EVAR, TEVAR, and CHEVAR: Transforming Vascular Surgery with Minimally Invasive Techniques

Aortic aneurysms are life-threatening conditions where the walls of the aorta weaken, leading to a bulge that can rupture if untreated. Traditionally, such aneurysms required open surgical repair, which posed significant risks, especially for older or high-risk patients. The advent of minimally invasive techniques like EVAR (Endovascular Aneurysm Repair), TEVAR (Thoracic Endovascular Aneurysm Repair), and CHEVAR (Chimney Endovascular Aneurysm Repair) has revolutionized vascular surgery, providing safer and more effective treatment options.

What Are EVAR, TEVAR, and CHEVAR?

1. EVAR (Endovascular Aneurysm Repair)

EVAR treats abdominal aortic aneurysms (AAA) by placing a stent graft inside the aneurysm through small incisions in the groin.

• Indications: Suitable for infrarenal or juxtarenal aneurysms.

2. TEVAR (Thoracic Endovascular Aneurysm Repair)

TEVAR is designed for thoracic aortic aneurysms (TAA), particularly in the chest region.

• Indications: Aneurysms, dissections, or traumatic injuries in the thoracic aorta.

3. CHEVAR (Chimney Endovascular Aneurysm Repair)

CHEVAR is an advanced technique used for complex aneurysms involving the aortic branches near the kidneys or intestines. It uses additional stents (chimneys) to maintain blood flow to these vital arteries while repairing the aneurysm.

• Indications: Juxtarenal or pararenal aneurysms where branch arteries are involved.

How Do These Procedures Work?

All three techniques involve the placement of a stent graft, which reinforces the aortic walls, isolates the aneurysm from blood flow, and reduces the risk of rupture.

Steps in the Procedure:

1. Access: Small incisions are made, typically in the femoral artery in the groin.

2. Guidewire Insertion: A catheter is inserted and guided to the aneurysm under fluoroscopic imaging.

3. Stent Graft Deployment: The stent graft is positioned and expanded to fit securely within the aorta.

4. Blood Flow Restoration: The graft reroutes blood flow, relieving pressure on the aneurysm walls.

Advantages of EVAR, TEVAR, and CHEVAR

1. Minimally Invasive: Avoids large incisions and the risks of open surgery.

2. Reduced Recovery Time: Most patients can return to normal activities within a few weeks.

3. Lower Risk of Complications: Decreased risk of infection, bleeding, and organ damage.

4. Effective for High-Risk Patients: Ideal for elderly or medically unfit individuals.

5. Preserves Vital Organ Function: CHEVAR ensures blood supply to kidneys and intestines is maintained.

Indications and Contraindications

Indications:

• Diagnosed aortic aneurysms (abdominal or thoracic)

• Symptomatic aneurysms or rapid enlargement

• Patients unfit for open surgery

Contraindications:

• Extremely small or calcified arteries (complicating stent delivery)

• Poor overall health or severe comorbidities

• Unsuitable anatomy for stent graft placement

Complications to Consider

While these procedures are safe, potential complications include:

• Endoleak (blood leakage around the graft)

• Graft migration or dislodgment

• Arterial injury during catheter insertion

• Rarely, infection or rupture

Post-Procedure Care and Follow-Up

1. Monitoring: Regular imaging (CT or ultrasound) to check graft position and aneurysm size.

2. Medications: Blood pressure control with antihypertensives to reduce stress on the aorta.

3. Lifestyle Changes: Smoking cessation, healthy diet, and regular exercise to maintain vascular health.

Future of Endovascular Repairs

Innovations like branched and fenestrated stent grafts are expanding the scope of endovascular techniques, allowing the treatment of more complex aneurysms. Advances in imaging and robotic-assisted systems promise even greater precision and safety.