The interactive force between fat, oil, and grease (FOG) deposits and the effect of food waste disposers on kitchen drainage systems

Food waste disposers (FWDs) streamline kitchen waste management and facilitate waste classification, whether they would increase the potential of blockage in kitchen drainage system is still unknown. This study conducted a theoretical analysis of the interactive forces between fat, oil, and grease (FOG) deposits and their aggregation on pipe walls. The study involved grading food waste particles processed by FWDs using sieving and weighing techniques to determine the mean weight diameter (MWD) of various aggregations. A full-scale experimental system, implemented in a 60-m high test tower, simulated blockages in horizontal pipes of high-rise buildings. The effect of pipeline materials and particle sizes on blockage were examined by measuring the adhesion of deposits on horizontal pipes. Energy dispersive spectrometer (EDS) analysis suggested that liquid bridge force is a primary factor in aggregate formation. Hand-cut particles formed aggregates with the highest MWD value. Particle size analysis revealed that sizes ranging from 2.36 to 4.75 mm, 1.18-2.36 mm, and 0.60-1.18 mm constituted over 80 % of particles ground by FWDs, with an average size of 2.16 mm. Results of full-scale experiment indicate particle diameters, friction coefficients and lipophilic coefficient significantly affected the propensity of these aggregates to adhere to pipes. Notably, particles processed by FWDs tended to cause blockages more frequently than hand-cut particles. These findings elucidate the deposition mechanism of FOG deposits and offer strategies to reduce blockages in kitchen drainage systems, such as reducing current grinding particle size by 18 % to 1.77 mm or selecting pipes like cast iron and high-density polyethylene.

Experimental mmWave WiGig-based backhaul network dataset

The wireless backhaul has emerged as an attractive alternative to traditional fiber backhaul for 5G technology, offering greater flexibility and cost-effectiveness thanks to the availability of high bandwidths capable of achieving fiber-like data rates. However, the millimeter-wave-based (mmWave) protocols, namely IEEE 802.11ad and later IEEE 802.11ay, suffer from a high susceptibility to obstruction, which only allows correct operation under Line-of-Sight conditions (LOS). Any sudden obstructions can significantly reduce the maximum achievable throughput, leading to delays exceeding acceptable limits for critical applications, and may even culminate in link failure in certain circumstances. Therefore, it is essential to assess how different types and durations of obstructions impact different network OSI layers to determine the feasibility of mmWave. WiGig-based technologies for wireless backhaul scenarios. This article describes a dataset collected from an experimental IEEE 802.11ad backhaul network, mmWave-based mesh network at 60 GHz, deployed in an outdoor environment. The data contains multi-layer information, including MAC, PHY, and network data, which provides valuable insights into the WiGig network behavior under three distinct scenarios. These scenarios include normal operation, long-term blocked scenario, and short-term blocked scenario, based on the type and duration of the blockage event crossing the LOS path. The dataset presents an extensive PHY, MAC and transport layer measurement campaign for an outdoor WiGig network, and thus it is a valuable resource for researchers and professionals interested in understanding the behavior and performance of real-life mmWave-based WiGig networks aimed for 5G backhauling.

Beneficial and adverse effects of dam construction in canal tannery wastewater effluent with a high content of chromium in Hazaribagh, Bangladesh

BACKGROUND

Blockage to divide downstream canals into upstream canals, into which tannery wastewater including a high concentration of trivalent chromium [Cr(III)] is directly discharged, has been constructed in Hazaribagh, a tannery built-up area in Bangladesh. However, there has been no study to verify the environmental significance of blockage construction for water pollution of Cr in nature.

METHODS

Consecutive fixed area monitoring for a total of 164 water samples collected outside and inside Hazaribagh from 2014 to 2023 was carried out to clarify the effects of stagnant and flowable canal water in the presence or absence of blockage on Cr(III) and hexavalent Cr [Cr(VI)] concentrations.

RESULTS

Since pollution of Cr(III) and Cr(VI) in Buriganga River (outside Hazaribagh) was not serious, this study then focused on their pollution in canal water (inside Hazaribagh) in the nonblockage period, blockage construction period and blockage destruction period. As expected, the mean Cr(III) concentration in downstream canal water samples in the blockage construction period was more than 98% lower than that in the upstream canal water samples in the same period, while the concentrations were comparable in downstream and upstream canal water samples in the nonblockage period and blockage destruction period. Unexpectedly, the mean concentration of Cr(VI) in the upstream canal water samples in the blockage construction period was 38.6-fold and 3.3-fold higher than that in the downstream canal water samples and the Cr(VI) guideline value by the US-EPA, respectively.

