Dissertations / Theses on the topic 'Critical limb threatening ischemia'

This thesis investigates the use of Convolutional Neural Networks (CNNs) toperform semantic segmentation of feet during endovascular surgery in patientswith Critical Limb Threatening Ischemia (CLTI). It is currently being investigatedwhether objective assessment of perfusion can aid surgeons during endovascularsurgery. By segmenting feet, it is possible to perform automatic analysis of perfusion data which could give information about the impact of the surgery in specificRegions of Interest (ROIs). The CNN was developed in Python with a U-net architecture which has shownto be state of the art when it comes to medical image segmentation. An imageset containing approximately 78 000 images of feet and their ground truth segmentation was manually created from 11 videos taken during surgery, and onevideo taken on three healthy test subjects. All videos were captured with a MultiExposure Laser Speckle Contrast Imaging (MELSCI) camera developed by Hultman et al. [1]. The best performing CNN was an ensemble model consisting of10 sub-models, each trained with different sets of training data. An ROI tracking algorithm was developed based on the Unet output, by takingadvantage of the simplicity of edge detection in binary images. The algorithmconverts images into point clouds and calculates a transformation between twopoint clouds with the use of the Iterative Closest Point (ICP) algorithm. The resultis a system that perform automatic tracking of manually selected ROIs whichenables continuous measurement of perfusion in the ROIs during endovascularsurgery.

El tractament endovascular de la malaltia arterial perifèrica està basat en les imatges angiogràfiques. La interpretació subjectiva feta a partir d’elles és com més habitualment s’avalua l’èxit del tractament durant la revascularització. L’angiografia de perfusió 2D (AP) és un software de processat de la imatge que podria donar peu a la quantificació de la perfusió distal. Endemés, un sistema de classificació anatòmic més senzill, capaç de descriure la càrrega de malaltia arterial per sota de l’engonal, és necessari per poder triar el millor tractament per un pacient concret. La intenció d’aquesta tesis és identificar una mesura objectiva per avaluar l’èxit del tractament endovascular basant-se en la quantificació de la perfusió del teixit amb l’AP; i per consegüent tenir la capacitat de predir amb major precisió la curació de les úlceres isquèmiques. Secundàriament, hem buscat adaptar un sistema de classificació que pugui ser aplicat amb facilitat a la pràctica clínica diària i que permeti la comparació entre pacients a assajosi estudis clínics. La investigació del projecte present es va realitzar amb un estudi de cohorts retrospectiu amb pacients consecutius sotmesos a tractament endovascular en un únic centre especialitzat en tractament de la isquèmia crítica de l’extremitat. Als pacients se’ls va realitzar una AP abans i després del tractament, i també es van classificar d’acord amb els sistemes de classificació més utilitzats (Rutherford, TASC i WIfI) i amb una nova classificació proposta: l’score d’Abano Terme (ATS). Les dades demogràfiques i clíniques es van recollir i es va realitzar un seguiment clínic al mes i als 6 mesos. Els paràmetres de l’AP van ser el temps d’arribada (AT), el temps de pic (PT), la velocitat del rentat (WS), l’amplada (W), l’àrea sota la corba (AUC) i el temps de trànsit mig (MTT). Les dos cohorts es van definir en base a un temps de curació major o menor a 30 dies. Des del gener de 2015 fins al juliol de 2016, 580 pacients consecutius van ser tractats endovascularment i van ser estudiats amb AP. D’entre ells, 332 complien els criteris d’inclusió, dels quals 123 van ser exclosos posteriorment de l’anàlisi per la curació de les úlceres (en 34 casos la imatge de l’AP tenia mala qualitat, 50 pacients no presentaven úlceres, 20 van finar i 19 no van completar el seguiment). L’edat mitja va ser de 72 anys i el 67,5% eren homes. 133 pacients presentaven lesions Rutherford 5 i en 76 les lesions eren Rutherford 6. El risc WIfI d’amputació va ser baix en un 24%, moderat en un 14% i alt en un 62%. Vam trobar taxa de curació als 30 dies, amb diferències estadísticament significatives entre els grups, per als següents punts de tall dels paràmetres de l’AP: AT > 6 segons i MTT > 4.1 23 segons o un increment del mateix MTT > 1,7 segons. L’ATS, sent un sistema de classificació més senzill que es existents actualment, no només es va correlacionar millor que amb la TcPO2 i amb l’AP; sinó que en un posterior anàlisis va demostrar millor correlació amb la curació de les úlceres i la supervivència lliure d’amputació en pacients amb lesions Rutherford 5.
El tratamiento endovascular de la enfermedad arterial periférica está basado en las imágenes angiográficas. La interpretación subjetiva hecha a partir de ellas es el modo más habitual de evaluar el éxito del tratamiento durante la revascularización. La angiografía de perfusión 2D (AP) es un software de procesado de la imagen que podría permitir la cuantificación de la perfusión distal. Además, un sistema de clasificación anatómico más sencillo, capaz de describir la carga de enfermedad arterial por debajo de la ingle, es necesario para decidir el mejor tratamiento para un paciente dado. La intención de esta tesis es identificar una medida objetiva para evaluar el éxito del tratamiento endovascular basado en la cuantificación de la perfusión del tejido con la angiografía de perfusión; y por ende ser capaz de predecir con mayor precisión la curación de las úlceras isquémicas. Secundariamente, hemos tratado de adaptar un sistema de clasificación que pueda ser aplicada fácilmente a la práctica clínica diaria y que permita comparaciones entre pacientes en ensayos clínicos y estudios. La investigación de este proyecto se basó en un estudio de cohortes retrospectivo con pacientes consecutivos sometidos a tratamiento endovascular en un único centro especializado para el tratamiento de la isquemia crítica de la extremidad. Los pacientes fueron analizados con AP antes y después del tratamiento, y también se clasificaron de acuerdo con los sistemas más utilizados (Rutherford, TASC y WIfI) y con una nueva clasificación propuesta: el score de Abano Terme (ATS). Los datos demográficos y clínicos se recogieron y se realizó un seguimiento clínico a al primer mes y a los 6 meses. Los parámetros de la AP fueron tiempo de llegada (AT), el tiempo de pico (PT), la velocidad de lavado (WS), la amplitud (W), el área bajo la curva (AUC) y el tiempo de tránsito medio (MTT). Las dos cohortes se definieron en base a un tiempo de curación de menor o mayor a 30 días. De enero de 2015 a julio de 2016, 580 pacientes consecutivos se sometieron a un tratamiento endovascular, realizándose en ellos un análisis con AP. Entre ellos, 332 cumplieron los criterios de inclusión, de los cuales 123 se excluyeron del análisis de curación de úlceras (34 debido a la mala calidad de la imagen de AP, 50 pacientes no presentaban úlceras, 20 fallecieron y 19 no completaron el seguimiento). La edad media fue de 72 años y el 67,5% eran hombres. 133 pacientes presentaban lesiones Rutherford 5 y en 76 las lesiones eran Rutherford 6. El riesgo WIfI de amputación fue bajo en 24%, moderado en 14% y alto en 62%. Encontramos una tasa curación a los 30 días , con diferencias estadísticamente significativas entre los grupos, para los siguientes valores de corte de los parámetros de la AP: 25 AT > 6 segundos y MTT> 4.1 segundos o un incremento del mismo MTT > 1.7 segundos. El ATS, siendo un sistema de clasificación más simple que los actualmente empleados, no sólo se correlacionó mejor con la TcPO2 y la angiografía de perfusión; sino que en un posterior análisis demostró una mejor correlación con la curación de las úlceras y la supervivencia libre de amputación en pacientes con lesiones Rutherford 5.
The endovascular treatment (EVT) of Peripheral Arterial Disease (PAD) is based on angiographic imaging and post-revascularization treatment success is based on the subjective interpretation of this visual assessment. 2D perfusion angiography (PA) is an image- processing software which may allow for the quantification of perfusion. In addition, a simpler anatomic classification system, able to describe the arterial disease burden below the groin, needs to be designed to determine the best therapy for any given patient.(1) The aim of this thesis is to create an objective system to assess the success of EVT based on the quantification of tissue perfusion through PA, capable of accurately predicting the healing probability of ischemic ulcers. Secondly, we seek to describe a classification system of easy application during daily clinical practice that will also facilitate comparison of patients among clinical trials. The Project was designed as a retrospective cohort study with consecutive patients undergoing EVT at a single specialized center for critical limb ischemia (CLI). The cases were analyzed with PA before and after treatment, and also ranked according to current classification systems (Rutherford, TASC and WIfI) and a new proposed classification: the Abano Terme Score (ATS). Demographic and clinical data were recorded and clinical follow- up was performed (at 1 and 6 months). The PA parameters were Arrival Time (AT), Peak Time (PT), Wash-in Rate, Width, Area Under Curve and Mean Transit Time (MTT). Two cohorts were defined based upon a time to heal of less or longer than 30 days. From January 2015 to July 2016, PA analysis was performed on 580 consecutive patients that underwent EVT. Among them, 332 met the inclusion criteria to be studied, from which 123 were excluded for ulcer healing analysis (34 because of poor image quality, 50 patients had no ulcer, 20 died and 19 were lost at follow-up). Mean age was 72 years and 67.5% were men; 133 patients had Rutherford 5 and 76 had Rutherford 6 lesions, with similar distribution in both groups. The WIfI risk for amputation was also similar for both groups, and it was low in 24%, moderate in 14% and high in 62%. We found significant differences between groups in the healing time for the following cut-off values of PA parameters: AT>6 seconds and improvement of MTT>1.7 seconds or the MTT>4.1 seconds after the treatment. The ATS, while being a simpler classification than current used system, not only showed a better correlation with parameters such as the transcutaneous pressure of oxygen (TcPO2) and PA; but also demonstrated, in a subsequent analysis, a better correlation with ulcer healing and amputation free-survival in patients with Rutherford 5 lesions.

