Thoracic aortic surgery

11 min read Last updated April 8, 2026

Surgical approach

  • Procedures included
    • Open descending thoracic aortic aneurysm (DTAA) repair ± left heart bypass / full CPB
    • Thoracoabdominal aortic aneurysm (TAAA) repair (Crawford extent I–IV) with visceral/renal revascularisation
    • Aortic dissection repair (type B complicated; sometimes open, often endovascular)
    • TEVAR (thoracic endovascular aortic repair) ± debranching / hybrid arch procedures
  • Typical open DTAA/TAAA steps (high level)
    • Position: right lateral decubitus; left thoracotomy (DTAA) ± thoraco-laparotomy (TAAA); single-lung ventilation often required
    • Proximal and distal aortic control with cross-clamps; intercostal arteries may be reimplanted (esp. T8–L2) to reduce spinal cord ischaemia
    • Adjunct perfusion: left heart bypass (LA/LV to femoral/descending aorta) or CPB; selective visceral/renal perfusion in TAAA
    • Aneurysm opened; thrombus removed; graft sewn in; visceral/renal arteries reattached (TAAA) via patch or separate grafts
    • Haemostasis challenging; large raw surfaces; chest drains; closure
  • Typical TEVAR steps
    • Access via femoral/iliac arteries (percutaneous or cutdown); large-bore sheaths; heparinisation
    • Stent-graft deployed under fluoroscopy; may cover left subclavian artery (LSA) → consider pre-op revascularisation (carotid-subclavian bypass) depending on anatomy/indication
    • Rapid ventricular pacing or controlled hypotension may be used to reduce aortic movement during deployment
    • Completion angiography; closure; monitor for endoleak, stroke, spinal cord ischaemia, access complications

Anaesthetic management (overview)

  • Type of anaesthesia
    • Open DTAA/TAAA: GA with lung isolation (DLT or bronchial blocker) + invasive monitoring; often planned post-op ventilation
    • TEVAR: GA commonly (airway control, immobility, TEE possible); selected cases under regional/LA with sedation in experienced centres
  • Airway
    • Open: DLT usually; bronchial blocker if difficult airway or need post-op ventilation with single-lumen tube
    • TEVAR: single-lumen cuffed ETT (or LMA rarely) depending on access/positioning and need for apnoea/TEE
  • Duration
    • Open DTAA: typically 4–8 h; TAAA: 6–12+ h (variable with extent/complexity)
    • TEVAR: typically 1–3 h (longer if hybrid/debranching)
  • How painful?
    • Open thoracotomy/thoracoabdominal: very painful; requires multimodal analgesia (regional often beneficial)
    • TEVAR: usually moderate (groin/iliac access) unless surgical cutdown or hybrid incisions
  • Key anaesthetic goals
    • Prevent rupture/dissection propagation (smooth induction, controlled BP/HR)
    • Maintain organ perfusion during cross-clamp or stent deployment (brain, spinal cord, kidneys, viscera)
    • Manage massive haemorrhage/coagulopathy; temperature and acid-base control

Indications and pathology

  • Descending thoracic aneurysm (degenerative, connective tissue disorders, post-dissection aneurysm)
  • Thoracoabdominal aneurysm (Crawford I–IV) involving visceral/renal arteries
  • Acute aortic syndrome: complicated type B dissection (malperfusion, rupture/impending rupture, refractory pain or hypertension) → often TEVAR
  • Penetrating atherosclerotic ulcer / intramural haematoma (selected cases)

Pre-operative assessment and optimisation

  • History/exam focus
    • Symptoms: chest/back pain, hoarseness, dysphagia, claudication, neurological symptoms; red flags for rupture
    • Comorbidity: IHD, LV dysfunction, COPD (often significant), CKD, cerebrovascular disease, frailty
    • Medication: beta-blockers, antihypertensives, antiplatelets/anticoagulants; statins
  • Investigations
    • CTA anatomy: extent, landing zones (TEVAR), involvement of LSA/visceral/renal arteries; access vessel calibre/tortuosity
    • ECHO (LV function/valves), ECG; consider stress testing/coronary assessment if time and indicated
    • PFTs/ABG if severe COPD; baseline neuro status; renal function and electrolytes; group & save/crossmatch
  • Risk discussion (key complications)
    • Spinal cord ischaemia/paraplegia, stroke, MI, renal failure, respiratory failure, bleeding, death
  • Planning for spinal cord protection
    • Consider CSF drain (esp. extensive coverage/open TAAA, prior AAA repair, planned LSA coverage, long segment stenting)
    • Define MAP targets and haemoglobin targets post-op; plan ICU bed

