Biomedical subjects

Hisataka Yasui

Publications and source records attributed to Hisataka Yasui.

At least 19 recordsLinked to original sources

PubMed2006

Regulatory roles of NKT cells in the induction and maintenance of cyclophosphamide-induced tolerance.

We have previously reported the sequential mechanisms of cyclophosphamide (CP)-induced tolerance. Permanent acceptance of donor skin graft is readily induced in the MHC-matched and minor Ag-mismatched recipients after treatment with donor spleen cells and CP. In the present study, we have elucidated the roles of NKT cells in CP-induced skin allograft tolerance. BALB/c AnNCrj (H-2(d), Lyt-1.2, and Mls-1(b)) wild-type (WT) mice or Valpha14 NKT knockout (KO) (BALB/c) mice were used as recipients, and DBA/2 NCrj (H-2(d), Lyt-1.1, and Mls-1(a)) mice were used as donors. Recipient mice were primed with 1 x 10(8) donor SC i.v. on day 0, followed by 200 mg/kg CP i.p. on day 2. Donor mixed chimerism and permanent acceptance of donor skin allografts were observed in the WT recipients. However, donor skin allografts were rejected in NKT KO recipient mice. In addition, the donor reactive Vbeta6(+) T cells were observed in the thymus of a NKT KO recipient. Reconstruction of NKT cells from WT mice restored the acceptance of donor skin allografts. In addition, donor grafts were partially accepted in the thymectomized NKT KO recipient mice. Furthermore, the tolerogen-specific suppressor cell was observed in thymectomized NKT KO recipient mice, suggesting the generation of regulatory T cells in the absence of NTK cells. Our results suggest that NKT cells are essential for CP-induced tolerance and may have a role in the establishment of mixed chimerism, resulting in clonal deletion of donor-reactive T cells in the recipient thymus.

Animals↗

PubMed2006

Prostaglandin E1 attenuates impairment of cellular immunity after cardiopulmonary bypass.

OBJECTIVE: It is well documented that cardiopulmonary bypass (CPB) severely impairs cellular immunity. The objective of this study was to investigate the effect of prostaglandin E1 (PGE1) on cellular immunity after CPB. METHODS: Patients who underwent elective cardiac surgery were randomly divided into the PGE1 group (n=12) and the control group (n=12). In the PGE1 group, PGE1 was administered at 20 ng/kg/min from just after the induction of anesthesia to the end of surgery. Peripheral blood mononuclear cells (PBMCs) were taken before anesthesia and on postoperative days 1, 3 and 7 (POD 1, POD 3 and POD 7). Proliferation responses of T cells to phytohemagglutinin (PHA) and pure protein derivative (PPD) antigen were measured as indicators of cellular immunity. RESULTS: PGE1 significantly attenuated the impairment of both PHA and PPD response after cardiac surgery on POD 1 (PHA response, 30 +/- 21% vs. 53 +/- 32%, control vs. PGE, p=0.048; PPD response, 18 +/- 21% vs. 39 +/- 27%, control vs. PGE, p=0.046). The reduced glutathione content of PBMCs in the control group was significantly decreased on POD 1. CONCLUSION: PGE1 attenuated the impairment of cellular immunity after cardiac surgery with CPB by reducing oxidative stress on PBMCs.

Aged↗

PubMed2006

Minor infection encouraged by steroid administration during cardiac surgery.

The aim of this study was to investigate whether steroid administration would increase the risk of postoperative infection. Sixty adults who underwent elective cardiac surgery under cardiopulmonary bypass were prospectively randomized into two groups. Thirty-one patients received hydrocortisone (50 mg x kg(-1)) before and after cardiopulmonary bypass, the other 29 served as controls. Various hemodynamic and pulmonary measurements were obtained perioperatively, and the white blood cell counts and levels of C-reactive protein were checked up to the 14(th) postoperative day. Steroid administration did not have any favorable effects during the perioperative period. Re-administration of antibiotics was needed in 7 patients (22.6%) after the 7(th) postoperative day in the steroid group, and in 3 (10.3%) in the control group. The peak white cell counts and C-reactive protein levels after the 7(th) postoperative day were significantly higher in the steroid group. Steroid administration offered no clinical benefit to patients undergoing cardiac surgery with cardiopulmonary bypass, and it may encourage minor infections in the late postoperative period.

