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Toshifumi Murashita

Publications and source records attributed to Toshifumi Murashita.

At least 19 recordsLinked to original sources
PubMed2006

Proximal aortic replacement with ascending-descending bypass for a diffuse aneurysm: report of a case.

We performed successful ascending-arch aortic replacement and concomitant ascending-to-descending aorta bypass with exclusion of a descending thoracic aneurysm, via median sternotomy, for a ruptured aortic aneurysm involving the entire thoracic aorta. The patient was an 80-year-old man with cardiopulmonary dysfunction and a history of lung tuberculosis. This operation, which has been used for complex descending thoracic aortic lesions such as recoarctation, is a feasible option for a diffuse thoracic aortic aneurysm when single-stage repair is mandatory.

Aged, 80 and over↗
PubMed2006

Bileaflet mechanical valve sound analysis using a continuous wavelet transform.

Bileaflet mechanical valve closing sounds have splits, the duration of which is not constant in normally functioning valves. However, no reports have discussed the influences of valve malfunction on the split interval, neither have any studies discussed the fact that mechanical valve closing sound signals must be analyzed using a time-frequency analysis because they are nonstationary signals. The continuous wavelet transform (CWT), a time-frequency analyzing method using mother wavelets modified by scale numbers, was selected in this study for analyzing bileaflet valve closing sounds because it is easy to understand and has no limitations such as the cross-terms in the Wigner-Ville distribution or the tradeoff between time and frequency resolutions of the short-time Fourier transform. This study compares the properties of the mother wavelets of various CWTs and selects one that is suitable for detection of the clear split in bileaflet mechanical valve closing sound signals. This article also establishes a standard frequency analyzing system for bileaflet mechanical valve sounds. A preliminary study with chirp Doppler signals for comparing the frequency properties of the mother wavelets of various CWTs suggested that Ishikawa's modified Morlet CWT has better time and frequency resolution at the highest frequency scale. Morlet/power CWT analysis of normal in vivo bileaflet valve closing sounds of the ST. Jude Medical (SJM), ATS, and Carbomedics (CM) valves demonstrated clear splits of very short interval at the highest level of frequency. Detection of the disappearance of the split by using this analytical method may be the key to identifying bileaflet mechanical valve malfunction in outpatient departments.

Aortic Valve↗
PubMed2006

Novel technique for volume reduction of giant left atrium: simple and effective "spiral resection" method.

Despite some controversial studies, an enlarged left atrium has an impact on postoperative complications, and surgical correction should be considered, particularly in patients with a markedly enlarged left atrium. We present herein 2 patients with a giant left atrium (left atrial dimensions of 107 and 93 mm on echocardiograms), and describe an effective and simple procedure, the "spiral resection" method, to reduce any part of the dilated wall of the left atrium with a single incision.

Aged↗
PubMed2006

Apicoaortic valved conduit for a patient with porcelain aorta.

A 69-year-old woman had severe aortic stenosis with a circumferentially calcified aorta from the ascending aorta to the aortic arch, and moderately impaired left ventricular function. Implantation of an apicoaortic valved conduit was performed as aortic clamping was not feasible. The early results were excellent.

Aged↗
PubMed2005

[Novel stent/CEA strategy for patients with bilateral carotid artery stenosis and coronary artery disease: report of 2 cases].

Recently, there are increasing numbers of patients with occlusive carotid artery disease and coronary artery disease. Simultaneous or two-staged surgery for both lesions has been recommended for these patients to reduce the incidence of perioperative complications. However, therapeutic options for the patients with bilateral carotid artery stenosis and coronary artery disease have not been established. In this report, we describe two patients who successfully underwent carotid endarterectomy (CEA) and carotid artery stenting (CAS) on each carotid artery in parallel with coronary artery bypass grafts (CABG). A 49-year-old male with severe stenosis of the bilateral internal carotid artery (ICA) and heart failure underwent CAS on the right side. Next day, he successfully underwent CABG and CEA on the left side at the same time. A 62-year-old male with severe stenosis of the bilateral ICA and coronary artery disease underwent CAS on the right side and CEA on the left side with an interval of 7 days. Subsequently, CABG was performed uneventfully. No perioperative complication occurred in either patient. The results suggest that combination therapy of CAS and CEA would be a valuable option for patients with complex carotid/coronary artery diseases.

