Biomedical subjects

Y Sezai

Publications and source records attributed to Y Sezai.

At least 55 records · Page 3Linked to original sources

PubMed1998

One-stage repair of interrupted aortic arch and aortopulmonary window.

Interrupted aortic arch type A with aortopulmonary window was diagnosed in a 12-day-old neonate. A successful one-stage repair was undertaken through a midline sternotomy without circulatory arrest. The aortopulmonary window was closed through the anterior wall of communication between ascending aorta and main pulmonary artery with a patch. Position of the arterial cannula was changed during the repair, which made it possible to mobilize and expose the aortic arch for the completion of direct anastomosis.

Aorta, Thoracic↗

PubMed1998

Clinical experiences of percutaneous cardiopulmonary support: its effectiveness and limit.

In recent years, several types of centrifugal pumps have been widely used as the main pumps for cardiopulmonary bypass (CPB) and postcardiotomy cardiac support. From April 1990 to March 1997, a percutaneous cardiopulmonary support (PCPS) system was used in 20 patients with an average age of 58 years (13 males and 7 females). They comprised 11 ischemic, 6 valvular, 2 aortic, and 1 congenital heart disease patients. Our PCPS system consists of a centrifugal pump (BioMedicus BP-80), an oxygenator, and a reservoir. The entire blood contacting surface, including that of the thin wall cannulas, is coated by heparin bonded materials. As a result of this new technology, this system can be used for the long term without systemic heparinization. No major critical thrombi were revealed inside the pumps or circuits. Of the 20 patients, 7 (35%) (Group 1) could be weaned from PCPS, and the remaining 13 (Group 2) could not. In Group 1 although 2 patients suffered from renal failure and pneumonia, respectively, both were discharged from our hospital. The long-term survival rate was 35%. In Group 2 cerebral vascular damage was recognized in 3 patients, renal failure in 4, multiple system organ failure in 4, bleeding in 2, arrhythmia in 1, and leg ischemia in 2. Pulse pressure was significantly elevated due to the recovery of the native heart in Group 1, 2 days after support. However, in Group 2, it did not elevate, and the left ventricular ejection fraction was less than 30%, associated with high left atrial pressure. In conclusion, this heparin coated PCPS system was very simple and easy to control. It demonstrated long-term biocompatibility and was very effective in recovering deteriorated cardiac function. Quicker application of this system can play an important role in preventing severe complications and obtaining better clinical results. If long-term support is necessary, a ventricular assist device (VAD), which is more powerful, durable, and biocompatible, has to be applied instead of PCPS.

Acute Kidney Injury↗

PubMed1998

Less invasive coronary artery bypass without cardiopulmonary bypass.

Minimally invasive coronary artery bypass grafting (CABG) aims to avoid cardiopulmonary bypass and take maximum advantage of a smaller incision. Minimally invasive direct coronary artery bypass (MIDCAB) surgery is performed on selected arteries of the beating heart under direct vision through a choice of small incisions. Short-term results show good patency rates and a dramatic impact in terms of shorter hospital stays and cost effectiveness. The procedure is also being used increasingly in Japan. However, valid concerns have been raised about the quality of the anastomosis fashioned on a beating heart with pharmacologic bradycardia, and the long-term result of this technique is still questionable. The combined use of circulatory assist devices and mechanical stabilizing devices will be expected to expand access to coronary arteries by allowing for decompression of the left ventricle, permitting retraction and rotation of the heart, and hopefully further improvement of the results. Less invasive coronary surgery should be proven to be as effective and safe as conventional CABG before widespread adoption.

Anastomosis, Surgical↗

PubMed1998

[Mediastinal neurilemmoma originating in the right phrenic nerve: a case report].

