Leakage Volume Research Articles

Incidence, risk factors and management of chylothorax post-oesophagectomy for oesophageal carcinoma in an Australian institution

Background: Chylothorax is a potentially fatal complication of oesophagectomy. This study aims to report the incidence, risk factors and management of chylothorax in patients undergoing oesophagectomy for oesophageal carcinoma. Methods: This study reviewed all patients who underwent oesophagectomy from 2009 to 2018 in an Australian institution. Preoperative, perioperative and postoperative data were collected retrospectively and analysed. Results: Chylothorax occurred in 13 out of 144 patients (9%). Pre-operative albumin [odds ratio (OR) 0.836, P=0.027) and the number of lymph nodes resected (OR 1.141, P=0.001) were significant predictors of chylothorax. Chylothorax was associated with increased reoperation rate (77% vs. 11%, P<0.001) and prolonged hospital stay (29 vs. 15 days, P=0.001), but no increase in short term mortality or other complications. Average chyle leak volume of multiple days were significantly different between the conservative and reoperation groups. Using the cut off value of 1,000 mL/day for average chest drain output of 2, 3, 4 and 5 days following the diagnosis of chylothorax, the sensitivity and specificity for reoperation were 75% and 100%, 75% and 80%, 71% and 100%, 86% and 100% respectively. Conclusions: Chylothorax is associated with increased reoperation rate and prolonged hospital stay. Preoperative albumin and the number of harvested lymph nodes were significant predictors of chylothorax following oesophagectomy. This study suggested that averaged chest drain output of multiple days would be a better representation of chyle leak volume than an isolated chest drain output. Reoperation should be considered when the average chyle leak output, of at least 2 consecutive days following the diagnosis of chylothorax, exceeds 1,000 mL/day.

The Role of laryngeal ultrasound in comparison with cuff leak test in prediction of post extubation stridor

Abstract Background Endotracheal intubation is commonly used in (ICU) for different causes. However, intubation/extubation may lead to the development of complications such as post-extubation stridor (PES), one of the most frequent causes of reintubation, prolonged mechanical ventilation, and increased morbidity in the ICU patients. PES and upper-airway obstruction are multifactorial in etiology and can occur as a result of laryngotracheal edema, intubation trauma, excessive cuff pressure with mucosal ulceration, and prolonged intubation with secondary inflammation and granuloma formation. Objective: The aim of this study was to evaluate the value of laryngeal ultrasonography versus cuff leak test in predicting post-extubation stridor. Patients and Methods Our study included fifty patients admitted to the critical care department, Misr University for Science and Technology Hospitals from the period of November 2017 to July 2018 intubated for different causes for a minimum of 24 h. excluded patients primarily intubated for the upper airway obstruction, patients with laryngeal carcinoma, Previous tracheostomy, neck radiotherapy. All patients will undergo for laryngeal ultrasonography versus cuff leak test to predict post-extubation stridor. Results In our study CLT identified PES patients with a sensitivity of 75%. But with low PPV of 50% for leakage volume of (132.5 mm ) . Laryngeal ultrasound showed a sensitivity of 50% for those patients with air column width before deflation less than 10.955 mm and ACWD 0.905 mm with PPV of 11.8% and 14.3% for air column width and ACWD respectively Conclusion Both CLT (Cuff leak test) and laryngeal US (ultrasound) might have sensitivity in predicting PES and should be used with caution in this regard.

Assessment of noninvasive positive pressure ventilation in healthy young volunteers using salivary stress biomarkers.

Aim:We performed a stress assessment of noninvasive positive pressure ventilation (NPPV) using the salivary biomarkers chromogranin A.Materials & methods:Twenty healthy volunteers were subjected to NPPV for 30 min. We collected saliva samples before and after NPPV and evaluated chromogranin A.Results:We collected saliva samples from 13 volunteers for enzyme measurement. Of the 13 volunteers, 11 showed elevated chromogranin A levels, which were significantly higher after NPPV than before NPPV (p < 0.01). The chromogranin A increase group displayed significantly increased leak flow and reduced respiratory rate and absolute humidity compared with the chromogranin A reduction group.Conclusion:The increase of leak volume might be a stress factor in patients receiving NPPV.

