'I'm not sure how long they can last'

Dr Samer Attar is an orthopaedic surgeon. He lives and works in Chicago but has worked in the city of Aleppo, in Syria, several times. He has just come back from his most recent visit.

He tells Eddie Mair about the difficult decisions he had to make in the underground hospital, with few medical supplies.

(Photo: A man walks through the rubble in Aleppo. Credit: Getty Images)