The lining you are referring to is probably the dura mater or dura for short. This is one of the many layers that help protect the brain and spinal cord. The dura also helps provide a tight seal for the cerebrospinal fluid (CSF) that cushions and bathes the brain and spinal cord.
Once the repair or reconstruction has been done the patient must rest. The goal is to reduce pressure against the repair site until healing has gotten a good foothold. For tears in the cervical spine, sitting upright reduces fluid pressure. For the lumbar spine, lying flat is best. It sounds like your wife might be having a lumbar dural repair since she will have to lie still after surgery.
How long does the patient have to stay in the prescribed position? Well, that’s a matter of debate. The old standard was 10 days — until healing took place. Gradually, that has been reduced with the use of medications to one to three days.
But more recent studies have even looked at no bed rest as a possible option with some good results. The surgeon will decide the optimal time for bed rest based on the size and location of the tear as well as the type of surgery done. That’s probably why you haven’t been given an exact time frame. Once the repair has been done, then the surgeon can decide more exactly just what the patient needs.
Be aware that even with a dural repair, the problem can come back. In fact, studies show that five to 10 per cent of all patients who have a dural repair procedure will spring a leak again. The main reason for this is that cerebrospinal fluid can leak out of the suture holes made to thread the stitches through the tissue. Efforts are being made to come up with alternate ways to repair the tear without using sutures.
You will be given instructions including what to watch for that might suggest a leak — headache, nausea, sensitivity to light — and what to do if that happens.