One-year follow-up after active aortic aneurysm sac treatment with shape memory polymer devices during endovascular aneurysm repair.

OBJECTIVE: To determine the safety and efficacy of treating abdominal aortic aneurysm (AAA) sacs with polyurethane shape memory polymer (SMP) devices during endovascular aneurysm repair (EVAR), using a technique to fully treat the target lumen after endograft placement (aortic flow volume minus the endograft volume). SMP devices self-expand in the sac to form a porous scaffold that supports thrombosis throughout its structure. METHODS: Two identical prospective, multicenter, single-arm studies were conducted in New Zealand and the Netherlands. The study population was adult candidates for elective EVAR of an infrarenal AAA (diameter of ≥55 mm in men and ≥50 mm in women). Key exclusion criteria were an inability to adequately seal a common iliac artery aneurysm, patent sac feeding vessels of >4 mm, and a target lumen volume of <20 mL or >135 mL. Target lumen volumes were estimated by subtracting endograft volumes from preprocedural imaging-based flow lumen volumes. SMP devices were delivered immediately after endograft deployment via a 6F sheath jailed in a bowed position in the sac. The primary efficacy end point was technical success, defined as filling the actual target lumen volume with fully expanded SMP at the completion of the procedure. Secondary efficacy outcome measures during follow-up were the change in sac volume and diameter, rate of type II endoleak and type I or III endoleaks, and the rate of open repair and related reinterventions, with data collection at 30 days, 6 months, and 1 year (to date). Baseline sac volumes and diameters for change in sac size analyses were determined from 30-day imaging studies. Baseline and follow-up volumes were normalized by subtraction of the endograft volume. RESULTS: Of 34 patients treated with SMP devices and followed per protocol, 33 patients were evaluable at 1 year. Preprocedural aneurysm volume was 181.4 mL (95% confidence interval [CI], 150.7-212.1 mL) and preprocedural aneurysm diameter was 60.8 mm (95% CI, 57.8-63.9 mm). The target lumen volume was 56.3 mL (95% CI, 46.9-65.8 mL). Technical success was 100% and the ratio of SMP fully expanded volume to estimated target lumen volume was 1.4 ± 0.3. Baseline normalized sac volume and diameter were 140.7 mL (95% CI, 126.6-154.9 mL) and 61.0 mm (95% CI, 59.7-62.3 mm). The adjusted mean percentage change in normalized volume at 1 year was -28.8% (95% CI, -35.3 to -22.3%; P < .001). The adjusted mean change in sac diameter at 1 year was -5.9 mm (95% CI, -7.5 to -4.4 mm; P < .001). At 1 year, 81.8% of patients (95% CI, 64.5%-93.0%) achieved a ≥10% decrease in normalized volume and 57.6% of patients (95% CI, 39.2%-74.5%) achieved a ≥5 mm decrease in diameter. No device- or study procedure-related major adverse events occurred through 1 year after the procedure. CONCLUSIONS: Treatment of AAA sacs with SMP devices during EVAR resulted in significant sac volume and diameter regression at 1 year with an acceptable safety profile in this prospective study.

Active aortic aneurysm sac treatment with shape memory polymer during endovascular aneurysm repair.

Preprocedural image analysis and intraprocedural techniques to fully treat infrarenal abdominal aortic aneurysm sacs outside of the endograft with shape memory polymer (SMP) devices during endovascular aneurysm repair were developed. Prospective, multicenter, single-arm studies were performed. SMP is a porous, self-expanding polyurethane polymer material. Target lumen volumes (aortic flow lumen volume minus endograft volume) were estimated from the preprocedural imaging studies and endograft dimensions. SMP was delivered immediately after endograft deployment via a 6F sheath jailed in a bowed position in the sac. Technical success was achieved in all cases, defined as implanting enough fully expanded SMP volume to treat the actual target lumen volume.

Clinical feasibility of diffuse speckle contrast analysis for real-time tissue perfusion monitoring.