We report on a 31-year-old man with a mediastinal neurilemmoma originating in the right phrenic nerve. The patient was admitted because of abnormal chest X-ray shadows observed during a routine checkup. A preoperative diagnosis of bronchial cyst in the mediastinum was made. The tumor was resected by video-assisted thoracic surgery. It was 3 x 4 x 3 cm in size, weighted 15 g, and originated in the right phrenic nerve. The histopathologic diagnosis was mediastinal neurilemmoma. Only 14 cases have been reported in the Japanese literature.

Adult↗

PubMed1998

Coronary artery surgery results 1996.

This survey on ischemic heart disease surgery began in 1974 and has continued to report the current status of surgical treatment in Japan. Coronary artery bypass grafting (CABG) has increased markedly and surgical results have become increasingly favorable. This report describes CABG and surgery for postinfarction complications in 1996, including the first investigation on CABG without cardiopulmonary bypass (off-pump CABG) and minimally invasive direct coronary artery bypass grafting (MIDCAB).

Coronary Artery Bypass↗

PubMed1998

Left atrial myxoma with an atrial septal defect: a case report and review of the literature.

We report a case of a 49 year-old Japanese woman with a left atrial myxoma complicated by an atrial septal defect diagnosed intraoperatively, which was classified as in secundum defect and was 28x110 mm in diameter. The tumor, which was attached by a pedicle to the posterior wall of the left atrium near the posterior commissure of the mitral valve, was removed together with a small portion of the left atrial wall. The postoperative course was uneventful. The pathologic findings were consistent with the diagnosis of myxoma. Since the defect was functionally canceled by the myxoma, the diagnosis of an atrial septal defect was not confirmed preoperatively even by color Doppler echocardiography and cardiac catheterization. Tumor embolization is one of the critical complications of myxoma. Fortunately, she didn't suffer from either systemic or pulmonary emboli. During surgery of myxoma with atrial septal defect, careful manipulation is needed, especially at caval cannulation so as not to damage the tumor directly. In the cases with atrial septal defect or patent foramen ovale, myxomas are generally situated on the interatrial septum. However, in this case the tumor was located on the posterior wall of the left atrium.

Cardiac Catheterization↗

PubMed1998

Mechanical cardiac assistance.

In our institute, we have intensively introduced both pulsatile and non-pulsatile mechanical cardiac assist devices, such as the pneumatic ventricular assist device (VAD) and percutaneous cardiopulmonary support (PCPS), using a centrifugal pump. From various kinds of clinical views, these cases were estimated and evaluated retrospectively according to the weaning results, long-term survival rate and cause of death. Based upon our experiences and clinical results, an alternate strategy of mechanical cardiac assistance for severe heart failure is suggested as follows. In the case of post-cardiotomy cardiogenic shock or low output syndrome, PCPS system should be applied firstly under intra-aortic balloon pumping (IABP) assist for a maximum of 2-3 days. If the native cardiac function does not recover and more long-term support is needed, several types of VAD, which are more powerful and durable devices should be introduced, according to end organ function and expected support duration. In order to obtain better clinical results, we have to select an appropriate device depending on the limited availability of supporting duration. Generally speaking, centrifugal pumps can support in short-term duration, while pulsatile devices cover the broad spectrum of the supporting period. Pneumatic VADs can cover short-term to long-term support up to a year, and electric VADs can cover over 1 year, and can be used as a bridge to heart transplantation.

Cardiac Surgical Procedures↗

PubMed1998

Macroscopic aspects of cloth-covered Starr-Edwards prostheses at reoperation: what the precursory valve teaches us.

