Mnemonic for retroperitoneal organs.

Kids-------Kidneys
Under-----Ureter
Swings----Suprarenal Gland
Are--------Aorta
In----------Inferior Vena Cava
Severe----Sympathetic trunk
Pain-------Pancreas (except tail)
And-------Ascending Colon
Deep------Descending Colon
Danger----Duodenum (segments 2 & 3)