Systematic Review and Meta-analysis of Fenestrated and Chimney/Snorkel Techniques for Endovascular Repair of Juxtarenal Aortic Aneurysms.

OBJECTIVES: Comparative effectiveness of fenestrated endovascular aneurysm repair (FEVAR) and chimney graft endovascular aneurysm repair (ChEVAR) for juxtarenal aortic aneurysms (JAAs) remains unclear. Our objective was to identify and analyze the current body of evidence comparing the effectiveness of both techniques for JAA. METHODS: We performed a systematic review and meta-analysis comparing the effectiveness of FEVAR and ChEVAR for JAA repair. We searched MEDLINE, EMBASE, and Cochrane Register for Controlled Trials from January 1, 1990, for randomized and non-randomized studies assessing outcomes of FEVAR and ChEVAR for JAA repair. Screening, data extraction, risk of bias assessment, and GRADE (Grading of Recommendations, Assessments, Development, and Evaluations) certainty of evidence were performed in duplicate. Data were pooled statistically where possible. RESULTS: Nine retrospective cohort studies comparing the use of FEVAR and ChEVAR for juxtarenal aneurysm were included for meta-analysis. The FEVAR and ChEVAR arms of the meta-analysis consisted of 726 participants and 518 participants, respectively. There were 598 (86.8%) and 332 (81.6%) men in each arm. The mean diameter was larger in the ChEVAR arm (59 mm vs 52.5 mm). Both techniques had similar rates of postoperative 30-day mortality, 3.38% (8/237) versus 3.52% (8/227), acute kidney injury, 16.76% (31/185) versus 17.31% (18/104), and major adverse cardiac events, 7.30% (46/630) versus 6.60% (22/333). The meta-analysis supported the use of FEVAR for most outcomes, with significant advantage for technical success (odds ratio [OR]: 3.24, 95% CI: 1.24-8.42) and avoidance of type 1 endoleak (OR: 5.76, 95% CI: 1.94-17.08), but a disadvantage for spinal cord ischemia (OR: 10.21, 95% CI: 1.21-86.11), which had a very low number of events. The quality of evidence was "moderate" for most outcomes. CONCLUSION: Both endovascular techniques had good safety profiles. The evidence does not support superiority of either FEVAR or ChEVAR for JAA. CLINICAL IMPACT: While lack of equipoise has hampered the design of randomised trials of open versus endovascular repair of juxtarenal aortic aneurysms, concern about the durability of endovascular repair highlights the need for stronger evidence of the comparative efficacy of endovascular techniques. This review performed meta-analysis and evidence appraisal of recent data from large observational studies comparing fenestrated and chimney techniques, using a comprehensive outcome set. Superiority of either intervention could not be established due to differences in participants' baseline risk in each study arm. However, data suggests that both techniques are safe and suitable for use when indicated.

Application of Novosorb biodegradable temporising matrix in wounds of different aetiologies: a case series.

DECLARATION OF INTEREST: The authors have no conflicts of interest to declare.

Effect of Pseudomonas colonisation on lower limb venous ulcer healing: a systematic review.

OBJECTIVE: Pseudomonas aeruginosa is a Gram-negative bacillus that commonly colonises lower limb venous ulcers. Its effects on venous ulcer healing are widely debated. It produces exotoxins and elastase, as well as forming biofilms in hard-to-heal wounds. It is postulated that these virulence factors lead to slower healing times in patients with lower limb venous ulcers colonised with Pseudomonas. This review aimed to summarise the available evidence pertaining to this topic. METHOD: A systematic review was performed in August 2019, where the Pubmed, Cochrane and Embase databases were searched for relevant literature according to PRISMA guidelines. Retrospective and prospective studies examining the effect of Pseudomonas colonisation on any measure of ulcer healing were included. RESULTS: Some 282 articles were screened, of which seven studies including 491 patients were ultimately included for analysis. Of these, no study demonstrated a significant association between Pseudomonas colonisation and delayed healing of venous ulcers. In five of the seven studies, the effect of Pseudomonas aeruginosa on initial ulcer size at presentation was recorded. CONCLUSION: All the studies demonstrated an association between ulcer size and the presence of Pseudomonas aeruginosa. While Pseudomonas aeruginosa may colonise larger ulcers or those with a worse prognosis, no evidence was found to support the hypothesis that this colonisation had a negative impact on lower limb venous ulcer healing.

