Abdominal aortic aneurysm calcification and thrombus volume are not associated with outcome following endovascular abdominal aortic aneurysm repair

Objectives

Aortic calcification and thrombus have been postulated to worsen outcome following endovascular abdominal aortic aneurysm repair (EVAR). The purpose of this study was to assess the association of abdominal aortic aneurysm (AAA) calcification and thrombus volume with outcome following EVAR using a reproducible, quantifiable computed tomography (CT) assessment protocol.

Methods

Patients with elective EVAR performed between January 2002 and 2012 at the Townsville Hospital, Mater Private Hospital (Townsville) and Royal Brisbane and Women’s Hospital (RBWH) were included if preoperative CTAs were available for analysis. AAA calcification and thrombus volume were measured using a semiautomated workstation protocol. Outcomes were assessed in terms of clinical failure, endoleak (type I, type II) and reintervention. Univariate and multivariate analyses were performed. Median follow-up was 1.7 years and the interquartile range 1.0–3.8 years.

Results

One hundred thirty-four patients undergoing elective EVAR were included in the study. Rates of primary clinical success and freedom from reintervention were 82.8 % and 88.9 % at the 24-month follow-up. AAA calcification and thrombus volume were not associated with clinical failure, type I endoleak, type II endoleak or reintervention.

Conclusions

AAA calcification and thrombus volume were not associated with poorer outcome after EVAR in this study.

Key Points

? The association of calcification and thrombus volumes with EVAR outcome is unclear ? Quantifiable methods for assessing calcification and thrombus were not used previously ? This study used reproducible methods for assessing AAA calcification and thrombus volumes     

Complications following endovascular abdominal aortic aneurysm repair

There is a growing population of patients who have undergone endovascular abdominal aortic aneurysm repair (EVAR) and thus there is an increasing likelihood that radiologists who are unfamiliar with this technique and its complications will have to report radiological investigations on one of these patients. The purpose of this review is to describe and illustrate the normal and abnormal radiological appearances after EVAR on plain radiography, ultrasound and CT.     

腹主动脉瘤腔内修复术22例围手术期处理回顾性总结

目的 总结腹主动脉瘤腔内修复术(EVAR)围手术期处理的临床经验.方法 回顾分析22例腹主动脉瘤患者EVAR临床经过,通过术前对主要脏器功能进行评估和保护,CTA测量近远侧瘤颈长度、直径、角度和构型,瘤体与分支动脉的关系,最低肾动脉开口至腹主动脉分叉的距离,导入途径的直径、扭曲和钙化程度.根据CTA测量结果,选择覆膜支架和手术方式.术时采用局麻20例,中转全麻l例,1例通过髂总动脉重建导人途径采用硬膜外麻醉,1例合并Stanf.0rd A型主动脉夹层,术时采用全麻.在支架释放前准确定位最低肾动脉位置,至少保留一侧通畅的髂内动脉,若双侧需要覆盖,分期覆盖或髂内动脉重建.支架植入后复查造影,有无内漏.正确判断内漏类型并进行相应处理.支架近端Ⅰ内漏2例,球囊扩张1例,植入Cuff 1例;支架远端Ⅰ内漏1例,球囊扩张时,动脉破裂,行人工血管补片修补术;Ⅲ型内漏3例,球囊扩张后支架植入1例.1例合并Starford A型主动脉夹层先行胸主动脉腔内修复术,后行EVAR.术后7一10 d复查CTA,以后每年复查1次.结果 EVAR手术全获成功.主要并发症为单侧髂肢扭结继发血栓形成,Fogarty导管取栓并支架植人1例;腹壁切口裂开1例,清创缝合;无手术死亡,随访6个月～5年,患者均存活.结论 CTA图像质量高、测量准确,是EVAR术前评估和术后随访的金标准.EVAR是高危、高龄腹主动脉瘤患者有效的治疗方法.     

Renewed endovascular repair for recurrent acute abdominal aortic aneurysm

The aim of the study was to describe the successful endovascular management of a patient who was admitted urgently with a second episode of acute abdominal aortic aneurysm (AAA) 30 months after emergency endovascular abdominal aortic aneurysm repair (eEVAR) for a ruptured AAA. The patient, an 84 year-old male physician, presented with severe acute abdominal and back pain. Contrast-enhanced computer tomography scanning showed type III endoleak owing to complete disconnection of both graft limbs and the prosthetic main body. Treatment consisted of acute stent-grafting with two bridging stent-grafts to seal the endoleak and reline the graft. The patient is alive and well 6 months postoperatively. This case indicates the need for follow-up after eEVAR, but also that complications can be managed endovascularly.     

