Treatment Of Peripheral Vascular Disease Research Articles

Therapeutic Angiogenesis and Cardiovascular Disease: A Review.

After the success of novel angiogenesis inhibitors in cancer treatment, angiogenesis promotors for the treatment of peripheral vascular disease and coronary artery disease became the target of significant research. Promising results in animal models led to numerous randomized control trials that failed to translate into meaningful clinical results. The goal of this review is to describe the history of investigation into therapeutic angiogenesis for cardiovascular disease and discuss the lessons learned and future directions.

Light physical activity improves lower limb perfusion asymmetries in older sedentary adults — an exploratory study

Perfusion asymmetries between lower limbs are common even in healthy young individuals, although their physiological significance is unknown. Even in the absence of vascular disease, ageing is among the determinants that seem to accentuate those differences. While it is known that physical activity affects vascular hemodynamics, its specific impact on perfusion asymmetries in healthy elderly individuals is still unclear. This study aimed to identify vascular asymmetries and their variations after a regular program of light exercise in older individuals with age-related comorbidities in the absence of peripheral vascular disease (PVD). Ten participants, mean age 62.4 ± 5.6 years old, were selected following specific criteria. Participants were mostly sedentary, combining one or more common morbidities for this age group — in particular hypertension, overweight and / or diabetes (T2D). Exclusion criteria were an abnormal Ankle-Brachial Index assessed in a standing position at rest and evidence of compromised mobility. All procedures respected the principles of good clinical practice, being previously submitted and approved by the institutional Ethical Commission. Lower limb perfusion was assessed in both feet (anteromedial region) at two time points — day zero (D0) and thirty days later (D30) — using two optical-based technologies — Laser Doppler Flowmetry (LDF) and Polarized Spectroscopy (PSp). These two technologies measure at different depths, with LDF providing deeper tissue readings. During this evaluation period, participants underwent a daily structured program of light exercises based on the FITT principles (F, frequency; I, intensity; T, time and T, type of activity/activity performance) centred in the lower limb perfusion. The group revealed significant asymmetries at D0, where the right foot consistently showed higher values with both technologies correlating positively. At D30, LDF values increased by 57.5% in both feet, meaning that asymmetries disappeared. No significant changes were observed with PSp. Basic cardiovascular functions such as blood pressure and mean arterial pressure were also evaluated, showing significant decreases in systolic pressure and mean arterial pressure. These encouraging results suggest that regular physical activity, even if light in intensity and duration, improves overall hemodynamics and specifically raises perfusion in the lower limbs. These findings should be further explored with the aimof prevention and treatment of PVD. This research was financed by national funds through FCT - Foundation for Science and Technology, I.P. (Portugal), under the [UIDB/04567/2020] and [UIDP/ 04567/2020] programs. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Alt Ekstremite Periferik Arter Hastalığında Endovasküler Girişimlerden Kaynaklanan Akut Komplikasyonların Cerrahi Yönetimi: Eskimeyen Yeni

Aim: The importance of endovascular procedures in the diagnosis and treatment of peripheral vascular diseases has seen a notable rise in recent years. Nevertheless, this surge has resulted in a corresponding rise in iatrogenic vascular complications and subsequent interventions associated with peripheral endovascular procedures. This study involved a retrospective evaluation of acute complications associated with endovascular treatments performed for lower limb peripheral artery diseases, as well as a closer look of the related therapeutic strategies for these challenges.
 Materials and Methods: A retrospective evaluation was conducted on a cohort of 400 patients who received endovascular intervention for lower extremity peripheral artery disease at our clinic. The study included 27 patients (6.7%) from this cohort who received surgical or endovascular treatment for acute complications following endovascular intervention. Our preference for endovascular or surgical treatments was chosen based on the type and localization of the complications.
 Results: The mean age of patients who experienced complications was 63.7±6 years. The complications were as follows in order of frequency: dissection 14 (51.9%) patients, arterial perforation 5 (18.5%) patients, major hematoma 3 (11.1%) patients, pseudoaneurysm 2 (7.4%) patients, distal embolism 2 (7.4%) patients and arterio-venous fistula 1 (3.7%) patient. In the treatment of complications, endovascular methods were preferred in 19 (4.7%) patients and surgical approaches were used in 8 (2%) patients. Following endovascular intervention, minor amputation was performed in one patient.
 Conclusion: The rapid and effective management of complications related to peripheral endovascular procedures in the lower extremities is of utmost importance. Despite the notable advancements in endovascular procedures in recent years, there are scenarios where these interventions may be insufficient for dealing with complications. The management of such problems may necessitate surgical intervention. Hence, the integration of well-established and validated vascular surgical techniques with endovascular interventions is believed to yield optimal outcomes.