BACKGROUND AND AIMS OF THE STUDY: Cloth-covered Starr-Edwards ball valves were the first choice in prosthetic substitution at the authors' institution between June 1968 and March 1977. This study investigated, retrospectively, macroscopic aspects of the prostheses at reoperation. METHODS: Among 59 survivors who underwent isolated aortic or mitral valve replacement, 12 required reoperation for valve dysfunction (five aortic valve replacements, seven mitral valve replacements). Reoperation was necessitated by valvular endocarditis, paravalvular leak, hemolysis, thromboembolism, orifice stenosis attributable to pannus, and inappropriate sizing related to growth and thrombus. The mean time to reoperation was 11.7 +/- 6.2 years after initial surgery (range: 2 years 4 months to 21 years 8 months). RESULTS: Marked cloth wear was observed in all aortic prostheses, but only slight wear in mitral valves. Pannus formation was observed around the orifice in both aortic and mitral prostheses, but strut cloth was not extensively covered by autologous tissue. In mitral valves, strut cloth was only slightly worn and less loose than that of the aortic valve. These changes notably affected prosthetic valve function, the most significant problem in mitral prostheses being thrombus (four of seven valves). CONCLUSIONS: Pannus formation and thrombus caused by the reaction of the patient's tissues remain major problems in the use of artificial valves, and require further work for their improvement.

Adolescent↗

PubMed1998

Post-operative effects of olprinone after coronary artery bypass grafting.

The aim of this study was to test the effects of olprinone after coronary artery bypass grafting (CABG). In order to prevent hypotension caused by olprinone, low doses of catecolamines were used concomitantly. Total 22 elective CABG cases were evaluated. In all cases, moderate hypothermia and cardioplegic cardiac arrest were performed. In 10 cases, continuous intravenous 0.1 microg/kg/min of olprinone, 3 microg/kg/min of dobutamine (DOB) and dopamine (DOA) as the initial doses, were used concomitantly (Group I). As a control, the same initial doses of catecolamine (DOB and DOA) of Group I were administered in another 12 patients (Group II). When the pump flow of cardiopulmonary bypass (CPB) was decreased to half, these drugs were administered in both groups. Hemodynamics were recorded before CPB, just after the operation and 3, 6, 12, 24, 48, and 72 hours after the operation. Three hours after the operation, both mean aortic pressure (AoP) and pulmonary artery pressures (PAP) of Group I demonstrated significantly lower values than those of Group II. Cardiac index (CI) of Group I showed significantly higher values than that of Group II until 6 hours after surgery. The systemic vascular resistance index (SVRI) of Group I indicated a significantly lower value than that of Group II until 24 hours after the operation. Pulmonary capillary wedge pressure (PCWP) of Group I demonstrated a significantly lower value than that of Group II. There were no significant differences in urine output, oxygen delivery (DO2) and oxygen consumption (VO2) between both groups. Olprinone increased CI and decreased SVRI, and it showed easy weaning from CPB, demonstrating excellent hemodynamics after CABG. These results suggested that this new phosphodiesterase inhibitor may be effective for not only weaning from CPB but also post-cardiotomy cardiogenic shock.

Aged↗

PubMed1998

Congenital coronary artery fistula treated surgically in the right atrium and the atrial septum.

Various surgical techniques have been employed according to the type of the coronary fistula. In this case, preoperative examinations by aortography and MRI revealed a coronary artery fistula which originated from a site just proximal of the RCA, ran through the interatrial septum and drained into the posterior wall of right atrium. The ratio of pulmonary to systemic blood flow (Qp/Qs) was 1. 95. During surgery, we were not able to ligate or divide the fistula on the cardiac surface because the fistulous vessel originated from the posterior aspect of the proximal RCA. After establishing a cardiopulmonary bypass, the opening of the fistula in the right atrium was closed with an autologous pericardium patch, the surface of the interatrial septum was incised and the fistula was identified. The conduit was then divided and closed in the atrial septum. The postoperative course was uneventful. This approach is able to interrupt the fistula safely without interfering with normal coronary flow. Closure of the outlet and division of the fistula itself is a recommendable method to insure interruption of fistulous communication.

Adult↗

PubMed1997

A newly developed silicone-coated membrane oxygenator for long-term cardiopulmonary bypass and cardiac support.

