Biomedical subjects

Y Orime

Publications and source records attributed to Y Orime.

At least 37 records · Page 2Linked to original sources

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↗

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↗

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

Hypoplastic left heart syndrome: "Which is the best operative strategy?".

Therapy for the hypoplastic left heart syndrome (HLHS) is still under debate. We report about our experience in the treatment of this cardiac malformation using heart transplantation and Norwood palliation. From 1988 to 1997 a total number of 30 infants with hypoplastic left heart underwent heart transplantation. Mean age at transplantation was 66 days. Mean waiting time was 53 days. Donor-recipient weight ratio ranged from 0.6 to 3.9. There were 6 early hospital deaths and one late death until now. Causes of death were rejection (3), right heart failure (2), infection (1) and multi system organ failure (1). Overall survival was 77%. Increasing experience improved results substantially. From 1988 to 1993 (n=12) survival rate was 58%, whereas from 1994 to 1997 (n=18) survival rate increased to 88%. Quality of life is excellent in the 23 surviving infants. Only one infant shows severe morbidity (neurological defect). The Norwood procedure has been performed in 18 patients since 1993. Five patients died after the first stage. Up until now 10 infants have undergone the second stage and one infant the third stage procedure. None of them have died. Survival rate is 72% for the whole group. Taking into account that 12 infants died on the waiting list for transplanatation (28%), we have comparable results in terms of the survival rate for transplantation and the Norwood procedure in infants with HLHS since 1994. However quality of life and physical development are far better in infants after transplantation according to our experience. Therefore we prefer, whenever possible heart transplantation in the treatment of hypoplastic left heart syndrome. Certainly not all infants with this malformation can undergo transplantation because of the lack of donor organs. Criteria for the decision regarding the operative strategy in our opinion are function of the right ventricle and tricuspid valve, size of the interaterial communication and parental request.

Cardiac Surgical Procedures↗

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

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

[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↗