Vikram Vattipally, MD, Raymond P Onders, MD, MaryJo Elmo, ACNP, Eric M Pauli, MD. 1 Penn State Hershey Medical Center, Hershey, Pennsylvania. 2 University Hospitals Case Medical Center, Cleveland, Ohio.
Introduction:
Electrical pacing of the diaphragm was introduced over 40 years ago to treat patients with chronic apnea due to injury or diseases of the central nervous system. It provides a means to improve ventilation and eliminate the need for continuous ventilator support in patients with a variety of neurologic disorders. Laparoscopic implantation of diaphragm pacemaker system (DPS) electrodes directly into the diaphragm is an FDA approved procedure for diaphragmatic dysfunction from spinal cord injury or ALS (Lou Gehrig’s disease). Little data exists about the efficacy of DPS use in patients with diaphragm dysfunction from unknown etiology. Here we present a case of DPS implantation in a patient with off label indication of idiopathic diaphragm dysfunction with improved symptoms and quality of life.
Case:
A 46 year old obese male (Body Mass Index 47) was referred for consideration of DPS implantation. Months prior, the patient presented with dyspnea on exertion and subjective shortness of breath. Routine investigations for pneumonia demonstrated elevated left hemi diaphragm. Symptoms were progressive and were affecting quality of life and ability to perform activities of daily living. There was no evidence of underlying cardiopulmonary disease and no history of traumatic injury to the phrenic nerve. Pulmonary function tests demonstrated a restrictive pattern.FEV1, FVC, CT confirmed persistent left diaphragm elevation and no thoracic or cervical mass. Fluoroscopy showed limited excursion of the left dome of diaphragm without paradoxical movement, ruling out total paralysis. Electromyography revealed intact phrenic nerve bilaterally. Pulmonary, neurologic and thoracic evaluations failed to reveal source of his dysfunction. With institutional review board approval for off label use, the NeuRx DPS TM (Synapse Biomedical Inc. USA) system was successfully placed laparoscopically. During the mapping process, there was evidence of bilateral weakness as demonstrated by poor diaphragm contraction when electrically stimulated. Successful implantation was achieved and confirmed bilaterally.
Post-operatively the patient had no acute issues and was discharged on day 2. He developed a superficial surgical site infection along the electrode tract controlled with antibiotics. Over a 5 month interval his symptoms improved dramatically. He is again able to carry out all his daily activities and can walk a mile without shortness of breath. He is currently enrolled in our surgical weight loss program for consideration of a bariatric procedure to facilitate weight loss and further improve his pulmonary function. Repeat pulmonary function testing is pending.
Conclusion:
This case shows the successful use of DPS in a patient with idiopathic diaphragm dysfunction. Careful patient selection, including thorough evaluation for recognized diseases and an intact phrenic nerve is warranted. Further investigation into the use of DPS in the setting of idiopathic dysfunction is necessary to further elucidate the role of this technology in alleviating symptoms and restoring pulmonary function.
Reference:
1. Onders RP, et al. Complete worldwide operative experience in laparoscopic diaphragm pacing: results and differences in spinal cord injured patients and amyotrophic lateral sclerosis patients. Surg Endosc 2009;
2. Glenn WW, et al. Ventilatory support by pacing of the conditioned diaphragm in quadriplegia. N Engl J Med 1984
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