An external ventricular drainage catheter impregnated with rifampicin, trimethoprim and triclosan, with extended activity against MDR Gram-negative bacteria: an in vitro and in vivo study

Endoscopic Ventricular Lavage in Pediatric Pyogenic Cerebral Ventriculitis Associated with Shunt: Outcomes and Technical Notes

OBJECTIVE

Pyogenic cerebral ventriculitis (PCV) is a rare infectious entity characterized by a potent inflammatory reaction of the ventricular ependyma, which in most cases leads to death. We aim to present the technical note and protocol, based on our center's 10-year experience of the use of endoscopic ventricular lavage (EVL) in pediatric patients with PCV and ventricular peritoneal shunt.

METHODS

For this study, all pediatric patients (<16 years) with VP shunts and PCV who were treated with EVL between January 2012 and January 2022 were included.

RESULTS

Thirty-four pediatric patients with ventriculitis were analyzed. The median age was 6 years, with 61.7% being male. Most consultations occurred on Day 2 of symptoms. Fever (38.2%) and altered consciousness (26.5%) were the most common initial symptoms. Early ventriculitis was observed in 67.7% of patients. Pathogen identification in the initial cerebrospinal fluid sample was 70.6%, while samples from ventricular peritoneal shunt yielded 23.53% and catheter culture 79.4%. Gram-positive bacteria, mainly S.epidermidis (44.1%), was the most commonly isolated agent. EVL was performed in 73.5% on the second or third day. Reinfection occurred in 23.5%, and 26.5% of patients died. Concordance analysis showed 85.3% agreement between LP and catheter tip samples. Functionality improved, with 55.88% achieving a Lansky score of 90. Early ventriculitis was associated with better Lansky scores.

CONCLUSION

EVL can be a useful tool in the management of PCV in cases with VP shunts. Our study suggests a higher chance of isolating an infection-causing germ in the catheter tip culture specimen compared to the cerebrospinal fluid culture. However, future studies with a larger number of patients, or multicentric studies are required for further analysis.

Facile Modification of Medical-Grade Silicone for Antimicrobial Effectiveness and Biocompatibility: A Potential Therapeutic Strategy against Bacterial Biofilms

A one-step modification of biomedical silicone tubing with N,N-dimethyltetradecylamine, C14, results in a composition designated WinGard-1 (WG-1, 1.1 wt % C14). A surface-active silicon-amine phase (SAP) is proposed to account for increased wettability and increased surface charge. To understand the mechanism of antimicrobial effectiveness, several procedures were employed to detect whether C14 leaching occurred. An immersion-growth (IG) test was developed that required knowing the bacterial Minimum Inhibitory Concentrations (MICs) and Minimum Biocidal Concentrations (MBCs). The C14 MIC and MBC for Gm- uropathogenic E. coli (UPEC), commonly associated with catheter-associated urinary tract infections (CAUTI), were 10 and 20 μg/mL, respectively. After prior immersion of WG-1 silicone segments in a growth medium from 1 to 28 d, the IG test for the medium showed normal growth for UPEC over 24 h, indicating that the concentration of C14 must be less than the MIC, 10 μg/mL. GC-MS and studies of the medium inside and outside a dialysis bag containing WG-1 silicone segments supported de minimis leaching. Consequently, a 5 log UPEC reduction (99.999% kill) in 24 h using the shake flask test (ASTM E2149) cannot be due to leaching and is ascribed to contact kill. Interestingly, although the MBC was greater than 100 μg/mL for Pseudomonas aeruginosa, WG-1 silicone affected an 80% reduction via a 24 h shake flask test. For other bacteria and Candida albicans, greater than 99.9% shake flask kill may be understood by proposing increased wettability and concentration of charge illustrated in the TOC. De minimis leaching places WG-1 silicone at an advantage over conventional anti-infectives that rely on leaching of an antibiotic or heavy metals such as silver. The facile process for preparation of WG-1 silicone combined with biocidal effectiveness comprises progress toward the goals of device designation from the FDA for WG-1 and clearance.

