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Biomedical subjects

S Aoyagi

Publications and source records attributed to S Aoyagi.

At least 145 records · Page 8Linked to original sources
PubMed1998

Nonfunctioning islet cell carcinoma--a twenty-one years survival case after distal pancreatectomy.

A case of nonfunctioning islet cell carcinoma was reported. A 40-year-old woman was admitted with epigastralgia. Abdominal angiography and other diagnostic modalities suggested pancreatic malignancy. After distal pancreatectomy, histopathological study revealed her pancreatic tumor to be a nonfunctioning islet cell carcinoma. Fourteen years later, postoperative computed tomographic examination (CT) detected the recurrence of para-aortic lymph node metastases. Five years later, distal gastrectomy was performed to control bleeding from a gastric ulcer. Twenty-one years after the original operation, she died because of underlying metastatic carcinoma. In this case, slow growth and a low grade malignancy were characteristic. Operative removal of the tumor would be the treatment of choice even if metastatic lesions existed.

Adenoma, Islet Cell↗
PubMed1998

Ventricular septal defect of the atrioventricular canal type--report of a surgically treated case.

A 19-month-old male infant with Down syndrome was referred for investigation of heart murmur. An electrocardiogram showed normal axis (+100 degrees) of the QRS complex, incomplete right bundle branch block, and biventricular hypertrophy. Echocardiography revealed a ventricular septal defect (VSD) and a cleft of the anterior mitral leaflet with mild value regurgitation. The anterior mitral leaflet and the septal tricuspid leaflet attached to the same level of the ventricular septum were also delineated, however, no atrial septal defects were detected. Cardiac catheterization demonstrated pulmonary hypertension and a left to right shunt at the right ventricle. During operation, no defects in the atrial septum and no cleft of the septal tricuspid leaflet were found. Cleft of the anterior mitral leaflet, continuity between the mitral anterior leaflet and the tricuspid septal leaflet, and a VSD of the atrioventricular canal type were confirmed. The cleft of the anterior mitral leaflet and the VSD were repaired with the aid of cardiopulmonary bypass. The patient recovered uneventfully.

Electrocardiography↗
PubMed1998

Valve surgery in elderly patients 70 years or older: early and late results.

Between April 1986 and March 1997, 75 patients (Group E) who were 70 years or older underwent valvular operations, and another 73 patients who were under 70 years constituted a comparison group (Group Y). Valve replacement was performed on 131 patients (Group E; 65 patients, Group Y; 66 patients), reparative procedures on 11 patients (Group E; 7, Group Y; 4), and aortic root replacement on 5 (Group E; 3, Group Y; 2). Coronary artery bypass grafting was concomitantly performed on 13 patients (Group E; 7, Group Y; 6). In the elderly patients, preoperative clinical status, including cardiac and non cardiac organ functions, was not necessarily more severe than that in the younger patients, however, perioperative restoration of cardiac and pulmonary functions required a longer time in Group E than Group Y. There were no significant differences in operative mortality rate, long-term survival rate, the probability of freedom from all events related to native and prosthetic valves, and in activity of daily life between Group E and Group Y. These results suggest that valvular operation for elderly patients 70 years or older may be safely performed with operative risks similar to those of younger patients by application of modern surgical techniques.

Aged↗
PubMed1998

Safety management of a patient undergoing thoracic aortic surgery by spinal evoked potential monitoring.

We have presented a patient (48 year-old male) in whom the evoked spinal potential monitor detected impending spinal ischemia after aortic cross-clamping, which allowed surgical intervention to be modified so as to restore the decaying evoked spinal potential. The patient received replacement of the dissecting aneurysm in the thoracic descending aorta with clamping of the aorta at the sites immediately proximal and distal to the aneurysm and initiation of femoro-femoral venoarterial bypass under normothermia. The evoked spinal potential was recorded via the T12/L1 epidural electrode in response to transdural electric stimulation of the spinal cord at the C7/T1 level. As the evoked spinal potential gradually decreased in amplitude without latency prolongation after aortic cross-clamping, the distal clamp was moved from the T6 vertebral level to the T4. The reduced spinal potential then returned to the baseline amplitude. This episode was repeated twice from surgical necessity. The patient was free from any neurological disorders postoperatively.

Aortic Dissection↗
PubMed1998

Prosthetic valve thrombosis after abdominal surgical procedures: a case report.

