Endovascular Aneurysm RepairEdit
Endovascular Aneurysm Repair (EVAR) has transformed the treatment landscape for aortic aneurysms by offering a less invasive alternative to open surgery. Instead of opening the chest or abdomen, EVAR uses small groin incisions to thread a stent graft through the blood vessels and deploy it across the aneurysm, sealing it off from circulation. The result is a shorter initial recovery, less physiological stress, and a quicker return to daily life for many patients. However, EVAR requires careful patient selection, lifelong follow-up, and an understanding that not every aneurysm is a good candidate for this approach. The technology spans infrarenal abdominal aortic aneurysms as well as thoracic aneurysms and related conditions, with ongoing refinements in devices and imaging.
EVAR stands within a broader family of endovascular techniques that have reshaped vascular surgery. The core idea is to create a new, durable conduit for blood flow that shields the weakened aneurysm sac from blood pressure while maintaining perfusion to essential branches. In practice, this means delivering a graft made of fabric and metal components through the femoral arteries, fixing the graft at secure proximal and distal landing zones, and ensuring the aneurysm sac no longer expands or ruptures. Like other high-stakes medical technologies, EVAR has generated important debates about when it is best used, how to balance early benefits against long-term durability, and how to manage the follow-up requirements that come with implantable devices. See endovascular aneurysm repair for the broader topic, and note how it relates to abdominal aortic aneurysm and thoracic aortic aneurysm care.
History
The concept of endovascular treatment of aneurysms emerged in the late 20th century and matured through incremental device improvements, imaging advances, and clinical experience. Early attempts demonstrated that a graft could be delivered inside the aorta via arterial access and thereby exclude the aneurysm from the circulation. Over time, randomized trials and observational studies helped define the relative strengths and limitations of EVAR compared with traditional open surgical repair for suitable patients. Key milestones include the development of modular stent grafts, improvements in delivery systems, and enhanced imaging to guide precise deployment. The evolution continues today with ongoing refinement of customization options (such as fenestrated and branched grafts) to accommodate complex anatomy.
The evidence base surrounding EVAR grew with large trials and registry data. Trials comparing EVAR to open repair showed a consistent reduction in short-term mortality and morbidity with EVAR, but raised questions about long-term durability and the need for ongoing surveillance and possible reinterventions. Contemporary practice rests on this balance: EVAR offers an attractive option for many patients who are not ideal candidates for open repair, while anatomy, access, and the commitment to lifelong imaging determine the ultimate suitability. See EVAR-1 trial and DREAM trial for examples of how randomized data have informed practice patterns, and explore how these findings relate to abdominal aortic aneurysm treatment in different patient populations.
Indications and patient selection
Endovascular repair is most commonly used for infrarenal abdominal aortic aneurysm when anatomy and patient factors align. Ideal candidates typically have a aneurysm that can be sealed securely by a stent graft within suitable proximal and distal landing zones, adequate access vessels, and reasonable life expectancy to benefit from reduced perioperative risk. Key anatomical considerations include neck length and angulation, diameter, and mural quality, as well as the condition of the iliac arteries that provide distal access. When anatomy is unfavorable, alternatives such as continued surveillance of a small aneurysm or a plan for open repair may be considered.
In addition to infrarenal AAA, the endovascular approach has expanded to select thoracic aneurysms through thoracic endovascular aortic repair TEVAR. TEVAR is used for thoracic aneurysms and certain dissections or traumatic injuries where conventional open repair would be high risk. Customized and off-the-shelf devices—fenestrated or branched grafts—allow physicians to accommodate visceral or renal branches in more complex anatomy, though these options introduce additional technical considerations and follow-up requirements. See abdominal aortic aneurysm and thoracic aortic aneurysm for related conditions and their treatment pathways.
Not every patient is a candidate for EVAR. Contraindications include certain aneurysm shapes, very short or severely angulated necks, extensive disease of the access vessels, or life expectancy that undermines the long-term surveillance burden. For those who are not candidates, or for whom open repair remains preferable due to anatomy or comorbidity profiles, traditional open surgical repair continues to be a viable option.
Procedure and devices
The general EVAR workflow begins with imaging assessment to map the aneurysm and surrounding anatomy, followed by planning of the graft size and the delivery route. The procedure itself is performed through small incisions in the groin to access the femoral arteries. Under imaging guidance, a delivery catheter advances the stent graft to the aneurysm, where it is deployed to span the aneurysm neck and create a new flow pathway within the aorta. The graft is designed to exclude the aneurysm sac from circulation, reducing the risk of rupture while preserving blood flow to downstream branches.
