Chimney technique in combination with a sac-anchoring endograft for juxtarenal aortic aneurysms: technical aspects and early results.

BACKGROUND: Juxtarenal aortic aneurysms (JAAs) pose clinical challenges for vascular specialists. Chimney endovascular sealing (Ch-EVAS) might be an ideal endovascular solution in the treatment of JAAs. We present technical aspects and early clinical results of a multicenter experience with Ch-EVAS. METHODS: This was a retrospective, multicenter study. Between November 2014 and March 2016, 16 patients underwent elective endovascular repair of JAAs with Ch-EVAS of 1 or 2 renal and/or superior mesenteric artery vessels. Essential technical steps, early complications, chimney stent patency, gutter formation, type IA endoleak, 30-day outcome, renal function, and neck characteristics were the endpoints. RESULTS: There were 26 chimney stents implanted with 100% technical success. The intraoperative death and 30 day mortality was 0%. Secondary interventions were required in 3 patients each due to type IA endoleak, limb occlusion and brachial dissection. The latter patient presented with renal chimney stent occlusion and required hemodialysis. One patient was known to have a pulmonary malignancy and left-sided carotid stenosis and sustained a left hemispheric stroke after the endovascular procedure. The preoperative median aortic neck length was 3 mm, after Ch-EVAS the median seal length between endobags and the aortic neck was 25 mm. No further significant changes in neck morphology were found at the one-month follow-up. CONCLUSIONS: Ch-EVAS is an off-the-shelf solution to treat JAAs with high technical success. Longer-term follow-up with a substantial number of patients can answer the question of whether Ch-EVAS is a sustainable technique that is preferred over open surgery or fenestrated endovascular aneurysm repair.

Molecular MRI of murine atherosclerotic plaque targeting NGAL: a protein associated with unstable human plaque characteristics.

AIMS: Neutrophil gelatinase-associated lipocalin (NGAL) is an effector molecule of the innate immune system. One of its actions is the prolongation of matrix metalloproteinase-9 (MMP-9) activity by the formation of a degradation-resistant NGAL/MMP-9 complex. We studied NGAL in human atherosclerotic lesions and we examined whether NGAL could act as a target for molecular imaging of atherosclerotic plaques. METHODS AND RESULTS: Increased levels of NGAL and the NGAL/MMP-9 complex were associated with high lipid content, high number of macrophages, high interleukin-6 (IL-6) and IL-8 levels, and low smooth muscle cell content in human atherosclerotic lesions obtained during carotid endarterectomy (n= 122). Moreover, plaque levels of NGAL tended to be higher when intra-plaque haemorrhage (IPH) or luminal thrombus was present (n= 77) than without the presence of IPH or thrombus (n= 30). MMP-9 and -8 activities were strongly related to NGAL levels. The enhancement on magnetic resonance (MR) images of the abdominal aorta of ApoE(-/-)/eNOS(-/-) mice was observed at 72 h after injection of NGAL/24p3-targeted micelles. The specificity of these results was validated by histology, and co-localization of micelles, macrophages, and NGAL/24p3 was observed. CONCLUSION: NGAL is highly expressed in atheromatous human plaques and associated with increased MMP-9 activity. NGAL can be detected in murine atherosclerotic arteries using targeted high-resolution MR imaging. Therefore, we conclude that NGAL might serve as a novel imaging target for the detection of high-risk plaques.