Biomedical subjects

Sugato Nawa

Publications and source records attributed to Sugato Nawa.

6 recordsLinked to original sources

PubMed2006

An experimental study on pumpless extracorporeal membrane oxygenation (ECMO) support in a canine model.

This study was carried out to determine whether an extracorporeal membrane oxygenation (ECMO) support could be sufficiently conducted by the right ventricle alone from the viewpoint of the hemodynamics and blood gas state. Six infant dogs underwent a bypass between the left pulmonary artery and left atrium with an in-line oxygenator after a left pneumonectomy. Partial ECMO support was conducted simply by opening the circuit, and total ECMO support was conducted by ligating the right pulmonary artery. After the establishment of partial ECMO, approximately one-third of the right ventricular output was passively shunted through the bypass circuit, and the cardiac index and central venous pressure did not change. The mean pulmonary arterial pressures increased significantly. After a complete ligation of the right pulmonary artery, all 6 dogs survived for 12 h, but the cardiac output and blood pressure decreased significantly. The blood gas state was sufficiently maintained throughout the experiment. The results suggest the possibility of using the pumpless ECMO support. However, the flow resistance of the membrane oxygenator proved to still be too high for use in a total pumpless ECMO. Further studies on long-term ECMO and the development of a membrane oxygenator with a considerably low flow-resistance are needed.

Animals↗

PubMed2005

Hemodynamic effects of pumpless extracorporeal membrane oxygenation (ECMO) support for chronically pressure-overloaded right heart failure in a canine experimental model.

PURPOSE: This study was done to evaluate the hemodynamic effects of a pumpless implantable extracorporeal membrane oxygenation (ECMO) circuit between the right ventricle (RV) and left atrium (LA) in a chronic canine model with an RV pressure overload. METHOD: We created a model of right-sided heart failure by pulmonary artery banding in ten dogs for a duration of more than 3 months. After demonstrating that the RV pressure increased, a bypass circuit was created between the RV and LA with an in-line oxygenator. Both the hemodynamics and gas exchange were measured. RESULTS: The effects of a pulmonary bypass in nine dogs were studied. Approximately half of the RV output was passively shunted through the bypass circuit, and a marked reduction in the RV pressure and recovery from right heart failure were observed. After a complete ligation of the main pulmonary artery, five of the nine dogs survived more than 6 h. The RV pressure did not change significantly, but the cardiac output and blood pressure gradually decreased. The blood gas state was sufficiently maintained throughout the experiment. CONCLUSION: The present study indicates the hemodynamic benefit of a partial pumpless ECMO system in dogs with chronically pressure-overloaded right heart failure; however, the experimental preparation of the total pumpless ECMO circuit proved to be unstable.

Animals↗

PubMed2005

Abdominal wall and thigh abscess resulting from the penetration of ascending colon cancer.

An unusual case is described in which an abdominal wall and thigh abscess was an initial symptom of ascending colon cancer. A 76-year-old woman was referred to our hospital for investigation of fever and abdominal and thigh swelling. Computed tomography revealed a right abdominal wall, retroperitoneal, psoas and thigh abscess formation suspected to be caused by colon perforation. Due to the patient's poor general condition, local drainage of the abscess was performed on the following day of hospitalization. Histological examination of necrotic tissues removed form the retroperitoneal cavity demonstrated adenocarcinoma of the colon. The patient subsequently underwent right hemicolectomy with lymph nodal dissection after 19 days of the drainage procedure and was transferred to another hospital on the 49th day following the second surgery.

Abdominal Wall↗

PubMed2004

Intercostal hemangioma.

This paper presents a case of intercostal hemangioma, in which a complete surgical resection was accomplished based upon a tentative diagnosis provided by magnetic resonance imaging (MRI). A 27-year-old man visited our hospital for the evaluation of chest pain and shortness of breath after exertion. Computed tomography showed a soft tissue mass, 5.5 x 3.5 cm in size, arising from the right lateral 7th intercostal space. Dynamic MRI showed that the mass was enhanced rapidly in the early phase and that this early enhancement was maintained during the delayed phase, which was compatible with a diagnosis of intercostal hemangioma. The patient underwent surgery, and a complete resection of the tumor with the right 7th and 8th ribs and their intercostal muscles was accomplished. Histopathological examination confirmed the diagnosis of intramuscular hemangioma of the large-vessel type. Presently, 6 months after the operation, the patient is doing well, without any evidence of local recurrence.

Adult↗

PubMed2003

A true aneurysm of axillary-subclavian artery with cystic medionecrosis: an unusual manifestation of Marfan syndrome.

We report a case of a 69-year-old female patient diagnosed with an axillary-subclavian artery(ASA) aneurysm, 7 cm long and 4 cm in diameter. The aneurysm had recently developed during follow-up for aortic sinus dilation associated with Marfan syndrome, which had been diagnosed in 1987. The patient underwent corrective surgery for the ASA aneurysm, and the aneurysm was histologically diagnosed as a true type with cystic medionecrosis.

Aged↗

PubMed2003

Multisaccular aneurysm developing in association with abdominal aortic coarctation: report of a surgical case.

This paper reports a rare case of a 65-year-old woman diagnosed with a multisaccular, abdominal aortic aneurysm (AAA), 35 mm in diameter, which was revealed developing just distal to an abdominal aortic coarctation (AAC), with a 20 mmHg pressure gradient. The patient underwent corrective surgery for both lesions, with success. Intraoperatively, the aneurysm wall was found to be so thin and transparent that the inner blood turbulence could be seen, and it appeared highly susceptible to rupture. When a saccular, thin-walled AAA develops in association with AAC, early surgical intervention is mandatory regardless of the size of the aneurysm. (Ann Thorac Cardiovasc Surg 2003; 9: 326-9)

Aged↗