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Hironori Izutani

Publications and source records attributed to Hironori Izutani.

14 recordsLinked to original sources
PubMed2006

Internal thoracic artery to left anterior descending anastomosis performed on the beating heart by endoscopic robot assistance using a new distal connector.

BACKGROUND: Automated distal connecting devices have been recently introduced to facilitate coronary anastomosis. This could have a large impact on the capacity of robotic systems to perform completely endoscopic off-pump bypass, where the quality of anastomosis and the prolonged operative time for the performance of the anastomosis have until now been cause for concern. Our group tried to determine the feasibility and efficacy of the JoMed distal graft connector using the ZEUS robotic system. METHODS: Six swine, with a mean weight of 25.8 (standard deviation [SD] 2.2) kg, underwent endoscopic off-pump internal thoracic artery-left anterior descending (ITA-LAD) anastomosis with a special stabilizing system using ZEUS robotic assistance. The anastomosis was performed with the JoMed distal connector. RESULTS: The connector was employed successfully in 4 of 6 cases using a special delivery instrument. Two animals fibrillated within 2 minutes after the application of proximal occluding snares and were excluded from the analysis. The total device deployment time was 2 minutes 4 seconds (SD 50 s) in 4 of 6 survivors, which remained hemodynamically stable and in sinus rhythm until euthanasia. Coronary angiography and transonic flow measurements were used to verify patency. CONCLUSION: The JoMed distal graft connector may facilitate the use of robot-assisted endoscopic bypass on a beating heart. Long-term patency issues will need to be assessed.

Animals↗
PubMed2005

Evaluation of platelet indexes in patients with aortic aneurysm.

The purpose of this study was to investigate whether platelet indexes [platelet count, mean platelet volume (MPV), platelet-large cell ratio (P-LCR), and platelet distribution width (PDW)] could serve as diagnostic tools to evaluate the potential significance of platelet heterogeneity on thrombus formation. Blood samples were obtained from 54 patients with aortic aneurysm (AA; mean age 73 years; 40 males, 14 females), from 120 age-matched controls (AC; mean age 74 years; 61 males, 59 females), and from 38 young controls (YC; mean age 30 years; 20 males, 18 females). We measured the blood platelet indexes using an automated counter, as well as plasma D-dimer and thrombin-antithrombin III complex (TAT) using ELISA. The AA patients were divided into two groups, group A (platelet count more than 150 x 10(9)/l, n = 36) and group B (platelet count below 150 x 10(9)/l, n = 18). There was no difference in the platelet count between AC and YC. However, P-LCR was significantly higher (p = 0.0113) in AC. MPV and PDW were also higher, but not significantly so. The platelet count was not different between group A and AC. MPV (p = 0.0024 and <0.0001, respectively), P-LCR (p < 0.0012 and <0.0001, respectively) and PDW (p = 0.0006 and 0.0005, respectively) were significantly lower in group A than in group B and AC. The platelet indexes were significantly lower in the 54 AA patients than in the AC. There were significant inverse relationships between the platelet count and other indexes in the AC and 54 AA patients; however, no relationships were observed in group A, B and YC. The D-dimer and TAT levels were significantly higher in group B than in groups A and YC. In conclusion, these findings suggest that large platelets decrease rather than increase in patients with AA.

Adolescent↗
PubMed2005

Impact of ostial stenosis on the Doppler flow profiles in internal thoracic artery graft.

As ostial stenoses of internal thoracic artery (ITA) grafts rarely occur after coronary artery bypass grafting, little is known about their Doppler flow profile. This report describes changes in the Doppler flow of ITA grafts with ostial stenosis after surgical repair of the stenosis. A 54-year-old male underwent coronary artery bypass grafting (CABG) in which the left ITA was anastomosed to the left anterior descending coronary artery. The follow-up coronary angiography revealed an ostial 90% stenosis of the ITA. The patient underwent elective surgery during which the radial artery was interposed between the left subclavian artery and the ITA. Intraoperative ultrasonography was performed immediately before cut down of the ITA graft and again immediately after completion of all anastomoses. Both diastolic and systolic velocities and the velocity time integral increased more than 2-fold after the repair. Neither the diastolic-to-systolic peak velocity ratio nor the diastolic velocity time integral fraction showed remarkable change. These profiles were different from those reported previously for distal stenosis.

Constriction, Pathologic↗
PubMed2004

Plasma brain natriuretic peptide reflects left ventricular function during percutaneous cardiopulmonary support.

