Biomedical subjects

Y Sezai

Publications and source records attributed to Y Sezai.

At least 37 records · Page 2Linked to original sources

PubMed2000

Operative management of abdominal aortic aneurysm with left-sided inferior vena cava.

Abdominal aortic aneurysm with left-sided inferior vena cava (IVC) is rare. In preoperative examination, it is important to conduct roentgenologic studies and determine any venous anomalies. Proximal anastomosis is technically difficult because the IVC crosses to the right on the aneurysmal neck. In this case of a 71-year-old Japanese man, proximal anastomosis was conducted safely under wide vena cava mobilization and contraction in the superior direction. In vein resection, vessels should be reconstructed because vein communication is not methodical.

Aged↗

PubMed2000

[A case report of treatment for tracheal fistula after radical esophagectomy].

We report our experience of the treatment of a 60-year-old man with upper tracheal fistula which developed on the 11th day after radical surgery for esophageal cancer. Primary treatment to close the fistula was unsuccessful, resulting in the involvement of empyema due to infection. Controlled ventilation with T-tube and drainage through a chest tube for 2 months lead to depuration of the thoracic cavity. As a strategy for secondary closure of the fistula, fenestration was performed on the 87th day postoperatively. The patient's overall condition improved thereafter and closure was being considered. However, the patient died on the 116th day postoperatively due to supervenient aspiration pneumonia. Thus, long-term controlled ventilation with a T-tube was beneficial for the treatment of central airway injury.

Esophageal Neoplasms↗

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

Doppler features of occlusion of the internal thoracic artery due to preoperative branch embolization.

A 61-year-old male was referred to the surgical ward by cardiologists because of a diagnosis of unstable angina with 3-vessel disease. On preoperative left internal thoracic arteriography, a large first intercostal branch was found at the proximal portion. Selective arterial embolization of the branch of the left internal thoracic artery (LITA) was carried out preoperatively. At 2 days after embolization, the Doppler peak flow velocity and diameter of the LITA were increased and enlarged compared with before the procedure. However, a large reverse wave following after the first systolic peak flow of the LITA was newly detected after embolization. Upon operation, the LITA was found to be occluded at the 2nd intercostal space due to thrombus formation. Therefore, the right internal thoracic artery was anastomosed to the left anterior descending artery and coronary reversed saphenous vein grafts were joined to segment 4PD of the right coronary artery. The postoperative course was uneventful. There has been no previous report of an LITA branch being embolized preoperatively. It was possible to diagnose the graft problem by detecting the altered Doppler wave form of the LITA.

Angina Pectoris↗

PubMed1999

[A trial case of coronary bypass surgery under heart beat in a patient with severe functional disorders of kidney].

Coronary artery bypass grafting (CABG) was performed under heart beat without conducting extracorporeal circulation in a patient with severe functional disorders of kidney, and satisfactory results were attained. The patient was a 71-year-old male with past history of severe functional disorders of kidney and cerebral infarction. He had triple-vessel disease. First, CABG was performed for the primary branches under heart beat without adopting extra-corporeal circulation, then later, percutaneous transluminal coronary angioplasty (PTCA) was performed for the residual lesions, which lead to complete revascularization without causing aggravation of cerebral infarction or functional disorders of kidney or subjective symptoms such as chest pain. CABG conducted under heart beat is less aggressive not only to myocardium but to other important organs, and is thought to be effective for patients who have severe concurrent diseases to which extracorporeal circulation is likely to entail risks. Furthermore, concurrent therapy with PTCA is thought to expand the scope of application of CABG under heart beat including the cases of multiple-vessel diseases.

Aged↗

PubMed1999

Myocardial revascularization without cardiopulmonary bypass in patients with operative risk factors.

We have treated 7 myocardial revascularization cases with operative risk factors, using the beating heart technique without cardiopulmonary bypass. Operative risk factors included left ventricular dysfunction, calcified aorta, chronic renal failure, cerebrovascular accident, immunosupressive state and old age. The 6 males and 1 female ranged in age from 54 to 84 years (mean age 70 years). The mean number of grafts was 1.3 per patient. All were extubated within 3 hours of arrival at the intensive care unit. Inotropic catecholamin support was not necessary on postoperative days. None of our patients had perioperative myocardial infarction. Postoperative angiography showed that all grafts were patent. We have found, based on our experiences, that selected patients can safely undergo CABG without cardiopulmonary support.

