Biomedical subjects

A Sezai

Publications and source records attributed to A Sezai.

At least 19 recordsLinked to original sources

PubMed2003

[Reoperation for a Starr-Edwards ball valve prosthesis implanted in mitral position 31 years ago].

The patient is a 61-year-old woman who had undergone mitral valve replacement with the Starr-Edwards cloth-covered ball valve 31 years ago. She had dyspnea on effort 1 month before admission. The echocardiography revealed mitral and tricuspid regurgitation. Re-replacement of the mitral prosthetic valve with an ATS valve and tricuspid annuloplasty were successfully performed without any complication. The cloth wear of the Starr-Edwards ball valve cage was recognized and no thrombus was found at operation. To our knowledge, there has been no such a reoperative case who underwent so long postoperative period after initial implantation of the Starr-Edwards ball valve in Japan. This experience made us realize again the importance of attention to the complications related to a prosthetic valve like a cloth wear during long-term follow-up for the Starr-Edwards ball valve.

Female↗

PubMed2001

Doppler echocardiographic evaluation of St. Jude Medical valves in the tricuspid position: criteria for normal and abnormal valve function.

BACKGROUND: Although this examination for mitral and aortic prosthetic valves has been frequently reported to be available for the early diagnosis of complications, there are few reports on examinations for tricuspid prosthetic valves, particularly the mechanical valve such as the St. Jude Medical (SJM) valve. Furthermore, the criteria for early diagnosis of complications are unknown. The purpose of this study is to evaluate the SJM valve in the tricuspid position by Doppler echocardiography and to analyze valve-related complications. METHODS: Between September 1978 and March 1997, 46 patients underwent tricuspid valve replacements with SJM valves; these cases were evaluated by Doppler echocardiography. We divided the cases into Normal and Complication groups. RESULTS: In the Normal group, peak pressure gradient was 4.2+/-1.5 mmHg and pressure half-time was 123.5+/-22.9 msec. In the Complication group, peak pressure gradient was 12.7+/-3.6 mmHg and pressure half-time was 271.8+/-76.4 msec. In the Complication group, the lowest peak pressure gradient case was 8.0 mmHg and the shortest pressure half-time was 160.0 msec. CONCLUSIONS: We concluded that when the peak pressure gradient is more than 8 mmHg or the pressure half-time is more than 160 msec, there is a possibility of complications. Despite the problems, the absence of any structural change after more than ten years suggests that the SJM valve can be used in the tricuspid position with careful follow-up.

Adult↗

PubMed2001

Evaluation of St. Jude Medical valve's long-term function by Doppler echocardiography.

In this study, the long-term function of St. Jude Medical valve (SJM valve) is evaluated by Doppler echocardiography. The subjects were 191 patients who underwent mitral or aortic valve replacement using SJM valve in our institute since July 1978 and had no clinical problem showing more than 50% of left ventricular ejection fraction. The patients were classified into 3 groups according to measurement period (within 5 years, 10 years and 15 years and more), and further classified by size and their results were compared. In every group by size, there was no significant difference among groups by measurement period. In the mitral valve position, peak pressure gradient and pressure half-time were not significantly different among groups by size. On the other hand, in the aortic valve position, pressure gradient in 21-mm group was significantly high among 21-mm, 25-mm, and 27-mm groups, showing a negative correlation with size. As the result, it was suggested that SJM valve kept a good function more than 15 years after operation. From these results, it was considered that the patients with small annlus of the aortic valve needed annulus-enlarging procedure or use of Hemodynamic Plus series valves to keep the size of more than 23 mm.

Adult↗

PubMed2000

Evaluation of valve sound and its effects on ATS prosthetic valves in patients' quality of life.

BACKGROUND: We interviewed patients and carried out frequency analyses to compare the closing sounds of ATS and St. Jude Medical (SJM) prosthetic valves. METHODS: Forty-five patients undergoing valve replacements using ATS valves were investigated. We interviewed patients at 1 month and 1 year after the operation, and carried out frequency analysis to investigate the prosthetic valve's closing sound. RESULTS: According to the results of the interviews, 84.4% of patients with ATS valves were not aware of the valve sounds. ATS valves scored significantly lower than SJM valves on audibility of the valve sound, disturbance during daytime, sleep disturbance, request for replacement with a soundless prosthetic valve, audibility to others, and noise index. According to the frequency analysis on the prosthetic valve's closing sound, the sound peak of the ATS valves was around 1.2 kHz, and the sound pressure of the ATS valves was significantly lower than that of the SJM valves. CONCLUSIONS: Though a further long-term observation on thromboembolism and hemolysis is needed for evaluation of prosthetic valves, the ATS valve is presently considered to impart a better quality of life.

