Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial

Functional and molecular imaging techniques in aortic aneurysm disease

PURPOSE OF REVIEW

Functional and molecular aortic imaging has shown great promise for evaluation of aortic disease, and may soon augment conventional assessment of aortic dimensions for the clinical management of patients.

RECENT FINDINGS

A range of imaging techniques is available for evaluation of patients with aortic disease. Magnetic resonance blood flow imaging can identify atherosclerosis prone aortic regions and may be useful for predicting aneurysm growth. Computational modeling can demonstrate significant differences in wall stress between abdominal aortic aneurysms of similar size and may better predict rupture than diameter alone. Metabolic imaging with fluorodeoxyglucose-PET [(FDG)-PET] can identify focal aortic wall inflammation that may portend rapid progression of disease. Molecular imaging with probes that target collagen and elastin can directly exhibit changes in the vessel wall associated with disease.

SUMMARY

The complexity of aortic disease is more fully revealed with new functional imaging techniques than with conventional anatomic analysis alone. This may better inform surveillance imaging regimens, medical management and decisions regarding early intervention for aortic disease.

Novel biomarkers of abdominal aortic aneurysm disease: identifying gaps and dispelling misperceptions

Abdominal aortic aneurysm (AAA) is a prevalent and potentially life-threatening disease. Early detection by screening programs and subsequent surveillance has been shown to be effective at reducing the risk of mortality due to aneurysm rupture. The aim of this review is to summarize the developments in the literature concerning the latest biomarkers (from 2008 to date) and their potential screening and therapeutic values. Our search included human studies in English and found numerous novel biomarkers under research, which were categorized in 6 groups. Most of these studies are either experimental or hampered by their low numbers of patients. We concluded that currently no specific laboratory markers allow screeing for the disease and monitoring its progression or the results of treatment. Further studies and studies in larger patient groups are required in order to validate biomarkers as cost-effective tools in the AAA disease.

Abdominal aortic aneurysm repair: long-term follow-up of endovascular versus open repair

INTRODUCTION

To compare early and long-term outcomes of endovascular abdominal aortic aneurysm repair (EVAR) versus open repair (OPEN).

DESIGN

Prospective observational, per protocol, non-randomized, with retrospective analyses.

MATERIAL AND METHODS

Between 2000 and 2005, a total of 311 patients having EVAR or OPEN repair of infrarenal abdominal aortic aneurysms were identified and included in this prospective single-center observational study. A propensity score-based optimal-matching algorithm was employed, and 138 patients undergoing EVAR procedures were matched (1: 1) to OPEN repair.

RESULTS

Open repair showed higher hospital mortality (17% vs. 6%, p = 0.004), respiratory failure (p < 0.026), transfusion requirement (p < 0.001), and intensive care unit admission (27% vs. 7%, p < 0.001), and longer hospitalization (p < 0.001). Median follow-up was 70 months (25(th) to 75(th) percentile, 24 to 101). Actuarial survival estimates at 1, 5 and 10 years were 93%, 74%, 49% for the OPEN group compared to 89%, 69%, 59% for the EVAR group (p = 0.465). A significant difference between groups was observed in younger patients (< 75 years) only (p < 0.044). Late complication and re-intervention rates were significantly higher in EVAR patients (p < 0.001 and p = 0.002, respectively). Freedom from late complications at 1, 5 and 10 years was 96%, 92%, 86%, and 84%, 70%, 64% for OPEN and EVAR procedures, respectively.

CONCLUSIONS

Our experience confirms the excellent results of the EVAR procedures, offering excellent early and long-term results in terms of safety and reduction of mortality. Patients < 75 years seem to benefit from EVAR not only in the immediate postoperative period but even in a long-term perspective.

Clinical significance of type I endoleak on completion angiography

Purpose

Type I endoleak is known to be associated with sac enlargement and occasional rupture, therefore, the treatment of type I endoleak is recommended at the time of diagnosis. The aim of this study was to identify the significance of early type I endoleak found on completion angiography.

Methods

Between January 2000 and December 2012, a total of 86 patients underwent endovascular abdominal aortic aneurysm repair (EVAR) and 10 patients (11.6%) were diagnosed with type Ia endoleak on completion angiography. Clinical and radiologic data were reviewed retrospectively.

Results

Of the 10 patients, two underwent EVAR with custom-made stent-grafts in the initial stage and both of them needed immediate treatment: one case involved open repair while the other involved insertion of an additional stent-graft. In 8 patients, the amount of leakage decreased after repeated balloon molding. They were managed conservatively and followed up with computed tomography angiography within 2 weeks after EVAR. In 7 of the 8 cases, type Ia endoleaks disappeared. In one patient with a persistent endoleak and a folded posterior wall of the stent-graft, coil embolization was performed 1 week after EVAR. With a median follow-up of 12 months (range, 1-61 months), no patients showed recurrence of type I endoleak or sac expansion.

Conclusion

Type I endoleaks diagnosed on completion angiography sealed spontaneously in 7 of 10 patients (70.0%). In cases of decreased amounts of leakage after balloon molding, simple observation may be an alternative to repetitive procedures. The long-term follow-up of patients with self-sealed type I endoleaks is mandatory.

Designation as "unfit for open repair" is associated with poor outcomes after endovascular aortic aneurysm repair

BACKGROUND

Endovascular aortic aneurysm repair (EVAR) is often offered to patients with abdominal aortic aneurysms (AAAs) considered preoperatively to be unfit for open AAA repair (oAAA). This study describes the short- and long-term outcomes of patients undergoing EVAR with AAAs <6.5 cm who are considered unfit for oAAA.

