20680
In December 1964 Michael E. DeBakey operated on him in Houston for an aneurysm of the abdominal aorta , and in February 1965 Sir Stewart Duke-Elder treated a detached retina in his left eye .
 Michael E. DeBakey, Houston, aneurysm, Stewart Duke-Elder
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Michael E. DeBakey, Houston, aneurysm, Stewart Duke-Elder