Are concerns about EVAR durability relevant with modern devices?

Endovascular aneurysm repair (EVAR) is now universally adopted as first-line therapy for the management of large abdominal aortic aneurysms (AAA). The applicability has broadened such that up to 80% of patients are morphologically suitable for EVAR. In-spite of the evidence base demonstrating improved early outcomes following EVAR compared to open surgery, and informed patients' preference, EVAR-sceptics remain. The doubters voice anxieties regarding the durability of an endovascular repair and cite evidence of graft failures from the EVAR-1 trial results. Historically, graft migration and endoleak development have been the Achilles heel of EVAR. However, EVAR is an evolving technology that over the last 10 years has seen significant development from industry, and greater experience among clinicians. This has combined with centralisation of expertise in larger vascular units, with increased case-volume, leading to more appropriate periprocedural and long-term care. Current devices offer a durable repair for patients with infra-renal aortic aneurysms. The risk of graft migration is minimised by devices with secure fixation systems, potentially limiting de-novo type 1 and 3 endoleaks. Appropriate surveillance and timely endovascular re-interventions are perhaps the most important factors to ensure robust long-term outcomes from endovascular repair, even when native vessel morphology changes. Industry registry evidence and large single unit case series are now generating a healthy evidence base of EVAR durability in contemporary endovascular practice, that affirms its role as first-line therapy in the majority of morphologically suitable patients.

Progress in endovascular management of type A dissection.

Proximal acute aortic dissection [type A] remains a disease with a poor prognosis. High peri-operative open surgical mortality [up to 30%] and a significant turn-down rate [up to 40%] substantiate the bleak prospects for patients with this disease. Thoracic endovascular stent grafting has revolutionized the treatment of distal [type B] acute aortic dissection. Endovascular surgeons are now looking to improve the treatment of type A dissection by offering endovascular techniques to supplement conventional surgical therapy. Less invasive endovascular therapy, obviates the need for sternotomy and cardiopulmonary bypass, may reduce perioperative morbidity and offers a solution for those patients declined conventional intervention due to co-morbidity or severe complications of the disease. Thoracic stent grafting in the ascending aorta presents specific challenges due to proximity to the aortic valve, navigation over the steep aortic arch and pulsatile aortic movement. Endovascular surgeons have treated type A dissection off-license using aortic cuffs and stents designed for infra-renal aortic surgery. Now grafts specifically designed for treating type A dissection are being developed and deployed under trial [compassionate license] in patients deemed unfit for open surgery. This paper explores how endovascular solutions may fit into the future care of patients with acute type A dissection.

Patient-reported symptoms are independent of disease severity in patients with primary varicose veins.

The objective of this paper is to explore patterns of incompetence and disease distribution in patients with chronic venous disorders and to correlate this with CEAP (Clinical, Etiologic, Anatomic and Pathologic) classification and presenting symptoms to determine which features of chronic venous disorder (CVD) could be used to guide a patient pathway for referral and treatment. Consecutive patients attending a one-stop venous clinic at a university teaching hospital were recruited over a 12-month period. Patients were clinically assessed, assigned CEAP scores, duplex-scanned and categorized. Data were analyzed to identify associations between symptomatology and disease. Four hundred twenty-four limbs were divided into groups A (C2-3) (339) and B (C4-6) (85). The number of men, mean patient age, varicose vein diameter and quality-of-life score (Aberdeen Varicose Vein Questionnaire - AVVS) were significantly higher in group B (P < 0.01). Ache occurred more commonly in group A and in women (P < 0.01). Ache and pain were seen more frequently with saphenofemoral junction reflux (P < 0.05). Group A women were more likely to be offered surgical intervention while men were managed conservatively (P < 0.05). In conclusion, CVD symptoms are independent of disease severity assessed by CEAP score. Advanced disease is associated with larger venous diameters, older age and corresponds to a poorer quality of life. Objective markers such as CEAP, Venous Clinical Severity Score and AVVS should be used in determining a patient pathway for referral and treatment of CVD.

Should the role of EVAR be re-evaluated in light of the 10 year results of EVAR-1?