METHODS AND RESULTS

We analyzed elective EVARs for AAAs <6.5 cm diameter in the Vascular Study Group of New England (2003-2011). Patients were designated as fit or unfit for oAAA by the treating surgeon. End points included in-hospital major adverse events and long-term mortality. We identified patient characteristics associated with being unfit for open repair and predictors of survival using multivariable analyses. Of 1653 EVARs, 309 (18.7%) patients were deemed unfit for oAAA. These patients were more likely to have advanced age, cardiac disease, chronic obstructive pulmonary disease, and larger aneurysms at the time of repair (54 versus 56 mm, P=0.001). Patients unfit for oAAA had higher rates of cardiac (7.8% versus 3.1%, P<0.01) and pulmonary (3.6 versus 1.6, P<0.01) complications and worse survival rates at 5 years (61% versus 80%; log rank P<0.01) compared with those deemed fit for oAAA. Finally, patients designated as unfit for oAAA had worse survival, even adjusting for patient characteristics and aneurysm size (hazard ratio, 1.6; 95% confidence interval, 1.2-2.2; P<0.01).

CONCLUSIONS

In patients with AAAs <6.5 cm, designation by the operating surgeon as unfit for oAAA provides insight into both short- and long-term efficacy of EVAR. Patients unable to tolerate oAAA may not benefit from EVAR unless their risk of AAA rupture is very high.

[Aortic stent migration: a rare complication after endovascular repair]

Migration of an aortic stent is one of the most serious complications that can occur during follow-up after endovascular repair of an abdominal aortic aneurysm. We report the case of a 75-year-old man who underwent endovascular treatment for an infra-renal aortic aneurysm using an aorto-mono-iliac stent associated to a femoro-femoral bypass. The angiography performed at the end of procedure showed complete exclusion of the aneurysm. The postoperative course was uneventful. CT scans at 1, 6 and 12 months were normal. The CT scan at the 18th month showed a proximal migration of the stent, which was complicated by a type 1 endoleak and a stent disjunction with a type 3 endoleak. Revision surgery was indicated but the patient died from aneurismal rupture pending treatment. The migration of an aortic stent is a rare but serious complication of endovascular aneurysmal repair. Prevention requires a precise anatomical selection and adequate deployment of the stent graft.

Endovascular treatment of abdominal aortic aneurysms

Patients with abdominal aortic aneurysms (AAAs) are usually treated with endovascular aneurysm repair (EVAR), which has become the standard of care in many hospitals for patients with suitable anatomy. Clinical evidence indicates that EVAR is associated with superior perioperative outcomes and similar long-term survival compared with open repair. Since the randomized, controlled trials that provided this evidence were conducted, however, the stent graft technology for infrarenal AAA has been further developed. Improvements include profile downsizing, optimization of sealing and fixation, and the use of low porosity fabrics. In addition, imaging techniques have improved, enabling better preoperative planning, stent graft placement, and postoperative surveillance. Also in the past few years, fenestrated and branched stent grafts have increasingly been used to manage anatomically challenging aneurysms, and experiments with off-label use of stent grafts have been performed to treat patients deemed unfit or unsuitable for other treatment strategies. Overall, the indications for endovascular management of AAA are expanding to include increasingly complex and anatomically challenging aneurysms. Ongoing studies and optimization of imaging, in addition to technological refinement of stent grafts, will hopefully continue to broaden the utilization of EVAR.

Endovascular repair of abdominal aortic aneurysm

BACKGROUND

An abnormal dilatation of the abdominal aorta is referred to as an abdominal aortic aneurysm (AAA). Due to the risk of rupture, surgical repair is offered electively to individuals with aneurysms greater than 5.5 cm in size. Traditionally, conventional open surgical repair (OSR) was considered the first choice approach. However, over the past two decades endovascular aneurysm repair (EVAR) has gained popularity as a treatment option. This article intends to review the role of EVAR in the management of elective AAA.

OBJECTIVES

To assess the effectiveness of EVAR versus conventional OSR in individuals with AAA considered fit for surgery, and EVAR versus best medical care in those considered unfit for surgery. This was determined by the effect on short, intermediate and long-term mortality, endograft related complications, re-intervention rates and major complications.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (January 2013) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 12). The TSC also searched trial databases for details of ongoing or unpublished studies.

SELECTION CRITERIA

Prospective randomised controlled trials (RCTs) comparing EVAR with OSR in individuals with AAA considered fit for surgery. and comparing EVAR with best medical care in individuals considered unfit for surgery. We excluded studies with inadequate data or using an inadequate randomisation technique.

DATA COLLECTION AND ANALYSIS

Three reviewers independently evaluated trials for appropriateness for inclusion and extracted data using pro forma designed by the Cochrane PVD Group. We assessed the quality of trials using The Cochrane Collaboration's 'Risk of bias' tool. We entered collected data in to Review Manager (version 5.2.3) for analysis. Where direct comparisons could be made, we determined odds ratios (OR). We tested studies for heterogeneity and, when present, we used a random-effects model; otherwise we used a fixed-effect model. We tabulated data that could not be collated.

