Biomedical subjects

S Nawa

Publications and source records attributed to S Nawa.

At least 19 recordsLinked to original sources

PubMed2001

[A case of advanced hepatocellular carcinoma with portal invasion resected after treatment by continuous intra-arterial chemotherapy with cisplatin and 5-fluorouracil].

A 67-year-old male diagnosed as having inoperable advanced hepatocellular carcinoma with portal invasion was able to undergo resection after continuous intra-arterial chemotherapy with 5-fluorouracil (5-FU) and cisplatin (CDDP). These were continuously administered for 24 hours at doses of 5-FU of 250 mg and CDDP of 5 mg/day, from day 1 to day 5 in a week, repeated 6 times. In additions to the reductions of the levels of AFP and PIVKA-II from 212.6 ng/ml and 16,100 mAU/ml to 11.8 ng/ml and 12 mAU/ml, respectively, the volume of the tumor and the portal invasion were diminished remarkably. As a result, a left extended hepatectomy could be performed. No sign of recurrence was seen during 16 months of follow-up after the operation. Given the above results, continuous intra-arterial chemotherapy with 5-FU and CDDP therapy may be effective for patients with hepatocellular carcinoma.

Aged↗

PubMed2000

Choledochal stenosis and lithiasis caused by penetration and migration of surgical metal clips.

A 71-year-old woman, who had undergone laparoscopic cholecystectomy 1 year previously at our hospital, presented with abdominal pain, high fever, and jaundice. She was diagnosed with choledochal stenosis caused by migration of the clips that were used at the previous operation. At reoperation, the common bile duct was successfully dissected, including the stenotic site, where a metal clip was found to be penetrating the duct wall. The stenotic site was sufficiently resected, when a black-brown gallstone was found proximally to the stenosis. Interestingly, the stone was found to contain two metal clips, which were considered to have migrated into the bile duct and to have acted as a nidus for stone formation. The common bile duct was reconstructed by direct end-to-end anastomosis. Surgeons must exercise caution in the use of metal clips, keeping in mind the potential risk of clip migration.

Aged↗

PubMed1999

Identification and selective perfusion of the spinal cord-feeding arteries by intrathecal pO2 monitoring for spinal cord protection.

OBJECTIVES: to study whether spinal cord-feeding arteries could be identified by the changes in the intrathecal pO2 (I-pO2), and to examine whether selective perfusion of feeding arteries identified by this method could protect the spinal cord against ischaemia. DESIGN: controlled animal experiments. MATERIALS AND METHODS: in experiment 1, using 16 mongrel dogs, 18 segmental arteries were cannulated through which oxygenated saline was injected and the I-pO2 change was observed. When the I-pO2 increase was more than 0.5 mmHg, the artery was considered to be a spinal cord-feeding artery. In experiment 2, involving 10 dogs, the segmental arteries identified as spinal cord-feeding arteries were perfused with arterial blood and the recovery of I-pO2 and evoked spinal potentials (ESP) was examined. RESULTS: of 208 segmental arteries examined, 176 (84.6%) arteries were correctly judged and 32 (15.4%) were not. It was observed that the I-pO2 recovered from 13.9 to 30.5 mmHg and the ESP recovered from 20.9% and 8.2% to 66.5% and 44.7% of each control for the first negative (N1) and second negative (N2) components, respectively. CONCLUSION: spinal cord-feeding arteries were successfully identified using the I-pO2 monitoring method. Perfusion of these arteries with arterial blood improved the I-pO2 and ESP, which were significantly depressed by ischaemia.

Animals↗

PubMed1998

Idiopathic renal arteriovenous fistula demonstrating a huge aneurysm with a high risk of rupture: report of a case.

This paper reports a case of an idiopathic renal arteriovenous fistula demonstrating a huge guitar-shaped aneurysm, which required a total nephrectomy. Although the patient insisted on having been asymptomatic, echocardiography and cardiac catheterization clearly revealed that the influence on hemodynamics was unexpectedly significant. Interestingly, the aneurysm was also considered to have a high risk of rupture, which was preoperatively suggested by an aneurysm wall projection discernible on both computerized tomograms and angiograms, and this suspicion was also convincingly supported by the perioperative and histopathological findings.

Aneurysm↗

PubMed1997

Endothelin-1 levels in portal venous blood in relation to hepatic tissue microcirculation disturbance and hepatic cell injury after ischemia/reperfusion.

