An intracranial aneurysm on the feeding artery of a cerebellar hemangioblastoma. Case report

Solid vs. cystic predominance in posterior fossa hemangioblastomas: implications for cerebrovascular risks and patient outcome

BACKGROUND

Hemangioblastomas (HGBs) are highly vascular benign tumors, commonly located in the posterior fossa, and 80% of them are sporadic. Patients usually present with features of raised intracranial pressure and cerebellar symptoms. HGB can be classified as either mostly cystic or solids. Although the solid component is highly vascularized, aneurysm or hemorrhagic presentation is rarely described, having catastrophic results.

METHODS

We identified 32 consecutive patients with posterior fossa HBG who underwent surgery from 2008 through 2020 at our medical center. Tumors were classified as predominantly cystic or solid according to radiological features. Resection was defined as gross total (GTR) or subtotal (STR).

RESULTS

During the study period, 32 posterior fossa HGBs were resected. There were 26 cerebellar lesions and 4 medullar lesions, and in 2 patients, both structures were affected. Predominant cystic tumors were seen in 15 patients and solids in 17. Preoperative digital subtraction angiography (DSA) was performed in 8 patients with solid tumors, and 4 showed tumor-related aneurysms. Embolization of the tumors was performed in 6 patients, including the four tumor-related aneurysms. GTR was achieved in 29 tumors (91%), and subtotal resection in 3 (9%). Three patients had postoperative lower cranial nerve palsy. Functional status was stable in 5 patients (16%), improved in 24 (75%), and 3 patients (9%) deteriorated. One patient died 2 months after the surgery. Two tumors recurred and underwent a second surgery achieving GTR. The mean follow-up was 42.7 months (SD ± 51.0 months).

CONCLUSIONS

Predominant cystic HGB is usually easily treated as the surgery is straightforward. Those with a solid predominance present a more complex challenge sharing features similar to arteriovenous malformations. Given the important vascular association of solid predominance HGB with these added risk factors, the preoperative assessment should include DSA, as in arteriovenous malformations, and endovascular intervention should be considered before surgery.

A Classification for the Anterior Inferior Cerebellar Artery-Subarcuate Artery Complex Based on the Embryological Development

Objective  To hierarchize the anterior inferior cerebellar artery (AICA)-subarcuate artery (SAA) complex's variations in the surgical field. Background  The AICA's "subarcuate loop" (SL) presents multiple variations, closely related to the SAA. AICA-SAA complex's variations may represent major issues in cerebellopontine angle (CPA) surgery. As the spectrum of configurations is originated during the development, a systematized classification was proposed based on the interaction between the petrosal bone and the AICA in the embryonic period. Methods  The variations were defined as follow: Grade 0: free, purely cisternal AICA, unidentifiable or absent SAA; Grade 1: purely cisternal AICA, loose SL, SAA > 3 mm; Grade 2: AICA near the subarcuate fossa, pronounced SL, SAA <3 mm; Grade 3: "duralized" AICA, unidentifiable SAA, or included in the petromastoid canal (PMC); and Grade 4: intraosseous AICA, unidentifiable SAA, or included in the PMC. The classification was applied to a series of patients assessed by magnetic resonance constructive interference in steady state sequence. Surgical examples were also provided. Results  Eighty-four patients were evaluated, including 161 CPA. The proportions found in the gradation remained within the range of previous publications (Grade 0: 42.2%; Grade 1: 11.2%; Grade 2: 35.4%; Grade 3: 10.6%; and Grade 4: 0.6%). Moreover, the degrees of the classification were related to the complexity of the anatomical relationships and, therefore, to the difficulty of the maneuvers required to overcome them. Conclusion  The proposed AICA-SAA complex classification allowed to distinguish and objectify pre- and intraoperatively the spectrum of variations, to thoroughly plan the required actions and instrumentation.

