Masaki Otaki

Expanded Polytetrafluoroethylene Monocuspid Valve for Right Ventricular Outflow Tract Reconstruction

BACKGROUND Numerous materials have been used for reconstruction of the right ventricular outflow tract (RVOT) in patients with complex congenital heart defects. METHODS Between January 1982 and March 1999, 19 patients (10 boys and 9 girls; mean age, 8.5 years) with severe RVOT obstruction underwent reconstruction using a transannular patch and expanded polytetrafluoroethylene (ePTFE) monocuspid valve. RESULTS There were no perioperative deaths. Postoperatively, the mean +/- standard deviation RVOT gradient was 12 +/- 9 mm Hg. Echocardiography showed good motion of all cusps, and most had no or trivial pulmonary regurgitation. The difference between the preoperative and postoperative mean ratio of right-to-left ventricular peak systolic pressure was significant (p = 0.0001). In the 8 patients followed for 3 years or longer, pulmonary regurgitation was mild or better in 5 and moderate in 2, and the mean peak systolic RVOT gradient was 16.3 +/- 5.9 mm Hg. Five patients had good mobility of the monocusps. Two patients needed reoperation because of stenosis at the distal anastomosis of the transannular patch; 1 patient died. CONCLUSIONS The ePTFE monocuspid valve may be useful in reconstruction of the RVOT.

Disseminated Cholesterol Embolism After Coronary Artery Bypass Grafting

Blue toe syndrome caused by cholesterol emboli is a relatively benign disease. However, disseminated cholesterol embolism is a life‐threatening condition. We describe here the case of a 71‐year‐old female admitted because of anterior chest pain and intermittent claudication. Following cardiac catheterization, warfarin potassium was administered. However, the patients toes soon darkened bilaterally, and BUN and creatinine levels increased from the normal value. Skin discoloration and renal failure were improved after stopping warfarin potassium administration. The patient underwent coronary artery bypass grafting and left femoropopliteal bypass. Cerebral infarction and renal failure occurred postoperatively due to disseminated cholesterol embolism. The patient died from renal failure on the 16th postoperative day without regaining consciousness following surgery. For high risk patients, interventional procedures to the ascending aorta must be avoided. When CABG cannot be avoided for coronary revascularization, off‐pump bypass and use of arterial grafts are recommended.

Modification of De Vega's Tricuspid Annuloplasty for Experimental Tricuspid Regurgitation

We propose a new experimental model of tricuspid annular dilatation and provide some modifications to De Vegas tricuspid annuloplasty to treat this condition. Tricuspid annular dilatation was done by creating ten 1.5‐mm incisions around the circumference of the tricuspid annulus. The annulus became significantly dilated from 7.6 cm to 9.4 cm (p < 0.01). After dilatation, 2–0 polypropylene stitches were placed circumferentially around the tricuspid annulus and the suture ends were brought outside the heart through the right atrial wall. After cardiac resuscitation, the following hemodynamic variables were measured as preload was increased incrementally: mean right atrial pressure, v wave of atrial pressure, right ventricular end‐diastolic pressure, and cardiac output. Measurements were obtained and preload‐output curves were constructed for three time periods: before annular dilatation (Control); after dilatation, but before external adjustment (Before); and after external modification of the annulus (After). Following cardiac resuscitation, right atrial and ventricular pressures were significantly higher after annular dilatation, compared to control values. The preload‐output curve was shifted to the right, and cardiac output could not be increased above 0.9 L/min. Once the extracardiac adjustment was accomplished, these pressures were returned to control values, and the preload‐output relationship was returned to normal curve. (J Card Surg

Surgical Treatment of Pacemaker Induced Left Innominate Vein Occlusion Using a Spiral Vein Graft

INOUE, T., et al.: Surgical Treatment of Pacemaker Induced Left Innominate Vein Occlusion Using a Spiral Vein Graft. Superior vena cava syndrome due to transvenous pacing leads is an uncommon but potentially life‐threatening complication. This case involves a 54‐year‐old man who developed left innominate vein occlusion due to a pacemaker lead. This complication induced a progressive swelling on the left side of his face, neck, arm, and upper chest. The left innominate vein occlusion was surgically treated using a composite spiral saphenous vein graft. Postoperatively, the patient has received anticoagulation therapy with warfarin to prevent thrombosis and, thereby, the long‐term patency of the graft. He has undergone follow‐up on a regular outpatient basis without showing any recurrence of clinical symptoms.

