To compare between the clinical and surgical efficacies of bi-portal endoscopic and microscopic decompressive laminectomy in patients with degenerative lumbar spinal stenosis.

Lumbar canal stenosis is a disease caused by the compression of the dural sac and nerve root due to various factors such as hypertrophy of the ligamentum flavum (LF), facet joint hypertrophy, disc herniation, and spondylolisthesis, resulting in low back pain, leg pain with or without numbness, intermittent claudication, and bladder and bowel dysfunction in which intermittent neurogenic claudication is the main feature (1, 2).

Traditional surgical approaches include open laminotomy decompression, foraminotomy, discectomy, and fusion. Conventional open lumbar decompression has a long history and has the advantages of adequate decompression and clear visualization of neural structures, while surgical invasiveness and extensive stripping of paraspinal muscles and soft tissues may lead to a series of problems such as postoperative low back pain, spinal instability, and prolonged hospital stay and time to return to normal life after the operation (3).

Minimally invasive spine surgery has become increasingly popular in recent years. Unilateral bi-portal endoscopy (UBE) was proposed by Heo in 2017 to treat degenerative lumbar spinal diseases with less damage to the paraspinal muscles (4).

Minimally invasive decompression was introduced as a tissue-sparing alternative and applied to lumbar central stenosis. Minimally invasive decompression revealed good clinical outcomes comparable to those of conventional surgery (5, 6). It also showed a reasonable operative time, shorter hospital stay, and reduced blood loss, time to mobilization, postoperative pain, and narcotic use when compared to that seen with conventional surgery (7).

However, it presents some disadvantages, including poor visualization, difficulty of instrument manipulation, potential to induce inadequate decompression, and longer operative time than other minimally invasive surgeries (8).

Inclusion Criteria:

• Patients with acquired degenerative lumbar canal stenosis. Age >40 years. Single or Double level stenosis

Exclusion Criteria:

• Post-traumatic lumbar canal stenosis. Previous spine surgery. Multi-level stenosis more than 2 levels. Associated instability e.g. spondylolisthesis. Spinal diseases (e.g., ankylosing spondylitis, infection, spine tumor, fracture, or neurologic disorders).