Arteriovenous Fistula Maturation in Patients with Ipsilateral Versus Contralateral Tunneled Dialysis Catheter: A Systematic Review and Meta-analysis.

BACKGROUND: Although it is evident that a prior history of tunneled dialysis catheter (TDC) affects arteriovenous fistula (AVF) function, it is unclear whether its location (contralateral versus ipsilateral to AVF) has any effect on AVF maturation and failure rates. We aimed to document this possible effect. METHODS: This systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies comparing outcomes between patients with contralateral TDC (CONTRA group) and those with ipsilateral one (IPSI group) were examined for inclusion. A random effects model meta-analysis of the odds ratio (OR) was conducted. Primary outcomes were AVF functional maturation, assisted maturation, and failure rates. RESULTS: Four eligible studies comprising 763 patients were included in the meta-analysis. There were no significant differences in terms of AVF functional maturation (OR: 1.49; 95% confidence interval [CI]: 0.64-3.47; I2 = 83.4%), assisted maturation (OR: 0.59; 95% CI: 0.29-1.19; I2 = 61.4%), and failure rates (OR: 0.67; 95% CI: 0.29-1.58; I2 = 83.3%) between the 2 study groups. CONCLUSIONS: TDC laterality seems not to affect fistula maturation rate in patients requiring TDC placement and concurrent AVF creation, but rather, vein- and patient-related characteristics might play a more important role in choosing TDC access site. Further studies are needed to validate these results.

Specific configurations of electrical synapses filter sensory information to drive choices in behavior.

Synaptic configurations in precisely wired circuits underpin how sensory information is processed by the nervous system, and the emerging animal behavior. This is best understood for chemical synapses, but far less is known about how electrical synaptic configurations modulate, in vivo and in specific neurons, sensory information processing and context-specific behaviors. We discovered that INX-1, a gap junction protein that forms electrical synapses, is required to deploy context-specific behavioral strategies during C. elegans thermotaxis behavior. INX-1 couples two bilaterally symmetric interneurons, and this configuration is required for the integration of sensory information during migration of animals across temperature gradients. In inx-1 mutants, uncoupled interneurons display increased excitability and responses to subthreshold temperature stimuli, resulting in abnormally longer run durations and context-irrelevant tracking of isotherms. Our study uncovers a conserved configuration of electrical synapses that, by increasing neuronal capacitance, enables differential processing of sensory information and the deployment of context-specific behavioral strategies.

Superficial Femoral Artery Remote Endarterectomy: A Systematic Review and Meta-Analysis.

BACKGROUND: Remote superficial femoral artery endarterectomy (RSFAE) is a hybrid procedure with low risk for perioperative complications and promising patency rates over time. The aim of this study was to summarize current literature and to determine the role of RSFAE in limb salvage with regards to technical success, limitations, patency rates and long-term outcomes. METHODS: This systematic review and meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses guidelines. RESULTS: Overall 19 studies were identified, comprising 1,200 patients with extensive femoropopliteal disease among whom 40% presented with chronic limb threatening ischemia. The average technical success rate was 96%, with a 7% rate for perioperative distal embolization and 13% rate for superficial femoral artery perforation. The primary patency was 64% and 56%, primary assisted patency was 82% and 77%, and secondary patency was 89% and 72% at 12 and 24 months follow-up, respectively. CONCLUSIONS: For long femoropopliteal TransAtlantic InterSociety ConsensusC/D lesions, RSFAE appears to be a minimally invasive hybrid procedure with acceptable perioperative morbidity, low mortality, and acceptable patency rates. RSFAE should be considered an alternative to open surgery or a bridge to bypass.

Acute thrombosis of a giant perimedullary arteriovenous fistula in a pediatric HHT patient.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant hereditary disorder that results in arteriovenous malformations (AVMs) in the nose, mucocutaneous surfaces and visceral organs, including lung, brain, liver, bowel and rarely spinal cord. We describe a case of a young child with HHT who presented with acute paraparesis due to acute thrombosis of a spinal perimedullary arteriovenous fistula. Patient underwent coil embolization of spinal arteriovenous shunt with resolution of clinical symptoms. This case highlights the possibility of catastrophic complications in young children with HHT, the potential preventive role of screening for spinal AVMs in HHT and the importance of timely intervention.

Sleep Analysis in Adult C. elegans Reveals State-Dependent Alteration of Neural and Behavioral Responses.

