Inducible nitric oxide synthase expression in coronary arteries of transplanted human hearts with accelerated graft arteriosclerosis

In the vast majority of burned patients, the injury is limited to the skin and superficial subcutaneous tissue, and the vasculature of the deeper fascia is spared. This fact encouraged me to design a flap in which the burned scar tissue is employed. The island fasciocutaneous flap is based only on the proximal septocutaneous perforators of the radial artery. The flap is used to resurface the anterior as well as the lateral burned cubital fossa after excision of the scar tissue and release of contracture. An anatomic study as well as clinical approach has been conducted.     

Vulnerable plaque. Relation of characteristics to degree of stenosis in human coronary arteries

BACKGROUND: The microanatomic features of the atherosclerotic plaque at risk of disruption include a large lipid core, a high macrophage content, and a thin cap. The relation between lipid core size, plaque size, and cap thickness either with each other or with the degree of stenosis has yet to be evaluated in human coronary arteries. METHODS AND RESULTS: Atherosclerotic coronary plaques (n = 160) were obtained from 31 subjects who died suddenly of ischemic heart disease. In coronary arteries perfused with formol saline at a pressure of 100 mm Hg, stenosis was measured by comparison of the minimal lumen size at the site of a plaque with that of the lumen in an adjacent normal segment of artery. Plaque size, the size of the lipid core, and the thickness of the cap were measured in histological sections. Lipid core size ranged from 0% to 82% of overall plaque size. Seventeen percent of plaques had a core size of > 50%. Linear regression showed no relation of core size to stenosis (r = .21). Absolute plaque size bore no relation to core size (r = .14). Minimal cap thickness was not related to core size (r = .06). Ten percent of plaques predicted to be angiographically invisible had cores of > 50%. CONCLUSIONS: Two major determinants of plaque vulnerability, core size and cap thickness, are not statistically related. Neither of these two factors that confer vulnerability are related to absolute plaque size or to the degree of stenosis.     

Electrical coupling between smooth muscle cells and endothelial cells in pig coronary arteries

The control of smooth muscle cells by endothelial cells has been well established by the identification of vasoactive factors released by the endothelial cells. In contrast, the possibility that smooth muscle cells influence the endothelial cells has been considered rarely. Some results suggest possible electrical communication between the smooth muscle and the endothelial cells but proof is lacking. We therefore tested for electrotonic conduction of signals from smooth muscle cells to endothelial cells. The endothelium was removed from half of a strip of porcine coronary artery. In a partitioned chamber, rectangular hyperpolarization or depolarization was applied to the de-endothelialized region by field stimulation. The resulting membrane potential changes in the smooth muscle cells spread electrotonically along the media into the area with intact endothelium. We recorded from endothelial cells to determine whether this electrical signal spreads into endothelial cells. Hyperpolarization or depolarization initiated in smooth muscle cells was recorded consistently in endothelial cells. This demonstrates a functional electrotonic propagation from smooth muscle to endothelial cells.     

Criteria of myocardial ischemia in bicycle ergometry of patients with stenosing arteriosclerosis of the cardiac coronary arteries depending on the initial ECG at rest

The sensitivity of various criteria of the physical exercise test in revealing myocardial ischemia was studied in 2 groups of patients with ischemic heart disease: 1st group of 64 patients with normal ECG at rest, 2nd group of 96 patients with cicatricial changes in the myocardium. Selective coronography demonstrated atherosclerotic narrowing (stenosis of more than 70%) of one or more coronary arteries of the heart in all patients. During physical exercise an attack of angina pectoris without "ischemic" changes on the ECG occurred in 36.1% of patients of the 1st group and in 22.4% of patients of the 2nd group. The frequency of other clinical signs of cessation of the exercise (dyspnoea, change of arterial pressure, extrasystole and others) was three and a half times higher in patients with cicatricial changes in the myocardium. It is concluded that the frequency with which signs of myocardial ischemia are revealed during physical exercise depends not only on the pronounced character of the pathological coronary condition and the development of collateral circulation but also by the sensitivity of the separate ECG leads and the presence and localization of cicatricial changes in the myocardium.     