Abstract 10434: Very Late Stent Thrombosis Caused by Rupture of In-Stent Neoatherosclerosis 15-Years After Bare Nitinol Stent Implantation in Superficial Femoral Artery Visualized With Multimodality Imaging

A 77-year-old man complained of intractable rest pain in his left leg, which occurred one week before hospital admission. His past medical history included diabetes mellitus and history of smoking. He was prescribed cilostazol for treatment of peripheral vascular disease. He underwent endovascular therapy (EVT) 15-years earlier with a bare nitinol stent (BNS) implantation in his left superficial femoral artery (SFA), and no restenosis was detected by annual duplex ultrasound (DUS) follow-up until this session. DUS observed restenosis with 14.8 peak systolic velocity ratio, and initial angiography ( Panel A , white arrow) revealed subtotal occlusion at the stented lesion. Intravascular angioscopy ( Panel C ) demonstrated disrupted cavity with red thrombus attached. Optical frequency domain imaging (OFDI) ( Panel D ) and intravascular ultrasound (IVUS) ( Panel E ) demonstrated fibrous cap disruption with a clear cavity formed inside the plaque (6 to 11 o’clock in Panel D and E), as well as thin sheet calcification. The other side (11 to 6 o’clock) shows a signal rich region with high attenuation that indicates fibroatheroma. The lesion was diagnosed as very late stent thrombosis (VLST) because multimodality images revealed rupture of in-stent neoatherosclerosis with red thrombus attached. After successful vessel preparation with a high-pressure 6mm balloon, 6 mm drug-coated balloons were used. The completion angiogram revealed an acceptable result with neither residual stenosis nor flow-limiting dissection ( Panel B ). Neoatherosclerosis has been reported as one of the major causes of VLST in the coronary arteries; however, it has rarely been reported in the peripheral arteries. This case illustrates valuable direct visualization with multimodality imaging of a case with VLST caused by rupture of in-stent neoatherosclerosis 15-years after BNS implantation, and the value of multimodality imaging for comprehensive evaluation to diagnose the mechanism of VLST in SFA.

Ultrasound-Guided Catheterization Using a Driller-Tipped Guidewire With Combined Magnetic Navigation and Drilling Motion

The endovascular intervention has been widely used to treat occlusive peripheral vascular disease (PVD). However, the current procedure has concerns such as low successful rate, undesired trauma, and radiation exposure. This article proposes a robotic solution to mitigate these limitations. A miniature magnetic driller-tipped guidewire (MDG) is designed, which performs 1) controllable bending under directional magnetic fields to navigate in complex vasculature and 2) mechanical drilling under rotating magnetic fields to pass through clogged regions. An integrated actuation system is adopted for magnetic control and ultrasound (US) imaging in a large workspace. A control framework composed of the preoperative and intraoperative stages is developed, which internally coordinates all system modules, addresses noisy US imaging, and provides convenient operation. Demonstrations under an optical camera verify the flexible steering ability and effective unclogging motion of the MDG. Furthermore, US image-monitored <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vitro</i> experiments validate the overall hardware platform and control strategy. The designed MDG realizes dual objectives, including controllability at bifurcations and penetrability at clots. The introduced US imaging modality largely reduces radiation hazards in conventional catheterization. This article studies the intervention of the MDG under electromagnetic field navigation and US imaging guidance. The proposed workflow has the potential to improve operational safety and clinical outcomes of the occlusive PVD treatment.

