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Biomedical subjects

A Elami

Publications and source records attributed to A Elami.

At least 55 records · Page 3Linked to original sources
PubMed1993

Smooth muscle cell abundance and fibroblast growth factors in coronary lesions of patients with nonfatal unstable angina. A clue to the mechanism of transformation from the stable to the unstable clinical state.

BACKGROUND: The mechanisms responsible for the transformation of stable angina to unstable angina, a major cause of morbidity and mortality, are commonly believed to be plaque rupture and thrombosis. We determined whether additional mechanisms are operative by analyzing the histopathology and immuno-histopathology of coronary plaques retrieved by directional atherectomy of patients with unstable angina in whom no intraluminal thrombus was demonstrated by angiography. METHODS AND RESULTS: The histological findings of atherectomy specimens from 34 patients with unstable angina were compared with those of 24 patients with postangioplasty restenosis, whose lesions are known to be composed of smooth muscle cells (SMCs), and 10 patients with stable angina, whose lesions contain relatively few SMCs. We also studied the expression of acidic and basic fibroblast growth factors (aFGF and bFGF), whose role in the vascular response to injury has been established. Specimens from unstable angina resembled those from postangioplasty restenosis in regard to SMC abundance (scale, 0 to 3; 1.4 +/- 0.9 versus 1.7 +/- 0.9; P = NS), and both differed from those of stable angina. Thrombus and/or hemorrhage occurred in only 34% of patients with unstable angina (compared with 8% of restenosis patients and in none of stable angina patients). Active lesions (defined as lesions (defined as lesions containing one or more of the following: thrombus, hemorrhage, abundant and disorganized SMCs in the presence of loose connective tissue, or inflammatory infiltrate) were observed in 56% of the unstable angina patients and in 50% of the restenosis patients but in none of the stable angina patients. The expression of aFGF and bFGF was detected in 80% to 100% of unstable angina (n = 11) and restenosis (n = 10) specimens but in only 1 of 5 stable angina specimens. CONCLUSIONS: Microscopic evidence of thrombosis and plaque rupture occurred in only one third of unstable angina patients, selected because they had no angiographic evidence of intracoronary thrombus. Moreover, their lesions resembled those of restenosis patients in regard to SMC abundance, lesion activity, and the expression of aFGF and bFGF. Our findings therefore suggest that an alternative mechanism to plaque rupture and thrombus formation may be operative in the precipitation of unstable angina; namely, in a subset of patients, SMC proliferation may lead to gradual plaque expansion and thereby to lumenal narrowing and unstable angina. Our data also suggest a role for aFGF and bFGF in this process.

Adult↗
PubMed1993

Use of the internal mammary artery for urgent myocardial revascularization.

The effect of using the internal mammary artery (IMA) as a conduit for revascularization on the outcome of early (< 30 days) coronary artery bypass graft surgery after acute myocardial infarction was determined. Forty patients were studied: 27 underwent urgent operation for ongoing ischaemia and/or haemodynamic instability early after acute myocardial infarction and 13 had emergency surgery for failed percutaneous transluminal coronary angioplasty associated with clinical and enzymatic evidence of myocardial infarction. Nine patients experienced low cardiac output before operation, in six of whom intra-aortic balloon counterpulsation was used to treat cardiogenic shock. In 26 patients (group 1) the left IMA was utilized with or without additional vein grafts. In the remainder (group 2, n = 14), only vein grafts were used. Group 1 patients were younger than those in group 2 (mean(s.d.) age 55(9) versus 67(8) years, P = 0.0001). Other preoperative and perioperative variables were similar in the two groups. There was one death in hospital (2%, group 2). Eight (31%) group 1 patients sustained postoperative low cardiac output compared with ten (71%) in group 2 (P < 0.04). Preoperative low cardiac output (P < 0.025) and non-use of the IMA (P < 0.05) were identified by univariate and multivariate analysis as the most significant independent predictors of low cardiac output after operation. Although age was excluded as a predictor of low cardiac output, it is concluded that the IMA is an adequate conduit that can safely be used in patients younger than 70 years of age undergoing myocardial revascularization during or early after acute myocardial infarction.

Adult↗
PubMed1992

Damus-Stansel-Kaye procedure: technical modifications.

