Effect of frailty on short- and mid-term outcomes in vascular surgical patients.

BACKGROUND: Frailty is a multidimensional vulnerability resulting from age-associated decline. The impact of frailty on outcomes was assessed in a cohort of vascular surgical patients. METHODS: The study included patients aged over 65 years with length of hospital stay (LOS) greater than 2 days, who were admitted to a tertiary vascular unit over a single calendar year. Demographics, mode of admission, diagnosis, mortality, LOS and discharge destination were recorded, as well as a variety of frailty-specific characteristics. The impact of frailty on LOS, discharge destination, survival and readmission rate was assessed using multivariable regression techniques. The ability of the models to predict these outcomes was also assessed. RESULTS: In total, 413 patients of median age 77 years were followed for a median of 18 (range 12-24) months. The in-hospital, 3- and 12-month mortality rates were 3·6, 8·5 and 13·8 per cent respectively. Receiver operating characteristic (ROC) curve analysis revealed that frailty-based regression models were excellent predictors of 12-month mortality (area under the ROC curve (AUC) = 0·81), prolonged LOS (AUC = 0·79) and discharge to a care institution (AUC = 0·84). A simple additive frailty score using six key features retained strong predictive power for 12-month mortality (AUC = 0·83), discharge to a care institution (AUC = 0·78) and prolonged LOS (AUC = 0·74). This frailty score was also strongly associated with readmission rates (P < 0·001). CONCLUSION: Frailty in vascular surgery patients predicts a multiplicity of poorer outcomes. Optimal management should include identification of at-risk patients and treatment of modifiable risk factors.

Incidence and Outcomes of Severe Renal Impairment Following Ruptured Abdominal Aortic Aneurysm Repair.

INTRODUCTION: Acute kidney injury (AKI) following ruptured abdominal aortic aneurysm (rAAA) repair is common and multifactorial. A standard definition of AKI after endovascular repair (EVAR), the Aneurysm Renal Injury Score (ARISe), has been proposed to facilitate standardised reporting and thus improve understanding of this issue. METHODS: Data were collected retrospectively on AKI in a prospectively maintained database of all patients treated for rAAA in a single tertiary referral centre since the availability of routine out of hours emergency EVAR. The ARISe score was used to describe the degree of AKI and factors which correlated with poor renal outcomes were assessed. RESULTS: Two-hundred and five patients were treated between January 2006 and April 2014. Of these, 125 were treated with open repair (OSR) and 80 were treated with EVAR. Severe AKI (defined as ARISe score ≥3) occurred in 36% of patients. After correction for confounders, patients treated with OSR were significantly more likely to develop severe AKI (43% vs. 26%, p = .02). There was no significant difference in preoperative serum creatinine between groups, but increased preoperative serum creatinine was strongly associated with severe AKI postoperatively (p < .001). Age, sex, endograft type, and preoperative CT scanning were not associated with differences in renal outcomes. Clamp position above renal arteries was predictive of severe AKI in patients treated with OSR (p < .01). Patients suffering severe AKI had significantly higher mortality at 30 days and 12 months (28% vs. 5% and 44% vs. 13%, p < .001 for both comparisons). CONCLUSION: Severe AKI is common following successful repair of rAAA. In this large case series of high-risk patients, OSR was associated with significantly higher rates of severe AKI compared with EVAR, despite the increased dose of contrast involved in EVAR and the older age of these patients. In turn, severe AKI was associated with higher mortality rates.

Survival following ruptured abdominal aortic aneurysm before and during the IMPROVE Trial: a single-centre series.

