Anomalies of the cranial venous sinuses when encountered unexpectedly at the operating table may be the cause of hesitation and confusion to the surgeon. If, however, the possibility of such an occurrence has been brought to his attention previously, he will be at least partially prepared with technical procedures to cope with the situation.
After the first presentation of a case of congenital absence of the sigmoid sinus found at operation, reported in the literature by one of us (Williams1) in 1930, Hoople,2 in 1936, presented a similar case. In the first case, the descending portion of the sigmoid sinus was absent and the lateral sinus reduced to the size of a thread. A large vein following the course of the superior petrosal sinus left the skull by way of the foramen for the emissary vein of the mastoid process.
In Hoople's case, in which the findings were confirmed by