Actuarial analysis of variables associated with rupture of small abdominal aortic aneurysms

This study identified risk factors associated with rupture of small abdominal aortic aneurysms in patients initially selected for nonoperative management. Sixty-seven patients, 53 men and 14 women, 50 to 91 years of age (mean 72 years) were followed 3 to 99 months (mean 36 months). All patients underwent serial aortic ultrasonography. The annual rate of aneurysm rupture was 6%, with an annual mortality rate caused by rupture of 5% and an annual mortality rate caused by coexistent disease of 6%. Thirty potential risk factors, including blood pressure, aneurysm size measured by ultrasonography, rate of aneurysm expansion, smoking, serum cholesterol levels, and cardiac, pulmonary, and renal risks, were analyzed by Cox proportional hazards regression to identify variables related to rupture. Aneurysm anteroposterior expansion rates varied from 0 to 1.5 cm/year but were not different in aneurysms that ruptured. Only diastolic blood pressure, initial aneurysm anteroposterior diameter, and degree of obstructive pulmonary disease were independently predictive of rupture (p less than 0.05, Wald test). With these data, actuarial rupture rates were predicted for patients with selected values of these three covariates. Predicted 5-year rupture rates varied from 2% when these risk factors were absent to 100% when all three risk factors were significant. Obstructive pulmonary disease, initial aneurysm size, and diastolic hypertension must be evaluated prospectively to assess their accuracy in predicting small aneurysm rupture.

Left ventricular systolic function in children with coronary arterial lesion following Kawasaki disease

Seventy-five children with Kawasaki disease underwent quantitative left ventricular cineangiography, and angiographic measurements were made to obtain left ventricular ejection fraction (LVEF) and mean velocity of circumferential fiber shortening (mVcf). In addition, left ventricular pressure and echocardiograms were taken simultaneously before and after nitroprusside infusion using a micromanometer. In the present study, the slope of the line describing end-systolic pressure-diameter relations (Emax) was calculated. The 75 children with Kawasaki disease were classified into five groups according to the severity or condition of associated coronary lesions: Grade 0 group (normal--no significant enlargement of the coronary artery is seen), grade 1 group (mild state of lesion--the maximum diameter of the coronary artery is 4.0 mm or less), grade 2 group (moderate state of lesion--the maximum diameter of the coronary artery is 4.0-8.0 mm), grade 3 group (serious state of lesion--the maximum diameter of the coronary artery is 8.0 mm or over, i.e., giant aneurysm), and stenotic lesion (SL) group (myocardial infarction or various other stenotic lesions are involved). Each group was investigated for each index of left ventricular function. In the grade 2 group, the averaged value of LVEF was slightly smaller than those for the grade 0 and 1 groups, while in the grade 3 and SL groups, the averaged values of LVEF were markedly smaller than those for all other groups. Grade 3 and SL groups showed averaged mVcf values that were smaller than those for other groups, while grade 2-3 and SL groups showed averaged values of Emax that were markedly smaller than those for the remaining groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Fate of nonobstructive aneurysmatic coronary artery disease: angiographic and clinical follow-up report

The incidence of coronary aneurysmatic dilatation without coronary stenosis is rare, and the clinical course of such an entity is unknown. We present five adult patients, four men and one woman, with such an anatomic finding. The age range was 44 to 60 years. In four patients the aneurysmatic dilatations involved multiple coronary sites. The clinical course in all five patients was suggestive of coronary insufficiency. Despite no obstructive disease, two of the patients developed transient ischemic ECG changes accompanied by chest pain, and another two patients demonstrated ischemic exercise nuclear ventriculography response. In time, all five patients developed acute myocardial infarction and recatheterization revealed complete occlusion of a previously nonstenosed aneurysmatic vessel. More information is needed in order to guide therapy. However, prevention of thrombus formation and close follow-up is highly recommended.

Pre-excitation due to accessory sinoventricular connexions associated with coronary sinus aneurysms. A report of two cases

Ventricular pre-excitation occurred in two cases in which the accessory pathways between the atria and the ventricles were histologically identified as being associated with aneurysmal malformations of the coronary sinus. In one case the connexions were in the posterior wall of the coronary sinus aneurysm and were not related to the atrioventricular annulus; in the other, a connexion was situated in the anterior wall of the aneurysm in close apposition to the annulus and superficially resembled a Kent fibre. These connexions were considered to be of sinus venosus origin and to represent a modification of the muscular sheath that normally surrounds the coronary sinus but does not continue along the coronary veins. One of the posterior wall connecting bundles was composed of abnormally large Purkinje-like fibres; this may have played some role in the manifestation of the pre-excitation by reducing any mismatch impedance.

