Endovascular and microsurgical treatment of superior cerebellar artery aneurysms

Navigating the Rare and Dangerous: Successful Clipping of a Superior Cerebellar Artery Aneurysm Against the Odds of Uncontrolled Hypertension

Background/Objectives: Superior cerebellar artery (SCA) aneurysms are exceedingly rare, posing unique diagnostic and management challenges due to their complex anatomical location within the posterior circulation. The proximity of the SCA to vital structures, such as the brainstem and cerebellum, along with the significant role of poorly controlled hypertension in aneurysm formation, further complicates treatment. This case aims to highlight the surgical approach and management strategies employed in treating a rare SCA aneurysm in a patient with longstanding hypertension. Methods: A 68-year-old female presented with an acute onset of severe headache, nausea, and vomiting, later confirmed to be due to a ruptured SCA aneurysm. The patient's history of poorly controlled hypertension was identified as a major contributing factor to the aneurysm's development and rupture. Due to the aneurysm's wide-neck morphology and irregular shape, microsurgical clipping was selected as the treatment method. The occipito-parietal far-lateral approach was employed to gain optimal access to the aneurysm, minimizing the risk to adjacent neurovascular structures. Results: Microsurgical clipping successfully excluded the aneurysm while preserving the parent artery. The surgical approach enabled precise aneurysm isolation and ensured no postoperative neurological deficits. The patient recovered well, with no significant complications, and hypertension management was emphasized as a vital element of the patient's long-term care. Conclusions: The surgical technique effectively achieved complete aneurysm exclusion with preservation of the parent artery and no associated neurological deficits. The patient's recovery was uneventful, highlighting the efficacy of the approach. Long-term management of hypertension remains a critical component to prevent recurrence and ensure sustained outcomes.

Current research status and future of endovascular treatment for basilar artery aneurysms

Aneurysms occurring along the basilar artery (BA) account for <1% of all intracranial aneurysms. Endovascular treatment (EVT) in particular is recommended for large unruptured BA aneurysms and ruptured BA aneurysms. Given that EVT techniques vary, a detailed review of EVT for BA aneurysms is necessary. In this review, the following issues were discussed: the anatomy and anomalies of the BA, the classification of BA aneurysms, the natural history of BA aneurysms, the status of open surgery, the use of EVT for various types of BA aneurysms and the deployment of new devices. According to the findings of this review and based on our experience in treating BA aneurysms, traditional coiling EVT is still the optimal therapy for most BA aneurysms. However, in some BA aneurysms, flow diverter (FD) deployment can be used. In addition, there are also some new devices, such as intrasaccular flow disruptors and stent-like devices that can be used to treat BA aneurysms. In general, EVT can yield good clinical and angiographic outcomes for patients with BA aneurysms. In addition, recent new devices and techniques, such as new-generation FDs generated via surface modification and virtual reality simulation techniques, show promise for EVT for BA aneurysms. These devices and techniques may further improve EVT outcomes for BA aneurysms.

Dissecting and fusiform aneurysms of the superior cerebellar artery: anatomy, clinical presentation, and treatment outcomes

The management of superior cerebellar aneurysms is still controversial. Although several techniques are available, the deep localization of the lesion and the limited number of cases increase the complexity of decision-making for optimal treatment. Only a few cases of dissecting and fusiform aneurysms of the superior cerebellar artery (SCA) are described in the literature, many of which are without long follow-ups. The study aims to offer an exhaustive retrospective analysis of patients affected by SCA fusiform and dissecting aneurysms treated at our institution from 2008 to 2023, highlighting outcomes and complications. Moreover, a comprehensive narrative review was performed. A total of seven patients were treated at our institution. After a title and abstract screen, fifty-five papers met the criteria for inclusion in the review. In our case series, conservative treatment was proposed as the first therapeutic option in four cases (57.1%), while endovascular treatment (EVT) was in three cases (42.9%). A good recovery was observed in 66% of patients presenting with subarachnoid hemorrhage (SAH), while every patient without SAH achieved a good clinical outcome. A poor outcome was observed only in one patient with a dissecting aneurysm causing SAH, who also suffered a pontine infarction. In the literature review, conservative treatment was proposed as a first therapeutic option in eleven cases (16.6%), open microsurgical techniques in 19 patients (28.8%), and EVT in 31 patients (46.9%). Fatal outcome was documented in five patients (7.5%), all characterized by the rupture of the vascular lesion, while 6.1% of cases had non-fatal poor outcomes.

