Anterior Temporal Approach Research Articles

Distal Basilar Artery Aneurysm Clipping by an Anterior Temporal Transcavernous Approach: 2-Dimensional Operative Video

Distal Basilar Artery Aneurysm Clipping by an Anterior Temporal Transcavernous Approach: 2-Dimensional Operative Video

Microsurgical Approach for True Posterior Communicating Artery Aneurysms: Literature Review and Illustrative Case.

True posterior communicating artery (PCoA) aneurysms are rare. Although true PCoA aneurysms have been reported to be located close to the internal carotid artery, at the middle part of PCoA, or close to the posterior cerebral artery; the best surgical approach to treat true PCoA aneurysms in each location remains unclear. We conducted a literature review using data from PubMed. Data on demographics, location, and projecting direction of the aneurysm, surgical approach, and surgical complications were collected. A total of 47 true PCoA aneurysms were included. Twenty-nine aneurysms originated from the proximal portion, 10 from the middle portion, and 6 from the distal portion; there were two giant aneurysms. The ipsilateral pterional approach was used for 37 true PCoA aneurysms (27 in proximal portion, 8 in middle portion, and 2 in distal portion of PCoA). The anterior temporal approach was used for two distal-portion aneurysms and one giant aneurysm. The anterior subtemporal approach was used for one distal-portion aneurysm. The subtemporal approach was used for two middle-portion aneurysms and one giant aneurysm. The contralateral pterional approach was used for two proximal-portion and one distal-portion aneurysms. Although most true PCoA aneurysms can be treated by the pterional approach, other means such as anterior temporal and subtemporal approaches can be applicable for aneurysms in the middle and distal portions of the PCoA or giant aneurysms. Surgeons should select an appropriate approach for each aneurysm while considering the advantages and disadvantages of each technique.

Management of Wide-Necked Basilar tip Aneurysms.

While the frequency of direct surgery for basilar tip aneurysms is decreasing, the need for safe and effective surgical treatments for difficult-to-treat aneurysms, including large or wide-necked aneurysms, is likely to continue. In this chapter, our surgical approach for large wide-necked basilar tip aneurysms using the orbitozygomatic approach, the anterior temporal approach, and hybrid surgery are described.

Superficial Temporal Artery–Posterior Cerebral Artery Bypass Through Zygomatic Anterior Temporal Approach for Complex Posterior Cerebral Artery Aneurysm

Posterior cerebral artery (PCA) aneurysms are rare, and most are giant, dissecting, or fusiform in morphology. Proximal occlusion of the PCA without revascularization causes high risk of ischemic complications. This study aimed to evaluate the safety and validity of using superficial temporal artery (STA)-PCA bypass through zygomatic anterior temporal approach in complex PCA aneurysms. Trapping or resecting of aneurysms and reconstruction of distal PCA through a zygomatic anterior temporal approach were performed in 6 patients from June 2017 to August 2020. Postoperative angiography confirmed obliteration of aneurysms and patency of bypass artery. Neurological function was assessed by the modified Rankin Scale (mRS). Patients were 4 men and 2 women with a mean age of 43.8 years (range, 21-58 years). Subarachnoid hemorrhage occurred in 5 patients. Hunt and Hess grade was IV in 3 patients, III in 2 patients, and I in 1 patient. All PCA aneurysms were treated with trapping or resection of the aneurysms and revascularization of distal PCA. Postoperatively, all aneurysms were eliminated, and no new permanent neurological deficit was found. During follow-up, mRS score of all patients improved: 2 patients had mRS score 0, 1 patient had mRS score 1, 1 patient had mRS score 3, and 2 patients had mRS score 4. Long-term graft patency rate was 100%. STA-PCA bypass appears to be safe and effective for the treatment of complex PCA aneurysms requiring supplementation of blood flow in the area of the PCA. We established a surgical route, allowing the procedure to be done through the zygomatic anterior temporal approach. This approach provides adequate operative field exposure and reduces retraction of temporal lobe.

