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Biomedical subjects

Y Sezai

Publications and source records attributed to Y Sezai.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Three-dimensional transesophageal echocardiographic assessment for prosthetic valves].

We evaluated three-dimensional transesophageal echocardiographic assessment of the implanted mechanical valves by rotational scanning method. Patients were 7 mitral valve replacement and one aortic valve replacement, 2 mitral and aortic valve replacement. In 2 cases of 7 mitral valve replacement, the prosthetic valve regurgitation was evaluated using by color Doppler echocardiography. In this study, multiplane transesophageal probe was used. It rotated at 2-degree intervals from 0 to 180 degrees and the three-dimensional reconstruction was performed by echo scan workstation system (TOMTEC Inc, Munich, Germany). In mitral valve replacement cases, the valve motion of bileaflet valve (St. Jude Medical valve and ATS valve) were showed very clearly. The struts was easily recognized in the St. Jude Medical valve (SJM valve) cases. In one of SJM valve cases, the pannus formation was revealed, but it did not disturb valve motion. The prosthetic valve regurgitation can be seen accurately. However, aortic valve and ball valve cases cannot be reconstructed because of artifact from prosthetic valve and ultrasonic direction. The prosthetic valve regurgitation, pannus formation which was difficult to be showed in two-dimensional echocardiography and relationship between annulus and sewing cuff can be evaluated by this three-dimensional echocardiography. In this study, this system has some problems, for example real-time evaluation is impossible, aortic valve and ball valve cases cannot be reconstructed. However, we think that this new technology is suitable for evaluating valve thrombus, valve dysfunction and paravalvular leakage. In conclusion, the three-dimensional echo-cardiography demonstrated, reliable and accurate examination, and it can evaluate various complications of prosthetic valve.

Adult↗
PubMed1997

[A correlation between atrial natriuretic peptide, brain natriuretic peptide, and perioperative cardiac and renal functions in open heart surgery].

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are homeostatic hormones secreted from the human heart which protect both cardiac and the renal function. It is well known that these hormones increase in patients along with increases in the severity of congestive heart failure or acute myocardial infarction. However, as yet there are no reports in the literature on changes of the secreted level of ANP or BNP in surgical patients undergoing cardiopulmonary bypass (CPB). We evaluated the relationship between ANP, BNP, and perioperative cardiac and renal functions in patients with heart failure caused by CPB. We selected 45 patients of elective open heart surgery. We measured plasma level of ANP in all 45 cases, and BNP in 18 cases at preoperation, postoperation, and postoperatively three days after, respectively. At the same time, the cardiac index (CI) was measured. These cases were divided into the following groups. Group A1 (n = 23): cases in which the preoperative ANP was less than 40 pg/ ml. Group A2 (n = 22): cases in which the preoperative ANP was more than 40. Group B1 (n = 8): cases in which the preoperative BNP is increased to the level of 5 times as mach as the normal level. Group B2 (n = 8): cases in which the preoperative BNP is increased to the level of 5 times as much as the normal level. Group B2 (n = 10): cases in which the preoperative BNP was more than that of 10 times as mach as normal level. We then carried out a comparative study of the perioperative cardiac and renal functions in group A1 and A2, and group B1 and B2, respectively. In the terms of preoperative cardiac and renal function, there were no significant differences between groups A1 and A2, and there were no significant differences in urinary volume during CPB or post operative CI. However, the urinary volume during CPB of group B1 was significantly more than that of B2. Furthermore, the incidence of postoperative CI in group B1. Furthermore, the incidence of postoperative CI in group B1 was significantly higher than in B2. The preoperative and post operative third day BNP level had significant negative correlations with postoperative CI and postoperative third day CI, respectively (r = -0.641, -0.514, p = 0.008, 0.012). The postoperative ANP and BNP levels tend to a mean level roughly similar to one another because of the easing of cardiac stress by surgery and postoperative management. According to these results and several instances in the literature, a preoperative high BNP is considered to suggest a potential perioperative risk for cardiac and renal function. We conclude that determination of the plasma BNP level can be helpful for decisions related to CPB flow and measures taken to enhance cardiac and renal protection during surgery, and therefore is a useful reference for perioperative management.

Aged↗
PubMed1996

Comparison studies of major organ microcirculations under pulsatile- and nonpulsatile-assisted circulations.

In these comparison studies, we examined changes in major organ microcirculations during circulatory support using pulsatile and nonpulsatile pumps. Acute myocardial infarction was created by left anterior descending (LAD) branch ligation. After the animals in these studies fell into cardiogenic shock, they were supported by mechanical assist devices: a pulsatile ventricular assist device (VAD) in 4 pigs, a nonpulsatile VAD in 4 pigs, and an intraaortic balloon pumping (IABP) plus nonpulsatile VAD in 4 pigs. Each group was supported for 3 h with an identical mean aortic pressure being maintained. As for parameters, the stomach mucosa, liver regional blood flow, stomach mucosal pH, and arterial blood keton body ratio (AKBR) were measured. Both regional blood flow and AKBR increased in the pulsatile group as compared with the nonpulsatile group. There were no differences in the stomach mucosal pH among the 3 groups. These results suggest that pulsatile assist rather than the nonpulsatile assist plays a significant role in the recovery of deteriorated splanchnic organs due to cardiogenic shock.

