Basilar trunk perforator artery aneurysms. Case report and literature review

Benign versus sinister aetiologies underlying basal cistern subarachnoid haemorrhage: a case series

BACKGROUND

Subarachnoid hemorrhage in the basal cisterns is usually identified on an unenhanced computed tomography scan of the head in patients presenting acutely with a characteristic sudden onset headache.

CASE PRESENTATION

Using imaging examples from our tertiary neurosciences center, we present six cases demonstrating a variety of causes for subarachnoid hemorrhage in the basal cisterns, ranging from benign to sinister causes. These include a venous perimesencephalic hemorrhage (35 years, female), pontine perforator aneurysm (54 years, male), vertebral artery dissection (69 years, male), cervical dural arteriovenous fistula (65 years, male), posterior fossa arteriovenous malformation (45 years, male), and vertebral artery aneurysm (78 years, female). Ethnically, all these patients were white. Specific imaging features are described and demonstrated.

CONCLUSION

A balance between avoiding excessive investigation and overlooking what may be a mimic of a venous perimesencephalic hemorrhage is important. To refine and establish more definitive indications on when to perform computed tomography angiogram, digital subtraction angiography, delayed angiography and magnetic resonance imaging in this context requires future research to focus on large-scale prospective multicenter studies with robust data.

Follow-Up Imaging in Angiography-Negative Spontaneous Subarachnoid Hemorrhage

BACKGROUND

The aim of this study was to assess the diagnostic yield of follow-up investigations in aneurysm-negative subarachnoid hemorrhage (SAH) patients.

METHODS

In 109 (25%) of 435 patients with SAH and initial negative digital subtraction angiography (DSA), the diagnostic yield of repeat DSA and magnetic resonance imaging (MRI) of the brain and craniocervical junction was reviewed.

RESULTS

Of the 109 patients with an initial negative DSA, 51 (47%) had perimesencephalic (PM), 54 (50%) had nonperimesencephalic (NPM) blood distribution, and 4 (3.7%) had computed tomography-negative SAH. A delayed bleeding source was determined in 3 of 82 (3.7%) patients who underwent repeat DSA and in 1 of 5 patients who underwent a third DSA. The bleeding patterns of these patients were all NPM (n = 4). Repeat DSA did not identify a bleeding source in patients with PM-SAH. MRI of the brain and craniocervical junction after 2 days revealed a bleeding source in 1 of 105 patients (1%) in a computed tomography-negative SAH. When all diagnostic modalities, including exploratory craniotomy and MRI of the spinal axis, were considered, the rate of delayed diagnosis of the bleeding source was 6.4% (7/109). In addition to the bleeding pattern, patients with delayed diagnosis of the bleeding source were characterized by worse disease severity parameters, worse radiological grading scales, and more in-hospital complications than patients without delayed diagnosis of a bleeding source.

CONCLUSIONS

The results of this study support the use of repeat DSA in patients with NPM-SAH; however, routine repeat DSA may not be indicated in PM-SAH patients. The routine use of MRI remains controversial.

Two Cases of Subarachnoid Hemorrhage with Microaneurysmal Changes and Spontaneous Disappearance in the Basilar Artery

A 79-year-old woman presented at our hospital with sudden headache and vomiting. Computed tomography revealed diffuse subarachnoid hemorrhage. Although digital subtraction angiography (DSA) performed on admission and on the following day revealed no vascular abnormalities, DSA on Day 22 revealed microaneurysmal changes in the dorsal basilar artery. However, the aneurysmal changes gradually became smaller during follow-up, and DSA on Day 73 revealed complete disappearance. A 53-year-old man also presented to our hospital with sudden headache and vomiting. Computed tomography revealed perimesencephalic subarachnoid hemorrhage. DSA on Days 9 and 16 revealed microaneurysmal changes in the dorsal basilar artery. Conservative treatment was continued, and DSA on Day 42 revealed spontaneous disappearance of the lesion. It has been reported that basilar artery perforating aneurysms cause angiogram-negative subarachnoid hemorrhage, which disappears spontaneously. The fact that lesions previously reported as basilar artery perforating aneurysms may include cases of acute dissection of the main trunk or perforating branches of the basilar artery implies that surgical or endovascular treatment may worsen the condition. Therefore, conservative treatment may be an important option.

Basilar artery perforator aneurysms: a comparison with non-perforator saccular aneurysms

BACKGROUND

Basilar artery perforator aneurysms (BAPAs) are rare. There is no systematic description of their presentation, imaging, natural history and outcomes and how these compare to conventional non-perforator aneurysms. Thus, the authors in this study aimed to compare BAPAs to non-perforator aneurysms.

METHODS

Cases were identified from a prospective neurovascular database, notes and imaging retrospectively reviewed and compared to a consecutive series of patients with non-perforator aneurysms. Blood volume on CT and vessel wall imaging (VWI) were compared to controls.

