Assessment of internal diameters of abdominal and femoral blood vessels in 250 living subjects using color Doppler ultrasonography.

Acquiring data about venous or arterial vessel size is important for several reasons, given the increasing incidence of thomboembolic phenomena and arterial aneurysms and the emerging new vascular techniques. We studied 250 healthy subjects (125 men and 125 women; age range: 50 to 91 years) with no known vascular pathology, nor hypertension, nor diabetes. We assessed the caliber of abdominal aorta, inferior vena cava, iliac and femoral arteries and viens by color doppler ultrasonography, and analyzed the results with regard to sex, height, weight and body surface of each subject. The mean caliber measure of the large abdominal vessels appeared lower than the value obtained from cadavers. There was a direct proportion between the left and right vessels of the same subject. The difference in vessel caliber between male and female subjects was statistically significant. There was no correlation between vessel caliber and age, height or body surface area.

Internal jugular vein valves: an assessment of prevalence, morphology and competence by color Doppler echography in 240 healthy subjects.

The presence of valves in the head and neck veins is known since classical anatomical dissections. Previous studies have investigated whether jugular veins show constant valves at their ostium and whether these valves are physiologically competent, but, unluckily, these studies have reported conflicting results. Further, recent observations have raised the question whether the incompetence of jugular vein valves might play a pivotal role in neurological disorders related to venous engorgement of the brain. In this study we examined 462 internal jugular veins by using an echocolorodoppler apparatus. In particular, we assessed the presence, morphology and competence of valves at their ostium. Unilateral jugular vein valves were present in 406 cases (88%), mainly on the right side. The most frequently observed morphology (75%, 305 cases) was the two-leaflet valve, and jugular vein valves were incompetent in the huge majority of cases (365 cases, 90%). Our findings confirm the anatomical variability predicted from classical anatomical studies but, unluckily, do not provide additional evidence on the possible role of jugular vein valves in physiology and pathology. Further studies are strongly needed to determine whether these valves actually play an important role in counteracting chest venous pressure and in preventing reflux towards the brain.