You are mixing spinal stenosis and epidural scar presence. It is exceedingly rare for scar to fill the entire canal so epidural scar is uncommon to cause central stenosis. Now, if there was previous surgery and an unappreciated preexisting narrowing of a section of the canal (lateral recess or foraminal stenosis), scar can make the nerve symptoms worse and redo surgery can be effective.
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.