Intracranial pseudoaneurysm

False aneurysms, also known as a pseudoaneurysm, requires all three layers of the arterial wall wall to be disrupted, and integrity of the vessel is only maintained by associated hematoma or surrounding connective tissue ¹⁾.

In true aneurysms, the adventitia is preserved.

Direct communication of blood flow exists between the vessel lumen and the aneurysm lumen through the hole in the arterial wall. The risk of rupture is higher than that of a true aneurysm of comparable size due to poor support of the aneurysm wall and thus false aneurysms generally require treatment.

The extracranial vertebral artery are traditionally believed to be more vulnerable to trauma than intracranial vessels owing to their relatively exposed location within the cervical vertebrae. However, a review demonstrates PICA to be the most common vessel involved, in 54 % of cases ²⁾.

Almost one third of cases were in patients aged under 16. The higher proportion of traumatic aneurysms in children may be due to the paediatric cervical spine and craniocervical junction being relatively mobile, exposing vessels to stretching and shearing forces. The overall young age of presentation across this review (mean age 24) and the male preponderance (75 %) ³⁾ also reflects the higher incidence of trauma in young males.

trauma (dissection or laceration):

In a brachial plexus injury: Progressive deficit is usually due to vascular injuries (pseudoaneurysm, A-V fistula, or expansile clot); these should be explored immediately.

Stroke risk due to carotid artery blunt injury 44 %.

It is an indication for neurosurgical intervention in gunshot wound to the brachial plexus.

iatrogenic (dissection, laceration or puncture), e.g. arterial catheterization (accounts for most cases in this category).

see Internal carotid artery injury after transsphenoidal approach.

biopsy, surgery

spontaneous dissection

fibromuscular dysplasia (dissection)

mycotic aneurysm (inflammatory digestion of the vessel wall)

myocardial infarction (left ventricular false aneurysm)

regional inflammatory process

acute pancreatitis

chronic pancreatitis

vessel injury/erosion due to a tumour: relatively uncommon

vasculitides

Behcet syndrome

giant cell arteritis

Takayasu arteritis

systemic lupus erythematosus

polyarteritis nodosa

penetrating atherosclerotic ulcer

They can involve any arterial segment or even a cardiac chamber. Examples include

aortic pseudoaneurysm: traumatic aortic pseudoaneurysm

femoral artery pseudoaneurysm: relatively common site due to femoral punctures

carotid artery pseudoaneurysm

visceral arterial pseudoaneurysm

hepatic arterial pseudoaneurysm

gastroduodenal arterial pseudoaneurysm

splenic arterial pseudoaneurysm

renal arterial pseudoaneurysm

peripheral arterial (limb) pseudoaneurysm

left ventricular pseudoaneurysm

brachiocephalic artery pseudoaneurysm

Some of the imaging features may be dependent on location.

Ultrasound

Due to the turbulent forward and backward flow, a characteristic yin-yang sign may be seen on colour flow while a “to and fro” pattern may be seen with pulsed Doppler.

CT

hypodense (non-contrated) or hyperdense (contrast-enhanced) smooth walled sac adjacent to an artery, usually with a communication.

In view of the aggressive natural history of posterior circulation traumatic intracranial aneurysm TICA, deSouza et al., recommend that CTA of the head and neck vessels be performed for cases presenting with post-traumatic disproportionate cisternal and or third or fourth ventricular SAH. In the event of initial CTA being negative, repeat CTA and if negative DSA should be performed between 5 to 7 days, with a low threshold for further repeat at 10 days if a traumatic dissection is still suspected. Close monitoring for hydrocephalus and vasospasm is required during hospital admission and significant therapy input is likely to be required post discharge from acute care ⁴⁾.

Common carotid artery pseudoaneurysm.

see Internal carotid artery pseudoaneurysm.

see Superficial temporal artery pseudoaneurysm.

Traumatic pseudoaneurysm.

Full-endoscopic Transforaminal lumbar endoscopic discectomy is based on a puncture technique using a guide needle to reach the target area of the foramen via a percutaneous posterolateral/lateral approach. It may correlate with specific approach-related complications, as exiting nerve root injury.

Panagiotopoulos et al., report the first case of pseudoaneurysm of the lumbar segmental artery secondary to a transforaminal full-endoscopic surgery in the treatment of a lumbar disc herniation. A 39-year-old man underwent left L4-L5 full-endoscopic transforaminal lumbar discectomy for a herniated disc. Three hours after surgery, he experienced acute progressive abdominal pain. An abdomen CT scan showed contrast extravasation in the left paraspinal compartment at L4 vertebral body level. The selective left lumbar angiogram revealed a pseudoaneurysm of a side branch of the left lumbar segmental artery, which was treated by endovascular coiling. The patient made a rapid postoperative recovery without further complications and was discharged 4 days later. This report identifies a rare complication of transforaminal full-endoscopic surgery in the treatment of a herniated lumbar disc. This is the first case of pseudoaneurysm formation of the lumbar artery following a full-endoscopic transforaminal lumbar discectomy ⁵⁾.

see Posterior communicating artery pseudoaneurysm.

With the advances in techniques and materials, endovascular treatment has been an alternative to surgery for the treatment of intracranial pseudoaneurysms. Endovascular procedures include coiling, stent-assisted coiling, occlusion of the parent artery with or without aneurysm, and flow diversion.