An Update on the Superior Cerebellar Artery Origin Type

Background and Objectives: The microanatomy of the superior cerebellar artery (SCA) is clinically significant. We, thus, aimed at patterning unilateral and bilateral possibilities of SCA origin. Materials and Methods: In total, 205 archived records of computed tomography and magnetic resonance angiograms were used. There were defined types of SCA origin from the basilar artery (BA): "0"-absent SCA, "1"-preterminal, "2"-collateral SCA, with SCA appearing as a terminal branch of BA, and "3"-SCA from the posterior cerebral artery (PCA) of the cerebral type. Fenestrations and duplications of SCA were recorded. Bilateral combinations of types were recorded as follows: A (1 + 0), B (1 + 1), C (1 + 2), D (1 + 3), E (1 + duplicated SCA), F (2 + 2), G (2 + 3), H (3 + 3), I (3 + duplicated SCA), J (1 + fenestrated SCA). Results: Type 0 SCAs were found in 0.25%, type 1 in 71.29%, type 2 in 19.06%, and type 3 in 9.41%. Absent and fenestrated SCAs were each found in a single case. The most frequent combinations were B (58.05%), C (13.17%) and F (13.17%). Bilateral symmetrical types occurred in 70.7% of cases. Fetal types of PCA and the artery of Percheron modified the BA ends. Combinations of C, F, and G changed the BA ends or tips; thus, different subtypes resulted in five BA bifurcation patterns, including five BA trifurcations and one BA quadrifurcation. BA trifurcation was also found in cases with duplicated SCAs. Conclusions: The SCA has various anatomical possibilities of origin and bilateral combinations that are not presented in anatomical lectures. Details on the specific end of the BA should be gathered on a case-by-case basis.

Endoscopic endonasal transclival clipping of a cerebellar arteriovenous malformation feeding vessel and associated aneurysm; a 2D operative video

Positioned along the ventral surface of the pons, proximal superior cerebellar artery (SCA) aneurysms account for only 1.7% of all intracranial aneurysms [1]. Unlike more commonly encountered basilar artery aneurysms, patients often experience good outcomes when treated via endovascular coiling or surgical clipping [1,2]. These lesions frequently have a lateral projection and paucity of perforator arteries [2]. With further development of endoscopic endonasal techniques, access to this region is possible via a direct frontal exposure to the ventral brainstem, basilar artery and branching vessels. To date, there are only a limited number of reports describing an endoscopic endonasal transclival (EETC) approach for surgical clipping [3-5]. In this operative video, we detail the surgical clipping of a cerebellar arteriovenous malformation feeding vessel and an associated aneurysm using the EETC approach in a 59-year-old woman who presented with sudden onset of a severe headache. The feeding vessel and aneurysm's midline location, just below the take-off of the SCA made it a good candidate for this surgery. Major steps included in this video include 1) transsphenoidal exposure of and subsequent drilling of the clivus, 2) dural opening into the pre-pontine cistern and dissection of the aneurysm, 3) clipping of the aneurysm, and 4) multi-layered closure of the skull base defect. Overall, the patient tolerated the procedure well and was found to have no residual filling of the aneurysm or the AVM feeding vessel at 2-year follow-up. EETC is a viable surgical option for the treatment of aneurysm located along the midline of the pre-pontine cistern.

Management of saccular superior cerebellar artery aneurysms: The Buffalo experience case series and systematic review

BACKGROUND

Results of the management of superior cerebellar artery (SCA) aneurysms are typically reported in combination with those for all posterior circulation aneurysms. We report our experience with the management of SCA aneurysms and a systematic review of the endovascular management of these rare aneurysms.

