Early Institutional Experience with One-Piece Bifurcated-Fenestrated Stentgraft in the Treatment of Abdominal Aortic Aneurysms

Fenestrated Endovascular Repair Using Short Tipped Distal Components with No Cross Concept to Prevent Crushing of Target Vessel Bridging Stents

OBJECTIVE

To compare and evaluate early and midterm outcomes of a novel no cross approach with short tip vs. standard tip introducer systems for all distal components to prevent target vessel bridging stent kink or collapse during fenestrated endovascular aortic repair (FEVAR).

METHODS

A retrospective analysis was conducted on all patients who underwent FEVAR at a tertiary referral centre between October 2016 and July 2022. The inclusion criterion was the use of renal artery fenestrations. Patients who had chronic dissections were included. Endpoints were analysed in two groups comprising the no cross group and the standard group, with all cases being consecutive in their respective groups. Cone beam computed tomography was used intra-operatively in all cases, and post-operative computed tomography angiograms and re-interventions were reviewed. Primary endpoints included technical success, intra-operative adjunctive procedures, adverse events related to the fenestration, and re-interventions, while secondary endpoints were secondary interventions and overall mortality rate.

RESULTS

Seventy patients (35 in each group) were enrolled in the study, with 64 (91%) having juxtarenal aneurysms. There were no differences in demographics, cardiovascular risk factors, or aneurysm characteristics between the two groups. The no cross group demonstrated a significantly higher technical success rate (100% in all cases) compared with the standard group (29 cases, 83%; p = .010). Additionally, there were statistically significantly fewer intra-operative adjunctive procedures required in the no cross group (1.5% of fenestrations) compared with the standard group (8.2% of fenestrations) (p = .013). The overall median follow up was 32 months (interquartile range 22, 62 months).

CONCLUSION

Implementation of a novel no cross concept during FEVAR, using a short dilator introducer tip on the distal bifurcated component and iliac extensions, significantly reduced intra-operative fenestration related adverse events and enhanced technical success. Further studies with larger patient populations and longer follow up are needed to confirm these findings.

Outcomes of fenestrated-branched endovascular aortic repair in patients with or without prior history of abdominal endovascular or open surgical repair

OBJECTIVE

The aim of this study was to compare outcomes of fenestrated-branched endovascular aortic repair (FB-EVAR) of complex abdominal (CAAAs) and thoracoabdominal aortic aneurysms (TAAAs) in patients with or without prior history of abdominal open surgical (OSR) or endovascular aortic repair (EVAR).

METHODS

The clinical data of consecutive patients enrolled in a prospective, non-randomized study to evaluate FB-EVAR for treatment of CAAAs and TAAAs was reviewed. Clinical outcomes were analyzed in patients with no previous aortic repair (Controls), prior EVAR (Group 1), and prior abdominal OSR (Group 2), including 30-day mortality and major adverse events (MAEs), patient survival and freedom from aortic-related mortality (ARM), secondary interventions, any type II endoleak, sac enlargement (≥5 mm), and new-onset permanent dialysis.

RESULTS

There were 506 patients (69% male; mean age, 72 ± 9 years) treated by FB-EVAR, including 380 controls, 54 patients in Group 1 (EVAR), and 72 patients in Group 2 (abdominal OSR). FB-EVAR was performed on average 7 ± 4 and 12 ± 6 years after the index EVAR and abdominal OSR, respectively (P < .001). All three groups had similar clinical characteristics, except for less coronary artery disease in controls and more TAAAs and branch stent graft designs in Group 2 (P < .05). Aneurysm extent was CAAA in 144 patients (28%) and TAAA in 362 patients (72%). Overall technical success, mortality, and MAE rate were 96%, 1%, and 14%, respectively, with no difference between groups. Mean follow up was 30 ± 21 months. Patient survival was significantly lower in Group 2 (P = .03), but there was no difference in freedom from ARM and secondary interventions at 5 years between groups. Group 1 patients had lower freedom from any type II endoleak (P = .02) and sac enlargement (P < .001), whereas Group 2 patients had lower freedom from new-onset permanent dialysis (P = .03).

CONCLUSIONS

FB-EVAR was performed with high technical success, low mortality, and similar risk of MAEs, regardless of prior history of abdominal aortic repair. Patient survival was significantly lower in patients who had previous abdominal OSR, but freedom from ARM and secondary interventions were similar among groups. Patients with prior EVAR had lower freedom from type II endoleak and sac enlargement. Patients with prior OSR had lower freedom from new-onset dialysis.

Engineering In Situ Weldable Vascular Devices

(1) Background: The minimally invasive implantation of medical devices is largely limited by their insertion profile, and, therefore, minimizing them constitutes a leading trend in the field. (2) Methods: This study introduces the in situ welding strategy, whereby the components of the stent grafts used to treat abdominal aortic aneurysms were decoupled, deployed sequentially, and welded together at the aneurysmal site, greatly reducing their insertion profile. Polyurethane elastomers were used to produce the graft and to coat the metallic struts of the stent to render it in vivo weldable. Results: The composition of the polyurethanes was fine-tuned, so to minimize the insertion profiles and optimize the welding properties and the clinical performance of the devices assembled. The stent and graft were deployed successively in pigs via a small 8F introducer, in situ welded, and the patency of the bi-component device was confirmed over a three-month post-implantation period. The strength of the stent/graft welded connection was fully retained, with no de-welding observed. Conclusions: The in situ welding strategy resulted in implantations that were easier to perform and markedly less injurious to tissues and organs, largely expanding the applicability of these ultra-minimally invasive procedures to especially frail segments of the population.