Adult↗

PubMed2000

Low-dose continuous infusion of human atrial natriuretic peptide during and after cardiac surgery.

BACKGROUND: We evaluated the effects of human atrial natriuretic peptide (hANP) during cardiopulmonary bypass (CPB). METHODS: Forty patients undergoing coronary artery bypass grafting were investigated. A group of patients given hANP for 24 hours from the start of CPB (hANP group) was compared with a non-hANP group. Parameters examined were hemodynamics, urine volume, dosage of furosemide, respiratory index, pleural effusion, ANP, cyclic guanosine monophosphate, renin activity (renin), angiotensin-II, aldosterone, and glomerular filtration rate. RESULTS: Central venous pressure, systemic vascular resistance index, and pulmonary vascular resistance index were significantly lower in the hANP group than in the non-hANP group. The hANP group showed significantly higher levels of ANP, cyclic guanosine monophosphate, glomerular filtration rate, and respiratory index, and significantly lower levels of renin, angiotensin-II, aldosterone, and pleural effusion, as compared with the non-hANP group. The dosage of furosemide was significantly lower and the urine volume was significantly larger in the hANP group. CONCLUSIONS: hANP can satisfactorily compensate for the shortcomings of CPB by decreasing the peripheral vascular resistance, suppressing the renin-angiotensin-aldosterone system, and exerting a strong diuretic effect.

Atrial Natriuretic Factor↗

PubMed2000

Clinical results of coronary artery bypass grafting with use of the internal thoracic artery under low free flow conditions.

OBJECTIVE: Even when left internal thoracic artery flow is very low, we have used the artery for grafting without any further maneuvers. In this study, we investigated the clinical results of coronary bypass surgery using the left internal thoracic artery with low free flow. METHODS: A total of 163 patients were divided into 2 groups: group L (n = 43) had free flow of 20 mL/min or less and group H (n = 120) had free flow of more than 20 mL/min. We performed a comparative study on the basis of coronary angiography and pulsed Doppler echocardiography. Furthermore, 12 months' postoperative graft angiography was carried out in 11 patients from group L. RESULTS: No patient had low output syndrome or perioperative myocardial infarction. One month after the operation, 3 cases of graft occlusion and 9 cases of the "string sign" were identified in group H. However, group L had no graft occlusion and only 1 case of the "string sign." The 1-month postoperative Doppler echocardiographic study showed no significant differences in the diastolic fraction of velocity time integrals and the diastolic/systolic peak velocity ratio of the grafts. In the 11 patients undergoing angiography after 1 year, graft patency was excellent. Moreover, the graft diameter was significantly larger than it was 1 month after the operation. CONCLUSION: These results suggest that the left internal thoracic artery can be used for coronary artery bypass grafting even when the flow is less than 20 mL/min.

Blood Flow Velocity↗

PubMed2000

A clinical use of the Kyocera Gyro C1E3 centrifugal pump.

The Kyocera Gyro C1E3 centrifugal blood pump was clinically applied for a cardiopulmonary bypass (CPB) of coronary artery bypass grafting (CABG). The patient was 72-year-old male with postinfarction unstable angina. The surgery was carried out on November 20, 1998. The air inside the pump was easily and quickly removed, and its controllability was excellent. The pump flow during operation was maintained 2.2 L/m2. Total CPB time was 173 min. Perioperative parameters of hemolysis and cytotoxicity were not remarkably changed. Macroscopically and microscopically, there were no thrombi inside the pump after usage. This is the first reported case of clinical use of the Kyocera Gyro C1E3 pump.

Aged↗

PubMed2000

Jostra Rota Flow RF-30 pump system: a new centrifugal blood pump for cardiopulmonary bypass.

