Differences in microorganisms causing infection after cranial and spinal surgeries.

OBJECTIVE: The primary aim of this retrospective study was to assess differences in the pathogens causing surgical site infections (SSIs) following craniectomies/craniotomies and open spinal surgery. The secondary aim was to assess differences in rates of SSI among these operative procedures. METHODS: ANOVA tests with Bonferroni correction and incidence risk ratios (RRs) were used to identify differences in pathogens by surgical site and procedure using retrospective, de-identified records of 19,993 postneurosurgical patients treated between 2007 and 2020. RESULTS: The overall infection rates for craniotomy/craniectomy, laminectomy, and fusion were 2.1%, 1.1%, and 1.5%, respectively, and overall infection rates for cervical, thoracic, and lumbar spine surgery were 0.3%, 1.6%, and 1.9%, respectively. Craniotomy/craniectomy was more likely to result in an SSI than spine surgery (RR 1.8, 95% CI 1.4-2.2, p < 0.0001). Cutibacterium acnes (RR 24.2, 95% CI 7.3-80.0, p < 0.0001); coagulase-negative staphylococci (CoNS) (methicillin-susceptible CoNS: RR 2.9, 95% CI 1.6-5.4, p = 0.0006; methicillin-resistant CoNS: RR 5.6, 95% CI 1.4-22.3, p = 0.02); Klebsiella aerogenes (RR 6.5, 95% CI 1.7-25.1, p = 0.0003); Serratia marcescens (RR 2.4, 95% CI 1.1-7.1, p = 0.01); Enterobacter cloacae (RR 3.1, 95% CI 1.2-8.1, p = 0.02); and Candida albicans (RR 3.9, 95% CI 1.2-12.3, p = 0.02) were more commonly associated with craniotomy/craniectomy cases than fusion or laminectomy SSIs. Pseudomonas aeruginosa was more commonly associated with fusion SSIs than craniotomy SSIs (RR 4.4, 95% CI 1.3-14.8, p = 0.02), whereas Escherichia coli was nonsignificantly associated with fusion SSIs compared to craniotomy SSIs (RR 4.1, 95% CI 0.9-18.1, p = 0.06). Infections with E. coli and P. aeruginosa occurred primarily in the lumbar spine (p = 0.0003 and p = 0.0001, respectively). CONCLUSIONS: SSIs due to typical gastrointestinal or genitourinary gram-negative bacteria occur most commonly following lumbar surgery, particularly fusion, and are likely to be due to contamination of the surgical bed with microbial flora in the perianal area and genitourinary tract. Cutibacterium acnes in the skin flora of the head and neck increases risk of infection due to this microbe following surgical interventions in these body sites. The types of gram-negative bacteria associated with craniotomy/craniectomy SSIs suggest potential environmental sources of these pathogens. Based on the authors' findings, neurosurgeons should consider using a two-step skin preparation with benzoyl peroxide, in addition to a standard antiseptic such as alcoholic chlorhexidine for cranial, cervical, and upper thoracic surgeries. Additionally, broader gram-negative bacterial coverage, such as use of a third-generation cephalosporin, should be considered for lumbar/lumbosacral fusion surgical antibiotic prophylaxis.

Coagulopathy in Penetrating Ballistic Cranial Trauma: A 7-Year Experience.

BACKGROUND AND OBJECTIVES: Penetrating ballistic cranial trauma (PBCT) carries significant mortality when compared with blunt trauma. The development of coagulopathy in PBCT is a strong predictor of mortality. The goal of the study was to describe the incidence and risk factors of coagulopathy in PBCT and to report the value of tranexamic acid administration in PBCT. METHODS: We retrospectively analyzed 270 patients who presented with PBCT to a single, Level 1 trauma center between 2016 and 2023. RESULTS: A total of 47% (127/270) of patients with PBCT developed coagulopathy at presentation. Fifty-seven patients received tranexamic acid at presentation, which did not affect the development of coagulopathy. Coagulopathic patients were more likely to have more serious injury patterns (bihemispheric [adjusted odds ratio, aOR: 2.6 CI: 1.4-4.9, P = .004] or transventricular trajectories [aOR: 4.9 CI: 1.9-19.6, P = .03]). In addition, they presented with a larger base deficit (aOR: 0.9 CI: 1.002-1.2 per mEq/L, P = .006) which negatively correlated with the international normalized ratio (ρ: -0.46, P < .0001, Spearman correlation). Using thromboelastography helped to identify an additional 20% of patients who presented with normal coagulation on conventional testing. CONCLUSION: Coagulopathy is prevalent in approximately 50% of patients with PBCT and is persistent despite treatment in a substantial subset of patients. The addition of thromboelastography with its increased coagulopathy sensitivity can potentially guide treatment more efficiently than traditional coagulopathy laboratory tests and fibrinogen alone. Patients with a significant base deficit on arterial blood gas are at higher risk for coagulopathy.

