Disseminated head and neck cancer is a serious, often life-threatening medical problem that requires immediate and heroic therapeutic intervention. Treatment typically begins with extensive surgery followed as soon as possible by an intense series of radiation and chemotherapy treatments. Typically the patient has recovered sufficiently from the surgery by 2-4 weeks to withstand the new assaults that will result from chemoradiation therapy (CRT), which kills cancer cells, but also causes muscle atrophy and scarring that can permanently ruin the swallowing apparatus. Thus, the majority of patients who undergo CRT develop severe swallowing problems, called dysphagia, that typically becomes worse by about 3-4 weeks following the beginning of CRT. In anticipation of all of these problems, subjects have a tube placed in the stomach (gastrostomy tube) so that they can be fed through the tube in the immediate postoperative period when the incision is fragile and when dysphagia develops during CRT. Clearly the management of dysphagia during CRT is of primary importance to the prognosis of the patient. Recent studies have shown that electrical activation of swallowing muscles during and after CRT can improve the prognosis by reducing dysphagia, but currently available technology requires the current to be applied transcutaneously. Thus, large electrical currents must be applied to the damaged skin, and the electrical stimulation that results is uncomfortable, diffuse and uncontrolled. It is difficult with this approach to stimulate the deepest muscles that are the preferred targets for the stimulation. The primary goal of the proposed study is to improve the long-term swallowing capabilities of subjects undergoing radical or modified radical neck surgeries followed by CRT, by more selective stimulation of the swallowing muscles using implanted microstimulators called BIONs. The mechanism of the electrical stimulation is thought to be the same as that for other rehabilitative approaches to muscle, i.e.,to help maintain strength and mobility of these muscles during the post-operative treatment period when the muscles are not being used and are particularly vulnerable to scarring and atrophy.
Two different paradigms of stimulation will be employed in order to compare and gain insight into the mechanisms involved in the remediation. This study also presents the opportunity to examine directly the changes in muscle produced by stimulation. Thus, a secondary research goal of the study that takes advantage of the opportunity presented by this intervention is to gain insight into the cellular changes that are thought to underlie the effects of radiation and subsequent electrical stimulation. By implanting these devices at the time of the neck surgeries, it is possible to target the nerves that supply specific muscles and thus ensure the excitation of specific muscles using current strengths much lower than those required with transcutaneous stimulation.
