Yongxue Zhang

Endovascular management of pararenal aortic aneurysms with multiple overlapping uncovered stents

OBJECTIVE This study aims at evaluating the safety and efficacy of a porous stent system consisting of multiple overlapping uncovered stents in the treatment of complex aortic aneurysms with vital branches. METHODS Data of all patients with aortic aneurysms treated in our center with multiple overlapping uncovered stents between February 2010 and December 2011 were retrospectively reviewed. Preoperative characteristics, intraoperative details, and follow-up outcomes were documented. Technical success was defined as successful deployment of the stents to target locations without procedure-related complications. Clinical success was characterized by complete shrinkage or stabilization of the aneurysm, preservation of vital branches, and absence of major complications. Patients were grouped, according to rapidity of aneurysm thrombosis, into fast-thrombosis group (complete thrombosis of aneurysmal sac was achieved in ≤6 months) and a delayed-thrombosis group (>6 months required for complete thrombosis). Possible factors affecting the speed of thrombosis were analyzed statistically with the Fisher exact test and the t-test. RESULTS This porous stent system was used to treat 34 patients (23 men, 11 women; mean age, 65.7 years). Technical success was achieved in all patients (100%). Regular follow-up over 6 months was achieved in 29 patients (mean length of follow-up, 11.4 months). Complete thrombosis of the aneurysm sac within 12 months was observed in 24 patients (83%). Aneurysm shrinkage was documented in seven patients (24%) and stabilization in 21 (72%). All branch arteries covered by bare stents stayed patent during follow-up. The overall clinical success rate reached 97% in the follow-up group. Risk factors for delayed thrombosis included fewer stents implanted (P = .013), longer sac entrance (P = .043), and use of antiplatelet medication (P = .040). CONCLUSIONS An alternative method of management of complicated aortic aneurysm appears to be feasible using overlapping bare stents, which may prevent aneurysm growth while preserving vital branches. The short-term outcome of our study seems encouraging but is not sufficient to draw a robust conclusion. Further hemodynamic and clinical studies are warranted to evaluate long-term efficacy.

Total Endovascular Repair of Thoracoabdominal Aortic Aneurysms With Non-Customized Stent Grafts

BACKGROUND Total endovascular repair of thoracoabdominal aortic aneurysms with customized branched or fenestrated endografts could be technically challenging outside large-volume centers. This study aims to describe a new endovascular strategy for use of both noncustomized stent grafts and flow-diverting stents in treating complicated thoracoabdominal aortic aneurysms. METHODS Patients diagnosed with thoracoabdominal aortic aneurysms and deemed unfit for open surgical repair were recruited. The aim of the procedure was to cover the renovisceral segment of the aorta with flow-diverting uncovered stents, while covering the remaining aneurysm with stent grafts. Aneurysm morphologic evolution and the patency of the visceral branches were assessed at follow-up. RESULTS Between February 2012 and August 2013, 6 selective patients (4 men, mean age 58 years) underwent the novel joint procedure. During mean follow-up of 14 months, aneurysm shrinkage (maximum diameter decrease ＞5 mm) was demonstrated in 4 patients and aneurysm stabilization (maximum diameter decrease ＜5 mm) was observed in 2 patients. No aneurysm expansion was observed in any participants. Mean aneurysm diameter decreased from 65.0±8.8 mm to 58.5±12.2 mm (p=0.054), with a significant increase in average sac thrombus deposition volume (sac thrombosis ratio increased from 23.3%±7.4% to 98.0%±3.3%, p＜0.001). The majority of side branches (23 of 24) were successfully preserved. CONCLUSIONS Complete endovascular repair of thoracoabdominal aortic aneurysms with this novel joint procedure may be a feasible alternative in high surgical risk patients. Further validation of this technique is required to substantiate these results.

Should the distal tears of aortic dissection be treated? The risk of distal tears after proximal repair of aortic dissection

BACKGROUND Patients with distal residual after proximal repair of aortic dissection (AD) have shown unsatisfactory long-term prognosis. However, possible mechanisms and risk factors for distal aortic segmental enlargement (DSAE) have been poorly understood. METHODS We analyzed 962 AD patients repaired to the descending aorta between 1999 and 2014. Aortic morphological characteristics of 419 patients (including 75 DSAE and 344 non-DSAE patients) were investigated and compared. Potential risk factors associated with DSAE were explored using logistic regression analysis or natural logarithmic transformation. Logistic multi regress equations were performed to identify independent risk factors. RESULTS Independent risk factors of DSAE are listed as follow: more tears in the thoracic descending aorta (odds ratio [OR], 1.65; 95% confidence interval [CI],1.24 to 2.19; P = .0005); fewer tears in the infra-renal abdominal aorta (OR, 3.00; 95% CI,2.04 to 4.55; P < .0001); closer distance of the first intimal tear to the left subclavian artery (OR, 1.51; 95% CI,1.28 to 1.69; P < .0001); larger average distance between tears (OR, 11.81; 95% CI,3.39 to 41.08; P = .0001); larger maximum distance between two tears (OR, 1.79; 95% CI,1.48 to 2.16; P < .0001), and larger area of remained tears (OR, 1.56; 95% CI, 1.38 to 1.76; P < .0001). CONCLUSIONS The location and size of remained tears are the key risk factors of DSAE patients. Long-segment aortic repair and aggressive exclusion of all distal tears located on the thoracic descending aorta in their initial therapy will be an optimal strategy.