Fei Xiong

Inhibition of AAA in a rat model by treatment with ACEI perindopril

BACKGROUND The purpose of the present study was to evaluate the effect of a new angiotensin converting enzyme inhibitor perindopril on the formation of experimental abdominal aortic aneurysms (AAAs) in a rat model induced by intraluminal elastase infusion and extraluminal calcium chloride (CaCl2) application. MATERIALS AND METHODS Thirty-six male Sprague-Dawley rats were randomly distributed into three groups (n = 12 per group): model (A), sham (B), and perindopril (C). Rats in model and perindopril groups underwent intra-aortic elastase perfusion and extraluminal CaCl2 application to induce AAAs. Rats in the sham group received aortic perfusion and extraluminal application of saline. A dose of 3 mg/kg/d of perindopril was fed orally in the perindopril group. The maximum abdominal aortic diameter was measured in vivo on days 0 and 28 and by ultrasound on days 7, 14, and 21. The arterial blood pressure was measured directly using a pressure transducer after cannulation in surgery and before death. AAA tissue samples were harvested at day 28 and evaluated using normal hematoxylin and eosin stain, Verhoeff-van Gieson stain for elastin, and image analysis technique. RESULTS Aortic diameters of rats in the model group consistently increased within 28 d, coinciding with the development of a transmural inflammatory response, thickening of intima, and destruction of the elastic media. Without alteration in blood pressure, the AAA formation rate and mean maximal diameter of aorta at day 28 were significantly lower in the perindopril group compared with the control group (1.71 ± 0.20 versus 2.70 ± 0.69 mm, P < 0.001; 0% versus 90.91%, P < 0.001) and were similar to those in the sham group (1.79 ± 0.29 mm, P = 0.175; 0%, P = 1). The thickness of intima in the perindopril group was lower than that in the model group (20.68 ± 9.96 versus 58.49 ± 32.01 μm, P = 0.001), but higher than that in the sham group (7.23 ± 2.68 μm, P = 0.005). The intensity of elastin fiber showed the opposite trend (0.8541 ± 0.0495 in sham group versus 0.7376 ± 0.1024 in perindopril group versus 0.5413 ± 0.0912 in model group, P < 0.001). CONCLUSIONS Perindopril inhibited the aortic degeneration and AAA formation in the experimental AAA model induced by elastase and CaCl2. This effect, which was independent of its influence on hemodynamics, appeared to be induced by the suppression of the inflammatory cell influx and intimal thickening and the preservation of aortic medial elastin.

A Systematic Review of Ultrasound or Magnetic Resonance Imaging Compared With Computed Tomography for Endoleak Detection and Aneurysm Diameter Measurement After Endovascular Aneurysm Repair

Purpose: To analyze the literature comparing ultrasound [duplex (DUS) or contrast-enhanced (CEUS)] or magnetic resonance imaging (MRI) with computed tomography angiography (CTA) for endoleak detection and aneurysm diameter measurement after endovascular aneurysm repair (EVAR). Methods: A systematic review identified 31 studies that included 3853 EVAR patients who had paired scans (DUS or CEUS vs CTA or MRI vs CTA) within a 1-month interval for identification of endoleaks during EVAR surveillance. The primary outcome was the number of patients with an endoleak detected by one test but undetected by another test. Results are presented for all endoleaks and for types I and III endoleaks only. Aneurysm diameter measurements between CTA and ultrasound were examined using meta-analysis. Results: Endoleaks were seen in 25.6% (985/3853) of patients after EVAR. Fifteen studies compared DUS with CTA for the detection of all endoleak types. CTA had a significantly higher proportion of additional endoleaks detected (214/2346 vs 77/2346 for DUS). Of 19 studies comparing CEUS with CTA for the detection of all endoleak types, CEUS was more sensitive (138/1694) vs CTA (51/1694). MRI detected 42 additional endoleaks that were undetected by CTA during the paired scans, whereas CTA detected 2 additional endoleaks that MRI did not show. CTA had a similar proportion of additional types I and III endoleaks undetected by CEUS or MRI. Of 9 studies comparing ultrasound vs CTA for post-EVAR aneurysm diameter measurement, the aneurysm diameter measured by CTA was greater than ultrasound (mean difference −1.70 mm, 95% confidence interval −2.45 to −0.96, p<0.001). Conclusion: This study demonstrated that CEUS and MRI are more accurate than CTA for the detection of post-EVAR endoleaks, but they are no better than CTA for detecting types I and III endoleaks specifically. Aneurysm diameter differences between CTA and ultrasound should be considered when evaluating the change in aneurysm diameter postoperatively.