Cavernous Sinus Aneurysm Associated With Cerebellar Hemangioblastoma in an Adult With von Hippel-Lindau Disease

A case of cerebellar hemangioblastoma with von Hippel-Lindau disease and an aneurysm of the cavernous sinus segment of the internal carotid artery is presented here. A 60-year-old woman presented with a cerebellar solid tumor manifesting as headache of 4 months, progressive vomiting, and ataxia of half a month. Four-vessel angiography revealed a high stain mass tumor located in the posterior fossa; an aneurysm on the cavernous sinus segment of the internal carotid artery was demonstrated at the same time. The ipsilateral anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) branches were the main feeding vessels of the hemangioblastoma. The patient underwent left-lateral suboccipital craniectomy to remove the highly vascular hemangioblastoma. Successful total excision of the tumor was demonstrated on postoperative magnetic resonance (MR) images. The unruptured cavernous sinus aneurysm in this case was not on the feeding artery, which was asymptomatic and has not been treated further. The patient was in good condition in 1-year follow-up.

Subarachnoid Hemorrhage Associated with Intratumoral Aneurysm Rupture within a Posterior Fossa Hemangioblastoma: The Importance of Continued Surveillance for Cerebral Vasospasm

Cerebellar hemangioblastomas are rare tumors of the neuraxis. Only seven cases of hemangioblastoma associated with a cerebral aneurysm have been reported. We report a case of a patient who presented with acute onset headache as a result of subarachnoid hemorrhage (SAH) and hydrocephalus. Radiographic workup revealed a hemangioblastoma with an intratumoral aneurysm. Preoperative cerebral angiography was performed for both embolization as well as characterization of the aneurysm. The patient underwent a suboccipital craniotomy for tumor resection. The patient’s postoperative course was unexpectedly complicated by delayed ischemic neurologic deficit secondary to flow-limiting left internal carotid artery vasospasm. We present a case report, review of the literature, and management considerations for patients who present with tumors and an associated ruptured aneurysm.

Coexistence of intracranial aneurysm and hemangioblastoma: A case report and literature review

The association of intracranial aneurysm and hemangioblastoma is extremely rare. This report regards a patient affected by Von Hippel-Lindau syndrome with multiple hemangioblastoma and two intracranial aneurysms, of which one was on a hemangioblastoma feeder vessel and the other on an unrelated vessel. Review of the literature revealed 13 other previously reported cases. Possible mechanisms to explain the association are discussed.

Aneurysm of the posterior meningeal artery embedded within a dorsal exophytic medullary hemangioblastoma: surgical management and review of literature

Hemangioblastomas are World Health Organization (WHO) Grade I neoplasms of the hindbrain and spinal cord, whose management can be complicated by preoperative hemorrhage. We report on a case of a young female in extremis with posterior fossa hemorrhage following rupture of a fusiform posterior meningeal artery aneurysm embedded within a medullary hemangioblastoma. We discuss management options, including operative staging and embolization, and review similar cases of hemangioblastoma associated with aneurysm.

Successful treatment of a ruptured flow-related aneurysm in a patient with hemangioblastoma: Case report and review of literature

Background:

No cerebral aneurysms on the feeder associated with hemangioblastomas that ruptured before resection have been reported. We report a patient with a ruptured flow-related aneurysm associated with cerebellar hemangioblastoma and a tumor feeder treated simultaneously by a single procedure of embolization using N-butyl cyanoacrylate before tumor removal.

Case Description:

A 36-year-old female with a cerebellar tumor was admitted to our institute. Four days later, she suffered a massive subarachnoid hemorrhage mainly in the posterior fossa. Left vertebral angiograms showed an aneurysm on the feeding artery, posterior inferior cerebellar artery. Both the aneurysm and its main feeder were simultaneously treated by a single procedure of embolization using N-butyl cyanoacrylate. Their complete obliteration was confirmed angiographically. Four days after the procedure, we removed the tumor and the embolized aneurysm. The pathological diagnosis was hemangioblastoma and flow-related ruptured aneurysm.

Conclusion:

Cerebral angiography should be performed to rule out vascular abnormalities such as cerebral aneurysms adjacent to the tumor in patients with hemangioblastoma who present with intracranial hemorrhage. We emphasize the usefulness of embolization with N-butyl cyanoacrylate for hemangioblastoma with ruptured feeder aneurysm, by which the aneurysm and the feeder could be simultaneously embolized.

Sequence variations in the von Hippel-Lindau tumor suppressor gene in patients with intracranial aneurysms

BACKGROUND

The rupture of intracranial aneurysms leads to subarachnoid hemorrhage, which is often associated with poor outcome. Preventive treatment of unruptured intracranial aneurysms is possible and recommended. However, the lack of candidate genes precludes identifying patients at risk by genetic analyses. We observed intracranial aneurysms in 2 patients with von Hippel-Lindau (VHL) disease and the known disease-causing mutation c.292T > C (p.Tyr98His) in the VHL tumor suppressor gene. This study investigates whether the VHL gene is a possible candidate gene for aneurysm formation.