RESULTS

9/739 patients with aneurysmal subarachnoid haemorrhage (aSAH) harboured BAPAs. Compared to 103 with aSAH from posterior circulation aneurysms, they were more likely to be male (6/9, p = 0.008), but of equal severity (4/9 poor grade, p = 0.736) and need of CSF drainage (5/9, p = 0.154). Blood volume was similar to controls (30.2 ml vs 26.7 ml, p = 0.716). 6/9 BAPAs were initially missed on CTA. VWI showed thick (2.9 mm ± 2.7) bright enhancement (stalk ratio 1.05 ± 0.12), similar to controls with ruptured aneurysms (0.95 ± 0.23, p = 0.551), and greater than unruptured aneurysms (0.43 ± 0.11, p < 0.001). All were initially managed conservatively. Six thrombosed spontaneously. Three grew and had difficult access with few good endovascular options and were treated through a subtemporal craniotomy without complication. None rebled. At 3 months, all presenting in poor grade were mRS 3-4 and those in good grade mRS 1-2.

CONCLUSIONS

Despite their small size, BAPAs present with similar volume SAH, WFNS grade and hydrocephalus to other aneurysms. They are difficult to identify on CTA but enhance strikingly on VWI. The majority thrombosed. Initial conservative management reserving treatment for growth was associated with no rebleeds or complications.

Micro-guidewire electrocoagulation for the treatment of intracranial aneurysms that are inaccessible by microcatheterization: a case series and review of the literature

BACKGROUND

The use of traditional endovascular techniques for aneurysms that are difficult to catheterize is challenging. We present our experience of using micro-guidewire electrocoagulation for the treatment of aneurysms that were inaccessible by a microcatheter.

METHODS

Seven consecutive patients who underwent endovascular electrocoagulation for the treatment of aneurysms between January 2020 and May 2022 were retrospectively included. Patient demographics, treatment procedures, and follow-up outcomes were assessed. A review of the literature was also performed.

RESULTS

All of the seven treated aneurysms were ruptured, and micro-guidewire electrocoagulation was only conducted if the microcatheter could not advance into the aneurysm or parent artery. After electrocoagulation for 1-4 min, all seven aneurysms disappeared on contrast angiography. Parent artery occlusion was observed in six cases, and post-procedure infarctions of the operating region were identified in three patients. The 3-month follow-up modified Rankin Scale score was 0 in all except one patient. Follow-up angiography was available in six patients, and complete obliteration of the aneurysm was observed in all of them. With a mean follow-up time of 13.6 months, there was no rebleeding in any of the cases. To date, there are only eight published cases of aneurysms treated using micro-guidewire electrocoagulation, and seven of them achieved total occlusion of the aneurysm without neurological deficits.

CONCLUSIONS

Endovascular electrocoagulation is practicable and effective for the treatment of aneurysms that are inaccessible by a microcatheter during short-term observation. Studies on larger populations are needed to further confirm the safety and long-term outcomes for this technique.

Ruptured Basilar Artery Perforator Aneurysm Definitely Diagnosed with Intraoperative Microsurgical Findings: Case Report and Literature Review

Initial three-dimensional computed tomography and cerebral angiography fail to identify any aneurysm in 20% of cases of subarachnoid hemorrhage. Basilar artery (BA) perforator aneurysms are rare, and approximately 30%-60% were not identified by initial angiography. A 71-year-old male was transferred with a sudden onset of headache and loss of consciousness. Computed tomography demonstrated subarachnoid hemorrhage, but no ruptured aneurysm was detected. Repeat preoperative cerebral angiography indicated a bifurcation aneurysm of the circumflex branch of the superior cerebellar artery perforator, but microsurgical observation identified the BA perforator aneurysm. If the location of the BA perforator aneurysm cannot be clearly identified, as in this case, repeat angiography should be considered, and the treatment strategy should be decided based on a detailed consideration of the site of the aneurysm.

Transpetrosal Approach to a Ruptured Distal Basilar Perforating Artery Aneurysm

Basilar perforating artery aneurysms are rare and underreported vascular anomalies in the cerebrovascular literature. Various open and endovascular treatment approaches can be employed to treat these aneurysms based on several patient- and aneurysm-specific factors. Some authors have even advocated for conservative, nonoperative management. Here, we report a case of a ruptured distal basilar perforating artery aneurysm secured by an open transpetrosal approach. A 67-year-old male presented to our institution with a Hunt-Hess grade 2, modified Fisher grade 3 subarachnoid hemorrhage (SAH). Initial cerebral digital subtraction angiography (DSA) did not identify an intracranial aneurysm or other vascular lesions. However, the patient had a re-rupture event several days after presentation. DSA at this time revealed a posteriorly projecting distal basilar perforating artery aneurysm. Initial attempts with endovascular coil embolization were unsuccessful. Thus, an open transpetrosal approach was taken to gain access to the middle and distal basilar trunk to secure the aneurysm. This case underscores the unpredictability of basilar perforating artery aneurysms and the challenges encountered when considering active treatment. We demonstrate an open surgical approach with an intraoperative video for definitive management after failed attempted endovascular treatment.

