Significant Peripheral Arterial Disease Research Articles

Peripheral artery disease recognition, diagnosis, and management in general practice in the Republic of Ireland and England: an online survey.

Peripheral artery disease (PAD) is common and associated with future cardiovascular events. PAD is underdiagnosed, which limits opportunities to address secondary prevention of cardiovascular disease. It is unknown how closely guidelines for detection of PAD are followed in primary care. To survey GPs' attitudes to diagnosis and follow-up of patients with PAD. Online survey of GPs in England and the Republic of Ireland (RoI). GPs' approaches to management of PAD were assessed using likelihood ratings (scales of 0-10) and discrete questions. Findings were summarised as proportions, or median and interquartile ranges (IQR). In total, 111 responses were analysed; 68 (61%) from England and 43 (39%) from the RoI. Considering a hypothetical patient at risk of PAD, likelihood of GPs enquiring about PAD symptoms (leg pains: 3/10 or erectile dysfunction: 2/10) was low. GPs in the RoI compared with GPs in England more often examined the heart (10/10 versus 7/10) or carotid vessels (5/10 versus 1/10). Lower limb pulses were palpated in response to symptoms or signs of PAD. In England 25% of practitioners, and in the RoI 55% of practitioners, reported that they do not measure ankle-brachial index (ABI). Currently, detection of PAD is generally triggered by 'classical' leg claudication symptoms, while known vascular risk factors appear to elicit little consideration. ABI measurement is not performed by many practitioners, suggesting that a proportion of vascular referrals must be based on history and examination findings alone. Opportunities to recognise PAD are missed.

Does the Mode of Anaesthesia (General or Regional) Affect Survival and Complications Following Femoropopliteal and Femorodistal Bypass?

Femoropopliteal and femorodistal bypasses are indicated in the management of severe claudication or critical limb ischaemia. The choice of type of anaesthesia between generalanaesthesia (GA) and regionalanaesthesia (RA; epidural/spinal) has remained controversial. The study aimed tocompare the rates of graft failure, perioperative mortality,and other major complications (including graft failure) associated with GA versus RA for lower limb bypass revascularisation in patients presenting with significant peripheral arterial disease. All patients who had femoropopliteal and femorodistal bypass at the vascular unit of Colchester Hospital between January 2016 and September 2018 were included. The primary outcome measure was survival, and secondary outcome measures were respiratory, wound, cardiac, and graft failure complications. Technical success was defined as asuccessful operation with demonstrated graft patency at discharge and up to 30 days of follow-up. Secondary outcome measures included respiratory, wound, and cardiac complications. Statistical analysis included descriptive statistics and tests of association using chi-square for graft failure outcomes and the Mann-Whitney U test for the length of stay. All analyses were done at a 5% level of significance. There were 139 patients identified during the study period who fulfilled the inclusion criteria, of which 127 had complete records. The overall mortality and morbidity in this study were 1.6% and 14.229%, respectively. The proportion of patients who had ischaemic heart disease is almost threefold amongst those who had failed bypass compared to the successful bypass group (33.3% versus 11.9%, p = 0.018). A total of 65 patients received GA and 62 patients underwent RA; there were no significant differences in baseline preoperative comorbidities, postoperative mortality and complications, and length of stay. The majority (84%) of the patients who had RA had combined spinal and epidural (CSE) anaesthesia. The overall mortality and morbidity in this study were 1.6% and 14.2%, respectively. The proportion of patients with graft failure was 14.5% for GA versus 13.8% for RA (p = 0.914); there was no significant difference for conduit type, quality of vein conduit, the prevalence of heart failureand postoperative hypotensive episodes, redo-surgery, and major amputation, and length of stay (GA: 5.0, RA: 6.0, p = 0.854) did not differ significantly between the two groups.The proportion of patients who had ischaemic heart disease is almost threefold amongst those who had failed bypass compared to the successful bypass group (33.3% versus 11.9%, p = 0.018). The mode of anaesthesia, GA or the use of CSE RA in approximately half of the patients, did not influence survival, respiratory, cardiac, wound, graft failure, or length of stay in this study.There was a relationship between the presence of cardiac comorbidity and bypass failure, indicating a need for a standard care protocol to further optimise cardiac perioperative care to improve outcomes.

