Editor's Choice - Comparison of Open Surgery and Endovascular Techniques for Juxtarenal and Complex Neck Aortic Aneurysms: The UK COMPlex AneurySm Study (UK-COMPASS) - Peri-operative and Midterm Outcomes.

OBJECTIVE: Treatment of juxtarenal and complex neck abdominal aortic aneurysms (AAAs) is now commonly by endovascular rather than open surgical repair (OSR). Published comparisons show poor validity and scientific precision. UK-COMPASS is a comparative cohort study of endovascular treatments vs. OSR for patients with an AAA unsuitable for standard on label endovascular aneurysm repair (EVAR). METHODS: All procedures for AAA in England (November 2017 to October 2019) were identified, AAA anatomy assessed in a Corelab, peri-operative risk scores determined, and propensity scoring used to identify patients suitable for either endovascular treatment or OSR. Patients were stratified by aneurysm neck length (0 - 4 mm, 5 - 9 mm, or ≥ 10 mm) and operative risk; the highest quartile was considered high risk and the remainder standard risk. Death was the primary outcome measure. Endovascular treatments included fenestrated EVAR (FEVAR) and off label standard EVAR (± adjuncts). RESULTS: Among 8 994 patients, 2 757 had AAAs that were juxtarenal, short neck, or complex neck in morphology. Propensity score stratification and adjustment method comparisons included 1 916 patients. Widespread off label use of standard EVAR devices was noted (35.6% of patients). The adjusted peri-operative mortality rate was 2.9%, lower for EVAR (1.2%; p = .001) and FEVAR (2.2%; p = .001) than OSR (4.5%). In standard risk patients with a 0 - 4 mm neck, the mortality rate was 7.4% following OSR and 2.3% following FEVAR. Differences were smaller for patients with a neck length ≥ 5 mm: 2.1% OSR vs. 1.0% FEVAR. At 3.5 years of follow up, the overall mortality rate was 20.7% in the whole study population, higher following FEVAR (27.6%) and EVAR (25.2%) than after OSR (14.2%). However, in the 0 - 4 mm neck subgroup, overall survival remained equivalent. The aneurysm related mortality rate was equivalent between treatments, but re-intervention was more common after EVAR and FEVAR than OSR. CONCLUSION: FEVAR proves notably safer than OSR in the peri-operative period for juxtarenal aneurysms (0 - 4 mm neck length), with comparable midterm survival. For patients with short neck (5 - 9 mm) and complex neck (≥ 10 mm) AAAs, overall survival was worse in endovascularly treated patients compared with OSR despite relative peri-operative safety. This warrants further research and a re-appraisal of the current clinical application of endovascular strategies, particularly in patients with poor general survival outlook owing to comorbidity and age.

Editor's Choice - Comparison of Open, Standard, and Complex Endovascular Aortic Repair Treatments for Juxtarenal/Short Neck Aneurysms: A Systematic Review and Network Meta-Analysis.

OBJECTIVE: Abdominal aortic aneurysms (AAAs) with adverse morphology of the aneurysm neck are "complex". Techniques employed to repair complex aneurysms include open surgical repair (OSR) and a number of on label endovascular techniques such as fenestrated endovascular aneurysm repair (FEVAR) and endovascular aneurysm repair (EVAR) with adjuncts (including chimneys and endo-anchors), as well as off label use of standard EVAR. The aim was to conduct a network meta-analysis (NMA) of published comparative outcomes. DATA SOURCES: An electronic search was performed in Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials (CENTRAL). These databases were interrogated using the PubMed interface and the Healthcare Databases Advanced Search (HDAS) interface developed by the National Institute of Health and Care Excellence. REVIEW METHODS: Online databases were interrogated up to April 2020. Studies were included if they compared outcomes between at least two methods of repair for complex aneurysms (those with at least one adverse neck feature: absent/short neck, conicality, angulation, calcification, large diameter, and thrombus). The primary outcome measure was peri-operative death. Pre-registration was done in PROSPERO (CRD42020177482). RESULTS: The search identified 24 observational studies and 7854 patients who underwent OSR, FEVAR, off label EVAR, or chimney EVAR. No comparative studies included EVAR with endo-anchors. NMA was performed on 23 studies that reported outcomes of aneurysms with short/absent infrarenal neck. Compared with OSR, off label EVAR (relative risk [RR] 0.10, 95% confidence interval [CI] 0.01 - 0.41) and FEVAR (RR 0.62, 95% CI 0.32-0.94) were associated with lower peri-operative mortality. This difference was not seen at the midterm follow up (30 months). Compared with OSR, FEVAR was associated with a lower peri-operative myocardial infarction (MI) rate (RR 0.37, 95% CI 0.16 - 0.62) but a higher midterm re-intervention rate (hazard ratio 1.65, 95% CI 1.04 - 2.66). All studies had a "moderate" or "high" risk of bias. Confidence in the network findings (GRADE) was generally "low". CONCLUSION: This NMA demonstrated a peri-operative survival benefit for off label EVAR and FEVAR compared with OSR, potentially due to reduced risk of MI. FEVAR carries a greater midterm re-intervention risk than OSR, with potential implications for cost effectiveness. There is paucity of comparative data for cases with adverse neck features other than short length.