METHODS

Patients with saccular SCA aneurysms that were not associated with arteriovenous malformations and who presented to our institute between 2000 and 2017 were identified. Patient demographics, aneurysm characteristics, interventions, and follow-up data were collected, compared, and analyzed. For the review, data including number of aneurysm treated, outcomes, follow-up, and occlusion rates were collected.

RESULTS

Mean age of the 31 identified patients was 57.4 ± 12.3 years; 19.4% were men. Mean aneurysm size was 5.1 ± 2.9 mm. Seven of 21 patients with unruptured aneurysms were managed conservatively. Ten patients (32.3%) presented with ruptured aneurysms (mean aneurysm size, 6.2 ± 3.2 mm). Treatment was successfully completed in 22 patients: 13-primary coiling, 7-stent-assisted coiling, and 2-microsurgical clipping. Complete angiographic aneurysm occlusion after primary treatments was achieved in 19 (86.4%) patients. The total complication rate among treated patients was 4.2% (1 of 24 treated aneurysms). No minor complications occurred. However, in 2 patients, coil embolization was attempted but aborted due to coil protrusion into the parent artery. Clinical and angiographic follow-up data were available for 26 observed or treated patients. Mean follow-up duration was 5.3 ± 4.5 years. Six articles met our review inclusion criteria and demonstrated similar mean treated aneurysm sizes ranging from 4.6-7.7 mm, and follow-up from these articles ranged from 15.3-50 months.

CONCLUSIONS

Endovascularly treated patients with ruptured and unruptured SCA aneurysms, of which most were <7 mm, had good clinical outcomes with minimal complications.

Anatomic Risk Factors for S1 Segment Superior Cerebellar Artery Aneurysm Rupture: A Radiologic Study on 81 Consecutive Patients

BACKGROUND

Due to treatment associated risks, it is still debatable which unruptured aneurysm should be treated. Anatomic and morphologic characteristics may aid to predict the rupture risk of superior cerebellar artery (SCA) aneurysm and possibly support in decision- making during treatment.

OBJECTIVES

To identify morphologic characteristics that could predict the rupture of SCA aneurysms.

METHODS

A retrospective analysis of computed tomography angiography images of 81 consecutive patients harboring SCA aneurysm who were treated between 1980 to 2014 at Helsinki University Hospital was performed.

RESULTS

Of the 81 analyzed SCA aneurysms, 30 (37%) were unruptured and remaining 51 (63%) presented with subarachnoid hemorrhage. The mean ± SD size of unruptured SCA aneurysms was 6.2 ± 6.3 mm; mean size of ruptured SCA aneurysms was 5.9 ± 5.4 mm. The mean ± SD aspect ratio was 0.9 ± 0.3 in unruptured and 1.14 ± 0.44 in ruptured SCA aneurysms. The mean ± SD degree angle between basilar artery and aneurysm was 74.7 ± 24.4 in unruptured and 65.9 ± 23 ruptured SCA aneurysms. Patients with ruptured SCA aneurysm showed significantly higher aspect ratio (Mann-Whitney U, P = 0.01) and smaller aneurysm to basilar artery angle (Mann-Whitney U, P = 0.039). Aspect ratio >1.1 had 2.3 times higher risk of rupture (odds ration [OR] 2.3, 95% confidence interval [CI] 0.84-6.34). An aneurysm to basilar angle <70 degrees had 2.8 times higher risk of rupture (OR 2.75, 95% CI 1.086-6.96).

CONCLUSIONS

Ruptured SCA aneurysms are usually small in size. Higher aspect ratio and smaller angle between SCA aneurysm and basilar artery had significantly higher risk of SCA (S1 segment) aneurysm rupture.

Health-related quality of life outcomes and influencing factors in patients with unruptured intracranial aneurysms after endovascular treatment

BACKGROUND

Health-related quality of life (HRQoL) is an important indicator when evaluating prognosis and disease-related treatments. Our current knowledge of the HRQoL outcomes of unruptured intracranial aneurysm (UIA) patients treated by the endovascular intervention appeared to be very limited. To fill this gap, the present study investigated the HRQoL outcomes and identified the influencing factors in UIA patients treated by endovascular intervention.