Tunneled antibiotic-impregnated vs. bolt-connected, non-coated external ventricular drainage: a comparison of complications

Background

External ventricular drainage (EVD) is a common emergency neurosurgical procedure, but it is not free of adverse events. The aim of this study is to compare the complication rate of two frequently used EVD types, namely, tunneled antibiotic-impregnated catheters (Bactiseal©) and bolt-connected non-coated devices (Camino©).

Methods

All EVDs placed between 1 March 2015 and 31 December 2017 were registered. Procedures performed with any catheter different from Bactiseal© or Camino© EVD with incomplete follow-up and those EVDs placed due to infectious disease were excluded. Demographic and clinical variables, as well as the overall complication rate (infection, hemorrhage, obstruction, malposition of the catheter, and involuntary pull-out of the device) and the need for replacement of the EVD, were collected.

Results

A total of 77 EVDs were finally considered for analysis (40 Bactiseal® and 37 Camino®). There was a statistically significant difference in diagnosis and also in the location of the procedure, as more bolt-connected EVD was placed outside the operating room (97.3 vs. 23.5%, p < 0.001) due to emergent pathologies such as vascular diseases and spontaneous hemorrhages. In the univariate analysis, a statistically significantly higher rate of catheter involuntary pull-out (29.7 vs. 7.5%, p = 0.012) and the need for EVD replacement (32.4 vs. 12.5%, p = 0.035) was found in the Camino cohort. However, those differences could not be confirmed with multivariable analysis, which showed no association between the type of catheter and any of the studied complications. Ventriculostomy duration was identified as a risk factor for infection (OR 1.09, 95% CI 1.02-1.18).

Conclusion

No significant differences were observed regarding infection, hemorrhage, obstruction, malposition, involuntary catheter pull-out, and the need for EVD replacement when comparing non-impregnated bolt-connected EVDs (Camino®) with tunneled antibiotic-impregnated catheters (Bactiseal®). The duration of EVD was associated with an increased risk of infection.

Current Perspectives on the Diagnosis and Management of Healthcare-Associated Ventriculitis and Meningitis

Ventriculitis or post-neurosurgical meningitis or healthcare-associated ventriculitis and meningitis (VM) is a severe infection that complicates central nervous system operations or is related to the use of neurosurgical devices or drainage catheters. It can further deteriorate patients who have already presented significant neurologic injury and is associated with high morbidity, mortality, and poor functional outcome. VM can be difficult to distinguish from aseptic meningitis, inflammation that follows hemorrhagic strokes and neurosurgical operations. The associated microorganisms can be either skin flora or nosocomial pathogens, most commonly, Gram-negative bacteria. Classical microbiology can fail to isolate the culprit pathogen. Novel cerebrospinal fluid (CSF) biomarkers and molecular microbiology can fill the diagnostic gap and expedite pathogen identification and treatment. The pathogens may demonstrate significant resistant patterns and their antibiotic treatment can be difficult, as many important drug classes, including the beta-lactams and the glycopeptides, hardly penetrate to the CSF, and do not achieve therapeutic levels at the site of the infection. Treatment modifications, such as higher daily dose and prolonged or continuous administration, might increase antibiotic levels in the site of infection and facilitate pathogens clearance. However, in the case of therapeutic failure or infection due to difficult-to-treat bacteria, the direct antibiotic instillation into the CSF, in addition to the intravenous antibiotic delivery, may help in the resolution of infection. However, intraventricular antibiotic therapy may result in aseptic meningitis and seizures, concerning the administration of aminoglycosides, polymyxins, and vancomycin. Meanwhile, bacteria form biofilms on the catheter or the device that should routinely be removed. Novel neurosurgical treatment modalities comprise endoscopic evacuation of debris and irrigation of the ventricles. VM prevention includes perioperative antibiotics, antimicrobial impregnated catheters, and the implementation of standardized protocols, regarding catheter insertion and manipulation.

Advances in CSF shunt devices and their assessment for the treatment of hydrocephalus

INTRODUCTION

Hydrocephalus is a neurological disorder caused by excessive accumulation of the cerebrospinal fluid (CSF) in the ventricles of the brain. It can be treated by diverting the extra fluid to different parts of the body using a device called a shunt. This paper reviews different shunt devices that are used for this purpose.

AREAS COVERED

Shunts have high failure rates either due to infection or mechanical failure, therefore there is still ongoing work to address these two main handicaps. They require additional devices for performance assessment. Here, the paper also reviews different approaches for assessing shunt limitations. Moreover, future prospects are also discussed.

