Objectives: There are an increasing number of reports concerning mitral valve repair by reconstru... more Objectives: There are an increasing number of reports concerning mitral valve repair by reconstruction of the chordae tendinae with the use of expanded polytetrafluoroethylene (PTFE) sutures. However, little information is available about the extended application or results of this technique for extended prolapse of bilateral mitral leaflets, which is considered to be difficult to repair. Methods: Between October 1993 and May 1998, 17 patients (age range 16-74 years) who had from moderate to severe mitral regurgitation as the result of a prolapse of bilateral leaflets underwent mitral valve repair by reconstruction of artificial chordae with CV-4 expanded PTFE sutures. Either bilateral or unilateral Kay's suture annuloplasty was also performed to correct annular dilatation in all patients. Results: No operative death or late mortality was observed. Before discharge, immediate postoperative echocardiography showed less than moderate mitral regurgitation in 16 of 17 patients. The follow-up was completed in all cases by a clinical examination and serial echocardiograms, and the median follow-up period was 52 months (range 27-82 months). There was one failure that required re-operation because of worsening mitral regurgitation (elongation of the anchored side of papillary muscle). When the re-operated patient was excluded from the following data, the degree of mitral regurgitation, estimated by echocardiography performed at recent follow-up, was none in four patients, trivial in eight patients, and mild in four patients. The systolic and diastolic dimensions of the left ventricle decreased significantly (P , 0:01). Conclusions: Because replacement of artificial chordae was not complicated and seemed to preserve fine relationships 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.
BACKGROUND No method has been available to assess the right ventricular (RV) pressure-volume rela... more BACKGROUND No method has been available to assess the right ventricular (RV) pressure-volume relation in the operating room or intensive care unit. Left ventricular cross-sectional area measured by echocardiography using the technology of automated border detection has been used to construct left ventricular pressure-area (P-A) loops. In the human right ventricle, however, this approach has not been validated. METHODS We recorded RV P-A loops in 14 patients in the intensive care unit using transesophageal echocardiography. Multiple RV P-A loops were obtained by reducing preload with intravenous nitroglycerin, thereby elucidating the end-systolic P-A relation. RESULTS With an incremental dose of dobutamine, the slope of the RV end-systolic P-A relation increased (from 4.56+/-2.42 to 7.34+/-3.62 mm Hg/cm2, p<0.01), with no change in the x-axis intercept, which implied increased contractility. Furthermore, in the operating room we validated the use of RV cross-sectional area as a surrogate for RV volume by demonstrating the close correlation between the stroke area (maximal RV area minus minimal RV area) and stroke volume (r = 0.962; p<0.0001). CONCLUSIONS Transesophageal echocardiography with automated border detection is a promising tool for elucidating RV function through the analysis of RV P-A loops.
Journal of Heart and Lung Transplantation, Feb 1, 2006
Background: We have previously reported the cardiac functional and metabolic benefits of administ... more Background: We have previously reported the cardiac functional and metabolic benefits of administration of extracellular-type cardioplegia before preservation with University of Wisconsin solution. Celsior solution was designed to be used both as an arresting solution and a storage solution for heart transplantation. The objective of the present study is to compare cardiac function of hearts arrested and preserved with Celsior solution to hearts arrested with cardioplegia followed by preservation with UW solution. Methods: Rabbit hearts were divided into 4 groups: in the Celsior group, hearts were arrested and preserved with Celsior solution; in the C-Celsior group, hearts were arrested by an extracellular-type cardioplegia and preserved with Celsior solution; in the UW group, hearts were arrested and stored in University of Wisconsin solution; and, in the C-UW group, hearts were arrested with extracellulartype cardioplegia and stored in University of Wisconsin solution. After 6 hours of preservation, cardiac function was measured using modified Frank-Starling curves in the isolated blood-perfused working heart. Results: Cardiac function in the Celsior group was inferior to that in both the C-UW group and UW group. The C-Celsior group demonstrated inferior cardiac function compared with the Celsior group (p Ͻ 0.01), whereas no significant difference was observed between the C-UW and UW groups. Conclusions: Celsior solution did not surpass UW solution regardless of the use of cardioplegia. Further studies are required to develop optimal solution for use as both an arresting solution and a storage solution.
European Journal of Cardio-Thoracic Surgery, Oct 1, 2006
Objective: Risk stratification in thoracic aortic surgery is a topic of major interest. Recent st... more Objective: Risk stratification in thoracic aortic surgery is a topic of major interest. Recent studies have shown the European System for Cardiac Operative Risk Evaluation (EuroSCORE) to be an extremely useful and reliable risk stratification score and also a good indicator of quality of care in cardiac surgery. The purpose of this study was to evaluate the significance of the additive and logistic EuroSCOREs in patients undergoing surgery on the thoracic aorta in Japan. Methods: We calculated the predicted mortality according to the additive and logistic EuroSCORE algorithms in 327 consecutive patients who underwent surgery of the thoracic aorta during a 30-year period (between 1976 and 2005). We compared the score validity between the two algorithms and also evaluated the score validity for the patients who underwent thoracic aortic surgery. The score validity was assessed by calculating the area under the receiver operating characteristic (ROC) curve. Results: The overall in-hospital mortality was 13%. The area under the ROC curve was satisfactorily high for the additive (0.68, 0.73, 0.73) as well as the logistic EuroSCORE (0.69, 0.74, 0.75) in the patients who underwent thoracic aortic surgery during 30-, 20-, and 10-year periods, respectively. The actual mortality was 7% (Group 1; an additive EuroSCORE of 3-6), 16% (Group 2; 7-11), and 37% (Group 3; >12). The mortality expected by the additive and logistic EuroSCORE in the three different risk groups were (5%, 9%, 19%) and (5%, 14%, 43%), respectively. Namely, the mortality expected by the logistic EuroSCORE perfectly matched with the actual mortality in any of the three risk groups. In contrast, the mortality expected by the additive EuroSCORE tended to dissociate when the number of risks increased. Significant difference was observed between the observed mortality and the mortality expected by the additive EuroSCORE algorithm in the high-risk group (p = 0.0473). Conclusions: Although both the additive and the logistic EuroSCORE reliably predicted the overall operative mortality for thoracic aortic surgery in 327 Japanese patients, the logistic EuroSCORE better matched with the actual mortality in the operative risk especially in the high-risk group.
