Left Atrial Wall Hematoma/Dissection After Mitral Valve Replacement
A 63-year-old woman with a significant history of rheumatic mitral stenosis/regurgitation, tricuspid regurgitation, atrial fibrillation, and giant left atrium (LA; 90 mm in diameter) underwent mitral valve replacement with a mechanical valve, tricuspid annuloplasty, and LA appendage closure. The mitral valve was approached by a conventional left atriotomy from the right side of the LA. The postoperative course was uneventful initially, and the patient was extubated on postoperative day 1. On postoperative day 2, however, acute hemodynamic deterioration occurred that required reintubation and a high dose of inotropes. Transthoracic echocardiography showed a large mass in the LA that occupied almost the entire LA cavity (Figure 1A; online-only Data Supplement Movie I). An emergent surgery was performed. Intraoperative transesophageal echocardiography revealed that the LA mass significantly compromised blood flow into the left ventricle (Figure 1B; online-only Data Supplement Movie II). The median sternotomy was reentered, and the LA was exposed in a routine fashion. There was a dissection in the posterior LA wall, and the resulting cavity was filled with a large hematoma (Figure 2). There were no continuities between the cavity and the LA, left ventricle, posterior pericardial space, or mitral annulus. For better exposure, the inferior vena cava was transected temporarily. The area of the dissection was excised by a wedge resection. Then, the LA was closed with 4-0 Prolene continuous suture, and the inferior vena cava was reconstructed with 5-0 Prolene continuous suture. Complete resection of the dissected area was confirmed by intraoperative transesophageal echocardiography.
LA dissection is an extremely rare complication that occurs predominantly after mitral valve replacement. Blunt cardiac trauma, acute myocardial infarction, and prosthetic endocarditis can also cause LA dissection.1–3 The incidence of LA dissection after mitral valve replacement is reported to be 0.84%.1 Only a handful of isolated cases have been published. Almost all of the reported LA dissection cases have continuity between the dissected cavity and the left ventricle, which is one of the reasons that LA dissection is closely associated with left ventricular rupture and may represent a form of type I left ventricular rupture (Treasure’s classification).4 In the present case, however, there was no continuity between the false cavity and the heart chambers. To the best of our knowledge, such a presentation of LA dissection has not been published previously. Possible causes include excessive traction of sutures in the posterior annulus and mechanical injury in the LA posterior wall during surgical manipulation including the LA appendage closure.
The expert assistance of Hidekazu Tanaka, MD, is gratefully acknowledged.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/121/4/584/DC1.