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Biomedical subjects

A Ihaya

Publications and source records attributed to A Ihaya.

At least 19 recordsLinked to original sources
PubMed2000

Primary aortosigmoid fistula treated by descending thoracic aortofemoral bypass.

Primary aortoenteric fistula is a rare disease with a fatal outcome unless it is diagnosed accurately and treated surgically. We present an elderly patient with primary aortosigmoid fistula confirmed by endoscopy. Descending thoracic aortofemoral bypass was performed and the aortoiliac aneurysm and sigmoid colon were then resected in continuity. The patient maintains a good quality of life 6 years after the operation with good graft patency and no sign of graft infection.

Aged↗
PubMed1999

Postoperative inflammatory reactions of impregnated Dacron grafts.

The clinical efficacy of Dacron grafts that are impregnated with collagen or gelatin has been well demonstrated, but inflammatory reactions during the first few postoperative weeks have been reported. We experienced two patients, an 87-year-old man with a reconstruction of an abdominal aorta and a 7-year-old boy with a reconstruction of aortic arch with a collagen-impregnated graft (Hemashield), who continued to demonstrate a high fever with a high serum level of C-reactive protein (CRP) and immunoglobin for more than 5 months. The body temperature, the white blood cell (WBC) counts, and the serum level of CRP were compared on the seventh and 14th postoperative day among the 37 patients who underwent a reconstruction of either a thoracic or abdominal aorta using the Hemashield graft (Hemashield group) and a nonimpregnated graft (control group) in our hospital. An elevation of body temperature above 38 degrees C was seen 29% of the patients in the Hemashield group and 0% in the control group. No significant differences were seen in the WBC counts, but the serum level of CRP was significantly higher on the 14th postoperative day in the Hemashield group. We should therefore pay careful attention to inflammatory reactions after the implantation of the impregnated grafts.

Aged↗
PubMed1999

Experimental determination of the safe minimum perfusion flow rate for low-flow hypothermic cardiopulmonary bypass.

This study investigated the safe minimum perfusion flow rate for low-flow hypothermic cardiopulmonary bypass in a canine model. The adequacy of cerebral oxygenation was determined from the adenosine concentration, the oxygen saturation of cerebral venous blood and brain oxyhemoglobin level. In experiment 1, nine beagles were cooled on bypass to a nasopharyngeal temperature of 18 degrees C and the perfusion flow rate was reduced in a stepwise fashion every 30 min from 100 to 50, 30, 20 and 10 ml/kg per min. In experiment 2, six beagles were cooled on bypass as in experiment 1, and flow was maintained at 30 ml/kg per min for 120 min. At a perfusion flow rate of 30 ml/kg per min, adequate cerebral oxygenation was maintained for 120 min. In contrast, perfusion flow rates of 20 and 10 ml/kg per min were associated with cerebral ischemia.

Adenosine Triphosphate↗
PubMed1999

Low-potassium University of Wisconsin solution for cardioplegia: improved protection of the isolated ischemic neonatal rabbit heart.

Recovery of cardiac function and high-energy phosphates following ischemia and reperfusion were determined for hearts perfused with low potassium University of Wisconsin solution, high potassium University of Wisconsin solution, St Thomas' solution, or subjected to hypothermia alone. Isolated hearts were arrested for either 3 h at 15 degrees C or 6 h at 20 degrees C (n = 7 for each group) with one of the four solutions and then reperfused. Aortic flow after ischemic arrest at 20 degrees C was 40.3 +/- 13.3%, 79.3 +/- 10.0%, 64.3 +/- 11.9% and 43.9 +/- 15.9% of control values for high potassium University of Wisconsin solution, low potassium University of Wisconsin solution, St Thomas' solution and hypothermia alone, respectively. Similar results were observed in hearts subjected to ischemic arrest at 15 degrees C. Myocardial adenosine triphosphate and creatine phosphate after reperfusion tended to be higher in the low potassium University of Wisconsin solution group. It is concluded that low potassium University of Wisconsin solution may provide reliable cardioplegia during surgery that requires prolonged cardiac arrest in neonates and infants.

Adenosine↗
PubMed1998

[Removal of retained transvenous pacemaker electrodes under cardiopulmonary bypass].

