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Biomedical subjects

M I Turina

Publications and source records attributed to M I Turina.

At least 145 records · Page 8Linked to original sources
PubMed1993

Low-dose heparin versus full-dose heparin with high-dose aprotinin during cardiopulmonary bypass. A preliminary report.

Perfusion during cardiopulmonary bypass with low-dose heparin (activated clotting time, > 180 sec) versus full-dose heparin (activated clotting time, > 480 sec) combined with high-dose aprotinin was evaluated prospectively. Fifteen patients undergoing elective myocardial revascularization were randomly assigned to 1 of 2 groups. No significant differences between the groups were found for age, sex, body surface area, preoperative hematocrit level, duration of cardiopulmonary bypass, aortic cross-clamp time, mean number of bypasses per patient, or mean number of arterial grafts per patient. In all patients, heparin-coated cardiopulmonary bypass equipment was used, including heparinized hollow-fiber membrane oxygenators and tubing sets. In each group, protamine sulfate was given equivalent to the heparin loading dose; additional doses were administered according to the ACT. The mean total dosage of heparin was 9.5 +/- 1.4 x 10(3) IU for the group given low systemic heparinization (Group 1) compared with 34.6 +/- 3.4 x 10(3) IU for the group given full systemic heparinization in combination with high-dose aprotinin (Group 2) (p < 0.0001). The mean amount of aprotinin administered in Group 2 was 5.6 +/- 0.3 x 10(6) KIU; aprotinin was not used in Group 1. The mean protamine dosage necessary in Group 1, 7.0 +/- 0.9 x 10(3) IU, was significantly less than the 22.9 +/- 3.2 x 10(3) IU needed in Group 2 (p < 0.0001). In Group 1, shed blood recovery was achieved by a red-cell spinning device; in Group 2, cardiotomy suction was used. The total chest tube drainage (i.e., postoperative blood loss) per patient in Group 1 totaled 432 +/- 162 mL/m2; in Group 2, it was 311 +/- 111 mL/m2 (difference not significant). Transfusion requirements comprised a mean volume of 143 +/- 165 mL/m2 concentrated homologous red blood cells per patient in Group 1 and 416 +/- 128 mL/m2 in Group 2 (p < 0.01). Heparin-coated perfusion equipment allowed a significantly lower dosage of systemic heparin and protamine in Group 1 than that in Group 2, and a lower dosage in Group 2 than that in previous studies. Postoperative blood loss appeared to be similar between groups. The combination of heparin-coated perfusion equipment with low systemic heparinization and a red-cell spinning device provides promising results.

Adult↗
PubMed1993

Ruptured abdominal aortic aneurysms: predictors for early complications and death.

BACKGROUND: Urgent operation for ruptured aneurysm is still associated with a high operative mortality rate. The purpose of the study was to determine the risk factors that truly influence early complications and death. METHODS: Between 1979 and 1991, 314 consecutive patients with a mean age of 69 years were treated surgically for a ruptured infrarenal abdominal aortic aneurysm. Twenty-two preoperative, perioperative, and intraoperative variables were subjected to a multivariate analysis to identify the independent predictors. RESULTS: Early death occurred in 92 (29%) of 340 patients. Significant primary predictors for early death were duration of cross-clamp (p < 0.0001), preoperative shock (p = 0.0005), suprarenal cross clamp (p = 0.002), and a history of coronary artery disease (CAD) (p = 0.004). The following postoperative complications were risk factors for death: myocardial failure (p < 0.0001), renal failure (p < 0.0001), sepsis (p = 0.01), and colon ischemia (p = 0.03). Predictors for postoperative myocardial insufficiency were a history of CAD (p < 0.0001), amount of intraoperative volume substitution (p < 0.0001), suprarenal cross clamp (p = 0.0007), and preoperative shock (p = 0.05). CONCLUSIONS: Preoperative and perioperative risk factors that result in fatal postoperative complications can be partially influenced by the surgeon. Short clamping time and infrarenal position of aortic clamp may lower overall early mortality rates. A history of CAD is a highly significant predictor for postoperative complications and early death.

