OBJECTIVES: We developed a new sensor system for in situ measurement of myocardial tactile stiffness-stiffness in a direction perpendicular to the wall-and validated its use for providing a reasonable estimation of regional myocardial function. BACKGROUND: Numerous attempts have been made to directly assess regional myocardial function. The complexity and highly invasive nature of the measuring devices have hampered their in situ application. METHODS: In open chest mongrel dogs, myocardial tactile stiffness, ventricular pressure and ventricular volume were monitored. Under the preload reduction, these variables were measured to determine the relation between the end-systolic pressure-volume relation (ESPVR) and the end-systolic tactile stiffness-volume relation (ESSVR). The changes in myocardial tactile stiffness were monitored in the regional ischemic myocardial model and infarcted model to evaluate their usefulness as indexes of regional myocardial function. RESULTS: Myocardial tactile stiffness changed cyclically and followed a time course similar to left ventricular pressure. When preload was altered, the ESSVR was as linear as the ESPVR. The slope of the ESSVR and that of the ESPVR showed a strong correlation over a wide range of contractility. These results suggest that myocardial tactile stiffness can be a good index of regional wall stress or fiber stress. End-systolic myocardial tactile stiffness of ischemic and infarcted regions decreased significantly, with a concomitant increase in end-diastolic stiffness compared with that of intact myocardium. CONCLUSIONS: Using our tactile sensor system, regional myocardial tactile stiffness of a beating heart was measured with reasonable temporal resolution. We consider myocardial tactile stiffness to be a useful index of regional myocardial function.

Animals↗

PubMed1998

Value of mild hypothermia in patients who have severe circulatory insufficiency even after intra-aortic balloon pump.

STUDY OBJECTIVE: To evaluate the effectiveness of mild hypothermia in postcardiac surgical patients with severe heart failure in spite of conventional medical therapy and the use of intra-aortic balloon pumping (IABP). DESIGN: Prospective, clinical study. SETTING: Teaching hospital. PATIENTS: 10 postcardiac surgical patients with severe heart failure despite the use of IABP with massive doses of catecholamine. INTERVENTIONS: Patients underwent mild hypothermia produced by surface cooling (to approximately 34.5 degrees C). Hemodynamic criteria for the induction of hypothermia included a cardiac index (CI) of less than 2.2 L/min/m2 with a pulmonary capillary wedge pressure (PCWP) of up to 18 mmHg despite the use of IABP with massive doses of catecholamine. MEASUREMENTS AND MAIN RESULTS: After control measurements had been taken at normal core body temperature (37 degrees C), patients were cooled to approximately 34.5 degrees C (using a cooling blanket and gastric lavage with cold water) to decrease tissue oxygen (O2) demand. Patients showed significant improvements in CI (1.9 +/- 0.3 to 2.2 +/- 0.3 L/min/m2), mixed venous O2 saturation, (SvO2; 55 +/- 7 to 64 +/- 6%), and urine output (2.1 +/- 1.1 to 3.4 +/- 2.2 ml/kg/hr). Patients were rewarmed while SvO2 was being monitored. The duration of the hypothermia was 38 +/- 41 hours. Oxygen delivery increased in 8 of the 10 patients, the mean value (+/- SD) for the group rising from 309 +/- 65 ml/min/m2 to 358 +/- 57 ml/min/m2 as temperature was reduced from 36.7 +/- 0.4 degrees C to 34.7 +/- 0.3 degrees C. All patients were successfully weaned from IABP at 140 +/- 107 hours after admission to the intensive care unit. CONCLUSIONS: Mild hypothermia is a simple and useful procedure for improving the circulation of postcardiac surgical patients with severe heart failure despite the use of IABP.

Aged↗

PubMed1998

Thoracic aortic aneurysm associated with congenital bicuspid aortic valve.

Congenital bicuspid aortic valve is a relatively rare malformation. It is reported that the presence of this anomaly predisposes the patient to development of true aortic aneurysms or dissecting aortic aneurysms. Between 1981 and August 1997, 25 patients with an aneurysm of the thoracic aorta associated with congenital bicuspid aortic valve underwent surgical treatment at the authors' institution. There were 20 males and five females. The age of the patients ranged from 27 to 74 years (mean 53 years). There were 18 patients with true ascending aortic aneurysms (of which 10 presented with annulo-aortic ectasia) and seven with dissecting aortic aneurysms (four with DeBakey type I dissection, two with type II and one with type IIIb). These 25 patients constituted 2.6% (25/973) of all cases of surgical operations for aneurysms in the thoracic aorta. Aortic valve dysfunction was noted in 20 patients. The authors performed a valved conduit operation in nine patients, aortic valve replacement and wrapping of the ascending aorta in six, graft replacement of the ascending aorta in five, graft replacement of the ascending aorta and aortic arch in four, and graft replacement of the descending aorta in one. No hospital deaths occurred in the authors' patients. Pathological examination of surgical specimens of the aortic wall showed cystic medial necrosis in 11 patients and mucoid degeneration in nine. In patients with congenital bicuspid aortic valve, attention should be paid to aneurysmal dilatation and aortic dissection as complications in addition to valve dysfunction.

