Aortic Slimgraft: ex vivo and in vivo study

Stapled fascial suture: ex vivo modeling and clinical implications

BACKGROUND

Recently, in the field of abdominal wall repair surgery, some minimally invasive procedures introduced the use of staplers to provide a retromuscular prosthetic repair. However, to the knowledge of the authors, there are little data in the literature about the outcomes of stapled sutures adoption for midline reconstruction. This study aims to investigate the biomechanics of stapled sutures, simple (stapled), or oversewn (hybrid), in comparison with handsewn suture. From the results obtained, we tried to draw indications for their use in a clinical context.

METHODS

Human cadaver fascia lata specimens, sutured (handsewn, stapled, or hybrid) or not, underwent tensile tests. The data on strength (maximal stress), ultimate strain (deformability), Young's modulus (rigidity), and dissipated specific energy (ability to absorb mechanical energy up to the breaking point) were recorded for each type of specimens and analyzed.

RESULTS

Stapled and hybrid suture showed a significantly higher strength (handsewn 0.83 MPa, stapled 2.10 MPa, hybrid 2.68 MPa) and a trend toward a lower ultimate strain as compared to manual sutures (handsewn 344%, stapled 249%, hybrid 280%). Stapled and hybrid sutures had fourfold higher Young's modulus as compared to handsewn sutures (handsewn 1.779 MPa, stapled 7.374 MPa, hybrid 6.964 MPa). Handsewn and hybrid sutures showed significantly higher dissipated specific energy (handsewn 0.99 mJ-mm3, stapled 0.73 mJ-mm3, hybrid 1.35 mJ-mm3).

CONCLUSION

Stapled sutures can resist high loads, but are less deformable and rigid than handsewn suture. This suggests a safer employment in case of small defects or diastasis (< W1 in accord to EHS classification), where the presumed tissutal displacement is minimal. Oversewing a stapled suture improves its efficiency, becoming crucial in case of larger defects (> W1 in accord to EHS classification) where the expected tissutal displacement is maximal. Hybrid sutures seem to be a good compromise.

The inside-out endograft: a proposed method to decrease the profile of aortic stent-grafts

PURPOSE

To test the novel hypotheses that (1) endograft profile can be reduced if the components do not overlap in the carrier catheter and (2) the inside-out deployment technique can produce a device with overlapping layers.

TECHNIQUE

This study evaluated an endograft in which the graft and stents were connected to each other in an end-to-end fashion without overlap. The endograft was released into a water flow model to become overlapping layers of graft and stents. Then, a Zenith endograft was modified and deployed using this technique, which reduced the Zenith endograft introducer from 20 to 14 French.

CONCLUSION

Inside-out endograft deployment combined with the end-to-end connection of components without overlap may be an effective method to decrease the entry profile of aortic endografts.