Does the Introduction of a Vascular Limb Salvage Service Improve One Year Amputation Outcomes for Patients with Chronic Limb-Threatening Ischaemia?

OBJECTIVE: Vascular limb salvage services are recommended by the Global Vascular Guidelines to help improve outcomes for patients with chronic limb-threatening ischaemia (CLTI), although their description within the literature is limited. This study reports the 12 month outcomes for an outpatient based vascular limb salvage (VaLS) clinic. METHODS: An analysis of a prospectively maintained database, involving all consecutive patients diagnosed with CLTI within the VaLS clinic from February 2018-February 2019, was undertaken. Data were compared with two comparator cohorts, identified from coding data: 1) patients managed prior to the clinic, between May 2017 and February 2018 (Pre-Clinic [PC]); and 2) patients managed outside of clinic, between February 2018 and February 2019 (Alternative Pathways [AP]). Freedom from major amputation at 12 months was the primary outcome. Kaplan-Meier plots and adjusted Cox's proportional hazard models (aHR) were used to compare outcomes. RESULTS: Five hundred and sixty-six patients (VaLS 158, AP 173, PC 235) were included (median age 74 years). Patients managed within the VaLS cohort were statistically significantly more likely to be free from major amputation (90.5%) compared with both the AP (82.1%, aHR 0.52, 95% confidence interval [CI] 0.28 - 0.98, p = .041) and the PC (80.0%; aHR 0.50, 95% CI 0.28 - 0.91, p = .022) cohorts at 12 months, after adjustment for age, disease severity, and presence of diabetes. CONCLUSION: This study supports the recommendations of the Global Vascular Guidelines that vascular limb salvage clinics may improve the rate of major amputation. Furthermore, the study provides a reproducible service model that delivers timely vascular assessment in an ambulatory setting. Further evaluation is required to assess longer term outcomes.

Prevalence of Cognitive Impairment in Individuals with Vascular Surgical Pathology: a Systematic Review and Meta-Analysis.

OBJECTIVE: A significant proportion of vascular surgery patients may have undiagnosed cognitive impairment; however, its true prevalence and impact on outcomes are unknown. The aim of this review was to estimate the prevalence of cognitive impairment among individuals with clinically significant vascular surgical pathology and investigate its associations with post-operative outcomes in those undergoing vascular surgery. METHODS: MEDLINE, EMBASE, EMCare, CINAHL, PsycINFO, and Scopus were searched for relevant studies. Included studies assessed cognitive function among individuals with either symptomatic vascular surgical pathology, or disease above threshold for intervention, using a validated cognitive assessment tool. The primary outcome measure was prevalence of cognitive impairment. Secondary outcomes included incidence of post-operative delirium (POD). Two reviewers independently extracted relevant study data and assessed risk of bias (ROBINS-E or RoB 2 tool). Prevalence (%) of cognitive impairment was calculated for individual studies and presented with 95% confidence intervals (CI). Prevalence data from comparable studies were pooled using the Mantel-Haenszel method (random effects model) for separate vascular disease types. Certainty of effect estimates was assessed using the GRADE criteria. RESULTS: Twenty-four studies (2 564 participants) were included in the systematic review, and nine studies (1 310 participants) were included in the meta-analyses. The prevalence of cognitive impairment was 61% (95% CI 48 - 74; 391 participants; low certainty) in studies including multiple vascular surgical pathologies, 38% (95% CI 32 - 44; 278 participants; very low certainty) in carotid artery disease, and 19% (95% CI 10 - 33; 641 participants; low certainty) in those with intermittent claudication. Lower cognitive assessment scores were associated with POD (five studies; 841 participants), but data were not suitable for pooling. CONCLUSION: Screening elective vascular surgery patients for cognitive impairment may be appropriate given its high prevalence, and the association of worse cognition with POD, among individuals with clinically significant vascular surgical pathology.

Frailty Factors and Outcomes in Vascular Surgery Patients: A Systematic Review and Meta-analysis.