Aneurysm growth, survival, and quality of life in untreated thoracic aortic aneurysms: the effective treatments for thoracic aortic aneurysms study.

AIMS: To observe, describe, and evaluate management and timing of intervention for patients with untreated thoracic aortic aneurysms. METHODS AND RESULTS: Prospective study of UK National Health Service (NHS) patients aged ≥18 years, with new/existing arch or descending thoracic aortic aneurysms of ≥4 cm diameter, followed up until death, intervention, withdrawal, or July 2019. Outcomes were aneurysm growth, survival, quality of life (using the EQ-5D-5L utility index), and hospital admissions. Between 2014 and 2018, 886 patients were recruited from 30 NHS vascular/cardiothoracic units. Maximum aneurysm diameter was in the descending aorta in 725 (82%) patients, growing at 0.2 cm (0.17-0.24) per year. Aneurysms of ≥4 cm in the arch increased by 0.07 cm (0.02-0.12) per year. Baseline diameter was related to age and comorbidities, and no clinical correlates of growth were found. During follow-up, 129 patients died, 64 from aneurysm-related events. Adjusting for age, sex, and New York Heart Association dyspnoea index, risk of death increased with aneurysm size at baseline [hazard ratio (HR): 1.88 (95% confidence interval: 1.64-2.16) per cm, P < 0.001] and with growth [HR: 2.02 (1.70-2.41) per cm, P < 0.001]. Hospital admissions increased with aneurysm size [relative risk: 1.21 (1.05-1.38) per cm, P = 0.008]. Quality of life decreased annually for each 10-year increase in age [-0.013 (-0.019 to -0.007), P < 0.001] and for current smoking [-0.043 (-0.064 to -0.023), P = 0.004]. Aneurysm size was not associated with change in quality of life. CONCLUSION: International guidelines should consider increasing monitoring intervals to 12 months for small aneurysms and increasing intervention thresholds. Individualized decisions about surveillance/intervention should consider age, sex, size, growth, patient characteristics, and surgical risk.

A risk-adjusted and anatomically stratified cohort comparison study of open surgery, endovascular techniques and medical management for juxtarenal aortic aneurysms-the UK COMPlex AneurySm Study (UK-COMPASS): a study protocol.

