Distal Repair After Total Aortic Arch Replacement With Frozen Elephant Trunk in Patients With Chronic Multilevel Thoracic Aortic Disease

OBJECTIVE

To examine the management of distal aortic disease after total arch replacement with the frozen elephant trunk (TAR + FET) in patients with chronic thoracic aortic disease.

METHODS

Two centre retrospective study of consecutive patients treated between January 2010 and December 2019. The primary endpoint was 30 day or in hospital death. The secondary endpoint was midterm survival. Data are presented as median (interquartile range [IQR]). The χ2 or Fisher's exact test was used as appropriate. Estimated survival (standard error) was assessed by calculating the Kaplan-Meier product limit estimator with right censoring of survival data. A p value of < .050 was considered statistically significant. STROBE guidelines were followed.

RESULTS

A total of 158 patients (72 men; median age 70 years, IQR 64, 75; median distal aortic diameter 58 mm, IQR 46, 68; 127 aneurysmal disease, 31 chronic dissection) underwent TAR + FET. The peri-operative mortality rate was 10.1% (9/107 elective, 7/51 non-elective). Of 74 (46.8%) patients with a primary distal seal, seven (9.5%) died peri-operatively, the distal seal was maintained during follow up in 51, nine underwent late distal repair (two planned, seven unplanned; one open, eight endovascular; one peri-operative death) with a median interval to unplanned repair of 777 days (IQR 462, 1480), and seven with loss of seal had no intervention. Distal seal failed in 2/28 (7%) patients with a distal seal length > 30 mm and device oversizing > 10%, compared with 12/39 (31%) patients who did not meet these criteria (p = .031). In 84 patients without a primary distal seal, nine (10.7%) died peri-operatively, the distal aorta remained below the size threshold for repair during follow up in 12 patients, 44 had distal repair (median aortic diameter 64 mm, IQR 60, 75; eight open, one hybrid, 35 endovascular repairs; no deaths) at a median of 256 days (IQR 135, 740), and 19 did not have distal repair at the end of the follow up period: six died before planned repair at a median interval of 115 days (IQR 85, 120); eight were considered unfit; one was assessed as fit but declined; and four patients were awaiting assessment. Median follow up was 46 months (IQR 26, 75): no patients were lost to follow up. Estimated ± standard error five year survival was 61.5 ± 4.1%: elective 70.6 ± 4.7%, non-elective 43.2 ± 7.2%.

CONCLUSION

TAR + FET achieved primary distal seal in 47% of patients, but late failure occurred in 21%. Distal repair was ultimately indicated in 84% of survivors without a primary distal seal and of these 70% underwent repair, almost 10% died before planned repair, and 13% were considered unfit. Earlier distal endovascular repair and better assessment of patient fitness may improve midterm outcomes.

Editor's Choice - Meta-Analysis of Compliance with Endovascular Aneurysm Repair Surveillance: The EVAR Surveillance Paradox

OBJECTIVE

To compare the survival of patients who attended surveillance after endovascular aneurysm repair (EVAR) with those who were non-compliant.

DATA SOURCES

MEDLINE and Embase were searched using the Ovid interface.

REVIEW METHODS

A systematic review was conducted complying with the PRISMA guidelines. Eligible studies compared survival in EVAR surveillance compliant patients with non-compliant patients. Non-compliance was defined as failure to attend at least one post-EVAR follow up. The risk of bias was assessed with the Newcastle-Ottawa scale, and the certainty of evidence using the GRADE framework. Primary outcomes were survival and aneurysm related death. Effect measures were the hazard ratio (HR) or odds ratio (OR) and 95% confidence interval (CI) calculated using the inverse variance or Mantel-Haenszel statistical method and random effects models.

RESULTS

Thirteen cohort studies with a total of 22 762 patients were included. Eight studies were deemed high risk of bias. The pooled proportion of patients who were non-compliant with EVAR surveillance was 43% (95% CI 36 - 51). No statistically significant difference was found in the hazard of all cause mortality (HR 1.04, 95% CI 0.61 - 1.77), aneurysm related mortality (HR 1.80, 95% CI 0.85-3.80), or secondary intervention (HR 0.66, 95% CI 0.31 - 1.41) between patients who had incomplete and complete follow up after EVAR. The odds of aneurysm rupture were lower in non-compliant patients (OR 0.63, 95% CI 0.39 - 1.01). The certainty of evidence was very low for all outcomes. Subgroup analysis for patients who had no surveillance vs. those with complete surveillance showed no significant difference in all cause mortality (HR 1.10, 95% CI 0.43 - 2.80).

CONCLUSION

Patients who were non-compliant with EVAR surveillance had similar survival to those who were compliant. These findings question the value of intense surveillance in all patients post-EVAR and highlight the need for further research on individualised or risk adjusted surveillance.

Open Retroperitoneal Repair for Complex Abdominal Aortic Aneurysms

Background  Open surgical repair (OSR) of complex abdominal aortic aneurysms (CAAAs) can be challenging. We frequently utilize the retroperitoneal (RP) approach for such cases. We audited our outcomes with the aim of establishing the utility and safety of this approach.

Methods  Retrospective analysis was performed of all patients undergoing OSR of an unruptured CAAA via a RP approach in our center over a 7-year period. Data on repairs via a transperitoneal (TP) approach were collected to provide context. Demographic, operative, radiological, and biochemical data were collected. The primary outcome measure was 30-day/inpatient mortality. Secondary outcomes included the need for reoperation, incidence of postoperative chest infection, acute kidney injury (AKI) and length of stay (LOS). All patients received aortic clamping above at least one main renal artery.