Effect of iron deficiency on skeletal muscle metabolism in heart failure with preserved ejection fraction

Abstract Background Iron deficiency (ID) is suggested to be one of the key comorbidities contributing to heart failure with preserved ejection fraction (HFpEF) and concomitant exercise intolerance, possibly by inducing systemic inflammation and microvascular dysfunction (MVD). ID is associated with poorer prognosis in HFpEF, but its exact impact on exercise capacity in HFpEF patients remains to be further investigated. Purpose To evaluate the effect of ID on exercise capacity in HFpEF patients by assessing skeletal muscle metabolism. Additionally, to assess the association between ID and MVD in HFpEF patients. Methods This prospective study included patients diagnosed with HFpEF according to the ESC Heart Failure 2016 guidelines between January 2018 and May 2021. Patients were excluded if they were of childbearing potential, had any iron supplementation 6 months or chemotherapy 1 year prior to inclusion, were known with significant peripheral artery disease, or had any contraindication for phosphorus-magnetic resonance spectroscopy (31P-MRS). Iron status was defined as absolute ID (serum ferritin <100μg/L), relative ID (serum ferritin 100–299μg/L and transferrin saturation <20%), and no ID. Skeletal muscle oxidative capacity of the upper leg was evaluated by determining phosphocreatine (PCr) recovery kinetics with 31P-MRS in the vastus lateralis muscle after isometric knee extension exercise. Microvascular function was assessed as heat-induced skin hyperemia using laser-Doppler flowmetry. Clinical data up to 6 months prior to or after inclusion was used. Results Twenty-four HFpEF patients without ID and 18 with ID were included, including 14 patients with absolute ID. Clinical characteristics of patients without ID and with ID were comparable: median age 74 [69–79] vs. 77 [69–81] years, 13 (54%) vs. 14 (78%) were females, and 20 (83%) vs. 16 (89%) had a history of hypertension (Table 1). Both groups showed similar halftime of PCr recovery after exercise (29.2 [22.8–33.2] vs. 27.0 [21.1–31.4] seconds, p=0.416), and similar skin hyperaemic flow increase (1142 [576–2247] vs. 1023 [574–1511] %, p=0.554). These measures of skeletal muscle metabolism and microvascular function were not correlated. In a subset of patients (11 without ID and 13 with ID), elevated high-sensitive C-reactive protein (hsCRP) was correlated with PCr recovery halftime in those with ID (R2 0.565, p=0.003). This correlation was not found in patients without ID (R2 0.119, p=0.300) in the original data (Figure 1), but was found after removal of a prominent outlier (R2 0.654, p=0.005). Conclusion HFpEF patients without ID showed comparable skeletal muscle oxidative capacity and microvascular skin hyperaemia compared to HFpEF patients with ID. Post-hoc analysis suggests that inflammation affects skeletal muscle metabolism in HFpEF patients, possibly regardless of ID. Future studies on the effects of ID and inflammation on cellular metabolism could suggest therapeutic targets in HFpEF. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): This study was funded by Vifor Pharma. The funder had no influence on the study results.

S2128 Rectal Ischemia in a Patient After EVAR and COVID-19

Introduction: Ischemic proctitis is a rare, but serious, source of GI bleeding as mortality rates approach 20-40%. Patients for which ischemia should be considered are those with previous surgery, older patients, and those with known peripheral arterial disease. Case Description/Methods: 80-year-old male with history of hyperlipidemia and hypertension presented to the hospital for shortness of breath secondary to COVID-19 pneumonia. His respiratory status continued to decline requiring mechanical ventilation and ICU admission. During his admission, he was found to have acute left lower extremity ischemia requiring stenting of his superficial femoral artery and abdominal endovascular aneurysm repair (EVAR). He was started on anticoagulation with heparin infusion. His hospital course was further complicated large volume maroon-colored stools concerning for lower GI bleed. Colonoscopy was performed at the bedside to further evaluate. In the rectum, there were circumferential ulcerations with inflammation and exudate, extending 10 cm from the anal verge. Biopsies were consistent with rectal ischemia. Unfortunately, soon after the patient developed worsening acidosis requiring CVVHD and increased requirement for pressor support. The family ultimately decided to pursue comfort care and the patient was palliatively extubated (Figure). Discussion: Rectal ischemia is rare as the rectum has blood supply from the inferior mesenteric and bilateral iliac arteries. In our patient, during EVAR graft repair, the IMA was occluded by a stent, the iliac arteries however, remained intact providing the middle rectal and pudendal artery as sources of collateral blood supply. It is hypothesized that a hypercoagulable state caused by COVID-19 infection coupled with ongoing hypotension in the setting of critical illness in our patient with significant peripheral arterial disease led to the low flow state in bilateral iliac arteries causing ischemic proctitis. Rectal ischemia must be considered early in patients because, while most cases of lower GI bleeding can be treated conservatively, rectal ischemia is an indication for prompt surgical intervention. Surgical intervention is required to remove necrotic bowel and potential sources of infection causing septic shock.Figure 1.: Circumferential rectal ischemia as seen by colonoscopy.