Atrial fibrillation is the most common type of serious dysrhythmia, with increasing prevalence in older age groups. Thromboembolism is a serious complication seen with atrial fibrillation and can range from ischemic stroke, mesenteric ischemia to acute limb ischemia. The annual incidence of acute limb ischemia secondary to atrial fibrillation is 0.14%[1]. Here we report a case of critical limb ischemia with brachial artery occlusion due to an embolus in a patient with new onset atrial fibrillation. A 90 year-old female patient presented to the hospital with complaints of shortness of breath on exertion, orthopnea and palpitations of one week duration. She denied any chest pain, dizziness, or syncope. Past medical history was significant for longstanding hypertension well controlled with amlodipine and a provoked deep vein thrombosis of the leg 40 years prior to presentation complicated by heparin-induced thrombocytopenia. On examination, she had an irregularly irregular rhythm and an HR in 120s, no murmurs or gallops were appreciated. 12 lead EKG was suggestive of atrial fibrillation with rapid ventricular response. She was started on metoprolol tartrate for rate control and Apixaban for anticoagulation. TSH was normal and serial troponins returned negative. A Transthoracic echocardiogram was obtained and showed an ejection fraction of 55-60%, mildly dilated left atrium, mild MR, there was no evidence of a thrombus or patent foramen ovale. Three hours after the first dose of Apixaban, and right prior to discharge, the patient started complainig of sudden onset sharp pain and paresthesia of the left upper extremity below the elbow. On Inspection, the left upper extremity was pale and cold to touch. Radial and ulnar pulses were absent, confirmed by doppler ultrasound. A stat computed tomography angiography of the left upper extremity showed complete occlusion of the brachial artery at the level of the elbow joint. She was started on Argatroban drip en route for emergent brachial embolectomy after Vascular Surgery consultation. Blood circulation to the arm was fully restored. Apixaban was resumed post-operatively and with clinical improvement, the patient was safely discharged home. Atrial fibrillation, irrespective of the type (persistent, paroxysmal, permanent or silent) leads to increased risk of thromboembolism owing to atrial clot formation[2]. However, the timing of initiation of antithrombotic therapy has been widely discussed and needs to be individualized based on the presence of risk factors for thromboembolism and bleeding. Acute limb ischemia may be defined as sudden loss of blood flow to the limb. The cause being either thrombotic (60%) or embolic (30%). It has been noted that 80% of peripheral emboli originate in the heart secondary to atrial fibrillation[3]. A timely diagnosis and treatment is of utmost importance to decrease morbidity and mortality and to salvage the limb’s functionality. References 1.Thromboembolism in atrial fibrillation Menke J1, Lüthje L, Kastrup A, Larsen J. 2.Writing Committee Members, January CT, Wann LS, et al. 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. Circulation. 2014;130(23):e199-e267. doi:10.1161/CIR.0000000000000041. 3.Callum K, Bradbury A. Acute limb ischaemia. BMJ : British Medical Journal. 2000;320(7237):764-767.

