Flow recovery after posterior clinoidectomy for surgical clipping of anterior choroidal aneurysm

Abstract

Inadvertent flow alterations in the parent artery during microsurgical clipping might produce postoperative ischemic complications. Intraoperative recognition of such alterations and its correction might improve operative outcomes in these patients. We present the case of a thirty-five-year-old male with an incidental small left anterior choroidal aneurysm. Microsurgical clipping induced an external compression of the anterior choroidal artery against the posterior clinoidal process which was identified in situ through surgical exploration and the loss of arterial doppler signal in the vessel. After failed attempts at clip repositioning, a posterior clinoidectomy was performed to decompress the artery. This resulted in arterial flow recovery. The aneurysm was successfully treated, and a severe ischemic complication was likely avoided. This intraoperative phenomenon has not yet been described in the literature.

Keywords: Aneurysm; Anterior choroidal aneurysm; Anterior choroidal artery; Stroke; Vascular compression.

Fig. 1.

(A) CT angiography with bone reconstruction (lateral view): an aneurysm arising in the left AChA is observed. Inferiorly and medial to the aneurysm, the PCP with two bony prominences projecting superiorly and posteriorly. (B) Superior view of the same CT angiography. (C) Exposure of the sylvian fissure via a mini-pterional approach. (D) Surgical view under the operative microscope after the carotid cistern was dissected. The aneurysm sac was exposed and the origin of the AChA was identified. The PCP is medial to the aneurysm. (E) Intraoperative image of the clipped aneurysm, the compression of the AChA against the PCP is evidenced. (F) Use of Doppler probe on the AChA, which showed absence of flow. (G) Posterior clinoidectomy using Kerrison rongeur. (H) AChA liberated after the posterior clinoidectomy. CT, computed tomographic; AChA, anterior choroidal artery; PCP, posterior clinoid process; An, aneurysm; KR, kerrison rongeur.

Fig. 2.

(A) Macroscopic view of the surgical field after aneurysm clipping and posterior clinoidectomy. (B) Post-surgical CT angiography showing the clip and its projection in the space previously occupied by the superior projection of the PCP. (C) Artistic illustration of the concept detailed in the present report (the black arrow points at the site of vascular compression of the AChA against the PCP). CT, computed tomographic; PCP, posterior clinoid process; An, aneurysm; AChA, anterior choroidal artery; ICA, internal carotid arter; MCA, middle cerebral artery.