Animals↗
PubMed1996

[Chest wall reconstruction after the resection of primary chest wall tumors].

Between April 1983 and June 1994, we performed chest wall reconstructions on 9 patients (7 males and 2 females) out of 27 all of whom underwent the radical resection for the primary chest wall tumors. Histological diagnosis of tumors included 6 chondrosarcomas, 1 Ewing's sarcoma, 1 plasmacytoma and 1 giant cell tumor. Six lesions were located on the rib and 3 on the sternum. For the materials for reconstruction of the chest wall use a polyethylene plate in 2 patients, a Marlex mesh in 5 patients and a Marlex mesh with a methyl methacrylate utilizing the sandwich method in 2 patients. The polyethylene plate proved to be satisfactory for maintaining stability of the chest wall. However, our experience using this plate showed intensive foreign body reactions, and discovering these we have not use the polyethylene plate. Marlex mesh had an affinity with human tissue and was very easy to use and produced no complications. We use Marlex mesh for flat surfaces on the anterior or posterior chest wall. Marlex mesh and methyl methacrylate utilizing the sandwich method, combined the solidity and shaping of methyl methacrylate with the benefit such as easy fixation and excellent incorporation of the mesh.

Adult↗
PubMed1996

[A case report of a left atrial ball thrombus at 16 years after mitral valve replacement].

A free floating ball thrombus in left atrium is very rare, only 2 cases that develop ball thrombus after mitral valve replacement (MVR) have been reported. This case was a 55-year-old female who underwent MVR and tricuspid annuloplasty (TAP) in 1978. After 16 years, she developed replaced mitral valve stenosis due to pannus formation and tricuspid regurgitation (TR), with a free floating ball thrombus in the giant left atrium. A ball thrombus was taken out, and Re-MVR and tricuspid valve replacement (TVR) was carried out. Post operative course was uneventful. Because a free floating ball thrombus easily causes "Hole-in-one" sudden death, early surgical treatment must be considered.

Female↗
PubMed1996

[Primary pulmonary cryptococcosis treated by thoracoscopic resection].

A 37-year-old man was admitted to the hospital because of an abnormal shadow in the right lower field on a chest roentgenogram. The lesion was calcified and was therefore suspected to be benign. Thoracoscopic resention was performed. The pathological diagnosis was cryptococcosis of the lung. The lesion was completely resected, so no antifungal drug was given. The patient was doing well as of 12 months after the operation.

Adult↗
PubMed1996

Coronary microcirculation during left heart bypass with a centrifugal pump.

To estimate coronary microcirculation during left heart bypass (LHB), we performed an experimental comparison study of LHB and intraaortic balloon pumping (IABP). LHB was performed with a BioMedicus BP-80 pump supporting half of the flow of cardiac output whereas the IABP was pumped in a 1:1 mode for cardiogenic shock in a swine model. Coronary circulations were analyzed by electromagnetic flowmeter, pulsed Doppler velocimeter, and laser Doppler flowmeter. Left ventricular end-diastolic pressure (LVEDP) was reduced significantly by LHB. Although there was no significant difference in epicardial flow between the LHB and IABP groups, endo cardial flow was increased significantly by LHB. In the LHB group, the systolic reverse wave of the coronary velocity called a myocardial invalid circulation was reduced remarkably. There was a significant inverse correlation between endocardial flow and LVEDP. These results suggested that LHB was more effective for myocardial microcirculation than was IABP.

Animals↗
PubMed1996

Effect of pulsatile and nonpulsatile assist on heart and kidney microcirculation with cardiogenic shock.

To estimate microcirculation of the heart and kidney in pulsatile and nonpulsatile-assisted circulation, a comparison study was done using a swine model. Acute myocardial infarction was made by ligation of the left coronary artery branches. After cardiogenic shock, animals were divided into 3 groups as follows: Group C (n = 6), no assist provided; Group NP (n = 6), assisted by a nonpulsatile pump (Bio-Medicus BP-80); Group P (n = 6), supported by a pulsatile pump (Nippon Zeon). left coronary artery flow, endocardial and epicardial regional flows, and renal cortex and medulla tissue blood flows were measured. Left coronary artery flow and endocardial and epicardial tissue blood flows decreased in cardiogenic shock, and they recovered to the control level soon after support in both Group N and Group P. Renal medulla and cortex tissue blood flows decreased in cardiogenic shock, and these flows did not recover in either Group N or P. However, cortex blood flow in Group P did improve, but it did not improve in Group N. These results suggested that pulsatile assist was more effective than nonpulsatile assist for microcirculation after cardiogenic shock to avoid deterioration of major organ functions.

