Biomedical subjects

K Onoguchi

Publications and source records attributed to K Onoguchi.

At least 19 recordsLinked to original sources

PubMed2006

[Infectious endocarditis associated with multiple mycotic aneurysms; report of a case].

A 68-year-old man was referred to our hospital with infectious endocarditis (IE) of the mitral valve complicated by mycotic aneurysms located in the right middle cerebral artery (MCA) and the superior mesenteric artery (SMA). After coil embolization of the SMA aneurysm during angiography, surgical treatment of the MCA aneurysm was carried out. Antibiotic therapy for Enterococcus faecalis was continued throughout this period. After his IE was controlled, mitral valve repair was performed. The old vegetation on the edge of the anterior leaflet was resected and the defect was covered by transferring the posterior leaflet using the flip-over technique. Since there is no agreement about the optimum treatment of IE associated with multiple mycotic aneurysms, it is important to carefully plan the management of individual cases.

Aged↗

PubMed2004

[Multiple myxoma in the left ventricle and the left atrium].

Left ventricular myxoma is particulary rare. Our case is a 77-year-old female. Transesophageal echocardiography showed a giant tumor in the left atrium. An urgent operation was performed. A giant mass was excised en bloc via a transinteratrial septal approach. Histopathologically it was myxoma. As a transthoracic echocardiography at 1-year postoperation showed a tumor in the left ventricle. A mass was excised en bloc via a vertical approach. Histopathologically it was diagnosed again as myxoma. We looked at the earliest transesophageal echocardiogram again, and found the small tumor on the same area under the posterior mitral leaflet. At the diagnose of cardiac tumor, possibility of multiple formation should be always considered.

Aged↗

PubMed2003

[Left ventricular papillary fibroelastoma associated with chief complaints of palpitation, general fatigue, and feverish].

Papillary fibroelastoma is one of the commonest benign tumor in the heart. In almost all of cases, symptoms never develop and the tumors are usually discovered coincidentally. Even though papillary fibroelastoma is a benign tumor, surgical extirpation is usually indicated for reason of productive serious complications. The tumors may cause left ventricular outflow obstruction, cerebral embolic infarction, myocardial infarction and even sudden death. The case we reported here is unusual case, because the patient developed symptoms and complaints such as palpitation, feverish and general fatigue. We measured tumor markers, interleukin 6, serotonin and histamine, but none of those was elevated in the blood samples. Surgical removal of the tumor attached to the base of posterior papillary muscle was carried out without causing mitral incompetence, and the pathological findings were compatible with papillary fibroelastoma. After the operation, the both symptoms and complaints disappeared unexpectedly.

Fatigue↗

PubMed2001

Jaundice after surgery for an aortic arch aneurysm.

A 57-year-old patient who developed hyperbilirubinemia after surgery for an aortic arch aneurysm subsequently suffered pseudomonas sepsis. Low-volume biliary drainage from the common bile duct was colorless. A disturbance in the liver's excretory system caused jaundice. Sepsis and jaundice were resolved when hepatic excretory function recovered.

Aortic Aneurysm, Thoracic↗

PubMed2001

Right atrial myxoma complicated with pulmonary embolism.

A 25-year-old woman was admitted to our hospital with chest pain and dyspnea, and was diagnosed as having a right atrial myxoma complicated with pulmonary embolism. An emergency operation was performed with cardiopulmonary bypass. A papillary pedunculated tumor was found having a narrow-based attachment to the free atrial wall. After the tumor was carefully removed together with the atrial wall around the attachment, pulmonary embolectomy was performed. Several fragments of the tumor were removed, and sufficient back-flow from the pulmonary artery was established. The postoperative course was uneventful. However, a non-perfused area was observed in the left lower lung on pulmonary hemodynamic scintigraphy at 3 months after the operation. Long-term observation is required due to the high risk for metastasis and recurrence, and further surgical treatment remains the most appropriate treatment option. A second operation may be needed to prevent progression in complications.