INTRODUCTION: In one-third of all abdominal aortic aneurysms (AAAs), the aneurysm neck is short (juxtarenal) or shows other adverse anatomical features rendering operations more complex, hazardous and expensive. Surgical options include open surgical repair and endovascular aneurysm repair (EVAR) techniques including fenestrated EVAR, EVAR with adjuncts (chimneys/endoanchors) and off-label standard EVAR. The aim of the UK COMPlex AneurySm Study (UK-COMPASS) is to answer the research question identified by the National Institute for Health Research Health Technology Assessment (NIHR HTA) Programme: 'What is the clinical and cost-effectiveness of strategies for the management of juxtarenal AAA, including fenestrated endovascular repair?' METHODS AND ANALYSIS: UK-COMPASS is a cohort study comparing clinical and cost-effectiveness of different strategies used to manage complex AAAs with stratification of physiological fitness and anatomical complexity, with statistical correction for baseline risk and indication biases. There are two data streams. First, a stream of routinely collected data from Hospital Episode Statistics and National Vascular Registry (NVR). Preoperative CT scans of all patients who underwent elective AAA repair in England between 1 November 2017 and 31 October 2019 are subjected to Corelab analysis to accurately identify and include every complex aneurysm treated. Second, a site-reported data stream regarding quality of life and treatment costs from prospectively recruited patients across England. Site recruitment also includes patients with complex aneurysms larger than 55 mm diameter in whom an operation is deferred (medical management). The primary outcome measure is perioperative all-cause mortality. Follow-up will be to a median of 5 years. ETHICS AND DISSEMINATION: The study has received full regulatory approvals from a Research Ethics Committee, the Confidentiality Advisory Group and the Health Research Authority. Data sharing agreements are in place with National Health Service Digital and the NVR. Dissemination will be via NIHR HTA reporting, peer-reviewed journals and conferences. TRIAL REGISTRATION NUMBER: ISRCTN85731188.

Review new concepts in pharmacotherapy for peripheral arterial disease.

PURPOSE OF REVIEW: To provide an overview of new concepts in the pharmacotherapy of patients with peripheral artery disease (PAD). RECENT FINDINGS: Modern therapeutic strategies for patients with PAD include specific symptom management and multidisciplinary prevention of cardiovascular events. Low-dose rivaroxaban in combination with aspirin improves outcomes compared with aspirin monotherapy among patients with PAD. Other novel concepts include the use of bosentan, vorapaxar or sildenafil among symptomatic patients with PAD. Likewise, lipid-lowering therapy reduces the risk of major cardiovascular and limb events. SUMMARY: Personalized management, identification of risk factors and shared-decision making are crucial in improving the best medical therapy for patients with PAD. Further studies are needed to assess the long-term safety and efficacy of novel strategies in real-world patients.

Characterising the incidence and mode of visceral stent failure after fenestrated endovascular aneurysm repair (FEVAR).

BACKGROUND: In FEVAR, visceral stents provide continuity and maintain perfusion between the main body of the stent and the respective visceral artery. The aim of this study was to characterise the incidence and mode of visceral stent failure (type Ic endoleak, type IIIa endoleak, stenosis/kink, fracture, crush and occlusion) after FEVAR in a large cohort of patients at a high-volume centre. METHODS: A retrospective review of visceral stents placed during FEVAR over 15 years (February 2003-December 2018) was performed. Kaplan-Meier analyses of freedom from visceral stent-related complications were performed. The outcomes between graft configurations of varying complexity were compared, as were the outcomes of different stent types and different visceral vessels. RESULTS: Visceral stent complications occurred in 47/236 patients (19.9%) and 54/653 stents (8.3%). Median follow up was 3.7 years (IQR 1.7-5.3 years). There was no difference in visceral stent complication rate between renal, SMA and coeliac arteries. Visceral stent complications were more frequent in more complex grafts compared to less complex grafts. Visceral stent complications were more frequent in uncovered stents compared to covered stents. Visceral stent-related endoleaks (type Ic and type IIIa) occurred exclusively around renal artery stents. The most common modes of failure with SMA stents were kinking and fracture, whereas with coeliac artery stents it was external crush. CONCLUSION: Visceral stent complications after FEVAR are common and merit continued and close long-term surveillance. The mode of visceral stent failure varies across the vessels in which the stents are located.

Reducing the risk of venous thromboembolism following superficial endovenous treatment: A UK and Republic of Ireland consensus study.

