I have bouts of sciatica and when I had my most recent about a month ago, a friend who also suffers suggested I tried tennis balls, or other hardish rubber balls of that size! Slide them/it (depending on if it is both sides or one) under your buttocks to the point where the pain is. (As you have a medical background you may be aware of the piriformis muscle) It opens up the muscles where the nerve is trapped and offers some reasonable relief. Normally I would recommend a type of massage called myofascial release (MFR) as this has worked brillianty for me, but like most massages there are contraindications in the first six weeks after surgery.
I have also used a Tens machine.
Hope it soon passes.