Pseudoaneurysms,
also known as false aneurysms,
are formed when there is a breach in the inner layer of the vessel wall such that blood seeps through it but is contained by the tunica adventitia or the surrounding perivascular soft tissue.
The defect acts as a means of direct communication between the arterial blood flow and the sac of the aneurysm.1,2
Causes of pseudoaneurysms as are listed below1,2:
-
Trauma
-
Iatrogenic (e.g.
arterial catheterisation,
biopsy,
surgery)
-
Spontaneous dissection
-
Fibromuscular dysplasia
-
Regional inflammatory process
-
Vessel injury/erosion due to a tumor: relatively uncommon
-
Vasculitides
Parts to identify are the parent artery,
neck and the sac.
The interventional radiologist has to be aware of which of the two types of pseudoaneurysms the lesion she deals with belongs to.
It could either be3:
The clinical features of pseudoaneurysms depend upon whether they are superficial or visceral in location3,4:
Superficial pseudoaneurysms: Symptomatic patients present with a tender,
pulsatile mass with or without ecchymosis.
A bruit may be auscultated.
If infection ensues,
the triad of fever,
leukocytosis,
and surrounding erythema may also be present.
Visceral pseudoaneurysms: Abdominal pain or discomfort,
vomiting,
diarrhoea,
gastrointestinal bleed,
anaemia or frank shock.
Imaging in pseudoaneurysms:
With the advent of multimodality approach in diagnostic radiology,
it has become imperative for residents to be aware of the imaging appearances of pseudoaneurysms,
the incidence of which is on the rise.
Non-invasive and minimally invasive endovascular procedures are being employed more frequently in an effort to reduce the morbidity associated with invasive surgical repair.