Adult↗
PubMed2004

Relationship between fibril length and tissue ingrowth in the healing of expanded polytetrafluoroethylene grafts.

PURPOSE: To determine whether fibril length is correlated with graft healing as well as cellular and capillary ingrowth in a canine carotid implantation model. METHODS: Expanded polytetrafluoroethylene (ePTFE) vascular grafts with three different fibril lengths (30, 60, and 90 microm) were implanted into the carotid artery in dogs. They were retrieved 4 weeks later, and subjected to histomorphometric analysis. RESULTS: Endothelial healing was best in the 60-microm grafts. Not only cellular ingrowth but also capillary ingrowth was most evident in the 60-microm grafts, followed by the 90-microm grafts and then the 30-microm grafts. CONCLUSION: Better endothelial healing of ePTFE vascular grafts is correlated with more cellular and capillary ingrowth, but more cellular and capillary ingrowth is not correlated with longer fibril length or higher air porosity.

Animals↗
PubMed2004

Use of bioresorbable membrane to prevent postoperative small bowel obstruction in transabdominal aortic aneurysm surgery.

PURPOSE: To evaluate the efficacy of Seprafilm (Genzyme, Cambridge, MA, USA), a bioresorbable membrane, in preventing or reducing early postoperative small bowel obstructions after transabdominal abdominal aortic aneurysm (AAA) surgery. METHODS: Fifty-one patients underwent aortic reconstruction via a midline transperitoneal approach for infrarenal AAAs. Twenty-one patients underwent surgery with Seprafilm (Seprafilm group) and the remaining 30 patients did not (control group). The incidence of early small bowel obstruction was examined, and the time before liquid and solid diet were resumed was also compared to assess postoperative paralytic ileus. RESULTS: Patients in the Seprafilm group resumed a liquid diet on postoperative day (POD) 2.4 +/- 1.1 and a solid diet on POD 4.0 +/- 1.3, whereas the patients in the control group resumed a liquid diet on POD 3.3 +/- 1.9 and a solid diet on POD 5.4 +/- 3.4. These values were not significantly different between the two groups; however, the incidence of early postoperative small bowel obstruction was significantly lower ( P < 0.05) in the Seprafilm group (0/21) than in the control group (6/30). CONCLUSION: These findings suggest that Seprafilm may help to prevent early postoperative small bowel obstructions after transabdominal AAA surgery.

Absorbable Implants↗
PubMed2004

Improved healing of small-caliber, long-fibril expanded polytetrafluoroethylene vascular grafts by covalent bonding of fibronectin.

PURPOSE: To evaluate the intermediate performance of small-caliber, long-fibril expanded polytetrafluoroethylene (ePTFE) vascular grafts pretreated with covalent bonding of fibronectin in dogs. METHODS: Small-caliber (4 mm), long-fibril (60 microm), ePTFE vascular grafts, 10 cm in length, were pretreated by covalent bonding of fibronectin. Bilateral iliac grafting was done in dogs using a fibronectin-bonded graft on one side and a nonbonded control graft on the other side. The grafts were retrieved 12 weeks after implantation, and subjected to histomorphometric analysis. RESULTS: Although the patency rates of the fibronectin-bonded and control grafts were the same (3/7, 43%), the fibronectin-bonded grafts showed almost complete neointimal healing, whereas the nonbonded control grafts showed only partial neointimal healing, proximally and distally. CONCLUSIONS: Small-caliber, long-fibril ePTFE vascular grafts with covalent bonding of fibronectin achieved almost complete neointimal healing by the time of retrieval at 12 weeks. This indicates that, with further modifications, our new technique for covalent bonding of fibronectin has great potential in the development of small-caliber arterial prosthetic grafts.