Adult↗

PubMed2001

Chronic dissecting aneurysm of the thoracic aorta following minor blunt trauma.

A 64-year-old man admitted for treatment of a thoracic aneurysm had experienced severe back pain 10 years earlier after falling heavily on his forearms. From the night following the fall, hoarseness and pleuritic chest wall pain continued for about 3 months. Preoperative imaging showed a chronic dissecting aneurysm near the aortic isthmus. The patient's history suggested that the fall 10 years before surgery was the most likely cause.

Aortic Dissection↗

PubMed2001

Hemodynamic evaluation of 19-mm Carpentier-Edwards pericardial bioprosthesis in aortic position.

BACKGROUND: The aortic Carpentier-Edwards pericardial bioprosthesis offers good long-term clinical outcomes with a low rate of structural deterioration. However, little in vivo hemodynamic data is available for this bioprosthesis. METHODS: To determine the hemodynamic performance of the 19-mm Carpentier-Edwards pericardial valve, both cardiac catheterization and dobutamine stress echocardiography were electively performed in 10 patients. The mean age at the study was 71.6 +/- 4.4 years and the mean body surface area was 1.39 +/- 0.11 m2. The peak-to-peak gradient, instantaneous peak gradient, mean gradient, and valve orifice area were measured by standard cardiac catheterization. The Doppler-derived gradients and valve orifice area were also measured both at rest and during dobutamine infusion. RESULTS: The average peak-to-peak gradient, instantaneous peak gradient, mean gradient, and valve orifice area measured by catheterization were 13.0 +/- 5.4 mmHg, 28.5 +/- 7.7 mmHg, 12.0 +/- 4.9 mmHg, and 1.55 +/- 0.45 cm2, respectively. The peak and mean Doppler gradients, and valve orifice area by resting echocardiography were 27.7 +/- 9.5 mmHg, 12.3 +/- 4.8 mmHg, and 1.39 +/- 0.26 cm2, respectively. At a dosage of 10 microg/kg/min of dobutamine, the mean Doppler gradient rose mildly to 22.2 +/- 4.8 mmHg, while the cardiac output increased from 4.49 +/- 0.44 to 6.64 +/- 0.87 L/min. The valve orifice area during the 10 microg/kg/min dobutamine infusion (1.55 +/- 0.25 cm2) was significantly larger than its value at rest (p < 0.05). CONCLUSIONS: With acceptable hemodynamic performance, use of the aortic 19-mm Carpentier-Edwards pericardial valve is a reliable option for elderly patients with a small annulus.

Aortic Valve↗

PubMed2001

Congenital mitral regurgitation from absence of the anterolateral papillary muscle.

A 21-year-old woman had congenital mitral regurgitation. Echocardiography showed absence of the anterolateral papillary muscle and corresponding marginal chordae. This rare abnormality was corrected by anterolateral commissural annuloplasty and insertion of artificial chordae to prevent prolapse of the anterior leaflet. Postoperatively, there was no regurgitation, and an appropriate mitral valve area was achieved.

Adult↗

PubMed2001

Superior hepatic mitochondrial oxidation-reduction state in normothermic cardiopulmonary bypass.

