PRELIMINARY STUDY OF THE DURAL VENOUS SINUS OF THE CHINESE

Fifty systems of dural venous sinuses of the Chinese people were investigated with the purpose to clarify their anatomical patterns of confluence. Four types of patterns were classified.In the first type,“simple confluence” (22%),the superior longitudinal and rectal sinuses met in the mid-line to form a typical sinus confluence,from which the two transverse sinuses arose.In the second type,“double bifurcation”(26%),both the superior longitudinal and rectal sinuses bifurcated with the union of the right and left branches to form the corres- ponding transverse sinuses.In the third type,“rectal sinus deviation”(20%), the rectal sinus deviated to one side of the transverse sinus,while the superior longitudinal sinus bifurcated.In the fourth type,“superior longitudinal sinus deviation”(32%),the superior longitudinal sinus turned to one side of the trans- verse sinus,while the rectal sinus bifurcated or opened in one side of the trans- verse sinus. The third and fourth types were subdivided into 2 subtypes respectively,i.e., the rectal sinus turned to left(18%)and the rectal turned to right(2%)for the third;the superior longitudinal sinus turned to right(30%)and the superior longitudinal sinus turned to left(2%)transverse sinus for the fourth. The cross-sectional areas of superior longitudinal,rectal,right and left trans- verse sinuses were measured in 50 systems in order to find out the capacity of these sinuses.The capacities of both transverse sinuses of each system were com- pared.In 22%,the size of the right transverse sinuses was larger than that of the left one,while in 14%,the reverse obtained.Twenty per cent showed that the size of the right transverse sinuses,was three times larger than that of the left one,while 20% showed the contrary pattern only. The occipital sinus was studied in 44 specimens.It was noted that the occi- pital sinus was present as a single vessel or in the form of 2-4 branches.In 21 specimens occipital sinuses were measured more than 1mm,of these,3 sinus were 4-6mm in cross-section.The latter might play the role of collateral branches of the transverse sinus.