Table 1 Yerdel Classification (2000)
Grade | Characteristic |
|---|---|
Grade 1 | Minimally or partially thrombosed PV where thrombus is mild or confined to < 50% of the lumen with or without extension into the SMV. |
Grade 2 | > 50% occlusion including total occlusion with or without minimal extension into the SMV. |
Grade 3 | Complete thrombosis of both the PV and proximal SMV. |
Grade 4 | Complete thrombosis of the PV and both proximal and distal SMV. |