[Radionuclide renal scintigraphy in assessment of nephroprotective effect of hypoxic preconditioning for myocardial revascularization under artificial circulation].

ABSTRACT

OBJECTIVE: Using renal scintigraphy to assess the nephroprotective efficacy of hypoxic preconditioning (HP) during myocardial revascularization under the conditions of artificial circulation (AC). MATERIALS AND METHODS: We examined a total of forty-seven patients with CAD (mean age 52.81 +/- 1.40 years) who endured coronary artery bypass grafting (CABG) under AC. All patients were randomly divided into 2 groupspatients (n = 16) who during CABG underwent HP (study group) and those (n = 31) without renal protection (comparison group). HP was performed in the mode of one cycle of 10-minute hypoxemia followed by a 5-minute period of reoxygenation. Dynamic radionuclide renal scintigraphy with 99mTc-DTPA was carried out before and 6-7 days after surgical treatment with calculating the parameters of the filtrating and excreting renal function. RESULTS: The comparison-group patients after CABG were found to have negative dynamics of the parameters of the renal filtration activity. Thus there was a significant decrease in the mean values of total and individually for each kidney glomerular filtration rate (GFR) combined with deceleration of the blood clearance. Besides patients of this group showed a significant increase in the mean value of the half-period of excretion of the indicator from the pelvicalyceal system of the left kidney and the parenchyma of the both kidneys. The study group patients showed no alterations in the values of the filtration activity of the kidneys as compared with the baseline measures, with the exception of the GFR of the right kidney. Thus a decrease in the filtration function of either one kidney or both kidneys under the influence of non-pulsating blood flow was observed only in three (19%) patients and was not pronounced. Alterations in the indices reflecting the excretory renal function in the study group were also insignificant. CONCLUSION: Radionuclide renal scintigraphy makes it possible to objectively and with a high level of the informative value to determine the degree and pattern of the effect of open-heart surgery on renal functional activity. HPC exerts a nephroprotective effect action on the renal functional activity in patients with endured open-heart surgery in the conditions of assisted circulation.