BACKGROUND: Plasma levels of brain natriuretic peptide (BNP), a cardiac hormone secreted predominantly from the ventricle, are elevated in patients with myocardial infarction, hypertension, and dilated cardiomyopathy. In this study, we assessed the usefulness of measuring BNP to evaluate left ventricular function in patients with severe heart failure receiving mechanical circulatory support. METHODS: Plasma BNP and creatine kinase (CK)-MB levels were measured serially in 8 consecutive patients with cardiogenic shock who received percutaneous cardiopulmonary support (PCPS) at Osaka Police Hospital from August 1999 to March 2000. Coronary artery bypass grafting or percutaneous transluminal coronary angioplasty was also performed in 5 patients during PCPS; in addition, 1 patient underwent insertion of a left ventricular venting catheter and implantation of a left ventricular assist system after PCPS. RESULTS: Five patients were weaned from PCPS, and 3 died. In survivors, plasma BNP and CK-MB levels correlated positively and significantly (r = 0.968, p = 0.03). After PCPS was initiated, plasma BNP levels gradually decreased in survivors, but not in patients who died (p = 0.003). CONCLUSIONS: These results suggest that plasma BNP levels accurately reflect myocardial damage in patients undergoing PCPS. A decrease in BNP might appear to indicate improved left ventricular function and predict successful weaning from mechanical support.

Adult↗
PubMed2004

Migration of an inferior vena cava filter to the right ventricle and literature review.

Migration of an inferior vena cava (IVC) filter to the heart after placement is an extremely rare complication. The case of a 42-year-old man who presented with ventricular arrhythmia and tricuspid valve regurgitation, and underwent open heart surgery to extract an IVC filter from the right ventricle 12 days after infrarenal IVC filter placement, is reported.

Adult↗
PubMed2004

Robotically assisted endoscopic transmyocardial laser revascularization.

BACKGROUND: The surgical approach to transmyocardial laser revascularization (TMR) via thoracotomy has been approved for the treatment of angina in inoperable patients, but it has had limited use as a stand-alone procedure. OBJECTIVES: To assess the feasibility and efficacy of robotically assisted endoscopic TMR using the Zeus robotic surgical system (Computer Motion, USA) and an excimer TMR system (Spectranetics, USA) in a porcine model. METHODS: Five pigs weighing 20 kg to 40 kg were used. A 10 mm endoscope, two 5 mm instrument ports and a 1.4 mm TMR probe were introduced into the left hemithorax. Endoscopic TMR was performed on the anterolateral or lateral left ventricular wall using Zeus instruments to hold and guide the TMR probe. RESULTS: The mean system set-up time was 4.2+/-0.6 min, the mean port placement time was 11+/-1.7 min, the mean TMR procedure time was 5.0+/-0.7 min and the mean number of transmural TMR channels was 10+/-3.6. All pigs tolerated the entire procedure. Histological examination showed that transmural channels were successfully created. CONCLUSIONS: Endoscopic TMR using the Zeus system was feasible, in a pig model, in creating transmural laser channels on the anterior and lateral left ventricle, and may provide a significant advantage over the open chest approach in reducing perioperative morbidity and improving recovery.

Animals↗
PubMed2003

Baboons undergoing orthotopic concordant cardiac xenotransplantation surviving more than 300 days: effect of immunosuppressive regimen.

OBJECTIVE: We reviewed long-term survival among hosts in 3 consecutive series of a rhesus monkey-baboon orthotopic cardiac xenotransplantation model with reference to host immune response, including the effectiveness in preventing rejection and limiting toxicity concerning infection, to evaluate specific immunosuppressive regimens for long-term outcomes. METHODS: Six juvenile baboons surviving more than 300 days after transplantation were reviewed. Regimen A consisted of splenectomy, FK506, methotrexate, and antilymphocyte globulin. Regimen B consisted of pretransplantation and chronic maintenance with cyclosporine A (INN: ciclosporin), methotrexate, and antithymocyte globulin. Regimen C was the same as regimen B plus pretransplantation total lymphoid irradiation and intraoperative donor bone marrow cell infusion. Rejections were detected by means of echocardiography. RESULTS: Long-term survivors in 3 groups were followed for a range of 332 to 515 days (mean, 436 days). Rejection frequency in regimens A, B, and C was 0.35, 0.58, and 0.18 per month, and rescue therapy days were 23 (4.8%), 123 (9.5%), and 20 (2.4%), respectively (P <.0001). Infection frequency was 0.58, 0.56, and 0.19 per month, and therapy days were 192 (38.2%), 164 (12.6%), and 7 (0.9%), respectively (P <.0001). Concerning the host immune response, interleukin 2-activated T cells of all groups during rejection-free periods showed lower numbers compared with those of control animals (P <.0005), and regimen C was the lowest among 3 groups (P <.01). The production of xenoantibody was sufficiently attenuated in all groups. CONCLUSION: Regimen C leads to long-term survival with fewer rejection and infection episodes by means of suppression of the interleukin 2 pathway and xenoantibody production.

Actuarial Analysis↗
PubMed2003

Fate of polytetrafluoroethylene monocusp pulmonary valves in an animal model.