A novel cross-species model of Barlow's disease to biomechanically analyze repair techniques in an ex vivo left heart simulator

ObjectiveBarlow's disease remains challenging to repair, given the complex valvular morphology and lack of quantitative data to compare techniques. Although there have been recent strides in ex vivo evaluation of cardiac mechanics, to our knowledge, there is no disease model that accurately simulates the morphology and pathophysiology of Barlow's disease. The purpose of this study was to design such a model. MethodsTo simulate Barlow's disease, a cross-species ex vivo model was developed. Bovine mitral valves (n = 4) were sewn into a porcine annulus mount to create excess leaflet tissue and elongated chordae. A heart simulator generated physiologic conditions while hemodynamic data, high-speed videography, and chordal force measurements were collected. The regurgitant valves were repaired using nonresectional repair techniques such as neochord placement. ResultsThe model successfully imitated the complexities of Barlow's disease, including redundant, billowing bileaflet tissues with notable regurgitation. After repair, hemodynamic data confirmed reduction of mitral leakage volume (25.9 ± 2.9 vs 2.1 ± 1.8 mL, P < .001) and strain gauge analysis revealed lower primary chordae forces (0.51 ± 0.17 vs 0.10 ± 0.05 N, P < .001). In addition, the maximum rate of change of force was significantly lower postrepair for both primary (30.80 ± 11.38 vs 8.59 ± 4.83 N/s, P < .001) and secondary chordae (33.52 ± 10.59 vs 19.07 ± 7.00 N/s, P = .006). ConclusionsThis study provides insight into the biomechanics of Barlow's disease, including sharply fluctuating force profiles experienced by elongated chordae prerepair, as well as restoration of primary chordae forces postrepair. Our disease model facilitates further in-depth analyses to optimize the repair of Barlow's disease.

Numerical Approaches for Estimating Daily River Leakage from Arid Ephemeral Streams

Despite the significance of river leakage to riparian ecosystems in arid/semi-arid regions, a true understanding and the accurate quantification of the leakage processes of ephemeral rivers in these regions remain elusive. In this study, the patterns of river infiltration and the associated controlling factors in an approximately 150-km section of the Donghe River (lower Heihe River, China) were revealed using a combination of field investigations and modelling techniques. The results showed that from 21 April 2010 to 7 September 2012, river water leakage accounted for 33% of the total river runoff in the simulated segments. A sensitivity analysis showed that the simulated infiltration rates were most sensitive to the aquifer hydraulic conductivity and the maximum evapotranspiration (ET) rate. However, the river leakage rate, i.e., the ratio of the leakage volume to the total runoff volume, of a single runoff event relies heavily on the total runoff volume and river flow rate. In addition to the hydraulic parameters of riverbeds, the characteristics of ET parameters are equally important for quantifying the flux exchange between arid ephemeral streams and underlying aquifers. Coupled surface/groundwater models, which aim to estimate river leakage, should consider riparian zones because these areas play a dominant role in the formation of leakage from the river for recharging via ET. The results of this paper can be used as a reference for water resource planning and management in regulated river basins to help maintain riparian ecosystems in arid regions.

Abstract TP105: The Neuroprotective Efficacy of Regional Cerebral Hypothermia Induced via a New Intrajugular Cooling Method in Experimental Ischemic Stroke

