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Biomedical subjects

S Takamoto

Publications and source records attributed to S Takamoto.

At least 181 records · Page 10Linked to original sources
PubMed1996

Predictive factors for postoperative cerebral complications in patients with thoracic aortic aneurysm.

OBJECTIVE: Perioperative factors affecting the outcomes of postoperative brain function in patients with thoracic aortic aneurysm were demonstrated. PATIENTS AND METHODS: From December 1977 to September 1994, 745 patients with thoracic aortic aneurysm underwent 846 operations. The mean age at surgery was 57.1 +/- 14.2 years old. Four hundred seventy-four patients had true aneurysm and 372 had aortic dissection. Two hundred forty-four patients underwent repair in the ascending aorta, 189 arch repair, 242 repair in the descending aorta. 79 replacement of the thoracoabdominal aorta, and 92 extra-anatomical bypass or thrombo-exclusion of the aorta. Conventional cardiopulmonary bypass was used in 297 patients, partial cardiopulmonary bypass through femoral access in 167, selective cerebral perfusion in 253, deep hypothermic circulatory arrest and retrograde cerebral perfusion in 50, temporary shunt in 29, and no circulatory support was applied in 50. Postoperative cerebral complications were divided into permanent cerebral dysfunction. RESULTS: The early mortality rate was 15.5% (131 patients). Incremental risk factors for hospital mortality were non-preexisting cardiac lesions, ruptured aneurysm, postoperative cerebral complications, sepsis, bleeding, low output syndrome and renal failure. Cerebral complications occurred in 81 patients (9.6%), involving 47 permanent and 34 transient sequelae. The early mortality rate in patients with postoperative brain damage was 42.0%. The etiologies of the brain damage diagnosed by computed tomography were embolism in 41 patients, cerebral hypoperfusion in 16 and unknown in 24. Incremental risk factors for postoperative cerebral complications were: operation early in the series advanced age at surgery, preoperative renal failure, aortic arch lesions, atherosclerotic aneurysm, aortic arch procedures and clamping of the aortic arch. CONCLUSIONS: Although there was an increased incidence of advanced age and complex lesions in patients with aortic aneurysm, an improvement in surgical results has recently been achieved using advanced diagnostic and surgical techniques.

Adult↗
PubMed1996

Surgery for aortic dissection with intimal tear in the transverse aortic arch.

OBJECTIVES: This study reports surgical experience of 72 cases of aortic dissection with intimal tear in the transverse aortic arch. METHODS: Of 325 patients with aortic dissection, 72 (22.2%) had a tear in the arch, including 27 with acute dissection and 45 with chronic dissection. Mean age at surgery was 60.8 +/- 14.1 years. The dissection was localized from the ascending aorta to the arch in 30 patients and extensive from the ascending aorta to the descending aorta in 42. Surgeries consisted of total arch replacement in 50 patients, hemiarch replacement in 20, and extra-anatomical bypass in 1. In the initial series, cardiopulmonary bypass for brain protection during arch procedures was selective cerebral perfusion (61 patients), but since July 1993 deep hypothermic circulatory arrest with retrograde cerebral perfusion was exclusively utilized (8 patients). RESULTS: Hospital mortality was 9.7%, 11.1% of the patients who had acute dissection and 8.8% with chronic dissection. There has been no mortality since February 1993. The mean follow-up period was 51 +/- 37 months, and there were 3 late deaths. The 5 and 10 year survival rate was 85.3 +/- 4.8 in all patients, 84.3 +/- 8.9% with acute dissection, and 85.5 +/- 5.7% with chronic dissection. The 5 and 10 year survival was 79.8 +/- 7.1 with extensive dissection, and 93.5 +/- 6.5% with localized dissection. During follow-up, 6 patients underwent subsequent aortic surgeries. The freedom from reoperation at 5 years and at 10 years was 91.4 +/- 4.8% and 65.6 +/- 14.4%, respectively. In patients with acute dissection it was 92.3 +/- 7.4% and 61.5 +/- 25.6% at 5 years and 10 years, while with chronic dissection it was 87.0 +/- 7.0% and 44.0 +/- 17.3% at 5 years and 10 years, respectively (n.s.). The freedom from subsequent reoperation for the aorta in all patients was 91.4 +/- 4.8% at 5 years and 10 years was 65.6 +/- 14.4%. With acute dissection it was 92.3 +/- 7.4% at 5 years and 61.5 +/- 25.6% at 10 years, while that with chronic dissection it was 91.3 +/- 5.9% and 65.7 +/- 16.8% at 5 years and 10 years respectively (n.s.). The freedom from all reoperations with extensive dissection at 5 years and 10 years was 86.6% +/- 7.2% and 34.2 +/- 17.3%, respectively, moreover, the freedom from reoperations with localized dissection at 5 and at 10 years was 90.0 +/- 9.5% (n.s.). However, the freedom from subsequent aorta reoperation with extensive dissection at 5 years and 10 years was 86.6 +/- 7.2% and 56.0 +/- 16.0%, respectively, while with localized dissection it was 100% at 10 years (P < 0.01). CONCLUSION: Early and late surgical result for arch dissection was satisfactory with a surgical principle of resecting the aortic segment that contains the initial intimal tear and graft replacement.