Evaluation of Robotic-Assisted Carotid Artery Stenting in a Virtual Model Using Motion-Based Performance Metrics

Purpose: Robotic-assisted carotid artery stenting (CAS) cases have been demonstrated with promising results. However, no quantitative measurements have been made to compare manual with robotic-assisted CAS. This study aims to quantify surgical performance using tool tip kinematic data and metrics of precision during CAS with manual and robotic control in an ex vivo model. Materials and Methods: Transfemoral CAS cases were performed in a high-fidelity endovascular simulator. Participants completed cases with manual and robotic techniques in 2 different carotid anatomies in random order. C-arm angulations, table position, and endovascular devices were standardized. Endovascular tool tip kinematic data were extracted. We calculated the spectral arc length (SPARC), average velocity, and idle time during navigation in the common carotid artery and lesion crossing. Procedural time, fluoroscopy time, movements of the deployed filter wire, precision of stent, and balloon positioning were recorded. Data were analyzed and compared between the 2 modalities. Results: Ten participants performed 40 CAS cases with a procedural success of 100% and 0% residual stenosis. The median procedural time was significantly higher during the robotic-assisted cases (seconds, median [interquartile range, IQR]: 128 [49.5] and 161.5 [62.5], p=0.02). Fluoroscopy time differed significantly between manual and robotic-assisted procedures (seconds, median [IQR]: 81.5 [32] and 98.5 [39.5], p=0.1). Movement of the deployed filter wire did not show significant difference between manual and robotic interventions (mm, median [IQR]: 13 [10.5] and 12.5 [11], p=0.5). The postdilation balloon exceeded the margin of the stent with a median of 2 [1] mm in both groups. Navigation with robotic assistance showed significantly lower SPARC values (–5.78±3.14 and –8.63±3.98, p=0.04) and higher idle time values (8.92±8.71 and 3.47±3.9, p=0.02) than those performed manually. Conclusions: Robotic-assisted and manual CAS cases are comparable in the precision of stent and balloon positioning. Navigation in the carotid artery is associated with smoother motion and higher idle time values. These findings highlight the accuracy and the motion stabilizing capability of the endovascular robotic system. Clinical Impact Robotic assistance in the treatment of peripheral vascular disease is an emerging field and may be a tool for radiation protection and the geographic distribution of endovascular interventions in the future. This preclinical study compares the characteristics of manual and robotic-assisted carotid stenting (CAS). Our results highlight, that robotic-assisted CAS is associated with precise navigation and device positioning, and smoother navigation compared to manual CAS.

A Combined Treatment Effect of Cilostazol and Pentoxifylline in the Treatment of Peripheral Vascular Disease

Background: (50 mg BD) and pentoxifylline (400 mg TDS) therapy in patients with PVD. Additionally, the adverse effects and economic burden of the combination was taken in to account.&#x0D; Methodology: An Observational antegrade study was done among 100 patients. A Patient with PVD visited to OPD of the vascular department was enrolled in the study. Data was collected as per the Case Record Form.&#x0D; Results: The mean age was found to be 58.4 ± 11.3 years of total 100 patients. An improvement in a Doppler testing (follow-up at the time interval after 1 month, 3 months and 6 months) and increased in peak systolic velocity in distal vessels as well as collaterals were observed in all patients. The PVD was prevalent in 50 to 60 years of age groups and hypertension and smoking were the most common risk factors present in PVD patients. There was more than 70% increase in walking distance after 24 weeks of treatment. Headache 24 (36.4%) and Dizziness 9 (13.6%) were observed as common side effect of therapy. The total cost of the combination therapy was affordable with improved quality of life.&#x0D; Conclusion: The combination treatment showed symptomatic improvement in peripheral vascular disease in the study. The peak systolic velocity gradually increased in the distal vessel and the combination was found to be cost-effective.