EXPERT OPINION

This study shows that shunt devices still remain an important treatment option for hydrocephalus. However, further efforts are required to design more advanced shunts, to eliminate high failure rates in clinical use. Sophisticated sensor systems that can accurately detect and regulate changes in CSF drainage to optimize drainage for individual needs. Moreover, shunt infection problem is still present despite recent improvements such as antibiotic impregnated catheters.

Gram-Negative Ventriculostomy-Associated Infections Predict Shunt Dependency in Stroke Diagnoses and Other Brain Injuries

BACKGROUND

Several predictors have been studied for shunt dependency after stroke and other brain injuries. However, little is known about the association between ventriculostomy-associated infections (VAIs) and impaired cerebrospinal fluid (CSF) outflow. Moreover, gram-negative (GN) VAIs induce a potent neuroinflammatory process and are clinically challenging to treat.

OBJECTIVE

To assess if GN-VAIs predict ventriculoperitoneal shunt (VPS) dependency.

METHODS

Retrospective analysis of postprocedure infection rates was performed in 586 patients with external ventricle drainage (EVD) placed on site between 2012 and 2018. We collected sex, age, stroke and nonstroke related, location of EVD placement, type of hospital, EVD duration, and EVD exchange.

RESULTS

Among 586 patients requiring an EVD, 55 developed a VAI. Most were caused by gram-positive (GP) pathogens (61.8%). A total of 120 patients required a conversion from EVD to VPS. Patients with VAIs had higher rates of VPS placement (49.09% vs 17.65%, P < .001), whereas patients with GN-VAIs had significantly higher rates of EVD conversion to VPS (77.78% vs 35.29%, P = .012) compared with GP-VAIs. The multivariate analysis showed that GN-VAIs were an independent predictor for shunt dependency (odds ratio = 12.896; 95% CI 3.407-48.82, P < .001). In receiver operating characteristics analysis, those less than 44.5 yr of age and more than 12 d of EVD duration were identified as the best cutoff values to discriminate the development of GN-VAI.

CONCLUSION

Patients who experience a GN VAI are in greater risk of impaired CSF outflow, thus requiring VPS placement.

Minimising Blood Stream Infection: Developing New Materials for Intravascular Catheters

Catheter related blood stream infection is an ever present hazard for those patients requiring venous access and particularly for those requiring long term medication. The implementation of more rigorous care bundles and greater adherence to aseptic techniques have yielded substantial reductions in infection rates but the latter is still far from acceptable and continues to place a heavy burden on patients and healthcare providers. While advances in engineering design and the arrival of functional materials hold considerable promise for the development of a new generation of catheters, many challenges remain. The aim of this review is to identify the issues that presently impact catheter performance and provide a critical evaluation of the design considerations that are emerging in the pursuit of these new catheter systems.

Controlling Particle Size and Release Kinetics in the Sustained Delivery of Oral Antibiotics Using pH-Independent Mucoadhesive Polymers

Copolymers synthesized from acrylic acid and methacrylic acid used as gastroprotective and mucoadhesive enteric coatings have been used to prepare micro- (∼2 μm), submicro- (∼200 nm), and nanoparticles (∼20 nm) containing rifampicin (Rif) to obtain time-controlled drug release kinetics. Different particle sizes and drug release kinetics have been obtained using different synthesis conditions and fabrication techniques including the use of an electrosprayer and an interdigital microfabricated micromixer. The antimicrobial action of the encapsulated Rif has been demonstrated against Staphylococcus aureus ATCC 25923 and compared with the effect of the equivalent dose of the free macrolide antibiotic. At low concentrations, the encapsulated antibiotic showed superior antimicrobial activity than the free drug. The stability of the developed particles has been evaluated in vitro under simulated gastric and intestinal conditions. At the concentrations tested, a reduced cytotoxicity against different human cell lines was observed after analyzing their subcytotoxic doses and the influence on their cell cycle by flow cytometry. Drug release kinetics can be tuned by adjusting particle sizes, and it would be possible to reach the minimum inhibitory concentration or the minimum bactericidal concentration at different time points depending on the medical needs.