Results  One hundred and three patients underwent OSR of an unruptured CAAA; 55 via a RP approach, 48 TP. The RP group demonstrated a more advanced pattern of disease with a larger median maximum diameter (65 vs. 61 mm, p = 0.013) and a more proximal extent. Consequently, the rate of supravisceral clamping was higher in RP repair (66 vs. 15%, p  < 0.001). Despite this there were no differences in the observed early mortality (9.1 vs. 10%, NS); incidence of reoperation (10.9 vs. 12.5%, NS), chest infection (32.7 vs. 25%, NS), and AKI (52.7 vs. 45.8%, NS); or median LOS (10 vs. 12 days, NS) following RP and TP repair.

Conclusion  OSR of CAAAs carries significant 30-day mortality. In patients unsuitable for fenestrated endovascular aortic repair or those desiring a durable long-term solution, OSR can be performed through the RP or TP approach. This study has demonstrated that in our unit RP repair facilitates treatment of more advanced AAA utilizing complex proximal clamp zones with similar perioperative morbidity and mortality compared with TP cases utilizing more distal clamping.

Time-dependent mechanical behaviour of the aortic chronic dissection flap

OBJECTIVES

The transition of aortic dissection from acute to chronic is poorly understood. We examined time-dependent mechanical behaviour and biochemical properties of chronic dissection tissues.

METHODS

Aorta samples were obtained from 14 patients with mixed aetiology who were undergoing elective surgery for chronic dissected aneurysms, ranging from 3 months to 15 years post-dissection. The tissue elastic modulus and tissue deformation following application of loading for 5 h were measured for the false lumen (FL), true lumen (TL) and flap (FP) tissues with a custom-indentation technique. Collagen, elastin and glycosaminoglycan levels were determined with established biochemical assays. Elastin fragmentation was graded from histological sections. The number of tissues characterized was as follows: FP (n = 10), TL (n = 5 for biomechanical testing, n = 8 for biochemical analysis, n = 8 for histological assessment) and FL (n = 4).

RESULTS

Tissues stiffness was highest in FP [59.8 (14.8) kPa] as compared with TL [50.7 (6.2) kPa] and FL [40.5 (4.7) kPa] (P = 0.023 and P = 0.006, respectively). FP [0.5 (0.08) mm] also exhibited reduced deformation relative to TL [0.7 (0.02) mm] and FL [0.9 (0.08) mm] (P = 0.003 and P = 0.006, respectively), lowest collagen concentration [FP: 40.1 (19.6) µg/mg, TL: 59.9 (19.5) µg/mg, P = 0.008; FL: 79.1 (32.0) µg/mg, P = 0.006] and the lowest collagen: elastin ratio [0.4 (0.1)] relative to the other tissues [TL; 0.6 (0.3), P = 0.006, FL; 1.5 (0.4); P = 0.003]. Significant elastin loss was evident in the FL-stained tissue sections whereas highly aligned, long fibres were visible in the FP and TL. A linear relationship was found between the stiffness, deformation and the time from the dissection event to surgical intervention for the FP. All data are presented as median (interquartile range).

CONCLUSIONS

FP exhibited reduced time-dependent deformation and distinct biochemical properties relative to TL and FL irrespective of connective tissue disorder or the anatomical region of the dissection.

Risk factors, risk stratification and risk-specific surveillance strategies after endovascular aneurysm repair: study protocol for a Delphi study by the International RIsk Stratification in EVAR (IRIS-EVAR) working group

INTRODUCTION

Several risk factors for adverse events after endovascular aneurysm repair (EVAR) have been described, but there is no consensus on their comparative prognostic significance, use in risk stratification and application in determining postoperative surveillance.

METHODS AND ANALYSIS

A scoping review of the literature was conducted to identify risk factors for adverse events after EVAR. Main adverse events were considered post-EVAR abdominal aortic aneurysm rupture and reintervention. Risk factors were grouped into four domains: (1) preoperative anatomy, (2) aortic device, (3) procedure performance and (4) postoperative surveillance. The Delphi methodology will be used to steer a group of experts in the field towards consensus organised into three tiers. In tier 1, participants will be asked to independently rate risk factors for adverse events after EVAR. In tier 2, the panel will be asked to independently rate a range of combinations of risk factors across the four domains derived from tier 1. A risk-stratification tool will then be built, which will include algorithms that map responses to signalling questions onto a proposed risk judgement for each domain. Domain-level judgements will in turn provide the basis for an overall risk judgement for the individual patient. In tier 3, risk factor-informed surveillance strategies will be developed. Each tier will typically include three rounds and rating will be conducted using a 4-point Likert scale, with an option for free-text responses.

ETHICS AND DISSEMINATION

Research Ethics Committee and Health Research Authority approval has been waived, since this is a professional staff study and no duty of care lies with the National Health Service to any of the participants. The results will be presented at regional, national and international meetings and will be submitted for publication in peer-reviewed journals. The risk stratification tool and surveillance algorithms will be made publicly available for clinical use and validation.

