Evaluating Target: Stroke guideline implementation on assessment and treatment times for patients with suspected stroke.

OBJECTIVES: Immediate ischemic stroke treatment improves outcomes and early alteplase administration is recommended for patients within window. We implemented stroke guidelines through a neuro-resuscitation initiative (NRI) and hypothesized that the intervention would decrease times to assessment and treatment. METHODS: We analyzed quality assurance data for EMS and triage patients arriving to our academic emergency department with suspected ischemic stroke to compare outcomes 12 months before to 6 months after initiative implementation at an academic certified primary stroke center in the U.S. Southwest. We examined four time-based outcomes: neurology at bedside, CT head without contrast, CT head angiogram, and alteplase administration. We summarized times with median and IQR values and compared pre and post times to event (in minutes) with Wilcoxon rank sum tests and Kaplan-Meier survival curves. RESULTS: We identified 203 EMS (83 pre, 120 post) and 66 (11 pre, 55 post) triage Stroke Alert patients. We observed decreased times for all outcomes in both the EMS and triage samples; however, only those in the EMS sample were significant. In the EMS sample, neurology at bedside median times decreased from 20 min to 2 min (p < 0.001); median minutes to CT head without contrast decreased from 16 min to 9 min (p < 0.001); median minutes to CT head angiogram decreased from 71 min to 21 min (p = 0.007); and, median minutes to alteplase decreased from 72 min to 49.5 min (p = 0.04). CONCLUSIONS: An academic ED led stroke care initiative streamlined evaluation and care with significantly shortened times to all four events.

Blood Pressure and Hospital Discharge Outcomes in Acute Ischemic Stroke Patients Undergoing Reperfusion Therapy.

INTRODUCTION: Acute management of blood pressure in ischemic stroke treated with reperfusion therapy remains uncertain. We evaluated blood pressures during the first 24-hours after reperfusion therapy in relation to in-hospital outcomes. METHODS: We conducted a single-center retrospective study of blood pressure in the first 24 hours among ischemic stroke patients who underwent reperfusion therapy with intravenous thrombolysis (IVT) or mechanical thrombectomy (MT) at a tertiary referral center. Blood pressure variability was expressed as the range between the highest and the lowest pressures. Outcomes of interest were discharge disposition and in-hospital mortality. Favorable outcome was defined as a discharge destination to home or inpatient rehabilitation facility (IRF). Multivariable logistic regression analysis was performed with adjustment for age, National Institutes of Health Stroke Scale score, and patients receiving reperfusion therapy. RESULTS: Among the 140 ischemic stroke patients (117 IVT, 84 MT and 61 both), 95 (67.8%) had favorable discharge disposition and 24 (17.1%) died. Higher 24-hour peak systolic blood pressures (SBPs) and peak mean arterial pressures (MAPs) were independently associated with a lower likelihood of favorable discharge disposition, with an adjusted odds ratio (aOR) 0.868, 95 % CI 0.760 - 0.990 per 10 mm Hg for SBP and aOR 0.710, 95% CI 0.515 - 0.980 for MAP, and with increased odds of death aOR 1.244, 95% CI 1.056-1.467 and aOR 1.760, 95% CI 1.119 - 2.769 respectively. Greater variability of SBP and MAP was also associated with odds of death aOR 1.327, 95% CI 1.104 - 1.595 and aOR 1.577, 95% CI 1.060- 2.345 respectively, without a significant effect on discharge disposition. CONCLUSION: In the first 24 hours after reperfusion therapy, higher peak and variable blood pressures are associated with unfavorable discharge outcomes and increased in-hospital mortality. Further studies in stroke patients undergoing reperfusion therapy might target blood pressure reduction and variability to improve patient outcomes.

Is Reconstruction of Large Mandibular Defects Using Bioengineering Materials Effective?

