A Neuroprotective Locus Modulates Ischemic Stroke Infarction Independent of Collateral Vessel Anatomy

Although studies with inbred strains of mice have shown that infarct size is largely determined by the extent of collateral vessel connections between arteries in the brain that enable reperfusion of the ischemic territory, we have identified strain pairs that do not vary in this vascular phenotype, but which nonetheless exhibit large differences in infarct size. In this study we performed quantitative trait locus (QTL) mapping in mice from an intercross between two such strains, WSB/EiJ (WSB) and C57BL/6J (B6). This QTL mapping revealed only one neuroprotective locus on Chromosome 8 (Chr 8) that co-localizes with a neuroprotective locus we mapped previously from F2 progeny between C3H/HeJ (C3H) and B6. The allele-specific phenotypic effect on infarct volume at the genetic region identified by these two independent mappings was in the opposite direction of the parental strain phenotype; namely, the B6 allele conferred increased susceptibility to ischemic infarction. Through two reciprocal congenic mouse lines with either the C3H or B6 background at the Chr 8 locus, we verified the neuroprotective effects of this genetic region that modulates infarct volume without any effect on the collateral vasculature. Additionally, we surveyed non-synonymous coding SNPs and performed RNA-sequencing analysis to identify potential candidate genes within the genetic interval. Through these approaches, we suggest new genes for future mechanistic studies of infarction following ischemic stroke, which may represent novel gene/protein targets for therapeutic development.

Collateral Formation from Left Lateral Thoracic Artery to the Adamkiewicz Artery

A 68-year-old man who had undergone descending thoracic aortic replacement was referred to our hospital with a thoracoabdominal aortic aneurysm. During the original surgery, the Adamkiewicz artery was directly reconstructed. However, multidetector row computed tomography showed occlusion of the reconstructed artery at its orifice, with supply by a collateral vessel from the left lateral thoracic artery. With careful incision to avoid damage to the collateral vessel, no postoperative neurological deficit was observed.

Clinicopathological and radiological significance of the collateral vessels of renal cell carcinoma on preoperative computed tomography

This study aimed to investigate the clinicopathological and radiological significance of the collateral vessel of renal cell carcinoma (RCC) on preoperative computed tomography (CT). Preoperative contrast-enhanced CT of 236 consecutive patients with pathological documented RCC were retrospectively reviewed during the period of 2014. The associations of the presence of collateral vessels with perioperative clinicopathological and radiological features, as well as long term survival outcomes were analyzed. Totally, collateral vessels were detected by contrast-enhanced CT in 110 of 236 patients. The presence of collateral vessels was significantly associated with higher pathologic T stage, higher Fuhrman grade, higher overall RENAL scores, greater tumor size and enhancement, and more tumor necrosis (all P < 0.05). In patients with clear cell RCC, those harboring collateral vessels had significantly higher SSIGN scores (P < 0.001) and shorter overall survival (P = 0.01) than those without collateral vessel. The incidence of intraoperative blood loss, blood transfusion, radical nephrectomy (RN) and open surgery were also significantly higher in patients with collateral vessels (all P < 0.05). In multivariate analysis, the presence of collateral vessels was significantly associated with RN (P = 0.021) and open surgery (P = 0.012). The presence of collateral vessels was significantly associated with aggressive clinicopathological parameters and worse prognosis. It is worth paying attention to its association with the choice of RN and open surgery in clinical practice.

