Is the percentage of stenosis of the internal carotid artery a reliable measure of the risk of ischemic stroke? A morphometric study by duplex ultrasound of aortic arch branches in 500 normal adults.

BACKGROUND: The percentage of stenosis has been considered for the last 20 years, and still continues to be, the main criterion of choice between a surgical and a medical treatment of the atherosclerotic lesions of the aortic arch branches, particularly as regards the internal carotid artery. On the other side, it has been demonstrated that the risk of adverse acute cerebrovascular events, besides being related to the characteristics of the plaque, such as softness, subintimal haemorrhage or surface ulcer, is strictly related to the actual residual lumen of the internal carotid artery. The pre-eminent role of the percentage of stenosis in the choice of the treatment, hence, presumes a narrow range of variation of the original calibre of the vessel, yet to be proven. METHODS: Five-hundred normal adults underwent the measurement of the internal calibre of the aortic arch branches by duplex ultrasound in order to find out their actual range of variation. RESULTS: The range of variation of the internal calibre of the aortic arch branches, expressed as the ratio between the maximum and the minimum value found for each vessel, was very wide in all cases (from 180% for the right common carotid artery to 340% for the right vertebral artery). With reference to the internal carotid arteries, the range of variation was 219% for the right internal carotid artery and 241% for the left internal carotid arteries. CONCLUSIONS: Due to the wide range of variation of the original calibre of the aortic arch branches, the percentage of stenosis alone cannot be considered an accurate measure of the severity of the stenosis, and hence a reliable criterion of choice of the treatment.

The circle of Willis in healthy older persons.

BACKGROUND: The current indication for carotid surgery is based upon the percentage of stenosis of the internal carotid artery. This approach shows many limitations, one of which is to presume the anatomical completeness of the circle of Willis in all patients who are evaluated. On the contrary, there is increasing evidence of a great natural variability in the configuration of the circle of Willis. METHODS: The aim of the present paper was to investigate, by magnetic resonance angiography, the variability of the circle of Willis in a cohort of 118 healthy older persons. RESULTS: The circle of Willis showed an entirely complete configuration in 47% of the subjects, a complete configuration of its anterior part in 90% of the subjects, and a complete configuration of its posterior part in 48.5% of the subjects. CONCLUSIONS: These findings confirm the great variability of the circle of Willis even in healthy older persons and suggest that, in indicating carotid surgery, the configuration of the circle of Willis should also be taken into account.

Relationship between the calibre of carotid arteries and the configuration of the circle of Willis in healthy older persons.

AIM: Recent papers have pointed out that the severity of brain damage that follows carotid occlusion is largely influenced by the state of integrity and functionality of the circle of Willis. In spite of this, duplex scanning investigation of carotid arteries has traditionally been focused on the assessment of the degree of the stenosis, while other features, such as the calibre of carotid arteries and their possible asymmetry, have often been neglected. The aim of the present paper was to verify, in a cohort of older persons, whether, based on the calibre of internal carotid arteries and their possible asymmetry, abnormalities of the circle of Willis can be predicted. Such information could be used to identify high risk patients in whom the status of the circle of Willis should be investigated by MR angiography. METHODS: We studied 118 healthy older persons with both duplex scanning investigation of carotid arteries and MR angiography of the circle of Willis. RESULTS: We found that the finding of abnormal internal carotid artery calibres was always associated with abnormalities of the precommunicating segments either of the anterior or of the posterior cerebral arteries. Abnormalities of communicating arteries did not affect the calibre of internal carotid arteries, but abnormalities of anterior communicating arteries could always be detected by contralateral common carotid artery compression manoeuvres. CONCLUSION: In conclusion our findings show that, in healthy older persons, duplex scanning investigation of carotid arteries may provide useful information about the integrity and functionality of the circle of Willis. Future studies should confirm our findings in patients with atherosclerotic lesions of internal carotid arteries.

Collateral circulation in internal carotid artery occlusion. A study by duplex scan and magnetic resonance angiography.

