Male-female differences in acute type B aortic dissection: the DisSEXion study

Background/Introduction

Acute type B aortic dissection (ATBAD) is a cardiovascular emergency with high risk of morbidity and mortality. Elucidating male-female differences in ATBAD might help optimize patient-specific care, while data is scarce on this topic.

Purpose

The aim of this study was to identify differences between male and female ATBAD patients in presentation, management and outcomes.

Methods

A retrospective cohort study was conducted including all consecutive patients who presented with ATBAD between 2007–2017 in four tertiary centers. Non-acute, traumatic, and iatrogenic dissections were excluded. We included patients presenting with an intramural hematoma or penetrating aortic ulcer in acute setting.

Results

The study population consisted of 384 patients, of which 41% (n=156) was female. In comparison to males, females presented at an older age (67 [IQR: 57–73] vs. 62 [IQR: 52–71], p=0.015) and fewer female patients had a history of abdominal aortic aneurysm (6% vs. 15%, p=0.009). Imaging diagnostics revealed a smaller proportion of patients with distally extended dissections in females. DeBakey type IIIb was diagnosed less frequently in females (73% vs. 85%, p=0.008) as was renal artery involvement (48% vs. 66%, p=0.009). Furthermore, classical type B dissection was less often observed in female patients compared to male patients (56% vs. 78%, p<0.001). Absolute maximum thoracic aortic diameters were not significantly different in females and males (44.0 [38.0–50.0] mm vs. 42.0 [39.0–49.0], p=0.870). No male-female differences were found in treatment strategy (p=0.561, Figure 1). In-hospital/30-day mortality was 9.6% in female patients and 11.8% in male patients (p=0.603). Long-term mortality did not show a significant male-female difference (p=0.90) during a median follow-up duration of 6.1 [IQR: 4.1–9.1] years (Figure 2).

Conclusion

This study showed that female patients were older at presentation, while male patients more often had distally extended dissections. Although mortality was not significantly different, we encourage male-female specific risk factor studies on late mortality. In this way ATBAD male and female patients at high risk of mortality can be identified and patient-specific care can be implemented.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ZonMw

SPECT/CT imaging of inflammation and calcification in human carotid atherosclerosis to identify the plaque at risk of rupture

BACKGROUND

Calcification and inflammation are atherosclerotic plaque compositional biomarkers that have both been linked to stroke risk. The aim of this study was to evaluate their co-existing prevalence in human carotid plaques with respect to plaque phenotype to determine the value of hybrid imaging for the detection of these biomarkers.

METHODS

Human carotid plaque segments, obtained from endarterectomy, were incubated in [111In]In-DOTA-butylamino-NorBIRT ([111In]In-Danbirt), targeting Leukocyte Function-associated Antigen-1 (LFA-1) on leukocytes. By performing SPECT/CT, both inflammation from DANBIRT uptake and calcification from CT imaging were assessed. Plaque phenotype was classified using histology.

RESULTS

On a total plaque level, comparable levels of calcification volume existed with different degrees of inflammation and vice versa. On a segment level, an inverse relationship between calcification volume and inflammation was evident in highly calcified segments, which classify as fibrocalcific, stable plaque segments. In contrast, segments with little or no calcification presented with a moderate to high degree of inflammation, often coinciding with the more dangerous fibrous cap atheroma phenotype.

CONCLUSION

Calcification imaging alone can only accurately identify highly calcified, stable, fibrocalcific plaques. To identify high-risk plaques, with little or no calcification, hybrid imaging of calcification and inflammation could provide diagnostic benefit.

Multicenter Experience of Upper Extremity Access in Complex Endovascular Aortic Aneurysm Repair

PURPOSE

Upper extremity access (UEA) for antegrade cannulation of aortic side branches is a relevant part of endovascular treatment of complex aortic aneurysms and can be achieved using several techniques, sites and sides. The purpose of this study was to evaluate different UEA strategies in a multicenter registry of complex endovascular aortic aneurysm repair (EVAR).

METHODS

In six aortic centers in the Netherlands, all endovascular aortic procedures from 2006 to 2019 were retrospectively reviewed. Patients who received upper extremity access during complex EVAR were included. Primary outcome was a composite endpoint of any access complication, excluding minor hematomas. Secondary outcomes were access characteristics, access complications considered individually, access reinterventions and incidence of ischemic cerebrovascular events.

RESULTS

417 patients underwent 437 UEA for 303 fenestrated/branched EVARs, and 114 chimney EVARs. Twenty patients had bilateral, 295 left-sided, and 102 right-sided UEA. 413 approaches were performed surgically and 24 percutaneously. Distal brachial access was used in 89 cases, medial brachial in 149, proximal brachial in 140 and axillary access in 59 cases. No significant differences regarding the composite endpoint of access complications were seen (DBA 11.3% vs. MBA 6.7% vs. PBA 13.6% vs. AA 10.2%; p=.29). Postoperative neuropathy occurred most after proximal brachial access (DBA 1.1% vs. MBA 1.3% vs. PBA 9.3 % vs. AA 5.1%; p=.003). There were no differences in cerebrovascular complications between access sides (right 5.9% vs. left 4.1% vs. bilateral 5%; p=.75). Significantly more overall access complications were seen after a percutaneous approach (29.2% vs. 6.8%; p=.002). In multivariate analysis the risk for access complications after open approach was decreased by male gender (OR 0.27; CI 95% 0.10 - 0.72; p= .009), while an increase in age per year (OR 1.08; CI 95% 1.004 - 1.179; p=.039) and diabetes mellitus type 2 (OR 3.70; CI 95% 1.20 - 11.41; p= .023) increased the risk.

CONCLUSION

Between the four access localizations, there were no differences in overall access complications. Female gender, diabetes mellitus type 2 and ageing increased the risk for access complications after surgical approach. Furthermore, a percutaneous upper extremity access resulted in higher complication rates than a surgical approach.

