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Biomedical subjects

A Elami

Publications and source records attributed to A Elami.

At least 37 records · Page 2Linked to original sources

Positive end-expiratory pressure increases pulmonary venous vascular resistance in patients after coronary artery surgery.

OBJECTIVE: To investigate the effect of positive and-expiratory pressure (PEEP) on the longitudinal distribution of pulmonary vascular resistance in patients immediately after coronary artery bypass grafting. DESIGN: Prospective, intervention study. SETTING: Postcardiac surgery intensive care unit in a teaching institution. PATIENTS: Twenty patients after elective coronary artery bypass grafting. INTERVENTION: The effect of PEEP on pulmonary circulation, at four different levels (0, 5, 10, and 15 cm H2O), was analyzed in 20 patients. MEASUREMENTS AND MAIN RESULTS: Mean pulmonary arterial pressure, left atrial pressure, pulmonary artery occlusion pressure, and pulmonary capillary pressure were measured at each PEEP level. A model consisting of two resistances in series was used to analyze the effect of PEEP on the pulmonary circulation. The pulmonary vascular resistance for each area (arterial and venous) of the circulation was calculated. Pulmonary vascular resistance increased from 216 +/- 70 dyne.sec/cm5 at a PEEP of 0 cm H2O to 308 +/- 125 dyne.sec/cm5 at a PEEP of 15 cm H2O (p < .001). This increase, however, resulted solely from an increase in the resistance of the venous part of the pulmonary circulation from 66 +/- 29 to 134 +/- 69 dyne.sec/cm5 (p < .001), without any change in pulmonary arterial resistance. CONCLUSIONS: PEEP increases pulmonary vascular resistance solely by increasing pulmonary venous resistance. When applying PEEP, changes in pulmonary vascular resistance may impede the resorption of pulmonary edema fluid.

Aged↗

Single pass lead VDD pacing in children and adolescents.

Implantation of permanent pacemakers in children and adolescents is possible but usually is limited to single chamber generators. The natural growth of these patients may require physiological pacing, but until recently two leads were required for this type of pacing. The single pass lead VDD pacing mode makes possible physiological pacing by using only one lead, for both atrial sensing and ventricular sensing and pacing. The feasibility of VDD pacing using endocardial lead was evaluated in 16 children and adolescents with congenital or postsurgical atrioventricular block. Their mean age was 7.9 +/- 4.9 years (range 1-16 years) and the smallest patient's weight was 8.2 kg. In all the patients, a single pass pacing lead with atrial sensing rings and bipolar ventricular pacing and sensing capability was implanted through the left or right subclavian vein. The pacemaker generator was implanted in a rectopectoral position. The mean atrial electrogram during the implantation was 4.2 +/- 2.1 mV and 2.6 +/- 1.9 mV after a mean of 1 week. The ventricular pacing threshold was 0.5 +/- 0.2 V; the ventricular pacing impedance was 560 +/- 95 omega; and the ventricular electrogram amplitude was 9.9 +/- 2.1 mV. This is a first report to demonstrate the feasibility of atrial synchronous ventricular endocardial pacing using a single pass lead in a relatively large group of children and adolescents.

Adolescent↗

Autologous monocusp pulmonary valve: preliminary results.

BACKGROUND: There is growing recognition that postoperative pulmonary regurgitation may result in early or late progressive right heart failure. METHOD: A technique for fashioning an autologous monocusp pulmonary valve from the wall of the pulmonary artery was developed. The monocusp valve was fashioned from the anterior wall of the main pulmonary artery, and the remaining defect was filled with autologous pericardium. The procedure was performed in 8 dogs and 5 children. RESULTS: Early follow-up and serial echocardiographic assessment in both dogs and children proved the functionality of this monocusp pulmonary valve. All valves were pliable and demonstrated mild to moderate pulmonary stenosis and insufficiency. CONCLUSIONS: Construction of the autologous monocusp pulmonary valve is a feasible technique, and the valve performs efficiently. The acute performance in the canine model was excellent, and preliminary midterm results in the clinical study are reasonable. It is logical to assume that the monocusp, being an integral part of the arterial wall, will retain its viability and share in the subsequent growth of the pulmonary artery. Should follow-up studies demonstrate its long-term competence, this autologous valve may provide a good solution for various forms of pulmonary regurgitation and be useful in pulmonary autograft replacement of the aortic valve.

