Spinal Cord Safety During Aortic Surgery
Key takeaways
Complex aortic surgeries, especially repairs on the thoracic and thoracoabdominal aorta, have a risk of temporary or permanent leg paralysis. This is because the aorta provides the primary blood supply to the spinal cord.
If blood flow to the spinal cord, also called spinal cord perfusion, is reduced or blocked during a procedure, it can cause tissue damage due to a lack of oxygen. This is called spinal cord ischemia.
The UF Health Aortic Disease Center has specialized care teams that use a lumbar spinal drain to lower fluid pressure around the spine. Lowering this pressure makes it easier for oxygen-rich blood to reach the spinal cord.
Our cardiovascular surgical team uses advanced neuromonitoring (SSEP and MEP testing). These track the spinal cord's electrical activity during surgery. They also provide an immediate warning if blood flow drops.
After surgery, keeping blood pressure high-normal and conducting hourly neurological exams in the CVICU are important steps to maintain long-term spinal health and successful physical rehabilitation.
Why is spinal cord safety and neuroprotection a concern during aortic surgery?
The aorta is the main artery through which blood travels. As it travels down from your heart through your chest and abdomen, it supplies blood to dozens of tiny, critical branch arteries. Some of these smaller branches provide blood to your spinal cord. They deliver the oxygen and nutrients your nerves need to work properly.
When a surgeon repairs a large thoracic aortic aneurysm (TAA) or a thoracoabdominal aortic aneurysm (TAAA), they must seal off or replace the damaged section of the aorta. Whether this is done via traditional open surgery or a minimally invasive endovascular procedure such as TEVAR, those tiny branch arteries feeding the spinal cord may be temporarily blocked or permanently covered.
If the spinal cord is deprived of oxygen-rich blood, spinal cord ischemia occurs. If this drop in blood flow is severe or prolonged, it can cause neurological damage. This may cause temporary leg weakness or permanent paralysis called paraplegia. Protecting this blood supply to avoid a spinal cord injury is a primary focus of the surgical team.
What the care team considers to protect your spinal cord
At a high-volume center like the UF Health Aortic Disease Center, protecting your spinal cord begins long before the first incision and continues throughout the entire aortic repair procedure. Your care team uses a mix of advanced techniques to protect the spinal cord.
1. Lumbar spinal drains
One of the most effective ways to protect the spinal cord is to manage the fluid pressure within your spinal column. Your brain and spinal cord float in a protective fluid called cerebrospinal fluid. If the pressure of this fluid is too high, it squeezes the blood vessels. This makes it very difficult for blood to push its way into the spinal cord.
To avoid this, an anesthesiologist places a tiny, flexible tube called a lumbar drain into the lower back before surgery.
By slowly draining small amounts of spinal fluid to lower the fluid pressure, the care team allows blood to flow much more freely to the spinal cord, even if some of the natural branch arteries have been closed off.
2. Real-time neuromonitoring
During your surgery, specialists use advanced electrical monitoring systems to watch your nerve pathways while you are under anesthesia. The two primary tests used are:
Somatosensory Evoked Potentials, or SSEPs: Measures how well sensory signals travel from your legs up to your brain.
Motor Evoked Potentials, or MEPs: Measures how well movement signals travel from your brain down to the muscles in your legs.
If the monitoring screen shows that these electrical signals are slowing down or weakening during the surgery, it serves as an immediate early warning sign. The surgical team can then instantly react. They can do this by:
Adjusting blood pressure
Draining more spinal fluid
Changing their surgical technique to ensure blood continues to flow before any permanent damage occurs
3. Optimizing blood pressure and oxygen
Your surgical and anesthesia teams work collaboratively to manage your body's hemodynamics, or blood flow metrics. During the critical parts of the surgery, they will intentionally raise your blood pressure to a high-normal level. This extra physical pressure helps force blood through "collateral" networks, which are alternative, smaller blood vessels that can step up and feed the spinal cord when the main aortic branches are blocked.
4. Staged surgical approaches
Sometimes an aneurysm is exceptionally massive. An example would be a Crawford Extent II thoracoabdominal aneurysm. This type of aneurysm spans the entire chest and belly. Operating on the whole vessel at once can overwhelm the spinal cord's blood supply. In these intricate cases, UF Health surgeons may choose to perform the repair in two separate stages. These surgeries may be weeks or months apart. This deliberate delay gives the body time to naturally adapt and grow new, alternative blood vessel networks to keep the spinal cord safe.