The Neurosurgeon's Dilemma-Do Antiplatelet/Anticoagulant Medications Increase the Risk of Catheter-Associated Hemorrhage in External Ventricular Drain Placement?

OBJECTIVE: External ventricular drain (EVD) placement is a common neurosurgical procedure that can be performed at bedside. A frequent complication following EVD placement is catheter-associated hemorrhage (CAH). The hemorrhage itself is rarely clinically significant but may be complicated in patients taking anticoagulant or antiplatelet (AC/AP) medications. METHODS: A total of 757 patients were who underwent EVD placement at bedside were included as part of a retrospective study at a large academic medical center. Demographic factors, use of AC/AP therapies, and several other clinical variables were recorded and assessed in univariate and multivariate regression analysis for association with CAH and mortality. RESULTS: One hundred (13.2%) patients experienced CAH within 24 hours of the procedure. After univariate analysis, in 2 tandem-run multivariate regression analyses after stepwise variable selection, use of 2 or more AC/AP agents (odds ratio [OR] = 2.362, P = 0.020) and dual antiplatelet therapy with aspirin and clopidogrel (OR = 3.72, P = 0.009) were significantly associated with CAH. Use of noncoated catheters was a protective factor against CAH compared to use of antibiotic-coated catheters (OR = 0.55, P = 0.019). Multivariate analysis showed age, multiagent therapy, and thrombocytopenia were significantly associated with increased mortality. CONCLUSIONS: There was increased risk of CAH after EVD placement in patients taking more than one AC/AP agent regardless of presenting pathology. In particular, use of aspirin and clopidogrel combined was associated with significantly higher odds of CAH, although it was not associated with higher mortality. In addition, there appears to be an association between use of antibiotic-coated catheters and CAH across univariate and multivariate analysis.

Reducing ventriculoperitoneal shunt infection with intraoperative glove removal.

BACKGROUND: Contamination of ventriculoperitoneal shunts (VPS) by cutaneous flora, particularly coagulase-negative staphylococci, is a common cause of shunt infection and failure, leading to prolonged hospital stay, higher costs of care, and poor outcomes. Glove contamination may occur during VPS insertion, increasing risk of such infections. METHODS: We performed a systematic search of the PubMed database for studies published January 1, 1970, through August 31, 2021 that documented VPS infection rates before and after implementing a practice of double gloving with change or removal of the outer glove immediately prior to shunt insertion. RESULTS: Among 272 reports screened, 4 were eligible for review based on our inclusion criteria. The incidence of VPS infection was reduced in all 4 quasi-experimental studies with an aggregate incidence of VPS infection of 11.8% before the change in intraoperative protocol and 4.9% after protocol change. One study documented reduced hospital stay with this change in protocol. CONCLUSION: The risk of VPS infection is reduced by removal or replacement of the outer surgical gloves immediately prior to intraoperative insertion of a VPS as part of an infection control bundle.

Near-lifespan longitudinal tracking of brain microvascular morphology, topology, and flow in male mice.