A 63-year-old woman with a prosthetic mitral valve who developed valve thrombosis after abdominal surgical procedures is reported. She had undergone mitral valve replacement with a Sorin-Bicarbon valve 3 years previously, and was referred for an operation due to rectal cancer with anal bleeding. On admission, the patient was on oral anticoagulant therapy with warfarin, and the intensity of anticoagulation was around 40% of Thrombotest. Doppler echocardiography showed that the prosthetic mitral valve function was normal. Low anterior resection of the rectum was uneventful. Management of the perioperative anticoagulation was peformed with heparin, however, the postoperative anticoagulation using intravenous infusion of heparin was imperfectly achieved. Consequently, thrombosis of the prosthetic mitral valve occurred 8 days after the operation. Replacement of the thrombosed prosthetic valve was performed with successful results. The imperfect postoperative anticoagulation with heparin may have been the cause of the valve thrombosis. The management of perioperative anticoagulation during noncardiac operations is discussed.

Abdomen↗
PubMed1998

[Surgical treatment of an aortic arch aneurysm: reports of 2 cases with lesion of the arch vessels].

A 48-year old woman underwent surgery for an aortic arch aneurysm with stenosis or dilatation of three arch vessels caused by aortitis syndrome. Total arch replacement and reconstruction of three arch vessels were performed with hypothermic selective cerebral perfusion (SCP). To avoid atheroembolism and malperfusion to the brain, the rt. common carotid artery was perfused via the rt. subclavian artery through the dacron vascular graft and the lt. subclavian artery was cannulated and perfused distally to stenosis. A 65-year-old man who had an atherosclerotic aortic arch aneurysm with severe stenosis of the brachiocephalic artery underwent operation. In the operation, extracorporeal circulation was instituted with the arterial return through the lt. subclavian artery. Same as case 1, total arch replacement and reconstruction of three arch vessels were performed under hypthermic SCP. In this case, the left common carotid artery was transected and cannulated directly into the vessel, instead of cannulation through the aortic lumen because of atheromatous plaques in the orifice of the left common carotid artery. The patients recovered uneventfully and doing well now.

Aged↗
PubMed1997

Coronary artery revascularization concomitant with vascular surgery.

Patients with vascular disease and coronary disease are usually treated initially by coronary artery bypass grafting (CABG), and vascular surgery is generally performed later. In this study we assessed the feasibility of combined CABG and vascular surgery in a single operation. Between 1988 and 1995, 16 patients received combined operations for vascular and cardiac lesions and the clinical results were assessed. There were no operative or hospital deaths. The mean time for operation was 421 min and the duration of the stay in the intensive care unit (ICU) was a mean of 3.6 days. In one patient with an ischemic left leg, the left internal thoracic artery (ITA) had become a collateral source of the ischemic leg, and the need for preoperative angiography of the ITA in such patients was indicated. The combined operation clearly takes longer than either vascular surgery or CABG alone, but the length of the postoperative intensive care unit stay was essentially the same as that after a single operation and the patient was still managed safely after the combined operation. In patient requiring both operations, the combined procedure therefore appears to be safe and to have a good clinical outcome.

Aged↗
PubMed1997

Operation for type B aortic dissection using hypothermic selective cerebral perfusion.

A 56-year-old man who had a huge type B dissecting aortic aneurysm extending from the distal arch to the thoracoabdominal aorta underwent replacement of the descending thoracic and thoracoabdominal aorta under hypothermic circulatory arrest with selective cerebral perfusion. The intercostal arteries at the T-8 to T-11 level were preserved with beveled distal anastomosis, and the celiac artery and the intercostal arteries at the T-5 and T-6 levels were reconstructed. The patient recovered uneventfully and is presently doing well 1 year after the operation.

Aortic Dissection↗
PubMed1997

Effects of minimal-dose aprotinin on coronary artery bypass grafting.

