Biomedical subjects

J Utoh

Publications and source records attributed to J Utoh.

At least 37 records · Page 2Linked to original sources

PubMed1999

The effects of cardiopulmonary bypass on postoperative oxygen metabolism.

The relationships between oxygen delivery (DO2), oxygen consumption (VO2), and the extraction rate (ER = VO2/DO2 x 100) in patients undergoing cardiopulmonary bypass (CPB) may differ from the normal physiologic state due to the oxygen debt acquired during CPB. Blood gas analysis and hemodynamic parameters were repeatedly measured for the determination of DO2 and VO2 in 40 patients undergoing CPB, every 8 h during the first 48 h postoperatively. As a control, 20 patients who had suffered acute myocardial infarction (AMI) were also studied using the same protocol. In the CPB group, a regression analysis showed that VO2 was significantly dependent on DO2, even within the physiologic range of DO2 (>500 ml/min per m2); VO2 = 121.4 + 0.0844 x DO2 (r = 0.254, P = 0.023). Conversely, in the AMI group, no such supply-dependent consumption was observed within the same range of DO2. At an ER of 30%, which is the optimal value in general, the DO2 of the CPB group was 575 ml/min per m2 and that of the AMI group was 493 ml/min per m2. All these results suggest that patients undergoing CPB need a much higher oxygen supply to recover from the oxygen debt acquired during open heart surgery.

Aged↗

PubMed1999

Transient dysfunction of the freestyle stentless xenograft.

After replacement of a bicuspid aortic valve with a Freestyle stentless xenograft, right coronary leaflet dysfunction and an elevated pressure gradient developed. Attempts to match the right and left ostia of the prosthesis, which were located at an angle of less than 120 degrees, to the native right and left ostia, which were located at 180 degrees, may have resulted in the leaflet distension. This is a suggestive finding about its implantation technique.

Aortic Valve↗

PubMed1999

Recovery from metabolic impairments after hypothermic cardiopulmonary bypass: postoperative changes in arterial-venous carbon dioxide tension difference.

Arterial-venous carbon dioxide tension differences (Pv-aCO2) are known to increase during the resuscitation phase following several types of shock. We hypothesized that Pv-aCO2 increases immediately following hypothermic cardiopulmonary bypass (CPB) because of the metabolic impairments that occur during CPB. Fifty-six adult patients underwent hypothermic CPB for cardiac surgery. Arterial and mixed venous blood gases were analyzed every 6 hours for the first 24 hours following cardiac surgery. Immediately after surgery, the Pv-aCO2 was elevated (8.2 +/- 2.9 mmHg), but gradually returned to a normal range within 12 hours (6.2 +/- 3.2 mmHg, p < 0.001). Factors (X) which correlated significantly with the postoperative Pv-aCO2 (Y) included the minimum rectal temperature during CPB (Y= 27.3 - 0.664X, p = 0.011) and the duration of CPB (Y= 5.6 + 0.0172X, p = 0.047). The abnormally high Pv-aCO2 during the early postoperative period may be caused by metabolic impairments during hypothermic CPB. The recovery stage following open heart surgery is therefore similar to the resuscitation phase after shock.

Aged↗

PubMed1999

[Stentless aortic root bioprosthesis (freestyle) to patients of bicuspid aortic valve with abnormal positioning of the coronary ostia].

Stentless aortic root bioprosthesis (Freestyle) was implanted to two patients of bicuspid aortic valve stenosis with anatomically abnormal positioning of the coronary ostia. In a patient of LR type bicuspid valve, the left coronary artery was located at 180 degrees against the right coronary ostium. To match the Valsalva sinus of the patient with bioprosthesis, the left half of the native annulus, 23 mm in the diameter, was plicated corresponding to the one third of the Freestyle inflow, 21 mm in the diameter. In the other patient of AP type bicuspid valve, both coronary ostia were closely positioned at 90 degrees. To keep both ostia in the sinus of bioprosthesis, careful trimming and suturing were required in the narrow part of both ostia. Their postoperative courses were uneventful and no regurgitation has been observed in either case.

Aged↗

PubMed1999

Direct expiratory gas analysis after hypothermic cardiopulmonary bypass.