Animals↗

Early experience in lung transplantation.

Lung transplantation is becoming an acceptable mode of therapy worldwide for the end-stage lung disease. We present our initial experience with the first 10 consecutive lung transplant patients at Hadassah University Hospital. There were 5 males and 5 females with an age range 27 to 59 years. Eight patients underwent single lung transplantation, one patient had double lung transplantation and one had heart-lung transplantation. Indications were: pulmonary fibrosis in 4, emphysema in 4, cystic fibrosis in 1, and cystic bronchiectasis in 1. Two patients had primary graft failure (1 death). Nine patients had a serious infection after transplantation (1 death). Four patients developed airway complications including dehiscence of bronchial anastomosis (1 death), bronchial stenosis requiring placement of a stent in 2 patients, and pneumothorax in 1 patient. One patient required tracheostomy. One patient died of massive brain infarction secondary to pulmonary venous thrombosis and embolization. Six patients are intermediate-term survivors, with a follow-up period of 4-24 months. Four of them had at least one episode of rejection each. In all survivors pulmonary functions and quality of life improved and they do not need supplemental oxygen. We conclude that lung transplantation is a viable option for end-stage lung disease. Better selection of patients and perhaps improved immunosuppression agents will further improve outcome in lung transplantation. Shortage of donor supply is currently the limiting factor in successful lung transplantation in Israel.

Adult↗

[Aortopulmonary window: influence of associated cardiovascular lesions on surgical management].

Aortopulmonary (AP) window is an uncommon cardiac anomaly which is frequently associated with other cardiac anomalies. Concomitant repair of all intra- and extracardiac anomalies is usually recommended. Between October 1993 and July 1994, 4 patients aged 37 days, 4 weeks, 3.5 and 1.5 years, respectively, underwent repair of AP window and associated malformations. The associated anomalies consisted of interrupted aortic arch (IAA), and atrial and ventricular septal defects in the 1st patient, patent ductus arteriosus in the 2nd, inlet ventricular septal defect in the 3rd and congenital narrowing of the right pulmonary artery and a patent foramen ovale in the 4th. Extreme metabolic acidosis after repair of IAA in the 1st, dictated ligation of the AP window before repair of the intracardiac anomalies at 2 months of age. In the 2nd and 3rd, repair of the window and associated anomalies was performed in a single stage. In the 4th, left pulmonary artery banding preceded complete repair. All patients are doing well at 18, 13, 12 and 11 months, respectively, of follow-up after their last operation. Surgical management of AP window may have to be staged according to the physiological influence of the associated anomalies in each patient, to minimize the cumulative risk of complete repair.

Abnormalities, Multiple↗

[Treatment of concomitant coronary and carotid disease].

The optimal surgical treatment for concomitant carotid and coronary artery disease is controversial. Between 1991 and 1995 we performed 34 procedures for combined disease of the carotid and coronary arteries. The first 8 operations were carotid endarterectomies followed by coronary artery bypass grafting (staged procedure). The next 26 operations were performed during a single anesthesia (combined procedure). The patients were 28 men and 6 women, aged 58-81 years (mean 68). 80% were in functional class III or IV. In 40% ventricular function was moderately or severely reduced. There was an average of 3.6 grafts per patient, and in all except 3 patients the left internal thoracic artery was used as a conduit for coronary artery bypass grafting. 30% had symptomatic carotid stenosis; there was no perioperative mortality. In the staged procedure group, 2 patients had postoperative cardiac complications: in 1 acute coronary insufficiency and acute myocardial infarction in the other. 1 had postoperative, transient, amaurosis fugax. In the combined procedure group, 1 had a myocardial infarction and 1 a minor occipital stroke. During follow-up, 1 patient died 4 months after operation of myocardial infarction, and 1 had a minor stroke. The results suggest that the combined procedure is safe and carries low risk of both mortality and morbidity. Whenever cardiac disease is stable and there is no main coronary artery disease, a staged procedure should be considered. In any other situation we continue to perform the combined procedure.

Aged↗

Intraoperative detection of unsuspected distal coronary obstruction by thermal coronary angiography.

