Case report
A patient in her late seventies was incidentally found to have a large infrarenal abdominal aortic aneurysm in 2013 for which she had undergone an uneventful percutaneous endovascular aortic repair with left chimney. She lived alone, remained independent in her activities of daily living and was community ambulant without aid.
She was electively admitted in September 2019 for embolization of a type 2 endoleak by the interventional radiologist. Super selective cannulation of the distal aspect of the iliolumbar branch supplying the nidus with a micro catheter was performed. Embolization was carried out using Onyx® until complete exclusion of the nidus.  This was followed by repeat aortogram which showed complete exclusion of the nidus from right-sided branches.  However, there was continued filling of the nidus from the left lumbar branches.  It was therefore decided to embolise the left side. Post embolization, angiogram showed complete exclusion of the endoleak and the left sided branches supplying the endo leak.
Five hours after the procedure the patient complained of bilateral lower limb weakness and numbness, right more than left. Physical examination revealed lower motor neurone pattern of weakness over bilateral lower limbs, right worse than left (Table 1). Sensation testing revealed normal sensation over left, impaired sensation for right L2 to S1. Proprioception at bilateral big toes were intact. Reflexes were absent in bilateral lower limbs.
Lumbar spinal drain was inserted to decompress the spinal cord to allow more arterial flowas there was concern with spinal cord ischaemia. The patient was started on fluid replacement to maintain the mean arterial pressure above 80mmHg. Urgent CT aortogram followed by MRI thoracolumbar spine were performed. Aortogram showed post interval embolization of bilateral feeding arteries. Onyx material was seen within a branch of the embolised right iliolumbar artery which extends into the spinal canal at the level of L3 and appears to exit at the level of L2. It ran external to the thecal sac. MRI thoracolumbosacral spine showed no abnormal cord signal or restricted diffusion.
She was subsequently admitted for inpatient multidisciplinary rehabilitation. On initial functional assessment, she required moderate assistance for bed mobility and transfer with poor dynamic sitting and standing balance. She did not complain of pain. After 1 month of inpatient rehabilitation, she made some neurological recovery with functional improvement. She had good dynamic sitting balance and was able to transfer under supervision. She can self-propel wheelchair within the ward. However she had poor standing balance and was still unable to ambulate. She was discharged to a sub-acute rehabilitation facility before being discharged home. Please see her functional improvement over time using the Functional Independence Measure (FIM) instrument illustrated in table 1.
Electrophysiology study was performed 12 weeks later showed electrophysiological evidence of an acute right lumbar plexopathy involving the right obturator and femoral nerves, with no evidence of axonal continuity.
She was reviewed in the outpatient clinic 14 weeks later. Neurologically remained largely unchanged for right lower limb, however left lower limb power had further improved to about 4 on manual motor testing. Functionally she had also made slight progression, she was able to walk 25 metres using walking frame with 1 person providing standby assist. However she was still dependent on wheelchair for longer distance ambulation.