OBJECTIVES: Venous thromboembolism is a potentially fatal complication of superficial endovenous treatment. Proper risk assessment and thromboprophylaxis could mitigate this hazard; however, there are currently no evidence-based or consensus guidelines. This study surveyed UK and Republic of Ireland vascular consultants to determine areas of consensus. METHODS: A 32-item survey was sent to vascular consultants via the Vascular and Endovascular Research Network (phase 1). These results generated 10 consensus statements which were redistributed (phase 2). 'Good' and 'very good' consensus were defined as endorsement/rejection of statements by >67% and >85% of respondents, respectively. RESULTS: Forty-two consultants completed phase 1. This generated seven statements regarding risk factors mandating peri-procedural pharmacoprophylaxis and three statements regarding specific pharmacoprophylaxis regimes. Forty-seven consultants completed phase 2. Regarding venous thromboembolism risk factors mandating pharmacoprophylaxis, 'good' and 'very good' consensus was achieved for 5/7 and 2/7 statements, respectively. Regarding specific regimens, 'very good' consensus was achieved for 3/3 statements. CONCLUSIONS: The main findings from this study were that there was 'good' or 'very good' consensus that patients with any of the seven surveyed risk factors should be given pharmacoprophylaxis with low-molecular-weight heparin. High-risk patients should receive one to two weeks of pharmacoprophylaxis rather than a single dose.

Contrast-enhanced ultrasound and/or colour duplex ultrasound for surveillance after endovascular abdominal aortic aneurysm repair: a systematic review and economic evaluation.

BACKGROUND: Endovascular abdominal aortic aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) is less invasive than open surgery, but may be associated with important complications. Patients receiving EVAR require long-term surveillance to detect abnormalities and direct treatments. Computed tomography angiography (CTA) has been the most common imaging modality adopted for EVAR surveillance, but it is associated with repeated radiation exposure and the risk of contrast-related nephropathy. Colour duplex ultrasound (CDU) and, more recently, contrast-enhanced ultrasound (CEU) have been suggested as possible, safer, alternatives to CTA. OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of imaging strategies, using either CDU or CEU alone or in conjunction with plain radiography, compared with CTA for EVAR surveillance. DATA SOURCES: Major electronic databases were searched, including MEDLINE, EMBASE, Science Citation Index, Scopus' Articles-in-Press, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE) and NHS Economic Evaluation Database from 1996 onwards. We also searched for relevant ongoing studies and conference proceedings. The final searches were undertaken in September 2016. METHODS: We conducted a systematic review of randomised controlled trials and cohort studies of patients with AAAs who were receiving surveillance using CTA, CDU and CEU with or without plain radiography. Three reviewers were involved in the study selection, data extraction and risk-of-bias assessment. We developed a Markov model based on five surveillance strategies: (1) annual CTA; (2) annual CDU; (3) annual CEU; (4) CDU together with CTA at 1 year, followed by CDU on an annual basis; and (5) CEU together with CTA at 1 year, followed by CEU on an annual basis. All of these strategies also considered plain radiography on an annual basis. RESULTS: We identified two non-randomised comparative studies and 25 cohort studies of interventions, and nine systematic reviews of diagnostic accuracy. Overall, the proportion of patients who required reintervention ranged from 1.1% (mean follow-up of 24 months) to 23.8% (mean follow-up of 32 months). Reintervention was mainly required for patients with thrombosis and types I-III endoleaks. All-cause mortality ranged from 2.7% (mean follow-up of 24 months) to 42% (mean follow-up of 54.8 months). Aneurysm-related mortality occurred in < 1% of the participants. Strategies based on early and mid-term CTA and/or CDU and long-term CDU surveillance were broadly comparable with those based on a combination of CTA and CDU throughout the follow-up period in terms of clinical complications, reinterventions and mortality. The economic evaluation showed that a CDU-based strategy generated lower expected costs and higher quality-adjusted life-year (QALYs) than a CTA-based strategy and has a 63% probability of being cost-effective at a £30,000 willingness-to-pay-per-QALY threshold. A CEU-based strategy generated more QALYs, but at higher costs, and became cost-effective only for high-risk patient groups. LIMITATIONS: Most studies were rated as being at a high or moderate risk of bias. No studies compared CDU with CEU. Substantial clinical heterogeneity precluded a formal synthesis of results. The economic model was hindered by a lack of suitable data. CONCLUSIONS: Current surveillance practice is very heterogeneous. CDU may be a safe and cost-effective alternative to CTA, with CTA being reserved for abnormal/inconclusive CDU cases. FUTURE WORK: Research is needed to validate the safety of modified, more-targeted surveillance protocols based on the use of CDU and CEU. The role of radiography for surveillance after EVAR requires clarification. STUDY REGISTRATION: This study is registered as PROSPERO CRD42016036475. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Prospective, single UK centre, comparative study of the predictive values of contrast-enhanced ultrasound compared to time-resolved CT angiography in the detection and characterisation of endoleaks in high-risk patients undergoing endovascular aneurysm repair surveillance: a protocol.

