Faculty Bibliography

Carotid cavernous aneurysms are distinct entities. The anatomy of the cavernous sinus region has been well defined, and most spontaneous aneurysms of the cavernous sinus region carry a benign prognosis. Progressively symptomatic, traumatic, or infectious aneurysms require treatment. This can be accomplished by carotid occlusion, extra cranial to intracranial bypass, or direct surgery

OBJECTIVE AND IMPORTANCE: We present a patient who experienced a subarachnoid hemorrhage secondary to a dissecting aneurysm of the right posteroinferior cerebellar artery (PICA). The use of an encircling clip in treating the aneurysm while preserving supply to brain stem perforators originating near the dissecting segment and the distal PICA territory was key in the operative management. CLINICAL PRESENTATION: A 48-year-old patient with a history of hypertension presented with subarachnoid hemorrhage confirmed by computed tomography of the brain. Successive cerebral angiography revealed a dynamic change in the configuration of the dissection, with expansion of the associated focal ectasia. OPERATIVE MANAGEMENT: At surgery, three brain stem perforators adjacent to the aneurysm were visualized. The dissecting segment was reconstructed with an encircling Sundt clip and muslin wrap, which preserved the flow through the PICA and brain stem perforators. CONCLUSION: A patient suffering from a dissecting PICA aneurysm and subarachnoid hemorrhage was successfully treated with direct surgical reconstruction of the parent artery, sparing the perforators to the medulla

We present the case of a traumatic posterior cerebral artery aneurysm from a self-inflicted pneumatic nail-gun missile injury through the roof of the mouth. The patient presented to us in a coma with subarachanoid and intraventricular hemorrhage. Cerebral angiography revealed an aneurysm of the left posterior cerebral artery with no distal filling. The patient died 6 days after admission. At autopsy, a pseudoaneurysm of the posterior cerebral artery was seen. This aneurysm resulted from direct disruption of the arterial wall by the intracranial nail

The majority of intracranial arteriovenous malformations (AVMs) do not require acute surgical intervention. Some patients, however, require emergent surgical treatment because of a profound neurological deterioration from a mass effect. We report 10 patients who underwent emergency AVM surgery after experiencing neurological deterioration from an intracranial hemorrhage. Two patients bled spontaneously, whereas eight had an intracranial hemorrhage secondary to an embolization procedure. When the patients demonstrated neurological deterioration, they were intubated, hyperventilated, and underwent osmotic diuresis. Barbiturate anesthesia was initiated, and surgery was performed within 30 minutes in most cases. The hematomas were evacuated, and an attempt was made to excise the AVMs at the same time. Postoperatively, intracranial pressure was monitored, and barbiturate coma was maintained until the intracranial pressure returned to normal. Cerebral perfusion pressure was maintained above 55 mm Hg. The operation was confined to evacuating the hematoma in two patients with inoperable AVMs. The other eight patients underwent concomitant total AVM resection. Because of the severity of neurological deterioration, one patient who bled spontaneously underwent surgery based only on a computed tomographic scan of the brain. Nine patients made a good-to-excellent recovery. One patient with a large motor-strip AVM remained hemiplegic. We conclude that in patients presenting with profound neurological deterioration after a spontaneous intracranial hemorrhage or one associated with an embolization procedure, prompt hematoma evacuation with simultaneous AVM excision as well as perioperative intracranial pressure control with mannitol and barbiturates can yield a good-to-excellent outcome

In 15% of patients with spontaneous subarachnoid hemorrhage (SAH), the source of bleeding cannot be determined despite repeated cerebral angiography. However, some patients diagnosed as having 'SAH of unknown cause' actually harbor undetected aneurysms. The authors report six patients with SAH who, despite multiple negative cerebral angiograms, underwent exploratory surgery due to a high clinical and radiographic suspicion for the presence of an aneurysm. Brain computerized tomography (CT) scans revealed blood located mainly in the basal frontal interhemispheric fissure in four patients, in the sylvian fissure in one patient, and in the interpeduncular cistern in one patient. The patients were evaluated as Hunt and Hess Grades I to III, and had undergone at least two high-quality cerebral angiograms that did not reveal an aneurysm. Vasospasm was visualized in two patients. Three patients rebled while in the hospital. Exploratory surgery was performed at an average of 12 days post-SAH. Five aneurysms were discovered at surgery and were successfully clipped. All four patients with interhemispheric blood were found to have an anterior communicating artery (ACoA) aneurysm. The patient with blood in the sylvian fissure was found to have a middle cerebral artery aneurysm. These aneurysms were partially thrombosed. No aneurysm was detected in the patient with interpeduncular SAH, despite extensive basilar artery exploration. Five patients had an excellent outcome and one patient developed diabetes insipidus. These results show that exploratory aneurysm surgery is warranted, despite repeated negative cerebral angiograms, if the patient manifests the classical signs of SAH with CT scans localizing blood to a specific cerebral blood vessel (particularly the ACoA) and if a second SAH is documented at the same site

Endovascular therapy of cerebral arteriovenous malformations (AVM's) is an accepted adjunct to surgical therapy. However, the literature has not characterized the benefits or the liabilities of preoperative embolization. This series compares two groups of patients who underwent surgical resection of a cerebral AVM; one group (20 patients) received preoperative transfemoral selective embolization with N-butyl cyanoacrylate (NBCA) and the other group (13 patients) did not. In the group with preoperative embolization, the AVM's were larger (3.9 vs. 2.3 cm) and of a higher Spetzler-Martin grade (3.2 vs. 2.5) as compared to the nonembolized group. The NBCA embolization facilitated surgical resection. Arteries supplying the vascular malformation were readily distinguished from those supplying the normal brain parenchyma. Embolized vessels were compressible and easily cut with microscissors. No bleeding occurred from transected vessels. Operative time and intraoperative blood loss for the two groups were not statistically different, despite the significant differences in lesion size and grade. Endovascular complications included immediate and delayed hemorrhage (15%) and transient ischemia (5%); there were no embolization-related deaths. Postoperative complications for both groups included hemorrhage (15%), residual AVM (6%), and cerebrospinal fluid leak (3%); the mortality rate was 3%. There was no statistically significant difference in surgical complications between the embolized and nonembolized groups. Most patients (91%) in both groups had an excellent or good late neurological outcome, with no significant difference between the groups. This study concludes that preoperative NBCA embolization of AVM's makes lesions of larger size and higher grade the surgical equivalent of lesions of smaller size and lower grade by reducing operative time and intraoperative blood loss, with no statistically significant difference in surgical complications or long-term neurological outcome