Aged↗

PubMed2005

Requirement of a higher degree of chimerism for skin allograft tolerance in cyclophosphamide-induced tolerance.

By using a cyclophosphamide (CP)-induced tolerance system, we previously raised the possibility that the degree of chimerism might determine the induction of heart and skin allograft tolerance. When C3H (H-2k; Thy1.2, Mls-1b) mice were intravenously primed with 1 x 10(8) spleen cells (SCs) from H-2 matched AKR (H-2k; Thy1.1, Mls-1a) mice and then treated intraperitoneally with 200 mg/kg CP, the survival of AKR skin grafts was permanently prolonged in a tolerogen-specific fashion. After this treatment, a minimal degree of mixed chimerism and the clonal destruction of Mls-1a-reactive CD4+Vbeta6+ T cells in the periphery were observed. When AKR SCs and 100 mg/kg CP were used for conditioning, the survival of the AKR skin grafts was mildly prolonged. The clonal destruction of CD4+Vbeta6+ T cells in the periphery was induced and a minimal degree of mixed chimerism was detectable. The degree of mixed chimerism induced with AKR SCs and 200 mg/kg CP was significantly higher than that with AKR SCs and 100 mg/kg CP during the observation. On the other hand, neither skin allograft prolongation nor permanent mixed chimerism could be induced when C3H mice were treated with AKR SCs and 50 mg/kg CP. In order to increase the degree of mixed chimerism, we injected 1 x 10(8) tolerant AKR SCs on day 3 into the recipient C3H mice that had been treated with AKR SCs on day 0 and with 100 mg/kg CP on day 2. The reason that we used tolerant SCs was that untreated AKR SCs caused graft-versus-host disease in most of the recipients. Tolerant AKR SCs were harvested from AKR mice that had been treated with C3H SCs and 200 mg/kg CP 2 weeks earlier, and did not contain regulatory cells. By adoptive transfer, the degree of chimerism was stably and significantly increased in all recipients, and AKR skin graft tolerance was induced in half of the recipients. T-cell-depleted bone marrow cells (BMCs) from untreated AKR mice induced skin allograft tolerance in 83% of recipients. Thus, the present study strongly confirmed the hypothesis that a higher degree of chimerism is required for the induction of skin allograft tolerance in CP-induced tolerance.

Adoptive Transfer↗

PubMed2005

Absent mRNA accumulation of Th1 or Th2 cytokines in heart allografts with chimerism-based drug-induced tolerance.

PURPOSE: We recently described using cyclophosphamide (CP) plus busulfan (BU) to create drug-induced skin and heart allograft tolerance capable of regularly overcoming fully H-2 mismatched barriers in mice. The present study investigates the intragraft mRNA expressions of Th1 and Th2 cytokines. METHODS: This method consists of the intravenous (i.v.) injection of 1 x 10(8) allogeneic spleen cells on day 0, the intraperitoneal injection of 200 mg/kg CP and 30 mg/kg BU on day 2, and the i.v. injection of 1 x 10(7) T cell-depleted allogeneic bone marrow cells from the same strain of mice on day 3. Heart grafting (HG) was performed on day 28. Chimerism in the peripheral blood was monitored by flow cytometric (FCM) analysis. The frequency of certain V(beta) families was determined by FCM to assess deletion of donor-reactive T cells. Th1 (interleukin [IL]-2, interferon [IFN]-gamma) and Th2 (IL-4, IL-10) cytokine expression in the heart grafts was analyzed with reverse transcription-polymerase chain reaction. RESULTS: In a fully MHC mismatched combination of B10.D2 (H-2d, IE+) --> B10 (H-2b, IE-), B10.D2 heart grafts were accepted permanently in a donor-specific manner, mixed chimerism was observed, and IE-reactive V(beta)11+ T cells were specifically reduced in the periphery from the recipient B10 mice. In the donor B10.D2 heart grafts, there was no accumulation of Th1 (IL-2, IFN-gamma) or Th2 (IL-4, IL-10) cytokines. CONCLUSIONS: These results show that the drug-induced tolerance we established can regularly induce long-lasting heart allograft tolerance without intragraft mRNA accumulation of Th1 or Th2.