OBJECTIVES: The first large-scale randomised trial (Immediate Management of the Patient with Rupture: Open Versus Endovascular repair [IMPROVE]) for endovascular repair of ruptured abdominal aortic aneurysm (rEVAR) has recently finished recruiting patients. The aim of this study was to examine the impact on survival after rEVAR when the IMPROVE protocol was initiated in a high volume abdominal aortic aneurysm (AAA) centre previously performing rEVAR. METHODS: One hundred and sixty-nine patients requiring emergency infrarenal AAA repair from January 2006 to April 2013 were included. Eighty-four patients were treated before (38 rEVAR, 46 open) and 85 (31 rEVAR, 54 open) were treated during the trial period. A retrospective analysis was performed. RESULTS: Before the trial, there was a significant survival benefit for rEVAR over open repair (90-day mortality 13% vs. 30%, p = .04, difference remained significant up to 2 years postoperatively). This survival benefit was lost after starting randomisation (90-day mortality 35% vs. 33%, p = .93). There was an increase in overall 30-day mortality from 15% to 31% (p = .02), while there was no change for open repair (p = .438). There was a significant decrease in general anaesthetic use (p = .002) for patients treated during the trial. Randomised patients had shorter hospital and intensive treatment unit stays (p = .006 and p = .03 respectively). CONCLUSIONS: The change in survival seen during the IMROVE trial highlights the need for randomised rather than cohort data to eliminate selection bias. These results from a single centre reinforce those recently reported in IMPROVE.

Selection, thirty day outcome and costs for short stay endovascular aortic aneurysm repair (SEVAR).

BACKGROUND: Endovascular aortic aneurysm repair (EVAR) offers the potential for a reduced hospital stay. The aim of this study was to identify patients suitable for short stay EVAR (SEVAR) with a single night in hospital and document their outcome. METHOD: Patients for EVAR were assessed prospectively for SEVAR over a 21-month period using UK Day Surgery Guidelines. Joint anaesthetic and surgical approval were necessary for these patients to be included in this vascular pathway. Patients were admitted on the day of surgery with a designated care protocol for discharge the day after. RESULTS: 101 patients were assessed for SEVAR. 33 (33%) patients met the criteria for SEVAR and 27 of these (81%) were successfully discharged one day post-operatively. Total SEVAR median LOS was one day (IQR = 0) versus four days (IQR = 2) for the standard EVAR group (P < 0.0001) reducing costs from £13,360 (CI = ±1074) to £9844 (CI = ±628). Increased utilisation of SEVAR during the study period led to reduced overall average EVAR costs, £12,102(CI = ±795) to £10,330(CI = ±757). CONCLUSION: SEVAR protocol reduces hospital stay for selected patients. The outcomes from a larger cohort of such patients require further study. This would identify whether SEVAR could be expanded to more patients.

Mid-term outcomes following emergency endovascular aortic aneurysm repair for ruptured abdominal aortic aneurysms.

OBJECTIVE: Emergency Endovascular Aortic Aneurysm Repair (eEVAR) is a rapidly evolving approach to ruptured Abdominal Aortic Aneurysms (rAAA). Yet longer-term outcomes following eEVAR remain unclear. This study compares mid-term outcomes of eEVAR and open rAAA. METHODS: A prospective database for all patients undergoing eEVAR and open rAAA from January 2006 to April 2010 was analysed. Patients were offered eEVAR if anatomically suitable. RESULTS: 52 patients (45 male, median age 78 years (62-92 years), underwent eEVAR, 50 patients (44 male, median age = 71 (62-95 years) underwent open rAAA repair. In-hospital mortalities were 12% (6/52) for eEVAR, 32% (16/50) for open repair. There were five re-interventions (10%) in the eEVAR group. The peri-operative survival benefits of eEVAR over open rAAA repair were maintained at 1 and 2 years post-operatively with open repair demonstrating a two-fold increased risk of mortality (Hazard ratio 2.2, Fisher Exact test, 95% Confidence Interval (CI) 1.108-4.62, p = 0.0122). Overall survival was 81% at 1 year, 73% at 2 years for eEVAR, and 62% at 1 year and 52% at 2 years for open rAAA repair. CONCLUSION: EEVAR is associated with excellent mid-term survival in this cohort. We would recommend eEVAR as the management of choice for rAAA in anatomically suitable patients where local facilities and expertise exist.

Abdominal aortic aneurysm surgery in renal, cardiac and hepatic transplant recipients.

