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Biomedical subjects

S Shimokawa

Publications and source records attributed to S Shimokawa.

At least 73 records · Page 4Linked to original sources

The management of patients with dissection of the descending thoracic aorta: a comparison between closing and nonclosing dissections.

This study was designed to clarify and compare the clinical characteristics and prognoses of patients with closing and nonclosing dissection of the descending thoracic aorta. Between January 1991 and December 1994, 19 patients with closing dissection (Group A) and 20 with nonclosing dissection (Group B) underwent surgical repair or medical treatment at our institution. There were 29 men and 10 women, aged between 37 and 74 years, with a mean age of 62 years. There was a significant difference in age between the two groups, being 67 +/- 7 and 58 +/- 12 years for Groups A and B, respectively (P = 0.009). The presence of a concurrent abdominal aortic aneurysm was confirmed in 32% and 10% of Groups A and B, respectively (P = 0.095). A total of 15 patients experienced a variety of complications related to the dissection, but there were no significant differences in the morbidity rate between the two groups. Visceral ischemic disorders such as renal failure, leg ischemia, and ileus were the most common complications. The overall survival rate 4 years after the development of dissection was 80%, with no significant difference between the two groups. These findings led to the establishment of our policy to place all patients with dissection of the descending thoracic aorta on careful antihypertensive therapy and frequent follow-up imaging studies to assess the aorta, regardless of the condition of the false lumen.

Adult↗

Retrohepatic cavoatrial shunt with a ringed polytetrafluoroethylene graft for the Budd-Chiari syndrome. A case report.

This report describes a patient with Budd-Chiari syndrome who was operated on successfully by means of shunt formation with polytetrafluoroethylene graft between the inferior vena cava (IVC) and right atrium. The patient is a sixty-two-year-old woman suffering from persistent edema of the lower limbs for four years. The examination disclosed complete obstruction of the IVC at the level of the diaphragm with a patent right inferior hepatic vein. Following the operation, edema of the limbs disappeared, hypersplenism improved, and the serum ammonium concentration decreased to the normal range. In conclusion, a retrohepatic cavoatrial shunt is feasible and useful in treating a patient with the Budd-Chiari syndrome who has patent major hepatic veins.

Blood Vessel Prosthesis↗

Acute type A aortic dissection following intramural hematoma of the aorta. A case report.

A seventy-three-year-old woman had symptoms of aortic dissection. Initial computed tomographic (CT) scan and angiography showed an extensive intramural hematoma (IMH) of the aortic segment from the ascending aorta to the bulk of the descending aorta without intimal tear or false lumen. Two weeks later the patient's symptoms recurred. A repeat CT demonstrated a classic type A aortic dissection with a false lumen and an intimal defect. The patient underwent a successful hemiarch repair with use of selective cerebral perfusion under profound hypothermic circulatory arrest. This case suggests extensive IMH as an important underlying pathology of the aortic dissection.

Acute Disease↗

[Successful emergency coronary artery bypass grafting in a patient with systemic lupus erythematosus under hemodialysis therapy].

A 38-year-old woman, who had been suffering from systemic lupus erythematosus (SLE) and receiving steroid therapy for the past 25 years, underwent a successful emergency coronary artery bypass grafting for unstable angina. She had also been treated with a 10-year period of hemodialysis therapy for chronic renal failure. Her coronary angiography revealed the heavily calcified ectatic right coronary artery with a thrombus formation in its proximal portion associated with severe stenosis in the proximal left coronary artery. The left internal thoracic artery was anastomosed to #7 and the saphenous vein to #3, respectively. Postoperative coronary angiography performed one month later revealed both grafts to be patent with no stenosis. Ischemic heart disease (IHD) is one of the major complication limiting the prognosis of the patient with SLE. We discuss the point related to cause of IHD and the surgical management.

Adult↗

[Abdominal aortic aneurysm and annuloaortic ectasia in siblings with Marfan syndrome].

A combination of annuloaortic ectasia (AAE) and abdominal aortic aneurysm (AAA) appeared in siblings with Marfan syndrome is presented. The patients were a 53-year-old female and her younger brother. The brother died of arrhythmia twenty years before while waiting for surgical repair of AAE. His AAA and Marfan syndrome were ascertained at autopsy. The female patient received surgical repair for AAA and AAE subsequently. Pathologic study of the resected aneurysm revealed cystic medial necrosis. A combination of AAE and AAA developed in two members of a family with Marfan syndrome is extremely rare.

Aortic Aneurysm, Abdominal↗

[Clinical experience with the gelatin-resorcine-formol biological glue in acute type A aortic dissection].