EVAR-1 published its 10 year results in 2010. The principal finding of the study was that the endovascular group (EVR) had a significant reduction in early aneurysm related mortality compared to open surgery (OR), but the benefit was lost by the end of the study (adjusted hazard ratio [HR], 0.92; 95% confidence interval [CI] 0.57-1.49; P=0.73). By the end of follow-up, there was no significant difference between the OR and EVR group in terms of death from any cause (HR 1.03; 95% CI 0.86-1.23; P=0.72). Despite these findings the uptake of EVR continues to increase. EVR is driving improved surgical outcomes in elective abdominal aortic aneurysm (AAA) surgery, and may yet establish itself as an essential tool in the emergency setting. Elective AAA mortality may be reducing in the U.K. as a consequence of broader application of EVR. This article presents and examines the EVAR-1 data and reports the additional wealth of evidence supporting EVR from prospective registries. It proposes that EVR should be re-evaluated, but not as a consequence of the long-term EVAR-1 results. Clinicians' expertise, understanding and the technology of EVR have progressed significantly since the establishment of the EVAR-1 trial, such that the results, though valuable, may not translate to modern practice. It is essential to maintain excellence in vascular surgery and the evidence-base now demonstrates that best practice in AAA management is in specialist vascular centres, performing high volume surgery offering EVR to all patients who are morphologically suitable.

Sizing fenestrated aortic stent-grafts.

INTRODUCTION: Fenestrated aortic stent-grafts are increasingly being used to treat patients with juxtarenal abdominal aortic aneurysms (AAA). Sizing of these stent-grafts is critical to ensure success and requires detailed expert assessment of aortic morphology. At present little is known about how sizing of these stent-grafts varies between observers and the necessary tolerances involved to ensure a successful procedure. METHODS: CT scans of 19 consecutive patients with juxtarenal aortic aneurysms that underwent successful endovascular repair with fenestrated stent-grafts were selected. Sizing of fenestrated aortic stent-grafts was performed independently by four experienced endovascular surgeons and results were compared. Data from the stent-graft manufacturer was available for comparison in 12 cases. RESULTS: All observers agreed on the number of fenestrations; 16 devices had 3 fenestrations and 3 had 4. The overall inter-observer measurement error for all target vessel orientation was ± 12.6° (10.8-14.4 95% CI), and for distance between target vessels ± 5.3 mm (4.4-6.2 95% CI). The median difference in internal stent-graft diameter was 1 stent size. Agreement on fenestration type ranged from (84-95%). Comparison was performed with the manufactured stent-graft in 12 cases. The overall mean difference of target vessel orientation between the manufactured devices and the four observers was -1.3° (SD ± 6.9,-3.8-1.2 95% CI). There was less agreement between observers and device manufacturers on body and limb lengths and distal limb diameters. CONCLUSIONS: There was generally a high level of agreement between experienced endovascular surgeons in sizing the fenestrated stent component. There were differences in component lengths but these could have been accommodated by varying the degree of overlap between components.

The requirement for smart catheters for advanced endovascular applications.

Endovascular techniques are well established in minimally invasive vascular surgery. Stent-graft technology is evolving. This will allow more complex aortic pathology to be treated. Current limitations in this equipment include the reliance on selective catheters along with trial and error to cannulate visceral or aortic arch branch vessels. This can lead to prolonged operations with increased radiation and contrast load to the patient with inevitable increase in peri-operative morbidity. A smart catheter that could expedite target vessel catheterization, minimize repeat catheter changes, and provide greater haptic feedback would enhance the endovascular surgeon's armamentarium. This would lead to broader and safer application of endovascular surgery.

Risk of reintervention after endovascular aortic aneurysm repair.

BACKGROUND: The role of symptomatic presentation in directing reintervention after endovascular aortic aneurysm repair (EVAR) was investigated. METHODS: All patients undergoing infrarenal EVAR between 2001 and 2009 were studied. Those needing reintervention were divided into symptomatic and asymptomatic presentations. Kaplan-Meier survival curves were used to calculate freedom from reintervention, and log rank tests for subgroup analyses. Multivariable analysis identified risk factors for reintervention. RESULTS: The study included 553 patients with a mean(s.d.) age of 75(7) years and aneurysm diameter of 65(13) mm. The 30-day mortality rate was 2.5 per cent. Median follow-up was 31 (range 1-97) months. There were 86 reinterventions in 69 (12.5 per cent) of 553 patients; 41 presented with symptoms and 28 were asymptomatic. Reintervention-free survival rates at 1, 3 and 5 years were 90.1, 85.3 and 81.2 per cent. The reintervention rate was higher in patients who needed an intraoperative adjunct during the index procedure (P = 0.014) and in those who did not have intraoperative computed tomography angiography (P = 0.024). Intraoperative adjuncts were an independent risk factor for future reintervention (hazard ratio 2.62, 95 per cent confidence interval 1.18 to 3.76; P = 0.012). CONCLUSION: Most patients requiring reintervention presented symptomatically. A high-risk subgroup may be identifiable to rationalize a postoperative surveillance programme.

