A case of an endovascularly treated aneurysm
An unusual vascular association with tuberous sclerosis in a young child, and the value of endovascular techniques in paediatric neurosurgery.
A 9 month old boy with the clinical hallmarks of tuberous sclerosis presented to the ophthalmology clinic for evaluation of a lazy right eye. Examination revealed a right third nerve palsy. MRI of the brain demonstrated a right sided 2.2 x 2.0 cm distal ICA aneurysm with mass effect on mesial temporal lobe (figure 1). No evidence of subarachnoid hemorrhage was found. Cerebral angiography further defined the aneurysm to the intra-cavernous portion of the right ICA (figure 2). Delayed filling of the right MCA was noted due to pooling of contrast within the aneurysm dome on right carotid injection.
A temporary balloon test occlusion of the right ICA revealed good blood flow into the right anterior and middle cerebral arteries from the left ICA via the anterior communicating artery. The test occlusion did not correlate with any neurologic deficits. The patient underwent coil embolization of the right internal carotid artery proximal to the site of the aneurysm. Follow-up injections of the right internal carotid artery demonstrated complete occlusion of the intra-cavernous ICA proximal to the site of the aneurysm (figure 3). The patient tolerated the procedure well and the remainder of his hospitalization was without complication. No new neurological deficits were appreciated after the endovascular procedure. The patient’s third nerve palsy was noticeably improved prior to discharge.
At three months follow up, the patient was still doing well neurologically. His extra-ocular movements were full, and his right pupil was still sluggishly reactive to light. CTA demonstrated persistent occlusion of the right ICA with good collateral circulation noted through the anterior communicating arteries and the posterior communicating arteries.
After 6 months the patient, now 15 months old, had a conjugate gaze with complete resolution of right third cranial nerve palsy. MRI/MRA of the brain again demonstrated occlusion of the right internal carotid artery with collateral filling of the right ACA and MCA through the anterior and posterior communicating arteries respectfully. The mass effect from the aneurysm dome had resolved (figure 4). There were no ischemic changes and no evidence of hemorrhage.
Intracranial aneurysms within the pediatric population are rare. Distinctive clinical features, etiology, location, morphology, presentation, and therapeutic outcome have been previously described 1-3, 6-10, along with major differences from aneurysms arising in the adult population. The previously documented association with connective tissue disorders gives some merit to the hypothesis that aneurysms in this population arise, at least in part, secondary to a defect in the vascular wall. Indeed patients with tuberous sclerosis have been documented to have aneurysms arising from extracranial locations, including the abdominal aorta and iliofemoral arteries 11, 12. However, no pathophysiological process has yet been elucidated to account for these associations. The presence of multiple intracranial aneurysms in an adult patient with tuberous sclerosis has also been documented 13. The need for a prospective study to assess the prevalence of intracranial aneurysms in patients with tuberous sclerosis has been previously suggested by Blumenkopf et al in 1985 while reporting the fifth case of intracranial aneurysms and tuberous sclerosis 5, however no such study has been performed to date.
Surgical and endovascular management of pediatric cerebral aneurysms have proven to be the treatment of choice when compared to nonsurgical management in terms of outcome 4, 8. Although the technical aspects of surgical management remain similar to adults, pediatric patients require special attention due to the smaller size of anatomical structures, decreased tolerance to blood loss, temperature changes, and physiological stress making surgery for pediatric aneurysms distinctively challenging in their own right. Alternatively, endovascular management has gained popularity in recent years owing to the advance in technology and technical experience.
The success of both endovascular and surgical management for pediatric cerebral aneurysms has been well documented 1-3, 6, 7, 14. In regards to endovascular management, the primary concern is of durability and the ability to achieve complete obliteration with embolization 6. In our particular case, the option of endovascular intervention was favored secondary to the intracavernous location of the aneurysm. Parent vessel occlusion was opted for in this particular instance because of the brisk cross filling of right ICA and right MCA from a left sided injection. This strategy was also favored because it gave the best chance minimizing the mass effect from the aneurysm dome, which was contributing to our patient’s visual disturbances. In fact, on follow-up evaluation 15 months later, no pupillary abnormalities or CN III palsy was detected on formal ophthalmological evaluation.
The durability of aneurysm management via coil embolization in the pediatric population has been called into question 6. Long-term follow up data for endovascular management is relatively limited due to the recent innovation of this particular technique and infrequent number of pediatric aneurysms in the general population. Most follow up results are composed of case reports from various centers with heterogenous endovascular treatment modalities 7, 14.
1. Huang J, et al. Intracranial aneurysms in the pediatric population: case series and literature review. Surg Neurol. 2005;63:424-32; discussion 432-3.
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11. Moon SB, et al. An abdominal aortic aneurysm in an 8-month-old girl with tuberous sclerosis. Eur J Vasc Endovasc Surg. 2009;37:569-571.
12. Calcagni G, et al. Arterial aneurysms and tuberous sclerosis: a classic but little known association. Pediatr Radiol. 2008;38:795-797.
13. Sabat SB, Cure J, Sullivan J, Gujrathi R. Tuberous sclerosis with multiple intracranial aneurysms: atypical tuberous sclerosis diagnosed in adult due to third nerve palsy. Acta Neurol Belg. 2010;110:89-92.
14. Agid R, Souza MP, Reintamm G, Armstrong D, Dirks P, TerBrugge KG. The role of endovascular treatment for pediatric aneurysms. Childs Nerv Syst. 2005;21:1030-1036.
This case was kindly supplied by Samer K Elbabaa, Michael Raber, and Eren Erdem, from the team at Saint Louis University School of Medicine.