OBJECTIVE: This study is the first comparative investigation of hepatic blood flow and oxygen metabolism during normothermic and hypothermic cardiopulmonary bypass. METHODS: Twenty-four patients undergoing coronary bypass operations were randomly divided into 2 groups according to their perfusion temperatures, either normothermia (36 degrees C) or hypothermia (30 degrees C). The clearance of indocyanine green was measured at 3 points. Arterial and hepatic venous ketone body ratios (an index of mitochondrial redox potential) and hepatic venous saturation were measured. RESULTS: Hepatic blood flow in both groups was identical before, during, and after cardiopulmonary bypass (normothermia, 499 +/- 111, 479 +/- 139, and 563 +/- 182 mL/min, respectively; hypothermia, 476 +/- 156, 491 +/- 147, and 560 +/- 202 mL/min, respectively). The hepatic venous saturation levels were significantly lower during cardiopulmonary bypass in the normothermic group (normothermia, 41% +/- 13%; hypothermia, 61% +/- 18%; P <.01), indicating a higher level of oxygen extraction use. The arterial ketone body ratio in the hypothermic group decreased severely after the onset of cardiopulmonary bypass (P <.01) and did not return to its subnormal value (>0.7) until the second postoperative day. However, the reduction in arterial ketone body ratio was less severe in the normothermic group. The difference in hepatic venous ketone body ratios was more obvious, and the hepatic venous ketone body ratios in the normothermic group were statistically superior to those of the hypothermic group throughout the course (P <.05-.01). CONCLUSIONS: Normothermic cardiopulmonary bypass provides adequate liver perfusion and results in a better hepatic mitochondrial redox potential than hypothermic cardiopulmonary bypass. Because arterial ketone body ratios reflect hepatic energy potential, normothermia was considered to be physiologically more advantageous for hepatic function.

Aged↗

PubMed2001

Beneficial effect of balloon-induced pulsatility on brain oxygenation in hypothermic cardiopulmonary bypass.

BACKGROUND: Sufficient O2 delivery to meet the demand is an important factor for protecting the brain during cardiopulmonary bypass (CPB). This study was designed to investigate the influences of temperature, pulsatility of blood flow (intra-aortic balloon pump-induced) and flow rate during CPB on the cerebral oxygenation. METHODS: Patients were divided into five groups. Normothermia (36 degrees C): pulsatile (n=8, 2.5 L/min/m2), nonpulsatile (n=12, 2.5 L), and nonpulsatile perfusion (n=12, 2.8 L); hypothermia (30 degrees C): pulsatile (n=9, 2.5 L) and nonpulsatile perfusion (n=11, 2.5 L). The oxygen saturation (SjVO2), lactate and CPK-BB levels in the jugular venous blood were measured. RESULTS: In all of the normothermic groups, the SjVO2 value decreased during the CPB (p<0.1-0.01). No remarkable change was observed in the hypothermic groups, with the exception during the rewarming period in the nonpulsatile group. A higher SjVO2 and a lower frequency of SjVO2 values <50% were observed in the hypothermic pulsatile group, as compared with those in the normothermic groups (p<0.05). The levels of CPK-BB were nearly the same, however the levels of lactate were higher in the normothermic pulsatile and nonpulsatile (2.5 L) groups (p<0.05). CONCLUSIONS: We concluded that the hypothermic CPB was advantageous over normothermic CPB in regard to the SjVO2 levels and lactate production. The beneficial effect of intra-aortic balloon pump assist was only obtained in the hypothermic CPB.

Aged↗

PubMed2001

[Three-dimensional computed tomography angiography of coronary artery bypass graft with electron beam tomography].

OBJECTIVES: Assessment of coronary artery bypass graft patency by three-dimensional reconstructed computed tomography angiography (3D-CTA) derived from electrocardiography-gated contrast-enhanced electron beam tomography (EBT) was evaluated. METHODS: Thirty-nine patients with 99 grafts (45 arterial grafts and 54 venous grafts) underwent 3D-CTA and selective coronary angiography within a 3-week interval. 3D-CTA images of the coronary bypass grafts were compared with the coronary angiography images used as the control. RESULTS: 3D-CTA defined 42 of 44 arterial grafts as patent (sensitivity: 95%), all 47 venous grafts as patent (sensitivity: 100%) and all 7 venous grafts as occlusive (specificity: 100%). The overall sensitivity and specificity were 98% and 88%, respectively. CONCLUSIONS: 3D-CTA is an useful noninvasive technique with adequate sensitivity and specificity to assess coronary artery bypass graft patency.

Aged↗

PubMed2000

Influence of cardiopulmonary bypass temperature on circulatory pathophysiology and clinical outcomes.