Aged↗
PubMed1993

[Hemodynamic effects of implantation of an intracaval gas exchanger].

Treatment of severe respiratory failure by extracorporeal membrane oxygenation (ECMO) is complex. However, there is now an intravascular gas exchanger (IVOX) available that provides extrapulmonary gas transfer without requiring an extracorporeal blood path. The present study was performed to determine the hemodynamic effects resulting from the intracaval placement of the intravascular device. A bovine model (n = 6; bodyweight = 72 +/- 5 kg) was selected for temporary lung support with the intravascular device. The latter was placed in the caval axis under fluoroscopic control after full instrumentation of the animal for hemodynamic measurements including a pulmonary artery catheter for determination of cardiac output by thermodilution and continuous read out of mixed venous oxygen saturation. All measurements were taken after a stabilization period of 15 min. The heart rate moved from 65 +/- 8 before to 72 +/- 10 after implantation and 68 +/- 9 after onset of intravascular gas exchange (NS). Right atrial pressure was 13 +/- 3 mm Hg before, 12 +/- 3 mm Hg after implantation and 10 +/- 3 mm Hg after onset (NS) whereas femoral venous pressure moved from 14 +/- 3 mm Hg to 17 +/- 4 mm Hg (p < 0.05) and remained at 17 +/- 4 mm Hg after onset. Cardiac output was 5.3 +/- 0.7 l/min before, 5.4 +/- 0.7 l/min after implantation and 5.3 +/- 1.1 l/min after onset (NS) and mixed venous oxygen saturation dropped from 60 +/- 7% to 54 +/- 11% and moved to 57 +/- 11 after onset of the device (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Single cusp homograft implantation in the reconstruction of right ventricular outflow tract in the correction of tetralogy of Fallot].

From 1987 to 1990, 37 children underwent surgical correction for tetralogy of Fallot. The mean age was 38.2 months (2-156 months). The indication for right ventricular outflow tract (RVOT) obstruction in 19/37 (51%) children was: hypoplastic pulmonary valve (n = 10), annular hypoplasia (n = 12), RVOT obstruction and hypoplastic pulmonary artery (n = 10). In 18/37 (49%) children, the repair of the RVOT was done without homograft. The RVOT morphology was the only indication for reconstruction with homograft. All other pre-, intra- and postoperative data were identical for both groups. There was no operative or late death. After a mean follow-up of 4.4 months, all 19 children with homograft were in NYHA class I and echocardiographic evaluation showed mild and moderate pulmonary regurgitation in 8 and 4 children respectively. Out of the 18 children without homograft, 16 were in NYHA class I and 2 in NYHA class II. Two children had early postoperative right heart failure. The mean follow-up time in this group was 5.5 months. Echocardiography revealed residual pulmonary regurgitation in 4 children, pulmonary stenosis in 6 and combined residual pulmonary valve defect in 6. If severe malformation of the RVOT or the pulmonary artery is present, a valved homograft is recommended for repair of tetralogy of Fallot. Good morphological and functional results may be achieved.

Adolescent↗
PubMed1992

Temporary lung support using an intravascular gas exchanger.

Severe respiratory failure may be difficult to overcome by conventional mechanical ventilation. As an alternative to the very demanding lung support using various modalities of extracorporeal circulation (ECMO, ECLA, etc.) we evaluated an intravascular gas exchanger (IVOX) in a "reversible" bovine model. Several degrees of hypoventilation were studied with and without intravascular gas exchange in 5 endotracheal intubated, anaesthetized, and volume-controlled ventilated animals (body weight 73 +/- 4 kg). After systematical heparinization (300 IU/kg body weight) the animals were instrumented with EKG electrodes, thermodilution pulmonary artery catheter with continuous measurement of O2-saturation, central venous and femoral arterial catheter, etc. The intravascular gas exchanger made from siliconized microporous polypropylene hollow fibres was placed in the caval veins under radiofluoroscopic control. The following scenarios were studied without and with intravascular gas exchange (gas inlet 100% O2): Normoventilation (with 14-20 strokes/min) at F10(2) 0.50 and at F10(2) 0.21; Hypoventilation (ventilator frequency reduced to 50% and tidal volume reduced to 50% of normoventilation) at F10(2) 0.50 and at F10(2) 0.21. Hemodynamics, mixed venous O2-saturation, arterial and venous blood gases, and gas-exchanger exhaust were analyzed after stabilization over 15 minutes (mean +/- standard deviation). Blood gas analyses showed significant improvement with intravascular gas exchange during hypoventilation at F10(2) 0.21: pH moved from 7.10 +/- 0.17 to 7.19 +/- 0.15*, PaCO2 moved from 9.9 +/- 4.2 kPa to 8.7 +/- 2.8*, PaO2 moved from 6.5 +/- 1.2 kPa to 7.3 +/- 0.8* and mixed venous O2-saturation moved from 33.9 +/- 16.0% to 48.1 +/- 4.6* (* = p less than 0.05 for without versus with intravascular gas exchange).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Valvotomy for isolated congenital aortic stenosis in children: prognostic factors for outcome.