INTRODUCTION: Diagnosis of endoleaks is imperative to prevent failure of endovascular aneurysm repairs (EVARs). The gold standard for diagnosis of endoleaks is catheter-directed subtraction angiography, which is not a practicable choice for surveillance. CT angiography (CTA) is the historical surveillance modality of choice. Concerns over cost, potential nephrotoxicity of contrast agents and repeated radiation exposure led to colour duplex ultrasound scan (CDUS) becoming an established alternative. CDUS has a lower sensitivity and specificity for endoleaks detection compared to CTA. Contrast-enhanced ultrasound scan (CEUS) represents an improvement of ultrasound imaging but comparisons against CTA report widely varying results, likely due to technical factors of CEUS and limitations of single-phase CTA.The development of time-resolved CTA (tCTA) offers timing information that much more closely mirrors the dynamic information available from CEUS. Theoretically, these two imaging modalities have the best potential for diagnostic accuracy. The aim of this study will be to compare CEUS to tCTA and investigate the utility of other measurements available from tCTA. METHODS AND ANALYSIS: This is a prospective, single UK centre, comparative study of paired binary diagnostic imaging modalities. Patients identified in routine post-EVAR surveillance as at risk of having a graft-related endoleak will undergo a CEUS and tCTA on the same day. This will allow the first comparison of CEUS to a semidynamic form of CTA. CEUS sensitivity and specificity to endoleak detection will be calculated. ETHICS AND DISSEMINATION: The study has achieved ethical approval. We hope the results will define the diagnostic accuracy of CEUS in comparison to a semidynamic form of CTA, representing a methodological improvement from previous studies. Results will be submitted for presentation at national and international vascular surgeryandradiology meetings. The full results are planned to be published in a medical journal. TRIAL REGISTRATION NUMBER: NCT02688751.

The ETTAA study protocol: a UK-wide observational study of 'Effective Treatments for Thoracic Aortic Aneurysm'.

INTRODUCTION: Chronic thoracic aortic aneurysm (CTAA) affecting the arch or descending aorta is an indolent but life-threatening condition with a rising prevalence as the UK population ages. Treatment may be in the form of open surgical repair (OSR) surgery, endovascular stent grafting (ESG) or best medical therapy (BMT). Currently, there is no consensus on the best management strategy, and no UK-specific economic studies that assess outcomes beyond the chosen procedure, but this is required in the context of greater demand for treatment and limited National Health Service (NHS) resources. METHODS AND ANALYSIS: This is a prospective, multicentre observational study with statistical and economic modelling of patients with CTAA affecting the arch or descending aorta. We aim to gain an understanding of how treatments are currently chosen, and to determine the clinical effectiveness and cost-effectiveness of the three available treatment strategies (BMT, ESG and OSR). This will be achieved by: (1) following consecutive patients who are referred to the teams collaborating in this proposal and collecting data regarding quality of life (QoL), medical events and hospital stays over a maximum of 5 years; (2) statistical analysis of the comparative effectiveness of the three treatments; and (3) economic modelling of the comparative cost-effectiveness of the three treatments. Primary study outcomes are: aneurysm growth, QoL, freedom from reintervention, freedom from death or permanent neurological injury, incremental cost per quality-adjusted life year gained. ETHICS AND DISSEMINATION: The study will generate an evidence base to guide patients and clinicians to determine the indications and timing of treatment, as well as informing healthcare decision-makers about which treatments the NHS should provide. The study has achieved ethical approval and will be disseminated primarily in the form of a Health Technology Assessment monograph at its completion. TRIAL REGISTRATION NUMBER: ISRCTN04044627.

Meta-analysis of the effects of statins on perioperative outcomes in vascular and endovascular surgery.