Physiology and haemodynamic consequences

  • Aortic cross-clamp (open surgery): proximal hypertension + increased afterload
    • ↑ SVR and LV wall stress → myocardial ischaemia, pulmonary oedema (esp. poor LV)
    • Distal ischaemia: spinal cord, kidneys, gut, lower limbs; metabolic acidosis and lactate
  • Cross-clamp release: vasodilation + washout of metabolites
    • Hypotension from ↓ SVR, relative hypovolaemia (splanchnic reperfusion), myocardial depression, hyperkalaemia, acidosis
    • Bleeding may increase due to coagulopathy/hypothermia and surgical factors
  • TEVAR haemodynamics
    • Controlled hypotension or rapid pacing during deployment; then higher MAP targets post-op to protect spinal cord

Monitoring and access

  • Standard + invasive
    • Arterial line pre-induction; consider right radial (arch/LSA issues) and/or femoral line (distal perfusion) depending on clamp site
    • Large-bore IV access; rapid infuser; fluid warmer; consider central line for vasoactive infusions
    • Urinary catheter (hourly output); temperature (core); frequent ABG, lactate, electrolytes, Hb
    • Cardiac output monitoring (pulse contour) and/or TOE (esp. hybrid/complex haemodynamics); TOE limited in some thoracic cases but useful for LV function/volume
  • Neuro/cord monitoring (centre dependent)
    • MEP/SSEP during open TAAA; near-infrared spectroscopy (cerebral) in arch/hybrid cases
    • CSF pressure monitoring if drain in situ (target CSF pressure often ≤10–12 mmHg; follow local protocol)

Anaesthetic technique (open DTAA/TAAA)

  • Induction and maintenance
    • GA with controlled ventilation; avoid tachycardia/hypertension (risk of rupture) but maintain perfusion
    • Balanced technique (volatile or TIVA) + opioid; consider neuromuscular blockade (especially if MEP monitoring requires specific regimen)
    • One-lung ventilation: optimise with recruitment/PEEP to dependent lung, CPAP to non-dependent if needed; accept permissive hypercapnia only if haemodynamics allow
  • Haemodynamic management around cross-clamp
    • Before clamp: ensure adequate preload, vasopressors/inotropes ready; communicate timing
    • Clamp on: treat proximal hypertension/afterload (vasodilators e.g. GTN, SNP; deepen anaesthesia; beta-blockade if appropriate) while maintaining coronary perfusion
    • Clamp off: volume loading as appropriate, vasopressors (noradrenaline/vasopressin), correct acidosis/hyperkalaemia, calcium if needed; gradual release if possible
  • Organ protection strategies (open)
    • Spinal cord: maintain MAP (often higher post-op), CSF drainage, minimise clamp time, reimplant key intercostals, mild hypothermia (centre dependent), avoid anaemia/hypoxia
    • Renal: avoid hypotension, consider selective cold renal perfusion in TAAA, minimise nephrotoxins, maintain Hb and cardiac output
    • Viscera: selective visceral perfusion, limit ischaemia time, correct acidosis early
  • Temperature and metabolic control
    • Active warming (forced air, fluid warmers) but anticipate deliberate mild hypothermia in some centres; avoid severe hypothermia (coagulopathy, arrhythmia)
    • Frequent ABGs: manage acidosis, K+, ionised Ca2+; lactate trend guides perfusion

Anaesthetic technique (TEVAR)

  • Key priorities
    • Immobility for deployment, control BP/HR, manage anticoagulation, detect neuro complications early, protect kidneys (contrast)
  • Haemodynamic phases
    • Pre-deployment: avoid hypertension (risk of rupture/dissection propagation) but maintain organ perfusion
    • Deployment: controlled hypotension or rapid pacing to reduce aortic movement and migration (agree targets with operator)
    • Post-deployment: higher MAP targets to reduce spinal cord ischaemia risk (especially long-segment coverage/LSA coverage)
  • Anticoagulation and access issues
    • Systemic heparinisation common; ensure ACT monitoring if used locally; plan reversal (protamine) balancing bleeding vs thrombosis
    • Large-bore arterial access: risk of bleeding, limb ischaemia, retroperitoneal haematoma; monitor distal pulses and Hb
  • Contrast nephropathy prevention
    • Optimise volume status, avoid hypotension, minimise contrast load, consider bicarbonate/acetylcysteine only per local policy (evidence mixed)

Analgesia (open and TEVAR)