The Correlation Between Wall Shear Stress and Plaque Composition in Advanced Human Carotid Atherosclerosis

The role of wall shear stress (WSS) in atherosclerotic plaque development is evident, but the relation between WSS and plaque composition in advanced atherosclerosis, potentially resulting in plaque destabilization, is a topic of discussion. Using our previously developed image registration pipeline, we investigated the relation between two WSS metrics, time-averaged WSS (TAWSS) and the oscillatory shear index (OSI), and the local histologically determined plaque composition in a set of advanced human carotid plaques. Our dataset of 11 carotid endarterectomy samples yielded 87 histological cross-sections, which yielded 511 radial bins for analysis. Both TAWSS and OSI values were subdivided into patient-specific low, mid, and high tertiles. This cross-sectional study shows that necrotic core (NC) size and macrophage area are significantly larger in areas exposed to high TAWSS or low OSI. Local TAWSS and OSI tertile values were generally inversely related, as described in the literature, but other combinations were also found. Investigating the relation between plaque vulnerability features and different combinations of TAWSS and OSI tertile values revealed a significantly larger cap thickness in areas exposed to both low TAWSS and low OSI. In conclusion, our study confirmed previous findings, correlating high TAWSS to larger macrophage areas and necrotic core sizes. In addition, our study demonstrated new relations, correlating low OSI to larger macrophage areas, and a combination of low TAWSS and low OSI to larger cap thickness.

Patient-Reported Outcomes of Yearly Imaging Surveillance in Patients Following Endovascular Aortic Aneurysm Repair

Little is known about the impact of standardized imaging surveillance on anxiety levels and well-being of patients after endovascular aortic aneurysm repair (EVAR). We hypothesize that patient anxiety levels increase just before receiving the imaging results compared with standard anxiety levels.

METHODS

Prospective cohort study from November 2018 to May 2020 including post-EVAR patients visiting the outpatient clinics of 4 Dutch hospitals for imaging follow-up. The Patient-Reported Outcomes Measurement Information System (PROMIS) was used. Patients completed the PROMIS Anxiety v1.0 Short Form (SF) 4a, PROMIS-Global Health Scale v1.2, and PROMIS-Physical Function v1.2 SF8b at 2 time points: prior to the result of the imaging study (T1: pre-visit) and 6-8 months later (T2: reference measurement). Mean T-scores at T1 were compared to T2, and T2 to the general 65+ Dutch population.

RESULTS

Altogether 342 invited patients were eligible, 214 completed the first questionnaire, 189 returned 2 completed questionnaires and 128 patients did not participate. Out of 214 respondents, 195 were male (91.1%) and the mean (standard deviation) age was 75.2 (7.0) years. There were no significant differences between T1 and T2 in anxiety levels (0.48; 95% confidence interval[CI] -0.42-1.38), global mental health (0.27; 95% CI -0.79-0.84), global physical health (0.10; 95% CI -0.38-1.18) and physical function (0.53; 95% CI -0.26-1.32). Compared with the 65+ Dutch population, at T2 patients experienced more anxiety (3.8; 95% CI 2.96-5.54), had worse global physical health (-3.2; 95% CI -4.38 - -2.02) and physical function (-2.4; 95% CI -4.00 - -0.80). Global mental health was similar (-1.0; 95% CI -2.21 - 0.21).

CONCLUSIONS

Post-EVAR patients do not experience more anxiety just before receiving surveillance imaging results than outside this period, but do suffer from more anxiety and worse physical outcomes than the 65+ Dutch population.

Solitary Iliac Branch Endoprosthesis placement for iliac aneurysms

INTRODUCTION

Isolated iliac artery aneurysms (IAA), accounting for 2-7 percent of all abdominal aneurysms, are nowadays often treated with the use of iliac branched endografts. Although outside of the manufacturer's instructions for use, iliac branched devices can be used solely, without the adjunctive placement of an EVAR device, for the treatment of isolated IAA. In this study we aim to describe the outcomes of the use of the Gore IBE device, without support of an infrarenal EVAR device, for the exclusion of isolated IAA.

DESIGN

This study is an international multicenter retrospective cohort analysis.

METHOD

All patients that were treated with a solitary IBE for IAA exclusion from 11-01-2013 up to 31-12-2018 were retrospectively reviewed. The primary outcome was technical success. Secondary outcomes included mortality, intraoperative and postoperative complications, and re-interventions.

RESULTS

In total 18 European and American centers participated, including 51 patients in which 54 IAAs were excluded. The technical success rate was 94.1%, with an assisted technical success rate of 96.1%. There was no 30-day mortality and a 98.1% patency of both the internal and external iliac artery was found at 24-months follow-up. At 24-months follow-up, 81.5% of patients were free of complications and 90% were free of a secondary intervention.

CONCLUSION

Treatment with a solitary IBE is a safe and, at midterm, effective treatment strategy in selected patients with a solitary IAA.

Short-term outcomes of open surgical abdominal aortic aneurysm repair from the Dutch Surgical Aneurysm Audit

Background

The sharp decrease in open surgical repair (OSR) for abdominal aortic aneurysm (AAA) has raised concerns about contemporary postoperative outcomes. The study was designed to analyse the impact of complications on clinical outcomes within 30 days following OSR.

Methods

Patients who underwent OSR for intact AAA registered prospectively between 2016 and 2019 in the Dutch Surgical Aneurysm Audit were included. Complications and outcomes (death, secondary interventions, prolonged hospitalization) were evaluated. The adjusted relative risk (aRr) and 95 per cent confidence intervals were computed using Poisson regression. Subsequently, the population-attributable fraction (PAF) was calculated. The PAF reflects the expected percentage reduction of an outcome if a complication were to be completely prevented.

Results

A total of 1657 patients were analysed. Bowel ischaemia and renal complications had the largest impact on death (aRr 12·44 (95 per cent c.i. 7·95 to 19·84) at PAF 20 (95 per cent c.i. 8·4 to 31·5) per cent and aRr 5·07 (95 per cent c.i. 3·18 to 8.07) at PAF 14 (95 per cent c.i. 0·7 to 27·0) per cent, respectively). Arterial occlusion had the greatest impact on secondary interventions (aRr 11·28 (95 per cent c.i. 8·90 to 14·30) at PAF 21 (95 per cent c.i. 14·7 to 28·1) per cent), and pneumonia (aRr 2·52 (95 per cent c.i. 2·04 to 3·10) at PAF 13 (95 per cent c.i. 8·3 to 17·8) per cent) on prolonged hospitalization. Small effects were observed on outcomes for other complications.

