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Biomedical subjects

T Sueda

Publications and source records attributed to T Sueda.

At least 73 records · Page 4Linked to original sources
PubMed1999

Endovascular stent-grafting via the aortic arch for distal arch aneurysm: An alternative of endovascular stent-grafting in a complicated case.

A 67-year-old man with severe discomfort was diagnosed with a rupture of the thoraco-abdominal aneurysm, a distal arch aneurysm and triple coronary artery disease. After emergency surgery for a thoracoabdominal aneurysm, a scheduled surgery for coronary artery bypass grafting and endoluminal stent-grafting for the distal arch aneurysm was performed simultaneously. A stent-graft was introduced into the descending aorta via a small incision on the arch aorta. Open endovascular stent-grafting via the arch aorta is an alternative for repairing a distal arch aneurysm with coronary artery bypass grafting.

Aged↗
PubMed1999

Protective effects of pretreatment with ginsenosides on cardiac and coronary vascular function after hypothermic rat heart preservation.

Prevention of cardiac and vascular dysfunction with pretreatment has been accepted as an important factor in heart transplantation. Ginsenosides (GS) have been reported to have some beneficial effects on the cardiac and vascular system. We hypothesized that pretreatment with GS would result in an improvement of functional recovery after a 12 hour (hr) rat heart preservation. A Langendorff apparatus was applied to estimate the cardiac and vascular function in an isolated rat heart preparation. The hearts were preserved in University of Wisconsin solution at 0 degree C for 12 hr, after pretreatment with 0.9% sodium chloride or GS 100 mg/kg, respectively, in control (n = 9) and GS (n = 14) groups. After storage, the cardiac function, myocardial water content, and coronary vasodilatory response were evaluated. The GS group showed a significantly higher recovery percentage of cardiac function compared with the control group: aortic flow 81.4 +/- 21.4% versus 57.2 +/- 11.0% (p = 0.0052); coronary flow 81.4 +/- 14.5% versus 57.2 +/- 6.0% (p = 0.0001); +/- dp/dt max 72.5 +/- 16.1% and 66.0 +/- 16.1% versus 53.7 +/- 4.1% and 51.4 +/- 7.1% (p = 0.0027 and p = 0.0189) respectively. The GS group showed a lower increase in myocardial water content. With Langendorff perfusion, the endothelial and vascular smooth-muscle cell function were evaluated by an increasing percentage of coronary flow in response to acetylcholine chloride (0.3 x 10(-7) mol/liter) and nitroglycerin (0.5 x 10(-5) mol/liter). It was significantly higher in the GS group than that in the control group (19.2 +/- 8.8% and 28.0 +/- 14.1% versus 9.9 +/- 4.7% and 14.7 +/- 8.1%, p = 0.008 and p = 0.0187, respectively) at the first minute. These results suggest a protective effect on ventricular and coronary vascular function in the rats pretreated with Ginsenosides, indicating potential benefits for long-term heart preservation.

Animals↗
PubMed1999

Effect of FC43se on endotoxin-induced disseminated intravascular coagulation in rats.

Perfluorotributylamine/Pluronic F68 Stem-Emulsion (FC43se), which is a blood substitute, was assessed for its effectiveness on disseminated intravascular coagulation (DIC) in the rat model. Rats were infused intravenously with 2.5 mg/kg of Escherichia coli lipopolysaccharide (Escherichia coli 055:B5 lipopolysaccharide B) for four hours. At the same time, FC43se or normal physiological saline was infused at 2.5 ml/kg/hr. The white blood cell and platelet counts, prothrombin time (PT), activated partial thromboplastin time (APTT), and the plasma levels of interleukin-1 beta (IL-1 beta), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor alpha (TNF alpha) were determined at 4 hr. The infusion of FC43se markedly prevented a decrease in platelet counts (p = 0.0004) and a prolongation of both PT and APTT (p < 0.05 and p < 0.03 each). The serum level of IL-1 beta and IL-4 showed no significant change. The serum level of IL-6, IL-10 and TNF alpha increased significantly (p = 0.0007, p = 0.0004 and p < 0.05 each) with infusion of FC43se in rats treated with bacterial endotoxin. FC43se has beneficial effects on endotoxin-induced DIC as an anticoagulant and anti-inflammatory cytokine induced agent.

