Narrative Review of Risk Assessment of Abdominal Aortic Aneurysm Rupture Based on Biomechanics-Related Morphology.

CLINICAL IMPACT: Studies have shown that the biomechanical indicators based on multi-scale models are more effective in accurately assessing the rupture risk of AAA. To meet the need for clinical monitoring and rapid decision making, the typical morphological parameters associated with AAA rupture and their relationships with the mechanical environment have been summarized, which provide a reference for clinical preoperative risk assessment of AAA.

Detailed analysis of a series of explanted Talent AAA stent-grafts: biofunctionality assessment.

Six Talent stent-grafts were harvested at reoperations (N=5) and autopsy (N=1). The explants were observed nondestructively, including gross morphology, X-rays, CT scans and closed pressure system analysis. The Nitinol frames in three devices harvested at reoperations and another harvested at autopsy were intact. One had a stent fracture of the proximal bare stent, and one had a wire fracture of a thin proximal external supporting stent as well as a hole in the fabric just above the bifurcation. For the three devices structurally intact, reoperations were performed for a type 1A endoleak (one patient) and aorto-enteric fistulas (two patients). The healing characteristics were poor or absent. The fabric in the main body of the grafts harvested after aorto-enteric fistula was devoid of biological deposits. Two of the grafts harvested at reoperation demonstrated fabric holes of up to 4 mm 2. The device obtained at autopsy showed an almost continuous internal capsule with variable thickness. The luminal surface was smooth, but the capsule detached easily. The devices explanted at reoperations showed various levels of impaired biofunctionality associated with adverse outcomes. The stent-graft retrieved from autopsy was intact.

Newly developed hybrid suture without lubricant: noninvasive in vivo assessment of biocompatibility with multiparametric MR imaging.

Magnetic resonance imaging (MRI) and magnetic resonance (MR) relaxometry were used to assess noninvasively the tissue response of a new uncoated hybrid braided suture made from a combination of ultra-high-molecular-weight polyethylene (UHMWPE) and polyester (polyethylene terephthalate) (PET) yarns in comparison to a silicone impregnated braided 100% polyester (PET) control suture (Ticron). Both biomaterials were monitored for a period of 30 days following implantation in both incised and nonincised paravertebral rabbit muscles. In all cases, MR images and relaxometry demonstrated that the hybrid suture elicited either a milder or a similar tissue and cellular response compared to the control suture. These findings were confirmed by conventional histological analysis of the surrounding tissues. They also demonstrated that the hybrid suture promoted faster healing in terms of collagen infiltration between the yarns and individual filaments. This milder inflammatory reaction and improved biocompatibility represent a real advantage in the healing performance of sutures for cardiac and vascular surgery, and support the need for continued research and development of hybrid structures. This study also demonstrated the ability of MRI techniques to noninvasively evaluate the biocompatibility of biomaterials. By extending the capacity of MR diagnostic tools from patients to experimental animals, it is now possible to validate the healing performance of foreign materials with statistical reliability and fewer animals.