Background. Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide ... more Background. Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide cerebral protection. However, its optimum management and limitations remain unclear. Transcranial Doppler has been used to monitor cerebral perfusion. Using this Doppler technique, we compared cerebral blood flow for RCP with that for selective cerebral perfusion. Methods. Thirty-two consecutive patients underwent elective surgical repair of an aortic aneurysm involving the aortic arch at Kyushu University Hospital. Retrograde cerebral perfusion was used in 15 patients and selective cerebral perfusion, in 17 patients. Continuous measurement of middle cerebral artery blood flow velocities was performed by transcranial Doppler technique. Results. Retrograde middle cerebral artery blood flow velocities during RCP could be measured in only 3 patients, whereas middle cerebral artery blood flow velocities during selective cerebral perfusion could be measured in all but 1 woman. The increase in middle cerebral artery blood flow velocities after RCP was significantly greater than that after selective cerebral perfusion. Conclusions. The measurement of middle cerebral artery blood flow velocities with transcranial Doppler technique is practicable during selective cerebral perfusion but difficult during RCP. The increase in middle cerebral artery blood flow velocities after RCP indicates reactive hyperemia and reflects the critical decrease in cerebral blood flow during this type of perfusion.
at less than 90 days. Group II early deaths had donor risk factor combinations of CAD, left ventr... more at less than 90 days. Group II early deaths had donor risk factor combinations of CAD, left ventricle hypertrophy, and long distance. Freedom from rejection Ͼ ISHLT grade 3A was 100% in group I and 84.6% in group II. Freedom from GCAD was 100% at 2-years in group I and 87.5% in group II excluding pre-existing disease. Conclusions: Use of certain donor hearts with CAD, possibly requiring revascularization, is acceptable in selected recipients. Early deaths are related to recipient factors as well as associated donor risk factors.
The Japanese Journal of Thoracic and Cardiovascular Surgery, Jun 1, 1999
Histological changes in the right atrial flap used in repair of total anomalous pulmonary venous ... more Histological changes in the right atrial flap used in repair of total anomalous pulmonary venous connection were observed when the patient underwent repair of peripheral pulmonary venous stenosis after two months. The flap, 35 mm in length and 15 mm in width, was thin and soft. Microscopically, endocardium and myocardium were preserved well, with only moderate thickening of the epicardium. We can anticipate the viability of the right atrial flap, but care should be taken to keep blood supply to the flap intact.
Before they are used in the clinical setting, the effectiveness of artificially produced human-de... more Before they are used in the clinical setting, the effectiveness of artificially produced human-derived tissue-engineered medical products should be verified in an immunodeficient animal model, such as severe combined immunodeficient mice. However, small animal models are not sufficient to evaluate large-sized products for human use. Thus, an immunodeficient large animal model is necessary in order to properly evaluate the clinical efficacy of human-derived tissue-engineered products, such as artificial grafts. Here we report the development of an immunodeficient pig model, the operational immunodeficient pig (OIDP), by surgically removing the thymus and spleen, and creating a controlled immunosuppressive protocol using a combination of drugs commonly used in the clinical setting. We find that this model allows the long-term accommodation of artificial human vascular grafts. The development of the OIDP is an essential step towards a comprehensive and clinically relevant evaluation of...
Table 1 Influences of the contractility, diastolic function, afterload, body/heart size, and valv... more Table 1 Influences of the contractility, diastolic function, afterload, body/heart size, and valve function on the parameters of the ventricular function. Contractility-sensitive Diastolic function-sensitive Afterload-independent Size (body, heart)-independent Valve function-independent PRSW Yes Yes Yes Yes Yes EF Yes No No Yes No Ees Yes No Yes No Yes PRSW, preload-recruitable stroke work (ventricular end-diastolic volume and stroke work relationship); EF, ejection fraction; Ees, end-systolic elastance (ventricular endsystolic pressure and volume relationship).
The Japanese Journal of Thoracic and Cardiovascular Surgery, 1999
Histological changes in the right atrial flap used in repair of total anomalous pulmonary venous ... more Histological changes in the right atrial flap used in repair of total anomalous pulmonary venous connection were observed when the patient underwent repair of peripheral pulmonary venous stenosis after two months. The flap, 35 mm in length and 15 mm in width, was thin and soft. Microscopically, endocardium and myocardium were preserved well, with only moderate thickening of the epicardium. We can anticipate the viability of the right atrial flap, but care should be taken to keep blood supply to the flap intact.
