This document discusses strategies for spinal cord protection during aortic surgeries. Key points include maintaining distal aortic pressures of 50-80 mmHg to prevent paraplegia, such as through the use of volume expanders, inotropes, or left heart bypass if needed. The artery of Adamkiewicz is an important radicular artery supplying the distal spinal cord. CSF drainage is highly recommended to improve spinal perfusion by reducing CSF pressure competing with blood flow. Limiting cross-clamp times to less than 30 minutes and hypothermia can also help protect the spinal cord during surgery.

1. Spinal cord protection in Coa
surgeries.

2. • Balloon aortoplasty with or without stenting is
the procedure of choice in adults
Indications of surgery are:
• Complex arch anatomy(arch hypoplasia)
• Aneurysms
• Stenotic tube grafts not amenable for balloon
dilatation and stenting.

3. • Hybrid procedures such as debranching of
arch vessels( carotid-carotid and/or carotid-
subclavian graft) along with stenting of
isthmus and DTA

4. Surgical options in adults
• Extraanatomic bypass.
• Interposition graft
• Prosthetic patch aortoplasty

5. Physiology of aortic clamping
Sudden increase in LV afterload – acute
increase in LV wall tension and ischaemia may
occur – decreased contractility and VF
Maintain adequate proximal aortic BP, so that
adequate MAP is maintained distal to the
clamp, to help prevent the complications of
paraplegia.

6. • Distal mean aortic pressures of 50-80mmhg
should be maintained.
Various maneuvers are used to maintain this
pressure
• Administration of volume expanders
• Start inotropes- Dobutamine and/or dopamine.
• Reduced anaesthetic during the period of aortic
cross clamp.

7. • Readjust the proximal clamp to exclude the
subclavian artery if feasible.
• Allow intercostal arteries to remain open.
• If still not maintaining , left heart bypass, fem-
fem bypass, gotts shunt

8. • Arises from the Vertebral arteries
• Cruciate anastomosis at the conus
medullaris which is the sole
communication between the
anterior and posterior spinal artery
• Extremely variable in diameter &
continuity
• Diameter decreases in the middle
thoracic region
• May be discontinuous
• Branches of ASA along with PSA
supply the cord BIDIRECTIONALLY

9. • CERVICAL
• COSTOCERVICAL, SUBCLAVIAN
ARTERY, VERTEBRAL ARTERY
• THORACIC - THORACOLUMBAR
• INTERCOSTAL ARTERIES
• LUMBAR ARTERIES
• CONUS (DISTAL COLLATERAL)
LATERAL LUMBAR,
• BRANCHES OF HYPOGASTRIC
ILIOLUMBAR ARTERY

10. • Two in Number
• On postero – lateral aspect of the Cord
• Arises from the posterior Inferior
Cerebellar artery or sometimes
Vertebral Artery
• Continues from the Medulla to the
Conus Medullaris
• PSA is rarely discontinuous
• Cruciate anastomosis – communication
between anterior and posterior spinal
artery

12. Artery of adamkiewicz
• Major Radicular Artery
• From T7  L1
• Usually arises from
• an INTERCOSTAL A’
• May also arise from
• AORTA directly or
• from multiple arborizing branches
• Larger than the other
• Most commonly on the LEFT and
• Most commonly SINGLE in number
• On the Right and Bilateral in 10%
• Perfuses the spinal cord distal to junction
with ASA
• ASA above ARM is smaller in diameter
than below the ARM

13. Spinal cord protection
Incidence of spinal ischemia lies at 0.5-5%,
which increases as the person ages.
Known risk factors:
Advanced age
Prolonged clamp time
Aortic dissection
Comorbid renal dysfunction

14. Situations that may fail to develop collaterals
• Coa proximal to left subclavian
• Coa with stenosis at origin of left subclavian
artery
• Coa with aberrant right subclavian arising distal
to coarctation
• Less than severe narrowing at coarcted area
• Re-repair.

