Thoracoscopic Vertebral Body Tethering (VBT)
Dr. Aaron Wey · pediatric AIS, motion-preserving growth modulation
CPT 0656T/0657T (anterior VBT, initial / each addl). Implant: The Tether™ (ZimVie / Zimmer Biomet Spine), HDE — skeletally immature AIS, major Cobb 30–65°, failed/intolerant bracing.
System detail per The Tether Surgical Technique Guide; confirm tray name/catalog at new SPD.
Attire
Size 8 gloves — Biogel underneath + size 8 white gloves on top
Size XL gown ×3
Anesthesia / airway
GA with single-lung ventilation — double-lumen ETT (or bronchial blocker) for thoracoscopic exposure. Arterial line; large-bore access; type & screen.
Position & table
- Lateral decubitus, CONVEX side UP, on a radiolucent table. Most idiopathic thoracic curves are convex right → left lateral decubitus most common.
- Beanbag/axillary roll; secure fully lateral (lateral positioning accessories or tape directly to table); arm holder; Foley.
Prep, drape & cautery
| Item — exact product | Size | Vendor | Catalog # | Open | PRN |
|---|---|---|---|---|---|
| Positioning · warming · DVT prophylaxis (non-sterile, in room) | |||||
| Sequential compression device (SCD) pump | Cardinal / Kendall | SCD 700 | 1 | ||
| SCD compression sleeves (Vasopress), size to patient | M / L | Cardinal | VP501MG / VP501LG | 1 pr | |
| Forced-air warming blanket, upper body (Bair Hugger) + unit | 3M | 52200 | 1 | ||
| Foam positioning kit / arm pads / gel rolls | Xodus | SPK10113 | 1 | ||
| Surgical skin marker (black) + field marker (purple) | Viscot | 1450XL | 1 | ||
| Foley catheter + insertion tray, 16 Fr | 16 Fr | BD | 903016A | 1 | |
| Skin prep · antisepsis | |||||
| Chlorhexidine (Hibiclens) scrub brush | 1 | ||||
| ChloraPrep applicator — 2% CHG / 70% IPA, tinted | 26 mL | BD (CareFusion) | 930815 | 2 | |
| BD Surgiphor wound irrigation — 0.5% PVP-I | 450 mL | BD | 910110 | 1 | |
| Major basin pack (RSP) | Novo Health | 124514C | 1 | ||
| Mastisol liquid adhesive vial | 0.66 mL | Ferndale | 52348 | 1 | |
| Draping | |||||
| Blue OR towels (per pack) | 17×30 in | Medical Action | 7048 | 2 | |
| Steri-Drape impervious towel drape ('1010') | 23×35 in | 3M | 1010 | 4 | |
| Medline InvisiShield towel drape ON ROLL (prep stand) | 18×12 in | Medline | DYNJSD1000RL | 1 | |
| Medline Sterile Surgical Utility Drapes with Tape, 200 EA/CS | 38×66 cm | Medline | DYNJP2405 | 4 | 2 |
| Ioban 2 antimicrobial incise drape (iodophor) | 33×35 in | 3M | 6651EZ | 1 | |
| Spine custom pack (PPMC) | Medline | DYNJ69083 | 1 | ||
| Split-sheet drape | 77×120 in | Medline | DYNJP8304 | 1 | |
| 3/4 sheet drape | Medline | DYNJP2414 | 1 | ||
| C-arm drape (PPMC Ecolab / CCH Tidi C-Armor) | 27×60 in | Ecolab / Tidi | 4951 / 5523 | 1 | |
| Skin stapler | 35 W | Covidien Appose | 8886803712 | 1 | |
| Sponges | |||||
| Raytec gauze sponge, 12-ply, X-ray detectable | 4×4 in | Cardinal Health | 6939 | 2 | |
| Laparotomy sponge (lap pad), 18×18, per pack | 18×18 in | Medline | MDS72038 | 2 | |
| Lap-tape sponge (long/thin), X-ray detectable — narrow channels / gutters | 4×18 in | Medline | MDS251504LF | 2 | |
| Cottonoid patty (neuro) | 0.5×0.5 in | Integra | 801400 | 1 | |
| Sharps · needles · syringes | |||||
| Surgeon's blade #10 / #15 | #10 / #15 | Aspen | 371110 / 371115 | 1 ea | |
| Surgeon's blade #11 | #11 | Aspen | 371211 | 1 | |
| Hypodermic needle 22G / 25G | BD | 305127 | 1 | ||
| IV catheter / angiocath 18G (local / irrigation) | 18G | BD | 381454 | 1 | |
| Luer-lock syringe 20 cc | BD | 302830 | 1 ea | ||
| Spinal needle — level localization 18G | BD | 405181 | 1 | ||
| Needle counter box, magnetic | 40-ct | Medline | NC40FBR | 1 | |
| Hemostasis | |||||
| Bone wax, sterile | 2.5 g | Medtronic / Covidien | BW25G | 1 | |
| Floseal hemostatic matrix | 10 mL | Baxter | 1503350 | 1 | |
| Recothrom thrombin topical | 5000 u | Baxter | ADS202110 | 1 | |
| Surgifoam / Gelfoam absorbable gelatin | Ethicon | 1974 | 1 | ||
| Aquamantys bipolar sealer wand + cover | Medtronic | 01-0020 | 1 | ||
| Cautery & suction | |||||
| ESU pencil + integrated holster | Valleylab / Bovie | E2515H / ESPH | 1 | ||