MAIN RESULTS

Four high-quality trials comparing EVAR with OSR (n = 2790) and one high-quality trial comparing EVAR with no intervention (n = 404) fulfilled the inclusion criteria. In individuals considered fit for surgery, a pooled analysis, including 1362 individuals randomised to EVAR and 1361 randomised to OSR, found short-term mortality (including 30-day or inhospital mortality, excluding deaths prior to intervention) with EVAR to be significantly lower than with OSR (1.4% versus 4.2%, OR 0.33, 95% confidence interval (CI) 0.20 to 0.55; P < 0.0001). Using intention-to-treat analysis (ITT) there was no significant difference in mortality at intermediate follow-up (up to four years from randomisation), with 221 (15.8%) and 237 (17%) deaths in the EVAR (n = 1393) and OSR (n = 1390) groups, respectively (OR 0.92, 95% CI 0.75 to 1.12; P = 0.40). There was also no significant difference in long-term mortality (beyond four years), with 464 (37.3%) deaths in the EVAR and 470 (37.8%) deaths in the OSR group (OR 0.98, 95% CI 0.83 to 1.15; P = 0.78). Similarly, there was no significant difference in aneurysm-related mortality between groups, either at the intermediate- or long-term follow up.Studies showed that both EVAR and OSR were associated with similar incidences of cardiac deaths (OR 1.14, 95% CI 0.86 to 1.52; P = 0.36) and fatal stroke rate (OR 0.81, 95% CI 0.42 to 1.55; P = 0.52). The long-term reintervention rate was significantly higher in the EVAR group than in the OSR group (OR 1.98, 95% CI 1.12 to 3.51; P = 0.02; I(2) = 85%). Results of the reintervention analysis should be interpreted with caution due to significant heterogeneity. Operative complications, health-related quality of life and sexual dysfunction were generally comparable between the EVAR and OSR groups. However, there was a slightly higher incidence of pulmonary complications in the OSR group compared with the EVAR group (OR 0.36, 95% CI 0.17 to 0.75; P = 0.006).In individuals considered unfit for conventional OSR, the one included trial found no difference between the EVAR and no-intervention groups with regard to all-cause mortality at final follow up, with 21.0 deaths per 100 person-years in the EVAR group and 22.1 deaths per 100 person years in the no-intervention group (adjusted hazard ratio (HR) with EVAR 0.99, 95% CI 0.78 to 1.27; P = 0.97). Aneurysm-related deaths were, however, significantly higher in the no-intervention group than in the EVAR group (adjusted HR 0.53, 95% CI 0.32 to 0.89; P = 0.02). There was no difference in myocardial events (HR 1.07, 95% CI 0.60 to 1.91) between the groups in this study.

AUTHORS' CONCLUSIONS

In individuals considered fit for conventional surgery, EVAR was associated with lower short-term mortality than OSR. However, this benefit from EVAR did not persist at the intermediate- and long-term follow ups. Individuals undergoing EVAR had a higher reintervention rate than those undergoing OSR. Most of the reinterventions undertaken following EVAR, however, were catheter-based interventions associated with low mortality. Operative complications, health-related quality of life and sexual dysfunction were generally comparable between EVAR and OSR. However, there was a slightly higher incidence of pulmonary complications in the OSR group than in the EVAR group.In individuals considered unfit for open surgery, the results of a single trial found no overall short- or long-term benefits of EVAR over no intervention with regard to all-cause mortality, but individuals may differ and individual preferences should always be taken into account.

Current practice of aneurysm management in the UK

INTRODUCTION

The aim of this study is to establish the current practice of aneurysm management, to assess the introduction of fenestrated endovascular aneurysm repair (FEVAR) and to establish the criteria for its use and its role in the UK.

METHODS

All UK centres performing FEVAR and centres with an established interest in infra-renal endovascular aneurysm repair (EVAR) were invited to respond to an open-ended questionnaire about abdominal aortic aneurysm (AAA) management.

RESULTS

A response was obtained from over 90% of UK FEVAR centres. Results showed marked regional differences in aneurysm management, in particular with regard to indications for complex aneurysm management.

CONCLUSION

The trend in the UK is towards endovascular repair. However, there are still variations in unit policies, indicating regional differences in patient management.

High-intensity interval exercise training before abdominal aortic aneurysm repair (HIT-AAA): protocol for a randomised controlled feasibility trial

INTRODUCTION

In patients with large abdominal aortic aneurysm (AAA), open surgical or endovascular aneurysm repair procedures are often used to minimise the risk of aneurysm-related rupture and death; however, aneurysm repair itself carries a high risk. Low cardiopulmonary fitness is associated with an increased risk of early post-operative complications and death following elective AAA repair. Therefore, fitness should be enhanced before aneurysm repair. High-intensity interval exercise training (HIT) is a potent, time-efficient strategy for enhancing cardiopulmonary fitness. Here, we describe a feasibility study for a definitive trial of a pre-operative HIT intervention to improve post-operative outcomes in patients undergoing elective AAA repair.

METHODS AND ANALYSIS

A minimum of 50 patients awaiting elective repair of a 5.5-7.0 cm infrarenal AAA will be allocated by minimisation to HIT or usual care control in a 1:1 ratio. The patients allocated to HIT will complete three hospital-based exercise sessions per week, for 4 weeks. Each session will include 2 or 4 min of high-intensity stationary cycling followed by the same duration of easy cycling or passive recovery, repeated until a total of 16 min of high-intensity exercise is accumulated. Outcomes to be assessed before randomisation and 24-48 h before aneurysm repair include cardiopulmonary fitness, maximum AAA diameter and health-related quality of life. In the post-operative period, we will record destination (ward or critical care unit), organ-specific morbidity, mortality and the durations of critical care and hospital stay. Twelve weeks after the discharge, participants will be interviewed to reassess quality of life and determine post-discharge healthcare utilisation. The costs associated with the exercise intervention and healthcare utilisation will be calculated.