Background: Therapeutic hypothermia as a neuroprotective strategy after stroke has been well established in animal models, but its application in humans has been limited by logistical challenges. To provide a solution to these challenges, this study was designed to determine the hypothermic and neuroprotective efficacy of infusing cold saline directly into the internal jugular (IJ) vein, and compare the effects of IJ regional cerebral hypothermia to those achieved by intra-carotid (IC) artery regional hypothermia in an ischemic stroke model. Methods: Middle cerebral artery occlusion was established in rats using an intraluminal filament. Regional cerebral hypothermia was then achieved by infusion of 6 ml of 0 °C isotonic saline by micro-catheter into the right IJ or right IC for 30 minutes immediately after the initiation of reperfusion. Infarct sizes, neurological deficits, edema volume, blood brain barrier (BBB) damage, BBB associated molecules (MMP-9 and AQP-4), and apoptosis associated proteins (Bcl-2 and cleaved Caspase-3) were measured. Results: Both IJ and IC infusion led to a significant, rapid reduction in brain temperatures while having a minimal effect on rectal temperatures. Infarct sizes were significantly reduced at 24 hours after reperfusion by IC and IJ treatments. Neurologic deficits were also significantly improved by IC and IJ infusion compared to control models over a 28-day observation period. Both IC and IJ significantly reduced Evans Blue leakage and edema volume compared with control groups. MMP-9 and AQP-4 expression were also reduced, Bcl-2 increased, and cleaved Caspase-3 decreased in the IC and IJ groups. Conclusion: Compared to IC infusion, IJ infusion conferred a similar degree of regional cerebral hypothermia and neuroprotection following ischemic stroke. Given the ease of establishing vascular access via the internal jugular vein and the powerful neuroprotection that hypothermia provides, IJ regional brain cooling could be utilized as a promising hypothermia-induction modality due to its safe, quick, and effective features.

Витік інформації як ключова проблема інформаційно-аналітичного забезпечення економічної безпеки підприємства в умовах цифровізації економіки

The article is aimed at researching the key problem of information and analytical provision of enterprise in the context of digitalization of the economy. The publication indicates the growth of the role of information in the implementation of management activities by an economic entity and its general role in the operation of the modern enterprise. Approaches to interpretation of the concepts of «information» and «information provision» are examined. It is defined that today the main problem of information-analytical provision of economic activity is the leakage of confidential information as one of the forms of materialization of threats to the information security of enterprise, which consists in violation of confidentiality, integrity and availability of information. It is further defined that the leakage of information at the enterprise is usually caused by the following actions: unauthorized access to confidential information; disclosure of confidential information (including the unintentional disclosure); leakage of information via the imperfect technical channels. The channels of possible information leakage are considered. In addition, the analysis of statistical data on information leakage in the global dimension was carried out. According to the researches, in 2019, among the total volume of information leakage, 49.7% of the volume is accounted for by external actors and 50.3% by internal offenders. In general, in the system of information and communication provision, special attention of the management of enterprise should be directly paid to internal communications, since more than 90% of the information comes in from employees. It should be noted that the reasons for the leakage of the enterprise’s information due to the fault of internal actors may be: unintentional actions on the part of the enterprise’s employees related to errors in the processing, storage or transmission of confidential data; the caused by certain reasons actions of employees who have access to confidential information. This may include the actions of employees who use the enterprise’s data for fraud purposes, as well as the actions of former employees who, motivated by their desire for retaliation for dismissal, «contribute» to the leakage of confidential information, passing it on to competitors or using it for their own mercenary purposes.

Contemporary lymphatic interventions for post-operative lymphatic leaks.

Post-operative lymphatic injuries are uncommon but increase morbidity and mortality in vulnerable patient populations. Post-surgical lymphatic leaks are most commonly a consequence of radical neck dissection, esophagectomy, and lung cancer resections or retroperitoneal surgeries such as radical nephrectomy and lymphadenectomy. Injury may occur anywhere along the lymphatic chains with most serious leaks occurring along the axial skeleton between the inguinal region and the left venous angle. The resultant clinical manifestations of a lymphatic leak are dependent on the location and severity of the lymphatic injury as well as patient factors. Treatment strategies are tailored toward the causative etiology, symptom severity, and daily leak volume with higher volume leaks warranting a more aggressive approach. Lymphangiography and lymphatic interventions, such as embolization, are increasingly applied for both the diagnosis and as a minimally invasive therapy for lymphatic injuries. Herein, a review of lymphatic anatomy, lymphangiography, and lymphatic interventions for the treatment of post-operative chylothorax, chylous ascites, and lymphocele is presented.

Effect of Two Regimens of Fluid Administration on Airway Edema in Prone-Position Surgery.