| Bovie tip scratch pad | Bovie | ESSP | 1 | ||
| Bipolar forceps cord + adaptor (Storz) + pedal | Storz | — | 1 | ||
| Grounding pad / return electrode (REM) | Medtronic | 7507 | 1 | ||
| Yankauer suction tip | Sage | 006629 | 1 | ||
| Disposable plastic Frazier suction tips — 16Fr ×2, 12Fr ×2, 10Fr ×2 | 1 | ||||
| Neptune 2 Ultra suction unit + tubing + canister | Stryker | — | 1 | ||
| Closure · drains · dressing | |||||
| Port sites layered; intercostal block. Skin 4-0 Monocryl. Chest-tube site purse-string. | ✓ | ||||
| Sylke dressing + 4×4 + Tegaderm (Prineo alternative); chest-tube dressing. | ✓ | ||||
| Cautery settings: Bovie 35 / 35 cut-coag, Bipolar 35 · 1 bovie (open) + 1 additional bovie PRN (if co-surgeon) · 2 suctions off bottom of field · grounding pad on thigh. Meds (pharmacy): 0.25% Marcaine w/ epi 1:200,000 (port sites / intercostals); Vancomycin 1 g; have Tobramycin 1.2 g available (syndromic) | |||||
Imaging
C-arm (AP + lateral) for screw trajectory/depth; level localization. Optional 1.45 mm guidewire with cannulated screws.
Neuromonitoring — every case
MEP + SSEP baselines before positioning; monitor throughout.
Thoracoscopy tower & access
- Scope (30°), camera, light source, monitor(s); CO₂ insufflator (low-flow, optional) + tubing; suction-irrigation.
- 3–4 ports / trocars; endoscopic graspers, scissors, dissectors, Kittners, endoscopic clip applier (segmental vessels), fan / lung retractor.
- Pleural dissection over lateral vertebral bodies (convexity).
⚠️ Convert-to-open precaution (must be in room)
Thoracotomy tray + Harms Chest Retractors open and available — convert if bleeding/exposure demands. Chest tube + drainage system ready.
The Tether — implants (rep-brought / loaner)
- Vertebral body anchor (Ti, 3 straight tines) — recommended at all levels.
- Vertebral body bone screw — cannulated, HA-coated, top-loading; Ø 5.5 / 6.0 / 6.5 / 7.0 mm, lengths 20–50 mm (2.5 mm increments); 1.75 mm cannula.
- PET tensioning cord (Sulene) — only the functional zone is implanted.
- Set screw (Ti, T20 hexalobe, reverse buttress).
The Tether — instruments
- All-Through-One (ATO): anchor inserter inner sleeve + outer sleeve/handle; anchor inserter 90° handle.
- Awl (standard + long); cannulated taps 5.0/5.5/6.0/6.5, non-cannulated taps 4.5–6.5; sounder, right-angle sounder, standard sounder; 4.5 mm probe; targeting + alignment markers.
- Screwdrivers ×2; ratcheting handle ×1; ratcheting handle (palm) ×1 — use with K-wire; set screwdriver ×2; torque-limiting handle (50 in-lb) ×2 (set screws only).
- Tensioning: cord alignment rod ×2, extension spring tube (short + long), fine-adjustment knob, counter-tensioner ×2, cord tensioner ×2, counter-tensioner remover, rack tensioner.
- Tensioning options: sequential/segmental or multi-segment.
Technique cautions (per IFU)
- Caution extending proximal to T5 (small VB, variable venous anatomy).
- Do not rotate screw counterclockwise after insertion.
- New/increasing coronal angulation between screws on x-ray may indicate cord breakage.
- Tension carefully in patients with large growth remaining / open triradiate / flexible curves (overcorrection risk).
Power
Stryker Sumex Pi Drive 2+ (primary) / MR8 (alt) — minimal; primarily screw instrumentation.
Blood management
Cell saver. TXA (tranexamic acid): 30 mg/kg load + 1 mg/kg/hr infusion throughout.
Hemostasis (open generously)
Floseal, Recothrom + Thrombin-JMI, Surgifoam ± 4 mg dex, Gelfoam size 100, Surgicel, bone wax / HemaSorb Plus. Endoscopic clip appliers for segmental vessels. Do not mix Floseal with Gelfoam — confirm first.
Medications
- 0.25% Marcaine w/ epi 1:200,000 (port sites / intercostals).
- Vancomycin 1 g; have Tobramycin 1.2 g available (syndromic).
Chest tube / drain
Chest tube to water-seal drainage; confirm lung re-expansion before closure.
Closure
Port sites layered; intercostal block. Skin 4-0 Monocryl. Chest-tube site purse-string.
Dressing
Sylke dressing + 4×4 + Tegaderm (Prineo alternative); chest-tube dressing.
Postop note
Optional protective bracing up to 6 months per bone quality/activity; tether does not preclude bracing compensatory curves.