ETHICS AND DISSEMINATION

Ethics approval was secured through Sunderland Research Ethics Committee. The findings of the trial will be disseminated through peer-reviewed journals, and national and international presentations.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN09433624.

Aortic dissection occurring 18 months after successful endovascular repair in an anatomically difficult case of abdominal aortic aneurysm

We report an autopsy case of aneurysm dissection that occurred 18 months after the implantation of a Zenith stent graft. A 94-year-old woman, who had undergone an endovascular repair with postoperative reintervention, died of shock due to retroperitoneal hematoma. An autopsy indicated that the stent graft remained firmly fixed to the native aorta, whereas the dissection occurred near the proximal edge of the stent graft but not at the point of attachment between the suprarenal stent hook and the aorta. The luminal surface of the stent graft was almost completely covered with a transparent film with an endothelial cell lining, which might reflect the tissue regeneration observed on histological examination. This was a rare case of acute aortic dissection that occurred 18 months after EVAR, in which the autopsy indicated interesting microscopic findings and the mechanisms underlying the aortic dissection. We believe that aggressive reintervention at the proximal site in elderly women might cause the dissection of the native aorta.

Endovascular repair of aortoiliac aneurysm using bifurcated stent grafts with sandwich technique for preserving the internal iliac artery

In this case, we describe a case of a 76-year-old male with extensive aortoiliac aneurysms treated by endovascular aneurysm repair using the sandwich technique in order to preserve left internal iliac artery perfusion. The sandwich technique refers to the deployment of multiple paralleled stent grafts into main distal and side branches in overlapping with a single proximal stent graft. The procedure was successfully performed without complications. Post-procedural CT angiography demonstrated patent stent grafts without any endoleak. The strengths and limitations of the sandwich technique need to be investigated in large-scale, long-term clinical trials.

Evidence-based health care policy in reimbursement decisions: lessons from a series of six equivocal case-studies

Context

Health care technological evolution through new drugs, implants and other interventions is a key driver of healthcare spending. Policy makers are currently challenged to strengthen the evidence for and cost-effectiveness of reimbursement decisions, while not reducing the capacity for real innovations. This article examines six cases of reimbursement decision making at the national health insurance authority in Belgium, with outcomes that were contested from an evidence-based perspective in scientific or public media.

Methods

In depth interviews with key stakeholders based on the adapted framework of Davies allowed us to identify the relative impact of clinical and health economic evidence; experience, expertise & judgment; financial impact & resources; values, ideology & political beliefs; habit & tradition; lobbyists & pressure groups; pragmatics & contingencies; media attention; and adoption from other payers & countries.

Findings

Evidence was not the sole criterion on which reimbursement decisions were based. Across six equivocal cases numerous other criteria were perceived to influence reimbursement policy. These included other considerations that stakeholders deemed crucial in this area, such as taking into account the cost to the patient, and managing crisis scenarios. However, negative impacts were also reported, in the form of bypassing regular procedures unnecessarily, dominance of an opinion leader, using information selectively, and influential conflicts of interest.

Conclusions

‘Evidence’ and ‘negotiation’ are both essential inputs of reimbursement policy. Yet, purposely selected equivocal cases in Belgium provide a rich source to learn from and to improve the interaction between both. We formulated policy recommendations to reconcile the impact of all factors identified. A more systematic approach to reimburse new care may be one of many instruments to resolve the budgetary crisis in health care in other countries as well, by separating what is truly innovative and value for money from additional ‘waste’.

The financial implications of endovascular aneurysm repair in the cost containment era

OBJECTIVE

Endovascular aneurysm repair (EVAR) is associated with significant direct device costs. Such costs place EVAR at odds with efforts to constrain healthcare expenditures. This study examines the procedure-associated costs and operating margins associated with EVAR at a tertiary care academic medical center.

METHODS

All infrarenal EVARs performed from April 2011 to March 2012 were identified (n = 127). Among this cohort, 49 patients met standard commercial instruction for use guidelines, were treated using a single manufacturer device, and billed to Medicare diagnosis-related group (DRG) 238. Of these 49 patients, net technical operating margins (technical revenue minus technical cost) were calculated in conjunction with the hospital finance department. EVAR implant costs were determined for each procedure. DRG 238-associated costs and length of stay were benchmarked against other academic medical centers using University Health System Consortium 2012 data.

RESULTS

Among the studied EVAR cohort (age 75, 82% male, mean length of stay, 1.7 days), mean technical costs totaled $31,672. Graft implants accounted for 52% of the allocated technical costs. Institutional overhead was 17% ($5495) of total technical costs. Net mean total technical EVAR-associated operating margins were -$4015 per procedure. Our institutional costs and length of stay, when benchmarked against comparable centers, remained in the lowest quartile nationally using University Health System Consortium costs for DRG 238. Stent graft price did not correlate with total EVAR market share.

CONCLUSIONS

EVAR is currently associated with significant negative operating margins among Medicare beneficiaries. Currently, device costs account for over 50% of EVAR-associated technical costs and did not impact EVAR market share, reflecting an unawareness of cost differential among surgeons. These data indicate that EVAR must undergo dramatic care delivery redesign for this practice to remain sustainable.