Pretreatment of donors with endothelin receptor antagonist TAK-044 improves cardiac functional recovery following preservation with University of Wisconsin solution.

Objective : Previous studies suggest that endothelin-1 (ET-1) plays a role in myocardial ischemia/reperfusion injury. Although administration of an endothelin receptor antagonist to the recipient has been shown to improve myocardial function after ischemia/reperfusion in a rat heart transplantation model, the effect of administering an endothelin receptor antagonist to the donor has not yet been examined. This study was designed to investigate the effects of pretreating donors with an ET A /ET B endothelin receptor antagonist (TAK-044) on myocardial function after cold preservation of a rat heart. Design : Male rats were pretreated with normal saline (control group, n = 8), TAK-044 (TAK group, n = 8, 1 mg/kg). Following cardiac arrest using cardioplegia, we washed out the coronary vascular beds with cold University of Wisconsin solution followed by 6-h preservation. After preservation, the hearts were mounted on a Langendorff apparatus to estimate aortic flow (AF), coronary flow (CF), cardiac output (CO), systolic pressure (SP), heart rate (HR), and rate-pressure product (RPP: HR 2 SP). The concentration of lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) within the coronary perfusate during reperfusion was measured. Results : AF, SP, and CO were significantly greater in the TAK group than in the control group ( p = 0.0045, 0.004, and 0.0295, respectively). Conclusion : Pretreatment of donors with a nonselective endothelin receptor antagonist (TAK-044) improved cardiac functional recovery following preservation and may be beneficial for prolonged myocardial preservation.

Physiologic atrial cardiac pacing for the prevention of chronic atrial fibrillation associated with sick sinus syndrome.

Long-term results of physiologic atrial pacing have been analyzed for the possibility of avoiding the recurrence of paroxysmal atrial fibrillation and the progression to chronic permanent atrial fibrillation in patients with paroxysmal atrial fibrillation related to sick sinus syndrome. Seventy four patients were evaluated and divided into two groups; 39 patients underwent atrial pacing (AAI, 53%) and 35 had ventricular pacing by single-lead pacing (VVI, 47%). All patients had been evaluated periodically on an out-patient basis by 24 hour Holter monitoring. Basic rhythms in all AAI patients were based on atrial pacing, resulting from the suppression of paroxysmal atrial fibrillation. Basic rhythms in the VVI paced patients were variable, consisting of regular sinus rhythm, transient atrial fibrillation, and ventricular pacing in 30 of 35 patients in the VVI group. The remaining five patients progressed to chronic permanent atrial fibrillation (0% in AAI vs. 14% in VVI, p < 0.05). Thromboembolic complications were not observed in the AAI pacing group. Three patients demonstrated thromboembolic complications (0% in AAI vs. 8.6% in VVI, p < 0.05). The effect of preventing paroxysmal atrial fibrillation and the progression to chronic atrial fibrillation was evident in the AAI paced group, but VVI pacing cannot prevent paroxysmal atrial fibrillation and chronic atrial fibrillation. In addition, potential risks of thromboembolic complications caused by atrial fibrillation were not decreased in VVI paced patients.

Experimental heterotopic heart transplantation without cardiopulmonary bypass : Auxiliary support for the recipient heart