CAN WE USE NEUROTROPHINS FOR CAROTID PLAQUE VULNERABILITY ASSESSMENT – IVUS VH CASE SERIES

Objective: Defining carotid atherosclerotic plaque vulnerability is problematic. The combination between imaging and biomarkers may be of practical significance for future assessment of extracranial stenoses. Brain derived neurotrophic factor (BDNF) and neuronal growth factor (NGF) are neurotrophins. There are some studies, which suggest association between endothelial dysfunction and circulating BDNF, impaired neurotrophins’ endothelial secretion in atherosclerosis and correlation between BDNF concentration and Agatson’s score, as well as coronary plaque vulnerability. Neurotrophins also play important role in cerebral functioning. Their role in carotid atherosclerosis is not known. Design and method: We share the results of 13 patients with angiographically significant carotid stenoses. The plaque morphology was assessed with IVUS VH and we evaluated their serum BDNF and NGF concertation. All the patients were without coronary artery disease or fully revascularized, as well as without significant or symptomatic peripheral artery disease. We had the results for BDNF and NGF from a reference group without any atherosclerotic disease. SPSS (IBM) was used for the statistical analysis, p < 0.05, CI 95%. Results: The patients with significant carotid stenoses had lower mean BDNF values than the reference group. There was correlation between luminal diameter and BDNF (p = 0.049; r = -0.605), total Ca2+ area (mm2) and BDNF (r = 0.681, p = 0.021), Proximal Ca2+area and BDNF (p = 0.007, r = 0.784), Necrotic core % in the proximal plaque area and NGF (r = 0.891, p = 0.001) Conclusions: BDNF concentration was negatively correlated with the maximal values for minimal luminal diameter and positively with total Ca2+ plaque area, t.i. with plaque stability. We found positive correlation with necrotic core % and NGF values. This case series is small, and a much larger sample is needed to define precisely any association. Nevertheless, this is a beginning of the study for the potential role of neurotrophins in carotid plaque morphology, either by their local endothelial secretion or by modification of their central secretion from the altered cerebral hemodynamics. They may be both markers and factors for carotid plaque vulnerability. The work was partially funded by a Research GRANT 2020 number 133 from Medical University Sofia, Bulgaria.

Distal venous arterialisation for ‘no-option’ chronic limb-threatening ischaemia

Chronic limb-threatening ischaemia (CLTI), defined as significant peripheral arterial disease causing ischaemic rest pain and/or tissue loss, is associated with a high amputation and mortality rate. Avoiding amputation in CLTI is crucial and restoration of blood flow is usually achieved using endovascular or open surgical revascularisation. However, significant occlusion of the distal limb vasculature may result in ‘no option’ CLTI, where there are no available target vessels for angioplasty or bypass. An emerging procedure to treat patients with ‘no option’ CLTI is distal venous arterialisation (DVA). This involves using the distal venous system as a conduit for arterial blood to revascularise the lower limb. This report describes a patient presenting with ‘no option’ CLTI who underwent limb-saving treatment with DVA. The case highlights how worsening clinical outcomes may occur despite technical success of DVA. It also emphasises complications of the procedure. Finally, the evidence base surrounding DVA for CLTI is examined.

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

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. 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 (TcPO<inf>2</inf>) measurements were recorded concurrently for comparison. Pedra sensors detected perfusion changes significantly more quickly than TcPO<inf>2</inf> 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 TcPO<inf>2</inf> sensors, respectively. One minute into induced ischemia, Pedra sensors had reached 50.5% of the 5-minute ischemia reading whereas TcPO<inf>2</inf> 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 TcPO<inf>2</inf> 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 TcPO<inf>2</inf> sensors. 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.