Animals↗

PubMed2005

Surgical application for a prolapse of the anterior mitral leaflet by replacing artificial chordae with polytetrafluoroethylene grafts.

PURPOSE: There are an increasing number of reports concerning mitral valve repair by a reconstruction of the chordae tendinae using expanded polytetrafluoro-ethylene (PTFE) sutures. However, little information is available about extended application or results of this technique for an extended prolapse of the anterior mitral leaflets. METHODS: Between July 1991 and August 2003, 28 patients with moderate to severe mitral regurgitation as a result of a prolapse of anterior leaflets (age range, 15-73 years) underwent mitral valve repair by reconstruction of the artificial chordae with 4-CV expanded polytetrafluoroethylene sutures without a leaflet resection. Either Kay's suture technique or ring annuloplasty was also performed to correct annular dilatation in all patients. RESULTS: No operative death or late mortality was observed. The prolapsed segment, which was successfully repaired, was within 33% of the anterior mitral leaflet (AML) in 6 patients, from 33% to 50% in 5, from 50% to 99% in 11, and 100% in 6 patients. Before discharge, immediate postoperative echocardiography showed less than moderate mitral regurgitation in 28 of 28 patients. The follow-up, consisting of a clinical examination and serial echocardiograms, was complete in all cases and the mean follow-up period was 80.6 months (range, 12-146). There were two failures that required a reoperation because of a worsening mitral regurgitation and hemolytic anemia (elongation of anchored side of papillary muscle). The other two patients required mitral valve replacement due to a progressive regression of the left ventricular function, although the regurgitation worsened from a mild level to a moderate one. When the reoperated patients were excluded from the following data, the degree of mitral regurgitation, estimated by echocardiography performed at recent follow-up period, was none in 10 patients, trivial in 13 patients, and mild in 1 patient. In addition, the systolic and diastolic dimensions of the left ventricle decreased significantly (P < 0.01). CONCLUSIONS: The replacement of artificial chordae was not complicated and it seemed to help to preserve a good relationship among leaflet tissues, chordae, and papillary muscles. We therefore suggest that the extensive use of PTFE artificial chordae appears to be a promising procedure for the repair of all kinds of mitral lesions causing mitral regurgitation.

Adolescent↗

PubMed2005

Compression of trachea and left main bronchus by arch aneurysm.

We report on the case of a 70-year-old woman who presented dyspnea. Contrast-enhanced computed tomography of the chest revealed the compression of the lower part of the trachea and left main bronchus by an aneurysm of the ascending aorta and aortic arch. Although we performed a replacement of the ascending aorta and aortic arch, we were unable to relieve the stenosis of the trachea and bronchus. By the suspension of the posterior wall of the native aneurysm, we were able to successfully relieve the compression and alleviate the respiratory insufficiency.

Aged↗

PubMed2005

A 10-year experience with the Carbomedics cardiac prosthesis.

