Internal Ventricular Cerebrospinal Fluid Shunt for Adult Hydrocephalus: A Systematic Review and Meta-Analysis of the Infection Rate

Hydrocephalus is a common neurological condition that usually requires internal ventricular cerebrospinal fluid shunt (IVCSFS). The reported infection rate (IR) varies greatly from below 1% up to over 50%, but no meta-analysis to assess the overall IR has ever been performed.

OBJECTIVE: To determine the IVCSFS overall IR in the adult population and search for associated factors.

METHODS: Six databases were searched from January 1990 to July 2022. Only original articles reporting on adult IVCSFS IR were included. Random-effects meta-analysis with generalized linear mixed model method and logit transformation was used to assess the overall IR. RESULTS: Of 1703 identified articles, 44 were selected, reporting on 57259 patients who had IVCSFS implantation and 2546 infections. The pooled IR value and its 95% CI were 4.75%, 95% CI (3.8 to 5.92). Ninety-five percent prediction interval ranged from 1.19% to 17.1%. The patients who had IVCSFS after intracranial hemorrhage showed a higher IR (7.65%, 95% CI [5.82 to 10], P-value = .002). A meta-regression by year of publication found a decreasing IR (À0.031, 95% CI [À0.06 to 0.003], P-value = .032) over the past 32 years.

CONCLUSION: IVCSF is a procedure that every neurosurgeon should be well trained to perform. However, the complication rate remains high, with an estimated overall IR of 4.75%. The IR is especially elevated for hydrocephalic patients who require IVCSFS after intracranial hemorrhage. However, decades of surgical advances may have succeeded in reducing IR over the past 32 years.

Neurosurgery 92:894–904, 2023

Spontaneous empyema and brain abscess in an intensive care population: clinical presentation, microbiology, and factors associated with outcome

Acta Neurochirurgica (2023) 165:651–658

Data on critically ill patients with spontaneous empyema or brain abscess are limited. The aim was to evaluate clinical presentations, factors, and microbiological findings associated with the outcome in patients treated in a Neurocritical Care Unit.

Methods In this retrospective study, we analyzed 45 out of 101 screened patients with spontaneous epidural or subdural empyema and/or brain abscess treated at a tertiary care center between January 2012 and December 2019. Patients with postoperative infections or spinal abscess were excluded. Medical records were reviewed for baseline characteristics, origin of infection, laboratory and microbiology findings, and treatment characteristics. The outcome was determined using the Glasgow outcome scale extended (GOSE).

Results Favorable outcome (GOSE 5–8) was achieved in 38 of 45 patients (84%). Four patients died (9%), three remained severely disabled (7%). Unfavorable outcome was associated with a decreased level of consciousness at admission (Glasgow coma scale < 9) (43% versus 3%; p = 0.009), need of vasopressors (71% versus 11%; p = 0.002), sepsis (43% versus 8%; p = 0.013), higher age (65.1 ± 15.7 versus 46.9 ± 17.5 years; p = 0.014), shorter time between symptoms onset and ICU admission (5 ± 2.4 days versus 11.6 ± 16.8 days; p = 0.013), and higher median C-reactive protein (CRP) serum levels (206 mg/l, range 15–259 mg/l versus 17.5 mg/l, range 3.3–72.7 mg/l; p = 0.036). With antibiotics adapted according to culture sensitivities in the first 2 weeks, neuroimaging revealed a progression of empyema or abscess in 45% of the cases.

Conclusion Favorable outcome can be achieved in a considerable proportion of an intensive care population with spontaneous empyema or brain abscess. Sepsis and more frequent need for vasopressors, associated with unfavorable outcome, indicate a fulminant course of a not only cerebral but systemic infection. Change of antibiotic therapy according to microbiological findings in the first 2 weeks should be exercised with great caution.

Reducing the risks of proximal and distal shunt failure in adult hydrocephalus

J Neurosurg 136:877–886, 2022

Patient outcomes of ventriculoperitoneal (VP) shunt surgery, the mainstay treatment for hydrocephalus in adults, are poor because of high shunt failure rates. The use of neuronavigation or laparoscopy can reduce the risks of proximal or distal shunt catheter failure, respectively, but has less independent effect on overall shunt failures. No adult studies to date have combined both approaches in the setting of a shunt infection prevention protocol to reduce shunt failure. The goal of this study was to determine whether combining neuronavigation and laparoscopy with a shunt infection prevention strategy would reduce the incidence of shunt failures in adult hydrocephalic patients.

