19th February 2024

A 56-year-old male presents to the acute medical unit after a 5-hour history of sudden loss of power in his legs.

A 56-year-old male presents to the acute medical unit after a 5-hour history of sudden loss of power in his legs. He reported experiencing an acute onset of lower lumbar pain, accompanied by a loss of power in both his legs and bilateral leg pain. He was not involved in any trauma, and there was no preceding neck pain. He has been unable to pass urine since his back pain occurred. 

On examination, he had 2/5 power on both his lower limbs. Reduced sensation was noted in temperature and pain sensation up to the level of L2. Vibration and light touch sensation were normal. PR examination revealed reduced anal tone.

Given the likely diagnosis, which of the following arteries has been occluded?