Right pterional craniotomy for right posterior communicating artery aneurysm
This case illustrates issues in the clipping of a right posterior communicating artery aneurysm.
Presented with a holocephalic headache. A CAT scan showed a right temporal intracerebral hemorrhage. A CT angiogram showed an underlying right posterior communicating artery aneurysm measuring 6.3 x 3.6 mm.
Pterional Craniotomy 翼点开颅
The scalp and temporalis are reflected as separate layers, and a frontotemporal craniotomy is performed.
The sphenoid ridge is burred down with a high-speed drill.
The dura is opened in a curvilinear fashion medially.
Conservative medical management with serial observation Interventional radiology for coiling
A curvilinear skin incision was made behind the hairline, was chosen for sufficient exposure and cosmetic effect.
Head position for the pterional craniotomy.
Supine/Flat Left 45 degrees
Course of the superficial temporal artery and frontalis braches of the facial nerve in the subcutaneous tissue.
The patient was subsequently positioned supine with the head turned approximately 45-50 degrees towards the left, and the malar eminence being the highest point.
We then performed an incision in a pterional fashion and reflected first the skin and then the temporalis muscle which was dissected and reflected via a subfascial dissection technique, and these were held in place and reflected anteriorly with fish hooks to the bar, after which we then turned a standard pterional flap and the bone was removed with the dura intact.
We subsequently then opened the dura in a C-shaped fashion and this was reflected and held in place with 4-0 Nurolon sutures. A vascular drain was placed, and we then brought in the operative microscope which had been prepped and draped to begin our microdissection.
With the relaxation of the brain, we were able to initially separate and cut through the arachnoid which led us right down to the optic nerve. We then opened up the optical carotid when there was further egress of CSF and cleared the arachnoid membranes to further allow egress of CSF.
Once this was done, we were able to adequately visualize both the optic nerve as well as the proximal and distal carotid. We then were able to visualize adequately the dome of the aneurysm. Once this was done, we then had a trial of temporary clip placed on the proximal carotid.
We settled on a 4 mini bayonet clip which was placed over the neck of the aneurysm. We then released the temporary clip which was placed on the proximal carotid
We tested both the distal and proximal ICA with Doppler, which we confirmed to be open via the brisk sound of the Doppler, as well as an ICG run.
The dura was loosely approximated with interrupted 4-0 Vicryls, and then a compressed Gelfoam placed over the wound and the bone flap then placed and secured and held in place with titanium clips. We then next copiously irrigated the wound.
Closure was performed with initially starting with the galea in which we applied 2-0 interrupted Vicryl sutures, and then approximated and closed the skin with staples
On POD 6 patient showed mild right supraclinoid internal cerebral artery spasm that was not treated. Patient discharged without complications on POD 10.
No complications 5 week follow up showed no continuing headaches. Patient is being seen for a follow-up Neurosurgical visit. 49 year old female presents for annual follow up -history of craniotome for SDH and aneurysm clipping on on the right in Jan 2014- denies headaches or seizures, states forgetfulness has gotten worse, and lightheaded at times- went to Healthspan in December and had CT head but was told it was negative and did not bring disc with her-
Pearls and Pitfalls
This case demonstrates a patient with vasospasm after rupture of a posterior communicating artery aneurysm. Cerebral vasospasm and delayed ischemic neurological deficit are common in subarachnoid hemorrhage after rupture of an intracranial aneurysm but they rarely occur following elective clipping of unruptured aneurysms.
Numerous pharmacological agents for vasospasm have been studied, however most failed to improve outcomes. Drugs with no or limited beneficial effect on delayed ischemic neurological deficit are: magnesium, statins, erythropoietin, tirilazad, anti platelet therapy, LMWH, nitric oxide donors, and papaverine. Nimodipine is the only treatment that provided a significant benefit across multiple studies.