The ornamental design for a subduralvacuumport, as shown and described.
FIG. 1 is a top perspective view of the subdural vacuum port of the instant
invention; and,
FIG. 2 is a bottom perspective view of the subdural vacuum port illustrated
in FIG. 1, further stating that the device is symmetrical and that side
views/end views will not add further clarity to the claimed ornamental
design.