After a delay in getting TGA approval, the Xen Gel Sten has finally been approved for use in Australia.
The stent will get prosthesis listing in mid March and should then be available for all to use.
What is the Xen Sten?
In one of my previous postings, I wrote about the Cypass shunt, which became available in Australia late last year. The Cypass shunt is one of a number of MIGS devices of which the Xen stent also belongs.
The main differences are where the stent is placed, the main indication for its use and most importantly, the fact that the Xen stent does not require concomitant cataract surgery. This means that anyone, cataract or not can have this stent.
The Xen stent is used ab interno and unlike the Cypass which drains into the suprachoroidal space, drains subconjunctivally. In this regard, it is in essence, a filtration procedure but without the need to create a scleral flap or a conjunctival dissection.
In some regards it is also like tube surgery as there is a gel stent which drains subconjunctivally.
How is the Xen Stent implanted?
The procedure can be performed with or without cataract surgery. Through a 1.5mm clear corneal incision, the stent is introduced into the anterior chamber, across to the opposite side and inserted through scleral wall to lie externally, subconjunctivally.
Before this is done, Mitomycin C is injected at the exit site to raised the conjunctiva and create space for the stent to drain into. That is essentially all there is to it.
There have been reports of a high rate of Tenon cyst formation however this is not a great problem and can to a large extent be mitigated by needling at the time of the procedure.
Who is this for?
The ideal patient is one who is on maximally tolerated topical therapy and who has exhausted all other pressure lowering means such as SLT
A typical example would be a patient with poorly controlled pressure and possible evidence of worsening visual fields and or progressive rim loss
What is involved?
The procedure is performed as a day case under local anaesthetic. Surgical time is expected to be around 15 minutes
What is the expected outcome?
Most likely better pressure control with a likely reduction in the need for medication and even possibly, a complete cessation of all medications. Like all procedures and treatments however there will always be a spread of outcomes.
What is the cost?
This procedure is covered by Medicare and the health funds. For uninsured patients, the cost is not yet known until the actual cost of the stent is announced