Prevalence and risk factors of type II endoleaks after endovascular aneurysm repair: A meta-analysis

Objectives This systematic review and meta-analysis aims to determine the current evidence on risk factors for type II endoleaks after endovascular aneurysm repair (EVAR). Materials and methods A systematic literature search was carried out for studies that evaluated the association of demographic, co-morbidity, and other patient-determined factors with the onset of type II endoleaks. Pooled prevalence of type II endoleaks after EVAR was updated. Results Among the 504 studies screened, 45 studies with a total of 36,588 participants were included in this review. The pooled prevalence of type II endoleaks after EVAR was 22% [95% confidence interval (CI), 19%–25%]. The main factors consistently associated with type II endoleaks included age [pooled odds ratio (OR), 0.37; 95% CI, 0.31–0.43; P<0.001], smoking (pooled OR, 0.71; 95% CI, 0.55–0.92; P<0.001), patent inferior mesenteric artery (pooled OR, 1.98; 95% CI, 1.06–3.71; P = 0.012), maximum aneurysm diameter (pooled OR, 0.23; 95% CI, 0.17–0.30; P<0.001), and number of patent lumbar arteries (pooled OR, 3.07; 95% CI, 2.81–3.33; P<0.001). Sex, diabetes, hypertension, anticoagulants, antiplatelet, hyperlipidemia, chronic renal insufficiency, types of graft material, and chronic obstructive pulmonary diseases (COPD) did not show any association with the onset of type II endoleaks. Conclusions Clinicians can use the identified risk factors to detect and manage patients at risk of developing type II endoleaks after EVAR. However, further studies are needed to analyze a number of potential risk factors.

8-Year Long-Term Outcome Comparison: Two Ways to Exclude the Internal Iliac Artery during Endovascular Aorta Repair (EVAR) Surgery

Purpose To evaluate the 8-year long-term outcome after internal iliac artery (IIA) coverage with or without embolization in EVAR. Patients and Methods From January 2006 to December 2013, abdominal aortic aneurysm (AAA) subjects that underwent EVAR and IIA exclusion were recruited and analyzed retrospectively. All the subjects were divided into group A or B based on the presence or absence of intraoperative IIA embolization before coverage (group A: without embolization; group B: with embolization). The 30-day mortality, stent patency, and the incidences of endoleaks and ischemia of the buttocks and lower limbs were compared. The follow-up period was 96 months. Result There were 137 subjects (A: 74 vs. B: 63), 124 male (91.1%) and 13 female (9.5%), with a mean age of 71.6 years. There were no significant differences in the early outcomes of intraoperative blood loss (87.23±14.07 ml; A: 86.53±9.57 ml vs. B: 88.06±18.04 ml, p = .545) and surgery time (87.13±9.25 min; A: 85.99±7.07 min vs. B: 88.48±11.19 min, p = .130). However, there were significant differences in contrast consumption (65.18±9.85 ml; A: 61.89±7.95 ml vs. B: 69.05±10.50 ml, p<.001) and intraoperative X-ray time (5.9±0.86 min; A: 5.63±0.49 min vs. B: 6.22±1.07 min, P<.001). The 30-day mortality was approximately 0.73%. In the follow-up analysis, no significant differences were identified in the incidence of endoleak (22 subjects; type I: A: 2 vs. B: 2, p = 1.000; type II: A: 8 vs. B: 4, p = .666; type III: A: 4 vs. B: 3, p = 1.000), occlusion (5 subjects; 4.35%; A: 1 vs. B: 4, p = .180), or ischemia (9 subjects; 7.83%; A: 3 vs. B: 6, p = .301). In the analysis of group B, although there were no significant differences between subjects with unilateral and bilateral IIA embolization, but longer hospital stays were required (P<.001), and a more severe complication (skin and gluteus necrosis) occurred in 1 subject with bilateral IIA embolization. Conclusion IIA could be excluded during EVAR. IIA coverage without embolization had a good surgical and prognostic outcome, and this procedure was not different significantly from coverage with embolization in terms of endoleaks, patency and ischemia.

