Biomedical subjects

T Yokosawa

Publications and source records attributed to T Yokosawa.

At least 19 recordsLinked to original sources

PubMed1999

Treatment of mediastinitis arising after replacement of the ascending aorta.

Mediastinitis due to graft infection is a serious and potentially lethal complication associated with replacement of the ascending aorta. We present the case of a 67-year-old man with this condition for the aneurysm and chronic dissection. Mediastinitis and sepsis were diagnosed and debridement, irrigation with povidone solution and omental transposition were performed successfully. Continuous closed irrigation prior to omental transposition without replacement of the infected graft is useful for treating mediastinitis after ascending aortic or arch replacement.

Aged↗

PubMed1993

[A case who developed mechanical pulsus alternans after Bentall's operation for annuloaortic ectasia].

Left ventricular pulsus alternans developed immediately after Bentall's operation in a 37-year-old patient with Marfan's syndrome accompanied by severe left heart failure due to annuloaortic ectasia. Echocardiographic examination suggested that this symptom was caused by alternating contractility based on left ventricular myocardial failure. Left heart failure disappeared early after operation, but pulsus alternans persisted until 7 months after operation, when EDVI decreased from 225 ml/m2 to 113 ml/m2.

Adult↗

PubMed1993

[A case of quadricuspid aortic valve associated with mitral regurgitation].

A case of a 60-year-old man associated with quadricuspid aortic valve and mitral regurgitation is reported. The aortic valve consisted of three larger cusps and a small accessory cusp situated between the right and the non-coronary cusps. The aortic regurgitation resulted from malcoaptation of the four cusps and the mitral regurgitation resulted from annulus dilatation and thickening of the anterior leaflet. The surgical treatment was performed successfully by the aortic and mitral valve replacements with St. Jude Medical valves. The patient is doing well fifteen months postoperatively. Sixteen Japanese cases of quadricuspid aortic valve which were corrected surgically are reviewed.

Aortic Valve↗

PubMed1990

[Subdural hematoma following surgery of an aneurysm of the diverticulum of the ductus arteriosus with partial cardiopulmonary bypass].

The patient was a 72-year-old man, who had an aneurysm of the descending thoracic aorta with left recurrent laryngeal nerve palsy identified by preoperative examination. Thoracotomy revealed an aneurysm of a diverticulum of the ductus arteriosus measuring 2.7 X 3.4 cm. The aneurysm was excised under partial cardiopulmonary bypass and the defect of the aortic wall was repaired with a Dacron patch. Two days after surgery, he developed mild deterioration of consciousness and right hemiparesis. An acute subdural hematoma which covered the left frontal, parietal, and temporal lobes was found by CT examination. Craniotomy was performed 16 days after the previous surgery, and 100 g of hematoma was removed. Following craniotomy, complete recovery of cerebral function was observed. This appears to be a valuable report of a patient who developed acute subdural hematoma following surgery of aneurysms of the descending thoracic aorta with partial cardiopulmonary bypass.

Aged↗

PubMed1990

[Successful mitral valve replacement for infective endocarditis in pregnancy].

A 27 weeks' pregnant women exhibited infective endocarditis due to alpha-streptococcus. As echocardiography showed vegetations on both mitral leaflets, cesarean section was performed at 35 weeks' gestation and a healthy male infant weighing 2,430 g was delivered. Antibiotic therapy was continued for fever after the cesarean section but macrohematuria and Osler's nodes developed. Emergency mitral valve replacement was performed successfully despite the presence of active infective endocarditis. She was discharged after completion of a 10-week course of antibiotic therapy.

Adult↗

PubMed1990

[Successful repair of an acute type A dissection during pregnancy].

