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Purpose: The widespread adoption of endovascular aneurysm repair (EVAR) as preferred treatment modality for abdominal aortic aneurysm (AAA) has enlarged the number of patients needing open surgical conversion (OSC). The relationship between adherence to Instructions For Use (IFU) and EVAR long-term outcomes remains controversial. The aim of this study is to compare preoperative differences and postoperative outcomes between EVAR patients not adjusted to IFU and adjusted to IFU who underwent OSC. Methods: This multicenter retrospective study reviewed 33 explanted EVARs between January 2003 and December 2019 at 14 Vascular Units. Patients were included if OSC occurred >30 days after implantation and excluded if explantation was performed to treat an endograft infection, aortic dissection, or traumatic transections. Variables analyzed included baseline characteristics, adherence to IFU, implant and explant procedural details, secondary reinterventions, and postoperative outcomes. Results: Fifteen explanted patients (15/33, 45.5%) were identified not accomplished to IFU (out-IFU) at initial EVAR vs 18 explanted patients adjusted (in-IFU). During follow-up, a mean of 1.73±1.2 secondary reinterventions were performed, with more type I endoleaks treated in the subgroup out-IFU: 16.7% vs 6.3% in-IFU patients and more type III endoleaks (8.3% vs 0%). Patients out-IFU had shorter mean interval from implant to explant: 47.60±28.8 months vs 71.17±48. Type II endoleak was the most frequent indication for explantation. Low-flow endoleaks (types II, IV, V) account for 44% of indications for OSC in subgroup of patients in-IFU, compared with 13.3% in patients out-IFU and high-flow endoleaks (types I and III) were the main indication for patients out-IFU (33.3% vs 16.7% in-IFU). Total endograft explantation was performed in 57.5% of cases (19/33) and more suprarenal clamping was required in the subgroup out-IFU. Overall, 30-day mortality rate was 12.1% (4/33): 20% for patients out-IFU and 5.6% in-IFU. Conclusions: In our experience, type II endoleak is the most common indication for conversion and differences have been found between patients treated outside IFU with explantation taking place earlier during follow-up, mainly due to high-flow endoleaks and with higher mortality in comparison with patients adjusted to IFU. Ongoing research is required to delve into these differences.

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En el presente estudio se analizaron los principales mecanismos de falla generados en la pista de frenado de 3 frenos de disco de uso comercial, teniendo en cuenta como par tribológico el sistema pastilla-pista. Inicialmente, todas las muestras fueron limpiadas y pulidas para la estimación de propiedades, físicas, mecánicas y químicas, a través de pruebas de dureza Rockwell, Microscopia Electrónica de Barrido (SEM, por sus siglas en ingles), Espectrometría de Dispersión de Energía de Rayos X (EDS, por sus siglas en ingles) y Difracción de Rayos X (XRD, por sus siglas en ingles). Los resultados mostraron que los mecanismos de falla predominantes sobre la pista de frenado fueron el arado, aglomeración de materia, agrietamiento y debris. Finalmente, se confirmó por EDS la presencia de óxidos de hierro que funcionan como lubricantes sólidos y por lo tanto ayudan a la reducción  el desgaste generado por el contacto mecánico.