Post-surgery recovery and rehabilitation
Spinal cord safety does not stop when the surgery ends. The first 48 to 72 hours inside the cardiovascular intensive care unit (CVICU) are just as critical for protecting your neurological health.
Intensive care Unit tracking
Once you wake up from anesthesia, CVICU nurses will perform detailed neurological exams every single hour. They will ask you to wiggle your toes, flex your ankles and lift your legs to verify your motor strength and physical sensation.
Your blood pressure will be tightly managed with continuous IV medications to keep it elevated. If a patient develops sudden leg weakness in the CVICU, the team can immediately take steps to reverse the weakness. This may include lowering spinal fluid pressure via the lumbar drain and boosting blood pressure to quickly reverse the deficit.
Early physical and occupational therapy
Once your surgical team determines that your aorta is stable and the risk window has closed, the lumbar spinal drain is removed. This is usually 2 to 3 days post-op.
Immediately following its removal, inpatient physical therapists (PTs) and occupational therapists (OTs) will get you out of bed to begin your rehabilitation:
Mobility Training: You will start with sitting up, transferring to a chair and taking short walks down the CVICU hallway to rebuild core stability.
Circulation Support: Early movement forces blood to circulate efficiently throughout your lower extremities. This helps your spinal cord adjust to its new blood supply route.
Strength Restoration: A personalized exercise plan will be established to help you combat muscles weakened from bed rest. This ensures you can safely go back to your daily independent routine at home.
Continued Therapy: Therapies such as cardiac rehab and physical therapy may be needed after a patient is discharged. We will make sure necessary outpatient appointments are scheduled for you.
Frequently asked questions
Is the risk of paralysis the same for all aortic surgeries?
No. The risk depends entirely on the location and length of the aorta being treated, as well as the endovascular repair technique being utilized. Standard abdominal aortic aneurysms (AAAs) located low in the belly carry a very low risk of paralysis. The highest risks are associated with complex thoracic aortic repairs (TAAs) and thoracoabdominal aortic aneurysm repairs (TAAAs) because the section of the aorta in the chest is the primary provider of blood to the spinal cord.
Does placing a lumbar spinal drain hurt?
The lumbar drain is placed in the operating room or pre-op holding area before your main vascular surgery begins. The clinical team will use a local anesthetic to completely numb the skin on your lower back. You will feel a pressure sensation, but you should not feel sharp pain. It is similar to receiving an epidural during childbirth.
How long does the spinal drain stay in after surgery?
In most cases, the lumbar drain stays in place for 48 to 72 hours after your aortic surgery. This is the period when the spinal cord is most vulnerable to blood pressure fluctuations. Once you are consistently moving your legs well and your blood pressure has stabilized, the drain is easily and painlessly removed at your bedside.
Can spinal cord weakness that happens after surgery be reversed?
Yes, in many cases it can. If a patient has leg weakness or loss of sensation in the CVICU, it is usually a sign of temporary ischemia, or a lack of blood flow, rather than permanent damage. Because the care team monitors patients hourly, they can immediately increase blood pressure and drain spinal fluid. This rapid response frequently restores full blood flow and completely reverses the weakness.
Why choose the UF Health Aortic Disease Center?
The UF Health Aortic Disease Center is an elite, high-volume academic institution equipped with the specialized infrastructure required to safely manage spinal cord protection. Spinal cord safety procedures require seamless communication between thoracic surgeons, vascular surgeons, neuro-anesthesiologists, neuromonitoring technicians and dedicated CVICU nursing staff.
Our multidisciplinary center uses standardized, data-driven safety pathways that have considerably reduced neurological complications. This is how we consistently deliver unparalleled safety and success rates for patients with complex aortic disease.
To consult with an expert or learn more about our advanced spinal protection procedures, please contact the UF Health Aortic Disease Center by calling (352) 273-5494.
This entry was written by Gabrielle Massari, Marketing Content Writer, and reviewed for accuracy by Eric Jeng, MD. Generative AI was leveraged as part of the content creation process.