Options for Failing VP Shunt

[Sammy-I]

I have an 8-year old son who was born with Dandy Walker malformation & hydrocephalus. To date he has had over 10 revisions in the last two years due to shunt (catheter) occlusion.  CT and MRI scans show good communication between the ventricles and opportune areas for catheter placement.  However we experience occlusion usually within 1-2 weeks after the revision.  We have repositioning the occipital insertion point from the right side to left and still have a problem.

It appears a Choroid membrane is lapsing as the fluid drains and eventually occluding the catheter. Also, due to his atypical anatomy, this is exacerbated the catheter positioning.  While midline revision and clearing the ventricles of excess membrane is an option, dur desire is to find a process in lieu of this due to the trauma, neurological risk, and risk of infection.  While we have read of using ultrasound and lasers to clear the holes in the catheter but have not seen anything to address this. Are there other methods/options available to avoid the midline revision?