On the association between circulating biomarkers and atherosclerotic calcification in a cohort of arterial disease participants.

BACKGROUND AND AIMS: Atherosclerotic calcification is a powerful predictor of cardiovascular disease. This study aims to determine whether circulating levels of a local/systemic calcification inhibitor or a marker of bone formation correlate with measures of coronary or extracoronary calcification. METHODS AND RESULTS: Clinical computed tomography (CT) was performed on 64 arterial disease participants undergoing carotid and lower extremity endarterectomy. Coronary artery calcium (CAC) scores and volumes were acquired from the CT scans (n = 42). CAC scores and volumes were used to derive CAC density scores. Micro-CT was performed on excised carotid (n = 36) and lower extremity (n = 31) plaques to quantify the volume and volume fraction of extracoronary calcification. Circulating levels of dephospho-uncarboxylated Matrix Gla Protein (dp-ucMGP), fetuin-A, carboxylated and uncarboxylated osteocalcin (ucOC) were quantified using commercial immunoassays. Carotid participant CAC density scores were moderately negatively correlated with plasma dp-ucMGP (rs = -0.592, P = 0.008). A weak negative association was found between CAC scores and %ucOC for all participants (rs = -0.335, P = 0.040). Another weak negative correlation was observed between fetuin-A and the volume of calcification within excised carotid specimens (rs = -0.366, P = 0.031). Despite substantial differences in coronary and extracoronary calcium measurements, the levels of circulating biomarkers did not vary significantly between carotid and lower extremity subgroups. CONCLUSION: Correlations identified between circulating biomarkers and measures of coronary and extracoronary calcium were not consistent among participant subgroups. Further research is required to determine the association between circulating biomarkers, coronary and extracoronary calcium.

Correlating Ex Vivo Carotid Calcification Measurements With Cerebrovascular Symptoms: A Proof-of-Concept Study.

BACKGROUND AND PURPOSE: The purpose of this study is to examine the ability of ex vivo derived Agatston, Volume, and Density-Volume calcium scores or calcium density measurements to differentiate between carotid plaques based on preoperative cerebrovascular symptomatology. METHODS: Thirty-eight carotid plaques were acquired from standard endarterectomy. Micro-computed tomography was performed on the ex vivo samples. Image series were downsampled to represent the resolution of clinical multidetector computed tomography. Agatston, Volume, and Density-Volume carotid calcium scores were then calculated using coronary methodologies. The fractions of low- and high-density calcification were also determined. RESULTS: The coronary calcium scores could not differentiate between carotid plaques from asymptomatic versus symptomatic patients. However, plaques from asymptomatic patients contained significantly lower fractions of low-density calcification and higher fractions of high-density calcification. CONCLUSIONS: Screening for carotid calcium density in noncontrast computed tomography could reflect plaque stability.

On the influence of wall calcification and intraluminal thrombus on prediction of abdominal aortic aneurysm rupture.