[Pathophysiology and methods of treatment in renal hypertension in renal artery aneurysms]

Aneurysms of the renal artery occur infrequently and remain mostly asymptomatic. A review of the pertinant literature reveals approximately 300 reports. Hypertension is the predominant sign and affects two thirds of all patients, particularly in aneurysms complicated by stenosis or thromboembolism of renal artery, which is caused by the renin-angiotensin-mechanism. A solitary renal aneurysm causes no renal hypertension; 66% of all diagnosed renal artery aneurysms require no treatment. Resection of the aneurysm and direct suture was done in half of all operated patients. Only in 27 cases operative treatment consisted of extirpation and patch-plastic (autologic or alloplastic). Two additional cases in our own hospital with resection and patch-plastic are described. By using those techniques it is possible to normalize renal artery blood flow as well as blood pressure. Other well-known surgical procedures are nephrectomy, aorto-renalbypass and several others.

Evolution of a retinal arterial macroaneurysm

A 58-year-old hypertensive male developed a superior temporal branch vein occlusion in the left eye in 1979. Fluorescein angiography documented the venous occlusion, as well as normal arterial flow. Subsequent laser photocoagulation was performed for cystoid macular edema. In 1981 the patient developed a pre- and sub-retinal hemorrhage in the left eye due to a retinal arterial macroaneurysm in the superior temporal quadrant. Fluorescein angiography documented normal retinal arterial blood flow in the affected vessel at the time of development of the macroaneurysm, but the vessel subsequently occluded. This case adds to the scant literature documenting the evolution of a retinal arterial macroaneurysm.

Cardiovascular complications of mucocutaneous lymph node syndrome

The clinical and pathologic changes seen in patients with Kawasaki disease are discussed. Emphasis is placed on the cardiovascular manifestations and the present treatment and suggested long-term follow-up of this disorder.

Measurement of left ventricular ejection fraction after acute myocardial infarction. A serial cross sectional echocardiographic study

Left ventricular ejection fraction was assessed by biplane cross sectional echocardiography in 65 patients with a first acute myocardial infarction on the first day. In 30 patients (group 1) measurements were repeated on the third day and in another 35 patients (group 2) at three months. Changes in ejection fraction of 0.05 or less were arbitrarily called insignificant. In group 1 only two patients showed a decrease of more than 0.1 between days 1 and 3, and both had an enzymatically confirmed infarct extension. The remaining patients had no complications. In group two 11 patients had decreases of more than 0.1 between day 1 and three months: three of them had an enzymatically confirmed reinfarction (perioperative in one) and four a possible reinfarction, and in two an angiographically confirmed left ventricular aneurysm developed. In two no complications occurred. The other complications that occurred were an enzymatically confirmed but small reinfarction, an angiographically confirmed but circumscript aneurysm, and an uncomplicated bypass operation in one patient each. These three patients had a small increase (between 0.05 and 0.1) in ejection fraction. Reproducibility of the method of measuring the ejection fraction was assessed concurrently in 20 outpatients with a previous myocardial infarction who were studied twice on the same day (with a 30 minute interval) by two different observers. The mean absolute difference in ejection fraction between the paired observations was 0.036 +/- 0.023 with a range of 0 to 0.07. Thus only changes in ejection fraction of more than 0.1 correlate with clinically recognised complications. Changes between 0.05 and 0.1 may be due to spontaneous variability or to the limited reproducibility of the method.

Calculation of pulsatile flow and particle paths in an aneurysm-model

The velocity field and the wall shear stress have been calculated numerically by the finite element method to the time-dependent Navier-Stokes equations for pulsatile flow in a model of an aneurysm. The results show a complex flow field with two eddies growing and disappearing during the cardiac cycle. Downstream at the outlet vessel high wall shear stress occurs, which may lead to a downstream-growing of the aneurysm. With the knowledge of a sufficiently accurate flow field, the calculation of several particle paths has been carried out. Starting points and starting time are varied. The paths demonstrate the time-dependent development, shift and disappearance of vortices during the pulsatile cycle and provide hints on zones of stasis. These are significant factors in thrombogenesis.

Elastolytic and collagenolytic studies of arteries. Implications for the mechanical properties of aneurysms

Studies were performed in vitro on cylindrical segments of 56 canine common carotid arteries, 32 human external iliac arteries, nine internal iliac arteries, and ten common iliac arteries, using purified elastase and purified collagenase. Treatment with elastase caused the canine vessels to dilate but to remain intact. Similar results were obtained with the human vessels, except that treatment with elastase caused only slight dilation. All canine and human vessels treated with collagenase ruptured. We concluded that wall integrity depends on intact collagen rather than elastin. Comparison between external iliac arteries and internal and common iliac arteries showed that the latter vessels exhibited dramatically greater dilatation and compliance changes after treatment with collagenase. This finding corresponds to the greater tendency of aneurysms to develop in internal and common iliac arteries.

