Guojun Zeng

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.

Resection of Carotid Body Tumors and the Additional Choice of Intraoperative Shunt in Complicated Tumors

BACKGROUND The purpose of this article is to describe an additional choice of intraoperative shunt in the surgical repair of complicated carotid body tumors (CBTs). METHODS Between January 2005 and August 2010, 47 CBT resections were performed at our division. Thirty-seven patients underwent routine tumor resection (78.7%). However, 10 of the tumor resections were complicated because of severe adhesions and involvement of the carotid artery. It was difficult to excise the tumors using routine methods. Intraoperative shunts were used for resection of these 10 complicated tumors (21.3%). RESULTS All patients underwent successful resection of the CBTs. No severe intraoperative or postoperative complication was observed in the shunted group. There were two cases with hypotension and one case with blood pressure fluctuation in the unshunted group. The mean follow-up duration was 35.3 (range, 12-60) months. CONCLUSION Surgical resection is the treatment of choice for CBTs. Shunts are not routinely used in the repair and represent just an additional choice for the resection of complicated CBTs. In this study, shunts have been shown to maintain cerebral circulation, decrease the size of tumor by excluding the vascular supply of the external carotid artery, and guide the resection when the tumors were complicated and difficult to excise. Shunt insertion was found to be safe and not associated with severe cerebrovascular complications.

A Comparison Between the Treatments of Functional and Nonfunctional Carotid Body Tumors

BACKGROUND It is well known that carotid body tumors (CBTs) are rare and almost nonfunctional, and that functional CBTs are even less frequently seen, with or without catecholamine-induced symptoms. Objective of this study is to make comparison between the treatment effects on functional and nonfunctional CBTs. METHODS The medical records of 46 patients (16 men and 30 women) of our unit who underwent surgical intervention for CBTs were retrospectively reviewed from January 2005 to July 2010. Patients were divided into two groups by function: group A (n = 5, functional CBTs) and group B (n = 41, nonfunctional CBTs). Perioperative and postoperative details were compared accordingly. RESULTS All the patients successfully underwent tumor resection. Although symptoms were nonspecific, intraoperative hypertension (5/5, 100%) and persistent postoperative hypotension (3/5, 60%) were found in group A. No statistical difference was found in perioperative details and complications between two groups. No recurrence occurred in two groups during the follow-up period for a mean of 35.3 months (with a range of 12-60 months). CONCLUSION Surgical resection is safe and effective even if the CBT is functional. Besides routine preparation, preoperative measurement of serum catecholamine, treatment with α- and β-adrenergic blockade and gentle manipulation during operation are necessary.

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.

Use of an intraoperative shunt for easy resection of complicated carotid body tumors.

This study was carried out to explore the use of an intraoperative shunt during surgical resection of complicated carotid body tumors (CBTs).

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.

Clinical characteristics and strategy for treatment of functional carotid body tumours

Functional carotid body tumours are rare, but linked to malignant hypertension, postoperative persistent hypotension, cranial nerve injury and stroke. The aim of this study is to analyze the treatment options for functional carotid body tumours. Six patients with functional carotid body tumours who underwent surgical procedures were studied retrospectively. They all had abnormal levels of preoperative catecholamine (norepinephrine, 721±452.2 ng/l). One patient presented preoperative hypertension. Preoperative alpha- and beta-adrenergic blockade was carried out. Surgical methods included complete resection (6), saphenous vein interposition (3) and carotid shunt (1). With thorough supervision and treatment, the 6 patients underwent tumour resection. They all experienced intraoperative hypertension while the tumours were being resected. Postoperative problems included endurance hypotension (3/6, 50%), coughing when drinking (3/6, 50%) and deviation of the tongue on protrusion (3/6, 50%). The clinical highlights of functional carotid body tumour include preoperative abnormal catecholamine, peroperative fluctuations of blood pressure level, and regime issues. Operative resection could be the best option for functional carotid body tumours. Careful preoperative evaluation, measurement of serum catecholamine, treatment for alpha- and beta-adrenergic blockade, and gentle intraoperative manipulation are essential to avoid life-threatening complications.