Experimental high-altitude intracerebral hemorrhage in minipigs: histology, behavior, and intracranial pressure in a double-injection model

The effect of hematoma puncture drainage before decompressive craniectomy on the prognosis of hypertensive intracerebral hemorrhage with cerebral hernia at a high altitude

PURPOSE

Rapid decompressive craniectomy (DC) was the most effective method for the treatment of hypertensive intracerebral hemorrhage (HICH) with cerebral hernia, but the mortality and disability rate is still high. We suspected that hematoma puncture drainage (PD) + DC may improve the therapeutic effect and thus compared the combined surgery with DC alone.

METHODS

From December 2013 to July 2019, patients with HICH from Linzhi, Tibet and Honghe, Yunnan Province were retrospectively analyzed. The selection criteria were as follows: (1) altitude ≥1500 m; (2) HICH patients with cerebral hernia; (3) Glascow coma scale score of 4-8 and time from onset to admission ≤3 h; (4) good liver and kidney function; and (5) complete case data. The included patients were divided into DC group and PD + DC group. The patients were followed up for 6 months. The outcome was assessed by Glasgow outcome scale (GOS) score, Kaplan-Meier survival curve and correlation between time from admission to operation and prognosis. A good outcome was defined as independent (GOS score, 4-5) and poor outcome defined as dependent (GOS score, 3-1). All data analyses were performed using SPSS 19, and comparison between two groups was conducted using separate t-tests or Chi-square tests.

RESULTS

A total of 65 patients was included. The age ranged 34-90 years (mean, 63.00 ± 14.04 years). Among them, 31 patients had the operation of PD + DC, whereas 34 patients underwent DC. The two groups had no significant difference in the basic characteristics. After 6 months of follow-up, in the PD + DC group there were 8 death, 4 vegetative state, 4 severe disability (GOS score 1-3, poor outcome 51.6 %); 8 moderate disability, and 7 good recovery (GOS score 4-5, good outcome 48.4 %); while in the DC group the result was 15 death, 6 vegetative state, 5 severe disability (poor outcome 76.5 %), 4 moderate disability and 4 good recovery (good outcome 23.5 %). The GOS score and good outcome were significantly less in DC group than in PD + DC group (Z = -1.993, p = 0.046; χ² = 4.38, p = 0.043). However, there was no significant difference regarding the survival curve between PD + DC group and DC group. The correlation between the time from admission to operation and GOS at 6 months (r = -0.41, R² = 0.002, p = 0.829) was not significant in the PD + DC group, but significant in the DC group (r = -0.357, R² = 0.128, p = 0.038).

CONCLUSION

PD + DC treatment can improve the good outcomes better than DC treatment for HICH with cerebral hernia at a high altitude.

Animal models of stroke

Stroke is a devastating disease with high morbidity and mortality. Animal models are indispensable tools that can mimic stroke processes and can be used for investigating mechanisms and developing novel therapeutic regimens. As a heterogeneous disease with complex pathophysiology, mimicking all aspects of human stroke in one animal model is impossible. Each model has unique strengths and weaknesses. Models such as transient or permanent intraluminal thread occlusion middle cerebral artery occlusion (MCAo) models and thromboembolic models are the most commonly used in simulating human ischemic stroke. The endovascular filament occlusion model is characterized by easy manipulation and accurately controllable reperfusion and is suitable for studying the pathogenesis of focal ischemic stroke and reperfusion injury. Although the reproducibility of the embolic model is poor, it is more convenient for investigating thrombolysis. Rats are the most frequently used animal model for stroke. This review mainly outlines the stroke models of rats and discusses their strengths and shortcomings in detail.

