Thoracoscopic patch insulation to correct phrenic nerve stimulation secondary to cardiac resynchronization therapy

Abstract

Cardiac resynchronization therapy is an established therapy for heart failure, improving quality of life and prognosis. Despite advances in technique, available leads and delivery systems, trans-venous left ventricular (LV) lead positioning remains dependent on the patient's underlying venous anatomy. The left phrenic nerve courses over the surface of the pericardium laterally and may be stimulated by the LV pacing lead, causing uncomfortable diaphragmatic twitch. This paper describes a video-assisted thoracoscopic (VATS) procedure to correct phrenic nerve stimulation secondary to cardiac resynchronization therapy. Most current ways of avoiding phrenic stimulation involve either electronic reprogramming to distance the phrenic nerve from the stimulation circuit or repositioning the lead. We describe a case where the phrenic nerve was surgically insulated from the stimulating current by insinuating a patch of bovine pericardium between the epicardium and native pericardium of the heart thus completely resolving previously intolerable and incessant diaphragmatic twitch. The procedure was performed under general anaesthesia with single-lung ventilation and minimal use of neuromuscular blocking agents. Surgical patch insulation of the phrenic nerve was performed using minimally invasive VATS surgery, as a short-stay procedure, with no complications. No diaphragmatic twitch occurred post-surgery and the patient continued to gain symptomatic benefit from cardiac synchronization therapy (New York Heart Association Class III to II), enabling return to work. In cases where the trans-venous position of a LV lead is limited by troublesome phrenic nerve stimulation, thoracoscopic surgical patch insulation of the phrenic nerve could be considered to allow beneficial cardiac resynchronization therapy.