Micromechanical and Ultrastructural Properties of Abdominal Aortic Aneurysms

Abdominal aortic aneurysms are a common condition of uncertain pathogenesis that can rupture if left untreated. Current recommended thresholds for planned repair are empirical and based entirely on diameter. It has been observed that some aneurysms rupture before reaching the threshold for repair whilst other larger aneurysms do not rupture. It is likely that geometry is not the only factor influencing rupture risk. Biomechanical indices aiming to improve and personalise rupture risk prediction require, amongst other things, knowledge of the material properties of the tissue and realistic constitutive models. These depend on the composition and organisation of the vessel wall which has been shown to undergo drastic changes with aneurysmal degeneration, with loss of elastin, smooth muscle cells, and an accumulation of isotropically arranged collagen. Most aneurysms are lined with intraluminal thrombus, which has an uncertain effect on the underlying vessel wall, with some authors demonstrating a reduction in wall stress and others a reduction in wall strength. The majority of studies investigating biomechanical properties of ex vivo abdominal aortic aneurysm tissues have used low-resolution techniques, such as tensile testing, able to measure the global material properties at the macroscale. High-resolution engineering techniques such as nanoindentation and atomic force microscopy have been modified for use in soft biological tissues and applied to vascular tissues with promising results. These techniques have the potential to advance the understanding and improve the management of abdominal aortic aneurysmal disease.

Onyx™ Cast Fragmentation After Embolization of Endoleaks

PURPOSE

Endoleaks are common following endovascular aneurysm repair (EVAR), and the liquid embolic material Onyx has been widely used in their treatment. We report our experience of long-term morphological changes of Onyx casts on surveillance imaging.

MATERIALS AND METHODS

We identified 10 patients over 10 years who underwent Onyx embolization in our institution. Morphological changes of Onyx casts were assessed on surveillance radiographs and computed tomography (CT) scans. Relevant outcome data and sequelae were obtained via electronic patient records.

RESULTS

Twelve procedures were performed on 10 cases, 9 for type 2, and 1 for a type 1a endoleak. Five cases showed evidence of Onyx fragmentation on follow-up imaging ranging from a single fracture to gross fragmentation with migration of fragments. Of these 5, 3 had achieved primary success but 2 went on to develop recurrence of endoleak. Onyx volume ranged from 4 to 46.5 ml (median 10.5 ml) per patient with larger volumes demonstrating the most marked fragmentation on follow-up. Follow-up ranged from 9 months to 8 years (median 2.25 years).

CONCLUSION

To our knowledge, this is the first report of Onyx fragmentation after endoleak embolization. If long-term morphological stability of the Onyx cast is necessary to maintain aneurysm seal, then Onyx may not offer a permanent solution to some patients with post-EVAR endoleaks. Our study cannot ascertain whether the observed changes were the cause or the effect of ongoing aneurysm growth, persistent endoleak, and/or other forces acting on the solidified polymer, but it raises important questions on the use of Onyx in this setting.

An International, Multicenter Retrospective Observational Study to Assess Technical Success and Clinical Outcomes of Patients Treated with an Endovascular Aneurysm Sealing Device for Type III Endoleak

INTRODUCTION

Type III endoleaks post-endovascular aortic aneurysm repair (EVAR) warrant treatment because they increase pressure within the aneurysm sac leading to increased rupture risk. The treatment may be difficult with regular endovascular devices. Endovascular aneurysm sealing (EVAS) might provide a treatment option for type III endoleaks, especially if located near the flow divider. This study aims to analyze clinical outcomes of EVAS for type III endoleaks after EVAR.

METHODS

This is an international, retrospective, observational cohort study including data from 8 European institutions.

RESULTS

A total of 20 patients were identified of which 80% had a type IIIb endoleak and the remainder (20%) a type IIIa endoleak. The median time between EVAR and EVAS was 49.5 months (28.5-89). Mean AAA diameter prior to EVAS revision was 76.6±19.9 mm. Technical success was achieved in 95%, 1 patient had technical failure due to a postoperative myocardial infarction resulting in death. Mean follow-up was 22.8±15.2 months. During follow-up 1 patient had a type Ia endoleak, and 1 patient had a new type IIIa endoleak at an untreated location. There were 5 patients with aneurysm growth. Five patients underwent AAA-related reinterventions indications being: growth with type II endoleak (n=3), type Ia endoleak (n=1), and iliac aneurysm (n=1). At 1-year follow-up, the freedom from clinical failure was 77.5%, freedom from all-cause mortality 94.7%, freedom from aneurysm-related mortality 95%, and freedom from aneurysm-related reinterventions 93.8%.

CONCLUSION

The EVAS relining can be safely performed to treat type III endoleaks with an acceptable technical success rate, a low 30-day mortality rate and no secondary ruptures at short-term follow-up. The relatively low clinical success rates, related to reinterventions and AAA enlargement, highlight the need for prolonged follow-up.

298 Incidence and Causes of Aneurysm Growth Following Endovascular Sealing of Abdominal Aortic Aneurysms

Objective

To analyse the incidence of aneurysm growth after endovascular aneurysm sealing (EVAS) and its relationship with adherence to the instructions for use (IFU).

Method

This study observed the clinical outcomes of patients who had an elective infrarenal EVAS procedure performed at the Royal Liverpool Hospital between 2013 and 2018. The primary outcome measure was the occurrence of aneurysm growth after EVAS. Aneurysm growth was defined as a 5% increase in the aortic volume between the renal arteries and the aortic bifurcation from the 1-month scan to subsequent annual scans.

Results

There were 71 patients with a mean (standard deviation) age of 76 (6) years who were eligible for inclusion in this study. Aneurysm growth was observed in 8 of 19 (42%) within IFU and 14 of 52 (27%) outside IFU (P ¼ .35). There was no relationship between aneurysm growth and adherence to IFU. Among the patients with aneurysm growth, the median (range) increase in abdominal aortic aneurysm volume was 11% (5%-20%).

