Factors associated with delays in revascularization in patients with chronic limb-threatening ischaemia: population-based cohort study.

BACKGROUND: Prompt revascularization in patients with chronic limb-threatening ischaemia (CLTI) is important, and recent guidance has suggested that patients should undergo revascularization within 5 days of an emergency admission to hospital. The aim of this cohort study was to identify factors associated with the ability of UK vascular services to meet this standard of care. METHODS: Data on all patients admitted non-electively with CLTI who underwent open or endovascular revascularization between 2016 and 2019 were extracted from the National Vascular Registry. The primary outcome was interval between admission and procedure, analysed as a binary variable (5 days or less, over 5 days). Multivariable Poisson regression was used to examine the relationship between time to revascularization and patient and admission characteristics. RESULTS: The study analysed information on 11 398 patients (5973 open, 5425 endovascular), 50.6 per of whom underwent revascularization within 5 days. The median interval between admission and intervention was 5 (i.q.r. 2-9) days. Patient factors associated with increased risk of delayed revascularization were older age, greater burden of co-morbidity, non-smoking status, presentation with infection and tissue loss, and a Fontaine score of IV. Patients admitted later in the week were less likely undergo revascularization within 5 days than those admitted on Sundays and Mondays (P < 0.001). Delays were slightly worse among patients having open compared with endovascular procedures (P = 0.005) and in hospitals with lower procedure volumes (P < 0.001). CONCLUSION: Several factors were associated with delays in time to revascularization for patients with CLTI in the UK, most notably the weekday of admission, which reflects how services are organized. The results support arguments for vascular units providing revascularization to have the resources for a 7-day service.

Chronic limb-threatening ischaemia (CLTI) is a severe form of peripheral artery disease that reduces blood flow to the legs and can lead to amputation. Between 2016 and 2019, only 50.6 per cent of patients admitted to UK vascular units urgently with CLTI underwent revascularization within 5 days from admission. Several factors were associated with delays in time to revascularization, most notably the weekday of admission, which reflects how services are organized. The results support arguments for vascular units providing revascularization to have resources for a 7-day service.

Long-term survival after endovascular and open repair of unruptured abdominal aortic aneurysm.

BACKGROUND: The aim of this study was to examine patterns of 10-year survival after elective repair of unruptured abdominal aortic aneurysms (AAAs) in different patient groups. METHODS: Patients having open repair or endovascular aneurysm repair (EVAR) in the English National Health Service between January 2006 and December 2015 were identified from Hospital Episode Statistics data. Postoperative survival among patients of different age and Royal College of Surgeons of England (RCS) modified Charlson co-morbidity score profiles were analysed using flexible parametric survival models. The relationship between patient characteristics and risk of rupture after repair was also analysed. RESULTS: Some 37 138 patients underwent elective AAA repair, of which 15 523 were open and 21 615 were endovascular. The 10-year mortality rate was 38·1 per cent for patients aged under 70 years, and the survival trajectories for open repair and EVAR were similar when patients had no RCS-modified Charlson co-morbidity. Among older patients or those with co-morbidity, the 10-year mortality rate rose, exceeding 70 per cent for patients aged 80 years. Mean survival times over 10 years for open repair and EVAR were often similar in subgroups of older and more co-morbid patients, but their survival trajectories became increasingly dissimilar, with open repair showing greater short-term risk within 6 months but lower 10-year mortality rates. The risk of rupture over 9 years was 3·4 per cent for EVAR and 0·9 per cent for open repair, and was weakly associated with patient factors. CONCLUSION: Long-term survival patterns after elective open repair and EVAR for unruptured AAA vary markedly across patients with different age and co-morbidity profiles.

ANTECEDENTES: El objetivo de este artículo fue examinar los patrones de supervivencia a 10 aáos tras reparación electiva de aneurismas de la aorta abdominal sin rotura (abdominal aortic aneurysms, AAA) en diferentes grupos de pacientes. MÉTODOS: Se identificaron pacientes sometidos a reparación abierta (open repair, OR) o reparación endovascular (endovascular aneurysm repair, EVAR) del aneurisma en el Sistema Nacional de Salud Inglés entre enero de 2006 y diciembre de 2015, a partir de los datos del Hospital Episode Statistics. Se analizaron la supervivencia postoperatoria entre los pacientes de diferentes edades y los perfiles de comorbilidad con la puntuación de Charlson modificada del Royal College of Surgeons of England (RCS) utilizando modelos de supervivencia paramétricos flexibles. También se analizó la relación entre las características de los pacientes y el riesgo de rotura tras la reparación. RESULTADOS: Un total de 37.138 pacientes fueron sometidos a reparaciones electivas de AAA, de las cuales 15.523 fueron reparaciones abiertas y 21.615 endovasculares. La mortalidad a los 10 aáos fue del 38% para los pacientes de edad inferior a los 70 aáos, y las curvas de supervivencia de la OR y EVAR fueron similares cuando los pacientes no tenían comorbilidad con el Charlson modificado del RCS. Entre los pacientes de edad avanzada y aquellos pacientes con comorbilidad, la mortalidad a los 10 aáos aumentó, excediendo el 70% para los pacientes de más de 80 aáos de edad. La media de los tiempos de supervivencia superior a 10 aáos para OR y EVAR fueron similares dentro de los subgrupos de pacientes de edad avanzada y más comorbilidad, pero las curvas de supervivencia se hicieron cada vez más diferentes, con la OR mostrando un mayor riesgo a corto plazo en los primeros 6 meses pero tasas de mortalidad a los 10 aáos más bajas. El riesgo de rotura mas allá de los 9 aáos fue 3,4% para EVAR y 0,9% para la reparación abierta, con una débil asociación con los factores inherentes a los pacientes. CONCLUSIÓN: Los patrones de supervivencia a largo plazo tras OR y EVAR electivas para AAA sin rotura varían notablemente entre pacientes con perfiles de edad y comorbilidad diferentes.

