Normobaric Hyperoxia Reduces Blood Occludin Fragments in Rats and Patients With Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Damage of the blood-brain barrier (BBB) increases the incidence of neurovascular complications, especially for cerebral hemorrhage after tPA (tissue-type plasminogen activator) therapy. Currently, there is no effective method to evaluate the extent of BBB damage to guide tPA use. Herein, we investigated whether blood levels of tight junction proteins could serve as biomarker of BBB damages in acute ischemic stroke (AIS) in both rats and patients. We examined whether this biomarker could reflect the extent of BBB permeability during cerebral ischemia/reperfusion and the effects of normobaric hyperoxia (NBO) on BBB damage. METHODS: Rats were exposed to NBO (100% O2) or normoxia (21% O2) during middle cerebral artery occlusion. BBB permeability was determined. Occludin and claudin-5 in blood and cerebromicrovessels were measured. Patients with AIS were assigned to oxygen therapy or room air for 4 hours, and blood occludin and claudin-5 were measured at different time points after stroke. RESULTS: Cerebral ischemia/reperfusion resulted in the degradation of occludin and claudin-5 in microvessels, leading to increased BBB permeability in rats. In blood samples, occludin increased with 4-hour ischemia and remained elevated during reperfusion, correlating well with its loss from ischemic cerebral microvessels. NBO treatment both prevented occludin degradation in microvessels and reduced occludin levels in blood, leading to improved neurological functions in rats. In patients with AIS receiving intravenous tPA thrombolysis, the blood occludin was already elevated when patients arrived at hospital (within 4.5 hours since symptoms appeared) and remained at a high level for 72 hours. NBO significantly lowered the level of blood occludin and improved neurological functions in patients with AIS. CONCLUSIONS: Blood occludin may be a clinically viable biomarker for evaluating BBB damage during ischemia/reperfusion. NBO therapy has the potential to reduce blood occludin, protect BBB, and improve outcome in AIS patients with intravenous tPA thrombolysis. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02974283.

Higher serum occludin after successful reperfusion Is associated with early neurological deterioration.

AIMS: Early neurological deterioration (END) is an important factor that affects prognosis in patients with acute ischemic stroke. We explored the relationship between serum occludin levels after successful reperfusion and END in patients treated with endovascular thrombectomy (EVT). METHODS: We prospectively enrolled 120 stroke patients who underwent EVT with successful reperfusion. Enzyme-linked immunosorbent assay was used to detect the serum occludin levels on admission and within 1 h after successful reperfusion. Receiver operating characteristic curves (ROC) and regression analysis were used to compare the relationship between serum occludin and END after thrombectomy. RESULTS: Among the 120 patients, 36 (30%) experienced END. The END group had higher serum occludin levels than the non-END group after successful reperfusion [4.31 (3.71-5.38) vs 6.32 (5.88-6.99), p < 0.001]. The ROC curve showed that postoperative serum occludin levels had a significant prediction value for END (AUC: 0.86, p < 0.001). Regression analysis showed that serum occludin was an independent risk factor for END in EVT patients (adjusted odds ratio: 4.46, 95% confidence interval: 1.92-10.32; p < 0.001). CONCLUSIONS: The higher serum occludin levels were strongly related to END after successful reperfusion. Serum occludin may be an independent risk factor for END in EVT patients.

Incidence, and preoperative and intraoperative prognostic factors of deep venous thrombosis in patients with glioma following craniotomy.

OBJECTIVES: The aim of this study was to investigate the incidence of deep vein thrombosis (DVT) and the preoperative and intraoperative risk factors associated with DVT in glioma patients METHODS: We conducted a retrospective analysis of data obtained from glioma patients at Sanbo Hospital (Beijing, China) between 2018 and 2021. Symptomatic DVT was confirmed by Doppler ultrasonography. Multivariable logistic regression analysis was used to identify preoperative and intraoperative characteristics associated with DVT. Basic clinical variables and laboratory results were analyzed. RESULTS: A total of 492 glioma patients were included. Of these, 73 (14.84%) developed DVT, and three (0.61%) developed DVT and pulmonary embolism (PE). Multivariate analyses revealed that the following factors were highly predictive of post-operative DVT: older age ranges of 46--55 years (odds ratio [OR]: 2.94; 95% confidence interval [CI]: 1.41--6.13; p = 0.004), 56--65 years (OR: 7.86; 95% CI: 3.63--17.03; p < 0.001), and > 65 years (OR: 4.94; 95% CI: 1.83--13.33; p = 0.002); partial thromboplastin time (APTT; OR: 0.91; 95% CI: 0.84--1.00; p = 0.040); D-dimer (OR: 2.21; 95% CI: 1.28--3.82; p = 0.005); and surgery duration (OR: 2.87; 95% CI: 1.6 --5.07; p < 0.001) CONCLUSIONS: Older age, preoperative APTT, D-dimer, and surgery duration independently increased the risk of developing postoperative DVT. These findings may facilitate the development of a thrombosis risk score that will allow physicians to develop individualized strategies to prevent DVT as early as possible.