Isolated retrograde puncture for the endovascular treatment of peripheral vascular disease

The risks of femoral puncture encourage the search for alternative accesses. Angioplasties through the isolated retrograde puncture of an artery of the foot were described (Tibiopedal Arterial Minimally Invasive Retrograde Revascularization - TAMI) but the data remain very limited. We present here a study of feasibility and safety of the TAMI technique conducted in two centers.

Abstract 364: Vascular Endothelial Growth Receptor 2 (Flk1) Donor Exosomes Drive Angiogenesis

Objectives: Peripheral arterial disease is a significant cause of morbidity and mortality. The goal of this study was to develop a novel treatment to promote angiogenesis. Platelets have been previously implicated in angiogenic events; however, platelet activation rather than presence of growth factors has been associated with new blood vessel formation. This study evaluated exosomes purified from activated platelets to determine their potential in promoting angiogenesis both in vitro and in vivo. Methods &amp; Results: Under Current Good Manufacturing Practices, conditioned medium processed from apheresis platelet cultures yielded a purified exosome product (PEP) enriched for CD63, CD9 and Alix. In vitro, PEP drove HUVEC proliferation, migration, and vascular tube formation. Proteomic evaluation showed Flk1 (VEGFR2) was one of the key angiogenic proteins in PEP. HUVECs treated with Flk1 antibody neutralized PEP (anti-Flk1-PEP) showed reduced vascular tube formation compared to PEP. To evaluate in vivo angiogenesis, a rodent model of hindlimb ischemia was treated with sustained release PEP embedded in fibrin glue (PEP/TISSEEL) with blood flow evaluated by SPY angiography at 28 days post-treatment. Animals treated with PEP/TISSEEL showed improved blood flow with significant difference (p&lt;0.001) as compared to sham, TISSEEL, and anti-Flk1-PEP/TISSEEL. Muscle tissue stained with α smooth muscle actin showed a significant increase (p&lt;0.001) in vascular area in PEP/TISSEEL treated animals compared to TISSEEL alone. To further evaluate clinical translatability, a rabbit ear ischemia wound model was then treated with PEP/TISSEEL. Rabbit ears showed accelerated wound healing and restored blood flow on SPY angiography. Histologic evaluation of vascular area showed a significant increase in vascular area (p&lt;0.05) compared to sham and TISSEEL alone animals. Conclusions: Exosome driven donation of Flk1 here promoted angiogenic events and was successfully translated into healing outcomes in the setting of two animal models of peripheral ischemia. This novel insight into biotherapy achievable pro-angiogenesis establishes a clinical-grade off-the-shelf exosome technology for the treatment of peripheral vascular disease.

The VA vascular injury study: A glimpse at quality of care in Veterans with traumatic vascular injury repair