This study was conducted to clarify the role of endothelin-1 in the portal vein after hepatic ischemia/ reperfusion and to ascertain whether it is related to hepatic microcirculation disturbance. Using a canine ischemic liver model, the portal and systemic endothelin-1 levels were measured before ischemia, then after 1 h and 2 h of reperfusion, and comparatively evaluated with the serum levels of GOT and lactic dehydrogenase (LDH). As an indicator of liver tissue microcirculation, tissue blood flow volume (TBF) was also measured in the site subjected to ischemia. The animals were divided into: group 1, which received ischemia for 30 min; group 2, which received ischemia for 60 min; and group 3, which received a sequence repeated four times of 15 min ischemia and 10 min reperfusion. The portal endothelin-1 level became significantly elevated after reperfusion compared to that before ischemia in all groups, being significantly higher in group 2 than in the other groups. The systemic endothelin-1 level also increased after reperfusion; significantly in group 2. The portal endothelin-1 level was generally higher than the systemic level, which again was statistically significant in group 2. After 2 h of reperfusion, a significant positive correlation was found between the portal endothelin-I level and serum LDH, whereas a significant negative correlation was found between the portal endothelin-1 level and TBF. The finding that the portal endothelin-1 level became elevated after hepatic ischemia/reperfusion suggests that it probably plays an essential role in hepatic ischemia/ reperfusion injury by adversely influencing tissue microcirculation.

Animals↗

PubMed1997

Fistula formation from neovascularity developing in malignant fibrous histiocytoma of the heart.

Neovascularity in cardiac tumours is uncommon and fistula formation from such neovascularity is extremely rare. Fistula formation from neovascularity developing in a malignant fibrous histiocytoma of the heart is described in a 48-year-old man. The the case illustrates that cardiac tumour is not only a cause of cardiac output obstruction but also of coronary artery fistula.

Coronary Disease↗

PubMed1997

Intrathecal oxygen concentration as a new indicator of spinal cord ischemia.

A number of approaches have been put forward to monitor spinal cord ischemia during thoracic and thoracoabdominal aortic occlusion. However, none of these can ultimately prevent devastating complications which result from ischemic spinal cord injury. A direct measurement of the oxygen content of the spinal cord may accurately indicate the perfusion state, but in practice it is impractical. We surmised that intrathecal and/ or epidural oxygen concentration(I-pO2 and E-pO2, respectively) accurately reflect oxygen content in the spinal cord. So, we examined whether or not I-pO2 and/or E-pO2 correlated with the spinal cord pO2 (S-pO2) in dogs. In nine mongrel dogs, a model of graded spinal cord ischemia was developed by stepwise alternation of the level of aortic occlusion with an intraaortic balloon catheter. I-pO2, E-pO2 and S-pO2 were measured with a mass spectrometer. Our results show that, both I-pO2 and E-pO2 significantly correlated with S-pO2. I-pO2 correlated with S-pO2 better than E-pO2 did. Therefore, I-pO2 can be used as a new indicator for spinal cord ischemia, and I-pO2 monitoring would be useful to prevent paraplegia associated with thoracic aortic surgery.

Animals↗

PubMed1996

Clinical and angiographic analysis of congenital coronary artery fistulae in adulthood. Is there any new trend?

Fifteen (2.1%) patients were diagnosed as having congenital coronary artery fistula (CAF) in a consecutive series of 704 adult patients undergoing selective coronary arteriography; the incidence was astonishingly higher than previous observations. The presentation of clinical symptoms and the electrocardiographic changes at rest and/or after exercise testing probably attributable to the CAF were observed unexpectedly often in spite of the fact that the magnitude of the shunt seemed not to be significant. With respect to the anatomy of the CAF, the incidence of origination from plural coronary arteries and that of fistulation into the left ventricle were also unexpectedly high. These observations presented a striking contrast to those of previous reports, but we were unable to determine the reason. In four cases, the CAF was ligated either electively or concurrently with mitral valve surgery, and the results were satisfactory. Taking these circumstances into consideration, we should not minimize the impact of a CAF with a seemingly small shunt.

Adult↗

PubMed1996

Continuous measurement of tissue oxygen and carbon dioxide gas tensions in dog liver in ischemia/reperfusion.