Animals↗
PubMed1999

Open stent-graft repair for acute type A aortic dissection with an intimal tear in the descending aorta.

A 47-year-old man with acute retrograde aortic dissection (Stanford type A) was treated with total aortic arch replacement and endoluminal stent-grafting for an intimal tear in the descending aorta. A stent-graft was introduced into the descending aorta via the transected arch aorta and the entry of the dissecting aneurysm was closed. Open endovascular stent-grafting via the arch aorta is an alternative for repair of acute type A aortic dissection with an intimal tear in the descending aorta, in cases where direct closure of the intimal tear is difficult.

Aortic Dissection↗
PubMed1999

Evoked spinal cord potential monitoring reveals peroneal nerve ischemia during thoracoabdominal repair: a case report.

An 82-year-old man underwent thoracoabdominal aortic replacement under cardiopulmonary bypass with left femoral artery cannulation. Lumber descending evoked spinal cord potentials and segmental evoked spinal cord potentials were monitored simultaneously for detecting spinal cord damage. When the cardiopulmonary bypass was terminated, a peripheral nerve ischemia pattern was evident. Left peroneal nerve paralysis was present at emergence from anesthesia. This monitoring system revealed that peroneal nerve paralysis can occur due to leg ischemia caused by femoral artery cannulation. This is, to our knowledge, the first report that segmental evoked spinal cord potential monitoring reveals peroneal nerve ischemia during thoracoabdominal surgery.

Aged↗
PubMed1999

A new suture technique for reconstruction of intercostal arteries during thoracoabdominal aortic aneurysmal surgery.

Reconstruction of several intercostal arteries is inevitable in surgical treatment of thoraco-abdominal aortic aneurysm. A Dacron inverted-Y shaped graft was fashioned by cutting one of two graft legs and making an elliptical patch, like a cobra-head. Once the elliptical patch was sutured to the orifices of the intercostal arteries (usually from T9 to T12) with running sutures, selective intercostal arterial perfusion was initiated. After completion of aneurysmectomy, the distal end of the elliptical patch graft was sutured to the main tube graft. This method is easier and faster and results in a decreased incidence of spinal cord injury.

Aortic Aneurysm, Abdominal↗
PubMed1998

Occlusive effects of lactic acid-glycolic acid copolymer membrane on gingival fibroblasts in vitro.

The cell occlusive effects on human gingival fibroblasts of degradable lactic acid-glycolic acid copolymer membranes (noncoated membranes) and membranes coated with a sucrose ester of fatty acid (coated membranes) were studied and compared with those of expanded polytetrafluoroethylene (e-PTFE) membranes. The membranes were immersed in a culture medium periodically for 21 days and interposed into a chemotaxis chamber, and the fibroblasts then were cultured in the chamber for another 7 days. The passage rate of cells through the membranes was calculated and the change in surface structure of each membrane after immersion for 28 days was observed by an environmental scanning electron microscope. The passage rate of coated membranes (3.4+/-2.2%) was significantly lower than that of noncoated (25.7+/-5.1%) at the 28th day whereas the passage rate of e-PTFE membranes was 0.8-1.5%. Many pores were observed on the noncoated membranes before immersion while the coating material covered most of the pores on the coated membranes. The average pore size of the noncoated membranes was larger than that of the coated membranes at day 28. The structure of the e-PTFE membranes underwent no change. The passage rate of the coated membranes was not different from the e-PTFE membranes, suggesting an effect that might be useful for a guided tissue regeneration procedure.

Fibroblasts↗
PubMed1998

Ergonovine-induced alterations in coronary flow velocity preceding onset of occlusive spasm in patients without significant coronary artery stenoses.

