An 82-year old patient presented with increase in aortic aneurysmal sac size increase following an EVAR in 2007 (72-years old at time of EVAR). In 2007 he was treated with a first generation Cook Zenith HLB endo-graft for an asymptomatic infra-renal aortic aneurysm measured 6.0 cm in maximum AP. The right internal iliac artery demonstrated a 5.3 cm aneurysm and the left internal iliac artery measured 1.3 cm. Due to his co-morbidities he was deemed unfit for open aneurysmal repair. He underwent simultaneous bilateral internal iliac artery embolization and EVAR which extended in to both external iliac arteries.
The patient was compliant with annual duplex ultrasound surveillance and had been free of any EVAR-related complications or re-interventions, with a nadir diameter of approximately 6.1 cm to 6.3 cm. In 2018, a routine surveillance with duplex ultrasound demonstrated that the aneurysm sac had grown by 0.5 cm (from 6.3 cm to 6.8 cm) and subsequently in 2019, aneurysm sac had grown to maximum AP diameter of 7.3 cm. The patient had been completely asymptomatic.
At time of current presentation his past medical history included ischaemic heart disease with coronary artery bypass graft in 1993 and pacemaker for cardiomyopathy, atrial fibrillation (on warfarin), dyslipidaemia, hypertension, right peripheral vestibulopathy and previous right cerebellar infarct. The CT with arterial phase and delayed phase was reviewed and demonstrated pooling of contrast on the arterial phase posterior in the aneurysmal sac near the right L4 artery orifice, thought to be the feeding artery (Fig. 1). There is further accumulation of contrast on the delayed phase and the left L4 lumbar artery was presumed to be the draining artery. These imaging findings were interpreted as a type 2 endoleak and given the sac expansion an intervention was indicated based on the guidelines from Society for Vascular Surgery (Zhou 2020). With both internal iliac arteries embolised the decision was made to proceed with percutaneous direct sac puncture and subsequent embolisation. After obtaining informed consent and under antibiotic prophylaxis the patient was put prone on the table and cone-beam computed tomography (CBCT, DynaCT Siemens, Erlingen, Germany) was performed. Using landmarks, the perfused part of the aneurysmal sac was punctured with a 20 G needle via a right translumbar approach. Hand runs during breath holds with iodinated contrast were performed. Multiple angiographic runs in various directions showed a network of channels within the partially thrombosed aneurysmal sac however no feeding or draining arteries, in particular no lumbar arteries, were identified (Fig. 2). Further consultation between the Interventional Radiologist and Vascular Surgeon occurred and in consensus the decision was made to embolise the perfused part of the aneurysmal sac. A mixture of Lipiodol (Guerbet, Villepinte, France) and Hystoacryl (B Braun, Rubi, Spain) with a 4:1 ratio was injected under continuous fluoroscopic (roadmap) control. Opacification of the channels was again observed and only after there was a globule of the embolic material apparent within the stent graft lumen the injection was ceased. Up on further imaging it was noted this globule of embolic material had dislodged (Fig. 2). At this stage the needle was removed and the patient put in the supine position. CBCT confirmed the type 3b endoleak with a small amount of embolic mixture within the stent graft lumen at the site of the fabric tear (Fig. 2). Clinical examination revealed bilateral palpable femoral and popliteal pulses. The left dorsalis pedis as well as right dorsalis pedis and posterior tibial had a strong pulse palpable. The patient did not suffer from motor or sensory deficit. Non-target embolization was confirmed with a non-contrast enhanced and CTA on that same day. The embolic material was noted in the right distal posterior tibial artery and dorsalis pedis, left distal and proximal posterior tibial artery as well as the left popliteal artery (Fig. 3). In the absence of any symptoms, it was decided no further intervention was required and strict 3 monthly surveillance for 12 months with continuation of anti-coagulation. No further sac size increase was observed during initial 6-month follow-up.