Early and late results after surgery for isolated congenital valvar aortic stenosis were evaluated in a total of 86 children under 16 years of age (mean 7.4 years). Primary procedure was always conservative. There were 7/86 (8.1%) early deaths. All infants who died after the operation were younger than 4 months of age. Among the clinical variables tested by the univariate analysis only age and duration of cardiopulmonary bypass were significant prognostic factors for early death. There were 6/67 (7.7%) valve-related late deaths. Multivariate analysis could not identify any risk factors for early and late mortality. Actuarial survival was 97% (95% CL 93-101%) after 5 years, 94% (88-100%) after 10 years, 90% (82-98%) after 15 years, and 87% (77-97%) after 20 years. A total of 22/79 (28%) early survivors had a first reoperation and 5 had a second reoperation. Long follow-up interval was the only significant factor for reoperation. Actuarial reoperation-free interval was 91% (85-98%) after 5 years, 70% (58-81%) after 10 years, and 50% (34-64%) after 15 years. Significant factors for poor valve function were long duration of follow-up, endocarditis, and young age at operation. The probability of normal valve function was 91% (84-98%) after 5 years, 67% (55-79%) after 10 years, and 54% (40-68%) after 15 years.

Actuarial Analysis↗
PubMed1992

Reduction and elimination of systemic heparinization during cardiopulmonary bypass.

After extensive experimental evaluation, heparin-coated perfusion equipment was clinically evaluated with low or no systemic heparinization in three different groups of patients (n = 47). In group 1, resection of descending thoracic aortic aneurysms (n = 24) was performed with heparin-coated equipment used for left heart bypass (n = 12) or partial cardiopulmonary bypass (n = 12) for proximal unloading and distal protection (heparin 5000 IU, autotransfusion). All devices remained functional throughout the procedures and no systemic emboli were detected. The sole death (1 of 24, 4%) occurred in a patient with ruptured thoracoabdominal aortic aneurysm requiring operation in extremis. Paraparesis with spontaneous recovery occurred in one patient (1 of 24, 4%). In group 2, coronary artery revascularization randomized for low (activated clotting time greater than 180 seconds) versus full (activated clotting time greater than 480 seconds) systemic heparinization was prospectively analyzed in 22 patients. All patients recovered without sequelae, and no myocardial infarction was diagnosed. Low dose of heparin (8041 +/- 1270 IU versus 52,500 +/- 17,100 IU; p less than 0.0005) resulted in reduced protamine requirements (7875 +/- 1918 IU versus 31,400 +/- 14,000 IU; p less than 0.0005), reduced blood loss (831 +/- 373 ml versus 2345 +/- 1815 ml; p less than 0.01), reduced transfusion requirements of homologous blood products (281 +/- 415 ml versus 2731 +/- 2258 ml; p less than 0.001), and less patients transfused (5 of 12 versus 10 of 10; p less than 0.05). Lower D-dimer levels in the group perfused with low systemic heparinization (0.50 +/- 0.43 mg/L versus 1.08 +/- 0.59 mg/L; p less than 0.05) were attributed to the absence of cardiotomy suction in this group. In group 3, rewarming in accidental hypothermia by cardiopulmonary bypass was successfully performed without systemic heparinization in a patient with hypothermic cardiac arrest (23.3 degrees C) and intracranial trauma. We conclude that systemic heparinization for clinical cardiopulmonary bypass can be reduced and eliminated in selected patients if perfusion equipment with improved biocompatibility is used. Bypass-induced morbidity can be reduced.

