Endovascular abdominal aortic aneurysm repair: how many patients are eligible for endovascular repair?

PURPOSE: The purpose of this study was to determine how many patients with abdominal aortic aneurysm (AAA) are eligible for endovascular abdominal aortic aneurysm repair (EVAR). MATERIALS AND METHODS: We retrospectively reviewed computed tomography (CT) angiograms obtained between January 2002 and June 2003 in 182 patients with suspected AAA. Indication for surgical or endovascular treatment was based on clinical and radiological criteria. The percentage of patients eligible for EVAR was evaluated. RESULTS: Out of a total of 182 patients with suspected AAA studied by CT angiography, after combined radiological-surgical assessment, 130 were considered eligible for surgical or endovascular treatment (71.4%). EVAR was indicated in 51 patients (39.3%, group A) and surgical repair was indicated in 79 patients (60.7%, group B). The reasons for ineligibility for EVAR were the following: unfavourable anatomy of the proximal neck in 41 patients (51.9%), diameter of the aneurysm sac >7 cm in 13 patients (16.4%), markedly tortuous/dilated iliac axis in six patients (7.6%), age <65 years in 17 patients (21.5%) and patient refusal in two cases (2.5%). There were no statistically significant differences in aneurysm diameter (52.7+/-0.8 versus 49.8+/-1.2 mm, p=ns), patients' age (73.2+/-1.2 versus 70.6+/-2.02 years, p=ns) or proximal neck length (2.95+/-1 versus 3.03+/-1.2 cm, p=ns) between groups A and B. CONCLUSIONS: Endovascular repair of abdominal aortic aneurysms through the placement of aortic stent-grafts has now become a viable alternative to open surgery. In recent years, the number of patients treated with EVAR has steadily risen as a result of increased physician experience, availability of new and more versatile devices and improvements in noninvasive imaging techniques. Unfavourable neck anatomy is the primary factor for exclusion from endovascular repair.     

Delayed complications following EVAR

More than a decade after the first clinical attempts, two large randomized studies have proven that endovascular aortic aneurysm repair (EVAR) provides immediate advantages over open repair. In the long run, however, a relatively high number of reinterventions is necessary to improve the long-term efficacy of EVAR, which may outweigh the early benefits. Since EVAR is gaining popularity in the medical community and in patients with abdominal aortic aneurysm (AAA), it is expected that a growing number of patients will present with delayed complications requiring some kind of reinterventions. For the patient's safety, vascular surgeons and interventional radiologists involved in EVAR must be well aware of these complications and the ways to overcome them. We began our endovascular program for AAA in 1994 and currently follow 485 patients with a variety of manufactured grafts. In this article we describe the delayed complications observed with EVAR, their mechanisms, favoring factors, and ways to treat them.     

Financial Impact of PEVAR Compared With Standard Endovascular Repair in Canadian Hospitals

Objectives

The percutaneous endovascular abdominal aortic repair (PEVAR) approach is a minimally invasive technique that has demonstrated clinical benefit over traditional surgical cut down associated with standard endovascular abdominal aortic aneurysm (AAA) repair (EVAR). The objective of our study was to evaluate the budget impact to a Canadian hospital of changing the technique for AAA repair from the EVAR approach to the PEVAR approach.

Die interventionelle/endovaskuläre Therapie des infrarenalen abdominellen Aortenaneurysmas

The catheter-based interventional therapy (endovascular aortic repair EVAR) of abdominal aortic aneurysms (AAA) has gained an established place in the spectrum of therapeutic options. The procedure is characterized by low peri-interventional morbidity and mortality. Multislice computed tomography (CT) has a dominant role in defining the correct indications and in selecting an appropriate stent graft prior to the intervention. The rate of acute conversions could be reduced from 2.9 % to 0?% in our own elective patient population since 2010. In our vascular centre the proportion of patients treated by EVAR was 39.5?% (102 out of 258). The procedure is used routinely in patients who have an increased risk for general anesthesia or open surgery due to concomitant diseases. It is also used in patients with a reduced local operability due to prior surgery, abdominal diseases or radiation therapy. Arterial closure devices allow a completely percutaneous approach in a certain group of patients. However, after EVAR a life-long surveillance is mandatory because delayed therapy failure has been described. In younger patients who do not have a higher risk open surgery is still an option. The paper describes techniques, results und complications of EVAR.     

