Technical nuances of subtemporal approach for the treatment of basilar tip aneurysm

Subtemporal Approach for the Treatment of Ruptured and Unruptured Distal Basilar Artery Aneurysms: Is There a Contemporary Use?

BACKGROUND AND OBJECTIVES

Distal basilar artery aneurysms (DBAs) are high-risk lesions for which endovascular treatment is preferred because of their deep location, yet indications for open clipping nonetheless remain. The subtemporal approach allows for early proximal control and direct visualization of critical posterior perforating arteries, especially for posterior-projecting aneurysms. Our objective was to describe our clinical experience with the subtemporal approach for clipping DBAs in the evolving endovascular era.

METHODS

This was a retrospective, single-institution case series of patients with DBAs treated with microsurgery over a 21-year period (2002-2023). Demographic, clinical, and surgical data were collected for analysis.

RESULTS

Twenty-seven patients underwent clipping of 11 ruptured and 16 unruptured DBAs with a subtemporal approach (24 female; mean age 53 years). Ten patients had expanded craniotomies for treatment of additional aneurysms. The aneurysm occlusion rate was 100%. Good neurological outcomes as defined by the modified Rankin Scale score ≤2 and Glasgow Outcome Scale score ≥4 were achieved in 21/27 patients (78%). Two patients died before hospital discharge, one from vasospasm-induced strokes and another from an intraoperative myocardial infarction.

CONCLUSION

These results demonstrate that microsurgical clip ligation of DBAs using the subtemporal approach remains a viable option for complex lesions not amenable to endovascular management.

Combined subtemporal and pterional approach for clipping of multiple aneurysms

Background:

Despite ongoing improvements in endovascular techniques, open surgical management of basilar apex aneurysms is occasionally necessary.[2] Critical dissection of perforating vessels from the aneurysm is facilitated by the lateral trajectory of the subtemporal approach.[1] Incorporation of additional trajectories can facilitate treatment of multiple aneurysms within the same procedure.

Case Description:

A 48-year-old woman presented with a Hunt and Hess 1 and Fisher Grade 3 subarachnoid hemorrhage from a small and broad-necked basilar apex aneurysm that was not amenable to endovascular management. An unruptured left A1-A2 anterior cerebral artery aneurysm was also noted on vascular imaging. The patient underwent a combined right subtemporal and pterional approach for sequential clipping of the basilar and anterior communicating artery aneurysms. The third nerve, running between the posterior cerebral artery and the superior cerebellar artery, guided dissection to the basilar artery in the subtemporal approach. A temporary clip was placed on a vessel-free zone of the basilar trunk during dissection of perforators off the posterior aspect of the aneurysm dome. A fenestrated clip around the right P1 segment was used to ensure complete occlusion of the aneurysm. Indocyanine green angiography was used to confirm successful clipping and patency of parent and perforating vessels. The unruptured A1-A2 aneurysm was clipped without difficulty from the pterional trajectory. The patient had an uneventful postoperative recovery with the exception of transient right third nerve palsy.

Conclusion:

As highlighted by this case, maintenance of open surgical skills for the treatment of complex aneurysms unamenable to endovascular therapies is critical.

Institutional Experience of Microsurgical Management in Posterior Circulation Aneurysm

Introduction:

Posterior circulation aneurysm constitutes 15%–20% of all intracerebral aneurysms. With the advancement of endovascular techniques, the microsurgery for posterior circulation aneurysms has been pushed back a little. Even the International Subarachnoid Aneurysmal Trial gave support to the concepts of endovascular procedures, but microsurgical modality should not be discouraged. We present our institutional experience of microsurgical techniques on posterior circulation aneurysms.

Materials and Methods:

We performed a retrospective analysis of 37 patients of posterior circulation aneurysm from 2015 to 2019, referred to Bantane Hospital, Japan. We included all posterior circulation aneurysms such as basilar tip, basilar trunk, and vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysms, admitted and treated with clipping or bypass and trapping. We assessed the outcome as measured by modified Rankin Score (mRS), complications, and mortality.

