Dura is the thin outer lining, covering the spinal cord and nerve roots in the spine. It is continuous with the covering in the brain. The dura keeps the cerebrospinal fluid (CSF) from leaking out. CSF is necessary for the nutrition of the brain, spinal cord, and nerve roots. If it leaks out then it will lead to decreased fluid inside the brain, which can then lead to headaches and in severe cases cause brain stem herniation.
It is exposed during the spine surgeries and can inadvertently be cut or injured during the surgery. Dura may also be incised as a part of the surgery on the spinal cord or nerve roots. In either case, the dural tear needs to be repaired in a watertight fashion to avoid the leakage of the fluid from inside.
Dural repair is performed whenever there is a dural tear: inadvertently or planned. Sometimes, the dural tear may not be evident at the time of surgery and the patient may have symptoms of CSF leakage after the surgery. Such patients are initially treated without surgery by bed rest and fluids along with pain medications. If it does not get better then surgery may be needed to explore the dural tear and repair it.
Dural repair is done by the use of very fine sutures and instruments. The use of magnification by microscope or loop is necessary, a watertight seal is always attempted. The repair is secondarily strengthened by the use of additional synthetic material. Occasionally, a dura may not be repairable. In this case, local or synthetic grafts are needed. Dural repair is checked by performing the Valsalva maneuver with the help of the anesthesiologist.
The patients with dural tear need to be on bed rest. They are gradually weaned out of bed rest to check if they do not develop symptoms of CSF leak in the form of headaches. Most of the patients usually do very well and there is no difference between the recovery of patients with or without a dural tear.
Result and Prognosis
A dural tear is an inadvertent complication of spine surgery. They have repaired primarily or secondary and patients do well after the surgery.