Small caliber vascular prostheses are not clinically available because synthetic vascular prosthe... more Small caliber vascular prostheses are not clinically available because synthetic vascular prostheses lack endothelial cells which modulate platelet activation, leukocyte adhesion, thrombosis, and the regulation of vasomotor tone by the production of vasoactive substances. We developed a novel method to create scaffold-free tubular tissue from multicellular spheroids (MCS) using a "Bio-3D printer"-based system. This system enables the creation of pre-designed three-dimensional structures using a computer controlled robotics system. With this system, we created a tubular structure and studied its biological features. Using a "Bio-3D printer," we made scaffold-free tubular tissues (inner diameter of 1.5 mm) from a total of 500 MCSs (2.5× 104 cells per one MCS) composed of human umbilical vein endothelial cells (40%), human aortic smooth muscle cells (10%), and normal human dermal fibroblasts (50%). The tubular tissues were cultured in a perfusion system and implante...
Tracheo-innominate artery fistula is fatal unless treated surgically. We describe our surgical ap... more Tracheo-innominate artery fistula is fatal unless treated surgically. We describe our surgical approach and results in seven patients. The average patient age was 15.7 years; all patients had prior severe neurological deficits. Three of seven patients were in hemorrhagic shock; control of preoperative bleeding was achieved with tracheostomy tube cuff overinflation. The innominate artery and the trachea were exposed through a collar incision and partial upper sternotomy. The innominate artery was divided at the aortic arch and at the bifurcation, with one exception. Cerebral blood flow was monitored by the blood pressure difference in the bilateral upper extremities and by near-infrared spectroscopy. The tracheal fistula was left adherent to the innominate artery in all but one patient. All patients were discharged without new neurologic deficits or severe morbidity. Overall survival was 84% at 37 months, without any vascular, tracheal, or neurological events.
The Journal of Heart and Lung Transplantation, 2006
Background: We have previously reported the cardiac functional and metabolic benefits of administ... more Background: We have previously reported the cardiac functional and metabolic benefits of administration of extracellular-type cardioplegia before preservation with University of Wisconsin solution. Celsior solution was designed to be used both as an arresting solution and a storage solution for heart transplantation. The objective of the present study is to compare cardiac function of hearts arrested and preserved with Celsior solution to hearts arrested with cardioplegia followed by preservation with UW solution. Methods: Rabbit hearts were divided into 4 groups: in the Celsior group, hearts were arrested and preserved with Celsior solution; in the C-Celsior group, hearts were arrested by an extracellular-type cardioplegia and preserved with Celsior solution; in the UW group, hearts were arrested and stored in University of Wisconsin solution; and, in the C-UW group, hearts were arrested with extracellulartype cardioplegia and stored in University of Wisconsin solution. After 6 hours of preservation, cardiac function was measured using modified Frank-Starling curves in the isolated blood-perfused working heart. Results: Cardiac function in the Celsior group was inferior to that in both the C-UW group and UW group. The C-Celsior group demonstrated inferior cardiac function compared with the Celsior group (p Ͻ 0.01), whereas no significant difference was observed between the C-UW and UW groups. Conclusions: Celsior solution did not surpass UW solution regardless of the use of cardioplegia. Further studies are required to develop optimal solution for use as both an arresting solution and a storage solution.
The Journal of Heart and Lung Transplantation, 2005
Background: Rapid hemodynamic deterioration is caused by induction of brain death, but the exact ... more 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 subdurally 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 Ϯ 0.6 to 3.7 Ϯ 0.3 mm Hg/ml (p Ͻ 0.01) in the control group, but was not decreased in the TAK group (7.7 Ϯ 0.8 to 7.3 Ϯ 0.9 mm Hg/ml, p ϭ 0.75). Coronary flow reserve, measured by direct injection of acetylcholine (3 g) into the coronary artery, was significantly reduced at 60 minutes after brain death in the control group (264.8% to 176.6%, p Ͻ 0.01), but not in the TAK group (291.2% to 301.3%, p ϭ 0.84). Exactly the same results were obtained when sodium nitroprusside (SNP; 100 g) 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.
Objective: Risk stratification in thoracic aortic surgery is a topic of major interest. Recent st... more Objective: Risk stratification in thoracic aortic surgery is a topic of major interest. Recent studies have shown the European System for Cardiac Operative Risk Evaluation (EuroSCORE) to be an extremely useful and reliable risk stratification score and also a good indicator of quality of care in cardiac surgery. The purpose of this study was to evaluate the significance of the additive and logistic EuroSCOREs in patients undergoing surgery on the thoracic aorta in Japan. Methods: We calculated the predicted mortality according to the additive and logistic EuroSCORE algorithms in 327 consecutive patients who underwent surgery of the thoracic aorta during a 30-year period (between 1976 and 2005). We compared the score validity between the two algorithms and also evaluated the score validity for the patients who underwent thoracic aortic surgery. The score validity was assessed by calculating the area under the receiver operating characteristic (ROC) curve. Results: The overall in-hospital mortality was 13%. The area under the ROC curve was satisfactorily high for the additive (0.68, 0.73, 0.73) as well as the logistic EuroSCORE (0.69, 0.74, 0.75) in the patients who underwent thoracic aortic surgery during 30-, 20-, and 10-year periods, respectively. The actual mortality was 7% (Group 1; an additive EuroSCORE of 3-6), 16% (Group 2; 7-11), and 37% (Group 3; >12). The mortality expected by the additive and logistic EuroSCORE in the three different risk groups were (5%, 9%, 19%) and (5%, 14%, 43%), respectively. Namely, the mortality expected by the logistic EuroSCORE perfectly matched with the actual mortality in any of the three risk groups. In contrast, the mortality expected by the additive EuroSCORE tended to dissociate when the number of risks increased. Significant difference was observed between the observed mortality and the mortality expected by the additive EuroSCORE algorithm in the high-risk group (p = 0.0473). Conclusions: Although both the additive and the logistic EuroSCORE reliably predicted the overall operative mortality for thoracic aortic surgery in 327 Japanese patients, the logistic EuroSCORE better matched with the actual mortality in the operative risk especially in the high-risk group.