BACKGROUND: There are few reports on the long-term results of Carbomedics prosthetic heart valves. METHODS: Five hundred five patients who underwent valve replacement with this prosthesis in the aortic or mitral position were chosen for this study. Patients' mean age was 57 years. There were 173 aortic (AVR), 253 mitral (MVR), and 79 double (DVR) valve implants. The mean follow-up was 5.1 years, and cumulative follow-up was 2,590 patient-years with an overall follow-up rate of 99.2%. RESULTS: The early mortality rate for the total population was 2.8% (AVR 1.2%, MVR 3.6%, DVR 3.8%). Actuarial freedom from thromboembolism at 10 years was 81.8% +/- 5.1%, 85.7% +/- 3.2%, and 88.8% +/- 6.8% for AVR, MVR, and DVR, respectively. At 10 years, 92.7% of AVR, 85.4% of MVR, and 94.7% of DVR patients were free of valve-related death. Overall survival rate at 10 years was 77.6% +/- 4.6%, 71.8% +/- 4.2%, and 81.3% +/- 5.8% for AVR, MVR, and DVR, respectively. The linearized rate of thromboembolism was 1.45%/patient-year, 1.78%/patient-year, 0.67%/patient-year; of major bleeding events, 0.52%/patient-year, 0.85%/patient-year, 0.45%/patient-year; of valve thrombosis, 0%/patient-year, 0.25%/patient-year, 0%/patient-year; of prosthetic valve endocarditis, 0.1%/patient-year, 0.25%/patient-year, 0.22%/patient-year; and of all reoperations, 0.31%/patient-year, 0.93%/patient-year, 1.1%/patient-year for AVR, MVR, and DVR, respectively. CONCLUSIONS: The Carbomedics prosthetic heart valves showed comparable or even better results than those of other mechanical valves with respect to morbidity and mortality. These results may justify the use of Carbomedics valves as one of the mechanical heart valves.

Adult↗

PubMed2005

Successful treatment of tachycardia-induced cardiomyopathy with LVAD in a 12-year-old boy.

Tachycardia-induced cardiomyopathy is an unusual cardiac disease that is life-threatening if tachycardia is not controlled. We report a 12-year-old boy who suffered from ectopic left atrial tachyarrhythmia that was refractory to medications and caused tachycardia-induced cardiomyopathy with severe heart failure. The patient required a left ventricular assist device (ABIOMED BVS5000 [ABIOMED Inc, Danvers, MA]) as a bridge to recovery. Tachycardia was finally controlled with flecainide while the patient was on left ventricular assist device support. The device was successfully explanted after 28 days of support. The temporary use of a left ventricular assist device was necessary to maintain a good hemodynamic status during the treatment of pharmacological refractory tachycardia, and it allowed a successful bridge to recovery.

Anti-Arrhythmia Agents↗

PubMed2005

Endothelin-1 receptor antagonist prevents deterioration of left ventricular function and coronary flow reserve in brain-dead canine heart.

BACKGROUND: Rapid hemodynamic deterioration is caused by induction of brain death, but the exact mechanism is still uncertain. The aim of this study was to investigate the contribution of endothelin-1 by using endothelin-1 receptor antagonist (TAK-044) in a canine brain-death model. METHODS: Dogs were divided into 2 groups: (1) the TAK group, in which TAK-044 was intravenously injected 30 minutes before brain-death induction at a dose of 3 mg/kg; and (2) the control group. Brain death was induced by rapid inflation of a sub-durally placed balloon catheter. Left ventricular function and coronary flow reserve was compared between the 2 groups. RESULTS: Brain death caused a transient hyperdynamic response followed by hemodynamic deterioration after 60 minutes in both groups. Left ventricular function, evaluated by the slope of the end-systolic pressure-volume relation was significantly decreased from 7.7 +/- 0.6 to 3.7 +/- 0.3 mm Hg/ml (p < 0.01) in the control group, but was not decreased in the TAK group (7.7 +/- 0.8 to 7.3 +/- 0.9 mm Hg/ml, p = 0.75). Coronary flow reserve, measured by direct injection of acetylcholine (3 microg) into the coronary artery, was significantly reduced at 60 minutes after brain death in the control group (264.8% to 176.6%, p < 0.01), but not in the TAK group (291.2% to 301.3%, p = 0.84). Exactly the same results were obtained when sodium nitroprusside (SNP; 100 microg) was administered. CONCLUSIONS: TAK-044 can prevent the deterioration of left ventricular function and coronary flow reserve that follows induction of brain death, suggesting that endothelin-1 could play an important role in hemodynamic deterioration by impairment of coronary microcirculation after brain death.