Aged↗
PubMed1991

[Mechanical circulatory support today].

Invasive mechanical circulatory support is the approach of choice in patients with acute myocardial failure resistant to conventional therapy. Today survival rates between 24% for postcardiotomy cardiac failure and 40% for bridge to heart transplantation can be achieved. However, a broad armamentarium of devices for mechanical circulatory support is necessary to provide optimum assistance for the failing heart in the various clinical situations. The available devices and their potential indications and limitations are reviewed.

Assisted Circulation↗
PubMed1991

[Clinical experience with a second-generation cardioverter-defibrillator].

Implantable cardioverter defibrillators (ICD's) are effective for reducing mortality in refractory malignant ventricular arrhythmias (MVA). Second generation ICD's (Telectronics Guardian 4202/4203) were implanted in 7 patients (all male, mean age 58.1 years) with ventricular fibrillation (VF) in 2, ventricular tachycardia (VT) in 1, and both VF and VT in 4. Underlying heart disease was coronary artery disease in 4 patients, and valvular heart disease, dilated cardiomyopathy and no obvious cause (documented primary VF, reproducible at electrophysiologic study) in 1 patient each. Mean ejection fraction was 40 +/- 14%. Mean defibrillation threshold of the two epicardial patches at implantation by means of median sternotomy was 18 +/- 9 joule, and patch impedance 35 +/- 7 ohms. Post defibrillation bradypacing via epicardial electrode was programmed in 5 patients (70%). Mean follow-up was 10.1 months (1-25 months). Successful defibrillation of 28 spontaneous VT/VF episodes was noted in 2 patients, while the other 5 have had no further episodes of MVA so far. One device was explanted following tissue necrosis at the battery site after a MVA-recurrence-free interval of 15 months. The reconfirmation algorithm prevented false shock delivery in 2 patients.

Cardiac Pacing, Artificial↗
PubMed1991

[Early results following surgical treatment of heart tumors].

Between December 1968 and March 1990 a total of 51 patients (24 male, 27 female) with a mean age of 49 years (7 months to 76 years) underwent surgery for primary or secondary cardiac tumor. In 46/51 cases (90%) the tumor was benign and in 5/51 (10%) malignant; 41/51 (80%) were myxomas. In 40 patients complete resection of myxoma was possible, whereas in one patient only biopsy was performed. In 6 patients an additional procedure was necessary (CABG 4 times, double valve replacement once, mitral valve reconstruction once). In 17/41 patients (41%) rhythm disturbances were observed postoperatively. No patient died after operation. In one patient surgery of a recurrent myxoma was necessary 18 months after primary operation. In 5/51 patients (10%) surgery of benign non-myxomatous tumor was performed (lipoma twice, cavernous hemangioma once, fibroma once fibrous leiomyoma once). Radical excision of tumor was not possible in 2 cases; both died soon after operation. Surgery of malignant heart tumors was performed in 5/51 patients (10%) (synovialoma once, lymphoma twice, metastasis twice). In 3 patients tumor excision was radical; there was nevertheless recurrence in all patients despite adjuvant therapy. Only 1 patient is still alive 6 months after surgery. Prognosis after surgery for heart tumors is dependent on histology and resectability. Mortality after resection of myxoma is very low, but postoperative rhythm disturbances are frequent. Survival after excision of benign non-myxomatous tumors is dependent on resectability. Malignant cardiac tumors have a very bad prognosis despite chemotherapy and radiotherapy.

Adult↗
PubMed1991

Early and late results after surgery for massive pulmonary embolism.

