Biomedical subjects

S Aoyagi

Publications and source records attributed to S Aoyagi.

At least 217 records · Page 12Linked to original sources

PubMed1993

Doppler echocardiographic evaluation of St. Jude Medical valves in the tricuspid position.

Sixteen of 20 patients who underwent tricuspid valve replacement with a St. Jude Medical valve at our hospital were followed for three to 164 months. Doppler echocardiographic and cineradiographic examinations of the replacement device were performed in 13 patients. There were six males and seven females in the study, with a mean age of 41.9 years. A St. Jude Medical prosthesis had also been implanted in the mitral or mitral and aortic positions of eight of these thirteen patients. Ten patients had normally functioning valves in the tricuspid position and three were diagnosed as malfunctioning. The peak velocity in those patients with normally functioning tricuspid valves was 1.3 +/- 0.2 m/sec. The calculated peak and mean pressure gradients were 6.7 +/- 1.9 mmHg and 2.6 +/- 1.1 mmHg, respectively, and the mean pressure half-time was 120 +/- 22 msec. All normally functioning valves in the tricuspid position had peak velocities of less than 1.55 m/sec, and peak and mean pressure gradients of less than 9.6 mmHg and 5 mmHg, respectively, with the pressure half-time being less than 140 msec in all cases, except for one of the three Doppler studies performed in one patient. However, three Doppler studies performed in two patients with a malfunctioning tricuspid valve revealed peak velocities, peak and mean pressure gradients and pressure half-times which were above these values. After replacement of the malfunctioning valve, or thrombolysis, all of the Doppler-derived values returned to the range found in normally functioning valves.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

[Partial brachiocephalic perfusion in aortic arch replacement].

Twenty patients with aneurysm or dissection of the aortic arch underwent surgical treatment using partial brachiocephalic perfusion (PBP). The right subclavian artery (SA) and common femoral artery were separately cannulated and perfused by individual pump heads. The flow to SA was 4.5-11 (9.9 +/- 1.4) ml/min/kg. The mean distal stump pressure of the left superficial temporal arteries before beginning the CPB were 36-64 (50.6 +/- 8.3) mmHg. The rectal temperature during PBP was maintained at 20.1-25.0 degrees C. The PBP time ranged 32 to 157 min. We studied the oxygen saturation of left internal jugular vein (SjO2) and cerebral circulatory index (CCI) during the PBP. SjO2 ranged from 72.9 to 99.4% and CCI were maintained at more than twice the CCI measured before beginning the CPB. We applied this simplified method (PBP) to the 20 patients with aortic aneurysms. No neurological complication were seen in these 19 patients without one patient. These clinical studies suggest that the PBP under hypothermic CPB is a safe and reliable method of cerebral protection for replacement of the aortic arch.

Adult↗

PubMed1993

[Post-transfusional syndrome like graft versus host disease].

We studied clinical and immunological changes of the post-transfusional syndrome like graft versus host disease (GVDH) in six patients after open heart surgery and in one patient after hepatectomy. In the patient with hepatocellular carcinoma, transcatheter arterial embolization had been previously done. All patients received homologous blood transfusion during and after surgery and erythroderma associated hyperthermia occurred approximately 10 days after operation. Patients receiving open heart surgery died on between postoperative 17th and 21st day. One patient with hepatectomy died on the 29th day after operation. Skin biopsies in all patients showed the findings of acute GVHD. The number of CD3+ and CD4+ T lymphocytes decreased at postoperative day 1, however, the number of CD3+ T lymphocyte increased in three patients after postoperative day 14. The postoperative value of interleukin-2 production was low in patients in whom the value was measured. The immunological status in host has not been clearly resolved. However, the postoperative changes of lymphocytes subsets were abnormal and IL-2 production in two patients showed low level. Therefore, it was considered that pre and postoperative measurement of cell-modiated immunity might predict the occurrence of the post-transfusional GVHD and might be one of useful examinations to prevent the disease.