Conclusion

The greatest clinical impact following OSR can be made by focusing on measures to reduce the occurrence of bowel ischaemia, arterial occlusion and pneumonia.

P6500Genetics links abdominal and thoracic aorta aneurysm

Introduction

Familial disease, with a genetic cause, occurs in at least 20–30% of the families of patients with an aortic aneurysm. In these families there is an increased risk for relatives. Therefor family screening is recommended around the age of 50–60 years for first degree relatives of patients with an abdominal aneurysm (AAA) and relatives of patients with thoracic aorta aneurysms (TAA). However current guidelines do not specify the extend of aorta screening for relatives of patients with AAA and patients with TAA. Current practice is that first degree relatives of AAA patients are offered abdominal echo screening for AAA and relatives of TAA patients cardiologic echo for TAAA. Although co- occurrence of AAA with TAAA in rare genetic disease is well known, for other familial aneurysm disease, the frequency of the co-occurrence of AAA and TAAA has not been established.

Purpose

To improve family screening for familial aneurysm, and identify the role of underlying genetic defects.

Methods

To determine the genetics of AAA, whole exome sequencing and CT family screening of the complete aorta was performed in 391 families with familial aneurysm. These families are nested in a patient cohort ascertained form unselected consecutively diagnosed AAA patients visiting the Vascular Surgery Clinic at the our MC.

Results

In 391 families, 360 relatives had a dilated aorta. The spectrum of aortic features in the relatives included 210 (58%) relatives with AAA, 102 (28%) relatives with TAA. Co-occurrence of AAA and TAA was noted in 41 (11%) relatives. In addition 66 (18%) and 79 (22%) had a dilation in the arteria iliaca communis sinistra resp. dextra. In 18 families pathogenic mutations in 11 aneurysm genes were detected.

Conclusion

To reduce underdiagnoses of relatives of AAA patients, CT screening of the total aorta and the iliac arteries is the method of choice, and should replace echo screening of specific parts of the aorta in relatives. Updating the guidelines for family screening for aortic aneurysms is needed to improve early detection and treatment of family members with aorta dilatations.

Acknowledgement/Funding

Stichting Lijf en Leven

Perioperative Complications are Associated With Adverse Long-Term Prognosis and Affect the Cause of Death After General Surgery

BACKGROUND

It is unclear how mortality and causes of death vary between patients and surgical procedures and how occurrence of postoperative complications is associated with prognosis. This study describes long-term mortality rates and causes of death in a general surgical population. Furthermore, we explore the effect of postoperative complications on mortality.

METHODS

A single-centre analysis of postoperative complications, with mortality as primary endpoint, was conducted in 4479 patients undergoing surgery. We applied univariate and multivariable regression models to analyse the effect of risk factors, including surgical risk and postoperative complications, on mortality. Causes of death were also explored.

RESULTS

75 patients (1.7 %) died within 30 days after surgery and 730 patients (16.3 %) died during a median follow-up of 6.3 years (IQR 5.8-6.8). Significant differences in long-term mortality were observed with worst outcome for patients undergoing high-risk vascular surgery (HR 1.5; 95 % CI 1.2-1.9). When looking at causes of death, high-risk surgery was associated with a twofold higher risk of cardiovascular death (HR 1.9; 95 % CI 1.2-3.1), whereas the intermediate-risk group had a higher risk of dying from cancer-related causes (HR 1.5; 95 % CI 1.1-2.0). Occurrence of complications-particularly of cardiovascular nature- was associated with worse survival (HR 1.9; 95 % CI 1.3-2.7).

CONCLUSION

High-risk vascular surgery and occurrence of postoperative complications are important predictors of late mortality. Further focus on these groups of patients can contribute to reduced morbidity. Improvement in quality of care should be aimed at preventing postoperative complications and thus a better outcome in a general surgical population.

Higher 30 Day Mortality in Patients with Familial Abdominal Aortic Aneurysm after EVAR

OBJECTIVES

To determine the influence of a positive family history for aneurysms on clinical success and mortality after endovascular aneurysm repair (EVAR).

METHODS

From 2009 to 2011, 1262 patients with abdominal aortic aneurysms (AAA) treated by EVAR were enrolled in a prospective, industry sponsored clinical registry ENGAGE. Patients were classified into familial and sporadic AAA patients according to baseline clinical reports. Clinical characteristics, aneurysm morphology, and follow-up were registered. The primary endpoint was clinical success after EVAR, a composite of technical success and freedom from the following complications: AAA increase >5 mm, type I and III endoleak, rupture, conversion, secondary procedures, migration, and occlusion. Secondary endpoints were the individual components of clinical success, 30 day mortality, and aneurysm related and all cause mortality.

RESULTS

Of the 1262 AAA patients (89.5% male and mean age 73.1 years), 86 patients (6.8%) reported a positive family history and were classified as familial AAA. Duration of follow-up was 4.4 ± 1.7 years. Patients with familial AAA were more often female (18.6% vs. 9.9%, p = .012). No difference was observed in aneurysm morphology. There was no significant difference in clinical success between patients with familial and sporadic AAA (72.1% vs. 79.3%, p=.116). Familial AAA patients had a higher 30 day mortality after EVAR (4.7% vs. 1.0%, adjusted HR 5.7, 1.8-17.9, p = .003) as well as aneurysm related mortality (5.8% vs. 1.3%, adjusted HR 5.4, 1.9-14.9, p = .001), while no difference was observed in all cause mortality (19.8% vs. 24.3%, adjusted HR 0.8, 0.5-1.4, p = .501).

CONCLUSIONS

The current study shows a higher 30 day mortality after EVAR in familial AAA patients. Future studies should determine the role of family history in AAA treatment, suitability for endovascular or open repair, and on adaptation of post-operative surveillance. For the time being, patients with familial forms of AAA should be considered at higher risk for EVAR and warrant extra vigilance.

Development and External Validation of a Model Predicting Death After Surgery in Patients With a Ruptured Abdominal Aortic Aneurysm: The Dutch Aneurysm Score

OBJECTIVE

The decision whether or not to proceed with surgical intervention of a patient with a ruptured abdominal aortic aneurysm (rAAA) is very difficult in daily practice. The primary objective of the present study was to develop and to externally validate a new prediction model: the Dutch Aneurysm Score (DAS).