Spontaneous subarachnoid hemorrhage caused by ruptured aneurysm of basilar trunk perforator: a case report and literature review

Background

Aneurysm of basilar perforator was rarely reported in the literature. It is difficult to treat due to its small size and deep-seated location. Excessive treatment may cause complications that resulted from ischemic events of parent perforators. Therefore, it is important to make clinical strategy for such patients to improve the prognosis.

Case presentation

One case, who presented as spontaneous subarachnoid hemorrhage, despite the negative result in computed tomography angiography firstly, was diagnosed angiographically as a ruptured aneurysm of the basilar perforator. A good clinical outcome of the case was achieved during the follow-up after conservative observation for 2 months, as well as the disappearance of previous lesion from angiography.

Conclusions

Aneurysm located at perforator of basilar trunk was rare and difficult to treat. Conservative observation for certain cases with periodic angiography follow-up was considered in order to prevent the patients from potential iatrogenic effects.

Ruptured basilar artery perforator aneurysm: a novel mechanism of pure subarachnoid hemorrhage in moyamoya disease. Illustrative case

BACKGROUND

Pure subarachnoid hemorrhage (SAH) in patients with moyamoya disease is a rare occurrence. Three underlying mechanisms have been described previously, except for ruptured aneurysm of the circle of Willis. Herein, the authors describe a novel mechanism: rupture of a perforator aneurysm in moyamoya disease.

OBSERVATIONS

A 51-year-old man experienced sudden onset of severe headache and vomiting. Computed tomography showed diffuse SAH. Digital subtraction angiography (DSA) showed unilateral moyamoya disease without remarkable etiology of SAH. The patient underwent conservative management with antihypertensive agents. The second DSA on day 17 revealed a slow-filling aneurysm emerging from the basilar top perforating artery. The diagnosis of SAH due to unknown origin was changed to ruptured basilar artery perforator aneurysm (BAPA). The third follow-up DSA on day 159 revealed the resolution of BAPA.

LESSONS

In the case of pure SAH, it is crucial to consider the possibility of perforator aneurysms due to hemodynamic stress caused by moyamoya disease. Repeated DSA is essential for detecting the lesion.

Intravascular Wrap for Treatment of Basilar Artery Perforator Aneurysm

Basilar artery perforator aneurysms are very rare and usually present with subarachnoid hemorrhage. High-quality imaging systems with digital subtraction angiography and three-dimensional rotational angiography are crucial for the detection of these posterior circulation vascular lesions, which may still be missed on the initial angiogram. We present the first use of a Flow Re-Direction Endoluminal Device (Microvention, Aliso Viejo, California) for treatment of a ruptured basilar artery perforator aneurysm via snuffbox vascular access and use of cangrelor for antiplatelet management.

Endovascular Therapy for Basilar Arterial Trunk Aneurysms

Background: Although aneurysms rarely occur in the basilar artery (BA) trunk, the majority of those that do are dissection aneurysms. Currently, the mainstream therapy for BA trunk aneurysms is endovascular therapy (EVT), which mainly includes single coiling or conventional low-metal-coverage stent-assisted EVT, but the efficacy remains to be evaluated. Methods: A retrospective study was performed for the patients who were admitted to our institution for BA trunk aneurysms and underwent EVT. A total of 28 patients were collected in this study. Results: The patients were aged 23-71 years (53.7 ± 11.5 years on average); nine were female (32.1%, 9/28), and 19 were male (67.9%, 19/28). The patients were given single coiling or conventional low-metal-coverage stent-assisted EVT. Among the 28 patients, 10 (35.7%, 10/28) developed complications, 90% (9/10) of which were ischemic and 10% (1/10) were hemorrhagic. Among the 28 patients, 5 (17.9%, 5/28) died. The surviving 23 patients (82.1%, 23/28) recovered well. Conclusions: This study found that for BA trunk aneurysms, single coiling or conventional low-metal-coverage stent-assisted EVT still had some risks. The risks are mainly from brainstem ischemia. Therefore, the perforators of the BA trunk must be carefully evaluated and prevented from receiving damage from the EVT procedure. This study also shows that 82.1% of patients recovered well. Therefore, EVT can result in an acceptable prognosis.

Endovascular electrothrombosis: A promising alternative for basilar artery perforator aneurysm treatment

BACKGROUND

Basilar artery perforator aneurysms (BAPAs) are rare. Traditional surgical clipping and endovascular coiling have proven to be challenging. We present three patients treated with endovascular electrothrombosis and describe the characteristics of this new approach.

METHODS

Three patients presented with subarachnoid hemorrhages (SAHs). Cerebral angiography identified BAPAs. Endovascular electrothrombosis was performed after obtaining informed consent. We placed the microwire into the sac of the aneurysms through the microcatheter and connected its proximal tip to the Solitaire stent detachment system. Electrothrombosis was conducted using 1.0 mA current.