Conclusions

Abdominal aortic aneurysm growth occurs in a significant proportion of patients at 1 year after EVAS and is not associated with adherence to IFU. Longer follow-up on a larger sample size is essential to understand the long-term clinical outcomes after EVAS.

Effect of treatment of peripheral arterial disease on the onset of anaerobic exercise during cardiopulmonary exercise testing

OBJECTIVE

Cardiopulmonary exercise testing (CPET) is often used to assess pre-operative fitness in elderly patients, in whom peripheral arterial disease (PAD) is highly prevalent, but may affect the results of CPET by early lactate release due to muscle ischemia. This study investigated the effect revascularization of PAD on oxygen delivery (VO2 ) during CPET.

METHOD

We conducted a prospective cohort study of 30 patients, who underwent CPET before and after treatment of ilio-femoral PAD. The primary outcome measure was difference in VO2 at the lactate threshold (LT) before and after revascularization. Secondary outcome measures were the relationship between change in VO2 at LT and peak exercise and change in ankle-brachial index (ABI) differential.

RESULTS

The study was approved by the North West-Lancaster Research and Ethics committee (reference 15/NW/0801) and registered in clinicaltrial.gov (reference NCT02657278). As specified in the study protocol, 30 patients were recruited but only 20 (15 men), with a mean age of 62 years, completed pre- and post-treatment CPETs. Twelve patients demonstrated an improvement in VO2 at LT after revascularization, but the difference did not achieve statistical significance (mean difference (95% CI) = 1.43 (-0.21 to 3.08) ml/kg/min; (p = 0.085). There was, however, a significant improvement in VO2 , VE/CO2 , workload and Borg breathlessness and leg fatigue score at peak exercise after revascularization. There was no significant correlation between change in VO2 at LT (r = -0.11, p = 0.65) or change in VO2 at peak and ABI differential (r = -0.14, p = 0.55).

CONCLUSION

Revascularization of PAD led to significant improvement in multiple peak/maximal exercise parameters within a few weeks and without exercise training. We were unable to demonstrate a statistically significant improvement in VO2 at LT albeit in a majority of subjects this exceeded what we pre-defined as clinically significant.

COVID-19 and cardiac surgery: A perspective from United Kingdom

The emergence of severe acute respiratory syndrome coronavirus 2 in December 2019, presumed from the city of Wuhan, Hubei province in China, and the subsequent declaration of the disease as a pandemic by the World Health Organization as coronavirus disease 2019 (COVID‐19) in March 2020, had a significant impact on health care systems globally. Each country responded to this disease in different ways, however this was done broadly by fortifying and prioritizing health care provision as well as introducing social lockdown aiming to contain the infection and minimizing the risk of transmission. In the United Kingdom, a lockdown was introduced by the government on March 23, 2020 and all health care services were focussed to challenge the impact of COVID‐19. To do so, the United Kingdom National Health Service had to undergo widespread service reconfigurations and the so‐called “Nightingale Hospitals” were created de novo to bolster bed provision, and industries were asked to direct efforts to the production of ventilators. A government‐led public health campaign was publicized under the slogan of: “Stay home, Protect the NHS (National Health Service), Save lives.” The approach had a significant impact on the delivery of all surgical services but particularly cardiac surgery with its inherent critical care bed capacity. This paper describes the impact on provision for elective and emergency cardiac surgery in the United Kingdom, with a focus on aortovascular disease. We describe our aortovascular activity and outcomes during the period of UK lockdown and present a patient survey of attitudes to aortic surgery during COVID‐19 pandemic.

Aneurysm Growth After Endovascular Sealing of Abdominal Aortic Aneurysms (EVAS) with the Nellix Endoprosthesis

OBJECTIVE

The aim of this study was to measure the incidence of post endovascular aneurysm sealing (EVAS) abdominal aortic aneurysm (AAA) growth, and its association with stent migration, in a cohort of patients with differing compliance to old and new Instructions For Use (IFU).

METHODS

A retrospective single centre study was conducted to review the computed tomography (CT) and clinical data of elective, infrarenal EVAS cases, performed as a primary intervention, between December 2013 and March 2018. All included patients had a baseline post-operative CT scan at one month and at least one year follow up. The primary outcome measure was the incidence of AAA growth and its association with stent migration. AAA growth was defined as a ≥5% increase in aortic volume between the lowermost renal artery and the aortic bifurcation post EVAS at any time during follow up, in comparison to the baseline CT scan. Migration was defined according to the ESVS guidelines, as > 10 mm downward movement of either Nellix stent frame in the proximal zone.

RESULTS

Seventy-six patients were eligible for inclusion in the study (mean age 76 ± 7.4 years; 58 men). AAA growth was identified in 50 of 76 patients (66%); adherence to IFU did not affect its incidence (mean growth within IFU-2016 compliant cohort vs. non-compliant: 16% vs. 13%, p = .33). Over time, the incidence of AAA growth increased, from 32% at one year to 100% at four years. AAA growth by volume was progressive (p < .001), as its extent increased over time. Migration was detected in 16 patients and there was a statistically significant association with AAA growth (13 patients displayed migration and AAA growth, p = .036).

CONCLUSION

Patients treated with EVAS are prone to AAA growth, irrespective of whether their aortic anatomy is IFU compliant. AAA growth by volume is associated with stent migration. Clinicians should continue close surveillance post EVAS, regardless of whether patients are treated within IFU.

