A Review of UK-based National and International Scientific Meeting Published Abstracts in Response to the Draft NICE Aortic Aneurysm Guidelines.

BACKGROUND: UK National Institute for Health and Care Excellence (NICE) draft clinical guidelines (CG) (2018) regarding aortic aneurysm repair were disputed internationally. We aim to appraise the academic response to the draft CG in terms of quantity and scientific quality by reviewing published conference abstracts from three major national and international, UK meetings. METHODS: Abstracts related to aortic practice from The Vascular Societies Annual Scientific Meeting, British Society for Endovascular Therapy (BSET) & Charing Cross (CX) meetings from 2019 were reviewed for methodology, sample size, data collection period, scientific quality and conclusions that supported or conflicted the draft guideline. RESULTS: A total of 549 abstracts were identified from VSGBI, BSET and CX abstract books of which, 226 (41.2%) were related to aortic practices. Of these, 115 (50.9%) were related to EVAR. Twenty-two of these abstracts (19.1%) were identified as having findings relevant to the draft guidelines. Eighteen (15.7%) were identified as findings that potentially conflict the draft CG and 4 (3.5%) that could support the initial recommendations. Six abstracts (5.2%) made direct reference to or challenged the draft CG. The median data collection period was 4 years. The median sample size was 102 patients. In general, scientific quality was poor, with 82% of selected abstracts were graded at level 2b. CONCLUSION: We have demonstrated a concerted response to the draft NICE clinical guidelines relating to the treatment of abdominal aortic aneurysms at three large scientific meetings. As a result of which and other factors, significant changes were made to the finalized NG156. There is still paucity in evidence regarding the long-term safety and cost-effectiveness of EVAR.

Impact of Frailty on Outcomes in Patients Undergoing Open Abdominal Aortic Aneurysm Repair.

BACKGROUND: Frailty is a global state that does not relate directly to comorbidities and is prevalent among patients with vascular disease. The Clinical Frailty Scale (CFS) is a rapid assessment tool to identify vulnerable and frail patients. In this study, we sought to evaluate whether the preoperative CFS score could be used to independently predict mortality and morbidity after elective open abdominal aortic aneurysm (AAA) repair. METHODS: We retrospectively reviewed our institutional National Vascular Registry (NVR) data to identify all patients who underwent an elective open juxta or infrarenal AAA repair between January 2014 and December 2018. The NVR data set included preoperative risk factors, imaging findings, intraprocedural variables, and postprocedural outcomes. RESULTS: A total of 184 patients were assessed using the CFS before they underwent elective open AAA repair. Among 26 (14%) individuals categorized as vulnerable using the CFS, there was no significant difference in age or preoperative cardiac and respiratory testing compared with nonfrail patients. However, vulnerable patients were significantly more likely to have a longer length of stay (12.2 days vs. 8.8 days, P-value 0.044), suffer from respiratory complications (35% vs. 15%, P-value 0.022) and renal failure (23% vs. 6%, P-value 0.013), or die (23% vs. 2%, P-value 0.0003). The regression analysis identified a vulnerable frailty score to be the only significant predictor of mortality (odds ratio = 36.7, P < 0.001), all other factors were not shown to be independent predictors. CONCLUSIONS: The CFS is a practical tool for assessing preoperative frailty among patients undergoing elective open AAA repair and can be used to predict mortality and morbidity after surgery.

The Transposed Femoral Vein Fistula: The Native Choice in Desperate Vascular Access.

BACKGROUND: This is a review of our experience in creating transposed femoral vein (TFV) fistulas and some of the lessons we have learnt while performing this challenging procedure over the last 5 years. METHODS: This is retrospective review of patients who underwent TFV fistula formation between January 2013 and December 2017. RESULTS: Fifteen patients underwent FV fistula formation with 4 cases being excluded from analysis. Median follow-up was 1.17 years (interquartile range 0.19-3.59 years). Primary and primary-assisted patency rates were 75% and 100% at 6 months, respectively, and 66.7% and 100% at 1 year. CONCLUSIONS: Our patient group showed good fistula patency at 1 year and did not experience any incidence of ischemic steal syndrome. We believe this to be due to careful preoperative patient assessment and meticulous surgical technique. Our experience suggests that such procedures should be performed by surgeons with vascular expertise wherever possible to reduce the incidence of complications.

Role of compression therapy in pathophysiology of the venous system in lower limbs.

The management of varicose veins and their sequelae are estimated to cost the NHS approximately £400-600 m annually. Along with interventional procedures, the National Institute for Health and Care Excellence (NICE) also recommends the use of compression therapy. With the vast array of different compression therapies available, prescribing the correct method can be challenging, with patients receiving incorrect compression being a matter of concern. This review summarises the key principles underpinning the management of these patients with particular emphasis on the pathophysiology and different classes of compression.