The Anterior Trans–Superior Temporal Gyrus Approach for Selective Amygdalohippocampectomy

Different surgical approaches have been described for selective amygdalohippocampectomy in patients with pharmacoresistant temporal lobe epilepsy. The aim of this study was to report the results of the innovative anterior trans-superior temporal gyrus approach in a single-center series. Patients' characteristics, postoperative outcomes, and complications were reviewed in a series of 8 consecutive patients with temporal lobe epilepsy operated on using the anterior trans-superior temporal gyrus approach between November 2015 and April2017. Over a mean 2.5-year follow-up, 7 of 8 patients (87.5%) remained seizure-free (Engel class I). Only 1 patient (12.5%) was not cured (Engel class III) with no clear explanation for treatment failure. Mean operative time was 237 minutes, which was 80 minutes shorter compared with the classic transsylvian approach. No perioperative deaths were recorded and there were no visual field defects or visual acuity impairments secondary to the approach. One patient experienced a left posterior thalamocapsular stroke. The anterior trans-superior temporal gyrus approach is feasible, fast, and safe for selective amygdalohippocampectomy in patients with drug-refractory temporal lobe epilepsy. This approach allows preservation of the optic radiation but cuts part of the uncinate fasciculus and potentially the anterior aspect of the anterior bundle of the middle longitudinal fasciculus.

Extradural anterior temporal fossa approach to the paranasal sinuses, nasal cavities through the anterolateral and anteromedial triangles: Combined microscopic and endoscopic strategy.

To demonstrate the utility and limitations of the extradural endoscopic-assisted anterior temporal fossa approach to the pterygopalatine fossa (PPF), infratemporal fossa (ITF), paranasal sinuses (PS), parapharyngeal region (PPR), nasal cavities (NC), epipharynx (EP), and clivus. A frontotemporal orbitozygomatic craniotomy is performed. The dura is elevated from the cavernous sinus (CS). The anterior temporal fossa floor is drilled. Foramen rotundum and ovale are opened. The PPF is exposed andthe lateral margin of inferior orbital fissure (IOF) is removed. The anterolateral triangle (ALT) is drilled and the vidian nerve (VN) is exposed. Drilling between the maxillary nerve (V2) and theVN provides access to the sphenoid sinus (SphS). The medial pterygoid plate is drilled exposing the EP. The maxillary sinus (MaxS) is opened anterior to the PPF. V2 is transposed laterally to enlarge the anteriomedial triangle (AMT). The orbital muscle of Muller is removed as well as the medial margin of theIOF, which opens the SphS. Anteriorly, the posterior ethmoid air cells are opened. Morphometric measurements evaluating the size of the ALT were done and the PS, NC, EP were explored with the endoscope. The ALT and AMT triangle provides a wide exposure of the PPF, ITF, PPR. In addition, those triangles represent a deep entry point to explore the PS, NC, and EP. The ALT and AMT are useful corridors to access to the SphS, MaxS, PS, NC, and EP via a transcranial approach. The use of the endoscope through this corridor widely extend the extradural anterior temporal fossa approach which may be considered as a valuable alternative to the extended endoscopic endonasal approach for selected skull base lesions extending both intracranial and into the PS, NCand EP.

Anterior Temporal Approach for Clipping Posterior-Projecting Supraclinoid Carotid Artery Aneurysms: A More Lateral Corridor to Better Visualize the Aneurysm Neck and Related Branches

Direct visualization of the aneurysm neck and its related branches during microsurgical clipping of supraclinoid internal carotid artery (SICA) aneurysms using a standard pterional approach may be difficult, especially when aneurysms are posteriorly projected. We evaluated the efficacy and safety of an anterior temporal approach for clipping posterior-projecting SICA aneurysms. Between December 2017 and March 2020, 26 patients with posterior-projecting SICA aneurysms who received microsurgical clipping via an anterior temporal approach were retrospectively reviewed. The percentage of complete aneurysm obliteration, intraoperative visualization, and preservation of related branches were evaluated. Aneurysm locations were the posterior communicating artery (PCoA) (internal carotid artery [ICA]-PCoA) in 22 patients (84.6%), the anterior choroidal artery (AChA) (ICA-AChA) in 3 patients (11.5%), and both locations in 1 patient (3.9%). Complete aneurysm obliteration was achieved in all patients. For ICA-PCoA aneurysms in which the PCoA was preoperatively identified, the artery was intraoperatively identified in all cases and preserved 100% after surgery. For ICA-AChA aneurysms, AChAs were intraoperatively identified and preserved in all cases after surgery. Procedural-related infarction was 8.7% for ICA-PCoA aneurysms and 7.7% for all SICA aneurysms. Transient oculomotor nerve palsy was found in 2 patients (7.7%). No postoperative temporal contusion was detected. A good outcome at 3 months after surgery was achieved in 90% of patients for good clinical-grade subarachnoid hemorrhage and unruptured cases. The anterior temporal approach is safe and effective for clipping SICA aneurysms with posterior projection, with a high preservation rate of the related branches.

