Citations

Abstract Sidewall aneurysm treatment often requires complex management strategies. These can include advanced clipping techniques or stent-assisted coiling techniques. Endovascular coiling alone has been associated with high recurrence rates and is often not feasible. 1-4 Flow-diversion embolization has recently become a standard of care for many aneurysms, demonstrating high occlusion rates. 4,5 However, the third generation of coil-assist stents can be delivered with 0.0165” microcatheters, being an ideal adjunct to manage this group of aneurysms in more distal locations. In this video, a 16-yr-old teenager with Parry-Romberg syndrome and congenital adrenal hyperplasia had an incidental finding of a 6.5-mm sidewall aneurysm arising off the angular branch of the left middle cerebral artery, found during the work-up of complex partial seizures. The patient consented to the procedure. Due to his young age and aneurysm size, a decision was made to treat the aneurysm through an endovascular approach. Under general anesthesia, a transfemoral approach was carried out using a 6-French short sheath. A 6-French guiding catheter was left in the distal cervical left internal carotid artery; a 0.0165” microcatheter was used to first deploy a 3.0 × 15 mm Neuroform Atlas stent, completely covering the length of the aneurysm. Then, the stent was traversed with the microcatheter to coil the aneurysm. Follow-up cerebral angiogram confirmed complete occlusion of the aneurysm.

Background The COVID-19 pandemic has disrupted established care paths worldwide. Patient awareness of the pandemic and executive limitations imposed on public life have changed the perception of when to seek care for acute conditions in some cases. We sought to study whether there is a delay in presentation for acute ischemic stroke patients in the first month of the pandemic in the US. Methods The interval between last-known-well (LKW) time and presentation of 710 consecutive patients presenting with acute ischemic strokes to 12 stroke centers across the US were extracted from a prospectively maintained quality database. We analyzed the timing and severity of the presentation in the baseline period from February to March 2019 and compared results with the timeframe of February and March 2020. Results There were 320 patients in the 2-month baseline period in 2019, there was a marked decrease in patients from February to March of 2020 (227 patients in February, and 163 patients in March). There was no difference in the severity of the presentation between groups and no difference in age between the baseline and the COVID period. The mean interval from LKW to the presentation was significantly longer in the COVID period (603±1035 min) compared with the baseline period (442±435 min, P<0.02). Conclusion We present data supporting an association between public awareness and limitations imposed on public life during the COVID-19 pandemic in the US and a delay in presentation for acute ischemic stroke patients to a stroke center.

Hydrogen sulfide (H 2 S) has long been associated with the gastrointestinal tract, especially the bacteria-derived H 2 S present in flatus. Along with evidence from other organ systems, the finding that gastrointestinal tissues are capable of endogenous production of H 2 S has led to the hypothesis that H 2 S is an endogenous gaseous signaling molecule. In this review, the criteria of gasotransmitters are reexamined, and evidence from the literature regarding H 2 S as a gaseous signaling molecule is discussed. H 2 S is produced enzymatically by gastrointestinal tissues, but evidence is lacking on whether H 2 S production is regulated. H 2 S causes well-defined physiologic effects in gastrointestinal tissues, but evidence for a receptor for H 2 S is lacking. H 2 S is inactivated through enzymatic oxidation, but evidence is lacking on whether manipulating H 2 S oxidation alters endogenous cell signaling. Remaining questions regarding the role of H 2 S as a gaseous signaling molecule in the gastrointestinal tract suggest that H 2 S currently remains a molecule in search of a physiologic function. Antioxid. Redox Signal. 12, 1135–1146.

Carbon monoxide (CO) is proposed as a physiological messenger. CO activates cGMP and has a direct effect on potassium channels. Both actions of CO lead to hyperpolarization of a cell's resting membrane potential, suggesting that CO may function as a hyperpolarizing factor, although direct evidence is still lacking. Here we take advantage of the known membrane potential gradient that exists in the muscle layers of the gastrointestinal tract to determine whether CO is an endogenous hyperpolarizing factor. We find that heme oxygenase-2-null mice have depolarized smooth muscle cells and that the membrane potential gradient in the gut is abolished. Exogenous CO hyperpolarizes the membrane potential. Regions of the canine gastrointestinal tract that are more hyperpolarized generate more CO and have higher heme oxygenase activity than more depolarized regions. Our results suggest that CO is a critical hyperpolarizing factor required for the maintenance of intestinal smooth muscle membrane potential and gradient.