An in situ forming biodegradable hydrogel-based embolic agent for interventional therapies

We present here the characteristics of an in situ forming hydrogel prepared from carboxymethyl chitosan and oxidized carboxymethyl cellulose for interventional therapies. Gelation, owing to the formation of Schiff bases, occurred both with and without the presence of a radiographic contrast agent. The hydrogel exhibited a highly porous internal structure (pore diameter 17±4 μm), no cytotoxicity to human umbilical vein endothelial cells, hemocompatibility with human blood, and degradability in lysozyme solutions. Drug release from hydrogels loaded with a sclerosant, tetracycline, was measured at pH 7.4, 6 and 2 at 37°C. The results showed that tetracycline was more stable under acidic conditions, with a lower release rate observed at pH 6. An anticancer drug, doxorubicin, was loaded into the hydrogel and a cumulative release of 30% was observed over 78 h in phosphate-buffered saline at 37°C. Injection of the hydrogel precursor through a 5-F catheter into a fusiform aneurysm model was feasible, leading to complete filling of the aneurysmal sac, which was visualized by fluoroscopy. The levels of occlusion by hydrogel precursors (1.8% and 2.1%) and calibrated microspheres (100-300 μm) in a rabbit renal model were compared. Embolization with hydrogel precursors was performed without clogging and the hydrogel achieved effective occlusion in more distal arteries than calibrated microspheres. In conclusion, this hydrogel possesses promising characteristics potentially beneficial for a wide range of vascular intervention procedures that involve embolization and drug delivery.

Endovascular treatment of infrarenal abdominal aortic aneurysm with short and angulated neck in high-risk patient

Endovascular treatment of abdominal aortic aneurysms (AAA) is an established alternative to open repair. However lifelong surveillance is still required to monitor endograft function and signal the need for secondary interventions (Hobo and Buth 2006). Aortic morphology, especially related to the proximal neck, often complicates the procedure or increases the risk for late device-related complications (Hobo et al. 2007 and Chisci et al. 2009). The definition of a short and angulated neck is based on length (<15 mm), and angulation (>60°) (Hobo et al. 2007 and Chisci et al. 2009). A challenging neck also offers difficulties during open repairs (OR), necessitating extensive dissection with juxta- or suprarenal aortic cross-clamping. Patients with extensive aneurysmal disease typically have more comorbidities and may not tolerate extensive surgical trauma (Sarac et al. 2002). It is, therefore, unclear whether aneurysms with a challenging proximal neck should be offered EVAR or OR (Cox et al. 2006, Choke et al. 2006, Robbins et al. 2005, Sternbergh III et al. 2002, Dillavou et al. 2003, and Greenberg et al. 2003). In our case the insertion of a thoracic endograft followed by the placement of a bifurcated aortic endograft for the treatment of a very short and severely angulated neck proved to be feasible offering acceptable duration of aneurysm exclusion. This adds up to our armamentarium in the treatment of high-risk patients, and it should be considered in emergency cases when the fenestrated and branched endografts are not available.

Bicarbonates for the prevention of postoperative renal failure in endovascular aortic aneurysm repair: a randomized pilot trial

Purpose. Contrast-induced nephropathy (CIN) can contribute to acute kidney injury (AKI) in patients undergoing endovascular aortic aneurysm surgery. We evaluated the incidence of AKI together with the evolution of early biomarkers of renal injury in patients receiving bicarbonates or NaCl 0.9%. Methods. This study involved endovascular aortic aneurysm surgery patients. Group A (n = 17) received bicarbonates 3 mL/kg/h for 1 h before the procedure and then 1 mL/kg/h until 6 h after surgery, whereas group B (n = 17) received NaCl 0.9% using the same protocol. Biomarkers of renal injury from urine (interleukin-18 (IL-18), neutrophil gelatinase-associated lipocalin (NGAL), N-acetyl-β-D-glucosaminidase (NAG), and kidney injury molecule 1 (KIM-1)) and blood (NGAL, cystatin C) were measured at baseline and 3, 24, and 48 h postoperatively. Results. AKI occurred in 1 patient (2.9%), in the bicarbonates group. IL-18, NAG, NGAL, and KIM-1 significantly rose in both groups after the surgery. There was a greater rise in NGAL and IL-18 after 3 h in the bicarbonates versus NaCl 0.9% group: 1115% versus 240% increase (P = 0.03) and 338% increase versus 1.4% decrease (P = 0.01). Conclusions. Despite significant elevation in biomarkers of renal injury, we demonstrated a low rate of AKI following endovascular aortic surgery.

Risk stratification by pre-operative cardiopulmonary exercise testing improves outcomes following elective abdominal aortic aneurysm surgery: a cohort study

BACKGROUND

In 2009, the NHS evidence adoption center and National Institute for Health and Care Excellence (NICE) published a review of the use of endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs). They recommended the development of a risk-assessment tool to help identify AAA patients with greater or lesser risk of operative mortality and to contribute to mortality prediction.A low anaerobic threshold (AT), which is a reliable, objective measure of pre-operative cardiorespiratory fitness, as determined by pre-operative cardiopulmonary exercise testing (CPET) is associated with poor surgical outcomes for major abdominal surgery. We aimed to assess the impact of a CPET-based risk-stratification strategy upon perioperative mortality, length of stay and non-operative costs for elective (open and endovascular) infra-renal AAA patients.