METHODS

We conducted a single-center cross-sectional study on patients who underwent endovascular treatment for UIAs. HRQoL outcomes were assessed by the 36-item Short Form Health Survey (SF-36). The SF-36 results of the Chinese reference population were used as the reference data. The independent variables with a univariate analysis result of P < 0.05 were included in the multivariate analysis. Finally, multivariable linear regression analysis was performed to identify the factors influencing HRQoL. Bonferroni correction was utilized for multiple testing correction.

RESULTS

A total of 200 patients (83 males and 117 females, mean age of 55.2 ± 9.48 years) with UIAs treated by endovascular intervention were enrolled. The scores of SF-36 in 8 domains for UIA patients treated by endovascular intervention did not all reach the average level of the Chinese reference population after an average recovery period of 30.67 ± 8.6 months. Ischemic cerebrovascular disease history, advanced age, and mRS progression at discharge were independent risk factors of HRQoL for UIA patients treated by endovascular intervention, but physical exercise at least once a week and daily sleep time no < 6 h were independent protective factors.

CONCLUSION

The HRQoL of UIA patients treated by the endovascular intervention was decreased to varying degrees compared with those of the Chinese reference population. The influencing factors of HRQoL explored by this study provide insights for improving the clinical management and daily lives of these patients. HRQoL assessment should be included in future aneurysm prognostic studies to provide better evidence.

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.

Superior Cerebellar Artery Aneurysms Causing Facial Pain: A Comprehensive Review

BACKGROUND

Trigeminal neuralgia caused by superior cerebellar artery aneurysms (TGN-SCAAs) is a rare event without previous analysis.

OBJECTIVE

To describe the features of TGN-SCAA based on 8 cases (7 from literature +1 illustrative case).

METHODS

All cases were thoroughly studied with gathering of their epidemiological, radiological, clinical, therapeutic, and outcome data.

RESULTS

The mean age at diagnosis was 61 yr. Gender distribution showed a female predominance (M: F = 2:6). Side distribution had a left dominance (75%). The aneurysms mean size was 15.4 mm (range: 5-27). All 5 proximal SCAAs (SCA-Basilar junction) presented a lateral-posterior projection, while all 3 distal SCAAs (s2 segment) had variable projections but constant direct trigeminal nerve (TN) contact. No hemorrhage occurred. TGN was the clinical onset in all 8 cases. The most frequent pain distribution was V1-2-3 (n = 3), followed by V1-2 (n = 1) and V1 alone (n = 1). Proximal SCAAs caused TGN through direct TN compression (n = 1), third nerve compression (n = 1), cavernous sinus compression (n = 1), or a combination thereof (n = 2). However, all distal SCAAs caused TGN by direct TN compression (n = 3). Two different treatment options were used: clipping (n = 4) and coiling (n = 4). The post-treatment Barrow Neurological Institute score for pain control was I in all cases (100%). The mRS score was 0 in 75% of cases.

CONCLUSION

TGN-SCAAs are infrequent lesions, characterized by large size, variable TGN mechanisms depending on their anatomic location, and mostly affecting the first and second trigeminal divisions. Both SCAA clipping and coiling were used equally, providing good neurological and pain relief results.

The Superior Cerebellar Artery Aneurysm: A Posterior Circulation Aneurysm with Favorable Microsurgical Outcomes

BACKGROUND

Superior cerebellar artery (SCA) aneurysms are usually grouped with aneurysms that arise from the upper basilar artery or more broadly, the posterior circulation. However, the SCA aneurysm has distinctive anatomy that facilitates safe surgical management, notably few associated perforating arteries, and excellent exposure in the carotid-oculomotor triangle.

OBJECTIVE

To demonstrate the outcomes of patients treated with microsurgery in a continuous surgical series.

METHODS

Sixty-two patients harboring 63 SCA aneurysms were retrospectively reviewed from a prospectively maintained database, focusing on clinical characteristics, surgical techniques, and clinical outcomes.