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.

Anterior Temporal Approach for Clipping of Upper Basilar Artery Aneurysms: Surgical Techniques and Treatment Outcomes

Upper basilar artery (BA) aneurysms, which consist of basilar tip and BA-superior cerebellar artery aneurysms, are challenging to treat with microsurgical clipping. The anterior temporal approach is one surgical approach used to treat aneurysms in this region. Most previous reports on this approach have consisted of unruptured cases. Assessing mostly ruptured cases in this study, we describe the surgical technique, patient characteristics, and surgical outcomes. Twenty-three patients with aneurysms arising from the upper BA who received aneurysm clipping via an anterior temporal approach between December 2015 and January 2019 were retrospectively evaluated. The location of the aneurysms was the basilar tip in 15 patients (65.2%) and the BA-superior cerebellar artery junction in 8 patients (34.8%). Twenty-one patients (91.3%) presented with subarachnoid hemorrhage. Good outcomes (modified Rankin Scale score 0-2) at 3 months were achieved in 55.6% of all patients and in 80% of good-grade patients (World Federation of Neurosurgical Societies grades I-III) and patients with unruptured aneurysms. For patients with subarachnoid hemorrhage, a good outcome was achieved in 75% of good-grade patients. Postoperative transient oculomotor nerve palsy and thalamic infarctions were detected in 7 patients (30.4%) and 2 patients (8.7%), respectively. With appropriate case selection, the anterior temporal approach was effective and safe for clipping of upper BA aneurysms, especially under subarachnoid hemorrhage conditions.

Impact of the Intracranial Course of Internal Carotid Artery on Optimal Surgical Approach for Posterior Communicating Artery Aneurysms

The anterior temporal approach (ATA) has been reported as suitable for surgical clipping of posteriorly projecting internal carotid artery (ICA) aneurysms. As the ICA follows a variable course, tortuosity of the ICA may affect visualization of the aneurysm. The aim of this study was to investigate the impact of the intracranial course of the ICA and aneurysm projection on surgical approach. Consecutive patients with posterior communicating artery aneurysms treated with clipping at our hospital between May 2015 and April 2018 were retrospectively reviewed. When the transsylvian approach (TSA) could not achieve adequate exposure of the aneurysm, the ATA was subsequently performed. Distance between the ICA and the anterior and posterior clinoid line, angle between the midline and the C1 segment of the ICA, and aneurysm projection were compared between ATA and TSA groups. Of 52 patients (40 ruptured, 12 unruptured), 12 were in the ATA group, and 40 were in the TSA group. Mean ICA-anterior and posterior clinoid distance was significantly shorter in the ATA group than in the TSA group (P= 0.002), and mean midline-C1 angle was significantly larger in the ATA group than in the TSA group (P < 0.0001). The ATA group was associated with a greater frequency of posteriorly projecting aneurysms (12 of 12; 100%) than the TSA group (9 of 40; 22.5%) (P < 0.00001). A low-lying, laterally projecting intracranial ICA and posteriorly projecting aneurysm are predictors of the necessity for the ATA in the surgical clipping of posterior communicating artery aneurysms.

Combined supra-infrasellar approach to pituitary macroadenoma with oculomotor cistern extension: surgical strategy and experience.