METHODS Adult patients (age ≥ 18 years) undergoing VP shunt surgery at a tertiary care institution prior to (pre–Shunt Outcomes [ShOut]) and after (post-ShOut) the start of a prospective continuous quality improvement (QI) study were compared. Pre-ShOut patients had their proximal and distal catheters placed under conventional freehand approaches. Post-ShOut patients had their shunts inserted with neuronavigational and laparoscopy assistance in placing the distal catheter in the perihepatic space (falciform technique). A shunt infection reduction protocol had been instituted 1.5 years prior to the start of the QI initiative. The primary outcome of interest was the incidence of shunt failure (including infection) confirmed by standardized criteria indicating shunt revision surgery.

RESULTS There were 244 (115 pre-ShOut and 129 post-ShOut) patients observed over 7 years. With a background of shunt infection prophylaxis, combined neuronavigation and laparoscopy was associated with a reduction in overall shunt failure rates from 37% to 14%, 45% to 22%, and 51% to 29% at 1, 2, and 3 years, respectively (HR 0.44, p < 0.001). Shunt infection rates decreased from 8% in the pre-ShOut group to 0% in the post-ShOut group. There were no proximal catheter failures in the post-ShOut group. The 2-year rates of distal catheter failure were 42% versus 20% in the pre- and post-ShOut groups, respectively (p < 0.001).

CONCLUSIONS Introducing a shunt infection prevention protocol, placing the proximal catheter under neuronavigation, and placing the peritoneal catheter in the perihepatic space by using the falciform technique led to decreased rates of infection, distal shunt failure, and overall shunt failure.

Negligible Systemic Uptake of Suprafascial Vancomycin Powder Following Instrumented Posterior Spinal Fusion

Neurosurgery 89:967–972, 2021

Intrawound vancomycin powder is an emerging strategy to reduce surgical site infections (SSIs) in spine surgery. However, there are concerns relating to its safety profile and toxicity. Data on systemic uptake of suprafascially administered vancomycin powder following instrumented spinal fusion is lacking.

OBJECTIVE: To study the systemic uptake and safety of suprafascially administered vancomycin powder in the early postoperative phase following open instrumented posterior spinal fusion.

METHODS: This was a substudy of an ongoing randomized clinical trial. Eligible adult patients were randomized 1:1 to either receive suprafascial vancomycin powder before wound closure or not to receive vancomycin powder. Serum vancomycin levels were assessed on postoperative days 1 and 2, serum creatinine levels were measured pre- and post-operatively. Adverse events up to 6 wk following surgery were recorded.

RESULTS:Among34 randomized patients (mean age 62 yr, range 31-84 yr; 18 [53%]women), 17 received vancomycin powder. No detectable serum vancomycin levels (>4.0mg/L)were found. Proportion of adverse events per patient in the vancomycin and control group, respectively,were 29.4% (5/17) vs 11.8% (2/17) (OR 3.12;95%CI, 0.52; 19.38; P=.398).No patient had nephrotoxicity or ototoxicity in either group. CONCLUSION: Suprafascial vancomycin powder in open instrumented spinal fusion surgery is safe and results in negligible systemic uptake. Final results of the VANCO Trial need to be awaited for conclusive data on the efficacy of vancomycin for SSI prevention and its impact on wound healing.

 

Removal of instrumentation for postoperative spine infection: systematic review

J Neurosurg Spine 35:376–388, 2021

Currently, no consensus exists as to whether patients who develop infection of the surgical site after undergoing instrumented fusion should have their implants removed at the time of wound debridement. Instrumentation removal may eliminate a potential infection nidus, but removal may also destabilize the patient’s spine. The authors sought to summarize the existing evidence by systematically reviewing published studies that compare outcomes between patients undergoing wound washout and instrumentation removal with outcomes of patients undergoing wound washout alone. The primary objectives were to determine 1) whether instrumentation removal from an infected wound facilitates infection clearance and lowers morbidity, and 2) whether the chronicity of the underlying infection affects the decision to remove instrumentation.

METHODS PRISMA guidelines were used to review the PubMed/MEDLINE, Embase, Cochrane Library, Scopus, Web of Science, and ClinicalTrials.gov databases to identify studies that compared patients with implants removed and patients with implants retained. Outcomes of interest included mortality, rate of repeat wound washout, and loss of correction.

RESULTS Fifteen articles were included. Of 878 patients examined in these studies, 292 (33%) had instrumentation removed. Patient populations were highly heterogeneous, and outcome data were limited. Available data suggested that rates of reoperation, pseudarthrosis, and death were higher in patients who underwent instrumentation removal at the time of initial washout. Three studies recommended that instrumentation be uniformly removed at the time of wound washout. Five studies favored retaining the original instrumentation. Six studies favored retention in early infections but removal in late infections.

