One-year volume growth of abdominal aortic aneurysms measured by extended field-of-view ultrasound

One-year follow-up after active aortic aneurysm sac treatment with shape memory polymer devices during endovascular aneurysm repair

OBJECTIVE

To determine the safety and efficacy of treating abdominal aortic aneurysm (AAA) sacs with polyurethane shape memory polymer (SMP) devices during endovascular aneurysm repair (EVAR), using a technique to fully treat the target lumen after endograft placement (aortic flow volume minus the endograft volume). SMP devices self-expand in the sac to form a porous scaffold that supports thrombosis throughout its structure.

METHODS

Two identical prospective, multicenter, single-arm studies were conducted in New Zealand and the Netherlands. The study population was adult candidates for elective EVAR of an infrarenal AAA (diameter of ≥55 mm in men and ≥50 mm in women). Key exclusion criteria were an inability to adequately seal a common iliac artery aneurysm, patent sac feeding vessels of >4 mm, and a target lumen volume of <20 mL or >135 mL. Target lumen volumes were estimated by subtracting endograft volumes from preprocedural imaging-based flow lumen volumes. SMP devices were delivered immediately after endograft deployment via a 6F sheath jailed in a bowed position in the sac. The primary efficacy end point was technical success, defined as filling the actual target lumen volume with fully expanded SMP at the completion of the procedure. Secondary efficacy outcome measures during follow-up were the change in sac volume and diameter, rate of type II endoleak and type I or III endoleaks, and the rate of open repair and related reinterventions, with data collection at 30 days, 6 months, and 1 year (to date). Baseline sac volumes and diameters for change in sac size analyses were determined from 30-day imaging studies. Baseline and follow-up volumes were normalized by subtraction of the endograft volume.

RESULTS

Of 34 patients treated with SMP devices and followed per protocol, 33 patients were evaluable at 1 year. Preprocedural aneurysm volume was 181.4 mL (95% confidence interval [CI], 150.7-212.1 mL) and preprocedural aneurysm diameter was 60.8 mm (95% CI, 57.8-63.9 mm). The target lumen volume was 56.3 mL (95% CI, 46.9-65.8 mL). Technical success was 100% and the ratio of SMP fully expanded volume to estimated target lumen volume was 1.4 ± 0.3. Baseline normalized sac volume and diameter were 140.7 mL (95% CI, 126.6-154.9 mL) and 61.0 mm (95% CI, 59.7-62.3 mm). The adjusted mean percentage change in normalized volume at 1 year was -28.8% (95% CI, -35.3 to -22.3%; P < .001). The adjusted mean change in sac diameter at 1 year was -5.9 mm (95% CI, -7.5 to -4.4 mm; P < .001). At 1 year, 81.8% of patients (95% CI, 64.5%-93.0%) achieved a ≥10% decrease in normalized volume and 57.6% of patients (95% CI, 39.2%-74.5%) achieved a ≥5 mm decrease in diameter. No device- or study procedure-related major adverse events occurred through 1 year after the procedure.

CONCLUSIONS

Treatment of AAA sacs with SMP devices during EVAR resulted in significant sac volume and diameter regression at 1 year with an acceptable safety profile in this prospective study.

Abdominal aortic aneurysms volume growth patterns with three-dimensional ultrasound

BACKGROUND

Three-dimensional ultrasound (3D-US) and computed tomography (CT) have proven abdominal aortic aneurysm (AAA) volume a more sensitive measure of growth than diameter. This proof-of-concept study aimed to investigate the clinical applicability of two-dimensional ultrasound and 3D-US for AAA diameter and volume growth pattern evaluation.

METHODS

AAA patients with at least three follow-ups within a minimum of 24 months were included prospectively and consecutively from the COpenhagen Aneurysms CoHort (COACH). Individual diameter and volume growth rates were categorized as rapid, slow, or no growth (>6.0, 3.8-6.0, and ≤3.7 mm/year for diameter. >17.4, 8.8-17.3, and ≤8.7 mL/year for volume). Similarly, diameter and volume growth patterns were categorized as as linear, exponential, staccato, and indeterminate growth, based from individual regressions.

RESULTS

Thirty patients were included, of which 19 (63%) had no diameter growth, 10 (33%) had slow growth, and one (3%) had rapid growth. Regarding volume, 11 (37%) patients had no growth, 12 (40%) had slow growth, and seven (23%) had rapid growth. Growth patterns according to diameter showed that 18 (60%) patients had linear growth, none had staccato or exponential growth. Twelve (40%) were indeterminate. Volume growth patterns found 19 (63%) patients with linear growth, 3 (10%) with staccato, and none with exponential growth. Eight (27%) were indeterminate.

CONCLUSIONS

Analysis of AAA volume growth patterns is a practical and safe modality that seems more sensitive at detecting growth patterns than AAA diameter. Volume also detects more AAA growth than diameter.