BACKGROUND Auxiliary cardiac support using heterotopic heart transplant is of considerable interest, but the outcome is not known. To investigate technical feasibility and the possibility of using auxiliary support from heterotopic heart transplantation without cardiopulmonary bypass, we evaluated hemodynamics including the pressure-volume relationship in experimental animals. METHODS In heterotopic heart transplantation, we tailored the donor heart by removing the pulmonary and tricuspid valves, and by wide removal of the inter-atrial septum. Next, we anastomosed the descending aorta and left atrium of the donor heart to the descending aorta and left atrium of the recipient, without using cardiopulmonary bypass. Consequently, declamping the recipients descending aorta allowed the donor heart to fill with blood and to start beating. We performed hemodynamic assessments including the effects of adrenergic stimulation. We measured the pressure and volume relationship of the recipient heart by closing and opening inflow of the donor left atrium to change the pre-load of the donor left ventricle. RESULTS The donor left ventricle produced a systolic blood pressure that was augmented by the recipient blood pressure and responded to adrenergic stimulation. When inflow of the donor left atrium was opened, the pressure-volume loop of the recipient heart shifted to the left and pressure-volume area decreased. Simultaneously, the mechanical efficiency and E(max) (the slope of the end-systolic pressure-volume relationship) of the recipient heart increased when inflow of the donor left atrium was opened. CONCLUSIONS This transplant model, without cardiopulmonary bypass, is feasible and can be applied to transplant investigations as a working heart model on the basis of the response of adrenergic stimulation. The increased pre-load of the donor left atrium from the recipient left atrium resulted in a recipient leftward shift of the pressure-volume relationship, suggesting that this transplant model with adequate pre-load acts as auxiliary assistance in the recipient intrathoracic cavity.

Right Atrial Pedunculated Ball Thrombus

Two rare cases of right atrial pedunculated ball thrombus associated with constrictive pericarditis and systemic lupus erythematosus are reported. Under cardiopulmonary bypass, the large thrombus in each patient was removed with care to avoid pulmonary embolism. Both patients have been doing well postoperatively and warfarin has been administered to prevent a recurrence of intracardiac thrombotic episodes.

A New Modification of Debridement Valvuloplasty for Acquired Aortic Valve Disease

A high speed electric rasp was used to remove fibrous thickening from the aortic valve in conjunction with aortic valve commissurotomy in ten patients. All patients had moderate rheumatic aortic valve disease combined with severe mitral valve disease, and were treated by mitral valve replacement and aortic valve repair. All patients survived the operative procedure. There were no deaths or complications during hospitalization related to the valve repair process. The transaortic valve gradient was relieved from an average of 21.0 ± 8.6 mmHg to 5.6 ± 4.0 mmHg (catheterization), and from moderate to less‐than‐mild stenosis (echocardiography). Aortic valve regurgitation was reduced from an average of 2.2+ to 0.7+ on a scale of 0 to 4+ (aortography), and from an average of 2.5+ to 1.1+ on a scale of 0 to 4+ (echocardiography). During the follow‐up period, no patients were reoperated on because of aortic valve dysfunction. Follow‐up echocardiographic study demonstrated that the transaortic pressure gradient and valvular regurgitation had not progressed, and immediate postoperative conditions were maintained. There were two late deaths not related to the aortic valve. One patient died of prosthetic valve endocarditis in the mitral prosthesis 14 months postoperatively, and the other of a cerebrovascular accident 21 months postoperatively. Based on these data, we believe that aortic valve repair with a high speed electric rasp can effectively relieve aortic stenosis, reduce valvular regurgitation, and provide an excellent hemodynamlc result at early and mid‐term follow‐up. (J Card Surg 1994;9:103–108)

Refractoriness to Platelet Transfusion Following Double Valve Replacement in an ITP Patient Who Had Undergone Splenectomy

Abstract Reports of patients with idiopathic thrombocytopenic purpura (ITP) undergoing cardiac surgery are rare, and almost all of the reported cases required platelet transfusion. ITP patients, especially those having a history of splenectomy or a history of heavy bleeding, may have to undergo multiple platelet transfusions. Such transfusions may induce al‐loimmunization against the human leukocyte antigen (HLA) and result in refractoriness to subsequent platelet transfusions. We report a case of a 63‐year‐old female with ITP, with a history of splenectomy and multiple platelet transfusions, who underwent aortic and mitral valve replacement. Although corticosteroid administration, high‐dose immunoglobulin therapy, and repeated platelet transfusion led to a temporary increase in platelet count and successful hemostasis, refractoriness to platelet transfusion occurred postoperatively because of the presence of the anti‐HLA antibody. In addition, the patient showed complications of pyothorax. Corticosteroids might have exerted an inhibitory influence on the occurrence of pyothorax.