Objective: Many previous studies have suggested an increase in hydroxyl radical (OH) production a... more Objective: Many previous studies have suggested an increase in hydroxyl radical (OH) production after myocardial ischemia-reperfusion; however, traditional techniques have not been able to conclusively prove this phenomenon. We investigated whether the production of OH was increased during myocardial reperfusion using a novel electron paramagnetic resonance (EPR) technique using an OH-specific spin probe. An OH scavenger, 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), was used to examine the relationship between OH production and post-ischemic functional recovery or the degree of myocardial injury. Methods: We used an isolated rabbit-heart preparation perfused with support-rabbit blood, and the heart was reperfused after normothermic global ischemia. Heart samples were reacted with the OH-specific spin probe, 4hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (hydroxyl-TEMPO). The rate of decay of the EPR signal showed OH production. We investigated the rate of EPR signal decay and cardiac function. Results: The rate of signal decay was significantly increased just after reperfusion compared with that of pre-ischemia (2.00 Â 10 À2 AE 0.77 Â 10 À2 min À1 vs 0.11 Â 10-2 AE 0.02 Â 10 À2 min À1 , p < 0.01). Administration of MCI-186 reduced the rate of decay to 0.86 Â 10 À2 AE 0.14 Â 10 À2 min À1 just after reperfusion (p < 0.01). Cardiac function was significantly improved 60 min after reperfusion using MCI-186 compared without MCI-186 (left ventricular developed pressure was 95 AE 9 mm Hg vs 60 AE 6 mm Hg and the first derivative of the left ventricular pressure (dP/dt) was 1843 AE 200 mm Hg s À1 vs 1182 AE 127 mm Hg s À1). Conclusions: A novel EPR spin-probe technique demonstrated the relation between the production of OH and ischemia-reperfusion injury. We confirmed that OH production influenced cardiac function and myocardial ischemia-reperfusion injury.
A 76-year-old woman presented with multiple brain infarctions in the right middle cerebral artery... more A 76-year-old woman presented with multiple brain infarctions in the right middle cerebral artery and vertebral artery area. Carotid sonography revealed a large mobile pedunculated mass in the brachiocephalic artery, which showed rapid growth despite treatment with heparin and aspirin. Graft replacement of the brachiocephalic artery was performed under selective cerebral perfusion with deep hypothermia. Histology of the resected specimen revealed aortic atherosclerotic plaque.
Background. Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide ... more Background. Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide cerebral protection. However, its optimum management and limitations remain unclear. Transcranial Doppler has been used to monitor cerebral perfusion. Using this Doppler technique, we compared cerebral blood flow for RCP with that for selective cerebral perfusion. Methods. Thirty-two consecutive patients underwent elective surgical repair of an aortic aneurysm involving the aortic arch at Kyushu University Hospital. Retrograde cerebral perfusion was used in 15 patients and selective cerebral perfusion, in 17 patients. Continuous measurement of middle cerebral artery blood flow velocities was performed by transcranial Doppler technique. Results. Retrograde middle cerebral artery blood flow velocities during RCP could be measured in only 3 patients, whereas middle cerebral artery blood flow velocities during selective cerebral perfusion could be measured in all but 1 woman. The increase in middle cerebral artery blood flow velocities after RCP was significantly greater than that after selective cerebral perfusion. Conclusions. The measurement of middle cerebral artery blood flow velocities with transcranial Doppler technique is practicable during selective cerebral perfusion but difficult during RCP. The increase in middle cerebral artery blood flow velocities after RCP indicates reactive hyperemia and reflects the critical decrease in cerebral blood flow during this type of perfusion.
BACKGROUND No method has been available to assess the right ventricular (RV) pressure-volume rela... more BACKGROUND No method has been available to assess the right ventricular (RV) pressure-volume relation in the operating room or intensive care unit. Left ventricular cross-sectional area measured by echocardiography using the technology of automated border detection has been used to construct left ventricular pressure-area (P-A) loops. In the human right ventricle, however, this approach has not been validated. METHODS We recorded RV P-A loops in 14 patients in the intensive care unit using transesophageal echocardiography. Multiple RV P-A loops were obtained by reducing preload with intravenous nitroglycerin, thereby elucidating the end-systolic P-A relation. RESULTS With an incremental dose of dobutamine, the slope of the RV end-systolic P-A relation increased (from 4.56+/-2.42 to 7.34+/-3.62 mm Hg/cm2, p<0.01), with no change in the x-axis intercept, which implied increased contractility. Furthermore, in the operating room we validated the use of RV cross-sectional area as a surrogate for RV volume by demonstrating the close correlation between the stroke area (maximal RV area minus minimal RV area) and stroke volume (r = 0.962; p<0.0001). CONCLUSIONS Transesophageal echocardiography with automated border detection is a promising tool for elucidating RV function through the analysis of RV P-A loops.