Adult↗

PubMed1998

Right ventricular rupture in minimally invasive direct coronary artery bypass grafting.

We report a rare case of the rupture of the right ventricle which occurred in a minimally invasive direct coronary artery bypass grafting (MIDCABG) for a redo bypass surgery. A 52-year-old male patient underwent a left internal thoracic artery (LITA) to the left anterior descending artery (LAD) bypass. Rupture of the right ventricle occurred abruptly during dissection to find the LAD. Too much dissection of the interventricular groove under undue traction of the pericardium may cause a rupture of the heart.

Humans↗

PubMed1998

Cardiac surgery and inhaled nitric oxide: indication and follow-up (2-4 years).

We studied the effect of inhaled nitric oxide (NO) on 80 patients who had undergone cardiac surgery in our center. The indications for receiving NO inhalation and the number of patients were as follows: Pp/Ps > 0.5 for pulmonary hypertension (PH) (n = 32; 21 children and 11 adults), severe PH crisis (n = 9), high pulmonary vascular tone (Glenn pressure more than 18 mm Hg after bidirectional Glenn operation) or arterial oxygen saturation (SaO2) less than 70% despite an FiO2 of 1.0 after Blalock-Taussig shunt (n = 6), mean pulmonary artery pressure (PAP) > 15 mm Hg and transpulmonary gradient (TPG) (mean PAP - left atrial pressure [LAP]) > 8 mm Hg after Fontan-type operation (n = 18), elevated pulmonary vascular tone (mean PAP > 30 mm Hg and left ventricular assist system [LVAS] flow rate < 2.5 L/min/m2) in patients with LVAS (n = 3), and impaired oxygenation (PaO2/FiO2 < 100 under positive end-expiratory pressure [PEEP] > 5 cm H2O) (n = 12). Low dose inhaled NO (10 ppm) had the following effects. In adult PH patients, it significantly reduced the mean PAP (from 37.3 to 27.0 mm Hg; average values are given) and increased the mean systemic arterial pressure (SAP) (64.7 to 75.3 mm Hg). In infant PH patients, it increased the mean SAP (51.8 to 56.1 mm Hg). In patients with a PH crisis, it significantly reduced the central venous pressure (CVP) (13.3 to 8.8 mm Hg) while increasing both the mean SAP (49.4 to 57.9 mm Hg) and PaO2/FiO2 (135 to 206). In patients after a Fontan-type operation, it significantly reduced the mean PAP (16.8 to 13.8 mm Hg) and TPG (9.5 to 5.8 mm Hg). In patients under LVAS, it reduced the CVP (11.7 to 8.0 mm Hg) and mean PAP (32.0 to 24.7 mm Hg). In impaired oxygenation patients, PaO2/FiO2 was increased (75 to 106). Sixty-five patients were all followed for 2.0-4.3 years (average, 3.1 years). All 65 patients remained free from oxygen requirement, and possible chronic adverse effects including the occurrence of malignant tumors or chronic inflammation in the respiratory tract were not observed.

Administration, Inhalation↗

PubMed1998

Reversible ischemia in hippocampal areas by retrograde cerebral circulation surgery for thoracic aortic aneurysm with Tc-99m ECD brain SPECT.

Because hippocampal neurons are quite vulnerable to the anoxic brain injury that sometimes occurs in aortic arch surgery in humans, hippocampal ischemia should be a sensitive indicator of global cerebral ischemia. It was concluded that the hypothermic retrograde cerebral circulation technique for aortic arch surgery could not only be performed safely with respect to the brain, but could also increase blood flow to the hippocampal areas, probably as a result of restoration of blood flow in the thoracic aorta.

Adult↗

PubMed1998

Oxygen utilization and hemodynamic response during exercise in children after Fontan procedure.

Eight patients, 9.1 to 16.5 years of age, were studied 2.8 to 8.5 years after Fontan operation. Oxygen utilization was determined during upright bicycle exercise. The cardiac index and stroke index were measured by echocardiography and the anaerobic threshold was determined. The results were compared with 10 patients after surgical closure of the atrial septal defect. Anaerobic threshold (AT) in Fontan patients was lower than in the control subjects. Oxygen consumption at each stage of exercise was significantly lower in the Fontan group compared with the control subjects. From the beginning of exercise until AT, the increase in stroke index was lower in the Fontan patients than in the control subjects. After that point, the stroke index decreased significantly in the Fontan patients while it remained almost at the same level in the control subjects. Significant correlations were observed between the oxygen pulses and the stroke index at AT both in the control and Fontan groups. These results suggest that impaired exercise capacity in Fontan patients is mainly due to a subnormal response of the stroke index at AT and to the decreased response of the stroke index and the heart rate at the maximal workload.

