Publications (47)104.42 Total impact
-
Article: Early mitral valve surgery for chronic severe mitral regurgitation optimizes left ventricular performance and left ventricular mass regression.
[show abstract] [hide abstract]
ABSTRACT: OBJECTIVE: The optimal timing of mitral valve surgery for severe mitral regurgitation is controversial. We aimed to evaluate the changes in left ventricular performance using ventricular energetics and left ventricular mass regression after the surgery to determine the appropriate surgical timing in asymptomatic patients with severe mitral regurgitation. METHODS: Fifty consecutive asymptomatic or minimally symptomatic patients who electively underwent the surgery for severe mitral regurgitation were studied retrospectively. Contractility (end-systolic elastance), afterload (effective arterial elastance), and efficiency (ventriculoarterial coupling and ratio of stroke work to pressure-volume area), and left ventricular mass index were measured echocardiographically before and 1 month after surgery. Two-way repeated-measures analysis of variance was used to compare the parameters between patients with (n = 17) and without (n = 33) left ventricular dysfunction (ie, ejection fraction ≤60% and/or end-systolic dimension ≥40 mm). RESULTS: Contractility did not change significantly (P = .94) but the afterload increased significantly (P < .0001) in both groups. Consequently, the efficiency deteriorated significantly (ventriculoarterial coupling, P = .0004; ratio of stroke work to pressure-volume area, P < .0001). Furthermore, the left ventricular mass index improved remarkably in both groups (P < .0001). Alternatively, the patients with normal left ventricular function had greater contractility (P < .0001), less worsened efficiency (P < .0001 and P < .0001, respectively), and a better left ventricular mass index (P = .0002) after surgery. CONCLUSIONS: Early surgery for severe mitral regurgitation preserves left ventricular performance and improves left ventricular mass regression in asymptomatic patients with normal ventricular function.The Journal of thoracic and cardiovascular surgery 06/2012; · 3.41 Impact Factor -
Article: Cardio-aortic operation in octogenarians
[show abstract] [hide abstract]
ABSTRACT: Objective: Aging of the population is a current phenomenon in Japan, and life expectancy at 80 years old is getting longer. So we reviewed cardio-aortic operations on octogenarians at our institution.Subjects and Methods: Thirty-three consecutive octogenarian patients who had undergone cardio-aortic operations from 1992 to 1998 were studied. There were 14 men and 19 women. The mean age was 81.9 years. Of the 33, 19 patients (58%) were in New York Heart Association class IV, and 21 patients (64%) were operated on urgently or in emergency. The procedures undergone were operation for coronary artery disease in 17 patients, operation for valvular disease in 7 patients, operation for thoracic-aorta in 7 patients, and others in 2 patients.Results: The hospital mortality rate was 27% (9 patients). However, 89% of patients experiencing hospital death were in New York Heart Association class IV preoperatively and had required an emergency/urgent operation. On the other hand, there was only one hospital death (1/12, 8.3%) among the elective patients. The statistically significant risk factors for hospital death were renal insufficiency, shock, New York Heart Association class IV, intra-aortic balloon pumping, and longer cardiopulmonary bypass time. The one-, three-, and five-year-survival rate was 73%, 68%, and 55%, respectively. Of the survivors, 77% were in class I or II.Conclusion: Although octogenarians' hospital mortality was still very high, the mid-term results were acceptable and the survivors' quality of life was satisfactory. These data suggested that we should operate on cardio-aortic patients before they reach a very serious state, especially in octogenarians.The Japanese Journal of Thoracic and Cardiovascular Surgery 04/2012; 49(1):47-52. -
Article: Early results with the Carbo-seal composite valve conduit for aortic root replacement: Comparison with the St. Jude Medical/Hemashield composite graft
[show abstract] [hide abstract]