CONCLUSION

This study demonstrated for the first time not only a merit of decreased Cr(III) pollution but also a demerit of increased Cr(VI) pollution in stagnant water derived from blockage construction in natural environments. This bitter lesson obtained by the enclosure of Cr(III)-polluted water is globally applicable for water pollution of Cr(III), which is used in various industries including the leather industry.

Mechanical Complications of External Ventricular and Lumbar Drains

BACKGROUND

External ventricular drain (EVD) and lumbar drain insertion are 2 of the most commonly performed neurosurgical procedures worldwide for acute hydrocephalus. Mechanical complications, such as obstruction or cerebrospinal fluid (CSF) leakage, are often seen and may contribute toward significant patient morbidity. Different CSF drainage methods are advocated to reduce the incidence of complications, but evidence regarding comparative effectiveness is limited.

METHODS

In this single-center prospective cohort study, the incidence of mechanical complications and associated interventional factors, including choice of drain, collecting system, and location, were studied in patients requiring CSF diversion for acute hydrocephalus. Univariate analyses were performed to explore trends within the data, followed by a repeated-measures mixed-effects regression to determine the independent influence of drain device on mechanical failure.

RESULTS

Sixty-one patients required CSF diversion between January 2020 and March 2021, via 3 different drain types (lumbar drain, tunneled, and bolted EVD) and 2 collection systems (LiquoGuard 7 and AccuDrain), performed in either theater or intensive care. Twenty-one patients (39%) experienced a mechanical complication, with blockage being the most common. Multivariate analyses showed that bolted EVDs (odds ratio, 0.08; confidence interval, 0.01-0.58) and LiquoGuards (OR, 0.23; CI, 0.08-0.69) were significantly associated with fewer mechanical complications compared with tunneled EVDs and gravity-based collection systems, respectively (P ≤ 0.01).

DISCUSSION

Drain device has an influence on the occurrence of EVD-related complications. These preliminary findings suggest that choosing bolted EVDs and motor-assisted drainage can reduce drain-associated mechanical failure. A randomized controlled trial comparing drain devices is required to confirm these findings.

Catheters at home: managing urinary catheters in the home environment

In England, there are some 90000 people with catheters in the community, and community nurses often have to manage catheter-related problems. This article looks at these common catheter problems found in the community, for example, blockage, infections and positioning problems. These problems were identified by a literature review and from the author's experience, from many years working in the community. It has been found that education, knowledge, empowerment and communication are vital factors affecting patients' ability to manager their catheters themselves. The article begins with a discussion about how patients can be involved in and manage many aspects of care for their own catheters. It goes on to talk about the common catheter-associated problems and how these can be avoided or addressed. It is hoped that better management of catheter-associated complications in the community settings can prevent unnecessary visits to the emergency department, which will save time and costs for the health service, as well as avoid the negative impact of these on patient lives.

Channel Prediction for mmWave Ground-to-Air Propagation under Blockage

Ground-to-air (GA) communication using unmanned aerial vehicles (UAVs) has gained popularity in recent years and is expected to be part of 5G networks and beyond. However, the GA links are susceptible to frequent blockages at millimeter wave (mmWave) frequencies. During a link blockage, the channel information cannot be obtained reliably. In this work, we provide a novel method of channel prediction during the GA link blockage at 28 GHz. In our approach, the multipath components (MPCs) along a UAV flight trajectory are arranged into independent path bins based on the minimum Euclidean distance among the channel parameters of the MPCs. After the arrangement, the channel parameters of the MPCs in individual path bins are forecasted during the blockage. An autoregressive model is used for forecasting. The results obtained from ray tracing simulations indicate a close match between the actual and the predicted mmWave channel.