Devices used in EVAR are endovascular grafts consisting of a fabric conduit supported by metal stents. They come in modular configurations to allow customization for proximal and distal sealing zones. In some cases, branched or fenestrated grafts are employed to maintain perfusion to visceral arteries or the renal arteries when the aneurysm involves branches near the renal or mesenteric vessels. For thoracic disease, TEVAR devices perform a similar function in the thoracic aorta. See stent graft for the generic term and fenestrated graft or branched graft for specialized configurations.
A critical aspect of the EVAR pathway is post-procedure surveillance. Patients undergo periodic imaging—often CT angiography (computed tomography angiography) or duplex ultrasound—to monitor graft position, seal integrity, and aneurysm sac behavior. This lifelong follow-up is a hallmark of endovascular therapy and reflects the possibility of late complications such as endoleaks, graft migration, or new aneurysmal changes in untreated segments. See duplex ultrasound and computed tomography angiography for related imaging modalities and interpretation.
Outcomes and surveillance
EVAR generally reduces perioperative mortality and short-term morbidity compared with open repair in appropriately selected patients. The trade-off is a higher likelihood of late complications that may require additional interventions and ongoing imaging to ensure continued exclusion of the aneurysm. Long-term survival benefits depend on multiple factors, including patient comorbidities and the durability of the graft implantation. The need for surveillance imaging and potential reinterventions highlights a fundamental difference between EVAR and open repair: the endovascular approach shifts part of the management burden into the long term, rather than concentrating it entirely in the initial operation.
Outcomes are continually refined through experience, device improvements, and patient selection refinements. In practice, EVAR has become a preferred option for many patients who face high perioperative risk with open surgery, while those with anatomy or comorbidity profiles better suited to open repair may still pursue that route. See open surgical repair and vascular surgery for broader context on how these approaches fit into vascular care.
Complications
Complications after EVAR tend to cluster around three areas: issues with the graft seal and integrity (endoleaks), problems related to the prosthetic graft itself (migration, fracture, kinking), and access-site issues from the groin incisions. Endoleaks are categorized by type: Type I (inadequate seal at the proximal or distal ends), Type II (retrograde flow from collateral arteries), Type III (graft junction or component failure), and rarer Type IV and others. Type I and II endoleaks are among the most clinically significant because they can permit continued pressurization of the aneurysm sac. Management may involve observation for certain low-flow leaks, endovascular reintervention to re-seal, or, in some cases, conversion to open repair. See endoleak for a framework of these complications.
Other potential issues include graft migration or material fatigue, which can alter the seal and require redraw or secondary procedures, and access-site complications such as hematoma or pseudoaneurysm at the groin. Contrast-related nephropathy and radiation exposure are concerns during the imaging-heavy follow-up, especially in patients with preexisting kidney disease or other risk factors. Spinal cord ischemia and stroke are notable risks in the thoracic region, particularly with extensive disease or arch involvement managed by TEVAR. Careful patient selection, meticulous technique, and coordinated multidisciplinary care help mitigate these risks. See spinal cord ischemia and stroke in the broader context of TEVAR.
Controversies and debates
As with any major medical technology, EVAR has sparked ongoing discussion about when it is most appropriate to use and how to balance immediate benefits with long-term needs. Proponents emphasize reduced short-term mortality, faster recovery, and the ability to offer treatment to patients who might not tolerate open surgery. Critics point to the need for lifelong surveillance, potential late complications, and the possibility that long-term survival advantages may not extend to all patient groups. The debate also extends to cost-effectiveness, given the ongoing imaging and potential reinterventions required over a patient’s lifetime. See cost-effectiveness and healthcare economics for related discussions in the broader medical policy landscape.
Some critics have highlighted disparities in access to endovascular therapies and the importance of maintaining high standards of training and center experience. Others emphasize patient-centered decision-making, tailoring treatment to anatomy, comorbidity, and personal preferences. In this context, comparisons with open repair remain critical: for selected patients, EVAR offers meaningful short-term benefits; for others, open repair may provide durable results with different trade-offs. See medical ethics and quality of life for related considerations in modern vascular care.