Intractable mechanical hemolytic anemia complicating mitral valve surgery: a case series study

Intractable, mechanical hemolytic anemia (IMHA) is a rare catastrophic complication following mitral valve surgery. We analyzed patient characteristics and IMHA management by reoperations after mitral valve surgery.

We collected medical records from mitral valve patients requiring reoperation due to IMHA.

hemoglobin < 100 g/L; positive hemolysis tests and echocardiography results; and exclusion of other hemolysis causes.

Data from 25 IMHA cases included 10 (40%) early onset (1.3 (0.3,3.0) months) and 15 (60%) late onset (120 (24,204) months) cases. Early IMHA etiologies included surgical defects (6, 60%), uncontrolled infection (3, 30%) and Bechet's disease (1, 10%). Late IMHA etiologies included degeneration (13, 87%), new infection (1, 7%) and trauma (1, 7%). There were more mechanical valves (15, 88%) than bio-valves (2, 12%); the main valvular dysfunction was paravalvular leak (16, 64%). IMHA manifestations included jaundice (18, 72%), dark urine (21, 84%), heart failure (16, 64%), acute kidney injury (11, 44%), hepatomegaly (15, 60%), splenomegaly (15, 60%) and pancreatitis (1, 4%). Laboratory results showed decreased hemoglobin (70 ± 14 g/L) and increased bilirubin (72 ± 57 μmol/L), lactate dehydrogenase (2607 ± 2142 IU/L) and creatinine (136 ± 101 μmol/L) levels. Creatinine level negatively correlated with hemoglobin level (B = -3.33, S.E. B = 1.31, Exp(B) = 368.15, P = 0.018). Preoperative medications included iron supplements (20, 80%), erythropoietin (16, 64%) and beta-blocker (22, 88%). Two patients died of cardiac causes before reoperation. The other 23 underwent reoperation with long surgical times (aortic cross clamp 124 ± 50 min, cardiopulmonary bypass 182 ± 69 min) and blood transfusions (red blood cells 6 (6, 8) units, plasma 600 (400,800) ml, platelet 1(0,2) units). Postoperative complications included cardiac dysfunction (5, 22%), arrhythmia (10, 43%), sepsis (6, 26%), pulmonary infection (5, 22%), gastrointestinal bleeding (3, 13%), cerebral hemorrhage (2, 9%), chronic renal dysfunction (1, 4%) and surgical hemorrhage (1, 4%). Five (33%) patients died after reoperation from cardiac dysfunction (3, 60%), septic shock (1, 20%) and self-discharge (1, 20%).

IMHA induces severe multi-organ dysfunction, contributing to high mortality. Perioperative management should focus on etiological treatment, organ protection, and blood management.