Objectives: There are an increasing number of reports concerning mitral valve repair by reconstru... more Objectives: There are an increasing number of reports concerning mitral valve repair by reconstruction of the chordae tendinae with the use of expanded polytetrafluoroethylene (PTFE) sutures. However, little information is available about the extended application or results of this technique for extended prolapse of bilateral mitral leaflets, which is considered to be difficult to repair. Methods: Between October 1993 and May 1998, 17 patients (age range 16-74 years) who had from moderate to severe mitral regurgitation as the result of a prolapse of bilateral leaflets underwent mitral valve repair by reconstruction of artificial chordae with CV-4 expanded PTFE sutures. Either bilateral or unilateral Kay's suture annuloplasty was also performed to correct annular dilatation in all patients. Results: No operative death or late mortality was observed. Before discharge, immediate postoperative echocardiography showed less than moderate mitral regurgitation in 16 of 17 patients. The follow-up was completed in all cases by a clinical examination and serial echocardiograms, and the median follow-up period was 52 months (range 27-82 months). There was one failure that required re-operation because of worsening mitral regurgitation (elongation of the anchored side of papillary muscle). When the re-operated patient was excluded from the following data, the degree of mitral regurgitation, estimated by echocardiography performed at recent follow-up, was none in four patients, trivial in eight patients, and mild in four patients. The systolic and diastolic dimensions of the left ventricle decreased significantly (P , 0:01). Conclusions: Because replacement of artificial chordae was not complicated and seemed to preserve fine relationships 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.
BACKGROUND No method has been available to assess the right ventricular (RV) pressure-volume rela... more BACKGROUND No method has been available to assess the right ventricular (RV) pressure-volume relation in the operating room or intensive care unit. Left ventricular cross-sectional area measured by echocardiography using the technology of automated border detection has been used to construct left ventricular pressure-area (P-A) loops. In the human right ventricle, however, this approach has not been validated. METHODS We recorded RV P-A loops in 14 patients in the intensive care unit using transesophageal echocardiography. Multiple RV P-A loops were obtained by reducing preload with intravenous nitroglycerin, thereby elucidating the end-systolic P-A relation. RESULTS With an incremental dose of dobutamine, the slope of the RV end-systolic P-A relation increased (from 4.56+/-2.42 to 7.34+/-3.62 mm Hg/cm2, p<0.01), with no change in the x-axis intercept, which implied increased contractility. Furthermore, in the operating room we validated the use of RV cross-sectional area as a surrogate for RV volume by demonstrating the close correlation between the stroke area (maximal RV area minus minimal RV area) and stroke volume (r = 0.962; p<0.0001). CONCLUSIONS Transesophageal echocardiography with automated border detection is a promising tool for elucidating RV function through the analysis of RV P-A loops.
Journal of Heart and Lung Transplantation, Feb 1, 2006
Background: We have previously reported the cardiac functional and metabolic benefits of administ... more Background: We have previously reported the cardiac functional and metabolic benefits of administration of extracellular-type cardioplegia before preservation with University of Wisconsin solution. Celsior solution was designed to be used both as an arresting solution and a storage solution for heart transplantation. The objective of the present study is to compare cardiac function of hearts arrested and preserved with Celsior solution to hearts arrested with cardioplegia followed by preservation with UW solution. Methods: Rabbit hearts were divided into 4 groups: in the Celsior group, hearts were arrested and preserved with Celsior solution; in the C-Celsior group, hearts were arrested by an extracellular-type cardioplegia and preserved with Celsior solution; in the UW group, hearts were arrested and stored in University of Wisconsin solution; and, in the C-UW group, hearts were arrested with extracellulartype cardioplegia and stored in University of Wisconsin solution. After 6 hours of preservation, cardiac function was measured using modified Frank-Starling curves in the isolated blood-perfused working heart. Results: Cardiac function in the Celsior group was inferior to that in both the C-UW group and UW group. The C-Celsior group demonstrated inferior cardiac function compared with the Celsior group (p Ͻ 0.01), whereas no significant difference was observed between the C-UW and UW groups. Conclusions: Celsior solution did not surpass UW solution regardless of the use of cardioplegia. Further studies are required to develop optimal solution for use as both an arresting solution and a storage solution.
European Journal of Cardio-Thoracic Surgery, Oct 1, 2006
Objective: Risk stratification in thoracic aortic surgery is a topic of major interest. Recent st... more Objective: Risk stratification in thoracic aortic surgery is a topic of major interest. Recent studies have shown the European System for Cardiac Operative Risk Evaluation (EuroSCORE) to be an extremely useful and reliable risk stratification score and also a good indicator of quality of care in cardiac surgery. The purpose of this study was to evaluate the significance of the additive and logistic EuroSCOREs in patients undergoing surgery on the thoracic aorta in Japan. Methods: We calculated the predicted mortality according to the additive and logistic EuroSCORE algorithms in 327 consecutive patients who underwent surgery of the thoracic aorta during a 30-year period (between 1976 and 2005). We compared the score validity between the two algorithms and also evaluated the score validity for the patients who underwent thoracic aortic surgery. The score validity was assessed by calculating the area under the receiver operating characteristic (ROC) curve. Results: The overall in-hospital mortality was 13%. The area under the ROC curve was satisfactorily high for the additive (0.68, 0.73, 0.73) as well as the logistic EuroSCORE (0.69, 0.74, 0.75) in the patients who underwent thoracic aortic surgery during 30-, 20-, and 10-year periods, respectively. The actual mortality was 7% (Group 1; an additive EuroSCORE of 3-6), 16% (Group 2; 7-11), and 37% (Group 3; >12). The mortality expected by the additive and logistic EuroSCORE in the three different risk groups were (5%, 9%, 19%) and (5%, 14%, 43%), respectively. Namely, the mortality expected by the logistic EuroSCORE perfectly matched with the actual mortality in any of the three risk groups. In contrast, the mortality expected by the additive EuroSCORE tended to dissociate when the number of risks increased. Significant difference was observed between the observed mortality and the mortality expected by the additive EuroSCORE algorithm in the high-risk group (p = 0.0473). Conclusions: Although both the additive and the logistic EuroSCORE reliably predicted the overall operative mortality for thoracic aortic surgery in 327 Japanese patients, the logistic EuroSCORE better matched with the actual mortality in the operative risk especially in the high-risk group.
