Physician-modified EVAR endografts

The role of physician-modified endografts in contemporary aortic care

In recent years, the landscape of aortic repair has evolved significantly, with physician-modified endografts (PMEGs) emerging as a crucial component of the endovascular armamentarium, especially in the treatment of complex abdominal and thoracoabdominal aortic aneurysms. [1, 2] PMEGs offer a practical and often life-saving solution in scenarios where custom-made devices (CMDs) are not feasible due to time constraints, anatomical complexities, or limited device availability. [3]

Background and development

Endovascular aortic repair (EVAR) has become the standard of care for many patients with abdominal aortic aneurysms (AAA), primarily due to its minimally invasive nature and reduced perioperative morbidity compared to open surgery. However, standard endografts are often inadequate for aneurysms involving visceral branches or for patients with hostile neck anatomies. While CMDs—such as fenestrated and branched endografts—have been developed to address such anatomical challenges, their use is hindered by the manufacturing delay, which can be up to several weeks.

To bridge this gap, the technique of physician modification of off-the-shelf devices emerged. Initially coined by Starnes et al., PMEGs applied in urgent and emergent cases, such as symptomatic or ruptured aneurysms involve the in-lab creation of fenestrations or branches on existing commercial endografts to match patient-specific anatomy. [4] This practice requires a meticulous preoperative planning process, including detailed imaging analysis, precise measurement, and a high level of technical expertise. [5-7]

Clinical applications

PMEGs have predominantly been used in juxtarenal and pararenal AAAs, as well as thoracoabdominal aneurysms, where the preservation of one or more visceral arteries is necessary. The technique involves identifying the location of the visceral arteries on preoperative imaging, transferring these coordinates onto the graft, and creating fenestrations or branches accordingly. Bridging stents are then used intraoperatively to revascularize these arteries.

While initially reserved for high-risk or inoperable patients, growing experience and promising outcomes have led to the expanded use of PMEGs in elective settings. Notably, in the United States, PMEGs have been reported as the predominant modality for complex AAA repair outside of investigational device exemptions, a trend not yet widely adopted in Europe due to regulatory and institutional variations.

Outcomes and safety

Multiple single-centre and registry-based studies have demonstrated that PMEGs can be used with a high degree of technical success and low periprocedural complication rates when performed by experienced teams. [1] Technical success rates are commonly reported above 90%, with low incidences of endoleaks, stent occlusion, or reintervention. Moreover, when compared to CMDs, PMEGs often provide comparable short-term outcomes, with the added benefit of immediate availability.

Importantly, the learning curve for PMEGs is non-negligible. Accurate planning and meticulous intraoperative execution are key determinants of successful outcomes. To facilitate this process and enhance reproducibility, various planning software tools and workflow enhancements – such as 3D printing or digital planning applications – have been developed, further bridging the gap between manual craftsmanship and standardized manufacturing.

Challenges and limitations

Despite their benefits, PMEGs come with inherent challenges. The off-label nature of device modification implies legal and regulatory hurdles, including the need for informed consent and institutional approval. Variability in operator experience and technique can also influence outcomes. Additionally, durability remains a concern, as long-term data are still limited compared to CMDs.

Moreover, PMEG procedures are typically confined to high-volume aortic centres with the infrastructure, imaging capability, and expertise to perform them safely. As such, widespread adoption is currently limited, although educational initiatives and international collaborations are working to change this.

Future directions

Looking forward, PMEGs are likely to play an increasingly important role in aortic care, especially as the technology and tools for graft modification continue to improve. Hybrid models, incorporating partially pre-manufactured devices with in-lab modifications, are already being explored. In parallel, registries and multicentre collaborations are generating vital evidence to guide clinical practice and support guideline revisions. [8, 9]

In conclusion, PMEGs represent a vital extension of endovascular therapy, particularly for patients with complex aneurysms for whom traditional solutions are not immediately available. As experience accumulates and evidence grows, physician-modified devices are expected to take on a more central role—not only as a fallback option, but as a legitimate first-line therapy in the comprehensive management of complex aortic disease.