Creation of a competent pulmonary monocusp valve facilitates transition from pressure to volume overload following right ventricular outflow tract reconstruction. To determine intermediate-term results and performance of the different types of polytetrafluoroethylene membrane used to construct monocusp valves and transannular patches, 12 infant lambs underwent excision of the native pulmonary valve and insertion of a monocusp valve and transannular patch made from one of 4 types of membrane. Echocardiography was performed after 3, 6, 9, and 12 months, and cardiac catheterization was carried out prior to animal sacrifice at 6 (n = 4) or 12 (n = 8) months. There was no postoperative morbidity or mortality. On echocardiography, 6 valves were mobile (50%), 4 had diminished mobility (33%), and 2 were fixed (17%) prior to sacrifice. At catheterization, mild, moderate, and severe pulmonary regurgitation was observed in 4 valves each (33%), with no stenosis. Right ventricular outflow tract reconstruction with polytetrafluoroethylene monocusp valves can be safely accomplished with good early competence, variable degrees of late insufficiency, and no stenosis. Compared to an open microstructure, the closed polytetrafluoroethylene microstructure showed a milder fibroinflammatory reaction and fewer foci of microcalcification, with sparing of the free edge of the monocusp; this correlated with better intermediate-term hemodynamic performance.

Animals↗
PubMed2002

Beating coronary bypass with right-heart bypass. A safer option in patients at high risk for stroke.

Two patients with bilateral obstructive carotid artery disease underwent beating heart coronary bypass including revascularization of the circumflex branch using right-heart bypass in a stable hemodynamic state. Without this mechanical support, lifting the left ventricle for the exposure of the posterior wall could impair the hemodynamic state of the patient. Right-heart bypass in addition to aortic no-touch technique can be a safer option for complete coronary revascularization in patients at high risk for neurological complications.

Aged↗
PubMed2002

Biventricular pacing for congestive heart failure: early experience in surgical epicardial versus coronary sinus lead placement.

OBJECTIVE: Biventricular pacing (BVP) has recently been introduced for the treatment of refractory congestive heart failure. Coronary sinus lead placement for left ventricular pacing is technically difficult, has a risk of lead dislodgement, and has long procedure times. Surgical epicardial lead placement has the potential advantage of the visual selection of an optimal pacing site, does not need exposure to ionic radiation, and allows lead multiplicity, but it does require a thoracotomy and general anesthesia. We report our early experience of BVP with both modalities. METHODS: BVP was performed in 12 patients with New York Heart Association (NYHA) class IV congestive heart failure (10 men, 2 women). Mean patient age was 68.7 years (range, 41-83 years). Surgical epicardial leads were placed through a 2- to 3-inch incision via a left fourth or fifth intercostal thoracotomy in 4 patients with single lung ventilation under general anesthesia. The other 8 patients underwent transvenous coronary sinus lead placement under conscious sedation. RESULTS: Postoperative NYHA class status improved from class IV to class II in 8 patients and to class III in 3 patients. In 5 of the 8 patients who had undergone follow-up echocardiography with mitral regurgitation, the severity of the mitral regurgitation improved. The mean left ventricular ejection fractions before and after BVP were 18.3% +/- 8.3% and 20.5% +/- 8.0%, respectively (P =.16). Mean fluoroscopy and total procedure times for transvenous lead placement were 77 +/- 19 minutes and 266 +/- 117 minutes, respectively. The mean surgery time for epicardial lead placement was 122 +/- 13 minutes. There were no differences between the 2 methods in pacing threshold or in lead dislodgement. There were no complications related to the surgery or the laboratory procedure. CONCLUSION: In patients with NYHA class IV congestive heart failure, epicardial lead placement through a minithoracotomy for BVP was performed safely with benefits equivalent to those of coronary sinus lead placement and with a shorter procedure time.

Adult↗
PubMedDate not supplied

Relationship between hemostatic markers and circulating biochemical markers of collagen metabolism in patients with aortic aneurysm.

Our objective was to determine the relationship between plasma levels of hemostatic molecular markers--D-dimer and thrombin-antithrombin III complex (TAT)--and circulating biochemical markers of collagen metabolism--aminoterminal propeptide of type III procollagen (PIIIP) and carboxyterminal propeptide of type I procollagen (PICP)--in patients with aortic aneurysm. The subjects were 43 patients with aortic aneurysm (AA; mean age 71 years) and 26 age-matched controls (mean age 75 years). The mean D-dimer, TAT and PIIIP levels were higher in the patients than in the controls (p < 0.0001, 0.0001 and 0.012, respectively), while the mean PICP level was similar to that in the controls. Increased D-dimer had a significant correlation with PIIIP (r = 0.412, p = 0.006) and PICP (r = 0.342, p = 0.0246), while TAT correlated with PIIIP (r = 0.3194, p = 0.0374), but not with PICP. There was also a significant correlation (r = 0.306, p = 0.0463) between PIIIP and PICP. As shown by the significant positive correlations among D-dimer, TAT and PIIIP, accelerated fibrinolysis and thrombogenesis induce an increase of collagen degradation and procollagen synthesis in atherosclerotic lesions. These findings show that D-dimer and TAT, especially the former, may be useful markers to monitor the progression and predict the prognosis of AA.

Aged↗