The retrograde approach: a consideration for the endovascular treatment of aneurysms

Abstract

Background and purpose: The traditional endovascular approach to a cerebral aneurysm is anterograde, with the embolization and balloon protection catheters introduced via the parent vessel. Unfortunately, this approach may be restrictive, because these catheters cannot always be navigated at an optimal angle into the arterial branch that needs balloon protection or the part of the aneurysm that needs coiling. The purpose of this study was to determine the efficacy of a retrograde approach.

Methods: Twelve patients, seven women and five men, 28 to 65 years old (mean age, 45 years), were treated via the retrograde approach between March 1998 and February 1999. Three patients were treated for acutely ruptured aneurysms following subarachnoid hemorrhage. The rest had asymptomatic, unruptured aneurysms.

Results: We were able to accomplish endovascular treatment in 10 cases. In the other two, the attempted retrograde route of access could not be achieved. The treatment afforded complete embolization in nine of the 10 patients. Symptomatic distal clot embolization occurred in one patient who had some residual, albeit improving, deficits at discharge. No other patients worsened with the treatment. There were two intraprocedural aneurysmal ruptures. None of the aneurysms restudied within 6 months (eight of 12) showed evidence of recanalization.

Conclusion: Our results indicate that it is possible to safely and effectively access a cerebral aneurysm via a retrograde approach. We believe that the anatomic benefits afforded by this technique outweigh the potential risks associated with the catheterization of another major cerebral arterial feeder.

fig. 1. Case 6. A, Anteroposterior right vertebral angiogram shows a large wide-necked aneurysm at the basilar tip; B, lateral view of same; C, 3D reconstruction, lateral view, note width of neck in anteroposterior diameter; D, anteroposterior view of microcatheter, with coil ready for deployment, introduced into aneurysm via right VA; also visible is the remodeling balloon catheter with guidewire, introduced via the right ICA, then coursing through the PCom, right P1, and across the neck of the aneurysm, with the wire extending into the left P1 and P2; E, schematic illustration of catheter deployment; F, final phase of embolization, just before detachment of last coil (arrow on proximal marker of embolization catheter), with remodeling balloon inflated, anteroposterior view; G, lateral view of same, note how the top of the BA has been remodeled with the balloon, reconstructing the normal vascular lumen; H, final postembolization anteroposterior vertebral angiogram; I, same, lateral view, note the curve of the top of the BA and the proximal P1 due to balloon remodeling.

fig. 2. Case 4. A, Skull radiograph, anteroposterior view, shows coils in previously embolized left ICA aneurysm; B, right anterior oblique projection of right ICA angiogram shows bilobate lateral-wall ICA aneurysm (wide arrow) and unilobar medial-wall aneurysm (thin arrow); C, 3D reconstruction, same view, shows bilobate lateral-wall aneurysm (large straight white arrow) and medial-wall aneurysm (small straight white arrow) of right ICA (curved arrow) as well as coil mass from embolized left ICA aneurysm (wide arrow), gray arrows are orientation markers from the reconstruction; D, same projection, higher magnification, shows nonsubtracted view of balloon and embolization catheters during embolization of anterior lobe of the lateral-wall aneurysm; the balloon catheter and wire are coming up the ICA and extending into the MCA (white arrows); the embolization catheter, which has a coil in it, comes up the right VA, into the BA, then into the right P1, PCom, ICA, and aneurysm (black arrows); E, schematic view shows course of balloon and embolization catheters in this case; F, post-embolization right ICA angiogram shows complete packing of the lateral wall ICA aneurysm; G, post-treatment skull radiograph, anteroposterior view, shows coils in right ICA bilobate aneurysm.