Intraoperative assessment of graft patency and completeness of revascularization can increase the success of coronary artery bypass grafting. A 56-year-old man underwent a quadruple bypass operation. Flow in the graft to the anterior descending artery was verified after completion of the distal anastomosis using a Doppler flow detector. Visualization of the native artery by thermal coronary angiography demonstrated that the flow passed into the second diagonal branch and not into the distal anterior descending artery, which had an unsuspected obstruction just distal to the anastomosis. The obstruction was dilated. Patency was verified with cold solution, and flow of warm blood to the entire artery was accomplished. This case demonstrates how the early (intraoperative) recognition of an unsuspected coronary obstruction using an infrared imaging system can improve the results of myocardial revascularization and avoid potential postoperative complications.

Coronary Angiography↗

Usefulness of late potentials on the immediate postoperative signal-averaged electrocardiogram in predicting ventricular tachyarrhythmias early after isolated coronary artery bypass grafting.

The present study was undertaken to determine the value of abnormal late ventricular potentials on signal-averaged electrocardiograms (ECG) in identifying patients at risk of developing ventricular tachycardia or ventricular fibrillation in the early postoperative period after coronary artery bypass grafting. Signal-averaged ECGs were recorded immediately after operation in 72 patients. Abnormal late potentials were defined as the presence of 2 or 3 of the following: (1) root-mean-square amplitude of the last 40 ms of the QRS < 20 microV; (2) duration of the terminal QRS potentials (after 40 microV) > or = 39 ms; and (3) high-frequency QRS duration > 120 ms (in patients with conduction defects, only the first 2 criteria were used). Abnormal late ventricular potentials were present on the immediate postoperative signal-averaged ECG in 26 of the 72 patients (36%). Life-threatening ventricular tachyarrhythmias occurred in 6 patients. Late potentials were present in all 6 patients, but only in 20 of 66 (30%) who did not develop ventricular tachyarrhythmias (p < 0.005) (sensitivity 100%, specificity 70%, predictive accuracy 72%). Of 12 pre- and perioperative variables examined by univariate and multivariate regression analysis, the presence of late potentials on the signal-averaged ECG and low cardiac output postoperatively were found to be independent predictors of life-threatening tachyarrhythmias.

Action Potentials↗

Open heart operation after pneumonectomy.

A coronary artery bypass operation was performed successfully on a 70-year-old patient who had undergone left pneumonectomy 40 years earlier. This case, together with a search of the literature and a mail survey among 118 cardiothoracic surgeons worldwide, yielded data on 27 such patients for review. Two patients died perioperatively. Three patients had pneumothorax, and 1 patient had recurrent pleural effusion. Difficulty in exposing the circumflex marginal branches was reported in 2 patients after left pneumonectomy. We conclude that with attention to the specific features of the preoperative, intraoperative, and postoperative management, open heart procedures can be performed on patients after pneumonectomy with acceptable operative mortality and morbidity.

Aged↗

Truncal valve repair: initial experience with infants and children.

The truncal valve regurgitation that frequently arises in patients with truncus arteriosus accounts for increased operative and late mortality. Five patients underwent truncal valve repair at UCLA Medical Center between August 1990 and September 1991. This group consisted of 2 infants who underwent complete repair and 3 who underwent valve repair together with right ventricle-pulmonary artery conduit replacement. The techniques used for repair were individualized according to the specific valve morphology, and consisted of the suturing of partially developed commissures, suspension of the cusps, resection of redundant portions of the cusps, annuloplasty at the commissures, and resection of excrescences on the surface of valve leaflets. In 1 infant who had a severely dysplastic truncal valve, stenosis and regurgitation recurred and progressed, and he died 4 months after truncal valve replacement. The remaining 4 patients, who were followed for from 8 to 21 months after repair, are in New York Heart Association class I, and have minimal or no aortic regurgitation. Except in patients with severely deformed and dysplastic valves, truncal valve repair can be an attractive and successful alternative to valve replacement.

Child↗

Cardiac decompression after operation for congenital heart disease in infancy.