Animals↗
PubMed1996

Experiences of postcardiotomy assist: pneumatic ventricular assist device or venoarterial bypass with percutaneous cardiopulmonary support.

From October 1982 to the present, 16 patients have been supported by a pneumatic ventricular assist device (VAD). Since April 1990, we have introduced a venoarterial bypass (VAB) with percutaneous cardiopulmonary support (PCPS) system. This PCPS system was used in 12 patients. The long-term survival rate of PCPS cases (41%) was much better than that of VAD cases (19%). The main cause of death in VAD cases was multiple organ failure (MOF). Although VAB was initiated more recently than VAD, the duration on support was longer in the VAD group than in the VAB group. Because of the longer support duration and the presence of many patients with MOF, coagulopathy deteriorated more readily in the VAD group than in the VAB group. In the case of postcardiotomy cardiopulmonary bypass weaning or low-output syndrome (LOS), the VAB with PCPS system should be applied first under intraaortic balloon pumping assist because of its simplicity and low cost. Thereafter, VAD should be applied in cases refractory to VAB support.

Adult↗
PubMed1996

[A case of giant cell tumor originating in the rib].

We have experienced a rare case of giant cell tumor originating in the rib. A 25-year-old male was admitted to our hospital with the abnormal shadow in chest X-ray film. Chest CT, MRI, Bone scintigram showed tumor originating from the right 4th rib. Needle biopsy was performed. As the result, this tumor was suspected giant cell tumor of bone. The tumor was completely resected, and the chest wall defect was covered with the marlex mesh. The pathological diagnosis was a giant cell tumor of bone. The patient is now doing well without recurrence for 14 months after the operation.

Adult↗
PubMed1996

Preliminary experimental study about the feasibility of combining pulsatile cardiopulmonary support system and a membrane oxygenator.

A cardiopulmonary support (CPS) device that incorporated a pneumatic ventricular assist device (VAD) and a membrane oxygenator was developed for the support of patients with profound heart and/or respiratory failure. This device has an advantage of being both a pulsatile assist device and membrane oxygenator. A "triple flow" regulator was included in this system to control the blood flow through the oxygenator. The purpose of this study was to clarify the efficacy of this system in supporting an animal model with combined cardiac and respiratory failure. In vitro tests showed 3.7 L/min of pump flow under 1.6 L/min of oxygen supply to the oxygenator even though there was a 50% clamp of a "triple flow" regulator with sufficient pulsatility. In 14 acute canine experiments, cardiogenic shock and acute respiratory failure were introduced by coronary ligation and mechanical hypoventilation simultaneously. The pump flow was maintaned at 1.95-0.6 L/min (average 1.2 L/min) and the driving pressure of the pump was controlled between 200 and 300 mmHg positive pressure and -20 to -50 mmHg negative pressure. The driving rate was fixed at 100 bpm and systolic/diastolic ratio was controlled between 35-50%. The canines were divided into control group (n = 4) and pumped group (drained from the right atrium n = 7, drained from the left atrium n = 3). By using CPS system, flow and aortic pressure recovered to the initial baseline level. Without this support, the canine model could not maintain systemic circulation. In the group drained from right atrium, central venous pressure decreased with the device from 13.9 +/- 2.4 to 5.6 +/- 1.4 cm H2O (p < 0.01), returned to the initial level without this device (p < 0.01). In the group drained from left atrium, pulmonary capillary wedge pressure decreased from 37.9 +/- 4.6 to 20.8 +/- 5.7 mmHG (p < 0.01), and returned to the initial level without the device, arterial oxygen tension levels increased tension levels increased (p < 0.01), and also arterial oxygen saturation levels recovered (p < 0.01). The results suggest that the current model of the pulsatile CPS has a potential to support the animal model with combined cardiac and respiratory failure.

Animals↗
PubMed1995

[A case of localized fibrous tumor of the pleura with bloody pleural effusion].

A 25-year-old female came to our hospital with the chief complaint of right dorsal pain. On her initial chest X-ray, the tumor (5 x 3 cm) was recognized in the right lower lung field. The tumor grew rapidly during the three month period between the initial X-ray taken on her first visit and her getting admitted in the hospital. A preoperative diagnosis was done by percutaneous aspiration biopsy. Initial diagnosis of spindle cell tumor was made. Partial resection of right lower lobe with chest wall resection was carried out. There were about 500 ml of bloody pleural effusion. Macroscopically, the tumor was encapsulated, measuring 8.0 x 6.0 x 5.0 cm. The cross section was of a yellowish brown solid tumor. The histological diagnosis was of a low grade malignant fibrous mesothelioma. Only 14 cases of localized mesothelioma with pleural effusion including our case have been reported in Japan. She is still alive nine months after surgery. This patient should be carefully followed for the recurrence of the disease.

