Long-term outcome after Talent endograft implantation for aneurysms of the abdominal aorta: A multicenter retrospective study

No Difference in Medium-Term Outcome Between Zenith and Talent Stent-Grafts in Endovascular Aneurysm Repair

Background Many devices are available for endovascular aneurysm repair (EVAR). Our aim was to analyze morphological effects of the Zenith and Talent systems.

Methods Patients included underwent EVAR from June 1999 to June 2005 using a Zenith or Talent stent-graft, with computed tomography follow-up. Aortic dimensions over time and clinical outcome were analyzed.

Results Twenty-nine patients with Zenith stent-grafts and 33 with Talent devices were included. Mean preoperative age was similar (75.5 ± 6.0 years vs 74.2 ± 6.7 years; P = .29). Preoperative neck length was longer in the Zenith group (29.9 ± 15.2 mm vs 25.5 ± 10.8 mm; P = .10), and stent-graft oversizing was greater in the Talent patients (20.2% ± 7.9% vs 23.0% ± 11.3%). There was proximal aortic dilatation and aneurysm sac shrinkage in each group. Complication rates were comparable, with 83% of both groups free from 10-mm migration.

Conclusion Although device designs differ, there is no difference in clinical outcome between Zenith and Talent stent-grafts. Migration rates were not influenced by suprarenal fixation.

A magnetic device to eliminate endograft migration: theory and experiment

Endograft migration is a recognized problem in endovascular aneurysm repair, which may lead to aneurysm rupture, acute vessel thrombosis, or occlusion. This study presents a novel device to eliminate endograft migration that involves the use of a ferromagnetic stent graft (internal of vessel) and two magnetic rings (external to vessel, at the two necks of the stent). The magnetic rings (proximal and distal on the graft) with sufficient adhesion force were proposed to eliminate migration without overcompression of the aorta. Specifically, the objectives of the study are (1) to design the geometry and magnetic properties of the magnetic ring based on a mathematical model to produce the necessary tangential force to prevent endograft migration and (2) to validate the theoretical model with in vitro experiments. Our experimental results were in agreement with the numerical model, which showed feasibility of the approach to eliminate migration. This magnetic approach to eliminate endograft migration may lay the foundation for improvement of endograft repair of aortic aneurysm.

Factors Affecting Survival after Endovascular Aneurysm Repair: Results from a Population Based Audit

OBJECTIVES

To determine the effect of pre-operative factors on mid-term survival of patients enrolled in an Australian audit of endovascular aneurysm repair (EVAR).

DESIGN

Prospective longitudinal national register (audit) of patients undergoing EVAR.

METHODS

961 individuals who had elective or semi-urgent EVAR of abdominal aortic aneurysms were enrolled in the audit between November 1999 and May 2001. Data was contributed by 81 surgeons from 64 hospitals. Kaplan-Meier survival analysis was used to determine survival rates and factors significantly influencing survival. Parametric survival analysis with log-exponential distribution was used to estimate expected 3 and 5 year survival for different ages, ASA, creatinine and aneurysm sizes.

RESULTS

Overall survival was 93% at 1 year, 80% at 3 years and 67% at five years. Survival rates were found to be statistically associated with ASA, age, aneurysm size and creatinine levels. ASA has the largest effect. Five year survival rates for aneurysms >or=65 mm and <55 mm were 54% and 76% respectively. Pre-operative creatinine levels >or=160 micromol/L lowered the survival rate from 71% to 40%.

CONCLUSIONS

Survival for EVAR patients is strongly correlated with a number of pre-operative factors. This survival analysis provides a useful decision-making tool for surgeons particularly for individuals with smaller aneurysms.

Long-Term Single-Center Results with Aneurx Endografts for Endovascular Abdominal Aortic Aneurysm Repair

PURPOSE

To evaluate the long-term single-center results with the AneuRx stent-graft in endovascular abdominal aortic aneurysm (AAA) repair (EVAR).

METHODS

Between December 1996 and August 2003, 212 patients (197 men; mean age 71.3+/-7.0 years) were treated with the AneuRx stent-graft for an infrarenal AAA. Postoperatively, patients were enrolled in a fixed surveillance protocol, and data were prospectively captured into a database.

RESULTS

Graft deployment was successful in 98.6% (209/212). Thirty-day mortality was 2.4%. Median hospital stay was 4.3+/-5.5 days. Median follow-up was 52.0 months (range 1-109); only 1 patient was lost to follow-up. At 9 years, patient survival was 56% and freedom from secondary interventions was 48%. In 68% of cases, these reinterventions were needed for a fixation-related complication, and most of these complications (75%) encompassed the area of the proximal aneurysm neck. Primary clinical success was 37% at 9 years. After secondary interventions, the assisted primary clinical success improved to 73% at 9 years. Freedom from aneurysm-related death was 97% at 1 year and 90% at 9 years.

CONCLUSION

As an alternative to open repair, EVAR with the AneuRx device has low perioperative mortality. Reinterventions are mostly due to fixation-related complications. While the overall mortality risk in this population was 5% per year, annual aneurysm-related death was only 1%. The focus should be on surveillance and reducing the rate of long-term complications, which might be possible with improved proximal stent-graft fixation.

Methods for Three-Dimensional Geometric Characterization of the Arterial Vasculature

Complex vascular anatomy often affects endovascular procedural outcome. Accurate quantitative assessment of three-dimensional (3D) in-vivo arterial morphology is therefore vital for endovascular device design, and preoperative planning of percutaneous interventions. The aim of this work was to establish geometric parameters describing arterial branch origin, trajectory, and vessel curvature in 3D space that eliminate the errors implicit in planar measurements. 3D branching parameters at visceral and aortic bifurcation sites, as well as arterial tortuosity were determined from vessel centerlines derived from magnetic resonance angiography data for three subjects. Errors in coronal measurements of 3D branching angles for the right and left renal arteries were 3.1 +/- 3.4 degrees and 7.5 +/- 3.7 degrees , respectively. Distortion of the anterior visceral branching angles from sagittal measurements was less pronounced. Asymmetry in branching and planarity of the common iliac arteries was observed at aortic bifurcations. The renal arteries possessed considerably greater 3D curvature than the abdominal aorta and common iliac vessels with mean average values of 0.114 +/- 0.015 and 0.070 +/- 0.019 mm(-1) for the left and right, respectively. In conclusion, planar projections misrepresented branch trajectory, vessel length, and tortuosity proving the importance of 3D geometric characterization for possible applications in planning of endovascular interventional procedures and providing parameters for endovascular device design.