Thesis (DSc)--Stellenbosch University, 2013.
AFRIKAANSE OPSOMMING: Hierdie DSc is fundeer op ‘n aantal aspekte rondom ‘n sentrale tema naamlik die algemene en streeksfunksie van die normale hart of die hart blootgestel aan die risiko van miokardiale isgemie. Die werk is oor ‘n bestek van 25 jaar gedoen en sluit in eksperimentele werk in groot en kleindiere sowel as data verkry in pasiënte. Hoofstuk 1 handel met globale en streeksfunksie in die normale hart met die klem op die meer moderne benadering tot die koppeling van die hart met die sirkulasie en effek van middels op die twee komponente. Hierdie hoofstuk het waardevolle inligting gegee t.o.v. fisiologie maar ook gehelp om die middels te kies vir daaropvolgende studies. Hoofstuk 2 bevat navorsing wat verwys na die hart met kroonaarstenose. Onder andere word gesteun op ‘n dieremodel van kroonaarstenose. Die hoofstuk sluit data in wat , as eerste en unieke bydrae, gewys het dat inhalasie narkose middels die reperfusie besering van die hart kan verminder. Hierdie data het spesifiek bygedra om die kliniese praktyk van narkose vir hierdie pasiënte te verander. Hoofstuk 3 verwys na werk gedoen om die hart gedurende elektiewe chirurgiese arres te oksigeneer. Die effektiwiteit van verskillende kardioplegiese vloeistofsamestellings is ook krities ontleed. Die vierde hoofstuk handel met ‘n ernstige kliniese probleem naamlik akute pulmonêre hipertensie. By pasiënte met akute long besering is hierdie verskynsel baiemaal die oorsaak van dood en of moeitevolle oksigenasie. Die werk het gelei tot beter insigte t.o.v. pasiënt hantering tot die punt dat baie van die pasiënte vandag gered kan word.
ENGLISH ABSTRACT: This thesis is based on a number of aspects with a central theme of global and regional cardiac function in the normal heart and the heart at risk of ischemia. It summarizes work done over 25 years and includes experimental work in large and small animals as well as data obtained from human clinical practice. Chapter one deals with global and regional heart function and especially the physiological concept of ventriculo-arterial coupling as a mechanism to explain and understand the effects of inter alia commonly used drugs. Chapter 2 summarizes work done in hearts with a coronary artery stenosis. One of the interesting ,and at that time, unique findings was that inhalation anesthetic drugs are effective in limiting the reperfusion injury of the heart. This insight helped to redirect techniques used to anaesthetize patients with coronary artery disease. The third chapter examines methods to improve myocardial oxygenation during elective surgical cardiac arrest. It also includes data showing that not all the cardioplegic solutions are equally effective. Chapter four deals with a significant clinical problem i.e. acute pulmonary artery hypertension. This condition is often responsible for patient death, or contributes to, difficult oxygenation in patients with acute lung injury. The work in this chapter assisted in understanding the pathophysiology of the condition and improved the management thererof. This insight, combined with progress in other areas in the pathology or acute lung injury, has led to many of the patients today surviving their illness.

Background: The literature tends to support the notion that diabetic patients typically suffer from tibio-peroneal artery occlusive disease (1) (2) (11) (5) (10) (8) with relative sparing of the foot arteries (1). This study seeks to investigate the pattern and distribution of peripheral artery occlusive disease and the arterial foot arch status in diabetic patients with critical limb ischaemia Methods: This is a one year prospective study -(January 2014 to December 2014) carried out on consecutive patients seen at Groote Schuur Hospital, Vascular Department. The inclusion criteria is: diabetic patients ≥18 years of age with critical limb ischemia who had pre- and post-intervention vascular imaging. The calculated minimum sample size of 63 limbs [756 patency levels (63x12)] was needed to achieve a power of 86% to detect a difference of 0.1900 (19%) with a target significance level of 0.05 (using PASS 11 software). The equality of distribution of categories was analyzed using the One sample Chi-square test (SPSS 22) with our Null hypothesis (N0) assuming that categories occur with equal proportions. In this case categories refers to the 5 patency levels used in this study. All 12 main arteries from infra-renal aorta to crural arteries had their patency levels graded from category 1 to category 5 (widely patent to occluded). The findings were then stratified according to gender, age group ( <40 years, 40-54 years and ≥ 55 years) and risk factor combinations [ Group1 = (DM, HPT, Dyslipidemia); Group 2= (DM, HPT, dyslipidemia, exsmoker); Group 3 = (DM, HPT, dyslipidemia, smoker)]. The three risk combination groups formed the majority of our study group (79%).

Les maladies artérielles périphériques athéromateuses sont graves : l'atteinte des troncs supra-aortiques est à risque d'accident vasculaire cérébral et l'atteinte des artères des membres inférieurs est à risque d'amputation et de décès cardiovasculaire. Le développement de stratégies innovantes capables d'optimiser le diagnostic précoce et le traitement de ces maladies est un enjeu considérable.Nous montrons une corrélation entre deux biomarqueurs inflammatoires, les microparticules leucocytaires (MPL) et la lipoprotéine phospholipase A2, et l'instabilité de la plaque carotidienne définie histologiquement, dans une population de patients porteurs d'une sténose carotidienne serrée. Les MPL sont élevées de façon significative et indépendante y compris chez les patients asymptomatiques porteurs d'une sténose carotidienne serrée instable. Ainsi, le taux circulant de MPL aider à sélectionner les meilleurs candidats à une chirurgie carotidienne préventive parmi les patients ayant une sténose carotidienne serrée asymptomatique. Deuxièmement, nous montrons que l'administration ex vivo d'érythropoïétine (EPO) améliore les capacités proangiogéniques des progéniteurs endothéliaux circulants tardifs in vitro et in vivo sur un modèle d'ischémie de patte de souris nude. Ces effets semblent médiés par la sous-unité CD131 du récepteur à l'EPO. Si ces résultats se confirment chez l'homme, l'EPO pourrait être utilisée pour améliorer les capacités de revascularisation des progéniteurs endothéliaux circulants tardifs circulants humains avant réinjection autologue comme produit de thérapie cellulaire chez des patients atteints d'ischémie critique des membres inférieurs
Atherosclerotic peripheral arterial diseases are frequent and severe. They undertake the functional and vital prognosis of patients: lesions of supra-aortic trunks are at risk of stroke and lesions of lower limb arteries are at risk of amputation and cardiovascular death. The development of innovative strategies that optimize early diagnosis and therapeutic management of these diseases is thus a considerable challenge.In this work, we show a correlation between inflammatory biomarkers, leukocyte microparticles and lipoprotein phospholipase A2, and carotid plaque instability defined histologically, in a population of patients with tight carotid stenosis with or without neurological symptoms. Leukocyte microparticles are elevated significantly and independently including asymptomatic patients with tight unstable carotid stenosis. Thus, the circulating levels of leukocyte microparticles could be a tool in the future to select the best candidates for carotid surgery among patients with asymptomatic carotid stenosis tight.Second, we show that ex vivo administration of erythropoietin improves the proangiogenic capacity of late circulating endothelial progenitor in vitro and in vivo in a mouse model of hindlimb ischemia. These effects appear mediated by CD131 subunit of the receptor for erythropoietin. If these results are confirmed in humans, erythropoietin could be used to improve the revascularization capacity of late circulating endothelial progenitor before reinjection as autologous cell therapy product in patients with critical ischemia of the lower limbs