METHODS

Patients with intracranial aneurysms admitted to our department between 2006 and 2009 were enrolled. The peripheral leukocyte DNA of 200 patients was investigated for sequence variations in the VHL gene using denaturing high performance liquid chromatography. Peripheral leukocyte DNA of 100 randomly sampled probands was investigated as a control group. The allelic frequencies of sequence variations between both groups were compared using the Fisher exact test.

RESULTS

Fourteen of 200 patients with intracranial aneurysms had sequence variations at 6 different loci in the VHL gene. In contrast, no sequence variations were identified in 100 probands in the control group (P = 0.0062). However, none of the single-sequence variations had a statistically significant difference in the allelic frequencies compared to the control group.

CONCLUSIONS

There is accumulating evidence for a genetic basis of aneurysm development. Our investigations lead to the conclusion that the VHL gene is potentially involved in the formation of intracranial aneurysms in a subset of patients. Additional candidate genes need to be identified in order to develop sensitive genetic screening for at-risk patients.

Clinical presentation and treatment of distal anterior inferior cerebellar artery aneurysms

Aneurysms located at the distal portion of the anterior inferior cerebellar artery (AICA) are rare, and their clinical features are not fully understood. We report the clinical features and management of nine distal AICA aneurysms in nine patients treated during the past decade at Kagoshima University Hospital and affiliated hospitals. Our series includes seven women and two men. Of their nine aneurysms, eight were ruptured and one was unruptured; six were saccular and three were dissecting aneurysms. The most prevalent location was the meatal loop (n = 5) followed by the postmeatal (n = 3) and premeatal segment (n = 1) of the AICA, suggesting hemodynamic stress as an etiology of these distal AICA aneurysms. Of the nine patients, five presented with angiographic features suggestive of increased hemodynamic stress to the AICA and the common trunk of the posterior inferior cerebellar artery, with vertebral artery stenosis, marked laterality, and a primitive hypoglossal artery. We addressed eight aneurysms (eight patients) surgically; one aneurysm in one patient disappeared in the course of 3 months without surgical treatment. Of the eight surgically treated aneurysms, seven were ruptured and one was unruptured, five were clipped via lateral suboccipital craniotomy, two were trapped via lateral suboccipital craniotomy, and one was embolized. Good outcomes were obtained in six of the eight patients who underwent operation (75 %). We consider increased hemodynamic stress attributable to anatomic variations in the AICA and related posterior circulation to be the predominant contributor to the development of distal AICA aneurysms. Direct clipping and trapping yielded favorable outcomes in our series.

A case of ruptured peripheral aneurysm of the anterior inferior cerebellar artery associated with an arteriovenous malformation : a less invasive image-guided transcortical approach

A 47-year-old man presented with a subarachnoid hemorrhage (SAH) and right cerebellar hematoma was referred for evaluation. Cerebral angiography revealed a distal anterior inferior cerebellar artery (AICA) aneurysm associated with an arteriovenous malformation (AVM). Successful obliteration and complete removal of the aneurysm and AVM were obtained using transcortical approach under the guidance of neuronavigation system. The association of a peripheral AICA aneurysm and a cerebellar AVM by the same artery is unique. The reported cases of conventional surgery for this disease complex are not common and their results are variable. Less invasive surgery using image-guided neuronavigation system would be helpful and feasible for a peripheral aneurysm combining an AVM of the posterior fossa in selective cases.

Persistent primitive trigeminal artery aneurysm associated with cerebellar hemangioblastoma. Case report

A 72-year-old man presented with a cerebellar vermian tumor manifesting as headaches and vertigo. Angiography disclosed a vascular tumor fed by the superior cerebellar artery and an aneurysm of a primitive trigeminal artery. The patient underwent right occipital craniotomy to remove the highly vascular tumor via an occipital transtentorial approach. Association of a cerebral aneurysm with a hemangioblastoma has been reported previously in only five cases. Only three aneurysms were located on the feeding artery. The aneurysm in this case was not on the feeding artery. Simple coincidence might account for this case.