With advancements in transplantation and improved long-term allograft survival, the once rare clinical scenario of an abdominal aortic aneurysm (AAA) in a patient with a functioning allograft has become much more frequent. In transplant recipients, AAA repair has the potential to cause irreversible ischaemic injury to the transplanted organ. Different case series and case reports have mentioned a variety of techniques to offer protection to the transplanted organs during aneurysm repair such as cold perfusion, shunting, temporary surgical bypass and extracorporeal circuits etc. Critical review of these adjuncts seems to suggest that that they do not give any better results than just using a "clamp and go" approach. Endovascular aneurysm repair (EVAR) may offer some advantages for transplant patients who have suitable anatomy for endovascular stent deployment. In addition to these surgical techniques, various aspects of medical management for renal, cardiac and hepatic transplant recipients undergoing AAA repair are discussed.

Association between biomechanical structural stresses of atherosclerotic carotid plaques and subsequent ischaemic cerebrovascular events--a longitudinal in vivo magnetic resonance imaging-based finite element study.

BACKGROUND: High-resolution magnetic resonance (MR) imaging has been used for MR imaging-based structural stress analysis of atherosclerotic plaques. The biomechanical stress profile of stable plaques has been observed to differ from that of unstable plaques; however, the role that structural stresses play in determining plaque vulnerability remains speculative. METHODS: A total of 61 patients with previous history of symptomatic carotid artery disease underwent carotid plaque MR imaging. Plaque components of the index artery such as fibrous tissue, lipid content and plaque haemorrhage (PH) were delineated and used for finite element analysis-based maximum structural stress (M-C Stress) quantification. These patients were followed up for 2 years. The clinical end point was occurrence of an ischaemic cerebrovascular event. The association of the time to the clinical end point with plaque morphology and M-C Stress was analysed. RESULTS: During a median follow-up duration of 514 days, 20% of patients (n = 12) experienced an ischaemic event in the territory of the index carotid artery. Cox regression analysis indicated that M-C Stress (hazard ratio (HR): 12.98 (95% confidence interval (CI): 1.32-26.67, p = 0.02), fibrous cap (FC) disruption (HR: 7.39 (95% CI: 1.61-33.82), p = 0.009) and PH (HR: 5.85 (95% CI: 1.27-26.77), p = 0.02) are associated with the development of subsequent cerebrovascular events. Plaques associated with future events had higher M-C Stress than those which had remained asymptomatic (median (interquartile range, IQR): 330 kPa (229-494) vs. 254 kPa (166-290), p = 0.04). CONCLUSIONS: High biomechanical structural stresses, in addition to FC rupture and PH, are associated with subsequent cerebrovascular events.

Entrapment syndromes.

Entrapment syndromes represent a pathological process that vascular specialists encounter infrequently. However symptomatic patients are often young with impaired quality of life and successful treatment can produce great benefit, making knowledge of these conditions essential. The purpose of this review was to bring together the entrapment syndromes to understand and gain consensus on the aetiology, pathogenesis, diagnosis and modern management of these rare and interesting vascular disorders. This includes entrapment syndromes of the popliteal artery, superior mesenteric artery, coeliac artery, renal vein and iliac vein.

An emergency EVAR service reduces mortality in ruptured abdominal aortic aneurysms.

OBJECTIVES: The aim of this study was to compare all in-hospital mortality for ruptured abdominal aortic aneurysms (rAAAs) before and after the establishment of an emergency EVAR (eEVAR) service. DESIGN AND METHODS: An eEVAR service was established in January 2006, since when all patients presenting with rAAAs have been considered for endovascular repair. Data for all rAAAs presenting between January 2006 and December 2007 was prospectively collected (Group 1). This patient group was compared to those presenting with rAAA between January 2003 and December 2005 when eEVAR was not offered at our institution (Group 2). These records had also been collected prospectively and submitted to the National Vascular Database (NVD). RESULTS: A total of 50 rAAAs (17 eEVAR, 29 open repairs, 4 palliated) presented after the introduction of eEVAR (Group 1) and 71 in the historical Group 2 of which 54 underwent open repair and 17 were palliated. The total in-hospital mortality was significantly lower in Group 1 20% (eEVAR (n=1), 6%: Open (n=5), 17%: palliated (n=4), 100%) when compared to Group 2 54% (Open (n=21), 39%: palliated (n=17), 100%) (p=0.000001). Furthermore similar significant differences were seen in 30-day operative mortalities between the two groups 13% in Group 1 versus 39% in Group 2 (p=0.0003). In addition the proportion of patients who were palliated has significantly decreased (8% Group 1 versus 24% Group 2, p=0.01). CONCLUSIONS: The establishment of an eEVAR service has significantly reduced in-hospital mortality for patients presenting with ruptured abdominal aortic aneurysms.