An experiment was conducted to determine whether the oxygen and carbon dioxide gas tensions in liver tissue (PtO2 and PtCO2, respectively) reflect the state of microcirculation and/or metabolism in the ischemic liver. Subjects were divided into three groups: group 1, 30 min ischemia; group 2, 60 min ischemia; group 3, four times of intermittent 15 min ischemia after every 10 min of reperfusion. PtO2, PtCO2 and tissue blood flow (TBF) were measured by mass spectrometry, comparatively studied with the serum GOT level as an indicator of liver tissue damage. Furthermore, the time point at which the PtCO2 increase for 1 min initially became less than 1/2 of the maximum value was located on the transit curve of PtCO2, referred to as the critically anaerobic (CA) point, with which new indices of critically anaerobic score (CAS) and time (CAT) (see details in text) were developed. The profiles of PtO2 and PtCO2 during ischemia and reperfusion were clearly demonstrated, and the CA point was observed 12.7 +/- 2.9 min after induction of ischemia. PtO2 was positively correlated with TBF and negatively with the serum GOT level. Furthermore, not only CAS but also CAT were significantly correlated with PtO2, TBF, and the serum GOT level. It was concluded that PtCO2 reflects the state of anaerobic tissue metabolism during ischemia and PtO2 reflects the magnitude of microcirculatory disturbance and tissue injury caused by ischemia/reperfusion. Therefore, continuous monitoring of not only PtO2 but also PtCO2 is beneficial for patients undergoing hepatic surgery with ischemia.

Animals↗

PubMed1996

[A proposal of a composite patch for early repair of ventricular septal perforation after acute myocardial infarction].

A 68-year-old female presented ventricular septal perforation (VAP) 3 days after acute myocardial infarction. The patient, supported with intraaortic balloon pumping, underwent surgical repair with success on day 15. At operation, the VAP, measuring 2.5 x 1.5 cm, was repaired using a composite patch consisting of Dacron felt and xenopericardium attached each other with fibrin glue. The composite patch was found really useful for repair of VSP in such early phase as when VSP-sorrounding myocardium was very fragile, particularly in respect to the prevention of residual and/or recurrent shunt. This was because the composite patch was considered to have such excellent characteristics as: 1) toughness with sufficient compressibility and extensibility, 2) high antithrombogenesity and good tissue compatibility, 3) zero porosity, and 4) easy handling because of unification of two materials.

Aged↗

PubMed1995

Malignant fibrous histiocytoma of the right ventricle of the heart.

Right-sided cardiac malignant fibrous histiocytoma (MFH) is extremely rare, and to the authors' knowledge only three cases have been reported. In this study, a case of MFH in the right ventricle, the septum, and the pulmonary valves and artery in a 47 year old male is described. The tumor showed typical pathological features of MFH, such as cellular pleomorphism, storiform pattern and abundant mitoses. Immunohistochemical and electron microscopical findings were compatible with MFH, and excluded the possibility of leiomyosarcoma and angiosarcoma. Whole body examination, including Gallium scintigram, localized the primary site to the heart. The details of this case are presented with a review of the reported cases of cardiac MFH.

Heart Neoplasms↗

PubMed1995

The presentation of a double aortic arch in adulthood in association with congestive heart failure attributed to a previously silent aortic regurgitation.

This paper describes an adult case of a double aortic arch (DAA; Edwards type IA). The patient had been asymptomatic for DAA but presented difficulty in swallowing in association with congestive heart failure, which she experienced as the result of attending to her sick husband while she apparently suffered from a silent aortic regurgitation. The symptoms disappeared and the patient recovered from heart failure following medical treatment. The patient soon discontinued the outpatient treatment and, after 2 years, the identical symptoms recurred under similar circumstances. In this paper we demonstrate that an asymptomatic case of DAA has the potential to clinically manifest itself.

Aorta, Thoracic↗

PubMed1995

[Fontan-type procedure for an adult case of double-outlet right ventricle (S, D, L)].

The double-outlet right ventricle with L-malposition (DORV (S, D, L)) is one of the rare congenital heart diseases. Intracardiac rerouting with a internal conduit has been indicated in principle to it as the radical operation. DORV (S, D, L) is often combined with the pulmonic stenosis (PS), and Rastelli's operation is indicated to the case in which release of PS is difficult. We report a case of DORV (S, D, L) combined with PS and the hypoplastic right ventricle which is treated by the Fontan-type procedure. The patient was a 35-year-old female who had undergone Glenn's operation at 10 years of age under the diagnosis of transposition of the great arteries. Recently she complained of aggravation of the cyanosis and dyspnea on exertion. After thorough examinations, the disease was diagnosed as DORV (S, D, L) with doubly committed VSD which was combined with severe PS, hypoplastic right ventricle (29% of normal) and left-sided juxtaposition of atrial appendages. The development of her distal pulmonary arteries was estimated well enough (PA-index 448 mm2/m2). We judged that intracardiac rerouting with an internal conduit could not be applied due to her severe pulmonic stenosis, and that Rastelli's operation as the biventricular repair was also impossible because of her hypoplastic right ventricle. Thus we adopted the Fontan-type procedure with a new septation in the right atrium, namely oblique partition, and attained a good result. To our knowledge, this case is the fourth case report in Japan of DORV (S, D, L) treated with the Fontan-type procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Development of an experimental model of an acute respiratory failure by intratracheal sea water infusion: a comparison with a conventional oleic acid induction.