Background:Surgeries in prone position expose a patient to multitude of complications including laryngeal edema which may be related to the volume of fluid administered. Administering larger volumes of fluid intraoperatively may contribute to significant tissue edema, leading many anesthesiologists to practice a restrictive fluid infusion strategy. Although previous studies have compared fluid infusion strategies, changes in airway dimensions leading to airway edema have not been extensively investigated. Here, we compared two fluid infusion regimens in patients undergoing spine surgery in the prone position, and assessed their association with airway edema by means of the cuff leak test (CLT).Aims:The aim of this study was to test the hypothesis whether a larger volume of crystalloid administration in spine surgeries performed in prone position would result in greater chances of airway edema, than would a restricted infusion policy, utilizing the CLT.Materials and Methods:After ethical committee approval, thirty patients, aged 21–60 years, American Society of Anesthesiologists Status I or II, scheduled for elective spine surgery in the prone position, were selected. Group 1 (restrictive group) received 3 mL.kg − 1.h − 1, whereas Group 2 (permissive group) received 5 mL.kg − 1.h − 1 of crystalloids plus urine output replacement. The airway edema was assessed by CLT which was performed soon after intubation (T1) and before extubation (T2). Cuff leak volume (CLV) was calculated from the difference in tidal volumes before (VTi) and after cuff deflation (VTe). Airway edema was evaluated by calculating the differences in the CLV at T1 and T2 (ΔCLV); the more the value of Δ CLV which means greater difference between these two points, the more the decrease in laryngeal lumen, signifying an increased risk of airway edema.Results:Decrease in laryngeal lumen was observed in patients who received permissive fluid regimen than that of the restrictive group, signifying more chances of airway edema in the former group. In addition, a poor correlation was found between the duration of anesthesia and development of airway edema in our study group.Conclusions:Because surgeries in the prone position are at risk of airway edema, restrictive fluid regimen strategy should be preferred over the liberal one as there are more chances of reduction in laryngeal lumen dimensions with permissive fluid infusions.

Environmental risk assessment and mapping of oil installations to Chamshir Dam water basin using GIS and HAZOP method

Oil pipelines can be affected by natural features, inappropriate design, and maintenance systems leading to environmental pollution, mainly when the pipelines and installations are located near freshwater reservoirs. This study analyses the possible environmental risk that could arise from the oil pipeline systems in the basin of the Chamshir Dam. The potential environmental risk of oil installations was determined based on environmental factors, and the oil leakage volume of installations. The factors were determined and mapped using ArcGIS; then, the maps were combined to locate vulnerable zones. Finally, the risk of oil leakage in the pipelines was calculated using the HAZOP method to recognise high-risk pipelines. The result showed that oil installations posing a high threat to the dam's lake were nearby the lake, crossed sub-basins with a steep slope, and also under specific hydrological conditions. The analysis of oil spill risk showed that the risk was exceptionally high.

Environmental risk assessment and mapping of oil installations to Chamshir Dam water basin using GIS and HAZOP method

Oil pipelines can be affected by natural features, inappropriate design, and maintenance systems leading to environmental pollution, mainly when the pipelines and installations are located near freshwater reservoirs. This study analyses the possible environmental risk that could arise from the oil pipeline systems in the basin of the Chamshir Dam. The potential environmental risk of oil installations was determined based on environmental factors, and the oil leakage volume of installations. The factors were determined and mapped using ArcGIS; then, the maps were combined to locate vulnerable zones. Finally, the risk of oil leakage in the pipelines was calculated using the HAZOP method to recognise high-risk pipelines. The result showed that oil installations posing a high threat to the dam's lake were nearby the lake, crossed sub-basins with a steep slope, and also under specific hydrological conditions. The analysis of oil spill risk showed that the risk was exceptionally high.

