Abdominal aortic aneurysms: screening,epidemiology and open surgical repair

Abdominal Aortic Aneurysm (AAA) is a dilatation of the infra-renal abdominal aorta to greater than 3 cm. Population screening is offered to men in their 65th year in the UK. Patients with small AAAs (<5.5 cm) are entered into surveillance programs and should have cardiovascular risk factors managed aggressively. An AAA with ≥5.5 cm diameter should be considered for surgical repair to prevent rupture. Open surgical repair has proven to be a durable treatment for AAA and while less often performed than endovascular aneurysm repair (EVAR) it remains a common approach in the surgical management of AAA. While associated with higher short-term risks than EVAR, the long-term outcomes are similar and many younger patients have a preference for open repair as routine follow-up is not required.     

我国腹主动脉瘤腔内修复技术发展现状和展望

近30年来,我国的主动脉腔内修复手术(EVAR)技术发展迅速,凭借其创伤小、恢复快、严重并发症少等优势在腹主动脉瘤(AAA)的手术治疗中得到了广泛应用.随着各类新型技术和支架等耗材的不断出现,诸多解剖条件复杂的AAA不再是EVAR的禁忌证.EVAR未来发展离不开临床医学、基础医学、材料科学、生物工程、3D打印甚至人工智...     

Assessment of pre-operative delays in the management of elective abdominal aortic aneurysms

INTRODUCTION

Successful endovascular aneurysm repair (EVAR) requires detailed pre-operative imaging to allow device planning. This process may delay surgery and some aneurysms may rupture prior to intervention. The aim of this study was to quantify these delays.

PATIENTS AND METHODS

Data were collected prospectively on all patients presenting with non-ruptured abdominal aortic aneurysms (AAAs) between January 2003 and October 2005. The delay between referral, the first out-patient visit, CT-scan, follow-up appointment and surgery were quantified in all patients and compared between two groups undergoing open repair and EVAR.

RESULTS

A total of 146 patients underwent AAA repair during the study (48 EVAR versus 98 open repair). There was no significant differences in the wait for CT scans between the groups (median 42 days for EVAR versus 47 days for open repairs [P = 0.48]) or the median interval between decision to operate and surgery (56 days versus 42 days [P = 0.075]). However, the median delay between referral and surgery was significantly longer in those patients undergoing EVAR at 129 days versus 77 days for open repair (P = 0.02).

CONCLUSIONS

Patients presenting electively with AAAs experienced significant delay from referral to surgery. This delay was significantly greater in those patients undergoing endovascular repair. Inevitably, some patients will rupture whilst waiting and strategies aimed at reducing delay should be pursued.     

基质金属蛋白酶-9在腹主动脉瘤体组织中的表达及其临床意义

目的 通过检测基质金属蛋白酶-9（MMP-9）在人腹主动脉瘤（AAAs）组织中的定位表达，探讨MMP-9在腹主动脉瘤发病机制中的作用及临床意义。方法 应用免疫组织化学技术，检测了MMP-9在20例AAAs瘤体组织中的定位表达，并与15例动脉硬化闭塞性疾病（AODs）的病变管壁及10例正常动脉管壁组织中的MMP-9组织学表达进行对照研究。结果 AAAs动脉壁中富含大量MMP-9颗粒，MMP-9阳性表达率达95．0％（19／20）；正常动脉管壁组织未检测到MMP-9的表达；AODs病变血管壁内可见散在分布的MMP-9阳性颗粒，MMP-9阳性表达率为26．7％（4／15）。与AODs和正常动脉管壁相比较，MMP-9在AAAs瘤体组织中的表达差异具有意义（P〈0．01）。结论 腹主动脉瘤体组织中MMP-9的高表达，促进主动脉中层细胞外基质崩解进而导致动脉弹性下降、动脉扩张及进一步的瘤体形成，在AAAs的发病机制中具有重要作用。     

Outcomes associated with hyperglycemia after abdominal aortic aneurysm repair

Objective

We evaluated the association between postoperative hyperglycemia and outcomes after abdominal aortic aneurysm (AAA) repair.