ABSTRACT: The Carbo-seal (C-S) composite valve conduit incorporates the CarboMedics mechanical prosthetic aortic valve in a gelatin-impregnated, twill-woven Gelweave tube graft. We evaluated the early results of the C-S composite graft in patients undergoing elective aortic root replacement. Five aortic root replacements with the C-S were compared with nine similar surgeries with St. Jude Medical/Hemashield (S-H) composite grafts, which were assembled during surgery. Both the Gelweave and the Hemashield graft fabrics are relatively thin and soft, allowing improved needle passage and surgical manipulation. No device-related complication was observed in the C-S group, although one low-output syndrome due to poor cardiac protection was found. In the S-H group, a non-infectious fever and a pleural effusion were observed. Body temperatures in both groups recovered to less than 37°C within 3 days after operation. The two groups demonstrated similar time courses in CRP, white blood cell count, red blood cell count, and LDH and no statistically significant intergroup differences. In terms of valve function (peak velocity and pressure gradient were determined by Doppler echo cardiography), both types of valves have remained within normal range through the last routine examination. Graft dilation also remained within an acceptable range at 6 months after operation, with no significant intergroup differences. In conclusion, the initial results indicated that the C-S composite valve conduit is a reliable device for use in aortic root replacement and may be considered comparable to the S-H. A longer follow-up in a larger patient population is necessary to confirm this positive early result.Journal of Artificial Organs 04/2012; 3(2):120-125. · 1.59 Impact Factor -
Article: New design bioprosthesis: early outcome of Carpentier-Edwards PERIMOUNT Magna in the small annular aortic position.
[show abstract] [hide abstract]
ABSTRACT: The Carpentier-Edwards PERIMOUNT (CEP) Magna (Edwards Lifesciences, Irvine, CA, USA) is a newly developed bioprosthesis with an improved cuff design that allows its implantation into the smaller aortic annulus. We evaluated the hemodynamic performance of the CEP Magna for smaller aortic annulus cases. Patients who underwent aortic valve replacement for aortic stenosis receiving a Magna 19 mm (n = 13), were compared with a standard CEP (n = 19). In the 19-mm series, the real annular size was significantly smaller in the Magna than the standard (21.1 ± 0.8 vs. 19.8 ± 0.8 mm, p = 0.007). The Magna was significantly superior with respect to effective orifice area index (EOAI) at postoperative 3 months; however, no significant difference was seen in other factors (peak pressure gradient, left ventricular mass index, ejection fraction). At postoperative 3 months, despite the lack of statistical significance, the incidence of patient-prosthesis mismatch (PPM) was lower with the Magna. Using the same label size, the Magna can be implanted in a smaller aortic annulus with performance comparable with or better than hemodynamic performance with the standard CEP. The Magna is a useful prosthesis for the small aortic annular patient.Journal of Artificial Organs 06/2011; 14(4):284-8. · 1.59 Impact Factor -
Article: Mitral stenosis due to pannus overgrowth after rigid ring annuloplasty.
[show abstract] [hide abstract]
ABSTRACT: Although mitral stenosis (MS) due to pannus overgrowth after mitral valve repair for rheumatic mitral regurgitation (MR) is not uncommon, it is extremely rare in relation to non-rheumatic mitral regurgitation. Whilst it has been suggested that the rigid annuloplasty ring induces pannus overgrowth in the same manner as the flexible ring, to date only in cases using the flexible ring has pannus formation been confirmed by a pathological examination after redo surgery. The case is described of a woman who had undergone mitral valve repair using a 28 mm rigid ring three years previously because of non-rheumatic MR, and subsequently suffered from MS due to pannus formation over the annuloplasty ring. To the present authors' knowledge, this is the first report of MS due to pannus formation after mitral valve repair using a rigid annuloplasty ring to treat non-rheumatic MR documented at reoperation.The Journal of heart valve disease 03/2010; 19(2):257-9. · 0.81 Impact Factor -
Article: Multidirectional computed tomography for the left sinus of Valsalva aneurysm with aortic regurgitation.
European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 11/2009; 37(4):952. · 2.40 Impact Factor -
Article: Pannus overgrowth after mitral valve replacement with a Carpentier-Edwards pericardial bioprosthesis.
