Distal limb protection during cardiopulmonary bypass.
Explore the source record for details and available documents.
Aged↗
Biomedical subjects
S Fukunaga
Publications and source records attributed to S Fukunaga.
Past, present, and future of total artificial heart development at research institute of replacement medicine, Hiroshima University School of Medicine.
The history and recent progress in total artificial heart (TAH) development were reviewed and divided into three stages. The first stage was between 1966 and 1972, when a trial developing an artificial heart (AH) driver was begun using poppet valves. Fluid amplifiers and air operated valves were then employed as a controller. The second stage was between 1973 and 1983. Several models of pneumatic AH were manufactured and implanted into animals, and it was confirmed that animals could survive with their circulation supported by these mechanical hearts. The third stage was from 1984 to the present, and now a trial to construct a totally implantable type of AH is under way. On the basis of the experience of developing TAHs, the following points are discussed as future problems to be solved: first, the production of small yet powerful actuators; second, the establishment of safe and reliable controls and an energy supply method; third, the development of a durable blood chamber containing valves; and fourth, the acquisition of large research funds for TAH from governments and other granting agencies.
Animals↗
Mock test characteristic of intraaortic balloon pump using linear motor.
This article describes the composition of the intraaortic balloon pump (IABP) system, which uses a linear pulse motor, that is, the linear type of IABP, and the results of the mock test that was performed. The expansion time is 100-110 ms, and the contraction time is 85-95 ms at the balloon of the linear type IABP. This level is similar to that of the IABP system used in the market. When the speed of the mover is 0.3 m/s, the necessary thrust of the linear pulse motor to drive the balloon of the IABP is 200 N. The conversion efficiency from the bellows to the balloon is 5.6%, and the efficiency of the entire linear type IABP system is 0.6%. The volume of the entire system is 45 L, and the mass is 40 kg excluding the chassis. Therefore, there is an expectation that the IABP system can be miniaturized to about half of the conventional model.
Electrocardiography↗
In vitro evaluation of linear motor-driven total artificial heart.
This paper deals with the in vitro evaluation of a newly developed linear motor-driven total artificial heart (linear TAH). The linear TAHs have been developed and evaluated in mock testing and acute animal experiments. The new linear TAH was made based on experience with acute animal experiments. The maximum static thrust of the new linear pulse motor is 146 N with exciting current of 1.69 A. The weight and the volume of this linear TAH are 1.9 kg and 560 ml, respectively. The linear TAH has a kinetic thrust of 85 to 43 N and provides the maximum flow rate of 6.8 L/min in mock circulatory testing.
Animals↗
Reconstruction of the mitral annulus with porcine pericardium--report of a case with mitral annular disruption due to staphylococcal endocarditis.
A 60-year-old man was admitted to our hospital for investigation of dyspnea and disorientation with right hemiplegia. Echocardiography showed thickened mitral valve leaflets with vegetations and severe mitral regurgitation. Blood cultures grew Staphylococcus aureus. During the operation, perforation and destruction of the mitral valve leaflets and vegetations were confirmed. Debridement of the infected tissues resulted in segmental disruption of the posterior mitral fibrous annulus. Reconstruction of the mitral annulus with porcine pericardium treated with glutaraldehyde and mitral valve replacement were successful. The patient's postoperative course was complicated with metastatic cerebral and splenic abscesses. After splenectomy on the 8th postoperative day, he gradually recovered without major neurologic sequelae. We believe that reconstruction of the mitral valve annulus with pericardium, especially autologous pericardium, is reliable and useful for the treatment of patients with disruption of the mitral valve annulus.
Animals↗
Valve detachment after aortic valve replacement--a successfully reoperated case with the Cabrol technique.
A 50-year-old Japanese male was admitted with a 1 month history of progressive shortness of breath, palpitations, and intermittent low-grade fever. On admission, a musical diastolic murmur (sea-gull murmur) was heard on the 3rd left sternal border. Blood studies showed an accelerated erythrocyte sedimentation rate, and positive C-reactive protein. Retrograde aortography revealed severe aortic regurgitation. At the operation, the aortic wall was remarkably thickened, and the aortic valve commissures between the right and left coronary cusps and between the left and non-coronary cusps had completely detached from the aortic wall. The aortic valve was replaced with a St Jude Medical valve using pledgeted sutures. Histologic studies of the aorta and aortic valve revealed no evidence of any pathologic changes. Echocardiography performed 82 days after aortic valve replacement showed severe paravalvular leakage and valve detachment. At the reoperation, the prosthetic valve was detached from the extremely edematous and fragile native aortic annulus. There was no vegetation or abscess formation. Aortic root replacement with the Cabrol technique was performed using a composite graft in which the prosthetic valve was placed 1 cm above the proximal extremity to reduce the tension on the suture line and the aortic annulus. Histologic study of the aorta after the reoperation showed non-specific inflammatory disease. The patient, who received steroid therapy, has recovered without any signs of graft detachment or pseudoaneurysm formation.
Aortic Valve↗
Aortic valve replacement for aortic regurgitation due to Kawasaki disease. Report of two cases.