Animals↗
PubMed2004

Postoperative renal function after elective abdominal aortic aneurysm repair requiring suprarenal aortic cross-clamping.

PURPOSE: To examine postoperative renal function after suprarenal aortic cross-clamping performed without renal hypothermia in patients undergoing elective abdominal aortic aneurysm (AAA) surgery. METHODS: Between 1991 and 2000, 18 patients underwent surgery for a juxtarenal AAA, which required a suprarenal aortic cross-clamp. All AAAs were repaired with a proximal anastomosis just below the renal arteries. We divided the patients into two groups according to the duration of the renal ischemia: <45 min (n = 12) and > or =45 min (n = 6). The postoperative changes in renal function were analyzed. RESULTS: There were no hospital deaths and none of the patients needed permanent hemodialysis. The postoperative peak in the serum creatinine level after suprarenal cross-clamping for > or =45 min was significantly higher than that after cross-clamping for <45 min. The percentage changes in serum creatinine and blood urea nitrogen were correlated positively with the duration of renal ischemia, and were significantly greater in the group with renal ischemia of <45 min than in the group with prolonged renal ischemia (> or =45 min). CONCLUSIONS: Suprarenal aortic cross-clamp without performing renal hypothermia is safe and able to be tolerated well by the patient during elective AAA surgery, although careful attention must be paid to limiting the period of renal ischemia.

Acute Kidney Injury↗
PubMed2004

Minimal access surgery for the repair of simple congenital heart defects: factors affecting hospital stay after surgery.

OBJECTIVE: We reviewed our experience of minimal access surgery to elucidate the efficacy and safety of this approach and determine the factors affecting hospital stay. METHODS: Seventy-seven patients (age, 11.8 +/- 11.0 years), with body weight of more than 10 kg, were operated using various forms of minimal access approach for repair of simple congenital heart defects [atrial septal defect (ASD) in 40, ventricular septal defect in 37]. These included lower partial sternotomy (n = 68) and mini-thoracotomy (n = 9, ASD only) with limited skin incision of 4-11 cm. The anesthetic protocol was modified to wean all patients from ventilator soon after operation. The protocol of discharge from hospital (critical pass) was 14 days in the early period (n = 30) and 10 days in the late period (n = 47). RESULTS: There were no hospital or late death, and no hospital re-admission. None of patients required blood transfusion. The endotracheal tube was extubated in the operating room in 48 cases (62%). Twenty-four patients (31%) failed to fulfill conditions of the critical pass. Univariate analysis of factors affecting unfavorably the critical pass demonstrated that the median approach, retention of pericardial effusion and social reasons were statistically significant, while an opened pleura and aortic cross-clamp time were marginally significant. Multivariate analysis indicated that the retention of pericardial effusion was the only significant factor that failed critical pass [p = 0.007, odds ratio (OR) 5.7, 95% confidence interval (CI) 1.61 -19.8]. In addition, a pericardio-pleural fenestration was the only significant factor that affected favorably the pericardial effusion (p = 0.035, OR 0.2, 95% CI 0.47-0.89) by multivariate analysis. CONCLUSIONS: Our experience demonstrated that minimal access surgery of the simple congenital heart defects provided excellent cosmetic results. Retention of pericardial effusion, possibly due to pericarditis, was a major risk factor of the prolonged hospital stay. The pericardio-pleural fenestration could reduce the risk of retention of effusion.

Adolescent↗
PubMed2004

Left atrioventricular valve regurgitation after repair of incomplete atrioventricular septal defect.