METHODS

With a prospective cohort of 10 hospitals (n = 508) the DAS was developed using a multivariate logistic regression model. Two retrospective cohorts with rAAA patients from two hospitals (n = 373) were used for external validation. The primary outcome was the combined 30 day and in-hospital death rate. Discrimination (AUC), calibration plots, and the ability to identify high risk patients were compared with the more commonly used Glasgow Aneurysm Score (GAS).

RESULTS

After multivariate logistic regression, four pre-operative variables were identified: age, lowest in hospital systolic blood pressure, cardiopulmonary resuscitation, and haemoglobin level. The area under the receiver operating curve (AUC) for the DAS was 0.77 (95% CI 0.72-0.82) compared with the GAS with an AUC of 0.72 (95% CI 0.67-0.77). The DAS showed a death rate in patients with a predicted death rate ≥80% of 83%.

CONCLUSIONS

The present study shows that the DAS has a higher discriminative performance (AUC) compared with the GAS. All clinical variables used for the DAS are easy to obtain. Identification of low risk patients with the DAS can potentially reduce turndown rates. The DAS can reliably be used by clinicians to make a more informed decision in dialogue with the patient and their family whether or not to proceed with surgical intervention.

Defective Connective Tissue Remodeling in Smad3 Mice Leads to Accelerated Aneurysmal Growth Through Disturbed Downstream TGF-β Signaling

Aneurysm-osteoarthritis syndrome characterized by unpredictable aortic aneurysm formation, is caused by SMAD3 mutations. SMAD3 is part of the SMAD2/3/4 transcription factor, essential for TGF-β-activated transcription. Although TGF-β-related gene mutations result in aneurysms, the underlying mechanism is unknown. Here, we examined aneurysm formation and progression in Smad3^-/- animals. Smad3^-/- animals developed aortic aneurysms rapidly, resulting in premature death. Aortic wall immunohistochemistry showed no increase in extracellular matrix and collagen accumulation, nor loss of vascular smooth muscle cells (VSMCs) but instead revealed medial elastin disruption and adventitial inflammation. Remarkably, matrix metalloproteases (MMPs) were not activated in VSMCs, but rather specifically in inflammatory areas. Although Smad3^-/- aortas showed increased nuclear pSmad2 and pErk, indicating TGF-β receptor activation, downstream TGF-β-activated target genes were not upregulated. Increased pSmad2 and pErk staining in pre-aneurysmal Smad3^-/- aortas implied that aortic damage and TGF-β receptor-activated signaling precede aortic inflammation. Finally, impaired downstream TGF-β activated transcription resulted in increased Smad3^-/- VSMC proliferation. Smad3 deficiency leads to imbalanced activation of downstream genes, no activation of MMPs in VSMCs, and immune responses resulting in rapid aortic wall dilatation and rupture. Our findings uncover new possibilities for treatment of SMAD3 patients; instead of targeting TGF-β signaling, immune suppression may be more beneficial.

[A girl with a cold foot]

A 14-year-old girl presented with a progressively cold, pale foot. Pedal pulses were absent and there was sensory and motor loss. CT angiography revealed a thromboembolic occlusion of the crural arteries and a popliteal artery entrapment. Following thromboembolectomy with popliteal artery patch angioplasty and release of the gastrocnemius muscle, the girl fully recovered.

Review: Quality of life in lower limb peripheral vascular surgery

PURPOSE

Vascular intervention studies generally consider patency and limb salvage as primary outcomes. However, quality of life is increasingly considered an important patient-oriented outcome measurement of vascular interventions. Existing literature was analyzed to determine the effect of different treatments on quality of life for patients suffering from either claudication or critical limb ischemia.

BASIC METHODS

A review of the literature was undertaken in the Medline library. A search was performed on quality of life in peripheral arterial disease. Results were stratified according to treatment groups.

PRINCIPAL FINDINGS

Twenty-one articles described quality of life in approximately 4600 patients suffering from peripheral arterial disease. Invasive treatment generally results in better quality of life scores (at a maximum of 2 years of follow-up), compared with non-invasive treatment. In patients with critical limb ischemia, successful revascularization improves quality of life scores. Only one study reported long-term results.

CONCLUSIONS

Increase in quality of life scores can be found for any intervention performed for peripheral arterial disease. However, there is scarce information on long-term quality of life after vascular intervention.

Early sac shrinkage predicts a low risk of late complications after endovascular aortic aneurysm repair

Background

Aneurysm shrinkage has been proposed as a marker of successful endovascular aneurysm repair (EVAR). Patients with early postoperative shrinkage may experience fewer subsequent complications, and consequently require less intensive surveillance.

Methods

Patients undergoing EVAR from 2000 to 2011 at three vascular centres (in 2 countries), who had two imaging examinations (postoperative and after 6–18 months), were included. Maximum diameter, complications and secondary interventions during follow-up were registered. Patients were categorized according to early sac dynamics. The primary endpoint was freedom from late complications. Secondary endpoints were freedom from secondary intervention, postimplant rupture and direct (type I/III) endoleaks.

Results

Some 597 EVARs (71·1 per cent of all EVARs) were included. No shrinkage was observed in 284 patients (47·6 per cent), moderate shrinkage (5–9 mm) in 142 (23·8 per cent) and major shrinkage (at least 10 mm) in 171 patients (28·6 per cent). Four years after the index imaging, the rate of freedom from complications was 84·3 (95 per cent confidence interval 78·7 to 89·8), 88·1 (80·6 to 95·5) and 94·4 (90·1 to 98·7) per cent respectively. No shrinkage was an independent risk factor for late complications compared with major shrinkage (hazard ratio (HR) 3·11; P < 0·001). Moderate compared with major shrinkage (HR 2·10; P = 0·022), early postoperative complications (HR 3·34; P < 0·001) and increasing abdominal aortic aneurysm baseline diameter (HR 1·02; P = 0·001) were also risk factors for late complications. Freedom from secondary interventions and direct endoleaks was greater for patients with major sac shrinkage.

Conclusion

Early change in aneurysm sac diameter is a strong predictor of late complications after EVAR. Patients with major sac shrinkage have a very low risk of complications for up to 5 years. This parameter may be used to tailor postoperative surveillance.