Utility and safety of the MANTA device for access site closure after removal of the mechanical hemodynamic support device Impella on the intensive care unit

Abstract Background The percutaneously implanted hemodynamic mechanical support devices Impella are commonly used in patients at risk for or with cardiogenic shock (CS). Impella removal after hemodynamic stabilization on the intensive care unit (ICU) remains a major challenge and is prone to high rates of bleeding and vascular complications. Purpose It is unknown if the use of the novel large-bore access closure device MANTA® is safe and facilitates access management compared to manual compression. Methods Between January 2017 and December 2020, 172 CS patients were treated with an Impella® device at our centre. Of those, in 89 patients the Impella® was removed on the ICU and access site management occurred with either MANTA® device or manual compression. The criteria for MANTA® 14 french device deployment included: (i) femoral artery Diameter &amp;gt;6mm and (ii) absence of significant peripheral arterial disease (PAD). Bleeding and vascular access site complications were assessed and adjudicated according to the Valve Academic Research Consortium-2 (VARC-2) criteria. Results Among the 89 included patients, Impella® removal was performed using the MANTA® device in 31 cases and manual compression in 58 cases. Mean age was 66±11 years, and 50 (56.2%) patients had a CS classified as Society for Cardiovascular Angiography and Interventions (SCAI) D or higher due to myocardial infarction. Median support time was 40 (IQR 24; 69) hours. Baseline characteristics are displayed in Table 1. Immediate haemostasis was more frequently achieved by MANTA® device compared to manual compression (p=0.034). Moreover, we observed significantly less overall (2 (6.5%) vs. 22 (37.9%), p=0.001) and minor bleedings (1 (3.2%) vs. 15 (25.9%), p=0.006) with the MANTA® device when compared to manual compression. Of note, there were no significant differences in vascular complications between the two groups (Table 2). Conclusions In patients requiring Impella® support and residing on ICU, the MANTA® device, compared to standard of care manual compression, seems to be a safe and effective option for access site management, especially with regards to the reduction of bleeding events. However, physicians should carefully assess the vascular anatomy and degree of calcification prior to deployment of the MANTA® device. Nevertheless, more prospective data is necessary for evaluating the optimal access closure among CS patients treated with a percutaneously implanted Impella® device. Funding Acknowledgement Type of funding sources: None. Table 1. Baseline demographicsTable 2. Outcomes

Pushing the limits for interventional treatment of aortic valve stenosis.

As we approach 20years of clinical experience with transcatheter aortic valve replacement (TAVR), avast portfolio of high-quality clinical data has accumulated, confirming the safety and efficacy of TAVR across the entire spectrum of surgical risk. Although many aspects of this innovative therapy have been thoroughly studied, several challenges remain. As TAVR is expanding to include younger low-risk patients, with longer life expectancy, one major unsolved issue is represented by transcatheter heart valve (THV) durability, since robust THV durability data are currently limited to approximately 5-6years. Additionally, steric interactions between THV components and coronary ostia may render coronary access particularly difficult, and thus personalized decisions regarding THV type and implanting techniques are of paramount importance to secure future coronary access. Since bicuspid aortic valve (BAV) stenosis may be associated with unfavorable anatomic factors, it has represented an exclusion criterion in major randomized TAVR trials. Albeit promising data are available from multicenter registries, results of specifically designed randomized trials are eagerly needed to inform use of TAVR for BAV stenosis. Although valve-in-valve (ViV) TAVR has emerged as an effective treatment option for degenerated aortic bioprostheses, ViV procedures are associated with specific risks, which mandated the development of specific techniques aimed at reducing the occurrence of periprocedural adverse events. Despite the transfemoral approach represents the access of choice for TAVR, asignificant proportion of patients have significant peripheral artery disease and alternative vascular access routes have been increasingly evaluated with encouraging data regarding their safety and feasibility.