BACKGROUND: Compelling evidence from large randomized trials demonstrates the salutary effects of statins on primary and secondary protection from adverse cardiovascular events in high-risk populations. Our objective was to investigate the role of perioperative statin therapy in noncardiac vascular and endovascular surgery. METHODS: Electronic information sources were systematically searched to identify studies comparing outcomes after noncardiac surgical or endovascular arterial reconstruction in patients who were and were not taking statin in the perioperative or peri-interventional period. The Cochrane Collaboration's tool and the Newcastle-Ottawa scale were used to assess the methodologic quality and risk of bias of the selected studies. Random-effects models were applied to calculate pooled outcome data. RESULTS: Four randomized controlled trials and 20 observational cohort or case-control studies were selected for analysis. The randomized studies enrolled 675 patients, and the observational studies enrolled 22,861 patients. Statin therapy was associated with a significantly lower risk of all-cause mortality (odds ratio [OR], 0.54; 95% CI, [CI], 0.38-0.78), myocardial infarction (OR, 0.62; 95% CI, 0.45-0.87), stroke (OR, 0.51; 95% CI, 0.39-0.67), and the composite of myocardial infarction, stroke, and death (OR, 0.45; 95% CI, 0.29-0.70). No significant differences in cardiovascular mortality (OR, 0.82; 95% CI, 0.41-1.63) and the incidence of kidney injury (OR, 0.90; 95% CI, 0.58-1.39) between the groups were identified. CONCLUSIONS: Our analysis demonstrated that statin therapy is beneficial in improving operative and interventional outcomes and should be considered as part of the optimization strategy for prevention of adverse cardiovascular and cerebrovascular events and death.

Computational fluid dynamic analysis of the effect of morphologic features on distraction forces in fenestrated stent grafts.

OBJECTIVE: Secure fixation of endovascular stent grafts is essential for successful endovascular aneurysm repair. Hemodynamic distraction forces are generated by blood pressure and blood flow and act against fixation force to encourage migration that may eventually lead to late stent graft failure. The aim of this in silico study was to determine which morphologic features were associated with greater distraction force. METHODS: Computer models of 54 in situ fenestrated stent grafts were constructed from postoperative computed tomography scans by use of image processing software. Computational fluid dynamic analysis was then performed by use of a commercial finite volume solver with boundary conditions representative of peak systole. Distraction force results were obtained for each component of the stent graft. Distraction force was correlated with lumen cross-sectional area (XSA) at the inlet and outlet of components and was compared between groups of components, depending on the magnitude of four predefined angles within the aortoiliac territory that we describe in detail. RESULTS: Median total resultant distraction force (RDF) acting on the fenestrated proximal bodies was 4.8 N (1.3-15.7 N); bifurcated distal bodies, 5.6N (1.0-8.0 N); and limb extensions, 1.7 N (0.6-8.4N). Inlet XSA exhibited strong, positive correlation with total RDF in proximal body and distal body components (Spearman correlation coefficient ρ, 0.883 and 0.802, respectively). Outlet XSA exhibited a similarly strong, positive correlation with total RDF in limb extension components (ρ, 0.822). Outlet angulation ≥ 45 degrees was associated with greater total RDF in the limb extension components only (P = .004). CONCLUSIONS: For a given blood pressure, XSA was the most important morphologic determinant of total RDF. Angulation within the aorta was not large enough to influence this, whereas iliac angulation affecting outlet angulation of limb extension components was associated with significantly greater total RDF.

Defining a role for contrast-enhanced ultrasound in endovascular aneurysm repair surveillance.