RESULTS

Two aneurysms were successfully occluded without treatment-related complication. The third one failed and converted to endovascular coiling using a 1.3-F microcatheter. The patient suffered brainstem infarction and finally died of severe SAH. At follow-up, the two patients were neurologically intact and angiography showed total occlusion of both aneurysms.

CONCLUSION

Endovascular electrothrombosis might be a potential alternative to traditional treatment for BAPAs. Close follow-up with caution should be mandatory. More research is needed to confirm its safety and efficacy.

Neurosurgical management of aneurysms of the vertebrobasilar system: increasing indications for endovascular therapy with a continued role for open microneurosurgery

Aneurysms of the vertebrobasilar system remain among the most challenging subsets of aneurysms to treat with an open surgical approach. Since Charles Drake's pioneering work in the 1960s, several advances in microsurgical techniques have improved outcomes and feasibility in the open surgical management of these aneurysms. In parallel, the field of endovascular neurosurgery has provided several safe and effective treatment options. Multiple trials have suggested that endovascular therapy for aneurysms of the vertebrobasilar system is superior to open surgical management in most cases. In some instances, however, open surgical management likely represents a more effective and durable option relative to endovascular therapy. Therefore, continued training of future cerebrovascular specialists in open surgery of vertebrobasilar aneurysms remains crucial. With widespread utilization of endovascular techniques, however, proper exposure of trainees to such aneurysms is growing increasingly difficult. In this review, we discuss the recent advances in the endovascular management of vertebrobasilar aneurysms while also emphasizing the continued importance of open microneurosurgery in such cases.

Comparison between stenting and conservative management of posterior circulation perforator aneurysms: Systematic review and case series

PURPOSE

Posterior circulation perforator aneurysms (PCPAs) are a rare type of intracranial aneurysms whose natural history and optimal clinical management are still largely unexplored. This study aims to report our experience with treating ruptured PCPAs and to provide a systematic review of the literature to compare the two most established treatment options, endovascular stenting, and conservative management including administration of antifibrinolytic drugs and watchful waiting.

METHODS

We performed a systematic review of the literature following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Major databases were searched for case reports and case report series written in the English language between 1995 and 2020. Additionally, we retrospectively reviewed our stroke center database for cases of ruptured PCPAs between January 2014 and July 2020. Endovascular stenting and conservative treatment were compared using endpoints, including favorable outcome rate (mRS 0-2), occlusion rate, mortality rate, periinterventional complication rate, and re-hemorrhage rate.

RESULTS

We identified 31 patients treated endovascularly using stents and 33 patients treated conservatively, with the administration of antifibrinolytic drugs in 3 of them. Our analysis showed no statistically significant difference between the groups, except for the occlusion rate.

CONCLUSIONS

The optimal management strategy of PCPAs is still unknown, but stenting can be considered as an effective occlusion method with an acceptable complication rate. Preventive ventricular drainage may be necessary due to the high hydrocephalus rate encountered in ruptured PCPAs.

Operative Treatment of a Superior Cerebellar Artery Perforator Dissecting Aneurysm

BACKGROUND AND IMPORTANCE

Superior cerebellar artery (SCA) perforator aneurysms are extremely rare, with only one other case published in the literature. There is no conclusive management strategy for these aneurysms, although endovascular treatment, open surgical treatment with clipping, and antifibrinolytic administration with spontaneous thrombosis have all been discussed.

CLINICAL PRESENTATION

A 61-yr-old male presented with intraventricular hemorrhage (IVH) primarily in the posterior fossa. He was found to have a dissecting left SCA perforator aneurysm lying on the floor of the fourth ventricle. The aneurysm was not amenable to endovascular treatment, and antifibrinolytic therapy failed to spontaneously thrombose the aneurysm. We performed a suboccipital craniotomy and used a supracerebellar transvermian approach to resect the aneurysm. There was total obliteration of the aneurysm on postoperative cerebral angiogram.

CONCLUSION

SCA perforator aneurysms represent an extremely uncommon subset of intracranial aneurysms. The best therapeutic strategy has yet to be definitively proven. When pursuing surgical treatment, the supracerebellar transvermian navigated approach can be a useful and safe option, as described and illustrated in this video.

Ruptured Basilar Artery Perforator Aneurysm: A Case Report and Review of the Literature

Basilar artery perforator aneurysms (BAPAs) are a rare cause of subarachnoid hemorrhage (SAH), and the natural history is still unknown. Herein, we report a case of ruptured BAPA that appeared during the observation period and then spontaneously disappeared; we have also conducted a review of the literature and performed an analysis based on the type of management. This case of BAPA had a unique course, and our observations may help establish a treatment strategy. A 60-year-old man presented with acute diffuse SAH, World Federation of Neurosurgical Societies (WFNS) Grade II and Fisher Grade 3. Initial three-dimensional digital subtraction angiography (DSA) did not show the source of the hemorrhage. DSA performed on day 39 showed a BAPA with a diameter of 3 mm at the posterior surface of the upper third of the basilar artery. Conservative treatment was chosen. DSA performed on day 64 showed complete resolution of the aneurysm. BAPAs are likely pseudoaneurysms, and not saccular aneurysms, caused due to dissection of basilar perforator arteries. BAPAs are often not recognized on initial imaging, and hence, it is necessary to repeat the DSA examination. Considering the relatively high rate of spontaneous resolution, we chose conservative management. When BAPAs enlarge or do not disappear after conservative treatment, additional therapy such as multiple stents should be considered.