[show abstract] [hide abstract]
ABSTRACT: A Carpentier-Edwards pericardial (CEP) bioprosthesis was explanted from an 81-year-old woman due to nonstructural dysfunction 9 years after mitral valve replacement. The nonstructural dysfunction produced severe regurgitation in the mitral position. During the surgery, excessive pannus overgrowth was seen on the left ventricular side of the CEP bioprosthesis. Pannus overgrowth was prominent on one leaflet. That leaflet was stiff and shortened due to the excessive overgrowth of pannus. In this patient, the distortion of one leaflet was the main reason for transvalvular leakage of the CEP bioprosthesis in the mitral position. A new CEP bioprosthesis was implanted in the mitral position. Pathological analysis revealed fibrotic pannus with a small amount of cellular material over the leaflets of the resected CEP valve. This change was marked on the distorted leaflet.Journal of Artificial Organs 02/2009; 12(1):55-7. · 1.59 Impact Factor -
Article: Effect of surgery for atrial fibrillation associated with mitral valve disease.
[show abstract] [hide abstract]
ABSTRACT: The purpose of this study is to evaluate the effect of surgery for atrial fibrillation (AF) associated with mitral valve disease. From September 1994 to December 2006, 244 patients who underwent mitral valve surgery were enrolled in this study. The maze procedure or pulmonary vein isolation was concomitantly performed in 147 patients, while the remaining 97 patients were not surgically treated for AF. The patients were divided into 3 groups based on their cardiac rhythm at discharge from the hospital: the sinus group (108 patients), the intractable AF group (39 patients), and the untreated AF group (97 patients). The clinical features and late results of patients were compared among these groups. Early mortality rate was 0.7% and no major morbid events had occurred. Follow-up was completed in 95.6% of the patients and the mean follow-up period was 6.03 years. Actuarial survival was not significant between the sinus and AF groups. Actuarial freedom from thromboembolism at 5 and 10 years was 96.5% in the sinus group, 82.4% and 78.1%, respectively, in the intractable AF group, and 93.4% and 89.1%, respectively, in the untreated AF group; statistical significance was observed among the 3 groups (p = 0.01). By means of multivariate analysis, intractable AF was found to be the only risk factor for thromboembolism and other complications. Atrial fibrillation associated with mitral valve disease should be treated, because restoration of the sinus rhythm might lead to a lower incidence of thromboembolism and valve-related complications in the later period.The Annals of thoracic surgery 11/2008; 86(4):1212-7. · 3.74 Impact Factor -
Article: Edge-to-edge repair for mitral regurgitation: a clinical and exercise echocardiographic study.
[show abstract] [hide abstract]
ABSTRACT: The durability and potential for creating functional mitral stenoses are major concerns in the edge-to-edge (E-to-E) repair of mitral regurgitation (MR). Valve repair for MR was performed using the classical Carpentier technique in 120 patients (group C), and with the E-to-E technique in 37 patients (group E). A ring annuloplasty was performed in all patients. The mid-term results were examined and exercise echocardiography was conducted. No significant differences were observed between the two groups with regards to early and late mortality rates, actuarial survival rate and valve-related complication-free rate at five years after surgery. Postoperatively, MR was decreased significantly in both groups. Exercise echocardiography was undertaken in 35 operative survivors (20 from group C, 15 from group E). At peak exercise, the mean transmitral pressure gradient (MTPG) increased significantly in both groups. Systolic pulmonary artery pressure (SPAP) was also significantly elevated, but still within the accepted upper limits in both groups. The mitral valve area (MVA) showed no significant increase in either group. At peak exercise there were no significant differences in MTPG, SPAP and MVA between the two groups. Edge-to-edge repair is equally effective and durable as a conventional repair using the Carpentier technique. A mitral valve redesigned by E-to-E repair with ring annuloplasty may be slightly restrictive compared to a normal healthy mitral valve under exercise conditions; however, the hemodynamic performance did not differ significantly from that of a valve repaired with the Carpentier technique. These hemodynamics were not related to the use of E-to-E repair per se as the only causal factor, but rather to the ring annuloplasty.The Journal of heart valve disease 10/2008; 17(5):476-84. · 0.81 Impact Factor -
Article: Long-term results of aortic valve replacement with a small St. Jude medical valve in Japanese patients.