Type II endoleak after endovascular aneurysm repair (Br j surg 2013; 100: 1262-1270

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Ruptured AAA: state of the art management

Since its introduction more than two decades ago, endovascular aneurysm repair (EVAR) has become the primary choice for elective treatment of abdominal aortic aneurysms (AAA) in many medical centers. The (dis)advantages, including 30-day mortality and long-term survival, of both open and endovascular elective AAA repair have been studied extensively, including four randomized trials. On the contrary, the survival benefit of EVAR for ruptured AAAs is not as well established as in elective situations. In the absence of randomized trials, the best treatment modality for ruptured AAA has not been revealed. In this manuscript, we describe the design and (preliminary) results of recently completed and ongoing randomized trials. Furthermore, the trends in management and the results of the treatment of ruptured AAA in our tertiary center over a 20-year period are presented. In the last decade, a progressive increase in the proportion of patients managed by EVAR was observed. This increase was associated with an overall increase in the number of treated patients and, simultaneously, a decrease in the overall 30-day mortality (53% versus 39%) was seen when comparing the two last decades. The 30-day mortality rates were significantly lower in the patients treated with EVAR (24%) compared to open repair (52%). The survival advantage for EVAR after ruptured AAA persisted during the first 5 years after repair, but was lost after that period. The estimated 5-year survival was 44% and 39% for EVAR and open repair, respectively. These data support that endovascular repair is an effective and safe strategy as a primary treatment modality for ruptured AAA.

Decision-making in type-B dissection: current evidence and future perspectives

Aortic dissection is a devastating cardiovascular condition with an incidence of 3,5:100 000. It is classified according to anatomic extent, mechanism of lesion, duration from index event and course (uncomplicated vs. complicated). Intramural hematoma and penetrating aortic ulcers share many of the features of classic dissections, but tend to occur in older patients with advanced atherosclerosis. In uncomplicated type-B dissection, conservative treatment with tight blood pressure and heart rate control is safe and effective. Early stent-graft implantation may, however, result in more favorable aortic remodeling and reduced late complications. For acute complicated cases intervention is usually required. Stent-graft coverage of the entry tear frequently resolves malperfusion, but the role of the false lumen in organ perfusion must be assessed and endovascular revascularization performed if necessary. In chronic type-B dissections, coverage of the entry tear likely results in continued pressurization of the false lumen due to rigidity of the dissecting membrane and distal fenestrations. Better understanding of the different disease mechanisms involved, imaging advances and introduction of dedicated stent-grafts are expected to further improve patient outcomes in the future. Primary and secondary pharmacological prevention, stricter follow-up protocols and screening of family members may also prove valuable. Better patient selection will allow preventive treatment with low morbidity for those at higher risk of complications.

Prognosis of vascular surgery patients using a quantitative assessment of troponin T release: is the crystal ball still clear?

BACKGROUND

Cardiac troponin T (cTnT) assays with increased sensitivity might increase the number of positive tests. Using the area under the curve (AUC) with serial sampling of cTnT an exact quantification of the myocardial damage size can be made. We compared the prognosis of vascular surgery patients with integrated cTnT-AUC values to continuous and standard 12-lead electrocardiography (ECG) changes.

METHODS

513 Patients were monitored. cTnT sampling was performed on postoperative days 1, 3, 7, 30 and/or at discharge or whenever clinically indicated. If cTnT release occurred, daily measurements of cTnT were performed, until baseline was achieved. CTnT-AUC was quantified and divided in tertiles. All-cause mortality and cardiovascular events (cardiac death and myocardial infarction) were noted during follow-up.

RESULTS

81/513 (16%) Patients had cTnT release. After adjustment for gender, cardiac risk factors, and site and type of surgery, those in the highest cTnT-AUC tertile were associated with a significantly worse cardiovascular outcome and long-term mortality (HR 20.2; 95% CI 10.2-40.0 and HR 4.0; 95% CI 2.0-7.8 respectively). Receiver operator analysis showed that the best cut-off value for cTnT-AUC was <0.01 days*ng m for predicting long-term cardiovascular events and all-cause mortality.

CONCLUSION

In vascular surgery patients quantitative assessment of cTnT strongly predicts long-term outcome.

Device-specific outcomes after endovascular abdominal aortic aneurysm repair

Over the last decade, endovascular aneurysm repair (EVAR) has been used extensively for the elective treatment of infra-renal abdominal aneurysms. However, it remains unclear how specific devices perform and how they compare to others. We provide an overview of currently used endografts, and discuss the current evidence regarding device-specific outcomes. Published literature confirms differences in results according to endograft selection. These differences were more pronounced with older generations of devices, in comparison to newer models. Contemporary results are generally good and one should remember that no randomized data exist regarding individual device performance. Moreover, by the time there is enough follow-up to draw conclusions, the data is relatively obsolete due to constant improvements in endograft technology and design. Results from EVAR have been steadily improving and individualized device selection has shown to be valuable. It appears that patients with favorable anatomy do well with most modern endografts. Those with challenging anatomies may benefit more from a particular design, delivery and deployment feature requiring greater knowledge and experience for adequate device selection.

Prognosis of transient new-onset atrial fibrillation during vascular surgery

BACKGROUND

Chronic atrial fibrillation (AF) in a non-surgical setting is associated with cardiovascular events. However, the prognosis of transient new-onset AF during vascular surgery is unknown.

OBJECTIVE

The purpose of this study is to investigate the prognosis of new-onset AF during vascular surgery using continuous electrocardiographic monitoring (continuous-ECG).

METHODS

In this study, 317 patients, all in sinus rhythm, scheduled for major vascular surgery were screened for cardiac risk factors. Continuous-ECG recordings for 72h and standard ECG on days 3, 7 and 30 were used to identify new-onset AF. Cardiac troponin T (cTnT) was measured routinely after surgery. Study endpoint was a composite of cardiac death, myocardial infarction, unstable angina and stroke (cardiovascular events) at 30 days after surgery and during late follow-up. Median follow-up was 12 (interquartile range 2-28) months.

RESULTS

New-onset AF was noted in 15 (4.7%) patients. All but three patients returned spontaneously to sinus rhythm. The composite endpoint of cardiovascular events within 30 days and during late follow-up occurred in 34 (11%) and 62 (20%) patients, respectively. Multivariate regression analysis showed that new-onset AF was associated with perioperative (hazard ratio (HR) 6.0; 95% CI: 2.4-15) and late cardiovascular events (HR 4.2, 95% CI: 2.1-8.8).