Secondary interventions following endovascular aneurysm repair (EVAR) and the enduring value of graft surveillance.

OBJECTIVE: Lifelong imaging surveillance is currently recommended for all patients following endovascular aortic aneurysm repair (EVR). The modality, timing and overall necessity of surveillance has recently been brought into question. This review reports contemporary secondary intervention rates and explores surveillance imaging pick-up rates and reports the evidence supporting modified EVR surveillance programs. DESIGN: Systematic review of literature (2002-2009) and meta-analysis of Kaplan-Meier re-intervention-free survival estimates. RESULTS: 32 Papers were included in final analysis. 17,987 EVR cases were reported. Crude annual secondary intervention rates from the US population registries were 3.7%/year (range 1.7-4.3%). Combined re-intervention-free survival estimates, from 14 series (10,365 cases), demonstrated a linear progression with 89.9%, 86.9% and 81.5% of grafts without secondary procedures at 2, 3 and 5 years respectively. 3 Reports (1249 cases) differentiated between interventions directed by surveillance or outside surveillance protocols. Surveillance imaging alone initiated the secondary interventions in 1.4-9% of cases; >90% of EVR cases received no benefits from surveillance scans. DISCUSSION: Some format of surveillance following EVR probably remains necessary despite a reduction in secondary interventions with modern stent-grafts. Surveillance should be targeted at those stent-grafts and patients at high risk of complications. Further work is justified to identify this group.

Endovascular treatment of chronic aortic dissection.

The optimal management of chronic aortic dissection is uncertain. Traditional strategies of best medical management for asymptomatic lesions and open surgical intervention for evolving complications have been challenged in the endovascular era. The concept of minimally invasive surgery in this high risk patient group is appealing. Endovascular stent graft deployment targets closure of the dissection entry tear. This can induce false lumen thrombosis, reducing risk of disease progression and aortic rupture. Initial reports were encouraging with a high level of technical success. However, long-term data demonstrating durability and improved survival are lacking. There remain no clear guidelines for the application of this technology. Its role as an adjunct to best medical therapy for uncomplicated dissections or an alternative to open surgery in complicated disease is yet to be elucidated. This review presents the current evidence for endovascular management of chronic aortic dissection.

EVAR for ruptured AAAs -- Do we need randomized controlled trials?

Endovascular abdominal aortic aneurysm (EVAR) repair has an established role in elective management of abdominal aortic aneurysms (AAA). The application of EVAR to ruptured AAAs (rAAA) is evolving and developing a strong evidence base in selected patients. Although EVAR has been utilized to manage rAAA for greater than ten years, to-date no randomized study has been completed to confirm superiority over traditional open surgical repair. Randomized controlled trials (RCTs) allow unbiased objective comparison of two techniques and are the most powerful scientific instrument available for clinical assessment; they form the corner-stone of surgical evidence-based practice. In light of current understanding, the role of a RCT to compare emergency EVAR (eEVAR) with open surgery has been challenged. Whether an RCT is necessary, is ethical or can mimic routine clinical practice are questions open to debate. This review presents the current best evidence for eEVAR, the arguments for and against an RCT, and details current and prospective clinical trials designed to identify the optimal management of rAAA.

Modern treatment of juxtarenal abdominal aortic aneurysms with fenestrated endografting and open repair--a systematic review.

INTRODUCTION: Advances in endovascular technology have led to the introduction of fenestrated stents to treat juxtarenal aneurysms (JRAs), previously deemed unsuitable for standard endovascular repair (EVR). This article reviews the outcomes of fenestrated technology and makes a comparison with open repair. METHODS: A systematic review of the literature was performed. RESULTS: No randomised studies were identified. 8 cohort studies reporting 368 f-EVR cases and 12 cohorts reporting 1164 open repairs of JRAs were identified. Analysis of outcome measures found the f-EVR and open cohorts to be homogeneous. Combining studies identified an increased 30-day mortality after open repair when compared to f-EVR (Relative risk (RR) 1.03, 95% Confidence interval (CI) 1.01-1.04, p=.02), 2% increased absolute mortality. No difference was identified in postoperative permanent dialysis dependence (RR 1.00, CI 0.99-1.01, p=1). Transient renal failure was more common following open repair (RR 1.06, CI 1.01-1.12, p=.03). Early re-interventions were less common following open repair (RR 0.87, CI 0.83-0.91, p=.0001). CONCLUSIONS: Selective f-EVR appears to have reduced peri-operative mortality compared with traditional open surgery, yet selectivity within the study groups and lack of a rigorous classification prohibit more robust comparison. Promising short-term results confirm a role for f-EVR in management of complex abdominal aneurysms.