Potential Risks and Limited Indications of the Supraorbital Keyhole Approach for Clipping Internal Carotid Artery Aneurysms

Abstract

Background: Internal carotid artery (ICA) aneurysm may be a good target for supraorbital keyhole clipping. We discuss the surgical indications and risks of keyhole clipping for ICA aneurysms based on long-term clinical and radiologic results.

Methods: This was a retrospective analysis of 51 patients (aged 35-75 years, mean 62 years) with ICA aneurysms (mean 5.8 ± 1.8 mm) who underwent clipping via the supraorbital keyhole approach between 2005 and 2017. Neurologic and cognitive functions were examined by several methods, including the modified Rankin Scale and Mini-Mental Status Examination. The state of clipping was assessed 1 year and then every few years after the operation.

Results: Complete clipping was confirmed in 45 patients (88.2%), dog-ear remnants behind the clip persisted in 4 patients, and wrapping was performed in 2 patients. Mean duration of postoperative hospitalization was 3.4 ± 6.9 days. The mean clinical follow-up period was 6.6 ± 3.2 years. The overall mortality was 0, and overall morbidity (modified Rankin Scale score ≥2 or Mini-Mental Status Examination <24) was 3.9%. Completely clipped aneurysms did not show any recurrence during the mean follow-up period of 6.3 ± 3.1 years, but the 2 (3.9%) aneurysms with neck remnants showed regrowth.

Conclusions: The risk of neck remnant behind the clip blade is a drawback of supraorbital keyhole clipping. The surgical indication requires preoperative simulation and careful checking of the clip blade state is essential.

Keywords: 3D, 3-Dimensional; AcomA, Anterior communicating artery; AntChoA, Anterior choroidal artery; BDI, Beck Depression Inventory; CT, Computed tomography; CTA, Computed tomography angiography; Clipping; DSA, Digital subtraction angiography; DWI, Diffusion-weighted imaging; HAM-D, Hamilton Depression Scale; HDS-R, Revised Hasegawa Dementia Scale; ICA, Internal carotid artery; ISUIA, International Study of Unruptured Intracranial Aneurysms; Internal carotid artery; Keyhole surgery; MCA, Middle cerebral artery; MMSE, Mini-Mental Status Examination; MRI, Magnetic resonance imaging; NIHSS, National Institutes of Health Stroke Scale; PcomA, Posterior communicating artery; UCA, Unruptured cerebral aneurysm; Unruptured cerebral aneurysm; mRS, Modified Rankin Scale.

Figure 1

Preoperative and postoperative images of a representative case of internal carotid artery (ICA)-posterior communicating artery (PcomA) aneurysm. (A) Preoperative digital subtraction angiography image showing laterally projecting ICA-PcomA aneurysm. (B) Preoperative simulation using 3-dimensional (3D) computed tomography angiography (CTA) multifusion image. The keyhole generated by computer graphics is applied to the skull to determine the optimal supraorbital keyhole. (C) Postoperative 3D CTA multifusion image.

Figure 2

Intraoperative photographs of clipping of a representative case of internal carotid artery (ICA)-posterior communicating artery (PcomA) aneurysm through the supraorbital keyhole approach. (A) After dural opening. (B) After exposing the ICA-PcomA aneurysm complex. Arrowhead indicates the partially resected cerebellar tent. (C) Dissecting the perforators (arrowhead) from the PcomA behind the dome. (D) After neck clipping.

Figure 3

Two cases of internal carotid artery (ICA)-posterior communicating artery (PcomA) aneurysms considered not suitable for supraorbital keyhole clipping. (A–B) ICA-PcomA aneurysm with short and low-lying ICA. Computer graphic image showing the proximal neck and the PcomA hidden by the anterior clinoid process (arrowhead). (C–D) Posteriorly projecting ICA-PcomA aneurysm. The aneurysm cannot be observed through the supraorbital keyhole (arrowhead) generated by computer graphics.

Figure 4

Preoperative and postoperative images of a representative case of internal carotid artery (ICA)-anterior choroidal artery (AntChoA) aneurysm. (A) Preoperative simulation using 3-dimesnional (3D) computed tomography angiography (CTA) multifusion image. The image shows the IC-AntChoA and anterior communicating artery; aneurysms. (B) Preoperative Digital subtraction angiography image showing the AntChoA running apart from the aneurysm neck (arrowhead). (C) Postoperative 3D CTA multifusion image.

Figure 5

Pre-, intra-, and postoperative images of a representative case of internal carotid artery (ICA) bifurcation aneurysm. (A) Preoperative digital subtraction angiography image showing anteriorly projecting ICA bifurcation aneurysm. (B) Intraoperative photograph showing anteriorly projecting ICA bifurcation aneurysm. (C) Postoperative 3-dimensional computed tomography angiography multifusion image.

Figure 6

Intraoperative and postoperative images of a representative case of internal carotid artery (ICA) paraclinoid aneurysm. (A) Intraoperative photograph showing small ICA paraclinoid aneurysm. (B) Intraoperative photograph showing the partially resected anterior clinoid process (arrowhead). (C) Postoperative dimensional computed tomography angiography multifusion image.