A comparison of two supraglottic airway devices in general anaesthesia: baska mask® vs. I-gel®

Objective: The aim of this was to compare the Baska® mask and the I-gel® airway in paralyzed patients during general anaesthesia in terms of clinical performance, the risk of aspiration, and intraoperative and postoperative characteristics.&#x0D; Material and Methods: The two devices were compared in 100 paralyzed anesthetized adult patients. Primary outcomes of the study were to evaluate the characteristics of the airway devices within respect to the success of first insertion attempt, the insertion time, the ease of insertion, leak volume, and peak airway pressure. The blood staining on the mask, and the presence of gastric reflux or sore throat two hours postoperatively were evaluated. Hemodynamics, end-tidal CO2 and the peripheral oxygen saturation measurements were secondary outcomes.&#x0D; Results: No statistically significant difference was observed between the groups in the criteria of first attempt success rate, ease of insertion, blood staining upon removal of the masks, gastric regurgitation, or sore throat two hours after the procedure. The insertion time was significantly longer for the Baska® mask compared with the I-gel® airway. The leak volume was significantly higher in the Baska® mask patients throughout the surgical procedure. The heart rate and mean arterial pressure measurements were significantly higher in the Baska® mask patients.&#x0D; Conclusions: Both the Baska® mask and the I-gel ® device can be used effectively for selected paralyzed patients under general anaesthesia. The insertion time was significantly longer for the Baska® mask compared with the I-gel® device.

Comparison of videolaryngoscope-guided versus standard digital insertion techniques of the ProSeal\u2122 laryngeal mask airway: a prospective randomized study

BackgroundThis study were designed to investigate the usefulness of the videolaryngoscope-guided insertion technique compared with the standard digital technique for the insertion success rate and insertion conditions of the Proseal™ laryngeal mask airway (PLMA).MethodsProspective, one hundred and nineteen patients (ASA I–II, aged 18–65 yr) were randomly divided for PLMA insertion using the videolaryngoscope-guided technique or the standard digital technique. The PLMA was inserted according to the manufacturer’s instructions in the standard digital technique group. The videolaryngoscope-guided technique was performed a C-MAC® videolaryngoscope with D-Blade, under gentle videolaryngoscope guidance, the epiglottis was lifted, and the PLMA was advanced until the tip of the distal cuff reached the oesophagus inlet. The number of insertion attempts, insertion time, oropharyngeal leak pressure, leak volume, fiberoptic bronchoscopic view, peak inspiratory pressure, ease of gastric tube placement, hemodynamic changes, visible blood on PLMA and postoperative airway morbidity were recorded.ResultsThe first-attempt success rate (the primary outcome) was higher in the videolaryngoscope-guided technique than in the standard digital technique (p = 0.029). The effect size values with 95% confidence interval were 0.19 (0.01–0.36) for the first and second attempts, 0.09 (− 0.08–0.27) for the first and third attempts, and not computed for the second and third attempts by the groups, respectively.ConclusionVideolaryngoscope-guided insertion technique can be a help in case of difficult positioning of a PLMA and can improve the PLMA performance in some conditions. We suggest that the videolaryngoscope-guided technique may be a useful technique if the digital technique fails.Trial registrationClinicalTrials.gov NCT03852589 date of registration: February 22th 2019.

Effect of the leakage location pattern on the speed of recovery in water supply networks

The International Water Association states that Non-Revenue Water is an efficient indicator of the performance of a water company that has been implemented internationally. The volume of water loss expressed as Non-Revenue Water at the global level shows a high number. Every year more than 32 billion m3 of treated water is lost due to leakage from the distribution network. There are four pillars in the network leakage management strategy include management of pressure, speed of recovery, active leakage control, and asset management. These components influence how leakage is managed and affect the volume and value of economic leakage - in a distribution network of water companies. The current annual volume of physical losses tends to increase along with the expansion service area of the distribution network. The rate of increase can be inhibited by the right strategy combining the four components into an effective leakage management strategy. This study analyzes the distribution pattern of leakage points in water distribution pipelines in Malang City, and how much they affect the speed of recovery. The data in this study consist of 5449 pipeline leakage points which include spatial and attributes data. The method used in this study is the Spatial Point Process. The results of the analysis show that the distribution pattern of leakage is an inhomogeneous pattern. It is found that the parameters of the model -with Euclidean distance- the leakage pattern affects the occurrence of leakage and the Geographical Weighted Regression model -with fixed Gaussian Kernel Weight Function with Manhattan distance- the leakage pattern affects the speed of recovery.