OBJECTIVE: To describe and critique tools used to assess frailty in vascular surgery patients, and investigate its associations with patient factors and outcomes. BACKGROUND: Increasing evidence shows negative impacts of frailty on outcomes in surgical patients, but little investigation of its associations with patient factors has been undertaken. METHODS: Systematic review and meta-analysis of studies reporting frailty in vascular surgery patients (PROSPERO registration: CRD42018116253) searching Medline, Embase, CINAHL, PsycINFO, and Scopus. Quality of studies was assessed using Newcastle-Ottawa scores (NOS) and quality of evidence using Grading of Recommendations Assessment, Development, and Evaluation criteria. Associations of frailty with patient factors were investigated by difference in means (MD) or expressed as risk ratios (RRs), and associations with outcomes expressed as odds ratios (ORs) or hazard ratios (HRs). Data were pooled using random-effects models. RESULTS: Fifty-three studies were included in the review and only 8 (15%) were both good quality (NOS ≥ 7) and used a well-validated frailty measure. Eighteen studies (62,976 patients) provided data for the meta-analysis. Frailty was associated with increased age [MD 4.05 years; 95% confidence interval (CI) 3.35, 4.75], female sex (RR 1.32; 95% CI 1.14, 1.54), and lower body mass index (MD -1.81; 95% CI -2.94, -0.68). Frailty was associated with 30-day mortality [adjusted OR (AOR) 2.77; 95% CI 2.01-3.81), postoperative complications (AOR 2.16; 95% CI 1.55, 3.02), and long-term mortality (HR 1.85; 95% CI 1.31, 2.62). Sarcopenia was not associated with any outcomes. CONCLUSION: Frailty, but not sarcopenia, is associated with worse outcomes in vascular surgery patients. Well-validated frailty assessment tools should be preferred clinically, and in future research.

A systematic review investigating the identification, causes, and outcomes of delays in the management of chronic limb-threatening ischemia and diabetic foot ulceration.

OBJECTIVE: Patients presenting with chronic limb-threatening ischemia and diabetic foot ulceration (DFU) are at high risk of major lower limb amputation. Long-standing concern exists regarding late presentation and delayed management contributing to increased amputation rates. Despite multiple guidelines existing on the management of both conditions, there is currently no accepted time frame in which to enact specialist care and treatment. This systematic review aimed to investigate potential time delays in the identification, referral, and management of both chronic limb-threatening ischemia and DFU. METHODS: A systematic review conforming to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards was performed searching MEDLINE, Embase, The Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature from inception to November 14, 2018. All English-language qualitative and quantitative articles investigating or reporting the identification, causes, and outcomes of time delays within "high-income" countries (annual gross domestic product per person >$15,000) were included. Data were extracted independently by the investigators. Given the clinical crossover, both conditions were investigated together. A study protocol was designed and registered at the International Prospective Register of Systematic Reviews. RESULTS: A total of 4780 articles were screened, of which 32 articles, involving 71,310 patients and 1388 health care professionals, were included. Twenty-three articles focused predominantly on DFU. Considerable heterogeneity was noted, and only 12 articles were deemed of high quality. Only four articles defined a delay, but this was not consistent between studies. Median times from symptom onset to specialist health care assessment ranged from 15 to 126 days, with subsequent median times from assessment to treatment ranging from 1 to 91 days. A number of patient and health care factors were consistently reported as potentially causative, including poor symptom recognition by the patient, inaccurate health care assessment, and difficulties in accessing specialist services. Twenty articles reported outcomes of delays, namely, rates of major amputation, ulcer healing, and all-cause mortality. Although results were heterogeneous, they allude to delays being associated with detrimental outcomes for patients. CONCLUSIONS: Time delays exist in all aspects of the management pathway, which are in some cases considerable in length. The causes of these are complex but reflect poor patient health-seeking behaviors, inaccurate health care assessment, and barriers to referral and treatment within the care pathway. The adoption of standardized limits for referral and treatment times, exploration of missed opportunities for diagnosis, and investigation of novel strategies for providing specialist care are required to help reduce delays.

Renal Function is the Main Predictor of Acute Kidney Injury after Endovascular Abdominal Aortic Aneurysm Repair.