Peripheral vascular diseases such as peripheral artery disease (PAD) and critical limb ischemia (CLI) are growing at an ever-increasing rate in the Western world due to an aging population and the incidence of type II diabetes. A growing economic burden continues because these diseases are common indicators of future heart attack or stroke. Common therapies are generally limited to pharmacologic agents or endovascular therapies which have had mixed results still ending in necrosis or limb loss. Therapeutic angiogenic strategies have become welcome options for patients suffering from PAD due to the restoration of blood flow in the extremities. Capillary sprouting and a return to normoxic tissue states are also demonstrated by the use of angiogenic cytokines in conjunction with bone marrow cell populations. To this point, it has been determined that spatial and temporal controlled release of growth factors from vehicles provides a greater therapeutic and angiogenic effect than growth factors delivered intramuscularly, intravenously, or intraarterialy due to rapid metabolization of the cytokine, and non-targeted release. Furthermore, bone marrow cells have been implicated to enhance angiogenesis in numerous ischemic diseases due to their ability to secrete angiogenic cytokines and their numerous cell fractions present which are implicated to promote mature vessel formation. Use of angiogenic peptides, in conjunction with bone marrow cells, has been hypothesized in EPC mobilization from the periphery and marrow tissues to facilitate neovessel formation. For this purpose, controlled release of angiogenic peptides basic fibroblast growth factor (FGF-2) and granulocyte-colony stimulating factor (G-CSF) was performed using tunable ionic gelatin hydrogels or fibrin scaffolds with ionic albumin microspheres. The proliferation of endothelial cell culture was determined to have an enhanced effect based on altering concentrations of growth factors and method of release: co-delivery versus sequential. Scaffolds with these angiogenic peptides were implanted in young balb/c mice that underwent unilateral hindlimb ischemia by ligation and excision of the femoral artery. Endpoints for hindlimb reperfusion and angiogenesis were determined by Laser Doppler Perfusion Imaging and immunohistochemical staining for capillaries (CD-31) and smooth muscle cells (alpha-SMA). In addition to controlled release of angiogenic peptides, further studies combined the use of a fibrin co-delivery scaffold with FGF-2 and G-CSF with bone marrow stem cell transplantation to enhance vessel formation following CLI. Endpoints also included lipophilic vascular painting to evaluate the extent of angiogenesis and arteriogenesis in an ischemic hindlimb. Tissue engineering strategies utilizing bone marrow cells and angiogenic peptides demonstrate improved hindlimb blood flow compared to BM cells or cytokines alone, as well as enhanced angiogenesis based on immunohistochemical staining and vessel densities.

L’ischémie critique chronique définit un stade avancé d’insuffisance artérielle chronique. Le diagnostic d’ischémie critique chronique nécessite trois éléments : des signes cliniques, des mesures de perfusion artérielle témoignant de l’ischémie, ainsi qu’une durée des symptômes supérieure à 15 jours. Nous avons mis au point un modèle d’ischémie critique chronique valide chez la souris, et reproduisant au plus proche les lésions observées chez l’homme, en réalisant une ligature fémorale droite associée à une ligature iliaque droite 4 jours plus tard. Nous avons ensuite étudié à partir de ce modèle l’atteinte mitochondriale liée à l’ischémie critique chronique, notamment l’altération de la fonction respiratoire mitochondriale, la diminution de la capacité de rétention calcique, et la production de radicaux libres. Nous avons testé différents protocoles de conditionnement pharmacologique et avons mis en évidence un effet protecteur de la N acétyl cystéine, des statines et de la L arginine. Les voies de protection RISK et SAFE seraient potentiellement impliquées dans cet effet protecteur
Critical limb ischemia defines an advances stage of peripheral arterial disease and peripheral arterial insufficiency. The diagnosis of critical limb ischemia requires three elements: clinical signs, arterial perfusion measures demonstrating the level of ischemia, as well as a duration of symptoms for more than 15 days. We developed a critical limb ischemia model in mice, nearly mimicking human pathology, by right femoral artery ligatuon followed by right artery ligation 4 days later. We then studied from this model the mitochondrial impairment associted with critical limb ischemia, including impaired mitochondrial respiratory function, reduced calcium retention capacity, and increased production of free radicals. Once these changes highlighted, we wanted to test different pharmacological conditioning, in order to identify protective molecules in critical limb ischemia. We thus demonstrated a protective effetct of N acetyl cysteine, statins and L-arginine. The protection pathways RISK and SAFE may be involved in this protective effect

