Complications of the Medtronic Endurant Stent Graft

Background of the Medtronic Endurant Stent Graft Device

The Endurant stent graft system is an evolution of previous abdominal stent graft systems to meet the challenges of hostile abdominal aortic aneurysm anatomy. After gaining CE marking in Europe in 2008 and FDA approval in 2010, it has become one of the preeminent endograft systems in the world. It consists of a high-density multifilament polyester graft with low porosity, externally supported by a nitinol stent structure ( Fig. 6.1 ).

Proximally, there is a suprarenal fixation system consisting of a nitinol stent with anchoring pins. Next is a series of nitinol stents constructed into a low amplitude sinusoidal M-shape, which allows more flexibility, conformability, and improved seal in short and angulated proximal aneurysm necks. The reduction of columnar strength also contributes to the flexibility of the stent graft. The Endurant II improved upon the previous iteration by extending the hydrophilic coating, loading the 28 mm graft into the smaller 18 French delivery system, introducing more contralateral limb lengths, and increasing the radiopacity of the markers for better visualization. Recently, the Endurant IIs (EIIs) was added to the armamentarium. The EIIs is a 3-piece system with standardized limbs, which allows more options with a smaller range of components and streamlines sizing and inventory.

The Endurant II and EIIs stent graft systems are indicated in treatment of aneurysms with a proximal neck ranging from 19 mm to 32 mm in diameter, length greater than or equal to 10 mm, and infrarenal neck angulation less than or equal to 60 degrees. The Endurant delivery system provides a stepwise, gradual deployment for utmost precision. The tip capture mechanism allows for fine adjustments until the very last moment before release of the suprarenal fixation pins. Combined with its low profile, hydrophilic delivery sheath, the Endurant system has been developed to become an industry standard.

The evolution of the Endurant endograft has not been without its growing pains. Minor, early design flaws and physician inexperience have occasionally resulted in suboptimal deployment, inadvertent occlusion of inflow or outflow vessels, additional procedures, and occasional conversion to an open repair. Some of these difficulties have been eliminated or reduced by improvements in design. For example, the graft fabric was changed to reduce the incidence of Type IV endoleaks ( Fig. 6.2 ), and a minor geometry change to the spindle component of the tip capture mechanism was made right after commercial launch in the United States. However, occasional complications still arise. These issues will be addressed in the following sections, along with some tips in managing these challenging situations.

Endurant Specific Complications