DIAPHRAGM PACING WITH A QUADRIPOLAR PHRENIC-NERVE ELECTRODE - AN INTERNATIONAL STUDY

We sought to determine the international experience with the quadripol ar diaphragm pacer system and to test two hypotheses: the incidence of pacer complications would be (1) increased among pediatric as compare d to adult patients; and (2) highest among active pediatric patients w ith idiopathic congenital central hypoventilation syndrome (CCHS). Dat a were collected via a questionnaire coupled with the Atrotech Registr y data for a total of 64 patients (35 children and 29 adults) from 14 countries. Thoracic implantation of electrodes and bilateral pacer use each occurred in 94% of all subjects. Tetraplegic (vs pediatric CCHS) patients were more typically paced 24 hours/day (P = 0.001). Pacing d uration averaged 2.0 +/- 1.0 years among children and 2.2 +/- 1.1 year s among adults. Infections occurred among 2.9% of surgical procedures, all in pediatric CCHS patients (vs pediatric tetraplegic patients, P = 0.01). The incidence of mechanical trauma was 3.8%, without signific ant differences among patient groups. The incidence of presumed electr ode and receiver failure were 3.1% and 5.9%, respectively with inferna l component failure greater among pediatric CCHS than pediatric tetrap legic patients (P < 0.01). Intermittent or absent function of 0-4 elec trode combinations occurred among 19% of all patients, with increased frequency among pediatric CCHS than pediatric tetraplegic patients (P < 0.03). Complication-free successful pacing occurred in 60% of pediat ric and 52% of adult patients. In all, 94% of the pediatric and 86% of the adult patients paced successfully after the necessary interventio n. Although pacer complications were not increased among pediatric as compared to adult patients, the incidence of complications was highest among the active pediatric patients with CCHS. Longitudinal study of these patients will provide invaluable information for modification an d improvement of the quadripolar system.