La prévalence du diabète et de l’ischémie critique chronique (ICC) est en constante augmentation. Ces pathologies demeurent incurables et souvent intriquées. Des résultats suggèrent que la signalisation Hedgehog (Hh) participe au maintien de l'intégrité des microvaisseaux, et une régulation négative de Desert Hh (Dhh) est associée aux facteurs de risque cardiovasculaires, tels que l'âge, le diabète et l'obésité.L’objectif principal de cette thèse était d’explorer les mécanismes physiopathologiques conduisant à l’ICC avec pour hypothèse que la protéine Dhh dérivée de l'endothélium est essentielle au maintien de l'intégrité vasculaire.Nous avons démontré que Sonic Hh (Shh) endogène ne favorise pas l'angiogenèse post-ischémie et que l'absence de Shh conduit à une inflammation tissulaire ischémique aberrante et à une angiogenèse transitoire accrue. Chez l’homme, l'ICC était associée à des capillaires dysfonctionnels plutôt qu'à une diminution de la densité capillaire et Dhh était exprimé dans les cellules endothéliales (CE). Chez la souris, une carence en Dhh induisait une activation des CE et une fuite capillaire en raison d'une altération des jonctions adhérentes. L'agoniste de la signalisation Dhh améliorait significativement la fonction des CE sans favoriser l'angiogenèse, ce qui améliorait par la suite la perfusion musculaire.Ainsi, la restauration de la fonction des CE conduit à une récupération significative de la perfusion et de la réparation musculaire dans un contexte d’ICC de membre. La voie Hh, et plus particulièrement Dhh, semble être une cible thérapeutique prometteuse pour prévenir le dysfonctionnement endothélial impliqué dans les pathologies vasculaires ischémiques
The prevalence of diabetes and critical limb ischemia (CLI) is steadily increasing. These pathologies remain incurable and often intertwined. Results suggest that Hedgehog (Hh) signaling is involved in maintaining microvessel integrity, and downregulation of Desert Hh (Dhh) is associated with cardiovascular risk factors, such as age, diabetes, and obesity.The main objective of this thesis was to explore the pathophysiological mechanisms leading to CLI with the hypothesis that endothelial Dhh is essential for the maintenance of vascular integrity.We have shown that endogenous Sonic Hh (Shh) does not promote post-ischemic angiogenesis and that the absence of Shh leads to aberrant ischemic tissue inflammation and increased transient angiogenesis. In humans, CLI was associated with dysfunctional capillaries rather than a decrease in capillary density, and Dhh was expressed in endothelial cells (EC). In mice, Dhh knockdown was associated with EC activation and capillary leakage secondary to the alteration of adherent junctions. Dhh's agonist significantly improved EC function without promoting angiogenesis, which subsequently improved muscle perfusion.Thus, restoration of EC function leads to a significant recovery of perfusion and muscle repair in the context of CLI. The Hh signaling pathway, and more particularly Dhh, appears to be a promising therapeutic target for preventing the endothelial dysfunction involved in ischemic vascular pathologies

L’incidence de l’ischémie critique est en augmentation depuis ces vingt dernières années. La revascularisation diminue le taux d’amputation. Les plaies ischémiques infectées avec l’exposition des tendons, des os ou des articulations, ne peuvent pas cicatriser avec la revascularisation et le débridement local. La chirurgie, associant un pontage veineux distal ou une recanalisation et un lambeau libre, permet de traiter les pertes de substances et présente un avantage hémodynamique en augmentant le débit du pontage grâce au lit vasculaire ajouté par le lambeau. Nous proposons une nouvelle technique chirurgicale basée sur l’utilisation d’une unité anatomique unique, le lambeau-pontage épiploïque (LPE). Il est composé d’un axe artériel, l’artère gastroépiploïque (AGE), qui procure le greffon, et du grand épiploon, utilisé comme lambeau irrigué par une ou plusieurs branches épiploïques. Le but de ce travail était d’analyser la faisabilité anatomique d’un LPE et de valider le scanner pour l’évaluation préopératoire de l’AGE. Nous avons également évalué les effets hémodynamiques de cette technique et analysé la première expérience clinique. 100 dissections anatomiques ont été réalisées afin de mesurer les diamètres et les longueurs de l’AGE droite et de ses branches, ainsi qu’une radiographie après injection de produit radio-opaque. Pour évaluer la faisabilité préopératoire, nous avons étudié 30 tomodensitométries. Nous avons également exploré les effets hémodynamiques dans le modèle porcin. Notre étude anatomique confirme la faisabilité d’un LPE. La longueur moyenne de l’AGE est de 24,5 cm. Le diamètre proximal moyen est de 3 mm et celui distal est de 1,5 mm. Les données de l’étude radiologique montrent que le scanner peut être utilisé pour le repérage préopératoire de l’AGE et la faisabilité d’un LPE. Les mesures hémodynamiques ont montré que, grâce au lambeau épiploïque, le débit sanguin du pontage augmente et que les résistances distales diminuent. Le LPE est une technique chirurgicale qui doit permettre de repousser les limites de sauvetage de membre dans les conditions de cette pathologie extrême, réalisant une revascularisation distale et une couverture simultanée des pertes de substances chez les patients atteints d’artériopathie
The incidence of critical limb ischemia increases with the ageing of the population. Often, revascularization decreases the rate of amputation. In some cases, infected wounds with exposure of the tendons, bones or articulations will not heal only with revascularization and local debridement. Surgery combining a distal venous bypass or recanalisation and a free flap can treat those wounds, the vascular bed added by the flap improve the hemodynamic and increases the flow in the bypass. We proposed a new surgical method based on the use of a single anatomical unit, the epiploic flow-through flap (FTF), the gastroepiploic artery (GEA) as the vascular substitute and the greater omentum as the flap. The aim of this work was to analyze the anatomical feasibility of an epiploic BF, and to validate CT scan for preoperative assessment of the suitability of the GEA. We also aimed to evaluate the hemodynamic effects of this technique and to analyze the first clinical experience. 100 anatomical dissections were performed in order to measure the diameters and the lengths of GEA and its branches. An extensive X-ray study was also carried out with injection of a radiopaque product. To evaluate preoperative feasibility of the omental FTF, we studied radiological properties of the GEA on 30 routine CT scans. Finally, we also explored the hemodynamic behavior of this artery and its related flap in porcine models. Our anatomical study confirms the feasibility of a FTF. The average available length of GEA is 245 mm. The average proximal diameter is 3 mm and the distal one is 1.5 mm. Data of radiological study show that CT scan can be used to indicate GEA suitability for an epiploic FTF. The hemodynamic measures showed that thanks to the flap, the blood flow increase in the bypass. Ultimately,we report our first clinical application of the omental FTF for distal lower limb revascularization combined to wound coverage, with successful outcome. Epiploic FTF is a surgical technique, which allows distal revascularization and a simultaneous cover of the limb extremity. This technique can be useful in patients requiring a distal revascularization associated with the coverage of large the wounds