We hypothesized that patients who have undergone hypothermic cardiopulmonary bypass may have abnormal oxygen metabolism after cardiac surgery because of oxygen debts that occurred during cardiopulmonary bypass. A prospective study was designed to determine oxygen consumption and carbon dioxide production using an indirect calorimeter in 45 adult patients who underwent hypothermic cardiopulmonary bypass. Inspiratory and expiratory gases were analyzed and the respiratory exchange ratio (carbon dioxide production/ oxygen consumption) was obtained every 6 hours up to 24 hours after surgery. The respiratory exchange ratio immediately following cardiopulmonary bypass was abnormally high then gradually decreased. The respiratory exchange ratio at 18 or 24 hours after surgery was significantly lower than the one on admission to the intensive care unit. Duration of cardiopulmonary bypass was the most significant parameter which correlated to the respiratory exchange ratio on admission to the intensive care unit (r = 0.82, p < 0.001). We conclude that the respiratory exchange ratio can be used to monitor systemic metabolism, especially during the recovery phase from metabolic abnormality following hypothermic cardiopulmonary bypass.

Adult↗

PubMed1999

[Clinical results of surgical repair for thoracic aortic aneurysms: intraoperative blood loss and morbidity].

Clinical results of 64 patients who underwent surgical repair for thoracic aortic aneurysms were studied, focusing on the relationship between intraoperative blood loss and postoperative morbidity. Operative mortality was 22% in the urgent repair group and 9% in the elective repair group. Deep hypothermia, operative death, postoperative complication were the factors which significantly correlated to the amount of intraoperative blood loss. In patients who received deep hypothermia, larger blood loss and higher incidence of mortality and morbidity were observed. There was a significant relationship between the lowest core temperature during cardiopulmonary bypass and the lowest platelet count. Intraoperative blood loss revealed as a strong risk factor to directly influence postoperative clinical outcome of thoracic aortic operation.

Aortic Aneurysm, Thoracic↗

PubMed1998

Cardiovascular Effects of Bolus-Administered Vasodilators in Elderly Patients with Atherosclerotic Disease: A Comparative Study of Nitroglycerin and Prostaglandin E1

To evaluate the hemodynamic effects of vasodilators in elderly patients with atherosclerotic disease, systemic hemodynamics were examined during cardiac catheterization study. After the intravenous bolus injection of nitroglycerin (NTG, 5 µg/kg, n = 20) or prostaglandin E1 (PGE1, 0.2 µg/kg, n = 20), significant reduction of mean arterial pressure, pulmonary capillary wedge pressure (PCWP), systemic vascular resistance index (SVRI), and rate-pressure product (RPP) was observed. In contrast, cardiac index and stroke index were not significantly deteriorated in either group. In conclusion, bolus-administered NTG and PGE1 had beneficial vasodilating effects without harmful impact on cardiac functions in elder patients with atherosclerotic disease.

Journal Article↗

PubMed1998

Anticoagulant Effects of Argatroban on the Pre-DIC State in Patients with an Aortic Aneurysm: A Comparative Study of Heparin

We compared the efficacy of argatroban, a new synthetic thrombin-specific inhibitor, with that of heparin in pre-DIC state patients with abdominal aortic aneurysm (AAA). A pre-DIC state was diagnosed by a detection of soluble fibrin monomer complex (FM) and increased levels of thrombin-antithrombin III complex (TAT) of more than 20 ng/ml. Twelve patients showing a pre-DIC condition were treated with argatroban (40 mg/day, n = 6) or heparin (10,000 U/day, n = 6) for 5 days. Coagulation and fibrinolytic profiles were analyzed before and after drug administration. FM became negative in two (33%) patients after the argatroban treatment and in all (100%) of the heparin-treated patients. Plasma levels of TAT were significantly decreased after the heparin treatment, however, there was no significant alteration in this parameter after the argatroban treatment. In conclusion, the anticoagulant effects of heparin were superior to those of argatroban in controlling the pre-DIC state associated with AAA.

Journal Article↗

PubMed1998

[Cardiac hemangioma of the right ventricle--report of a case].

A 74-year-old male was admitted to our hospital with a diagnosis of intra-cardiac tumor on echochardiography, CT, and MRI. The tumor was located on the free wall of the right ventricle and protruded into the outflow tract. The surgical excision of the tumor was performed under cardiopulmonary bypass. The size of the tumor was 5 x 5 x 4 cm. Histological examination disclosed cavenous hemangioma. The post opertive course was uneventful. This is the forth case reported in Japan and the fifteenth case in the world.

Aged↗

PubMed1998

[A surgical case for concomitant coronary artery disease and ASO with advanced colon cancer].