采用血管缝合器治疗复杂型腹主动脉瘤腔内隔绝术一例

腹主动脉瘤腔内修复术(TEVAR)常规采用双侧股动脉切开途径置入.我们采用血管缝合器顺利完成1例复杂型TEVAR,现报道如下.患者男,56岁.既往有10年高血压、糖尿病及糖尿病肾病史,行口服药物治疗.3年前发现腹部搏动性包块,CT确诊断为肾下型腹主动脉瘤,当时测得瘤体最大径约35 mm.     

Abdominal aortic aneurysms: cost-effectiveness of elective endovascular and open surgical repair

PURPOSE: To evaluate the cost-effectiveness of elective endovascular and open surgical repair of infrarenal abdominal aortic aneurysms (AAAs) by taking into account short- and long-term outcomes. MATERIALS AND METHODS: A Markov decision model was developed to evaluate quality-adjusted life-years (QALYs) and lifetime costs of endovascular and open surgical repair. The incremental cost-effectiveness ratio (CER) was calculated for endovascular repair relative to open surgery in a cohort of 70-year-old men with an AAA between 5 and 6 cm in diameter. Clinically effectiveness data were derived from the literature. Cost data were derived from Medicare reimbursement rates, the hospital database, and the literature. One- and multiple-way sensitivity analyses were performed on uncertain model parameters. Costs were converted to year 2000 U.S. dollars; future costs and outcomes were discounted at 3%. RESULTS: The incremental CER of endovascular repair was 9,905 dollars per QALY. QALYs and lifetime costs were higher for endovascular repair than for open surgery (6.74 vs 6.52 and 39,785 dollars vs 37,606 dollars, respectively). In sensitivity analyses, the incremental CER was insensitive to immediate conversion rate and procedure mortality rate. The incremental CER was sensitive (ie, more than 75,000 dollars per QALY or endovascular repair was ruled out by dominance) to systemic-remote complications, long-term failures, and ruptures. CONCLUSION: The results suggest that endovascular repair is a cost-effective alternative compared with open surgery for the elective repair of AAA. The benefits and cost-effectiveness are highly dependent on uncertain outcomes, however, particularly long-term failure and rupture rates.     

Low-dose multidetector-row CT-angiography of abdominal aortic aneurysm after endovascular repair

Purpose

To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm.

Materials and methods

In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement.

Results

Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p < 0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p = 0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63 ± 6.97 vs. 11.48 ± 8.13; p = 0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol.

Conclusion

In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.     

Abdominal aortic aneurysm in Behçet's disease: treatment with endovascular stent graft

A case of acute rupture of an abdominal aortic aneurysm in a patient with Beh?et's disease is reported. The patient was successfully treated by implantation of an endovascular stent graft. The preinterventional diagnostic procedures and the postinterventional follow-up are described and the benefit and risk vs open surgery is discussed.     

Abdominal aortic aneurysm: contrast-enhanced US for missed endoleaks after endoluminal repair

PURPOSE: To evaluate contrast material-enhanced ultrasonography (US) for depiction of endoleaks after endovascular abdominal aortic aneurysm repair (or endovascular aneurysm repair [EVAR]) in patients with aneurysm enlargement and no evidence of endoleak. MATERIALS AND METHODS: From November 1998 to February 2003, 112 patients underwent EVAR. At follow-up, duplex US and biphasic multi-detector row computed tomographic (CT) angiography were performed. In 10 patients (group A), evident aneurysm enlargement was observed, with no evidence of complications, at both CT angiography and duplex US. Group A patients, 10 men (mean age, 69.6 years +/- 10 [standard deviation]), underwent US after intravenous bolus injection of a second-generation contrast agent, with continuous low-mechanical index (0.01-0.04) real-time tissue harmonic imaging. Group B patients, 10 men (mean age, 71.3 years +/- 8.2) with aneurysm shrinkage and no evidence of complications, and group C patients, 10 men (mean age, 73.2 years +/- 6) with CT angiographic evidence of endoleak, underwent contrast-enhanced US. Digital subtraction angiography (DSA) was performed in groups A and C. Endoleak detection and characterization were assessed with imaging modalities used in groups A-C; at contrast-enhanced US, time of detection of endoleak, persistence of sac enhancement, and morphology of enhancement were evaluated. RESULTS: In group A, contrast-enhanced US depicted one type I, six type II, one type III, and two undefined endoleaks that were not detected at CT angiography. All leakages were characterized by slow and delayed echo enhancement detected at longer than 150 seconds after contrast agent administration. DSA results confirmed findings in all patients; percutaneous treatment was performed. In group B, contrast-enhanced US did not show echo enhancement; in group C, results with this modality confirmed findings at CT angiography and DSA. CONCLUSION: Contrast-enhanced US depicts endoleaks after EVAR, particularly when depiction fails with other imaging modalities.     