OBJECTIVE: Endovascular aneurysm repair (EVAR) surveillance includes duplex ultrasound, abdominal radiography, and computed tomography angiography. Contrast-enhanced ultrasound (CEUS) has emerged as an additional modality whose role remains undefined. We evaluated whether a potential role for CEUS was the elucidation of unresolved issues following standard surveillance modalities. METHODS: All patients undergoing EVAR at a tertiary referral center had surveillance based on plain abdominal radiograph and duplex ultrasound, with single arterial phase computed tomography angiography reserved for abnormalities or nondiagnostic imaging. In this prospective evaluation, from April 2010 to July 2011, discordance between imaging modalities or unresolved surveillance issues prompted CEUS. Cases and imaging were discussed in a multidisciplinary setting and outcomes recorded. RESULTS: During the study period, 539 patients underwent EVAR surveillance, of whom 33 (6%) had CEUS for unresolved issues (median age, 79; range, 66-90; 28 male). Median follow-up after EVAR was 23 months (range, 0-132). In all cases, CEUS was able to resolve the clinical issue, resulting in secondary intervention in 10 patients (30%). The remaining patients were returned to surveillance. Within the cohort of 33 patients, the clinical issues were categorized into three groups. Group 1: Endoleak of uncertain classification (n = 27: 21 type II, four type I, two had endoleak excluded). Group 2: Significant aneurysm expansion (≥ 5 mm) without apparent endoleak (n = 4: one type II, three had endoleak excluded). Group 3: Target vessel patency following fenestrated EVAR (n = 2: patency confirmed in both). CONCLUSIONS: CEUS can enhance EVAR surveillance through clarification of endoleak and target vessel patency when standard imaging modalities are not diagnostic.

Comparison of fenestrated endovascular and open repair of abdominal aortic aneurysms not suitable for standard endovascular repair.

BACKGROUND: Abdominal aortic aneurysms that are unsuitable for a standard endovascular repair (EVAR) could be considered for fenestrated endovascular repair (f-EVAR). The aim of this study was to conduct a risk-adjusted retrospective concurrent cohort comparison of f-EVAR and open repair for such aneurysms. METHODS: All patients who underwent repair of an abdominal aortic aneurysm that was unsuitable for a standard EVAR due to inadequate neck within one institution between January 2006 and December 2010 were identified. Case notes were retrieved for clinical data, Vascular Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (V-POSSUM) score, and aneurysm morphology. Computed tomography scans were reviewed to establish aneurysm morphology. RESULTS: A total of 107 patients were identified. The open surgery cohort included 54 patients (35 men) who were a median age of 72 years (interquartile range [IQR], 9.5; range, 60-86 years). The aortic cross-clamp was infrarenal in 20 patients, suprarenal or above in 21, and inter-renal in eight. Postoperatively, 63 major complications were noted in 30 patients, nine of whom required 16 reinterventions. Cumulative hospital stay of the cohort was 1170 days (median, 12; IQR, 13; range, 1-205 days) of which 234 days (median, 28; IQR, 36; range, 1-77 days) were in the intensive therapy unit (ITU). Perioperative mortality was 9.2% (n = 5), exactly as estimated by V-POSSUM. The f-EVAR cohort included 53 patients (47 men) who were a median age of 76 years (IQR, 11.50; range, 55-87 years). Two fenestrations and one scallop was the most frequent configuration (n = 31). Postoperatively, 37 major complications were noted in 18 patients, six requiring reintervention. Hospital stay was 559 days (median, 7; IQR, 4.5; range, 4-64 days), of which 31 days (median, 4; IQR, 10.5; range, 1-15 days) were in the ITU. Two patients died perioperatively (3.7%), resulting in an observed crude absolute risk reduction of 5.5% compared with open repair. The V-POSSUM estimated perioperative death in five patients (9.4%) in the f-EVAR cohort. In a hypothetic scenario of the f-EVAR cohort undergoing open repair, V-POSSUM estimated seven deaths (13.2%), resulting in an estimated risk-adjusted absolute risk reduction due to f-EVAR of 9.5%. CONCLUSIONS: In this group of patients, f-EVAR reduced mortality and morbidity substantially compared with open repair and also reduced total hospital stay and ITU utilization.

Fractured superior mesenteric artery stents after fenestrated endovascular aneurysm repair.

Stent fracture after fenestrated endovascular aneurysm repair is a recognized complication. In this report, we record the occurrence of superior mesenteric artery stent fractures in our series and describe the management of embolized stent fragments during secondary intervention.

Use of a superficial femoral artery autograft as a femoral vein replacement during en bloc sarcoma resection.

INTRODUCTION: Soft tissue malignancy encasing axial vessels presents a surgical challenge when the goal is limb-preserving radical excision. REPORT: We describe a case where limb-preserving resection of a myxoid liposarcoma involving the femoral vessels was successfully performed in the absence of autologous superficial vein for vascular reconstruction. The proximal ipsilateral superficial femoral artery was harvested as an autograft for venous reconstruction, with the arterial defect bridged using a polytetrafluoroethylene interposition graft. DISCUSSION: This technique may be selectively extended to other indications where limb viability is dependent upon availability of a high-quality graft, and conventional conduits are either unavailable or unreliable.

