Optimizing the Definition of Ischemic Core in CT Perfusion: Influence of Infarct Growth and Tissue-Specific Thresholds

BACKGROUND AND PURPOSE

CTP allows estimating ischemic core in patients with acute stroke. However, these estimations have limited accuracy compared with MR imaging. We studied the effect of applying WM- and GM-specific thresholds and analyzed the infarct growth from baseline imaging to reperfusion.

MATERIALS AND METHODS

This was a single-center cohort of consecutive patients (n = 113) with witnessed strokes due to proximal carotid territory occlusions with baseline CT perfusion, complete reperfusion, and follow-up DWI. We segmented GM and WM, coregistered CTP with DWI, and compared the accuracy of the different predictions for each voxel on DWI through receiver operating characteristic analysis. We assessed the yield of different relative CBF thresholds to predict the final infarct volume and an estimated infarct growth-corrected volume (subtracting the infarct growth from baseline imaging to complete reperfusion) for a single relative CBF threshold and GM- and WM-specific thresholds.

RESULTS

The fixed threshold underestimated lesions in GM and overestimated them in WM. Double GM- and WM-specific thresholds of relative CBF were superior to fixed thresholds in predicting infarcted voxels. The closest estimations of the infarct on DWI were based on a relative CBF of 25% for a single threshold, 35% for GM, and 20% for WM, and they decreased when correcting for infarct growth: 20% for a single threshold, 25% for GM, and 15% for WM. The combination of 25% for GM and 15% for WM yielded the best prediction.

CONCLUSIONS

GM- and WM-specific thresholds result in different estimations of ischemic core in CTP and increase the global accuracy. More restrictive thresholds better estimate the actual extent of the infarcted tissue.

231 Diagnostic Outcomes in Suspected Appendicitis Before and During the COVID-19 Pandemic

Introduction

Routine operative treatment of appendicitis was temporarily interrupted during the COVID-19 pandemic. Non-operative management in suspected appendicitis makes a definitive diagnosis difficult. This study investigated diagnostic outcomes of suspected appendicitis patients before and during COVID-19.

Method

A retrospective review of patients aged 16–45 undergoing treatment for suspected appendicitis pre-COVID-19 (1st January 2019–1st January 2020) and during the COVID-19 pandemic (1st March 2020 to 31st June 2020) was performed. Patients were followed up for one year (31st June 2021) to explore diagnostic outcomes.

Results

At one year follow up, 206 patients were identified in the pre-COVID-19 cohort with 100% (n = 206) undergoing an appendicectomy. On histopathological examination 77.2% (n = 159) had appendicitis; 10.7% (n = 22) another pathology; 2.9% (n = 6) neuroendocrine tumour. There were 62 patients in the COVID-19 cohort in which 79% (n = 49) underwent appendicectomy (56% (n = 35) immediate appendicectomy; 23% (n = 13) interval appendicectomy). On histopathological examination 61% (n = 38) had appendicitis; 13% (n = 8) another pathology; 5% (n = 3) neuroendocrine tumour.

Of the remaining 13/62 patients, one had undergone a CT scan and colonoscopy for gastrointestinal symptoms demonstrating signs of chronic caecal inflammation treated conservatively. One underwent a CT scan alone for gastrointestinal symptoms finding no pathology. The remaining 11/62 patients had no further reported symptoms or diagnostics.

Conclusions

This study demonstrates that the risk of appendiceal malignancy and chronic inflammation is important in non-operative management of suspected appendicitis and establishing consistent follow up pathways is essential.

Effectiveness of Thrombectomy in Stroke According to Baseline Prognostic Factors: Inverse Probability of Treatment Weighting Analysis of a Population-Based Registry

Background and Purpose

 In real-world practice, the benefit of mechanical thrombectomy (MT) is uncertain in stroke patients with very favorable or poor prognostic profiles at baseline. We studied the effectiveness of MT versus medical treatment stratifying by different baseline prognostic factors.

Methods

 Retrospective analysis of 2,588 patients with an ischemic stroke due to large vessel occlusion nested in the population-based registry of stroke code activations in Catalonia from January 2017 to June 2019. The effect of MT on good functional outcome (modified Rankin Score ≤2) and survival at 3 months was studied using inverse probability of treatment weighting (IPTW) analysis in three pre-defined baseline prognostic groups: poor (if pre-stroke disability, age >85 years, National Institutes of Health Stroke Scale [NIHSS] >25, time from onset >6 hours, Alberta Stroke Program Early CT Score <6, proximal vertebrobasilar occlusion, supratherapeutic international normalized ratio >3), good (if NIHSS <6 or distal occlusion, in the absence of poor prognostic factors), or reference (not meeting other groups’ criteria).

