Endoscopy and Stereotaxy for Aneurysms

Frameless stereotaxy-assisted clipping of distal anterior cerebral artery aneurysm: technical note and case series

OBJECTIVE

Microsurgery for the clipping of cerebral aneurysms requires a working knowledge of the anatomy of the cerebral vasculature and its relationship to landmarks on the surface of the brain and along the skull base. However, for more distally located aneurysms of the anterior cerebral artery (ACA), locating the lesion can prove frustrating and may require much more extensive interhemispheric dissection than is otherwise needed for proximal control, exposure of the aneurysm, and clip application. We report a case series of five patients in which frameless stereotaxy and CT angiographic data sets were used to minimize the extent of surgery required to clip distal ACA aneurysms.

CLINICAL PRESENTATIONS

Five patients were found to have distal ACA aneurysms during the work-up of subarachnoid hemorrhage or other neurologic symptoms. The patients comprised two with subarachnoid hemorrhage, one with dizziness, one with stroke, and one with migraines and polycystic kidney disease. Each patient was found to have an aneurysm at the pericallosal/callosal marginal junction.

INTERVENTION

All five patients underwent a right parasagittal craniotomy and clipping of a distal ACA aneurysm. The location of the craniotomy and subsequent interhemispheric dissection were guided by CT angiographic data sets and computer-assisted frameless stereotaxy.

CONCLUSION

Frameless stereotaxy using a CT angiographic data set is a useful adjunct to routine microsurgery in the clipping of distal ACA aneurysms. Its use obviates the need for extensive interhemispheric dissection, allows the surgeon to gain proximal control and expose the aneurysm more efficiently, and should minimize complications related to unwitting aneurysm exposure.

Endoscopic assisted microneurosurgery for cerebral aneurysms

While there have been many advances in the field of microneurosurgery, the clipping of aneurysms remains an intricate procedure. Technical complications include residual aneurysm, perforator injuries, parent artery occlusion and cranial nerve injuries. The neuroendoscope is a useful tool and adjunct to the microsurgical clipping of these aneurysms. We study the usefulness of the neuroendoscope in enhancing visualisation during surgery. Twenty-four cases of ruptured cerebral aneurysms were operated on over a duration of 6 months in which a 1mm diameter rigid endoscope was used. We discuss our preliminary results and examine the advantages of the neuroendoscope. These include the ability to look around corners and behind obstructions. While this provides an additional view to the surgeon, the high magnification gives good definition of the surrounding structures. With less brain retraction, smaller operative exposures and yet better visualisation offered, neuroendoscopy may reduce operative morbidity.