Oculomotor cistern extension (OMCE) of pituitary adenoma through the oculomotor triangle may be one of the major characteristics of multi-lobulated adenoma. The OMCE may be hard to remove only through the endonasal approach. We applied the simultaneous combined supra-infrasellar approach to remove pituitary adenoma with relatively large OMCE. Four (7.3%) of 55 consecutive patients with initially operated pituitary macroadenoma (> 10mm) had OMCE. The combined supra-infrasellar approach was adopted in two cases with relatively large OMCE. The simultaneous combined supra-infrasellar approach was performed with the transcranial microscopic transsylvian anterior temporal approach and the nasal endoscopic approach. The medial main mass was removed through the nasal side. The lateral OMCE was also removed through the nasal side by pushing the tumor in the sellar direction from the transcranial side. The oculomotor nerve was confirmed with electrical nerve stimulation. The main medial mass and the OMCE were mostly removed in both cases. Remnant tumor in the cavernous sinus was treated by gamma knife radiosurgery. Endoscopic transsphenoidal removal was performed in the other two cases with relatively small OMCE. Pituitary macroadenomas with OMCE are a newly recognized form of progression with important implications for surgical strategy. The combined supra-infrasellar approach performed with the transcranial microscopic transsylvian anterior temporal approach using electrical nerve stimulation and the nasal endoscopic approach may be useful for this type of multi-lobulated pituitary adenoma.

PCA動脈瘤への手術アプローチの検討

To identify safe and appropriate surgical approaches, we analyzed our experience with posterior cerebral artery (PCA) aneurysms (ANs), and reviewed the literature. We encountered 3 patients with PCA ANs. Two had ruptured ANs, and the third case had an unruptured PCA AN associated with a ruptured anterior communicating artery AN. The locations of the 3 PCA ANs were the P1, P2a, and P2p segments, respectively. All patients had saccular ANs and underwent direct surgery. The anterior temporal approach was selected for the P1 and P2a ANs. For the P2p AN, we initially selected a transchoroidal fissure (trans-CF) approach via the left inferior temporal gyrus. With this approach, exposure of the AN was difficult, as it was located well below the anterior choroidal artery. We then switched to a subtemporal approach intraoperatively to expose the AN. Neck clipping was successful for all the PCA ANs, and there were no complications. P1 and P2a ANs are safely accessed by an anterior temporal approach. A subtemporal approach is suitable for a low-positioned P2p AN; however, a high-positioned P2p and the anterior part of a P3 AN are candidates for a trans-CF approach. The choice of an appropriate surgical approach depends on the segment of the PCA; however, these ANs can be safely treated with direct surgery.

Bypass Revascularization Applied to the Posterior Cerebral Artery

The application of bypass procedures to the posterior cerebral artery (PCA) in combination with proximal clipping or trapping is a useful option for the treatment of complex posterior circulation aneurysms, especially those of the PCA. Because of its course around the midbrain through various cisterns, different approaches are required to access the PCA. The presented study analyzes a retrospective case series of bypass procedures to the PCA to investigate the relevant treatment strategies and their outcomes. Seven patients with bypass procedures to the PCA bypass were analyzed. The location of the aneurysms, approaches, site of anastomosis, bypass patency, pre- and postoperative modified Rankin Scale scores, and transient and permanent morbidity were assessed. Analyzed patients were treated for intracranial aneurysm located on the P2 (n= 3) or P3 (n= 2) of the PCA, bilateral vertebral artery dissecting aneurysm (n= 1) or internal carotid artery-posterior communicating artery aneurysm (n= 1). The following approaches were used: anterior temporal approach (n= 2), anterior temporal approach combined with subtemporal approach (n= 2), combined transpetrosal approach (n= 1), posterior interhemispheric approach (n= 1), and posterior interhemispheric approach with subtemporal approach (n= 1). All bypasses were patent. Permanent morbidity occurred in 2 patients via cognitive dysfunction (n= 1) and hemiparesis (n= 1). Bypass revascularization of the PCA territory is effective for the treatment of complex vascular lesions affecting the posterior circulation. To address the various surgical segments of the PCA, different approaches are required. Combined approaches allow access to the PCA proximal and distal from the lesion.