Endovascular treatment of endoleaks after endovascular abdominal aortic aneurysm repair: personal experience

PURPOSE: This paper describes the different endovascular treatments (cuffs, endografts and embolisation) available for types I, II and III endoleaks occurring after endovascular abdominal aortic aneurysm repair (EVAR). MATERIALS AND METHODS: From January 2000 to June 2006, 134 patients (118 men, 16 women; mean age 75.1 years) underwent EVAR. Ten patients (7%) developed significant endoleaks requiring endovascular treatment. RESULTS: Five endoleaks were type I, two were type II and three were type III. Of the five type I endoleaks, four were proximal and one was distal. The proximal endoleaks were treated by cuff deployment, whereas the distal endoleak was treated with a bifurcated graft. Of the two patients with type II endoleak, one was treated by translumbar puncture and coil embolisation, and the other was treated by superselective embolisation of the lumbar feeding vessel with nonresorbable particles. Of the three patients with type III endoleak, two were treated by deploying an aortouniiliac endograft inside the bifurcated graft and the other by implanting a cuff to restore continuity between the graft body and the contralateral limb. Endovascular treatment was successful in 6/10 cases, whereas three cases required surgical conversion. One patient did not undergo surgery owing to poor general condition. CONCLUSIONS: The reported incidence of endoleaks after EVAR is 10%-20%. Significant endoleaks should be treated promptly. Endovascular treatment can be done with different techniques, but success in not constant due to adverse anatomical conditions and technical difficulties.     

Follow-up of abdominal aortic aneurysm after endovascular aortic repair: comparison of volumetric and diametric measurement

Purpose

To determine the correlation of maximal diameter measurements with volumetric evaluation of size after endovascular aortic repair (EVAR) of abdominal aortic aneurysms (AAA) using computed tomography angiography (CTA) and to survey its applicability for clinical follow-up.

Materials and methods

73 consecutive patients (2 females, 71 males; age 38–84 years; mean age, 69.1 ± 8 years) with AAA were treated with percutaneous EVAR in a single institution. For follow-up, CTA was performed periodically after EVAR. Images were evaluated for maximal diameter in consensus by two experienced radiologists. Using OsirixTM, volumetric measurements were done by one radiologist, including the entire infrarenal abdominal aorta.

Results

In 73 patients 220 CTA examinations were performed after EVAR with a mean follow-up of 17.3 months (range, 1.8–42.7 months). The mean postinterventional volume of aneurysm was 165.63 ml ± 93.29 ml (range, 47.94–565.67 ml). The mean maximal postinterventional diameter was 5.91 ± 1.52 cm (range, 3.72–13.82 cm). At large over the entire observation period a slight, non-significant decrease of 1.6% (2.58 ml ± 69.05 ml, range 82.82–201.92 ml) in volumes and a 9.3% (mean 0.55 cm ± 1.22 cm, range 2.85–1.93 cm) in diameters were observed. For all examinations a high correlation of volume and diameter was calculated (r = 0.813–0.905; α < 0.01).

Conclusion

For follow-up of abdominal EVAR using CTA there is a high correlation between volumetric and diametric measurements of aneurysm. Based on a daily clinical routine setting, measurements of maximal diameters in cross sectional imaging of AAA after EVAR seems to be sufficient to exclude post interventional enlargement.     

Midterm results of endovascular abdominal aortic aneurysm repair: comparison of instruction-for-use (IFU) cases and non-IFU cases

Purpose

To investigate the midterm results of abdominal aortic aneurysm repair (EVAR) and compare the endoleak (EL) and abdominal aortic aneurysm (AAA) prognoses between instruction-for-use (IFU) patients and non-IFU patients.