BACKGROUND: Clinical effects of internal carotid artery (ICA) occlusion may range from the absolute absence of symptoms to lethal hemispheric stroke. In this paper symptoms of patients with ICA occlusion have been related to the development of collateral circulation, different types of developed collateral circulation have been assessed, and the degree of sensitivity and specificity of duplex scan has been appraised. METHODS: Forty-eight patients with ICA occlusion or subocclusion, 24 males and 24 females, aged between 50 and 83 years (67.7+/-7.15), underwent duplex scan and magnetic resonance (MR) angiography. Nineteen patients were completely asymptomatic, 20 patients showed permanent neurological symptoms and 9 patients had shown transient symptoms. RESULTS: Twelve patients (25%) did not show any collateral circulation, 29 patients (60%) showed collateral circulation through homolateral external carotid artery branches and 7 patients (15%) showed collateral circulation through other circuits. Of the 20 patients with permanent symptoms only 8 showed collateral circulation. On the contrary, all the 19 asymptomatic patients and the 9 patients with transient symptoms showed collateral circulation. Eventually, duplex scan showed 78% sensitivity, 100%, specificity and 83% diagnostic accuracy. CONCLUSIONS: Our data show: 1) a clear-cut prevalence of collateral circulation through homolateral external carotid artery branches with respect to other possible collateral circulation; 2) an inverse relationship between the development of collateral circulation and the appearance of permanent symptoms; 3) a good diagnostic accuracy of duplex scan in revealing collateral circulation in the case of ICA occlusion.

Macroscopic anatomy of the superficial veins of the lower limb: a systematic review based upon echography.

Saphenous Veins are described in Anatomy textbooks as superficial veins running in the amorphous fatty layer of the lower limbs. Recent papers have demonstrated the complex fascial relationship of Saphenous Veins with the connective framework of the lower limb hypodermis. The aim of the present paper was to systematically review the anatomy of lower limb superficial veins, based upon echographic findings, in a series of normal subject. Our results offer new insight into lower limbs superficial veins anatomy, with important clinical and surgical implications.

A comparison between the heart of young athletes and of young healthy sedentary subjects: a morphometric and morpho-functional study by echo-color-doppler method.

Morphologic and morpho-functional heart differences between healthy young athletes and healthy young subjects who do not practice agonistic sport have been studied using Color Doppler Echography (CDE). Overall, 68 subjects were enrolled in the study (age range: 19-26 yrs). Of them, 34 subjects (17 men and 17 women) were practicing sport agonistically; the 34 controls (17 men and 17 women) did not practice any sport on a regular basis. In each subject, age, height, weight, body mass index, practiced sport, systolic and diastolic blood pressure were recorded. CDE measures included telediastolic left and right ventricular diameters (LVDd and RVDd, respectively), interventricular septum thickness (IVSd), posterior wall thickness of the left ventricle (PLVWd), left and right atrium diameters during ventricular systole (LAD and RAD respectively), and continence of each heart valve (mitral; tricuspid; aortic; pulmonic). In women, LADd was significantly higher in the athletes than in the controls (35.04+/-4.13 vs 31.81+/-3.34; p<0.02). Physiological regurgitation in at least one heart valve was observed in 15 out of 17 (88.2%) of the athletes; in 12 cases only one valve was involved: the mitral valve presented physiological regurgitation in 8 women, the tricuspid in 4, the aortic in 2 and the pulmonic in 6. In the control female population (17 persons), only 2 women showed evidence of regurgitation. In men, except for RVDd, CDE measurements were all significantly higher in the athletes than in the controls: LVDd (49.4+/-3.13 vs 46.02+/-4.46; p<0.02); IVSd (9.79+/-1.24 vs 8.59+/-0.91; p<0.003); PLVWd (8.63+/-1.29 vs 7.48+/-0.66; p<0.002). Physiological regurgitation through one or more heart valves was demonstrated in all the 17 male athletes studied; in 9 cases (52.9%) only one valve was involved. Mitral regurgitation was ob- served in 8 cases (47%); tricuspid in 6 (35.3%). No physiological regurgitation through the aortic valve was found, while 15 cases (88.2%) presented a pulmonic regurgitation. Among male controls, physiological regurgitation was demonstrated only in 2 persons out of 17 (11.8%), both involving the pulmonic and the aortic valve. In the total population of athletes compared to controls, analyzing men and women jointly, we found that LAD (p<0.001),RAD (p<0.001), LIVD (p<0.01) were significantly larger in cases than in controls, while for RVD, IVSd and PLVWd such a difference did not reach statistical significance. No relationship was fouhd between CDE data and either age, height, weight or blood pressure.

Descriptive and morphometric anatomy of the architectural framework of microcirculation: a Videocapillaroscopic study on healthy adult subjects.

Conventional Capillaroscopy allows the observation of a limited number of areas, classically the fingernail-fold. Videocapillaroscopy, on the contrary, can be performed on any part of the skin and of clinically accessible mucosae. The aim of the present paper was to investigate the architectural frameworks of microcirculation in the various regions of the body and their morphometric parameters in healthy adult subjects. Our findings showed four basic architectural patterns plus two special patterns. The calibre of capillary loops ranged from 15 to 20 micrometers, and capillary density ranged from 14 to 30 capillary loops each square millimetre. These findings might be used as normal reference data for future studies.