腹主动脉瘤的腔内治疗

腹主动脉瘤（AAA）常发生于老年人，破裂是其最常见、最凶险的并发症，病死率可高达63%。传统开腹性手术是治疗AAA十分有效的手段，但对于高危患者其病死率显著增加。因此，发展一种微创方法治疗AAA对于降低病死率十分必要。经股动脉放置血管内支架-移植物是治疗AAA的一个重要里程碑，尤其对于那些高危患者。这一新技术作为外科修复的替代疗法已经得到广泛的应用。内支架-移植物植入后的常见并发症包括内漏、移植物移位或变形和移植物血栓形成，以内漏最常见且最重要。内漏是指移植物植入后仍有持续性血液进入动脉瘤囊，主要通过某些影像学技术证实，螺旋CT增强检查是检出内漏的首选方法。术后30天内发生的或早期内漏可通过一段时期观察，然后对待持续性内漏进行血管内介入治疗，30天后的晚发内漏应及时进行介入处理，无观察期。     

Endovascular Aneurysm Repair and Sealing (EVARS): A Useful Adjunct in Treating Challenging Morphology

An 81-year-old male with previous open abdominal aortic aneurysm repair presented with asymptomatic large pseudoaneurysms at both ends of an open surgical tube graft. Endovascular aneurysm sealing (EVAS) in combination with the iliac limbs of a standard endovascular aneurysm repair (EVAR) successfully excluded both pseudoaneurysms from circulation. We describe the combination of elements of EVAS and EVAR and have termed this endovascular aneurysm repair and sealing (EVARS). EVARS has the advantage of harnessing the benefits of endobag sealing in aortic necks unsuitable for standard EVAR whilst providing the security of accurate stent placement within short common iliac arteries. In conclusion, EVAS may be combined with standard endovascular iliac limbs and is a possible treatment option for pseudoaneurysm following open aneurysm repair.     

Matched-pair analysis of endovascular versus open surgical repair of abdominal aortic aneurysms in young patients at low risk

PURPOSE: To compare clinical outcomes of endovascular and open aortic repair of abdominal aortic aneurysms (AAAs) in young patients at low risk. It was hypothesized that endovascular aneurysm repair (EVAR) compares favorably with open aneurysm repair (OAR) in these patients. MATERIALS AND METHODS: Twenty-five patients aged 65 years or younger with a low perioperative surgical risk profile underwent EVAR at a single institution between April 1994 and May 2007 (23 men; mean age, 62 years+/-2.8). A sex- and risk-matched control group of 25 consecutive patients aged 65 years or younger who underwent OAR was used as a control group (23 men; mean age, 59 years+/-3.9). Patient outcomes and complications were classified according to Society of Vascular Surgery/International Society for Cardiovascular Surgery reporting standards. RESULTS: Mean follow-up times were 7.1 years+/-3.2 after EVAR and 5.9 years+/-1.8 after OAR (P=.1020). Total complication rates were 20% after EVAR and 52% after OAR (P=.0378), and all complications were mild or moderate. Mean intensive care unit times were 0.2 days+/-0.4 after EVAR and 1.1 days+/-0.4 after OAR (P<.0001) and mean lengths of hospital stay were 2.3 days+/-1.0 after EVAR and 5.0 days+/-2.1 after OAR (P<.0001). Cumulative rates of long-term patient survival did not differ between EVAR and OAR (P=.144). No AAA-related deaths or aortoiliac ruptures occurred during follow-up for EVAR and OAR. In addition, no surgical conversions were necessary in EVAR recipients. Cumulative rates of freedom from secondary procedures were not significantly different between the EVAR and OAR groups (P=.418). Within a multivariable Cox proportional-hazards analysis adjusted for patient age, maximum AAA diameter, and cardiac risk score, all-cause mortality rates (odds ratio [OR], 0.125; 95% CI, 0.010-1.493; P=.100) and need for secondary procedures (OR, 5.014; 95% CI, 0.325-77.410; P=.537) were not different between EVAR and OAR. CONCLUSIONS: Results from this observational study indicate that EVAR offers a favorable alternative to OAR in young patients at low risk.     

Endovascular repair of thoracic and abdominal aortic aneurysms: pre- and postprocedural imaging

Endovascular repair of thoracic and abdominal aortic aneurysms is a safe alternative to conventional open surgical repair. Clinical success, however, is highly dependent on patient selection. Diagnostic vascular imaging has an essential role for this selection process. Following endovascular aneurysm repair (EVAR), patients require long-term surveillance and again vascular imaging serves an integral function. This article reviews EVAR selection criteria and post-EVAR assessment and then discusses the imaging modalities used to evaluate these patients, namely multi-detector-row computed tomographic angiography, magnetic resonance imaging/angiography, duplex ultrasonography, and catheter angiography.     