From May 1995 through June 1996, the gelatin-resorcine-formol (GRF) biological glue was used for tissue reinforcement in 20 patients operated on for acute type A aortic dissections at our institution. The results in these patients (Group I) were compared to those in 37 patients operated on between 1992 and 1994 with conventional techniques (Group II). There were no significant differences between the two groups concerning demographic data. Operative procedures in Group I consist of replacement of the ascending aorta with or without proximal arch (n = 10), total arch replacement (n = 7), and aortic root reconstruction (n = 2), whereas those in Group II were 22, 12, and 3, respectively. Cardiopulmonary bypass time was significantly shorter in Group I than Group II (164 +/- 39 vs 265 +/- 122, p < 0.05). Average blood loss in first 24 hours after operation was 688 +/- 601 ml in Group I and 1481 +/- 1505 ml in Group II (p < 0.05). Consequently operative mortality was significantly (p < 0.05) reduced from 40.5% (Group II) to 15.0% (Group I). In conclusion, the use of GRF glue reduces perioperative bleeding and improves results of operation for acute aortic dissections.

Acute Disease↗

[Ventricular septal perforation due to coronary artery spasm--a case report].

A 70-year-old female was referred due to chest pain and cardiogenic shock. Echocardiogram showed ventricular septal perforation (VSP) with large left to right shunt. ECG indicated ischemia on the left anterior descending region. Instantaneous coronary angiogram was done under the support of IABP. Neither obstructive nor stenotic lesions were found in the coronary arteries. Coronary artery spasm was a likely cause of VSP. The patient underwent emergency surgery within 12 hours from the onset. The VSP, 2 cm in diameter, was located on the postero-apical portion of the ventricular septum. The defect was closed by endocardial patch method using an equine pericardium. Postoperative course was uneventful, and the patient was transferred 3 weeks after the operation.

Aged↗

[Cerebral cytochrome oxidase monitoring by near infrared spectroscopy during selective cerebral perfusion].

To evaluate selective cerebral perfusion (SCP) for brain protection, the redox state of cytochrome oxidase (Cyt. aa3) in brain tissue were studied in 27 patients with thoracic aortic repair. The redox state of Cyt. aa3 was monitored by near infrared spectroscopy (NIRS) (OM-110, Shimazu). There were no significant changes in the Cyt. aa3 redox state in 13 (Group I), the oxidation state of Cyt. aa3 decreased then recovered to control levels in 12 (Group II), and the oxidation state decreased but did not recover in 2 patients (Group III). Postoperative cerebral damage was observed in 5 patients; blindness occurred in one patient in Group I (8.3%), 2 patients developed hemiplegia in Group II (15.4%), and the 2 patients in Group III failed to reawaken (100%). The incidence of cerebral damage was significantly higher in Group III than in Groups I and II (p < 0.05). We conclude that monitoring the redox state of Cyt. aa3 using NIRS is useful in predicting postoperative cerebral damage. However, it is necessary to increase the number of measurement sites since NIRS can reflect the state in only a small area of the brain.

Aged↗

[Composite valve graft replacement in patients with type A aortic dissection--a modified cabrol procedure].

Composite valve graft replacement of the ascending aorta and aortic valve is indicated for a variety of conditions affecting the aortic root. However, a major drawback in this operation is bleeding from the proximal suture line and coronary anastomosis especially in patient with friable root tissue involved by aortic dissection. We describe here a modified technique to take advantage of the aortic button and cabrol techniques to reattach the coronary artery ostia. We have experienced seven patients with the aortic root replacements for type A dissection using the described technique over the past two years. In view of our favorable experience, we recommend this technique especially for patient with acute dissection involving nondilated aortic annulus, in addition to the patients with Marfan syndrome or annulo-aortic ectasia.

Aged↗

[Temporary extracorporeal axillofemoral venous bypass--a beneficial device in operation for superior vena caval syndrome due to intrathoracic malignancies].

Life-threatening complications can occur unexpectedly during general anesthesia in operations for superior vena caval (SVC) syndrome due to intrathoracic tumors. To prevent such sequelae, we have placed a temporary extracorporeal axillofemoral venous bypass graft with satisfactory results. In six patients (malignant mediastinal tumor, four; lung cancer, two), under local anesthesia before induction of general one, the cannulas, each appropriately sized in accordance with the diameter of the axillary and femoral veins, were directly introduced into the corresponding veins after systemic heparinization. The two cannulas were connected with a tube to which a side arm, which was usually clamped, was connected. The venous pressure of the internal jugular vein decreased immediately after establishment of the temporary bypass in all patients. The symptoms that accompanied SVC syndrome did not worsen and the life-threatening complications at the time of induction of general anesthesia were avoided with this procedure. In each case cardiopulmonary bypass on stand-by was unnecessary at this time. Venous bypass grafting with vascular prostheses were mainly performed under cardiopulmonary bypass, which was required for such operative procedures. In three patients the side arms were used for part of the venous drainage during cardiopulmonary bypass. The SVC syndrome instantly disappeared after operations in all patients including one in hospital death. No serious complications related to the temporary bypass procedure have been observed. This temporary bypass procedure has several advantages. It can be safely performed under local anesthesia with no special technique for the cannulation. Venous blood naturally drains from the upper part to the lower part of the body by pressure gradient, that warrants the safe induction of general anesthesia and ensuing operative procedures. The side arm is available for venous drainage during cardiopulmonary bypass. There are no serious complications related to the bypass procedure. Thus this temporary bypass is recommended as a life-saving and auxiliary device in urgent operations for acute progressive SVC syndrome with symptoms of cerebral edema and upper airway obstruction due to intrathoracic malignancies.

