1	Posterior Lateral Endoscopic Thoracic Discectomy with Laser Thermodiskoplasty John C. Chiu, M.D., FRCS (US), D.Sc. Chief, Neurospine Surgery California Spine Institute, USA President, ISMISS/SICOT President AAMISMS
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3	Overview of This Presentation To discuss posterior lateral endoscopic thoracic discectomy (PETD) with laser thermodiskoplasty Related non-fusion technique Introduction of a triad in surgical approach and denervation of sinu-vertebral nerve to further improve the results of PETD
4	Introduction: In many cases, conservative treatments bring relief: Bed rest Exercise Physiotherapy Pain Medication Spinal injectional treatment (i.e. epidural injection, facet injection, denervation, and nerve blocks)
5	Introduction: Due to tight and confined anatomical relationship of the spinal cord and spinal canal, at thoracic spine, the use of thoracic laminectomy for the treatment of herniated discs has been associated with an unacceptable high rate of neurological morbidity The development of various surgical techniques for treating thoracic disc disease is a sad chapter in the history of neurosurgery with the road “paved with the crosses of the dead” (Harvey Cushing), i.e., paraplegics and others Appropriate surgical technique for treatment of thoracic spinal disease/disc herniation is obvious
6	Introduction: Therefore, spinal surgeons have long sought to find a better procedure to treat thoracic disc herniations effectively and less traumatically The approaches have been traumatic, complicated, and lengthy, including: Posterior lateral approach Lateral approach Trans thoracic approach Trans sternal approach Thoracoscopic endoscopic approach/with collapse of lung Commonly, surgery is not contemplated unless severe symptoms and even cord compression and neurologic deficit are present
7	Material and Methods: Since 1996, 401 patients with 499 herniated thoracic discs (39 extruded) from T-1 through T-12 had PETD with laser thermodiskoplasty, mostly from T7 disc down Males: 252 Females: 149 Age: average 44.9 (16-72) Each failed at least 12 weeks of conservative care PETD is a form of minimally invasive surgical technique (MIST)
8	Demographics of Herniated Thoracic Discs (499)
9	Indications for Surgery: Pain in the thoracic spine, often with pain, numbness and parasthesia of the chest wall due to herniated thoracic disc MRI or CT scan or CT myelogram positive for a fully contained thoracic disc herniation No relief after at least twelve weeks of conservative therapy Positive pre-operative or intra-operative provocative discogram and/or pain provocation disc injection test EMG can be positive Positive 3 Legs of bar stool – symptoms, physical findings and testing (e.g. EMG, imaging and provocative discogram)
10	Surgical Instruments/Equipment: Video digital endoscopic tower Thoracic endoscopes 0°, 6°, 30° and tri-chip digital camera Endoscopic working cannula systems, trephines, rasp, and burs Long and short discectomes, various type of forceps and ronguers
11	Surgical Instruments/Equipment: Mini spinal instruments: Including stylette, dilator , working channels (ID-2.5, 3.5, 4.2mm), forceps, curette, rasp, drill, burr, trephine, discectome, laser probe and thoracic endoscope (ID 2.2mm, OD 3.5mm)
12	Surgical Instruments/Equipment:
13	Surgical Instruments and Equipment:
14	Surgical Instruments/Equipment:
15	Surgical Procedure/Technique:
16	Surgical Procedure/Technique: Selective nerve blocks, epidural block and thoracic facet nerve block Facet arthralgia (medial branch of posterior primary rami) and intra-articular injection Spinal discogenic pain (related to sinu-vertebral nerve)
17	Surgical Procedure/Technique: EEG monitoring with the newest computerized SNAP device (SNAP index or BIS Monitor) improves anesthesia and reduces drug requirement EMG monitoring prevents undue trauma to the spinal nerve to be decompressed
18	Surgical Procedure/Technique:
19	Surgical Procedure/Technique: Posterior lateral endoscopic thoracic discectomy (PETD) surgical approach (mid thoracic)
20	Surgical Procedure/Technique: Incrementally advanced at a 35 – 45 degree angle from the sagital plain toward the center of the disc Through the “safety zone” between the inter-pedicular line and the rib head
21	Surgical Procedure/Technique:
22	Surgical Procedure/Technique: A small 3mm skin incision A thin stylette and a #20 spinal needle are introduced into center of the disc followed by provocative discogram After removal of the needle, a dilator with a working cannula are passed over the stylette The position of the instrument is verified with fluoroscopy Under endoscopy, microdecompressive discectomy with micro-instruments, the discectome and laser Aggressive trephines, drill, burr and laser application are used for removal of osteophyte
23	Surgical Procedure/Technique:
24	Surgical Procedure/Technique Under fluoroscopy, corresponding X-ray photos demonstrate PETD performed with mini spinal instruments
