J. Ross Veal

Blood oxygen changes following intermittent venous occlusion

Abstract The results of this study would seem to indicate that complete vascular occlusion in the presence of a normal circulatory system is followed by a true reactive hyperemia immediately upon release of the compression. The maintenance of complete compression over periods of five to eight minutes was generally followed by a definite rise in the oxygen saturation of the venous blood one minute after its release, and in most cases the elevation was maintained at the end of three minutes. It may therefore be assumed that the reactive hyperemia produced by this type of occlusion brings about a more rapid flow of blood through the extremity, as well as a marked increase in the volume of the flow. Intermittent venous occlusion, on the other hand, even in the presence of a normal circulatory system, is usually followed by a lowering of the oxygen saturation of the venous blood at one minute as well as three minutes after the release of the occlusion. This would seem to indicate that under the circumstances of this test (with a pressure varying from 60 to 80 mm. Hg, and with a ratio of compression and release of 2:2 and 2:1) a true reactive hyperemia is not produced. Any favorable effects claimed for this type of therapy must therefore result not so much from an increase in the rate or the volume of the blood flow as from some chemical changes produced in the tissues incident to the venous congestion and the changes produced by the increased venous pressure. It might be said in conclusion that these findings bear out those of Allen and McKechnie 5 in their study of the effect of intermittent venous occlusion on the skin temperature under controlled circumstances. In nineteen patients (nine normal subjects, and ten with hypertension, arthritis, and peripheral vascular disease) they found no evidence that any significant or consistent vasodilatation resulted from the procedure.

Exstrophy of the bladder (Persistent cloaca) associated with intestinal fistulas

Summary 1. A case is reported of multiple congenital anomalies of the urinary and lower intestinal tract, resulting chiefly from a retention of the cloaca. 2. Reference is made to yon Gelderns exhaustive study of the etiology of exstropby of the bladder, and to his report of a similar case. 3. Thirty-six cases of congenital malformations of the anus and rectum, from the records of Charity Hospital in New Orleans, are analyzed from the standpoints of pathology and mortality. 4. The correction ol such malformations is considered, and the ethics of operation in the presence of extensive anomalies is discussed.

The mode of development of collateral venous circulation in the extremities

Abstract Collateral veins develop from pre-existing veins and venules, but not by a simple mechanical process. The venous, arterial, lymphatic, and tissue fluid circulation are all involved. The main changes that occur in an extremity after obstruction of the large venous trunks are caused by the concomitant rise in the local venous pressure and the retardation of the venous blood flow. There is often an associated arterial spasm which may produce severe pain and other signs of impaired arterial circulation. The changes in the lymphatic and tissue fluid circulation are secondary to the increased venous pressure. The newlydeveloped collateral circulation often fails because of its structural deficiencies, its superficial position, and because of the long and devious course which it often pursues. Venographic studies and venous pressure measurements are of considerable value in ascertaining the degree and extent of the venous obstruction. Repeated venous pressure studies, made at rest and during active exercise, provide the most accurate criterion of the progress of the formation of collateral venous circulation in the extremities.