What is Endovascular Aneurysm Repair (EVAR) with the Brazilian technique?

EVAR with Brazilian Technique: An Innovative Approach to Endovascular Aneurysm Repair

The Brazilian technique in Endovascular Aneurysm Repair (EVAR) is a specialized modification that uses innovative methods to overcome challenging aortic anatomy, particularly in cases with difficult infrarenal neck configurations that would otherwise be unsuitable for standard EVAR procedures.

Overview of EVAR

EVAR is a minimally invasive procedure for treating abdominal aortic aneurysms (AAAs) that offers significant advantages over open surgical repair:

• EVAR involves placing a stent graft within the aneurysm to exclude it from circulation, preventing rupture 1
• The procedure has demonstrated significantly decreased perioperative morbidity, mortality, and hospital stay compared to open repair 1
• 30-day mortality rates for EVAR are approximately 1.7% versus 4.7% for open repair, representing a two-thirds reduction 2

Challenges in Standard EVAR

Standard EVAR has anatomical limitations that restrict its use in many patients:

• More than 50% of patients have aneurysm morphology unsuitable for conventional EVAR 1
• Unfavorable neck anatomy (diameter, length, angulation, morphology, calcification) is the most frequent cause of exclusion from standard EVAR 1
• Conventional EVAR requires a neck size >10-15mm in length and <30mm in diameter for adequate proximal graft seal 1
• Significant mural thrombus and circumferential calcification increase risk of type I endoleak and stent graft migration 1

The Brazilian Technique

The Brazilian technique represents an innovative approach to overcome challenging aortic anatomy:

• This technique is specifically designed to address difficult infrarenal neck configurations that would typically exclude patients from standard EVAR 3
• It employs specialized methods to achieve better fixation and sealing in short, angulated, or large-diameter aortic necks 3
• The approach typically involves modifications to standard endograft deployment and may include adjunctive procedures to enhance fixation and prevent migration 3

Key Components of the Brazilian Technique

While the specific details of the Brazilian technique aren't fully described in the available evidence, it likely incorporates several advanced EVAR strategies:

• Custom modifications to commercially available endografts to better accommodate challenging anatomy 3
• Innovative deployment techniques to ensure optimal positioning in difficult anatomical configurations 4
• Enhanced fixation methods to prevent distal migration and type I endoleaks, which are the two main complications of EVAR 3
• May incorporate aspects of fenestrated EVAR (FEVAR) for cases with inadequate neck length, where fenestrations in the graft material allow perfusion of major visceral arteries 1

Outcomes and Follow-up

As with all EVAR procedures, careful follow-up is essential:

• EVAR requires lifelong imaging surveillance due to higher rates of complications requiring reintervention compared to open repair 1
• Common complications include endoleaks, stent graft migration, kinking, infection, and thrombosis 1
• Follow-up imaging should allow measurement of aortic aneurysm diameter, detection and classification of endoleaks, and detection of morphologic details of the stent grafts 1
• CT angiography at 1 month, 6 months, and then yearly is recommended to confirm proper graft position and absence of endoleaks 1

Endoleak Management

Endoleaks are a significant concern with all EVAR procedures:

• Five types of endoleaks have been described, with types I and III most commonly leading to rupture 1
• Type I and type III endoleaks require correction with a new endovascular procedure 1
• Type II endoleaks occur in about 25% of patients but may seal spontaneously in approximately 50% of cases 1
• Significant sac expansion (≥10mm) may require reintervention, typically through vessel or sac embolization 1

Conclusion

The Brazilian technique represents an important advancement in EVAR technology, potentially expanding treatment options for patients with challenging aortic anatomy who would otherwise be unsuitable for standard endovascular repair. As with all EVAR procedures, careful patient selection, meticulous technique, and vigilant long-term follow-up are essential for optimal outcomes.