Materials and methods

Of 124 patients (104 men, 20 women; mean age 76.2 years; age range 58–93 years) with AAA who underwent EVAR with the Zenith (68 patients) or Excluder device (56) and were analyzed, 86 were IFU and 38 non-IFU.

Results

The mean absorbed dose of radiation exposure was 1907 mGy in the IFU group and 2283 mGy in the non-IFU group (p = 0.013). Thirty-five patients experienced EL: 8 (6.5 %) type I and 27 (21.8 %) type II. Type I ELs were observed in 3 patients in the IFU group (3.5 %) and 5 patients in the non-IFU group (13.2 %). Of the 14 patients with AAA diameter expansion of ≥5 mm, 6 (6/86, 7.0 %) belonged to the IFU group and 8 (8/38, 21.1 %) to the non-IFU group (p = 0.027).

Conclusion

The frequency of AAA expansion ≥5 mm was higher in non-IFU patients than in IFU patients. Therefore, careful follow-up is necessary for non-IFU patients rather than IFU patients.     

腔内修复治疗累及左锁骨下动脉的主动脉夹层动脉瘤

目的 探讨累及左锁骨下动脉的主动脉夹层动脉瘤腔内修复治疗的手术方式及疗效.方法 回顾性分析2004年1月至2014年12月采用不同腔内修复术式治疗56例主动脉夹层动脉瘤患者临床资料,其中男42例,女14例.采用“烟囱”技术重建左锁骨下动脉血流26例(A组),分支支架技术重建10例(B组),复合手术重建20例(C组).术中使用国产覆膜支架26例,进口覆膜支架30例;全身麻醉48例,局部麻醉8例.结果 手术全部成功(100％),无手术死亡患者.A组植入裸支架11例,覆膜支架15例;C组4例先植入胸主动脉覆膜支架,直接覆盖左锁骨下动脉,再作腋-腋动脉人工血管旁路移植术;16例先作腋-腋动脉人工血管旁路移植术,再行主动脉腔内修复覆盖左锁骨下动脉.3组患者出院时CTA检查显示支架形态均良好,无明显移位,组间差异无统计学意义(P＞0.05).内漏发生在A组有4例(15.4％),B组1例(11％),C组1例(5％),组间差异均无统计学意义(P＞0.05).52例(92.9％)患者获平均23.5个月随访,死亡5例(9.6％),原因为心肌梗死(2例)、肿瘤(3例).47例CTA随访发现6例仍有部分内漏,24例远端胸腹主动脉仍有夹层但未扩大,未作特殊处理,目前均在随访中.结论 “烟囱”技术、分支支架技术和复合手术修复治疗累及锁骨下动脉的主动脉夹层动脉瘤是安全有效的.     

Use of contrast-enhanced ultrasound in follow-up after endovascular aortic aneurysm repair.

PURPOSE: To investigate the use of contrast-enhanced ultrasound in the detection of endoleak after endovascular repair of abdominal aortic aneurysm. MATERIALS AND METHODS: Eighteen patients underwent follow-up on 20 occasions after endovascular aortic aneurysm repair by arterial-phase contrast-enhanced spiral computed tomography (CT). All patients had unenhanced color Doppler ultrasound and Levovist-enhanced ultrasound on the same day. The ultrasound examinations were reported in a manner that was blind to the CT results. CT was regarded as the gold standard for the purposes of the study. RESULTS: There were three endoleaks shown by CT. Unenhanced ultrasound detected only one endoleak (sensitivity, 33%). Levovist-enhanced ultrasound detected all three endoleaks (sensitivity, 100%). Levovist-enhanced ultrasound indicated an additional six endoleaks that were not confirmed by CT (specificity, 67%; positive predictive value, 33%). In one of these six cases, the aneurysm increased in size, which indicates a likelihood of endoleak. Two of the remaining false-positive results occurred in patients known to have a distal implantation leak at completion angiography. CONCLUSION: In this small group of patients, contrast-enhanced ultrasound appears to be a reliable screening test for endoleak. The false-positive results with enhanced ultrasound may be due to the failure of CT to detect slow flow collateral pathways. Although the number of patients in this study is small, enhanced ultrasound may be more reliable than CT in detecting endoleak.