The Rota Flow pump is a fully integrated centrifugal pump system in the Jostra heart-lung machine HL-20 with features such as a less friction mono-pivot bearing system, sealless pump housing, and spiral housing. To evaluate its biocompatibility, antithrombogenesity, and hemolysis, we used it as a main pump of cardiopulmonary bypass (CPB) in coronary artery bypass grafting (CABG) cases and compared it with the BioMedicus pump. From February 1999 to May 1999, 30 consecutive patients underwent CABG under conventional CPB. Fifteen cases were supported by the Rota Flow RF-32 (Group R), and the remaining 15 were pumped by the BioMedicus BP-80 (Group B). In both groups, the flow rate was controlled in an equivalent value. Blood sampling was as follows: preoperative, 60 min after, postoperative Days (POD) 0, 1, and 2. We evaluated the plasma free hemoglobin (fHb) as the hemolysis parameter, beta-thromboglobulin (beta-TG) and platelet factor IV (PF-4) as the platelet deterioration index, C3, C4, and CH50 as complement activation, coagulation function, fibrinolytic factor and thrombomodulin, nitric oxide (NO), and endothelin as endothelial deterioration. This system was very easily and simply controlled and had excellent response. Perioperative laboratory data were not markedly changed in either group. The Rota Flow demonstrated equivalent value of biocompatibility and hemolysis as compared with the BioMedicus BP-80, which is a standard centrifugal pump. After pumping, no thrombus formation or pivot wear was observed inside the pump. This atraumatic, small centrifugal pump is suitable not only for CPB but also for long-term circulatory support.

Analysis of Variance↗

PubMed2000

Morbidity and outcome after mechanical ventricular support using Thoratec, Novacor, and HeartMate for bridging to heart transplantation.

Between September 1989 and June 1999, 228 patients were supported with a ventricular assist device as a bridge to heart transplantation. In this study, the results of implantation were evaluated in patients supported with one type of device, including 85 supported with a Thoratec, 61 with a Novacor, and 37 with a HeartMate. The mean support time was 49, 148, and 124 days, respectively. Successful transplantation and weaning rates were 64. 7% with Thoratec, 59.0% with Novacor, and 62.0% with HeartMate. Cerebral embolism and drive-line and pocket infection were major causes of postoperative morbidity and mortality. We recommended that a Thoratec system be employed as a bridge to heart transplantation for patients with biventricular heart failure, and that a Novacor or HeartMate system be implanted in patients requiring a long-term circulatory support.

Adolescent↗

PubMed2000

Mid-term results of ATS open pivot bileaflet mechanical prosthetic heart valve.

We investigated mid-term results of the patients with an ATS bileaflet valve in our institution. In the past 6 years, 69 patients received valve replacement with an ATS valve. We assessed the changes of serum lactate dehydrogenase (LDH) level in the hospital, and the valve's closing sound. The serum LDH level had almost normalized one week postoperatively and they have maintained normal levels since then. According to the questionnaire about the valvular sound at a random period after surgery, it was unnoticeable in 61 (88.4%) of the patients with ATS valve. In the 8 patients (12.6%) who recognized the valve sound, 7 of them were reoperation cases. As to the frequency analysis for the valve's closing sound, the sound peak was indicated at around 1.2 kHz in the patients with ATS valves. In patients with St. Jude Medical (SJM) valves, it appeared not only around 1.2 kHz but also around 2 to 7 kHz. Postoperative cerebral infarction was complicated in one patient. Mortality occurred in 4 (5.7%) of the patients with ATS valves. The follow up periods were from one to 66 months. Thromboembolic event free and actuarial survival rate in the patients with ATS valves were 98.6% and 94.2%, respectively. These results indicated that the ATS valve is considered to be a safe valve and mid-term follow-up shows excellent results in terms of the patients quality of life.

Female↗

PubMed2000

Two cases of quadricuspid aortic valve: preoperative diagnosis and surgical treatment.

Two cases of severe aortic regurgitation were treated surgically. Both patients had a quadricuspid aortic valve, which was diagnosed preoperatively by aortography and/or transesophageal echocardiography (TEE). In the first patient, both aortic and mitral valve replacement were performed with an ATS prosthetic valve. In the second patient, only aortic valve replacement was performed. The postoperative course was uneventful in both cases. Quadricuspid aortic valve is relatively rare. We discuss the preoperative diagnosis of quadricuspid aortic valve, as well as reviewing the relevant literature.

Aortic Valve↗

PubMed1999

Major organ function under mechanical support: comparative studies of pulsatile and nonpulsatile circulation.