Effects of filler voidage on pressure drop and microbial community evolution in fungal bio-trickling filters

Bio-trickling filters (BTFs) can be used to remediate pollution by volatile organic compounds such as toluene. To investigate the effect of filler voidage on pressure drop (△P), two parallel BTFs were constructed using ceramsite with different voidages (47.5% for BTF1 and 55% for BTF2) and inoculated with Fusarium fungus to purify toluene. Commutation and stagnation operations were explored as ways to relieve △P. In BTF1, commutation temporarily relieved △P and maintained it for 7 days. Implementing stagnation on the 178th day for 69 days effectively reduced the △P from 720 Pa/m to below 20 Pa/m, which was maintained for 36 days. Compared with BTF1, the filler in BTF2 effectively delayed the increase in △P for 70 days or more and ensured stable operation for as long as 174 days. High-throughput sequencing revealed that Fusarium was mainly replaced by Protoctista, Fronsecaea and other fungi in both BTFs, although there were significant differences in their microbial communities. The influences of commutation and stagnation operations on fungal evolution were more obvious in BTF2, in relation to both time and space. The results provide guidance for designing better BTFs to treat hazardous pollutants.

Predictors of postoperative complications in paediatric patients receiving grommets - A retrospective analysis

BACKGROUND

Insertion of middle ear ventilation tubes (MEVT), tympanostomy tubes or grommets is one of the most common paediatric surgical procedures performed by ENT surgeons worldwide. Outcomes may be complicated by postoperative otorrhoea and ventilation tube blockage.

OBJECTIVE

To identify risk factors associated with early postoperative complications of MEVT insertion.

METHOD

In a case-control study, set in a tertiary hospital in Melbourne, Australia, 590 paediatric patients undergoing grommet insertion between February 2017 and February 2018, 311 patients (205 males & 106 females; median age of 3.86 years) met the inclusion criteria and had identical middle ear status bilaterally.

INTERVENTION

Tympanostomy tube insertion and postoperative topical otic antibiotic drops.

MAIN OUTCOME AND MEASURES

Patient age, gender, weight/BMI percentile, intraoperative middle ear status, number of previous grommets, type of surgery, season of surgery, diagnosis and time to first medical review were examined. The duration of topical otic antibiotic drops used and tube patency and presence of otorrhoea at 6-week postoperative review were also recorded.

RESULTS

At the first medical review, 8.7% of patients (n = 27) developed otorrhoea from one or both ears, 6.4% of patients (n = 20) had an obstructed MEVT in one or both ears. Exposure to intraoperative [IO] and postoperative [PO] antibiotic drops were significantly less associated with developing postoperative otorrhoea compared to non-exposure (IO: Odds Ratio [OR] = 0.15, 95%CI 0.04 to 0.57, p = 0.005; PO: OR = 0.21, 95%CI 0.58 to 0.76, p = 0.017). There were no statistically significant associations between antibiotic drop exposure and grommet blockage (p > 0.05). There was a significant association between developing postoperative otorrhoea and patients receiving surgery during the colder months of Winter/Autumn (OR = 3.17, 95%CI 1.14 to 8.84, p = 0.028), as well as patients aged less than 3 years (OR = 2.66, 95%CI 1.01 to 7.03, p = 0.049). There was a statistically significant association between serous effusions and grommet blockage compared to no effusion (OR = 4.03, 95%CI 1.03 to 15.7, p = 0.045). There were no statistically significant associations identified between otorrhoea and gender, weight/BMI percentile, intraoperative middle ear status, number of previous grommets, type of surgery, diagnosis and time to first medical review. There were no statistically significant associations between grommet blockage and age, gender, indication for surgery, concurrent surgery, season or number of previous grommets.

CONCLUSIONS

8.7% of patients developed otorrhoea within 6 weeks post-operatively. Undergoing the procedure during winter/autumn, age <3 years were associated with developing otorrhoea. Topical antibiotic exposure was inversely associated with developing postoperative otorrhoea. 6.4% of patients had grommet blockage. Presence of serous middle ear effusion intraoperatively was a statistically significant indicator for developing grommet blockage.

Chemoport-associated Complications and Its Management

Chemoport is being routinely used to administer chemotherapy, blood, blood products, total parenteral nutrition, and also to draw blood for investigations. We started using chemoport in our institute. We use it exclusively to administer chemotherapy. We analyzed our results of chemoport usage and confirm that the rate of complications associated with chemoport usage is at par with the available literature. We also conclude that with regular use, the intra-op and post-op complications will reduce further.

