I am going to have a lumbar fusion in a few weeks and have stopped taking Rapamycin several weeks ago. I would like to get perspectives on resuming after surgery and whether it could benefit my recovery or not?
This is a common topic of discussion. Generally there is a risk with rapamycin of reduced wound healing (due to lowered cell growth and division). I recommend you review the past discussions around this topic for a more indepth understanding:
Rapamycin should be stopped for at least 4 months after any major surgery (Including laparoscopic).
It significantly delays wound healing, including the healing of internal structures (Soft tissues, Bones…etc). While externally a surgical incision might appear to have been healed 2-4 weeks after the operation. There is a critical collagen remodeling phase that lasts for months which is extremely important to restore the skin’s and tissue’s original strength. Rapamycin will most definitely interfere with this. Theoretically increasing the likelihood of hernias (especially for abdominal surgeries).
For operations that involve the bones, Theoretically, it might also cause malunion, Non-union of bones, Or make them more prone to future fractures due to inadequate remodeling of the bone. A process that like the skin will take many months.
There is also the increased risk of infection. Both superficial and visceral. The latter can be utterly devastating and life-threatening if it occurs after a spine operation.
The absolute minimum is 4 months for a major operation in my professional opinion. In your case, I would recommend 6 months due to the sensitive nature of the operation site. After that, you can gradually return to your regular dose. But even after that, you should always be vigilant in the future to any sign of infection. Such as fever, especially with new back pain, Or new numbness/anesthesia in your limbs. If any of those occur alone or in combination. Stop rapamycin immediately and go to the emergency department so they can rule out any infection in your spine.
It makes sense, then how long should we stop Rapamycin Before surgery in your opinion? Is 2 weeks washout time long enough or more?
You need approximately 5 half-lives to consider a drug completely cleared. Since Rapa’s HL is about 70 hours. Two weeks is enough to clear the blood from Rapa. However, Rapa can still somewhat inhibit mTOR even after it’s no longer present in the blood.
Hence, I would recommend stopping Rapamycin at least 3 weeks before any surgical operation.