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Biomedical subjects

T Masai

Publications and source records attributed to T Masai.

At least 37 records · Page 2Linked to original sources
PubMed1995

Overseas transport of a patient with an extracorporeal left ventricular assist device.

An 18-year-old boy with end-stage cardiomyopathy who was undergoing support with an extracorporeal pneumatic left ventricular assist device was transported from Japan to the United States. During the 17-hour flight, the patient's condition was stable, and the pneumatic assist device worked well under low atmospheric pressure in the cabin. Subsequently, he had a successful heart transplantation after 119 days of left ventricular assist device support.

Adolescent↗
PubMed1994

[A successful use of VAS for bridge to heart transplantation after oversea transportation in a 18-year-old patient with dilated cardiomyopathy].

An 18-year-old boy with dilated cardiomyopathy developed a relatively rapid deterioration and went into severe congestive heart failure. After short-while use of percutaneous cardiopulmonary support system (PCPS) and IABP, LVAS was indicated because of persisting low cardiac output syndrome and deterioration of organ functions. An LVAS (TOYOBO) was implanted on June 26, 1992 in a fashion of left atrium to ascending aorta bypass. Satisfactory circulatory support (flow rates of 4-5 L/min) was achieved resulting in complete recovery of the organ functions. After two months of LVAS support, the patient was transported to U.S.A.. The LVAS system was working well without any problems during 17 hrs flight under low atmospheric pressure (0.8 atm) in the plane. The patient successfully underwent heart transplantation (HTx) at Texas Heart Institute after 119 days support of LVAS. The patient is doing well enjoying active life after HTx. This is the first case of successful bridge use of extracorporeal LVAS to HTx in Japan.

Adolescent↗
PubMed1993

[2 cases report of open heart surgery with non-blood transfusion in severe valvular heart disease with cardiac cachexia--the efficacy of recombinant human erythropoietin].

Open heart surgery with non-blood transfusion was performed in 2 cases of severe mitral valve disease with cardiac cachexia by administering recombinant human erythropoietin (EPO). Case 1 was a 72-year-old and case 2 was a 66-year-old woman whose % usual body weight was 71-79% and Ht value on admission was 28.5-30%. Both patients were administered 9000-18000 U/week of EPO and ferrous sulfate pre- and postoperatively. In each case 800-1200 ml of autologous blood was drawn within 3 weeks preoperatively without hemodynamic change or decrease of Ht value. Both patients were received mitral valve replacement with non-blood transfusion. Preoperative administration of EPO and autologous blood preservation allowed open heart surgery with non-blood transfusion even in such a serious case as cardiac cachexia.

Aged↗
PubMed1992

Recent advances in assisted circulation using centrifugal pump in surgical and non-surgical patients with acute heart failure or related conditions.

During the last 3 years, left or bi-ventricular support using a centrifugal pump as a ventricular assistance device was performed in 10 patients after open heart surgery. The basic lesions were coronary heart disease in 8 and valvular disease in 2 patients. Bypass support ranged in time from 33 to 240 h (average 114 h), and 3 patients received biventricular support. Six patients have survived in this group. Other supportive methods, in the form of emergency or elective use of portable cardiopulmonary bypass support, were used in 8 patients; 4 with cardiogenic shock and 4 for supported percutaneous coronary angioplasty. These assisted circulations appear to be useful and promising in the management of the critical cardiac patient.

Adolescent↗
PubMed1992

[A case report of successful surgical treatment following the emergency circulatory assist by percutaneous cardiopulmonary support system for acute postinfarction left ventricular free wall rupture].

Percutaneous cardiopulmonary support system (PCPS) was applied for a 85 years old man with circulatory collapse caused by left ventricular free wall blow out rupture following acute anterior myocardial infarction. PCPS was started after the cardiac massage for 7 minutes without thoracotomy or release of cardiac tamponade and flow of ranging from 2.3 to 2.7 L/min/m2 was achieved. The patient was transferred to operating room and closure of the ventricular rupture was performed under the usual cardiopulmonary bypass. Postoperative recovery of cardiac function and consciousness was satisfactory but he was died of multiple organ failure caused by sepsis at 36 postoperative day. PCPS and consecutive surgical therapy seemed useful method for the treatment of left ventricular free wall blow out rupture.

