An inflatable device that helps strengthen muscles in the throat can improve symptoms in some people with dysphagia, new research shows.

The study showed large improvements, including resolution of aspiration, in training sessions conducted over six to 18 weeks with the device, which trains the pharyngeal and suprahyoid muscles.

“Of the 17 patients with aspiration at baseline, resolution was achieved by week 6 in four patients and by week 12 in another four,” said Dilpesh Agrawal, MD, a fellow in gastroenterology and hepatology at the Medical College of Wisconsin, in Milwaukee.

Objective improvements in swallowing were evident on video fluoroscopic examinations. These included change in the diameter of the opening to the upper esophageal sphincter (UES) and anterior displacement of the hyoid and larynx. Patients also reported gains.

Oropharyngeal dysphagia affects an estimated 16 million people in the United States. Exercise to improve swallowing function makes sense, Dr. Agrawal said. Overloading and fatiguing the muscles involved in the pharyngeal phase of swallowing could lead to improved strength, as occurs when other striated muscles are worked.

However, several previous attempts to use exercise to improve swallowing muscle strength have produced little if any meaningful clinical improvement.

The device used in this study features an inflatable bag that fits over the thyroid cartilage and provides resistance to muscles involved in the pharyngeal phase of swallowing. This technique is known as swallowing against laryngeal restriction (SALR).

For the new study, the bag was inflated to 40 mm Hg with the exerciser device strapped around the neck. Patients (N=29) were instructed to perform 30 consecutive swallows at 15-second intervals during each of three daily training sessions. The exercises were safe and well tolerated, Dr. Agrawal said.

The causes of dysphagia in the study patients included stroke, damage from cancer therapy, aging, a stab wound to the pharynx, esophagectomy, cervical spine injury, cervical osteophytes and proximal esophageal hypomotility. Symptoms had been present for as little as six months and as long as 15 years.

All patients had failed conventional swallowing training without the device. The initial treatment program lasted for six weeks. If symptoms did not resolve, patients were permitted to extend the exercise program for an additional 12 weeks.

The researchers observed incremental improvement over time that was consistent with muscle strenghtening. Of the 29 study participants, 17 improved and terminated training at six weeks; 10 by 12 weeks; and the remaining two by 18 weeks. Half of the patients with aspiration at baseline reported resolution of the problem after resistance training. In addition, Dr. Agrawal and his colleagues found the treatment was associated with a significant increase in the opening diameter of the UES (P<0.01), anterior displacement of the hyoid and larynx (P<0.05), and in swallowing function (P<0.01), as measured by a validated questionnaire for dysphagia.

The results provide “a foundation for future studies” that may lead to a commercially available tool, Dr. Agrawal said.

Another study assessed a related approach (Laryngoscope 2017 Aug 22. [Epub ahead of print]) in 26 patients with radiation-associated aspiration following treatment for head and neck cancer, who underwent expiratory muscle strength training (EMST) with a device-driven exercise therapy.

“We used EMST, which is a spring-loaded respiratory device rather than the submental resistive bag,” explained Katherine A. Hutcheson, MD, associate professor at the University of Texas MD Anderson Cancer Center, in Houston.

The 23 patients who completed training experienced significant improvement in an objective measure of swallowing safety (P=0.03) and a trend for improvement in perceived dysphagia (P=0.13), Dr. Hutcheson said.

Like benefit from training seen in Dr. Agrawal’s study, “our data would support the premise of benefit from progressive EMST,” she added.

Dysphagia is particularly common in the elderly, and Dr. Agrawal said muscle training could help prevent the problem or offer early treatment.

These data have “important clinical ramifications,” according to Dr. Agrawal. “Considering the strengthening effect of the proposed exercise and its ease of performance, it can be envisioned that it could potentially offer a viable approach for developing a swallow health maintenance program in the elderly population.”

—Ted Bosworth

Drs. Agrawal and Hutcheson reported no relevant financial conflicts of interest.