Oblique Clip Technique via Anterior Temporal Approach for Blood Blister Aneurysm of Distal Portion of Internal Carotid Artery

Blood blister aneurysms (BBAs) of theinternal carotid artery (ICA) are challenging vascular lesions for neurosurgeons because they are fragile and difficult to clip. They are commonly found at the dorsal wall of the ICA. Trapping is an alternative for these lesions, accompanied by vascular reconstruction. However, they are sometimes close to the posterior communicating artery and anterior choroidal artery. A 30-year-old man presented with subarachnoid hemorrhage caused by rupture of a BBA in the right distal ICA. After construction of a high-flow bypass, the BBA was accessed via the standard pterional approach to end only in proximal clipping. Two weeks later, the remnant of the BBA showed a tendency to grow. Therefore, the anterior temporal approach was successfully used to obliterate the BBA using an oblique clip technique under direct inspection of patency of the perforators. The anterior temporal approach to a BBA in the distal ICA is amenable to application of the oblique clip technique, which can provide direct inspection of the perforators emanating from the posteromedial wall of the ICA as well as obliteration of the pathologic wall. Furthermore, less retraction of the frontal lobe is also reasonable for avoidance of premature rupture of a fragile BBA.

A Novel Surgical Approach to Chronic Temporal Headaches.

The targets for the surgical treatment of temporal headaches are the zygomaticotemporal branch of the trigeminal nerve and the auriculotemporal nerve. The former is often accessed by means of an endoscopic brow approach or potentially by laterally extending a transpalpebral incision. An established surgical approach, the Gillies incision, was modified to access the zygomaticotemporal nerve, as it was felt to combine the advantages of the traditional techniques. Nineteen patients underwent zygomaticotemporal nerve decompression and neuroplasty or neurectomy and muscle implantation using this surgical approach. A 3.5-cm incision was made behind the anterior, temporal hairline and the zygomaticotemporal branch of the trigeminal nerve was approached directly, remaining superficial to the deep temporal fascia. Each patient was assessed preoperatively and postoperatively with regard to the frequency, duration, and severity of their symptoms to calculate a Migraine Headache Index score. All evaluations were performed at least 1 year postoperatively. The mean preoperative Migraine Headache Index score was 131.7 and the mean postoperative score was 52 (p < 0.0001). There were no surgical complications. There appeared to be no differences between those patients that had decompression and neuroplasty versus those that underwent neurectomy and implantation, as both groups experienced significant reductions in Migraine Headache Index scores following the procedure. The anterior temporal approach to the zygomaticotemporal nerve is both safe and effective. The advantages of this approach include a hidden scar, the ability to directly manipulate the nerve for transection or preservation, and access to the auriculotemporal nerve through the same incision.

Radical resection of a craniopharyngioma via the extradural anterior temporal approach with zygomatic arch osteotomy.

Background:Though the extradural anterior temporal approach (EDATA) with zygomatic osteotomy is useful, there are only few reports of this approach being used for craniopharyngioma resection. Herein, we report our surgical case series and the technical importance of EDATA for the radical removal of a craniopharyngioma.Methods:We report 7 cases of craniopharyngiomas treated surgically between April 1999 and October 2015. The surgical approaches, clinical presentation, pre and postoperative radiographic examination results, surgical outcomes, and morbidity were analyzed.Results:The mean follow-up period was 89.1 months. The surgical approach was EDATA with zygomatic osteotomy in 4, combined interhemispheric translamina terminalis approach (IHTLA) and trans-sylvian anterior temporal approach (ATA) in 2, and IHTLA in 1 patient. Complete tumor resection was achieved in all cases, without any recurrence during the follow-up period. Transient morbidities were oculomotor nerve palsy in 2, and meningitis and hydrocephalus in 1 patient. There was 1 case of permanent morbidity due to hydrocephalus that needed a ventriculoperitoneal shunt, and 1 case of blindness on the operative side. Visual acuity and visual field improved in 4 cases, showed no change in 2 cases, and deteriorated in 1 case. Though the pituitary stalk was preserved in 2 cases, all 7 cases needed total hormone replacement therapy.Conclusion:EDATA with zygomatic osteotomy ensures sufficient mobility of the internal carotid artery, and provides a good lateral and look up operative view. Hence, it can be used effectively for radical resection of craniopharyngiomas through the opticocarotid space and retrocarotid space.

