Characteristics and Surgical Outcomes of Distal Anterior Cerebral Artery Aneurysms / 대한뇌혈관외과학회지

OBJECTIVE: Distal anterior cerebral artery (dACA) aneurysms are uncommon, and they require special treatment because of the narrow exposure in the interhemispheric fissures, the dense adhesions between the cingulate gyri and their association with multiple aneurysms or traumatic pseudoaneurysm. The aim of this study was to assess the characteristics and surgical outcomes of dACA aneurysms. METHODS: Among the 520 cases of cerebral aneurysms that were operated on from 1997 to April 2007, we experienced 31 cases of dACA aneurysms that developed in 30 patients. The medical records and radiological findings were retrospectively reviewed. RESULTS: The clinical characteristics of the patients with dACA aneurysms included the following. (1) The incidence of the dACA aneurysm was 5.9% of the total 520 cases, and the dACA aneurysms displayed a female predominance. (2) The most common location of the dACA aneurysms was the junction of the pericallosal and callosomarginal arteries. (3) Multiple aneurysms were found in 12 patients (40%), and the most concomitantly found aneurysm was MCA aneurysm. (4) The larger aneurysms more than 10 mm size all had thrombus in the sac, and their angiographic findings were underestimated compared with their findings on the operative fields. (5) dACA aneurysms shows frequent intracerebral hemorrhage (ICH) and subdural hemorrhage on the initial brain CT scan (28.5%). They also had a higher rate of intraoperative rupture (12.9%) than the rupture rate for the aneurysm at other locations (7.9%). (6) Traumatic pseudoaneurysms on the dACA were observed in two cases, and one of these cases showed massive ICH shortly after head trauma. (7) Twenty-six out of 30 patients (86.7%) showed a good outcome with a mortality rate of 3.3%. CONCLUSIONS: The dACA aneurysms are uncommon and they have unique characteristics compared to intracerebral aneurysms at other sites. Especially, a very careful surgical approach must be used for dACA aneurysms because they have a higher rate of intraoperative rupture. Yet the surgical outcome for dACA patients was good for the ruptured or unruptured aneurysm cases in our study. Therefore, dACA aneurysms have to be treated with considering their special characteristics.

Interhemispheric Approach for Intracranial Aneurysms / 대한뇌혈관학회지

The author describes the basic and standard operative method of interhemispheric(IH) approach for intracranial aneurysms especially aneurysm in anterior cerebral artery territory.Though most neurosurgeons prefer to pterional approach for anterior communicating artery aneurysm, some neurosurgeons select IH approach routinely for this aneurysm because of least brain retraction and excellent anatomical orientation with this approach. But IH approach should be chosen for distal anterior cerebral artery aneurysms and certain cases of anterior communicating artery aneurysms such as high positioned aneurysm or aneurysm with significant hematoma at frontal lobe. interhemispheric approach.

Surgical Treatment of Distal Anterior Cerebral Artery Aneurysms

The incidence of the distal anterior cerebral artery(DACA) aneurysm comprises about 2-6% of all intracerebral aneurysms. Because of the low incidence, unique anatomies of the distal anterior cerebral arteries and some technical difficulties in surgery, these aneurysms present such challenge to neurosurgeons. Presently, early surgery using interhemispheric approach is preferred. The auhtors experienced six patients with DACA aneurysms in 130 consecutive intracerebral aneurysms surgically treated between May. 1994 and Dec. 1997. The patients received operations within five days from the ictus, except one patient because of symptomatic vasospasm. The surgical approaches were all unilateral interhemispheric approaches. During the operations, infusion of large amount of mannitol and CSF volume removal were applied, although there were few difficulties in the interhemispheric dissections, the outcomes of the patients were excellent in three, good in three. The authors suggest that early operative interventions using unilateral interhemispheric approach without generous craniotomy can improve the outcomes of the patients with ruptured DACA aneurysm.

Four Cases of Surgically Managed Distal Anterior Cerebral Artery Aneurysm

A series of 4 patients with aneurysm of distal anterior cerebral artery(DACA), operated with microtechniques, is reviewed. Because the incidence of aneurysms in this location was only 2 to 4% of that of total aneurysm, little expericences on surgical management of this aneurysm have been reported. An aneurysm in this location is difficult to approach surgically because of their multiplicity, characteristically broad and sclerotic base, with small subarachnoid space in the interhemispheric fissure. We surgically treated DACA aneurysms of 4 cases through the interhemispheric approach via the unilateral frontal paramedian craniotomy on the nondominant side.

Microsurgical Treatment of Distal Anterior Cerebral Artery Aneurysm

Between Jan. 1983 and Dec. 1990, 17 Patients with distal anterior cerebral artery(DACA) aneurysms were admitted to our institute and underwent microsurgical neck clipping of their aneurysms. This group comprised 3.7% of the 437 aneurysms managed surgically during this period. There were 11 females and 6 males. The mean age was 48.5 years. Most of DACA aneurysms were located at the genu portion of the anterior cerebral artery. Three cases were at the proximal protion of A2 close to the anterior communicating artery. Two cases were at the dista pericallosal artery and distal callosomarginal artery. Eight patients had additional vascular anomalies documented by angiography such as multiple aneurysms, azygos DACA and duplication of DACA. Direct neck clipping was possible in all cases through the interhemispheric approach or the frontotemporal approach according to the location. For the interhemispheric apporach preoperative evaluation of the exact location and direction of the aneurysms on the angiogram was important for operative planning. The surgical outcome was good or excellent without any neurological deficits in 17 of the cases. Operative management, clinical features and incidence of vascular anomalies associated with DACA aneurysms are discussed.

Surgical Management of the Distal Anterior Cerebral Artery Aneurysms

The authors described different type of aneurysms in the distal anterior cerebral artery(DACA), which is difficult to approach surgically. there are anomalies of distal anterior cerebral artery in about one fourth and narrow space, which made more careful surgical dissection. We experienced 7 cases of DACA aneurysm, 6 cases of which were treated surgically through the interhemispheric approach via the unilateral frontal paramedian craniotomy on the non-dominant side. Surgical results were anatomical complexities, modern microsurgical technique aided by microscope make the approach more exactly and safely.