Results

 Patients receiving MT (n=1,996, 77%) were younger, had less pre-stroke disability, and received systemic thrombolysis less frequently. These differences were balanced after the IPTW stratified by prognosis. MT was associated with good functional outcome in the reference (odds ratio [OR], 2.9; 95% confidence interval [CI], 2.0 to 4.4), and especially in the poor baseline prognostic stratum (OR, 3.9; 95% CI, 2.6 to 5.9), but not in the good prognostic stratum. MT was associated with survival only in the poor prognostic stratum (OR, 2.6; 95% CI, 2.0 to 3.3).

Conclusions

 Despite their worse overall outcomes, the impact of thrombectomy over medical management was more substantial in patients with poorer baseline prognostic factors than patients with good prognostic factors.

Cerebral Venous Sinus Thrombosis in COVID-19 Patients: A Multicenter Study and Review of Literature

BACKGROUND

COVID-19 infection has been known to predispose patients to both arterial and venous thromboembolic events such as deep venous thrombosis, pulmonary embolism, myocardial infarction, and stroke. A few reports from the literature suggest that Cerebral Venous Sinus Thrombosis (CVSTs) may be a direct complication of COVID-19.

OBJECTIVE

To review the clinical and radiological presentation of COVID-19 positive patients diagnosed with CVST.

METHODS

This was a multicenter, cross-sectional, retrospective study of patients diagnosed with CVST and COVID-19 reviewed from March 1, 2020 to November 8, 2020. We evaluated their clinical presentations, risk factors, clinical management, and outcome. We reviewed all published cases of CVST in patients with COVID-19 infection from January 1, 2020 to November 13, 2020.

RESULTS

There were 8 patients diagnosed with CVST and COVID-19 during the study period at 7 out of 31 participating centers. Patients in our case series were mostly female (7/8, 87.5%). Most patients presented with non-specific symptoms such as headache (50%), fever (50%), and gastrointestinal symptoms (75%). Several patients presented with focal neurologic deficits (2/8, 25%) or decreased consciousness (2/8, 25%). D-dimer and inflammatory biomarkers were significantly elevated relative to reference ranges in patients with available laboratory data. The superior sagittal and transverse sinuses were the most common sites for acute CVST formation (6/8, 75%). Median time to onset of focal neurologic deficit from initial COVID-19 diagnosis was 3 days (interquartile range 0.75-3 days). Median time from onset of COVID-19 symptoms to CVST radiologic diagnosis was 11 days (interquartile range 6-16.75 days). Mortality was low in this cohort (1/8 or 12.5%).

CONCLUSIONS

Clinicians should consider the risk of acute CVST in patients positive for COVID-19, especially if neurological symptoms develop.

Susceptibility Vessel Sign in Deep Perforating Arteries in Patients with Recent Small Subcortical Infarcts

OBJECTIVES

Recent small subcortical infarcts (RSSI) are considered an acute manifestation of cerebral small vessel disease. Paramagnetic signals in perforating arteries supplying RSSI may be detected on T2*-relaxation derived sequences on MRI and is defined as susceptibility vessel sign (SVS). We aimed to study the prevalence of SVS in patients with RSSI, and explore whether its identification is related to cerebral small vessel disease markers.

MATERIALS AND METHODS

We selected patients with RSSI identified on MRI during admission from a single-center stroke registry. The main demographic and clinical features, including vascular risk factors, were collected. Radiological features of RSSI and cerebral small vessel disease [white matter hyperintensities in deep and periventricular regions, enlarged perivascular spaces, lacunae, microbleeds, and brain atrophy] were described using validated qualitative scores. The presence of SVS was assessed on T2*gradient-echo or other susceptibility-weighted imaging. We compared the clinical and radiological features of patients with or without SVS in uni- and multivariate models.

RESULTS

Out of 210 patients with an RSSI on an MRI, 35 (17%) showed SVS. The proportion of SVS+ patients was similar in different susceptibility imaging modalities (p=.64). Risk factor profiles and clinical course were similar in SVS+ and SVS- patients. SVS+ patients had a higher grade of deep white matter hyperintensities and brain atrophy, more lacunae (p=.001, p=.034, p=.022, respectively), and a similar degree of the rest of radiological variables, compared to SVS- patients. In the multivariate analysis, the grade of deep white matter hyperintensities was the only independent factor associated with SVS [OR 3.1 (95% CI, 1.5-6.4)].

CONCLUSIONS

SVS in patients with RSSI is uncommon and related to a higher grade of deep white matter hyperintensities. Pathophysiological mechanisms underlying the deposition of hemosiderin in the path of occluded perforating arteries are uncertain and might include endothelial dysfunction or embolic mechanisms.

Acute Stroke Care Is at Risk in the Era of COVID-19: Experience at a Comprehensive Stroke Center in Barcelona

BACKGROUND AND PURPOSE

The purpose of the study is to analyze how the coronavirus disease 2019 (COVID-19) pandemic affected acute stroke care in a Comprehensive Stroke Center.