The surface of polypropylene hollow fiber was successfully coated with a very thin (0.2 micron) silicone layer. Experimental studies were performed in long-term (6 h) normothermic cardiopulmonary bypass (CPB) using 10 goats. A conventional membrane oxygenator (Mera Excelung HPO-15H, MERA, Tokyo, Japan) was used for 5 goats as a control (Group C) and a new silicone-coated membrane oxygenator, which is of the same construction as that of the one used for Group C, for 5 (Group S). The O2 transfer and CO2 removal functions showed the same ranges. In the other parameters, there were no differences between the 2 groups. As for hemolysis, however, the plasma free hemoglobin of Group S was lower than that of Group C. Currently, 3 chronic percutaneous cardiopulmonary support (PCPS) experimental models have been conducted, and there has been no evidence of thromboembolism or deterioration of the oxygenator. In conclusion, this new oxygenator is suitable not only for CPB, but also for long-term cardiac support.

Animals↗

PubMed1997

Renal circulation and cellular metabolism during left ventricular assisted circulation: comparison study of pulsatile and nonpulsatile assists.

We examined left ventricular assist during 6 h for an acute myocardial infarction model in pigs. The outflow cannula was placed in the ascending aorta and an inflow cannula in the left atrium. A pump (Pulsatile group: Zeon Medical and Nonpulsatile group: Nikkiso HPM-15) was connected to each cannula. Items measured were the regional blood flow of the cortex and the medulla in the kidney, renal arterial flow, arterial blood ketone body ratio (AKBR), lactate/pyruvic acid, BUN, creatinine and beta 2-microglobulin. After experimental study, the kidneys were removed, and a pathological study was performed. In the pulsatile assisted group, renal cortical blood flow increased but medulla blood flow decreased. On the other hand, in the nonpulsatile assisted group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved, rather than in the nonpulsatile assisted group. The results of our study indicated that pulsatile assist produced superior circulation in the kidney, and the microcirculation on the cell level was superior as well in early treatment of acute left heart failure.

Animals↗

PubMed1997

[Urgent replacement of aortic arch and descending aorta following replacement of ascending aorta for Stanford a aortic dissection--a case report].

A 37-year-old male who was on chronic dialysis regimen for IgA nephropathy developed acute Stanford A type aortic dissection. Replacement of the ascending aorta was performed with the aid of extracorporeal circulation, selective cerebral perfusion, and open distal anastomosis technique. The site of the intimal tear in the ascending aorta was resected and the gelatin-resorcin-formaldehyde (GRF) glue was applied to both stumps. The outside of dissecting aortic wall was reinforced with Teflon-felt strips. Two months after the operation, the patient required an urgent operation due to threatening spindle evolution of a persisting dissection in the descending aorta. Replacement of the total arch and the descending aorta was carried out via the median sternotomy with the left anterior thoracotomy, and a subclavian incision. Continuous veno-venous hemofiltration was initiated immediately after both operations and the water balance was maintained well. The patient was discharged 1 month postoperatively. It was suggested that the inside of the dissected aortic wall should be also reinforced even when the GRF glue was used in patients who have a fragile intimal flap and a wide tear.

Acute Disease↗

PubMed1997

[A simultaneous operation of aortic root, arch replacement, and sternal elevation for Marfan's syndrome--a case report].

A 42-year-old male was transferred to our institution by his family doctor because of suspected type A aortic dissection with cardiac tamponade. His physical constitution gave the appearance of Marfan's syndrome. Contrast CT revealed DeBaky type 1 aortic dissection. Angiography detected an Annulo-aortic ectasia complicated by an aortic regurgitation (AR) grade IV. He also suffered from a severe funnel chest. We performed simultaneous procedures of aortic root, arch replacement, and sternal elevation. Upon operation, a staged aortic clamp technique was employed to reduce the period of cardiac arrest. In the sternal elevation, the bilateral internal thoracic arteries were preserved. Post operative course was uneventful. We consider it effective to employ the staged aortic clamp technique in a reconstruction of the entire thoracic aorta in the case of poor cardiac function and to preserve the bilateral internal thoracic arteries in sternal elevation in order to prevent infection.

