Infrarenal endovascular aneurysm repair: New developments and decision making in 2016

Atypical Renal Artery Preservation with an Iliac Branch Device in an Infrarenal Abdominal Aortic Aneurysm

Anatomical variations of the renal arteries may complicate endovascular repair of infrarenal abdominal aortic aneurysms (AAA). Occlusion of renal branches may be necessary to seal the aneurysm sac efficiently. Depending on the size of the affected renal arteries and the supplied parenchyma, this can lead to loss of renal function. Iliac branch devices (IBDs) have been created in order to preserve the internal iliac artery in aortoiliac or isolated iliac aneurysms; however, IBDs have the potential to maintain patency of other arteries as well. This case report describes the off-label use of an IBD inside the main body of a bifurcated endoprosthesis in a patient with an AAA and multiple renal arteries in order to preserve the main renal artery that emerges directly out of the aneurysm sac. Special considerations such as limited craniocaudal dimensions for endoprosthesis placement and the reduced vascular space are discussed.

Morphology-Related Limitations of Endovascular Aneurysm Repair Applicability in the Treatment of Abdominal Aortic Aneurysm in West-Central Poland

BACKGROUND

Morphology is one of the most important factors influencing the long-term durability of endovascular repair of an infrarenal abdominal aortic aneurysm (AAA). The knowledge of morphological characteristics of AAA that may differ in various populations seems to be important for further development of a technology of endovascular repair as well as for planning of treatment strategies. To analyze the current applicability of endovascular aneurysm repair (EVAR) in patients with an infrarenal AAA with an indication for elective treatment in west-central Poland.

METHODS

Computed tomography angiograms of 100 consecutive patients with infrarenal AAA deemed to require treatment were analyzed with an OsiriX DICOM viewer in 3D-multiplanar reconstruction mode. Proximal neck diameter, length, angulation, shape, the presence of thrombus and calcification, distal neck diameter, and morphology of the iliac arteries were determined. Three sets of morphological criteria were established. The optimal criteria consisted of a nonconical proximal neck without moderate or severe calcification or thrombus, with a diameter of 18-28 mm, length of ≥15 mm, and β angulation of <60%; a distal neck with a diameter of ≥20 mm; a landing zone in the common iliac arteries (CIAs) with a length of ≥10 mm and diameter of ≤20 mm; and external iliac arteries with diameters of ≥7 mm. The suboptimal criteria included proximal neck diameters of 18-32 mm, neck lengths ≥10 mm, infrarenal neck angulations of up to 75°, and CIA diameters of up to 25 mm. Finally, the extended suboptimal criteria included proximal neck diameters of 16-34 mm and infrarenal neck angulations ≤90°, without limits in the maximal diameter of the CIAs.

RESULTS

The median maximum aneurysm diameter was 61 mm. The optimal, suboptimal, and extended suboptimal criteria were met by 23%, 32%, and 53% of patients, respectively. The most common deviations were wide, conical, and angulated proximal necks and aneurysmal iliac arteries.

CONCLUSIONS

The majority of patients with AAA deemed to be candidates for elective repair do not meet the most favorable criteria for EVAR. Availability of better endovascular solutions for conical, angulated, and wide necks and aneurysmal iliac arteries would likely expand EVAR applicability. Open repair remains a valid option.

Evolution of the Proximal Sealing Rings of the Anaconda Stent-Graft After Endovascular Aneurysm Repair

Purpose: To provide insight into the evolution of the saddle-shaped proximal sealing rings of the Anaconda stent-graft after endovascular aneurysm repair (EVAR). Methods: Eighteen abdominal aortic aneurysm patients were consecutively enrolled in a single-center, prospective, observational cohort study (LSPEAS; Trialregister.nl identifier NTR4276). The patients were treated electively using an Anaconda stent-graft with a mean 31% oversizing (range 17–47). According to protocol, participants were to be followed for 2 years, during which 5 noncontrast electrocardiogram-gated computed tomography scans would be conducted. Three patients were eliminated within 30 days (1 withdrew, 1 died, and a third was converted before stent-graft deployment), leaving 15 patients (mean age 72.8±3.7 years; 14 men) for this analysis. Evolution in size and shape (symmetry) of both proximal infrarenal sealing rings were assessed from discharge to 24 months using dedicated postprocessing algorithms. Results: At 24 months, the mean diameters of the first and second ring stents had increased significantly (first ring: 2.2±1.0 mm, p<0.001; second ring: 2.7±1.1 mm, p<0.001). At 6 months, the first and second rings had expanded to a mean 96.6%±2.1% and 94.8%±2.7%, respectively, of their nominal diameter, after which the rings expanded slowly; ring diameters stabilized to near nominal size (first ring, 98.3%±1.1%; second ring, 97.2%±1.4%) at 24 months irrespective of initial oversizing. No type I or III endoleaks or aneurysm-, device-, or procedure-related adverse events were noted in follow-up. The difference in the diametric distances between the peaks and valleys of the saddle-shaped rings was marked at discharge but became smaller after 24 months for both rings (first ring: median 2.0 vs 1.2 mm, p=0.191; second ring: median 2.8 vs 0.8 mm; p=0.013). Conclusion: Irrespective of initial oversizing, the Anaconda proximal sealing rings radially expanded to near nominal size within 6 months after EVAR. Initial oval-shaped rings conformed symmetrically and became nearly circular through 24 months. These findings should be taken into account in planning and follow-up.