Acute Disease↗
PubMed1996

[Review of results after surgery for pulmonary embolism].

The results of direct pulmonary embolectomy in 20 cases of pulmonary embolism treated in our facility from 1982 to May, 1995 was analyzed. The ages of the patients ranged from 25 to 72 years (mean: 46 years). The male-to-female ratio was 12:8. The 20 cases were divided into three groups based on the type of pulmonary embolism: Group I (4 cases of acute massive pulmonary thrombo-embolism). Group II (12 cases of chronic pulmonary thrombo-embolism) and Group III (4 cases of tumor embolism). In Group I, 2 patients developed shock and 2 developed severe right heart failure. Emergency thrombectomy using cardiopulmonary bypass succeeded in saving the lives of 3 patients in this group. In Group II, the preoperative NYHA grade was II in 1 case, III in 9 cases, and IV in 2 cases. The preoperative systolic pressure of the pulmonary artery ranged from 24 to 90 mmHg (mean: 74 mmHg). Surgery through a thoracotomy was carried out on 7 cases (on the right side in 4 cases on the left in 3 cases). Of these 7 patients, 2 died of heart failure and respiratory failure because thromboendarterectomy was inadequate. In another 2 patients, symptoms improved enough to allow them to resume their previous lives. The other three patients showed no change in their symptoms after surgery, but they could be discharged. The remaining 5 patients in Group II underwent surgery through the median approach. Deep hypothermia with circulatory arrest was used in the latter 4 of these 5 patients during surgery. 3 patients died during the perioperative period because adequate thromboendarterectomy was not possible and because their preoperative condition was very poor. 2 patients who were able to be performed adequate thromboendarterectomy showed good postoperative courses. Of the 4 patients in Group III, one patient survived 11 months after surgery, but the other 3 died during the preoperative period because very little embolus could be removed. These results allow us to conclude that the lives of patients with acute pulmonary thromboembolism can be saved by early detection and prompt surgery, but that management of chronic pulmonary thromboembolism involves difficulties in selecting surgical cases and in performing thromboendarterectomy.

Adult↗
PubMed1996

[Acute type A aortic dissection after replacement of descending thoracic aorta for type B aortic dissection].

Two cases of acute type A aortic dissection after replacement of descending thoracic aorta for type B dissection were reported. One case involved a 75-year-old male who had hypertension. The second case involved a 33-year-old female with a familial history of thoracic aneurysms. Both patients underwent simultaneous graft replacement of the ascending aorta and total aortic arch using selective perfusion to the brain. Both patients survived the operations, and the postoperative courses were satisfactory. Acute type A dissection after replacement of descending thoracic aorta for type B dissection is rare, and careful and long-term follow-up is needed for the patients.

Acute Disease↗
PubMed1996

[Papillary muscle rupture complicating acute myocardial infarction--treatment with mitral valve replacement and coronary bypass surgery in acute phase].