BACKGROUND: Postoperative acute kidney injury (AKI) may occur in up to 18% of elective endovascular abdominal aortic aneurysm repair (EVAR) and has been associated with poor outcome; however, it is not clear which patients are at highest risk, to target renoprotection effectively. We sought to determine the predictive factors of AKI after elective EVAR. METHODS: Overall, 947 patients undergoing elective EVAR between January 2004 and December 2014 were analyzed, using prospectively collected data. Postoperative AKI was defined by serum creatinine change within 48 hr, as per the Kidney Disease Improving Global Outcomes guidelines. Cardiovascular and kidney-disease risk factors were entered in univariate and multivariate analyses to assess influence on AKI development. RESULTS: Overall, 167 (17.6%) patients developed AKI but only 2 patients required dialysis perioperatively. At multivariate analysis, adjusted for established AKI-risk factors and parameters that differed between groups at baseline, preoperative estimated glomerular filtration rate (eGFR; as per the chronic kidney disease epidemiology [CKD] formula); odds ratio (OR): 1.02 (per unit decrease); 95% confidence interval (CI): 1.003-1.041; P = 0.025; and chronic kidney disease (CKD) stage > 2 (OR: 1.28; 95% CI: 1.249-2.531, P = 0.001) were associated with development of AKI. CONCLUSIONS: AKI was common after elective infrarenal EVAR and preoperative renal function appears to be the main factor associated with AKI. Patients with a low eGFR need to be targeted with more aggressive renal protection.

Shear wave elastography imaging of carotid plaques: feasible, reproducible and of clinical potential.

BACKGROUND: Shear Wave Elastography (SWE) imaging is a novel ultrasound technique for quantifying tissue elasticity. Studies have demonstrated that SWE is able to differentiate between diseased and normal tissue in a wide range clinical applications. However its applicability to atherosclerotic carotid disease has not been established. The aim of this study was to assess the feasibility and potential clinical benefit of using SWE imaging for the assessment of carotid plaques. METHODS: Eighty-one patients (mean age 76 years, 51 male) underwent greyscale and SWE imaging. Elasticity was quantified by measuring mean Young's Modulus (YM) within the plaque and within the vessel wall. Echogenicity was assessed using the Gray-Weale classification scale and the greyscale median (GSM). RESULTS: Fifty four plaques with stenosis greater than 30% were assessed. Reproducibility of YM measurements, quantified by the inter-frame coefficient of variation, was 22% within the vessel wall and 19% within the carotid plaque. Correlation with percentage stenosis was significant for plaque YM (p = 0.003), but insignificant for plaque GSM (p = 0.46). Plaques associated with focal neurological symptoms had significantly lower mean YM than plaques in asymptomatic patients (62 kPa vs 88 kPa; p = 0.01). Logistic regression and Receiver Operating Characteristic (ROC) analysis showed improvements in sensitivity and specificity when percentage stenosis was combined with the YM (area under ROC = 0.78). CONCLUSIONS: Our study showed SWE is able to quantify carotid plaque elasticity and provide additional information that may be of clinical benefit to help identify the unstable carotid plaque.

Non-ST elevation myocardial infarction, non-obstructive coronary arteries and severe regional microvascular dysfunction in a patient with dilated cardiomyopathy.

Cardiac magnetic resonance (CMR) imaging with late gadolinium enhancement (LGE) is a key modality in providing localisation and characterisation of myocardial injury in patients diagnosed with myocardial infarction with non-obstructive coronary arteries (MINOCA). We present a case that demonstrates the unique ability of CMR to provide crucial information in instances of uncertainty. A 71-year-old patient with dilated cardiomyopathy (DCM) presented with symptoms suggestive of acute myocardial infarction. The diagnosis of MINOCA was confirmed following coronary angiography. CMR imaging with LGE confirmed presence of apical infarction. Quantitative myocardial perfusion mapping demonstrated severely reduced blood flow in the non-infarcted septal segments proximal to the distal infarcted territory. The precise aetiology of apical infarction remains uncertain and is likely attributed to coronary plaque rupture. However, concomitant severe regional microvascular dysfunction is also appreciated. This is a recognised, but not well described, phenomenon in DCM and may contribute to repetitive ischaemic injury and disease progression.

Leg ischaemia management collaboration (LIMb): study protocol for a prospective cohort study at a single UK centre.