Background. Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide ... more Background. Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide cerebral protection. However, its optimum management and limitations remain unclear. Transcranial Doppler has been used to monitor cerebral perfusion. Using this Doppler technique, we compared cerebral blood flow for RCP with that for selective cerebral perfusion. Methods. Thirty-two consecutive patients underwent elective surgical repair of an aortic aneurysm involving the aortic arch at Kyushu University Hospital. Retrograde cerebral perfusion was used in 15 patients and selective cerebral perfusion, in 17 patients. Continuous measurement of middle cerebral artery blood flow velocities was performed by transcranial Doppler technique. Results. Retrograde middle cerebral artery blood flow velocities during RCP could be measured in only 3 patients, whereas middle cerebral artery blood flow velocities during selective cerebral perfusion could be measured in all but 1 woman. The increase in middle cerebral artery blood flow velocities after RCP was significantly greater than that after selective cerebral perfusion. Conclusions. The measurement of middle cerebral artery blood flow velocities with transcranial Doppler technique is practicable during selective cerebral perfusion but difficult during RCP. The increase in middle cerebral artery blood flow velocities after RCP indicates reactive hyperemia and reflects the critical decrease in cerebral blood flow during this type of perfusion.
at less than 90 days. Group II early deaths had donor risk factor combinations of CAD, left ventr... more at less than 90 days. Group II early deaths had donor risk factor combinations of CAD, left ventricle hypertrophy, and long distance. Freedom from rejection Ͼ ISHLT grade 3A was 100% in group I and 84.6% in group II. Freedom from GCAD was 100% at 2-years in group I and 87.5% in group II excluding pre-existing disease. Conclusions: Use of certain donor hearts with CAD, possibly requiring revascularization, is acceptable in selected recipients. Early deaths are related to recipient factors as well as associated donor risk factors.
The Japanese Journal of Thoracic and Cardiovascular Surgery, Jun 1, 1999
Histological changes in the right atrial flap used in repair of total anomalous pulmonary venous ... more Histological changes in the right atrial flap used in repair of total anomalous pulmonary venous connection were observed when the patient underwent repair of peripheral pulmonary venous stenosis after two months. The flap, 35 mm in length and 15 mm in width, was thin and soft. Microscopically, endocardium and myocardium were preserved well, with only moderate thickening of the epicardium. We can anticipate the viability of the right atrial flap, but care should be taken to keep blood supply to the flap intact.
Before they are used in the clinical setting, the effectiveness of artificially produced human-de... more Before they are used in the clinical setting, the effectiveness of artificially produced human-derived tissue-engineered medical products should be verified in an immunodeficient animal model, such as severe combined immunodeficient mice. However, small animal models are not sufficient to evaluate large-sized products for human use. Thus, an immunodeficient large animal model is necessary in order to properly evaluate the clinical efficacy of human-derived tissue-engineered products, such as artificial grafts. Here we report the development of an immunodeficient pig model, the operational immunodeficient pig (OIDP), by surgically removing the thymus and spleen, and creating a controlled immunosuppressive protocol using a combination of drugs commonly used in the clinical setting. We find that this model allows the long-term accommodation of artificial human vascular grafts. The development of the OIDP is an essential step towards a comprehensive and clinically relevant evaluation of...
Table 1 Influences of the contractility, diastolic function, afterload, body/heart size, and valv... more Table 1 Influences of the contractility, diastolic function, afterload, body/heart size, and valve function on the parameters of the ventricular function. Contractility-sensitive Diastolic function-sensitive Afterload-independent Size (body, heart)-independent Valve function-independent PRSW Yes Yes Yes Yes Yes EF Yes No No Yes No Ees Yes No Yes No Yes PRSW, preload-recruitable stroke work (ventricular end-diastolic volume and stroke work relationship); EF, ejection fraction; Ees, end-systolic elastance (ventricular endsystolic pressure and volume relationship).
The Japanese Journal of Thoracic and Cardiovascular Surgery, 1999
Histological changes in the right atrial flap used in repair of total anomalous pulmonary venous ... more Histological changes in the right atrial flap used in repair of total anomalous pulmonary venous connection were observed when the patient underwent repair of peripheral pulmonary venous stenosis after two months. The flap, 35 mm in length and 15 mm in width, was thin and soft. Microscopically, endocardium and myocardium were preserved well, with only moderate thickening of the epicardium. We can anticipate the viability of the right atrial flap, but care should be taken to keep blood supply to the flap intact.
