Three-Year Results of the Nellix Endovascular Aneurysm Sealing System for Treatment of Abdominal Aortic Aneurysms in Frail Patients with Poor Anatomical Features.

INTRODUCTION: Endovascular aneurysm sealing represents an alternative to advanced technology devices for compromised patients with abdominal aortic aneurysms. We report our results of 15 fragile patients with very low-quality infrarenal necks treated with endovascular aneurysm sealing. MATERIAL AND METHODS: All patients treated with Nellix device in our hospital between June 2015 and October 2016 were retrospectively reviewed. The primary endpoints are the following: overall survival and freedom from reintervention rates. The secondary endpoints are the following: technical success; 30-day mortality; abdominal aortic aneurysm-related mortality; and freedom from endoleak rate, complications, and surgical conversion rate. RESULTS: Nellix was used in 15 patients, median age 75.5 years, of which 67% were unfit for open surgery. Mean aneurysm diameter was 60 mm. One-third (5/15) of the patients were inside the Nellix instructions for use. Technical success rate was 93.3%. No perioperative complications existed, and 30-day mortality was 0%. Median follow-up was 35 (interquartile range: 11-37) months. Survival rates at 1 and 3 years were 80% and 59.3%. Abdominal aortic aneurysm-related mortality occurred in 3 of 15 cases. Freedom from rupture rates at 1 and 3 years were 92.9% and 66%. Freedom from endoleak rates at 1 and 3 years were 92.9% and 74.5%. Freedom from reintervention rates at 1 and 3 years were 86.7% and 70.6%, with a dramatic drop to 37.1% at 4 years of follow-up. Three open surgery conversions were needed. There were no statistically significant differences in results between patients treated inside and outside instructions for use. CONCLUSION: The endovascular aneurysm sealing has shown encouraging short-term results, but its safety and effectiveness during time is questionable, because this system still carries high rates of reintervention, conversions for type IA endoleaks, and secondary aneurysm ruptures.

The Concept of Risk Assessment and Being Unfit for Surgery.

The concept of risk assessment and the identification of surgical unfitness for vascular intervention is a particularly controversial issue today as the minimally invasive surgical population has increased not only in volume but also in complexity (comorbidity profile) and age, requiring an improved pre-operative selection and definition of high risk. A practical step by step (three steps, two points for each) approach for surgical risk assessment is suggested in this review. As a general rule, the identification of a "high risk" patient for vascular surgery follows a step by step process where the risk is clearly defined, quantified (when too "high"?), and thereby stratified based on the procedure, the patient, and the hospital, with the aid of predictive risk scores. However, there is no standardized, updated, and objective definition for surgical unfitness today. The major gap in the current literature on the definition of high risk in vascular patients explains the lack of sound validated predictive systems and limited generalizability of risk scores in vascular surgery. In addition, the concept of fitness is an evolving tool and many traditional high risk criteria and definitions are no longer valid. Given the preventive purpose of most vascular procedures performed in elderly asymptomatic patients, the decision to pursue or withhold surgery requires realistic estimates not only regarding individual peri-operative mortality, but also life expectancy, healthcare priorities, and the patient's primary goals, such as prolongation of life versus maintenance of independence or symptom relief. The overall "frailty" and geriatric risk burden, such as cognitive, functional, social, and nutritional status, are variables that should be also included in the analyses for stratification of surgical risk in elderly vascular patients.