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Platelets May 2020Hemostasis is the normal process that produces a blood clot at a site of vascular injury. Mice are widely used to study hemostasis and abnormalities of blood coagulation... (Review)
Review
Hemostasis is the normal process that produces a blood clot at a site of vascular injury. Mice are widely used to study hemostasis and abnormalities of blood coagulation because their hemostatic system is similar in most respects to that of humans, and their genomes can be easily manipulated to create models of inherited human coagulation disorders. Two of the most widely used techniques for assessing hemostasis in mice are the tail bleeding time (TBT) and saphenous vein bleeding (SVB) models. Here we discuss the use of these methods in the evaluation of hemostasis, and the advantages and limits of using mice as surrogates for studying hemostasis in humans.
Topics: Animals; Bleeding Time; Blood Coagulation; Disease Models, Animal; Hemorrhage; Hemostasis; Humans; Lacerations; Liver; Mice; Saphenous Vein; Tail
PubMed: 31992118
DOI: 10.1080/09537104.2020.1719056 -
Brazilian Journal of Cardiovascular... Sep 2022In this review, I summarise the circumstances leading to the collaboration between London and Örebro on the basic research performed to study potential mechanisms... (Review)
Review
In this review, I summarise the circumstances leading to the collaboration between London and Örebro on the basic research performed to study potential mechanisms underlying the improved patency of saphenous veins harvested by the no-touch technique. Histological studies reveal various forms of vascular damage to saphenous vein grafts harvested in conventional coronary artery bypass grafting (CABG) whereas no-touch grafts retain a normal architecture. The perivascular fat that remains intact on no-touch saphenous vein grafts seems to play a particularly important role as the "protector" of all layers of the graft. In addition, the perivascular fat is a source of adipose cell-derived factors that may contribute to the success of the no-touch technique. While a number of trials have compared no-touch with conventional grafts following CABG, these have generally been limited to short follow-up periods, low patient numbers, and inadequate histological data. When handling no-touch saphenous vein at harvesting, there is no direct contact of the vein by surgical instruments, spasm does not occur, and high-pressure intraluminal distension is not required. While damage to both endothelial and vascular smooth muscle cells are evident at the microscopic and ultrastructural level in conventional saphenous vein grafts, their structure in no-touch grafts is preserved. Also, in no-touch veins, the vasa vasorum remains intact and transmural blood supply is maintained. This microvascular network is disrupted during conventional harvesting, a situation likely to stimulate processes involved in graft occlusion. The use of excess graft material for histology is to be encouraged for the assessment of vascular damage and even surgeon competence. If you don't look, you don't find.
Topics: Coronary Artery Bypass; Humans; London; Saphenous Vein; Vasa Vasorum; Vascular Patency
PubMed: 36053997
DOI: 10.21470/1678-9741-2022-0024 -
VASA. Zeitschrift Fur Gefasskrankheiten May 2017Since the end of the nineties endovenous thermal ablation and more recently non-thermal, non-tumescent techniques have been developed and improved. Until now, because of... (Review)
Review
Since the end of the nineties endovenous thermal ablation and more recently non-thermal, non-tumescent techniques have been developed and improved. Until now, because of their favourable side effect profile in conjunction to sustained efficacy, in many countries they already replaced high ligation and stripping in the treatment of refluxing saphenous veins as well as for treatment of perforators and selected tributaries. Now, studies and comparative trials are available with long-term follow-ups for most of the techniques, providing valid data on occlusion and reflux rates, side effect profiles, and health related quality of life.
Topics: Ablation Techniques; Catheter Ablation; Humans; Laser Therapy; Postoperative Complications; Risk Factors; Saphenous Vein; Steam; Time Factors; Treatment Outcome; Venous Insufficiency
PubMed: 28238282
DOI: 10.1024/0301-1526/a000610 -
Journal of Cardiovascular Translational... Feb 2021Obstructive arterial disease is a major cause of morbidity and mortality in the developed world. Venous bypass graft surgery is one of the most frequently used... (Review)
Review
Obstructive arterial disease is a major cause of morbidity and mortality in the developed world. Venous bypass graft surgery is one of the most frequently used revascularization strategies despite its considerable short and long time failure rate. Due to vessel wall remodeling, inflammation, intimal hyperplasia, and accelerated atherosclerosis, vein grafts may (ultimately) fail to revascularize tissues downstream to occlusive atherosclerotic lesions. In the past decades, little has changed in the prevention of vein graft failure (VGF) although new insights in the role of innate and adaptive immunity in VGF have emerged. In this review, we discuss the pathophysiological mechanisms underlying the development of VGF, emphasizing the role of immune response and associated factors related to VG remodeling and failure. Moreover, we discuss potential therapeutic options that can improve patency based on data from both preclinical studies and the latest clinical trials. This review contributes to the insights in the role of immunomodulation in vein graft failure in humans. We describe the effects of immune cells and related factors in early (thrombosis), intermediate (inward remodeling and intimal hyperplasia), and late (intimal hyperplasia and accelerated atherosclerosis) failure based on both preclinical (mouse) models and clinical data.