Between 1978 and 1990 emergency pulmonary embolectomy with the aid of extracorporeal circulation (ECC) was performed for massive pulmonary embolism (PE) in 44 patients (19-73 yrs; 49 +/- 15 yrs). Cardiopulmonary circulation was stable in 16/44 patients but unstable in 28/44; of the latter, 15 had undergone previous cardiopulmonary resuscitation due to cardiac arrest. Diagnosis of PE was obtained clinically in 15/44 patients, by angiography in 13/44, by echocardiography in 10/44, and by perfusion scintigraphy of the lung in 6/44 patients. There were 9/44 (20%) postoperative deaths. Early mortality was significantly higher in previously resuscitated patients (p less than 0.05). There were 2/36 (6%) late deaths. Actuarial survival was 75% after 4 yrs and 71% after 8 yrs. 77% or 35 survivors were in NYHA-class I and 23% in NYHA-class II after a mean follow-up of 4.6 yrs. Pulmonary embolectomy is indicated in patients with central PE and shock; it is advisable in patients with embolism of the main pulmonary artery or its major branches or in patients with contraindication to thrombolysis. Intraoperative insertion of a vena cava filter is recommended for prevention of recurrent embolism. Preoperative resuscitation and duration of ECC are predictors for early death.

Actuarial Analysis↗
PubMed1991

Atrial repair for transposition of the great arteries: current approach in Zürich based on 24 years of follow-up.

Long-term survival after atrial repair of a transposition of the great arteries between 1964 and 1988 is analyzed in 254 thirty-day survivors. For the complete series, overall survival is 99.6% after one year, 94.9% after 6 years, 89.6% after 12 years, 84.9% after 18 years, and 64.0% after 24 years. Broken down for simple (154/254) versus complex (95/254) transposition survival, it is 99.4% versus 100.0% for one year, 94.7% versus 99.5% for 6 years, 90.8% versus 88.3% for 12 years, 85.1% versus 85.8% for 18 years and 77.7% versus 46.8% at 24 years. Survival for patients without or with VSD is 95.3% versus 96.2% after 6 years, 91.2% versus 87.9% after 12 years, 87.5% versus 84.0% after 18 years, and 83.7% versus 52.5% after 24 years. Cumulative survival as a function of the surgical approach for VSD closure is 94.3% for transatrial versus 92.3% for transventricular at 6 years, 82.2% versus 92.3% after 12 years, 82.2% versus 83.0% after 18 years and 82.2% versus 41.5% after 24 years. Survival for patients operated upon before 1978 is 94.3% versus 96.0% thereafter at 6 years, and 90.7% versus 89.2% at 12 years (NS). Linearized mortality rates are 1.49% per patient year for the complete series, 0.93 for simple transpositions, 2.21% for complex transpositions (including VSD, obstruction of the left ventricular outflow tract, or both), 0.68% for transpositions without VSD, 1.98% for transpositions with VSD, 2.43% for transposition with transventricular repair of a VSD, 1.74% for transposition with transatrial closure of a VSD, and 0.90% for all cases operated upon after 1978.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1991

Clinical application of heparin-coated perfusion equipment with special emphasis on patients refusing homologous transfusions.

Clinical application of heparin-coated cardiopulmonary bypass equipment during perfusion with low systemic heparinization is reported with special emphasis on patients refusing any transfusion of homologous blood or blood products. Using the described technique, coronary artery revascularization was successfully performed in three Jehovah's witnesses. During perfusion, the activated clotting time (ACT) was maintained above 180 seconds. Prebypass haematocrit was 38 +/- 3% and dropped to 22 +/- 1% after seven days. Hence, cardiopulmonary bypass with low systemic heparinization may further reduce bypass induced morbidity and improve the final outcome in selected patients.

Aged↗
PubMed1991

Fatal fungal pericarditis after cardiac surgery and immunosuppression.

The cases of two patients with fulminant pericarditis after cardiac surgery are reported. Both fungal infections developed after rethoracotomy for open-chest cardiac resuscitation and high-dose glucocorticoid treatment. Although the time course of both infections from the inoculation of fungi during rethoracotomy and immunosuppression with glucocorticoids to the lethal outcome was strikingly similar, histopathologic studies disclosed the disparate character of the two fungal pathogens responsible: the yeast Candida albicans and the angiotropic mold Aspergillus fumigatus.

Aged↗