15. Limit cross clamp time to not more than 30 min
Do not sacrifice intercostal arteries
Systemic hypothermia (34-35 deg C)
Methylprednisolone (25 mg/kg) and Mannitol (1
gm/kg)
Intrathecal papavarine
Wash left pleural cavity with ice cold slush

16. • CSF drainage: highly recommended by current
guidelines
• Improves spinal perfusion by reducing the
competing CSF pressure.
• After induction, 18G spinal needle inserted.
• CSF drained passively, pressure monitoring.
• Target pressure(8-10 mmhg)
• Left in place for 48 hours.

17. • Spinal perfusion pressure: distal arterial
pressure- CSF pressure
• Proposed mechanism
• Reduction of CSF pressure increases the Spinal
Cord Perfusion Pressure
• It counters the abrupt increases in the CSF
pressures consequent to aortic clamping,
reperfusion, increased CVP or spinal cord
edema

18. Complications
• CSF Leak
• Spinal Headache
• Intracranial Hemorrhage
• Meningitis
• Fractured retained catheter

19. Contraindications
• Acute Trauma
• Active Infection
• Aortic Rupture
• Prior Paraplegia
• Inexperienced Center

22. Left heart bypass

23. • Useful in proximal aortic repairs of
• Type 1 and 2 TAAA
• Adult coarctation of aorta
• Less extensive TAAA repairs, if patient has
previous history of infrarenal abdominal aortic
repair.
• Patients with poor LV function

24. • Proximal cannulation: left inferior pulmonary
vein, left superior pulmonary vein, left atrial
appendage.
• Distal cannulation: distal DTA, Femoral artery,
abdominal aorta
• In line centrifugal pump
• No heat exchanger, oxygenator, cardiotomy
reservoir

26. • Heparin (1mg/kg)
• Isothermic oxygentated blood distal to the
aortic clamp.
• Start the pump with 500ml/min
• Goal MAP of 80 mmhg
• Flows gradually increased to 1.5-2.5l/min

27. Benefits of LHB
• Rapid adjustment of proximal arterial pressure
• Effective reduction of preload
• Effective unloading of left ventricle
• Reduced need for pharmacological
intervention
• Spinal cord protection by providing the
surgeon more time for creating secure
anastomosis
• Lower heparin requirement than formal CPB

28. Hypothermia
Normally procedures are done at 33-35 deg.
DHCA (18 deg) is used in cases of
• Where clamping is difficult such as aortic rupture
• Very large aneurysms and aneurysm extending to
aortic arch.
• Previous endovascular repair.
• Large thrombus.
• Severely atherosclerosed and calcified aorta.

30. • Venous cannula: femoral vein, with vaccum
suction. Flows of 1.8-2.4l/min/m2
• Vent through la appendage
• Arterial cannula: Distal DTA or Femoral artery
• DHCA at 18 deg during proximal anastomosis
• After proximal anastomosis, flows started
through side branch of graft and clamp
applied distal to the branch.

31. Postop management
• Maintain systolic BP at 80-90 mmhg for first 24
hours
• Hypotension is avoided as this can lead to
ischemic complications
• Even brief hypertension can lead to disruption
of suture lines, bleeding, pseudoaneurysm
formation.

32. • CSF drain is kept and pressure maintained at
10-12 mmhg.
• After awakening, motor function checked.
• If normal, CSF pressure target maintained at
12-15mmhg
• CSF drain can be removed by 48 hours

33. Paraplegia or paraparesis if occurred
Insert a spinal needle and drain CSF to keep
pressure at 10mmhg
Maintain hemodynamics(SBP above 80-
90mmhg)
Steroids , mannitol are given
Correcting anemia
Reduce fever if any

34. Renal protection strategy
• Intraop Mannitol (class 2b level of evidence C)
• Maintain adequate distal perfusion
pressure(85-95mmhg).
• Mild hypothermia (32-35 deg)
• Avoid nephrotoxic drugs

35. • Pulmonary complications are common, proper
ventilatory strategies should be used.
• It is crucial to prevent infection of the graft,
hence broad spectrum antibiotics are started
initially

36. Complicatons
• Bleeding
• Recurrent or persistent gradient
• False aneurysm formation
• Paraplegia
• Renal failure
• Pulmonary complications
• Graft infection, sepsis

37. • Late aneurysm formation in adults is found
between (5-12%).
• In redo coa it can go upto 21%