A leakage risk assessment method for hazardous liquid pipeline based on Markov chain Monte Carlo

Pipeline is now a commonly-used transportation mode for hazardous liquid, whereas followed by frequent pipeline leakage accidents. Research on the leakage post-assessment of hazard liquid pipeline has received increasing attention, but the in-situ data are hard to be accurately captured, resulting in a series of uncertainties affecting the accuracy and practicality of the risk assessment. This paper puts forward a novel method, which is able to accurately achieve leakage detection, cause analysis and leakage volume forecast by avoiding deviation of in-situ data, model parameters and the uncertainties caused by method, thereby quickly assessing the impact on the surrounding environment. The Markov Chain Monte Carlo (MCMC) algorithm is employed for repeatedly sampling leakage position and coefficient, furthermore, the transient hydrothermal and the leakage risk assessment model are established for determining the leakage volume and the risk grade. The influence of real-time measurement data and the deviation of the method are taken into consideration through the frequency distribution statistics of numerous sampling data. Based on two real examples, it is verified that the risk assessment method has practical value for the in-situ analysis and emergency treatment.

Impact of Using a Novel Gastric Feeding Tube Adaptor on Patient's Comfort and Air Leaks During Non-invasive Mechanical Ventilation

IntroductionThe presence of oral or naso-enteral probes during non-invasive mechanical ventilation (NIMV) increases the risk of leakage and patient discomfort. The objective of this study was to evaluate the effectiveness of a novel tube adapter for NIMV (TA-NIMV) in relation to leakage and comfort level. MethodsA non-randomized quasi-experimental design was performed in an adult intensive care unit of a highly complex hospital, in which patients were their own controls. We included adult patients who required NIV with oronasal mask and who simultaneously had oral or naso-enteric tubes. The interventions were as follows: every participant received two therapies, one with the TA-NIMV and one conventional therapy of NIMV (CT-NIMV). Comfort could be evaluated in 99 patients with a Glasgow Coma Scale of 15. The outcomes of interest was the average percentage of air leak and patient comfort during each intervention. Results196 patients were included in the study during a 16-month period. The mean air leak percentage was 9.2% [standard deviation (SD), 7.7] during TA-NIMV and 32.5% (SD, 12.5) during CT-NIMV (p<0.001). 84.9% reported being comfortable or very comfortable during TA-VMNI. 66.7% Uncomfortable or Very uncomfortable during CT-NIMV (p<0.001). ConclusionHigher comfort levels and lower air leakage volume percentages were achieved using the TA-NIMV than those achieved by CT-NIMV.

Sensitivity analysis of gas leakage through a fault zone during subsurface gas storage in porous formations

Abstract. Subsurface gas storage in porous media is a viable option to mitigate shortages in energy supply in systems largely based on renewable sources. Fault systems adjacent to or intersecting with gas storage could potentially result in a leakage of stored gas. Variations in formation pressure during a storage operation can affect the gas leakage rates, requiring a site and scenario specific assessment. In this study, a geological model of an existing structure in the North German Basin (NGB) is developed, parameterised and a methane gas storage operation is simulated. Based on the observed storage pressure, a sensitivity study aimed at determining gas leakage rates for different parametrisations of the fault damage zone is performed using a simplified 2-D model. The leakage scenario simulations show a strong parameter dependence with the fault acting as either a barrier or a conduit for gas flow. Furthermore, the storage operation greatly affects the gas leakage rates for a given parametrisation with significant leakage only during the injection periods and thus during increased overpressures in the storage formation. During injection, the peak leakage rates can be as high as 2308 Sm3 d−1 for damage zone permeabilities of 10 mD and a capillary entry pressure of 4 bar. Increasing capillary entry pressure results in a sealing effect. If the capillary entry pressure is scaled according to the damage zone permeability, peak leakage rates can be higher, i.e. 3240 Sm3 d−1 for 10 mD and 0.13 bar. During withdrawal periods, the pressure gradient between a storage formation and a fault zone is reduced or even reversed, resulting in greatly reduced leakage rates or even a temporary stop of the leakage. Total leakage volume from storage formation was assessed based on the 2-D study by considering the exposure of the gas-filled part of the storage formation to the fault zone and subsequently compared with gas in place volume.