Aged↗

PubMed1993

[Left atrial free-floating ball thrombus in a patient without mitral valve disease].

A free-floating ball thrombus in the left atrium is a rare clinical problem with potentially catastrophic consequences. Thus, early diagnosis and prompt surgical intervention are mandatory. This report dealt with a free-floating ball thrombus in the left atrium in a case without mitral valve disease. A 82-year-old woman was presented with dyspnea, hypotension, and fever. On admission she had cardiac arrhythmia, but had no cardiac murmur. The electrocardiogram revealed atrial fibrillation. Chest X-ray examination showed marked cardiomegaly (cardio-thoracic rate; 94%) without evidence of pulmonary venous congestion. Coagulation studies revealed decreased coagulability. Transthoracic and transesophageal echocardiograms showed retention of pericardial effusion, and a free-floating ball thrombus in the dilated left atrium. Thickening, calcification, and restricted motion of the mitral leaflets were not observed by echocardiography. Removal of the free-floating ball thrombus in the left atrium was successfully performed on the emergency basis. The intact mitral valve was also confirmed at operation. The patient recovered uneventfully. Usefulness of echocardiography, particularly transesophageal echocardiography, for precise diagnosis and intraoperative management of a free-floating ball thrombus in the left atrium is discussed.

Aged↗

PubMed1992

Partial brachiocephalic perfusion under hypothermic cardiopulmonary bypass. An experimental study.

We studied electrophysiological, oxygen metabolic, and histological variables in dogs to establish the reliability and safety of partial brachiocephalic perfusion (PBP) under hypothermic cardiopulmonary bypass (CPB) at 23 degrees-25 degrees C. Sixteen mongrel dogs were divided into two groups. Six (control group) underwent typical hypothermic CPB for 90 min, and 10 (PBP group) underwent PBP under hypothermic CPB for 90 min. During core cooling on the CPB, a progressive reduction in voltage and slowing of frequency of the electroencephalogram (EEG) was observed. At around 23 degrees C nasopharyngeal temperature the tracing became almost flat and remained so throughout the hypothermic CPB or the PBP under hypothermic CPB. Consistent recovery of the EEG was, however, observed during the period of rewarming on the CPB, and the voltage and frequency of the EEG recovered to control levels on weaning off CPB at 36 degrees C in both groups. In the PBP group, the cerebral arteriovenous oxygen (AVO2) difference was 12.4 +/- 4.0 vol% before beginning the CPB, and it was 5.6 +/- 2.7, 5.7 +/- 3.1, 5.4 +/- 3.3, and 4.9 +/- 2.9 vol% at 10, 30, 60, and 90 min respectively after commencement of the PBP under hypothermic CPB. The cerebral AVO2 difference measured 10 min after commencement of the PBP was significantly less than that in the control group (P less than 0.05), but otherwise there were no significant differences between cerebral AVO2 differences in the two groups. Concentration of serum creatine kinase-BB (CK-BB) gradually increased in proportion to the duration of CPB in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Congenital quadricuspid aortic valve associated with aortic regurgitation.

A case of quadricuspid aortic valve is described. The aortic valve consisted of 3 equal-sized and 1 smaller cusps, and a supernumerary cusp located between the right and noncoronary cusps. A right coronary ostium was close to the accessory commissure, and in a lower position. Three fenestrations were found at the supernumerary commissure. Aortic valve replacement was performed successfully with a St. Jude Medical prosthetic valve. On histological examination, the resected cusps showed fibrotic thickening with calcification and no sign of previous inflammatory disease. Quadricuspid aortic valve must be considered a malformation capable of leading to severe valve failure in later life.

Aortic Valve↗

PubMed1992

Modified De Vega's annuloplasty for functional tricuspid regurgitation--early and late results.