OBJECTIVE: To evaluate the effects of minimal-dose aprotinin in patients undergoing coronary artery bypass grafting, we conducted a prospective randomized study. METHODS: A total of 167 patients were randomized to receive no aprotinin treatment (control, n = 57), minimal-dose aprotinin (1.0 x 10(6) KIU; n = 55), or low-dose aprotinin (2.7 +/- 0.5 x 10(6) KIU; n = 55). Blood loss and transfusion requirements, parameters of clotting and fibrinolysis, renal function, and early graft patency rates were assessed. RESULTS: Postoperative blood loss and transfusion requirements were significantly (p = 0.01) lower in both the minimal-dose and low-dose groups than in the control group. The increase in D-dimer level after cardiopulmonary bypass was significantly (p < 0.05) less marked in the low-dose group than in the control group. The alpha 2-plasmin inhibitor and plasminogen activator inhibitor-1 levels were significantly (p < 0.05) greater in the minimal-dose and low-dose groups than in the control group after bypass, suggesting the prevention of fibrinolysis by both aprotinin doses. No statistically significant differences in postoperative renal function and early vein graft patency rates were noted (control group, 93.8%; minimal-dose group, 95.5%; low-dose group, 92.3%; p = 0.25). CONCLUSIONS: Aprotinin was not associated with a significant increase in the prevalence of renal dysfunction or early vein graft occlusion. Minimal-dose aprotinin inhibited enhanced fibrinolytic activity and reduced blood loss and transfusion requirements after bypass equivalently to low-dose aprotinin. The dose of 1 x 10(6) KIU added to the pump prime may be acceptably effective in reducing blood loss in patients undergoing primary coronary operations.

Aprotinin↗
PubMed1997

Aneurysm of aberrant right subclavian [corrected] artery arising from diverticulum of Kommerell. Report of a case with tracheal compression.

A 74-year-old woman presented with severe dyspnea without dysphagia. Computed tomographic scans and Digital subtraction angiography revealed the left aortic arch with an aberrant right subclavian artery arising from the Kommerell's diverticulum and tracheal compression. The aortic arch and the Kommerell's diverticulum were aneurysmal and were responsible for this compression. Surgical relief was accomplished by replacement of the aortic arch and reconstruction of the four brachiocephalic vessels with vascular prostheses through a median sternotomy incision extending into the right supraclavicular region.

Aged↗
PubMed1997

Coronary artery revascularization in an adult with coronary aneurysms probably secondary to childhood Kawasaki disease.

Kawasaki disease is an acute febrile illness affecting mainly infants and children. The fatal complication of Kawasaki disease is coronary involvement pertaining to coronary artery aneurysms. Surgical experience of adults that had childhood Kawasaki disease with coronary lesion has been rarely reported. We experienced coronary artery bypass grafting in a 44 year old man with no risk factors for atherosclerosis but with coronary lesions possibly secondary to Kawasaki disease. Coronary artery sequelae of Kawasaki disease may become part of a cause of coronary disease in young adults and we should recognize this condition in such patients with coronary disease but no coronary risk factors.

Adult↗
PubMed1997

Hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve.

The hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve (HP) for a small aortic annulus was compared to that of the standard St. Jude Medical valve (SJM). Doppler echocardiographic parameters were evaluated in patients undergoing aortic valve replacement with either a 19 mm HP (HP19, n = 7), a 21 mm HP (HP21, n = 8), a 19 mm SJM (SJM19, n = 16), or a 21 mm SJM (SJM21, n = 34). The peak and mean pressure gradients and peak flow velocity were significantly (p < 0.05) lower in both patients with the HP21 and those with the HP19 than patients with the SJM21 and those with the SJM19, respectively. The echocardiographic parameters of the patients with the HP19 corresponded closely to those of patients with the SJM21. The left ventricular mass index regressed markedly in patients with the HP19 during the late postoperative period. The results suggested that the hemodynamic performances of certain sizes of the HP were superior to those of the same size SJMs and were considered to be equivalent to those of the next size larger SJM.

Adolescent↗
PubMed1997

Distribution and neuropeptide content of nitric oxide synthase-containing nerve fibers in arteries and conduction system of the rat heart.

