A 55-year-old man with severe mitral valve regurgitation was admitted to our hospital and was scheduled for mitral valve replacement (MVR). He had undergone a Bentall surgery 3 years earlier due to aortic dissection. MVR with mechanical prosthetic valve was performed. Three days after surgery, hemoglobinuria was noticed. Bedside transthoracic echocardiography (TTE) showed a severe peri-prosthetic mitral leak and an emergency surgery of a redo MVR with mechanical prosthetic valve was performed. Post-bypass transesophageal echocardiography confirmed prosthetic valve with normal function. On postoperative day 5, acute hemodynamic deterioration occurred. His oxygen saturation was 88%, blood pressure was 85/43 mmHg. Bedside TTE revealed a severe atrioventricular disruption causing left atrial (LA) dissection (Fig. 1A, Suppl. Video 1). There was a markedly rocking motion of the mechanical mitral valve. Color flow Doppler imaging showed that the dissected cavity directly communicated with left ventricle via a massive atrioventricular separation, through which it received blood during left ventricular systole. In addition, the dissected cavity also communicated with the true left atrium through a 9-mm defect (Fig. 1B). With the use of a three-dimensional TTE, the dissected LA wall was displayed intuitively and the extent of atrioventricular separation was more readily appreciated (Fig. 1C, D). Patient died due to low cardiac output on the 6th day after surgery.
Left atrial dissection is an extremely rare complication after mitral valve surgery with an incidence of 0.84%. We report a rare case of LA dissection due to severe atrioventricular separation after a redo MVR.
Funding: The study was supported by National Key R&D Program of China (Grant Nos. 2018YFC0-114600) and the National Natural Science Foundation of China (Grant Nos. 81727805, 81922033, 81401432), the Key Research and Development Program of Hubei (Grant Nos. 2020DCD015, 2021BCA138).