This study examined serial changes in coronary flow velocity to elucidate the dynamic change of coronary circulation during coronary spasm. Twenty patients with variant angina and 27 control patients were studied. Coronary flow velocity was monitored using a Doppler guidewire following intracoronary ergonovine administration. In the control group, diastolic flow velocity either did not change or increased slightly in response to ergonovine. However, in patients with variant angina, 2 patterns of flow velocity alterations were observed. In the first pattern, flow initially increased and then suddenly decreased (16 of 20 patients). In the second pattern, flow gradually decreased (3 of 20 patients). In the remaining patient, the coronary flow alteration could not be detected because of branch spasm. When abnormally high flow velocity was defined as a 100% increase in flow after ergonovine administration within 1 minute, and abnormally low flow velocity was defined as a 50% decrease in flow to diagnose variant angina, sensitivities of 35%, 75%, and 85% were noted if flow was measured 1.0, 2.0, and 3.0 minutes after ergonovine administration, respectively. These abnormal flow velocities were observed before ischemic ST changes appeared. In conclusion, in patients with variant angina, characteristic serial changes in coronary flow velocity occur before occlusive spasm. Variant angina may be diagnosed earlier by monitoring flow velocity rather than by monitoring for ischemic electrocardiographic changes.

Aged↗
PubMed1998

Combined coronary artery bypass, mitral valve plasty, and abdominal aneurysmectomy in an 80-year-old patient: report of a case.

An 80-year-old man suffering from angina on exertion due to stenosis of the left main coronary artery, heart failure due to mitral valve regurgitation, and an abdominal aortic aneurysm (AAA) was successfully operated on with simultaneous surgical procedures. A coronary cineangiography revealed 90% stenosis of the left main coronary artery in segment 5, and 99% and 90% stenosis in segments 2 and 4AV, respectively, of the right coronary artery. Left ventriculography and aortography showed moderate mitral valve regurgitation and the presence of a fusiform-shaped AAA with a maximum diameter of 6 cm. It was thought that insertion of an intraaortic balloon pump (IABP) would prove difficult due to AAA; therefore, simultaneous surgery combining triple coronary artery bypass grafting (CABG), mitral valve plasty, and prosthetic replacement of the AAA was undertaken. The patient's postoperative course was uneventful, and subsequent angiography showed good patency of all coronary bypass grafts and the abdominal prosthesis, along with the disappearance of mitral regurgitation. This patient's clinical course suggests that an extended surgical procedure is effective for the treatment of complicated cardiovascular disease, even in very elderly patients.

Aged↗
PubMed1998

[Left atrial isolation for chronic atrial fibrillation associated with aortic arch dissection and aortic valve disease in a 70-year-old man].

A 70-year-old male with aortic regurgitation, chronic atrial fibrillation (Af) and chronic aortic dissection of the aortic arch was treated simultaneously. We found a limited dissection in front of aortic arch during operation. We performed total arch replacement using a branched prosthesis and aortic valve replacement in addition to a modified left atrial isolation for chronic Af under the aid of extracorporeal circulation, and selective cerebral perfusion. Left atrial isolation is a simpler procedure than maze procedure and left side maze procedure for eliminating Af. This simple procedure makes possible a simultaneous extended operation for complicated aortic and cardiac disease even in an elderly patient.

Aged↗
PubMed1998

An aortic balloon catheter incorporating a conduit for percutaneous cardiopulmonary support.

Circulatory support using both intraaortic balloon pumping (IABP) and percutaneous cardiopulmonary support (PCPS) can improve general hemodynamics; however, sometimes brain damage occurs caused by hypoperfusion. Such cerebral hypoperfusion is likely to be caused by PCPS when applying the conventional femoral cannulation. We have developed a new IABP catheter which incorporates a conduit for PCPS with an outlet at the catheter tip, the goal of which is the improvement of cerebral perfusion. The hemodynamic characteristics of this new IABP catheter were compared with those of the conventional combination of IABP and PCPS. Studies were performed by mock test using a pulsatile artificial heart. A polyvinyl chloride tube acted as the aorta with 2 branches at the proximal and distal portions representing the upper and lower portions of the body. The IABP balloon was positioned between the 2 branches, and changes in flow at the 2 branches were examined at varying PCPS flow rates. Flow in the proximal branch using the new device was greater than it was using the conventional PCPS device. We conclude that cerebral perfusion could be improved with the use of this new special IABP catheter.

