Abstract

Background: Advancements in endoscopic endonasal approaches (EEAs) allow the treatment of a wide variety of diseases including vascular pathology.

Case Description: A 56-year-old woman presented with thunderclap headache due to two aneurysms: Communicating segment of left internal carotid artery (ICA) and medial paraclinoid (Baramii IIIB). The ICA aneurysm was clipped through a conventional transcranial approach; the paraclinoid aneurysm was successfully clipped using an EEA guided with roadmapping assistance.

Conclusion: EEA is useful to treat aneurysms in selected cases and the use of adjuvant angiographical techniques such as roadmapping or proximal balloon control allow excellent control during the procedure.

Keywords: Aneurysm, Clipping, Endoscopic, Medial paraclinoid

INTRODUCTION

Recent advancements in endoscopic endonasal approaches (EEAs) have expanded its boundaries to adequately reach several skull base lesions. However, vascular pathology is rather unexplored through this route since, in the vast majority of cases, conventional transcranial approaches provide the best suited microsurgical treatment. Nonetheless, the feasibility of endoscopic endonasal aneurysm clipping has been examined by several authors.[ 7 ] In 1998, Perneczky and Boecher-Schwarz reported the first endoscope-assisted series of cerebral aneurysms. A total of 66 patients were treated through endoscope-assisted microsurgery, in which the main indication was for deep-seated lesions, especially for posterior circulation aneurysms,[ 6 ] withholding a wider operative field, a better control over the aneurysm, and less brain retraction with less intraoperative rupture.[ 10 ] Nowadays, no consensus of the utility of EEA for intracranial aneurysms exists. In this operative video, we present the case of a medially projecting paraclinoid aneurysm that was successfully clipped through an endoscopic endonasal approach assisted by intraoperative angiography with roadmapping and proximal balloon control.

CASE REPORT

We present the case of a 56-year-old woman with no previous relevant medical record who was admitted with a sudden onset thunderclap headache suggestive of aneurysmatic subarachnoid hemorrhage. At neurological examination, only mild nuchal rigidity was found. On angio-CT, two aneurysms: one at the communicating segment of the left ICA (pComm aneurysm) and a right medial paraclinoid (Baramii IIIB) aneurysm were found [ Figures 1a and b ]. The pComm aneurysm was clipped in a first surgical stage through a left conventional pterional approach. Even though an attempt to clip the right aneurysm was performed during this procedure, it was unreachable due to its infradiaphragmatic location; thus, a proper angle of visualization of the vascular anatomy could not be reached to perform a safe clipping technique, and the possibility of a new procedure, either surgical or endovascular, was proposed. Due to financial limitations, even though endovascular treatment was considered, this possibility was unfeasible; thus, an EEA approach assisted by intraoperative angiography was performed.

Figure 1:

AngioCT in axial (a) and coronal (b) projections showing a communicating segment of the left ICA (pComm) aneurysm (yellow arrow) and a right medial paraclinoid (Baramii IIIB) aneurysm (red circle).

After completing the nasal phase and removing the sphenoid rostrum to identify bony anatomical landmarks, drilling of sellar floor and tuberculum sella were performed. Baseline angiographic images were obtained for roadmapping to guide dural opening and initial dissection. After gaining proximal control with an intra-arterial balloon in the petrous internal carotid artery, the neck was dissected, and clipping was performed. Intraoperative angiography revealed complete occlusion of the aneurysm without parental vessel stenosis. Reconstruction was carried out with a nasoseptal flap and an autologous fat graft. Postoperative course was unremarkable; the patient was discharged home 7 days after the procedure [ Video 1 ].

Video 1.