Complete rupture of a papillary muscle following acute myocardial infarction is a severe complication that is typically associated with acute left ventricular failure, pulmonary edema, and relentless clinical deterioration. The reported mortality rates without surgical intervention is almost 90%, therefore, prompt operation without prolonged attempts at medical stabilization is the key to decrease operative mortality. Although the complete coronary revascularization in conjunction with mitral valve replacement is advocated in the western medical academic society, there is only a few case of conjunct surgery has been reported in Japan. Three successful cases of conjunct surgery of mitral valve replacement and coronary complete revascularization in acute phase within one week from the onset of acute myocardial infarction (AMI) are described. There were one male and two female patients with an average age of 60-year-old (range 48-67), who developed cardiogenic shock and admitted to our hospital. The average interval between onset of AMI and the appearance of mitral regurgitation (MR) was 38 hours, and that of the appearance of MR and admission was 40 hours. Surgeries were performed within 26 hours (average 13 hours) after admission. The mitral valve was replaced with a mechanical valve (St. Jude Medical Valve) and a complete coronary revasculatization was done using saphenous vein graft. The average period of operation time and aortic cross clamping time were 6 hours 22 minutes and 109 minutes respectively. The average number of coronary grafting was 2.3 (range 1-3). Postoperative recovery from cardiogenic shock was uneventful in all three patients. The average periods of ICU stay and hospital stay were 5 days and 43 days respectively. All patients have regained their social activities with mean follow up period of 52 months. Since ischemic heart disease remains the leading cause of death in such patients, it is suggested that complete coronary revascularization should be performed immediately in conjunction with valve replacement even in the acute phase after onset of AMI.

Aged↗
PubMed1996

[Clinical study of re-do surgery after Bentall-type operation].

Among patients who underwent reconstruction of the aortic root by Bentall-type procedure using a composite graft, we investigated patients who underwent reoperation for complications related to composite graft. We employed composite graft reconstruction of the aortic root in 155 patients for 16 years prior to December 1994. Annulo-aortic ectasia was observed in 112 patients, aortic dissection in 34, and aortitis without aneurysm formation in 9. The original Bentall procedure was performed in 36, the Cabrol method in 8, the interposition method in 26, and the Carrel patch method in 85 patients. Thirteen (8.4%) of these patients required reoperation for complications related to the composite graft. Three of 4 patients with graft infection early after surgery underwent reconstruction with composite graft, but died in the hospital. The remaining patient survived after combined treatment that included the graft washing with Iodine (Isozin) solution and omentopexy. Four patients developed pseudoaneurysm formation due to sutural insufficiency and 7 has prosthetic valve failure as late complications. Three of the 4 patients with pseudoaneurysm underwent reconstruction with a second composite graft by the interposition method, while one patient with aortitis required another reoperation. In the remaining one patient, the leak was directly close along with second aortic valve replacement. All prosthetic valves used in 7 patients with prosthetic valve failure were Ionescu-Shiley biological valves. Primary tissue failure was observed in 6 and prosthetic valve endocarditis in one patient. Second cardiac valve replacement using a mechanical valve was possible. All the patients who underwent late reoperation showed favorable results. Infection of the composite graft showed the poor prognosis, and prevention of infection is important. Sutural insufficiency at the anastomosed site can be prevented by appropriate surgical procedures such as reinforcing suture, but further countermeasures for sutural insufficiency were considered necessary for aortitis in conditions, such as Behcet's diseases.

Adult↗
PubMed1996

[Recent progress in adjunctive methods during surgery of aortic dissection].

Aortic dissection is severe disease, but recently surgery of aortic dissection is reported in good results. In order to improve results, three adjunctive methods have been progressed recently; intraoperative color Doppler retrograde cerebral perfusion and deep hypothermia. Intraoperative color Doppler reveals dynamic hemodynamics and structural information in aortic dissection in real time which leads to proper surgical treatment to obtain maximum effects with minimum invasiveness. To carry out thrombus obliteration in false lumen by informations of intraoperative color Doppler leads to a healing in aortic dissection. Retrograde cerebral perfusion during surgery of aortic dissection permitted simple procedure and good surgical results with reduced neurological complications. Deep hypothermia for protection of spinal cord and other organs also yielded good operative results and reduced rate of paraplegia.

Aortic Dissection↗
PubMed1995

Malignant transformation of rat embryo fibroblasts by cotransfection with eleven human mutant p53 cDNAs and activated H-ras gene.