Aged↗
PubMed1992

[Surgical repair of infarct-related ventricular septal perforation using Teflon felt patch].

Eight patients with infarct-related ventricular septal perforation underwent surgical repair using Teflon felt patch. The overall early operative mortality rate was 12% (1/8). One of three patients (33%) with cardiogenic shock preoperatively, one of five patients (20%) operated within 7 days after the onset of infarction died within 30 days after operation. A patient with inferior infarction died early after operation. In 5 of 8 patients (63%), IABP was removed within 24 hours after operation. A patient died due to the recurrence of gastric cancer in late postoperative phase. None of patients was found to have a recurrence of the ventricular septal perforation after the operation. Five of 6 patients (83%) surviving the operation are in NYHA class I or II.

Aged↗
PubMed1992

[Emergent cardiovascular operation in patients older than 75 years].

From January 1988 through December 1990, 7 patients older than 75 years underwent emergent cardiovascular operation. We evaluated those operative results. The mean age was 80.1 years (range 77 to 85 years) and there were 5 men and 2 women. Coronary artery bypass grafting for 2 cases, closure of ventricular septal perforation for 1 case, graft replacement of ascending aorta and suspension of aortic valve in 2 cases, closure of left ventricular free wall rupture (LVFWR) in 1 case and closure of arch aneurysm rupture for 1 case were performed. Operative mortality was 14.3% (1/7). There was one hospital death. Five survivors had uneventful course in early postoperative term, but they needed long elaborate hospital care because of complications in noncardiac general organs in late postoperative term. They need nutritional support, rehabilitation for muscle weakness and so on. Their mean postoperative hospital period was 53 days. All of them were improved in New York Heart Association I or II. We concluded that we attained a good operative result in emergent cardiovascular operation in patients older than 75 years by effective operation as a result of long elaborate postoperative hospital care.

Aged↗
PubMed1991

Hepatic venous oxygen saturation monitoring in patients with assisted circulation for severe cardiac failure.

In order to assess the adequacy of hepatic perfusion, hepatic venous oxygen saturation (ShvO2) was monitored in five patients undergoing mechanical circulatory support. Two patients were with intra-aortic balloon pumping (IABP), one was with a left ventricular assist device (LVAD), and two were with biventricular assist devices (BVAD). The mean ShvO2 values during assistance in each patient ranged from 27 to 84%. One patient with IABP showed persistently low ShvO2 (less than 30%) in spite of higher mixed venous oxygen saturation (SvO2) and subsequently developed hepatic dysfunction and multiple organ failure. In another patient, ShvO2 was 22% on average during LVAD, but increased to greater than 50% after adding a right ventricular assist device (RVAD). Of 3 patients with persistently high ShvO2 (44-80%, on average), only one developed hepatic failure--probably from prior severe shock--and the other two did not develop hepatic failure. There was a significant negative correlation between ShvO2 and splanchnic excess lactate, the parameter of anaerobic metabolism in the splanchnic area. In contrast, there was no correlation between simultaneously measured ShvO2 and SvO2 values when analyzed in a range of SvO2 below 70%. ShvO2 monitoring may be useful for evaluation of hepatic perfusion status in the management of critical patients, requiring assisted circulation.

Heart Failure↗
PubMed1991

[Percutaneous cardiopulmonary bypass as a bridge to coronary artery bypass surgery in 2 cases of circulatory collapse caused by severe myocardial ischemia].

