The role of cardiac imaging before and after left atrial appendage standalone thoracoscopic exclusion

Aims: To assess the characteristics of left atrial appendage (LAA) stump and left atrial (LA) volume after standalone totally thoracoscopic LAA exclusion in 40 patients with nonvalvular atrial fibrillation (NVAF) and contraindications to oral anticoagulation (OAC), using cardiac computed tomography (CCT) and transoesophageal echocardiography (TOE). Methods: Using CCT and TOE, we evaluated correct AtriClip Pro II positioning, the presence and characteristics of the LAA stump and the postprocedural LA volume, at 3 months' follow-up. Stump depth was measured with both CCT and TOE using a new method, based on left circumflex artery (LCX) course. Results: After placement of AtriClip, all 40 patients discontinued OAC, and no stroke occurred. LAA exclusion was achieved in 40/40 patients at 3 months' follow-up. LAA stump (depth <10 mm in 12/18 stump, 67%) was observed in 18 patients. The overall (LA + LAA) volume and isolated LA volume were statistically different when comparing cases with and without LAA stump (P < 0.02). LAA ostium dimensions (perimeter and area) and LAA volume correlate with stump depth (P < 0.02). There was a high correlation between CCT and TOE in stump identification and depth measurement (P < 0.02). Compared with the baseline, CCT LA volume increased (P < 0.01) at 3 months' follow-up. Conclusion: Preprocedural and postprocedural CCT and TOE are useful and comparable in patients undergoing standalone totally thoracoscopic exclusion of LAA, because these imaging methods can identify anatomical LAA and LA characteristics predisposing for a postprocedural residual stump.