CONCLUSION

New-onset AF during vascular surgery is associated with an increased incidence of 30-day and late cardiovascular events.

Endurant stent-graft system: preliminary report on an innovative treatment for challenging abdominal aortic aneurysm

The evolution of stent-grafts and endovascular delivery systems has substantially improved the application rate for and patient outcomes with endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA), but further development is needed in order to reduce the continuing incidence of complications and secondary re-interventions. Severe angulations at the proximal aneurysm neck and tortuous, calcified, and small iliac arteries are still recognized as important risk factors for successful EVAR of AAA and hence as criteria for exclusion of many potential patients. The Endurant stent-graft is part of a next-generation system that was designed with the clear intention of expanding the applicability of EVAR for AAA while also continuing to improve treatment outcomes and reduce complications. Innovative features of the system design include anchoring pins for ensuring proximal fixation, wire-formed M-shape body stents for improved flexibility and conformability, and a low-profile delivery system with hydrophilic coating that improves trackability and pushability to facilitate the vascular access even in small challenging arteries. Initial clinical experience with the Endurant stent-graft system, including preliminary results from the first-in-human European trial of the device, has demonstrated that the device can be delivered and deployed safely, even in highly angulated anatomies. Technical success was achieved in 90.3% of the patients in the trial. No device-related serious adverse events were seen during the first follow-up period, and no device-related deaths were reported. This new stent-graft will potentially enlarge the patient population suitable for EVAR of AAA.

Long-term cardiac outcome in high-risk patients undergoing elective endovascular or open infrarenal abdominal aortic aneurysm repair

OBJECTIVES

To assess long-term outcome of patients at high cardiac risk undergoing endovascular or open AAA repair.

METHODS

Patients undergoing open or endovascular infrarenal AAA repair with >or=3 cardiac risk factors and preoperative cardiac stress testing (DSE) at 2 university hospitals were studied. Main outcome was cardiac event free and overall survival. Multivariate Cox regression analysis was used to evaluate the influence of type of AAA repair on long-term outcome.

RESULTS

In 124 patients (55 endovascular, 69 open) the number and type of cardiac risk factors, medication use and DSE results were similar in both groups. In multivariable analysis, adjusting for cardiac risk factors, stress test results, medication use, and propensity score endovascular repair was associated with improved cardiac event free survival (HR 0.54; 95% CI 0.30-0.98) but not with an overall survival benefit (HR 0.73; 95% CI 0.37-1.46). Importantly, statin therapy was associated with both improved overall survival (HR 0.42; 95% CI 0.21-0.83) and cardiac event free survival (HR 0.45; 95% CI 0.23-0.86).

CONCLUSIONS

The perioperative cardiac benefit of endovascular AAA repair in high cardiac risk patients is sustained during long-term follow-up provided patients are on optimal medical therapy but it is not associated with improved overall long-term survival.

Endovascular treatment of traumatic ruptures of the thoracic aorta

Rupture of the thoracic aorta after a blunt traumatic accident is a life-threatening event. This injury is instantly fatal in about 80% of the victims, and half of those who initially survive the incident will die during the first day, if left untreated. Before 1997, patients were treated with an open repair, but the conventional surgical approach carries a high mortality and morbidity rate. Graft interposition and cross-clamping of the aorta are responsible for a high paraplegia rate. Despite the fact that active distal perfusion of the aorta lowers the incidence of neurological deficit, the timing of these extensive procedures in the severely injured multi-trauma patient is difficult. The endovascular repair of a traumatic thoracic aortic rupture has gained rapid acceptance as a better alternative. This minimally invasive procedure has a median operating time of <1 h, and it can be done during the same session in which other life-threatening injuries are repaired. There is no need for a thoracotomy or single lung ventilation, blood loss is minimal and systemic heparinization is not required. So far, no spinal cord ischemia has been described for the endovascular repair. Besides numerous advantages, a few problems can be expected. The narrow aortic diameter of these young trauma-victims, combined with a steep aortic arch, makes the adaptation of the endograft along the inner curvature sometimes difficult. Because the smallest endograft usually exceeds the narrow aortic diameter, only excessively oversized devices can be used, which explains the high type I endoleak encountered in the published series. No randomized studies are yet available comparing the open with the endovascular technique, but the initial results of the endovascular repair seem promising and lower mortality and morbidity rates are documented. Long-term outcome are lacking so far, but are needed to address the durability of the procedure. Further research and development should concentrate on the problems we have seen with steep and narrow aortic arches, and devices with more flexible curves and smaller diameters should become available in the near future.

Anatomic Variations in the Circle of Willis in Patients with Symptomatic Carotid Artery Stenosis Assessed with Multidetector Row CT Angiography

PURPOSE

To assess the presence of anterior and posterior collateral pathways in the circle of Willis in patients with symptomatic carotid artery stenosis (SCAS) and to compare this to patients without carotid artery stenosis.

MATERIALS AND METHODS

Multislice CT angiography was performed in 91 patients and 91 control subjects. Using consensus reading, 2 observers evaluated the presence and diameter of the anterior communicating artery (AcomA), the A1 segments of the anterior cerebral arteries, the posterior communicating arteries (PcomA) and the P1 segments of the posterior cerebral arteries. Anterior or posterior pathways were assumed to be present if the diameter of continuous arterial segments was >1 mm; both A1 segments and AcomA anterior, and ipsilateral P1 segment and PcomA posterior. Comparison between patients and controls was performed using the chi(2) test.

RESULTS

In the patients we found significantly more hypoplastic (<1 mm) or invisible A1 segments (16 and 14 vs. 4 and 1, respectively, p < 0.01). The AcomA was invisible in 4 patients versus 1 control. An isolated compromised anterior pathway and a combined compromised anterior and posterior pathway occurred more frequently in the patients as compared to the controls; 9 versus 1% (p < 0.01) and 26 versus 4% (p < 0.01).

CONCLUSION

A compromised anterior collateral pathway, usually combined with a compromised posterior pathway, occurs more frequently in patients with SCAS as compared to controls, which suggests a relation between symptomatic carotid stenosis and an incomplete circle of Willis.

