From the Guidelines
Prediction models in endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA) are crucial for assessing patient outcomes and guiding treatment decisions, and should be based on the most recent and highest quality evidence, such as the American College of Radiology Appropriateness Criteria 1.
Key Points to Consider
- These models typically incorporate multiple variables, including patient demographics, comorbidities, anatomical features of the aneurysm, and procedural factors, to predict perioperative mortality and complications 2.
- The most widely used models, such as the EVAR risk assessment models, the Medicare model, and the British Aneurysm Repair score, can identify high-risk individuals who may benefit from alternative treatments or more intensive monitoring.
- Prediction models can help with preoperative planning by anticipating technical challenges based on anatomical characteristics, such as the morphology of the proximal neck, which is a critical factor in evaluating an AAA for EVAR 2.
- However, it's essential to recognize the limitations of these models, as they may not account for surgeon experience, device selection, or center volume, which significantly impact outcomes 2.
- For optimal clinical use, these models should be regularly updated with contemporary data and validated across diverse patient populations, as most models were developed using data from older-generation devices, potentially limiting their applicability with newer technology.
Clinical Application
- When implementing prediction models in practice, they should complement rather than replace clinical judgment, serving as decision support tools within a comprehensive patient assessment.
- The American College of Radiology Appropriateness Criteria 1 provide evidence-based guidelines for specific clinical conditions, including AAA repair, and can help clinicians make informed decisions about patient care.
- By considering the key points and limitations of prediction models, clinicians can use these tools to improve patient outcomes and reduce morbidity and mortality associated with EVAR.
From the Research
Key Points to Know About Prediction Models in Endovascular Aneurysm Repair of Abdominal Aortic Aneurysm (AAA)
- Prediction models for mortality after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA) have been developed to improve patient outcomes 3, 4, 5, 6, 7
- These models use various preoperative variables, such as age, creatinine levels, systolic blood pressure, and presence of chronic obstructive pulmonary disease (COPD), to predict 30-day mortality and long-term survival 3, 4, 6, 7
- The models have been validated using different datasets and have shown good discrimination ability, with C-statistics ranging from 0.69 to 0.85 3, 4, 5, 6, 7
- The predictors of outcome after EVAR include: + Age: advanced age (>76 years) is associated with increased 30-day mortality and decreased long-term survival 3, 4, 6 + Creatinine levels: elevated creatinine levels (>1.5 mg/dL) are associated with increased 30-day mortality and decreased long-term survival 3, 6 + Systolic blood pressure: low systolic blood pressure (<70 mmHg) is associated with increased 30-day mortality 3 + Presence of COPD: COPD is associated with decreased long-term survival 4, 6 + Aortic neck angle and infrarenal neck diameter: these variables are associated with mid-term outcomes, such as reintervention rates and type I endoleaks 7
- The models can be used to stratify patients into different risk groups and to inform preoperative decision-making and patient counseling 3, 4, 5, 6, 7