  • Open thoracotomy/thoracoabdominal options
    • Thoracic epidural: excellent analgesia and respiratory mechanics but consider anticoagulation, coagulopathy, haemodynamic instability; careful timing with heparin/CPB and CSF drain
    • Paravertebral catheter or erector spinae plane (ESP) catheter: good alternative with potentially lower hypotension risk; still consider anticoagulation guidance
    • Systemic: PCA opioid + paracetamol ± ketamine infusion; avoid NSAIDs if renal risk/bleeding
  • TEVAR analgesia
    • Local infiltration at access site + opioids as needed; consider neuraxial only rarely (anticoagulation and need for neuro assessment)

Blood management and coagulation

  • Anticipate major haemorrhage (open surgery)
    • Pre-op: group and crossmatch large volumes; cell salvage; rapid infuser; MHP activation plan
    • Intra-op: point-of-care coagulation (TEG/ROTEM) to guide FFP/cryoprecipitate/fibrinogen/platelets; maintain Ca2+; avoid hypothermia
    • Consider antifibrinolytic (e.g. tranexamic acid) unless contraindicated; follow local cardiac/vascular protocols
  • TEVAR bleeding profile
    • Usually less blood loss, but catastrophic bleeding possible (iliac rupture, aortic rupture, access failure) → still plan for rapid transfusion

Post-operative care (ICU focus)

  • Ventilation
    • Open: often elective ventilation; aim early extubation if stable and analgesia adequate; aggressive physiotherapy
    • TEVAR: many extubate in theatre/recovery unless complications
  • Spinal cord ischaemia surveillance and treatment
    • Frequent neuro checks (power, sensation); maintain MAP target (often 80–100 mmHg per local protocol) and adequate Hb/oxygenation
    • If deficit suspected: raise MAP, drain CSF (reduce CSF pressure), optimise oxygenation/Hb, treat hypotension, consider revascularisation of LSA if covered and feasible; urgent senior escalation
  • Renal and metabolic
    • Monitor urine output, creatinine, lactate; avoid nephrotoxins; consider RRT early if severe AKI
  • Other complications
    • Bleeding, coagulopathy, arrhythmias/MI, stroke, bowel ischaemia (pain, lactate, acidosis), limb ischaemia, respiratory failure, chylothorax, recurrent laryngeal nerve palsy
You are anaesthetising for open descending thoracic aortic aneurysm repair. What are your main concerns and how will you plan the case?

Structure your answer: patient risk, monitoring/access, lung isolation, haemodynamics (clamp on/off), bleeding, organ protection, post-op ICU.

  • Major risks: massive haemorrhage, myocardial ischaemia (↑ afterload), spinal cord ischaemia, renal/gut ischaemia, respiratory failure (OLV + thoracotomy), stroke
  • Plan: invasive monitoring (A-line(s), CVC), large-bore access, rapid infuser, cell salvage, frequent ABGs/ACT/TEG/ROTEM, temperature control
  • Airway: DLT/bronchial blocker; optimise OLV strategy and recruitment; anticipate post-op ventilation
  • Haemodynamics: anticipate clamp-on hypertension (vasodilators, deepen anaesthesia) and clamp-off hypotension (volume + vasopressors, correct acidosis/K+)
  • Organ protection: spinal cord strategy (MAP, CSF drain, minimise ischaemia), renal/visceral perfusion considerations
Describe the physiological effects of thoracic aortic cross-clamping and how you manage them.

Split into clamp application and clamp release; include cardiac, pulmonary, metabolic and distal ischaemia effects.

  • Clamp on: ↑ SVR/afterload → ↑ LVEDP, ↑ myocardial O2 demand, risk of ischaemia/pulmonary oedema; proximal hypertension; reduced distal perfusion (kidney/gut/spinal cord/legs)
  • Management: optimise preload; treat hypertension with vasodilators (GTN/SNP) and anaesthetic depth; consider inotrope if LV fails; communicate clamp level and timing
  • Clamp off: ↓ SVR + reperfusion washout (acid, K+, lactate) → hypotension, arrhythmias; bleeding/coagulopathy may worsen
  • Management: volume, vasopressors (noradrenaline/vasopressin), correct acidosis and hyperkalaemia, calcium, gradual unclamping if possible
Spinal cord ischaemia in thoracic aortic surgery: explain the pathophysiology, risk factors, prevention and immediate management.

Common FRCA viva theme: define spinal cord perfusion pressure and the role of CSF drainage and MAP augmentation.