An experimental model of acute respiratory failure (ARF) was successfully developed in dogs by endotracheal sea water infusion. Serial changes in blood gases and hemodynamics, and histological changes in the lungs after use of this method were compared with those of the conventional model induced by oleic acid, and the following results were observed. Blood gases deteriorated more rapidly after sea water than after oleic acid, while the changes caused by oleic acid progressed with time, and those caused by sea water did not. Not only systemic but also pulmonary hemodynamics were adversely influenced by oleic acid, but not by sea water. Extravascular lung water was observed to increase significantly in both groups. The increase was linear after oleic acid treatment, however, while with the sea water method it leveled off to a plateau. There was no significant difference between the histological changes in lungs of the two models. Our model will provide many advantages over the conventional one using oleic acid, and will be useful for studying the pathophysiology of ARF and its therapeutic strategies, such as extracorporeal membrane oxygenation and/or carbon dioxide removal.

Acute Disease↗

PubMed1994

Coronary fistulous communications with left ventricular chamber and giant mural thrombus after myocardial infarction.

Selective coronary arteriography, performed in a 67-year-old man with post-infarction angina, demonstrated severe three vessel disease and coronary fistulous communications with the left ventricular chamber adjacent to a giant mural thrombus formed in the apical aneurysm. Most of the contrast media seemed to empty directly into the chamber without presenting hypervascular blushes of the thrombus itself. This was somewhat different from the observation previously reported in a case with coronary fistulae associated with a post infarction mural thrombus. It was stressed that one should not misinterpret this condition as a rare coronary artery-cardiac chamber shunt associating myocardial infarction.

Aged↗

PubMed1994

[Late progression of pulmonary hypertension in a patient operated for patent ductus arteriosus: pulmonary angiopathy or thromboembolism?].

A 16-year-old girl developed dyspnea 9 years after surgery for patent ductus arteriosus with pulmonary hypertension (pulmonary to systemic peak systolic pressure ratio; Pp/Ps 1.0). The postoperative course had been uneventful with a decreased Pp/Ps. It was revealed this time, however, that the pulmonary arterial pressure again elevated to be 186/133 mmHg (Pp/Ps 1.90). Postoperative progression of pulmonary angiopathy was first suspected. Whereas, the findings with pulmonary perfusion scintigraphy and arteriography were remarkably different between the right and left lungs, suggesting that the progression of pulmonary hypertension was not caused by that of pulmonary angiopathy but by the association of thromboembolism in small pulmonary arteries. The patient succumbed to intractable cardiopulmonary failure, strongly appealing for the necessity of organ-transplantation therapy in Japan. This case also indicated the particular importance of a close follow-up of the cases with pulmonary hypertension remaining after corrective surgery.

Adolescent↗

PubMed1994

[Total aortic root replacement exclusively with full-thickness suturing].

This paper describes two cases of total aortic root replacement using a valved conduit with a side branch. The full-thickness suturing technique was exclusively used at all anastomotic sites, and some technical devices are also presented. The conduit and a Hemashield Woven Double Velour graft used to make it were found very beneficial for the operation of this kind, and our procedure will equally provide every surgeon with a good result.

Aged↗

PubMed1994

[A case of emergent surgical salvage for the mitral prosthetic perivalvular leakage diagnosed only by the transesophageal Doppler echocardiography].

A case of the successful emergency surgery for the mitral prosthetic perivalvular leakage (PVL) which was diagnosed only by the transesophageal Doppler echocardiography (TEE) is reported. A 59-year-old male who had been diagnosed MS + TR + severe PH underwent mitral valve replacement with St. Jude medical valve 27 M. On the eighteenth postoperative day hemoglobinuria was noticed suddenly. Subsequently hemolysis and nonoriguric renal failure was aggravated, then we suspected PVL, but heart murmur was not audible or PVL could not been detected by the transthoracic echocardiography (TTE). PVL was detected for the first time by the TEE, then open heart resuture was emergently performed. The site of the PVL was the portion where the anterior mitral annulus adjoined the aortic annulus, that is, adjacent to the right fibrous trigone. This site is the portion which a surgeon should treat very carefully and where the PVL is very difficult to detect by the TTE. In regard to the detection of the PVL in mitral position, the TEE, which has ultrasonically no flow masking by the mitral prosthesis, is the very useful diagnostic means.

Echocardiography, Doppler↗