Indiana University-Purdue University Indianapolis (IUPUI)
Peripheral arterial disease is caused by plaque buildup in the peripheral arteries. Standard treatments are available when the blockage is proximal and focal, however when distal and diffuse the same type of the treatment options are not beneficial due to the diseased locations. Restoration of blood flow and further salvaging of the limb in these patients can occur in a retrograde manner through the venous system, called retroperfusion or arteriovenous reversal. Retroperfusion has been explored over the last century, where early side to side artery to venous connections had issues with valve competency prohibiting distal flows, edema buildup, and heart failure. However, more recent clinical studies create a bypass to a foot vein to ensure distal flows, and though the results have been promising, it requires a lengthy invasive procedure. It is our belief that the concerns of both retroperfusion approaches can be overcome in a minimally invasive/catheter based approach in which the catheter is engineered to a specific resistance that avoids edema and the perfusion location allows for valves to be passable and flow to reach distally. In this approach, the pressure flow relations were characterized in the retroperfused venous system in ex-vivo canine legs to locate the optimal perfusion location followed by in-vivo validation of canines. Six canines were acutely injured for 1-3 hours by surgical ligation of the terminal aorta and both external iliac arteries. Retroperfusion was successfully performed on five of the dogs at the venous popliteal bifurcation for approximately one hour, where flow rates at peak pressures reached near half of forward flow (37±3 vs. 84±27ml/min) and from which the slope of the P/F curves displayed a retro venous vasculature resistance that was used to calculate the optimal catheter resistance. To assess differences in regional perfusion, microspheres were passed during retroperfusion and compared to baseline microspheres passed arterially prior to occlusion in which the ratio of retroperfusion and forward perfusion levels were near the ratio of reversed and forward venous flow (0.44) throughout the limb. Decreases in critical metabolites during injury trended towards normal levels post-retroperfusion. By identifying the popliteal bifurication as a perfusion site to restore blood flow in the entirety of the distal ischemic limb, showing reversal of injury, and knowing what catheter resistances to target for further chronic studies, steps towards controlled retroperfusion and thus more efficient treatment options can be made for severe PAD patients.

Indiana University-Purdue University Indianapolis (IUPUI)
Objective: Gold standard therapy for chronic limb threatening ischemia (CLTI) is revascularization but in patients in whom below-the-knee bypass is indicated autologous vein conduit may not be available. Contemporary outcomes of distal bypass with suboptimal conduits have not been well described and recent advances in non-surgical therapies raise the question of whether in some cases there is evidence that these should be considered. Methods: Data was obtained from the Vascular Quality Initiative (VQI) registry as well as from a multi-center, randomized clinical trial of cell therapy. Incidence of major amputation after distal bypass was estimated for the VQI cohort by conduit type using non-parametric survival analysis with death as a competing risk. A cox proportional hazards model was then fit to the pooled data in a stepwise fashion with death as a competing risk, including evaluations for appropriate transformation, time dependency and interactions for each included covariate, and hazard ratios were estimated for the risk of major amputation by treatment. Results: At 365 days, the estimated cumulative incidence of major amputation with death as a competing risk is 25% after distal bypass with non-autologous biologic conduit (0.2499, 95% CI 0.2242 - 0.2785), 13% for prosthetic (0.1276, 95% CI 0.1172 - 0.1389) and 9% for GSV (0.0900, 95% CI 0.0848 - 0.0956). The cox proportional hazards model found a significant interaction between age and treatment. Compared to bypass with non-autogenous biologic, the hazard ratios for bypass with GSV were 0.41 (p<0.0001), 0.41 (p<0.0001), 0.42 (p<0.0001) and 0.42 (p<0.0001) respectively at ages 55, 60, 65 and 70 and for bypass with prosthetic were 0.68 (p=0.0043), 0.67 (p=0.0004), 0.65 (p<0.0001) and 0.64 (p<0.0001) respectively and for autologous cell therapy 0.22 (p=0.0005), 0.34 (p=0.0011), 0.52 (p=0.0196) and 0.76 (p=0.3677) respectively. No significant differences were found between best medical management and distal bypass with non-autologous biologic. Conclusion: The risk of major amputation after distal bypass is lowest in patients with GSV conduit and highest following bypass with non-autologous biologic. Using a semi-parametric model, cell therapy was estimated to significantly decrease the risk of amputation compared to distal bypass with non-autologous biologic conduit in younger patients.

碩士
國立中山大學
生物科學系研究所
102
Background: Erythropoietin (EPO) has been demonstrated to enhance recovery in ischemic organ through enhancing angiogenesis. The anti-apoptosis action of EPO was also found in vitro study. To reveal underlying mechanisms and directly examine the benefits of anti-apoptotic capacity of EPO in acute phase of limb ischemia and following blood flow recovery, we applied an experimental critical limb ischemia (CLI) rat model in present study. Methods: To determine the role of JAK2/STATs pathway in EPO-enhanced recovery after CLI, Male Sprague-Dawley rats (n=12 for each group) were divided into group 1 (normal control), group 2 (CLI treated with normal saline), group 3 (CLI treated with EPO), group 4 (CLI treated with AG490, a JAK2 inhibitor), and group 5 (CLI treated with EPO and AG490). Animals were sacrificed at either day 1 or day 14, followed by biochemical and histopathological examination on ischemic quadriceps. Results: At day 1, EPO administration reduced expression levels of apoptotic indices and activated the JAK2/STAT pathway, which inhibited by additional AG490 treatment.Furthermore, the decrease of infarcted area, as well as activation of ERK1/2 and JNK,showed similar regulatory trends with EPO and AG490. Of Interest, EPO and AG490 showed a synergistic effect in increasing expression levels of antioxidants (GR, GPx,NQO-1) and in decreasing transcriptional levels of pro-inflammatory factors (TNF-α,NF-κB). At day 14, laser Doppler analysis showed that the blood flow recovery were enhanced with EPO, AG490, or combined treatment. Conclusion: Although inhibition of JAK2/STAT pathways reduces the anti-apoptotic effects of EPO in early phase of CLI, the benefits of AG490 in anti-inflammation and anti-oxidation still play a positive role in enhancing blood flow recovery after CLI.

