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Biomedical subjects

S Takamoto

Publications and source records attributed to S Takamoto.

At least 127 records · Page 7Linked to original sources
PubMed1998

A surgical case of acute three-channeled aortic dissection in Marfan syndrome.

We surgically treated a 35-year-old male with acute 3-channeled aortic dissection in Marfan syndrome. He had acute type A aortic dissection, and underwent Bentall's type operation, simultaneous graft replacement of the ascending aorta and total aortic arch. Pain recurred 5 years and 9 months after the first operation. CT scan showed two adjacent false lumens in the descending aorta. The morphology of the first and second dissections was Stanford type A + B. The second dissection was acute. In the second false lumen, a re-entry formation was observed in the abdominal aorta. Because severe pain was persistent, we immediately replaced the descending aorta using a femoro-femoral partial cardiopulmonary bypass. The patient was doing well and was discharged. When pain recurs in a Marfan patient with an aortic dissection, a 3-channeled aortic dissection should be suspected, and we recommend emergency surgery.

Adult↗
PubMed1998

Surgery for aortic dissection associated with congenital bicuspid aortic valve.

Congenital bicuspid aortic valve is a relatively rare malformation. It is reported that the presence of this anomaly predisposes the patient to the development of dissecting aortic aneurysms. Between 1981 and October 1997, 7 patients with aortic dissection associated with congenital bicuspid aortic valve underwent surgical treatment at our institution. The patients consisted of six males and one female. The age of the patients ranged from 54 to 74 years (mean 61 years). The classification of dissecting aortic aneurysms was DeBakey type I dissection in 4 patients, type II dissection in 2 patients and type IIIb dissection in 1 patient. These 7 patients constituted 2.0% (7/356) of all cases of surgical operation for dissecting thoracic aneurysm. Aortic valve dysfunction was noted in 5 patients, 4 of whom had previously undergone aortic valve replacement. We performed graft replacement of the ascending aorta in 4 patients, graft replacement of the ascending aorta and aortic arch in 2 patients, and graft replacement of the descending aorta in 1 patient. There were no hospital deaths in any of the 7 patients. Pathological examination of surgical specimens of the aortic wall showed cystic medial necrosis in 2 patients and mucoid degeneration in 4 patients. In addition to complication by valve dysfunction, patients with congenital bicuspid aortic valve are at risk for the development of aortic dissection.

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PubMed1998

[Video-assisted MICABG for the patient with right mammary carcinoma--a case report].

A 69-year-old female with advanced right mammary carcinoma presented to us with diffuse stenosis of the proxymal left anterior descending artery (LAD). Right mastectomy had been suspended. The LAD was treated with minimally invasive CABG (MICABG) assisted with a thoracoscopic procedure. The left internal thoracic artery (LITA) was taken down through thoracoscopy from the upper margin of the 1st rib to the lower margin of the 5th rib using only the Harmonic Scalpel (Ethicon Endo-Surgery). Coronary anastomosis to the LAD was completed without cardiopulmonary bypass through a small thoracotomy on the anterior 4th intercostal space. The operation time was 4 h 30 min and the blood loss was 120 ml. Post operative course was uneventful. Doppler study and angiography demonstrated patent LITA to the LAD. Right mastectomy was achieved 29 days after MICABG. MICABG can be a veneficial alternative method for the patient with malignant disease, allowing quick convalescence and early cancer operation. Thoracoscopy allows for sufficient LITA harvest up to the 1st rib or higher with the Harmonic Scalpel.

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PubMed1998

[Mid-term evaluation of cryopreserved aortic allograft].

Recently aortic root replacement and free-hand aortic valve replacement with cryopreserved allograft are accepted and established as useful procedures in USA and Europe. Otherwise allograft aortic valve failure due to structural valve degeneration, progressive loss of leaflet extensibility or progressive aortic root dilatation are reported. Aortic root replacement and free-hand aortic valve replacement with cryopreserved allograft were performed on three patients in the Department of Cardiovascular Surgery, NCVC between March of 1992 and March of 1994. We evaluated the mid-term function of implanted allograft. Case 1, 2, 58-year-old male and 42-year-old male with aortic regurgitation due to Aortitis had modified Bentall procedures with composite graft and had redo surgery for aortic regurgitation due to graft detachment with cryopreserved allograft using "aortic root replacement". Case 3: 54-year-old male received a cryopreserved allograft for aortic stenosis/regurgitation using "free-hand technique". Postoperative echocardiogram showed excellent valve function without regurgitation any calcification in all cases. However chest computed tomography suggested the new calcification of allograft wall at 15 months after operation in Case 1 who was administered steroid agents, despite no calcification in Case 2 during 17 months follow-up.

Adult↗
PubMed1998

Atrial ablation with an IRK-151 infrared coagulator.

BACKGROUND: The purpose of this study was to develop a method of atrial ablation. In the IRK-151 infrared coagulator, light from a tungsten-halogen lamp is focused into a quartz rod. The distal exit plane is connected to a tip made of sapphire to allow linear ablation. METHODS: Thirty-six lesions were created in 9 mongrel dogs. The beating ventricular myocardium was ablated from the epicardium. In each dog, 4 lesions were created by using the following durations of application: 3, 9, 15, and 21 seconds. After the ablation, the myocardium was fixed and stained. A linear lesion on the beating right atrial free wall was created. Before and after the ablation, epicardial plaque-electrode mapping was performed. Three months after ablation, remapping was performed. RESULTS: The ablated myocardium had well-demarcated necrosis without carbonization or vaporization. The maximum depth was 10.3 +/- 0.8 mm. The conducting pathway was blocked. The block, once made, continued for 3 months. CONCLUSIONS: The IRK-151 produces well-demarcated lesions that were deep enough for atrial ablation to block the conducting pathway.

