VARIATIONS OF THE CRANIAL VENOUS SINUSES IN THE REGION OF THE TORCULAR HEROPHILI

Abstract

I. TYPES OF VARIATION Le Double¹ has stated that to "describe one by one all the variations in the venous sinuses is impossible, and if it were done today, it would be incomplete tomorrow." Anatomically that may be true, but the variations of surgical interest, especially in the torcular region, may be definitely ascertained. It has long been recognized that the major volume of venous blood is directed through the right lateral sinus, whereas the straight sinus usually directs its major volume into the left lateral sinus. This right-sided predominance of the venous outflow from the brain was recognized at an early date by both Hunauld² and Morgagni.³ For the sake of brevity, the evidence of right-sided predominance noted in studies of the skull, the jugular foramen and the dura has been summarized in table 1. Just why the right lateral sinus should develop to carry the