Small caliber vascular prostheses are not clinically available because synthetic vascular prosthe... more Small caliber vascular prostheses are not clinically available because synthetic vascular prostheses lack endothelial cells which modulate platelet activation, leukocyte adhesion, thrombosis, and the regulation of vasomotor tone by the production of vasoactive substances. We developed a novel method to create scaffold-free tubular tissue from multicellular spheroids (MCS) using a "Bio-3D printer"-based system. This system enables the creation of pre-designed three-dimensional structures using a computer controlled robotics system. With this system, we created a tubular structure and studied its biological features. Using a "Bio-3D printer," we made scaffold-free tubular tissues (inner diameter of 1.5 mm) from a total of 500 MCSs (2.5× 104 cells per one MCS) composed of human umbilical vein endothelial cells (40%), human aortic smooth muscle cells (10%), and normal human dermal fibroblasts (50%). The tubular tissues were cultured in a perfusion system and implante...
Tracheo-innominate artery fistula is fatal unless treated surgically. We describe our surgical ap... more Tracheo-innominate artery fistula is fatal unless treated surgically. We describe our surgical approach and results in seven patients. The average patient age was 15.7 years; all patients had prior severe neurological deficits. Three of seven patients were in hemorrhagic shock; control of preoperative bleeding was achieved with tracheostomy tube cuff overinflation. The innominate artery and the trachea were exposed through a collar incision and partial upper sternotomy. The innominate artery was divided at the aortic arch and at the bifurcation, with one exception. Cerebral blood flow was monitored by the blood pressure difference in the bilateral upper extremities and by near-infrared spectroscopy. The tracheal fistula was left adherent to the innominate artery in all but one patient. All patients were discharged without new neurologic deficits or severe morbidity. Overall survival was 84% at 37 months, without any vascular, tracheal, or neurological events.
The Journal of Heart and Lung Transplantation, 2006
Background: We have previously reported the cardiac functional and metabolic benefits of administ... more Background: We have previously reported the cardiac functional and metabolic benefits of administration of extracellular-type cardioplegia before preservation with University of Wisconsin solution. Celsior solution was designed to be used both as an arresting solution and a storage solution for heart transplantation. The objective of the present study is to compare cardiac function of hearts arrested and preserved with Celsior solution to hearts arrested with cardioplegia followed by preservation with UW solution. Methods: Rabbit hearts were divided into 4 groups: in the Celsior group, hearts were arrested and preserved with Celsior solution; in the C-Celsior group, hearts were arrested by an extracellular-type cardioplegia and preserved with Celsior solution; in the UW group, hearts were arrested and stored in University of Wisconsin solution; and, in the C-UW group, hearts were arrested with extracellulartype cardioplegia and stored in University of Wisconsin solution. After 6 hours of preservation, cardiac function was measured using modified Frank-Starling curves in the isolated blood-perfused working heart. Results: Cardiac function in the Celsior group was inferior to that in both the C-UW group and UW group. The C-Celsior group demonstrated inferior cardiac function compared with the Celsior group (p Ͻ 0.01), whereas no significant difference was observed between the C-UW and UW groups. Conclusions: Celsior solution did not surpass UW solution regardless of the use of cardioplegia. Further studies are required to develop optimal solution for use as both an arresting solution and a storage solution.
The Journal of Heart and Lung Transplantation, 2005
Background: Rapid hemodynamic deterioration is caused by induction of brain death, but the exact ... more 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 subdurally 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 Ϯ 0.6 to 3.7 Ϯ 0.3 mm Hg/ml (p Ͻ 0.01) in the control group, but was not decreased in the TAK group (7.7 Ϯ 0.8 to 7.3 Ϯ 0.9 mm Hg/ml, p ϭ 0.75). Coronary flow reserve, measured by direct injection of acetylcholine (3 g) into the coronary artery, was significantly reduced at 60 minutes after brain death in the control group (264.8% to 176.6%, p Ͻ 0.01), but not in the TAK group (291.2% to 301.3%, p ϭ 0.84). Exactly the same results were obtained when sodium nitroprusside (SNP; 100 g) 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.
Objective: Risk stratification in thoracic aortic surgery is a topic of major interest. Recent st... more Objective: Risk stratification in thoracic aortic surgery is a topic of major interest. Recent studies have shown the European System for Cardiac Operative Risk Evaluation (EuroSCORE) to be an extremely useful and reliable risk stratification score and also a good indicator of quality of care in cardiac surgery. The purpose of this study was to evaluate the significance of the additive and logistic EuroSCOREs in patients undergoing surgery on the thoracic aorta in Japan. Methods: We calculated the predicted mortality according to the additive and logistic EuroSCORE algorithms in 327 consecutive patients who underwent surgery of the thoracic aorta during a 30-year period (between 1976 and 2005). We compared the score validity between the two algorithms and also evaluated the score validity for the patients who underwent thoracic aortic surgery. The score validity was assessed by calculating the area under the receiver operating characteristic (ROC) curve. Results: The overall in-hospital mortality was 13%. The area under the ROC curve was satisfactorily high for the additive (0.68, 0.73, 0.73) as well as the logistic EuroSCORE (0.69, 0.74, 0.75) in the patients who underwent thoracic aortic surgery during 30-, 20-, and 10-year periods, respectively. The actual mortality was 7% (Group 1; an additive EuroSCORE of 3-6), 16% (Group 2; 7-11), and 37% (Group 3; >12). The mortality expected by the additive and logistic EuroSCORE in the three different risk groups were (5%, 9%, 19%) and (5%, 14%, 43%), respectively. Namely, the mortality expected by the logistic EuroSCORE perfectly matched with the actual mortality in any of the three risk groups. In contrast, the mortality expected by the additive EuroSCORE tended to dissociate when the number of risks increased. Significant difference was observed between the observed mortality and the mortality expected by the additive EuroSCORE algorithm in the high-risk group (p = 0.0473). Conclusions: Although both the additive and the logistic EuroSCORE reliably predicted the overall operative mortality for thoracic aortic surgery in 327 Japanese patients, the logistic EuroSCORE better matched with the actual mortality in the operative risk especially in the high-risk group.