Eleven different missense and one nonsense mutant-type p53 cDNAs, which have been frequently detected in human colorectal carcinomas, were constructed and examined for their ability to cooperate with activated human H-ras genes, pSK2 and pHs49, in transfection of rat embryo fibroblasts (REF). Each missense mutant-type p53 cDNA with either of the two activated H-ras genes transformed REF with a different frequency of transformation depending on the different kind of mutation, whereas wild-type p53 (with ras), nonsense mutant-type p53 (with ras), as well as mutant-type p53 (alone) and ras (alone), did not transform REF. Six transformed REF cell lines were established from cotransfection with missense mutant-type p53 cDNA and ras gene; all of them exhibiting exogenous human p53 DNA, RNA, protein, and H-ras DNA and RNA. All six transformed cell lines showed both tumorigenicity and lung metastatic potential in nude mice. They also exhibited 92 kilodalton gelatinase activity, which was not detected in parental REF. These results suggest that missense mutations in p53 gene have a role in malignant transformation as well as metastatic potential.

Animals↗
PubMed1995

Alterations of bone mineral density of the femurs in hemiplegia.

We evaluated the bone mineral density (BMD) of the bilateral femurs in 112 patients with hemiplegia using dual-energy X-ray absorptiometry in order to elucidate the effect of disuse and immobilization. BMD of the paretic side was significantly reduced compared with that of the non-paretic side in hemiplegic patients (femoral neck 0.582 +/- 0.014 g/cm2 versus 0.623 +/- 0.014 g/cm2 and total femur 0.645 +/- 0.02 g/cm2 versus 0.702 +/- 0.017 g/cm2; mean +/- SEM, P < 0.01, respectively). Femoral BMD in both the paretic and nonparetic limb had significantly (P < 0.01) lower values than in age- and sex-matched controls, but the paretic side had a more significant reduction of BMD; femoral neck -20% versus -14% and total femur -24% versus -18%. In addition, patients with impaired activities of daily living (ADL), evaluated by a mobility score, had significantly decreased BMD ratios of paretic/nonparetic side than patients with improved ADL (femoral neck 91% versus 97%, P < 0.01 and total femur 89% versus 94%, P < 0.05). Our results indicated that BMD of both femurs of patients with hemiplegia was reduced, although the paretic side showed a greater BMD decrease. This decrease might be prevented or reduced by improvement of ADL.

Activities of Daily Living↗
PubMed1995

Histologic modification by cryopreservation in rat aortic allografts.

Histologic changes after the cryopreserved rat aortic transplantation were studied, and the influences of the cryopreservation and of the allografting on the histology were examined. Four groups of Brown Norway (RT1n) and Lewis rats (RT1(1)) were used (n = 4 at each examined period in each group): the cryopreservation-allograft group (from Brown Norway to Lewis with cryopreservation), the cryopreservation-isograft group (from Lewis to Lewis with cryopreservation), the fresh allograft group (from Brown Norway to Lewis without cryopreservation), and the fresh isograft group (from Lewis to Lewis without cryopreservation). The graft was harvested from a descending thoracic aorta of a donor rat, implanted to an infrarenal abdominal aorta of a recipient rat, and extracted at 10 days, 1, 3, 6, and 12 months after the operation. The intimal thickening, cellular loss in the media, and cellular infiltration in the adventitia were observed, which were the same phenomena seen in chronic rejection of human organ allografts. Although the degree of intimal thickening and cellular loss in the media were higher in the cryopreserved groups than in the fresh groups, the cryopreservation procedure suppressed cellular infiltration in the adventitia after allotransplantation. The immunologic attack against the graft might be diminished by cryopreservation.

Animals↗
PubMed1995

Recombinant human erythropoietin (rhEPO) administration to marrow donors. Bone Marrow Transplantation (BMT) Team.

Reviewing 37 adult marrow donors, the hemoglobin (Hb) level at 3 weeks before marrow aspiration was predictive for the low Hb level just before the operation. Accordingly, erythropoietin was given to donors whose Hb level was less than 130 milligrams at 3 weeks before operation. One hundred units/kg of recombinant human erythropoietin (rhEPO) was given subcutaneously 3 times a week for 3 weeks. Four donors received rhEPO, and their data were compared with those from four historical controls. The initial average Hb level was 126.3 milligrams in the rhEPO group and 125.3 milligrams in the control group. The preoperative Hb level was 133.0 milligrams in the rhEPO group and 104.0 milligrams in the control group; the postoperative Hb levels were 123.8 and 90.8 milligrams, respectively. Engraftment was obtained in all patients who received the marrow from the donors treated with rhEPO and there was no significant delay in the recovery of white blood cell, reticulocytes and platelet counts. A 3-week regimen of erythropoietin may help prevent the donor's need to receive allogeneic blood transfusion, when the initial Hb levels were below 130 milligrams.