肾动脉下腹主动脉瘤腔内修复术42例分析

目的 探讨肾动脉下腹主动脉瘤腔内修复术的价值。方法 中山大学附属第一医院自2001年12月至2005年4月．共手术治疗42例肾动脉下腹主动脉瘤病人。采用单侧或双侧股动脉入路植入带膜支架对肾动脉下腹主动脉瘤进行腔内修复。结果42例肾动脉下腹主动脉瘤病人接受了血管腔内修复术，手术全部成功。围手术期死亡2例，其中1例为术前腹主动脉瘤破裂休克时间较长，已经合并急性肾功能不全；另1例为术后出现脑血管意外，2例均在术后3d死亡。其余40例随访1-40个月，全部存活。结论 肾动脉下腹主动脉瘤腔内修复术是一种安全、有效的治疗方法，长期疗效仍有待进一步观察。     

Simple renal cyst and its association with sac shrinkage after endovascular aneurysm repair for abdominal aortic aneurysms

ObjectivePatients with abdominal aortic aneurysm (AAA) frequently have simple renal cyst (SRC), a common manifestation of connective tissue degeneration. This study aimed to determine whether SRC is a risk factor for failure of sac shrinkage after endovascular aneurysm repair (EVAR).MethodsBetween October 2013 and May 2017, there were 155 consecutive patients with an infrarenal AAA or a common iliac artery aneurysm who underwent EVAR with the GORE C3 Excluder (W. L. Gore & Associates, Flagstaff, Ariz) at Tokyo Medical University Hospital. All these patients were registered in a prospectively maintained database. Any kidney lesion >5 mm in diameter, with no evidence of contrast enhancement or septation and with low attenuation, was defined as SRC. A change in sac size of >5 mm from baseline was considered significant. The patients were divided into those with SRC and those without SRC, and sac shrinkage at 1 year and 2 years was compared. The presence of SRC was assessed with respect to being a risk factor for failure of sac shrinkage at 1 year using univariate and multivariable logistic regression analysis.ResultsThe patients were divided into two groups: those with SRC (92 patients [59.0%]) and those without SRC (63 patients [41.0%]). At 1 year and 2 years, significant differences were observed in the proportion of sac shrinkage between patients with SRC and those without SRC (19.2% vs 42.4% [P = .003] and 19.6% vs 53.3% [P = .001], respectively). Patients with SRC showed significantly less sac shrinkage than those without SRC at 1 year and 2 years (−2.0 ± 5.5 mm vs −4.4 ± 6.2 mm [P = .002] and −1.8 ± 6.3 mm vs −6.4 ± 8.6 mm [P = .005], respectively). Multivariable analysis demonstrated that SRC (odds ratio, 0.28; 95% confidence interval, 0.12-0.63; P = .002) and initial sac size (odds ratio, 1.05; 95% confidence interval, 1.01-1.09; P = .027) were positive and negative risk factors for sac shrinkage, respectively.ConclusionsThe presence of SRC is a risk factor for failure of sac shrinkage after EVAR. This suggests that AAA in patients with SRC has a more degenerated wall than in those without SRC. The property of the aneurysm wall may be associated with sac shrinkage after EVAR.     

Diabetes mellitus is not associated with major morbidity following open abdominal aortic aneurysm repair

Background

It has been suggested that there is an increased morbidity and mortality risk for diabetics undergoing elective aortic surgery. This, however, is not universally accepted. In this study, we utilize a national database to determine if diabetes is associated with adverse outcomes following open, elective, infrarenal abdominal aortic aneurysm (AAA) repair.

Methods

The American College of Surgeons’ National Surgical Quality Improvement Program database was queried to identify all patients who underwent an open, elective, nonruptured AAA repair from January 1, 2005 to December 31, 2007. Patient demographics, comorbidities, and outcomes were compared by diabetes status. Multivariate analysis was performed adjusting for demographics and comorbidities.

Results

There were 2110 American College of Surgeons’ National Surgical Quality Improvement Program patients who underwent an open, elective, nonruptured AAA repair during this time period. Of these patients, 245 (11.6%) had diabetes mellitus. The overall mortality rate was 3.7% (5.3% for diabetics and 3.5% for nondiabetics, P = 0.171).On bivariate analysis, diabetics were more likely to present preoperatively with cardiovascular and renal comorbidities. Postoperatively, there was no significant difference in mortality or in cardiac, pulmonary, or renal complications. Diabetics were more likely to develop superficial surgical site infections (SSIs) (4.5% versus 1.6%, P = 0.002).On multivariate regression, there was no difference in mortality or major complications between diabetics and nondiabetics (OR 1.4, 95% CI 0.68–2.71). Diabetics, however, were almost three times more likely to develop superficial SSIs (OR 2.8, 95% CI 1.29–6.00).

Conclusions

Diabetes mellitus is not associated with significantly worse major outcomes following open, elective, infrarenal AAA repair. Diabetics, however, are more likely to develop superficial SSIs.     