Relevance of Porcine Stroke Models to Bridge the Gap from Pre-Clinical Findings to Clinical Implementation

In the search of animal stroke models providing translational advantages for biomedical research, pigs are large mammals with interesting brain characteristics and wide social acceptance. Compared to rodents, pigs have human-like highly gyrencephalic brains. In addition, increasingly through phylogeny, animals have more sophisticated white matter connectivity; thus, ratios of white-to-gray matter in humans and pigs are higher than in rodents. Swine models provide the opportunity to study the effect of stroke with emphasis on white matter damage and neuroanatomical changes in connectivity, and their pathophysiological correlate. In addition, the subarachnoid space surrounding the swine brain resembles that of humans. This allows the accumulation of blood and clots in subarachnoid hemorrhage models mimicking the clinical condition. The clot accumulation has been reported to mediate pathological mechanisms known to contribute to infarct progression and final damage in stroke patients. Importantly, swine allows trustworthy tracking of brain damage evolution using the same non-invasive multimodal imaging sequences used in the clinical practice. Moreover, several models of comorbidities and pathologies usually found in stroke patients have recently been established in swine. We review here ischemic and hemorrhagic stroke models reported so far in pigs. The advantages and limitations of each model are also discussed.

Hemoglobin Concentration Affects Hypertensive Basal Ganglia Hemorrhage After Surgery: Correlation Analysis in a High-Altitude Region

OBJECTIVE

Hypertensive cerebral hemorrhage leads to greater mortality and worse functional outcomes at high altitudes. Experimental studies have suggested that hemoglobin can lead to increased perihemorrhagic edema after intracerebral hemorrhage.

METHODS

Patients were divided into a high-hemoglobin (H-H) group (>180 g/L) and a low-hemoglobin (L-H) group (≤180 g/L). The distance from the cortex to the midline was used to indicate the degree of edema. At 1, 7, 14, and 21 days, the patients' status was scored using the Glasgow coma scale, and survival was plotted using Kaplan-Meier survival curves. Pearson correlation analysis showed that the difference between the postoperative and preoperative Glasgow coma scale score correlated with the hemoglobin concentration. The Glasgow outcome scale was used to assess neurological recovery after 6 months.

RESULTS

On days 7, 14, and 21, the edema of the H-H group was significantly greater than that of the L-H group (P < 0.01 and P < 0.001, respectively). The edema of the H-H group peaked at 14 and 21 days, but that of the L-H group peaked at 7 days. The hemoglobin concentration and postoperative neurological recovery had a linear relationship in the H-H group. The L-H group had greater survival compared with the H-H group (P < 0.05). The L-H group had higher Glasgow outcome scale scores compared with the H-H group (P < 0.05).

CONCLUSION

The hemoglobin concentration affects the mortality and morbidity from hypertensive cerebral hemorrhage in high-altitude regions, and a linear relationship exists between hemoglobin concentration and neurological recovery in the H-H group.

Risk of Complications After Intracranial Procedures at High Altitude

BACKGROUND

Postoperative hemorrhagic or ischemic complications cause significant morbidity and mortality after craniotomy. High altitude creates a state of relative hypoxia, resulting in increased cerebral blood flow for compensation. This potentially creates an increased risk at high altitude of having increased morbidity from hemorrhagic or ischemic events, and some neurosurgeons forbid air travel to patients immediately after craniotomy for this reason. We hypothesized there was no difference in postoperative complications based on altitude.

METHODS

We retrospectively reviewed all craniotomies performed at a high-altitude medical center to assess whether originating, surgical, or destination altitude affected postoperative outcomes.

RESULTS

Between 1 July 2014 and 30 June 2016, 1807 craniotomy procedures were performed. There were 53 (2.9%) postoperative hemorrhagic or ischemic complications during the first 30 days after surgery, 44 (2.4%) hemorrhagic events, and 9 (0.5%) ischemic events. From the 36 patients who had postoperative complications at the hospital, 10 of them lived in an altitude below the hospital, 26 lived in an altitude above the hospital, and 1 has no record of address. Excluding the patients who had complications at the hospital, we had 8 patients discharged to a ZIP code below the altitude of the hospital (7 hemorrhagic events and 1 ischemic) and 9 were discharged to a location at an altitude above that of the hospital (8 hemorrhagic events and 1 ischemic). There were no statistically significant differences between cohorts.

CONCLUSIONS

Altitude does not appear to have a significant impact on postoperative rates of hemorrhagic or ischemic complications.