Two cases of severe aortic regurgitation due to Kawasaki disease are reported. Both patients were diagnosed as having Kawasaki disease in their infancy, and were followed up by a pediatrician. Aortic regurgitation was detected 18 months in one case and 36 days in the other case after onset of the illness. With the passage of time, the aortic regurgitation increased and aortic valve replacement was scheduled in both patient at the age of 13. On admission, two-dimensional echocardiography showed thickening of the aortic cusps, and severe aortic regurgitation was detected by color flow Doppler studies. Successful aortic valve replacement was performed, and histological studies of the cusps showed sequelae of valvulitis. In conclusion, aortic regurgitation is a rare complication of Kawasaki disease, and the aortic valve function, especially occurrence of aortic regurgitation, should be carefully observed in patients with a past history of Kawasaki disease.
Adolescent↗
[Surgical treatment for active infective endocarditis].
Between April 1975 and December 1995, 33 patients with active infective endocarditis underwent surgical treatment at our hospital. The location of diseased valve was shown as ; 18 in aortic, 11 in mitral, and 4 in aortic and mitral position. Of these, 14 patients had an annular abscess or mycotic aneurysm. All patients achieved antibiotic therapy previously, and predominant indication for operation was congestive heart failure. All patients underwent valve replacement. The reconstructive procedures for 14 patients with paravalvular involvement were as follows ; direct closure : 5 cases, direct closure+tilted prosthesis technique : 5 cases, and another 4 cases were, patch closure of VSP resulting from a septal abscess, patch closure+translocation, translocation, and reconstruction of annulas with pericardial patch. There were five (15.2%) operative and hospital deaths and actuarial survival rate was 81% and 61% at 5 and 10 years after operation. Including one who died early after operation, there were 5 cases with postoperative paravalvular leakage and its main cause were persistent infection. In conclusion, it considered that the principles of treating active infective endocarditis is to decide the optimal timing for operation, debride the infected tissue, and close the defect completely.
Adolescent↗
[Surgery for aortic valvular disease with congenital quadricuspid aortic valve].
A case of quadricuspid aortic valve is reported. A 69-year-old man was hospitalized with chest oppression at rest and abnormal electrocardiogram and diagnosed aortic regurgitation by echocardiography and aortic angiography. Aortic regurgitation was grade III according to Seller. Aortic valve replacement was performed successfully with a 21 mm St. Jude Medical valve. The aortic valve showed four cusps consisting of two equal larger cusps and two equal smaller cusps which was type C according to Hurwitz. Each valve was thickened and adhered, and fenestrations were found at each commissure. The right coronary ostium was small but not displaced. Twenty five cases in literature which were corrected surgically are also reviewed. Quadricuspid aortic valve is a rare anomaly but must be considered as a malformation which leads to severe valve failure in later life.
Aged↗
[Acute aortic dissection complicated with acute myocardial infarction--a case report of successful operation for the case of DOA].
A 61-year-old woman who suddenly manifested chest and back pain was admitted after the diagnosis of acute type A dissection complicated with acute inferior myocardial infarction at another hospital. While being transported to our hospital by ambulance, her ECG repeatedly demonstrated ventricular fibrillation of cardiac arrest. She was in the state of dead on arrival (DOA) when arrived at our hospital. ECG demonstrated complete A-V block and cardiac arrest alternately. However, soon after right ventricular pacing was done, her blood pressure increased and she recovered consciousness. We therefore performed an emergency operation. We performed reconstruction of the ascending aorta and right coronary bypass grafting, since she had aortic dissection and conus brach avulsion. The postoperative course was uneventful.
Aortic Dissection↗
Numerical simulation of nonpulsatile left ventricular bypass.
A computer simulation was carried out to investigate the influence of nonpulsatile left ventricular assistance on hemodynamics. A simulation circuit was constructed to represent the circulatory system. A source of current was added to denote the nonpulsatile blood pump. The left and right ventricles were replaced by variable compliances. Left heart failure was simulated by decreasing the amount of compliance change of the left ventricle. We introduced a pulsatility indicator (PI) to clarify the pulsatility characteristics in the hemodynamics; this PI was defined as the ratio of the pulse pressure (PP) to the mean aortic pressure (AoP). When nonpulsatile bypass flow increased, the mean AoP, tension time index (TTI), and diastolic pressure time index (DPTI) increased, and cardiac output, PP, and PI decreased. When assisted flow increased with the constant total flow rate, the mean AoP and DPTI changed little; the PP, TTI, and PI decreased, and the endocardial viability rate increased. The PI would be helpful in evaluating the effect of pulsatility.
Blood Pressure↗
Pulsatile total artificial heart using a reversible rotary pump.
A pump circuit was assembled and examined for use as an implantable artificial heart. The circuit consisted of a gear pump and 4 artificial heart valves. Mitral and pulmonary arterial valves were placed at the inflow port of the pump, and aortic and tricuspid valves were placed at the outflow port. The mitral and the tricuspid valves were connected to each reservoir at 10 mm Hg, and the aortic and the pulmonary arterial valves were connected to the head tanks at 80 and 20 mm Hg, respectively. The pump discharged pulsatile flows into both systemic and pulmonary arteries alternately by switching the direction of rotation periodically. Because the rated discharge was 1.7 L/min for the gear pump used, the measured flow rate was 0.8-0.75 L/min at a heart rate of 60-110 bpm.