Technical Description of the Medial and Lateral Anterior Temporal Approach for the Treatment of Complex Proximal Posterior Cerebral Artery Aneurysms

Posterior cerebral artery (PCA) aneurysms are often fusiform and associated with multiple intracranial aneurysms. A bypass procedure in combination with proximal occlusion or aneurysm trapping is considered to be effective for the treatment of patients with complex PCA aneurysms. Because of the deep, narrowed surgical corridor and the surrounding sensitive neuroanatomic structures, microsurgical procedures applied to the PCA are technically demanding. The authors present a technical report of a complex aneurysm formation located at the postcommunicating segment of the PCA (PCA-P2) treated via an anterior temporal approach. A 68-year-old woman had an unruptured PCA-P2 aneurysm formation, which was discovered incidentally. The fusiform aneurysm shape of the distal aneurysm aggravated direct microsurgical and endovascular treatment. After an individual case discussion, the patient underwent a microsurgical clipping of the proximal P2 segment aneurysm and the distal PCA-P2 segment aneurysm was treated by trapping after the application of a superficial temporal artery (STA) to PCA-P2 bypass using an anterior temporal approach. Postoperative computed tomography angiography showed the exclusion of the proximal PCA-P2 aneurysm and an adequate flow from the STA to PCA-P2 bypass to the distal PCA segments. The patient showed a modified Rankin scale of 0 after follow-up at 1 and 3 months. The anterior temporal approach is feasible for the microsurgical management of complex postcommunicating PCA aneurysms and the application of bypass procedures.

Direct Microsurgical Embolectomy for an Acute Distal Basilar Artery Occlusion

Acute basilar artery occlusion is associated with high mortality rates, up to 35%-40%. Early revascularization by intravenous thrombolysis, intra-arterial thrombolysis, and endovascular mechanical embolectomy is considered the best option to date. The objective of this technical report is to present the direct microsurgical embolectomy technique for an acute distal basilar artery occlusion as an urgent life-saving revascularization procedure. A 71-year-old male patient suffered from an acute embolic basilar artery occlusion and became unconscious (Glasgow Coma Scale 4). Computed tomography angiography and MRA revealed the distal basilar artery occlusion along with an increased diffusion-weighted imaging signal in the corresponding territory. After an individual case discussion, the patient underwent a microsurgical embolectomy via a frontotemporal craniotomy and an anterior temporal approach. Intraoperative indocyanine green and postoperative computed tomography angiography revealed complete revascularization of the previously occluded basilar quadfurcation. The patient steadily recovered and was able to walk with assistance after 4 weeks. Microsurgical embolectomy can be an effective treatment option for acute distal basilar artery occlusion in selected cases with experienced surgeons, but a critical preoperative decision-making process is needed.

Localization in the Interpeduncular Cistern as Risk Factors for the Thalamoperforators' Ischemia, Poor Outcome, and Oculomotor Nerve Palsy in Patients with Complex Unruptured Basilar Apex Aneurysm Treated with Neck Clipping

We aimed to evaluate the relationship between aneurysm morphology, thalamoperforators' ischemia, outcome, and oculomotor nerve palsy (ONP) that continued during the follow-up period in 23 patients with complex unruptured basilar apex aneurysms (BAAs) treated with clipping. Aneurysm morphology included the size, distance of neck from the posterior clinoid process, dome projection, and localization in the interpeduncular cistern (LIC). BAAs with neck >4 mm, posterior projection, retro/subsellar, and dome-to-neck ratios <1.2 were considered as complex. The poor outcome was defined as modified Rankin Scale (mRS) 2-6 at the 12 months' follow-up examination. All patients were treated by anterior temporal approach. Size (P < 0.0001) and LIC (P < 0.0001) were related to thalamoperforators' ischemia (n = 3, 13%). Size (P = 0.0010), dividing-posterior communicating artery (P = 0.0050), thalamoperforator's ischemia (P = 0.034), and LIC (P < 0.0001) were related to poor outcome (mRS 2: n = 3, 13%). The mean follow-up period was 368 ± 52 days. No patients developed a bleed and showed evidence of any residual or recurrent aneurysm during follow-up. Postoperative ONP occurred in 15 patients (65%) and all were partial. During follow-up, full recovery of the ONP was seen in 13 patients (57%), and it continued in 2 (8.7%). Size (P = 0.010) and posterior projection (P = 0.043) and LIC (P = 0.0050) were related to continued ONP. The present study suggested that unruptured BAA patients with LIC should be meticulously treated in case of performing clipping because it was related to thalamoperforators' ischemia, poor outcome, and continued ONP.