Sleep, a state of quiescence associated with growth and restorative processes, is conserved across species. Invertebrates including the nematode Caenorhabditis elegans exhibit sleep-like states during development, satiety, and stress. Here, we describe behavior and neural activity during sleep and awake states in adult C. elegans hermaphrodites using new microfluidic methods. We observed effects of fluid flow, oxygen, feeding, odors, and genetic perturbations on long-term sleep behavior over 12 h. We developed a closed-loop sleep detection system to automatically deliver chemical stimuli to assess sleep-dependent changes to evoked neural responses in individual animals. Sleep increased the arousal threshold to aversive stimulation, yet the associated sensory neuron and first-layer interneuron responses were unchanged. This localizes adult sleep-dependent neuromodulation within interneurons presynaptic to the premotor interneurons, rather than afferent sensory circuits. However, sleep prolonged responses in appetitive chemosensory neurons, suggesting that sleep modulates responsiveness specifically across sensory systems rather than broadly damping global circuit activity.SIGNIFICANCE STATEMENT Much is known about molecular mechanisms that facilitate sleep control. However, it is unclear how these pathways modulate neural circuit-level sensory processing or how misregulation of neural activity contributes to sleep disorders. The nematode Caenorhabditis elegans provides the ability to study neural circuitry with single-neuron resolution, and recent studies examined sleep states between developmental stages and when stressed. Here, we examine an additional form of spontaneous sleep in adult C. elegans at the behavioral and neural activity levels. Using a closed-loop system, we show that delayed behavioral responses to aversive chemical stimulation during sleep arise from sleep-dependent sensorimotor modulation localized presynaptic to the premotor circuit, rather than early sensory circuits.

Cavernous sinus aneurysms: risk of growth over time and risk factors.

OBJECTIVE: Cavernous internal carotid artery (ICA) aneurysms are frequently diagnosed incidentally and the benign natural history of these lesions is well known, but there is limited information assessing the risk of growth in untreated patients. The authors sought to assess and analyze risk factors in patients with cavernous ICA aneurysms and compare them to those of patients with intracranial berry aneurysms in other locations. METHODS: Data from consecutive patients who were diagnosed with a cavernous ICA aneurysm were retrospectively reviewed. The authors evaluated patients for the incidence of cavernous ICA aneurysm growth and rupture. In addition, the authors analyzed risk factors for cavernous ICA aneurysm growth and compared them to risk factors in a population of patients diagnosed with intracranial berry aneurysms in locations other than the cavernous ICA during the same period. RESULTS: In 194 patients with 208 cavernous ICA aneurysms, the authors found a high risk of aneurysm growth (19.2% per patient-year) in patients with large/giant aneurysms. Size was significantly associated with higher risk of growth. Compared to patients with intracranial berry aneurysms in other locations, patients with cavernous ICA aneurysms were significantly more likely to be female and have a lower incidence of hypertension. CONCLUSIONS: Aneurysms of the cavernous ICA are benign lesions with a negligible risk of rupture but a definite risk of growth. Aneurysm size was found to be associated with aneurysm growth, which can be associated with new onset of symptoms. Serial follow-up imaging of a cavernous ICA aneurysm might be indicated to monitor for asymptomatic growth, especially in patients with larger lesions.

Vertebral Arteriovenous Fistula: A Review Article.

OBJECTIVE: Vertebrovertebral fistulas (VVFs) are uncommon lesions that can arise spontaneously or secondarily to iatrogenic or mechanical trauma. We performed a systematic review of the literature to obtain information regarding demographics, clinical presentation, treatment modalities, outcome, and complications associated with treatment. METHODS: A literature search was performed by a reference librarian and after screening, 128 case reports and 16 case series were left for inclusion in the review. All possible data were abstracted by 3 authors, results were tabulated, and descriptive statistics (mean, range, and proportions) were reported. No formal statistical analysis was performed as part of this study. RESULTS: A total of 280 patients were analyzed. VVFs can be categorized in 3 subgroups (iatrogenic, spontaneous, and traumatic), based on the mechanism of formation, and these different causes share different underlying demographics that bear important treatment considerations. Traumatic VVFs are more commonly seen in young men; the spontaneous form is more commonly seen in young women. Iatrogenic VVFs are more commonly seen in elderly people. Spontaneous VVFs are most commonly located between C1 and C2. Most iatrogenic (n = 39; 57%), spontaneous (n = 106; 82%), and traumatic (n = 53; 73%) VVFs were treated with deconstructive (defined as occlusion of fistula and feeding vessels) endovascular therapy. Overall treatment-related permanent morbidity was 3.3% (9/270) and mortality was 1.5% (4/270). CONCLUSIONS: VVFs are uncommon lesions, and treatment is often indicated, even in patients without retrograde venous drainage. When treatment is undertaken, the cause of presentation and associated patient demographics should be considered when planning the treatment strategy.

Integration of Plasticity Mechanisms within a Single Sensory Neuron of C. elegans Actuates a Memory.

Neural plasticity, the ability of neurons to change their properties in response to experiences, underpins the nervous system's capacity to form memories and actuate behaviors. How different plasticity mechanisms act together in vivo and at a cellular level to transform sensory information into behavior is not well understood. We show that in Caenorhabditis elegans two plasticity mechanisms-sensory adaptation and presynaptic plasticity-act within a single cell to encode thermosensory information and actuate a temperature preference memory. Sensory adaptation adjusts the temperature range of the sensory neuron (called AFD) to optimize detection of temperature fluctuations associated with migration. Presynaptic plasticity in AFD is regulated by the conserved kinase nPKCε and transforms thermosensory information into a behavioral preference. Bypassing AFD presynaptic plasticity predictably changes learned behavioral preferences without affecting sensory responses. Our findings indicate that two distinct neuroplasticity mechanisms function together through a single-cell logic system to enact thermotactic behavior. VIDEO ABSTRACT.