cells demonstrated many characteristics of a well-differentiated state, including the formation of ductal structures with polarized, long columnar-shaped cells, the presence of secretory granules in the cytoplasm, high DU-PAN-2 antigen expression in nude mouse xenografts, and a longer doubling time (42 h) in tissue culture. In contrast, CD18 cells exhibited characteristics of a poorly differentiated state, including solid nests of isoprismatic cells without luminal spaces and cellular polarization, absence of secretory granules and DU-PAN-2 antigen expression in xenografts, and a shorter doubling time (26 h) in tissue culture. Since no culture systems of normal pancreatic ductal cells are currently available, these two pancreatic adenocarcinoma clones may provide a unique system to study genes and antigens related to pancreatic ductal cell differentiation.