ACDF Dr. Ahn  

Complications 

• Dysphagia 
  • Usually short term that resolves in 1 months up to 50% 
• Dysphonia 
  • RLN – hoarseness 5-6% 
• Pseudarthrosis 
• Implant failure 
• Neurologic injury 
• Airway compromise 
• ASD – 3% 

Preop Imaging 

• CT 
  • Is there OPLL? 
  • Spurs? 
  • Calcified Disc? 
• MRI  
  • Level of compression 
  • Nerve Roots Free? 
  • Vertebral Artery position -5% are aberrant (sometimes TF is within the body) 
    • Close to the uncinate medial border? 
• Templating 
  • Screw Length (usually 12-16mm) 
  • Adjacent segment disc height (approx 5mm) 
  • Plate length  (12-14mm) 

Equipment 

• C Arm Large 
• Stryker Cervical Phantoms 
• Tritanium Cages & Plates 
• Headlight & Loupes (Approach) 
• Microscope 

Position 

• Supine 
• ETT on L side of mouth 
• Arms toboggan 
  • Gel pads – yellow to skin 
• Shoulders taped down 
• Head on beanbag then deflate 
• Sandbag between scapulae to increase extension 

Anesthesia Consideration 

• Dex 10mg preop 

Localize Levels 

• Landmarks 
  • C3 – hyoid bone 
  • C45 – thyroid 
  • C6 – first cricoid ring 
• 2 parallel longitudinal 18g needles taped 
• Xray Lateral 
  • Mark 

Marking 

• Sternal Notch 
• Medial Borders SCM 
• Levels (see above) 
• 8 cm incision centered midline to the SCM border 

Prep & Drape 

• Prep 
  • Scrub Brush water 
  • Green towel dry 
  • Chlorohexidine 
• Drape 
  • 3/4 Bottom 
  • 4 squares 
  • Bottom 
  • Top 
  • Side to Side 

Approach 

• Smith Robinson  

Superficial Dissection 

• 15 blade vs skin down to platysma 
• Identify platysma midline edge using metz or create on by pushing through with metz 
• Spread metz and burn in between in order to get through platysma 
• Bipolar all bleeders 
• Subplatysmal planes 
  • Surgeon and assistant each grab platysma with adsons 
  • Follow direction of SCM up and latera 
  • Follow SCM down and midline 

Deep Dissection 

• Identify SCM medial edge  
• Push through or cut the DEEP CERVICAL FASCIA  with metz to buy your edge 
• Palpate carotid (keep lateral) it is more superficial than you think 
• Peanut to blunt dissect between SCM and 3 straps (Sternohyoid, sternothyroid and omohyoid) 
• You are here now (below) 

Pearls 

• 3 Fascial Layers 
  • Deep Cervical 
    • Encapsulates the SCM 
    • Nick to enter it 
    • Only then can you create interval between SCM and strap 
  • Pretracheal 
    • Attaches Straps to Carotid sheath 
  • Prevertebral 
    • On top of Longus Colli 
    • Sympathetic Chain on top of it (laterally located over TPs) 
• SCM – CN11 Accessory Nerve 
• C6 TP – Carotid Tubercle 
  • Larger than other Anterior Tubercle of TPs 
  • Common Carotid bifurcates 
    • Vertebral enters C6 Lateral Mass 
    • Common Carotid anterior, can be pressed against C6 Carotid tubercle 
      • Massage for SVT 
• Carotid Sheath 
• Dangers 
  • RLN 
    • Br of Vagus 
      • Left- descends in sheaht, Wraps around aortic arch then up between trachea and esophagus 
      • Right – more variable 
        • Descends in sheath, wraps subclavian  
        • Can leave sheath early at level of thyroid 
    • Above longus colli 
    • Careful with retracotrs 
      • Put them UNDER the Longis Colli 
  • Sympathetic Nerves 
    • Lies on top of Longis Colli 
    • Don’t dissect too lateral to the TPs 
    • Horners Syndrome 
      • Pstosis, miosis, anhydrosis 
  • Inferior Thyroid Artery 
    • Br of Carotid 
    • Can cross the field in lower levels 
    • Tie it properly 

• Continue through the PRETRACHEAL FASCIA (connects carotid sheath to the straps) and use Rugel Retractor (Ahn calls it Rugel but it is Cloward Blade Retractor) 
  • Sympathetic Chain is on top of Longus Colli 
• PREVERTEBRAL FASCIA and Longus colli now looking at you 
• Midline incision through them 
• Don’t go too laterla or the sympathetic chain is there 
• Burn under the longus colli to lift them off the bone 
• Retractor under longus colli 
• Finish with peanut 
• Disc is hill, Body is valley 

Confirm Level 

• Step-Bend Spinal Needle 
• Needle into Vertebral Body 
  • Insertion into disc will accelerate degeneration 

• Lateral Xray 
• Remove Retractors 

Decompression 

• 3 main steps 
  • Discectomy 
  • Endplate Prep 
  • Foraminatomy 
• Decompression comes from: 
  • Indirect: Increased disc space height 
  • Direct: decompression of osteophytes 
• Insert Cervical Phantoms (measure length using stick) 
• Caspar Pin insertion 
  • Drill first (angle away from disc) 
  • Insert pin 
  • Distractors 
• Microscope in (see right for tip re: positioning microscope) 
• 15 blade rectangular cut 
• Kerrison Rongeurs + pituitary decompression 
• Improve visualization first 
  • Anterior lip of inferior endplate overhangs 
  • Bite with Kerrisons right awat 
  • Flatten Endplates (improves Graft-Endplate Contact) 
• DO NOT DECOMPRESSION TOO FAR LATERAL (cord is 13-14.5 mm so we only need to decompress 16mm. Width increase as you go down) 
  • Uncinate is the margins – lateral to that is the Vertebral arteries (1-1.5 mm away from uncinate) 
    • Dr. Rao who trained Dr. Lewis would actually go lateral and identify vertebral arteries 
• Posterior Foraminotomy 
  • PLL at the back 
  • Target the Posterior Uncinate  
    • Can go further lateral (see diagram at right) 
  • Can burr, then poke small hole through PLL enough to fit Kerrison 

• End Plate Preparation 

Instrumentation 

• Cage sizing 
  • Pack cage  
    • Vitoss 
    • Bone graft 
  • Insert 
    • Hold until distractors released 
    • Put it MIDLINE 
  • Lateral and AP XR to confirm 
• Plate Selection 
  • Center hole over the cage hole 
  • MIDLINE 
  • NOT too close to disc – ossification 
  • Temporary pin top and bottom 
    • Directed away from disc and toward midline 
  • Screws 
  • Top filled first 
    • Prevents lip – swallowing 
  • Lock 
  • Lateral and AP XR 

Closing 

• Flat white drain 
• Deep to superficial Kelly 
  • 15 blade to tip to cut 
• Pull drain through white end first 
• Platysma Fascia closure – 2-0 Vicryl deep running 
• 4-0 Monocryl subcuticular 
• 2 medpore, 3 tegaderm 
• Aspen Collar 

Post OP Considerations 

• Collar 6 weeks 
• Drainsx24h 
• Dexamethasone 10mg 12 hours post op 
• Airway emergency 
  • Signs  
    • First sign is pt complains of inability to swallow 
    • Drooling – later sign 
    • Intubate ASAP – waiting for decreased sats is bad 
  • Management 
    • Intubate 
    • Extubate when 
      • Cuff gets a leak (shows that swelling is gone down) 
      • (triggering ventilator)