RESULTS

Of 31 patients (49%) presenting with subarachnoid hemorrhage, the SCA aneurysm was the source in 16 (25%). Thirty-three aneurysms were complex (52%) and 43 patients (59%) had multiple aneurysms. Fifty-seven SCA aneurysms (90.5%) were clipped and 5 were bypassed/trapped or wrapped. Complete angiographic occlusion was achieved in 91.7%. Permanent neurological morbidity occurred in 3 patients and 3 patients that presented in coma after subarachnoid hemorrhage died. All patients with "simple" aneurysms and without subarachnoid hemorrhage had improved or unchanged modified Rankin scale scores. Overall, outcomes were stable or improved in 82.5% of patients.

CONCLUSION

SCA aneurysms are favorable for microsurgical clipping with low rates of permanent morbidity and mortality. Microsurgery should be considered alongside endovascular techniques as a treatment option in many patients.

Surgical treatment of unruptured distal basilar artery aneurysm: durability and risk factors for neurological worsening

BACKGROUND

Distal basilar artery aneurysms (DBAs) consist of basilar apex and basilar artery-superior cerebellar artery bifurcation (BA-SCA) aneurysms. The authors aimed to investigate clinical and radiological differences between two locations and to evaluate the 12-month surgical outcome in unruptured DBAs.

METHODS

Fifty-six consecutive patients who underwent surgical treatment (37 basilar apex and 19 BA-SCA aneurysms) between April 2012 and February 2016 were retrospectively evaluated. In patients with a preoperative modified Rankin Scale score (mRS) of more than 1, neurological worsening (NW) was defined as an increase in one or more mRS. In patients without symptoms, NW was defined as mRS ≥2.

RESULTS

The mean age of the patient population was 64 ± 9.6 years, and 48 (86%) were female. Mean follow-up period was 2.6 ± 0.94 years. An excellent (mRS 0 to 1) outcome was archived in 31 (55%), 45 (82%), and 48 (87%) patients at 30 days, 6 months, and 12 months, respectively. Clinical and radiological characteristics showed no differences between two locations. One early death (1.8%) and one severe morbidity (1.8%) due to rupture were observed. The postoperative annual rupture rate was 1.4% overall (145 patient-years). After adjustment for age and location, large or giant DBA was related to 30-day and 12-month NW [n = 22 (39%) and n = 6 (11%); p = 0.009 and 0.002, respectively], aneurysm localization in the interpeduncular cistern (LIC) and perforator territory infarction were related to 30-day NW (p = 0.002 and 0.002), and DBA that needed bypass surgery and previously treated recurrent DBA were related to NW at 12 months (p = 0.017 and 0.001). Multivariate analysis showed that LIC was significantly related to perforator territory infarction (p = 0.003).

CONCLUSIONS

Clinical and radiological characteristics were not different between basilar apex and BA-SCA aneurysms; therefore, they should not be discussed separately. To avoid neurological worsening, results of surgical treatment for unruptured DBAs should be improved.

Fusiform Superior Cerebellar Artery Aneurysm Treated with Endovascular Treatment

An aneurysm of the distal superior cerebellar artery (SCA) is a highly rare disease. Fusiform aneurysms of the distal SCA are particularly challenging to treat. Clipping, trapping with or without bypass using microsurgery or endovascular treatment (EVT) were used to treat this condition. We describe the case of fusiform distal SCA aneurysms treated successfully with endovascular coiling with a 3-month follow-up. A 39 year-old male was presented with subarachnoid hemorrhage (SAH) and a 15 mm fusiform aneurysm of the ambient segment of the left distal SCA. EVT for parent artery occlusion and packing of the aneurysm was done. Left sixth nerve palsy appeared after 1 day of EVT. The symptom completely recovered within 1 week of the post-procedural period. No neurological deficit was seen during the clinical 3-month follow-up. EVT of fusiform distal SCA aneurysms with coils is a safe and feasible option to manage this rare condition. However, the treatment options must be carefully selected depending on the neurologic condition, development of collateral circulation, and configuration of the dissection.