  • Pathophysiology: spinal cord perfusion pressure ≈ MAP − CSF pressure; reduced inflow (intercostal/segmental artery interruption, hypotension) and/or raised CSF pressure → cord hypoperfusion
  • Risk factors: extensive aortic coverage (long TEVAR, TAAA), prolonged clamp time, peri-op hypotension, anaemia/hypoxia, prior AAA repair, LSA coverage without revascularisation, embolism
  • Prevention: maintain MAP (especially post-op), avoid anaemia/hypoxia, CSF drain (selected), minimise ischaemia time, reimplant key intercostals (open), staged procedures (TEVAR), temperature management
  • Immediate management of deficit: urgent increase MAP, drain CSF to lower pressure, optimise oxygenation/Hb/CO, treat hypotension, consider LSA revascularisation or further endovascular optimisation; ICU protocol-driven
A TEVAR is planned with likely coverage of the left subclavian artery. What are the anaesthetic implications and what complications should you anticipate?

Think: posterior circulation/stroke risk, left arm ischaemia, spinal cord perfusion, monitoring site selection.

  • Implications: possible reduced left vertebral flow (posterior circulation), left arm ischaemia, increased spinal cord ischaemia risk (loss of collateral flow)
  • Monitoring: choose arterial line site thoughtfully (right radial often preferred if LSA compromised); consider bilateral pressures if concern
  • Planning: discuss need for pre-op or intra-op LSA revascularisation (carotid-subclavian bypass) depending on anatomy (dominant left vertebral, prior CABG using LIMA, dialysis access, etc.)
  • Post-op: maintain MAP targets for cord protection; low threshold for neuro imaging if posterior circulation symptoms
How would you manage anticoagulation and neuraxial/regional analgesia in thoracic aortic surgery?

Demonstrate safe sequencing: neuraxial timing vs heparinisation, and alternatives when anticoagulation is required.

  • Open/TEVAR often require systemic heparin; neuraxial techniques require strict adherence to anticoagulation timing and normal coagulation parameters
  • If epidural considered: place well before heparin, confirm atraumatic placement, document timing; avoid if coagulopathy/anticipated massive transfusion; plan removal with appropriate interval after last anticoagulant dose
  • Alternatives: paravertebral/ESP catheters, intercostal blocks, systemic multimodal analgesia; balance with need for post-op neuro assessment (esp. spinal cord monitoring)
List causes of hypotension after aortic unclamping and how you would treat them.

Aim for a differential + targeted treatment.

  • Vasodilation/relative hypovolaemia (splanchnic reperfusion) → treat with volume + vasopressors (noradrenaline/vasopressin)
  • Myocardial dysfunction/ischaemia from clamp stress → ECG/TOE, treat with inotrope (dobutamine/adrenaline) and optimise perfusion pressure
  • Acidosis/hyperkalaemia → ventilation, bicarbonate selectively, insulin-dextrose, calcium; treat underlying ischaemia time
  • Bleeding → surgical control + MHP, guided coagulation therapy, calcium and temperature correction
What factors increase the risk of renal failure in thoracic aortic surgery and what can you do to reduce it?

Include both open (ischaemia) and TEVAR (contrast) mechanisms.

  • Risk factors: pre-existing CKD, prolonged hypotension, prolonged clamp time/renal ischaemia (open), embolisation, contrast load (TEVAR), anaemia, low cardiac output
  • Reduce risk: maintain perfusion pressure/CO, avoid hypovolaemia, minimise clamp/ischaemia time, selective renal perfusion (surgical), minimise contrast, avoid nephrotoxins, close monitoring and early ICU optimisation
You are called to ICU: a patient post-TEVAR develops new leg weakness. What is your immediate management?

Treat as spinal cord ischaemia until proven otherwise; time-critical.

  • Immediate actions: urgent senior help (vascular/anaesthesia/ICU), focused neuro exam and document baseline/time of onset
  • Optimise spinal cord perfusion: increase MAP with vasopressors/fluids; ensure adequate oxygenation and haemoglobin
  • If CSF drain present: check function and CSF pressure; drain per protocol to lower CSF pressure; if not present consider urgent placement if appropriate and available
  • Exclude other causes: hypotension, sedation, electrolyte abnormalities, stroke; consider urgent imaging and discussion re LSA revascularisation or endovascular revision
Compare open thoracoabdominal aortic repair vs TEVAR from an anaesthetic perspective.

Contrast invasiveness, physiology, monitoring, analgesia, complications.

  • Open: major physiological insult (cross-clamp), OLV, massive bleeding risk, high pain burden, longer duration, higher risk of respiratory failure and coagulopathy
  • TEVAR: less blood loss and no cross-clamp physiology, but risks include stroke/embolism, spinal cord ischaemia (long coverage), contrast nephropathy, access vessel injury, endoleak; requires precise BP control during deployment
  • Both: require meticulous haemodynamic control, neuro monitoring/assessment, and clear post-op MAP strategy for cord perfusion

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