Prognostic Significance of Aneurysm Sac Shrinkage After Endovascular Aneurysm Repair

Purpose: To investigate whether patients who develop aneurysm sac shrinkage following endovascular aneurysm repair (EVAR) have better outcomes than patients with a stable or increased aneurysm sac. Materials and Methods: The Healthcare Databases Advanced Search interface developed by the National Institute for Health and Care Excellence was used to interrogate MEDLINE and EMBASE. Thesaurus headings were adapted accordingly. Case-control studies were identified comparing outcomes in patients demonstrating aneurysm sac shrinkage after EVAR with those of patients with a stable or expanded aneurysm sac. Pooled estimates of dichotomous outcome data were calculated using the odds ratio (OR) and 95% confidence interval (CI). Meta-analysis of time-to-event data was conducted using the inverse-variance method; the results are reported as a summary hazard ratio (HR) and 95% CI. Summary outcome estimates were calculated using random-effects models. Results: Eight studies were included in quantitative synthesis reporting a total of 17,096 patients (8518 patients with sac shrinkage and 8578 patients without sac shrinkage). The pooled incidence of sac shrinkage at 12 months was 48% (95% CI 40% to 56%). Patients with aneurysm sac shrinkage had a significantly lower hazard of death (HR 0.73, 95% CI 0.60 to 0.87), secondary interventions (HR 0.42, 95% CI 0.29 to 0.62), and late complications (HR 0.37, 95% CI 0.24 to 0.56) than patients with a stable or increased aneurysm sac. Furthermore, their odds of rupture were significantly lower than those in patients without shrinkage (OR 0.09, 95% CI 0.02 to 0.36). Conclusion: Sac regression is correlated to improved survival and a reduced rate of secondary interventions and EVAR-related complications. The prognostic significance of sac regression should be considered in surveillance strategies. Intensified surveillance should be applied in patients who fail to achieve sac regression following EVAR.

Editor's Choice - Endovascular vs. Open Repair for Abdominal Aortic Aneurysm: Systematic Review and Meta-analysis of Updated Peri-operative and Long Term Data of Randomised Controlled Trials

OBJECTIVE

The objective was to investigate whether endovascular aneurysm repair (EVAR) has better peri-operative and late clinical outcomes than open repair for non-ruptured abdominal aortic aneurysm.

METHODS

Electronic bibliographic sources (MEDLINE, EMBASE, and CENTRAL) were searched up to July 2019 using a combination of thesaurus and free text terms to identify randomised controlled trials (RCTs) comparing the outcomes of EVAR and open repair. The systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Pooled estimates of dichotomous outcomes were calculated using odds ratio (OR) or risk difference (RD) and 95% confidence interval (CI). A time to event data meta-analysis was performed using the inverse variance method and the results were reported as summary hazard ratio (HR) and 95% CI.

RESULTS

Seven RCTs reporting a total of 2 983 patients were included in quantitative synthesis. Three of the trials reported long term follow up that extended to 15.8 years, 14.2 years, and 12.5 years. Meta-analysis found significantly lower odds of 30 day (OR, 0.36; 95% CI 0.20-0.66) and in hospital mortality with EVAR (RD -0.03; 95% CI -0.04 to -0.02). Meta-analysis of the three trials reporting long term follow up found no significant difference in all cause mortality at any time between EVAR and open repair (HR 1.02; 95% CI 0.93-1.13; p = .62). The hazard of all cause (HR 0.62; 95% CI 0.42-0.91) and aneurysm related death within six months (HR 0.42; 95% CI 0.24-0.75) was significantly lower in patients who underwent EVAR, but with further follow up, the pooled hazard estimate moved in favour of open surgery; in the long term (>8 years) the hazard of aneurysm related mortality was significantly higher after EVAR (HR 5.12; 95% CI 1.59-16.44). The risk of secondary intervention (HR 2.13; 95% CI 1.69-2.68), aneurysm rupture (OR, 5.08; 95% CI 1.11-23.31), and death due to rupture (OR, 3.57; 95% CI 1.87-6.80) was significantly higher after EVAR, but the risk of death due to cancer was not significantly different between EVAR and open repair (OR, 1.03; 95% CI 0.84-1.25).

CONCLUSION

Compared with open surgery, EVAR results in a better outcome during the first six months but carries an increased risk of aneurysm related mortality after eight years.

Treatment strategies for in-stent restenosis in peripheral arterial disease: a systematic review

OBJECTIVES

Our purpose was to investigate the outcomes of different treatment strategies for in-stent restenosis (ISR) in patients with peripheral arterial disease of the lower limbs.

METHODS

We performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards. We searched MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials comparing different treatments for ISR in peripheral arterial disease. Recurrent ISR and freedom from target lesion revascularization were defined as the primary outcome measures. We performed an indirect comparison meta-analysis of different treatments.