Dynamic cine-CT angiography for the evaluation of the thoracic aorta; insight in dynamic changes with implications for thoracic endograft treatment

OBJECTIVE

Thoracic aneurysm preoperative imaging is performed using static techniques without consideration of normal aortic dynamics. Improved understanding of the native aortic environment into which thoracic endografts are placed may aid in device selection. It is unclear what comprises normal thoracic aortic pulsatility. We studied these phenomena dynamically using ECG-gated 64-slice CTA.

METHODS

Maximum diameter and area change per cardiac cycle was measured at surgically relevant anatomic thoracic landmarks in ten patients; 1.0 cm proximal and distal to the subclavian artery, 3.0 cm distal to the subclavian artery, and 3.0 cm proximal to the celiac trunk. Data was acquired using a novel ECG-gated dynamic 64-slice CT scanner during a single breath hold with a standard radiation dose and contrast load. Eight gated data sets, covering the cardiac cycle were reconstructed, perpendicular to the central lumen.

RESULTS

There is impressive change in both maximum diameter and area in the thoracic aorta during the cardiac cycle. Mean maximum diameter changes of greater than 10% are observed in the typical sealing zones of commercially available endografts corresponding to diameter increases of up to 5mm. Aortic area increases by over 5% per cardiac cycle.

CONCLUSIONS

ECG-gated dynamic CTA with standard radiation dose is feasible on a 64-slice scanner and provides insight into (patho) physiology of thoracic aortic conformational changes. Clinicians typically oversize thoracic endografts by 10%. With aortic pulsatility resulting in diameter changes of up to 17.8%, the potential exists for endograft undersizing, graft migration, intermittent type I endoleak, and poor patient outcome. Furthermore, aortic pulsatility is not evenly distributed, and non-circular stentgraft designs should be considered in the future since aortic distension in the aneurysm neck is not evenly distributed.

Endovascular repair for aorto-enteric fistula: a bridge too far or a bridge to surgery?

PURPOSE

To review our experience of endovascular treatment of aorto-enteric fistula (AEF).

METHODS

Between March 1999 and March 2005, 15 patients in five university and teaching hospitals in Belgium and The Netherlands were treated for AEF by endovascular repair. Twelve (80%) were male. The mean age was 67 years. Thirteen (87%) had had previous aortic or iliac surgery, 1.7-307 months before. All patients showed clinical or biochemical signs of bleeding. Eight (53%) were in shock, five (33%) had systemic signs of infection. Eight (53%) patients were treated in an emergency setting. Ten (67%) were treated with an aortouniiliac device, three (20%) with an aortobiiliac device, one with a tube graft and one with occluders only. All patients received antibiotics postoperatively for a prolonged period of time.

RESULTS

All AEF were successfully sealed, the 30-days mortality was nil. Mean hospital stay was 20 (2-81) days. One patient died 2.7 months later of postoperative complications, one died of lung cancer. Until now, there are no signs of reinfection in four (27%) patients (mean follow-up 15.7 (1-44) months). However, reinfection or recurrent AEF occurred in nine (60%) patients after 9.5 (0.61-31) months. Seven patients were reoperated successfully, two patients died after reintervention.

CONCLUSION

Endovascular sealing of AEF is a promising technique, which provides time to treat shock, local and systemic infection, and co-morbidity. This creates a better situation to perform open repair in the future with possibly better outcome. Danger of reinfection remains high. Endovascular sealing of AEF should, therefore, be seen as a bridge to open surgery when possible.

Improving Small-Diameter Vascular Grafts: From the Application of an Endothelial Cell Lining to the Construction of a Tissue-Engineered Blood Vessel

One of the main reasons why vascular reconstruction with synthetic small-diameter grafts has limited success is the absence of endothelial cells. To improve the outcome of nonvenous vascular bypass surgery, cell seeding of vascular grafts and other tissue-engineering techniques were developed. In this article, an overview is given of the artificial blood vessel as an alternative for venous vascular bypass surgery.

Robot-assisted versus Standard Videoscopic Aortic Replacement. A Comparative Study in Pigs

BACKGROUND

Reconstruction of the infrarenal aorta for aneurysms is routinely performed through laparotomy. A less invasive videoscopic approach has not gained wide acceptance due to technical difficulties. Robotic systems could potentially improve imaging of the operative field and surgeon's dexterity during videoscopic surgery and therefore might facilitate the performance of this procedure. The aim of this animal study was to compare the safety and efficacy of a robot-assisted videoscopic aortic replacement to the standard videoscopic approach.

MATERIALS AND METHODS

In 10 female pigs, the infrarenal aorta was partially replaced by a 10 mm polytetrafluoroethylene (PTFE) interposition graft through a videoscopic retroperitoneal approach, using the da Vinci robot system (robot group). Ten other pigs were operated on in a similar fashion, using standard videoscopic instruments (control group). Relevant procedure times, blood loss and complications were registered. Efficacy of the anastomoses was evaluated by measuring patency and blood loss after removing the clamps. Furthermore, circumference and number of stitches were evaluated at autopsy.

RESULTS

The procedure, suturing and clamping times were significantly shorter in the robot group and blood loss was less. In the control group, the inferior vena cava was injured in one pig. In two cases in the control group, haemostasis could not be established after clamp removal. At autopsy, all anastomoses in the robot group were adequate. In the control group, a stitch crossing the aortic lumen was found in two distal anastomoses and a large distance (>3 mm) between two stitches was encountered at least once in 12/20 suture lines. All 20 grafts were patent. No anastomotic narrowing was encountered. The number of stitches used for proximal and distal anastomosis was higher in the robot group.

CONCLUSION

This study demonstrates the superiority of robot-assisted videoscopic aortic replacement over standard videoscopic techniques in an animal model.

Decision-making in follow-up after endovascular aneurysm repair based on diameter and volume measurements: a blinded comparison

OBJECTIVE

to assess whether volume, in addition to diameter, measurements facilitate decision-making after endovascular aneurysm repair (EVAR).