BACKGROUND: Adequate tissue perfusion is an important prognostic and diagnostic factor during the management of lower limb peripheral arterial disease. Convenient and real-time tissue perfusion monitoring remains an elusive challenge. METHODS: Tissue perfusion on the dorsal and plantar surfaces of both feet of 20 participants was measured during and after cuff-induced ischemia using a novel 4-channel, laser-based perfusion monitoring device based on diffuse speckle contrast analysis technology (Pedra sensors). Participants were free of significant peripheral arterial disease. Transcutaneous partial pressure of oxygen (TcPO2) measurements were recorded concurrently for comparison. RESULTS: Pedra sensors detected perfusion changes significantly more quickly than TcPO2 sensors. One minute after induced ischemia, the mean percent changes from baseline values (before ischemia) were -22.7±32.0% and -3.1±8.8% (P<0.001) for Pedra and TcPO2 sensors, respectively. One minute into induced ischemia, Pedra sensors had reached 50.5% of the 5-minute ischemia reading whereas TcPO2 sensors had reached only 18.6% of the 5-minute reading (P=0.046). Pedra sensors reported hyperemia immediately after cuff release with a mean percent change from baseline of 143.8±122.3%/173.4±121.8% on the dorsal/plantar surfaces while TcPO2 measurements were still recording negative changes at that time (-26.7±19.4%/-18.6±24.4% dorsal/plantar). Pedra sensors exhibited markedly lower interobserver and intraobserver variability than TcPO2 sensors. CONCLUSIONS: A device based on diffuse speckle contrast analysis reported tissue perfusion in real time. Cuff-induced ischemia and hyperemia following cuff release were rapidly and consistently detected on both the dorsal and plantar surfaces of the foot. Diffuse speckle contrast analysis may have value for real-time perfusion monitoring during angiography procedures.

A pilot multi-centre prospective randomised controlled trial of RECELL for the treatment of venous leg ulcers.

Venous leg ulcers (VLUs) have a significant impact on approximately 3% of the adult population worldwide, with a mean NHS wound care cost of £7600 per VLU over 12 months. The standard care for VLUs is compression therapy, with a significant number of ulcers failing to heal with this treatment, especially with wound size being a risk factor for non-healing. This multicentre, prospective, randomised trial evaluated the safety and effectiveness of autologous skin cell suspension (ASCS) combined with compression therapy compared with standard compression alone (Control) for the treatment of VLUs. Incidence of complete wound closure at 14 weeks, donor site closure, pain, Health-Related Quality of Life (HRQoL), satisfaction, and safety were assessed in 52 patients. At Week 14, VLUs treated with ASCS + compression had a statistically greater decrease in ulcer area compared with the Control (8.94 cm2 versus 1.23 cm2 , P = .0143). This finding was largely driven by ulcers >10 to 80 cm2 in size, as these ulcers had a higher mean percentage of reepithelialization at 14 weeks (ASCS + compression: 69.97% and Control: 11.07%, P = .0480). Additionally, subjects treated with ASCS + compression experienced a decrease in pain and an increase in HRQoL compared with the Control. This study indicates that application of ASCS + compression accelerates healing in large venous ulcers.

Vascular Positron Emission Tomography and Restenosis in Symptomatic Peripheral Arterial Disease: A Prospective Clinical Study.

OBJECTIVES: This study determined whether in vivo positron emission tomography (PET) of arterial inflammation (18F-fluorodeoxyglucose [18F-FDG]) or microcalcification (18F-sodium fluoride [18F-NaF]) could predict restenosis following PTA. BACKGROUND: Restenosis following lower limb percutaneous transluminal angioplasty (PTA) is common, unpredictable, and challenging to treat. Currently, it is impossible to predict which patient will suffer from restenosis following angioplasty. METHODS: In this prospective observational cohort study, 50 patients with symptomatic peripheral arterial disease underwent 18F-FDG and 18F-NaF PET/computed tomography (CT) imaging of the superficial femoral artery before and 6 weeks after angioplasty. The primary outcome was arterial restenosis at 12 months. RESULTS: Forty subjects completed the study protocol with 14 patients (35%) reaching the primary outcome of restenosis. The baseline activities of femoral arterial inflammation (18F-FDG tissue-to-background ratio [TBR] 2.43 [interquartile range (IQR): 2.29 to 2.61] vs. 1.63 [IQR: 1.52 to 1.78]; p < 0.001) and microcalcification (18F-NaF TBR 2.61 [IQR: 2.50 to 2.77] vs. 1.69 [IQR: 1.54 to 1.77]; p < 0.001) were higher in patients who developed restenosis. The predictive value of both 18F-FDG (cut-off TBRmax value of 1.98) and 18F-NaF (cut-off TBRmax value of 2.11) uptake demonstrated excellent discrimination in predicting 1-year restenosis (Kaplan Meier estimator, log-rank p < 0.001). CONCLUSIONS: Baseline and persistent femoral arterial inflammation and micro-calcification are associated with restenosis following lower limb PTA. For the first time, we describe a method of identifying complex metabolically active plaques and patients at risk of restenosis that has the potential to select patients for intervention and to serve as a biomarker to test novel interventions to prevent restenosis.

