Termination of the UV in normal hemodynamics
In the normal group,
the UV was identified in 118 sides (74%) of 160 sides.
Among the 118 sides,
a single UV was identified in 116 sides,
and double UVs in 2 sides.
The single UV terminated into the CS in 41 sides (34%),
the superficial middle cerebral vein (SMCV) in 58 sides (48%),
the laterocavernous sinus (LCS) in 15 sides (13%),
and the paracavernous sinus (PCS) in 4 sides (3%).
The double UV in two sides terminated into the CS and LCS in 1 side,
and the CS and SMCV in 1 side.
(Table 1,
Fig.
3)
Termination of the SMCV in each type of UV termination
Type A: The UV terminating into the CS (41 sides).
(Table 2,
Fig.
4)
The SMCV terminated into the CS in 25 sides,
the LCS in 4 sides,
and the PCS in 7 sides.
In 5 sides,
the SMCV was absent (aplastic).
Among the 25 sides in which the SMCV terminated into the CS,
the SMCV terminated into the CS alone in the 22 sides.
In the remaining 3 sides,
the SMCV terminated into the CS with another termination into the PCS (n=2) or the pharyngeal plexus (n=1).
Type B: The UV terminating into the SMCV (58 sides).
(Table 3,
Fig.
5)
The SMCV terminated into the CS in 18 sides (31%),
the LCS in 25 sides (43%),
and the PCS in 15 sides (26%).
Among the 18 sides in which the SMCV terminated into the CS,
the SMCV terminated into the CS alone in 16 sides,
and the SMCV terminated into CS with another termination into the PCS in 2 sides.
In the 25 sides where the SMCV terminated into the LCS,
the LCS terminated into the CS in 8 sides,
the pterygoid plexus in 9 sides,
the CS and the pterygoid plexus in 9 sides,
and the CS and SPS in 1 side.
In one side,
the SMCV terminated into the LCS with another termination into the PCS.
Type C: The UV terminating into LCS (15 sides).
(Table 4,
Fig.
6)
The SMCV terminated into the LCS in 10 sides,
and the PCS in 3 sides.
The SMCV was absent in 2 sides.
Among the 10 sides in which the SMCV terminated into the LCS,
the LCS terminated into the CS alone in 2 sides,
both the CS and the pterygoid plexus in 5 sides,
and the pterygoid plexus alone in 3 sides.
Type D: The UV terminating into the PCS (4 sides).
(Table 5,
Fig.
7)
The SMCV terminated into the PCS in 2 sides,
and both CS and PCS in 1 side.
The SMCV was absent in 1 side.
In the normal group,
the deep cerebral venous blood via the UV draining into the CS directly (n=43) or through the SMCV and/or the LCS (n=43) was observed in 86 sides (54%).
Cases of CSDAVFs
In the 30 cases of CSDAVFs,
uncal venous drainage from CSDAVFs was found in 10 patients (33%) (Table 6).
CSDAVFs drained directly into the UV in 1 patient,
through the SMCV into the UV in 5 patients,
through the LCS and the SMCV to the UV in 3 patients,
and through the LCS into the UV in 1 patient (Table 7,
Fig.
8).
All cases were successfully treated by transvenous embolization with special attention given to the uncal venous drainage.