Aluminum Silicates↗
PubMed1998

Elephant trunk procedure for surgical treatment of aortic dissection.

BACKGROUND: In surgical intervention for aortic dissection, a highly radical operation can be performed by distal anastomosis with a true lumen resulting in thrombotic closure of the dissecting lumen. In this anastomosis, the elephant trunk procedure, in which a graft is inserted into the distal true lumen, prevents blood flow leakage into the dissecting lumen at the anastomosis site and also strengthens this area. METHODS: We performed this procedure in 15 patients (8 men and 7 women). Acute aortic dissection was observed in 9 patients and chronic dissection in 6. Stanford type A dissection was diagnosed in 10 patients and type B in 5. RESULTS: Graft replacement of the ascending aorta and total aortic arch was performed in 10 patients and descending aortic replacement in 5. A graft with a diameter of 16 to 24 mm was inserted into the true lumen of the descending aorta, and the false lumen was closed. Subsequently, distal anastomosis was performed on the true lumen. There were two hospital deaths. Postoperative digital subtraction angiography showed good results in living patients, and computed tomographic scanning showed thrombotic closure in the dissecting lumen of the descending aorta. CONCLUSIONS: The elephant trunk procedure is useful for closing the false lumen of the distal aorta.

Acute Disease↗
PubMed1998

Operation for chronic pulmonary thromboembolism accompanied by thrombophilia in 8 patients.

BACKGROUND: Medical therapy for chronic pulmonary thromboembolism is limited, and surgical treatment has become more frequent recently. We have performed pulmonary thromboendarterectomy on 8 patients with chronic pulmonary thromboembolism accompanied by thrombophilia. METHODS: The patients were 6 men and 2 women aged 21 to 56 years (mean, 35 years). Five patients had antiphospholipid syndrome, 2 had protein C deficiency, and 1 had congenital antithrombin III deficiency. The preoperative condition was New York Heart Association functional class III in 5 and class IV in 3. Hypoxemia, marked pulmonary hypertension (mean pulmonary artery pressure, 47+/-6.7 mm Hg), and low cardiac output were observed in all patients. After a median sternotomy, deep hypothermia was induced using a cardiopulmonary bypass, and pulmonary thromboendarterectomy in the bilateral pulmonary arteries was performed under intermittent circulatory arrest. RESULTS: There were no operative deaths. Long-term respiratory management was needed postoperatively by 3 patients. In the remaining 5 patients, no reperfusion injury was observed. The arterial blood oxygen concentration improved, and the mean pulmonary pressure decreased to 16+/-5.5 mm Hg. The cardiac output also increased, and New York Heart Association functional class improved to I in 4 and II in 4 patients. CONCLUSION: Pulmonary thromboendarterectomy under deep hypothermic intermittent circulatory arrest was effective for chronic pulmonary thromboembolism accompanied by thrombophilia for which medical treatment is of limited value.

Adult↗
PubMed1998

Mortality and cerebral outcome in patients who underwent aortic arch operations using deep hypothermic circulatory arrest with retrograde cerebral perfusion: no relation of early death, stroke, and delirium to the duration of circulatory arrest.

OBJECTIVE: Our goal was to investigate factors for mortality and cerebral outcome in patients with aneurysm of the aortic arch. METHODS: From 1993 to 1996, 148 patients with aortic arch aneurysm underwent operations involving deep hypothermic circulatory arrest with retrograde cerebral perfusion. Age was 63.9 +/- 11.6 years (mean +/- standard deviation) and 52 patients were older than 70 years. Twenty-eight had acute aortic dissection. Twelve had ruptured aneurysms. Fourteen had redo operations. Seventy had aortic dissection. The aneurysms were caused by atherosclerosis in 123 patients and by other causes in 25. Median sternotomy was used in 92 and left thoracotomy in 56. Twenty-eight patients underwent replacement of the ascending aorta to the proximal arch, 62 had total arch replacement, 38 had distal arch replacement, 12 had simultaneous replacement of the distal arch and the descending aorta or thoracoabdominal aorta, and 8 had patch repair. RESULTS: Fifteen (10.1%) early deaths occurred. New stroke occurred in six (4.0%) patients and transient delirium in 37 (25.0%). The duration of deep hypothermic circulatory arrest plus retrograde cerebral perfusion was 49 +/- 17 minutes, and it was more than 60 minutes in 36 patients. Patients awoke 7.5 +/- 8.2 hours after the operation. Logistic regression analysis demonstrated that risk factors for mortality were ruptured aneurysm, chronic obstructive pulmonary disease, arterial cannulation in the ascending aorta, and stroke. Risks for stroke were ruptured aneurysm and replacement of the distal arch. Risks for delirium were age older than 70 years and atherosclerotic aneurysm. Duration of circulatory arrest plus cerebral perfusion did not correlate with length of time before the patient regained consciousness. No difference was found in mortality, stroke, and delirium between patients with and those without more than 60 minutes of circulatory arrest and cerebral perfusion. CONCLUSION: Prolonged (> 60 minutes) deep hypothermic circulatory arrest with retrograde cerebral perfusion was not a risk factor for mortality and stroke in patients who underwent surgery for aneurysms of the aortic arch. However, the prevalence of transient delirium necessitates further investigations.

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