BACKGROUND: Excellent surgical results have been reported for repair of incomplete atrioventricular septal defect; however, left atrioventricular valve regurgitation (ltAVVR) is a major cause of late morbidity. We reviewed our entire experience with incomplete atrioventricular septal defect in order to investigate long-term results of ltAVVR after repair and determine the factors influencing the progression of ltAVVR in late follow-up. METHODS: Between 1983 and 2002, 61 patients underwent surgical repair of incomplete atrioventricular septal defect, including 7 patients with intermediate forms. The age of operation ranged from 1 month to 62 years old (median 5.3 years old). Thirteen patients were less than 2 years old, including 7 infants, while there were 15 adult patients. All patients underwent patch closure of the ostium primum defect. Before 1995, the cleft was left open in 7 patients and partial closure of the cleft was done in 41 patients, whereas complete closure of the cleft was performed in 9 patients since 1996. Preoperative and postoperative ltAVVR at hospital discharge and late follow-up were graded 0-IV by echographic evaluation. RESULTS: There was 1 early death and 4 late deaths with a 91% 10-year actuarial survival rate. Preoperative ltAVVR grade was I in 25 patients, II in 31 patients, III in 4 patients, and IV in 1 patient. Postoperatively, ltAVVR deteriorated in 3 patients. Left AVVR decreased in 21 patients, whereas in 37 patients it remained the same at hospital discharge. Consequently, ltAVVR remained grade II in 18 patients, grade III in 2, and there was no patient with grade IV. During the long-term follow-up, 24 patients were noted to have increased ltAVVR, including grade III in 8 patients and grade IV in 4. Reoperations for ltAVVR were required in 5 patients (8.3% of hospital survivors); valve replacement in 3 patients and valve repair in 2. Actuarial freedom from reoperation for ltAVVR was 91% at 10 years, whereas actuarial freedom from postoperative ltAVVR grade III or more was 89% at 5 years and 78% at 10 years. Multivariate analysis indicated that postoperative ltAVVR grade II or more at hospital discharge (p = 0.0032, odds ratio = 7.41, 95%CI: 1.95-28.10) was the only independent variable related to late ltAVVR, whereas age at operation, preoperative grade of ltAVVR, and the method of cleft repair were not significant risk factors. CONCLUSIONS: Left AVVR is still a significant risk in long-term follow-up. Because the postoperative grade of ltAVVR is the only independent risk factor for late ltAVVR, more efforts should be focused on left atrioventricular valve repair so as to minimize residual regurgitation, even mild regurgitation.

Adolescent↗
PubMed2004

Bilateral coronary ostial patch angioplasty with autologous pericardium in Takayasu arteritis: a case requiring replacement of the aortic valve and ascending aorta.

Since the lesions and stages of Takayasu arteritis vary with each patient, surgical treatment of this disease requires meticulous planning for the timing of operation, technique, material used, and postoperative medication. We report a rare complex lesion of Takayasu arteritis, which required simultaneous repairs for aortic regurgitation, a dilated ascending aorta and bilateral coronary ostial stenosis. Such multiple lesions have not been reported previously. A 47-year-old woman was referred to us because of heart failure and chest pain. The coronary ostial stenosis were enlarged with generously sized autologous pericardial patches, and separate aortic valve and ascending aortic replacements were performed since the diameter of the Valsalva sinus was 37 mm. The postoperative course was uneventful, but steroid therapy was commenced postoperatively because inflammatory reaction remained high.

Angioplasty↗
PubMed2004

Surgical results for active endocarditis with prosthetic valve replacement: impact of culture-negative endocarditis on early and late outcomes.

