Hypoglossal Nerve Stimulator Lead Extrusion Into the Pharynx

Hypoglossal nerve stimulator (HNS) is increasingly used as a treatment for obstructive sleep apnea (OSA) since its approval in 2014. Device extrusion was not reported in the initial Food and Drug Administration approval but has been reported at least 5 times since then.1, 2 All reported cases of device extrusion to-date have occurred through the skin. We report a case of stimulator lead extrusion into the pharynx presenting as a foreign body identified on esophagogastroduodenoscopy (EGD). A nonobese 71-year-old female presented to the sleep surgery clinic with moderate OSA (apnea-hypopnea index 14.7) intolerant of continuous positive airway pressure. She had a past medical history of severe acid reflux on pantoprazole, hiatal hernia, Barrett's esophagus, and sick sinus syndrome with a left-sided dual chamber pacemaker. She underwent uneventful 2-incision, right-sided HNS implantation. The anchor was secured to the digastric tendon, and the stimulation lead was tunneled in the subplatysmal plane in standard fashion. Postoperative course was uncomplicated, and device activation led to significant symptomatic improvement. One month postimplantation, she underwent an EGD for biopsy of Barrett's, showing low-grade dysplasia. She subsequently underwent Nissen fundoplication followed by 3-stage radiofrequency ablation of Barrett's. During the third stage performed 9 months postimplantation, the gastroenterologist identified a metallic foreign body in the pharynx/hypopharynx. An attempt at removal led to further displacement of the foreign body, at which point an exposed lead was suspected (Figure 1). Otolaryngology was called emergently to the endoscopy suite for airway management. Given the patient was breathing spontaneously without stridor or respiratory distress, she was awakened from sedation to discuss options. She expressed desire for future device reimplantation. Preoperative X-ray was obtained (Figure 2). The patient was then taken to the operating room and intubated uneventfully by anesthesia. The chest incision was opened, and the proximal end of the stimulation lead was cut, leaving the stimulation lead pin in the header to prevent tissue ingrowth and facilitate future reimplantation. The cervical incision was opened, and the electrode was cut just above the clavicle. The anchor was noted to be in good position on the digastric tendon. The central portion of the stimulation lead was removed, leaving the distal lead and cuff undisturbed on the nerve. Postoperative course was uncomplicated, and the patient was discharged on the day of surgery. Given that the small entry/exit points in the pharynx would likely heal quickly and the patient reported no immediate dysphagia postoperatively, additional swallow evaluation was deferred. At follow-up, she reported continued baseline odynophagia and no new dysphagia or globus sensation. She underwent successful reimplantation 3 months postoperatively without signs of infection. The remnant piece of the stimulation lead was removed. A new stimulation lead was placed and tunneled to the neck. The previous cuff around the hypoglossal nerve was removed and the cuff was replaced. The device was activated, and she again reported significant symptomatic improvement. This is the first reported case of extrusion of HNS lead into the pharynx. All prior reports of lead extrusion have been through the neck incision,1, 2 and successful reimplantation without infection has been reported.2 Other cervical foreign bodies have been reported to erode into the pharynx. Iatrogenic esophageal injury or thinning during anterior cervical disc fusion can lead to perforation/erosion.3 Vascular stents have also extruded into the pharynx, most commonly in patients previously treated with radiation, but also in the posttonsillectomy hemorrhage setting.4 Other than prior irradiation,5 there are no established risk factors for foreign body/implant erosion into the pharynx. Our patient did have multiple pharyngeal instrumentations (4 EGDs, 52F bougie during Nissen, and 1 intubation) within 9 months postimplantation, which could have increased pressure between the pharynx and the lead. There were no signs of complication during initial implantation; initial EGDs did not show lead extrusion; and neck exploration at the time of explantation showed the anchor secured to the digastric tendon. Together, these suggest that migration was not secondary to deep/medial tunneling. Given the patient's desire for continued HNS therapy and her left-sided cardiac pacemaker, we elected to attempt to preserve her current device. The device and leads did not seem grossly infected at the time of electrode explant, thus we elected to just remove the central portion of the electrode, keeping the pin in the header and the cuff on the nerve. The patient was discharged on antibiotics with no signs of infection after surgery. The patient was successfully reimplanted 3 months postoperatively without signs of infection. While this case did not show signs of deep neck space infection, this could represent an esophageal perforation and postoperative monitoring for signs of deep infection and mediastinitis is prudent. In conclusion, we present the first reported case of pharyngeal extrusion of the stimulator lead, a rare complication in HNS. A potential patient risk factor in this case is multiple pharyngeal instrumentations in the months following surgery. If the neck is not grossly infected, removal of only the stimulation lead allowed for preservation of the implantable pulse generator and facilitates reimplantation with decreased scarring. Ryan T. Judd, direct patient care and decision-making, manuscript writing, figure design, and final approval; Eugene Chio, direct patient care and decision-making, manuscript writing, figure design, and final approval. Eugene Chio, MD, is a consultant for INSPIRE Medical and Nyxoah. None.