A systematic review of non-trunk basilar perforator aneurysms: is it worth chasing the small fish?

BACKGROUND AND PURPOSE

Non-trunk basilar artery perforator aneurysms (BAPAs) are rare intracranial vascular pathologies that have long been underdiagnosed, under-reported, and under-analyzed. We performed a systematic review of the efficacy and safety endpoints between conservative and active treatment approaches for non-trunk BAPAs.

METHODS

Major databases were analyzed for relevant publications between 1995 and 2019. Studies comparing the outcomes between conservative and active treatment approaches such as coiling, stenting, clipping, liquid embolization, and flow diversion were included. Mortality rate, rate of permanent neurological deficit as determined by the modified Rankin Score (mRS), rate of second treatment occurrence, and perioperative complication rate were also assessed.

RESULTS

A total of 24 studies, including 54 patients with 56 non-trunk BAPAs, were included. The mean maximum aneurysm diameter was 2.70 mm (range 1-10). A diagnosis was achieved with the initial DSA in 50.0% (27/54) of the patients. A conservative approach was used in 16 patients while active treatment was used in the other 38. Thirteen of 15 (86.7%) patients in the conservative group and 27/34 (79.4%) in the active treatment group had an mRS score 0-2. A non-significant higher odds of a positive outcome was observed in the conservative group (OR 1.51, 95% CI 0.50 to 4.54). The event-related mortality rate was 3.55% (3/54) with one procedure-related death in the active treatment group.

CONCLUSIONS

In patients with non-trunk BAPAs unamenable to active treatment, conservative approaches may result in acceptable functional outcomes and low morbidity. Small sample sizes and under-reporting of outcomes warrant further study.

Pretruncal Nonaneurysmal Subarachnoid Hemorrhage with Underlying Hemophilia C

BACKGROUND

Pretruncal nonaneurysmal subarachnoid hemorrhage (PNSAH) accounts for 15%-12% of all case of subarachnoid hemorrhage. Its precise etiology is not yet established. Multiple theories and risk factors have been investigated to address the possible cause of this type of hemorrhage including basilar tip dissecting aneurysms, high spinal arteriovenous fistula, venous stenosis/hypertension or venous bleeding. Hereditary coagulopathies and hemophilias have rarely been reported in the literature as a potential cause of PNSAH.

CASE DESCRIPTION

Here, we reported a rare case of PNSAH with negative angiogram and magnetic resonance imaging who was also found to have hemophilia C (factor XI deficiency) confirmed by laboratory investigation. We also included a literature review of hereditary coagulopathies and their role as a possible cause of PNSAH.

CONCLUSIONS

Detailed medical history and physical examination of patients with PNSAH may lead to further hematologic evaluation for this group of patients, as in this case, and may reveal more cases of mild coagulopathy that require treatment.

Basilar artery perforator aneurysms: Report of 9 cases and review of the literature

Basilar perforator artery aneurysms (BAPA's) are an under-recognised cause of sub-arachnoid haemorrhage (SAH). We present our single centre experience of BAPA's and review of the literature. We performed a retrospective review of our prospectively maintained database to identify all BAPA's that presented acute SAH between February 2009 and February 2018. We identified 9 patients (male = 7), each with a single aneurysm, and average age 55 ± 9.7 years. All aneurysms were small, 2.1 ± 0.5 mm (range 1-3 mm). Three aneurysms were not detected on initial angiography. Six aneurysms were treated with flow diversion, 3 were managed conservatively. No repeat haemorrhage occurred in the flow diverted patients. One patient treated conservatively suffered a repeat haemorrhage and died (mRS 6). Follow up imaging (n = 7), at average 5.6 months (range 3-12 months), showed complete occlusion in all the flow-diverted aneurysms and no change in one conservatively managed patient. There was no evidence of perforator infarction on the follow-up post treatment imaging. Clinical follow-up data was available in 8 patients, 6 of whom (75%) had a good outcome (mRS ≤ 2). A high index of suspicion is required to diagnose BAPA. Flow diversion can be used to treat BAPA's with acceptable risk of perforator infarction and low risk of repeat haemorrhage.

