Anterior Cervicothoracic Spine Surgery

Preoperative Diagnosis

Discectomy r/t disc herniation

Stabilization of spinal fractures

Tumor resection

Spinal reconstruction

Instrumentation

Pt's age from 30-50 years old

The anterior approach is challenging due to the transition from cervical lordosis to thoracic kyphosis, which increases the wound depth. Risks are associated with the great vessels, the trachea and esophagus, and neural structures. Several options for the approach exist, such as transsternal or transclavicular

Preoperative Considerations

EBL

200-500 mL

Mortality

1-2%

Morbidity

Wound infection, injury to great vessels

Pain score

7-10

Surgical time

3-4 hr

Closing considerations

Soft cervical collar

Antibiotics

Cefazolin 1-2 g

Position

Supine

Keep the head in a neutral position

Roll under shoulders or neck, head moderately extended

Possible use of cervical strap below the chin and behind occiput, attached to 5-10lb hung over the head of the bed

Massage/reposition the head during lengthy procedures to prevent alopecia

Heels off mattress for prolonged procedures

Decreased FRC and HR

Increased venous return, leading to increased preload and CO

Increased intraabdominal pressure

Zone 3 (a-v-A) in the dorsal portion of the lungs

CNS: blood/cerebrospinal fluid drainage is gravity dependent, valve less; when supine = increased ICP, which decreases cerebral perfusion pressure (CPP= MAP-ICP/or CVP)

If BMI is elevated - decreased FRC. Difficulty maintaining tidal volumes due to body weight pressing down on the chest

Padding: Protect pressure points. Arms either with hands supinated <90degree (prevent Brachial Plexus injury from stretch) or alongside with hands facing body. Pad to prevent ulnae nerve injury. Possible pillow under knees if hx of back pain, maintain the lordotic curve in the spine, and avoid tension on the sciatic nerve. Prevent alopecia with padding of the head

Check eyes - always tape them to prevent corneal abrasion

Anesthetic Considerations

Preoperative

Monitors

Pulse ox, ECG, NIBP, Temp, Bair hugger, PNS, A-line, ?CVP, 2 large bore IVs, Foley cath

If SSEP monitoring is indicated, use <1MAC, opiates, and possible muscle relaxants – (check with the monitoring technician in the room)

Respiratory

Acute fractures may be associated with trauma to the spinal cord, leading to respiratory failure and inability to handle oropharyngeal secretions. Need immediate intubation with cervical stabilization - DO not flex or extend the head or move it laterally

Cardiovascular

If acute fractures of the C-spine, the patient may lose sympathetic tone, causing peripheral vasodilation and bradycardia.

• Tx with crystalloid/colloid and atropine to increase HR. May need A-line to keep MAP >80 to avoid vascular insufficiency of the spinal cord

Neurologic

Pts with herniation of cervical disc - may have neck pain, may have pain radiating down one arm, rarely both. Continued issues lead to weakness and atrophy of specific muscle groups in the arm

Fractures at the T1 level may cause degrees of paraplegia

Fractures above C5 may cause quadriplegia and loss of phrenic nerve function (note keeps diaphragm alive)

Hematologic

Antiplatelet agents should be stopped 10 days before elective surgery. 2 units of PRBCs should be available

Intraoperative

Induction

Preoxygenation

GETA, using orotracheal intubation if possible; if not, fiber optic laryngoscopy. After the neurologic exam after FOI, the patient is anesthetized

Consider using a wire-reinforced tube as it allows for maximal bending away from the surgical field, and the Dingman retractor will not compress it

Maintenance

Vecuronium 0.1 mg/kg/IV or Rocuronium 0.6 mg/kg/IV is helpful for positioning. Muscle relaxants are usually not needed further

Emergence

If the patient has a cervical fusion and is in the Halo device, leave ETT until the patient is fully awake, responds to commands, and can manage the airway

The patient is at risk for tissue occlusion or superior laryngeal nerve injury

• Unilateral—min effects
• Bilateral—hoarseness

Test airway patency by deflating the cuff and verifying air movement around the ETT

Consider LTA (Lidocaine 4%, 4ml) to prevent coughing or bucking

Complications

Esophageal perforation can be checked by flooding the surgical field, forcing air through the oropharynx, and checking for bubbles

Retraction nerve injury - superior laryngeal nerve, recurrent laryngeal nerve (Unilateral - hoarseness, Bilateral -Acute causes stridor, respiratory distress, chronic causes aphonia). Consider decreasing cuff pressure once the retractor is in place

Hypotension - venous pooling, acute drop usually associated with vascular injury

• Vertebral or occult from deep great vessels

VAE - if in a sitting position

• Decreased ETCO₂, Increased ETN₂, decreased BP, dysrhythmia

Postoperative Complications

Airway obstruction, edema - note the need for oral/nasal airway, may not be able to move the mandible forward due to postop traction/stabilization device

Hematoma

Neurological deficit

Tension pneumothorax - entrainment of air from surgical wound, bleeding

• How to distinguish airway obstruction from tension pneumothorax
  • Check for the puff sign. If there is obstruction, you will hear slow air movement in and out, but tension pneumothorax causes great speed (puff) due to high intrathoracic pressure