Superior Cerebellar Artery Aneurysms, the "Sui Generis" in Posterior Circulation: The Role of Microsurgery in the Endovascular Era

BACKGROUND

Endovascular treatment in the present form has almost taken over the management of posterior circulation aneurysms. However, superior cerebellar artery (SCA) aneurysms are among the few that are said to be surgeon friendly with comparable outcome with microsurgery. This study includes a comparative analysis of the SCA aneurysms treated with microsurgery and endovascular techniques at our institute along with a pooled analysis of available literature on overall outcomes in these 2 forms of treatment.

METHODS

This retrospective study included our patients with SCA aneurysms from 2000 to 2015. Clinical outcomes were assessed by the Glasgow Outcome Scale (GOS) at discharge and modified Rankin Scale (mRS) at follow-up. A literature review was performed for clinical series on SCA aneurysms from 1991 to 2015 describing more than 10 patients for pooled analysis.

RESULTS

Among the 20 patients (microsurgery, 12; endovascular, 8), 66% from microsurgery and 75% from the endovascular arm had good outcomes (GOS score >3 and mRS score <3) (P = 0.54). Microsurgery had an 88.8% complete occlusion rate compared with 75% in endovascular treatment (P = 0.45). Pooled analysis of 12 studies showed that endovascular coiling is significantly associated with good clinical outcome (88.1% vs. 76.9%; P = 0.003). Microsurgery provides better radiologic outcome in terms of complete occlusion rate (90.1% vs. 67.4%; P = 0.0001) and lower recurrence rate (0% vs. 11.8%; P = 0.005).

CONCLUSIONS

Individual series on SCA aneurysms have not proved any outcome benefit of either treatment modality over the other. However, pooled analysis suggests that microsurgery provides complete and sustainable aneurysm occlusion, although with an inferior clinical outcome.

Microsurgical management of aneurysms of the superior cerebellar artery - lessons learnt: An experience of 14 consecutive cases and review of the literature

Objective:

This is a retrospective study from January 2002 to December 2012 analyzing the results of microsurgical clipping for aneurysms arising from the superior cerebellar artery (SCA).

Materials and Methods:

All patients with SCA were evaluated with computerized tomography angiography and/or digital subtraction angiography (DSA) prior to surgery. All patients in our series underwent microsurgical clipping and postoperative DSA to assess the extent of aneurysm occlusion. The Glasgow outcome scale (GOS) and the modified Rankin's scale (mRS) were used to grade their postoperative neurological status at discharge and 6 months, respectively.

Results:

Fourteen patients had SCA aneurysms (ruptured-9, unruptured-5). There were 10 females and 4 males with the mean age of 47.2 years (median - 46 years, range = 24–66 years). Subarachnoid hemorrhage (SAH) was seen in 11 patients. The mean duration of symptoms was 2.5 days (range = 1–7 days). The WFNS score at presentation was as follows: Grade 1 in 10 cases, II in 2 cases, III in 1 case and IV in 1 case. In the 9 cases with ruptured SCA aneurysm, average size of the ruptured aneurysms was 7.3 mm (range = 2.5–27 mm, median = 4.9 mm). The subtemporal approach was used in the first 7 cases. The extradural temporopolar (EDTP) approach was used in the last 5 cases. Complications include vasospasm (n = 6), third nerve palsy (n = 5) and hydrocephalus (n = 3). Two patients died following surgery. At mean follow-up 33.8 months (median - 25 months, range = 19–96 months), no patient had a rebleed. At discharge 9 (64%), had a GOS of 4 or 5 and 3 (21%) had a GOS of 3. At 6 months follow-up, 10/14 (71%) patients had mRS of 0–2, and 2 (14%) had mRS of 5.

Conclusions:

Aneurysms of the SCA are uncommon and tend to rupture even when the aneurysm size is small (<7 mm). They commonly present with SAH. The EDTP approach avoids complication caused by temporal lobe retraction and injury to the vein of Labbe.