This study was designed to investigate the effects of cardiopulmonary bypass (CPB) perfusion temperature. Forty-four patients who had undergone elective coronary bypass surgery were randomly divided into 2 groups (22 patients each) according to their perfusion temperature (N group=36 degrees C; L group=30 degrees C). The concentrations of endogenous catecholamines, complements, elastase, serotonin, arachidonic acid metabolites and endothelin underwent various changes throughout the CPB but did not exhibit any statistical differences in either group. None of the substances measured correlated with systemic vascular resistance at any time. The temperature of the perfusion appears to be a major determinant of vascular tone. The postoperative PO2 was better, and postoperative pulmonary vascular resistance lower in the N group (p<0.05), most likely because of a much larger water balance during hypothermic CPB (p<0.01). The postoperative blood loss was statistically less in the N group (p<0.05). Although apparent brain damage, evidenced by the leakage of creatine kinase-BB, was not seen, the jugular bulb venous hemoglobin saturation levels (<50% in 27% of the N group, p<0.05) and higher lactate levels suggested that normothermic perfusion was relatively disadvantageous. It is concluded that normothermic CPB was relatively safe and advantageous with regard to hemostasis and pulmonary function.

Aged↗

PubMed2000

Aortic valve replacement with concomitant annular enlargement for small aortic annulus of less than 19 mm.

Three female patients with aortic stenosis associated with a severely small annulus underwent aortic valve replacement. In intraoperative measurements, a 19-mm obtulator could not pass through the aortic annulus in each case. We therefore concluded that it would be difficult to implant an appropriate-sized prosthesis in a routine fashion, so we performed an annular enlargement in a modified Nicks procedure. By using a wide teardrop-shaped patch for enlargement and slightly tilting insertion of a prosthesis, a 21 mm bileaflet mechanical prosthesis could be inserted into the enlarged annulus. Despite being a simpler method than other enlarging procedures, a two- or three-sizes larger prosthesis than the native annulus can be inserted with relative ease. Thus, the use of a 19 mm mechanical prosthesis may be avoidable in most adult cases.

Aged↗

PubMed2000

[Combined use of ante- and retrograde cardioplegia: limited efficacy in elective coronary artery bypass].

One Hundred and twenty-four patients undergoing elective coronary bypass surgery were retrospectively selected and divided into two groups according to their difference of cardioplegic methods, either antegrade (AC) only (n = 65) or combination of ante- and retrograde (AC + RC) cardioplegic delivery (n = 64). Myocardial blood flow in the right (RV) and left ventricles (LV) was measured during the cardioplegia by a laser Doppler. Peak CPK-MB levels were compared postoperatively between the two groups and more in detail according to extent of coronary obstructive disease. 1) The antegrade administration of cardioplegic solution provided preferential flow to the RV compared to the LV, whereas the retrograde administration resulted in the opposite result (AC; LV 6.9 +/- 4.7, RV: 8.6 +/- 5.3, p < 0.05, RC; LV: 9.0 +/- 4.9, RV: 5.9 +/- 4.6 ml/min/100 g, p < 0.05). This result suggested that the combination of both administrations was meaningful to obtain uniform distribution of cardioplegic solution. 2) The peak CPK-MB, compared in the entire two groups, was slightly low in the combination use (AC; 48 +/- 16, AC + RC; 43 +/- 15 IU/l, p = 0.08), but the clinical meaning did not exist. However, in the severe cases, which involved two of following criteria (left main disease, severe occlusion of left or right coronary), the max CPK-MB level was statistically decreased by the combined use of ante- and retrograde cardioplegia (AC; 50 +/- 16, AC + RC; 40 +/- 12 IU/l, p < 0.05). We concluded that the merit of combined use was limited to the cases with severely extended coronary obstructive disease.

Aged↗

PubMed1999

Strategy for balancing anticoagulation and hemostasis in aortocoronary bypass surgery: blood conservation and graft patency.