PURPOSE: Clinical tissue engineering has revolutionized surgery by improving surgical efficiency and decreasing the risks associated with traditional bone graft procurement techniques. Compared with autogenous bone grafts, composite tissue-engineered grafts fulfill the principles of osteoconduction, osteoinduction, and osteogenesis and provide adequate bone volume for maxillofacial reconstruction with less morbidity. The present study aimed to demonstrate the effectiveness, as defined by our success criteria, of a composite tissue-engineered bone graft in the reconstruction of mandibular defects. PATIENTS AND METHODS: We implemented a retrospective case series and enrolled a sample of patients with mandibular defects that had been reconstructed using allogeneic bone combined with recombinant human bone morphogenic protein-2 and bone marrow aspirate concentrate at our institution during a 5-year period. The success criteria were as follows: 1) bone union, defined as a homogenous radiopaque pattern continuous with native bone without mandibular mobility; and 2) volume of grafted bone adequate for implant placement, defined as at least 1.0 cm (height) by 0.8 cm (width). Clinical examinations and computed tomography scans were performed at 6 months postoperatively. Descriptive statistics were computed for each variable. RESULTS: From 2014 to 2019, tissue engineering reconstruction was used in 31 patients with and 3 patients without mandibular continuity defects, for a total of 34 patients. The median follow-up was 6 months. The mean length of the continuity defects was 5.5 cm (range, 1.0 to 12.5). Of the 30 patients with mandibular continuity defects, 27 achieved success according to our criteria, with an average gained height of 2.12 ± 0.64 cm and width of 1.53 ± 0.46 cm. Of the 34 patients, 1 was lost to follow-up, and treatment failed in 3 patients. CONCLUSIONS: Although the use of autogenous graft remains the reference standard, the evolving science behind clinical tissue engineering has resulted in an effective treatment modality for complex head and neck defects with less morbidity and graft material equal to that of autogenous bone.

Current Advances in the Utilization of Polydopamine Nanostructures in Biomedical Therapy.

Since the first time mussel-inspired polymer polydopamine (PDA) was discovered, it has gained enormous attention from numerous scientists, especially those working in the field of drug delivery and bacterial and tumor treatment, due to its distinctive properties, such as surface chemistry, biocompatibility, capability to adhere to any surface, and excellent photothermal conversion. Studies using PDA in various types of structures for therapeutic purposes have been carried out extensively in recent years. Considering the rapid development in the area, this review aims to cover and highlight the latest achievements (from 2016 to present) with respect to PDA-based materials for therapeutic purposes. A description of the diverse structures of PDA and its formation strategy, including colloidal particles, hollow structures, and coating films, are discussed. In addition, the main focus of this review is on the therapeutic applications of these PDA nanostructures.

Modeling vitamin D insufficiency and moderate deficiency in adult mice via dietary cholecalciferol restriction.

PURPOSE: We sought to develop and characterize a model of human vitamin D nutritional insufficiency/deficiency in the adult mouse, which could have broad utility in examining health consequences of this common condition. METHODS: Adult mice were fed diets containing cholecalciferol contents of 0.05 IU/g, 0.25 IU/g, 0.5 IU/g or 1.5 IU/g for four months. We studied induction of steady-state vitamin D insufficiency, and its consequences on primary cholecalciferol metabolite levels, calcium homeostasis, parathyroid physiology, and bone morphology. RESULTS: All diets were well tolerated, without adverse effects on body weight. Diets containing 0.05 IU/g and 0.25 IU/g cholecalciferol significantly lowered serum 25-hydroxyvitamin D levels (median 25OHD, 10.5 ng/ml, and 21.6 ng/ml, respectively), starting as early as one month following initiation of the diets, maintained through the four-month experimental period. The 0.05 IU/g diet significantly decreased 1,25-dihydroxyvitamin D (1,25OH2D) levels (median, 78 pg/ml). Despite these decreased 25OHD and 1,25OH2D levels, the diets did not alter parathyroid gland morphology or parathyroid cell proliferation. There were no statistical differences in the serum total calcium and serum PTH levels among the various dietary groups. Furthermore, the 0.05 IU/g diet did not cause any alterations in the cortical and trabecular bone morphology, as determined by microCT. CONCLUSIONS: The dietary manipulations yielded states of vitamin D insufficiency or modest deficiency in adult mice, with no overtly detectable impact on parathyroid and bone physiology, and calcium homeostasis. This model system may be of value to study health effects of vitamin D insufficiency/deficiency especially on extraskeletal phenotypes such as cancer susceptibility or immune function.

