A Comparative Study of Working Portal Placement in AFESS Surgery for Lumbar Spinal Stenosis

A prospective randomized controlled trial comparing working portal placement in assisted full-endoscopic spine surgery (AFESS) unilateral laminotomy with bilateral decompression for lumbar spinal stenosis, using the ipsilateral inferior articular process preservation rate as the primary endpoint - AFESS portal trial

Status

Recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000061276

Enrollment

Registered

2026-04-19

Start date

2026-04-15

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Lumbar spinal canal stenosis

Interventions

Group A (lateral group): Left-sided unilateral laminotomy with bilateral decompression using AFESS. The skin incision center of the working portal is placed 10 mm lateral to the midline on the left si

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: ? Patients scheduled to undergo elective left-sided unilateral laminotomy with bilateral decompression using AFESS for lumbar spinal stenosis at our institution ? Age 20 years or older ?Lumbar spinal stenosis involving 1 to 3 levels at L2/3, L3/4, L4/5, or L5/S1 (central canal stenosis and/or lateral recess stenosis), with concordance between imaging findings and symptoms and judged to require surgery ? Insufficient improvement after conservative treatment, including medication, nerve block, and/or physical therapy ? Able to undergo preoperative CT and MRI and routine postoperative CT evaluation within 4 days after surgery ? Written informed consent obtained

Exclusion criteria

Exclusion criteria: ? Reoperation at the same level ? Cases judged to require concomitant fusion surgery ? Cases with obvious instability (posterior opening angle >10 degrees) or degenerative spondylolisthesis of Meyerding grade II or higher ? Cases with severe ossification of the ligamentum flavum ? Cases in which the main pathology is not degenerative disease, such as infection, tumor, trauma, or cystic lesions ? Cases with marked degenerative scoliosis (Cobb angle >20 degrees), congenital or acquired bony deformity, or severe ossified lesions, in which standardized portal placement is expected to be difficult ? Cases judged inappropriate by the principal investigator

Design outcomes

Primary

Measure	Time frame
Postoperative CT-based preservation rate (%) of the ipsilateral inferior articular process within 4 days after surgery	—

Secondary

Measure	Time frame
Operative time (from skin incision to completion of skin closure), Amount of additional bone resection at the base of the ipsilateral spinous process, VAS for low back pain, VAS for leg pain, ODI, and EQ-5D at 3, 6, and 12 months postoperatively, Perioperative complications (including dural injury, neurologic injury, hematoma, infection, and reoperation), Presence or absence of radiographic instability on plain radiographs at 12 months postoperatively	—

Measure

Time frame

Operative time (from skin incision to completion of skin closure), Amount of additional bone resection at the base of the ipsilateral spinous process, VAS for low back pain, VAS for leg pain, ODI, and EQ-5D at 3, 6, and 12 months postoperatively, Perioperative complications (including dural injury, neurologic injury, hematoma, infection, and reoperation), Presence or absence of radiographic instability on plain radiographs at 12 months postoperatively

—

Countries

Japan

Contacts

Public ContactSadaaki Kanayama

Japan Community Healthcare Organization Osaka Hospital Department of Orthopaedic Surgery

drsada@jewel.ocn.ne.jp06-6441-5451

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026