Direct clipping of a large basilar trunk aneurysm via the posterior petrosal (extended retrolabyrinthine presigmoid) approach--case report

Quantitative analysis of the trajectory of simulated basilar apex aneurysms through the internal carotid artery to assess the need for an orbitozygomatic approach

Background

The aim of this study was to identify the correlation between the location of the internal carotid artery (ICA) and the need for an orbitozygomatic approach (OZA) when approaching a basilar apex (BX) aneurysm.

Materials and methods

By imaging the virtual trajectory to access the basilar artery (BA) through the ICA, the correlations among the height of the BX, the height and lateral breadth of the bifurcation of the ICA, and the need for removal of the orbital rim or zygomatic arch were investigated using three-dimensional computed tomography angiography (3DCTA) data of approximately 80 random samples not limited to BX aneurysms. Furthermore, the utility of 3D simulation to determine the need for the OZA was verified using data from five patients with BX aneurysms.

Results

The height of the bifurcation of the ICA was inversely correlated and the height of the BX was positively correlated with the need for the OZA (both p < 0.017). Among patients undergoing surgery, clipping was successfully performed without the OZA in two patients in whom the distance from the simulated skull point on the extended line from the BX through the bifurcation of the ICA was more than 4 cm from the zygoma and orbital rim.

Conclusions

It is necessary to determine the spatial relationship between the basilar artery and the ICA to decide whether the OZA is needed for surgery. Correlations of the height of the ICA and BX with the need for the OZA were not very strong individually, though they were significant. Therefore, simulation using 3DCTA appears to be important for planning the surgical approach for the treatment of BX aneurysms.

Superficial temporal artery to proximal posterior cerebral artery bypass through the anterior temporal approach

Background:

The superficial temporal artery (STA) to proximal posterior cerebral artery (PCA) (P2 segment) bypass is one of the most difficult procedures to perform because the proximal PCA is located deep and high within the ambient cistern. STA to proximal PCA bypass is usually performed through a subtemporal approach or posterior transpetrosal approach, and rarely through a transsylvian approach. The aim of this study was to describe the operative technique of STA to proximal PCA bypass through a modified transsylvian approach (anterior temporal approach).

Methods:

STA to proximal PCA bypass was performed through an anterior temporal approach in three patients with intracranial aneurysm. We describe the details of the surgical technique.

Results:

The STA was successfully anastomosed to the proximal PCA in all cases. One patient suffered hemiparesis and aphasia due to infarction in the anterior thalamoperforating artery territory.

Conclusions:

STA to proximal PCA bypass can be performed through an anterior temporal approach in selected patients. We recommend that every precaution, including complete hemostasis, placement of cellulose sponges beneath the recipient artery to elevate the site of the anastomosis, and placement of a continuous drainage tube at the bottom of the operative field to avoid blood contamination during the anastomosis, should be taken to shorten the temporary occlusion time.

Petrosal approaches to posterior circulation aneurysms

Complex posterior circulation aneurysms are formidable lesions with an abysmal natural history. Their management continues to present a challenge to both endovascular and open microsurgical approaches. Affording an expansive, combined supra- and infratentorial exposure, the petrosal approaches are well suited for these challenging lesions when located along the basilar trunk or at a low-lying basilar apex. This report evaluates the evolution and application of petrosal approaches to these lesions. Excluding transsigmoid, infratentorial, or labyrinth-sacrificing approaches, the authors found 23 reports with 61 posterior circulation aneurysms treated via a petrosal approach. Although early morbidity was not negligible, rates of aneurysm occlusion (95% overall) and long-term outcome were quite laudable in light of the challenge posed by these lesions. Moreover, with accumulating experience with petrosal approaches, rates of complications are likely to wane, as neurosurgeons capitalize on the expansive exposure afforded by these indispensable approaches.

Combined endoscope-assisted transclival clipping and endovascular stenting of a basilar trunk aneurysm: case report

OBJECTIVE

We describe a patient with a mid-basilar aneurysm treated with combined endoscope-assisted transsphenoidal clipping and endovascular stenting.

CLINICAL PRESENTATION

A 28-year-old woman was transferred to the cranial base surgery center with an acute Grade III subarachnoid hemorrhage. Cerebral angiography demonstrated a small basilar trunk aneurysm that was not amenable to acute endovascular treatment.

INTERVENTION

The patient underwent sublabial transsphenoidal/transclival endoscope-assisted clipping of the aneurysm and subsequent stenting of the affected segment. The aneurysm was repaired with a low-profile Weck clip (Weck Closure Systems Research, Triangle Park, NC) that permitted a watertight closure of the clival dura using cardiac Medtronic U-clips (Medtronic, Inc., Minneapolis, MN). Postoperatively, the patient had no evidence of cerebrospinal fluid leakage.

CONCLUSION

Watertight dural closure was possible due to the use of a low-profile aneurysm clip that did not protrude through the dural defect, as well as self-tying sutures.

Surgical management of petroclival meningiomas: factors determining the choice of approach

Petroclival meningiomas remain one of the most challenging intracranial tumors to treat surgically. This is attributable to their location deep within the skull base and their association with multiple critical neural and vascular structures. Over the years, many skull base approaches have been described that are meant to improve resection and decrease patient morbidity. Appropriate selection of the surgical approach requires a thorough preoperative evaluation of clinical and radiological factors. In this paper the authors retrospectively reviewed 97 patients treated surgically for petroclival meningiomas by the senior author (O.A.M.) between 1995 and 2005 to assess the factors used to determine the choice of surgical approach, and to assess complication rates based on the approach selected. The skull base approaches used in these patients included the middle fossa anterior petrosal, posterior petrosal, and combined petrosal approaches, and complete petrosectomy. Factors found to be important in determining the selection of approach included the size, location, and extension of the tumor, preoperative hearing evaluation, and venous sinus anatomy.