We report a successful surgical case of concomitant severe coronary artery disease and ASO with advanced sigmoid colon cancer. This patient underwent two-stage operation. Resection of the sigmoid colon was carried out first, then CABG and aortofemoral bypass was carried out simultaneously. The surgical strategy of a patient with coronary artery disease and malignant neoplasm is still controvertial, however, it should be decided considering the severity and the symptoms of both disease. In this case, ascending aorta was used as a donor artery for aortofemoral bypass. This technique will bring those benefits, i.e., consecutive operation procedures in same operating field, obtaining abundant blood flow to lower limb and safe IABP catheter insertion from subcutaneously tunneled bypass graft.

Adenocarcinoma↗

PubMed1998

[Clinical benefits of normothermic cardiopulmonary bypass on postoperative systemic metabolism].

To evaluate the influence of body temperature during cardiopulmonary bypass (CPB) on postoperative systemic metabolism, 32 patients undergoing elective cardiac surgery were randomly assigned to either hypothermia (n = 16) or normothermia (n = 16). Serial hemodynamic parameters and blood samples were obtained after surgery. CPB and operation times were significantly shorter and the platelet reduction ratio during CPB [ = (platelets before CPB-platelets after CPB)/platelets before CPB] was significantly lower in normothermic patients than in hypothermic patients. The platelet reduction ratio was dependent on the minimum rectal temperature during CPB, the operation time, and the CPB time. In the early postoperative period, hypothermic patients had abnormally high systemic vascular resistance and a reduced cardiac index compared with the normothermic patients. There were no differences between 2 groups in postoperative hepatic and renal functions, changes in oxygen consumption, arterial-venous PCO2 or arterial-venous pH gradient. This study suggested a beneficial influence of normothermic CPB on postoperative hemodynamics. Normothermic CPB was not associated with adverse effects on postoperative metabolic recovery.

Aged↗

PubMed1998

Dilatation of sealed Dacron vascular prostheses: a comparison of Gelseal and Hemashield.

OBJECTIVE: Early postoperative dilation of a gelatin-impregnated knitted dacron prosthesis (Gelseal, Vascutek) and a collagen-impregnated woven Dacron prosthesis (Hemashield, Meadox Medicals) was studied. EXPERIMENTAL DESIGN: Prospective study. SETTING: Institutional clinical research. MATERIALS AND METHODS: A total of 30 patients who underwent aortic repair for abdominal aortic aneurysm with a Gelseal (n=15) or Hemashield (n=15) were studied. Prior to and immediately following implantation, the diameter of each graft was measured with slide calipers. The external diameter was examined by CT scan 4 weeks after surgery. Early dilation of Gelseal and Hemashield was estimated and compared. RESULTS: Prior to implantation, the external diameter of the Gelseal and Hemashield was 120% and 113% of the package size (PS), respectively, while the internal diameter was 103% and 102% of the PS, respectively. Following implantation, the external diameter of the Gelseal and Hemashield was 122% and 113% (immediately after) and 129% and 118% (4 weeks later) of the PS, respectively. CONCLUSIONS: The actual dilation rate for the first 4 weeks after implantation was estimated as 8% with the Gelseal and 4% with the Hemashield.

Aged↗

PubMed1998

Routine coronary angiography prior to abdominal aortic aneurysm repair: incidence of silent coronary artery disease.

OBJECTIVE: Routine coronary angiogram (CAG) was performed in patients prior to elective repair of abdominal aortic aneurysm (AAA) to estimate the incidence of coronary artery disease (CAD) and to compare with risk factors for CAD and resting electrocardiogram (ECG). METHODS: History of CAD, risk factors for CAD, resting ECG, and standard CAG were assessed in 50 consecutive AAA patients. RESULTS: Nine patients had a history of CAD. Risk factors included: smoking in 82%, hypertension in 58%, hypercholesterolemia in 42%, and diabetes in 18%. CAG revealed that 46% of the patients had severe CAD with greater than a 75% stenosis of one or more coronary arteries. There was no relationship between the number of risk factors and prevalence of CAD. Eleven patients who had severe CAD as detected by CAG had no history of CAD and displayed no ischemic findings on ECG. No perioperative myocardial infarctions or angial attacks were noted despite the absence of prophylactic coronary interventions or revascularizations. CONCLUSIONS: The prevalence of severe CAD was 46% and incidence of silent CAD was 22% in this AAA population. The numbers of coronary risk factors and resting ECG were not worthwhile for predicting silent CAD.

Aged↗

PubMed1998

Successful treatment of aortoesophageal fistula resulting from aneurysm of the aortic arch.