A case of breakage and removal of a retained transvenous pacemaker electrode is described. A 22-year-old woman with complete A-V block underwent implantation of a transvenous pacemaker system on the left anterior chest wall in 1989. Three years later, a new generator was implanted on the right chest wall because of local infection of the pacemaker pockets. The old electrodes could not be removed and were left in place. Beginning in 1995, the patient complained of anterior chest pain. A chest roentgenogram revealed that one of the pacemaker electrodes had broken at the right costoclavicular ligament and a fragment was floating in the superior vena vava. The retained electrodes were removed under tot cardiopulmonary bypass. These electrodes had become firmly encased with fibrous tissue within the right ventricle and atrium, but they were easily removed under direct vision duting complete cardiac arrest. The postoperative course was uneventful and the patients had no further complaint.

Adult↗
PubMed1998

Effects of depletion of leukocytes and platelets on cardiac dysfunction after cardiopulmonary bypass.

BACKGROUND: This study examined the effects of the depletion of leukocytes and platelets from circulated blood on cardiac function after cardiopulmonary bypass in 37 patients who underwent coronary artery bypass grafting or aortic valve replacement. METHODS: Leukocytes and platelets were removed continuously using a blood cell separator, beginning immediately after the start of the operation and ending 1 hour after the release of the aortic cross-clamp in 19 patients (LPD group), but not in the remaining 18 patients (control group). Blood cell counts and levels of thromboxane B2, 6-keto-prostaglandin F1alpha, leukocyte elastase, complements C3a and C4a, thrombin-antithrombin III complex, and D-dimer were determined periodically during and after the operation. The cardiac index, the difference between the central and peripheral core temperatures, and the doses of catecholamines and vasodilators required to support the circulation in the early postoperative period also were assessed. RESULTS: Leukocyte and platelet counts and levels of leukocyte elastase, thromboxane B2, thromboxane2/6-ketoprostaglandin F1alpha, thrombin-antithrombin III complex, and D-dimer were significantly lower in the LPD group than in the control group before and after the release of the aortic cross-clamp and during the perioperative period. There were no significant differences in the levels of 6-keto-prostaglandin F1alpha or complements C3a and C4a between the two groups. The catecholamine dose was significantly lower in the LPD group than in the control group (1.1 +/- 2.5 versus 5.0 +/- 5.2 mg/kg, respectively). Fewer patients required the use of nitroprusside as a vasodilator in the LPD group than in the control group (1/19 versus 12/18, respectively). CONCLUSIONS: The depletion of leukocytes and platelets using a blood cell separator prevents the deterioration of cardiac function after cardiac operations using cardiopulmonary bypass.

6-Ketoprostaglandin F1 alpha↗
PubMed1998

Prolongation of total permissible circulatory arrest duration by deep hypothermic intermittent circulatory arrest.

OBJECTIVE: We determined whether the duration of permissible circulatory arrest could be prolonged by deep hypothermic intermittent circulatory arrest. METHODS: Twenty-five beagles were cooled on bypass to 18 degrees C to initiate deep hypothermia that was maintained for 3 hours. Five protocols were then studied: group 1, uninterrupted bypass during hypothermia; group 2, arrest for 40 minutes during hypothermia; group 3, arrest for 60 minutes during hypothermia; group 4, arrest for 80 minutes during hypothermia; and group 5, intermittent circulatory arrest, consisting of six cycles of 20 minutes of arrest followed by 10 minutes of systemic recirculation during hypothermia (total, 120 minutes of arrest). The oxyhemoglobin concentration in the brain was measured with near infrared spectrophotometry. RESULTS: In groups 2, 3, and 4, the oxyhemoglobin concentration in the brain decreased continuously after arrest, finally reaching a plateau after 24.9 +/- 1.2 minutes. This finding suggested that the available cerebral oxyhemoglobin was depleted. In contrast, the available cerebral oxyhemoglobin was not depleted during hypothermic intermittent arrest in group 5. The mitochondrial respiratory control index was significantly lower in group 4 than in the other groups (p < 0.05). However, there were no significant differences in the respiratory control index for groups 1, 2, 3, and 5. Moreover, the formation of brain edema was significantly lower in group 5 than in the other groups (p < 0.05). CONCLUSIONS: These results indicate that deep hypothermic intermittent arrest can increase the duration of total permissible circulatory arrest and will be a useful modality when prolonged arrest is anticipated.

Animals↗
PubMed1998

Deep hypothermic intermittent circulatory arrest--an adjunct technique for operations on aneurysms involving the aortic arch.