Post-treatment neutrophil-lymphocyte ratio independently predicts amputation in critical limb ischemia without operation

OBJECTIVES: Limited information is available concerning the post-treatment neutrophil-lymphocyte ratio in critical limb ischemia patients who receive conservative therapy. Accordingly, this study was designed to evaluate the predictive value of the post-treatment neutrophil-lymphocyte ratio in critical limb ischemia patients without surgery. METHOD: From January 2009 to January 2011, critical limb ischemia patients were admitted to a vascular center. The demographic data, patient histories, comorbidities and risk factors were documented, and the differential cell count was determined at admission and seven days later after conservative therapy. The cutoff value of the post-treatment neutrophil-lymphocyte ratio was determined by an ROC curve. Patients were divided into groups A and B according to the cutoff value. Amputation-free survival was compared between groups. Univariate and multivariate analyses were used to identify independent risk factors. RESULT: A total of 172 patients were identified with a mean age 71.98±10.09 years; among them, 122 were male. A value of 3.8 was identified as the cutoff value of the post-treatment neutrophil-lymphocyte ratio. Groups A (post-treatment neutrophil-lymphocyte ratio ≥3.8) and B (post-treatment neutrophil-lymphocyte ratio <3.8) showed a significant difference in amputation-free survival (P<0.001). The 1-year, 2-year and 3-year amputation-free survival rates were 79.6%, 55.6% and 46.3%, respectively, in group A; however, in group B, these values were 89.7%, 79.3% and 75.9%, respectively. The post-treatment neutrophil-lymphocyte ratio was identified as an independent predictive factor for amputation in critical limb ischemia patients (P<0.001). CONCLUSION: The post-treatment neutrophil-lymphocyte ratio is an independent predictive factor for amputation in critical limb ischemia patients. Patients with a post-treatment neutrophil-lymphocyte ratio ≥3.8 are likely to suffer from amputation; amputation-free survival usually occurs in patients with a post-treatment neutrophil-lymphocyte ratio <3.8.

Influence of distal entry tears in acute type B aortic dissection after thoracic endovascular aortic repair

Objective: This study evaluated the clinical influence of distal entry tears in acute type B aortic dissection (ATBAD) after thoracic endovascular aortic repair (TEVAR). Methods: From August 2009 to December 2014, the clinical outcomes of 130 patients who underwent TEVAR for ATBAD were retrospectively analyzed. According to whether distal entry tears existed after TEVAR, patients were divided into group A (n = 25, absence of distal entry tears) and group B (n = 105, presence of distal entry tears). We evaluated clinical outcomes, including mortality and morbidity in early and late follow‐up, as well as aortic remolding. Late aortic events were defined as aortic dissection‐related events occurring >30 days from the initial TEVAR procedures, which consisted of endoleak, retrograde type A aortic dissection, aortic enlargement, late rupture, repeat dissection, and stent‐induced new entry tear. Results: The study comprised 130 patients (114 men [87.7%] and 16 women [12.3%)] with a mean age of 53.71 years. The 30‐day mortality was 3.1%, and early morbidity included type I endoleak, 3.1%, organ failure, 3.8%; stroke, 3.1%; spinal cord ischemia, 0%; and early rupture 1.5%. The overall survival rate by Kaplan‐Meier analysis at 1, 3, and 5 years was 93.8%, 89.5%, and 79.2%, respectively. There were no significant differences in early morbidity and 30‐day mortality and late survival between group A and group B. However, group A had a significantly lower rate of late aortic events than group B (P = .028 by log‐rank test). Meanwhile, group A had better aortic remolding than group B in complete thrombosis of the thoracic aorta at 12 months postoperatively (100% vs 83.5%; P = .029). Conclusions: This study demonstrated that TEVAR for ATBAD had low perioperative morbidity and mortality and satisfactory midterm outcome. Distal entry tears increase the occurrence of late aortic events and inhibit aortic remolding but do not have a significantly negative effect on late survival. Repairing all entry tears to restore single‐lumen blood flow and enhance false lumen thrombosis might benefit selected patients.