The Impact of Operating Surgeon Experience, Supervised Trainee vs. Trained Surgeon, in Vascular Surgery Procedures: A Systematic Review and Meta-Analysis.

OBJECTIVE: The operative caseload of a surgeon has a positive influence on post-operative outcomes. For surgical trainees to progress effectively, maximising operating room exposure is essential, vascular surgery being no exception. Our aim was to ascertain the impact of supervised trainee led vs. expert surgeon led procedures on post-operative outcomes, across three commonly performed vascular operations. METHODS: A literature search was undertaken using the MEDLINE, Web of Science, and Cochrane databases up to 1 January 2018. Studies reporting outcomes following major lower limb amputation, fistula formation, or carotid endarterectomy (CEA) that involved a direct comparison between supervised trainee and experts were included, with odds ratios (ORs) calculated. Primary outcomes varied depending on the specific procedure: amputations-rate of amputation revision within 30 days; fistula formation-primary patency; CEA-stroke rate at 30 days. Meta-analysis with the Mantel-Haenszel method was performed for each outcome. RESULTS: Sixteen studies were included in the final review. Overall, trainees accounted for a third of all procedures analysed (n = 2 421/7 017; 34.5%). Only one study was identified that described rates of amputation revision, precluding any further analysis. Four studies on fistula formation were included, showing no significant difference in outcomes between trainees and experts in primary patency (OR 1.68, 95% confidence interval [CI] 0.42-6.75). Nine studies were identified reporting post-CEA stroke rates, also demonstrating no difference between trainees and experts (OR 0.89, 95% CI 0.59-1.32). CONCLUSION: In select cases, with appropriate training and suitable experience, supervised trainees can perform surgical procedures without any detriment to patient care. To ensure high standards for patients of the future, supported training programmes are essential for today's surgical trainees.

Association Between Abdominal Visceral Artery Calcification and All-Cause Mortality-A Computerized Tomography Imaging-Based Longitudinal Follow-Up Study.

Arterial calcification in different arterial beds has been observed to be an independent predictor of mortality. The association of abdominal visceral artery calcium with all-cause mortality remains unexplored. Patients who had undergone contrast-enhanced computerized tomography (CT) imaging for routine assessment of peripheral arterial disease (PAD) were considered for this study. A novel calcium score (abdominal visceral arteries calcium [AVAC]) for the abdominal visceral arteries (celiac axis, superior mesenteric, and renal arteries) was calculated using a modified Agatston score. Cumulative AVAC was defined as sum total of the calcium score of above individual arteries. The primary outcome was all-cause mortality. The association of AVAC with all-cause mortality was assessed. Of the 134 consecutive patients, 89 were included for analysis. Median follow-up duration was 72 (47-91) months since CT imaging; 35 (39%) patients died during this period. Hypertension and cumulative AVAC score had a significant association with all-cause mortality (P < .05). Cumulative visceral abdominal artery calcification is associated with all-cause mortality in patients with PAD. Future prospective studies are warranted to investigate this relationship in PAD and other patient cohorts.

Editor's Choice - Mid-term Migration and Device Failure Following Endovascular Aneurysm Sealing with the Nellix Stent Graft System - a Single Centre Experience.