Animals↗

PubMed2005

The regulatory functions of Ly-49A, Ly-49D and Ly-49G2 on NK cells in the recognition and rejection of the alloantigen in vivo.

Ly-49A is an inhibitory receptor that binds H-2Dd and H-2Dk. The downregulation of Ly-49A is thought to mediate NK self tolerance in vivo. In this study, we analyzed the regulation of Ly-49A, D and G2 on NK cells in an in vivo rejection model. After injection with 1 x 10(8) B10.D2 spleen cells (SC) into B 10 mice, we found Ly-49A downregulated within 3 h on NK cells of B10 mice, whereas expressions of Ly-49D and G2 were augmented. To investigate effects of different expression patterns of Ly-49 receptors on NK cells, Ly-49A, D or G2-depleted B10 mice were inoculated with B10.D2 SC. NK cells from SC of Ly-49A-depleted and B10.D2 SC-injected B10 mice showed enhanced cytotoxicity to Dd-positive targets in vitro. Furthermore, reduced numbers of B10.D2 SC were observed in Ly-49A or G2-depleted B10 mice, whereas increased numbers of B10.D2 SC were observed in Ly-49D-depleted B10 mice after inoculation with B10.D2 SC in vivo. These findings indicated that the downregulation of Ly-49A and the augmentation of Ly-49D expression may mediate NK cells to recognize and kill Dd antigen efficiently. In conclusion, each Ly-49 isoform may play independent roles in the regulation of activation or inhibition on NK cells.

Animals↗

PubMed2005

Limitation of venoarterial bypass. Early predictor and optimal conversion.

Conversion from venoarterial bypass to a ventricular assist device may be lifesaving for patients with severe heart failure, but the criteria for conversion have not yet been established. Forty patients who underwent venoarterial bypass for cardiac failure were reviewed. Of these, 18 (45%) could be weaned from venoarterial bypass, and 11 survived for more than 30 days after weaning (survival rate, 27.5%). Liver dysfunction, renal dysfunction, and the need for left-sided cardiac venting were risk factors for mortality. The appearance of patient's own cardiac pulse wave within 24 hours after the introduction of venoarterial bypass was a good indication for weaning. Delayed appearance of the cardiac pulse wave was considered to be a risk factor for death. According to these indices, conversion from venoarterial bypass to a ventricular assist device should be considered to prevent deterioration in the function of systemic organs.

Adult↗

PubMed2005

Effect of pravastatin on progression of coronary atherosclerosis in patients after coronary artery bypass surgery.

BACKGROUND: Although the anti-atherosclerotic effects of HMG-CoA reductase inhibitors are well known, their specific effect on saphenous vein grafts after coronary artery bypass graft (CABG) operation is not well documented and has not been studied in Japan, so the aim of the present prospective randomized controlled study involving 27 Japanese institutions was to investigate the effects of pravastatin on the progression of atherosclerosis in such grafts and native coronary arteries after CABG. METHODS AND RESULTS: A total of 303 patients who had undergone CABG were randomly assigned to either the pravastatin group (n =168) or the control group (n = 167). Paired coronary angiograms were obtained at baseline and at the end of 5-year follow-up in 182 (60%) patients. The low-density lipoprotein cholesterol concentration significantly decreased in the pravastatin group from 141.4 mg/dl to 113.7 mg/dl (-19.6%), compared with 141.1 mg/dl to 133.7 mg/dl (-5.2%) in the control group (p < 0.001). Although there was no significant difference in the quantitative coronary angiography measurements between the 2 groups, the global change score indicated a significant pravastatin-mediated reduction in plaque progression (p < 0.01). CONCLUSIONS: Pravastatin can potentially reduce atherosclerotic progression in both the bypass graft and native coronary arteries of patients after CABG.

Aged↗

PubMed2004

Does Down syndrome affect the long-term results of complete atrioventricular septal defect when the defect is repaired during the first year of life?