METHODS

On February 28, 2020, contingency plans were implemented at Hospital Clinic of Barcelona to contain the COVID-19 pandemic. Among them, the decision to refrain from reallocating the Stroke Team and Stroke Unit to the care of patients with COVID-19. From March 1 to March 31, 2020, we measured the number of emergency calls to the Emergency Medical System in Catalonia (7.5 million inhabitants), and the Stroke Codes dispatched to Hospital Clinic of Barcelona. We recorded all stroke admissions, and the adequacy of acute care measures, including the number of thrombectomies, workflow metrics, angiographic results, and clinical outcomes. Data were compared with March 2019 using parametric or nonparametric methods as appropriate.

RESULTS

At Hospital Clinic of Barcelona, 1232 patients with COVID-19 were admitted in March 2020, demanding 60% of the hospital bed capacity. Relative to March 2019, the Emergency Medical System had a 330% mean increment in the number of calls (158 005 versus 679 569), but fewer Stroke Code activations (517 versus 426). Stroke admissions (108 versus 83) and the number of thrombectomies (21 versus 16) declined at Hospital Clinic of Barcelona, particularly after lockdown of the population. Younger age was found in stroke admissions during the pandemic (median [interquartile range] 69 [64-73] versus 75 [73-80] years, P=0.009). In-hospital, there were no differences in workflow metrics, angiographic results, complications, or outcomes at discharge.

CONCLUSIONS

The COVID-19 pandemic reduced by a quarter the stroke admissions and thrombectomies performed at a Comprehensive Stroke Center but did not affect the quality of care metrics. During the lockdown, there was an overload of emergency calls but fewer Stroke Code activations, particularly in elderly patients. Hospital contingency plans, patient transport systems, and population-targeted alerts must act concertedly to better protect the chain of stroke care in times of pandemic.

Epidemiologic and Histopathologic Characterization of Cutaneous Metastases in Patients Who Visited 2 Hospitals in Santiago de Chile Between 2005 and 2017

BACKGROUND AND OBJECTIVE

Cutaneous metastases (CMs) account for 2% of skin tumors and their incidence varies between 0.7% and 9% in patients with cancer. The objective of this study was to describe and analyze the demographic, clinical, and histopathologic characteristics of CM in patients who visited 2 hospitals in the Santiago de Chile metropolitan region.

MATERIAL AND METHOD

We performed a retrospective, descriptive, analytical, observational, cross-sectional study. We reviewed the pathology reports, patient records, pathology slides, and dates of death for diagnosed cases of CM from the anatomic pathology departments of 2 hospitals in the Santiago de Chile metropolitan region between 2015 and 2017.

RESULTS

Ninety-six patients with CM were included in the study; 60.42% were women and 39.58% were men. The mean (SD) age was 67.95 (13.74) years, with a range of 28 to 96 years. The most common primary tumor was melanoma in 27.08% of cases (n=26), followed by breast cancer (18.75%, n=18), and adenocarcinoma (15.63%, n=15). The median time between diagnosis of the tumor and cutaneous metastasis was 9 months. Patients with CM of melanoma had a higher survival rate than patients with metastasis of other primary tumors (P<.05). A histopathologic study of 91 slides showed that diffuse infiltration of the tissue with tumor cells was the most common pattern and vascular invasion was rare.

CONCLUSIONS

The results are similar to those found worldwide. CM is a rare manifestation of internal tumors. It presents mainly at an advanced age and is equally prevalent in both sexes.

177Lu-DOTATATE treatment in neuroendocrine tumours. A preliminary study

Therapy with radiolabelled somatostatin analogue peptides is a promising new therapy to treat neuroendocrine tumours. The aim of this preliminary study is to present our experience with ¹⁷⁷Lu-DOTATATE therapy, and evaluate tolerability and short-term efficacy in patients with tumours expressing somatostatin receptors. A total of 7 patients with metastatic neuroendocrine tumours were treated, each with 4 doses of ¹⁷⁷Lu-DOTATATE. The treatment response was evaluated in the form of biochemical response (tumour markers), imaging methods (somatostatin receptor scintigraphy, computed tomography, and magnetic resonance), and functional and quality of life responses using the Karnofsky performance status scale. Treatment toxicity was also evaluated. The results obtained were as follows: Biochemical response: 60% of patients showed tumour marker levels returning to normal, while they decreased significantly in the remaining 40%. Imaging response: 85.7% had a partial response, while 14.3% showed stable disease. All (100%) patients showed a significant improvement in quality of life, with increased Karnofsky scale scores. No patient had acute or chronic toxicity, and subacute transient haematological toxicity was observed in 42.8% of patients. Despite being a preliminary study, it was found that treatment with ¹⁷⁷Lu-DOTATATE is a safe treatment with few side effects, and an objective response was achieved in most patients.