A neuroprotective locus modulates ischemic stroke infarction independent of collateral vessel anatomy

Ischemic stroke is caused by a disruption of the blood supply to the brain leading to neuronal cell death. Genetic studies of ischemic stroke have identified numerous gene variants that increase the risk to develop stroke. In stark contrast, genetic studies of stroke outcomes, such as the infarct territory size, are confounded by many uncontrollable variables, leading to a paucity of gene targets for treatment of an incipient stroke. Using genetically diverse inbred strains of mice and a surgically-induced model of ischemic stroke, we used quantitative trait locus mapping to identify novel gene targets modulating infarct size, which varies greatly across inbred strains. Although infarct size is largely determined by the extent of collateral vessel connection between arteries in the brain that enables reperfusion of the ischemic territory, we have identified strain pairs that do not vary in this phenotype, but which nonetheless exhibit large differences in infarct size. In this study we performed QTL mapping in mice from an intercross between two such strains, WSB/EiJ and C57BL/6J. We identified a strong locus on chromosome 8 that overlaps with a locus of similar direction and effect previously mapped in an intercross between C3H/HeJ and C57BL/6J strains. To identify causative genes within the overlapping genetic interval, we surveyed nonsynonymous coding SNPs and performed RNA sequencing data analysis for all three mapping strains. We identified Macrophage Scavenger Receptor 1 (Msr1) as a strong candidate gene that harbors multiple coding SNPs predicted to be damaging. Using Msr1-deficient mice, we demonstrated that cerebral infarct volume after stroke induction is dramatically increased in a strain background where reperfusion effects due to collateral vessels is blunted. Significantly, the identification of neuroprotective genes such as Msr1 provides new genes for future mechanistic studies of infarction following ischemic stroke and provides novel gene/protein targets for therapeutic development.Author summaryThe most common form of stroke arises when a blockage occurs in a blood vessel of the brain, thereby preventing delivery of oxygen and nutrients to areas supplied by the affected vessel, leading to tissue death. The main treatment for this form of stroke is medication to dissolve the blockage; however, more treatment options are required to better reduce the death and disability associated with stroke. In this study, we sought to identify genes that can decrease the amount of damage to brain tissue following a stroke, with a specific focus on examining genes that work to directly protect the neurons, rather than returning blood flow to the affected area. Since it is impossible to precisely control the nature of stroke and the genetic variability in humans, we used mice identify a genetic region that is associated with the amount of tissue damage following stroke. Within this genetic region, we identified a list of candidate genes, including the gene Msr1, which we found is important for controlling tissue damage in one genetic population of mice after stroke. The genes identified here require further follow-up to determine the impact on stroke outcomes and the usefulness of these candidates as therapeutic targets.

Right frontotemporal craniotomy for ECA-to-MCA direct and indirect bypass and occipital artery indirect bypass to the posterior circulation: case report

Moyamoya is an uncommon disease that presents with stenoocclusion of the major vasculature at the base of the brain and associated collateral vessel formation. Many pediatric patients with moyamoya present with transient ischemic attacks or complete occlusions. The authors report the case of a 9-year-old girl who presented with posterior fossa hemorrhage and was treated with an emergency suboccipital craniotomy for evacuation. After emergency surgery, an angiogram was performed, and the patient was diagnosed with moyamoya disease. Six months later, the patient was treated for moyamoya using direct and indirect revascularization; after surgery there was excellent vascularization in both regions of the bypass and no further progression of moyamoya changes. This case illustrates a rare example of intracerebral hemorrhage associated with moyamoya changes in the posterior vascularization in a pediatric patient and subsequent use of direct and indirect revascularization to reduce the risk of future hemorrhage and moyamoya progression.

Foot Angiosomes: Instructions for Use

In the last 15 years an abundance of literature has demonstrated that angiosome-targeted revascularization, either endovascular or open, can lead to better clinical results in patients with chronic limb-threatening ischemia. According to this literature, the angiosome concept should guide our treatment strategy in every chronic limb-threatening ischemia patient. However, in our daily practice, its application is often difficult or impossible. Most foot wounds spread over multiple angiosomes and, moreover, the value of an angiosome-guided revascularization approach can vary according to vascular anatomy, collateral vessel network, type of revascularization, and wound. The aim of this article is to explore values and limits of the angiosome concept, and to propose some “instructions for use” regarding its application in our daily practice.