OBJECTIVE: Parameters other than maximum diameter that predict rupture of abdominal aortic aneurysms (AAAs) may be helpful for risk-benefit analysis in individual patients. The aim of this study was to characterize the biomechanical-structural characteristics associated with AAA walls to better identify the related mechanistic variables required for an accurate prediction of rupture risk. METHODS: Anterior AAA wall (n = 40) and intraluminal thrombus (ILT; n = 114) samples were acquired from 18 patients undergoing open surgical repair. Biomechanical characterization was performed using controlled circumferential stretching tests combined with a speckle-strain tracking technique to quantify the spatial heterogeneity in deformation and localized strains in the AAA walls containing calcification. After mechanical testing, the accompanying microstructural characteristics of the AAA wall and ILT types were examined using electron microscopy. RESULTS: No significant correlation was found between the AAA diameter and the wall mechanical properties in terms of Cauchy stress (rs = -0.139; P = .596) or stiffness (rs = -0.451; P = .069). Quantification of significant localized peak strains, which were concentrated in the tissue regions surrounding calcification, reveals that peak strains increased by a mean of 174% as a result of calcification and corresponding peak stresses by 18.2%. Four ILT types characteristic of diverse stages in the evolving tissue microstructure were directly associated with distinct mechanical stiffness properties of the ILT and underlying AAA wall. ILT types were independent of geometric factors, including ILT volume and AAA diameter measures (ILT stiffness and AAA diameter [rs = -0.511; P = .074]; ILT stiffness and ILT volume [rs = -0.245; P = .467]). CONCLUSIONS: AAA wall stiffness properties are controlled by the load-bearing capacity of the noncalcified tissue portion, and low stiffness properties represent a highly degraded vulnerable wall. The presence of calcification that is contiguous with the inner wall causes severe tissue overstretching in surrounding tissue areas. The results highlight the use of additional biomechanical measures, detailing the biomechanical-structural characteristics of AAA tissue, that may be a helpful adjunct to improve the accuracy of rupture prediction.

A Systematic Review and Meta-analysis of Thrombotic Events Following Endovenous Thermal Ablation of the Great Saphenous Vein.

OBJECTIVES: A systematic review and meta-analysis was performed to determine the incidence of thrombotic events following great saphenous vein (GSV) endovenous thermal ablation (EVTA). METHODS: MEDLINE, Embase and conference abstracts were searched. Eligible studies were randomised controlled trials and case series that included at least 100 patients who underwent GSV EVTA (laser ablation or radiofrequency ablation [RFA]) with duplex ultrasound (DUS) within 30 days. The systematic review focused on the complications of endovenous heat induced thrombosis (EHIT), deep venous thrombosis (DVT), and pulmonary embolism (PE). The primary outcome for the meta-analysis was deep venous thrombotic events which were defined as DVT or EHIT Type 2, 3, or 4. Secondary outcomes for the meta-analysis were EHIT Type 2, 3, or 4, DVT and PE. Subgroup analyses were performed for both the RFA and EVLA groups. Pooled proportions were calculated using random effects modelling. RESULTS: Fifty-two studies (16,398 patients) were included. Thrombotic complications occurred infrequently. Deep venous thrombotic events occurred in 1.7% of cases (95% CI 0.9-2.7%) (25 studies; 10,012 patients; 274 events). EHIT Type 2, 3, or 4 occurred in 1.4% of cases (95% CI 0.8-2.3%) (26 studies; 10,225 patients; 249 events). DVT occurred in 0.3% of cases (95% CI = 0.2%-0.5%) (49 studies; 15,676 patients; 48 events). PE occurred in 0.1% of cases (95% CI = 0.1-0.2%) (29 studies; 8223 patients; 3 events). Similar results were found when the RFA and EVLA groups were analysed separately. CONCLUSION: Thrombotic events occur infrequently following GSV EVTA. Given the large numbers of procedures worldwide and the potential for serious consequences, further research is needed on the burden of these complications and their management.

Can a Neutrophil-Lymphocyte Ratio Derived from Preoperative Blood Tests Predict Arteriovenous Fistula Maturation?