Surveillance After Endovascular Abdominal Aortic Aneurysm Repair

Surveillance after endovascular abdominal aortic aneurysm repair (EVAR) is widely considered mandatory. The purpose of surveillance is to detect asymptomatic complications, so that early secondary intervention can prevent late aneurysm rupture. CT angiography has been taken as the reference standard imaging test, but there is increasing interest in using other modalities to reduce the use of ionising radiation and iodinated contrast. As a result, there is wide heterogeneity in surveillance strategies used among EVAR centres. We reviewed the current evidence available on the outcomes of different imaging modalities and surveillance strategies following EVAR.     

Endovascular Repair of Para-Anastomotic Aortoiliac Aneurysms

The purpose of this study is to evaluate the use of endovascular stent grafts in the treatment of para-anastomotic aneurysms (PAAs) as an alternative to high-risk open surgical repair. We identified all patients with previous open aortic aneurysm repair who underwent infrarenal endovascular aneurysm repair (EVAR) at our institution from June 1998 to April 2007. Patient demographics, previous surgery, and operative complications were recorded. One hundred forty-eight patients underwent EVAR during the study period and 11 patients had previous aortic surgery. Of these 11 redo patients, the mean age was 62 years at initial surgery and 71 years at EVAR. All patients were male. Initial open repair was for rupture in five (45%) patients. The average time between initial and subsequent reintervention was 9 years. All patients were ASA Grade III or IV. Fifty-five percent of the PAAs involved the iliac arteries, 36% the abdominal aorta, and 9% were aortoiliac. Ten patients had endovascular stent-grafts inserted electively, and one patient presented with a contained leak. Aorto-uni-iliac stent-grafts were deployed in seven patients, and bifurcated stent-grafts in four patients. A 100% successful deployment rate was achieved. Perioperative mortality was not seen and one patient needed surgical reintervention to correct an endoleak. Endovascular repair of PAAs is safe and feasible. It is a suitable alternative and has probably now become the treatment of choice in the management of PAAs.     

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.     

Endovascular repair of a recurrent aortocaval fistula and anastamotic false aneurysm

Aortocaval fistula (ACF) and false aneurysm are a recognized complication of open abdominal aortic aneurysm (AAA) repair. Untreated they are often fatal. However, open surgical repair of this complication is associated with a high operative mortality and a significant complication rate. Endovascular management using a stent-graft to exclude the false aneurysm and fistula is a technically feasible alternative and confers many advantages over open repair by virtue of its minimally invasive nature. We report the endovascular management of this rare but serious complication of open AAA repair.     

Intraoperative DynaCT Detection and Immediate Correction of a Type 1a Endoleak Following Endovascular Repair of Abdominal Aortic Aneurysm

Reintervention following endovascular aneurysm repair (EVAR) is required in up to 10% of patients at 30 days and is associated with a demonstrable risk of increased mortality. Completion angiography cannot detect all graft-related anomalies and computed tomographic angiography is therefore mandatory to ensure clinical success. Intraoperative angiographic computed tomography (DynaCT; Siemens, Germany) utilizes cone beam reconstruction software and flat-panel detectors to generate CT-like images from rotational angiographic acquisitions. We report the intraoperative use of this novel technology in detecting and immediately treating a proximal anterior type Ia endoleak, following an endovascular abdominal aortic repair, which was not seen on completion angiography. Immediate evaluation of cross-sectional imaging following endograft deployment may allow for on-table correction of clinically significant stent-related complications. This should both improve technical success and minimize the need for early secondary intervention following EVAR.     

Improving Results of Elective Abdominal Aortic Aneurysm Repair at a Low-Volume Hospital by Risk-Adjusted Selection of Treatment in the Endovascular Era