BACKGROUND: Down syndrome is known to affect the natural history of complete atrioventricular septal defect. We analyzed whether Down syndrome affect the long-term results of complete atrioventricular septal defect when the defect is repaired during the first year of life. METHODS: Repairs of complete atrioventricular septal defect were performed in 64 infants. Thirty-four infants were associated with Down syndrome, while the other 30 were non-Down patients. RESULTS: Complete follow-up rate was 95% with mean follow-up period of 99+/-47 months (maximum 169 months) in Down patients and 80+/-64 months (maximum 213 months) in non-Down patients. There was one operative death in each group (mortality rate of 2.9% in Down patients and 3.3% in non-Down patients), and three patients died at the late phase (one in Down patients and two in non-Down patients). Five patients underwent re-operation due to postoperative left atrioventricular valve regurgitation (one in Down patients and four in non-Down patients). Freedom from re-operation for left atrioventricular valve regurgitation and actuarial survival rate at 13 years were 96+/-4 and 94+/-4% in Down patients and 85+/-7 and 90+/-5% in non-Down patients (not significantly different). CONCLUSIONS: Down syndrome does not affect the long-term results of complete atrioventricular septal defect when the defect is repaired during the first year of life.

Age Factors↗

PubMed2004

Extracorporeal cardiac shock wave therapy markedly ameliorates ischemia-induced myocardial dysfunction in pigs in vivo.

BACKGROUND: Prognosis of ischemic cardiomyopathy still remains poor because of the lack of effective treatments. To develop a noninvasive therapy for the disorder, we examined the in vitro and vivo effects of extracorporeal shock wave (SW) that could enhance angiogenesis. METHODS AND RESULTS: SW treatment applied to cultured human umbilical vein endothelial cells significantly upregulated mRNA expression of vascular endothelial growth factor and its receptor Flt-1 in vitro. A porcine model of chronic myocardial ischemia was made by placing an ameroid constrictor at the proximal segment of the left circumflex coronary artery, which gradually induced a total occlusion of the artery with sustained myocardial dysfunction but without myocardial infarction in 4 weeks. Thereafter, extracorporeal SW therapy to the ischemic myocardial region (200 shots/spot for 9 spots at 0.09 mJ/mm2) was performed (n=8), which induced a complete recovery of left ventricular ejection fraction (51+/-2% to 62+/-2%), wall thickening fraction (13+/-3% to 30+/-3%), and regional myocardial blood flow (1.0+/-0.2 to 1.4+/-0.3 mL x min(-1) x g(-1)) of the ischemic region in 4 weeks (all P<0.01). By contrast, animals that did not receive the therapy (n=8) had sustained myocardial dysfunction (left ventricular ejection fraction, 48+/-3% to 48+/-1%; wall thickening fraction, 13+/-2% to 9+/-2%) and regional myocardial blood flow (1.0+/-0.3 to 0.6+/-0.1 mL x min(-1) x g(-1)). Neither arrhythmias nor other complications were observed during or after the treatment. SW treatment of the ischemic myocardium significantly upregulated vascular endothelial growth factor expression in vivo. CONCLUSIONS: These results suggest that extracorporeal cardiac SW therapy is an effective and noninvasive therapeutic strategy for ischemic heart disease.

Animals↗

PubMed2004

Usefulness of low-priming-volume cardiopulmonary bypass circuits and dilutional ultrafiltration in neonatal open-heart surgery.

In neonate open-heart surgery, cardiopulmonary bypass (CPB) with extreme hemodilution induces an increased capillary permeability and accumulation of extravascular fluid, resulting in organ dysfunction. We evaluated the effects of a reduced priming volume for CPB and dilutional ultrafiltration (DUF) during neonatal open-heart surgery. Nineteen consecutive neonates with complete transposition of the great arteries who underwent an arterial switch operation were retrospectively assigned into two groups: the high-priming-volume circuit group (group A, n = 9) and the low-priming-volume circuit group (group B, n = 10). Patients in group B underwent surgery with a miniaturized CPB circuit and using the DUF technique. The priming volume of group B was nearly two-thirds that of group A. The water balance value after CPB and surgery was significantly lower in group B (-126 +/- 118 ml, -116 +/- 116 ml) than in group A (88 +/- 218 ml, 83 +/- 165 ml). Systolic blood pressure just after CPB was higher in group B (67.9 +/- 9.1 mmHg) than in group A (55.4 +/- 10.3 mmHg). Postoperative ventilatory support was shorter in group B (45 +/- 19 h) than in group A (68 +/- 27 h). In neonatal cardiac surgery, low-priming-volume CPB circuits and DUF improve the water balance during surgery and may attenuate any inflammatory reaction, which would help preserve postoperative organ function.