Aneurysms involving the aortic arch were repaired in 12 patients using a technique known as deep hypothermic intermittent circulatory arrest (DHICA). This technique consists of repeated cycles of 20 min of circulatory arrest and 10 min of cerebral and systemic reperfusion. Aneurysms were of the following types: 2 true atherosclerotic aneurysm, 8 aortic dissections, and 2 traumatic aneurysm. There were 2 operative deaths caused by coagulopathy as a result of hepatic failure and difficulty with left ventricular venting. The frequency of circulatory arrest ranged from 2 to 5 cycles, and total circulatory arrest ranged from 20 to 71 min (mean 43.6 min). The lowest tympanic temperature ranged from 17.7 to 19.2 degrees C. No permanent cerebral complications occurred in 10 patients. We believe that this adjunct technique offers excellent results in the surgical treatment of aneurysms involving the aortic arch.

Adult↗
PubMed1998

[A case of type A dissecting aneurysm who are complicated by paraplegia at the 4th day after emergent operation].

The 62-year-old man was admitted to our hospital with chief complaints of chest and back pain. He was diagnosed type A acute dissecting aneurysm by chest computed tomography, and underwent urgent operation, replacement of the ascending aorta and resuspension of the aortic valve. He was recovered without any neurologic complications. However, he was complicated by paraplegia at the 4th postoperative day. We suspect that is due to early thrombotic occlusion of the false lumen where the anterior spinal arteries branch by the operation.

Aortic Dissection↗
PubMed1998

Abdominal aortic aneurysmectomy in the octogenarian.

The risks, results, and postoperative quality of life were evaluated in 11 patients aged 80 years or older who underwent resection of an abdominal aortic aneurysm (AAA). The operative mortality was 9% (1/11). Three patients underwent urgent operation, 1 for impending rupture, 1 for contained rupture, and 1 for rupture into the sigmoid colon. Preoperative risk factors such as hypertension, electrocardiographic abnormalities, and respiratory dysfunction were found in about half of the patients. Neither operative mortality nor long-term survival were influenced by the preoperative risk factors. The quality of life enjoyed by these patients was not adversely affected by AAA resection. Surgical treatment of AAA should be undertaken in selected octogenarians to prevent rupture. Physiologic status rather than chronologic age should determine which patients undergo aneurysm resection.

Aged↗
PubMed1997

Effect of spinal cord preconditioning on paraplegia during cross-clamping of the thoracic aorta.

BACKGROUND: Paraplegia is a devastating complication of operations for thoracic or thoracoabdominal aneurysms. Preconditioning the brain with sublethal ischemia induces resistance to subsequent ordinarily lethal ischemia (ischemic tolerance). We investigated whether ischemic tolerance could be induced by preconditioning canine spinal cord. The role of heat-shock proteins (HSP) in this process was investigated. METHODS: In experiment 1, the preconditioning group (n = 6) had aortic cross-clamping for 20 minutes, whereas controls (n = 6) had no cross-clamping. After 48 hours the aorta was cross-clamped for 60 minutes in both groups. Neurologic examination was performed 24 hours later and the spinal cord was studied for immunohistochemically. In experiment 2, either 48 hours after 20 minutes of clamping or after sham operation (n = 4), HSP were investigated immunohistochemically. RESULTS: In experiment 1, 3 of 6 controls became paraplegic but none of the 6 preconditioning group dogs became paraplegic. The HSP appeared on sections from all 6 PC dogs and 3 control dogs that did not exhibit paraplegia. In experiment 2, HSP were present in clamped animals but could not be detected after sham operation. CONCLUSIONS: Ischemic tolerance was induced by preconditioning the canine spinal cord, in which HSP are believed to be involved.

Animals↗
PubMed1997

[A simple device of chest wall reconstruction].

We devised a simple method of chest wall reconstruction in two cases of malignant tumor of the chest. We strained a suture (adsorbable or monofilament) to the intact ribs above and below the defect and fixed the sheets of Marlex mesh in double layers and closed the skin without any myocutaneous flap. The postoperative course was uneventful. This device is simple and effective method to maintain the stability of the chest wall defect.

Aged↗
PubMed1996

Surgical treatment of infected thoracic and abdominal aortic aneurysms.