We report a successful repair of an acute type-A aortic dissection during pregnancy. A 29-year-old pregnant woman in the 32 weeks of gestation with Marfan Syndrome was admitted to our hospital for the treatment of anterior chest and back pains. An urgent aortogram through pulmonary artery revealed an aortic dissection beginning from the ascending aorta to the aortic bifurcation. On the following day, an emergent Cesarean section was performed and a baby weighing 1944 g was delivered. Thereafter, cardiopulmonary bypass was instituted and the ascending aorta was opened. An intimal tear was found 2 cm above the aortic valve. The dissected space was closed with reinforcement of Teflon felt strip. A Dacron gusset was sutured to restore aortic continuity. During the weaning from the CPB, a retrograde aortic dissection developed and the heart became arrested. Therefore we immediately converted the aortic perfusion cannula from the right external iliac artery to graft of the ascending aorta, and the operation was completed successfully with a good recovery of the heart. The mother and her child have been alive and well for 3 years and 5 months after the operation.

Adult↗

PubMed1989

[Effects of cardioplegic solutions on coronary artery and myocardium--comparison of the glucose-insulin-potassium solution and the St. Thomas' Hospital cardioplegic solution].

Effects of two cardioplegic solutions on coronary artery and myocardium were experimentally investigated in three types of preparations. In the isolated perfused guinea pig heart, infusion of Glucose-Insulin-Potassium (GIK) solution (37 degrees C) caused contraction of coronary artery, whereas the St. Thomas' Hospital cardioplegic solution (37 degrees C) produced vasodilation. At the end of 30 minutes reperfusion after continuous infusion of cardioplegic solution, the St. Thomas' Hospital cardioplegic solution produced a greater recovery of cardiac function than GIK solution. In the isolated pig coronary artery, vasoconstriction caused by high potassium content was diminished by addition of magnesium in concentration dependent manner. In the electrophysiological examination, the membrane potential of the guinea pig papillary muscle was recorded by means of conventional glass microelectrodes. Though GIK solution produced greater depolarization of resting membrane potential than the St. Thomas' Hospital cardioplegic solution, effects of the two different cardioplegic solution was not so different after reperfusion of Tyrode solution. The St. Thomas' Hospital cardioplegic solution resulted in greater recovery of contracting activity after reperfusion than GIK solution. These data suggest that GIK solution causes coronary vasoconstriction and has deleterious effects on myocardium and that the St. Thomas' Hospital cardioplegic solution has a vasodilating action and produced a greater myocardial protection than GIK solution.

Animals↗

PubMed1989

Functional and metabolic protection of the neonatal myocardium from ischemia. Insufficient protection by cardioplegia.

The effects of ischemia and cardiac arrest by cardioplegia on the mechanical function and energy metabolism of the ventricular myocardium of the neonatal guinea pig were investigated in the isolated perfused heart preparation and compared with these effects in the adult guinea pig. Whereas reperfusion after ischemia resulted in better recovery of mechanical function and a higher adenosine triphosphase content in the neonatal myocardium than in the adult, recovery from cardiac arrest induced by St. Thomas' Hospital cardioplegic solution was not as good in the neonatal myocardium as in the adult. Contracture developed in the neonatal myocardium on administration of the cardioplegic solution, but did not in the adult. This was considered to be the reason that the protective effect of the cardioplegic solution was inferior in the neonatal myocardium to that in the adult.

Adenosine Triphosphate↗

PubMed1989

Difference in the mechanical response to a cardioplegic solution observed between the neonatal and the adult guinea pig myocardium.

We attempted in two types of preparations to delinate the difference in responses to St. Thomas' Hospital cardioplegic solution between the neonatal and the adult guinea pig myocardium. Isolated guinea pig hearts were perfused with Langendorff's method and the tension of the papillary muscle of the right ventricle was recorded. Continuous infusion of St. Thomas' Hospital cardioplegic solution (37 degrees C) for 30 minutes resulted in a significantly higher elevation of the resting tension (development of contracture) in the neonatal myocardium than in the adult. The recovery of normal contractile tension after the resumption of perfusion with normal Krebs-Ringer bicarbonate solution was smaller in the neonate with increases in the myocardial water and calcium contents. The membrane potential of the papillary muscle preparation was recorded by means of conventional glass microelectrodes. There was no significant difference in the control values of the resting membrane potential and in the degree of depolarization during exposure to St. Thomas' Hospital cardioplegic solution between the neonate and the adult. Thus the greater elevation of the resting tension produced in the neonatal myocardium by St. Thomas' Hospital cardioplegic solution was not due to a greater depolarization of the surface membrane.

Aging↗

PubMed1988