The Damus-Stansel-Kaye procedure has been applied for the relief of outflow tract obstruction caused by a restrictive bulboventricular foramen or subaortic stenosis in patients with complex univentricular heart disease. The procedure may also be part of a biventricular repair of a Taussig-Bing transposition of the great arteries. This report details technical modifications of the procedure to ensure unobstructed blood flow from the pulmonary artery to the aorta and to maintain the integrity of the pulmonary and aortic valves.

Anastomosis, Surgical↗
PubMed1992

The inferior epigastric arteries as coronary bypass conduits. Size, preoperative duplex scan assessment of suitability, and early clinical experience.

We are currently evaluating the inferior epigastric artery as an alternative arterial conduit for coronary bypass grafting. Fifty-seven inferior epigastric arteries were harvested from 47 adults. There were no differences in size between the right and left inferior epigastric arteries. Diameter was 2.5 to 3.5 mm proximally and 2 to 3 mm distally. Usable length was 6 to 16 cm (mean 11.2 +/- 0.25 cm). Grade I/IV atherosclerosis was found in one patient (2.1%). Duplex scanning was used for preoperative evaluation of the inferior epigastric arteries in 51 patients. In 21 patients the arteries were not harvested, in part because of duplex scan findings of small caliber or early bifurcation. In 30 patients the duplex findings could be compared with the surgical findings. The average length at operation was twice the length detected on duplex scan (11.2 cm versus 5.8 cm, p less than 0.001). There was a good correlation between diameter on duplex scan and that measured at operation (2.56 +/- 0.05 versus 2.62 +/- 0.07, p = not significant). Between December 1989 and May 1991, 38 patients (29 to 74 years, mean 56 years) received 42 inferior epigastric artery grafts. Proximal anastomoses were to the aorta in 17, to the vein graft hood in 20, or onto an internal mammary artery graft in 5. Distal anastomoses were to the left anterior descending artery in 2, the diagonal branch in 27, the marginal branch in 9, or the right coronary artery in 4. There were no early deaths. Complications included perioperative myocardial infarction in 1, deep sternal wound infection in 2, superficial infection at the harvest site of the inferior epigastric artery in 5, and reexploration for bleeding in 2. Because of its size and the low incidence of atherosclerosis, the inferior epigastric artery may evolve as an alternative arterial conduit for coronary bypass. Duplex scanning is a valuable noninvasive tool for preoperative evaluation of the artery's suitability. Long-term studies of patency of the inferior epigastric artery as a coronary bypass conduit are needed.

Abdominal Muscles↗
PubMed1991

[Early revascularization after acute myocardial infarction].

Coronary artery bypass grafting (CABG) was performed on 40 consecutive patients within the first month after acute myocardial infarction (AMI) between January 1985 and July 1988. Group I (N = 27) included patients with unstable postinfarction angina who underwent operation within 16 +/- 14 days after infarction. Group II (N = 13) underwent emergency operation after failed percutaneous transluminal coronary angioplasty (PTCA) which was complicated by AMI. This group was operated on within 4.5 +/- 3 hours after onset of symptoms. There was left ventricular dysfunction (ejection fraction less than .35) in 8 Group I patients. Ventricular function of Group II patients during and after infarction could not be evaluated. The internal thoracic (mammary) artery (ITA) was used in 26 patients. Early mortality was 2.5% (1 patient). Preoperative low cardiac output (LCO) was associated with increased need for inotropic and intra-aortic balloon pump support during termination of cardiopulmonary bypass (p less than 0.02), and it predicted postoperative LCO (p less than 0.03). Preoperative reduced ventricular function was associated with increased need for inotropic support, LCO, and ventricular arrhythmias (p less than 0.02, p less than 0.05, p less than 0.02, respectively). The postoperative course was complicated by LCO in 71% of those with saphenous vein grafts, but in only 30% of those with ITA grafts (p less than 0.02). Inotropic and mechanical support needed during weaning from cardiopulmonary bypass was significantly less in those with the ITA graft (p less than 0.05, p less than 0.03, respectively). Hospital stay after surgery was 12 +/- 7 and 9 +/- 2 days for Groups I and II, respectively (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1991

Preoperative duplex scan assessment of the inferior epigastric artery as a coronary bypass conduit.

