INTRODUCTION
Pseudoaneurysms (PSAs) of the internal carotid artery (ICA) and vertebral artery are uncommon lesions. PSAs can occur spontaneously or secondary to trauma, infections, iatrogenic causes or malignancies [
6]. Early diagnosis and management is essential as they may have a potentially lethal course with a very high risk of cerebral thromboembolism and rupture. Presenting symptoms depends on size and location of PSAs along with whether it is ruptured or unruptured. Commonly, these lesions can present as intracranial haemorrhage or infarction. Both surgical and endovascular techniques are available for their management. Lately, endovascular techniques have been proven to have edge over conventional surgical management. It is less invasive and is helpful especially when surgery is contraindicated due to various reasons. Vascular surgeries have a risk of intraoperative fatal haemorrhage and/or major vessel occlusion [
3]. There are neither randomised trial data nor specific guidelines regarding the management of ICA and vertebral PSAs. We describe our experience in the endovascular treatment of ICA and vertebral PSAs secondary to various etiological factors. We also present the management algorithm for ICA PSAs followed at our institute.
MATERIALS AND METHODS
This is an observational study conducted in the department of Neurosurgery, SMS Medical College, Jaipur (Rajasthan) from June 2015 to January 2019. All the patients were followed till June 2019. Pertinent clinical details, digital subtraction angiography (DSA), computed tomography angiography (CTA) data, mode of endovascular intervention and other relevant details were compiled for individual patient after approval from the institutional ethics committee. A total of 14 patients with ICA/vertebral PSAs were identified.
Endovascular techniques
The endovascular techniques chosen were individualized depending upon the anatomy, size and location of the lesion, cross circulation and course of parent artery. But due to lack of universal medical insurance, the financial status of patients also influenced the chosen intervention. Parent artery occlusion was done after testing for cross circulation by balloon occlusion test [
3,
4]. Patients were loaded with dual antiplatelets who underwent stenting. Dual antiplatelets were given for one month followed by lifelong single antiplatelets therapy. Coiling was done using single or double catheter technique, depending upon the size and location of the lesion. Flow diverters were used in two patients [
2,
5]. Following the endovascular treatment check DSA was done in all the cases to evaluate the effectiveness of procedure and patency of the distal circulation.
Outcome and follow up
Patients were followed up routinely and evaluated clinically. Magnetic resonance (MR) angiography/ CTA were done on follow up.
RESULTS
There were total 14 patients consisting of 8 (57.1%) anterior circulation PSAs and 6 (42.9%) posterior circulation PSAs. 10 of the 14 cases (71.4%) were female and only 4 (28.5%) were male with age ranging between 9 years to 65 years. Most of the PSAs were spontaneous in origin; except two cases (14.2%) who had preceding history of trauma (
Table 1).
The most common presenting symptom was headache (n=10). Other common complaints included altered sensorium/loss of consciousness (n=6), vomiting (n=4), hemiparesis (n=1), impaired vision (n=2), ptosis (n=1), spontaneous fall (n=1) and third nerve palsy (n=1). CT scan finding were suggestive of Subarachnoid haemorrhage (SAH) [n=6], intracerebral haemorrhage (ICH) [n=4], mass effect (n=3), intraventricular haemorrhage (n=4) and infarction (n=1).
A variety of endovascular techniques were employed for management of these lesions. Only coiling was done in 8 patients (57.1%) (
Fig. 1), stenting in 2 patients (14.2%) out of which one was stent assisted coiling, parent artery occlusion in 1 patient (7.1%), only glue in a single patient (7.1%) (
Fig. 2) while coiling with glue in 1 patient (7.1%) and flow diverter in 2 patient (14.2%) (
Fig. 3). There was no major procedure related complication except in two patients. One patient expired who had partial occlusion with contrast leakage following stent assisted coiling and other one had 7th nerve palsy secondary to coil migration. Out of total of 14 patients, 11 were under regular follow up (till June 2019) and none of them had experienced recurrence or neurological deficit.
DISCUSSION
The main goals for the treatment of intracranial PSAs are to prevent PSA rupture, embolic events and procedure related neurological deficit. In past PSAs were treated mainly by micro- neurosurgery while nowadays both surgical and endovascular management options are available. With improvement in endovascular skills and availability of newer technology, the endovascular techniques have become the treatment of choice. Depending upon the status of collateral circulation and site of PSA both circulation preserving and parent artery occlusion technique can be used for management of intracranial PSAs. Circulation preserving techniques include coiling of PSA, stenting, stent assisted coiling, balloon assisted coiling and flow diverter placement [
2,
5,
7].
Though it is relatively easy to place stents in extracranial PSAs owing to the straighter course of artery with no side branches, the arteries giving rise to intracranial PSAs are more tortuous giving out branches to vital neurological structures [
3]. The unavailability of soft intracranial stent grafts along with the anatomical factors makes coiling and parent artery occlusion preferred treatment option in intracranial PSAs.
In our series total 10 patients underwent coiling out of which one was stent assisted coiling and one was coiling with glue. Only one patient out of the ten had favourable anatomy for stenting and managed by intracranial stent placement. Parent artery occlusion with trapping may be performed in the patients with adequate collateralisation. In our series, adequate collateral circulation was evident in a single patient who was successfully managed with parent artery occlusion with trapping without incurring new neurological deficit [
1,
4].
Limitations
Even though our study showed consistent results with cure rates and complications similar to that reported in literature, there were few shortcomings in our study. The most important limitation was small sample size with short follow up duration. Another decisive factor was the financial status of patients and its influence on the chosen modality of treatment.
CONCLUSIONS
Although infrequent, intracranial pseudoaneurysms pose significant therapeutic challenges and are associated with considerable morbidity and mortality. Endovascular techniques have become the standard of care with few limitations.