ObjectiveThe high number of limb injuries among Post-9/11 Veterans and their long-term care pose significant challenges to clinicians. Current follow-up for extremity arterial vascular injury (EVI) is based on guideline-concordant care for treatment of peripheral vascular disease (GCC-PVD), including anticoagulant/antiplatelet or statin therapy and duplex ultrasound. No best practices exist for arterial EVI. Our goal was to determine correlates of GCC-PVD and other care among Post-9/11 Veterans with combat-related arterial EVI. Materials and methodsWe identified Post-9/11 Veterans with arterial EVI who underwent initial limb salvage repair or ligation (e.g., for single-vessel injury) attempt per DoD Trauma Registry validated by chart abstraction. Veterans Health Administration (VHA) data characterized the cohort in the first five years of VHA care. Models predicted (a) GCC-PVD, (b) pain clinic use, (c) mental/behavioral health care, (d) long-term opioid use, and (e) time to complication, controlling for injury severity and type, mental health parameters, and demographics. ResultsThe 490-Veteran cohort with validated arterial injury was 77% White averaging 25.2 years at injury (range: 18–56). Mechanism of injury was primarily explosive (63%). Veterans had Injury Severity Scores classified as mild (60%), moderate (25%) and severe (15%). Approximately 25% received at least one component of VHA GCC-PVD including 8% arterial ultrasounds, 5% statins, and 11% anticoagulants/antiplatelets; 77% had mental/behavioral healthcare. GCC-PVD, as well as PTSD and substance use disorders, were associated with receipt of mental/behavioral health care. Complications affected 46% of the cohort and were more common among those prescribed 90+ days of opioids or receiving GCC-PVD. ConclusionDespite injury severity (40% moderate/severe), only 25% of cohort patients received VHA GCC-PVD, and nearly half had complications from their arterial injury. Receiving GCC-PVD appeared to potentiate receiving care for mental and behavioral disorders. ImpactThe treatment gap in Veterans with arterial EVI may be due to lack of appropriate guidelines, lack of vascular specialists in VHA or accessing care outside the VHA. Focused study of care options and their outcomes will help define optimal care processes for combat Veterans with arterial EVI.

H2O2-responsive VEGF/NGF gene co-delivery nano-system achieves stable vascularization in ischemic hindlimbs

Peripheral vascular disease (PVD) is a common clinical manifestation of atherosclerosis. Vascular endothelial growth factor (VEGF) gene therapy is a promising approach for PVD treatment. However, due to single-gene therapy limitations and high H2O2 pathological microenvironment, VEGF gene therapy are not as expectations and its clinical application are limited. Synergistic effects of Nerve factors and vascular factors in angiogenesis have attracted attention in recent years. In this study, VEGF and nerve growth factor (NGF) genes co-delivery nanoparticles (VEGF/NGF-NPs) were prepared by using H2O2 responsive 6s-PLGA-Po-PEG as a carrier. 6s-PLGA-Po-PEG could react with H2O2 specifically due to the internal peroxalate bond. Angiogenic effects of VEGF/NGF-NPs has been evaluated in cells and hindlimb ischemia mice model. Results showed that VEGF/NGF-NPs promoted VEGF and NGF co-expression simultaneously, eliminated excessive H2O2, strengthened reactions between SH-SY5Ys and HUVECs, and finally enhanced migration, tube formation, proliferation and H2O2 damage resistance of HUVECs. VEGF/NGF-NPs also recovered blood perfusion, promoted the expression of VEGF, NGF, eNOS and NO, and enhanced vascular coverage of pericytes. Treatment effects of VEGF/NGF-NPs may related to VEGF/eNOS/NO pathway. Altogether, VEGF/NGF-NPs eliminated excessive H2O2 while achieving gene co-delivery, and promoted stable angiogenesis. It’s a promising way for PVD treatment by using VEGF/NGF-NPs.Graphical

Mixed-braided stent: An effective way to improve comprehensive mechanical properties of poly (L-lactic acid) self-expandable braided stent

For its unique flexibility, self-expandable braided stent has been wildly used in the treatment of peripheral vascular diseases, such as the superficial femoral artery stenosis. With the application of bioabsorbable polymer materials, stent braided by polymer filaments is explored, and expected to minimize the complications caused by long-term retention of commercial metallic stents in the human body. Poly (L-lactic acid) (PLLA) is the representative of degradable polymer materials, and has been broadly applied in stent for its good mechanical properties and biocompatibility. This study aimed to propose a new preparation method for PLLA self-expandable braided stent by mixed-braided technology, and evaluate its mechanical properties especially in radial supporting performance and flexibility. For this purpose, a series of stent samples were prepared by mixed braiding PLLA monofilament with different diameters. In addition, the pitch angle and monofilament diameter are also considered as two critical design parameters affecting stent mechanical performance. Then, the radial strength and flexibility of different samples were evaluated respectively. The results show that the mixed-braided stent keep the excellent flexibility of thin monofilament braided stent, meanwhile it possesses the good radial supporting performance of the thick monofilament braided stent. This paper provides an idea to improve the comprehensive mechanical properties of PLLA self-expandable braided stent.

