An apparatus and method for drilling an orifice in a human cranium at an
angle of substantially 90.degree. to a plane defined by a tangent to the
surface of the cranium at the orifice. The apparatus comprises a first
tubular guide for directing a drill at the proper angle, the first guide
being suppored upon the cranium by a plurality of leg members. The
invention further comprises a hand-operated twist drill device, configured
for insertion into the tubular guide. A second guide, of reduced diameter
relative to the first tubular guide is insertable into the first guide
upon completion of the burr hole to facilitate entry of a catheter into
the ventricular portion of the patient's brain. The method of the
invention comprises positioning the first drill guide upon the patient's
cranium, inserting the twist drill therein so as to prepare a burr hole
extending at an angle of substantially 90.degree. to a plane tangential to
the surface, replacing the drill with a catheter guide insertable within
the drill guide and inserting a catheter through the second guide, through
the burr hole and into a ventricular portion of the patient's brain.