Adult↗

PubMed1997

[A reconstruction of the left ventricle for post infarction left ventricular aneurysm complicated by ventricular septal perforation--a case report].

A 68-year-old male with post myocardial infarction left ventricular aneurysm (LVA) complicated by ventricular septal perforation (VSP) was treated surgically. At first, he was admitted with acute myocardial infarction by a physician. Coronary angiography (CAG) revealed a total occlusion of the left anterior descending coronary artery. It was improved to 99% of stenosis by PTCR. Echo cardiography revealed the VSP. However, the patient was approached conservatively because of complications of severe pneuminitis and acute hepatitis. Cardiac catheterization was performed three months after admission. The data on the catheterization are as follows: Left ventricular (LV) wall dyskinesis is presented at segment 1-5. Global ejection fraction (EF) = 26%, Corrected EF = 40%, LVEDP = 36 mmHg, Qp/Qs = 1.8. Elective surgery was then performed with IABP, LVA was resected 90 x 50 mm in size under ventricular fibrillation. VSP, which was 9 mm in size, was closed directly with Teflon felt strips. LV plication was then made with 3.0 polypropylene under cardiac arrest. Reconstruction of the LV was then performed with a double patch, of which a cow pericardium was laid on top of a Gore-Tex patch. Post operative cardiac function was improved remarkably. We consider this procedure excellent because of the avoidance of thrombus and the maintenance of the LV form.

Aged↗

PubMed1997

[A case of atrial septal defect complicated by persistent left superior vena cava in whom hemophagocytic syndrome appeared after operation].

The patient was a 22-year-old woman and suffered from atrial septal defect (ASD) complicated by persistent left superior vena cava (PLSVT). The patient underwent a patch closure using calf pericardium. Despite favorable progress immediately after the operation, fever, enlarged cervical lymph nodes, and leukocytopenia appeared beginning day 8 after the operation. Based on the results of cytodiagnosis of myeloaspiration specimen, the diagnosis of hemophagocytic syndrome (HPS) was made. Since an elevation of 2-5 oligo A synthetase (2-5 AS) levels was observed, the patient was diagnosed to suffer from virus-associated hemophagocytic syndrome (VAHS), and steroid was administered. The patient exhibited a good response to the treatment. The fever declined 3 days after the start of administration. Leukocyte counts were also increased gradually. The patient condition was improved and she was discharged from the hospital on day 28. At present, seven months after the operation, there is no evidence of recurrence and the patient's condition is still monitored.

Adult↗

PubMed1997

[A case of primary fibrous histiocytoma of the lung].

Fibrous histiocytoma is non-epithelial malignant tumor mainly arising from soft tissue in extremities and body. Those derived from lung are rare. A 71-year-old female was admitted to our hospital because of an abnormal shadow on chest X-ray film. Preoperative diagnosis was not obtained by various examination. The tumor was located in right upper lobe (S2) and partial resection of right upper lobe was performed. Pathological diagnosis was fibrous histiocytoma of borderline malignancy. After the operation, adjuvant therapy was not done. The patient is doing well without recurrence and metastasis, during 4 years after the operation. However, careful follow-up should be necessary for long term.

Aged↗

PubMed1997

[A case of coronary artery bypass grafting without cardiopulmonary bypass in a patient with left ventricular dysfunction].

A 54-year-old man who had severe deterioration of left ventricular function (cardiac index ; 1.6 l/min/m2, left ventricular ejection fraction ; 26%) due to two myocardial infarcts underwent bypass of the left anterior descending artery using the left internal thoracic artery under IABP assist without extracorporeal circuration or cardiac arrest. Two hours postoperatively, he was extubated. Subsequent clinical course was uneventful with a satisfactory outcome. These findings suggest that coronary artery bypass without extracorporeal circulation or cardiac arrest is a safe and effective procedure in patients with left ventricular dysfunction.

Cardiopulmonary Bypass↗