Anteroinferior Cerebellar Artery Aneurysms: Surgical Approaches and Outcomes—A Review of 34 Cases

OBJECTIVE:

Anteroinferior cerebellar artery (AICA) aneurysms are rare lesions whose treatment requires expertise in vascular, endovascular, and cranial base surgery. This article presents the largest series treated at one center.

METHODS:

We retrospectively analyzed presenting symptoms, aneurysm characteristics, surgical approaches, postoperative outcomes, and the application of endovascular techniques.

RESULTS:

We found 32 patients with 34 AICA aneurysms (11 men and 21 women; age range, 6–77 yr; mean age, 51 yr). Twenty-one aneurysms had ruptured; 13 were unruptured. Seven of the unruptured aneurysms presented with brainstem compression, and six were found incidentally. Surgical approaches included the retrosigmoid, far-lateral transcochlear, translabyrinthine, and orbitozygomatic. Eighteen patients (56%) had neurological complications. Thirty aneurysms were at proximal locations, and four were distal. Intraoperative hypothermic cardiac arrest was used to clip eight giant aneurysms. Follow-up was available in 56% of the patients for a mean of 41 months. The mean Glasgow Outcome Scale scores at discharge were not significantly different from the patients' status at their initial assessment.

CONCLUSION:

We recommend the standard retrosigmoid approach for treating small to medium aneurysms involving the lower two-thirds of the clivus or distal AICA aneurysms. Cranial base approaches are recommended for large or giant aneurysms or for those proximal to the emergence of the AICA from the basilar trunk. Hypothermic cardiac arrest facilitates dissection of giant aneurysms. Endovascular treatment is a useful adjunct for treating residual aneurysms but did not provide definitive treatment in any of our patients.

Isolated paramedullary hemangioblastoma originating from the first cervical nerve root: case report

STUDY DESIGN

A retrospective case of an isolated paramedullary hemangioblastoma originating from the first cervical root is reported.

OBJECTIVE

To describe an uncommon type of spinal hemangioblastoma and its operative treatment.

SUMMARY OF BACKGROUND DATA

Spinal hemangioblastoma, rare finding accounting for approximately 1.5% to 2.5% of all spinal cord tumors, may have an intramedullary, extramedullary, or extradural location. Cervical hemangioblastomas occur in approximately 45% of the cases and are intramedullary in about 83% of the cases.

METHODS

A 59-year-old man presented with acute subarachnoid hemorrhage in the basal cisterns. Four-vessel angiography showed a highly vascular small tumor at the dorsolateral side of the cervicomedullary junction fed by a branch of the vertebral artery. The lesion was surgically removed.

RESULTS

Total removal of the lesion was achieved after identification of both the arterial feeder and the draining vein with the aid of microvascular Doppler sonography. There were no complications, and the patient did well after surgery.

CONCLUSIONS

Although hemangioblastomas occurring in the cervicomedullary area usually may cause progressive neural compression, occasionally they also can present clinically as acute subarachnoid hemorrhage. This situation requires urgent and adequate treatment as in the reported case.

Distal anterior inferior cerebellar artery aneurysms. Report of four cases

Aneurysms of the distal anterior inferior cerebellar artery (AICA) are rare; fewer than 100 cases have been reported. The authors detail their experience with four cases and present endovascular as well as microsurgical management options. The medical records and neuroimaging studies obtained in four patients who were treated at a single institution were reviewed. Clinical presentations, neuroimaging and intraoperative findings, and clinical outcomes were analyzed. There were three men and one woman; their mean age was 43 years. Two patients presented with acute subarachnoid hemorrhage (SAH), and two presented with ataxia and vertigo (one with tinnitus, the other with hearing loss). Angiographic studies demonstrated aneurysms of the distal segment of the AICA. In one patient with von Hippel-Lindau syndrome and multiple cerebellar hemangioblastomas, a feeding artery aneurysm was found on a distal branch of the AICA. Three of the patients underwent successful surgical obliteration of their aneurysms, one by clipping, one by trapping, and one by resection along with the tumor. The fourth patient underwent coil embolization of the distal AICA and the aneurysm. All patients made an excellent neurological recovery. Patients with aneurysms in this location may present with typical features of an acute SAH or with symptoms referable to the cerebellopontine angle. Evaluation with computerized tomography, magnetic resonance (MR) imaging, MR angiography, and digital subtraction angiography should be performed. For lesions distal to branches coursing to the brainstem, trapping and aneurysm resection are viable options that do not require bypass. Endovascular obliteration is also a reasonable option, although the possibility of retrograde thrombosis of the AICA is a concern.