[show abstract] [hide abstract]
ABSTRACT: The use of small aortic valve prostheses is still controversial because of negative effects caused by residual obstruction of the left ventricular outflow tract. This study evaluated the long-term results after aortic valve replacement with a small valve from St. Jude Medical (St. Paul, MN). Between 1980 and 1999, 221 patients underwent isolated aortic valve replacement with a 23-mm or smaller St. Jude Medical valve. The mortality rate and complications were analyzed, echocardiography was performed, and peak pressure gradient, mean pressure gradient, indexed effective orifice area, and left ventricular mass index were measured. The follow-up rate in the 221 patients was 99.5% (maximum length, 24.1 years; mean, 10.3 years). Patients with a 19-mm valve were mainly women, older, and had smaller body surface areas. Freedom from valve-related death at 20 years was 100%, 86.0%, and 90.2% in patients with 19-, 21-, and 23-mm valves, respectively. There were no significant differences in the actuarial freedom from valve-related deaths. Echocardiography showed significantly higher peak (32.3 mm Hg) and mean pressure gradients (17.6 mm Hg) and a smaller indexed effective orifice area (0.70 +/- 0.15 cm(2)/m(2)) in patients with a 19-mm valve than in those with a 21- or 23-mm valve. Moderate prosthesis-patient mismatch was present in most patients with a 19-mm valve according to one definition; however, the improvements in ejection fraction and left ventricular mass index were significant, and functional recovery (mean New York Heart Association class, 1.3 +/- 0.5; mean specific activity scale, 5.1 +/- 0.8 metabolic equivalents) was satisfactory. The present long-term results demonstrate that a small St. Jude Medical valve can be advantageously used in most Japanese patients because their body size is generally smaller than that of Western patients. These findings also emphasize that it is not prosthesis size per se that matters but rather the relation between body size and prosthesis size.The Annals of thoracic surgery 05/2008; 85(4):1303-8. · 3.74 Impact Factor -
Article: Aortic root replacement in Behçet disease.
[show abstract] [hide abstract]
ABSTRACT: The patient presented with a history of recurrent aphthous stomatitis, genital ulceration, and a family history of positive for collagen disease. Echocardiography and retrograde aortography revealed aneurysm formation of the sinus of Valsalva, and dilatation of the aortic valve annulus with severe aortic regurgitation. On diagnosis of an aneurysm of the sinus of Valsalva and aortic regurgitation associated with Behçet's disease, aortic root replacement with the modified Bentall technique was successfully performed.Asian cardiovascular & thoracic annals 01/2008; 15(6):521-3. -
Article: Arginine vasopressin is an ideal drug after cardiac surgery for the management of low systemic vascular resistant hypotension concomitant with pulmonary hypertension.
[show abstract] [hide abstract]
ABSTRACT: Low systemic vascular resistance (SVR) hypotension concomitant with pulmonary hypertension (PH) is difficult to manage postoperatively because they are often catecholamine-resistant. So, we applied arginine vasopressin (AVP), which is a potent vasoconstrictor in a specific condition, for post-cardiotomy refractory low SVR hypotension concomitant with PH. We treated nine cases of postoperative refractory vasodilatory hypotension concomitant with PH even after conventional treatment that included nitric oxide inhalation and/or intraaortic balloon pump. AVP was administrated with 0.05 approximately 0.1 U/min intravenously. After AVP administration, the mean systemic arterial pressure increased from 47.3+/-9.5 to 76.5+/-12.2 mmHg (P<0.01) and SVR increased from 488.1+/-92.7 to 1188+/-87 dynes x s x cm(-5) (P<0.01). Fortunately, even though the cardiac index decreased, it remained in a normal range. Alteration in the PVR was not significant, but the Pp/Ps became somewhat lower (0.66+/-0.2 to 0.47+/-0.16, P<0.01). AVP increased the urine output and improved oxygenation. AVP improved systemic circulation (increased systemic blood pressure with maintaining cardiac output) without deterioration of pulmonary hypertension. AVP is an ideal drug for treating refractory low SVR hypotension concomitant with PH. But its indication must be limited.Interactive cardiovascular and thoracic surgery 12/2007; 6(6):715-9. -
Article: Benefits of a beta-blocker for intractable hemolysis due to paraprosthetic leakage.