Ascorbic acid ameliorates renal injury in a murine model of contrast-induced nephropathy.

BACKGROUND: Contrast induced nephropathy (CIN) is the commonest cause of iatrogenic renal injury and its incidence has increased with the advent of complex endovascular procedures. Evidence suggests that ascorbic acid (AA) has a nephroprotective effect in percutaneous coronary interventions when contrast media are used. A variety of biomarkers (NGAL, NGAL:creatinine, mononuclear cell infiltration, apoptosis and RBP-4) in both the urine and kidney were assayed using a mouse model of CIN in order to determine whether AA can reduce the incidence and/or severity of renal injury. METHODS: Twenty-four BALB/c mice were divided into 4 groups. Three groups were exposed to high doses of contrast media (omnipaque) in a well-established model of CIN, and then treated with low or high dose AA or placebo (saline). CIN severity was determined by measurement of urinary neutrophil gelatinase-associated lipocalin (NGAL):creatinine at specific time intervals. Histological analysis was performed to determine the level of mononuclear inflammatory infiltration as well as immunohistochemistry to determine apoptosis in the glomeruli by staining for activated caspase-3 and DNA nicking (TUNEL assays). Reverse transcriptase PCR (rtPCR) of mRNA transcripts prepared from mRNA extracted from mouse kidneys was also performed for both lipocalin-2 (Lcn2) encoding NGAL and retinol binding protein-6 (RBP4) genes. NGAL protein expression was also confirmed by ELISA analysis of kidney lysates. RESULTS: Urinary NGAL:creatinine ratio was significantly lower at 48 h with a 44% and 62% (204.3µg/mmol versus 533.6µg/mmol, p = 0.049) reduction in the low and high dose AA groups, respectively. The reduced urinary NGAL:creatinine ratio remained low throughout the time period assessed (up to 96 h) in the high dose AA group. In support of the urinary analysis ELISA analysis of NGAL in kidney lysates also showed a 57% reduction (12,576 ng/ml versus 29,393 ng/ml) reduction in the low dose AA group. Immunohistochemistry for apoptosis demonstrated decreased TUNEL and caspase-3 expression in both low and high dose AA groups. CONCLUSIONS: Ascorbic acid reduced the frequency and severity of renal injury in this murine model of CIN. Further work is required to establish whether AA can reduce the incidence of CIN in humans undergoing endovascular procedures.

Weekend effect in non-elective abdominal aortic aneurysm repair.

BACKGROUND: The 'weekend effect' describes the phenomenon where patient outcomes appear worse for those admitted at the weekend. It has been used recently to justify significant changes in UK health policy. Recent evidence has suggested that the effect may be due to a combination of inadequate correction for confounding factors and inaccurate coding. The effects of these factors were investigated in patients with acute abdominal aortic aneurysm (AAA). METHODS: Patients undergoing non-elective AAA repair entered into the UK National Vascular Registry from January 2013 until December 2015 were included in a case-control study. The patients were divided according to whether they were treated during the week (Monday 08.00 hours to Friday 17.00 hours) or at the weekend. Data extracted included demographics, co-morbidities, preoperative medications and baseline blood test results, as well as outcomes. Coding issues were investigated by looking at patients treated for ruptured, symptomatic or asymptomatic AAA within the non-elective cohort. The primary outcome was in-hospital mortality. Secondary outcomes included length of inpatient stay, and cardiac, respiratory and renal complications. RESULTS: The mortality rate appeared to be higher at the weekend (odds ratio (OR) 1·69, 95 per cent c.i. 1·47 to 1·94; P < 0·001), but this effect disappeared when confounding factors and coding issues were corrected for (corrected OR for ruptured AAA 1·09, 0·92 to 1·29; P = 0·330). Differences in outcomes were similar for prolonged length of hospital stay (uncorrected OR 1·21, 95 per cent c.i. 1·06 to 1·37, P = 0·005; corrected OR for ruptured AAA 1·06, 0·91 to 1·10, P = 0·478), and morbidity outcomes. CONCLUSION: After appropriate correction for confounding factors and coding effects, there was no evidence of a significant weekend effect in the treatment of non-elective AAA in the UK.

