[Extracardiac risk factors in heart surgery--the kidney]

There have been only a few investigations that have considered renal disease or any disturbance of renal function in the calculation of risk in cardiac surgery. Risks of cardiac surgery have to be considered for renal disease without direct connection to heart disease (e.g., infections of the kidney and of the urinary tract, primary and secondary glomerulonephritis, parenchymal renal disease, and impaired renal function of unknown origin), as well as in renal disease with concomitant influence on heart and kidney (e.g., infective endocarditis, arterial hypertension, systemic disease of heart and kidney such as with diabetes mellitus, disturbance of kidney function or electrolyte balance due to heart failure). In most cases, the problem is solved by therapeutic intervention and postponement of cardiac surgery. A limited or negative operative indication is found with untreatable infection of the kidney or urinary tract, with untreatable nephrotic syndrome, in advanced renal disease with heart transplantation, as well as in case of severe arterial hypertension with possible organ complications, and in advanced diabetes mellitus with ESRD and multiorgan involvement. After cardiac surgery, acute renal failure represents a critically important complication. Primary therapeutic procedures must include prophylaxis of hemodynamic unstable situations, as well as prophylaxis of infectious complications. Cardiac surgery in dialysis patients and post-transplant patients is basically possible and only has a slightly increased risk compared to patients with normal renal function. Seventy-seven dialysis patients were operated (49 aorto-coronary bypass operations, 19 single-valve and multiple-valve replacements, five patients with valve replacement and aorto-coronary bypass, and four other cardiac surgical operations). Only in valve replacement, was mortality significantly higher than in renal healthy persons, the main causes of death being cerebrovascular complications and septicemia.