Browsing by Author "IRARRAZAVAL, MJ"

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    DISK DISLODGMENT IN BJORK SHILEY MITRAL-VALVE PROSTHESIS - 2 SUCCESSFULLY OPERATED CASES
    (1986) DUBERNET, J; IRARRAZAVAL, MJ; URZUA, J; MATURANA, G; MORAN, S; LEMA, G; ASENJO, F; FAJURI, A
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    EFFECTS OF EXTRACORPOREAL-CIRCULATION ON RENAL-FUNCTION IN CORONARY SURGICAL PATIENTS
    (WILLIAMS & WILKINS, 1995) LEMA, G; MENESES, G; URZUA, J; JALIL, R; CANESSA, R; MORAN, S; IRARRAZAVAL, MJ; ZALAQUETT, R; ORELLANA, P
    We prospectively studied perioperative changes of renal function in 12 previously normal patients (plasma creatinine <1.5 mg/dL) scheduled for elective coronary surgery. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured with inulin and I-125-hippuran clearances before induction of anesthesia, before cardiopulmonary bypass (CPB), during hypo- and normothermic CPB, after sternal closure, and 1 h postoperatively. Renal and systemic vascular resistances were calculated. Urinary N-acetyl-beta-D-glucosaminidase (NAG) and plasma and urine electrolytes were measured, and free water, osmolal, and (creatinine clearances, and fractional excretion of sodium and potassium were calculated before and after surgery. I-125-hippuran clearance was lower than normal in all patients before surgery. During hypothermic CPB, ERPF increased significantly (from 261 +/- 107 to 413 +/- 261 mL/min) and returned toward baseline values during normothermia. GFR was normal before and after surgery and decreased nonsignificantly during CPB. Filtration fraction was above normal before surgery and decreased significantly during CPB (038 +/- 0.09 to 0.18 +/- 0.06). Renal vascular resistance (RVR) was high before surgery and further increased after sternotomy (from 18,086 +/- 6849 to 30,070 +/- 24,427 dynes . s . cm(-5)), decreasing during CPB to 13,9647 +/- 14,662 dynes . s . cm(-5). Urine NAG, creatinine, and free water clearances were normal in all patients both pre- and postoperatively. Osmolal clearance and fractional excretion of sodium increased postoperatively from 1.54 +/- 0.06 to 12.47 +/- 11.37 mL/min, and from 0.44 +/- 0.3 to 6.07 +/- 6.27, respectively. We conclude that renal function does not seem to be adversely affected by CPB. Significant functional alterations, such as decreased ERPF and increased RVR, were found before and during surgery, preceding CPB. These periods could contribute to postoperative renal dysfunction.
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    SURGICAL REMOVAL OF ENTRAPPED ENDOCARDIAL LEADS WITHOUT USING EXTRACORPOREAL-CIRCULATION
    (1985) DUBERNET, J; IRARRAZAVAL, MJ; LEMA, G; MATURANA, G; URZUA, J; MORAN, S; NAVARRO, M; FAJURI, A
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    ULTRASTRUCTURAL MYOCARDIAL PRESERVATION DURING CORONARY-ARTERY SURGERY - A CONTROLLED, PROSPECTIVE, RANDOMIZED STUDY IN HUMANS
    (1986) MORAN, SV; CHUAQUI, B; IRARRAZAVAL, MJ; THOMSEN, P; NAVARRO, M; URZUA, J; MATURANA, G
    Potassium cardioplegia was compared with normothermic, intermittent ischemic arrest in 30 patients undergoing multiple coronary artery bypass grafts. Group 1 comprised 15 patients in whom cold potassium cardioplegia with St. Thomas'' Hospital solution was used. In Group 2 were 15 patients who underwent intermittent ischemic arrest during the construction of the distal anastomoses. Two myocardial transmural left ventricular biopsies were done in each patient. There was no operative mortality. Electron microscopical examination showed normal myocardial ultrastructure in both groups. In particular, mitochondria were well preserved in all samples. The postoperative electrocardiogram demonstrated a new Q wave in 1 patient in Group 2 whose level of the myocardial isoenzyme of creatine phosphokinase (CPK-MB) was within the normal range. The peak CPK-MB release in Group 1 was 23.2 .+-. 20.1 IU and in Group 2, 19.9 .+-. 15.1 IU. This difference was not statistically significant. The mean period of anoxic arrest in Group 1 was 49.5 .+-. 15 minutes and in Group 2, 25.5 .+-. 8 minutes (p < 0.001). Total cardiopulmonary bypass time in Group 1 was 114.5 .+-. 20 minutes and in Group 2, 90.2 .+-. 16 minutes (p < 0.01). It is concluded that both techniques can preserve myocardial subcellular architecture during multiple coronary artery bypass grafting in patients with normal left ventricular function.