Massive IVC thrombus in asymptomatic patient - how aggressive should one be ?

A 55 yr old man presented with a large liver abscess which was drained under US guidance. Incidentally he was noted to have a large IVC thrombus extending from renal veins to RA. His hematological and coagulation profile is normal.

There is no lower limb DVT, no ascites or sign of raised IVC pressure . he has been placed on LMWH   Query : should he be aggressively treated with thrombolysis with tPA - IV or catheter directed ?