The inferior epigastric arteries are currently being evaluated as alternative autologous arterial conduits for coronary artery bypass operations. The inferior epigastric arteries are variable in diameter and length and require harvesting through separate abdominal incisions. There is a need, therefore, for a method to preoperatively assess the diameter and length of the inferior epigastric arteries to determine their suitability as a coronary artery bypass graft. We have found that the duplex scan is a valuable noninvasive preoperative imaging modality to evaluate the inferior epigastric arteries.

Abdominal Muscles↗
PubMed1990

[Balloon angioplasty for aortic coarctation].

Coarctation of the aorta is amenable to surgical correction or balloon dilatation. In a 6-month-old girl with multiple intracardiac anomalies, re-coarctation, which followed surgical repair at 16 days was successfully dilated.

Angioplasty, Balloon↗
PubMed1989

Frequency and significance of complete atrioventricular block after coronary artery bypass grafting.

Three hundred forty-eight consecutive patients were evaluated during 1985 and 1986 for the development of complete atrioventricular (AV) block after coronary artery bypass grafting. Cold (4 degrees) asanguineous potassium cardioplegia with temperature monitoring was used uniformly. AV block developed in 56 instances (16%). In 32 patients (group 1) the block was transient (less than 6 hours) and in 24 it was persistent (group 2). Left main coronary artery stenosis in conjunction with total obstruction of a dominant right coronary artery occurred more commonly in patients manifesting AV block (18 of 56, 32%) than in those without it (35 of 292, 12%) (p less than 0.05). Complete occlusion of a dominant right coronary artery was observed with equal frequency in patients with and without AV block. The presence of an ungraftable right coronary artery, however, was significantly more frequent in the AV block group: 16 of 37 (47%) vs 6 of 194 (3%) (p less than 0.01). Endarterectomy of the right coronary artery was performed in 8 of 24 patients (33%) with persistent AV block versus none in the patients with transient AV block (n = 32) or normal sinus rhythm postoperatively (n = 292) (p less than 0.0001). Persistent AV block (greater than 6 hours) was associated with myocardial infarction in 6 patients (25%) (p less than 0.05) and with low cardiac output in 18 patients (75%) (p less than 0.0001). In conclusion, AV block after myocardial revascularization was frequently associated with the presence of multivessel coronary disease and an ungraftable dominant right coronary artery. Persistent (greater than 6 hours) AV block was correlated with both perioperative myocardial infarction and low cardiac output.

Aged↗
PubMed1989

[Autotransfusion of shed mediastinal blood after cardiac surgery].

We have developed a technique for autotransfusion of shed mediastinal blood collected in the cardiotomy reservoir. Results in the first 50 consecutive patients in whom the system was employed were studied prospectively (group A) and were compared with those of the last 50 consecutive patients operated on before application of the new method (group B). The mean preoperative hematocrit (about 42%) and the total postoperative bleeding (about 11) were similar in both groups. Only 24 patients (48%) in group A required homologous blood transfusion, versus 43 (86%) in group B (p = 0.0001). This resulted in a 57% saving of blood units in group A (mean, 1.16 +/- 1.49 units per patient versus 2.72 +/- 1.99 in group B, p less than 0.0001). Foreign blood transfusion was thus avoided in 21 of the last 25 patients (84%) of group A. 7 days after operation, the mean hematocrit in group A was 30.9 +/- 4.3, compared with 33.0 +/- 3.8 in group B (p less than 0.001). Hemolytic jaundice occurred in 7 group B patients (14%) but in none in group A (p less than 0.01). A trend towards reduction in other complications was also demonstrated. We conclude that the use of foreign blood transfusions in those undergoing open heart surgery can be reduced significantly by this method, thus avoiding immediate transfusion reactions and minimizing the risks of late complications.

Anemia, Hemolytic↗
PubMed1989

The danger in skin grafting the bare mediastinum after sternectomy for postcoronary bypass dehiscence.

We describe a patient who underwent coronary bypass grafting, after which severe mediastinitis and sternal osteomyelitis occurred. Repair after sternectomy was undertaken with a rectus-abdominis myocutaneous flap. The distal fifth of the flap underwent necrosis and was replaced by a meshed split-thickness skin graft. A year later, a clip marking one of the bypass grafts nearly eroded through the skin graft, endangering the bypass graft. The skin graft was removed by abrasion, and the bypass graft was covered with a pectoralis muscle flap. We recommend that skin grafting of a granulating wound over coronary artery bypass grafts be avoided if possible.