OBJECTIVE: Endovascular aneurysm sealing (EVAS) with the Nellix stent graft system is a novel concept in the management of abdominal aortic aneurysm (AAA) that aims to reduce the prevalence of all endoleaks following endovascular repair. There are few data describing the longer-term durability of this approach. The aim was to report the longer-term outcomes following EVAS in a single centre. METHODS: This is a retrospective review of all patients that underwent Nellix at Cambridge University Hospitals Foundation Trust. Factors that are described as device failure include secondary sac rupture, graft explantation, further surgical procedures for Type 1 endoleak, or major migration of the stent grafts with pressurisation of the aortic sac. RESULTS: A total of 161 patients have been treated with Nellix. The indications included primary AAA (n = 115), ruptured AAA (n = 4), salvage of other aortic grafts (n = 18), primary iliac aneurysm (n = 6), and chimney EVAS (ChEVAS) for pararenal AAA (n = 18). In total there have been 42 graft failures in patients treated with EVAS for primary AAA. The 4 year freedom from graft failure was 42% in patients treated for primary AAA. Failures mostly occurred more than 2 years post-Nellix implant. There were eight secondary sac ruptures (incidence 2.4 per 100 person years) and there have been 14 graft explants. CONCLUSIONS: Failure of aneurysm sealing following treatment with Nellix has been more common than anticipated and can cause aortic rupture. Post-operative surveillance of Nellix stent grafts is crucial to identify features of failure.

18F-FDG Uptake on PET/CT in Symptomatic versus Asymptomatic Carotid Disease: a Meta-Analysis.

INTRODUCTION: The role of positron emission tomography (PET)/computed tomography (CT) in the determination of inflammation in arterial disease is not well defined. This can provide information about arterial wall inflammation in atherosclerotic disease, and may give insight into plaque stability. The aim of this review was to perform a meta-analysis of PET/CT with 18F-FDG (fluorodeoxyglucose) uptake in symptomatic and asymptomatic carotid artery disease. METHODS: This was a systematic review, following PRISMA guidelines, which interrogated the MEDLINE database from January 2001 to May 2017. The search combined the terms, "inflammation", "FDG", and "stroke". The search criteria included all types of studies, with a primary outcome of the degree of arterial vascular inflammation determined by 18F-FDG uptake. Analysis involved an inverse weighted variance estimate of pooled data, using a random effects model. RESULTS: A total of 14 articles (539 patients) were included in the meta-analysis. Comparing carotid artery 18F-FDG uptake in symptomatic versus asymptomatic disease yielded a standard mean difference of 0.94 (95% CI 0.58-1.130; p < .0001; I2 = 65%). CONCLUSIONS: PET/CT using 18F-FDG can demonstrate carotid plaque inflammation, and is a marker of symptomatic disease. Further studies are required to understand the clinical implication of PET/CT as a risk prediction tool.

Lower limb arterial calcification (LLAC) scores in patients with symptomatic peripheral arterial disease are associated with increased cardiac mortality and morbidity.

AIMS: The association of coronary arterial calcification with cardiovascular morbidity and mortality is well-recognized. Lower limb arterial calcification (LLAC) is common in PAD but its impact on subsequent health is poorly described. We aimed to determine the association between a LLAC score and subsequent cardiovascular events in patients with symptomatic peripheral arterial disease (PAD). METHODS: LLAC scoring, and the established Bollinger score, were derived from a database of unenhanced CT scans, from patients presenting with symptomatic PAD. We determined the association between these scores outcomes. The primary outcome was combined cardiac mortality and morbidity (CM/M) with a secondary outcome of all-cause mortality. RESULTS: 220 patients (66% male; median age 69 years) were included with follow-up for a median 46 [IQR 31-64] months. Median total LLAC scores were higher in those patients suffering a primary outcome (6831 vs. 1652; p = 0.012). Diabetes mellitus (p = 0.039), ischaemic heart disease (p = 0.028), chronic kidney disease (p = 0.026) and all-cause mortality (p = 0.012) were more common in patients in the highest quartile of LLAC scores. The area under the curve of the receiver operator curve for the LLAC score was greater (0.929: 95% CI [0.884-0.974]) than for the Bollinger score (0.824: 95% CI [0.758-0.890]) for the primary outcome. A LLAC score ≥ 4400 had the best diagnostic accuracy to determine the outcome measure. CONCLUSION: This is the largest study to investigate links between lower limb arterial calcification and cardiovascular events in symptomatic PAD. We describe a straightforward, reproducible, CT-derived measure of calcification-the LLAC score.

Mechanochemical Ablation for Treatment of Truncal Venous Insufficiency: A Review of the Current Literature.