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

[A case of mitral valve replacement combined with idiopathic thrombocytopenic purpura (ITP)].

We conducted mitral valve replacement (MVR) in a patient with mitral regurgitation (MR) complicated with idiopathic thrombocytopenic purpura (ITP). The patient was a 62-year-old male who was diagnosed to have grade IV MR. However, a decrease in platelet count was noted (5.6 x 10(4)/microliter) when he has admitted to this hospital for operation. After detailed examination, he was diagnosed to have ITP. Though mass intravenous infusion of gamma-globulin (400 mg/kg/day, for 5 days) was done before the operation, the treatment was not successful and splenectomy was consequently conducted. In view of the influence of invasive splenectomy, the change in platelet count was carefully observed thereafter. The count subsequently increased to reach a peak (26.9 x 10(4)/microliter) after 2 weeks from the splenectomy. MVR was conducted when the count started to decrease again after the peak. The operation was safely completed without any complication such as hemorrhage during and after the operation. Since gamma-globulin treatment and splenectomy are sometimes ineffective in ITP, it is advisable to wait an operation until the effects of these treatments are clarified.

Heart Valve Prosthesis Implantation↗

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↗

PubMed1999

Clinical use of Jostra Rota Flow centrifugal pump: the first case report in Japan.

A Jostra Rota Flow centrifugal blood pump was clinically applied for a cardiopulmonary bypass (CPB) of an ascending aortic replacement for type A aortic dissection. The patient was a 68-year-old female with Stanford type A, DeBakey type II thrombosed aortic dissection complicated by cardiac tamponade and moderate aortic regurgitation. The surgery was carried out on December 22, 1998. The air inside the pump was easily and quickly removed, and its mode of control was excellent. The pump flow during the operation was maintained at about 2.2 l/m2. Total CPB time was 179 minutes. Macroscopically and microscopically, there were no thrombi inside the pump, after usage. The postoperative course was uneventful. The clinical use of this pump was the first case in Japan. This pump is excellent in the ease by which it's controlled due to its compact size and low weight. Furthermore, the Rota Flow console can be fully integrated in the HL-20 heart-lung machine, and these systems have pulsatile flow mode possibility. This pump is suitable not only for the main pump of CPB but also circulatory support.

Aged↗

PubMed1999

The efficacy and mid-term results with use of gelatin resorcin formalin (GRF) glue for aortic surgery.

Twenty-six patients were treated by surgical procedure for aortic diseases with use of Gelatin Resorcin Formalin (GRF) glue. They consisted of 25 cases of emergency surgery for type A acute aortic dissection (AAD) and one elective case of distal arch aneurysm. Fifteen patients had moderate to massive aortic regurgitation (AR). We applied GRF glue to adhere the false lumen. It was further applied to anastomosed stitches from the outer side of the aorta. We evaluated the intraoperative effects of it in terms of adhesion and hemostasis and postoperative aortic regurgitation. Furthermore, the mid-term survival rate was investigated. In all cases, the 2 layers were able to be adhered successfully. Furthermore, it was very easy for suturing to pass through the aortic wall, even though the aortic stump was very hard. However, in the distal arch aneurysm case, additional sutures were needed to control the bleeding from the anastomosis. In postoperative aortography, residual AR was found in only one case. Operative deaths were indicated in 3 cases (11.5%). One patient died of hepatic failure on the 9th postoperative day. The other patients died of multiple organ failure. There were 3 cases of late death. The actuarial survival rate at 35 months was 76. 9%. According to these results, we recommend that GRF glue is very effective to reinforce the diseased aortic wall and will improve long-term survival. However, it is considered that the hemostasis effect of GRF glue is not sufficient to be used on anastomosed stitches from the outer side of the aorta.

Adult↗

PubMed1998

Effects of concomitant usage of milrinone and catecholamine for weaning from cardiopulmonary bypass.