Risk-adjusted outcome analysis of endovascular abdominal aortic aneurysm repair in a large population: how do stent-grafts compare?

PURPOSE: To compare differences in the applicability and incidence of postoperative adverse events among stent-grafts used for repair of infrarenal aortic aneurysms. METHODS: An analysis of 6787 patients from the EUROSTAR Registry database was conducted to compare aneurysm morphological features, patient characteristics, and postoperative events for the AneuRx, EVT/Ancure, Excluder, Stentor, Talent, and Zenith devices versus the Vanguard device (control) and each other. Annual incidence rates of complications were determined, and risks were compared using the Cox proportional hazards analysis. RESULTS: The annual incidence rates were: device-related endoleak (types I and III) 6% (range 4%-10%), type II endoleak 5% (range 0.3%-11%), migration 3% (range 0.5%-5%), kinking 2% (range 1%-5%), occlusion 3% (range 1%-5%), rupture 0.5% (range 0%-1%), and all-cause mortality 7% (range 5%-8%). After adjustment for factors influencing outcome, AneuRx, Excluder, Talent, and Zenith devices were associated with a lower risk of migration, kinking, occlusion, and secondary intervention compared to the Vanguard device. Significant increased risk for conversion (EVT/Ancure) and reduced risk of aneurysm rupture (AneuRx and Zenith) and all-cause mortality (Excluder) were found compared to the Vanguard device. CONCLUSIONS: Significant differences exist between stent-grafts of different labels in terms of applicability and complications during intermediate to long-term follow-up. Since each stent-graft has its drawbacks, no single label can be identified as the best. It is reassuring that developments in stent-grafts indeed result in better performance than the early stent-grafts. However, a single device incorporating all the perceived improvements should still be pursued.

Heterogeneity of tensile strength and matrix metalloproteinase activity in the wall of abdominal aortic aneurysms.

PURPOSE: To measure the tensile strength of the aneurysm wall and the matrix metalloproteinase (MMP) activity in similar samples of aortic tissue. METHODS: Detailed mechanical testing was conducted on 124 standardized specimens of aneurysm wall harvested from 24 patients undergoing elective aneurysm repair. The intrasac pressure required to cause aneurysm rupture was calculated based upon the Law of Laplace. In addition, MMP-2 and 9 were assayed from these specimens. Sixty specimens of nonaneurysmal aorta from 6 cadaveric organ donors served as controls. Intrasubject and intersubject variations were analyzed. RESULTS: In the aneurysm specimens, the Young's modulus was 1.80x10(6) N/m(2), the load at break was 6.36 N, the strain at break was 0.30, the ultimate strength was 0.53x10(6) N/ m(2), and the MMP activity was 312 for MMP-2 and 460 for MMP-9. In the controls, the circumferential measurements were a Young's modulus of 1.82x10(6) N/m(2), a load at break of 5.43 N, strain at break of 0.29, ultimate strength of 0.61x10(6) N/m(2), and MMP activity of 395 for MMP-2 and 2019 for MMP-9. Longitudinal measurements in controls were a Young's modulus of 1.38x10(6) N/m(2), a load at break of 11.39 N, a strain at break of 0.33, and ultimate strength of 1.30x10(6) N/m(2). Intra and intersubject variation of all parameters was very high. Based upon the lowest measured tensile strength for each aneurysm, the intrasac pressure required to cause rupture varied from 142 to 982 mmHg. CONCLUSIONS: Localized "hot spots" of MMP hyperactivity could lead to focal weakening of the aneurysm wall and rupture at relatively low levels of intraluminal pressure. These data suggest that tensile strength of the sac is just as important as intrasac tension in determining the risk of rupture. Moreover, these observations may explain why some small aneurysms rupture and larger aneurysms do not. Assessment of rupture risk based on computation or measurement of wall stress may be subject to error and inaccuracy due to variations in wall tensile strength.