Late atrioventricular groove disruption presenting 7 years after mitral valve replacement: a case report

BACKGROUND: Left ventricular rupture is the most feared complication in mitral valve surgery. Despite its low incidence, mortality rates can reach up to 75%. It usually presents on the operating room with a dissecting haematoma followed by massive bleeding after discontinuing cardiopulmomary bypass. However, cardiac rupture may be contained by adherent pericardium or scar tissue leading to chronic formation of a pseudoaneurysm (PSA). CASE SUMMARY: A 44-year-old man came to our institution with acute heart failure triggered by community-acquired pneumonia. He underwent mitral valve replacement with a mechanical prosthesis 7 years before and reported suffering from chronic worsening dyspnoea for 18 months. He underwent chest computed tomography scan and cardiac magnetic resonance imaging (CMRI), which showed two extensive left ventricular (LV) multilobulated PSAs. An operative approach was chosen and a tear was found on the posterior atrioventricular groove (AVG), communicating left ventricle with the PSA, which was closed with bovine pericardium patch. After weaning from cardiopulmonary bypass, he presented a diffuse life-threatening bleeding. The surgeons packed his chest with compresses before closing the sternum and he was operatively revised after 48 h. Post-operative CMRI showed that one of the PSAs remained connected with the LV. Despite of all, 1 year after hospital discharge, he remains asymptomatic without signs of heart failure. DISCUSSION: This case illustrates PSAs' potential to grow for a long period before causing symptoms, the complexity and risks of chronic AVG disruption surgery and the importance of careful annular manipulation and debridement as preventive measures in mitral valve surgery.