Adult↗
PubMed1995

Bilateral common iliac artery aneurysms secondary to fibromuscular dysplasia accompanied with a coronary aneurysm. A case report.

Fibromuscular dysplasia (FMD) is found in various arteries but the common iliac arteries and the coronary arteries are seldom involved. A 49-year-old woman was referred to our hospital with a pulsatile mass in her right lower quadrant. She had subdural hemorrhage in a postpartum state at the age of 27. After admission angiography diagnosed the bilateral iliac artery aneurysms and coronary angiography revealed a coronary artery aneurysm, the size of which was 12 mm x 19 mm in the region of the left main trunk. The bilateral iliac artery aneurysms were resected and Y-shaped vascular prosthesis was replaced. Microscopic sections of the aneurysm showed remarkable decrease of elastic fibers and thinning of the media, but no increase occurred in the smooth muscle. Histopathological diagnosis was FMD (periarterial fibroplasia). To our knowledge, no patient with a iliac arterial aneurysm caused by FMD has been reported and only a few cases with coronary arterial FMD have been described. This is the first report of iliac arterial aneurysm due to FMD. Since this case has multiple aneurysms, a long-term follow-up is definitely required, especially focusing on the coronary aneurysm.

Aneurysm↗
PubMed1994

Anatomical relationship between saphenous vein and cutaneous nerves.

The anatomical relationship between the saphenous veins and cutaneous nerves was investigated in 148 lower limbs of 74 cadavers in order to re-examine the stripping technique for treatment of varicose veins. The great saphenous vein frequently ran intimately along the saphenous nerve (59.5% in the middle third and 83.1% in the lower third of the leg) in the leg region. More than half of the latter cases showed an adhesive relationship in which the perineurium of the saphenous nerve was seen histologically to be attached to the adventitia of the vein. Moreover, in the thigh region as well, the great saphenous vein had an intimate relationship with the cutaneous nerves of various origin. In contrast, the small saphenous vein was often located close to the cutaneous nerves of the calf like the sural nerve. However, the adhesive relation between the small saphenous vein and nerves was rarely observed, in contrast to the case of the great saphenous vein. From these results, the anatomical relationship between the superficial vein and nerve in the lower limb were characterized according to each part of the lower limb. Based on our observations, limited extraction of the vein was recommended to reduce the risk of nerve injury during the stripping operation.

Adult↗
PubMed1994

[A case of thoracoscopic pulmonary lobectomy for lung cancer].

A case of thoracoscopic right lower pulmonary lobectomy is reported. A 79-year-old man was admitted to our hospital after the accidental finding of a right pulmonary growth. A computed tomography (CT) scan of the thorax confirmed the presence of a neoplasm, 2.5 cm in diameter, at the posterior-basal segment of the right lower lobe. Considering the general condition of the patient and the characteristics of the lesion, we decided to perform a assess the possibility of a thoracoscopic lobectomy instead of the traditional posterolateral approach. The pulmonary artery was dissected with the new endoscopic cherry dissector, and ligated with the polyester suture material and Endo Clip then dived with Endo scissors. The lower pulmonary vein was dissected with this endoscopic cherry dissector and divided with Endo GIA 30 clamping the new thoracoscopic De Bakey type vascular clamp. The specimen was extracted through the minimal thoracotomy (15 cm). The postoperative course was uneventful with minimal postoperative pain, and the patient was discharged after complete surgical recovery with excellent functional and cosmetic results.

Aged↗
PubMed1994

[A case of congenital solitary tricuspid regurgitation treated with tricuspid valvular replacement].

A case of congenital solitary tricuspid regurgitation was reported. The patient was a 43-year-old male. The echocardiogram and ventriculography showed severe tricuspid regurgitation. The tricuspid valve was hypoplastic in each leaflet and chordae without torn chordae and papillary muscles. A tricuspid valve replacement was performed using St. Jude Medical 33 mm valve. As of June 1993 nine patients with this disease undergoing surgery were reported around the world.

Adult↗
PubMed1994

[A case of primitive neuroectodermal tumor from rib].

Primitive Neuroectodermal Tumor (PNET) is a small round cell malignancy arising in bone and soft tissue. With the progress of immunohisto-chemical and ultrastructural studies, the tumor has getting attention. We report a rare case of PNET arising from rib. A 19-year-old man was admitted to our hospital complaining of chest and back pain. The tumor arised from 5th rib and en bloc resection was performed. Pathological diagnosis was PNET. After the operation, he is doing well, except being treated with chemotherapy (T9-protocol).

Adult↗