A surgical procedure is necessary to implant the electrode under the phrenic nerve and the receiver just under the surface of the skin. This procedure can be done cervically (via the neck) or thoracically (via the chest). For bilateral stimulation (stimulation of both phrenic nerves) two antennas, two electrodes and two receivers are needed. For unilateral stimulation (stimulation of only one phrenic nerve) one antenna, one electrode and one receiver are needed.
The procedure averages 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 as to which approach is appropriate is determined by the surgeon performing the procedure.
The thoracic approach involves a small (5-7 cm) incision made between a pair of ribs so that the phrenic nerve can be isolated alongside the heart. The surgeon places the electrode under or near the phrenic nerve and sutures it in place. The receiver is then placed just under the skin, usually from within the same incision.
The thoracic approach can be performed in a minimally invasive manner by using VATS (video-assisted thoracic surgery) techniques. Since a small camera is used to provide visualization of the operative site, the incision can be significantly smaller.
The thoracic approach can also be performed thoracoscopically and involves the use of multiple small (5-10 mm) incisions instead of one primary incision. Through these incisions, a camera and specially designed instruments are used to visualize the nerve and place the electrode. Thoracoscopic procedures can be performed with standard endoscopic instruments or by use of a surgical robot.
This approach is commonly chosen for the youngest pediatric patients since the anatomy of the neck is not sufficiently developed in these cases. It is also a common approach for patients who are suspected of having nerve damage so that the stimulation can occur below the presumed injury.
The cervical approach is also considered minimally invasive since it does not require a thoracotomy, or chest procedure.
It uses a small (3-5 cm) incision made in the area where the neck meets the torso. The phrenic nerve is isolated where it is most superficial, the scalenus anticus muscle. The surgeon places the electrode under the phrenic nerve and sutures it in place.
The receiver is then placed just under the skin, usually within a small pocket made on the upper part of the chest.
This approach is commonly chosen for older pediatric patients and adult patients who are known to have good phrenic nerve conduction. In addition to avoiding a thoracotomy, this approach has the advantage that it can be performed on an outpatient basis for some patients.
The primary purpose of intraoperative testing is to confirm stimulation of the phrenic nerve. Intraoperatively, diaphragm function can be confirmed via a number of methods including: visual observation of chest wall, palpation of the costal margin, observation of CO2 changes as measured by anesthesia equipment, and rarely, fluoroscopy.
The primary purpose of intraoperative testing is to confirm stimulation of the phrenic nerve. Additionally, preliminary threshold and amplitude settings can be assessed. These numbers can provide a baseline from which pacing can be established once healing is complete.
The thoracoscopic surgical technique is unique in that the camera allows for direct visualization of the diaphragm while under stimulation.
Breathing pacemakers have been implanted in hundreds of hospitals in over forty countries around the world. Upon request, ABD may be able to provide a referral to an experienced surgeon depending on the patient’s age, diagnosis, and geographical location.
Detailed instructions on the cervical and thoracic approaches are provided in the Instruction Manual. The thoracoscopic approaches and nerve grafting techniques are discussed in a number of peer-reviewed journal articles. An information packet — containing a manual and reprints of these articles — may be obtained by filling out an information request.