Supraorbital keyhole approach for paraclinoid aneurysms clipping: A case series with literature review

Background

Paraclinoid aneurysms (PcAs) are challenging aneurysms due to the complexity of their relation to the surrounding bony and neurovascular structures. Although over the past decade, their management strategy has shifted from transcranial to endovascular approaches; here, we try to revolve around a subcategory to which minimal invasive supraorbital keyhole (SOK) surgery is feasible depending on specific radiological criteria with a literature review.

Methods

A group of unruptured PcAs was managed surgically, with a subset that was clipped through the SOK approach. They were selected by preoperative simulation images using 3D computed tomography (CT) angiography (CTA). We also conducted an extensive literature review based on a database available on PubMed and Google Scholar, the yielded cases from the literature review plus our cases were analyzed according to six parameters including their size, location, dome direction, need for clinoidectomy and proximal cervical control, and surgical outcome.

Results

From February 2009 to August 2022, 49 cases of unruptured PcAs were managed by clipping, and of these, four cases were clipped by the SOK approach, in addition, four cases were yielded through the literature review. The sizes of the PcAs ranged from 3 to 8 mm. Their location fluctuated from anterior to the superomedial wall and their domes pointed superiorly except for one which points posteriorly. Six of eight cases required anterior clinoidectomy, the outcome was uneventful.

Conclusion

A subset of unruptured PcAs are amenable to SOK with criteria such as unruptured small aneurysm (<10 mm) and projected superiorly. These characteristics can be determined preoperatively using CTA.

Partial medial clinoidectomy with optic canal roof drilling for clipping of ophthalmic artery aneurysms: how I do it

BACKGROUND

Clipping of ophthalmic artery (OA) aneurysms present one of the treatment strategies for long-term disease management. Existing surgical techniques primarily require extra/intradural removal of the anterior clinoid process, carrying a higher risk of infection, damage to surrounding structures or technical complications.

METHODS

We present the technique of minimally invasive partial medial clinoidectomy with the unroofing of the optic canal for surgical clipping of OA aneurysms, and besides its pros and cons, we also discuss proper technical indications.

CONCLUSION

The partial medial clinoidectomy improves manoeuvrability around the paraclinoid region, provides better protection for adjacent structures and renders excellent treatment outcome.

Central Retinal Artery Thromboembolism without Ophthalmic Artery Occlusion During Stent-Assisted Coil Embolization of Ophthalmic Artery Aneurysm

BACKGROUND

Recent reports have described that endovascular treatment of coil embolization of opththalmic artery (OphA) aneurysms has a relative risk of visual disruption caused by thromboembolic infarction of the central retinal artery (CRA), especially the OphA when it originates within the body of the aneurysm. Patent microthrombus in the OphA might also cause retinal infarction that affects visual acuity. We describe stent-assisted coil embolization of an OphA aneurysm complicated with a severe visual disturbance, although normal flow was scrupulously maintained in the OphA during the procedure. The visual disturbance was recovered by early treatment.

CASE DESCRIPTION

A 40-year-old woman who presented with an intracranial aneurysm arising from the right OphA underwent stent-assisted coil embolization under general anesthesia. Although the area around the origin of the OphA was intentionally avoided and anterograde flow in the OphA was monitored by repeated angiography during this procedure, sight in the right eye was lost immediately thereafter. The immediate application of ocular massage and intraarterial fibrinolysis improved vision in the right eye to essentially normal status after discharge.

CONCLUSIONS

Despite good anterograde flow in the OphA during aneurysm embolization, the procedural risk of a visual disturbance due to thromboembolic complications of CRA occlusion cannot be avoided. Anterograde flow in the OphA and retinochoroidal blush should be monitored by repeated angiography during coil embolization to prevent vision loss. Should vision be lost, a rapid response including ocular massage and intraarterial fibrinolysis is required for recovery.

Endoscopic Endonasal Clipping of Anterior Circulation Aneurysm: Surgical Techniques and Results

BACKGROUND

Endoscopic endonasal clipping of intracranial aneurysms may use microsurgical techniques as an alternative to the transcranial approach. Here we report a series of patients who underwent microsurgical clipping of anterior circulation aneurysms via an endoscopic endonasal approach (EEA).

METHODS

This retrospective chart review included all the patients who underwent standard binostril EEA for aneurysm clipping. Surgical outcomes and complications are noted. The rationality and limitations of this procedure are discussed.

RESULTS

Seven patients with 12 aneurysms of the anterior circulation underwent EEA for clipping. These 12 aneurysms consisted of 5 anterior communicating artery (AComA) aneurysms, 4 paraclinoid aneurysms, 1 ophthalmic artery aneurysm, and 2 aneurysm located in the cavernous segment of internal carotid artery (ICA). Nine of the 12 aneurysms were successfully clipped. One giant paraclinoid aneurysm could not be clipped during operation and was coiled in second endovascular stage. The 2 aneurysms located in the cavernous segment of ICA were not clipped intentionally in a single-stage procedure, after weighing the surgical benefit against the difficulty of surgical exposure and feasibility. The proximal control of ICA was achieved in all cases. There was no death, no cerebrospinal fluid leak, or other complications. All patients recovered completely.

CONCLUSIONS

EEA can provide direct access for microsurgical clipping of strictly selected anterior circulation aneurysms. All the principles of cerebrovascular surgery must be followed. These procedures require a long learning curve. Only teams with adequate experience in microvascular and endoscopic skull base surgeries should attempt this approach for treating aneurysms.

Transient Cardiac Arrest Induced by Adenosine: A Tool for Contralateral Clipping of Internal Carotid Artery-Ophthalmic Segment Aneurysms

BACKGROUND

The disadvantages of a contralateral approach (CA) include deep and narrow surgical corridors and inconsistent ability to achieve proximal control of the supraclinoid internal carotid artery (ICA). However, a CA remains as a microsurgical option for selected ICA-ophthalmic (opht) segment aneurysms.

OBJECTIVE

To describe transient cardiac arrest induced by adenosine as an alternative tool to obtain proximal vascular control and soften the aneurysm sac in selected patients while performing a CA.

METHODS

From January 1998 to December 2013, we retrospectively identified 30 patients with ICA-opht segment aneurysms treated through a CA. Of those, 8 patients received an intravenous bolus of adenosine to induce transient cardiac arrest for softening of the aneurysm sac. We reviewed preoperative clinical status, characteristics of the contralateral aneurysm, adenosine doses, asystole time, recovery of normal circulation, outcome, and complications.

RESULTS

No preoperative cardiac or pulmonary pathologies were found in the study population. All contralateral ICA-opht segment aneurysms were unruptured, small, and saccular in shape. Transient cardiac arrest was induced because it was impossible to apply a temporary clip on the parent contralateral supraclinoid ICA. The median dose of adenosine was 22.5 mg (range, 5-50 mg) and the asystole time ranged from 20 to 40 seconds. All patients (n = 8) had good postoperative outcomes. No brain infarction or cardiac complications appeared postoperatively.

CONCLUSIONS

In selected patients, transient cardiac arrest induced by adenosine during a contralateral approach allows a brief flow arrest and softening of the aneurysm for safer exposure and clipping.