C6 IN VIVO CHIARI NETWORK REMOVAL. COMPLICATION OR INNOCENT SURPRISE

Abstract

Abstract A 78 years old man was admitted to our hospital because of a syncope and evidence of complete AV– block, low ventricular rate and suitable for definitive PM implantation. He had no other pathologies or previous surgical interventions. A transthoracic echocardiography was performed and any particular structural anomaly was detected and the left ventricular ejection fraction was normal. In the electrophysiology laboratory, a vascular access through the left axillary vein was used to insert a passive fixation catheter for the right ventricular using a 9 F sheath. When the ventricular lead reached the right atrium it was impossible to advance it farther into the right ventricle; the lead was blocked near tricuspid anulus without any possibility to move it towards any direction despite many and vigorous manual traction maneuvers were attempted. Immediately, a transesophageal echocardiography was performed and it showed the lead entrapment into a mobile structure, likely a Chiari network.The patient needed a PM implantation as soon as possible and also a temporary PM could further complicate the procedure. Since the hospital did not have a cardiac surgery department and our crew was not familiar with lead extractions, an expert hemodynamist, who suggested to remove the lead by using a snare, was consulted. The tip of the lead was stuck in the atrial wall so it was impossible to capture it as expected. So, from right femoral vein access, a 6F pig–tail catheter was inserted through a a 45 cm– 8 F Terumo Destination sheath in order to give more stability to the pig–tail catheter until it hooked the lead. A 0.035 mm normal hydrophilic Terumo wire was later passed into the pig–tail catheter, snared and externalized with an AndraSnare 25 catheter inserted through another 6F introducer. A vigorous traction was performed simultaneously pulling both the ends of the wire from the bottom and the lead from the top. After a few seconds, the lead was unstuck and removed from the axillary vein [Fig. 1a,b]. At the external examination, the tines of the lead were found attached to a net–like structure that was actually the Chiari network that had been completely removed from the atrium [Fig 2–3]. A transthoracic echocardiogram ruled out any pericardial effusion. The anatomical finding was sent to tissue analysis and was confirmed to be the tendon material. After that the patient was immediately implanted with a VDD PM without any complications, and dismissed after 2 days.