Edward A. Edwards

Clinical anatomy of lesser variations of the inferior vena cava; and a proposal for classifying the anomalies of this vessel.

rarer major anomalies of unusual termination, reduplication, or sinistrality. The incidence of such anomalies is variously reported as 1.5 to 4.4 per cent (1). The lesser variations comprise a variety of anomalous connections of the tributary veins with the main trunk. An idea of the frequency of the latter may 1}e gained from the fact that the 5 examples described below were selected from a group of only 33 human subjects consecutively dissected in the classrooms of the Department of Anatomy of the Harvard Medical School. If one enlarged the scope of these variations to include those seen in all the tributaries of the cava, there would hardly be an individual in whom some variation from the ordinary was not observed.

The fallacy of applying the Poiseuille equation to segmental arterial stenosis

Abstract 1. 1. In order to study the dynamics of flow through stenoses, we have performed a series of experiments in an arbitrary model in which blood and other fluids were passed through stenoses of previously known dimensions in a tubular system, and pressures, flow, and viscosity were recorded. 2. 2. Our data are summarized by the equation: F = b ΔP 10 a where F = flow, ΔP = the differential pressure, and a and b are exponents related to the radius of the stenosis and fluid viscosity, respectively. 3. 3. Our results reveal the following departures from the Poiseuille equation for flow through stenoses: (a) Flow is not proportional to the fourth power of the radius of the stenotic lumen, but varies with its absolute radius in relation to the differential pressure (and, therefore, is also dependent on peripheral resistance). (b) Flow is not linearly related to differential pressure because energy is progressively dissipated in turbulence as differential pressure rises. (c) Flow is not linearly related to viscosity, for, although an increased viscosity increases drag, it also tends to diminish turbulence. We conclude that the Poiseuille equation does not apply to flow through stenoses.

Cutaneous vascular changes in women in reference to the menstrual cycle and ovariectomy

Abstract The skin of trunk and limbs of three ovariectomized and five normal young women was studied with the Hardy recording spectrophotometer. In both groups of subjects the pigments of the skin were unchanged excepting reduced hemoglobin and oxyhemoglobin. Results in the hands and feet were inconclusive, and the face was not studied. After ovariectomy, the sexual characteristics of the female skin do not disappear, suggesting a genic control. A diminution in vascularity is noted, evidenced by lowering of the amount of hemoglobin with a relative preponderance of the reduced form. Administration of estrogen was followed by an increased cutaneous blood flow with an actual increase in oxyhemoglobin. Progestin markedly increased the proportion of oxyhemoglobin, but did not consistently increase the total hemoglobin. The combined administration of both hormones results in a diminution in hemoglobin with a predominance of the reduced form. In the early part of the normal cycle, the curves resemble those obtained from ovariectomized subjects. After mid-cycle, there is evidence of greatly increased vascularity which reaches a maximum in the premenstrual period. This is consistent with the observed effects of the two hormones acting in the latter half of the cycle, since previous workers have shown that progestin takes several days to modify estrogen effect. Unlike the situation in many other mammals, in which reactivity to the female sex hormones is localized in special areas, the human skin probably reacts in its entirety.

Operative anatomy of the lumbar sympathetic chain.

The proper performance of the operation of sympathectomy presupposes an accurate identification of the portions of the sympathetic chain to be removed. This proves particularly difficult in the lumbar region, since the ganglia are variable in number and position and the rami communicantes, while visible at their connections with the trunk, are hidden by the psoas muscle in the remainder of their courses.

Lumbar Sympathectomy for Arteriosclerosis of the Lower Extremities

MEDICAL therapy has been disappointing in the painful and disabling effects of arteriosclerosis of the lower extremities. In the past fifteen years an increasing number of patients have been subjec...

Choice of therapy for peripheral arteriosclerosis.

AS surgical methods become available in the management of peripheral arteriosclerosis, the proper choice of treatment, for a particular problem encountered, becomes important. Such a choice necessi...

Thromboangiitis obliterans in women; possible relation to rheumatic disease.

IN SO rare a disorder as thromboangiitis obliterans in women, an association with another disease appears noteworthy. This paper presents 6 personally observed cases of the vascular disease in wome...

Venous Surgery in the Lower Extremities

This is the record of a two-day symposium held in 1973 at the Walter Reed Army Institute of Research. The problem receiving greatest attention was limb salvage in the face of venous injury when it accompanies arterial division. Almost half of the 19 senior and prestigious participants were drawn from the Walter Reed Army Hospital or the Institute. The record is therefore of particular importance since such injuries are more numerous in war than in civilian life. Moreover, considerable research in vascular matters is in progress in the Institute and several reports of this research appear in the symposium. The change from ligation to repair of divided major vessels was begun during the Korean conflict and extended through the Vietnamese war. The Vietnam Vascular Registry established at the hospital under the direction of Norman Rich contains the case reports of injuries from the latter war and provides the data for

The Murmur of Peripheral Arteriovenous Fistula

THE detection of a continuous murmur with systolic accentuation is of the highest significance in the diagnosis and in the location of the site of an arteriovenous fistula. It is therefore appropri...

Auscultation in the Diagnosis of Compression of the Subclavian Artery

COMPRESSION of the subclavian artery is well known as an essential aspect of the pathology of cervical rib, the scalenus syndrome and anomalies of the first thoracic rib. The demonstration of this ...