Should we treat aneurysms in perforator arteries from the basilar trunk? Review of 49 cases published in the literature and presentation of three personal cases

Basilar trunk perforator artery aneurysms are rare. Their diagnosis and treatment are difficult, controversial, and challenging. Analysis of 52 cases (49 documented in the literature and three personal cases) clearly shows a re-bleeding rate of 15% in patients whose aneurysm has not been occluded and 0% in treated patients ( p < 0.05). The most effective treatment, and the one that presents the least complication, is double-stenting across the basilar trunk.

Posterior circulation perforator aneurysms: a proposed management algorithm

INTRODUCTION

Subarachnoid hemorrhage (SAH) from posterior circulation perforator aneurysms (PCPAs) is rare and its natural history is unknown. Diagnosis may be difficult, acute management is poorly defined, and long-term recurrent SAH rates and clinical outcome data are lacking.

METHODS

We searched our institution's records for cases of PCPA rupture and analyzed patient demographics, Hunt and Hess (HH) grades, diagnostic imaging, management, and clinical outcomes. We conducted telephone interviews to calculate modified Rankin Scale (mRS) scores.

RESULTS

We identified 9 patients (6 male, 3 female) with a ruptured PCPA who presented to the University of Virginia Health System (Charlottesville, VA, USA) between 2010 and 2016. Median and mean ages were 62 and 63 years, respectively. Median HH grade was 3. Seven of nine (78%) PCPAs were angiographically occult on initial imaging and median time to diagnosis was 5 days. Three conservatively managed patients had a mean mRS score of 0.67 (range 0-1) at mean follow-up of 35.3 months. Antifibrinolytic therapy was administered to all conservatively managed patients without thrombotic complication. Six patients receiving endovascular treatment had a mean mRS score of 2.67 (range 0-6) at mean follow-up of 49.2 months. No cases of recurrent SAH were seen in the study.

CONCLUSIONS

The rarity of PCPA has precluded long-term clinical follow-up until now. Our experience suggests low recurrent SAH rates. Until further studies are performed, conservative management, possibly combined with antifibrinolytic therapy, may be a viable treatment with acceptable long-term outcome.

Basilar Perforator Aneurysms: Presentation of 4 Cases and Review of the Literature

OBJECTIVE

Basilar perforator aneurysms (BPAs) are rare lesions that present a therapeutic challenge. We present 4 cases of ruptured BPAs treated either conservatively or by flow diverter deployment and review the literature.

METHODS

Patients (age 78, 59, 53, and 62 years) presented with World Federation of Neurological Societies grade I-IV and Fisher grade 3-4 subarachnoid hemorrhage. Initial angiography results were normal in 3 patients and necessitated a second angiography. BPA diameter was 0.5-3 mm; BPAs were located in the mid-third of the basilar artery in 2 patients and the upper third in 2 patients.

RESULTS

All patients were managed conservatively. One patient experienced rebleeding 10 days after initial ictus, which required the deployment of a flow diverter in the basilar artery. One patient developed a severe spontaneous pontine ischemic stroke with severe quadriparesis and refused further imaging. He was clinically stable at 1-year clinical follow-up. The other 3 patients showed complete resolution of BPAs on control follow-up imaging.

CONCLUSIONS

Ruptured BPAs are rare lesions that may heal spontaneously or be associated with spontaneous ischemic brainstem stroke or rerupture. These lesions can be managed conservatively initially with flow diverter deployment the most suitable therapeutic alternative in selected cases. Larger studies are needed to fully understand the natural history and refine the therapeutic strategy for these lesions.

Yield of Repeat 3D Angiography in Patients with Aneurysmal-Type Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Aneurysmal-type subarachnoid hemorrhage is a serious disease with high morbidity and mortality. When no aneurysm is found, the patient remains at risk for rebleeding. Negative findings for SAH on angiography range from 2% to 24%. Most previous studies were based on conventional 2D imaging. 3D rotational angiography depicts more aneurysms than 2D angiography. The purpose of this study was to evaluate the yield of repeat 3D rotational angiography in patients with aneurysmal-type SAH with negative initial 3D rotational angiography findings and to classify the initial occult aneurysms.

MATERIALS AND METHODS

Between March 2013 and January 2016, 292 patients with SAH and an aneurysmal bleeding pattern were admitted. Of these 292 patients, 30 (10.3%; 95% CI, 7.3%-14.3%) had initial negative 3D rotational angiography findings within 24 hours. These patients underwent a second 3D rotational angiography after 7-10 days.

RESULTS

In 8 of 30 patients (26.7%; 95% CI, 14.0%-44.7%) with initial negative 3D rotational angiography findings, a ruptured aneurysm was found on repeat 3D rotational angiography. Three of 8 initial occult aneurysms were very small (1-2 mm), 2 were supraclinoid carotid artery dissecting aneurysms (2 and 8 mm), 2 were small (1 and 3 mm) basilar perforator aneurysms, and 1 was a 3-mm vertebral artery dissecting aneurysm.