Investigation of early signs of peripheral artery disease in patients with schizophrenia using toe-brachial index

IntroductionPatients with schizophrenia have a reduced life expectancy compared to the general population, and cardiovascular diseases contribute to this. Peripheral arterial disease (PAD) is associated with excess all-cause mortality and specifically with cardiovascular morbidity and mortality. The risk factors for PAD, such as diabetes, smoking, hypertension, dyslipidaemia and obesity, are more common among patients with schizophrenia which could contribute to a possibly higher prevalence of PAD among patients with schizophrenia.ObjectivesTo investigate PAD utilizing toe brachial index (TBI) in a population of patients diagnosed with schizophrenia with the purpose of establishing prevalence rates amongst newly diagnosed as well as more chronic patients.MethodsA cross-sectional study of patients with schizophrenia (ICD10-diagnosis F20 or F25) with a study population of 57 patients diagnosed with schizophrenia within the last 2 years, psychiatric healthy controls matched by age, sex and smoking status and 142 patients with a schizophrenia diagnosis more than 10 years ago. The primary outcome is TBI in patients with schizophrenia stratified to the two subpopulations. The TBI will be calculated from the arm and toe systolic pressures. The toe pressures were measured using photoplethysmography (SysToe®, Atys Medical).ResultsNo results are available yet. The cohort will be described by age, sex, smoking status, body fat percentage and physical comorbidities. The TBI of the two subpopulations will be compared with psychiatrically healthy controls using paired t-tests if data is normally distributed. If transformation is unsuitable, Wilcoxon test will be carried out instead.ConclusionsNo results are available yet. Results will be presented at the EPA’s congress 2021.DisclosureNo significant relationships.

Epidemiological aspects of carotid disease

Carotid artery disease most commonly manifests as atherosclerotic carotid artery disease, which can lead to an ischemic stroke. Our aim was to present the epidemiological aspects of carotid disease and to demonstrate the association of risk factors with carotid disease. For that purpose, we prospectively followed 1031 patients at the University Clinic for Cardiology in Skopje, who were examined for carotid stenosis and its correlation with risk factors such as hypertension, smoking, hyperlipidemia, diabetes, obesity and peripheral arterial disease. Results: Carotid stenosis was correlated with arterial hypertension, hyperlipidemia, diabetes mellitus, smoking, and peripheral arterial disease. Conclusions: Our study found that conventional risk factors such as hypertension, diabetes, smoking, and dyslipidemia were independently associated with significant carotid artery disease and peripheral arterial disease.

A Functional Chopart’s Amputation With Tendon Transfers

Generally, forefoot osteomyelitis is treated with a reliable level of amputation such as at the transmetatarsal level. However, when osteomyelitis extends proximal to the midfoot and presents with significant peripheral arterial disease, it is generally thought that the next best functional level of amputation is a transtibial amputation. This is mostly in part due to the high failure rate of Chopart's amputations which can be attributed to poor biomechanical and tendon balancing. We present a new technique of tendon balancing with a Chopart's amputation that results in optimized ambulatory function, durable soft tissue envelope of amputation, and successful limb salvage.

Kidney dysfunction and short term all-cause mortality after transcatheter aortic valve implantation

BackgroundAcute kidney injury (AKI) after transcatheter aortic valve implantation (TAVI) has been associated with worse outcomes. However, the impact on outcome of AKI in TAVI-patients is not well established. MethodsInoperable patients with severe aortic stenosis (AS) undergoing TAVI in 2010-2018 were enrolled in this study. AKI and chronic kidney disease (CKD) were defined according to KDIGO guidelines. Patients were divided in two groups according to post-procedural AKI development. The primary endpoint was 30-day all-cause mortality across the two groups. ResultsA total of 373 patients (mean age 82.3 ± 6) were analyzed. Compared to non-AKI patients, those who developed AKI, were treated more frequently with trans-apical TAVI (66% vs 35%, p<0.01), with greater amount of contrast medium (200.6 vs 170.4 ml, p=0.02) and in presence of clinically significant peripheral artery disease (PAD, 33% vs 21%, p=0.04). Trans-apical access (OR 3.24, 95% CI 1.76-5.60, p<0.01) was associated with a 3-fold risk of AKI. After adjustment for age, Society of Thoracic Surgery risk score (STS), PAD, access type, EF and contrast medium amount, patients with AKI presented an increased risk of 30-day all-cause mortality (HR=1.25, 95%CI 1.09-1.69, p=0.008). Patients with CKD IV and V, who developed AKI, presented a 9-fold 30-day mortality risk (HR=9.71, 95% CI 2.40-39.2, p=0.001). ConclusionIn our analysis, AKI was a strong predictor of 30-day all-cause mortality. Particularly, patients with severe CKD with AKI showed the highest 30-day mortality risk. Thus, this group of patients might benefit from closer monitoring and specific kidney protection therapies.