[show abstract] [hide abstract]
ABSTRACT: We describe a 58-year-old man who was successfully treated with a beta-adrenergic receptor blocking agent for intractable hemolysis due to paraprosthetic leakage. After replacement of a mitral prosthetic valve with another mechanical valve, the patient suffered intractable intravascular hemolysis resulting from recurrent paraprosthetic leakage. With oral administration of a beta-adrenergic receptor blocker, betaxolol hydrochloride, for 3 months, the hemoglobin value increased from 9.7 g x dL(-1) to 12.4 g x dL(-1), although glutamic oxaloacetic transaminase and lactic dehydrogenase values remained elevated.Asian cardiovascular & thoracic annals 11/2007; 15(5):441-3. -
Article: Subdural hematoma after open-heart surgery.
[show abstract] [hide abstract]
ABSTRACT: Four cases are described of acute subdural hematoma that occurred after valve replacement in patients receiving anticoagulant therapy. All four patients experienced rapid deterioration of consciousness or neurological dysfunction, to varying degrees, between two and 42 days after valve replacement; emergency brain computed tomography scanning demonstrated the presence of subdural hematoma. The neurological problems were completely resolved by removal and drainage of the hematoma in three patients, while conservative management was performed with no aggravation of neurological symptoms in the fourth patient.The Journal of heart valve disease 08/2007; 16(4):450-3. · 0.81 Impact Factor -
Article: Embolic myocardial infarction and left ventricular rupture due to mitral valve endocarditis.
[show abstract] [hide abstract]
ABSTRACT: A left ventricular rupture due to embolic myocardial infarction is extremely rare. A 72-year-old woman developed an acute embolic myocardial infarction and mitral regurgitation due to infective endocarditis. Two days after the infarction, a left ventricular free wall rupture occurred after transesophageal echo examination. She received an epicardial patch and mitral valve replacement. Perioperatively, an intra-aortic balloon pump and long-term antibiotics were used. The postoperative course was uneventful, and she is doing well 10 months after surgery.Annals of thoracic and cardiovascular surgery: official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia 07/2007; 13(3):206-8. · 0.69 Impact Factor -
Article: Influence of angiogenesis by implantation of bone marrow mononuclear cells in the rat ischemic heart.
[show abstract] [hide abstract]
ABSTRACT: Bone marrow implantation (BMI) enhances angiogenesis in several animal models of ischemic diseases, and it is currently applied in the clinical treatment of humans. However, the mechanisms of this effect have not yet been fully described. Rat bone marrow mononuclear cells (BM-MNCs) were obtained by Histopaque density gradient centrifugation and injected directly into the ischemic myocardium of the test rats (BMI group), which were then examined and compared with the groups that received surgery only (Controls) or surgery and an injection of phosphate buffered saline (PBS group). Cardiac function was evaluated by echocardiography, and neovascularization was examined both histologically and immunohistochemically before, 1 day after, and 7 or 28 days after the operation. BM-MNCs were analyzed by fluorescence staining for the endothelial cell marker CD31 and alkaline phosphatase (ALP). The mechanisms of angiogenesis were examined by gene expression analysis. In the BMI group, cardiac function parameters at 7 days after operation were significantly improved and the number of capillaries in the myocardium was significantly larger than that in the PBS and Control groups. Gene analysis showed the expression of 12 genes in the BMI group 7 days after operation. The implantation of BM-MNCs into the myocardiumin cases of acute infarction enhances cytoprotection and angiogenesis by affecting gene expression.The Kurume Medical Journal 02/2007; 54(3-4):77-84. -
Article: Leaflet movement of the ATS valve in the aortic position: unique behavior observed in 19-mm valves.