The development of a VBHOM-based outcome model for lower limb amputation performed for critical ischaemia.

BACKGROUND: VBHOM (Vascular Biochemistry and Haematology Outcome Models) adopts the approach of using a minimum data set to model outcome and has been previously shown to be feasible after index arterial operations. This study attempts to model mortality following lower limb amputation for critical limb ischaemia using the VBHOM concept. METHODS: A binary logistic regression model of risk of mortality was built using National Vascular Database items that contained the complete data required by the model from 269 admissions for lower limb amputation. The subset of NVD data items used were urea, creatinine, sodium, potassium, haemoglobin, white cell count, age on and mode of admission. This model was applied prospectively to a test set of data (n=269), which were not part of the original training set to develop the predictor equation. RESULTS: Outcome following lower limb amputation could be described accurately using the same model. The overall mean predicted risk of mortality was 32%, predicting 86 deaths. Actual number of deaths was 86 (chi(2)=8.05, 8 d.f., p=0.429; no evidence of lack of fit). The model demonstrated adequate discrimination (c-index=0.704). CONCLUSIONS: VBHOM provides a single unified model that allows good prediction of surgical mortality in this high risk group of individuals. It uses a small, simple and objective clinical data set that may also simplify comparative audit within vascular surgery.

Invasive and non-invasive modalities of imaging carotid stenosis.

Despite recent therapeutic advances, acute ischemic complications of atherosclerosis remain the primary cause of morbidity and mortality in Western countries, with carotid atherosclerotic disease one of the major preventable causes of stroke. As the impact of this disease challenges our healthcare systems, we are becoming aware that factors influencing this disease are more complex than previously realized. In current clinical practice, risk stratification relies primarily on evaluation of the degree of luminal stenosis and patient symptomatology. Adequate investigation and optimal imaging are important factors that affect the quality of a carotid endarterectomy (CEA) service and are fundamental to patient selection. Digital subtraction angiography is still perceived as the most accurate imaging modality for carotid stenosis and historically has been the cornerstone of most of the major CEA trials but concerns regarding potential neurological complications have generated substantial interest in non-invasive modalities, such as contrast-enhanced magnetic resonance angiography. The purpose of this review is to give an overview to the vascular specialist of the current imaging modalities in clinical practice to identify patients with carotid stenosis. Advantages and disadvantages of each technique are outlined. Finally, limitations of assessing luminal stenosis in general are discussed. This article will not cover imaging of carotid atheroma morphology, function and other emerging imaging modalities of assessing plaque risk, which look beyond simple luminal measurements.

Five day antibiotic prophylaxis for major lower limb amputation reduces wound infection rates and the length of in-hospital stay.

OBJECTIVE: To compare wound infection, revision rates and hospital stay after major lower limb amputation between patients receiving 24 hours versus 5 days of prophylactic antibiotics. METHODS: The outcomes of a consecutive series of 40 major lower limb amputations in patients receiving a short 24-hour course of combined prophylactic antibiotics (flucloxacillin/vancomycin + gentamicin/ciproxin + metronidazole) were retrospectively analysed. Following this a further consecutive group of 40 major lower limb amputations were studied prospectively following the institution of a 5-day combined regime using the same antibiotics. RESULTS: The 2 groups of patients were similar in terms of demographics, vascular risk factors and level of amputation. The 5-day antibiotic regime led to a significant reduction in wound infection rates (5% vs. 22.5%, P=0.023) and a reduced length of hospital stay (22 vs. 34 days, P=0.001). Revision rates were lower (2.5% vs. 10%) but did not reach statistical significance (P=0.36). More patients in the prospective 5-day antibiotic series were operated on by the vascular trainee. (77.5% vs. 55% P=0.033). CONCLUSIONS: This data supports the use of a prolonged 5-day course of combined antibiotics after major lower limb amputation. This appears to reduce stump infection rates leading to shorter in-hospital stay.

