Breathing pacemakers are indicated for patients with diaphragm paralysis who would otherwise be completely or partially dependent on mechanical ventilation so long as the phrenic nerve(s) and diaphragm(s) are intact. Patients with diseases in which there is progressive demyelination of the phrenic nerves (such as ALS) or weakening of the diaphragm muscle (such as muscular dystrophy) are generally poor candidates for diaphragm pacing, however recent innovations have indicated that pacing options may exist for these patients under certain circumstances.
Careful preoperative evaluation (phrenic nerve conduction studies, pulmonary function tests, etc.) would be indicated in all cases. Benefits of diaphragm pacing for either unilateral or bilateral diaphragm paralysis include:
• Improved respiratory function since the inhaled air is drawn into the lungs by the diaphragm under negative pressure, rather than being forced into the chest under positive pressure.
• Lower infection rates due to the reduction in suctioning, elimination of external humidifier and ventilator circuits, and the potential removal of the tracheostomy tube.
• Improved mobility, normalized breathing and speech patterns, ease of eating and drinking.
For patients with unilateral diaphragm paralysis and non-functioning phrenic nerves, a phrenic nerve decompression or phrenic nerve transplant may be considered. A diaphragm plication procedure would be the last option if no other treatment options were appropriate. A phrenic nerve transplant involves harvesting a nerve graft from the leg, usually the sural nerve, and bypassing the site or area of injury in the neck and chest. To date, at the Institute for Advanced Reconstruction, we have performed approximately twenty phrenic nerve transplants with very high rates of success. The reconstructive microsurgeons at our Institute have pioneered this procedure and we are the only center nationally performing nerve transplants for unilateral diaphragm paralysis.
When a diaphragm pacemaker is the appropriate treatment, a surgical procedure is required to place the implanted electrode on the phrenic nerve and the implanted receiver just under the surface of the skin. This procedure can take place at the neck (cervically) or in the chest (thoracically). Usually patients receive two sets of implants, one on each side, unless their condition is limited to only one side.
At the New Jersey Institute for Advanced Reconstruction, many of our patients travel to see us from remote locations and we have staff members that are experienced and knowledgeable about arranging transportation and accommodations for ventilator dependent patients. We have a system in place to minimize the legwork required on the part of the patient and his or her families, and to make the entire process simple and easy. Diaphragm pacemaker surgery and phrenic nerve transplant surgery is performed at our University-based hospital affiliate, with staff that is comfortable caring for the special needs of our patients. The procedures average 2-4 hours in length, and the patient is typically discharged from the hospital 1-2 days later. Some procedures can be performed on an outpatient basis.
The decision regarding the appropriate procedure and approach for a given patient is made by our world renowned phrenic nerve transplant and diaphragm pacemaker surgeons who perform all procedures.