Aortic Valve↗
[Reconstructive surgery for acquired mitral regurgitation].
Between December, 1967, and July, 1994, 96 patients underwent repair of the mitral valve for acquired mitral valve regurgitation. According to Carpentier's classification, mitral valve pathology resulting in valve regurgitation was classified into three types; 4 patients assigned to type I, 63 type II, and 29 type III. The operative mortality rate was 1.0%. Follow-up data were available in 95 patients from 0.5 year to 25.3 years (mean average 8.8 years). The late mortality rate were not different between patients with valve pathology of type I, II and those with valve pathology of type III. Thromboembolism occurred on three patients for an embolic rate of 0.4% per patient-years. Twenty-eight patients required reoperation for residual MR and dehiscence of suture lines (type II; 10 cases, reoperation-free rate at 20 years, 83.2%) or recurrent MR due to progression of valve deformity (type III, 18 cases, reoperation-free rate at 20 years, 14.8%). These results demonstrate that patients with type I and II valve are good candidates for MVP, and that high incidence of reoperation for recurrent MR may limit the application of MVP to selected patients with type III valve.
Adolescent↗
Aortic regurgitation due to non-traumatic rupture of the aortic valve commissures: report of two cases.
Two cases of severe aortic regurgitation due to non-traumatic rupture of the aortic valve commissures are reported. The cause of rupture was hypertension in one patient, but it could not be identified in the other, where microscopic examinations of the aortic wall and the aortic cusps showed no particular pathologic changes. M-mode echocardiography revealed enlargement of the left ventricle, diastolic flutter of the anterior mitral leaflet and diastolic separation of the closure line of the aortic cusps in both patients. Two-dimensional echocardiography showed a downward displacement of the prolapsing motion of the aortic valve cusp during diastole toward the left ventricular outflow tract in one patient, and eccentricity of the coaptation point of the aortic valve without thickening of the cusps in the other. In addition to clinical features of progressive heart failure and characteristic cardiac murmur, echocardiographic studies provided correct diagnosis of aortic valve prolapse resulting from rupture of the aortic valve commissures. Both patients underwent aortic valve replacement successfully.
Aortic Valve↗
[Use of inferior epigastric artery for coronary artery bypass grafting].
The usefulness of the free inferior epigastric artery (IEA) as a coronary bypass graft was studied. Among 149 patients for coronary bypass grafting (CABG) between October 1992 and December 1994, the free IEA was used in 12 patients. The mean number of distal anastomosis was 3.7 per patient. The mean distal size of the IEA was 1.3 mm in diameter and the mean length was 9.4 cm. The IEA graft was anastomosed to the obtuse marginal branch in 5, to the diagonal branch in 4, and the right ventricular branch in 3. The proximal anastomosis of the IEA was constructed to the ascending aorta in three and to the saphenous vein (SVG) or to the internal thoracic artery (ITA) in 4 or 5, respectively. Postoperative angiogram demonstrated patent graft in ten and occluded graft in two in whom the size of IEA was less than 1.0 mm in distal diameter and the IEA was anastomosed to the aorta or to the SVG. The IEA was considered to be useful alternative arterial graft when it was used as "interposed graft" of which proximal anastomosis was made to the ITA and size-matching of the graft to the coronary artery was appropriate. The long-term patency of the graft can determine the true efficacy of the IEA for CABG.
Aged↗
Comparison studies of passive and active shunting during cross-clamping of the descending thoracic aorta.
The effects of passive (no pump) and active (using centrifugal pump) shunting on hemodynamics and metabolisms during cross-clamping of the descending thoracic aorta were compared in mongrel dogs. In Group I (control), the aorta was cross-clamped for 2 hours without shunting; in Group II (passive), a temporary shunt was placed between the left common carotid and left femoral arteries during cross-clamping; and in Group III (active), left heart by-pass, matching flow to that in group II, was performed. Hemodynamic and metabolic parameters were recorded prior to cross-clamping and following every 30 min for 4 hours. All animals in Group I suffered from hemodynamic instability, metabolic abnormal and neurologic injury and died within 12 hours. Hemodynamic changes were unstable in Group III than II, and three dogs in Group III, but none in Group II, suffered from neurologic injury. Metabolic changes between Group II and III were not significant. We conclude that passive shunting is superior to active shunting for aortic by-pass.
Animals↗
[Mitral valve surgery using combined superior-transseptal approach to the left atrium].
We performed mitral valve surgery in 5 patients using the combined superior-transseptal approach to the left atrium. Exposure of the mitral valve was excellent, and postoperative arrhythmias related to the operative procedures were not seen in all patients. The operative technique and indications are discussed in this paper.
Aged↗
[Application of simulation system in developing artificial heart].
Explore the source record for details and available documents.
Heart, Artificial↗