Biomedical subjects
Publications and source records attributed to L Chiariello.
A cardiac myxoma that arises from the inferior vena cava (an extremely rare finding) may interfere with caval cannulation. In such cases venous cannulation for cardiopulmonary bypass has been performed directly into the inferior vena cava or through the femoral vein. We present a case in which routine cannulation through the right atrium proved safe and gave good exposure for complete resection of the tumoral mass.
Formation of complexes between heparin and protamine (in saline), or heparin, plasma proteins, and protamine (in plasma) was assessed by measurements of light transmission through different test solutions. To examine the formation of these complexes, 125I-labeled protamine was used. Addition of 125I-protamine to plasma or blood resulted in the sedimentation of 125I-protamine in the form of insoluble complexes. This complex formation was not affected by the presence of heparin, suggesting that protamine-plasma protein interaction may be primarily responsible for precipitation of 125I-protamine. To assess the capability of these complexes to obstruct the pulmonary circulation, an in vitro experimental model was developed. Citrated serum, plasma, blood, or saline were allowed to flow through a glass bead column with the help of a peristaltic pump. A pressure transducer positioned before the column allowed pressure measurements at a constant flow rate during the experiment. Mixing of protamine with plasma or blood prior to their passage through the glass bead column resulted in a significant increase in pressure suggesting that the column was being clogged with insoluble complexes. The increase in pressure occurred both in the presence and absence of heparin in plasma or blood. Under identical experimental conditions, the increase in pressure was insignificant when protamine was added to saline or serum regardless of whether heparin was present or absent. This was further confirmed by the use of 125I-protamine. These observations suggest that protamine forms insoluble complexes with certain plasma proteins. Based on these observations, it is hypothesized that following intravenous administration, protamine immediately forms complexes in circulating blood.(ABSTRACT TRUNCATED AT 250 WORDS)
Multidose potassium cardioplegia is known to result in greater preservation of myocardial ATP content and better recovery of function as compared to cardiac arrest induced by aortic clamping. The present study was undertaken to assess the effects of this procedure on biochemical markers of tissue damage. Rat hearts undergoing either multidose cardioplegia or ischemic cardiac arrest were maintained at 18 degrees C for 1 or 2 hr and processed without reperfusion. Control hearts were processed at time zero. The activity of two lysosomal enzymes (beta-glucuronidase and acid phosphatase), as well as membrane phospholipid content, was measured in cardiac homogenates. One hour of arrest by either technique did not induce significant changes in these parameters. Two hours of arrest affected lysosomal integrity, as indicated by release of lysosomal enzymes into the cytosol. Soluble acid phosphatase activity averaged 44.7 +/- 1.3 mU/mg of protein in the hearts processed after 2 hr of cardioplegic arrest, and was significantly higher than that of control hearts (12.3 +/- 3.8 mU/mg of protein; P less than 0.01) and that of hearts subjected to 2 hr of ischemic arrest (29.2 +/- 4.5 mU/mg of protein; P less than 0.01 vs cardioplegic arrest; P less than 0.01 vs controls). Phospholipid content in hearts subjected to 2 hr of cardioplegic arrest was lower than in controls (0.49 +/- 0.06 micrograms Pi/mg of protein vs 0.76 +/- 0.03 micrograms Pi/mg of protein; P less than 0.01). In conclusion, 2 hr of hypothermic cardiac arrest was associated with biochemical indices of tissue damage.(ABSTRACT TRUNCATED AT 250 WORDS)
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The possibility of achieving effective mechanical ventricular assistance without the need for thoracotomy provides great clinical advantages. Two in vitro systems were used to assess left ventricular unloading by means of a small-diameter cannula inserted retrograde into the left ventricle by cannulation of the femoral artery. This cannula is connected to the inlet of a centrifugal blood pump (CP) that delivers the blood into the contralateral femoral artery. Steady-flow test circulation was used to pump fluid in a closed loop from a reservoir through the test cannula back into the reservoir. Pressure drops over cannulae with inner diameters of 4, 5, 6, 7, and 8 mm at flows of 2, 2.5, 3 L/min, against a pressure of 60, 80, 100, and 120 mmHg were calculated. A stationary pressure drop of 120 mmHg was measured at a flow of 3 L/min through a 100 cm cannula with an inner diameter of 6 mm. The second system was a pulsatile mock circulation composed of an atrial and an arterial reservoir linked by a pneumatic prosthetic ventricle. This system was coupled with a 100 cm cannula, 6.1 mm inner diameter, which was passed across the outflow valve of the pulsatile prosthetic ventricle and connected to a CP. Fluid was withdrawn from the ventricle and pumped back into the arterial reservoir. Pulsatile pressure drop over the cannula was measured at different CP flows for increasing systolic ventricular pressure; heart unloading was quantified as a function of CP flow under baseline and failing conditions of the prosthetic left ventricle model. At a constant CP flow the pressure drop over the cannula increased with the pulsatility inside the ventricle. The work of the prosthetic ventricle was reduced by more than 50% when the CP pump was set to 3 L/min; at the same flow setting, when the situation of a failing left ventricle was simulated, the CP was able to take over all the work of the prosthetic ventricle, establishing a stationary flow and a 25% higher mean aortic pressure. This approach to left ventricular assistance may have significant clinical relevance.