METHODS

A retrospective cohort study was undertaken. Pre-operative CPET-based selection for elective surgical intervention was introduced in 2007. An anonymized cohort of 230 consecutive infra-renal AAA patients (2007 to 2011) was studied. A historical control group of 128 consecutive infra-renal AAA patients (2003 to 2007) was identified for comparison.Comparative analysis of demographic and outcome data for CPET-pass (AT ≥ 11 ml/kg/min), CPET-fail (AT < 11 ml/kg/min) and CPET-submaximal (no AT generated) subgroups with control subjects was performed. Primary outcomes included 30-day mortality, survival and length of stay (LOS); secondary outcomes were non-operative inpatient costs.

RESULTS

Of 230 subjects, 188 underwent CPET: CPET-pass n = 131, CPET-fail n = 35 and CPET-submaximal n = 22. When compared to the controls, CPET-pass patients exhibited reduced median total LOS (10 vs 13 days for open surgery, n = 74, P < 0.01 and 4 vs 6 days for EVAR, n = 29, P < 0.05), intensive therapy unit requirement (3 vs 4 days for open repair only, P < 0.001), non-operative costs (£5,387 vs £9,634 for open repair, P < 0.001) and perioperative mortality (2.7% vs 12.6% (odds ratio: 0.19) for open repair only, P < 0.05). CPET-stratified (open/endovascular) patients exhibited a mid-term survival benefit (P < 0.05).

CONCLUSION

In this retrospective cohort study, a pre-operative AT > 11 ml/kg/min was associated with reduced perioperative mortality (open cases only), LOS, survival and inpatient costs (open and endovascular repair) for elective infra-renal AAA surgery.

An underused opportunity to introduce ACE inhibitors and influence prognosis: observational study of patients undergoing aortic surgery

OBJECTIVE

To asses whether Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are underused in patients with aortic disease due to concerns regarding flow limiting (>70%) renal artery stenosis (RAS).

DESIGN

A prospective analysis of patients admitted for aortic surgery was performed (January-July 2009). Co-morbidity, ACEI/ARB use and renal function were recorded. Computerised tomography (CT) angiograms were reviewed by a single blinded radiologist for the presence and severity of RAS.

SETTING

St Mary's Hospital, Vascular Unit, Imperial College Healthcare NHS Trust, London, UK.

PARTICIPANTS

75 randomly selected patients admitted to our vascular unit including elective and emergency admissions.

MAIN OUTCOME MEASURES

Indications for ACEI therapy were identified as determined by the National Institute of Health and Clinical Excellence (NICE) guidance. The ratio of the measurement distal to the stenosis and at the area of maximal stenosis on CT angiography were used to calculate the percentage RAS.

RESULTS

60 patients were identified (15 patients excluded due to previously modified renal vessels). The median age was 73 [interquartile range 68, 77]. Their underlying aortic disease included 52 (87%) aortic aneurysm, 6 (10%) with aortic dissection, 1 (1.7%) patient with occlusive disease and 1 (1.7%) patient with mycotic disease. Overall, 56/60 (93%) patients had at least one indication for ACEI therapy. 33/60 (55%) of patients were already receiving ACEI. CT angiogram examination demonstrated 17/60 (28%) patients have RAS of some degree, of which only 9/60 (15%) have flow limiting RAS.

CONCLUSION

A large proportion of aortic patients do not receive ACEI/ARB therapy despite definite indications and a low prevalence of flow-limiting RAS is low. After the exclusion of RAS at angiography, careful introduction of ACEI therapy with appropriate monitoring could be considered for many more patients.

Severity of chronic obstructive pulmonary disease is associated with adverse outcomes in patients undergoing elective abdominal aortic aneurysm repair

INTRODUCTION

Although chronic obstructive pulmonary disease (COPD) has been implicated as a risk factor for abdominal aortic aneurysm (AAA) rupture, its effect on surgical repair is less defined. Consequently, variation in practice persists regarding patient selection and surgical management. The purpose of this study was to analyze the effect of COPD on patients undergoing AAA repair.

METHODS

We reviewed a prospective regional registry of 3455 patients undergoing elective open AAA repair (OAR) and endovascular AAA repair (EVAR) from 23 centers in the Vascular Study Group of New England from 2003 to 2011. COPD was categorized as none, medical (medically treated but not oxygen [O2]-dependent), and O2-dependent. End points included in-hospital death, pulmonary complications, major postoperative adverse events (MAEs), extubation in the operating room, and 5-year survival. Survival was determined using life-table analysis based on the Social Security Death Index. Predictors of in-hospital and long-term mortality were determined by multivariate logistic regression and Cox proportional hazards analysis.

RESULTS

During the study interval, 2043 patients underwent EVAR and 1412 patients underwent OAR with a nearly equal prevalence of COPD (35% EVAR vs 36% OAR). O2-dependent COPD (4%) was associated with significantly increased in-hospital mortality, pulmonary complications, and MAE and was also associated with significantly decreased extubation in the operating room among patients undergoing both EVAR and OAR. Five-year survival was significantly diminished among all patients undergoing AAA repair with COPD (none, 78%; medical, 72%; O2-dependent, 42%; P < .001). By multivariate analysis, O2-dependent COPD was independently associated with in-hospital mortality (odds ratio 2.02, 95% confidence interval, 1.0-4.0; P = .04) and diminished 5-year survival (hazard ratio, 3.02; 95% confidence interval, 2.2-4.1; P < .001).