[show abstract] [hide abstract]
ABSTRACT: Leaflet opening angles of ATS valves in vivo tend to be less than those reported by the manufacturer, and there is a wide variation in opening angles even among valves of the same size. Leaflet movement of aortic ATS valves was evaluated by cineradiography in 77 patients. The mean period from valve replacement to cineradiography was 40.2 months, and during that period, the ATS valve was replaced due to prosthetic valve obstruction in 1 of the 77 patients. In 76 patients with a normally functioning ATS valve, the mean opening angle of 19-mm valves (66.3 degrees +/- 2.3 degrees) was significantly less (p < 0.0001) than that of ATS valves 21 mm or larger (72.2 degrees +/- 3.8 degrees in 21-mm, 72.4 degrees +/- 2.8 degrees in 23-mm, and 72.8 degrees +/- 2.9 degrees in 25-mm valves). No significant differences were found in the opening angles of ATS valves 21 mm or larger, and the opening angles exceeded 65 degrees in all 69 patients with valves in this category. In one case of obstruction in a 21-mm valve, the opening angle was 57.5 degrees. The closing angle was 24.9 degrees +/- 1.3 degrees, which corresponded well with the manufacturer's in vitro data. The opening angle in the 19-mm ATS aortic valve is significantly less than that in valves 21 mm or larger, and an opening angle of less than 65 degrees probably indicates prosthetic valve obstruction in aortic ATS valves sized 21 mm or larger.The Annals of thoracic surgery 10/2006; 82(3):853-7. · 3.74 Impact Factor -
Article: Long-term survivors after valve replacement with a Starr-Edwards mitral disk valve prosthesis.
[show abstract] [hide abstract]
ABSTRACT: We report four long-term survivors after valve replacement with a Starr-Edwards (S-E) mitral caged-disk valve. A model 6520 disk valve, size 3M, had been used in all of the four patients. Of the four patients, three underwent replacement of the disk valves 23, 24, and 26 years after mitral valve replacement (MVR), respectively. A pacemaker was implanted in the remaining patient 33 years after MVR. The S-E disk valves were considered hemodynamically slightly stenotic compared with modern bileaflet valves. No disk wear was detected in any of the three explanted valves, and in the remaining patient, a noninvasive evaluation of the disk showed that it was functioning normally. These results suggest the favorable long-term durability of the S-E disk valve.Artificial Organs 07/2006; 30(6):484-7. · 2.00 Impact Factor -
Article: Infection management in a patient with a left ventricular assist device: a case report of long-term cefazolin sodium hydrate administration.
[show abstract] [hide abstract]
ABSTRACT: A 55-year-old woman suffered from a bloodstream infection (Staphylococcus aureus), which originated from pump inflow and outflow skin exits, from 4 months after a parocorporeal left ventricular assist device (LVAD) had been implanted. In addition to local irrigation, repeated administration of a weekly unit of cefazolin hydrate was temporarily effective, but fever frequently recurred. Because short-term antibiotic administration had limited effectiveness, a much longer-term course of cefazolin was begun at 14 months post-LVAD implantation and was planned to continue until future transplantation. Unfortunately, the patient died from a cerebral embolism at 19 months after LVAD implantation; long-term consecutive cefazolin administration had suppressed the infection for over 5 months without side effects. To treat intractable LVAD-associated bloodstream infection, long-term administration of a narrow-spectrum beta-lactam drug is an effective option.Journal of Artificial Organs 02/2006; 9(2):118-21. · 1.59 Impact Factor -
Article: Intramural hematoma on acute phase: diagnostic pitfall.
The Journal of trauma 11/2005; 59(4):1032. · 2.48 Impact Factor
Top co-authors
Top Journals
Institutions
-
1999–2012
-
Kurume University
- Department of Surgery
Kurume, Fukuoka-ken, Japan
-
-
2009–2011
-
Kyushu Medical Center
Fukuoka-shi, Fukuoka-ken, Japan
-