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A 68 year old man had a diaphragmatic myocardial infarction and 9 months later was admitted with severe congestive heart failure (functional class IV). Cardiac catheterization demonstrated a postinfarction pseudoaneurysm. Because of a massive left to right shunt (pulmonary to systemic flow ratio = 2.7), concomitant rupture of the ventricular septum was suspected. At surgery the pseudoaneurysm communicated with the right ventricle through two different orifices and with the left ventricle through another ostium. The ventricular septum was intact. Therefore, the shunt was extracardiac through the pseudoaneurysm (left ventricle----pseudoaneurysm----right ventricle). The unique combination of lesions allowed the patient to survive. The false aneurysm was excised and primary repair was performed in the orifices of the right and left ventricular walls. The postoperative course was uneventful and 10 months later the patient was in functional class I.
An iliac arteriovenous fistula may rarely complicate lumbar laminectomy, particularly at the L4-L5 level. We present such a complication in a 45-year-old man who presented in our institution with a postlaminectomy iliac arteriovenous fistula and severe congestive heart failure. Repair of the fistulous orifice and tubular reconstruction of the iliac artery were successfully performed.
A case of criss-cross heart is presented in which there was situs solitus with atrioventricular (AV) discordance and single outlet, the aorta arising from the right ventricle. Associated lesions were pulmonary atresia and ventricular septal defect. The apparently normal AV relation in the presence of a discordant AV connection can be explained by the hypothesis that an embryonic l-bulboventricular loop developed and was followed by marked counter-clockwise rotation of the ventricles.
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The effects of coronary artery bypass (CAB) by comparison with medical treatment were evaluated on exercise tolerance in 68 patients with stable angina on effort, who underwent coronary and left ventricular cineangiography. Stress tests were performed by bicycle ergometer before medical and surgical treatment, and 6 and 12 months thereafter. Thirty-five patients (31 males and 4 females; 7 with one 70% stenosed vessel, 12 with two, 16 with three) underwent CAB; 33 (30 males and 3 females; 9 with one 70% stenosed vessel, 11 with two, 13 with three), having refused CAB, only underwent medical treatment. Both groups were given long-acting oral nitrates, none received digitalis and/or propranolol; antiarrhythmic drugs were only administered in 5% of medical and 4% of surgical patients. Both groups at 6 and 12 months follow-up showed a significant improvement in exercise tolerance. Surgical patients showed a significant increase in exercise tolerance with lower angina incidence (from the preoperative 100% to 26% and 22%, respectively), higher work load (P < .001), and a significant reduction of S-T segment depression (P < .001). Medical treatment induced an increase of exercise tolerance; angina on effort decreased (from 100% to 74% and 72%, respectively) with higher work load, and a significant reduction of S T depression (in both cases P < .001). Comparing the data of the two groups, we observed that surgical patients showed higher exercise tolerance (P < .01), lower S-T depression (P < .001) and angina incidence. Our results suggest that surgical treatment is able to improve exercise tolerance more remarkably than medical treatment.
Between January 1st, 1976 and October 31st, 1978 ten patients underwent simultaneour replacement or repair of a cardiac valve and coronary revascularization surgery. Six patients age ranged within 45 and 66 years presented mitral insufficiency, subsequent to myocardial infarction in five and rheumatic disease in one. Aortic valvular disease was present in four patients, it was atherosclerotic in three and congenital in one. All patients had both symptoms and signs of coronary insufficiency. Fifteen aortocoronary bypass grafts were inserted. Five mitral valve and four aortic valve replacements were performed; one patient underwent mitral valve annuloplasty. Best results were achieved in the aortic group, in which no deaths occurred; three deaths occurred in the mitral group. At the follow-up evaluation (average 14.2 months) all but one surviving patients showed marked symptomatic improvement, having moved to the upper functional class. The frequent incidence of coronary occlusive disease in patients with valvular heart disease recommends extensive use of selective coronary arteriography in preoperative evaluation. Simultaneous repair of all significant heart lesions is recommended.