What are the potential implications of identifying intracranial internal carotid artery atherosclerotic lesions on cone-beam computed tomography? A systematic review and illustrative case studies.

PURPOSE: A systematic literature review was performed to examine the clinical implications of intracranial internal carotid artery calcific atherosclerotic lesions (IICACALs) detected at cone-beam computed tomographic (CBCT) examinations. MATERIALS AND METHODS: The PubMed database was queried in 2 separate searches using the linked search terms non-contrast enhanced cone beam computed tomography and calcified intracranial vascular lesions and non-contrast enhanced computed tomography and calcified intracranial vascular lesions. Reviewed were all English-language articles using CBCT or CT imaging that enrolled neurologically asymptomatic and symptomatic patients. Excluded were studies describing patients with hemorrhagic stroke. Illustrative cases describing incidentally detected IICACALs on CBCT scans are provided. RESULTS: Three articles described identification of IICACALs on CBCT scans of almost 1,500 dental patients. Two of these fully addressed the subject, with 1 noting that IICACALs were benign and another urging patient referral for further workup. Five non-contrast-enhanced CT studies were evaluated in detail; all confirmed IICACALs as a substantive risk marker of advanced stenotic disease in the cerebral circulation, central brain atrophy, concomitant advanced atherosclerotic disease in the cardiovascular circulation, and an indicator of future ischemic events. Five CBCT examinations showing IICACALs in the cavernous and ophthalmic segments are presented. CONCLUSION: Few studies have denoted the importance of identifying IICACALs on CBCT scans. However, all non-contrast-enhanced CT studies emphasized the clinical significance of these lesions in relation to cerebral and cardiovascular disease. Therefore, IICACALs seen on CBCT and CT scans present the same risk and should prompt referral for further evaluation.

Uniform vascular contrast enhancement and reduced contrast medium volume achieved by using exponentially decelerated contrast material injection method.

PURPOSE: To investigate in computed tomographic (CT) angiography whether an exponentially decelerated contrast medium injection, as compared with a standard constant-rate injection, can facilitate uniform vascular contrast enhancement with a reduced contrast material volume. MATERIALS AND METHODS: CT angiography of the abdominal aorta was performed in 46 subjects by using an exponentially decelerated injection method: 134 mL of contrast medium was injected for 40 seconds, starting at 4.0 mL/sec and decreasing exponentially to 2.7 mL/sec by the end of the injection. Twenty-one of these subjects also underwent CT angiography with a constant-rate injection: 160 mL of contrast medium was injected for 40 seconds at a constant rate of 4 mL/sec. Time-enhancement curves and the magnitude of peak vascular enhancement were measured. Enhancement uniformity was evaluated by using three indexes: (a) duration of contrast enhancement achieved within 80% of the peak (80% DCE), (b) SD of the normalized contrast enhancement (SDNCE) measured from the beginning of spiral CT scanning to the time when the enhancement decreased to a level lower than the beginning level, and (c) slope of the enhancement curve calculated by using linear regression analysis. RESULTS: Exponentially decelerated injection resulted in more uniform enhancement. Mean values generated by using exponentially decelerated versus constant-rate injection in 21 paired comparisons were, respectively, 30.8 seconds +/- 5.0 versus 22.6 seconds +/- 7.6 for 80% DCE, 0.052 +/- 0.017 versus 0.086 +/- 0.031 for SDNCE, and 0.47 HU/sec +/- 0.70 versus 2.27 HU/sec +/- 0.87 for slope (P <.001 for all indexes). Compared with the peak enhancement resulting from the constant-rate injection, that resulting from the exponentially decelerated injection was reduced by a mean of 17.2% +/- 10.0. CONCLUSION: Uniform vascular contrast enhancement and reduced contrast medium volume, which are desirable in CT angiography, can be achieved with exponentially decelerated injection.