The minimal effective dose of aprotinin on hemostasis under normothermic perfusion, the influence of anticoagulant therapy on graft patency, and the thromboembolic and hemorrhagic events were investigated after aortocoronary bypass graft operation (CABG). One hundred CABG patients under normothermic perfusion were randomly divided into the following groups: (1) coumadin plus acetylsalicylic acid (ASA) (n=32); no aprotinin used during cardiopulmonary bypass (CPB); (2) minimal-dose, 10(6) KIU during CPB, aprotinin used, followed by ASA and coumadin (n=36); and (3) very low-dose, total of 2x10(6) KIU before CPB and during CPB; aprotinin used; anticoagulation therapy with heparin early after surgery and followed by replacement with ASA and coumadin (n=32). The patency of arterial grafts was 100% in all groups. The patency of vein grafts was 95-98% and there was no difference among the groups. The blood loss was significantly reduced in both aprotinin groups (groups 2 and 3) compared to the coumadin plus ASA group, although no difference existed between the 2 aprotinin groups. Postoperative thrombotic and hemorrhagic events were not observed in any group. From this study, it was concluded that 10(6) KIU aprotinin in pump-prime-only followed by oral ASA and coumadin was the recommendation from the benefit/cost consideration.

Adult↗

PubMed1999

Real time measurement of heparin concentration during cardiopulmonary bypass.

BACKGROUND: A heparin/protamine titration system for measurement of heparin levels (Hepcon) is promising for efficient anticoagulation during cardiopulmonary bypass (CPB). METHODS: Fifty-seven patients subjected to CPB were divided into two groups, control (n = 24) and Hepcon groups (n = 33). The Hepcon group was further divided into three subgroups according to perfusion temperature. For the control group, conventional administration of an anticoagulant (300 IU/kg of heparin) and reversal protocol (heparin 1: protamine 1) was performed. For the Hepcon group, a heparin dose-response assay directed the initial dose of heparin. Hepcon also determined the dose of protamine by the titration. The initial dose of heparin in the control group (300 IU/kg) was statistically less than that of Hepcon group (360+/-80 IU/kg). RESULTS: In the Hepcon group, the sensitivity to heparin was correlated with coagulation time (r = -0.78) and antithrombin III levels (r = 0.70), and individual difference of sensitivity resulted in a wide range of dosage (160 to 490 IU/kg). A strong correlation was observed between plasma and whole blood concentration of heparin (r = 0.86). However, they did not correlate with ACT values. Perfusion temperature didn't affect the heparin level, but did the ACT value. In the Hepcon group, the dose of protamine was significantly less and adverse events were rare. CONCLUSIONS: In conclusion, whole blood heparin measurements correlated well with plasma heparin concentration. Protamine titration of heparin reduced the dose of protamine and decreased the chance of adverse reactions.

Anticoagulants↗

PubMed1998

[Infective endocarditis associated with ruptured aneurysm of Valsalva: aortic valve replacement after reconstruction of left ventricular outflow tract].

Infective endocarditis associated with ruptured aneurysm of Valsalva disrupted the vicinity of aortic annulus (Valsalva, valve, left ventricular outflow tract). This condition did not accept insertion of prosthetic valve at normal position. Insertion of St. Jude valve was performed after the reconstruction of outflow tract with a xenopericardial patch. Proportionate sutures for the right cusp part was taken through the infundibular muscle at the right ventricular side, not in the pericardial patch. The bileaflet valve functioned properly in spite of the oblique insertion.

Adult↗

PubMed1998

[An experience with peeling technique with curettage of open mitral commissurotomy].

Ideally, the mitral valve is a soft, thin and flexible tissue. In severe rheumatic mitral stenosis, however, its motion is restricted due to the adhesion of fibrous tissues and calcium. Open mitral commissurotomy was not effective in successfully restoring it to normal condition. By using a peeling technique with curettage during open mitral commissurotomy, the calcium and fibrous tissues are sufficiently removed. This method is effective in improving the flexibility of the anterior leaflet of the restricted mitral valve.

Cardiac Surgical Procedures↗