Problem cases in renovascular hypertension

The clinical course and response to therapy of 16 patients with various complex forms of renovascular hypertension were investigated. Reconstructive surgery and/or transluminal dilatation was either ineffective (n = 5) or could not be performed for technical reasons (n = 11). The group contained 7 patients with multilocular fibromuscular disease involving both renal arteries, two cases with multiple arteriosclerotic vascular occlusions, 3 patients with branch renal artery aneurysms, 3 with renal artery stenosis in a solitary kidney and one patient with renal artery stenosis and contraction of the contralateral kidney due to a non-vascular cause. With antihypertensive treatment, particularly with the angiotensin converting enzyme inhibitor captopril (n = 7), blood pressure could be reduced from 214 +/- 40/124 +/- 23 mm Hg to 145 +/- 23/88 +/- 9 mm Hg (P less than 0.001). In 11 of the 16 patients (69%) the values decreased to less than 160/95 mm Hg. These results suggest that, in complex forms of renovascular hypertension, antihypertensive treatment may be a potent therapeutic alternative if surgery and/or transluminal dilatation can not be performed or seem to have too high a risk.

Relation of carotid stump pressure to safety of carotid artery ligation

Twenty-four patients underwent ligation of the internal carotid artery for a variety of clinical indications. These included cerebral embolization from surgically inaccessible carotid lesions, carotid disruption and resultant hemorrhage, unreconstructible carotid endarterectomies, and inoperable intracranial carotid aneurysms. The relation of preoperative stump pressures to safety of ligation was evaluated. the data reflect that a systolic stump pressure in excess of 70 mm Hg (13 patients) indicates adequacy of collateral hemispheric blood flow to allow safe ligation of the carotid artery. Pressures of 55 mm Hg or less constitute an unacceptable vulnerability to stroke (two of three patients), and intermediate pressures of 55 to 68 mm Hg constitute a genuine hazard (four of eight patients). The mechanisms of stroke appear to be thromboembolic with late propagation of thrombus into an intracranial low-flow system. Postligation maintenance of appropriate systemic blood pressure is essential, and systemic heparinization is recommended to reduce the morbidity and mortality in patients in the intermediate pressure zone (55 to 68 mm Hg). It is concluded that whenever carotid ligation becomes a therapeutic consideration, the preoperative or preligation measurement of carotid stump pressure is presently the most reliable determinant of safety of the operation.

Infected false femoral artery aneurysms secondary to monitoring catheters

Six patients who developed infected false femoral artery aneurysms secondary to monitoring catheters are reported. All aneurysms were infected and resulted in systemic sepsis. Initially the origin of the sepsis was not obvious. Findings which suggest this lesion include staphylococci. Appearance of distal petechial hemorrhages should lend a strong suspicion to the possibility of the lesion. Appearance of the pulsatile groin mass completes the diagnosis. Only aneurysmal resection combined with appropriate antimicrobial therapy is curative. For necessary revascularization procedures, autogenous vein grafts should be used when available.

Scanning electron-microscopic study of the inner surface of experimental aneurysms in rabbits

A scanning electron-microscopic study of the inner surface of experimental saccular aneurysms in rabbits was conducted to demonstrate the effects of haemodynamics on the aneurysmal wall. Animals with aneurysms were killed from 2 to 83 weeks postoperatively, and the controls from 7 to 51 weeks. In both series, re-endothelialization was complete in approximately 2 weeks. In control tissue endothelium was normal, and sutures caused mild distortion of the luminal surface. In the aneurysms, there were tracts of spindle-shaped cells, often arranged in whorl-like patterns and interspersed with regions of polyhedral cells with thickened intercellular borders, prominent stomata and numerous microvilli. In some areas, long filamentous intercellular processes were prominent. The few jet lesions seen were covered with polyhedral cells and were less complex than those in arteriovenous fistulae. Ridges, caused by elevated subendothelial connective tissues were crescentic or circular, outlining depressions and craters, as if delineating vortices. The carotid artery opposite the aneurysm exhibited endothelium similar to normal tissue, except in older aneurysms where corrugations caused by the internal elastic lamina were completely or partially absent. The experiments demonstrate the effect of intra-aneurysmal haemodynamics on the topography of the endothelium and subendothelial tissues of the sac wall, and support the concept that endothelial topography in the vascular system under physiological conditions is haemodynamically determined.

Circumflex coronary artery aneurysm visualized by real-time cross-sectional echocardiography. A possible sequelae of previously unrecognized coronary arteritis in the adult

Real-time cross-sectional echocardiography disclosed an aneurysm of the circumflex branch of the left coronary artery in an asymptomatic 30-year-old man. Plain chest roentgenogram showed an abnormal silhouette along his left heart border. He also was found to have an abnormal contraction pattern of the posterolateral wall of the left ventricle and a reduced left ventricular ejection fraction. Left ventricular and coronary angiography showed a similar impairment in left ventricular function and occlusion of the circumflex branch of the left coronary artery. Surgery and pathologic examination confirmed the presence of the aneurysm. The echocardiographic characteristics of this lesion and the left ventricular contraction abnormalities suggest the possibility that it resulted from a remote episode of coronary arteritis. Real-time cross-sectional echocardiography, by virtue of its ability to provide visualization of structures along the posterior border of the heart as well as information about regional wall motion, may be of considerable value in localizing and defining lesions occurring in this area.