ACC/AHA 2022: TEVAR over open for descending ONLY if no MFS/LDS/vEDS

CTD = different durability category — high secondary procedure rates after endo

Infection/fistula: needs resection + debridement, not temporizing stent

Young pts: lifetime reintervention burden, not age alone

Failed TEVAR conversion: complex, frequently infection/fistula driven

Landing zone = healthy wall above & below disease where stent seals. No zone = can't TEVAR. Open replaces diseased wall w/ Dacron → that graft becomes the new landing zone

Z0: prox to innominate. Z1: innominate-LCCA. Z2: LCCA-LSCA. Z3: prox DTA to T4. Z4: rest DTA

CPB = machine pumps blood while heart stopped. Cardioplegia = solution that arrests the heart

HCA = cool pt 18-28°C, stop pump, drain blood → bloodless field to sew arch. Brain tolerates ~20-25 min before injury risk

SACP = while body in arrest, separate pump line feeds brain through axillary/innominate artery. Brain still gets O2 while body does not. Extends safe time to 40-60+ min

Cannulation: axillary = antegrade flow + easy SACP hookup. Femoral = fast access but retrograde flow, embolic risk w/ atheromatous aorta. Direct aortic = situational

Extensive = disease spanning multiple segments (arch + descending +/- abdominal). Too much for one graft → needs ET/FET/hybrid staging

DHCA (deep hypothermic circ arrest): cool pt to ≤18°C, stop pump completely. ZERO blood flow anywhere — brain included. Cold reduces brain metabolic demand so it tolerates ~20-25 min w/o perfusion before injury risk rises. Gives bloodless field to sew arch.

SACP: during arrest, run separate pump line into R axillary artery (via 8mm side graft). Flow goes retrograde up subclavian → reaches vertebral artery + brachiocephalic trunk → then antegrade into carotids and vertebrals → Circle of Willis distributes to both hemispheres. Called 'antegrade' because final flow through brain arteries is forward direction. Brain never goes without blood, body stays in arrest. Extends safe time to 40-60+ min.

SACP flow: 6-15 mL/kg/min. >15 = worse neuro outcomes (2025 data). Perfusion pressure >50 mmHg. Temp 25-28°C.

Unilateral vs bilateral: unilateral ACP = lowest stroke 4.8% + lowest mortality 6.6% (2022 meta-analysis). Bilateral better only if arrest >40 min (maximizes vertebral/posterior flow). For shorter cases unilateral is fine.

RCP: pump cold blood BACKWARDS through SVC → flows retrograde through cerebral veins → out arch vessels. Not real perfusion — mainly flushes air/debris and keeps brain cool. Done via existing venous cannula, just redirect. Low pressure (CVP 20-25 mmHg), low flow (200-300 mL/min). Adjunct only.

CANNULATION = where you connect the heart-lung machine's arterial return line to the patient. This is the main circuit that pumps blood to the whole body during surgery (CPB). Site determines flow direction through the aorta.

- R axillary: 8mm graft sewn end-to-side on axillary artery. Blood flows retrograde into subclavian → antegrade through arch to body. When ready for arrest: clamp innominate proximal to takeoff → same axillary line now becomes brain-only SACP line. One site does double duty (full bypass + SACP) — that's what 'easy ACP' means. No extra cannula needed. Modern default.

- Femoral: cannula in groin. Blood flows retrograde up aorta — if plaque present, can dislodge debris → stroke. Fast access in emergencies. Would need separate line placed for SACP.

- Direct aortic: cannula directly into ascending aorta. Situational — depends on pathology.

NIRS: near-infrared spectroscopy. Monitors cerebral O2. >20% drop from baseline = intervene

KEY DISTINCTION: dissection vs aneurysm = different operations

DISSECTION (acute type A): hemiarch usually enough. Beveled anastomosis, lesser curvature. Arrest ~15-20 min. Goal = resect tear, not replace whole arch

ANEURYSM: total arch required. All 3 branches reimplanted. Arrest 30-50+ min w/ SACP. Arch IS the disease — must resect dilated segment

DISSECTION + arch tear extending past innominate → upgrade to total arch

CHRONIC dissection w/ arch involvement: treat like aneurysm. Elective total arch when size >5.5cm (or >5.0 in CTD)