Between January 1987 and July 1992, 641 infants (less than 1 year of age) underwent cardiac surgical procedures through a median sternotomy incision at the UCLA Medical Center. In 36 (5.6%), to achieve cardiac decompression, the chest was left open after the operation, or was re-opened immediately postoperatively because of low cardiac output. The incidence of cardiac decompression was 31% (4/13) after the Norwood procedure and 24% (7/29) after truncus arteriosus repair. Opening of the chest reduced intrathoracic pressure and allowed complete expansion of the lungs. Delayed sternal closure was carried out in 27 patients at a mean of 5 days (range, 2 to 14 days) postoperatively. By the time of chest closure, left atrial pressure had decreased from a mean of 12 +/- 1.4 to 8.4 +/- 0.8 mm Hg (p < 0.004), and inotropic drug support with dopamine and dobutamine had also decreased significantly. Thirteen (36%) patients died of low cardiac output and multiorgan failure (4 of them after delayed chest closure) that was complicated by sepsis in 2. The incidence of sternal wound infection was relatively low at 5.6% (2/36); 1 patient died of generalized sepsis complicating multiorgan failure and the second case occurred in a patient who survived long term after sternectomy. With optimal ventilatory and inotropic drug support and meticulous wound care, delayed sternal closure may improve the survival of infants in low cardiac output after cardiac surgical procedures.

Female↗

Acute hemodynamic effects of adjustable atrial septal defect closure in the lateral tunnel Fontan procedure.

OBJECTIVES: This study evaluated the acute hemodynamic changes with atrial septal defect closure in the postoperative period in patients undergoing the Fontan procedure. BACKGROUND: The adjustable atrial septal defect is a modification of the Fontan procedure designed to improve cardiac output and reduce systemic venous hypertension during the postoperative period. Limited information is available on the effects of inter-atrial shunting on the physiology of direct cavopulmonary connection. METHODS: In 11 patients (aged 9 months to 14.5 years), the atrial septal defect was closed 8 h to 4.6 days (mean 1.7 days) postoperatively. Indications for closure included mean right atrial pressure < 15 mm Hg or arterial oxygen saturation < 80%, or both. RESULTS: Data presented are mean values +/- 1 SD. Mean right atrial pressure was 13.4 +/- 3.0 mm Hg on admission to the intensive care unit, 10.0 +/- 2.0 mm Hg (p = 0.02) immediately before closure and 11.4 +/- 2.8 mm Hg (p = 0.02) after closure. There was a significant decrease in cardiac output, as calculated from arteriovenous oxygen saturation difference (26 +/- 9%, p = 0.003), Doppler aortic flow (19 +/- 9%, p = 0.0002) and ventricular volumes by two-dimensional echocardiography (20 +/- 8%, p = 0.0001). Arterial oxygen saturation increased from 82 +/- 5% to 94 +/- 4% (p = 0.0001), and arteriovenous oxygen saturation difference increased from 25 +/- 8% to 33 +/- 9% (p = 0.0001). Systemic oxygen delivery decreased from 727 +/- 354 to 655 +/- 325 ml/min per m2 (p = 0.02). One patient required reopening of the atrial septal defect. CONCLUSIONS: These data demonstrate that a controlled right to left atrial shunt improves cardiac output and systemic oxygen delivery and facilitates the postoperative management of patients after the Fontan procedure. Atrial septal defect closure increases systemic saturation to normal values and prevents potential systemic embolization but significantly decreases oxygen delivery and might limit exercise tolerance.

Adolescent↗

Technique for reoperative median sternotomy in the presence of a patent left internal mammary artery graft.

Damage to a patent left internal mammary artery (IMA) graft during reoperation can be catastrophic. An organized approach to reenter the mediastinum in the presence of a functioning left IMA graft is described. The sternum is opened using an oscillating saw to carefully divide the anterior and posterior tables. The right side is then dissected out first, exposing the aorta and right atrium. After placing pursestring sutures for cannulation, attention is turned to the left side. An IMA retractor is used to elevated the left edge of the sternum in incremental stages. The dissection is begun at the inferior end of the sternum, exposing the distal anastomosis first and then dissecting superiorly anterior to the IMA. A Doppler flow detector probe is used to assist in locating the artery in the adhesions.

Coronary Artery Bypass↗

Warm continuous antegrade blood cardioplegia: applications in congenital heart disease.