Adolescent↗

PubMed1998

Utility and safety of Hickman catheters for venous access after bone marrow transplantation.

Hickman catheters are useful for vascular access after bone marrow transportation because they can handle large volume and allow for easy transfusions and blood drawing through wide double lumens making it easier to case for patients under sterile conditions in a clean room. However, the safety of Hickman catheters as compared to Silastic catheters in marrow transplants has never been discussed. We therefore retrospectively reviewed the complications of two catheters in 71 allogeneic bone marrow transplant recipients between September 1986 and August 1994. The complication and infection rates of Hickman catheters were 0.21 and 0.09 per 100 device-life days, and rate of temperature >38 degrees C during leukocytopenia (<1,000 white blood cells) was 0.18. These rates were not different from those of Silastic catheters suggesting that Hickman catheters are safe and acceptable in marrow transplantation. The benefits and drawbacks of Hickman catheters relevant to catheter choice were also discussed.

Adolescent↗

PubMed1998

[Video-assisted mammary harvest technique with harmonic scalpel].

We have developed a video-assisted mammary harvest technique using the Harmonic Scalpel. The clinical method and results are reported here. Since Nov. 1995, 70 left and 5 right internal mammary arteries (L/RIMAs) were taken down thoracoscopically and utilized for minimally invasive coronary artery bypass grafting. Each of the IMAs was harvested up to the upper margin of the first rib or higher and down to the bifurcation. Coagulation and cutting of the branches were achieved with excellent hemostasis using only the Harmonic Scalpel with a hook dissector. A CO2 insufflation technique with 8-10 mmHg of intrathoracic pressure safely improved visualization of the IMA in each case. The mean operative time was 65 minutes (range 45-95) for the left and 35 minutes (range 25-45) for the right. All the pedicled IMAs but one which was lost due to intimal dissection had satisfactory free flows. Video-assisted mammary harvest can be accomplished with insufflation technique and facilitated by using the Harmonic Scalpel with a hook dissector.

Coronary Artery Bypass↗

PubMed1998

[Atrial septal defect and severe pulmonary hypertension in an adult who needed nitric oxide inhalation after repair].

A 51-year-old male was diagnosed as having an ostium secundum atrial septal defect with severe pulmonary hypertension. Although pulmonary artery pressure was as high as 96/32 and pulmonary vascular resistance was 14.2 U.m2, he underwent corrective surgery, because pulmonary to systemic blood flow ratio was 2.0. After he regained consciousness in ICU, pulmonary hypertensive crises recurrently occurred and the hemodynamics became quite unstable. Administration of conventional drugs proved to be ineffective. Since inhalation of low dose (3-4 ppm) nitric oxide was started, however, his condition was markedly improved and he recovered uneventfully thereafter. Two years later, pulmonary artery pressure was reduced to 52/28 and pulmonary vascular resistance was 9.9 U.m2. Although good outcome can not be expected in all surgically treated cases, we should refrain from deciding easily that surgery is contraindicated, because no criteria of surgical indication for atrial septal defect with pulmonary hypertension appears to be perfect.

Administration, Inhalation↗

PubMed1998

[Surgical treatment of DeBakey-I type aortic dissection--with special reference to patients receiving complete aortic replacement].

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Adult↗

PubMed1998

[Thoracoscopic decortication for chronic empyema thoracis: report of a case].

Thoracoscopic surgery for empyema thoracis treatment is still uncommon in Japan. We report a case of chronic empyema thoracis which was successfully treated with decortication through thoracoscopy. A 63-year-old man presented with respiratory distress, appetite loss and hoarseness. He had been suffering from diabetes mellitus for 13 months. His chest X-ray film revealed that he had suffered from the left chronic empyema. As the decortication procedure was feasible at the preliminary exploration, it was then performed through the thoracoscopy. The lung re-expanded well after the pleural peel was removed. His chest drainage tube was drawn out on 19th postoperative day.

Chronic Disease↗

PubMed1998

[Hemolytic uremic syndrome after bone marrow transplantation].

One hundred and thirteen patients who underwent autologous or allogeneic bone marrow transplantation (BMT) were investigated for the subsequent development of hemolytic uremic syndrome (HUS). HUS developed in seven patients (four males and three females, five acute lymphocytic leukemia (ALL), one acute myelogenous leukemia, one non-Hodgkin's lymphoma) between 36-196 days after BMT. Four patients were recipients of autologous BMT and three were those of allogeneic BMT. Six patients were preconditioned with the regimens including fractionated total body irradiation (TBI). ALL and preconditioning regimen with TBI were suspected to be the risk factors for the development of HUS. Cyclosporin A (CSP) administration was discontinued in three patients who had been given CSP for graft-versus-host disease prophylaxis. Predonisolone was given to the three patients and plasma exchange was performed in one patient. Both hemolytic anemia and thrombocytopenia were resolved in virtually all patients, while creatinine elevation has persisted along with hypertension in one patient.

Adolescent↗