Manual control of the upper esophageal sphincter.

OBJECTIVES/HYPOTHESIS: Oropharyngeal dysphagia (OPD) is common and costly. In order to improve quality of life for patients and costs to society, better treatments than currently available are needed. The author hypothesized that manual control of the upper esophageal sphincter (UES) is possible by pulling the larynx directly forward with anterior traction on the cricoid cartilage. The purpose of this investigation was to evaluate the effectiveness of manual control of the UES as a possible therapy for OPD.

STUDY DESIGN: Retrospective chart review, medical device development, prospective cadaver trial, and prospective animal experiment.

METHODS: Charts were reviewed of all persons with OPD who had a traction suture placed by the author around the anterior rim of the cricoid cartilage. The opening of the UES was assessed with and without traction on the suture. The ability of the cricoid suture to improve UES opening was evaluated under fluoroscopy. The Swallow Expansion Device (SED) was designed to manually control the UES. The ability of the SED to manually open the UES was evaluated. The SED was implanted in 10 cadavers, and 5,000 pulls of the device were performed on each specimen to evaluate for gross damage to the cricoid cartilage. The ability of the SED to open the UES was evaluated under direct laryngoscopy. The safety and efficacy of the SED was evaluated in an ovine model of OPD. The SED was implanted in eight sheep. Five thousand pulls of the device were performed on each animal weekly for 8 weeks. At the end of the study, damage to the cricoid cartilage was evaluated histologically, and the ability of the SED to open the UES and eliminate aspiration was assessed fluoroscopically.

RESULTS: Six patients with OPD who had a suture placed around the anterior aspect of the cricoid cartilage were identified. Anterior traction on the suture improved UES opening by 0.36 cm (+/-0.19 cm) (P < .01). A titanium-coated ferrous implant that secures to the cricoid cartilage was fabricated (SED). An external magnetic device that affixes to the implant across intact skin was developed. Anterior traction of the SED opened the UES in cadavers a mean of 1.16 cm (+/-0.22 cm) (P < .001). Anterior traction on the SED opened the UES in sheep a mean of 1.27 cm (+/-0.36) (P < .001). Aspiration was eliminated in 100% of the animals. The implant became infected and had to be removed in one (12.5%) animal. Remodeling of the cricoid cartilage was evident, but there was no histologic evidence of cartilage damage.

CONCLUSIONS: Manual control of the upper esophageal sphincter is possible. Simple anterior traction on the suture placed around the cricoid cartilage improved UES opening by 0.36 cm (+/-0.19) in a cohort of dysphagic patients. The Swallow Expansion Device opened the UES of cadavers and living sheep to superphysiologic proportions (P < .001). There was no histologic evidence of cricoid damage from prolonged use of the implant.