BACKGROUND: To evaluate the association between inflammatory markers expressed as neutrophil-lymphocyte ratio (NLR) and process of arteriovenous fistula (AVF) maturation. METHODS: A retrospective review of patients with end-stage renal disease referred for formation of a new AVF in one center. Patients referred to the vascular service in the University Hospital of Limerick for creation of vascular access between 2009 and 2013. The association between NLR, calculated from preoperative blood tests, and functional fistula maturation, as determined by successful use of the AVF for 6 consecutive hemodialysis sessions, was investigated using univariate and logistic regression analyses. A logistic regression analysis was carried out to assess potential influence from other factors related to AVF maturation. Stepwise regression test was performed including the NLR. RESULTS: Overall AVF functional maturation rate in our study was 53.7% (66/123). Patients with matured AVFs had an NLR of 4.850 (1.8-15.7) compared with 3.554 (1.7-15.0); this difference was found to be significant (P = 0.024). Female gender (P = 0.008) and a history of kidney transplant (P = 0.004) were the only independent factors of fistula maturation outcome in a logistic regression model. CONCLUSION: Increased level of NLR was found to be associated with fistula maturation; however, more studies are needed to validate this finding.

Microindentation of fresh soft biological tissue: A rapid tissue sectioning and mounting protocol.

Microindentation of fresh biological tissues is necessary for the creation of 3D biomimetic models that accurately represent the native extracellular matrix microenvironment. However, tissue must first be precisely sectioned into slices. Challenges exist in the preparation of fresh tissue slices, as they can tear easily and must be processed rapidly in order to mitigate tissue degradation. In this study, we propose an optimised mounting condition for microindentation and demonstrate that embedding tissue in a mixture of 2.5% agarose and 1.5% gelatin is the most favourable method of tissue slice mounting for microindentation. This protocol allows for rapid processing of fresh biological tissue and is applicable to a variety of tissue types.

Outcomes of Acute Limb Ischaemia in Patients with Underlying Malignancy: A Systematic Review.

OBJECTIVE: Previous studies have demonstrated amputation and mortality rates to be 14.3% - 30% and 11.4% - 28.9%, respectively, for all patients presenting with acute limb ischaemia (ALI). Rates of ALI are higher in patients with malignancy than in those without. Despite this, there remains uncertainty with regards to the most appropriate management for patients with cancer presenting with ALI. This is because of previously published high rates of associated morbidity and mortality in this population. The aim of this review was to summarise the available evidence reporting on outcomes of ALI in patients with underlying malignancy. METHOD: A systematic review was performed in August 2020 in accordance with the PRISMA guidelines. The Medline, Scopus, Cochrane, and Embase databases were searched with the following search string ((acute limb ischaemia) OR (acute limb ischemia)) AND ((cancer) OR (malignancy)). A total of 849 papers were identified and reviewed; six studies were included. Studies were assessed for bias using the National Institute of Health/National Heart, Lung and Blood Institute Quality Assessment Tool. Data including demographics, Rutherford classification, baseline performance scores, method of revascularisation, and peri-procedural outcomes were extracted and analysed. Data were pooled based on outcomes of interest and pooled prevalence was reported with 95% confidence intervals (CI). RESULTS: Six studies with 284 patients with cancer were included for analysis. The pooled overall risk of amputation was 15% (95% CI 5.9 - 26.9). The pooled 30 day mortality rate was 24% (95% CI 14.7 - 34.6). CONCLUSION: Despite limitations of interstudy selection bias and some clinical heterogeneity, the included studies demonstrated acceptable short and medium term outcomes for patients with cancer undergoing revascularisation for acute limb ischaemia. This is in line with current recommendations that patients with underlying malignancy should be considered strongly for revascularisation.

Necrotising fasciitis in the COVID-19 era: A consequence of caution - A case series.