Model test and numerical simulation research of water leakage in operating tunnels passing through intersecting faults

During operation of the Kaiyuansi Tunnel, water leakage from the lining frequently occurs in the rainy season, seriously impacting the safety of the tunnel structure. To study the occurrence mechanism and evolution law of water leakage in operating tunnels passing through intersecting faults under different burial depths, both a large-scale 3D physical model test and numerical simulations were carried out. The results of the water leakage volume, vertical displacement and hydraulic pressure of the monitoring sections in the physical and numerical models were analyzed. The vertical displacement and hydraulic pressure of the model increase with increasing applied load and water pressure. Because of the higher water conductivity and lower strength of the intersecting faults, the influence of intersecting faults on tunnel water leakage is greater than that of surrounding rock. The intersecting faults have a very close hydraulic connection, and the main fault plays a major role in the seepage of groundwater. The results show that the internal defects of the lining material and quality defects of the tunnel construction are the main factors leading to water leakage in operating tunnels, and the uneven settlement of strata is another important factor in lining cracking and water leakage of operating tunnels. Finally, some useful suggestions and conclusions for tunnel construction and operation were obtained from the test results.

White matter hyperintensities mediate the association between blood-brain barrier leakage and information processing speed

Blood-brain barrier (BBB) leakage is considered an important underlying process in both cerebral small vessel disease (cSVD) and Alzheimer's disease (AD). The objective of this study was to examine associations between BBB leakage, cSVD, neurodegeneration, and cognitive performance across the spectrum from normal cognition to dementia. Leakage was measured with dynamic contrast-enhanced magnetic resonance imaging in 80 older participants (normal cognition, n = 32; mild cognitive impairment, n = 34; clinical AD-type dementia, n = 14). Associations between leakage and white matter hyperintensity (WMH) volume, hippocampal volume, and cognition (information processing speed and memory performance) were examined with multivariable linear regression and mediation analyses. Leakage within the gray and white matter was positively associated with WMH volume (gray matter, p = 0.03; white matter, p = 0.01). A negative association was found between white matter BBB leakage and information processing speed performance, which was mediated by WMH volume. Leakage was not associated with hippocampal volume. WMH pathology is suggested to form a link between leakage and decline of information processing speed in older individuals with and without cognitive impairment.

Efficacy of unilateral transverse process-pedicle and bilateral puncture techniques in percutaneous kyphoplasty for Kummell disease.

In the present study, the efficacy of unilateral transverse process-pedicle and bilateral puncture techniques in percutaneous kyphoplasty (PKP) for Kummell disease was compared. Between March 2015 and June 2017, 63 patients with Kummell disease were recruited and underwent PKP with two different puncture techniques: A total of 38 patients were treated by unilateral transverse process-pedicle PKP and 25 patients were treated by bilateral PKP. The operative time, intra-operative fluoroscopy time, volume of bone cement injection and bone cement leakage were recorded. Prior to surgery and 1 day post-surgery, the visual analogue scale (VAS) pain score and Oswestry disability index (ODI) were determined, and the vertebral body height and Cobb angle were measured. The results indicated that the incidence of bone cement leakage in the unilateral group was similar with the bilateral group (15.79% vs. 16.00%), with no statistically significant difference between the two groups. None of the patients in the two groups had any obvious damage of the spinal cord. The operative time, intra-operative fluoroscopy time and volume of bone cement injection in the unilateral group were lower than those in the bilateral group. A chest X-ray examination at 1 day post-surgery revealed no pulmonary embolism in the two groups. The VAS score, ODI, vertebral body height and Cobb angle were significantly improved in the unilateral and bilateral groups at 1 day post-surgery and at the last follow-up (12 months post-surgery) as compared with these parameters prior to surgery. In conclusion, the unilateral transverse process-pedicle and bilateral puncture techniques in PKP exhibited good efficacy as a treatment for Kummell disease. The operative time, intra-operative fluoroscopy time and volume of bone cement injection were lower in the unilateral group.