Angioplasty, Balloon, Coronary↗
PubMed1998

Study of left ventricular bypass using Wankel type semipulsatile blood pump.

The influence of the Wankel type semipulsatile left ventricular assistance on hemodynamics was investigated with a computer simulation and an animal experiment. A simulation circuit was constructed to express the circulatory system. A current source was added to create a semipulsatile blood pump. The left and right ventricles were replaced by variable compliances. Left heart failure was simulated by decreasing the amount of compliance change of the left ventricle. Under the condition of heart failure when semipulsatile assist flow increased, the mean aortic pressure (AoP), tension time index (TTI), and diastolic pressure time index (DPTI) increased, and the cardiac output, pulse pressure (PP), and pulsatility indicator (PI) decreased. In an animal experiment, a Wankel type blood pump was used in a calf. With the increase of the assist flow, AoP curves became less pulsatile, and PP and PI decreased in accordance, which was predicted by the numerical simulation.

Animals↗
PubMed1998

Eccentric roller type total artificial heart designed for implantation.

In the process of developing a completely implantable total artificial heart system, we have made an eccentric roller type total artificial heart and evaluated it by means of a mock circulatory system and by an acute animal experiment. The actuator of the artificial heart consists of 2 cylindrical drum type rollers which squeeze 2 blood chambers. The blood chambers are made of silicone rubber and are torus in shape. There is no valve used in this artificial heart. The artificial heart appears to be a nearly circular cylinder, approximately 10 cm in length and 8 cm in diameter. In the Donovan mock test, the artificial heart worked at a roller speed of 100-125 rpm with flow rates of 2.5-3.0 L/min for the right side and 3.2-3.8 L/min for the left side, respectively. The electric power consumption was 19.0-24.7 W. Our artificial heart is characterized by an ejection of blood alternatively in the pulsatile mode without need for reversing the motor. In the ex vivo evaluation, circulation of an adult sheep was maintained with this artificial heart for 4 h.

Animals↗
PubMed1998

Immunochemical detection of CD14 on human gingival fibroblasts in vitro.

The activation of monocytes and macrophages induced by lipopolysaccharide has been shown to contribute to the binding of lipopolysaccharide and lipopolysaccharide-binding protein complex to the cell surface CD14 molecule. To clarify the mechanism of the lipopolysaccharide-induced modulation of the function of gingival fibroblasts, we investigated the effect of anti-CD14 on interleukin 6 (IL-6) production on human gingival fibroblasts in vitro. Immunochemical staining revealed weak positivity for CD14 on fibroblasts from healthy gingiva, while strong positivity for CD14 was found on fibroblasts from inflamed gingiva. Western blot profiles of the fibroblasts and monocytes showed a CD14-positive reaction at 55 kDa. Fluorescein isothiocyanate-conjugated Escherichia coli lipopolysaccharide bound to fibroblasts more strongly in the presence of 10% fetal bovine serum than without serum. This binding, as well as IL-6 production, was blocked by anti-CD14 monoclonal antibody. The results showed that CD14 was present on human gingival fibroblasts, which suggests that lipopolysaccharide modulation of gingival fibroblast function depends on CD14.

Animals↗
PubMed1998

Accidental entry of an implantable cardioverter defibrillator lead into the left hepatic vein detected by transesophageal echocardiography.

We report a case of accidental entry of an implantable cardioverter defibrillator lead into the hepatic vein, which was not noted on fluoroscopy but was apparent when transesophageal echocardiography (TEE) was used incidentally. The lead was depicted in the hepatic vein as strongly echogenic, accompanied by an acoustic shadow. Additional bending of the stylet was helpful for successful advancement of the lead. TEE provides additional information in such cases, although indications for its use should be explored because of its possible complications.

Adolescent↗