Results:

Out of 37 patients, 10 cases were a basilar tip, one case was the basilar trunk, and 26 cases were VA-PICA aneurysm. Intraoperatively, neuromonitoring, indocyanine green dye, dual-image videoangiography (DIVA), and neuro endoscope were used. Two patients of basilar tip aneurysm developed third cranial nerve paresis and six patients of VA-PICA aneurysm developed lower cranial nerve paresis which resolved spontaneously. All the patients were discharged with mRS of 0 or 1. No mortality was recorded in our study.

Conclusion:

Microsurgical clipping of posterior circulation aneurysm is safe in unruptured aneurysm with a very low risk of mortality and morbidity under experienced hands. All postoperative complications in our study were transient and resolved with time with no residual deficits. Preoperative simulation, intraoperative neuromonitoring, DIVA, and neuro endoscope help achieve complete obliteration of aneurysmal sac and avoid complications.

Anterior temporal approach for clipping of ruptured basilar tip aneurysms: Surgical techniques and treatment outcomes

BACKGROUND

Basilar tip (BT) aneurysms are challenging to treat with microsurgical clipping, especially in subarachnoid hemorrhage cases. The anterior temporal approach is one of the surgical approaches for the treatment of aneurysms in this area. The majority of the previous reports on this approach have described unruptured cases. For the ruptured cases assessed in our study, the authors describe the surgical technique, patient characteristics, and surgical outcomes following the use of this technique.

METHODS

Fourteen patients with ruptured BT aneurysms who received aneurysm clipping with an anterior temporal approach between December 2015 and August 2019 were retrospectively evaluated. The surgical techniques are described, an illustrative case is shown.

RESULTS

The average patient age was 62.2 years (range: 46-78) for ten women and four men. Nine patients (64.3%) were classified as having a poor grade (World Federation of Neurosurgical Societies Grades 4 and 5) at the first presentation. All of the cases demonstrated complete aneurysm obliteration. Good outcomes (mRS 0 to 2) at 6 months were achieved in 58.3% of the patients and in 77.8% of the patients who had a good Glasgow Coma Score after resuscitation before surgery. Postoperative transient oculomotor nerve palsy and thalamic infarctions were detected in six patients (42.9%) and two patients (14.3%), respectively.

CONCLUSION

With appropriate case selection, the anterior temporal approach was effective and safe for the clipping of ruptured BT aneurysms.

Anterior Temporal Approach and Clipping of a High-Riding Basilar Tip Aneurysm: Case Report and Review of the Surgical Technique

Basilar apex aneurysms constitute 5%–8% of all intracranial aneurysms. Microsurgical clipping of basilar tip aneurysms is still advocated for as it is safe, especially for unruptured basilar tip aneurysms which have a low risk of postoperative mortality or morbidity. Careful patient preparation is needed preoperatively because the risk of intraoperative rupture is significant. Good surgical techniques should be applied. The skill will need to be preserved as endovascular surgery becomes more popular. This is a case of basilar tip aneurysm managed by clipping through the anterior temporal approach, followed by a review of the literature.

Surgical Management of Brain Cavernous Malformations

Surgical removal of accessible lesions is the only direct therapeutic approach for cerebral cavernous malformations (CCMs). The approach should be carefully evaluated according to clinical, anatomical, and neuroradiological assessment in order to both select the patient and avoid complications. In selected cases, a quantitative anatomical study with a preoperative simulation of surgery could be used to plan the operation. Neuronavigation, ultrasound, and neurophysiologic monitoring are generally required respectively to locate the CCMs and to avoid critical areas. The chapter describes all the possible surgical approaches for supratentorial, infratentorial, deep seated and brain stem CCMs. In any case before performing surgery, the physicians should always consider the benign nature of the lesions and the absolute necessity to avoid not only neurological deficits, but also a neuropsychological impairment that could affect the quality of life of the patients.

Concomitant ruptured anterior circulation and unruptured posterior circulation aneurysms: Treatment strategy and review of literature

Basilar artery apex or bifurcation is the most common location for aneurysms arising from posterior cerebral circulation. Reports of unruptured aneurysms of the basilar bifurcation associated with ruptured anterior circulation aneurysms are rare. The presence of multiple intracranial aneurysms poses a significantly high risk to management than a single aneurysm due several factors involved. Surgical management is considered the best treatment modality for most aneurysmal types and location with quite a few limitations when applicable. Authors have conducted a literature review of anterior and posterior circulation concomitant aneurysms and report their own experience with a case of anterior communicating artery blister type aneurysmal rupture presented with the symptoms and signs of subarachnoid hemorrhage concomitant with an unruptured basilar artery bifurcation aneurysm. Moreover, the anomalous origin of thalamoperforators at the basilar apex instead of the posterior cerebral artery makes it reasonably challenging for the microsurgical clipping. Discussed is the clinical presentation, radiological studies obtained, surgical approach utilized with an adequate exposure of the entire circle of Willis as well as the critical decision making when managing these challenging cases.

