Inverted left atrial appendage masquerading as a left atrial mass

Abstract

An inverted left atrial appendage after cardiac surgery is a rare finding and can be misinterpreted as a thrombus, mass, or vegetation. We report a case where intraoperative transesophageal echocardiography assisted in making an accurate diagnosis.

Left Atrial Appendage Inversion Presenting as Acute Right Ventricular Failure after Left Ventricular Assist Device Implantation

“…The LAA inversion associated with CPB is usually diagnosed early by intraoperative TEE during or immediately after weaning off CPB. 3 , 4 , 5 , 9 , 10 In our case, initial intraoperative TEE after LVAD placement demonstrated no mass. Moreover, acute RV failure was seen 3 days later, suggesting that LAA inversion was unrelated to perioperative maneuvers and most likely due to negative pressure induced by the presence of LVAD.…”

“…The initial reports of LAA inversion were in pediatric patients usually in the postoperative setting, but spontaneous inversion has also been reported. 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 Allen et al. 1 first described this phenomenon by reporting two cases of LAA inversion in a 5-month-old undergoing tetralogy of Fallot repair and a 54-year-old female undergoing mitral valve repair.…”

“…Since then, there have been several other case reports on intraoperative discovery of LAA mass following aortic valve replacement, mitral valve repair, and, more recently, LVAD implantation. 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 The current prevailing theory is that the most likely cause of left atrial inversion is the intracardiac negative pressure environment created by an LV vent or as part of deairing maneuvers following cardiopulmonary bypass (CPB). 1 , 4 , 5 , 6 The appendage usually spontaneously reverts to its anatomical position as the increasing left atrial pressure in atrial diastole counteracts this negative pressure.…”

“…The likelihood of spontaneous eversion, reinversion, and complications based on LAA appendage orifice size and presence of triggering factors should be taken into consideration to determine the need for surgical intervention. 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 Digital manipulation, forceps eversion, and percutaneous and surgical LAA ligation are the current available modalities. In our case, the LAA reverted back to its anatomic position spontaneously during preparation for mediastinal exploration due to the reduction of LVAD speed and volume loading.…”

A new right atrial mass following cardiopulmonary bypass mimicking a thrombus

“…[ 4 ] Occurrence of such an inversion can be attributed to the negative pressure created by the de-airing maneuvers. [ 5 ] There also have been instances of a coumadin ridge being diagnosed as an intracardiac thrombus on the left side. [ 6 ] Other differential diagnoses that could be considered in this scenario are ruling out the possibility of a large hypertrophic trabecula[ 7 ] or stagnant blood.…”