INTRODUCTION: Severe limb ischaemia (SLI) is the end stage of peripheral arterial occlusive disease where the viability of the limb is threatened. Around 25% of patients with SLI will ultimately require a major lower limb amputation, which has a substantial adverse impact on quality of life. A newly established rapid-access vascular limb salvage clinic and modern revascularisation techniques may reduce amputation rate. The aim of this study was to investigate the 12-month amputation rate in a contemporary cohort of patients and compare this to a historical cohort. Secondary aims are to investigate the use of frailty and cognitive assessments, and cardiac MRI in risk-stratifying patients with SLI undergoing intervention and establish a biobank for future biomarker analyses. METHODS AND ANALYSIS: This single-centre prospective cohort study will recruit patients aged 18-110 years presenting with SLI. Those undergoing intervention will be eligible to undergo additional venepuncture (for biomarker analysis) and/or cardiac MRI. Those aged ≥65 years and undergoing intervention will also be eligible to undergo additional frailty and cognitive assessments. Follow-up will be at 12 and 24 months and subsequently via data linkage with NHS Digital to 10 years postrecruitment. Those undergoing cardiac MRI and/or frailty assessments will receive additional follow-up during the first 12 months to investigate for perioperative myocardial infarction and frailty-related outcomes, respectively. A sample size of 420 patients will be required to detect a 10% reduction in amputation rate in comparison to a similar sized historical cohort, with 90% power and 5% type I error rate. Statistical analysis of this comparison will be by adjusted and unadjusted logistic regression analyses. ETHICS AND DISSEMINATION: Ethical approval for this study has been granted by the UK National Research Ethics Service (19/LO/0132). Results will be disseminated to participants via scientific meetings, peer-reviewed medical journals and social media. TRIAL REGISTRATION NUMBER: NCT04027244.

Impact of hospital volume on outcomes following treatment of thoracic aortic aneurysms and type-B dissections.

Previous research suggests an association between hospital volume and outcomes in high-risk surgical pathologies. The association between hospital volume and outcomes in patients with isolated descending thoracic aortic aneurysms (DTAAs) and type-B thoracic aortic dissections (TBADs) is conflicting. We aimed to investigate this in a literature review and meta-analysis. A systematic review of the literature was performed to identify studies reporting mortality and morbidity following repair (elective or emergency) of DTAA and/or TBAD using the Medline and Embase Databases (2000-2015). Hospital volume was assessed based on the number of patients treated per institution: low volume (1-5 cases per year), medium volume (6-10) and high volume (>10). The primary outcome of interest was all-cause mortality during inpatient stay and at 30 days. Eighty-four series of non-dissecting DTAA or TBAD were included in data synthesis (4219 patients; mean age: 62 years; males: 73.5%). For all patients (emergency and elective) undergoing DTAA repair, in-hospital mortality was 8% [95% confidence interval (CI): 6-8%]. Results were not superior in high-volume centres (8 vs 6 vs 11% for high-, medium- and low-volume, respectively). Sub-analyses for emergency and elective repairs showed no significant differences. For TBAD repairs, in the combined population (emergency and elective), results reached borderline significance (P = 0.0475), favouring high-volume centres (6 vs 11 vs 14%), but this association disappeared when emergency and elective repairs were analysed separately. Nine series reported outcomes at 1 year and 5 series followed DTAA and 18 TBAD treatment. No meaningful long-term comparisons were possible due to the lack of data. No significant associations were detected between hospital volume and subsequent mortality following DTAA or TBAD treatment. Data were heterogeneous and long-term results were scarcely reported. A well-designed longitudinal study of sufficient size is required to inform future strategies in this area.

Shear wave elastography assessment of carotid plaque stiffness: in vitro reproducibility study.

This study assessed inter- and intra-observer reproducibility of shear wave elastography (SWE) measurements in vessel phantoms simulating soft and hard carotid plaque under steady and pulsatile flow conditions. Supersonic SWE was used to acquire cine-loop data and quantify Young's modulus in cryogel vessel phantoms. Data were acquired by two observers, each performing three repeat measurements. Mean Young's modulus was quantified within 2-mm regions of interest averaged across five frames and, depending on vessel model and observer, ranged from 28 to 240 kPa. The mean inter-frame coefficient of variation (CV) was 0.13 (range: 0.07-0.18) for observer 1 and 0.14 (range: 0.12-0.16) for observer 2, with mean intra-class correlation coefficients (ICCs) of 0.84 and 0.83, respectively. The mean inter-operator CV was 0.13 (range: 0.08-0.20), with a mean ICC of 0.76 (range: 0.69-0.82). Our findings indicate that SWE can quantify Young's modulus of carotid plaque phantoms with good reproducibility, even in the presence of pulsatile flow.