Coronary Artery Bypass↗
PubMed1988

Subclavian artery occlusion after radiotherapy for carcinoma of the breast.

Disturbance of the arterial circulation in the ipsilateral upper limb following mastectomy is a rare sequel attributed to adjuvant radiotherapy. A review of the literature revealed 20 such cases, and two more are presented. Different mechanisms of injury leading to arterial occlusion have been proposed. This is a late complication with a considerable time lag between irradiation and onset of symptoms. The symptoms vary in type and severity, but are consistent with peripheral occlusive arterial disease. To alleviate symptoms and prevent limb loss, reconstructive vascular surgery is advocated, and was successfully performed in one of our patients.

Aged↗
PubMed1986

Exercise performance in patients with impaired left ventricular function following aorto coronary bypass.

We studied 40 patients with preoperative ejection fraction (EF) of 0.35 or less who underwent aortocoronary bypass. An average of 3.1 saphenous vein grafts per patient were inserted and revascularization was considered complete in 33 (82%) of the subjects in the group. Mean follow-up period was 29 months (range 12-65 months). Early mortality was 5% (2 patients) and there were 7 late deaths (3 cardiac and 4 non-cardiac). The 5-year cardiac actuarial survival rate was 74 +/- 13% (+/- SEM). Angina has improved in 29 (94%) of the 31 long-term survivors with 23 (74%) being totally asymptomatic. Twenty-two of the long-term survivors performed an exercise test at the end of their follow-up period. These tests revealed that bypass surgery in such patients results in significantly enhanced myocardial oxygen consumption with concomitant increase in effort level and duration. The exercise ability is probably directly related to the degree of revascularization.

Adult↗
PubMed1985

Intermittent treatment with droperidol, a short-acting neuroleptic, increases behavioral dopamine receptor sensitivity.

Drug holidays have been proposed as a preventive strategy against the development of tardive dyskinesia. Three animal studies in which dopamine receptor hypersensitivity after chronic neuroleptic treatment was used as a model for tardive dyskinesia failed to find any reduction in dopamine receptor hypersensitivity with intermittent, as opposed to continuous, treatment. Since most neuroleptics have a long half-life in vivo, we hypothesized that truly drug-free periods may not have been achieved in previous studies. Droperidol, an ultrashort-acting butyrophenone neuroleptic, was administered to rats for 22 days in twice-daily injections or one injection every 48 hours. At 60 hours after the last dose there was no difference in apomorphine-induced stereotypy between continuously treated and intermittently treated animals. Thus, even totally drug-free periods do not reduce the development of dopamine receptor hypersensitivity.

Animals↗
PubMedDate not supplied

Mitral valve replacement in patients after aortic valve replacement.

BACKGROUND: Mitral valve replacement in patients who previously had undergone aortic valve replacement is a technical challenge. The rigid aortic prosthesis limits visualization of the anterior mitral annulus and placement of sutures. METHODS: Reoperative mitral valve replacement was performed in five patients after aortic valve replacement. Two patients underwent resternotomy to allow verification of normal aortic prosthetic valve function. Anterolateral right thoracotomy was used for reentry in the remaining three patients. Exposure of the anterior mitral annulus was accomplished by initial traction on the intact anterior leaflet, with resection of this leaflet only after placement of sutures. RESULTS: All patients survived the surgical procedure and are well 2 to 30 months after operation. In one patient it was impossible to open one cusp of the mitral prosthesis, nor was it possible to rotate the valve. The valve was reimplanted, but sutures were tied only after testing for full free cusp motion. CONCLUSIONS: When appropriate, right thoracotomy incision offers excellent exposure of the mitral valve with minimal dissection. Placement of sutures along the anterior portion of the annulus is facilitated by traction downwards on the anterior leaflet. Full range of motion of the prosthetic cusps should be verified before tying the sutures.

Aged↗
PubMedDate not supplied

Hemopericardium: a late complication after repair of pectus excavatum.

Hemopericardium and tamponade occurred in a 12 year old boy with Marfan's syndrome, two years after surgical repair of pectus excavatum. This life-threatening complication resulted from penetration of a fractured metal plate through the pericardium into the right atrium. The clinical details are reported and discussed.

Child↗