Simultaneous Iliac Vein Bovine Pericardial Patch Venoplasty and Creation of PTFE Lower Limb Arteriovenous Fistula Graft for Rescue Vascular Access.

BACKGROUND: We present a case of external iliac vein patch venoplasty to accommodate rescue vascular access via a polytetrafluoroethylene loop arteriovenous fistula graft (AVG) for a patient with multiple central venous stenoses. METHODS: A 35-year-old female with anti-glomerular basement membrane antibody disease required rescue vascular access for hemodialysis. Repeated occlusion and/or thrombosis of long-term central venous access cannulae, to facilitate dialysis, had caused stenosis of brachiocephalic veins: right external iliac vein and occlusion of the left common iliac vein. A previous right brachiobasilic fistula had occluded within 1 year. No other upper limb options for arteriovenous fistula (AVF) were available. A right external iliac vein bovine patch angioplasty concurrently with a polytetrafluoroethylene AV graft between common femoral artery and common femoral vein was performed to restore venous patency and allow rescue dialysis access. RESULTS: At 3-year follow-up, the fistula remains widely patent with 2 L/min flow rates and no recurrent stenosis to the treated iliac vein. She has not required any further surgical or interventional radiological procedures to maintain fistula or central venous patency. Central venous stenosis or occlusion is common for patients requiring dialysis, especially those with multiple previous long-term central venous cannulations. If restriction of outflow is present, AVF may fail. Venous patch angioplasty in these cases is a successful technique, allowing AVF formation and long-term patency. CONCLUSION: Central venous stenosis can be treated successfully with patch venoplasty to accommodate AVF/AVG formation for rescue vascular access; this is a potentially lifesaving intervention for patients requiring dialysis.

Increased levels of symmetric dimethyl-arginine are associated with all-cause mortality in patients with symptomatic peripheral arterial disease.

OBJECTIVE: Recent interest has focused on the role of the methyl-arginines, endogenous inhibitors of nitric oxide, as adverse prognostic indicators. To date, few studies have assessed the role of symmetric dimethyl-arginine (SDMA) in patients with peripheral arterial disease. We aimed to determine the relationship, if any, of SDMA to all-cause mortality and disease severity as assessed by the ankle-brachial index (ABI) in patients with symptomatic peripheral arterial disease (PAD). METHODS: In 238 patients with symptomatic PAD and an ABI of <0.8, l-arginine, asymmetric dimethyl-arginine (ADMA) and SDMA levels were measured by hydrophilic-interaction liquid chromatography-electrospray tandem mass spectrometry. RESULTS: The median follow-up was 6 years 11 months (interquartile range [IQR], 4 years 5 months-7 years 10 months). SDMA and ADMA levels were higher in those who died compared with those who survived (0.51 [IQR, 0.44-0.66] µmol/L vs 0.46 [IQR, 0.39-0.55] µmol/L, P ≤ .001; and 0.48 [IQR, 0.41-0.55] µmol/L vs 0.45 [IQR, 0.39-0.50] µmol/L, P = .007, respectively). l-arginine levels were similar in the two groups. On multivariate analysis, SDMA and ADMA as continuous variable were significantly associated with mortality (P = .001). For SDMA and ADMA, the highest compared with the lowest quartile levels were significantly associated with mortality (SDMA: hazard ratio, 3.855; 95% confidence interval, 1.625-9.143; P = .002; ADMA: hazard ratio, 2.277; 95% confidence interval, 1.114-4.654; P = .024). ADMA and SDMA showed a negative correlation with severity of PAD as assessed by ABI (r = -0.236, N = 216, P < .001; r = -0.209, N = 208, P = .002, respectively). CONCLUSIONS: The novel finding of this study is that SDMA levels were predictive of all cause-mortality and correlated with disease severity. Further studies should assess the role of nitric oxide donors in patients with high levels of SDMA.

N-terminal pro-B-type Natriuretic Peptides' Prognostic Utility Is Overestimated in Meta-analyses Using Study-specific Optimal Diagnostic Thresholds.