Cardiac Surgical Procedures↗

PubMed2004

Mechanical cardiac support system for patients with postcardiotomy cardiogenic shock: analysis of risk factors for survival.

OBJECTIVE: Mechanical cardiac support system (MCSS) has been used for adult patients in postcardiotomy cardiogenic shock and has been shown to provide excellent oxygenation and hemodynamic support. However, MCSS has a number of disadvantages that include high incidence rate of complications (e.g. stroke, bleeding) and limited duration of sufficient support. The objective of this study is to identify perioperative and postoperative factors for survival in patients having MCSS. METHODS: From January 1991 to April 2001, MCSS has been applied to 22 adult patients in postcardiotomy cardiogenic shock. These patients' charts were retrospectively reviewed. RESULTS: Of 22 patients, 9 patients (41%) were successfully weaned, and 6 (27%) were hospital survivors. The duration of assist ranged from 21 to 211 hours (median 66 hours). In 7 (78%) out of 9 patients who could be weaned from MCSS, MCSS were required for less than 3 days. Major complications were reexploration for bleeding (18%), leg ischemia (45%), renal dysfunction (77%), liver dysfunction (59%), infection (31.8%), hypoxia due to lung dysfunction (36%) and cerebral dysfunction (41%). pH, base excess, HCO3-, urine output, transfused platelets at first 24 hours of MCSS and preoperative body surface area were significant predictors for survival. CONCLUSION: The indices of insufficient hemodynamic support such as progression of acidosis or poor urine output are significant predictors for early death. Early conversion from MCSS to long-term assist device, such as left ventricular assist device, should be considered when these factors are associated with poor cardiac recovery.

Acidosis↗

PubMed2004

Late results after mitral valve replacement with bileaflet mechanical prosthesis in children: evaluation of prosthesis-patient mismatch.

BACKGROUND: Mechanical prosthesis is the choice of valve at the mitral position in children, although re-replacement of prostheses because of prosthesis-patient mismatch is almost inevitable when prostheses were implanted in small children. The methods to predict prosthesis-patient mismatch as a result of patients' somatic growth or pannus formation in children by noninvasive methods have not been well established. METHODS: Thirty-two children underwent mitral valve replacement with 37 bileaflet mechanical prostheses (26 St. Jude Medical prosthetic valves, and 11 CarboMedics prosthetic valves) and were followed up a mean of 6.8 years (maximum 18.3 years) with a complete follow-up rate of 94%. RESULTS: There were no operative deaths and 5 late deaths. Re-replacement of mitral valve because of prosthesis-patient mismatch was required in 5 patients. Freedom from valve-related events and re-replacement of mitral valve at 15 years were 32% +/- 23% and 54% +/- 18%, respectively. Actuarial survival rate was 63% +/- 19% at 15 years. Prosthetic valve orifice area index (manufactured geometric prosthetic valve area divided by patient's body surface area) was well correlated with maximum transprosthesis flow velocity estimated by Doppler echocardiography during follow-up, whereas valve orifice area index had no significant correlation with pulmonary artery wedge pressure assessed by cardiac catheterization. Maximum transprosthesis flow velocity had a significant correlation with pulmonary artery wedge pressure. CONCLUSIONS: Valve orifice area index itself was not a reliable index to predict prosthesis-patient mismatch. Maximum transprosthesis flow velocity was a useful index to predict pulmonary artery wedge. Invasive cardiac catheterization to determine re-replacement of the prosthesis should be considered when maximum transprosthesis flow velocity exceeds 270 cm/s.

Adolescent↗