Hydrokinetic turbines for moderate sized rivers

If hydrokinetic turbines are to make a significant contribution to small scale off-grid power supply, they will need to be affordable, reliable and easily deployed at many sites, not just a few with exceptional combinations of depth and high flow velocity. Few if any products currently on the market meet these criteria. This paper addresses the challenge of providing small scale electrical power and pumping from rivers, in particular for villages in high rainfall tropical areas where there is no mains power, not much wind or sunny weather in the wet season, and not enough elevation for conventional micro-hydro. Hydrokinetic power is proposed, and candidate turbines are evaluated, including multiple small axial flow turbines, various forms of horizontal axis Darrieus turbines, water wheels, and belt turbines. The importance of channel blockage in enhancing turbine power output is discussed.

Baerveldt-Baerveldt Apposition: A New Surgical Technique to Salvage Obstructed Glaucoma Drainage Tubes

Aim

Glaucoma drainage device (GDD) failure is usually rectified by the replacement of the entire device or using a tube extender, both of which were associated with postoperative complications. To minimize these risks, we developed a technique to replace the failing section of a tube while keeping the filtration plate in place, and without resorting to an extender clip.

Background

We describe the case of a 69-year-old man, whose left posttraumatic glaucoma was initially treated with a XEN-augmented Baerveldt procedure. Following recurrent obstructions, a kinked section of the Baerveldt tube was sectioned and replaced.

Technique

After sectioning the blocked section of the tube, a new Baerveldt tube was inserted into the anterior chamber. Its filtration plate was removed, and the posterior end of the new tube was connected to the anterior end of the existing device so that both lumens would be continuous. The adjoining tubes were stitched to each other with two 8-0 nylon sutures passing through the walls of the tubes. An allograft patch was replaced over the tubes and the conjunctival fornix was closed. Intraocular pressure (IOP) normalized immediately after surgery and remained stable through 6 months.

Conclusion

This surgical approach offers a new way to salvage a failing Baerveldt tube without replacing the filtration plate, repeating a complete surgery, or potentially compromising the conjunctiva with an extender. The minimal residual gap at the junction between the tubes appears to provide the same additional IOP-lowering effect as the “venting slits” that are sometimes performed to minimize the initial hypertensive phase without causing hypotony.

Clinical significance

This report illustrates a simple yet effective technique to replace the failing section of a GDD or lengthen a short GDD without replacing the entire device or using an extender clip, and thus minimizing the risks of complications.

How to cite this article

Gillmann K, Mansouri K, Bravetti GE, et al. Baerveldt–Baerveldt Apposition: A New Surgical Technique to Salvage Obstructed Glaucoma Drainage Tubes. J Curr Glaucoma Pract 2019;13(3):110–112.

Analyzing spatially and temporally visualized formation behavior of methane hydrate in unconsolidated porous media

An understanding of the nucleation and growth mechanism of methane hydrate in porous space is essential for exploitation and application of hydrates, but the mechanism is yet to be clarified. Magnetic resonance imaging (MRI) was employed to visually analyze the spatial and temporal formation behavior of methane hydrate in a porous media. Detailed information about the water distribution, initial nucleation sites, and hydrate growth was obtained, in addition to MRI images. The results demonstrated that the water molecules distributed in the vertical direction preferred the middle slice of a porous medium sample, and the decrease in the number of molecules in the middle slice and on both sides of the slice was similar during hydrate formation. The formation process are quite different in selected horizontal slices, which were contributed to the various distribution of water and gas in pore spaces and the randomness of methane hydrate formation. The extension of these predicted results could have important implications for optimizing the formation processes of gas hydrate in hydrate-based technologies.