Synthesis and Mesomorphic Properties of Azo Compounds Derived from Phenyl-and Thienyl-1,3,4-Thiadiazole

The synthesis and mesomorphic behaviour of new series of liquid crystals containing 1,3,4- thiadiazole and thiophene rings with azo central bond are reported (series 5a and 5b). All compounds of series 5a exhibit enantiotropic nematic mesophase and the higher homologues (n = 9 - 10) also show a monotropic smectic C phase. Series 5b show dimorphism SC - N (for n = 5 - 7 the SC is monotropic). These series are compared with the Schiff’s bases analogues, the imine bond gives rise to similar liquid crystals phase but larger mesomorphic range.

Cultivos Celulares como Alternativa para el Aislamiento y la Producción de Biológicos Contra el Virus de Influenza

<p>El virus de influenza ha sido reconocido como un importante patógeno en poblaciones humanas y animales, ya que es el principal causante de enfermedades respiratorias. Muchas vacunas y aislamientos de virus de influenza humana y animal son realizadas actualmente en huevos embrionados, siendo este el método usado tradicionalmente por décadas. Sin embargo, se han encontrado inconvenientes en la elaboración de vacunas ya que el proceso de fabricación es de capacidad limitada (se requiere aproximadamente un huevo para generar una dosis vacunal) y alta demanda tiempo, disminuyendo su habilidad para generar biológicos rápidamente en el caso de una pandemia. El empleo de líneas celulares continuas para la producción de vacunas virales nace como alternativa que ofrece diversas ventajas: (i) oportunidad de emplear células completamente caracterizadas y estandarizadas, (ii) producción y planeación permanente de vacunas y (iii) los biológicos pueden ser producidos de forma más rápida.</p><p>El objetivo de esta revisión es analizar las diferentes alternativas empleadas en el cultivo y/o aislamiento de virus de influenza, enfatizando en el uso de cultivos celulares como sustrato para el aislamiento y la producción de biológicos destinados a la salud humana y animal.</p>

Equivalence of a single saline nebulised dose of formoterol powder vs three doses of nebulised Albuterol every twenty minutes in acute asthma in children: a suitable cost effective approach for developing nations

BACKGROUND

An increase in asthma prevalence is reported from developed as well as developing nations, with rising costs from acute asthma and great expenditures to health care systems. Venezuela's Ministry of Health ambulatory facilities care for 80 % or more of a mostly urban and impoverished population of 26 million inhabitants, registering close to a million acute asthma visits per year; a nebulised fixed fenoterol-ipratropium bromide combination (Bero-dual, Boehringer-Ingelheim) in repeated dosing is the standard treatment.

OBJECTIVES

to simplify acute asthma care and management in a cost effective manner employing Formoterol Fumarate powder, a long acting beta agonist with immediate bronchodilator effects.

METHODOLOGY

Fifty acute asthmatic children (5-12 years old) were randomly assigned (25 patients in each group) to receive either a nebulised single dose (US $1.35) of two 12 microg Formoterol Fumarate capsules (Foradil 12 microg/cap, Novartis Pharma AG, Basel, Switzerland) diluted in 2.5 ml of sterile saline solution; or 3 doses of Albuterol (US $ 6.73) every twenty minutes for one hour (Glaxo Smith Kline Albuterol ampoules, 2.5 mg/2.5 ml, at a dose of 0.15 mg/kg/dose, maximum dose 2.5 mg). Symptoms score, oxygen saturation and lung function testing were recorded before and one hour after commencing treatments.

RESULTS

Both groups improved significantly on all parameters, except for FEV(1) in the Albuterol group.

CONCLUSIONS

Single dose nebulised Formoterol Fumarate (dry powder) in sterile saline solution, as depicted in this trial, is equivalent to three doses of Albuterol every twenty minutes for one hour in acute asthma in children, simplifying acute care management and at one fifth of medication costs. A pursuit of simpler and more cost effective approaches is found wanting in developing nations with depressed economies and unique cultural and socio-medical contexts; also, in countries where pharmaco-economics orients quality of health policies, novel approaches like this are worth exploring.

[Spontaneous pneumothorax and active pulmonary tuberculosis]

We report three HIV-negative patients with spontaneous pneumothorax as clinical manifestation of active tuberculosis acute chest pain and dyspnea was the cause of admission. Chest roentgen grams showed lung collapse and parenchymal cavitation in two of therm and hydropneumothorax in the other. Outcome was favorable with antituberculous drug therapy and placement of chest tube. Although spontaneous pneumothorax is frequent in fibrosis pulmonary tuberculosis, it seldom complicated active tuberculosis in spite of increase of its incidence.