A closed system of percutaneous cardiopulmonary bypass (PCPB) with centrifugal pump and membrane oxygenator was applied for 2 patients with circulatory collapse caused by acute reclosure of left anterior descending coronary artery after PTCA in case 1 and acute myocardial infarction due to left main coronary artery lesion in case 2. Both patients were brought to operating room under the circulatory support of PCPB and successful coronary artery bypass was performed. Case 1 survived and case 2 died from sepsis due to mediastinitis inspite of satisfactory recovery of cardiac function. PCPB was confirmed as a useful method for emergency circulatory support and a bridge to cardiac surgery in patients with cardiogenic circulatory collapse.

Cardiopulmonary Bypass↗
PubMed1990

Analysis of clinical factors for survival after left and biventricular bypass using centrifugal pump following open heart surgery in infants and adults.

A total of eight patients, including three infants, received left or biventricular assist using centrifugal pump (CFP) following open heart surgery. Three infants, aged 9-11 months and with complex cardiac lesions, were supported by left heart bypass (LHB) using pediatric type CFP for 63 h, 64 h, and 13 days. All were weaned from LHB, but long-term survival was not obtained, mainly due to complications. In five adult patients, LHB alone was used in three, and biventricular support in two for 33-240 h with three survivals. The factors related to unsuccessful recovery were delayed start of support and multiorgan failure.

Adult↗
PubMed1990

[Clinical experience of mechanical ventricular support with centrifugal pump for severe ventricular failure after open heart surgery].

Five adult patients (pts) with age 15-67 (mean 43) received mechanical circulatory support with centrifugal pump (Biomedicus, BP-80, Sarns centrifugal pump) for postcardiotomy profound shock. Three pts underwent left ventricular support (LVS) alone, and the other 2 required biventricular support (BVS). Duration of the LVS ranged from 33 to 240 hours (mean 126 hours) and the right ventricular support 92, 120 hrs. Pump flow rate was 1.1 to 2.5 (mean 1.9) L/min/m2. Sixteen pumps were used and the pump exchange was performed 9 times in five pts and an average perfusion time per pump was 57 hrs. Two of 3 pts with LVS alone survived and one died of multiorgan failure associated with right heart dysfunction. In two pts with BVS, one survived and the other died of persistent low cardiac output early after pump removal. As the complication during mechanical support, bleeding was seen in 3 pts and cerebral infarction in one. Although centrifugal pump has potential limitation in antithrombogenicity and durability, this device provides a simple and effective mechanical circulatory support.

Adolescent↗
PubMed1990

[Optimal perfusion criteria for deep hypothermic selective cerebral perfusion in patients with aortic aneurysm involving aortic arch].

Although selective cerebral perfusion (SCP) might be an useful supportive method for aortic arch surgery, its optimal perfusion criteria has not been established. We studied the relationship between the oxygen saturation of superior vena cava or internal jugular vein (SvO2) and the perfusion hemodynamics during deep hypothermic (DH) SCP in twenty patients (pts) (type A dissection; 10, arch aneurysm; 10). SCP was accomplished by perfusion to the brachiocephalic trunk (BCT) and the left common carotid artery (LCC) using separate pumps. Cardiopulmonary bypass and DHSCP time were 128-312 (222 +/- 43, mean +/- SD) minutes and 25-214 (122 +/- 49) minutes, respectively. The cerebral perfusion pressures (CPP) monitored at the bilateral temporal arteries were 20-60 (47 +/- 9) mmHg and cerebral perfusion flow (CPF) was 0.28-0.7 (0.43 +/- 0.10) L/min/m2. The cerebral perfusion score (CPS) defined as CPP X CPF was 7-39 (20 +/- 8). SvO2 ranged from 79 to 99 (94 +/- 7)%. Two operative deaths were encountered from unrelated causes to SCP in both cases. Cerebral infarction occurred in one patient possibly form prolonged low perfusion with low SvO2. When the safety range of SvO2 in DHSCP was defined as greater than 90%, essential criteria to keep this range was CPP greater than 40 mmHg. In 13 out of 15 pts with SvO2 greater than 90%, CPS were above 15. In conclusion, optimal perfusion criteria for DHSCP was defined as CPP greater than 40 mmHg and CPS(CPP X CPF) greater than 15 considering adequate cerebral oxygen consumption.