Allicin prevents the formation of Proteus-induced urinary crystals and the blockage of catheter in a bladder model in vitro

Stone formation and catheter blockage are major complications of Proteus UTIs. In this study, we investigated the ability of allicin to inhibit P. mirabilis-induced struvite crystallization and catheter blockage using a synthetic bladder model. Struvite crystallization inhibition study was carried out using P. mirabilis lysate as urease enzyme source in synthetic urine (SU). Struvite productions were monitored by phase contrast light microscopy and measurements of pH, Mg²⁺ and Ca²⁺ precipitation and turbidity. A catheter blockage study was performed in a synthetic bladder model mimicking natural UTI in the presence of allicin at sub-MIC concentrations (MIC = 64 μg/ml). The results of crystallization study showed that allicin inhibited pH rise and consequently turbidity and precipitation of ions in a dose-dependent manner. The results of catheter blockage study showed that allicin at sub-MIC concentrations (2, 4, 8 μg/ml) significantly increased the time for catheter blockage to occur to 61, 74 and 92 h respectively compared to allicin-free control (48 h). In a similar way, the results showed that allicin delayed the increase of SU pH level in bladder model in a dose-dependent manner compared to allicin-free control. The results also showed that following the increase of allicin concentration, Mg²⁺ and Ca²⁺ deposition in catheters were much lower compared to allicin-free control, further confirmed by direct observation of the catheters' eyehole and cross sections. We conclude that allicin prevents the formation of Proteus-induced urinary crystals and the blockage of catheters by delaying pH increase and lowering Mg²⁺ and Ca²⁺ deposition in a dose-dependent manner.

Analysis of inline-filter blockage with trastuzumab formulation using scanning-electron microscopy

The instability of pharmaceutical monoclonal antibodies are affected by physical stimuli including, temperature, denaturant, surfactant, stirring, solid phase adsorption, oxidation, and ultraviolet rays. Clinically, we frequently experience precipitation during preparation of several pharmaceutical monoclonal antibodies for cancer. Although it is possible to remove precipitates in the injection solution during the preparation procedure, potential filter blockade during administration remains a problem with adverse effects on the quality of life of patients. Therefore we sought to investigate factors contributing to this phenomenon. To closely observed the mechanisms involved in blockade of filters during trastuzumab preparation, we prepared samples under the same conditions used in clinical practice and observed them comprehensively. The precipitates that caused filter blockade were observed when the samples were vigorously shaken and left for several hours after dissolving. The precipitates were identified as proteins. The vigorous shaking caused contact between the protein and air, which induced protein precipitation caused by the surfactants derived from the foam formation. We discovered that the external stimulation may cause the instability of monoclonal antibody preparations and, so, it is important for procedures to be as rapid to avoid precipitate formation as much as possible.

Delayed Obstruction of XEN Gel Stent by Cell Debris in Primary Open-angle Glaucoma: A New Insight into the Pathophysiology of Filtration Device Failure

Aim

The aim of this report is to explore the risk factors of XEN stent obstruction, suggesting the need for a stricter control of these factors and highlighting areas for further research.

Background

Despite its proven effectiveness and safety profile, XEN gel stents (Allergan Plc, Dublin, Ireland) can become obstructed. The causes and predicting factors for such obstructions still require further research. While hyphema has long been known to be responsible for secondary glaucoma through trabecular obstruction, it has not been associated, to date, with XEN gel stent obstruction.

Case description

We describe the case of a 55-year-old female patient with primary open-angle glaucoma (POAG) who underwent bilateral XEN gel surgery. Her left eye developed a 2 mm postoperative hyphema, which resolved spontaneously within 8 days. Intraocular pressure (IOP) normalized at 12 mm Hg and increased to 50 mm Hg after 1 month in an otherwise normal-looking eye. Intraoperative examination revealed a nonfunctioning XEN gel stent, which was replaced and sent for laboratory analysis. Macroscopic examination of the tube confirmed obstruction with cellular debris. Tube replacement restored good filtration.

Conclusion

This case report confirms cellular debris as a potential cause of XEN gel stent occlusion, suggesting that aqueous red blood cells (RBCs) could potentially pose a threat to the microstents’ patency even in cases when the bleeding was minimal and self-limited and where the IOP was still controlled at the time of full hyphema resolution. This observation could lead to recommendations for a stricter control of bleeding risk factors prior to microinvasive glaucoma surgery (MIGS), and it raises the question of whether anterior chamber (AC) washout should be advised in postoperative hyphema.

Clinical significance

This case highlights some previously unreported risk factors for XEN stent obstruction and suggests that stricter control of bleeding and monitoring of patients following hyphema could improve surgical outcome.