Aortoesophageal fistulas from primary thoracic aortic aneurysms are almost always fatal. In the English literature we have found only four successfully managed cases, all descending thoracic aortic aneurysms. We report an elderly woman who developed an aortoesophageal fistula from an aortic arch aneurysm. She was successfully managed with graft replacement including reattachment of arch vessels and a staged esophagectomy which was accompanied by mobilization of the omentum into the space between the esophagus and the prosthetic graft. She was the first successfully treated patient with aortoesophageal fistula resulting from aortic arch aneurysm.

Aged↗

PubMed1998

Life-threatening reperfusion injury in skeletal muscle: a simple technique to control critical hyperkalemia.

A 55-year-old male suffering from acute abdominal aortic occlusion due to iatrogenic aortic dissection was urgently admitted to hospital. An axillo-bifemoral bypass was constructed 6 hours from the onset of dissection. Before and after revascularization, blood samples were repeatedly obtained from a systemic artery and femoral vein. The arterial potassium concentration gradually increased, reaching 7.3 mM/L. Oliguria and arrhythmias occurred, and the left lower limb became rigid 3 hours after reperfusion. The femoral artery and vein were clamped and within 30 minutes, the arterial potassium concentration fell to 4.8 mM/L. The urine output increased. The left lower limb was amputated, and the patient survived. Immediately following revascularization, hyperkalemia may occur. Clamping of the afferent and efferent vessels is recommended as a simple and practical technique to quickly control life-threatening hyperkalemia.

Amputation, Surgical↗

PubMed1997

[Arterial-venous carbon dioxide tension difference after hypothermic cardiopulmonary bypass].

Arterial-venous carbon dioxide tension difference (Pv-aCO2) is known to become high after severe hemorrhage shock and resuscitation. We hypothesized that Pv-aCO2 might be high after cardiac surgery because of the oxygen debt occurred during hypothermic cardiopulmonary bypass (CPB). Blood pressure, cardiac index, hemoglobin, the arterial and mixed venous blood gases were repeatedly measured every 6 hours for 24 hours following cardiac surgery in 60 adult patients who underwent hypothermic CPB. Immediately after the surgery, Pv-aCO2 was extremely high, then gradually decreased to within normal ranges 12 hours later (8.0 +/- 2.9 mmHg vs 5.9 +/- 3.1 mmHg. p < 0.01). Factors which significantly correlated to Pv-aCO2 were cardiac index, oxygen delivery, minimum rectal temperature and duration of CPB. Oxygen debt during hypothermic CPB might cause significantly high Pv-aDO2. At least 12 hours were necessary to recover from anaerobic status to physiological condition.

Adult↗

PubMed1997

Postoperative inflammatory reactions to sealed Dracon prostheses: a comparison of Gelseal and Hemashield.

OBJECTIVE: The purpose of this study was to assess and compare inflammatory reactions to two types of sealed vascular prostheses used in the repair of abdominal aortic aneurysm. EXPERIMENTAL DESIGN: Randomized prospective study with a follow-up period of 21 days. SETTING: University hospital study. PATIENTS: Sixty patients admitted for elective abdominal aortic aneurysm repair. INTERVENTION: Each patient underwent repair of abdominal aortic aneurysm with either a gelatin-sealed knitted Dacron prosthesis (Gelseal, Vascutek, n = 30) or a collagen-sealed woven Dacron prosthesis (Hemashield, Meadox Medicals, n = 30). MEASURES: As indicators of the presence of inflammation, the peripheral blood cell count, platelet count, and plasma C-reactive protein (CRP) concentration were determined in each patient on postoperative days (PODs) 1, 7, 14 and 21. Body temperature was measured every 8 hours. RESULTS: Patients in both groups revealed a low-grade fever and leukocytosis during the first 7 PODs. Significantly higher leukocyte counts were demonstrated in the Gelseal group on PODs 7 and 14. However, no difference in the leukocyte count, CRP concentration, or body temperature existed between the two groups on POD 21. Biphasis changes in the platelet count were observed in both groups. No complications were encountered. CONCLUSION: The Gelseal prosthesis was associated with higher inflammatory response during the second week following implantation, but this difference had resolved by POD 21. This finding may reflect an inflammatory reaction against impregnated gelatin.

Aged↗

PubMed1997

Acute aortic dissection without intimal tear.

A case of acute aortic dissection without intimal tear is reported. A 68-year-old woman with acute onset of Stanford type-B aortic dissection was admitted. Because of progressive anemia and pleural leakage, an operation was performed. False lumen of the descending thoracic aorta was occupied with fresh hematoma, but no sign of an intimal defect was found. Although aortic dissection without intimal tear has been reported via angiography, CT scan, MRI, and autopsy, surgically confirmed cases of this type of dissection have been rarely reported.

Acute Disease↗