Anatomic variations of the coronary arteries

PURPOSE: To study the coronary arteries and their main branches showing the aspects of source, trajectory and anastomoses of these vessels at the subepicardial level. METHODS: The study was carried out on 110 adult human hearts, of both sexes, fixed in 10% formaldehyde solution. The pericardium was removed to expose the coronary arteries and their branches at the subepicardial level. RESULTS: In 38.18% of the cases the left coronary artery presented a trifurcation into anterior interventricular, circunflex and left marginal branches (35.70%) and into anterior interventricular, circunflex and lateral branches (64.30%). In 60% of the hearts examined, the left coronary artery presented a bifurcation into anterior interventricular and circunflex branches. In 1.82% of the cases these two branches arise directly from the aorta. An anastomosis, at the subepicardial level, between the anterior and posterior interventricular branches was observed in 56.36% of the hearts. In 88.18% the posterior interventricular branch arised from the right coronary artery, whereas in 11.82% this vessel arises from the circunflex branch. Anastomoses between the right coronary artery and the circunflex branch were found in 10% of the hearts (crux cordis). The dominance of the right coronary artery was present in 69.09% of the cases, of the left coronary artery in 11.82% and in 19.09% of the hearts had balanced distribution. CONCLUSION: The coronary arteries and their main branches present a great quantity of variations with regard to source, trajectory and anastomoses. This knowledge is important for the interpretation of coronary angiography and surgical myocardial revascularization.     

Fibromuscular dysplasia of the renal arteries

Thirty-two cases of fibrous-muscular dysplasial of renal arteries (including one autopsy case) were studied. Sections of renal arteries removed at reconstructive operations from patients suffering from renovascular hypertension were examined. Two morphological variants of the process were distinguished: medial dysplasia (perimedial fibroplasia, medial fibroplasia, and dissecting aneurysm) and intimal proliferation. Morphologically, fibrous-muscular dysplasia is a manifestation of proliferation of smooth muscle cell which appears to have various forms and stages. Diagnostically, fibrous-muscular dysplasia should be differentiated from atherosclerosis, nonspecific arteritis, proliferation of the intima due to hypovolemia, and perivascular sclerosis of different etiologies.     

Scaffolding the coronary arteries: intracoronary stenting

Stenting is a new method for treating coronary artery stenosis. This article presents an overview of the rationale for the implantation of stents, the various types of stents available, and roles the home care nurse assumes in caring for these patients.     

Intravascular ultrasound imaging of atherosclerotic renal arteries: comparison between in vitro and in vivo studies

BACKGROUND: Intravascular ultrasound (IVUS) imaging, a new modality, may be feasible and useful for the assessment of atherosclerotic renal arteries. However, comparison between in vivo and in vitro studies to confirm pathological changes corresponding with IVUS findings obtained from renal arteries was not fully evaluated. METHODS: We evaluated ultrasound images of 18 post-mortem human renal arteries and cross-sectional IVUS images of main renal arteries in five patients with renal artery stenosis (RAS) or essential hypertension. RESULTS: In vitro studies have shown that renal-artery images had three layers when the arteries had fibrous intimal thickening and medial hypertrophy. Renal arteries, in which the fibrous intima was not well developed, showed circumferentially homogeneous bright echoes. In patients with atherosclerotic RAS and essential hypertension, IVUS images showed hyperechoic areas in the renal arterial walls, probably due to atherosclerosis. Typical three-layered ultrasound appearance was not easily seen during in vivo studies. CONCLUSION: Our findings suggest that hyperechoic images can be a diagnostic clue of atherosclerosis However, in vitro results do not always correspond exactly to in vivo findings, and caution is needed when findings from in vitro IVUS imaging studies are applied to in vivo studies.     