Mechanochemical ablation (MOCA) is a nonthermal nontumescent technique used in the treatment of superficial venous disease. This review analyzed the available data on the efficacy and safety of MOCA. A systematic literature search was performed. Of 101 studies identified, 14 were suitable for inclusion. The studies were found to be heterogeneous in design, and the quality of evidence was found to be low or very low. MOCA was demonstrated to be effective in the short-term with minimal complications. Consensus guidelines and definitions of reporting outcome measures must be standardized to allow comparison with other techniques.

Magnetic Resonance Imaging-Based Assessment of Carotid Atheroma: a Comparative Study of Patients with and without Coronary Artery Disease.

BACKGROUND: Functional magnetic resonance (MR) imaging of atheroma using contrast media enables assessment of the systemic severity of atherosclerosis in different arterial beds. Whether black-blood imaging has similar ability remains widely unexplored. In this study, we evaluate whether black-blood imaging can differentiate carotid plaques of patients with and without coronary artery disease (CAD) in terms of morphological and biomechanical features of plaque vulnerability, thereby allowing assessment of the systemic severity nature of atherosclerosis in different arterial beds. METHODS: Forty-one patients with CAD and 59 patients without CAD underwent carotid black-blood MR imaging. Plaque components were segmented to identify large lipid core (LC), ruptured fibrous cap (FC), and plaque hemorrhage (PH). These segmented contours of plaque components were used to quantify maximum structural biomechanical stress. RESULTS: Patients with CAD and without CAD had comparable demographics and comorbidities. Both groups had comparable prevalence of morphological features of plaque vulnerability (FC rupture, 44% versus 41%, P = .90; PH, 58% versus 47%, P = .78; large LC, 32% versus 47%, P = .17), respectively. The maximum biomechanical stress was not significantly different for both groups (241versus 278 kPa, P = .14) respectively. CONCLUSIONS: Black-blood imaging does not appear to have the ability to differentiate between the morphological and biomechanical features of plaque vulnerability when comparing patients with and without symptomatic atherosclerotic disease in a distant arterial territory such as coronary artery.

Endovascular Aneurysm Sealing: Early and Midterm Results From the EVAS FORWARD Global Registry.

PURPOSE: To report the early and 12-month results of a global registry of patients treated with endovascular aneurysm sealing (EVAS) for abdominal aortic aneurysms (AAAs). METHODS: The EVAS FORWARD Global Registry was a postmarket, multicenter, open-label, single-arm registry that enrolled 277 patients (mean age 75 years; 228 men) treated with the Nellix EVAS system for nonruptured AAAs at 18 sites over a 1-year period. The cohort had challenging aortic anatomy, with 17% having a proximal aortic neck length <10 mm, 8% a neck angulation >60°, and 20% an iliac diameter >25 mm. Baseline and follow-up computed tomography images were assessed by an independent core laboratory, and major adverse events were reviewed by an independent safety committee. RESULTS: Three patients died within 30 days of the procedure (none device-related). There were 13 endoleaks recorded in this time frame: 8 type Ia, 1 type Ib, and 5 type II. Root cause analysis demonstrated that the majority of type Ia endoleaks were due to technical error (low device placement and underfilling of the endobags). Between 30 days and 1 year, there were 4 new type Ia endoleaks; all were treated. There was also 1 type III endoleak between a Nellix device and a distal extension limb. At 1 year, the persistent endoleak rate was 0.7% (1 type Ia and 1 type II). The Kaplan-Meier estimates of freedom from types I and II endoleak at 12-month follow-up were 96% and 98%, respectively. The estimate of freedom from open conversion (n=7) was 98% at 12 months and the rate of freedom from any reintervention was 92%. The need for secondary intervention was associated with aortic morphology; for patients meeting the requirements of the instructions for use (IFU), the freedom from reintervention at 12 months was 98% compared with 86% when the implant was outside the IFU (p=0.009). At 1 year, the estimates of freedom from aortic-related and all-cause mortality were 98% and 95%, respectively. CONCLUSION: The EVAS FORWARD Global Registry documents the 12-month outcome of EVAS in an unselected group of patients with challenging aortic morphology. The results at present appear acceptable with regard to perioperative outcomes and complications. The type II endoleak rate is low. The place of EVAS in the armamentarium of techniques to treat AAAs will be defined by durability data in the longer term.