Left ventricular function was evaluated with serial recording of STI intervals in 78 patients with stable angina on effort undergoing coronary and left ventricular cineangiography. On the basis of these data the patients were divided into four groups: OV) nor or mild coronary disease (n. 11); 1V) 70% stenosed vessel; 2V) two significantly affected vessels (n. 32); 3V) three significantly affected vessels (n. 18). Thirty-six patients (9 with one stenosis, 17 with 2, 10 with 3) underwent coronary artery bypass. Thirty-one 8 with one, 15 with 2, 8 with 3) refused the treatment in spite of the same clinical situation and were medically treated. Recordings were performed before medical and surgical treatment and after 6 and 12 months. Initial average values of the patients of 2V and 3V groups showed a shorter LVETI, longer PEPI and higher PEP/LVET ratio than those of 1V and 0V groups. Subjects of 2V group and abnormal left ventricular wall motion showed longer PEPI and higher PEP/LVET than patients of 2V without abnormal wall motion. On first evaluation no differences were observed between surgical and medical groups. The latter did not show any difference after 6 and 12 months. Surgical patients of 2V and 3V showed a longer LVETI, shorter PEPI and a lower PEP/LVET than the medical group. In the surgical group PEPI and PEP/LVET were significantly decreased after surgery while LVETI was prolonged. Our results suggest an improvement of left ventricular performance by coronary artery bypass in patients with coronary artery disease.
Because of the continous increase of utilization of open heart surgery, whenever possible a more conservative use of blood is desirable. During 1977, 262 consecutive patients were operated upon using the hemodilution technique of cardiopulmonary bypass. Thirtyone operative deaths occurred (11.8%) and were not related to lack of blood administration. Mean hematocrit values were 32.4% two hours after surgery and between 31 and 32.5% in the following postoperative course. Hemoglobin concentration averaged from 9.9 to 10.4 g/100 ml during the first postoperative week. The estimated amount of blood transfused averaged 872 +/- 66 ml (+/- SE) per patient. Sixtyone patients (23%) didn't receive any transfusion. A conservative attitude towards blood administration is justified by transfusion related many risks and by the current shortage of blood.
A modified pacemaker lead has been designed for permanent cardiac pacing. This can be inserted by percutaneous puncture of the subclavian vein using the Seldinger technique. Its use may be advantageous when isolation of an adequate vein for electrode insertion is difficult or impossible.
The new bubble Oxybel oxygenator (Bellco Laboratories) has been used for routine clinical perfusions in this Institution. A comparison has been made between two groups of 51 patients each, one group perfused with on Oxybel oxygenator (OXY) and the other with the Harvey H 1000 oxygenator (H-H). Among these patients a wide range of acquired and congenital cardiac lesions have been encountered. Both series were comparable for patients' age, sex distribution, body weight, procedures performed, perfusion time and preoperative values of hematocrit, serum creatinine, platelet count, plasma hemoglobin. The gas/blood flow ratio was 2.09 +/- 0.07 (+/- SE) for the H-H oxygenator and 1.38 +/- 0.06 for the OXY series (P < 0.001). Serum-creatinine 24-hrs postoperative values (mg/100 ml) were 1.58 +/- 0.17 for the H-H and 1.30 +/- 0.06 for the OXY series (NS); 48-hrs postoperative values were 1.28 +/- 0.11 for the H-H and 1.20 +/- 0.11 for the OXY (NS). The 60 minutes postoperative platelet count was 127.9 +/- 7 X 10(3) for the H-H and 120.9 +/- 6 X 10(3) for the OXY series (NS). Fourtyeight-hrs postoperative platelet count was 153.0 +/- 5 X 10(3) for the H-H and 151.8 +/- 6 X 10(3) for the OXY series (NS). Postoperative plasma hemoglobin values (mg/100 ml) were 91.55 +/- 7.18 for H-H and 117 +/- 17.8 for the OXY series (NS). Total postoperative bleeding was 1037.9 +/- 94 ml in the H-H and 1056.7 +/- 98.9 ml in the OXY series (NS). The more favorable gas/blood flow ratio observed with the Oxybel oxygenator did not affect clinical and haematologic results. These were comparable in both series.
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Among 1,022 patients who underwent repair of tetralogy of Fallot, 252 received a pericardial patch of the right ventricular outflow tract; of these, 10 subsequently developed an aneurysm of the right ventricular outflow tract. Cardiac catheterization and angiography revealed moderate pulmonary insufficiency in all patients, a residual pressure gradient in the right ventricular outflow tract in 7, and a residual ventricular septal defect in 2 patients. Reoperation was indicated in 8 patients because of progressive distention of the aneurysm, residual infundibular or pulmonary artery stenosis, and recurrent ventricular septal defect. Reconstruction of the right ventricular outflow tract was accomplished by resection of the aneurysm and insertion of a woven Dacron patch in 5 patients, primary suture of the pulmonary artery in 2, and implantation of a woven Dacron conduit containing a Björk-Shiley cardiac valve prosthesis in 1 patient. There were no early or late deaths. When reconstruction of the right ventricular outflow tract is necessary, we recommend a woven Dacron patch because pericardium may form an aneurysm.