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.

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.

Successful use of a gastrocnemius flap for an exposed PTFE femorodistal graft: a case report.

Peripheral vascular disease (PVD) is a condition requiring aggressive management to minimise the associated increased morbidity and mortality. Femoro-distal bypass grafting is used in patients with extensive occlusion affecting the crural arteries and poor limb function, but is associated with infection, wound dehiscence and graft exposure. We report a case of a 73-year-old male with history of PVD and occluded ipsilateral femoro-distal bypass graft who underwent limb salvage surgery with a left 6 mm heparin-bonded polytetrafluoroethylene femoro-distal bypass graft in September 2011. He later presented with exposure of the graft over the lateral aspect of the knee following wound dehiscence. During surgery, the exposed portion of the graft was covered by a lateral gastrocnemius muscle flap with an overlying split thickness skin graft. Minor donor site healing problems were noted, but he otherwise made an excellent recovery. While gastrocnemius muscle flaps have been used to cover soft tissue tibial defects secondary to sarcoma and exposed knee joint prostheses, our case adds to the limited literature demonstrating successful salvage of an exposed synthetic graft as a viable alternative to amputation. We therefore recommend prompt referral to plastic services for the management of these complex wounds.

Benefits of remote ischaemic preconditioning in vascular surgery.

OBJECTIVES: Remote ischaemic preconditioning (RIPC) is a physiological mechanism to protect against ischaemia-reperfusion injury. It is a technique in which short pre-emptive periods of ischaemia and reperfusion are thought to protect against ischaemia-reperfusion injury during procedures requiring longer periods of ischaemia. Discovered in the 1980s, its clinical application has been investigated heavily since the first human study in 2006. The aim of this paper was to provide a review of this rapidly expanding subject. METHODS: This study consists of a narrative review of the literature focusing on previous meta-analyses and randomised control trials. RESULTS: Five small randomised trials have been published on the effects of RIPC in vascular surgery. Several randomised trials have been published in cardiac surgery and percutaneous coronary intervention. Meta-analysis shows a significant reduction in troponin levels and biomarkers of renal dysfunction in RIPC patients, but as yet no convincing clinical benefit. The largest powered randomised trial in cardiac surgery showed no benefit to RIPC. CONCLUSIONS: Current trials and therefore meta-analyses are generally underpowered. The technique is physiologically sound but remains lacking in clear clinical benefit.

Real-world performance of the new C3 Gore Excluder stent-graft: 1-year results from the European C3 module of the Global Registry for Endovascular Aortic Treatment (GREAT).

OBJECTIVES: The European C3 module of the Global Registry for Endovascular Aortic Treatment (GREAT) provides "real-world" outcomes for the new C3 Gore Excluder stent-graft, and evaluates the new deployment mechanism. This report presents the 1-year results from 400 patients enrolled in this registry. METHODS: Between August 2010 and December 2012, 400 patients (86.8% male, mean age 73.9 ± 7.8 years) from 13 European sites were enrolled in this registry. Patient demographics, treatment indication, case planning, operative details including repositioning and technical results, and clinical outcome were analyzed. RESULTS: Technical success was achieved in 396/400 (99%) patients. Two patients needed intraoperative open conversion, one for iliac rupture, the second because the stent-graft was pulled down during a cross-over catheterization in an angulated anatomy. Two patients required an unplanned chimney renal stent to treat partial coverage of the left renal artery because of upward displacement of the stent-graft. Graft repositioning occurred in 192/399 (48.1%) patients, most frequently for level readjustment with regard to the renal arteries, and less commonly for contralateral gate reorientation. Final intended position of the stent-graft below the renal arteries was achieved in 96.2% of patients. Thirty-day mortality was two (0.5%) patients. Early reintervention (≤30 days) was required in two (0.5%) patients. Mean follow-up duration was 15.9 ± 8.8 months (range 0-37 months). Late reintervention (>30 days) was required in 26 (6.5%) patients. Estimated freedom from reintervention at 1 year was 95.2% (95% CI 92.3-97%), and at 2 years 91.5% (95% CI 86.8-94.5%). Estimated patient survival at 1 year was 96% (95% CI 93.3-97.6%) and at 2 years 90.6% (95% CI 85.6-93.9%). CONCLUSIONS: Early real-world experience shows that the new C3 delivery system offers advantages in terms of device repositioning resulting in high deployment accuracy. Longer follow-up is required to confirm that this high deployment accuracy results in improved long-term durability.