Diaphragm Pacing with a Quadripolar Phrenic Nerve Electrode: An International Study

Abstract

We sought to determine the international experience with the quadripolar diaphragm pacer system and to test two hypotheses: the incidence of pacer complications would be (1) increased among pediatric as compared to adult patients; and (2) highest among active pediatric patients with idiopathic congenital central hypoventilation syndrome (CCHS). Data were collected via a questionnaire coupled with the Atrotech Registry 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 duration averaged 2.0 +/- 1.0 years among children and 2.2 +/- 1.1 years 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 significant differences among patient groups. The incidence of presumed electrode and receiver failure were 3.1% and 5.9%, respectively, with internal component failure greater among pediatric CCHS than pediatric tetraplegic patients (P < 0.01). Intermittent or absent function of 0-4 electrode 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 pediatric and 52% of adult patients. In all, 94% of the pediatric and 86% of the adult patients paced successfully after the necessary intervention. 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 and improvement of the quadripolar system.

Presentation and Treatment of Monozygotic Twins with Congenital Central Hypoventilation Syndrome

“…In addition, patients are bilaterally -as opposed to unilaterally -paced to ensure adequate ventilation given the compliant chest walls and higher metabolic rates (27). The main advantage of diaphragmatic pacing is the opportunity for mobility; this mode of ventilation should be considered as patients become ambulatory (29). Therefore, diaphragmatic pacing is of particular benefit for patients requiring mechanical ventilation 24 h/day to ensure the opportunity to participate in normal, age-appropriate activities of childhood.…”

Bioinspired Design of Peripheral Nerve Devices

“…104,106,114−118 Though the incidence of such complications dropped following the transition away from a cuff electrode, including a reduction in electrode-associated issues from 15.7% to 6.6%, 106 component failure and mechanical effects on the nerve associated with adhesion and fixation of unipolar and quadripolar electrodes persist. 104,106,115,117 Advances in implantation technique compared to traditional methods, 119 including advances in endoscopic and/or robot-assisted implantation 110,119−122 have yielded improvements in patient outcomes and time of surgery. It is anticipated that advances in stimulation technology, such as electrode-free magnetic phrenic nerve stimulation, 123−125 will further reduce complications.…”

Activation of inspiratory muscles via spinal cord stimulation

“…Other investigators have since developed systems with improved electrode design (Talonen et al, 1990; Thoma et al, 1987) and less-invasive methods of electrode placement (DiMarco et al, 2002, 2005a; Onders et al, 2004; Shaul et al, 2007). DP has been commercially available for several decades and is considered a safe and practical method of providing respiratory support in ventilator dependent patients with cervical spinal cord injury (DiMarco, 1999, 2001; DiMarco et al, 1994, 2002, 2005a; Glenn et al, 1980, 1984, 1985a, 1985b, 1986b, 1988; Onders et al, 2004; Thoma et al, 1987) and also central hypoventilation syndrome (Ali and Flageole, 2008; Brouillette et al, 1983; Hunt et al, 1988; Ilbawi et al, 1985; Tibballs, 1991; Weese-Mayer et al, 1992, 1996). …”

“…While diaphragm pacing (DP) is successful in many patients in terms of eliminating or reducing the need for mechanical ventilation, current methods to provide respiratory support have the capacity to sustain full-time ventilatory support in only ~50% of patients (DiMarco et al, 1994, 2005a, 2005b; Onders et al, 2007; Weese-Mayer et al, 1996). There is a clinical need, therefore, to develop better methods of inspiratory muscle stimulation with the capacity to generate larger inspired volumes on a repetitive basis without the development of fatigue.…”