Intradural Subtemporal Keyhole Approach with Neuronavigational Assistance to the Petroclival and Ventrolateral Brainstem Regions: Quantitative Analysis of Anatomic Exposure and Surgical Freedom

OBJECTIVE

The purpose of this study was to evaluate the advantages of endoscopy and navigational assistance in the intradural subtemporal keyhole approach and the intradural Kawase approach by studying anatomic exposure and surgical freedom in the posterior cranial fossa.

METHODS

Twenty endoscopic intradural subtemporal keyhole approaches (EISKA) were performed on 10 cadaveric heads. An intradural Kawase approach and a navigation-assisted intradural Kawase approach were then carried out on a random side of each specimen. Related anatomic structures were observed through a 0° endoscope and a microscope. Anatomic exposure and surgical freedom were measured by transparent graph paper and analyzed.

RESULTS

Compared with the microsurgical technique, the superior, inferior, and medial limits of the endoscopic anatomic exposure increased by 2.9, 15.65, and 10.2 mm, whereas the surgical freedom increased by 2.9, 7.55, and 6 mm (P < 0.05) in the intradural subtemporal keyhole approach. In the intradural Kawase approach and the navigation-assisted intradural Kawase approach, the endoscopic anatomic exposure and surgical freedom also increased (P < 0.05). Using a frameless navigational device, the inferior limit of the anatomic exposure increased 3.8 mm by endoscopy and 3.5 mm by microscopy, whereas the surgical freedom increased by 2.7 and 2.2 mm, respectively (P < 0.05).

CONCLUSIONS

The EISKA provides greater anatomic exposure and surgical freedom primarily in the superior, inferior, and medial directions of the brainstem region. Maximum anatomic exposure and surgical freedom of the posterior cranial fossa was obtained by navigational assistance with fewer complications.

Multimodality Techniques in Microsurgical Clipping as the Gold Standard Treatment in the Management of Basilar Tip Aneurysm: A Case Series

Introduction:

Basilar aneurysms represent 5%–7% of all intracranial aneurysms. The main goal of open surgery is to achieve complete obliteration of the aneurysmal sac using minimal invasive technique while emphasizing on avoidance of complication.

Materials and Methods:

We performed a retrospective cohort study of nine cases of unruptured basilar tip aneurysm referred to the Fujita Health University Banbuntane-Hotokukai Hospital, Japan. The objective of the study was to analyze the surgical outcomes of unruptured basilar tip aneurysm.

Results:

Nine patients with unruptured basilar tip aneurysm were referred to our hospital between 2015 and 2017. The median size of the aneurysm and age were 4.00 mm (interquartile range [IQR] = 3.25–6.75 mm) and 58 years (IQR = 54–70 years), respectively. Five patients (55.6%) were presented with multiple intracranial aneurysms. Surgical adjuncts such as intraoperative neuromonitoring, intraoperative indocyanine green (ICG) angiography with dual-image videoangiography (DIVA), and neuroendoscope were used. Two patients developed transient postoperative oculomotor nerve palsy which resolved spontaneously. The median duration of surgery and days of hospitalization were 292 min (IQR = 237.5–350.5 min) and 12 days (IQR = 12–25 days), respectively. There was no mortality recorded in this case series.

Conclusion:

Microsurgical clipping of basilar tip aneurysm is safe in unruptured basilar tip aneurysm with a low risk of postoperative mortality or morbidity. All complications reported in this case series were transient with no long-term sequalae. The improved safety profile of microsurgical technique is due to the availability of intraoperative neuromonitoring, neuroendoscope, ICG, and DIVA. The application of multimodality technique in neurovascular surgery has also helped to achieve complication avoidance. The obliteration of the aneurysmal sac helps to restore the laminar blood flow in the bifurcation and distal blood vessels and improves the brain perfusion.