Early results of endovascular treatment of peripheral artery diseases at Dong Nai General Hospital

Introduction: Peripheral artery disease is a chronic disease with long-term progression and risk of disability. Treatment includes surgery and endovascular interventions, the latter is becoming more and more developed. This approach has good early and medium-term outcomes&#x0D; Subjects: We report 07 cases of patients diagnosed with peripheral arterial disease who received endovascular intervention at Dong Nai General Hospital.&#x0D; Results: 7 patients with peripheral vascular disease was treated with endovascular approach at Dong Nai General Hospital. Stenosis or chronic occlusion of the superficial femoral artery accounts for 50% of cases, the rest are stenosis of common iliac arteries, external iliac arteries and below-the-knee lesions. The primary intervention results were good, there were no serious complications, the rate of early vascular patency was 100%, the wound healing rate was 100%, there were 3 cases with stenting after balloon angioplasty and 3 cases of minor amputation. No reintervention was needed in these patients.&#x0D; Conclusion: The initial results of endovascular intervention for peripheral vascular disease at Dong Nai General Hospital are encouraging, helping to expand the indications for intervention, including hybrid surgery and creating first steps in multispecialty treatment of cardiovascular disease, a new trend in the future.

Diagnosis and treatment of peripheral vascular disease. Literature review

Angiología es una revista científica bimensual editada desde 1949. Está dedicada al estudio de las enfermedades vasculares, incluyendo todos los aspectos de la medicina vascular, el diagnóstico no invasivo, el tratamiento quirúrgico tradicional arterial y venoso, así como el mínimamente invasivo y/o endovascular.

Expert consensus on Tongsaimai Tablets/Capsules in treatment of peripheral vascular diseases in clinical practice

Tongsaimai Tablets/Capsules are composed of Lonicerae Japonicae Flos, Angelicae Sinensis Radix, Achyranthis Bidentatae Radix, Codonopsis Radix, Dendrobii Caulis, Astragali Radix, Scrophulariae Radix, and Glycyrrhizae Radix et Rhizoma, and are effective in promoting blood circulation, removing blood stasis, supplementing Qi, and nourishing Yin. It is widely used in the treatment of peripheral vascular diseases. With 40 years of clinical application, it has accumulated substantial research data and application experience. Its good clinical efficacy and pharmacoeconomic benefits in improving the clinical symptoms of peripheral vascular diseases have been confirmed by relevant research. Meanwhile, this drug has also been recommended by many expert consensus, guidelines, and teaching materials, serving as one of the most commonly used Chinese patent medicines in clinical practice. To further improve the understanding of the drug among clinicians and properly guide its clinical medication, the China Association of Chinese Medicine took the lead and organized experts to jointly formulate this expert consensus. Based on the questionnaire survey of clinicians and the systematic review of research literature on Tongsaimai Tablets/Capsules with clinical problems in the PICO framework, the consensus, combined with expert experience, concludes recommendations or consensus suggestions by GRADE system with the optimal evidence available through the nominal group technique. This consensus defines the indications, usage, dosage, course of treatment, medication time, combined medication, and precautions of Tongsaimai Tablets/Capsules in the treatment of peripheral vascular diseases, and explains the safety of its clinical application. It is recommended for clinicians and pharmacists in the peripheral vascular department(vascular surgery), traditional Chinese medicine surgery(general surgery), and endocrinology department of hospitals at all levels in China.

