Morphologic characteristics and endovascular treatment of primary infrarenal aortic dissections

We report the morphologic characteristics and endovascular treatment of primary infrarenal aortic dissections (PIRADs).

A retrospective study was conducted with 38 consecutive PIRAD patients between January 2010 and May 2016 in our vascular center. Patient demographics, morphologic characteristics, endovascular modalities, and periprocedural and follow-up outcomes were recorded. Patients with symptomatic PIRADs or asymptomatic PIRADs of a maximum diameter >30 mm were indicated for endovascular aneurysm repair (EVAR). We proposed a morphologic categorization of PIRADs into two types (I and II) according to the location of the entry tears and an endovascular strategy for treating type I PIRADs with tubular stent grafts (SGs) and type II PIRADs with bifurcated SGs.

According to the categorization, the study recruited 13 patients with type I and 25 patients with type II PIRADs. The patients were predominantly men, with an average age of 60.8 ± 15.2 years. Type I PIRADs usually had larger true lumens (22.6 ± 6.3 vs 13.6 ± 4.0 mm; P = .002) and relatively smaller false lumens (8.4 ± 2.3 vs 19.9 ± 16.1 mm; P = .012). Type II PIRADs had more entry tears (2.2 ± 0.6 vs 1.7 ± 0.6; P = .024) and longer dissections (109.4 ± 38.8 vs 73.9 ± 39.0 mm; P = .011). All patients underwent EVAR, with 19 tubular and 22 bifurcated SGs. One patient died during the hospital stay. The technical success rate was 94.8% (36/38), and the clinical success rate was 97.4% (37/38). During follow-up of 36 patients for 28.8 ± 17.7 months, 2 patients with type II PIRADs developed left iliac extension occlusion at 3 and 6 months after EVAR, and only 1 patient underwent reintervention. All patients survived throughout the follow-up. No endoleak or aortic enlargement was observed. Computed tomography angiography demonstrated a patent infrarenal aorta with completely thrombosed false lumen in all PIRAD patients (36/36 [100.0%]). In both types of PIRAD, EVAR yielded a significant decrease in the maximum diameter of the infrarenal aorta, with a significant increase in the true lumen size and a significant decrease in the false lumen size (P < .05).

The morphologic categorization of PIRADs based on the location of the entry tears appeared to be feasible. The endovascular strategy was safe and effective, with high rates of technical success and clinical success and favorable follow-up outcomes.