BACKGROUND: N-terminal fragment B-type natriuretic peptide (NT-proBNP) prognostic utility is commonly determined post hoc by identifying a single optimal discrimination threshold tailored to the individual study population. The authors aimed to determine how using these study-specific post hoc thresholds impacts meta-analysis results. METHODS: The authors conducted a systematic review of studies reporting the ability of preoperative NT-proBNP measurements to predict the composite outcome of all-cause mortality and nonfatal myocardial infarction at 30 days after noncardiac surgery. Individual patient-level data NT-proBNP thresholds were determined using two different methodologies. First, a single combined NT-proBNP threshold was determined for the entire cohort of patients, and a meta-analysis conducted using this single threshold. Second, study-specific thresholds were determined for each individual study, with meta-analysis being conducted using these study-specific thresholds. RESULTS: The authors obtained individual patient data from 14 studies (n = 2,196). Using a single NT-proBNP cohort threshold, the odds ratio (OR) associated with an increased NT-proBNP measurement was 3.43 (95% CI, 2.08 to 5.64). Using individual study-specific thresholds, the OR associated with an increased NT-proBNP measurement was 6.45 (95% CI, 3.98 to 10.46). In smaller studies (<100 patients) a single cohort threshold was associated with an OR of 5.4 (95% CI, 2.27 to 12.84) as compared with an OR of 14.38 (95% CI, 6.08 to 34.01) for study-specific thresholds. CONCLUSIONS: Post hoc identification of study-specific prognostic biomarker thresholds artificially maximizes biomarker predictive power, resulting in an amplification or overestimation during meta-analysis of these results. This effect is accentuated in small studies.

Pseudoaneurysm of the sural artery: a rare complication of lower limb angioplasty.

INTRODUCTION: Percutaneous transluminal angioplasty (PTA) is a common therapeutic option for the treatment of peripheral vascular disease. Pseudoaneurysm at the puncture site is a well-documented complication in patients. CASE PRESENTATION: This case report describes a patient who presented to hospital several days following a left superficial femoral and popliteal artery PTA with lower limb pain and swelling. The working diagnosis included a deep vein thrombosis based on the Wells criteria. However, a combination of a duplex scan and computed tomography angiography confirmed a clinically rare occurrence of pseudoaneurysm of the sural artery, a branch of the popliteal artery. This was managed successfully with a thrombin injection, leading to complete resolution of the patient's symptoms. CONCLUSION: This case highlights the importance of the technical aspects of performing a PTA. We believe that the guide-wire position was not confirmed to be completely in the popliteal artery upon inflation of the balloon.

Comparison of two bicycle handlebar trauma cases.

Handlebar injury is an uncommon mechanism of blunt injury with a recognised risk of injury to groin vasculature. We describe two cases involving bicycle handlebar injury to the groin and their different respective outcomes. Patient A sustained a significant limb-threatening injury following significant arterial and venous disruption. Surgical intervention was able to restore arterial flow via interpositional vein graft, while venous injuries were ligated. As a result, the patient was discharged with a viable limb and a non-disabling swelling from venous pathology. Patient B, of identical age, also sustained a bicycle handlebar injury to the groin but without the need for surgical intervention. Active observation and the use of repeat imaging suggested spontaneous cessation of any minor arterial bleeding; the patient made a rapid recovery and was discharged soon thereafter. These cases highlight the variability in outcome stemming from this injury mechanism and that early recognition is vital for limb viability.

Postoperative B-type natriuretic peptide for prediction of major cardiac events in patients undergoing noncardiac surgery: systematic review and individual patient meta-analysis.

BACKGROUND: It is unclear whether postoperative B-type natriuretic peptides (i.e., BNP and N-terminal proBNP) can predict cardiovascular complications in noncardiac surgery. METHODS: The authors undertook a systematic review and individual patient data meta-analysis to determine whether postoperative BNPs predict postoperative cardiovascular complications at 30 and 180 days or more. RESULTS: The authors identified 18 eligible studies (n = 2,051). For the primary outcome of 30-day mortality or nonfatal myocardial infarction, BNP of 245 pg/ml had an area under the curve of 0.71 (95% CI, 0.64-0.78), and N-terminal proBNP of 718 pg/ml had an area under the curve of 0.80 (95% CI, 0.77-0.84). These thresholds independently predicted 30-day mortality or nonfatal myocardial infarction (adjusted odds ratio [AOR] 4.5; 95% CI, 2.74-7.4; P < 0.001), mortality (AOR, 4.2; 95% CI, 2.29-7.69; P < 0.001), cardiac mortality (AOR, 9.4; 95% CI, 0.32-254.34; P < 0.001), and cardiac failure (AOR, 18.5; 95% CI, 4.55-75.29; P < 0.001). For greater than or equal to 180-day outcomes, natriuretic peptides independently predicted mortality or nonfatal myocardial infarction (AOR, 3.3; 95% CI, 2.58-4.3; P < 0.001), mortality (AOR, 2.2; 95% CI, 1.67-86; P < 0.001), cardiac mortality (AOR, 2.1; 95% CI, 0.05-1,385.17; P < 0.001), and cardiac failure (AOR, 3.5; 95% CI, 1.0-9.34; P = 0.022). Patients with BNP values of 0-250, greater than 250-400, and greater than 400 pg/ml suffered the primary outcome at a rate of 6.6, 15.7, and 29.5%, respectively. Patients with N-terminal proBNP values of 0-300, greater than 300-900, and greater than 900 pg/ml suffered the primary outcome at a rate of 1.8, 8.7, and 27%, respectively. CONCLUSIONS: Increased postoperative BNPs are independently associated with adverse cardiac events after noncardiac surgery.