CONCLUSIONS

Patients with O2-dependent COPD undergoing AAA repair suffer increased pulmonary complications, overall MAE, and diminished long-term survival. This must be carefully factored into the risk-benefit analysis before recommending elective AAA repair in these patients.

The natural course of abdominal aortic aneurysms that meet the treatment criteria but not the operative requirements

INTRODUCTION

Abdominal aortic aneurysms (AAAs) of 55 mm diameter or growth >5 mm in 6 months are commonly accepted treatment criteria. The aim of this study was to establish the outcome of aneurysms that met the treatment criteria but not the operative requirements.

MATERIAL AND METHODS

Patients (n = 154) who were declined from operative care of AAA in Helsinki University Central Hospital (HUCH) during 2000-2010 were retrospectively analysed. Reasons for exclusion were identified. The follow-up period extended until the end of April 2012. The rupture rate and mortality were determined. The patients were analysed according to the aneurysm diameter: 55-60, 61-70 and >70 mm.

RESULTS

The reasons for exclusion from operative treatment were cardiorespiratory co-morbidities in 33%, cancer in 8%, overall condition in 33% and patient's choice in 21% of the patients. Regardless of the size of the aneurysm, the cause of death was aneurysm rupture in 43%, which was confirmed either in hospital or in autopsy for 76% of the patients. Of the ruptured aneurysms, 12 were operated of which five survived.

CONCLUSIONS

A ruptured aneurysm is the most common cause of death among patients unfit for surgery; this should be considered in the preoperative evaluation process, especially since 5 of the 12 patients survived the ruptured AAA (RAAA) operation.

Hemodynamic variations due to spiral blood flow through four patient-specific bifurcated stent graft configurations for the treatment of abdominal aortic aneurysms

Endovascular repair is now a recognised procedure for treating abdominal aortic aneurysms. However, post-operative complications such as stent graft migration and thrombus may still occur. To assess these complications numerically, the correct input boundary conditions, which include the full human aorta with associated branching, should be included. Four patient-specific computed tomography scanned bifurcated stent grafts (SGs) were modelled and attached onto a full human aorta, which included the ascending, aortic arch and descending aortas. Two of the SG geometries had a twisted leg configuration, while the other two had conventional nontwisted leg configurations. Computational fluid dynamics was completed for both geometries and the hemodynamics assessed. The complexity of the flow patterns and secondary flows were influenced by the inclusion of the full human aorta at the SG proximal section. During the decelerating phase significant recirculations occurred along the main body of all SG configurations. The inclusion of the full human aorta did not impact the velocity contours within the distal legs and there was no difference in drag forces with the SG containing the full human aorta and those without. A twisted leg configuration further promoted a spiral flow formation along its distal legs.

Changes in the management of infrarenal abdominal aortic aneurysm disease in Sweden

Background

Treatment of abdominal aortic aneurysm (AAA) has changed over time, with endovascular repair (EVAR) being the main technical revolution. This study assessed the effect of this change on outcome on a national basis over a 17-year interval.

Methods

Primary infrarenal AAA repairs in Swedish residents aged 50 years and older, in the Swedish Vascular Registry (Swedvasc) 1994–2010, were analysed. The rate per 100 000 population, patient characteristics, operative technique and outcome were assessed for the intervals 1994–1999, 2000–2005 and 2006–2010.

Results

Some 11 336 intact aneurysm repairs were performed. The overall rate per 100 000 increased (18·4 in 1994–1999, 19·4 in 2000–2005 and 24·0 in 2006–2010; P &lt; 0·001), most noticeably among older people (18 per cent increase among those aged 50–64 years, P = 0·004; 27 per cent in 65–79-year-olds, P &lt; 0·001; 128 per cent in those aged at least 80 years, P &lt; 0·001). The use of EVAR increased rapidly after 2005 (rate: 0·6 in 1994–1999, 4·4 in 2000–2005 and 11·8 in 2006–2010; P &lt; 0·001). The 30-day mortality rate decreased after open repair (4·7, 3·4 and 2·7 per cent respectively; P &lt; 0·001), but was stable after EVAR (2·6, 2·2 and 1·6 per cent; P = 0·227). Some 4972 ruptured aneurysm (rAAA) repairs were performed. The rate decreased after 2005 (9·3 in 1993–1999, 9·3 in 2000–2005 and 8·4 in 2006–2010; P = 0·006). The use of EVAR for rAAA increased over time (rate: 0, 0·5 and 1·6 respectively; P &lt; 0·001), whereas open repair decreased (9·3, 8·8 and 6·8; P &lt; 0·001). Thirty-day mortality decreased over time (38·3, 32·8 and 28·4 per cent; P &lt; 0·001).

Conclusion

The introduction of EVAR has been associated with an increased number of intact AAA repairs, which has accelerated recently, whereas the rate of rAAA repair has started to decline. Simultaneously, outcomes have improved.

Regional anesthesia for vascular surgery

Vascular surgical patients are a diverse group of patients who tend to be elderly, with multiple comorbidities, while vascular procedures may involve significant blood loss and ischemia of tissues beyond the arterial obstruction. Regional anesthesia techniques may offer benefits to patients undergoing vascular surgery because of their cardiorespiratory comorbidities. However, this group of patients is commonly receiving multiple medications, including anticoagulants, so regional techniques are not without risks. This review will discuss this topic based around 3 fundamental revascularization procedures, carotid, abdominal aortic aneurysm repair, and infrainguinal surgery, discussing the clinical applications of regional techniques relevant to each key area.