OBJECTIVE: Surgical treatment of active infective endocarditis requires not only hemodynamic repair, but also special emphasis on the eradication of the infectious focus to prevent recurrence. This goal can be achieved by the combination of aggressive debridement of infective tissue and appropriate and adequate antibiotic treatment. We reviewed our experience with active endocarditis and identified factors determining early and late outcomes, particularly focusing on the factor of culture-negative endocarditis. METHODS: Sixty seven patients with clinical evidence of active endocarditis who underwent operation between 1991 and 2001 were evaluated. The aortic valve was infected in 28 (42%), the mitral valve in 23 (34%), and multiple valves in 16 (24%). Native valve endocarditis was present in 58 (87%) and prosthetic valve endocarditis in 9 (13%). Mean follow-up was 5.7 years (range, 0.2-11.5 years). RESULTS: Microorganisms were detected in 46 (69%): Staphylococcus aureus in 9 (13%), other staphylococci in 9 (13%), streptococcus species in 19 (28%), and others in 9 (28%), whereas 21 (31%) patients had culture-negative endocarditis. Operative mortality was 17.8% (12 patients). Reoperation was required in 8 (12%), while 3 late deaths (5.5% of hospital survivors) occurred. All events, including death, reoperation, periprosthetic leak, and recurrence of infection, occurred within 2 years after operation. Actuarial freedom from reoperation, late survival, and events at 5 years were 81.6, 76.4, and 68.6%, respectively. On multivariate analysis, no independent adverse predictor was detected for hospital death, whereas the following independent adverse predictors were identified: preoperative heart failure (P=0.0375), prosthetic valve endocarditis (P=0.0391) and culture-negative endocarditis (P=0.0354) for poor late survival; culture-negative endocarditis (P=0.0354) and annular abscess (P=0066) for poor event-free survival. Freedom from events was similar between patients with Staphylococcus aureus infection (3-year freedom 55.6%) and culture-negative endocarditis (3-year freedom 47.6%), whereas events were significantly low in patients with streptococcus infection (3-year freedom 100%). CONCLUSIONS: In our analysis, no independent adverse predictor was detected for hospital death; however, culture-negative endocarditis was identified as an independent predictor for both late survival and events after surgery. Event-free survivals were similar between staphylococcus infection and culture-negative endocarditis, and all events occurred within 2 years after operation, suggesting the necessity of close follow-up during that period.

Adolescent↗
PubMed2004

Outcome of the perioperative use of percutaneous cardiopulmonary support for adult cardiac surgery: factors affecting hospital mortality.

Percutaneous cardiopulmonary bypass support (PCPS) has become a widespread standard modality for the treatment of circulatory collapse; however, its clinical use for postcardiotomy low cardiac output syndrome (LOS) has been reported to be unsatisfactory. We reviewed the clinical outcomes of twenty-three patients undergoing cardiac surgery and treated with PCPS. Solitary coronary artery grafting was undertaken for nine patients, while three had concomitant procedures. The remaining patients underwent valvular surgery. The indications for PCPS were preoperative shock in two patients and postcardiotomy LOS or shock in twenty-one patients. All patients except one underwent an intraaortic balloon pump. Sixteen of the twenty-three patients (69.6%) were weaned from PCPS and twelve patients (52.2%) reached hospital discharge. A univariate analysis revealed that risk factors for hospital mortality were age older than seventy years (P = 0.05), PCPS running time (P = 0.017), low cardiac function at the institution of PCPS (P = 0.004), and urine output within the initial 24 h (P = 0.041). The cardiac index (CI) in survivors was improved within 24 h, and eleven of the twelve survivors were weaned off PCPS within 48 h, whereas ten of the twelve nonsurvivors required PCPS for more than 48 h (P = 0.0006). There is little possibility of weaning patients from PCPS who do not show any signs of hemodynamic recovery within 48 h after its institution. Limited use of PCPS within 48 h may be applicable for postcardiotomy patients, but other cardiopulmonary support, such as a left ventricular assist device, may be required when hemodynamic recovery is not obtained within 48 h.

Adolescent↗
PubMed2003

Surgical management of aneurysms of the aortic arch vessels and their branches: report of four cases.

We review the cases of four patients with aneurysms of the aortic arch vessels and their branches. Two patients had a subclavian artery aneurysm, one had an innominate artery aneurysm, and one had a carotid artery aneurysm. We performed surgical reconstruction in all four patients in view of the life-threatening complications of these aneurysms. The approach, methods of surgical repair, and cerebral protection are discussed following these four case reports.

Aged↗
PubMed2003

Quantitative gated myocardial perfusion single photon emission computed tomography improves the prediction of regional functional recovery in akinetic areas after coronary bypass surgery: useful tool for evaluation of myocardial viability.