Ischemic Toe Ulceration Due to Foreign Body Embolus From Hydrophilic Polymer-Coated Intravascular Device

Hydrophilic polymer coatings are now widely applied to catheters and other intravascular devices used in neurovascular, cardiovascular, and peripheral vascular procedures. Emboli consisting of these materials have been previously identified in biopsies and autopsies following pulmonary infarction, stroke, gangrene, or death. We report a case involving a nonhealing foot ulcer that appeared following cardiac catheterization, stenting, and automatic implanted cardiac defibrillator (AICD) implantation in a patient without other evidence of significant peripheral artery disease. An 85-year-old woman with chronic atrial fibrillation, aortic valve stenosis, and coronary artery disease underwent coronary stenting and AICD implantation for ventricular tachycardia and syncope. She developed a toe ulcer shortly thereafter, which did not respond to standard treatment. A histological examination following amputation of the toe found amorphous basophilic material in capillaries adjacent to the edge of the ulcer, which was similar to material associated with hydrophilic polymer coatings. Ischemia and infarcts following endovascular procedures should not be presumed to result from thrombus or vascular disease, even if intravascular devices appear intact or properly placed after the procedure. To help establish the incidence of ischemia caused by hydrophilic polymer device coatings, if excision of ischemic or infarcted tissue after endovascular procedures using coated devices becomes necessary, the tissue should be evaluated microscopically. Surgeons should also consider the tolerance of distal organs to infarct or ischemia when selecting coated intravascular devices.

IP185. Novel Technique for Lower Extremity Reverse Saphenous Vein Bypass—Use of Fistula Formation During Great Saphenous Vein Harvest

Infrainguinal arterial bypass remains a mainstay in treatment of critical limb ischemia and significant peripheral artery disease. Our report describes a novel technique that uses fistula formation between native saphenous vein and the femoral artery. We present the case of a 64-year-old man with symptoms of tissue loss of the right lower extremity. Arterial duplex ultrasound demonstrated a >75% superficial femoral artery stenosis with occlusion of proximal popliteal with reconstitution into distal popliteal artery. With the inability to revascularize the artery endovascularly, the decision was made to bypass this femoral-popliteal lesion. The patient was taken to the operating room. The procedure began with dissection of the arterial supply at the common femoral artery suitable for bypass, which is identified and isolated, gaining proximal and distal control. Attention was then turned to dissection of the presumed distal arterial landing for the bypass, also gaining proximal and distal control. This distance between the two sites was measured to give approximate length of venous conduit required. Based on those measurements, the distal half of the great saphenous vein was then dissected out. Once completed, the distal end of the vein was transected and immediately taken up to the common femoral, spatulated, and anastomosed, creating a femoral artery to great saphenous vein fistula. The remaining vein was dissected under distention, allowing easier identification of branch points as well as any stenotic segments. The vein was transected proximally, the proximal end was brought down to the distal artery and spatulated, and the anastomosis was performed, completing the bypass. At 3-month follow-up, duplex ultrasound examination of the bypass demonstrated a patent bypass; with repeated noninvasive studies, ankle-brachial index improved to 1.02. The patient has not required any further intervention for the bypass. This technique minimizes intimal manipulation, which theoretically will improve long-term patency rates of infrainguinal bypasses. During the second portion of dissection of our venous conduit, the vein is under distention from the arterial supply. This has the additional benefit of allowing completion of the bypass to be performed without artificial dilation or manual irrigation, reducing insult to the intima and vasospasm. In addition, there is visualization of any potential stenotic segments of conduit that may require resection with end-to-end anastomosis. The vein is kept superficial, reducing the chance of kinking and allowing easier surveillance. Further study and long-term patency follow-up are required to determine the long-term feasibility of this technique.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Ankle Brachial Pressure Index: An update for the vascular specialist and general practitioner.

