This is so that you will not feel, or be aware of the procedure. The simplest form of anesthesia is local anesthesia. The most complex form of anesthesia is general anesthesia. General anesthesia is where you go completely to sleep during the surgical procedure. Special machines breathe for you, monitor your vital signs, and alert the anesthesiologist to any problems while you are asleep.
Most spinal operations require general anesthesia.
A very small number of patients may have problems with general anesthesia. These can be problems due to reactions to the drugs used, problems arising from your other medical problems, and problems due to the anesthesia. Be sure to discuss these complications with your anesthesiologist. This is a common problem following many types of surgical procedures. It is true that these blood clots can also form in certain individuals who have not undergone any recent surgery.