UNLABELLED: Continuous warm blood cardioplegia is utilized by many surgeons as their method of choice for myocardial protection during operations for acquired heart disease. OBJECTIVE: this study was performed to determine the feasibility and safety of this method for intracardiac procedures through the right atrium and in particular, total cavopulmonary connection. MATERIALS AND METHODS: procedures included closure of an atrial septal defect (23), atrial septectomy (2) and total cavopulmonary connection (4). Antegrade blood cardioplegia was delivered continuously for an average of 27 +/- 21 minutes at an average flow of 130 +/- 60 cc/min to maintain the aortic root pressure between 60 and 80 mmHg (mean 74 +/- 5 mmHg). Perfusion with regular blood commenced in the last 2 to 8 minutes and complete de-airing procedure was performed on the beating heart before removal of the aortic cross-clamp. RESULTS: all patients resumed sinus rhythm and all but one had normal cardiac output postoperatively. In one patient after cavopulmonary connection the inferior vena-cava to pulmonary-artery connection was taken down because of increased pulmonary vascular resistance resulting in low output state. All patients made an uneventful recovery without neurological complications. CONCLUSIONS: this initial experience suggests that normothermic aerobic arrest can be used safely in the repair of congenital defects and may provide superior myocardial protection for complex procedures such as the Fontan procedure.

Adolescent↗

Damus-Stansel-Kaye procedure: current indications and results.

Between October 1983 and August 1991, 29 consecutive Damus-Stansel-Kaye procedures were performed. Indications for operation included restrictive bulboventricular foramen or subaortic stenosis associated with complex univentricular congenital heart disease (25) and Taussig-Bing heart, subaortic stenosis, or both associated with complex biventricular congenital heart disease (4). Twelve patients underwent concurrent Fontan procedures. Average age at operation was 39.8 months (range, 1 to 132 months). Average outflow tract gradient was 28 mm Hg (range, dynamic to 80 mm Hg). Of the 29 patients, 23 were male and 6 were female. There were three early deaths (10%), two in patients who had a concurrent Fontan procedure. Although there was a trend toward lower age and higher outflow tract gradients in nonsurvivors, these and other factors were not statistically significant predictors of death. Actuarial freedom from cardiac-related death was 88% at 5 years (n = 7). In a mean follow-up of 3.5 years (range, 0.1 to 7.7 years), 3 patients have required reoperation (10%), 2 for aortic valve insufficiency (5 days and 2.75 years) and 1 for a gradient across the anastomosis (5.75 years). Actuarial freedom from reoperation related to a failed Damus-Stansel-Kaye procedure was 90% at 4 years and 75% at 6 years (n = 7).

Actuarial Analysis↗

Aortic valve replacement using a continuous suture technique.

The continuous suture technique has been proposed as an alternate method for aortic valve replacement (AVR). Advantages include a decreased ischemic and bypass time. Despite reports of a low incidence of perivalvular leak, wide use of the continuous suture technique has not been adopted. This report reviews our experience with the continuous suture technique. From January 1984 through November 1991, 181 consecutive patients underwent AVR using the continuous suture technique. The mean age was 61 years (range 6 to 88 years). Diagnoses included pure aortic stenosis (AS) in 41%, aortic insufficiency (AI) in 31%, and a combination of AS and AI in 28%. Fifty-six patients underwent isolated AVR and 125 underwent AVR combined with other procedures. The overall early mortality was 5.5%. Early mortality for isolated AVR was 0% (0/56) and was 8.0% (10/125) for those undergoing concomitant procedures. Late mortality was 4.7% in a mean follow-up of 30 months (range 1 to 86 months). The incidence of perivalvular leak was 2.3% (4/171 operative survivors). Perivalvular leak was mild in two, and moderate in two; none required reoperation. Perivalvular leak developed only in patients whose suture line was not reinforced with glutaraldehyde treated pericardium. The continuous suture technique is a quick and effective method for AVR and results in a low incidence of perivalvular leak.

Adolescent↗

Use of a Dacron mesh coated pericardium for aortic augmentation.

A technique is described for aortic augmentation with Dacron mesh coated pericardial patch. This method avoids the use of synthetic graft material with the potential for weak adherence of pseudointima and microembolization. Hemostasis is improved and fibrous tissue ingrowth into the mesh prevents late aneurysm formation. The incorporation of the pericardial patch into the aortic wall and the normal endothelialization of the patch is documented after a 5-year follow-up.

Adult↗