Objectives Ankle brachial pressure index (ABPI) is an invaluable tool for assessing the severity of peripheral arterial disease. In addition, it can be used as an independent marker of cardiovascular risk, with a predictive ability similar to the Framingham criteria. Identification of an abnormal ABPI should therefore trigger aggressive cardiac risk factor modulation for a patient. Unfortunately, the significance of abnormal ABPIs is poorly understood within the general medical community. This is compounded by the influence of various comorbidities on accurate measurement of ABPI, potentially leading to a wide variability in readings that need to be considered before interpretation in these patient populations. We aim to address these issues by revealing several common misunderstandings and pitfalls in ABPI measurement, describing accurate methodology, and highlighting patient cohorts in whom additional or alternative approaches may be required. Methods We present a narrative review of the role of ABPI in both the community and hospital setting. We have performed a literature review, exploring the validity and reproducibility of methodology for obtaining ABPI, alongside the utility of ABPI in different clinical scenarios. Results The measurement of ABPI is often performed incorrectly. Common pitfalls include inadequate patient preparation, failure to obtain the blood pressure from the correct lower limb artery in patients with tibial disease, failure to account for differences in brachial blood pressure between the arms, inappropriately chosen equipment and patient factors such as highly calcified arteries. Standardisation of methodology greatly improves reliability of the test. Exercise ABPI can identify significant peripheral arterial disease in patients with normal resting ABPI. In addition to its role in peripheral arterial disease, ABPI measurement has a role in assessing venous ulcers, entrapment syndromes and injured extremities; conversely, it has a more limited utility in the diabetic population. Conclusions A thorough understanding of the correct technique and associated limitations of ABPI measurement is essential in accurately generating and interpreting the data it provides. With this knowledge, the ABPI is an invaluable tool to help manage patients with peripheral arterial disease. Perhaps more importantly, ABPI can be used to identify and risk stratify patients with asymptomatic peripheral arterial disease, itself a major indicator of significant underlying cardiovascular disease. With the emergence of best medical therapy, targeted pharmacotherapy and lifestyle changes can reduce the risk of major cardiovascular events in high-risk patients by approximately 30%, particularly in diabetic patients. Therefore, the utility of ABPI transgresses vascular surgery, with an essential role in general practice and public health.

Sortilin levels are associated with peripheral arterial disease in type 2 diabetic subjects

BackgroundSortilin is a 95-kDa protein which has recently been linked to circulating cholesterol concentration and lifetime risk of developing significant atherosclerotic disease. Sortilin is found inside different cell types and circulating in blood. Higher circulating sortilin concentration has been found in patients with coronary atherosclerosis compared to control subjects. Sortilin concentration is influenced by statin therapy.MethodsWe enrolled statin-naïve subjects with type 2 diabetes mellitus and we performed a cross-sectional study to evaluate the association between sortilin levels and the presence of clinically significant lower limb peripheral artery disease (PAD) in a population of statin-free diabetic subjects.ResultsOut of the 154 patients enrolled in our study, 80 patients were free from PAD, while 74 had clinically significant PAD. Sortilin concentration was significantly higher in the latter group compared to the former (1.61 ± 0.54 ng/mL versus 0.67 ± 0.30 ng/mL, P < 0.01) and there was a trend toward increased sortilin levels as disease severity increased. The association of sortilin levels with PAD remained after adjusting for major risk factors in a multivariate analysis.ConclusionsWe showed that sortilin is significantly and independently associated with the presence of lower limb PAD in a statin-free diabetic population and it may be a promising marker for clinically significant atherosclerosis of the lower limbs. Further studies are needed to confirm this finding and to evaluate its clinical usefulness.

Changes in Microcirculation Following Percutaneous Angioplasty in Patients with Diabetic Foot Ulcers

Background: Diabetic foot disease is a condition with increasing worldwide prevalence. Diabetes mellitus (DM) affects the regulation of vascular tone and response to trauma of the skins microcirculation, increasing the risk of ulceration. How microcirculatory function changes following percutaneous angioplasty (PA) and during ulcer healing is poorly understood. This pilot study aims to examine this. Methods: Patients with DM and active foot ulceration were recruited from diabetic foot clinics into one of two cohorts. Group One (G1) had significant peripheral arterial disease (PAD) requiring PA and group Two (G2) had no significant PAD. At recruitment and prior to the procedure the patients pedal microcirculation was examined using laser Doppler fluxmetry. The main parameter examined was time to maximum flux (TtM) following a three-minute occlusion of the affected limb. These measurements were repeated monthly until the ulcer healed. Results: Nine patients were recruited to G1 and fourteen to G2. Six patients had healed by the end of the study in both groups. In G1, there was a reduction in the TtM following PA. At last visit, on the study toe, TtM had significantly reduced from 210.5s (72.18–231) to 50.71s (27.38–105.18, p=0.046) in those who healed. In G2, on both the study toe and dorsum, there was an increase in TtM (study toe, 13.40s (6.33–73.85) to 64.43 (22.05–114.20), p=0.028). Conclusion: PA appears to be related to significant improvement in microvascular reactivity. The increase in TtM in patients without PAD may be related to a reduction in inflammation following healing. A higher powered study is required.