The aim of this thesis is to determine the feasibility of an injectable delivery system based on 5-ethylene ketal ε-caprolactone for localized delivery of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) for treating critical limb ischemia. HGF and VEGF were chosen because of their ability to simultaneously stimulate the proliferation and migration of endothelial cells, to initiate the formation of blood vessels and the recruitment of pericytes to stabilize the blood vessels. Homopolymer of 5-ethylene ketal ε-caprolactone and its copolymer with D,L-Lactide were synthesized by ring opening polymerization using hydrophobic initiator (octan-1-ol) or an hydrophilic initiator (MPEG), and stannous octanoate as a co-initiator/catalyst. The resulting polymers were amorphous and viscous liquids at room temperature. The viscosity, biodegradation rate, and release rate were varied by copolymerizing with D,L-lactide and/or initiating with MPEG or octan-1-ol. In vitro, the polymers degraded with surface erosion characterized by a nearly linear mass loss with time with no significant change in number average molecular weight and glass transition temperature. The ratio of EKC to DLLA in the copolymer remained the same throughout the degradation studies. A similar degradation mechanism was observed in vivo when the copolymer initiated with octan-1-ol was implanted subcutaneously in rats. In vivo, the polymer exhibited a moderate chronic inflammatory response, characterized by the presence of neutrophils, macrophages, fibroblasts and fibrous capsule formation. The inflammatory response decreased with time but was still on going after 18 weeks of subcutaneous implantation. Protein release from the polymer was transported by convection through the hydrated polymer region, at a rate determined by the osmotic pressure generated and the hydraulic conductivity of the polymer. Highly bioactive VEGF and HGF were released in a sustained manner, without burst effect for over 41 days when delivered simultaneously, using the osmotic release mechanism. VEGF was released at the rate of 36 ± 7 ng/day for 41 days, while HGF was released at the rate of 16 ± 2 ng/day for 70 days. Factors that influenced release of proteins were their solubility in the concentrated trehalose solution and hydraulic permeability of the polymer. This delivery system can serve as a potential vehicle for controlled release of VEGF and HGF for treating critical limb ischemia or the controlled release of other proteins for other clinical applications.
Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-05-23 10:18:48.307

PhD Aims: The aim of our study was to evaluate an efficacy and safety of intra-arterial injection of bone marrow mononuclear cells (BMMCs) in patients with chronic critical limb ischemia (CLI) Methods.In average 400ml bone marrow blood was harvested from posterior iliac crests in 24 CLI patients. BMMCs were obtained from the blood by standard procedure used for bone marrow transplantation. After digital subtraction angiography was performed in each patient, BMMCs were injected into arteries of 28 limbs. Primary outcome was the efficacy of BMMCs injection measured as a successfull healing of limb defects, a change of Fontain ischemia grade and a rate of high limb amputations. Secondary outcomes were a safety of the BMMCs injections, changes in angiographic findings after BMMCs injections and changes in quality of life (questionnaire SF-36). Results: After one year follow-up all patients were alive and 2 patients have undergone high limb amputation. Out of 14 limb defects, eleven have been healed completely and the average Fontain ischemia grade has changed from baseline value of 3.5 to 2.0 after one year (P<0.0001). Angiographic findings have improved in all examined segments of limb vessels. One year after the procedure patients have reported significant improvement. Conclusion: The intra-arterial...

