Diaphragm pacing: the state of the art

Abstract

Diaphragm pacing (DP) is an orphan surgical procedure that may be proposed in strictly selected ventilator-dependent patients to get an active diaphragm contraction. The goal is to wean from mechanical ventilation (MV) and restore permanent efficient breathing. The two validated indications, despite the lack of randomised control trials, concern patients with high-level spinal cord injuries (SCI) and central hypoventilation syndromes (CHS). To date, two different techniques exist. The first, intrathoracic diaphragm pacing (IT-DP), based on a radiofrequency method, in which the electrodes are directly placed around the phrenic nerve. The second, intraperitoneal diaphragm pacing (IP-DP) uses intradiaphragmatic electrodes implanted through laparoscopy. In both techniques, the phrenic nerves must be intact and diaphragm reconditioning is always required after implantation. No perioperative mortality has been reported and ventilator-weaning rate is about 72% to 96% in both techniques. Improvement of quality of life, by restoring a more physiological breathing, has been almost constant in patients that could be weaned. Failure or delay in recovery of effective diaphragm contractions could be due to irreversible amyotrophy or chest wall damage. Recent works have evaluated the interest of IP-DP in amyotrophic lateral sclerosis (ALS). After some short series were reported in the literature, the only multicentric randomized study including 74 ALS patients was prematurely stopped because of excessive mortality in paced patients. Then, another trial analysed the place of IP-DP in peripheral diaphragm dysfunction but, given the multiple biases, the published results cannot validate that indication. Reviewing all available literature as in our experience, shows that DP is an effective method to wean selected patients dependent on ventilator and improve their daily life. Other potential indications will have to be evaluated by randomised control trials.

Diaphragm Dysfunction: Diagnostic Approaches and Management Strategies

“…A complete review of the technical aspects of this technique is beyond the scope of this text, and recent high-quality reviews have summarized the available knowledge on this subject [170]. Briefly, the phrenic nerves can be stimulated using implanted electrodes inserted either directly at the thoracic level or on the abdominal aspect of the diaphragm.…”

Evaluation of the Safety of Percutaneous Electrical Stimulation of the Phrenic and Femoral Nerves in a Chronic Porcine Model: A GLP Study

“…Sarnoff in 1948 [4]. The clinical use of implantable diaphragmatic pacemakers has subsequently been validated in patients requiring chronic, retracted MV [5]. Intermittent electrical stimulation of the phrenic nerves to pace the diaphragm has been suggested as a strategy to minimize the reduction in diaphragm atrophy and to potentially reduce weaning failure [2].…”

In Reply—Diaphragmatic Pacemaker for Perry Syndrome

“…We would like to mention another neurostimulation device, the diaphragmatic pacemaker, which is clinically indicated for patients with neurologic disorders that require chronic respiratory support, such as brain stem/upper spinal cord injuries and congenital central hypoventilation. 2 This device produces the diaphragm muscle contracture via direct stimulation of phrenic nerves. There are 2 types of devices.…”

“…There are 2 types of devices. 2 One requires that electrodes are placed on the diaphragm surface to stimulate the phrenic nerve at or near the neuromuscular junction. The electrodes come out through the skin and connect to the external pulse generator.…”