How to cite this article

Gillmann K, Bravetti GE, Mansouri K. Delayed Obstruction of XEN Gel Stent by Cell Debris in Primary Open-angle Glaucoma: A New Insight into the Pathophysiology of Filtration Device Failure. J Curr Glaucoma Pract 2019;13(3):113–115.

Efficacy and Safety of Digital Single-Operator Cholangioscopy for Difficult Biliary Stones

BACKGROUND & AIMS

It is not clear whether digital single-operator cholangioscopy (D-SOC) with electrohydraulic and laser lithotripsy is effective in removal of difficult biliary stones. We investigated the safety and efficacy of D-SOC with electrohydraulic and laser lithotripsy in an international, multicenter study of patients with difficult biliary stones.

METHODS

We performed a retrospective analysis of 407 patients (60.4% female; mean age, 64.2 years) who underwent D-SOC for difficult biliary stones at 22 tertiary centers in the United States, United Kingdom, or Korea from February 2015 through December 2016; 306 patients underwent electrohydraulic lithotripsy and 101 (24.8%) underwent laser lithotripsy. Univariate and multivariable analyses were performed to identify factors associated with technical failure and the need for more than 1 D-SOC electrohydraulic or laser lithotripsy session to clear the bile duct.

RESULTS

The mean procedure time was longer in the electrohydraulic lithotripsy group (73.9 minutes) than in the laser lithotripsy group (49.9 minutes; P < .001). Ducts were completely cleared (technical success) in 97.3% of patients (96.7% of patients with electrohydraulic lithotripsy vs 99% patients with laser lithotripsy; P = .31). Ducts were cleared in a single session in 77.4% of patients (74.5% by electrohydraulic lithotripsy and 86.1% by laser lithotripsy; P = .20). Electrohydraulic or laser lithotripsy failed in 11 patients (2.7%); 8 patients were treated by surgery. Adverse events occurred in 3.7% patients and the stone was incompletely removed from 6.6% of patients. On multivariable analysis, difficult anatomy or cannulation (duodenal diverticula or altered anatomy) correlated with technical failure (odds ratio, 5.18; 95% confidence interval, 1.26-21.2; P = .02). Procedure time increased odds of more than 1 session of D-SOC electrohydraulic or laser lithotripsy (odds ratio, 1.02; 95% confidence interval, 1.01-1.03; P < .001).

CONCLUSIONS

In a multicenter, international, retrospective analysis, we found D-SOC with electrohydraulic or laser lithotripsy to be effective and safe in more than 95% of patients with difficult biliary stones. Fewer than 5% of patients require additional treatment with surgery and/or extracorporeal shockwave lithotripsy to clear the duct.

Repeated Peritoneal Catheter Blockage Caused by Neurocysticercosis Following Ventriculoperitoneal Shunt Placement for Hydrocephalus

Cerebral cysticercosis is common, but the possibility for repeated occurrence of peritoneal catheter blockage caused by neurocysticercosis (NCC) after two revisions following ventriculoperitoneal shunt placement for hydrocephalus is unusual. Herein, we describe one rare case in which peritoneal catheter revision was performed two times unsuccessfully. Endoscopic cysternostomy rather than peritoneal catheter adjustment was performed successfully, and histopathological examination of excised cystic samples confirmed NCC in our hospital. The present case highlights the need for awareness of NCC as a possible etiology of hydrocephalus, especially in developing countries. Uncommon findings in both lateral ventricles following low-field magnetic resonance imaging scans as well as the rarity of this infection involved in unusual location play important roles in misdiagnosis and incorrect treatment for hydrocephalus; thus, endoscopic cysternostomy, rather than multiple shunt adjustment of the peritoneal end, is recommended in the selected patient. To the best of our knowledge, this is the first report describing the misdiagnosis and inappropriate treatment of hydrocephalus caused by cerebral cysticercosis in China.

Aspirin Use Is Associated With Reduced Risk of Occlusion of Metallic Biliary Stents

BACKGROUND & AIMS

Biliary self-expandable metallic stents (SEMSs) are widely used to treat malignant and benign conditions of bile duct. Despite their lower rate of occlusion and longer patency than plastic stents, SEMSs still have significant rates of occlusion. We aimed to identify factors associated with occlusion of biliary SEMS.