Sex, age, and other barriers for prosthetic referral following amputation and the impact on survival

BackgroundDespite advances in peripheral vascular disease treatment, lower extremity amputation continues to be necessary in a significant number of patients. Up to 80% of amputees are not referred for prosthetic fitting. The factors contributing to referral decisions have not been adequately investigated, nor has the impact of prosthetic referral on survival. We characterized differences between patients who were successfully referred to our in-house prosthetists and those who were not, and identified factors associated with prosthetic referral and predictive of survival. MethodsThis was a retrospective analysis of all patients who underwent lower extremity amputation by surgeons in our practice from January 1, 2010, to June 30, 2017. Data regarding age, sex, race, body mass index (BMI), diabetes, hypertension, hyperlipidemia, end-stage renal disease, prior coronary artery bypass graft surgery, congestive heart failure, tobacco use, American Society of Anesthesiologists (ASA) score, previous arterial procedure, chronic obstructive pulmonary disease, statin use, postoperative ambulatory status, level of amputation, stump revision, and referral for prosthesis were collected. Survival was determined from a combination of sources, including the Social Security Death Master Index, multiple genealogic registries, and internet searches. Multivariable logistic regression was used to determine risk factors associated with prosthesis referral. Multivariable Cox proportional hazard regression with time-dependent covariates was performed to assess risk factors associated with 5-year mortality. ResultsThere were 293 patients included in this study. Mean age was 66 years, and mean BMI 27 kg/m2. The majority of patients were male (69%), white (53%), with diabetes (65.4%) and hypertension (77.5%), and underwent below-the-knee amputation (BKA) (73%). Prosthetic referral occurred in 123 (42.0%). Overall 5-year survival was 61.7% (95% confidence interval [CI], 55.9%-68.1%) (BKA 64.7% [95% CI, 57.9%-72.3%]; above-the-knee amputation 53.8% [95% CI, 43.4%-66.6%]). On multivariate analysis, age >70 years, female sex, diabetes, ASA score 4 or 5, and current tobacco use were associated with no referral for prosthetic fitting. Patients with BMI 25 to 30, a previous arterial procedure, BKA, and history of stump revision were more likely to be referred. Factors associated with decreased survival were increasing age, higher ASA class, black race, and BMI; prosthetic referral was seen to be protective. ConclusionsWe identified multiple patient factors associated with prosthetic referral, as well as several characteristics predictive of reduced survival after amputation. Being referred for prosthetic fitting was associated with improved survival not explained by patient characteristics and comorbidities. Further research is needed to determine whether the factors identified as associated with nonreferral are markers for patient characteristics that make them clinically unsuitable for prosthetic fitting or if they are symptoms of unconscious bias or of the patient's access to care.

Abstract No. 159 Effect of bleeding disorders on postoperative outcomes following lower extremity endovascular intervention for peripheral vascular disease

Conditions which interfere with coagulation may increase the risk of post-procedural bleeding and/or complications during interventional radiology procedures. This study investigates the influence of bleeding disorders on acute post-operative outcomes following lower extremity endovascular interventions for peripheral arterial disease (PAD).

Patient and clinician experiences and opinions of the use of a novel home use medical device in the treatment of peripheral vascular disease - a qualitative study

