Cardiovascular changes after bilateral nephrectomy

Abstract

Patients with chronic renal failure necessitating long-term hemodialysis and/or consideration for renal transplantation often have significant hypertension. Though most patients can be successfully managed with antihypertensive medications, some patients are either resistant to aggressive management or demonstrate sufficient liability to make medication dosage difficult. Bilateral nephrectomy has been advocated as an adjunctive mode of therapy in such patients. Hypertension might be ameliorated or controlled completely if the chronically diseased kidneys had contributed to hypertension. Further, bilateral nephrectomy may be considered as an adjunctive form of therapy to aid in the management of patients with certain end-stage diseases. Indications include a wide spectrum from life-saving nephrectomy in patients with Goodpasture’s Syndrome [5] to the removal of huge polycystic kidneys to allow room for placement of a renal homograft [I 11. In general however, the largest group of patients in whom this measure is indicated are those with significant hypertension uncontrollable by aggressive dialysis and antihypertension medications [l, 8, 9, lo]. Such patients may even require emergency nephrectomy [8]. The perioperative care of patients with significant hypertension makes understanding of the relationships between the factors controlling stroke volume difficult. Distribution of extracellular volume, the relationship between intravascular volume and ventricular filling pressures, stroke volume and cardiac work, as well as the effects of increased afterload are difficult to predict with any accuracy in patients maintained on hemodialysis and receiving antihypertensive medications. With the advent of practical, precise cardiovascular monitoring, all important variables can be accurately measured and calculated. In addition, the actual effect of bilateral nephrectomy on the interrelationships between cardiac output, blood pressure, and peripheral resistance can be documented. Finally, in the case of hypotension or other cardiovascular abnormalities, appropriate interventions based on the demonstrated abnormalities could be instituted.