Twelve patients with infected aneurysms of the thoracic and abdominal aorta were evaluated. Aneurysmal location, aetiology, bacteriology and treatment modality were analysed to determine the relationship between these factors and outcome. Patients were divided into two groups based on the preoperative states of their infections. Group 1 patients (n = 7) underwent resection after resolution of their active infection. The causative organisms included Staphylococcus epidermidis (two cases). Salmonella spp. (one). Acinetobacter (one), Mycobacterium tuberculosis (one) and unknown organisms (two). Group 2 patients (n = 5) required urgent surgery because of uncontrolled sepsis despite intensive treatment with antibiotics. The causative organisms included Staphylococcus aureus (two cases). Pseudomonas aeruginosa (two) and Salmonella spp. (one). In group 1, three patients underwent closed en bloc excision of the aneurysm with in-situ graft replacement, and four underwent partial resection with in-situ graft replacement. In group 2, three patients underwent resection of the aneurysm with ligation of aorta and extra-anatomic bypass, and two underwent in-situ graft replacement after débridement of infected tissue. Overall, patients in group 1 had a mortality rate of 14% compared with 80% in group 2. These results suggest that the operative approach and method chosen to restore arterial continuity have less of an impact on outcome. The primary determinants of outcome are virulence of the infecting organism and the preoperative state of the infection.

Acinetobacter Infections↗
PubMed1996

Leukocyte and platelet depletion with a blood cell separator: effects on lung injury after cardiac surgery with cardiopulmonary bypass.

This study was undertaken to assess the effects of leukocyte and platelet depletion on postoperative lung injury in 42 patients who underwent heart operations. Blood was serially sampled before, during, and after cardiopulmonary bypass, and leukocyte count, platelet count, and thromboxane B2 6-keto-PGF1 alpha, leukocyte elastase, thrombin-antithrombin III complex, and D-dimer levels were determined. Postoperative respiratory function was assessed based on analyses of oxygenation and carbon dioxide elimination. Leukocyte and platelet depletion was performed in 21 patients (experimental group) but not in another (control group). In the experimental group, leukocytes and platelets were removed continuously by means of the blood cell separator CS-3000, beginning immediately after the start of the operation and ending 1 hour after the release of aortic occlusion. Leukocyte elastase, thromboxane B2, ratio of thromboxane B2 to 6-keto-PGF1 alpha, thrombin-antithrombin III complex, and D-dimer were significantly lower in the experimental group than in the control group. Of the various indexes of oxygenation, arterial oxygen tension was significantly higher in the experimental group and the alveolar-arterial oxygen pressure difference and respiratory index were significantly lower in the experimental group. The positive end-expiratory pressure needed to achieve an appropriate arterial oxygen tension was significantly lower in the experimental group. The elimination of carbon dioxide was lower in the experimental group. Depletion of leukocytes and platelets reduced respiratory dysfunction after heart operations with cardiopulmonary bypass. It was particularly effective in patients with a low preoperative oxygenation capacity and in those for whom an extended period of cardiopulmonary bypass was required.

6-Ketoprostaglandin F1 alpha↗
PubMed1995

The successful repair of annuloaortic ectasia using Cabrol's operation in a 5-year-old child with Marfan's syndrome of the forme fruste type.

This report describes our experience of treating a 5-year-old boy with annuloaortic ectasia and a presumptive diagnosis of Marfan's syndrome. He had elongation of the distal aortic arch and dilatation of the abdominal aorta. Surgical repair of annuloaortic ectasia was successfully carried out using Cabrol's operation, following which no significant perioperative complications developed. To our knowledge, this is the first reported case of Cabrol's operation being successfully performed on a child aged 5 years or less.

Aortic Diseases↗
PubMed1995

[A case of simultaneous treatment with mitral valve replacement and aorto-coronary bypass grafting of hypertrophic obstructive cardiomyopathy and coronary artery disease].

A case of surgical treatment of coexistent hypertrophic obstructive cardiomyopathy (HOCM) and coronary artery disease (CAD) in a 65-year-old male patient is reported. He had been diagnosed as HOCM and treated conservatively with beta-blocker and Ca-antagonist, but his complaints of chest oppression and palpitation had increased. Echocardiography revealed a systolic anterior motion of the mitral valve and mitral regurgitation. Cardiac catheterization showed a severe mitral regurgitation and peak systolic pressure gradient of 35 mmHg between the left ventricular and systemic artery. In addition, selective coronary angiography demonstrated a 99% stenosis in segment 7. He underwent aortocoronary bypass grafting and concomitant mitral valve replacement, and marked symptomatic and hemodynamic benefit could be achieved. This case shows the coexistence of HOCM and CAD in the same patient and suggest not only HOCM but also CAD should be routinely examined in the patient with angina, particularly when operative management is contempted. This case further suggests that simultaneous treatment of both diseases is more beneficial than single treatment of CAD or HOCM.

Aged↗