Topics: Coronary Artery Bypass; Coronary Artery Disease; Humans; Immunomodulation; Saphenous Vein; Vascular Patency; Vascular Remodeling
PubMed: 32542547
DOI: 10.1007/s12265-020-10001-y -
Annals of Cardiac Anaesthesia 2022
Topics: Coronary Artery Bypass; Endoscopy; Humans; Saphenous Vein; Tissue and Organ Harvesting
PubMed: 35799574
DOI: 10.4103/aca.aca_39_22 -
Vascular Medicine (London, England) Feb 2015
Review
Topics: Hemodynamics; Humans; Predictive Value of Tests; Regional Blood Flow; Risk Factors; Saphenous Vein; Treatment Outcome; Ultrasonography; Varicose Veins
PubMed: 25722421
DOI: 10.1177/1358863X14566224 -
Annals of Saudi Medicine 2011Autologous saphenous vein grafting has been broadly used as a bypass conduit, interposition graft, and patch graft in a variety of operations in cardiac, thoracic,... (Review)
Review
Autologous saphenous vein grafting has been broadly used as a bypass conduit, interposition graft, and patch graft in a variety of operations in cardiac, thoracic, neurovascular, general vascular, vascular access, and urology surgeries, since they are superior to prosthetic veins. Modified saphenous vein grafts (SVG), including spiral and cylindrical grafts, and vein cuffs or patches, are employed in vascular revascularization to satisfy the large size of the receipt vessels or to obtain a better patency. A loop SVG helps flap survival in a muscle flap transfer in plastic and reconstructive surgery. For dialysis or transfusion purposes, a straight or loop arteriovenous fistula created in the forearm or the thigh with an SVG has acceptable patency. The saphenous vein has even been used as a stent cover to minimize the potential complications of standard angioplasty technique. However, the use of saphenous vein grafting is now largely diminished in treating cerebrovascular disorders, superior vena cava syndrome, and visceral revascularization due to the introduction of angioplasty and stenting techniques. The SVG remains the preferable biomaterial in coronary artery bypass, coronary osteoplasty, free flap transfer, and surgical treatment of Peyronie disease. Implications associated with saphenous vein grafting in vascular access surgery for the purpose of dialysis and chemotherapy are considerable. Vascular cuffs and patches have been developed as an important and effective means of enhancing the patency rates of the grafts by linking the synthetic material to the receipt vessel. In addition, saphenous veins can be a cell source for tissue engineering. We review the versatile roles that saphenous vein grafting has played as well as its current status in therapy.
Topics: Angioplasty; Humans; Saphenous Vein; Stents; Vascular Grafting
PubMed: 21245602
DOI: 10.4103/0256-4947.75781 -
Radiologia 2022Although ultrasound-guided interventional procedures have resulted in great advances in many fields of medicine, this approach has revolutionized endovascular... (Review)
Review
Although ultrasound-guided interventional procedures have resulted in great advances in many fields of medicine, this approach has revolutionized endovascular procedures. This paper aims to review the basic principles to develop a strategy to follow in ultrasound-guided treatments of varices in the lower limbs, as well as to provide a brief overview of the main endovenous techniques available nowadays. We divide these techniques into those that use catheters to occlude straight saphenous axes (thermal / non-thermal ablation) and other options, such as foam sclerotherapy, which can be used in all types of varices, even in those originating in the pelvis.
