A Comparison of Manual and Three-Dimensional Modalities in Predicting Nellix Polymer Volume

PURPOSE: Achieving an effective seal with the Nellix endovascular aneurysm system is dependent on filling the stent bags with an appropriate volume of polymer. Calculating this volume preoperatively is essential and can be performed manually or using three-dimensional (3D) software. The aim of this project was to compare the accuracy of these two methods relative to the actual polymer volume used. MATERIALS AND METHODS: Consecutive patients undergoing Nellix aneurysm repair were included in this retrospective study. Operation notes were analysed for the polymer volume used intra-operatively. Predicted volumes for all patients had been calculated on picture archiving and communication system (PACS) using a manual ‘segmental cylinder’ method. Computed tomography angiograms were then re-analysed using the Synapse 3D PACS update. The difference between groups was assessed using a paired t-test. RESULTS: Twenty-eight patients were included in the analysis; 26 men (92.9%) and 2 women (7.1%); median age 80.9 years (interquartile range, 72.5–84.5 years). The mean volume of polymer used was 103 mL. The mean manual-derived prediction was 100.1 mL (P=0.365) and 3D-derived prediction 110.2 mL (P < 0.001). Manual prediction led to an average 2.8% underestimate of polymer volume whilst 3D prediction led to an average 7.0% overestimate. CONCLUSION: Calculating predicted polymer volume for the Nellix system is more accurate using a manual approach then the 3D alternative. Whilst this method is more time-consuming, there is no significant difference when compared to the actual volume used. Quicker 3D software predictions can be utilised, but their tendency to overestimate should be recognized and taken into account during planning.

EVAR utilizando Nellix, la endoprótesis con sellamiento en el saco / EVAR using the Nellix sa-sealing endoprosthesis

La endoprótesis Nellix es un nuevo dispositivo endoluminal diseñado para tratar los aneurismas aorto-ilíacos, sellando el saco del aneurisma, eliminando así la endofuga mientras se mantiene el flujo normal de las extremidades inferiores. Se compone de dos conductos dilatables por balón,cada uno rodeado por una endobolsa, que se llena in situ con un polímero. Cada conducto soporta la luz del flujo sanguíneo a través del saco del aneurisma hacia las arterias ilíacas. La endobolsa con polímero se mantiene alrededor de la luz y llena el saco del aneurisma, bloqueando el flujoretrógrado de las ramas laterales, anclando el dispositivo en el saco del aneurisma sin necesidad de fijación proximal y distal; además provee estabilidad posicional. Por lo tanto, este dispositivo puede ser utilizado para tratar no sólo los pacientes con cuello aórtico y anatomía ilíaca estándar,sino también en aquellos con anatomías adversas. Se presenta la primera experiencia clínica de Nellix en 34 pacientes durante el período 2008-2010. Los resultados auguran un buen futuro y la pronta aprobación por la Comunidad Europea.

A endoprótese Nellix é um novo dispositivo endoluminal desenhado para tratar os aneurismas aorto-ilíacos, fechando completamente a bolsa de aneurisma, eliminando assim a endofuga,enquanto é mantido o fluxo normal das extremidades inferiores. Compõe-se de dois condutos ampliáveis por um balão, cada um rodeado por uma endobolsa, que se enche “in situ” com umpolímero. Cada conduto suporta a luz do fluxo sanguíneo através da bolsa de aneurisma até as artérias ilíacas. A endobolsa com polímero é mantida ao redor da luz e enche a bolsa de aneurisma, bloqueando o fluxo retrógrado dos ramos laterais, funcionando como dispositivo âncora na bolsa de aneurisma, sem necessidade de fixação proximal e distal, e além disso proporciona estabilidade posicional. Portanto, este dispositivo pode ser utilizado para tratar não somente pacientes com colo aórtico e anatomia ilíaca standard, como também aqueles com anatomias adversas. Apresenta-se a primeira experiência clinica de Nellix em 34 pacientes durante o período 2008-2010. Os resultados auguram um bom futuro e a breve aprovação da Comunidade Européia.

The Nellix endoprosthesis is a new endoluminal device designed to treat aorto-iliac aneurysms by sealing the aneurysm sac, thus eliminating the endoleak space, while maintaining normal flow to the lower extremities. It consists of dual, balloon-expandable endoframes, each surroundedby an endobag, which is filled with an in-situ curing polymer. Each endoframe supports the blood flow lumen through the aneurysm sac to the iliac arteries. The polymer containing endobags surround the flow lumen and fill the aneurysm sac, blocking retrograde flow from side-branches, anchoringthe device within the aneurysm sax without the need for proximal and distal fixation, and further providing it with positional stability. Thus, this device can be used to treat not only patients with standard aortic neck and iliac anatomy but also those with adverse anatomies.We report the first clinical experience with Nellix in 34 patients during 2008-2010. The outcomes augur well and a speedy approval by the European Community.