Imaging After Nellix Endovascular Aneurysm Sealing: A Consensus Document.

Endovascular aneurysm sealing (EVAS) using the Nellix system is a new and different method of abdominal aortic aneurysm repair. Normal postoperative imaging has unique appearances that change with time; complications also have different and specific appearances. This consensus document on the imaging findings after Nellix EVAS is based on the collective experience of the sites involved in the Nellix EVAS Global Forward Registry and the US Investigational Device Exemption Trial. The normal findings on computed tomography (CT), duplex ultrasound, magnetic resonance imaging, and plain radiography are described. With time, endobag appearances change on CT due to contrast migration to the margins of the hydrogel polymer within the endobag. Air within the endobag also has unique appearances that change over time. Among the complications after Nellix EVAS, type I endoleak usually presents as a curvilinear area of flow between the endobag and aortic wall, while type II endoleak is typically small and usually occurs where an aortic branch artery lies adjacent to an irregular aortic blood lumen that is not completely filled by the endobag. Procedural aortic injury is an uncommon but important complication that occurs as a result of overfilling of the endobags during Nellix EVAS. The optimum imaging surveillance algorithm after Nellix EVAS has yet to be defined but is largely CT-based, especially in the first year postprocedure. However, duplex ultrasound also appears to be a sensitive modality in identifying normal appearances and complications.

Premorbid function, comorbidity, and frailty predict outcomes after ruptured abdominal aortic aneurysm repair.

OBJECTIVE: Strategies to improve outcomes for patients with ruptured abdominal aortic aneurysm (rAAA) are becoming more evident. The aging population, however, continues to make the decision to intervene often difficult, especially given that traditional risk models do not reflect issues of aging and frailty. This study aimed to integrate measures of function alongside comorbidity- and frailty-specific factors to determine outcome. METHODS: Patients treated for a rAAA between January 2006 and April 2014 were assessed. Demographics, mortality, and requirement for care after discharge as well as a variety of measures of function (physical, social, and psychological) and comorbidity were recorded. The primary outcome was 1-year mortality. Outcome models were generated using multivariate logistic regression and were compared with models of vascular frailty and AAA-related outcome. RESULTS: Of 184 patients treated, 108 (59%) underwent an open surgical repair. The overall 30-day and 1-year mortality were 21.5% and 31.4%, respectively, with an overall median hospital length of stay of 13 days (interquartile range, 6-27 days). An optimal logistic regression model for 12-month mortality used Katz score, Charlson score, number of admission medicines, visual impairment, hearing impairment, hemoglobin level, and statin use as predictors, achieving an area under the receiver operating characteristic curve of 0.84. CONCLUSIONS: This novel rAAA model incorporating function and comorbidity offers good predictive power for mortality. It is quick to calculate and may ultimately become helpful for both counseling and selection of patients and comparative audit at a time when outcome in patients with rAAA increasingly comes under the spotlight.

Use of ultrasmall superparamagnetic iron oxide particles for imaging carotid atherosclerosis.

Based on the results of histopathological studies, inflammation within atherosclerotic tissue is now widely accepted as a key determinant of the disease process. Conventional imaging methods can highlight the location and degree of luminal stenosis but not the inflammatory activity of the plaque. Iron oxide-based MRI contrast media particularly ultrasmall supermagnetic particles of iron oxide have shown potential in assessing atheromatous plaque inflammation and in determining efficacy of antiatherosclerosis pharmacological treatments. In this paper, we review current data on the use of ultrasmall superparamagnetic iron oxides in atherosclerosis imaging with focus on ferumoxtran-10 and ferumoxytol. The basic chemistry, pharmacokinetics and dynamics, potential applications, limitations and future perspectives of these contrast media nanoparticles are discussed.

Acute Limb Ischemia in Pediatric Population Secondary to Peripheral Vascular Cannulation: Literature Review and Recommendations.