Several studies have observed both higher mortality rates and lower utilization of endovascular aneurysm repair (EVAR) at low-volume centers. This article presents the results of elective abdominal aortic aneurysm (AAA) repair at a low-volume center in the endovascular era and investigates whether postprocedural mortality can be improved by extension of EVAR application also in this setting. This is an 11.6-year retrospective cohort study of 132 patients undergoing elective surgical or endovascular AAA repair at a tertiary care academic hospital between 1997 and July 2008, i.e., a median volume of 12 cases per year. The study was divided into two periods of time according to the respective indications and contraindications for EVAR, which substantially changed in 2005. During period 1, only aneurysms with necks ≥20 mm long and not involving the iliac arteries were treated endoluminally. Beginning in 2005, indication for EVAR was expanded to aortoiliac aneurysms with a minimum neck length of 15 mm. Preoperative risk was assessed by the SVS/AAVS comorbidity score. During the first period (1997–2004) 18.4% (16/87) of all patients received EVAR. By extending anatomical confines and indications for EVAR in 2005, the utilization rate of EVAR increased to 40.0% (18/45) during the second period (2005–July 2008; p = 0.007). Prevalence of preoperative risk factors did not change during the two observation periods. In contrast to period 1, high-risk patients were preferentially treated endoluminally during the second period, resulting in a significantly higher median SVS/AAVS score in the EVAR group (p < 0.001). A significant decrease in median length of stay at the intensive/intermediate care unit (5 vs. 2 days; p = 0.006) and length of in-hospital stay (20 vs. 12.5 days; p < 0.001) was observed during period 2. Overall perioperative mortality was reduced from 6.9% during the first period to 2.2% during the second period (p = 0.256). EVAR mortality was 0%, mortality after open repair was reduced from 8.5% to 3.7% (p = 0.414). In conclusion, by risk-adjusted selection of treatment and frequent application of EVAR, it is possible to improve perioperative outcome of elective AAA repair at a low-volume hospital. Mortality figures are similar to those of recent trials at high-volume centers, as reported in the literature.     

A Technique of “Chimney Nellix” for the Management of Type 1a Endoleak After EVAR

This report presents 3 procedures with visceral “chimney stenting” in conjunction with an endovascular aneurysm sealing (EVAS) device, known as chEVAS, for treatment of type 1a endoleak. It includes the first published chEVAS in a patient with previous fenestrated endovascular aneurysm repair (FEVAR). Cases include an 80-year-old man 8 years after FEVAR for a juxtarenal abdominal aortic aneurysm (AAA); an 85-year-old woman 9 months after endovascular aneurysm repair (EVAR) for a ruptured infrarenal AAA; and an 84-year-old woman 3 months after EVAR for a symptomatic infrarenal AAA. Technical success was achieved in all cases, with 1 postoperative death. The remaining 2 patients had no residual type 1a endoleak at 10 and 14 months respectively.     

Clinical experience with a customized fenestrated endograft for juxtarenal abdominal aortic aneurysm repair

Despite the numerous stent-graft devices available, unsuitable anatomy is still the greatest exclusion criterion for endovascular abdominal aortic aneurysm (AAA) repair (EVAR). The present report describes an on-site preprocedural customization of a conventional Zenith stent-graft device just before the endovascular procedure that includes the creation of fenestrations and scallops as necessary for the patient's anatomy. Three patients with difficult anatomy in whom conventional AAA repair posed a high degree of risk were treated with customization of the stent-graft device to fit disparate renal arteries. A single fenestration for the left renal artery was made in two cases, and a single scallop was made in the other case to accommodate the superior mesenteric artery. Gold beads were used to mark the location of the fenestration and scallop. The three cases were successfully performed without perceptible endoleaks in the follow-up period, which ranged from 4 to 14 months. No procedure-related complications were detected; however, pneumonia developed in one patient 3 weeks after EVAR. The initial results with this technique are encouraging, and the role of EVAR can be significantly increased with the use of this customization technique when the interventionalist does not have access to the commercially available devices or when the waiting time is too prolonged to accommodate the patient's clinical situation.     

Endovascular stent graft repair of abdominal aortic aneurysms: Current status and future directions

Endovascular stent graft repair of abdominal aortic aneurysm (AAA) has undergone rapid developments since it was introduced in the early 1990s. Two main types of aortic stent grafts have been developed and are currently being used in clinical practice to deal with patients with complicated or unsuitable aneurysm necks, namely, suprarenal and fenestrated stent grafts. Helical computed tomography angiography has been widely recognized as the method of choice for both pre-operative planning and post-operative follow-up of endovascular repair (EVAR). In addition to 2D axial images, a number of 2D and 3D reconstructions are generated to provide additional information about imaging of the stent grafts in relation to the aortic aneurysm diameter and extent, encroachment of stent wires to the renal artery ostium and position of the fenestrated vessel stents. The purpose of this article is to provide an overview of applications of EVAR of AAA and diagnostic applications of 2D and 3D image visualizations in the assessment of treatment outcomes of EVAR. Interference of stent wires with renal blood flow from the hemodynamic point of view will also be discussed, and future directions explored.     