DISCUSSION

Aneurysmatic intracranial lesions can be successfully treated using EEA in selected patients. Even though there is not an actual neurosurgical consensus to determine the utility of this approach for aneurysm treatment, technical advances in EEA can facilitate its treatment in certain cases allowing direct anatomic corridors to locate the lesion with an adequate vascular control depending of the location and characteristics of the lesion. Since the original report by Kassam et al. in 2006 of an aneurysmorrhaphy in a patient with a vertebral aneurysm previously treated with endovascular therapy, multiple case reports of the use of EEA for anterior and posterior circulation aneurysms have been published.[ 7 , 9 ] In the majority of these cases, a transplanumtranssellar EEA approach for anterior circulation lesions was used.[ 3 , 8 ] Reported complications included cerebrospinal fluid (CSF) leak, pneumonia, lacunar infarct, vasospasm, and hydrocephalus.[ 7 ]

In our case, we report a Baramii IIIB medial paraclinoid aneurysm. These lesions arise from the medial surface of the C6 segment of the ICA, being closely related to the superior hypophyseal artery; the medial projection of this type of aneurysms facilitates the surgical access using a midline corridor as the EEA.[ 2 ] Based in this technical principle, EEA should be specially considered for ophthalmic and superior hypophyseal artery aneurysms, as they arise from the medial surface of the ICA. Fischer et al. reported 124 surgeries, in which a total of 180 aneurysms were treated with endoscopic assistance during the microsurgical procedure, and three moments in which the endoscope becomes a key feature in these cases are described: (1) inspection previous to the definitive clipping, in cases when further topographical information regarding the aneurysm’s configuration is deemed necessary; (2) during the clipping; and (3) post clipping evaluation, which provides a better visualization and can determine if there is an incomplete clipping, neck remnant, and parent artery occlusion, among other anomalies, which require clip repositioning.[ 4 ]

Endovascular therapy has equally advanced in the aneurysm treatment since 2008 with a lower morbidity rate in comparison with open surgery;[ 11 , 13 ] nevertheless, intrinsic aneurysm characteristics and patient conditions can limit this therapeutic option; in addition, open surgery reports a lower rate of recurrence and re-treatment in these patients, allowing at the same time to eliminate mass effect in large volume aneurysms.[ 11 ] In this case, since it was not possible to perform endovascular treatment as initial therapy due to financial limitations, an EEA was chosen. Although we acknowledge that the latter would be the first option for treatment in most developed countries, this is not a feasible option for every single patient we treat, and regardless of any limitation, an efficient therapeutic modality was performed. A hybrid surgery was chosen, using intraoperative angiography with roadmapping and proximal balloon control. This technique allows early and precise identification of vascular lesions, including aneurysms and “live” complete occlusion of the lesion after clipping.[ 1 - 12 ] The use of intraoperative digital substraction angiography (iDSA) with roadmapping technique in an HOR for complex aneurysms offers not only diagnostic angiography as needed but also real-time image guidance during microdissection and clip positioning or repositioning, the latter being the main advantage for this technique. The use of roadmapping over conventional iDSA requires no additional equipment and provides a complementary tool that should be used in addition to iDSA to provide a safer clipping technique. Furthermore, the proximal control offered by an intra-arterial balloon, as well as the possibility of concomitant aneurysm embolization in selected cases, makes this intraoperative adjunct a valuable tool for vascular surgery. Another advantage of this modality is the ability to diagnose and treat vasospasm immediately after aneurysm occlusion has been confirmed. Besides from achieving these goals in a single stage, the patient’s transfer among different facilities is avoided, thus preventing further associated complications.

EEA clipping plus roadmapping technique with iDSA provides multiple benefits in this type of procedures including: direct aneurysm visualization (location and projection), effective proximal vascular control using a balloon, and direct evaluation of aneurysm residual and need of clip repositioning; potential risks of this technique may include: CSF leak, stereoscopic vision, restriction of arterial reconstruction techniques and bypass if necessary.

CONCLUSION

The utility of EEA for treatment of midline intracranial lesions continues to be unraveled, and even vascular lesions can be successfully treated using this approach in selected patients. Care must be taken in the selection of the patient, based on the aneurysm characteristics, particularly its accessibility and the possibility to have adequate proximal vascular control. The use of adjuvant endovascular techniques can facilitate the procedure, allowing proximal control and correct clip position, and reducing the incidence of complications, such as bleeding and remnant aneurysms. More reports are needed to objectively determine the security and effectiveness of this technique as well as its specific indications.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Videos available online at

https://doi.org/10.25259/SNI_1061_2022

Disclaimer

The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.

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