腔内修复术治疗腹主动脉瘤疗效及安全性系统评价

目的 系统评价血管腔内修复术（edovascular repair ER）与传统开腹术（open repair OR）治疗肾动脉下非破裂型腹主动脉瘤（abdominal aortic aneurysms AAA）的有效性与安全性。方法 计算机检索Cochrane Library（2008年第3期）、PubMed（1990?2008）、MEDLINE（OVID,1990?2008）、EMBASE.com（1990?2008）、中国生物医学文献数据库、中文科技期刊全文数据库及中国期刊全文数据库等数据库,并辅以手工检索。对纳入随机对照试验采用RevMan 5.0.18软件进行Meta分析。结果 纳入4个随机对照试验共6篇文献。Meta分析结果显示：与OR比较,ER能明显降低术后30d全因死亡率［OR=0.32, 95%CI（0.16, 0.62）,P=0.0008］和中期动脉瘤相关死亡率［OR=0.50,95%CI（0.30, 0.85）, P=0.010］,ER术后中期再次手术率高于OR［OR=2.43,95%CI（1.69, 3.50）,P＜0.00001］。中期全因死亡率及中期总并发症发生率差异无统计学意义（P＞0.2）。结论 ER是一种短期疗效肯定的治疗肾动脉下非破裂型AAA的微创治疗方式,ER发生再次手术危险性较高导致ER总体获益不确定,意味着合理筛选病例很重要。     

外科手术在肾下腹主动脉瘤治疗中的地位(附187例手术经验)

目的：就肾下型腹主动脉瘤的治疗经验，讨论外科手术的实用性和前途。方法：回顾分析1992年1月至2004年2月择期行肾下型腹主动脉瘤切除术187例，将其结果与经腔内治疗者作比较。结果：围手术期死亡1例(0．54％)，死亡原因是术后6h出现频发室性早搏、室颤，诱发大面积心肌梗死。手术时间平均为3．8h；出血量平均470ml．输血量445ml。ICU内恢复时间为12～24h。围手术期并发症包括心力衰竭17例，呼吸衰竭8例，急性心肌梗死2例，急性脑梗死1例，急性肾功能衰竭3例，无术后严重出血或失血性休克发生，也无下肢动脉栓塞发生。术后1、3、5年生存率分别为97．0％、84．6％及78.3％，随访期间病人死亡者的原因与腹主动脉瘤和手术无关。经腔内治疗手术目前仍有较高的中、远期并发症。结论：瘤体直径不能作为手术适应证的唯一指标。术前同时应确切评价全身重要脏器功能。影响腹主动脉瘤手术的危险因素主要是高龄、严重心、肺疾患及肾功能不全等。迄今，经腹手术仍是治疗腹主动脉瘤的主要方法。     

Reduced protease inhibitory capacity in patients with abdominal aortic aneurysms is reversed with surgical repair

BACKGROUND: Abdominal aortic aneurysm (AAA) disease is a complex degenerative process that is associated with elevated proteolytic activity. This increased proteolytic activity may be linked to an imbalance in the protease regulatory mechanisms. We hypothesize that reduced AAA plasma inhibitory capacity is related to increased elastolytic activity observed in patients with AAA, which promotes matrix degradation in the aortic wall and AAA expansion. METHODS: Preoperative plasma from patients with AAA (n = 86; mean age, 75 +/- 8 years) and healthy controls (n = 30; mean age, 72 +/- 10 years) was assayed for inhibitory capacity. Postoperative plasma inhibitory capacity was evaluated with comparison of the activity of porcine pancreatic elastase on succinylated elastin substrate, in the presence and absence of AAA and control plasma. RESULTS: AAA plasma showed a significantly reduced capacity to inhibit porcine pancreatic elastase (71.31% +/- 1.47%) compared with control plasma (85.52% +/- 1.70%; P <.001). Within the AAA group, the inhibitory capacity increased with AAA diameter (P <.05). In addition, surgical repair of AAA resulted in a significant increase in plasma inhibitory capacity (79.83% +/- 1.86%) as compared with preoperative levels (63.98% +/- 2.69%; P <.001). Of note, the postoperative plasma inhibitory capacity is not significantly different than that of control. CONCLUSION: AAA plasma has a significantly reduced inhibitory capacity, which varies with aortic diameter and returns to control levels after surgical repair of the AAA. This suggests that protease regulation is a dynamic balance that changes with AAA progression and may play an important role in AAA progression.     