Comparison of the inflammatory burden of truly asymptomatic carotid atheroma with atherosclerotic plaques in patients with asymptomatic carotid stenosis undergoing coronary artery bypass grafting: an ultrasmall superparamagnetic iron oxide enhanced magnetic resonance study.

INTRODUCTION: Inflammation is a recognized risk factor for the vulnerable atherosclerotic plaque. The aim of this study was to explore whether there is a difference in the degree of Magnetic Resonance (MR) defined inflammation using Ultra Small Super-Paramagnetic Iron Oxide (USPIO) particles, within carotid atheroma in completely asymptomatic individuals and the asymptomatic carotid stenosis in a cohort of patients undergoing coronary artery bypass grafting (CABG). METHODS: 10 patients awaiting CABG with asymptomatic carotid disease and 10 completely asymptomatic individuals with no documented coronary artery disease underwent multi-sequence MR imaging before and 36 hours post USPIO infusion. Images were manually segmented into quadrants and signal change in each quadrant, normalised to adjacent muscle signal, was calculated following USPIO administration. RESULTS: The mean percentage of quadrants showing signal loss was 94% in the CABG group, compared to 24% in the completely asymptomatic individuals (p<0.001). The carotid plaques from the CABG patients showed a significant mean signal intensity decrease of 16.4% after USPIO infusion (95% CI 10.6% to 22.2%; p<0.001). The truly asymptomatic plaques showed a mean signal intensity increase (i.e. enhancement) after USPIO infusion of 8.4% (95% CI 2.6% to 14.2%; p=0.007). The mean signal difference between the two groups was 24.9% (95% CI 16.7% to 33.0%; p<0.001). CONCLUSIONS: These findings are consistent with the hypothesis that inflammatory atheroma is a systemic disease. The carotid territory is more likely to take up USPIO if another vascular territory is symptomatic.

Efficacy of TNP on lower limb wounds: a meta-analysis.

This meta-analysis of the three RCTs that have compared topical negative pressure with conventional treatment in patients with lower limb ulcers found that it significantly reduced healing times and increased the number of healed wounds.

Peripheral arterial ischemia by a primary lung tumour invading left atrium.

Peripheral arterial embolism from a malignant tumour is an uncommon manifestation of a neoplasm. Here, we present a case of acute upper limb ischemia due to an embolus originating from primary lung malignancy invading the left atrium.

POSSUM models in open abdominal aortic aneurysm surgery.

OBJECTIVES: This study evaluated the Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM), Portsmouth (P) POSSUM and Vascular (V) POSSUM. The primary aim was to assess the validity of these scoring systems in a population of patients undergoing elective and emergency open AAA repair. The secondary intention was in the event that these equations did not fit all patients with an aneurysm; a new model would be developed and tested using logistic regression from the local data (Cambridge POSSUM). METHODS: POSSUM data items were collected prospectively in a group of 452 patients undergoing elective and emergency open AAA repair over an eight-year period. The operative mortality rates were compared with those predicted by POSSUM, P-POSSUM, V-POSSUM and Cambridge POSSUM. RESULTS: All models except V-POSSUM (physiology only) showed significant lack of fit when predicting mortality after open AAA surgery. It was found that the locally generated single unified model (Cambridge POSSUM) could successfully describe both elective and ruptured AAA mortality with good discrimination (chi(2)=9.24, 7 d.f., p=0.236, c-index=0.880). CONCLUSIONS: POSSUM, V-POSSUM and P-POSSUM may not be robust tools for comparing mortality between populations undergoing elective and emergency open AAA repair as once thought. The development and successful validation of Cambridge POSSUM provides a unified model to describe both elective and emergency AAAs together and should be validated in other geographical settings.

Comparison of risk-scoring methods in predicting the immediate outcome after elective open abdominal aortic aneurysm surgery.