We examined a major organ function during 3 h biventricular assisted circulation after acute myocardial infarction model in the pig. In left ventricular circulation, the outflow cannula was placed in the ascending aorta and an inflow cannula through the mitral valve in the left ventricle. A pump (pulsatile group, Zeon Medical, Inc., Tokyo, Japan and nonpulsatile group, Nikkiso HPM-15, Nikkiso, Inc., Tokyo, Japan) was connected to each cannula. In right ventricular circulation, the outflow cannula was placed in the pulmonary artery and an inflow cannula in the right ventricle. The right ventricular circulation was supported by a nonpulsatile pump (Nikkiso HPM-15). The items measured were the regional blood flows of the cortex and medulla in the kidney, white matter and gray mater in brain, and liver; renal arterial flow; carotid arterial flow; portal vein flow; common hepatic arterial flow; arterial ketone body ratio (AKBR); and lactate/pyrubic acid (L/P). In the pulsatile group, the renal cortical blood flow increased, and the medulla blood flow decreased. On the other hand, in the nonpulsatile group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved rather than in the nonpulsatile assisted group. In addition the liver regional blood flow, AKBR, and L/P showed significant differences between the pulsatile and nonpulsatile groups. On the other hand, the white matter and gray matter regional blood flows and carotid arterial flow did not show significant differences between the groups. The results of our study indicated that pulsatile circulation produced superior circulation in the kidney and liver, and microcirculation on the cell level was superior as well in early treatment of acute heart failure.

Animals↗

PubMed1999

Cytokine and endothelial damage in pulsatile and nonpulsatile cardiopulmonary bypass.

Recently, several types of centrifugal pumps have been widely used as the main pumps for cardiopulmonary bypass (CPB). However, according to the results of our experimental studies, after cardiogenic shock, pulsatile flow was effective in maintaining the functions and microcirculations of end organs, especially those of the liver and kidney. To estimate the effectiveness of pulsatility during CPB, cytokine and endothelin and other metabolic parameters were measured in clinical pulsatile and nonpulsatile CPB cases. From March to May 1997, CPB was performed in 18 elective cases (14 ischemic and 4 valvular disease). In 9 cases, pulsatile perfusion was achieved by the Jostra HL20, which is a newly developed CPB pump (Group P). A nonpulsatile centrifugal pump was used in 9 patients (Group NP). In both groups, as chemical and metabolic mediators, interleukin-8 (IL-8), endothelin-1 (ET-1), and plasma free hemoglobin were measured before and during CPB, and 0.5, 3, 6, 9, 18 h after weaning from CPB. This pulsatile CPB pump could be very simply and easily controlled and could easily produce pulsatile flow. There were no significant differences in CPB time (CPBT), aortic cross clamp time (ACCT), mean aortic pressure, or pump flow during CPB between the both groups. The ET-1 level of Group P was significantly (p < 0.05) lower than that of Group NP 9 h after CPB weaning. The IL-8 level of Group P also showed a lower value than that of Group NP. As for plasma free hemoglobin, there were no significant differences between the groups. These results suggested that even in conventional CPB, pulsatility was effective to reduce endothelial damage and suppress cytokine activation. It may play a important role in maintaining the functions and microcirculations of end organs during CPB.

Aged↗

PubMed1999

Effects of phosphodiesterase inhibitors after coronary artery bypass grafting.

The aim of this study was to estimate the postoperative effects of phosphodiesterase (PDE) inhibitors (milrinone and olprinone) after coronary artery bypass grafting (CABG). To prevent hypotension caused by the PDE inhibitors, low dose of catecholamines were used concomitantly. A total of 34 elective CABG cases were tested. In 12 cases, 0.25 microg kg(-1) min(-1) of milrinone, 3 microg kg(-1) min(-1) of dobutamine (DOB) and dopamine (DOA) were used concomitantly (Group-M). In another 10 patients, 0.1 microg kg(-1) min(-1) of olprinone and the same doses of the catecholamines were infused (Group-O). As a control, the same doses of DOA and DOB only were administered in 12 patients (Group-C). When the pump flow of the cardiopulmonary bypass (CPB) decreased to half, these drugs were given in all groups. Hemodynamics were recorded before CPB, just after the operation, and 3, 6, 12, 24, 48 and 72 h after the operation. Both milrinone and olprinone increased the cardiac index and decreased systemic vascular resistance to almost the same degree. Olprinone decreased mean aortic and pulmonary artery pressures, and also significantly reduced the preload of both right and left heart compared with milrinone. Significant hypotension was not detected due to the concomitant usage of low-dose catecholamines. This concomitant usage of PDE inhibitors and catecholamines allowed easy weaning from CPB, demonstrating excellent hemodynamics after CABG. Good oxygen demand and supply balance were maintained in peripheral tissue. These results suggest that these new PDE inhibitors may be effective not only for weaning from CPB but also for post-cardiotomy cardiogenic shock.

