Left Atrial Appendage Thrombus After Successful Surgical Exclusion on Anticoagulation: A Need for Closer Postintervention Monitoring

Abstract

A 59-year-old man with long-standing persistent atrial fibrillation underwent the first stage of a hybrid Maze by bilateral video-assisted thoracoscopy. Preoperative transesophageal echocardiogram (TEE) showed no atrial clot or mitral regurgitation. The left atrial appendage (LAA) was excluded with Endoloops (Ethicon, Somerville, NJ). He was discharged in sinus rhythm with prescriptions and instructions for continuing antiarrhythmic medications and warfarin. After 2 months, TEE demonstrated a 0.7-cm appendage stump (dotted arrow, Fig 1A) with thrombus (arrow, Figs 1A and 1B) despite adequate anticoagulation (INR 3.2). Six weeks later, TEE showed persistent, though smaller, thrombus (Fig 1C). Expert consensus on atrial fibrillation recommends complete LAA occlusion. Surgical literature defines remnant LAA as a stump or pouch longer than 1 cm [1Kanderian A.S. Gillinov A.M. Pettersson G.B. et al.Success of surgical left atrial appendage closure: assessment by transesophageal echocardiography.J Am Coll Cardiol. 2008; 52: 924-929Abstract Full Text Full Text PDF PubMed Scopus (377) Google Scholar]. After exclusion, late neurologic events occur at 0.2% with excision and 1.13% with nonexcisional techniques (median occurrence, 3.6 years) [2Lee R. Jivan A. Kruse J. et al.Late neurologic events after surgery for atrial fibrillation: rare but relevant.Ann Thorac Surg. 2013; 95: 126-132Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar]. This case demonstrates continued risk despite conventionally defined exclusion success. Similarly, reported endocardial thrombus after LARIAT (SentreHeart, Redwood City, CA) [3Giedrimas E. Lin A.C. Knight B.P. Left atrial thrombus after appendage closure using LARIAT.Circ Arrhythm Electrophysiol. 2013; 6: e52-e53Crossref PubMed Scopus (23) Google Scholar] implantation raises concerns with percutaneous techniques. These cases call for consideration of routine TEE monitoring, redefinition of successful exclusion, and improvement of current techniques.