Sex differences in Japanese patients with ruptured aortic aneurysms

ObjectiveThis study aimed to assess the sex differences in clinical presentation and outcomes of Japanese patients with ruptured aortic aneurysm (rAA) using a large nationwide claims-based database in Japan.MethodsWe identified patients hospitalized in certified teaching hospitals in Japan with rAA between April 1, 2012, and March 31, 2015. Patients' characteristics and in-hospital outcomes were compared between men and women. The Barthel index was used for evaluating functional status at discharge by examining the ability to perform basic daily activities.ResultsOf 7086 eligible patients, 32.3% (2291/7086) were women. Women were older than men (81.9 years vs 76.1 years; P < .001), had higher prevalence of coma at admission (33.2% vs 25.2%; P < .001), and were less likely to undergo emergency operation including endovascular aneurysm repair (35.7% vs 51.1%; P < .001). The unadjusted mortality rate (62.5% vs 52.0%; P < .001) and Barthel index at discharge (78.7 vs 86.1; P < .001) were significantly worse in women than in men. However, multilevel mixed-effect logistic regression analyses showed that female sex itself was not an independent predictor for in-hospital death (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.78-1.04; P = .17). Older age, coma at admission, and vasopressor use were detected as independent predictors for in-hospital death. The same results were confirmed for each rupture site. Stratified analyses showed that older women (threshold, 80 years; OR, 0.81; 95% CI, 0.66-0.98; P = .028) and those who underwent emergency operation (OR, 0.75; 95% CI, 0.61-0.93; P = .009) showed significantly better outcomes than men.ConclusionsIn a univariate analysis, female patients with rAA showed worse mortality than men because of their older age, more severe clinical presentation, and low emergency operation rate. However, after adjustment for covariates, female sex itself was not associated with increased mortality.     

Anticoagulants and reduced thrombus load in abdominal aortic aneurysms assessed with three-dimensional contrast-enhanced ultrasound examination

ObjectiveThe relationship between intraluminal thrombus (ILT) and abdominal aortic aneurysm (AAA) growth and rupture risk remains ambiguous. Studies have shown a limited effect of antiplatelet therapy on ILT size, whereas the impact of anticoagulant therapy on ILT is unresolved. This study aims to evaluate an association between antithrombotic therapy and ILT size assessed with three-dimensional contrast-enhanced ultrasound (3D-CEUS) examination in a cohort of patients with AAA.MethodsIn a cross-sectional study, 309 patients with small AAAs were examined with 3D-CEUS. Patients were divided into three groups based on prescribed antithrombotic therapy: anticoagulant (n = 36), antiplatelet (n = 222), and no antithrombotic therapy (n = 51). Patient ILT size was calculated in volume and thickness and compared between the three groups.ResultsPatients on anticoagulants had a significantly lower estimated marginal mean ILT volume of 16 mL (standard error [SE], ±3.2) compared with 28 mL (SE, ±2.7) in the no antithrombotic group and 30 mL (SE, ±1.3) in the antiplatelet group when adjusting for AAA volume (P < .001) and comorbidities (P < .001). In addition, patients on anticoagulant therapy had significantly lower estimated marginal mean ILT thickness of 10 mm (SE, ±1.1) compared with 13 mm (SE, ±0.9) in the no antithrombotic group of and 13mm (SE, ±0.4) in the antiplatelet group when adjusting for AAA diameter (P = .03) and comorbidities (P = .035).ConclusionsA 3D-CEUS examination is applicable for ILT assessment and demonstrates that patients with AAA on anticoagulant therapy have lower ILT thickness and volume than patients with AAA on antiplatelet therapy and those without antithrombotic therapy. Causality between anticoagulants and ILT size, and extrapolation to AAA growth and rupture risk, is unknown and merits further investigations, to further nuance US-based AAA surveillance strategy.     

The expression and role of tenascin C in abdominal aortic aneurysm formation and progression