Objective: Many previous studies have suggested an increase in hydroxyl radical (OH) production a... more Objective: Many previous studies have suggested an increase in hydroxyl radical (OH) production after myocardial ischemia-reperfusion; however, traditional techniques have not been able to conclusively prove this phenomenon. We investigated whether the production of OH was increased during myocardial reperfusion using a novel electron paramagnetic resonance (EPR) technique using an OH-specific spin probe. An OH scavenger, 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), was used to examine the relationship between OH production and post-ischemic functional recovery or the degree of myocardial injury. Methods: We used an isolated rabbit-heart preparation perfused with support-rabbit blood, and the heart was reperfused after normothermic global ischemia. Heart samples were reacted with the OH-specific spin probe, 4hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (hydroxyl-TEMPO). The rate of decay of the EPR signal showed OH production. We investigated the rate of EPR signal decay and cardiac function. Results: The rate of signal decay was significantly increased just after reperfusion compared with that of pre-ischemia (2.00 Â 10 À2 AE 0.77 Â 10 À2 min À1 vs 0.11 Â 10-2 AE 0.02 Â 10 À2 min À1 , p < 0.01). Administration of MCI-186 reduced the rate of decay to 0.86 Â 10 À2 AE 0.14 Â 10 À2 min À1 just after reperfusion (p < 0.01). Cardiac function was significantly improved 60 min after reperfusion using MCI-186 compared without MCI-186 (left ventricular developed pressure was 95 AE 9 mm Hg vs 60 AE 6 mm Hg and the first derivative of the left ventricular pressure (dP/dt) was 1843 AE 200 mm Hg s À1 vs 1182 AE 127 mm Hg s À1). Conclusions: A novel EPR spin-probe technique demonstrated the relation between the production of OH and ischemia-reperfusion injury. We confirmed that OH production influenced cardiac function and myocardial ischemia-reperfusion injury.
A 76-year-old woman presented with multiple brain infarctions in the right middle cerebral artery... more A 76-year-old woman presented with multiple brain infarctions in the right middle cerebral artery and vertebral artery area. Carotid sonography revealed a large mobile pedunculated mass in the brachiocephalic artery, which showed rapid growth despite treatment with heparin and aspirin. Graft replacement of the brachiocephalic artery was performed under selective cerebral perfusion with deep hypothermia. Histology of the resected specimen revealed aortic atherosclerotic plaque.
Background. Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide ... more Background. Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide cerebral protection. However, its optimum management and limitations remain unclear. Transcranial Doppler has been used to monitor cerebral perfusion. Using this Doppler technique, we compared cerebral blood flow for RCP with that for selective cerebral perfusion. Methods. Thirty-two consecutive patients underwent elective surgical repair of an aortic aneurysm involving the aortic arch at Kyushu University Hospital. Retrograde cerebral perfusion was used in 15 patients and selective cerebral perfusion, in 17 patients. Continuous measurement of middle cerebral artery blood flow velocities was performed by transcranial Doppler technique. Results. Retrograde middle cerebral artery blood flow velocities during RCP could be measured in only 3 patients, whereas middle cerebral artery blood flow velocities during selective cerebral perfusion could be measured in all but 1 woman. The increase in middle cerebral artery blood flow velocities after RCP was significantly greater than that after selective cerebral perfusion. Conclusions. The measurement of middle cerebral artery blood flow velocities with transcranial Doppler technique is practicable during selective cerebral perfusion but difficult during RCP. The increase in middle cerebral artery blood flow velocities after RCP indicates reactive hyperemia and reflects the critical decrease in cerebral blood flow during this type of perfusion.
BACKGROUND No method has been available to assess the right ventricular (RV) pressure-volume rela... more BACKGROUND No method has been available to assess the right ventricular (RV) pressure-volume relation in the operating room or intensive care unit. Left ventricular cross-sectional area measured by echocardiography using the technology of automated border detection has been used to construct left ventricular pressure-area (P-A) loops. In the human right ventricle, however, this approach has not been validated. METHODS We recorded RV P-A loops in 14 patients in the intensive care unit using transesophageal echocardiography. Multiple RV P-A loops were obtained by reducing preload with intravenous nitroglycerin, thereby elucidating the end-systolic P-A relation. RESULTS With an incremental dose of dobutamine, the slope of the RV end-systolic P-A relation increased (from 4.56+/-2.42 to 7.34+/-3.62 mm Hg/cm2, p<0.01), with no change in the x-axis intercept, which implied increased contractility. Furthermore, in the operating room we validated the use of RV cross-sectional area as a surrogate for RV volume by demonstrating the close correlation between the stroke area (maximal RV area minus minimal RV area) and stroke volume (r = 0.962; p<0.0001). CONCLUSIONS Transesophageal echocardiography with automated border detection is a promising tool for elucidating RV function through the analysis of RV P-A loops.
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Papers by Shigeki Morita