Table 2.

Grade of retroperitoneal extension of acute pancreatitis according to the concept of interfascial planes

Grade	Retroperitoneal extension
I	Fluid confined to the anterior pararenal space or the retromesenteric plane
II	Fluid spreading into the lateroconal or retrorenal plane
II	Fluid spreading into the combined interfascial plane
IV	Fluid spreading into the subfascial plane beyond the interfascial planes
V	Fluid clearly intruding into the posterior pararenal space

Please refer to our previous paper11 for detailed information.