MATERIAL/METHODS

patients (n = 82) with an immediately post-EVAR, and at least one follow-up (3-60 months), computed tomographic angiogram (CTA) were studied. The actual and all preceding proportional sac size changes were recorded. The resulting 347 diameter and 347 volume data were placed in random order and reviewed by three blinded observers who then recommended one of three treatment policies: "good/wait", "uncertain/intensify follow-up" or "not good/further diagnostics (Dx) or intervention (Rx)". The observers were instructed to consider changes of 10% relevant. One observer reviewed the graphs twice.

RESULTS

the interobserver agreements (kappa) for the diameter were 0.92, 0.81 and 0.76 and for volumes 0.91, 0.88 and 0.86. The intra-observer agreement was 0.93 for both diameter and volume. Volume data resulted in significantly more "good/wait" decisions out to 36 months. Diameter data resulted in more "not good/Dx or Rx"-decisions out to 36 months (all p < 50.005).

CONCLUSION

post-EVAR aneurysm sac volume data appears to provide earlier reassurance, reduce unnecessary interventions and to be more sensitive to secondary problems than diameter data alone.

Rapid, arteriovenous graft failure due to intimal hyperplasia: a porcine, bilateral, carotid arteriovenous graft model

BACKGROUND

The loss of patency constitutes the major complication of arteriovenous (AV) polytetrafluoroethylene hemodialysis grafts. In most cases, this graft failure is due to intimal hyperplasia at the venous outflow tract, including proliferation of vascular, smooth muscle cells and fibroblasts with deposition of extracellular matrix proteins. Thus far, procedures developed for improving patency have proven unsuccessful, which can be partly explained by the lack of relevant animal models. For this purpose, we developed a porcine model for AV graft failure that will allow the assessment of promising therapeutic strategies in the near future.

MATERIALS AND METHODS

In 14 pigs, AV grafts were created bilaterally between the carotid artery and the jugular vein using expanded polytetrafluoroethylene. Two, 4 or 8 weeks after AV shunting, the grafts and adjacent vessels were excised and underwent histologic analysis.

RESULTS

From 2 weeks onwards, a thick neo-intima developed at the venous anastomosis, predominantly consisting of alpha-actin-positive vascular smooth muscle cells (VSMC). Intimal area increased over time, coinciding with a decreased graft flow. Grafts remained patent for at least 4 weeks. At 8 weeks, patency rates declined to less than 50% due to thrombus formation superimposed on progressive neo-intima formation.

CONCLUSIONS

Implantation of an AV graft between the carotid artery and jugular vein in pigs causes a rapid neo-intimal response, accompanied by a loss of patency of 50% at 8 weeks after surgery. This model offers a suitable tool to study local interventions aimed at the improvement of AV graft patency rates.

Reduction of non-endothelial cell contamination of microvascular endothelial cell seeded grafts decreases thrombogenicity and intimal hyperplasia

INTRODUCTION

fat derived microvascular endothelial cells (MVEC) seeded on prosthetic vascular grafts, improve patency in animals. Results in humans were disappointing, due to thrombogenicity and progressive intimal hyperplasia. Also in animals intimal hyperplasia was found. We postulate that contaminating cells present in the transplant are involved in the intimal hyperplasia. We developed a method to further purify human MVEC from 40-90%. Here we tested the effects of enrichment upon thrombogenicity and seeding-related intimal hyperplasia.

METHODS

liposuction fat was enzymatically digested and centrifuged. To enrich MVEC, contaminating macrophages and fibroblasts were removed with dynabeads coated with macrophage- and fibroblast-specific antibodies. Thrombogenicity was assessed by measuring tissue factor and thrombomodulin activity, presence of endothelial nitric oxide synthase and via perfusion of the cells with whole blood. To investigate seeding-related intimal hyperplasia, PTFE grafts were seeded with the cells and cultured for 3 weeks.

RESULTS

tissue factor activity of purified cells was reduced compared to nonpurified cells. Purified cells showed thrombomodulin activity and eNOS expression. Fragment 1+2 and Fibrinopeptide A generation after perfusion of purified cells were significantly lower than after perfusion of nonpurified cells, and only nonpurified cells were covered with platelets and fibrin. Prostheses seeded with nonpurified cells showed an EC monolayer above a multilayer of myofibroblasts, prostheses seeded with purified cells only showed a single EC monolayer. Mixing experiments with human umbilical cord EC (HUVEC) and fibroblasts showed that when more than 25% HUVEC were present a confluent EC layer was formed. When the amount of fibroblasts was 25% or less, no development of a subendothelial multilayer of myofibroblasts was found within 3 weeks.

CONCLUSION

reduction of non-endothelial cell contamination of microvascular endothelial cell seeded grafts decreases thrombogenicity and might prevent seeding-related intimal hyperplasia.

Contaminants from the transplant contribute to intimal hyperplasia associated with microvascular endothelial cell seeding

OBJECTIVES

seeding prosthetic grafts with fat-derived microvascular endothelial cells (MVEC) results not only in a non-thrombogenic EC layer, but also in intimal hyperplasia. Here we investigated incidence, composition, progression, and cause of this intimal hyperplasia.

DESIGN

EPTFE grafts with MVEC were implanted as carotid interpositions in six dogs with 1 month, and in three dogs with 4, 8 and 12 months follow-up. Grafts seeded without cells, implanted in the contralateral carotid, served as a control. In another three dogs labelled cells were seeded to investigate the contribution of the seeded cells (2-3 weeks).

MATERIALS AND METHODS

MVEC were isolated from the falciform ligament. Cells were pressure seeded on ePTFE grafts. Labelling was performed using retroviral gene transduction. The grafts were analysed with immunohistochemical techniques.

RESULTS

after 1 month, all patent non-seeded grafts (5/6) showed fibrin and platelet deposition, and all patent seeded grafts (5/6) were covered with a confluent endothelial monolayer on top of a multilayer of myofibroblasts, elastin and collagen. After long term follow-up, all non-seeded grafts were occluded, all patent seeded grafts (4 and 12 months) were covered with an EC-layer with intimal hyperplasia underneath. The thickness of the intima did not progress after 1 month. Transduced cells were found in the endothelial monolayer, hyperplastic intima and luminal part of the prosthesis.

CONCLUSIONS

MVEC seeding in dogs results in intimal hyperplasia in all patent grafts, which contains myofibroblasts. Contaminants from the transplant contribute to this intimal hyperplasia.