From 1978 through 1987, 321 patients who had functional tricuspid regurgitation (TR) associated with mitral or combined mitral and aortic valve disease underwent tricuspid annuloplasty with our modification of the original De Vega's annuloplasty technique. The modified De Vega's annuloplasty consisted of two separate semicircular sutures placed around the anterior and lateral aspect of the tricuspid valve. Preoperatively, 229 (71.3%) of the 321 patients were in New York Heart Association functional class III or IV. There were nineteen early deaths (5.9%), and 15 patients died during a follow-up period of 15 to 126 months (mean follow-up, 26 months). Five patients (1.5%) required reoperation because of biological mitral valve failure and recurrence of mitral stenosis. The severity of TR was evaluated by two-dimensional and pulsed Doppler echocardiography, and was classified on a scale of 0 to Grade 3 according to the maximal distance and the flow pattern of the regurgitant signals in the right atrium. Postoperative echocardiographic evaluation of TR was performed in 121 randomly selected patients late after operation. TR reduced to Grade 1 or less in 107 (88.4%) of the 121 patients after operation. Ninety-six percent of the survivors were in New York Heart Association functional class I or II, postoperatively. The actuarial survival rate for the 321 patients with the modified De Vega's annuloplasty including early deaths was 88.2% at 10 years and the actuarial rate of freedom from reoperation on the tricuspid valve was 97.6%. Our surgical experience indicated that the modified De Vega's annuloplasty, as the method of first choice, is a simple, reliable procedure and resulted in reduction of the severity of TR in 88.4% of the patients with functional TR.

Adult↗

PubMed1992

[A case report of simultaneous procedure of Cabrol's operation and aortic arch replacement: method to reduce the duration of ischemic cardiac arrest].

A 57-year-old female underwent simultaneous Cabrol's operation and aortic arch replacement for aortic dissection. She was admitted with complaint of back pain. Aortography demonstrated acute dissecting aneurysm of the ascending, arch and descending aorta (DeBakey type I) as well as aortic valve regurgitation (Seller's II degree). The operation was undertaken using cardiopulmonary bypass (CPB) under hypothermia with selective cerebral perfusion. A new method to reduce the duration of ischemic cardiac arrest was applied. Initially a low-porosity woven Dacron tube graft (8 mm) was anastomosed to coronary arteries. Blood of CPB was perfused to this graft. This coronary perfusion contributed to shorten ischemic cardiac arrest time and cardiac function was favorable. This method to reduce the duration of ischemic cardiac arrest brought about good result.

Aortic Dissection↗

PubMed1991

The reduction of nonspecific binding in chemiluminescent sandwich enzyme immunoassays.

The reduction in nonspecific binding obtained in EIA procedures based on glucose oxidase (GO)-labelled antibody is determined by the origin of the antibodies used for both the solid phase and for GO labelling. We have examined the relationship between nonspecific binding and various antibody combinations for the purpose of establishing highly sensitive chemiluminescent sandwich enzyme immunoassays. It was shown that nonspecific binding could be reduced by the following combination of solid phase and GO labelled antibodies: (i) guinea pig IgG-guinea pig IgG, (ii) goat IgG-rabbit IgG, (iii) goat IgG-rabbit Fab'. On the basis of these results, we succeeded in establishing highly sensitive chemiluminescent sandwich enzyme immunoassays for human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP). The detection limit was 2.5 mIU/ml for hCG using combination (i), 1 ng/ml for AFP using combination (ii), and 0.05 ng/ml (70 amol/assay) for AFP using combination (iii).

Animals↗

PubMed1991

Spontaneous rupture of the ascending aorta.

A case of spontaneous non-traumatic rupture of the thoracic aorta in a hypertensive patient is presented. The clinical findings suggested acute aortic dissection, and a large pericardial effusion was detected by echocardiography. The typical angiographic features of aortic dissection were not found. Autopsy revealed a longitudinal intimal tear and a rupture in the postero-lateral aspect of the ascending aorta. No false lumen was seen in the ascending aorta. When acute intrapericardial or intrapleural bleeding develops with no evidence of aortic aneurysm or dissection, spontaneous aortic rupture should be suspected.