In age-related neurodegenerative diseases, pathology often develops slowly across the lifespan. As one example, in diseases such as Alzheimer's, vascular decline is believed to onset decades ahead of symptomology. However, challenges inherent in current microscopic methods make longitudinal tracking of such vascular decline difficult. Here, we describe a suite of methods for measuring brain vascular dynamics and anatomy in mice for over seven months in the same field of view. This approach is enabled by advances in optical coherence tomography (OCT) and image processing algorithms including deep learning. These integrated methods enabled us to simultaneously monitor distinct vascular properties spanning morphology, topology, and function of the microvasculature across all scales: large pial vessels, penetrating cortical vessels, and capillaries. We have demonstrated this technical capability in wild-type and 3xTg male mice. The capability will allow comprehensive and longitudinal study of a broad range of progressive vascular diseases, and normal aging, in key model systems.

Risk factors and outcomes associated with external ventricular drain infections.

BACKGROUND: Insertion of an external ventricular drain (EVD) is a common neurosurgical procedure which may lead to serious complications including infection. Some risk factors associated with EVD infection are well established. Others remain less certain, including specific indications for placement, prior neurosurgery, and prior EVD placement. OBJECTIVE: To identify risk factors for EVD infections. METHODS: We reviewed all EVD insertions at our institution from March 2015 through May 2019 following implementation of a standardized infection control protocol for EVD insertion and maintenance. Cox regression was used to identify risk factors for EVD infections. RESULTS: 479 EVDs placed in 409 patients met inclusion criteria, and 9 culture-positive infections were observed during the study period. The risk of infection within 30 days of EVD placement was 2.2% (2.3 infections/1,000 EVD days). Coagulase-negative staphylococci were identified in 6 of the 9 EVD infections). EVD infection led to prolonged length of stay post-EVD-placement (23 days vs 16 days; P = .045). Cox regression demonstrated increased infection risk in patients with prior brain surgery associated with cerebrospinal fluid (CSF) diversion (HR, 8.08; 95% CI, 1.7-39.4; P = .010), CSF leak around the catheter (HR, 21.0; 95% CI, 7.0-145.1; P = .0007), and insertion site dehiscence (HR, 7.53; 95% CI, 1.04-37.1; P = .0407). Duration of EVD use >7 days was not associated with infection risk (HR, 0.62; 95% CI, 0.07-5.45; P = .669). CONCLUSION: Risk factors associated with EVD infection include prior brain surgery, CSF leak, and insertion site dehiscence. We found no significant association between infection risk and duration of EVD placement.

Decreasing External Ventricular Drain Infection Rates in the Neurocritical Care Unit: 12-Year Longitudinal Experience at a Single Institution.

OBJECTIVE: External ventricular drain (EVD) placement is a common neurosurgical procedure, and EVD-related infection is a significant complication. We examined the effect of infection control protocol changes on EVD-related infection incidence. METHODS: Changes in EVD placement protocol and incidence density of infections after implementation of protocol changes in the neurocritical care unit were tracked from 2007 to 2019. EVD infections were defined using a modified U.S. Centers for Disease Control and Prevention National Healthcare Safety Network surveillance definition of meningitis/ventriculitis for patients with EVDs in situ for at least 2 days confirmed by positive culture. Contribution of protocol changes to EVD infection risk was assessed via multivariate regression. RESULTS: Fifteen major changes in EVD protocol were associated with a reduction in infections from 6.7 to 2.0 per 1000 EVD days (95% confidence interval [CI], 4.1-5.3; P < 0.001). Gram-positive bacterial infection incidence decreased from 4.8 to 1.7 per 1000 EVD days (95% CI, 2.3-3.9; P = 0.00882) and gram-negative infection incidence decreased from 1.9 to 0.5 per 1000 EVD days (95% CI, 0.6-2.3; P = 0.0303). Of all protocol changes since 2007, the largest reduction in incidence was 3.9 infections per 1000 days (95% CI, 0.50-7.30; P = 0.011), associated with combined standardization of reduced EVD sampling frequency, cutaneous antisepsis with alcoholic chlorhexidine before EVD placement, and use of a subcutaneous tunneling technique during EVD insertion. CONCLUSIONS: The most significant reduction in EVD infections may be achieved through the combination of reducing EVD sampling frequency and standardizing alcoholic chlorhexidine cutaneous antisepsis and subcutaneous tunneling of the EVD catheter.