Preoperative and intraoperative predictors of deep venous thrombosis in adult patients undergoing craniotomy for brain tumors: A Chinese single-center, retrospective study.

PURPOSE: Brain tumor resection by craniotomy is associated with a high risk of deep vein thrombosis (DVT). This study evaluated the incidence and preoperative and intraoperative risk factors for DVT within 30 days of surgery. METHODS: The analysis included: 1) basic clinical variables (patient age, sex, body mass index [BMI], tumor location, and tumor histology); 2) blood test results before operation, such as leukocytes, platelets, and coagulation parameters; and 3) surgical factors (total amount of blood lost, anesthesia mode, and surgery duration). RESULTS: Of the 1670 patients, 206 (12.34%) had DVT and nine (0.54%) had both DVT and pulmonary embolism (PE) after surgery. Preoperative and intraoperative factors independently associated with DVT/PE were: older age 46-55 years (odds ratio [OR]: 2.87; 95% confidence interval [CI]: 1.83-4.50; P < 0.001), age 56-65 years (OR: 5.24; 95% CI: 3.27-8.40; P < 0.001), age > 65 years (OR: 6.00; 95% CI: 3.45-10.45; P < 0.001), BMI (OR: 1.03; 95% CI: 1.00-1.05; P = 0.029), activated partial thromboplastin time [APTT] (OR: 0.91; 95% CI: 0.86-0.95; P = 0.000), D-dimer (OR: 1.69; 95% CI: 1.23-2.34; P = 0.001), high-grade glioma (OR: 2.09; 95% CI: 1.28-3.40; P = 0.003), glio-neuronal (OR: 3.30; 95% CI: 1.28-8.47; P = 0.013), craniopharyngioma (OR: 2.16; 95% CI: 1.13-4.10; P = 0.019), and surgery duration (OR: 1.82; 95% CI: 1.27-2.60; P = 0.001). CONCLUSIONS: Older age, BMI, preoperative APTT, D-dimer, tumor histology, and surgery duration independently increased the risk of developing postoperative DVT/PE. These findings provide prognostic information that will guide therapies aimed at minimizing the development of DVT/PE during hospitalization.

Peripheral Blood Occludin Level as a Biomarker for Perioperative Cerebral Edema in Patients with Brain Tumors.

OBJECTIVE: Cerebral edema is a common complication of brain tumors in the perioperative period. However, there is currently no reliable and convenient method to evaluate the extent of brain edema. The objective is to explore the effectiveness of serum occludin on predicting the extent of perioperative brain edema and outcome in patients with brain tumors. METHODS: This prospective study enrolled 55 patients with brain tumors and 24 healthy controls in Sanbo Brain Hospital from June 2019 through November 2019. Serum occludin levels were measured preoperatively and on postoperative day 1. Peritumoral edema was assessed preoperatively using MRI. Pericavity brain edema on postoperative day 1 was evaluated using CT. RESULTS: Compared with healthy controls, the serum occludin level was higher in patients with brain tumors both preoperatively and postoperatively (P < 0.001). The serum occludin level correlated positively with the degree of brain edema preoperatively (r = 0.78, P < 0.001) and postoperatively (r = 0.59, P < 0.001). At an optimal cutoff of 3.015 ng/mL, the preoperative serum occludin level discriminated between mild and severe preoperative brain edema with a sensitivity of 90.48% and specificity of 84.62%. At an optimal cutoff value of 3.033 ng/mL, the postoperative serum occludin level distinguished between mild and severe postoperative brain edema with a sensitivity of 97.30% and specificity of 55.56%. CONCLUSIONS: The serum occludin level is associated with cerebral edema and could potentially be used as a biomarker for perioperative cerebral edema. This trial is registered with ChiCTR1900023742.

Normobaric oxygen treatment in acute ischemic stroke: a clinical perspective.

Acute ischemic stroke is a common and serious neurological disease. Oxygen therapy has been shown to increase oxygen supply to ischemic tissues and improve outcomes after cerebral ischemia/reperfusion. Normobaric hyperoxia (NBO), an easily applicable and non-invasive method, shows protective effects on acute ischemic stroke animals and patients in pilot studies. However, many critical scientific questions are still unclear, such as the therapeutic time window of NBO, the long-term effects and the benefits of NBO in large clinic trials. In this article, we review the current literatures on NBO treatment of acute ischemic stroke in preclinical and clinical studies and try to analyze and identify the key gaps or unknowns in our understanding about NBO. Based on these analyses, we provide suggestions for future studies.