RESULTS

We identified 4 randomized controlled trials that fulfilled our inclusion criteria enrolling a total of 491 patients and another 4 ongoing trials. Each of the included trials reported 1 of the 4 comparisons: drug-coated balloon angioplasty versus standard balloon angioplasty; treatment with heparin-bonded Viabahn endoprosthesis versus standard balloon angioplasty; excimer laser atherectomy plus standard balloon angioplasty versus standard balloon angioplasty alone; and peripheral cutting balloon angioplasty versus standard balloon angioplasty. The risk of recurrent ISR at 12 months was significantly higher with standard balloon angioplasty than with drug-coated balloon angioplasty (P = 0.004). There was no significant difference in the risk of recurrent ISR at 6 months between cutting balloon angioplasty and standard balloon angioplasty (P = 0.73). Freedom from target lesion revascularization at 12 months was significantly higher with drug-coated balloon angioplasty (P < 0.001) and treatment with the heparin-bonded Viabahn endoprosthesis (P < 0.001) than with standard balloon angioplasty. Freedom from target lesion revascularization at 6 months was also significantly higher with excimer laser atherectomy plus standard balloon angioplasty than with standard balloon angioplasty (P = 0.003). Tested indirect comparisons revealed large confidence intervals and no statistically significant difference between treatments.

CONCLUSIONS

The results from individual trials suggest that drug-coated balloon angioplasty, treatment with the heparin-bonded Viabahn endoprosthesis and adjuvant excimer laser atherectomy confer improved outcomes compared with standard balloon angioplasty. Ongoing clinical trials may elucidate uncertainties in the optimal management of ISR in this setting.

State of the art and meta-analysis of secondary open aortic procedure after abdominal endovascular aortic repair

BACKGROUND

Secondary open aortic procedures (SOAP) treat complications of endovascular aneurysm repair, when further endovascular options are exhausted. We aimed at depicting the state of the art of SOAP with high-level evidence.

METHODS

A systematic review of the SOAP literature, with a meta-analysis of its outcomes (primary outcome operative mortality; secondary outcome major morbidity) and metaregression of risk factors for mortality (PROSPERO 42017075631).

RESULTS

Twenty-eight studies (1093 patients) were elected for analysis. SOAP was performed within the same hospitalization of or 30 days from domestic endovascular aneurysm repair (early SOAP) in 0.2% of the patients (85/40,256), and in a nonelective setting in 24.3% (95% confidence interval, 21.8-26.9). Most frequent indications were endoleak (44.4%; 95% confidence interval, 41.4-47.3) and rupture (12.7%; 95% confidence interval, 10.4-15.1). The most common procedures were infrarenal aortic replacement (85.2%; 95% confidence interval, 82.6-87.7) with high use of supravisceral clamping (suprarenal, 25% [95% confidence interval, 21.9-28.1] and supraceliac, 20.7% [95% confidence interval, 17.8-23.6]), and axillobifemoral bypass with stent explant (6.9%; 95% confidence interval, 5.1-8.7). Operative mortality (in-hospital or 30-day) was 10.9% (95% confidence interval, 8.7-13.5). The most frequent morbidities were respiratory (11.4%; 95% confidence interval, 8.1-15.9) and renal (9.5%; 95% confidence interval, 8.1-15.9). Risk factors for mortality were supravisceral clamping (Z = 3.007; Q = 9.044; P = .003) and nonelective status (Z = 3.382; Q = 11.440; P = .001).

CONCLUSIONS

Endoleak is the main indication for SOAP, which mostly consists of infrarenal aortic replacement. Risk factors for operative mortality are nonelective status and supravisceral clamping.

Thoraflex Graft in an Inverted Position for Post-Dissection Thoracoabdominal Aneurysm

We present the off-label use of a Thoraflex Hybrid Plexus prosthesis (Vascutek, Renfrewshire, Scotland, UK) to treat a post-dissection type IV thoracoabdominal aortic aneurysm (TAA) in a high-risk patient previously treated with a thoracic stent-graft for a chronic type B aortic dissection. The Thoraflex graft was used in a "reversed frozen elephant trunk" fashion: the stent graft portion deployed in the previously placed thoracic stent, and the branched portion used to revascularize visceral arteries and lower limbs. Our off-label use of the Thoraflex graft was technically successful. Further experiences are required to confirm the safety of this technique in high-risk patients.

Stent Frame Movement Following Endovascular Aneurysm Sealing in the Abdominal Aorta

Purpose: To investigate the incidence and extent of stent frame movement after endovascular aneurysm sealing (EVAS) in the abdominal aorta and its relationships to aneurysm growth and the instructions for use (IFU) of the Nellix endograft. Methods: A retrospective single-center study was conducted to review the clinical data and computed tomography (CT) images of 75 patients (mean age 76±7.6 years; 57 men) who underwent infrarenal EVAS and had a minimum 1-year follow-up. The first postoperative CT scan at 1 month and the subsequent scans were used to measure the distances between the proximal end of the stent frames and a reference visceral vessel using a previously validated technique. Device migration was based on the Society of Vascular Surgery definition of >10-mm downward movement of either Nellix stent frame in the proximal landing zone; a more conservative proximal displacement measure (downward movement ⩾4 mm) was also recorded. Patients were categorized according to adherence to the old (2013) or new (2016) Nellix IFU. Aneurysm diameter was measured for each scan; a change ⩾5 mm was deemed indicative of aneurysm growth. Results: Over a median follow-up of 24 months (range 12–48), proximal displacement ⩾4 mm occurred in 42 (56%) patients and migration >10 mm in 16 (21%), with similar incidences in the right and left stent frames. Proximal displacement was significantly more frequent among patients whose anatomy did not conform to any IFU (p=0.025). Presence of aneurysm growth ⩾5 mm was observed in 14 (19%) patients and was significantly associated with proximal displacement ⩾4 mm (p=0.03). Conclusion: Infrarenal EVAS may be complicated by proximal displacement and migration, particularly when performed outside the IFU. The definition of migration used for endovascular aneurysm repair may be inappropriate for EVAS; a new consensus on definition and measurement technique is necessary.