Adolescent↗
PubMed1995

Surgical strategies in managing organ malperfusion as a complication of aortic dissection.

Between December 1978 and March 1994, 48 of 312 patients who underwent surgery for aortic dissection were diagnosed with major vascular complications. There were 18 patients with type A dissection and 30 patients with type B. In 23 patients with acute dissection, the site of vascular obstruction was the abdominal aorta in 12 patients, brachiocephalic artery in 7, iliac artery in 4, left common carotid artery in 3 and thoracic aorta in 2. In 26 patients with chronic dissection, the site of vascular obstruction was the abdominal aorta in 13 patients, brachiocephalic artery in 10, renal artery in 5, iliac artery in 4, superior mesenteric artery in 2, left common carotid artery in 2 and celiac artery in 1. Fifteen patients underwent proximal repair of the aorta during the acute stage, including the ascending aorta in 6 patients, from ascending aorta to arch in 7, arch to descending aorta in 1, thoracoabdominal aorta in 1, and entry closure in 1. In the acute stage, eight patients had palliative surgery, including aortic fenestration in four patients, axillo-femoral bypass in two, cross-over bypass to the iliac or femoral artery in one, bypass to superior mesenteric artery in one, bypass to the renal artery in one, and ileum resection in one. During the chronic phase, seven patients with type B dissection, who had malperfused unilateral renal artery, underwent proximal aortic repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1995

An unruptured aneurysm in the right sinus of Valsalva presenting as coronary insufficiency.

A giant aneurysm in the right sinus of Valsalva compressed the right coronary artery and caused angina pectoris in a 44-year-old man. Surgical correction consisted of obliterating the orifice of the aneurysm with a Dacron patch and relocating the right coronary artery. Postoperative angiography demonstrated excellent results. Pathological study demonstrated the absence of normal elastic fibers in the media of the aneurysm.

Adult↗
PubMed1995

Utilization of triple-lumen balloon catheter for occlusion of the ascending aorta during distal aortic arch surgery with hypothermic retrograde cerebral circulation technique through left thoracotomy.

A technique of using a triple-lumen balloon catheter for occlusion of the ascending aorta in patients with distal aortic arch aneurysm during open proximal anastomosis utilizing hypothermic retrograde cerebral circulation technique through left thoracotomy was described. The balloon greatly facilitated (1) occlusion of the ascending aorta without cross clamping, (2) delivery of cardioplegic solution, (3) suctioning blood pooled in the aortic arch, and (4) prevention of entrance of debris into the left ventricle or coronary arteries.

Aged↗
PubMed1995

[Successful surgical treatment in a case of type IIIb acute aortic dissection complicated with acute myocardial infarction].

The patient was a 48-year-old man who was brought to our hospital complaining of chest pain, paresthesia of the lower extremities, and pain in the lumbar region. At first, acute myocardial infarction was diagnosed, but transthoracic echocardiogram revealed an intimal flap in the ascending aorta. The presence of an intimal tear below the left subclavian artery was confirmed by intraoperative transesophageal echocardiogram, and a diagnosis of myocardial infarction accompanying type IIIb aortic dissection with retrograde extension to the ascending aorta was made. Coronary artery bypass grafting to segment #2 using a section of saphenous vein and total aortic arch replacement with "elephant trunk" technique, which concurrently served as a means of amputated stump plasty, was performed. The cerebral circulation was preserved by retrograde cerebral circulation. The post operative progress was good, and thrombo-occlusion of the false lumens of the proximal descending aorta was verified. Type IIIb aortic dissection complicated with myocardial infarction is rare, but examination with both transthoracic and transesophageal echocardiograms were useful for the morphological diagnosis and for determining the surgical technique for the dissection.

Acute Disease↗