Anesthesia for TEVAR
Patients presenting for thoracic endovascular aortic repair (TEVAR) are generally older, with significant comorbidities including hypertension, coronary artery disease, pulmonary disease, renal disease, and congestive heart failure. Although this procedure is associated with less physiologic stress than traditional open surgical repairs, it carries significant risk of major adverse cardiac events (>5%) and thus is considered a high-risk procedure.
Note: Some endovascular aortic repairs may be done with regional anesthesia techniques, but GA is typical for reasons including patient comfort, vascular access issues, proceduralist preference and risk of hemodynamic instability
Lumbar drain considerations noted below are for patients at risk for spinal cord malperfusion related to coverage of intercostals and other perfusing arteries. For distal thoracic or subdiaphragmatic aortic repairs, setup is similar to below but typically truncated due to less concern for spinal cord ischemia.
Preparation
- Machine check, suction, backup airway equipment check (this is an out-of-OR location and things are sometimes not in their usual place – make sure you know where the LMAs and Ambubag are)
- Drugs to draw up
- Heparin: 10,000 unit syringe + 20,000 units immediately accessible
- Fentanyl 100-250mcg (remembers this is usually a minimally invasive procedure)
- Muscle relaxant of choice
- Propofol (or other induction agent of choice if previously discussed with attending)
- “Uppers”: phenylephrine, epinephrine +/- vasopressin or norepinephrine
- “Downers”: nitroglycerin +/- clevidipine
- Infusions (ask before you just spike everything available!): norepinephrine, nitroglycerin or others based on ventricular function, comorbidities and attending preference
- Drugs to have available (not drawn up): albumin, protamine, CaCl2, NaHCO3, KCl
- Lines: start with peripheral IV & pre-induction arterial line
- Post-induction volume lines: large bore peripherals (14G + 16G), rapid infusion catheter or introducer
- Blood: consider having it available in a cooler in the room. Bleeding may be brisk.
- Other supplies: lumbar drain with drainage bag and sterile non-flushing transducer setup to monitor ICP; TEE; neuromonitoring team for evoked potentials
Pre-graft deployment
- Antibiotics (usually cefazolin +/- vancomycin); baseline ABG (send to lab) and ACT (give to cath lab tech)
- Volume: maintain euvolemia, do not be stingy with balanced salt solutions as this is key to protecting against contrast-induced nephropathy (CIN)
- Hemodynamic goals: MAP at low-baseline, minimize hypertension, decrease shear stress on the aorta (dP/dt)
- Typically a volatile-based technique balanced with opioids and NMBDs. If SSEP or MEP monitoring in place, alter anesthetic accordingly, ie TIVA with minimal/no volatile)
- Keep an eye on insensible (or overt) blood loss related to large bore sheath access
- Lumbar drain management covered elsewhere, in essence drain 10mL/hr to goal CSF pressure </= 10mmHg
Graft Deployment
- Apnea usually requested while grafts deployed; may request temporary MAP 50-60mmHg and/or HR 50-60; in some centers rapid ventricular pacing is used at time of graft deployment
- Q30minute ACTs to ensure >250
- Serial blood gases to assist with goal-directed resuscitation and monitoring for malperfusion
- Once grafts deployed, spinal cord at risk for ischemia, goal is to maintaining spinal cord perfusion pressure
- SCPP = MAP – ICP. Maintain SCPP >70mmHg, therefore MAP>80mmHg, CSFP <10mmHg
Maintain euvolemia, optimize cardiac index, oxygen content, and urine output
Post-graft Deployment
- SCPP = MAP – ICP. Aggressively maintain MAP >80mmHg (sometimes >90-100mmHg) and continue lumbar CSF drainage and pressure monitoring
- Expeditious emergence and neuro exam prior to leaving cath lab. Consider extubation if meets criteria
- Avoid long-acting sedatives, frequent neuro checks mandatory post-op to assess for spinal cord ischemia