Aged↗

PubMed1991

Primary anastomosis for acute ascending aortic dissection.

Intimal tear resection and primary anastomosis of the aorta were used for the treatment of eight patients with DeBakey I and II type acute aortic dissection. Five patients were of DeBakey I type, and three patients were of the II type. Moderate or severe aortic regurgitation (AR) was observed in six of eight patients. The site of the intimal tear was diagnosed by intraoperative echocardiography, and the adventitia corresponding to the intimal tear was transversely opened under total cardiopulmonary bypass. While resuspension of the aortic valve was performed on only one of six patients, AR disappeared in four, postoperatively. Two of eight patients died early postoperatively. The cause of death was postoperative cardiac tamponade in one patient and cerebral herniation in the remaining one. The other six patients have been observed for a mean period of 27 months. There is no late death, and they show no dilatation of the aortic root and deterioration of AR. We believe that this operative method is a simple and safe emergency procedure for DeBakey I and II type acute aortic dissection.

Acute Disease↗

PubMed1991

Reoperation for acquired valvular heart disease--operative method and surgical results.

Between January, 1982 and December, 1989, 102 reoperations (repeat median sternotomy) in 101 patients with valvular heart disease were performed at Kurume University Hospital. In these operations, the heart was not mobilized from the pericardium to prevent tearing the heart or great vessels. All operative procedures were performed through the pericardium which adhered tightly to the heart. Adequate left ventricular hypothermic protection was obtained without total dissection of the heart by cold crystalloid cardioplegic solution and topical cooling which was accomplished by filling the left pleural space with cold saline during the operation. As to the surgical results, the early mortality rate was 4.0%, and the late mortality rate was 5.2%. The causes of death were not related to the operative procedures or perioperative myocardial protection. There was no significant difference in the early mortality rate between the reoperations and the initial operations. These results suggest that reoperation for valvular heart disease should be performed before the hemodynamic condition of the patient deteriorates.

Adult↗

PubMed1991

An evaluation of long-term results over 10 years after intracardiac repair of tetralogy of Fallot.

A follow-up study was conducted of 166 patients who had survived for more than 10 years after total correction of tetralogy of Fallot. The total number of patients in NYHA class I was 141 (85%); the other 25 patients had been medically treated or had followed a prudent life style. The factors which caused postoperative symptoms were residual lesions and ventricular arrhythmia. Ultrasonic echocardiography showed that among 72 patients with transannular patch, 68 (95%) showed moderate or severe pulmonary incompetence. There was a correlation of gamma = 0.43 between the severity of pulmonary incompetence and cardiothoracic ratio in the 48 patients without any residual lesions, while two cases with severe pulmonary incompetence showed obvious right ventricular failure. Ambulatory ECG monitoring was employed to study 53 patients. As a result, 21 patients were found to present solitary moderate or severe pulmonary incompetence, while premature ventricular contraction of Lown's grade 4A was seen in nine patients (42.9%). In conclusion, it is considered essential to carefully follow up patients after intracardiac repair of tetralogy of Fallot, especially those with severe pulmonary incompetence.

Adolescent↗

PubMed1991

Anomalous origin of the right coronary artery associated with congenital bicuspid aortic valve.

Anomalous origin of the right coronary artery is an infrequent anomaly. A case with anomalous origin of the right coronary artery from the ascending aorta above the left sinus of Valsalva is described. This patient was also found to have a bicuspid aortic valve. The aortic valve was markedly calcified and stenotic. The aortic valve was replaced with a St. Jude Medical prosthesis.

Aortic Valve↗

PubMed1991

[Surgical treatment of acute ascending dissection--a simplified operative method].