INTRODUCTION: In this article, we discuss published literature on the management of pediatric patients with acute limb ischemia and also present our center's experience. RESULTS: Literature review suggests that in the absence of imminent risk of limb loss, noninterventional management with anticoagulants and systemic thrombolysis is preferable and associated with better clinical outcomes than surgery such as reduced per operative morbidity and mortality. In selected more severe cases, surgery may be required. We propose an algorithm for improved clinical outcomes based on the published literature and the American College of Chest Physicians' recommendations for antithrombotic management in the pediatric population. CONCLUSION: Literature review suggests an inverse relationship between age and surgical success, particularly in preschool pediatric population. Conservative management as a preliminary strategy seems most beneficial. It is hoped that the proposed intercalated algorithm of medical and surgical management of these patients can further improve clinical outcomes.

Contrast Medium-Induced Acute Kidney Injury.

Contrast medium-induced acute kidney injury (CI-AKI) is a predominant cause of hospital-acquired renal insufficiency. With an increasing number of contrast medium-enhanced radiological procedures being performed in a rapidly increasing ageing population in the Western world, it is imperative that more attention is given to understand the aetiology of CI-AKI to devise novel diagnostic methods and to formulate effective prophylactic and therapeutic regimens to reduce its incidence and its associated morbidity and mortality. This article presents high-yield information on the above-mentioned aspects of CI-AKI, primarily based on results of randomised controlled trials, meta-analyses, systematic reviews and international consensus guidelines.

Atherectomy for peripheral arterial disease.

BACKGROUND: Symptomatic peripheral arterial disease may be treated by a number of options including exercise therapy, angioplasty, stenting and bypass surgery. Atherectomy is an alternative technique where atheroma is excised by a rotating cutting blade. OBJECTIVES: The objective of this review was to analyse randomised controlled trials comparing atherectomy against any established treatment for peripheral arterial disease in order to evaluate the effectiveness of atherectomy. SEARCH METHODS: The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2013) and CENTRAL (2013, Issue 10). Trials databases were searched for details of ongoing or unpublished studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing atherectomy and other established treatments were selected for inclusion. All participants had symptomatic peripheral arterial disease with either claudication or critical limb ischaemia and evidence of lower limb arterial disease. DATA COLLECTION AND ANALYSIS: Two review authors (GA and CT) screened studies for inclusion, extracted data and assessed the quality of the trials. Any disagreements were resolved through discussion. MAIN RESULTS: Four trials were included with a total of 220 participants (118 treated with atherectomy, 102 treated with balloon angioplasty) and 259 treated vessels (129 treated with atherectomy, 130 treated with balloon angioplasty). All studies compared atherectomy with angioplasty. No study was properly powered or assessors blinded to the procedures and there was a high risk of selection, attrition, detection and reporting biases.The estimated risk of success was similar between the treatment modalities although the confidence interval (CI) was compatible with small benefits of either treatment for the initial procedural success rate (Mantel-Haenszel risk ratio (RR) 0.92, 95% CI 0.44 to 1.91, P = 0.82), patency at six months (Mantel-Haenszel RR 0.92, 95% CI 0.51 to 1.66, P = 0.79) and patency at 12 months (Mantel-Haenszel RR 1.17, 95% CI 0.72 to 1.90, P = 0.53) following the procedure. The reduction in all-cause mortality with atherectomy was most likely due to an unexpectedly high mortality in the balloon angioplasty group in one of the two trials that reported mortality (Mantel-Haenszel RR 0.24, 95% CI 0.06 to 0.91, P = 0.04). Cardiovascular events were not reported in any study. There was a reduction in the rate of bailout stenting following atherectomy (Mantel-Haenszel RR 0.45, 95% CI 0.24 to 0.84, P = 0.01), and balloon inflation pressures were lower following atherectomy (mean difference -2.73 mmHg, 95% CI -3.48 to -1.98, P < 0.00001). Complications such as embolisation and vessel dissection were reported in two trials indicating more embolisations in the atherectomy group and more vessel dissections in the angioplasty group, but the data could not be pooled. From the limited data available, there was no clear evidence of different rates of adverse events between the atherectomy and balloon angioplasty groups for target vessel revascularisation and above-knee amputation. Quality of life and clinical and symptomatic outcomes such as walking distance or symptom relief were not reported in the studies. AUTHORS' CONCLUSIONS: This review has identified poor quality evidence to support atherectomy as an alternative to balloon angioplasty in maintaining primary patency at any time interval. There was no evidence for superiority of atherectomy over angioplasty on any outcome, and distal embolisation was not reported in all trials of atherectomy. Properly powered trials are recommended.