CTD + arch: always total arch — need definitive proximal landing zone for future distal completion

Meta-analyses hemi vs total: comparable mortality. Difference = patient selection + center volume

Type A acute per ACC/AHA: open distal anastomosis, resuspend valve if leaflets ok, root replacement only if destroyed/dilated/>4.5cm/genetic disorder

Borst 1983. Stage 1: total arch + free graft left dangling in DTA

Stage 2: distal surgeon clamps onto trunk — no redo arch dissection needed

Problem: interval between stages. Rupture risk in aneurysmal pts while waiting

Stage 2 completion rates: not 100% — pts deteriorate, comorbidities, lost to follow-up

Typical inter-stage interval: weeks to months. Some never get stage 2

This gap = reason FET and hybrid were developed

Single operation: open arch + antegrade stent deployed into proximal DTA

Prostheses: Thoraflex Hybrid, E-vita Open — multi-branch + stented distal component

Dissection: promotes false lumen thrombosis, aortic remodeling

Can still extend distally later via TEVAR if needed — staged platform

Morbidity (pooled): stroke 5-10%, SCI 3-8%, renal failure ~5%, 30d mortality 5-12%

Not benign — traded staging risk for single-op morbidity

SCI: 3-8% pooled. More coverage = more intercostals lost. Distal end at T6-T7 = lower risk than T8+

Mitigation: limit stent length, CSF drain, MAP augmentation, staged if possible

dSINE: ~10-18% in dissection pts. Stent spring-back tears new entry in flap. Oversizing >10% = risk factor

Risk factors: oversizing, rigid stent in curved dissected aorta, mechanical mismatch at transition zone

Stroke: 5-10% — embolic + hypoperfusion during arrest

Renal: ~5% — prolonged arrest, visceral malperfusion in dissection

TYPE I: isolated arch aneurysm, good native zones. Debranch via 4-branch graft to native ascending. Can do off-pump. Stent through graft or delayed femoral

TYPE II: disease extends into ascending (>3.7cm). Replace ascending w/ Dacron to CREATE zone 0. Needs CPB. Key: >4cm ascending = retrograde type A dissection risk on stent deploy

TYPE III: total arch + ET, then delayed TEVAR into descending. Needs circ arrest. Basically ET + staged TEVAR

All types: unsuitable for traditional open. Hybrid OR w/ fluoro

Open when: no landing zone, tortuous/small access, infected graft, CTD, failed TEVAR

Vignette: infected stent-graft + aorto-esophageal fistula → explant + reconstruction

LHB: LA appendage → distal aorta/femoral via centrifugal pump. Flow 1.5-2.5 L/min. Keeps distal MAP >60

LHB alone does NOT reliably prevent paraplegia — must bundle w/ CSF drain + MAP + avoid anemia

Sequential clamping: clamp-repair-move distally. Minimizes ischemic territory per segment

Renal/visceral perfusion: selective catheter perfusion from LHB circuit in thoracoabdominal cases

SCPP = MAP - CSF pressure. Goal SCPP >70 mmHg

CSF drain: target ICP ≤10-15 mmHg. Max drain 10-15 mL/hr. Keep 48-72hr postop

MAP: augment to 80-100 mmHg postop. Vasopressors PRN

Adamkiewicz: T8-L1 in 89%. Left-sided in 70%. Single dominant feeder in most pts

Hgb: keep >10 g/dL. Transfuse if deficit appears

Delayed deficit = emergency: bolus drain CSF, push MAP >90, check Hgb, stat imaging

Neuro checks: q1h x24hr, then q2h x24hr. Wiggle toes, dorsiflexion, sensation

Quick decision tree:

- Ascending/root/arch → open. Arch + prox DTA + dissection → FET. High-risk arch → hybrid debranch + TEVAR. CTD/infection → always lean open

Key numbers to remember:

- SACP 24-28°C, DHCA safe ~20-25 min alone

- Adamkiewicz T8-L1 89%, CSF drain ≤10-15, SCPP >70

- dSINE 10-18% post-FET in dissection, SCI 3-8%

- Bavaria hybrid Types I-III

Closer: CT chooses operation, physiology chooses protection