Construct domain analysis of patient health-related quality of life: physical and mental trajectory profiles following open versus endovascular repair of abdominal aortic aneurysm

Purpose

Many clinical trials comparing the outcomes of open surgical repair (OSR) versus endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) have been conducted, with varying results. Surprisingly, few outcomes studies have closely examined perceived physical and mental health-related quality of life (HRQOL) factors through a validated survey tool. The purpose of this prospective observational study was to describe the trajectory of HRQOL measures, from baseline to 1 year after surgery, in patients undergoing OSR or EVAR for AAA, and to explore for differences in physical and mental composite scores and their construct domains (subscales) using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36^®) tool.

Patients and methods

Over an 18-month period, a small sample of patients undergoing elective AAA repair in a community hospital setting were prospectively enrolled. Fifteen patients undergoing OSR and twenty patients undergoing EVAR were studied. Physical and mental HRQOL parameters were assessed using the SF-36.

Results

No significant differences in demographic and clinical variables were found between the OSR and EVAR groups. In the multivariable linear models with repeated measures, both groups showed a significant decline in physical health composite scores 30 days after the surgical procedure (P < 0.01). However, although the OSR group showed a statistically significant decline in three of the four physical health domains, the EVAR group declined in only one physical health domain. Only the OSR group showed a significant decline in three of the four mental health domains at 30 days; however, the decline of these domains was not reflected in the group’s mental health composite scores. By 90 days after surgery, both groups were not significantly different from their baseline in physical or mental health composite scores, or in any of their respective physical health domains.

Conclusion

In this small sample of patients undergoing AAA repair, EVAR resulted in less physical and emotional decline than OSR in the early postoperative period. However, patients in both groups may return to near baseline status at 90 days.

Meta-analysis of prospective trials determining the short- and mid-term effect of elective open and endovascular repair of abdominal aortic aneurysms on quality of life

Background

Repair of an abdominal aortic aneurysm (AAA) is undertaken to prevent rupture. Intervention is by either open repair (OR) or a more minimally invasive endovascular repair (EVAR). Quality-of-life (QoL) analysis is an important health outcome and a number of single studies have assessed QoL following OR and EVAR. This was a meta-analysis of published studies to assess the effect of an intervention on QoL in patients with an AAA.

Methods

A systematic literature search was undertaken for studies prospectively reporting QoL analysis in patients with an AAA undergoing elective intervention. A multivariable meta-analysis model was developed in which the outcomes were mean changes in QoL scores over time, both for all AAA repairs (OR and EVAR) and comparing OR with EVAR.

Results

Data were collated from 16 studies (14 OR, 12 EVAR). The results suggested that treating an AAA had an effect on patient-reported QoL, evident from the statistically significant changes predominantly in domains assessing physical ability and pain. QoL was affected most within the first 3 months after any form of intervention, and was more pronounced following OR. Furthermore, a deterioration in the Physical Component Summary score following an AAA repair (either OR or EVAR) was evident at 12 months after intervention.

Conclusion

Treating an AAA deleteriously affects patient-reported QoL over the first year following intervention.

Using risk models to improve patient selection for high-risk vascular surgery

Vascular surgeons frequently perform procedures aimed at limiting death, stroke, or amputation on patients who present with diseases such as aortic aneurysms, carotid atherosclerosis, and peripheral arterial occlusive disease. However, now more than ever surgeons must balance the potential benefits associated with these interventions with the risks of physiologic insult for these elderly patients, who often have significant comorbidity burdens and the potential for costly complications. In this paper, we highlight how regional and national datasets can help surgeons identify which patients are most likely to benefit from vascular operations and which patients are most likely to suffer complications in the postoperative period. By using these guidelines to improve patient selection, our risk models can help patients, physicians, and policymakers improve the clinical effectiveness of surgical and endovascular treatments for vascular disease.

Ruptured abdominal aortic aneurysm: the state of play

BACKGROUND

Ruptured abdominal aortic aneurysm (rAAA) remains a challenging problem: 2,410 cases were treated in Germany in 2010. Ruptured abdominal aortic aneurysm should be suspected in patients over age 50 who complain of pain in the abdomen or back and in whom examination reveals a pulsatile abdominal mass. The incidence of hospitalization for rAAA is 12 per 100,000 persons over age 65 per year (statistics for Germany, 2010), and rAAA carries an overall mortality of 80%.

METHODS

The current state of knowledge of rAAA was surveyed in a selective review of pertinent literature retrieved by an electronic search in the PubMed, Web of Science, and Cochrane Library databases with the keywords "abdominal aortic aneurysm," "ruptured," "open repair," and "endovascular." Publications in English or German up to and including March 2012 were considered, among them the Clinical Practice Guidelines of the European Society for Vascular Surgery (1).

RESULTS AND CONCLUSIONS

Recent reports show that the treatment of rAAA is still fraught with high mortality and high perioperative morbidity. Improvement is needed. It would be advisable for the care of rAAA to be centralized in specialized vascular centers implementing defined treatment pathways. Systematic screening, too, would be beneficial. An increasing number of reports suggest that endovascular treatment with stent prostheses improves outcomes; more definitive evidence on this matter will come from prospective, randomized trials that are now in progress.