Surgical angioplasty of the main coronary arteries in children

OBJECTIVE: To determine the safety and efficacy of surgical angioplasty of the coronary arteries in children. METHODS: We performed 9 surgical reconstructions of the left main coronary artery and 1 of the right coronary artery ostium in 10 children (mean age 5.7 years; range 2 months-15 years). The basic diseases included the following: congenital atresia of the left coronary artery (n = 2) and atresia of the right coronary artery in a patient with an aortoventricular tunnel (n = 1); stenosis of the left main coronary artery (1) in a patient with Williams syndrome (n = 1), (2) in a patient with familial hypercholesterolemia (n = 1), (3) after the arterial switch operation for transposition of the great arteries (n = 3), (4) after reimplantation of an anomalous left main coronary artery from the pulmonary artery (n = 1), and (5) by compression after a réparation à l'étage ventriculaire procedure (n = 1). Myocardial viability was assessed by single photon emission computed tomography (thallium 201; 7/10). The coronary artery stem was enlarged with a saphenous (n = 5), a pericardial (n = 4), or a polytetrafluoroethylene patch (n = 1). RESULTS: There was 1 hospital death and 9 patients are alive (mean follow-up 46 +/- 30 months; range 12 months to 10.5 years). Eight of 9 survivors had a selective coronary artery angiogram and had normal coronary artery ostia. Two patients had stenosis of the left anterior descending coronary artery, 1 of whom underwent successful internal thoracic artery grafting. CONCLUSIONS: Surgical angioplasty of the coronary stems restores physiologic coronary perfusion and conserves bypass material. It can be performed safely in children and provides encouraging midterm results.     

Obliterative arteriosclerosis of extremities in patients with coronary heart disease

In a group of 314 patients after past myocardial infarction or an episode of acute coronary insufficiency, angiological examination, repeated after a one-year interval, was performed. In the first examination, signs of obliterative arteriosclerosis in the lower extremities were found in 18.8% of the patients. It was noteworthy that 34% of patients with peripheral obliterative arteriosclerosis had no complaints connected with an impairment of circulation in the limbs. On the basis of the second examination, performed after a one-year interval, it was found that the annual incidence of obliterative arteriosclerosis in the lower extremities was 7.4%. In 66% of patients showing signs of obliterative arteriosclerosis at the first examination, objective impairment of peripheral circulation was observed after a one-year interval. In none of the patients did the investigators find signs of obliterative arteriosclerosis in the upper extremities.     

Intraluminal obliteration of the renal arteries in kidney tumors

A preoperative obliteration of the renal vascular bed was performed in 90 patients by means of Gelfoam emboli. This procedure facilitates the ligation of the renal vein and artery during transabdominal nephrectomy. The decreased vascularity lessens the risk of tumor embolization and reduces the duration of the surgical procedure by half. A simple routine percutaneous method of occlusion is described. Gelfoam emboli are unsuited for permanent obliteration in bleeding tumors.     

Medial fibroplasia: involvement of renal artery and small renal arteries in renal vascular hypertension

Dysplasia of the renal artery may cause renal vascular hypertension. The most common type of dysplasia is the medial fibroplasia. Medial fibroplasia, as well as the other types of dysplasia, has only been described in the main and primary branches of the renal artery. A case of medial fibroplasia, where arterial changes were seen far out in the small renal vessels is reported.     

An experimental study of coronary arteriosclerosis after heart transplantation

The purpose of this study is to evaluate the effects of Cyclosporine (CsA), FK-506 (FK) and 15-Deoxyspergualin (DOS) on coronary arteriosclerosis after rat heart transplantation. Three groups of Lewis rats (n = 7, each) received heterotopic heart transplants from F-344 donors and were treated with CsA (Group Cs), FK (Group FK) and DOS (Group DOS) intraperitoneally. All rats were sacrificed 60 days later and assessed microscopic grading score (GS) of rejection and arteriosclerosis, and measured serum lipid. There was no significant difference in the GS of rejection but the GS of arteriosclerosis in the groups Cs was significantly higher than the group DOS (1.71 +/- 0.24 versus 1.11 +/- 0.34, p < 0.01). Triglyceride in the groups Cs was significantly higher than the group FK and group DOS (99 +/- 23 versus 66 +/- 21, 56 +/- 30 mg/dl, p < 0.02), and LDL in the group Cs and group FK was significantly higher than group DOS (104 +/- 17, 81 +/- 23 versus 31 +/- 17 mg/dl, p < 0.01). We concluded that DOS had a superior protective effect against coronary arteriosclerosis after heart transplantation and it may depend on the different mechanism of immunosuppression and lipid metabolism abnormality causing by immunosuppressants.