Table 5.

Summary of the inside-out approach LE-ULBD or PSLD

Key points and rationale of inside -out approach LE-ULBD or PSLD
1. The inside-out approach is identical to the approach in open ULBD from skin incision down to laminotomy at the medial cranial hemilamina to access the spinal canal directly and will be most familiar to spine surgeons. This can flatten the learning curve.
2. Only lateral projection C-arm x-ray views were necessary in inside-out approach which can decrease ionizing radiation exposure.
3. Seven- to 8-mm skin incision was made directly on top of the cranial lamina just lateral to the spinous process to utilize the lateral fatty plane and the landing point was at the spinolaminar junction of the cranial hemilamina. This will further limit muscle injury which may be translated to less postoperative pain.
4. Starting point of laminotomy was at the spinolaminar junction to directly access the spinal canal early in the procedure with piecemeal flavectomy to decompress the ipsilateral spinal root. Early exposure of the lateral margin of the traversing nerve root (inside-out approach) may reduce nerve damage and save facet joint. It allows surgeon to find and protect the neural structure early in the procedure and bony decompression can be done just enough to decompress the nerve root avoiding excessive bone resection.
5. Continuation of semi-circumferential decompression of bone (medial facet and caudal lamina) and ligamentum flavum was guided by the visualized edges of the spinal root and dura. This may limit unnecessary bone resection.
6. Contralateral decompression was done by undercutting the spinous process and the contralateral lamina using a high-speed drill with careful piecemeal removal of the ligamentum flavum.

LE-ULBD, lumbar endoscopic unilateral laminotomy with bilateral decompression; PSLD, percutaneous stenoscopic lumbar decompression.