Pulse Oximetry as a Screening Test for Hemodynamically Significant Lower Extremity Peripheral Artery Disease in Adults with Type 2 Diabetes Mellitus.

ObjectiveThe main objective is to determine if digital pulse oximetry is an acceptable screening tool to detect hemodynamically significant lower extremity peripheral artery disease (PAD) in patients 50 years old and above with type 2 diabetes mellitus (T2DM) seen at the University of Santo Tomas Hospital (USTH).MethodologyA total of 78 subjects (155 limbs) were included. Using duplex ultrasonography as the reference standard for the presence of hemodynamically significant lower extremity PAD, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were obtained for abnormal percent oxygen saturation (SpO2) gradients and for ankle-brachial index (ABI).ResultsOf the 155 limbs, 38.7% had hemodynamically significant stenosis. Pulse oximetry had 76.7% sensitivity (95% CI, 65.2% to 88.1%), 85.3% specificity (95% CI, 78.0% to 92.6%), 76.7% PPV (95% CI, 66.5% to 84.4%) and 85.3% NPV (95% CI, 78.4% to 90.2%). ABI had 40.7% sensitivity (95% CI, 30.1% to 51.3%), 88.2% specificity (95% CI, 80.0% to 96.3%), 68.6% PPV (95% CI, 53.6% to 80.4%) and 70.1% NPV (95% CI, 65.1% to 74.5%). Combining both produces 88.1% sensitivity (95% CI, 78.5% to 97.8%), 74.2% specificity (95% CI, 65-83.4%), 68.4 PPV (95% CI, 60.3% to 75.6%) and 90.8% NPV (95% CI, 83.0% to 95.2%).ConclusionThe results of this study suggest that pulse oximetry has a higher sensitivity than ABI as a screening tool for hemodynamically significant lower extremity PAD in T2DM patients 50 years old and above. Combining these two tests may be done to achieve a higher sensitivity.

The Accuracy of a Volume Plethysmography System as Assessed by Contrast Angiography

Background: Conventional contrast angiography (CA) is the standard diagnostic modality for peripheral artery disease of the lower extremities. However, CA presents possible risks, including contrast nephropathy and radiation exposure. An invasive procedure, it is not chosen to evaluate non-invasive physiologic procedures testing for vascular disease. Alternatively, Duplex ultrasonography (Duplex) is used to assess other non-invasive procedures that evaluate the presence or extent of peripheral artery disease. However, Duplex is not an infallible tool. Rather, another non-invasive physiologic test for peripheral artery disease is a volume plethysmography system (VPS), a blood volume waveform visualization and evaluation tool. Objective: To determine the accuracy of a VPS as an aid for the primary care physician to more accurately identify patients with peripheral artery disease who might benefit from preventive management. Design: Retrospective case series and a case presentation. Patients: Community vascular laboratory group consisting of 48 patients. Methods and Findings: Patients were tested bilaterally with a VPS on all four limbs as per standard testing protocol. They subsequently underwent peripheral CA due to symptoms, physical examination, VPS or Duplex results suggestive of significant peripheral artery disease. Using CA as the gold standard for determining peripheral artery disease, the VPS had sensitivity of 86.0%, specificity of 100% and accuracy of 87.5%. Results indicated flow obstruction in 37 of 48 patients and showed no flow obstruction in 11 of 48 patients. The CA results confirmed peripheral artery disease in 37 of 37 patients with suspected peripheral artery disease by the VPS result. Conclusion: Accuracy of the VPS is verified by CA results, supporting its use as an aid for practicing physicians to accurately diagnose peripheral artery disease. VPS is intended to provide primary care physicians with a tool, which in combination with clinical judgment, to more accurately identify patients with peripheral artery disease who might benefit from preventive management. When appropriate, patients may be referred to a vascular specialist.