Σκοπός: Η μελέτη είχε ως σκοπό την διερεύνηση της ασφάλειας και της αποτελεσματικότητας των sirolimus-eluting stent, σε σχέση με τα απλά μεταλλικά stent, στα πλαίσια αγγειοπλαστικής των κνημιαίων αγγείων, σε ασθενείς με χρόνια κρίσιμη ισχαιμία του κάτω άκρου. Πρόκειται για μια προοπτική ελεγχόμενη, κλινική μελέτη με διπλό σκέλος. Τα stent τοποθετήθηκαν σε περιπτώσεις μη ικανοποιητικής αγγειοπλαστικής (δηλ. σε περιπτώσεις ελαστικής επαναφοράς-υπολειμματικής στένωσης >30% και σε περιπτώσεις διαχωρισμού). Οι ασθενείς ελέγχθηκαν κλινικά και αγγειογραφικά στο εξάμηνο και στο 1 έτος. Ασθενείς και μέθοδοι: 29 ασθενείς, εκ των οποίων 8 γυναίκες και 21 άνδρες, με μέση ηλικία τα 68,7 έτη υποβλήθηκαν σε αγγειοπλαστική στα κνημιαία αγγεία, με απλά μεταλλικά stent, ομάδα Β. Σε αυτή την ομάδα τοποθετήθηκαν απλά stent σε 65 αλλοιώσεις, εκ των οποίων 38 στενώσεις και 27 αποφράξεις σε συνολικά 40 κνημιαία αγγεία. Άλλοι 29 ασθενείς, 8 γυναίκες και 21 άνδρες, με μέση ηλικία τα 68,8 έτη αντιμετωπίστηκαν με sirolimus-eluting stent, ομάδα S. Σε αυτή την ομάδα αντιμετωπίστηκαν 66 αλλοιώσεις εκ των οποίων 46 στενώσεις και 20 αποφράξεις, σε 41 συνολικά αγγεία. Οι ασθενείς επανελέγχθηκαν κλινικά και με ενδαρτηριακή αγγειογραφία στους 6 μήνες και στο 1 έτος, μετά την αρχική επέμβαση. Έγινε στατιστική ανάλυση των αποτελεσμάτων. Αποτελέσματα: Οι συνοδές νόσοι ήταν περισσότερες στην ομάδα S (όπως η συμπτωματική νόσος από την καρδιά και τις καρωτίδες, καθώς και η υπερλιπιδαιμία, p<0.05). Η τεχνική επιτυχία ήταν 96,6% (28/29 άκρα) στην ομάδα Β έναντι 100% (29/29 άκρα) στην ομάδα S (p=0.16) Στον επανέλεγχο εξαμήνου: Η βατότητα ήταν 68,1% στην ομάδα Β και 92,0% στην ομάδα S, (p<0.002). Τα μεγαλύτερα ποσοστά βατότητας των sirolimus-eluting stent, μετά από πολυπαραγοντική regression analysis είχαν OR 5.625, με 95% CI 1.711- 18.493, που ήταν στατιστικά σημαντικό (p=0.004). Η δυαδική επαναστένωση εντός του stent ήταν 55,3% ενώ η επαναστένωση στα άκρα του stent ήταν 66,0% στους ασθενείς με τα απλά μεταλλικά stent. Αντιθέτως τα ποσοστά στους ασθενείς με sirolimus-eluting stent ήταν 4,0% και 32,0% αντίστοιχα. Συγκεκριμένα η επαναστένωση εντός του stent είχε OR 0.067, με 95% CI 0.021-0.017, και η επαναστένωση στα άκρα του stent είχε OR 0.229 με 95% CI 0.099-0.533. Και τα δύο ήταν ήταν στατιστικά σημαντικά με p<0.001 και p=0.001, αντίστοιχα. Τα συνολικά ποσοστά επανεπέμβασης (TLR) στο εξάμηνο ήταν 17,0% στην ομάδα Β έναντι 4,0% στην ομάδα S, (OR 0.057, με 95% CI 0.008-0.426). Το αποτέλεσμα ήταν επίσης στατιστικά σημαντικό υπέρ των sirolimus stent. (p=0.02) Η διάσωση του άκρου ήταν 100% και στις δύο ομάδες. Η θνησιμότητα και ο ελάσσων ακρωτηριασμός στο εξάμηνο ήταν 6,9% και 17,2% στην ομάδα Β έναντι 10,3% και 3,4% στην ομάδα S (p=0.32 και p=0.04, αντίστοιχα). Στον επανέλεγχο έτους: Τα sirolimus-eluting stent σχετίζoνταν και πάλι με καλύτερη πρωτογενή βατότητα (OR 10.401, με 95% CI 3.425-31.589, p<0.001) και σημαντικά μειωμένη δυαδική επαναστένωση εντός του stent (OR 0.156, με 95% CI 0.060-0.407, p<0.001), καθώς και στα άκρα του stent. (OR 0.089, με 95% CI 0.023-0.349, p=0.001) Τα ποσοστά επανεπέμβασης στις βλάβες (TLR) ήταν πολύ μικρότερα στην ομάδα του sirolimus (OR 0.238, με 95% CI 0.067-0.841, p=0.026) . Δεν υπήρξαν στατιστικά σημαντικές διαφορές ανάμεσα στις δύο ομάδες Β και S όσον αφορά στα ποσοστά θνησιμότητας 10,3% έναντι 13,8%, στη διάσωση του άκρου 100% έναντι 96% και στους ελάσσονες ακρωτηριασμούς 17,2% έναντι 10,3% αντίστοιχα. Συμπεράσματα: Τα sirolimus-eluting stents περιορίζουν την ενδοθηλιακή υπερπλασία στα κνημιαία αγγεία. Η εφαρμογή τους έχει ως αποτέλεσμα την σημαντική μείωση των ποσοστών επαναστένωσης και μειώνει την ανάγκη για επανεπεμβάσεις.
Aim : The purpose of our study was to investigate the 6-month and 1-year angiographic and clinical outcome in the setting of a controlled clinical study. The study examined the safety and relative effectiveness of sirolimus-eluting stents opposed to conventional metal stents, in the infrapopliteal vessels, in patients with critical limb ischemia (CLI). The stents were used in a bail-out setting during infrapopliteal endovascular procedures, i. e. stenting was carried out in cases of suboptimal angioplasty results (recoil - residual stenosis >30%, or in cases of dissection, after angioplasty). Patients and Methods: Twenty-nine patients comprising 8 women and 21 men with a mean age of 68.7 years were submitted to infrapopliteal revascularization with conventional (bare) metal stents, called group B. In these patients 65 lesions were treated with bare stents, of whom 38 stenoses and 27 occlusions, in a total of 40 infrapopliteal vessels. Another 29 patients, again 8 women and 21 men, with a mean age of 68.8 years were treated with sirolimus-eluting stents, named group S. There were 66 lesions in this group with 46 of them stenoses and 20 occlusions, in a total of 41 arteries. Patients were followed-up with clinical examination and intrarterial angiography 6 months and 1 year after the procedure. Both results were subsequently analyzed statistically. 135 Results: Co morbidities like symptomatic cardiac and carotid disease, as well as hyperlipidemia were more prominent in group S (p<0.05). Technical success was 96.6% (28/29 limbs) in group B against 100.0% (29/29 limbs) in group S (p=0.16). During 6-month patient follow-up: Primary patency was 68.1% in group B opposed to 92.0% in group S (p<0.002). Sirolimus-eluting stents exhibited higher primary patency with OR 5.625 and 95% CI 1.711-18.493, which was statistically significant (p=0.004). Binary in-stent restenosis rate was 55.3% while in-segment restenosis was 66.0%, in patients who had received bare metal stents. In opposition the respective restenosis rates, in patients with sirolimus-eluting stents were 4.0% and 32.0%. Diminished in-stent (OR 0.067 with 95% CI 0.021-0.017) and insegment (OR 0.229 with 95% CI 0.099-0.533) binary restenosis were both statistically significant with p values being p<0.001 and p=0.001 respectively. Collective target lesion re-intervention (TLR) at 6 month follow-up was 17.0% in group B against 4.0% (OR 0.057 with 95% CI 0.008-0.426) in group S, which proved again statistically significant for sirolimus stents (p=0.02). Six-month limb salvage rate was 100% in both groups. Six-month mortality and minor amputation rates were respectively 6.9% and 17.2%, in group B versus 10.3% and 3.4%, in group S (p=0.32 and p=0.04, respectively). During 1-year patient follow-up: 136 SES were still related with better primary patency rate (OR 10.401 with 95% CI 3.425-31.589, p<0.001) and considerably lesser events of in-stent binary restenosis (OR 0.156, 95% CI 0.060-0.407, p<0.001) as well as insegment (OR 0.089, 95% CI 0.023-0.349, p=0.001) binary restenosis. Target lesion re-intervention (TLR), was much lower in the SES patients group during 1-year follow-up (OR 0.238 with 95% CI 0.067-0.841, p=0.026) . At 1 year follow-up there were no statistically significant differences among group B and group S regarding mortality (10.3% against 13.8%), limb salvage rates (100% vs. 96%) and minor amputation (17.2% vs. 10.3%). Conclusions: Sirolimus-eluting stents appear to limit intimal hyperplasia in the infrapopliteal vessels. The use of sirolimus-eluting stents decreases considerably restenosis rates in the infrapopliteal vessels and reduces the need for repeat interventions

Diabetic foot disease (DFD) is a serious complication of diabetes and, along with critical limb ischemia, significantly exacerbates the prognosis of patients. Peripheral arterial disease in patients with diabetes has an atypical clinical course, its diagnosis is challenging and is one of the most common causes of morbidity and mortality of patients with DFD. The aim of this dissertation focused on the diagnosis and treatment of DFD was to identify a suitable method for evaluating the effect of autologous cell therapy (ACT), to assess options for early diagnosis of Charcot osteoarthropathy (COA) and, possibly, to establish the association between the incidence of cardiovascular disease and DFD. In our studies concerning therapeutic vasculogenesis, we observed a significant increase in the antiangiogenic factor endostatin after ACT in contrast to its unchanged levels after standard percutaneous transluminal angioplasty; the transient increase in endostatin seems to be a marker of therapeutic vasculogenesis after ACT. A benefit of using calf muscle perfusion scintigraphy in the assessment of microcirculation and ACT effect was not clearly demonstrated. By contrast, a promising method for the evaluation of microcirculation and the effect of revascularization after ACT was MR spectroscopy of calf...