Can a intralesional laser treatment be effective after hyaluronidase proved ineffective?

only hyaluronidase helps fillers reverse you can sometimes do RF treatments or inject 5fu to help but in general you have to keep using hyaluronidase till it's gone (sometimes many treatments).  Best, Dr. Emer.

There are no clinical studies on that. 
The options are :
-More Hyaluronidase
-5 FU
-Steroids
-Antibitoics
There are also some anecdotal reports about RF microneedling helping to dissolve threads and stubborn fillers. You might consider it as well. The worst that can happen is that you don't benefit in dissolving the filler but it would help rejuvenate your skin. 
Hope this helps

Depending on the amount used, repeated doses of HA-ase may be needed. International well-regarded consensus papers usually recommend injection of a combination of a steroid and 5-FU as the next step, with addition of antibiotics if there is a possibility of a biofilm / infection. I have seen no papers on use of lasers, although hypothetically a 1064 laser like ClearSilk or LaserGenesis could reduce inflammation +/or infection and a fractional ablative (non-ablative will not work) could be used to deliver medications.