Effect of beta-blockers on perioperative outcomes in vascular and endovascular surgery: a systematic review and meta-analysis

BACKGROUND

To investigate the role of perioperative beta-blocker use in vascular and endovascular surgery.

METHODS

We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards. The review protocol was registered with International Prospective Register of Systematic Reviews (registration number:CRD42016038111). We searched electronic databases to identify all randomized controlled trials and observational studies investigating outcomes of patients undergoing vascular and endovascular surgery with or without perioperative beta blockade. We used the Cochrane tool and the Newcastle-Ottawa scale to assess the risk of bias of trials and observational studies, respectively. Random-effects models were applied to calculate pooled outcome data.

RESULTS

We identified three randomized trials, five retrospective cohort studies, and three prospective cohort studies, enrolling a total of 32,602 patients. Our analyses indicated that perioperative use of beta-blockers did not reduce the risk of all-cause mortality [odds ratio (OR) 1.10, 95% confidence interval (CI) 0.59-2.04, P = 0.77], cardiac mortality (OR 2.62, 95% CI 0.86-8.05, P = 0.09), myocardial infarction (OR 0.89, 95% CI 0.59-1.35, P = 0.58), unstable angina (OR 1.34, 95% CI 0.41- 4.38, P = 0.63), stroke (OR 2.45, 95% CI 0.89-6.75, P = 0.08), arrhythmias (OR 0.76, 95% CI 0.41-1.43, P = 0.40), congestive heart failure (OR 1.12, 95% CI 0.77-1.63, P = 0.56), renal failure (OR 1.48, 95% CI 0.90-2.45, P = 0.13), composite cardiovascular events (OR 0.88, 95% CI 0.55-1.40, P = 0.58), rehospitalisation (OR 0.86, 95% CI 0.48-1.52, P = 0.60), and reoperation (OR 1.17, 95% CI 0.42-3.27, P = 0.77) in vascular surgery.

CONCLUSIONS

Beta-blockers do not improve perioperative outcomes in vascular and endovascular surgery.

Editor's Choice - Systematic Review and Meta-Analysis of Very Urgent Carotid Intervention for Symptomatic Carotid Disease

BACKGROUND

The optimum timing of carotid intervention for symptomatic carotid stenosis remains unclear. The objective was to investigate outcomes of very urgent (< 48 h from neurological event) in comparison to urgent (≥ 48 h from neurological event) carotid intervention for symptomatic carotid disease.

METHODS

A systematic literature review was carried out of randomised control trials (RCTs) and observational studies reporting peri-procedural outcomes of carotid intervention in relation to the length of time since the neurological event (PROSPERO registration number: CRD 42017075766). Ipsilateral stroke and death were defined as the primary outcome endpoints. Transient ischaemic attack (TIA) and myocardial infarction (MI) were secondary outcome parameters. Comparative outcomes were calculated and reported as dichotomous outcome measures using the odds ratio (OR) and associated 95% confidence interval (CI) for very urgent (< 48 h since neurological event) versus urgent (≥ 48 h) intervention. The combined overall effect size was calculated using a random effects model.

RESULTS

Twelve observational studies and one RCT representing 5751 interventions, 5385 carotid endarterectomies (CEAs) and 366 carotid artery stenting (CAS) procedures, were included in quantitative synthesis. Very urgent carotid intervention was associated with increased risk of stroke within 30 days of treatment compared with urgent carotid intervention (OR 2.19, 95% CI 1.46-3.26, p < .001). No significant difference was found in mortality (OR 1.55, 95% CI 0.81-2.96, p = .19), TIA (OR 1.33, 95% CI 0.55-3.19, p = .52) or MI (OR 1.33, 95% CI 0.41-4.33, p = .64).

CONCLUSIONS

Very urgent carotid intervention was found to be associated with increased risk of stroke.

Bowel ischaemia after endovascular aneurysm repair

The aim of this review was to investigate presentation, aetiology, management, and outcomes of bowel ischaemia following EVAR. We present a case report and searched electronic bibliographic databases to identify published reports of bowel ischaemia following elective infra-renal EVAR not involving hypogastric artery coverage or iliac branch devices. We conducted our review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards. In total, five cohort studies and three case reports were included. These studies detailed some 6,184 infra-renal elective EVARs, without procedure-related occlusion of the hypogastric arteries, performed between 1996 and 2014. Bowel ischaemia in this setting is uncommon with an incidence ranging from 0.5 to 2.8 % and includes a spectrum of severity from mucosal to transmural ischaemia. Due to varying reporting standards, an overall proportion of patients requiring bowel resection could not be ascertained. In the larger series, mortality ranged from 35 to 80 %. Atheroembolization, hypotension, and inferior mesenteric artery occlusion were reported as potential causative factors. Elderly patients and those undergoing prolonged procedures appear at higher risk. Bowel ischaemia is a rare but potentially devastating complication following elective infra-renal EVAR and can occur in the setting of patent mesenteric vessels and hypogastric arteries. Mortality ranges from 35 to 80 %. Further research is required to identify risk factors and establish prophylactic measures in patients that have an increased risk of developing bowel ischaemia after standard infra-renal EVAR.