The rat heart receives its blood supply not only from the coronary arteries but also from the accessory coronary arteries that supply mainly the atria. The distribution and chemical nature of nitric oxide synthase-containing nerve fibers in the conduction system as well as the coronary and accessory coronary arteries were investigated using immunohistochemistry and NADPH diaphorase (NADPH-d) histochemistry. A few NADPH-d-positive nerve fibers were observed mainly around the main trunk of the coronary arteries, while NADPH-d-positive fibers were found along the entire course of the accessory coronary arteries from their main branches to the arteriolar level. A double-staining method demonstrated that NADPH-d-positive fibers innervating both the coronary and accessory coronary arteries contained vasoactive intestinal polypeptide or neuropeptide Y. NADPH-d-positive fibers were relatively abundant in the sinus node and penetrating bundle but were very sparse in the atrioventricular node and right bundle branch. No NADPH-d-positive fibers were detected in the left bundle branch. Some of the NADPH-d-positive fibers innervating the penetrating bundle exhibited distinct immunoreactivity to calcitonin gene-related peptide. These results suggest that nitric oxide may play a role as a neurotransmitter and/or neuromodulator in the neural control of the cardiac blood flow and impulse conduction.

Animals↗
PubMed1997

Aortic root replacement for annuloaortic ectasia in Shprintzen-Goldberg syndrome: a case report.

Annuloaortic ectasia due to Shprintzen-Goldberg syndrome (SGS) is reported. A 10-year-old boy was admitted to our hospital for evaluation of chest pain. On admission, he was diagnosed as SGS on the basis of his various anomalies. Two-dimensional echocardiography showed a bicuspid aortic valve and marked annular dilatation, Doppler flow studies revealed severe aortic regurgitation, and retrograde aortography showed severe aortic regurgitation with annular dilatation. Successful aortic root replacement was performed; subsequent histologic examination of the ascending aorta demonstrated cystic medial necrosis. In conclusion, SGS is a generalized connective tissue dysplasia, with clinical manifestations of cardiovascular lesions similar to those in Marfan syndrome. Aortic root replacement was successfully performed; however, recurrence of aortic aneurysms outside of the ascending aorta should be carefully observed. Surgical treatment for cardiovascular disorders may be necessary to save the life of patients with SGS.

Abnormalities, Multiple↗
PubMed1997

Cineradiographic evaluation of ATS open pivot bileaflet valves.

BACKGROUND AND AIMS OF THE STUDY: Echocardiography and cineradiography are both valuable for the evaluation of prosthetic valve function, especially of mechanical valves. Although Doppler echocardiography data are available for the recently developed ATS valve, cineradiographic evaluation of leaflet movement of the valve has not been performed. MATERIALS AND METHODS: Five patients received aortic and another five mitral valve replacement with the open pivot ATS bileaflet prosthetic valve. There were three men and seven women; mean patient age was 58.8 years. Cineradiographic and Doppler echocardiographic evaluations of the ATS valve were performed early after surgery in all 10 patients. RESULTS: There were no early deaths after surgery or after discharge from the hospital. No valve-related complications were seen, and no clinical symptoms or signs of prosthetic malfunction were observed during the follow up period. Doppler-derived values of the ATS valve were comparable with those previously reported; however, cineradiography of the valve demonstrated that the mean angle enclosed by the two open leaflets was 37.6 degrees (range: 34 degrees to 44 degrees) in the aortic position and 29.7 degrees (range: 20 degrees to 35 degrees) in the mitral position. Mean leaflet mobility was 93.0 degrees (range: 86 degrees to 96 degrees) in the aortic position and 100.0 degrees (range: 92 degrees to 110 degrees) in the mitral position. Thus, the opening of the normally functioning ATS valves in vivo was less than that observed in vitro and reported by the manufacturer. CONCLUSIONS: These results suggest that unevenly distributed blood flows with different velocities through the two side orifices and the central orifice may result in incomplete opening of the ATS leaflets, which respond with great sensitivity to localized blood flow. Our findings appear to be important to avoid the removal of a normally functioning ATS valve only because the leaflet opening appears to be 'restricted'.

Adult↗
PubMed1997

[Combined superior-transseptal approach to left atrial myxoma].

A 60-year-old woman was referred to our hospital for treatment of an intracardiac tumor Echocardiography revealed a 47 x 30 mm tumor in the left atrium which had a short stalk attached to the atrial septum. At operation, a large left atrial myxoma was extirpated using a combine superior transseptal approach. Through this incision, exposure of the left atrial myxoma and it stalk was excellent and removal of the myxoma was easily performed with minimal minpulation. Postoperative arrhythmias related to the operative procedures were not observed. The patient recovered uneventfully. The operative technique and indications of the combined superior transseptal approach to the left atrium are discussed in this paper.

Cardiac Surgical Procedures↗