Selective Endoscopic Discectomy

Used to treat annular tears and herniated discs, this technique developed initially in the 1980s by Parviz Kambin, MD as an arthroscopic discectomy.  Through many refinements, Tony Yeung, MD perfected the technique known as selective endoscopic discectomy, or SED.  The technique is an extremely powerful tool by which both diagnosis and therapy can be achieved. In many cases, SED serves as a minimally invasive alternative to the invasive techniques of open discectomy (which includes microdiscectomy) and spine fusion surgery.  SED includes the following elements:

1. Placement of a needle into the disc from a 45 degree angle to the spine, thereby avoiding the spinal canal

2. Injection of a combination blue dye (which stains herniated and degenerative discs) and iodine dye visible on x-ray.  In most cases, discography with pain provocation is done to show annular tears.

3. Insertion of a wire through the needle, removing the needle, leaving the wire

4. Insertion of a blunt nosed dilator over the wire into the disc    

5. Placement of a portal (cannula) over the dilator into the disc

6. Removal of the dilator and wire

7. Introduction of an endoscope into the disc        

8. Mechanical dissection and removal of the posterior ¼ of the disc through the scope    

9. Use of a laser to further refine the opening in the disc

10. Use of both laser and radiofrequency energy to shrink the collagen next to the annular tears or disc herniation      

11. Exloring the epidural space for disc fragments and removal when necessary   

Decompression of the nerve root can be attained by careful dissection using small forceps:

SED can be used as a diagnostic aid.   

SED Indications:

1. Herniated Discs: Paracentral, Far lateral, Foraminal, Central

2. Annular Tears: Primary, Failed IDET, Above Fusion Sites

3. Foraminal Stenosis

4. Spinal Diagnostics

5.*  Endoscopic artificial nucleus placement

6.*  Disc reconstitution

*Future Uses

Contraindications:

Spinal instability, spinal stenosis with primarily bony encroachment, prior open disc surgery at that level, anatomically inaccessable.

Results:

Internal Disc Derangement/Annular Tears
81% Good-Excellent Outcome
World Congress of Minimally Invasive Spine Surgery Dec 2000
Anthony Yeung, MD

83% Good-Excellent Outcome
South Med J 2000 Sep;93(9):885-90 Marks RA
Transcutaneous lumbar diskectomy for internal disk derangement: a new indication.

Herniated Nucleus Pulposis
88% Success Rate 169 patients
Clin Orthop 1998 Feb;(347):150-67 Arthroscopic microdiscectomy and selective fragmentectomy. Kambin P

89% Success Rate 600 patients
Mt Sinai J Med 2000 Sep;67(4):283-7
Arthroscopic microdiscectomy: an alternative to open disc surgery.

86.4% Success Rate 500 patients
Mt Sinai J Med 2000 Sep;67(4):327-32 he evolution of percutaneous
spinal endoscopy and discectomy: state of the art.
Yeung AT.  Squaw Peak Surgical Facility, Phoenix, AZ, USA

85% Success Rate 49 patients Far Lateral HNP
J Neurosurg 2001 Apr;94(2 Suppl):216-20 Transforaminal percutaneous
endoscopic discectomy in the treatment of far-lateral and foraminal
lumbar disc herniations.   Lew SM, Mehalic TF, Fagone KL..

Advantages of SED over Microdiscectomy/Open Discectomy

*Minimizes scar tissue formation in the epidural space

*Minimizes chances of arachnoiditis development

*Avoids central disc enucleation and biomechanical mass transfer to the annulus thereby lessening the chance of long term disc degeneration due to loss of disc height

*Eliminates multifidus muscle dysfunction as a cause of failed back syndrome

*Does not preclude any open procedure if unsuccessful

*No cutting of bone or sensitive support ligament destruction (PLL)

*Outpatient procedure

*Far less tissue destruction

*Reduces need for fusion

*More rapid return to work (27days SED vs. 48days open discectomy)J Bone Joint Surg Am
1999 Jul;81(7):958-65