Topics: Humans; Radiology, Interventional; Saphenous Vein; Ultrasonography, Interventional; Varicose Veins; Venous Insufficiency
PubMed: 35180992
DOI: 10.1016/j.rxeng.2020.08.003 -
PloS One 2022Three-dimensional computed tomography venography is a useful tool to identify increased saphenous vein diameter and provides a complementary road map for surgery in... (Observational Study)
Observational Study
Three-dimensional computed tomography venography is a useful tool to identify increased saphenous vein diameter and provides a complementary road map for surgery in patients with varicose veins. In this study, we investigated the correlation between saphenous vein diameter on computed tomography venography and venous reflux detected on duplex ultraonography. We enrolled 152 patients (213 extremities) who underwent endovenous laser ablation therapy, following high ligation of the saphenofemoral junction between January 2014 and December 2019. All patients underwent preoperative computed tomography venography evaluation. The saphenous vein diameter was measured on computed tomography venography, and venous reflux was evaluated in the operating room using Doppler ultrasonography. Among the 152 patients included in the study, 61 showed varicose veins affecting the bilateral extremities. Among the 213 extremities investigated, 165 (77.5%) and 48 (22.5%) extremities showed varicosities involving the greater and lesser saphenous veins, respectively. Among all extremities, venous reflux was detected in 172 (80.8%). The mean diameter of the greater saphenous vein measured 5 cm distal to the saphenofemoral junction was 8.07±1.82 mm in patients with reflux and 5.11±1.20 mm in patients without reflux (p < .05). The small saphenous vein diameter measured 5 cm distal to the saphenopopliteal junction was 7.65±1.74 mm in patients with reflux and 5.04±1.80 mm in patients without reflux (p < .05). Based on the receiver operating characteristic curve, the greater saphenous vein threshold diameter of 5.880 mm measured 5 cm distal to the saphenofemoral junction was the optimal cut-off value to predict reflux (sensitivity 91.4%, specificity 81.8%). The lesser saphenous vein diameter of 5.285 mm measured 5 cm distal to the saphenopopliteal junction was the optimal cut-off value to predict reflux (sensitivity 94.9%, specificity 75.0%). Vein diameter cannot be used as an absolute reference for venous reflux; however, it may have predictive value in patients with varicose veins. Computed tomography venography based measurements of vein diameter may serve as a useful diagnostic tool to predict venous reflux and recommend treatment.
Topics: Adult; Aged; Female; Humans; Laser Therapy; Male; Middle Aged; Phlebography; Preoperative Period; Retrospective Studies; Saphenous Vein; Tomography, X-Ray Computed; Ultrasonography, Doppler; Varicose Veins
PubMed: 35167584
DOI: 10.1371/journal.pone.0263513 -
The Journal of Thoracic and... Nov 2022Little data exist regarding the potential of external stents to mitigate long-term disease progression in saphenous vein grafts. We investigated the effect of external... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
Little data exist regarding the potential of external stents to mitigate long-term disease progression in saphenous vein grafts. We investigated the effect of external stents on the progression of saphenous vein graft disease.
METHODS
A total of 184 patients undergoing isolated coronary artery bypass grafting, using an internal thoracic artery graft and at least 2 additional saphenous vein grafts, were enrolled in 14 European centers. One saphenous vein graft was randomized to an external stent, and 1 nonstented saphenous vein graft served as the control. The primary end point was the saphenous vein graft Fitzgibbon patency scale assessed by angiography, and the secondary end point was saphenous vein graft intimal hyperplasia assessed by intravascular ultrasound in a prespecified subgroup at 2 years.
RESULTS
Angiography was completed in 128 patients and intravascular ultrasound in the entire prespecified cohort (n = 51) at 2 years. Overall patency rates were similar between stented and nonstented saphenous vein grafts (78.3% vs 82.2%, P = .43). However, the Fitzgibbon patency scale was significantly improved in stented versus nonstented saphenous vein grafts, with Fitzgibbon patency scale I, II, and III rates of 66.7% versus 54.9%, 27.8% versus 34.3%, and 5.5% versus 10.8%, respectively (odds ratio, 2.02; P = .03). Fitzgibbon patency scale was inversely related to saphenous vein graft minimal lumen diameter, with Fitzgibbon patency scale I, II, and III saphenous vein grafts having an average minimal lumen diameter of 2.62 mm, 1.98 mm, and 1.32 mm, respectively (P < .05). Externally stented saphenous vein grafts also showed significant reductions in mean intimal hyperplasia area (22.5%; P < .001) and thickness (23.5%; P < .001).
CONCLUSIONS
Two years after coronary artery bypass grafting, external stenting improves Fitzgibbon patency scales of saphenous vein grafts and significantly reduces intimal hyperplasia area and thickness. Whether this will eventually lead to improved long-term patency is still unknown.
Topics: Coronary Angiography; Coronary Artery Bypass; Coronary Artery Disease; Disease Progression; Humans; Hyperplasia; Saphenous Vein; Stents; Treatment Outcome; Vascular Patency
PubMed: 34024615
DOI: 10.1016/j.jtcvs.2021.03.120