Supine: Subtemporal Approach 33

Gelatin
pad

Radiolucent
skull-fixation
device

1.52

Subtemporal Approach

The subtemporal approach is preferred
for basilar terminus aneurysms below the
posterior clinoid, aneurysms of the upper
basilar trunk, and arteriovenous malforma-
tions of the medial temporal lobe, lateral
mesencephalon, and tentorial incisura.

1.52 A radiolucent skull-fixa-
tion device permits intraoperative angiogra-
phy. The cranium is tilted 15 degrees down
so the zygoma is the highest point in the
surgical field. This position brings the skull
base and tentorial border into the operative
view, diminishing the need to retract the
temporal lobe. A skin flap, initiated posteri-
or to the midpoint of the mastoid process,
extends vertically to traverse the superior
temporal line and terminate at the mid-
zygoma. Injury to the facial nerve is
avoided.

1.53 Prior to positioning the
patient, a lumbar catheter is placed to drain
cerebrospinal fluid. While supine, the pa-
tient's right shoulder is elevated with a gel-
atin pad; the head is rotated so the sagittal
suture is parallel to the floor. If anatomic
considerations permit, a right-sided ap-
proach beneath the nondominant temporal
lobe is preferred.

1.53

34 Surgical Positioning and Exposures

1.54
is shown.

The site of the bone flap

1.55 Hemostatic clips are
placed on the skin edges and galea. The
temporalis muscle is reflected inferiorly
with the skin after a myofascial cuff is re-
tained to facilitate closure.

Myofascial
cuff

35

Supine: Subtemporal Approach

1.57

1.56 The cutaneomuscular
flap reflected downward is held in place
with retracting hooks. A single-entry burr
hole, made at the superior aspect of the
bone flap, is in line with the anterior border
of the mastoid. A free bone flap is cut with
a pneumatic-powered craniotome.

1.57 A rongeur is used to re-
move bone flush with the floor of the mid-
dle fossa.

36

Surgical Positioning and Exposures

Wire for bone
stabilization

Dural retention
sutures

1.58

1.58 The dura is secured to
the bone edge at multiple sites with absorb-
able sutures. Stainless steel wires are
placed for subsequent stabilization of the
bone flap. The dura is opened near the skull
base.

1.59 The inferiorly based du-
ral flap is sutured to the muscle flap. After
the halo retractor system is attached to the
skull-fixation device, gentle retraction is
applied with two 10-mm retractors as cere-
brospinal fluid is removed from the lumbar
catheter.

1.59

Supine: Subtemporal Approach 37

Vein of
Labbe

1.60 Bridging veins to the
sphenoparietal sinus are coagulated as the
tentorium is approached. The anterior tem-
poral vein and the anastomotic vein of
Labbe are preserved.

1.60

1.61

1.61 The tentorial margin is
retracted laterally with a suture.

Surgical Positioning and Exposures

Muscle

Methyl
methacrylate

1.64

1.62

Closure 1.62 A dural retention suture
is placed in the center of the craniotomy to
prevent an epidural hematoma. The bone
flap is secured with stainless steel wires
whose ends are tucked into the drill holes.
Bone defects are replaced with methyl
methacrylate and muscle to enhance the
cosmetic result.

1.63 The temporalis muscle
and fascia are reapproximated and then
firmly reattached to the superior cuff.

1.64 The surgeon closes the
galea with absorbable sutures and closes
the skin with metal clips. A drain is not
placed.

---