Primary anastomosis for acute ascending aortic dissection was performed in 8 patients. Primary anastomosis included resection of the intimal tear where applicable, a circumferential suture line in the ascending aorta at the site of the tear, and wrapping of the anastomosis of the ascending aorta with Dacron vascular prosthesis. The aortic valve was resuspended in 1 of 6 patients associated with aortic regurgitation. In 4 patients, aortic regurgitation disappeared postoperatively. Two patients show minor non-progressive valve regurgitation. Two of 8 patients died early postoperatively. There was no late death and dilatation of the aortic root in the follow-up period of mean 27 months. On the basis of these results, we believe that primary anastomosis is a simpler and safer operative method for acute dissection of the ascending aorta.

Acute Disease↗

PubMed1991

[Surgical treatment of the aortic arch dissection--a report of two cases operated by partial brachiocephalic perfusion, and open aortic anastomosis].

Two patients underwent aortic arch replacement for the dissecting aneurysm of the aorta using a simplified cardiopulmonary bypass (CPB) technique with partial brachiocephalic perfusion, moderate systemic cooling (22 degrees to 23 degrees C), and open aortic anastomosis were reported. The partial brachiocephalic perfusion was accomplished by perfusion to the right axillary artery using separate pump. Open distal anastomosis was performed under low flow hypothermic perfusion of the lower body during selective perfusion to the brain. Cardiopulmonary bypass and partial brachiocephalic perfusion time were 170 minutes, and 30 minutes in one case, and 207 minutes, 56 minutes in the other case. Both patients survived operations, and there were no postoperative strokes, and neurological complications. On the basis of these results, we discussed about supportive methods for aortic arch surgery.

Anastomosis, Surgical↗

PubMed1991

[Ten years experience with the St. Jude Medical valve prosthesis for mitral valve replacement].

During the 10-year period between 1980 and December 1989, isolated mitral valve replacement (MVR) with the St. Jude Medical (SJM) valve prosthesis was performed on 404 patients at our hospital, and a long-term postoperative follow-up was conducted. There were 161 males and 243 females ranged in age from 1 year to 73 years. Early operative mortality was 5.2%. Follow-up period for 383 patients who discharged from the hospital was 1970.7 patient-years. Twenty of these patients died during the follow-up period, and a late mortality rate was 5.2%. During 10 years, thromboembolic event occurred in 8 patients. Four patients had anticoagulant-related bleeding, 4 had paravalvular leak, and 5 underwent re-operations. There was neither structural valve failure nor prosthetic valve endocarditis. Therefore, the actuarial survival rate and the valve-related death-free rate at 10 years were 83.2%, and 96.8%. Of the patients who survived, New York Heart Association class improved significantly (93% in classes II and III preoperatively and 71% in class I postoperatively). Linearized rates for thromboembolism, anticoagulant-related bleeding, and hemolysis were 0.41%, 0.20% and 0.36%/100 patient-years, respectively. The actuarial estimate of incidence free from all complications was 92.0% at 10 years. On the basis of this 10 years' experience, we believe that the SJM valve prosthesis is an excellent mechanical prosthesis for mitral valve replacement, in terms of hemodynamic performance and low thrombogenicity in patients receiving anticoagulants.

Adolescent↗

PubMed1991

[Cardiovascular surgery in patients seventy years of age and older].

During 10 years between 1981 and 1990 surgical treatment was performed in 77 elderly patients (emergency 19) for cardiovascular disease at the 2nd Dept of Kurume Univ. Hospital. The 58 elective patients were studied. There were CABG in 29; valve replacement in 18; aneurysm operation in 11. The control patients were consisted of CABG in 60; valve replacement in 40; and aneurysm operation in 20 patients whose age were under 60 years. In the elderly group, operative mortality was 3 in 58 (5.2%) and there were no significant differences compared to that in the control patients. However, low output syndrome or respiratory complication was relatively prevented in the elderly patients and careful post operative management was required. The late results in the elderly patients NYHA or exercise tolerance was improved well. The 5 years actuarial survival rate was 93.3% in ischemic heart disease group, 87.7% in valvular heart disease group, and 90.0% in thoracic aneurysm group. No significant difference was seen compared to these results in control patients and no significant differences among these diseases.

Age Factors↗