Is management of complex abdominal aortic aneurysms consistent? A questionnaire-based survey

BACKGROUND

Complex abdominal aortic aneurysm (AAA) is a relatively common presentation to the vascular specialist. Despite this there is little consensus on how to manage the often comorbid group of patients. Recent advances in endovascular technology have led to the availability of multiple devices, many of which could be used to treat the same aneurysm. The aim of this study was to quantify this potential variability across vascular specialists from multiple countries.

METHODS

An online survey was emailed to members of the Vascular Society for Great Britain and Ireland (VSGBI), the Canadian Society for Vascular Surgery (CSVS) and the Australian and New Zealand Society for Vascular Surgery (ANZSVS). The survey presented a vignette of a 63-year-old woman with significant respiratory comorbidity and a 54 mm juxtarenal AAA (7 mm neck). There were no other adverse morphological features for endovascular repair. The survey included images and questions related to management of the aneurysm.

RESULTS

The survey received 238 responses; 61 from ANZSVS, 65 from CSVS and 112 from VSGBI. VSGBI specialists were significantly more likely to continue surveillance than both ANZSVS (odds ratio [OR] 3.41, 95% confidence interval [CI] 1.61-7.65; P<0.001) and CSVS counterparts (OR 2.61, 95% CI: 1.29-5.47; P<0.01). ANZSVS specialists were significantly more likely to perform an endovascular repair than those from CSVS (OR 3.28, 95% CI: 1.50-7.40; P<0.01) and VSGBI (OR 3.65, 95% CI: 1.81-7.59; P<0.001). CSVS specialists were significantly more likely to manage the aneurysm with open surgery than colleagues from the VSGBI (OR 6.57, 95% CI: 2.58-18.46; P<0.001) and ANZSVS (OR 7.18, 95% CI: 2.22-30.79; P<0.001).

CONCLUSIONS

Significant variation in the management of a juxtarenal AAA between countries was observed. The same patient would be more likely to have an endovascular repair in Australia and New Zealand, open surgery in Canada and continuing surveillance in the UK and Ireland. This variation reflects the lack of long-term evidence and international consensus on the optimal management of complex AAA.

Revision Using Distal Inflow for Treatment of Heart Failure Secondary to Arteriovenous Fistula for Hemodialysis

In patients on hemodialysis, cardiovascular disease can be precipitated or worsened by the presence of a high flow arteriovenous fistula. Fistula closure and banding are the traditional treatment methods of dialysis associated high output cardiac failure. We present a case of fistula-related high output cardiac failure treated by revision using distal inflow (RUDI).

Temporal Changes in Intraluminal Thrombus Volume Within Abdominal Aortic Aneurysms: Implications for Planning Endovascular Aneurysm Sealing

PURPOSE

To explore whether or not there are temporal changes in the abdominal aortic aneurysm (AAA) and intraluminal thrombus (ILT) volumes between planning and implantation of the endovascular aneurysm sealing (EVAS) device and how these changes influence lumen volume.

METHODS

A retrospective review was conducted of 51 AAA patients (mean age 76±7.1 years; 36 men) in whom 2 serial preoperative computed tomography angiograms (CTAs) had been performed within 1 to 18 months before fenestrated endovascular repair. The 2 preoperative CTAs were analyzed to identify changes in total sac, ILT, and lumen volumes.

RESULTS

Over a median 7.0 months (interquartile range 4, 10), 46 (90%) of 51 AAAs increased in volume between the 2 CTAs. ILT volume increased in 44 aneurysms. In contrast, lumen volume increased in 31 and decreased in 20 AAAs. There was a strong correlation between changes in AAA volume and ILT volume (r_s=0.859, p<0.001), which remained significant after adjustment for initial volumes (r_s=0.815; p<0.001). There was no correlation between the time interval separating the 2 CTAs and changes in AAA volume (r_s=0.115; p=0.421), changes in ILT volume (r_s=0.084; p=0.599), or changes in lumen volume (r_s=0.060; p=0.676). The AAA growth rate (defined as the change in AAA size/days between CTAs) showed a weak correlation with ILT volume (r_s=0.272, p=0.054), which disappeared after adjustment for initial AAA size (r_s=-0.002, p=0.991). Between the 2 CTAs, 12 aneurysms crossed the new <1.4 Nellix maximum aorta/lumen diameter ratio.

CONCLUSION

As AAAs grow, the increase in aortic volume is largely occupied by additional ILT formation, with minimal change in lumen volume. These changes may alter the suitability of the aneurysm for the Nellix device and could have implications for EVAS planning and device deployment.

Can Hospital Transfusion Committees Change Transfusion Practice?

Blood and blood products are commonly over-used in hospital practice. We investigated whether the introduction of a red-cell transfusion trigger (haemoglobin <8 g dL–1) influenced transfusion practice in surgery. Coronary artery bypass grafts (CABGs, n=400), total hip replacements (n=107), colectomies (n=85) and transurethral prostatectomies (TURPs, n=158) were reviewed over two periods of six months, before and after the introduction of the policy by the local hospital transfusion committee.

After introduction of the policy, the proportion of patients transfused fell from 57% to 45% with CABGs (P=0.02) and from 52% to 26% with hip replacements (P=0.006); for colectomies and TURPs there was no change. Hospital stay did not increase in any of the groups. In the second period, haemoglobin concentration on discharge was lower after total hip replacement, by a mean (95% CI) of 0.7 (0.3–1.2) g dL–1 (P=0.002) and after colectomy, by a mean of 0.6 (0.1–1.1) g dL–1 (P=0.03).

Although other factors cannot be excluded, we suggest that the reductions in red-cell transfusion were in large part attributable to the new transfusion policy.