To estimate the effectiveness of concomitant usage of milrinone and catecholamine for weaning from cardiopulmonary bypass (CPB), a clinical study was made, in elective coronary artery bypass grafting (CABG) cases. 24 consecutive patients underwent elective CABG in our institute. In all cases, moderate hypothermia and cardioplegic(St. Thomas solution) cardiac arrest were performed. In 12 cases, continuous intravenous 0.25 microgram/kg/min of milrinone, 3 micrograms/kg/min of dobutamine (DOB) and dopamine (DOA) as the initial doses, were used concomitantly as inotropic agents (Group-I). The same initial doses of catecholamine (DOB and DOA) as the Group-I were administered in another 12 patients (Group-II). When the pump flow of CPB decreased to a half, these drugs were administered in both groups. Hemodynamic data were measured before CPB, just after operation, 3, 6, 12, 24, 48, and 72 hours after operation. There were no significant differences in aortic and pulmonary artery pressure between both groups. However, cardiac index (CI) of the Group-I demonstrated significantly (p < 0.01) higher values than that of Group-II until 24 hours after surgery. Systemic vascular resistance index (SVRI) of the Group-I demonstrated significantly (p < 0.01) lower value than that of Group-II from 3 to 12 hours after operation. There were no significant differences in oxygen delivery (DO2) and oxygen consumption (VO2) between both groups. These results suggested that concomitant usage of milrinone and low dose catecholamine increased CI and decreased SVRI, and made weaning from CPB very easy, demonstrating excellent hemodynamics. This high potential phosphodiesterase inhibitor may be suitable for not only weaning from CPB but also post-cardiotomy cardiogenic shock.

Cardiopulmonary Bypass↗

PubMed1998

[Microcirculation of kidney and skin during left ventricular assisted circulation--comparative studies of pulsatile and nonpulsatile assists].

We examined microcirculation of the kidney and skin over a six-hour period in an acute myocardial infarction model in pigs. The outflow cannula was placed in the ascending aorta, the inflow cannula was placed the in left atrium, and a pump was connected to each (pulsatile group, Zeon Medical pneumatic pump; nonpulsatile group, Nikkiso HPM-15). Items examined included the regional blood flow of the cortex and medulla in the kidney and skin, renal and carotid arterial flow, arterial ketone body ratio (AKBR), lactate/pyruvic acid (L/P), BUN, creatinine, and beta 2-microglobulin. After the experimental study, the major organs were removed and a pathological study was performed. The mean aortic pressure after the assist could be maintained at about 100 mmHg. There were no significant differences between the two groups in mean aortic pressure and total cardiac output. Under assisted circulation, the pulse pressure was maintained at about 15 mmHg in the nonpulsatile group and about 40 mmHg in the pulsatile group. After the assist, there were no significant differences in the carotid arterial blood flow between the two groups. However, there were significant differences between the two groups in the renal arterial, renal cortical, and regional skin blood flows. In the laboratory data, there were significant differences between the two groups in AKBR, L/P, and beta 2-microglobulin. Pathological findings on the kidney in the nonpulsatile group showed expansion of the proximal tubes, retention of red blood cells, and expansion of blood capillaries within the glomerulus. On the other hand, the pulsatile group showed almost normal formation. In the lungs, the nonpulsatile group showed edematous change in the air cells and the pulsatile group showed almost normal formation. The results of the previous and current study indicated that the pulsatile assist produced superior circulation in the kidney and peripheral organs and superior cellular metabolism in the early treatment of acute left cardiac failure. On the other hand, nonpulsatile assisted circulation was found to be ineffective in maintaining the circulation in the body, and to be potentially capable of causing irreversible damage of major organs if continuous for more than three hours. The results also indicated that pulsatility was necessary to maintain normal circulation in the peripheral organs and cellular metabolism in the early treatment of acute left cardiac failure.

Animals↗

PubMed1998

[A case of coronary arterial fistula originating from both coronary artery and draining to the right atrium].

We encountered a case with bilateral fistulas of coronary arteries into the right atrium, a rare cardiac anomaly. The case was a 17-year-old woman, who visited our hospital at the age of 11 because of fever. At that time, the patient was diagnosed as having a left coronary artery-right atrial fistula through cardiac catheterization (CAG). When the patient developed staphylococcus infected endocarditis at the age of 16, a thick fistula of the coronary artery, directly running from the deformed left coronary arterial sinus, a fistula of the left circumflex branch, and also a fistula of the right coronary artery into the right atrium were detected by CAG. The outlets of these fistulas were closed from the inside of the right atrium under artificial cardiopulmonary circulation and cardiac arrest, and each fistula was ligated at the outside of cardiac chambers. At that time, we took particular care that any branch of the sinuatrial node was not injured. Although all fistulas were confirmed to be closed by postoperative CAG, and no evidence of ischemia was detected by myocardial scintigraphy, deformity of the left coronary arterial sinus remained, requiring further follow up.

Adolescent↗