Preliminary study on alterations of altitude road traffic in China from 2006 to 2013

Introduction

Road traffic can play an important role in strengthening regional economic activities, especially at high altitude, and it is necessary to know important traffic-related information. Although previous studies reported on road traffic in China, there has been little research on high-altitude road traffic to date.

Method

The annual official census of road traffic safety from 2006 to 2013 was used to obtain data on the general population, registered drivers, registered vehicles, newly built roads, road traffic accidents (RTAs), mortality rate per 100 000 populations and per 10 000 vehicles in high-altitude provinces, including Tibet, Qinghai, Xinjiang, Gansu, Yunnan, Sichuan, and Chongqing. These provincial data were reviewed retrospectively, with the national data as the reference. Statistical analysis (i.e., t test) was used to compare the estimated average annual change rate of population, number of registered drivers, registered vehicles, and newly built roads in high-altitude provinces with the national rates.

Results

Compared with the national data, there are significantly higher annual rates of population growth in Tibet and Xinjiang, registered drivers in Gansu, registered vehicles in Gansu, Sichuan, and Chongqing, and newly built roads in Tibet and Qinghai. Among the investigated provinces, Tibet, Qinghai, and Yunnan had a higher proportion of the roads with the high class. RTAs and RTA-induced casualties in the high-altitude provinces indicated a decreasing trend. The mortality rate per 10 000 vehicles and per 100 000 populations showed a decreasing trend, while the RTA-related mortality rate in Tibet, Qinghai, Xinjiang and Gansu remained high.

Conclusions

Major changes for road traffic in high-altitude provinces have occurred over the past decade; however, the RTA-related mortality rate in high-altitude provinces has remained high. This study furthers understanding about road traffic safety in China; further studies on road traffic safety at high altitude should be performed.

Hyperbaric oxygen therapy ameliorates acute brain injury after porcine intracerebral hemorrhage at high altitude

Introduction

Intracerebral hemorrhage (ICH) at high altitude is not well understood to date. This study investigates the effects of high altitude on ICH, and examines the acute neuroprotection of hyperbaric oxygen (HBO) therapy against high-altitude ICH.

Methods

Minipigs were placed in a hypobaric chamber for 72 h before the operation. ICH was induced by an infusion of autologous arterial blood (3 ml) into the right basal ganglia. Animals in the high-altitude ICH group received HBO therapy (2.5 ATA for 60 min) 30 min after ICH. Blood gas, blood glucose and brain tissue oxygen partial pressure (PbtO₂) were monitored continuously for animals from all groups, as were microdialysis products including glucose, lactate, pyruvate and glutamate in perihematomal tissue from 3 to 12 h post-ICH.

Results

High-altitude ICH animals showed significantly lower PbtO₂, higher lactate/pyruvate ratio (LPR) and glutamate levels than low-altitude ICH animals. More severe neurological deficits, brain edema and neuronal damage were also observed in high-altitude ICH. After HBO therapy, PbtO₂ was significantly increased and LPR and glutamate levels were significantly decreased. Brain edema, neurological deficits and neuronal damage were also ameliorated.

Conclusions

The data suggested a more serious disturbance of tissue oxygenation and cerebral metabolism in the acute stage after ICH at high altitude. Early HBO treatment reduced acute brain injury, perhaps through a mechanism involving the amelioration of the derangement of cerebral oxygenation and metabolism following high-altitude ICH.

Thrombocytopenia induces multiple intracranial hemorrhages in patients with severe burns: A review of 16 cases

The aim of this study was to explore the etiology and diagnosis of multiple intracranial hemorrhages (ICHs) following severe burns, with a retrospective review of 16 cases of severe burns further complicated by multiple ICHs. Using cranial CT scans of the brains, we identified that all patients presented with low platelet counts and coagulation abnormalities prior to intracranial hemorrhaging. Following conventional treatment and various supporting treatments, five cases succumbed following a progressive reduction in blood platelet levels and the ICHs were cured in 11 cases following the restoration of normal platelet levels. We conclude that low platelet counts and coagulation abnormalities may cause multiple ICHs following severe burns and early diagnosis and treatment is the key to successful treatment.