Cerebral collateral circulation is a network of blood vessels which stabilizes blood flow and maintains cerebral perfusion whenever the main arteries fail to provide an adequate blood supply, as happens in ischemic stroke. These arterial networks are able to divert blood flow to hypoperfused cerebral areas. The extent of the collateral circulation determines the volume of the salvageable tissue, the so-called “penumbra”. Clinically, this is associated with greater efficacy of reperfusion therapies (thrombolysis and thrombectomy) in terms of better short- and long-term functional outcomes, lower incidence of hemorrhagic transformation and of malignant oedema, and smaller cerebral infarctions. Recent advancements in brain imaging techniques (CT and MRI) allow us to study these anastomotic networks in detail and increase the likelihood of making effective therapeutic choices. In this narrative review we will investigate the pathophysiology, the clinical aspects, and the possible diagnostic and therapeutic role of collateral circulation in acute ischemic stroke.

Atherosclerosis-related coronary artery disease (CAD) is the leading cause of mortality and morbidity worldwide. This requires effective primary and secondary prevention in reducing the complications related to CAD; the regression or stabilization of the pathology remains the mainstay of treatment. Statins have proved to be the most effective treatment in reducing adverse effects, but there are limitations related to the administration and achievement of effective doses as well as side effects due to the lack of target-related molecular specificity. The implemented technological steps are polymers and nanoparticles for the administration of statins, as it has been seen how the conjugation of drug delivery systems (DDSs) with statins increases bioavailability by circumventing the hepatic–renal filter and increases the related target specificity, enhancing their action and decreasing side effects. Reduction of endothelial dysfunction, reduced intimal hyperplasia, reduced ischemia–reperfusion injury, cardiac regeneration, positive remodeling in the extracellular matrix, reduced neointimal growth, and increased reendothelialization are all drug-related effects of statins enhanced by binding with DDSs. Recent preclinical studies demonstrate how the effect of statins stimulates the differentiation of endogenous cardiac stem cells. Poly-lactic-co-glycolic acid (PLGA) seems to be the most promising DDS as it succeeds more than the others in enhancing the effect of the bound drug. This review intends to summarize the current evidence on polymers and nanoparticles for statin delivery in the field of cardiovascular disease, trying to shed light on this topic and identify new avenues for future studies.

Circulating biomarkers have been recently investigated among patients undergoing endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). Considering the plethora of small descriptive studies reporting potential associations between biomarkers and clinical outcomes, this review aims to summarize the current literature considering both the treated disease (post EVAR) and the untreated disease (AAA before EVAR). All studies describing outcomes of tissue biomarkers in patients undergoing EVAR and in patients with AAA were included, and references were checked for additional sources. In the EVAR scenario, circulating interleukin-6 (IL-6) is a marker of inflammatory reaction which might predict postoperative morbidity; cystatin C is a promising early marker of post-procedural acute kidney injury; plasma matrix metalloproteinase-9 (MMP-9) concentration after 3 months from EVAR might help in detecting post-procedural endoleak. This review also summarizes the current gaps in knowledge and future direction of this field of research. Among markers used in patients with AAA, galectin and granzyme appear to be promising and should be carefully investigated even in the EVAR setting. Larger prospective trials are required to establish and evaluate prognostic models with highest values with these markers.

Peripheral arterial disease (PAD) is an increasingly pathological condition that commonly affects the femoropopliteal arteries. The current fashionable treatment is percutaneous transluminal angioplasty (PTA), often with stenting. However, the in-stent restenosis (ISR) rate after the stenting of the femoropopliteal (FP) district remains high. Many techniques have been proposed for the treatment of femoropopliteal ISR, such as intravascular brachytherapy, laser atherectomy, second stenting and drug-coated balloons angioplasty (DCB). DCB showed a significantly lower rate of restenosis and target lesions revascularization (TLR) compared to conventional PTA. However, further studies and multi-center RCTs with dedicated long-term follow-up are needed to verify the true efficiency of this approach. Nowadays, the correlation between PAD and inflammation biomarkers is well known. Multiple studies have shown that proinflammatory markers (such as C-reactive proteins) and the high plasma levels of microRNA could predict the outcomes after stent placement. In particular, circulating microRNA-320a, microRNA-3937, microRNA-642a-3p and microRNA-572 appear to hold promise in diagnosing ISR in patients with PAD, but also as predictors of stent patency. This narrative review intends to summarize the current knowledge on the value of circulating biomarkers as predictors of ISR and to foster the scientific debate on the advantages of using DCB in the treatment of ISR in the FP district.

Introduction: Stump syndrome is defined as a clinical syndrome resulting from a distal intracranial vessel embolic stroke due to an extracranial vessel occlusion. Similar to the anterior circulation, the recurrence of ischemic strokes in territories supplied by the posterior circulation in the presence of vertebral artery occlusion is termed Vertebral Artery Stump Syndrome (VASS). Material and Methods: We conducted a literature review, identifying 72 patients with transient ischemic attacks (TIAs) or ischemic strokes attributed to VASS, according to Kawano criteria. We categorized all patients in two groups focusing on the therapeutic management those who underwent primary medical treatment and those who received endovascular or surgical treatment either in acute or chronic phase. Results: In the anticoagulant therapy group, only 1 patient had a stroke recurrence. Among the 4 on antiplatelets, all had recurrences, but 3 benefited from switching to anticoagulants or endovascular therapy. In the endovascular therapy group, worse outcomes were linked to acute large vessel occlusion. Endovascular treatment of the vertebral artery, in a chronic phase, was explored in literature for recurrent TIAs or minor strokes suggesting that this could be a viable therapeutic alternative when medical treatment failed in preventing recurrence of ischemic stroke. Conclusions: Some studies suggest that anticoagulant medical therapy may be beneficial for VASS and endovascular therapy has also been reported for selected patients. However, data on treatment outcomes and prognosis are still underreported, making treatment decisions challenging. Randomized Controlled Trials are needed to establish the optimal treatment approach.

Surgical bypass is the gold standard treatment in patients affected by chronic limb-threatening ischemia in advanced GLASS stages, according to the Global Vascular Guidelines. For patients in whom an autologous graft is not available, a prosthesis could be used with the adjunct of a distal arteriovenous fistula interposition. The aim of this study was to examine the long-term results of below-the-knee surgical revascularization using a prosthesis with the distal adjunct mentioned above. From 2010 to 2020, we performed 159 lower limb below-the-knee surgical revascularizations using a prosthesis with the creation of an arteriovenous fistula interposition on the distal anastomosis. The GLASS stage was 3 in 100% of patients. The primary patency rates were as follows: 86.7% at 1 year, 57.2% at 3 years, and 12.6% at 5 years. The graft thrombosis rates were 17.4% at 1 year, 42.1% at 3 years, and 64.5% at 5 years. The amputation-free survival rates were 79% at 1 year, 76% at 3 years, and 64% at 5 years. PTFE prosthetic bypass for below-the-knee arteries using an arteriovenous fistula interposition is a good solution in patients without an autologous conduit. This technique offers reasonable graft patency and limb salvage rates.