Adult↗
PubMedDate not supplied

A new method of assessing left ventricular function under assisted circulation using a conductance catheter.

A new method of assessing left ventricular (LV) systolic function without terminating assisted circulation (AC) was investigated using a LV volume catheter (conductance catheter) in canine cardiopulmonary bypass (CPB) (Group 1, n = 7) and left heart bypass (LHB) (Group 2, n = 5) models. The hearts were subjected to either 20 min of global ischemia (IS), with a subsequent 80 min of reperfusion under CPB, or regional IS under LHB. Instantaneous LV pressure-volume data acquisitions were repeated during transient (15 sec) acute volume loading without terminating bypass. The relationship between the stroke work (SW), determined as the area of the pressure-volume loop, and the end-diastolic volume (EDV), were highly linear at every study point (mean: r = 0.956-0.986 in Group 1, r = 0.974-0.987 in Group 2). The slopes of SW and EDV (preload recruitable stroke work: PRSW) significantly decreased after IS, in both Group 1 and Group 2. In conclusion, measurement of PRSW without terminating bypass seemed to be useful in evaluating LV systolic function in patients under AC.

Animals↗
PubMedDate not supplied

Normothermia has beneficial effects in cardiopulmonary bypass attenuating inflammatory reactions.

"Post perfusion syndrome" after cardiopulmonary bypass (CPB) has been known to be evoked by inflammatory reactions. To elucidate the effect of perfusate temperature during CPB on subsequent inflammatory reactions, serum levels of interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, IL-1 beta, and polymorphonuclear (PMN) elastase were measured before and after (0, 12 hours, and 24 hours after) CPB in adult patients undergoing cardiac operations. Patients were divided into two groups: the normothermic CPB group (NOR, 34 degrees C perfusate temperature, n = 8) and hypothermic CPB group (HYP, 28 degrees C perfusate temperature, n = 8). In both groups, IL-6, IL-8, and PMN elastase levels were elevated during CPB, while the increase of tumor necrosis factor-alpha and IL-1 beta was not detected. The increase in IL-8 and PMN elastase levels at 12 hours after CPB was significantly less in NOR than in HYP (IL-8; NOR versus HYP, 15.1 +/- 12.9 versus 62.5 +/- 30.6 pg/ml, p < 0.05, PMN elastase; 394 +/- 200 versus 1085 +/- 523 micrograms/L, p < 0.05) while neither group showed any difference in IL-8 and PMN elastase at 24 hours after CPB. There was no difference in IL-6 between the two groups, and no significant increase in tumor necrosis factor-alpha and IL-1 beta levels were detected in either group after CPB. These results demonstrate that although CPB activated inflammatory reactions detected by IL-8 and PMN elastase activity, post operative persistence of these reactions were attenuated by warm CPB.

Adult↗
PubMedDate not supplied

Clinical experience with long-term use of the Toyobo left ventricular assist system.

The Toyobo-NCVC extracorporeal pneumatic left ventricular assist system (LVAS) was used in four patients with advanced dilated cardiomyopathy. The duration of support ranged from 46 to 390 days (mean, 206 days). In all patients, stable hemodynamics were achieved with 3.5-5.5 L/min flow rates. Two patients survived long term. One was transported to the United States by a chartered jet while on LVAS and successfully underwent heart transplantation after 119 days of support. The other is on LVAS and is doing well for 390 days. The remaining two patients died of multi-organ failure while their hemodynamics were quite stable under LVAS. In these two patients, severe hepatic failure had developed before LVAS implantation. Minor cerebral embolisms occurred in the two survivors, but neither of them experienced permanent neurologic deficits. In only the initial patient were major thrombi noted on the diaphragm of the pump; the thrombi required pump exchange four times during 119 days. In the patient supported for 390 days, a small tear in the diaphragm was observed after 209 days of support, and the pump was safely exchanged. It is suggested that the Toyobo LVAS can provide consistent and reliable performance for long-term use.

Adolescent↗