BACKGROUND & OBJECTIVES: The aim of this study was to apply three simple risk - scoring systems to prospectively collected data on all elective open Abdominal Aortic Aneurysm (AAA) operations in the Cambridge Academic Vascular Unit over a 6 - year period (January 1998 to January 2004), to compare their predictive values and to evaluate their validity with respect to prediction of mortality and post-operative complications. METHODS: 204 patients underwent elective open infra-renal AAA repair. Data were prospectively collected and risk assessment scores were calculated for mortality and morbidity according to the Glasgow Aneurysm Score (GAS), VBHOM (Vascular Biochemistry and Haematology Outcome Models) and Estimation of Physiologic Ability and Surgical Stress (E-PASS). RESULTS: The mortality rate was 6.3% (13/204) and 59% (121/204) experienced a post-operative complication (30-day outcome). For GAS, VBHOM and E-PASS the receiver operating characteristics (ROC) curve analysis for prediction of in-hospital mortality showed area under the curve (AUC) of 0.84 (95% confidence interval [CI], 0.76 to 0.92; p<0.0001), 0.82 (95% CI, 0.68 to 0.95; p=0.0001) and 0.92 (95% CI, 0.87 to 0.97; p<0.0001) respectively. There were also significant correlations between post-operative complications and length of hospital stay and each of the three scores, but the correlation was substantially higher in the case of E-PASS. CONCLUSIONS: All three scoring systems accurately predicted the risk of mortality and morbidity in patients undergoing elective open AAA repair. Among these, E-PASS seemed to be the most accurate predictor in this patient population.

The development of an in vitro flow model of human saphenous vein graft intimal hyperplasia.

OBJECTIVE: Although the role of blood flow has been investigated in animal models of intimal hyperplasia, there have been no detailed studies in intact human vein owing to the difficulties in designing a suitable laboratory model. The aim of this study was to develop a flow model of human vein graft intimal hyperplasia. METHODS: Organ cultures of human saphenous vein were exposed to laminar flow by culturing in a closed circulatory system under predetermined conditions of venous and arterial shear stress for 14 days. Following fixation and processing, paraffin sections were immunostained and neointimal thicknesses measured. RESULTS: It was found that arterial flow completely inhibited neointima formation, but venous flow only partly suppressed the response when compared with vein cultured under static conditions. These results are in agreement with previous in vivo studies in a primate graft model, where increased shear stress inhibited intimal proliferation. CONCLUSION: The endothelial cell is believed to be the key mediator of haemodynamic effects which influence smooth muscle cell proliferation, and the flow rig developed in this study offers the potential to study inter-cellular interactions within the intact vessel. Furthermore, this method provides the facility to study the effects of different flow conditions on segments of vein from the same patient. This model has scope for further development and sophistication which may ultimately lead to increasing our understanding of the aetiology of vein graft stenoses, and hence formulation of preventative strategies.

Iatrogenic vascular injuries during arthroplasty of the hip.

Vascular injuries during total hip arthroplasty (THA) are rare but when they occur, have serious consequences. These have traditionally been managed with open exploration and repair, but more recently there has been a trend towards percutaneous endovascular management. We performed a systematic review of the literature to assess if this change in trend has led to an improvement in the overall reported rates of morbidity and mortality during the last 22 years in comparison with the reviews of the literature published previously. We found a total of 61 articles describing 138 vascular injuries in 124 patients. Injuries because of a laceration were the most prevalent (n = 51, 44%) and the most common presenting feature, when recorded, was bleeding (n = 41, 53.3%). Delay in diagnosis was associated with the type of vascular lesion (p < 0.001) and the clinical presentation (p = 0.002). Open exploration and repair was the most common form of management, however percutaneous endovascular intervention was used in one third of the injuries and more constantly during the last 13 years. The main overall reported complications included death (n = 9, 7.3%), amputation (n = 2, 1.6%), and persistent ischaemia (n = 9, 7.3%). When compared with previous reviews there was a similar rate of mortality but lower rates of amputation and permanent disability, especially in patients managed by endovascular strategies.