Aged↗

PubMed1999

Should use of the internal thoracic artery be avoided under conditions of low free flow? Postoperative hemodynamic assessment using pulsed Doppler echocardiography.

There are cases in which it is thought advisable to avoid the use of the left internal thoracic artery (LITA) in coronary artery bypass grafting (CABG) due to its low free flow (FF). However, even though the LITA flow is very low, anastomosis without any further maneuvers intraluminally is recommended. The present study investigated the clinical results of CABG, using a LITA with low FF. The 60 cases of CABG were divided into 2 groups: (i) Group L (n = 23), in which LITA FF was less than 20 ml/min; and (ii) Group H (n = 37) in which it was more than 20 ml/min. A comparative study on the basis of coronary angiography and pulsed Doppler echocardiography was performed. In both groups, no LITA graft occlusion was identified, and the 'string sign' was also absent. In the LITA blood waveform, all cases exhibited a biphasic pattern with a higher mid-diastolic and a lower end-systolic component. There were no significant differences in the LITA flow diastolic peak velocity, velocity time integrals and the diastolic/systolic peak velocity ratios. These results suggest that the LITA can be used for CABG even when the free flow is less than 20 ml/min.

Aged↗

PubMed1999

Spontaneous recanalization of postoperative severe graft stenosis. What is the cause and prognosis of the "string sign" in the internal thoracic artery?

A 68-year-old female with unstable angina was treated surgically. She was referred to the surgical ward by cardiologists because of a diagnosis of unstable angina with three vessel disease. On a coronary angiogram (CAG), 90% stenoses were found in the left anterior descending coronary artery (LAD), circumflex (CX), and right coronary artery (RCA). She received elective coronary artery bypass grafting (CABG), in which the left internal thoracic artery (LITA) was anastomosed to the LAD and reversed saphenous vein grafts (SVG) were made to segment 12 of the CX, and segment 4PD of the RCA, respectively. The postoperative course was uneventful, but postoperative early graftgraphy revealed distal narrowing of the LITA graft as the so-called "string sign". However, one year post surgery, the LITA string sign was not found and its patency had markedly improved on the second graftgram. It is reported that the LITA "string sign" might cause late graft occlusion. However, this LITA graft evidently enlarged the size and increased the flow of the artery in proportion to myocardial blood demand. To our knowledge, it has not been reported that an in situ LITA string sign on postoperative early graftgram has disappeared in the late phase. We hypothesize that the LITA string sign might be caused by several different factors such as flow competition, spasm, and/or technical problems. In any event, the LITA string sign does not cause graft occlusion in the late postoperative period in every case.

Aged↗

PubMed1999

[Effectiveness of low dose continuous infusion of alpha-hANP from the start of cardiopulmonary bypass].

In this study, we used alpha-human atrial natriuretic peptide (hANP) from staring on cardiopulmonary bypass and evaluated for the hemodynamics, ANP, renin activity, aldosterone, urine volume, glomerular filtration rate (GFR) and so on. The hANP decreased renin activity, aldosterone, systemic vascular resistance and increased urine volume, GFR and use of furosemide and KCL were decreased. We concluded that hANP was effective for hemodynamics, renal function and hormonal release on intra and post-operation in cardiac surgery, and low dose continuous infusion of alpha-hANP from staring on cardiopulmonary bypass will be expected as a newly application.

Aldosterone↗

PubMed1999

Surgical treatment of 22 cardiac myxomas: A review.

Twenty-two cases of cardiac myxomas were reviewed. The patients were 8 men and 14 women ranging in age from 12 to 73 (mean: 50.8 +/- 16. 6) at operation. They suffered from dyspnea, palpitation, and cough, similar to mitral disease symptoms, and cerebral emboli in 6 patients (30%) with left atrial myxomas. Echocardiography, especially transesophageal, was useful in diagnosing cardiac tumors and location. In 20 cases, tumors were at the left atrium and at the right in 2. Left atrial myxomas were approached through a septal incision in 17 cases; a large circular incision of the biatrium was used in 3 patients with large tumors or mitral regurgitation. Left atrial myxomas were attached to the atrial septum in 17 cases, the posterior wall of the left atrium in 2, and near the posterior commissure of the mitral valve in 1. Right atrial myxomas were attached to the atrial septum in 1 and posterior wall beside the inferior vena cava in 1. Resected myxomas weighed from 10 to 90 (mean: 39.1 +/- 19.1) g. No correlation was seen between features such as neurologic symptoms, feeding artery on coronary angiography, or functional status and tumor weight. No recurrence was seen.

Adolescent↗