METHODS

We performed a retrospective study of consecutive patients who underwent endoscopic retrograde cholangiopancreatography with biliary SEMS placement at the Cleveland Clinic Foundation from March 2011 to April 2016. We collected clinical, endoscopic, radiographic, and surgical data from medical records and performed multivariable analysis to identify factors associated with SEMS patency. Subjects that received minimal daily dose of 81 mg at the time of stent placement until the end of follow-up were assigned to the aspirin exposure group (n = 157) and compared with subjects with no aspirin exposure (n = 436). Patients were followed for a median 81 days. The primary outcome was hazard ratio for SEMS occlusion requiring an interventional maneuver for biliary drainage.

RESULTS

We analyzed data from patients receiving a total of 593 biliary SEMS for treatment of malignant and benign conditions of bile duct. Stent occlusion was observed in 126 cases. Multivariable analysis showed that daily use of aspirin (81 mg or more) was associated with 51% lower risk of stent occlusion than in patients without daily use of aspirin (hazard ratio, 0.49; 95% confidence interval, 0.32-0.75). Furthermore, SEMSs had a longer duration of stent patency in patients in the aspirin exposure group (434.4 days) versus the no aspirin exposure group (339.9 days) (P < .001). Stricture location limited to distal bile duct (in comparison with strictures involving proximal extrahepatic duct) was associated with lower risk of stent occlusion (hazard ratio, 0.39; 95% CI, 0.22-0.71).

CONCLUSIONS

In an analysis of a large cohort of subjects with metallic biliary stent placement for malignant and benign conditions of bile duct, we associated daily use of aspirin (81 mg or more) with lower risk of SEMS occlusion and longer stent patency duration.

Temporal changes of spinal subarachnoid space patency after graded spinal cord injury in rats

INTRODUCTION

Disturbances in spinal subarachnoid space (SSAS) patency after SCI have been reported as an incidental finding, but there is a lack of information on its in vivo extent and time course. For substances and cells carried in the cerebrospinal fluid (CSF) to reach damaged neural tissue and promote reparative processes, CSF must be able to flow freely in SASS.

OBJECTIVE

To characterise the extent and time course of SSAS patency disruption in vivo in a rat model after graded SCI.

MATERIALS AND METHODS

Anaesthetised rats were subjected to mild or severe cord contusion at T9. Estimation of SSAS patency was carried out at 1h and 1, 3, 7, 15, 30 and 90 days postinjury, as well as in naïve rats, by quantifying the passage of superparamagnetic beads injected into the CSF at the cisterna magna and recovered at spinal level L2. CSF volume recovery was measured simultaneously. Data were analysed by the two-way ANOVA test.

RESULTS

Estimation of SSAS patency revealed nearly complete blockage early after contusion that was unevenly restored entering the chronic stages. Volume of CSF recovered was also significantly decreased early after injury compared to naïve rats, but was fully restored by 1 month postinjury. Overall, although modestly different from each other, changes in both parameters were more pronounced after severe rather than mild injuries for each time point examined.

CONCLUSIONS

SCI alters SSAS patency. Its extent is a function primarily of time elapsed after lesion and secondly of injury severity. It is reasonable to expect that disturbances in SASS patency might alter CSF dynamics and impair self-reparative mechanisms and intrathecal therapeutics, making SSAS patency blockage a key target for SCI management.

Correlates of emotional congruence with children in sexual offenders against children: a test of theoretical models in an incarcerated sample

Emotional congruence with children is a psychological construct theoretically involved in the etiology and maintenance of sexual offending against children. Research conducted to date has not examined the relationship between emotional congruence with children and other psychological meaningful risk factors for sexual offending against children. The current study derived potential correlates of emotional congruence with children from the published literature and proposed three models of emotional congruence with children that contain relatively unique sets of correlates: the blockage, sexual deviance, and psychological immaturity models. Using Area under the Curve analysis, we assessed the relationship between emotional congruence with children and offense characteristics, victim demographics, and psychologically meaningful risk factors in a sample of incarcerated sexual offenders against children (n=221). The sexual deviance model received the most support: emotional congruence with children was significantly associated with deviant sexual interests, sexual self-regulation problems, and cognition that condones and supports child molestation. The blockage model received partial support, and the immaturity model received the least support. Based on the results, we propose a set of further predictions regarding the relationships between emotional congruence with children and other psychologically meaningful risk factors to be examined in future research.