Popliteal arterial aneurysms.

Aneurysms are associated with significant complications if not diagnosed and managed appropriately. Popliteal arterial aneurysms are the most common peripheral aneurysm, and can cause pain, nerve compression, ischaemia and limb loss. Vascular surgery is an emerging specialty under the remit of general surgery, with the primary objectives of preventing death and limb loss. This article summarises the epidemiology, investigation and management of popliteal arterial aneurysms for vascular and non-vascular trainees.

Acute cerebellar ischaemic stroke secondary to arterial thoracic outlet syndrome.

Arterial thoracic outlet syndrome comprises a collection of symptoms due to compression of the neurovascular structures of the thoracic outlet. Cervical ribs are rare congenital abnormalities that are a cause of thoracic outlet syndrome, leading to upper limb complications depending on the compressed structure. Management tends to be surgical in the form of rib resection. We report a case of arterial thoracic outlet syndrome secondary to a cervical rib in a 45-year-old male who presented with left-sided cerebellar stroke caused by subclavian artery thrombosis. Medical management in the form of anticoagulation was favoured. Oedema in the recent peri-infarct zone due to reperfusion may have caused compression of the fourth ventricle due to anatomical proximity, with the risk of further neurological compromise and coning. At follow-up appointments, the patient had no residual upper limb or neurological symptoms.

Carotid artery disease: knowing the numbers.

Ischaemic stroke and transient ischaemic attack are of particular interest to the vascular surgeon as over one-third of all strokes are caused by thromboembolism from a stenotic carotid artery, making carotid artery stenosis the leading cause of stroke. If detected early, stenosis can be managed medically, surgically or endovascularly. However, treatment decisions depend on the timing of the transient ischaemic attack and the degree of stenosis, and must be balanced against procedural risk. This article discusses the evidence outlining the epidemiology, measurement and surgical management of carotid artery stenosis that inform national guidelines. Vascular and non-vascular trainees should understand these guidelines because of the potentially debilitating or fatal consequences of untreated carotid stenosis.

Femoral artery aneurysms.

True aneurysms are dilatations of blood vessels, bounded by the tunica intima, tunica media and tunica adventitia. False aneurysms are dilatations bounded by the tunica adventitia only, and are more common than true aneurysms. The femoral artery is the second most common location for true peripheral artery aneurysms, and the most common site of false aneurysms. If left untreated, devastating complications can occur, such as infection, rupture, ischaemia and limb loss. Femoral artery aneurysms should be identified early and managed by a vascular specialist. This article outlines the evidence for the epidemiology, investigation and management of femoral artery aneurysms.

Abdominal aortic aneurysms.

Vascular surgery is a relatively new surgical sub-speciality in the UK, with treatment of abdominal aortic aneurysms forming a substantial proportion of the emergency and elective caseload. This article summarises the guidance from the National Institute of Health and Care Excellence and the European Society for Vascular Surgery that outlines the epidemiology, diagnosis and management of abdominal aortic aneurysms. This is important for both vascular and non-vascular trainees to understand because of the critical nature of the disease, which can cause catastrophic haemorrhage, limb loss and mortality. However, if discovered in time, abdominal aortic aneurysms are a very treatable condition.

Extensive subcutaneous emphysema from scalp to lower limbs in a 44-year old.

A 44-year-old man was admitted after being found suspended by his ankles from a bridge for 5 days. The events leading to it was not clearly known initially. On examination, the patient was hypotensive and hypothermic, airway was oedematous and both lower limbs were mottled with dusky feet. Both foot pulses were impalpable, with prolonged capillary refill time and sensation barely present. Doppler signals were not heard in the feet, but groin pulses and popliteal signals were present. On CT, the patient had bilateral pneumothoraxes, extensive subcutaneous emphysema throughout the body from the subcutaneous tissue of the scalp to both lower limbs and pneumomediastinum and pneumoperitoneum. CT angiogram showed opacification up to proximal crural vessels and absence beyond. After multispeciality input and optimisation of his physiology, he underwent bilateral below knee amputations as they were non-salvageable.