CONCLUSIONS

In 10% of patients with aneurysmal-type SAH, initial 3D rotational angiography findings were negative, and in 1 in 4, repeat 3D rotational angiography demonstrated a ruptured aneurysm. Initial occult aneurysms were dissecting aneurysms of perforators or main arteries or were very small (1-2 mm) or both. Our results indicate that repeat 3D rotational angiography is mandatory in patients with initial 3D rotational angiography findings negative for aneurysmal-type SAH.

A dissecting aneurysm of a basilar perforating artery

We report an additional case of a ruptured basilar trunk perforator aneurysm, for which an endovascular treatment was initially planned, but aborted due to the spontaneous regression of the aneurysm. Thus, a conservative management consisting on a close follow-up was decided that confirmed the favorable radiological outcome. Spontaneous regression of such aneurysm should be well-known by neurosurgeons and neuroradiologists in order to prevent the potential iatrogenic effects of the related treatment modalities.

Large basilar perforator pseudoaneurysm: A case report

Basilar perforator aneurysms are rare and a communication between a basilar perforator and a separate pseudoaneurysm cavity is extremely rare. We describe a case presenting with high grade subarachnoid hemorrhage which on further investigation delineated a 2-3 mm dissecting basilar perforator aneurysm communicating superiorly into a contained 6 mm pseudoaneurysm cavity. This case illustrates an unusual neurovascular pathology with low potential for successful endovascular treatment such as coil embolization or intracranial flow diverter stenting. Conservative medical management remains the main stay of treatment for such poor surgical candidates.

Basilar artery perforator aneurysms (BAPAs): review of the literature and classification

Basilar artery perforator aneurysms (BAPAs) are an uncommon subtype of perforating artery aneurysms, with only 18 published cases since their initial description in 1996 by Ghogawala et al To date, there are only seven published cases of ruptured BAPAs treated using endovascular techniques. Given the rarity of these aneurysms, the natural history and ideal approach to treatment has not been established. We describe a new endovascular approach to treating these aneurysms using staged telescoping stents, summarize all published cases of BAPAs, and present a unique classification system to enable future papers to standardize descriptions.

Ruptured basilar artery perforator aneurysms--treatment regimen and long-term follow-up in eight cases

INTRODUCTION

Basilar artery (BA) perforator aneurysms may lead to severe subarachnoid hemorrhage (SAH). The acute management is uncertain. The anatomic approach is challenging both for coiling and clipping, and flow diverter stenting may be dangerous due to the required antiplatelet therapy. We report on our experiences in eight patients.

METHODS

We retrospectively analyzed eight patients with ruptured BA perforator aneurysm, including clinical characteristics, imaging data, treatment regimen, clinical course, and long-term outcome.

RESULTS

Patients presented with major SAH and World Federation of Neurosurgical Societies (WFNS) scores of I in three, II in two, and V in three cases. In four patients, the aneurysm was detected in the initial angiography, in four only in follow-up angiography. Five patients were treated conservatively and three patients had endovascular therapy. In the conservative group, the aneurysm spontaneously thrombosed in three cases. One patient suffered from a re-SAH and stayed permanently dependent due to an associated perforator stroke (modified Rankin Scale (mRS) 5). The remaining four patients recovered well (mRS 0 and 1 in two cases, each) including three patients also exhibiting perforator strokes. Regarding the endovascular group, one parent vessel was an angioma feeder and embolized with Onyx. The second aneurysm spontaneously thrombosed periinterventionally. The third patient underwent coiling. Two parent vessels were occluded postinterventionally, resulting in perforator strokes. Final mRS scores were 0, 2, and 2, respectively.

CONCLUSION

Conservative management of ruptured BA aneurysms might be a first-line treatment option with common spontaneous aneurysm occlusion, low rate of re-SAH, and promising clinical outcome.

The FRED flow-diverter stent for intracranial aneurysms: clinical study to assess safety and efficacy

BACKGROUND AND PURPOSE

Flow-diverter stents are emerging for the endovascular treatment of difficult-to-treat or otherwise untreatable cerebral aneurysms (wide-neck, fusiform, dissecting, blisterlike, or giant). We assessed the clinical safety and efficacy of the Flow-Redirection Endoluminal Device.

MATERIALS AND METHODS

This was an institutional review board-approved single-center observational clinical study in 29 patients with 34 aneurysms elected to be treated by endovascular intervention. After providing informed consent, patients were included according to the following criteria: aneurysm fundus-to-neck ratio <2 or neck diameter >4 mm, fusiform, dissecting, or giant aneurysms. The primary end point for clinical safety was the absence of death, absence of major or minor stroke, and absence of transient ischemic attack. The primary end point for treatment efficacy was complete angiographic occlusion according to the O'Kelly Marotta grading scale immediately after the procedure and at follow-up after 3 and 6 months (O'Kelly Marotta D: complete occlusion).