Necrotising fasciitis (NF) is a severe soft tissue infection that is associated with a high risk of morbidity and mortality. During the coronavirus disease 19 (COVID-19) pandemic, the population has been actively discouraged from presenting to emergency medical services unless absolutely necessary. While this was an important step in allowing for preservation of limited resources in a time of crisis, it may have resulted in immeasurable 'secondary victims' of the pandemic as patients with time-critical conditions delay hospital presentation. In this case series, we describe three patients that noted symptoms of soft tissue infection, but delayed seeking healthcare advice due to concerns regarding COVID-19 exposure. All three progressed to NF, requiring highly morbid wide surgical debridement and prolonged hospital admission, with a high risk of potential mortality. The findings of this series demonstrate the importance of consistently delivering appropriate and timely healthcare interventions to patients with non-COVID-19-related conditions. While efforts must be made to ensure preservation of valuable healthcare resources in a global pandemic, patients must also be empowered to seek timely care for non-COVID-19-related conditions even in this time of crisis.

Systematic review on the incidence and management of endovenous heat-induced thrombosis following endovenous thermal ablation of the great saphenous vein.

OBJECTIVE: A systematic review and meta-analysis was performed to determine the incidence of endovenous heat-induced thrombosis (EHIT) and evaluate its management after endovenous thermal ablation of the great saphenous vein (GSV). METHODS: MEDLINE and Embase were searched for studies with at least 100 patients who underwent great saphenous vein endovenous thermal ablation and had duplex ultrasound follow-up within 30 days. Data were gathered on the incidence of thrombotic complications and on the management of cases of EHIT. The primary outcome for the meta-analysis was EHIT types 2 to 4 and secondary outcomes were deep venous thrombotic events (which we defined as types 2-4 EHIT plus deep vein thrombosis [DVT]), DVT, and pulmonary embolism (PE). Pooled proportions were calculated using random effects modelling. RESULTS: We included 75 studies (23,265 patients). EHIT types 2 to 4 occurred in 1.27% of cases (95% confidence interval [CI], 0.74%-1.93%). Deep venous thrombotic events occurred in 1.59% (95% CI, 0.95%-2.4%). DVT occurred in 0.28% (95% CI, 0.18%-0.4%). Pulmonary embolism occurred in 0.11% (95% CI, 0.06%-0.18%). Of the 75 studies, 24 gave a description of the management strategy and outcomes for EHIT and there was inconsistency regarding its management. Asymmetrical funnel plots of studies that reported incidence of EHIT 2 to 4 and DVT suggest publication bias. CONCLUSIONS: The recently published guidelines on EHIT from the Society for Vascular Surgery/American Venous Forum provide a framework to direct clinical decision-making. EHIT and other thrombotic complications occur infrequently and have a benign course.

Open repair of a type II endoleak facilitated by temporary disconnection of graft components.

Endoleaks are a frequent indication for reintervention after endovascular repair of an abdominal aortic aneurysm. Here we present a method of open repair of a persistent type II endoleak involving graft component separation and reconstruction, in a patient with symptomatic interval aneurysmal sac enlargement despite endovascular coiling and embolization. This case report demonstrates an alternative open technique of endograft component separation and reconstruction that may be required in cases where open repair with sac exploration and vessel oversewing is hindered by the graft position.

An international experience of electronic communication and implementation of eHealth solutions in a vascular surgery clinic.

INTRODUCTION: Communication is key to any successful relationship with the patient-physician partnership being no different. Recent advances in technology have provided us with an array of new communication tools such as the mobile phone, computer, internet, and email. This new technology has revolutionized communications; however, limitations to their widespread use include access, literacy, and willingness for both the physician and patient to change. METHODS: To gather international data, questionnaires were completed by patients attending vascular surgery outpatient clinics in hospitals in Ireland and Canada. RESULTS: Five hundred ninety-seven patients participated in the study. Of the participants, 83.2% were over 50 years old. The mean age was 63.1 years, with a range of 18-95 years. Overall, home phone call was the most preferred method of communication with 41.0% of patients selecting this option. Of the patients, 82.4% had a mobile phone but just 48.5% use text message. In those over the age of 70, 72.1% use a mobile phone and just 25.3% use text message. Of the participants, 64.1% had access to a computer, and 67.2% had access to the internet with a decline in the usage of both with increasing age. DISCUSSION: Within this patient population, the use of technologies decreases with increasing age of the patients. This demonstrates a large population of service users who are contented with conventional methods of communication. Change within healthcare ICT is inevitable, and therefore, these patients need to be guided and educated to allow a smooth transition from the old to the new.