25	Surgical Procedure/Technique: Mechanical decompressive microdiscectomy Herniated disc fragment removal
26	Surgical Procedure/Technique: Mechanical decompressive microdiscectomy Laser thermodiskoplasty for disc shrinkage and tightening
27	Surgical Procedure/Technique
28	Surgical Procedure/Technique
29	Surgical Procedure/Technique
30	Surgical Procedure/Technique Holmium: YAG laser side-fire probe (Trimedyne) is used to ablate (at 500 joules, 10 watts, 10 Hz, five seconds on - five seconds off) To shrink the disc, at a lower level laser energy (300 joules at 5 watts, 10 Hz) To shrink and tighten the disc further (thermodiskoplasty) Then the discetome is used to remove the debris
31	Surgical Procedure/Technique
32	Surgical Procedure/Technique: Surgical technique of LTD, fan sweep maneuver and endoscopic views of disc shrinkage
33	Post Operative Care: Prior to leaving operating room, the patient is checked neurologically An upright portable chest X-ray in the recovery room rules out pneumothorax Immediate ambulation after recovery Discharged in one hour May shower the following day Mild analgesics and muscle relaxant as needed an ice pack is helpful Progressive spine exercise second post operative day on Allowed to return to work in one to two weeks, providing heavy labor not required
34	Post Operative Care: Before and after MISS A physical medicine and rehabilitation unit with computerized assistance Motorized pool and hydro therapy equipped with video camera for monitoring and assessment
35	Surgical Outcome: Average follow-up 45.1months (6-65 months) Overall result: 91% with good to excellent results, fair results 5%, and poor 4% Response to treatment evaluated by using: MacNab, modified Mac Nab criteria, Oswestry disability score/index (ODI), visual analogue pain scale (VAS), patient satisfaction scoring, pain diagram and/or patient target achievement score (PTA) Average satisfaction score – 93.9% 21 patients (5.2%) had mild residual pain and parasthesia, although overall their pain lessened Complication rate: transient dysethesia (less than 1%) Average return to work: 10 days
36	Surgical Outcome:
37	Surgical Outcome: Average follow-up 45.1months (6-67 months) Overall result: 365 (91%) patients with good to excellent results, fair results 20 (5%) patients Response to treatment evaluated by using: MacNab, modified Mac Nab criteria, Oswestry disability score/index (ODI), visual analogue pain scale (VAS), patient satisfaction scoring, pain diagram and/or patient target achievement score (PTA) Average satisfaction score – 378 (94.2%) patients 21 (5.2%) patients had mild residual pain and parasthesia, although overall their pain lessened Complication rate: Transient dysethesia (less than 1%) Average return to work: 10 days
38	Surgical Outcome: Post Endoscopic Thoracic Discectomy – (401 cases)
39	Discussion: To perform a successful percutaneous endoscopic thoracic discectomy, the surgeon should appreciate the surgical anatomy involved and the relationships of the lung, the rib head, the pedicles, the inter-costal nerve and artery, and the spinal cord A probe placed too close to the midline may cause neurologic injury; if too anterior, there may be injury to the major vessels, or the sympathetic chain, and if too laterally, a possible pneumothorax
40	Potential Complications and their Avoidance: Operating wrong level: A major complication of all spine surgery Avoided by using digital C-arm fluoroscopy for accurate anatomic localization Provocative discogram verifies level Dural Tear: Gross dural tear very rare Dural injury evidenced by spinal headache and presumed csf leak (less than 1%) No surgery required to repair a CSF leak Spinal headache responds to epidural blood patch
41	Potential Complications and their Avoidance: Pneumothorax: potential complication for all approaches to thoracic discs Introduction of the micro instruments through the “safety zone” as described previously prevents complication Chest x-ray is obtained immediately after completing the operation to rule out pneumothorax
42	Education and Training for PETD: Thorough knowledge of the surgical anatomy and the surgical procedure Specific PETD training Hands-on experience in a laboratory including cadaveric Meticulous pre-operative surgical planning Working closely with an experienced endoscopic spine surgeon through the steep surgical learning curve Fluoroscopy as “The 3^rd Eye” or “Eye of Wisdom” for confirmation of location of instruments; endoscopy alone is not enough Use of digital imaging system PACS, enhanced 3D visualization
43	Conclusion: Posterolateral endoscopic thoracic discectomy with added thermodiskoplasty is an effective, safe, less traumatic, and less costly surgical treatment for herniated thoracic discs PETD combined with laser thermodiskoplasty with denervation of sinu-vertebral nerve, leads to excellent results and speedier recovery PETD is a smart way to perform thoracic spine surgery
44	Hope you enjoyed this presentation!