Open in a separate window OBJECTIVESUp-regulation of tenascin C (TNC), a matricellular protein, produced mainly by vascular smooth muscle cells (VSMC), is associated with the progression and dilation of abdominal aortic aneurysms (AAA). The aims of this study were (i) to evaluate whether serum levels of TNC in patients with AAA patients correlate with aortic diameter and (ii) to clarify the role of TNC in formation and progression of AAA in a murine model.METHODSIn 15 patients with AAA serum levels of TNC were measured and correlated with aortic diameters. Moreover, in a murine calcium chloride AAA model, the impact of TNC deficiency on AAA diameter was evaluated. Finally, human VSMC were incubated with TNC to clarify its regulating potential.RESULTSIn the clinical cohort, there was a trend of correlation between serum TNC levels and AAA diameter (P = 0.055). TNC knock out mice with AAA showed significantly lower diameter ratios compared to the wild-type group (WT) 3 weeks (P < 0.05) and 10 weeks (P < 0.05) after AAA induction. Immunohistochemistry revealed increased TNC expression in aortic tissue from WT with AAA as compared sham-operated mice. Furthermore, WT with AAA showed a more disrupted Elastin structure than TNC knock out mice 10 weeks after AAA induction. In human aortic VSMC, TNC incubation induced expression of remodelling associated proteins.CONCLUSIONSTNC might play a causative role in the formation, dilation and progression of AAA. Our results indicate that TNC might be a biomarker as well as a potential therapeutic target in the treatment of AAA.     

Predictors of acute kidney injury after infrarenal abdominal aortic aneurysm repair in octogenarians

Objective

Acute kidney injury (AKI) is a common postoperative complication after abdominal aortic aneurysm (AAA) repair and is associated with significant morbidity and mortality. However, limited studies have investigated this complication in elderly patients. This study aims to evaluate AKI in octogenarians after open endovascular AAA repair (OAR) and endovascular AAA repair (EVAR).

Aneurysm sac failure to regress after endovascular aneurysm repair is associated with lower long-term survival

Background

The early survival advantage of endovascular aneurysm repair (EVAR) compared with open repair reverses over time, possibly because of higher rates of reintervention related to endoleaks and aneurysm sac expansion. Therefore, we sought to examine the association between sac behavior, endoleaks, reintervention, and long-term survival.

Fenestrated endovascular aneurysm repair is associated with lower perioperative morbidity and mortality compared with open repair for complex abdominal aortic aneurysms

ObjectiveThe Zenith Fenestrated Endovascular Graft (ZFEN; Cook Medical, Bloomington, Ind) has expanded the anatomic eligibility of endovascular aneurysm repair (EVAR) for complex abdominal aortic aneurysms (AAAs). Current data on ZFEN mainly consist of single-institution experiences and show conflicting results. Therefore, we compared perioperative outcomes after repair using ZFEN with open complex AAA repair and infrarenal EVAR in a nationwide multicenter registry.MethodsWe identified all patients undergoing elective AAA repair using ZFEN, open complex AAA repair, and standard infrarenal EVAR between 2012 and 2016 within the American College of Surgeons National Surgical Quality Improvement Program targeted vascular module. Open complex AAA repairs were defined as those with a juxtarenal or suprarenal proximal AAA extent in combination with an aortic cross-clamping position that was above at least one renal artery. The primary outcome was perioperative mortality, defined as death within 30 days or within the index hospitalization. Secondary outcomes included postoperative renal dysfunction (creatinine concentration increase of >2 mg/dL from preoperative value or new dialysis), occurrence of any complication, procedure times, blood transfusion rates, and length of stay. To account for baseline differences, we calculated propensity scores and employed inverse probability-weighted logistic regression.ResultsWe identified 6825 AAA repairs—220 ZFENs, 181 open complex AAA repairs, and 6424 infrarenal EVARs. Univariate analysis of ZFEN compared with open complex AAA repair demonstrated lower rates of perioperative mortality (1.8% vs 8.8%; P = .001), postoperative renal dysfunction (1.4% vs 7.7%; P = .002), and overall complications (11% vs 33%; P < .001). In addition, fewer patients undergoing ZFEN received blood transfusions (22% vs 73%; P < .001), and median length of stay was shorter (2 vs 7 days; P < .001). After adjustment, open complex AAA repair was associated with higher odds of perioperative mortality (odds ratio [OR], 4.9; 95% confidence interval [CI], 1.4-18), postoperative renal dysfunction (OR, 13; 95% CI, 3.6-49), and overall complication rates (OR, 4.2; 95% CI, 2.3-7.5) compared with ZFEN. Compared with infrarenal EVAR, ZFEN presented comparable rates of perioperative mortality (1.8% vs 0.8%; P = .084), renal dysfunction (1.4% vs 0.7%; P = .19), and any complication (11% vs 7.7%; P = .09). Furthermore, after adjustment, there was no significant difference between the odds of perioperative mortality, postoperative renal dysfunction, or any complication between infrarenal EVAR and ZFEN.ConclusionsZFEN is associated with lower perioperative morbidity and mortality compared with open complex AAA repair, and outcomes are comparable to those of infrarenal EVAR. Long-term durability of ZFEN compared with open complex AAA repair warrants future research.