New pulsatile hydrostatic pressure bioreactor for vascular tissue-engineered constructs.

Mechanical conditioning represents a potential means to enhance the biochemical and biomechanical properties of tissue-engineered cell constructs. Bioreactors that can simulate physiologic conditions can play an important role in the preparation of tissue-engineered constructs. Although various forms of bioreactor systems are currently available, these have certain limitations, particularly when these are used for the creation of vascular constructs. The aim of the present report is to describe and validate a novel pressure bioreactor system for the creation of vascular tissue. Here, we present and discuss the design concepts, criteria, as well as the development of a novel pressure bioreactor. The system is compact and easily housed in an incubator to maintain sterility of the construct. Moreover, the proposed bioreactor, in addition to mimicking in vivo pressure conditions, is flexible, allowing different types of constructs to be exposed to various physiologic pressure conditions. The core bioreactor elements can be easily sterilized and have good ergonomic assembly characteristics. This system is a fundamental tool, which may enable us to make further advances in bioreactor technology and tissue engineering. The novel system allows for the application of pressure that may facilitate the growth and development of constructs needed to produce a tissue-engineered vascular graft.

Hybrid covered endovascular reconstruction of the aortic bifurcation (CERAB) procedure is preferable to aortobifemoral bypass for limb-threatening aortoiliac occlusive disease during the COVID-19 crisis.

The COVID-19 pandemic is disrupting the provision of acute vascular surgery across the globe. Limited evidence of the impact of nosocomial infection on patient outcomes as well as concerns about critical care capacity will likely have an impact on surgical decision-making. Endovascular therapy offers a way by which perioperative risk can be reduced for vascular patients while also reducing the impact of acute surgery on intensive care unit capacity. This case report describes the management of a patient with complex aortoiliac occlusive disease by a hybrid endovascular approach in light of these constraints, with a successful outcome.

Comparative analysis of calcification parameters with Agatston Score approximations for ex vivo atherosclerotic lesions.

BACKGROUND: The Agatston Calcium Score is a predictor of major adverse cardiovascular events but it is unable to identify high-risk lesions. Recent research suggests that examining calcification phenotype could be more indicative of plaque stability. OBJECTIVE: To examine the Agatston score's ability to determine atherosclerotic calcification phenotype. METHODS: Micro-Computed Tomography was performed on 20 carotid and 20 peripheral lower limb lesions. ImageJ pixel histogram analysis quantified the non-calcified (≥30HU, <130HU) and calcified (≥130HU) tissue volumes. ImageJ '3D Objects Counter' plugin determined the calcified particle count, volumes and maximum attenuation density of each particle. Image stacks were subsequently downsampled to a resolution of 0.7 × 0.7 × 3 mm and an approximation for the Extra-Coronary Calcium Scores (ECCS) were calculated. Spearman's correlation examined the relationships between ECCS approximations and calcification parameters. RESULTS: ECCS has a strong positive correlation with the Calcified Volume Fraction (CVF) (rs = 0.865, p < 0.0005), weak positive correlations with Calcified Particle Fraction (CPF) (rs = 0.422, p = 0.007) and Microcalcification Fraction (micro-CF) (rs = 0.361, p = 0.022). There is no correlation evident between ECCS and Calcified Particle Index (CPI) (rs = -0.162, p = 0.318). It is apparent that there is a high prevalence of microcalcifications in both carotid and peripheral lower limb lesions. Additionally, an inverse relationship exists between calcified particle volume and maximum-recorded attenuation density. CONCLUSION: The density-weighted Agatston calcium scoring methodology needs to be reviewed. Calcium scoring which differentiates between critical calcification morphologies, rather than presenting a density-weighted score, is required to direct high-risk plaques towards tailored treatment.