Adult↗

Magnetic resonance imaging of hepatocellular carcinoma in Long-Evans cinnamon rats under a magnetic field of 7.05 T.

Magnetic resonance (MR) images of livers in 3-, 12- and 29-month-old Long-Evans Cinnamon(LEC) rats (male) were taken under a magnetic field of 7.05 T. MR images of sagittal and transversal sections were obtained in 1-mm-thick slices by T1-weighted and two-dimensional Fourier transformation techniques. The data matrix size was 256 phase-encoded steps. Each image was obtained through four acquisitions. Three-month-old rats gave MR images with low signal intensity over the liver probably due to the shorting of its T1 and T2 relaxation times. However, 12-month-old rats gave hyperintense regions around hepatic veins in right hepatic lobe, which was assigned to hepatocellular carcinoma. In 29-month-old rats, MR images with hyperintensity throughout the hepatic lobe were observed. These MR images, therefore, suggested that hepatocellular carcinoma in LEC rats developed from the restricted regions surrounding hepatic veins. In the present study, T1-weighted MR imaging under a magnetic field of 7.05 T was shown to be applicable to the diagnosis of hepatic cancer in LEC rats.

Animals↗

Massive endobronchial hemorrhage after pulmonary embolectomy.

Massive endobronchial hemorrhage is a lethal complication in pulmonary embolectomy. We report a case of massive endobronchial hemorrhage occurring after successful restoration of pulmonary blood flow using cardiopulmonary bypass in a patient with pulmonary embolism. Two possible causative factors of this complication are described.

Adult↗

Extracorporeal venous bypass: a beneficial device in operation for superior vena caval syndrome.

Life-threatening complications can occur unexpectedly during general anesthesia in operations for acute progressive superior vena caval syndrome. We describe a temporary extracorporeal axillofemoral venous bypass procedure to reduce the high venous pressure in the upper part of the body before induction of general anesthesia. The bypass supports the operation for superior vena caval syndrome without life-threatening accidents. No serious complications related to the procedure have been observed.

Acute Disease↗

Successful application of hypothermia combined with intra-aortic balloon pump support to low-cardiac-output state after open heart surgery.

The authors report a successful application of hypothermia, along with intra-aortic balloon pump (IABP) support, to postcardiotomy ventricular failure. Surface-cooling hypothermia was applied in 8 patients after open heart surgery. The original cardiac procedure consisted of 3 aortocoronary bypass graftings (ACBGs), 2 aortic valve replacements (AVRs), 1 repair for left ventricular (LV) rupture after mitral valve replacement (MVR), 1 MVR + ACBG, and 1 MVR + AVR + tricuspid valve annuloplasty (TAP). Their ages ranged from fifty-two to sixty-eight years with a mean of sixty-one years. Hemodynamic criteria for induction of hypothermia included cardiac index (CI) less than 2.0 L/min/m2 with left atrial pressure greater than 18 mmHg despite the use of IABP and maximum pharmacologic support. Blood temperature was maintained at around 33 degrees C. By six hours after induction of hypothermia the tissue oxygen consumption decreased significantly with no hemodynamic deterioration as compared with that before cooling. The duration of hypothermia ranged from thirty-six to one hundred fifty-nine hours with a mean of seventy-eight hours. All 8 patients finally discontinued IABP support with a mean driving time of one hundred thirty-two hours. Five of them were ultimately discharged from the hospital and returned to their previous life-style. The authors believe that, from the perspective of monetary and personal resources, the use of hypothermia with IABP support could be a therapeutic option for patients with postcardiotomy ventricular failure.

Aged↗

[Open heart surgery in patients with chronic dialysis].

From January, 1986 to May, 1995, twelve patients with dialysis (11 hemodialysis; HD, and one continuous ambulatory peritoneal dialysis; CAPD) received open heart surgery. They consist of 10 males and two females aged between 35 and 66 with a mean of 58.8. The duration of dialysis was 6.8 years in a mean (the shortest for 2 months and the longest for 16 years). They classified into an equal number of four in NYHA class II, III and IV. Two of them had isolated coronary artery bypass grafting, four had aortic valve replacement (AVR) and two had mitral valve replacement (MVR). Others were each one of AVR and MVR, AVR plus MVR with tricuspid annuloplasty (TAP), AVR plus TAP, and removal of left atrial myxoma. All patients except for one of CAPD were dialysed daily 2 or 3 days before operation. Three patients were managed postoperatively with HD, one with PD, six with continuous hemodiafiltration, and two with continuous hemofiltration. The operative mortality was 25% (3/12). The causes of death were left ventricular rupture, bronchospasm, and respiratory failure. All patients who died were in class in III and IV. For the improvement of the results we emphasize the necessity of early operation that should be scheduled in class II period.

Adult↗