RESULTS

The Flow-Redirection Intraluminal Device deployment was technically successful in all cases. In 26/29 (89%) of patients, the primary end point of safety was reached; in the 3 remaining patients, 1 disabling ischemic stroke and 2 minor strokes with complete recovery at follow-up were observed. Angiographic (DSA and MRA) and clinical follow-up were available after 3 months in 29/29 (100%) and after 6 months in 25/29 (86%) patients (after 6 months, only MRA follow-up was performed according to our study protocol and institutional standard). At 3-month follow-up, complete occlusion was reached in 19/34 aneurysms (O'Kelly Marotta D: 19/34; 56%). At 6-month follow-up, aneurysm occlusion was complete in 22/30 aneurysms (O'Kelly Marotta D: 22/30; 73%).

CONCLUSIONS

Deployment of the Flow-Redirection Intraluminal Device flow-diverter stent is safe and effective in the treatment of difficult-to-treat or otherwise untreatable intracranial aneurysms.

Treatment of a basilar trunk perforator aneurysm with the pipeline embolization device: case report

BACKGROUND AND IMPORTANCE

Basilar trunk perforator (BTP) aneurysms are rare lesions that pose significant challenges to microsurgical clipping and endovascular coiling. We present the intriguing case of a ruptured BTP aneurysm that was successfully treated with the Pipeline Embolization Device (PED).

CLINICAL PRESENTATION

An elderly woman presenting with subarachnoid hemorrhage was found to have a 1.5-mm aneurysm arising from the proximal portion of a thin midbasilar perforator. The decision was made to treat this aneurysm with flow diversion in an attempt to preserve the patency of the perforator and to avoid the hazards associated with parent vessel trapping. A 3 × 12-mm PED was successfully deployed in the basilar trunk across the neck of the aneurysm, causing stasis in the aneurysm, with continuous flow through the parent vessel. The procedure and postoperative course were uneventful. A follow-up angiogram 2 weeks later showed complete disappearance of the aneurysm with preservation of the patency of the perforator. At the 6-month follow-up, the patient was asymptomatic and remained neurologically intact.

CONCLUSION

We present the first case of a BTP aneurysm treated with the PED. The aneurysm was successfully occluded, and the patency of the feeding vessel was preserved. In light of the limitations of coiling and the hazards associated with microsurgery and parent vessel trapping, the PED may be a valuable option for BTP aneurysms.

Flow diverter stent treatment for ruptured basilar trunk perforator aneurysms

OBJECTIVE

Basilar trunk perforator (BTP) aneurysms are rare. Treatment options traditionally considered for these uncommon lesions have included direct surgery, endovascular therapy, or conservative management. Flow diverters represent a newer therapeutic option for BTP aneurysms but pitfalls and complications are unknown. We describe three patients with BTP aneurysms treated with flow diverter stents.

METHODS

All three patients had ruptured BTP aneurysms and, after loading doses of dual antiplatelet agents, underwent treatment with a flow diverter alone (two patients) or in combination with an intracranial stent (one patient).

RESULTS

Complications directly (two thromboembolic events) or indirectly (one hemorrhage at the external ventricular drain site, probably facilitated by the dual antiplatelet therapy) occurred in all three patients and resulted in permanent morbidity in one case. Imaging follow-up confirmed obliteration in all three patients, and no episodes of rebleeding from the aneurysms were observed at follow-up.

CONCLUSIONS

Flow diverters are effective in obliterating BTP aneurysms. However, given the challenges and complications encountered, especially in patients with ruptured lesions, their use must be carefully weighed against other available therapeutic modalities, including observation.

Spontaneous resolution of perforator aneurysms of the posterior circulation

The authors present the cases of 3 patients with ruptured perforator aneurysms of the posterior circulation. Patients were 39, 55, and 59 years old. None of the patients had relevant past medical or family history. All presented with World Federation of Neurosurgical Societies Grade I and Fisher Grade 2 or 3 subarachnoid hemorrhage. Initial angiography results were normal. A second cerebral angiogram in each case revealed a small (< 3 mm) aneurysm of perforator arteries of the posterior circulation. Patients were successfully managed conservatively. None of the patients developed symptomatic vasospasm, rebleeding, or hydrocephaly. Control angiograms at 3 months showed spontaneous resolution of the aneurysm in all cases. Rupture of perforator aneurysms of the posterior circulation is a rare condition and it may be underdiagnosed because of limitations of imaging techniques. Treatments can lead to complications in highly functional territories and should be considered wisely, especially due to the fact that the causes and natural history of such aneurysms are unknown and spontaneous healing remains a possibility.

Repeated neurovascular imaging in subarachnoid hemorrhage when initial studies are negative

Approximately 15% of patients with non-traumatic subarachnoid hemorrhage have no causative lesion identified on their initial angiogram. We present two patients with non-traumatic subarachnoid hemorrhage with negative initial angiograms who were subsequently found to have small basilar perforator aneurysms on delayed neurovascular imaging. We discuss the possible mechanisms for false negative diagnostic cerebral angiograms. These patients support the current standard of care with repeat angiography in cases of subarachnoid hemorrhage when no causative lesion can be identified on initial neurovascular imaging.