BackgroundPeripheral vascular diseases have a significant impact on functional quality of life. Previous research has demonstrated the complex, limiting and costly economic implications of these conditions such as lower limb ulceration chronicity and ischaemic amputation. These complex, limb and life threatening conditions demand the development of novel interventions with objective research as part of that development. Hence, a novel intermittent negative pressure medical device in the form of a wearable boot (FlowOx™) was developed. As part of the development process, this study aimed to explore patient and clinician opinions of the boot.MethodsA qualitative approach was used to collect patient and clinician experiences in Norway. An advisory group informed the semi-structured questions used in seven patient interviews and one clinician focus group (n = 5). The data were recorded digitally and transcribed verbatim. Patient and clinician data were analysed as distinct groups using a thematic process.ResultsData analysis resulted in five themes from the patients which gave insight into; the impact of the disease process; practicalities of using the boot, positive experiences of use; perceived outcomes; reflecting on use. Six themes were created from the clinicians. These gave insight into; ideal outcomes and how to measure them; ways to potentially use the boot; using research in healthcare; positives of the device; observed effects and next steps; potential improvements to the device.ConclusionThis study provides insight into the experiences and opinions of FlowOx™. Patients and clinicians were positive about the device due to its ease of use. Those patients with peripheral arterial disease experienced significantly more benefit, especially for ischaemic ulceration than those with a chronic venous condition. Clinicians placed value on the patient reported outcomes in the treatment decision-making process. This preliminary study into experiences of FlowOx™ use provides valuable feedback that will inform design modification and ongoing research into implementation points and prospective user groups. FlowOx™ demonstrates potential as a conservative therapy offering users a convenient, home use, self-care management solution for improving symptomatic peripheral arterial disease and quality of life.

Modern approaches and innovations in the diagnosis and treatment of peripheral vascular diseases.

Amongst the three major vascular beds (coronary, cerebrovascular, and peripheral), peripheral vascular disease (PVD) has traditionally received the least attention, despite its growing global burden. The aging population has led to the increased prevalence of PVD, thereby increasing visibility to its various diagnostic and treatment modalities. In the past decade, research and development of innovations in the management of PVD has exploded. Modern advances in imaging, molecular technology, medical devices, and surgical techniques have reduced the morbidity and mortality of PVD. However, many challenges still remain due to the debilitating and progressive nature of this disease. In this article, we will introduce some common vascular diseases, the state of art in diagnosis and treatment, the limitations of modern technology, and our vision for this field over the next decade.

Abstract 14765: Exosome Shuttled VEGFR Promotes Angiogenesis in Peripheral Vascular Disease

Introduction: Counteracting the pandemic of peripheral vascular disease necessitates development of proangiogenic treatments. As stem cell benefit has increasingly been associated with paracrine influence on diseased tissue, a purified extracellular vesicle population (PEP) was established to promote tissue regeneration and neovascularization. The mechanistic basis for PEP-induced proangiogenic effects was here probed and validated in two separate in vivo models of vascular ischemia. Hypothesis: PEP drives pro-angiogenic effects though donation of VEGFR. Methods: Nanosight and immunoblotting were utilized to characterize PEP purity and identity. OMICs profiling identified VEGFR as highly prioritized, with downstream signaling was tested in human umbilical vascular endothelial cells using Matrigel assay, qPCR and immunoblotting. In vivo, blood perfusion (Fluorescent imaging - SPY) was quantified in a rodent model of hind-limb ischemia and in a rabbit model of critical ischemic ear, each treated with sham or PEP. Rabbit tissues were next examined by whole transcriptome analysis to assess PEP-induced proangiogenic signaling. Immunohistochemical staining with smooth muscle actin and von Willebrand factor probed de novo blood vessel formation. Results: PEP was characterized by size (mean: 128.6 +/-1 nm) and VEGFR expression. VEGFR knock-down diminished endothelial cell angiogenic activity in vitro, rescued with PEP (5.3x1010+/-109 vesicles/ml) was sufficient enhance total and phosphor-VEGFR expression, along with amplification of downstream VEGFR targets (MAPK, AKT, CXCL8, NOTCH4, MMP9) and enhanced tube formation. In both hind-limb (n=5) and critical ear (n=4) ischemia models, local delivery of PEP to ischemic tissue resulted in restoration of blood perfusion and prioritized proangiogenic signaling in tissue transcriptome pathway analysis, further confirmed by immunohistochemistry. Conclusions: Taken together, our study establishes a new regenerative paradigm documenting exosome-based delivery of VEGFR as a key driver for angiogenesis. This PEP-based platform broadens potential options available for treatment of peripheral vascular disease and may have therapeutic implications in restoration of microvasculature.