Endovascular repair of ruptured abdominal aortic aneurysm: feasibility and impact on early outcome

PURPOSE: Open repair of ruptured abdominal aortic aneurysms (AAAs) still has a high associated mortality rate. The impact of the introduction of endovascular treatment on the early outcomes of ruptured AAAs was examined at a single institution. The suitability of acute endovascular aneurysm repair (EVAR) in patients with ruptured AAAs was also assessed. MATERIALS AND METHODS: Retrospective review was conducted in 39 consecutive patients treated for ruptured AAA from 2001 to 2004. The patients were divided into 15 who underwent open repair from 2001 to 2002 (group I) and 24 who were treated with open repair (n=13; 54%) or endovascular repair (n=11; 46%) from 2003 to 2004 (group II). Hospital charts and computed tomographic scans were reviewed to evaluate the feasibility of EVAR. RESULTS: Age, sex, and aneurysm size were similar between the two groups. The 30-day mortality rates were 53% in group I and 8% in group II (P=.003). Median procedure times were shorter in the patients who underwent EVAR. Intensive care unit stay and hospital stay were 22.0 days+/-29.6 and 29.7 days+/-33.8, respectively, in group I, and 5.6 days+/-4.4 and 16.1 days+/-10.9, respectively, in group II (P<.03). Eleven patients were found ineligible for EVAR as a result of an unsuitable neck (n=5) or iliac arteries (n=3) or both (n=3). No graft failure was detected during follow-up. CONCLUSIONS: After introduction of acute EVAR, a total of 46% of patients with ruptured AAAs were treated with the procedure. Potentially, 54% of patients could have been suitable for EVAR. Endovascular stent-graft implantation has significantly improved outcomes in ruptured AAAs and may therefore be beneficial in the overall treatment strategy in these patients.     

Acute abdominal aortic aneurysms: cost analysis of endovascular repair and open surgery in hemodynamically stable patients with 1-year follow-up

PURPOSE: To retrospectively assess the in-hospital and 1-year follow-up costs of endovascular aneurysm repair and conventional open surgery in patients with acute infrarenal abdominal aortic aneurysm (AAA) by using a resource-use approach. MATERIALS AND METHODS: Institutional Review Board approval was obtained, and informed consent was waived. In-hospital costs for all consecutive patients (61 men, six women; mean age, 72.0 years) who underwent endovascular repair (n = 32) or open surgery (n = 35) for acute infrarenal AAA from January 1, 2001, to December 31, 2004, were assessed by using a resource-use approach. Patients who did not undergo computed tomography before the procedure were excluded from analysis. One-year follow-up costs were complete for 30 patients who underwent endovascular repair and for 34 patients who underwent open surgery. Costs were assessed from a health care perspective. Mean costs were calculated for each treatment group and were compared by using the Mann-Whitney U test (alpha = .05). The influence of clinical variables on the total in-hospital cost was investigated by using univariate and multivariate analyses. Costs were expressed in euros for the year 2003. RESULTS: Sex, age, and comorbidity did not differ between treatment groups (P > .05). The mean total in-hospital costs were lower for patients who underwent endovascular repair than for those who underwent open surgery (euro20 767 vs euro35 470, respectively; P = .004). The total costs, including those for 1-year follow-up, were euro23 588 for patients who underwent endovascular repair and euro36 448 for those who underwent open surgery (P = .05). The results of multivariate analysis indicated that complications had a significant influence on total in-hospital cost; patients who had complications incurred total in-hospital costs that were 2.27 times higher than those for patients who had no complications. CONCLUSION: Total in-hospital costs and total overall costs, which included 1-year follow-up costs, were lower in patients with acute AAA who underwent endovascular repair than in those who underwent open surgery.     

Endovascular Therapy of Ruptured Abdominal Aortic Aneurysm: Mid- and Long-Term Results

As an alternative to open aneurysm repair, emergency endovascular aortic repair (EVAR) has emerged as a promising technique for ruptured abdominal aortic aneurysm (rAAA) within the last decade. The aim of this retrospective study is to present early and late outcomes of patients treated with EVAR for rAAA. Twenty-two patients (5 women, 17 men; mean age, 74 years) underwent EVAR for rAAA between November 2000 and April 2006. Diagnostic multislice computed tomography angiography was performed prior to stent-graft repair to evaluate anatomical characteristics and for follow-up examinations. Periprocedural patient characteristics and technical settings were evaluated. Mortality rates, hospital stay, and early and late complications, within a mean follow-up time of 744 ± 480 days, were also assessed. Eight of 22 patients were hemodynamically unstable at admission. Stent-graft insertion was successful in all patients. The total early complication rate was 54%, resulting in a 30-day mortality rate of 23%. The median intensive care unit stay was 2 days (range, 2–48 days), and the median hospital stay was 16 days (range, 9–210 days). During the follow-up period, three patients suffered from stent-graft-related complications. The overall mortality rate in our study group was 36%. EVAR is an acceptable, minimally invasive treatment option in patients with acute rAAA, independent of the patient’s general condition. Short- and long-term outcomes are definitely comparable to those with open surgical repair procedures.