OBJECTIVE: Assessment of myocardial viability in akinetic areas is essential in surgery for ischemic heart disease, including coronary artery bypass grafting and left ventriculoplasty. The aim of this study is to evaluate the utility of quantitative indices of perfusion uptake, wall motion, and wall thickening of each region calculated by quantitative electrocardiogram-gated single photon emission computed tomography (SPECT) for prediction of functional recovery after coronary artery bypass grafting. METHODS: Forty patients scheduled for coronary artery bypass grafting were prospectively included. Electrocardiogram-gated SPECT was performed before and 1 week and 3 months after operation, and coronary angiography was performed before and after operation. The myocardium was divided into 9 segments and myocardial viability, assessed by improvement of the wall motion score using a cine mode display, and evaluated by radionuclide criteria (perfusion uptake, wall motion, wall thickening). Twenty-four segments with moderate hypokinesis and 14 segments with akinesis with patent grafts were assessed. RESULTS: All segments with moderate hypokinesis except 1 (96%) had improved wall motion scores postoperatively, whereas of 14 segments with akinesis only 7 segments (50%) had improved wall motion scores. The preoperative perfusion uptake in the improved segments was significantly higher than in the nonimproved segments (62.7% +/- 15.6% vs 46.4% +/- 24.5%, P =.01). There was a significant difference in wall motion between the improved and nonimproved segments (3.8 +/- 2.2 mm vs 1.4 +/- 1.4 mm, P =.001), and the preoperative wall thickening of the improved segments was significantly higher than in the nonimproved segments (27.2% +/- 14.1% vs 8.2% +/- 10.3%, P <.0001). The optimal cutoff level of perfusion uptake was 50%, with the highest accuracy of 72%, and the optimal cutoff levels of wall thickening and wall motion were 10% and 1.5 mm, with the highest accuracies of 76% and 85%, respectively. CONCLUSION: The regional functional index calculated by electrocardiogram-gated SPECT indicated that wall thickening was well correlated with functional recovery compared with wall motion or perfusion uptake. This suggests that the wall thickening calculated by electrocardiogram-gated SPECT may be more useful to predict functional recovery than regional myocardial perfusion. Or, it could suggest that in addition to perfusion uptake, wall thickening could enhance the objective assessment of myocardial viability.

Aged↗
PubMed2002

Long-term results of aortic valve regurgitation after repair of ruptured sinus of valsalva aneurysm.

BACKGROUND: We reviewed our 35-year-experience to investigate the determinants of long-term results of aortic valve regurgitation (AR) after surgical repair of ruptured sinus of Valsalva aneurysms (RSVA). METHODS: Between 1963 and 1998, a total of 35 patients aged 7 to 64 years underwent surgery for RSVA. The aneurysms ruptured into the right ventricle (n = 24), right atrium (n = 10), and left atrium (n = 1). In all, 19 patients had VSD and 9 patients had AR. A combined approach through aortotomy and the involved chamber was used for 24 patients. Either direct (n = 19) or patch (n = 16) closure was used to close the rupture hole. The AR was graded on a scale of 0 to IV by angiographic or echographic evaluation. RESULTS: There were no early deaths. Late death occurred in 1 patient, whose AR deteriorated to grade III 20 years later. Two patients (5.7%) required reoperations on the aortic valve, because grade III AR was noted 8 and 26 years after operation, respectively. Freedom from postoperative grade III AR or higher was 93% at 10 years and was 87% at 20 years. Late AR was associated with preoperative and early postoperative AR (p < 0.05) but not with the presence of VSD, location of the fistula, surgical approach, or type of repair (direct vs patch). Multivariate analysis indicated that early postoperative AR was the only independent variable. CONCLUSIONS: Late AR necessitating reoperation still confers significant risk in the long-term follow-up after repair of RSVA. No particular risk factor of preoperative conditions and surgical methods was elucidated in this study, and postoperative AR at discharge from the hospital was the only factor determining the long-term results of AR.

Adolescent↗