Aneurysm of the anterior inferior cerebellar artery (AICA) associated with high-flow lesion: report of two cases and review of literature

OBJECTIVE AND IMPORTANCE

Although aneurysms of the anterior inferior cerebellar artery (AICA) are rare lesions, their occurrence in combination with high-flow lesions in the same arterial territory is even more striking. Two cases of an AICA aneurysm in combination with a high -flow lesion are described.

CLINICAL PRESENTATION

In one case, a 52-year-old female presented with cerebellar syndrome as the result of a left-sided cerebellar tumor. Angiography revealed a highly vascularized tumor and a broad-based aneurysm at the offspring of the left AICA. In the second case, a 17-year-old female presented with a right-sided cerebellar hemorrhage. Angiography revealed a large peripheral AICA aneurysm and a distal arteriovenous malformation (AVM) fed by the AICA.

INTERVENTION

In the first case, a left lateral suboccipital craniotomy was performed and a highly vascularized tumor was removed. The AICA aneurysm could not be adequately clipped and was subsequently wrapped with muscle and reinforced with fibrin glue. Pathological examination of the tumor revealed a hemangioblastoma. Five years after surgery, the patient experienced a subarachnoid hemorrhage. Subsequent vertebral angiography revealed local enlargement of the known AICA aneurysm just at the superior aspect, but the patient refused further treatment. In the second case, the patient sustained a novel cerebellar rebleed while awaiting surgery. A right-sided lateral retromastoid suboccipital craniotomy was performed and the AICA aneurysm could be successfully clipped. More peripherally, the AVM with two draining veins could be totally removed. Postoperative angiography revealed no residual aneurysm or AVM.

CONCLUSION

Several aspects of these cases are discussed, such as the rare occurrence of AICA aneurysm and the contribution of high-flow lesions to the genesis of the AICA aneurysms.

Subarachnoid haemorrhage: diagnosis, causes and management

The incidence of subarachnoid haemorrhage (SAH) is stable, at around six cases per 100 000 patient years. Any apparent decrease is attributable to a higher rate of CT scanning, by which other haemorrhagic conditions are excluded. Most patients are <60 years of age. Risk factors are the same as for stroke in general; genetic factors operate in only a minority. Case fatality is approximately 50% overall (including pre-hospital deaths) and one-third of survivors remain dependent. Sudden, explosive headache is a cardinal but non-specific feature in the diagnosis of SAH: in general practice, the cause is innocuous in nine out of 10 patients in whom this is the only symptom. CT scanning is mandatory in all, to be followed by (delayed) lumbar puncture if CT is negative. The cause of SAH is a ruptured aneurysm in 85% of cases, non-aneurysmal perimesencephalic haemorrhage (with excellent prognosis) in 10%, and a variety of rare conditions in 5%. Catheter angiography for detecting aneurysms is gradually being replaced by CT angiography. A poor clinical condition on admission may be caused by a remediable complication of the initial bleed or a recurrent haemorrhage in the form of intracranial haematoma, acute hydrocephalus or global brain ischaemia. Occlusion of the aneurysm effectively prevents rebleeding, but there is a dearth of controlled trials assessing the relative benefits of early operation (within 3 days) versus late operation (day 10-12), or that of endovascular treatment versus any operation. Antifibrinolytic drugs reduce the risk of rebleeding, but do not improve overall outcome. Measures of proven value in decreasing the risk of delayed cerebral ischaemia are a liberal supply of fluids, avoidance of antihypertensive drugs and administration of nimodipine. Once ischaemia has occurred, treatment regimens such as a combination of induced hypertension and hypervolaemia, or transluminal angioplasty, are plausible, but of unproven benefit.

Iatrogenic Rupture of a Cerebral Aneurysm on the Feeding Artery of an Arteriovenous Malformation

We present the case of a patient with acute onset of headache who showed a flow-related acutely ruptured aneurysm on the feeding artery of an AVM in the angiogram. Rerupture of the aneurysm occurred during angiography after endovascular treatment with a Guglielmi detachable coil. The possible mechanisms leading to rupture of the aneurysm are discussed.