CONCLUSIONS The data on this topic remain heterogeneous and low in quality. Retention may be preferred in the setting of early infection, when the risk of underlying spine instability is still high and the risk of mature biofilm formation on the implants is low. However, late infections likely favor instrumentation removal. Higher-quality evidence from large, multicenter, prospective studies is needed to reach generalizable conclusions capable of guiding clinical practice.

Effect of Incisional Negative Pressure Wound Therapy vs Standard Wound Dressing on the Development of Surgical Site Infection after Spinal Surgery: A Prospective Observational Study

Neurosurgery 88:E445–E451, 2021

Use of a closed-incisional negative pressure therapy (ci-NPT) dressing is an emerging strategy to reduce surgical site infections (SSIs) in spine surgery that lacks robust data.

OBJECTIVE: To determine the impact of a ci-NPT, as compared with a standard dressing, on the development of SSIs after spine surgery.

METHODS: This was a prospective observational study over a 2-yr period. Indications for surgery included degenerative disease, deformity, malignancy, and trauma. Exclusion criteria included anterior and lateral approaches to the spine, intraoperative durotomy, or use of minimally invasive techniques. SSIs up to 60d following surgery were recorded.

RESULTS: A total of 274 patients were included. SSI rate was significantly lower with ci-NPT dressing (n = 118) as compared with the standard dressing (n = 156) (3.4 vs 10.9%, P = .02). There was no statistical difference in infection rate for decompression alone procedures (4.2 vs 9.1%, P = .63), but there was a statistically significant reduction with the use of a negative-pressure dressing in cases that required instrumentation (3.2 vs 11.4%, P = .03). Patients at higher risk (instrumentation, deformity, and malignancy) had less SSIs with the use of ci-NPT, although this did not reach statistical significance. There were no complications in either group.

CONCLUSION: SSI rates were significantly reduced with a ci-NPT dressing vs a standard dressing in patients who underwent spinal surgery. The higher cost of a ci-NPT dressing might be justified with instrumented cases, as well as with certain high-risk patient populations undergoing spine surgery, given the serious consequences of an infection.

Intrawound vancomycin application after spinal surgery: a propensity score–matched cohort analysis

J Neurosurg Spine 34:788–798, 2021

Surgical site infection (SSI) following spine surgery is associated with increased morbidity and healthcare costs. In an effort to reduce SSI rates, the application of intrawound vancomycin powder has gained popularity. However, there is limited high-quality evidence to support the safety and efficacy of this practice. The authors sought to determine if intrawound application of vancomycin powder improves 90-day overall SSI rates.

METHODS The authors performed a retrospective, vancomycin exposure–matched cohort study at a single tertiary care hospital over 21 months. They included all patients undergoing elective spinal surgery and stratified the patients into two groups: those who received intrawound vancomycin powder application and those who received no application of vancomycin powder. The primary outcome of interest was the 90-day overall SSI rate. Secondary outcomes included rates of superficial SSI, deep SSI, wound disruption, and a post hoc analysis of the microbiology and minimum inhibitory concentrations. Baseline patient demographics, clinical presentation, comorbidities, perioperative factors, and 90-day postoperative outcomes were manually abstracted from patient charts. To mitigate bias, we performed 1:1 matching after calculating propensity scores and identified 1 patient from the no-vancomycin cohort for each patient in the vancomycin cohort.

RESULTS A total of 997 patients met our inclusion criteria (473 patients receiving vancomycin and 524 patients not receiving vancomycin). Propensity score matching produced 221 matched pairs. Risk-adjusted analysis demonstrated similar overall SSI rates between the groups (OR 1.9, p = 0.329). On unadjusted analysis, the overall 90-day SSI rate was greater in the vancomycin group (n = 10 [4.5%]) than in the no-vancomycin group (n = 5 [2.3%]) (p < 0.001), as were the superficial SSI rate (7 [3.2%] vs 4 [1.8%], p < 0.001), deep SSI rate (3 [1.4%] vs 1 [0.5%], p < 0.001), and wound disruption rate (5 [2.3%] vs 1 [0.5%], p < 0.001). No cultured isolate demonstrated vancomycin resistance.

CONCLUSIONS The authors observed no difference in SSI rates after the intrawound application of vancomycin powder during spine surgery. Vancomycin use did not contribute to antimicrobial resistance; however, it may select out gram negative bacteria and increase rates of wound disruption.

Occult infection in pseudarthrosis revision after spinal fusion

The Spine Journal 21 (2021) 370−376

Pseudarthrosis after attempted spinal fusion is yet not sufficiently understood and presents a surgical challenge. Occult infections are sometimes observed in patients with pseudarthrosis and no inflammatory signs of infection. The prevalence of such occult infection and its association with patient demographics and inflammatory markers are largely unknown.

PURPOSE: To determine the prevalence of unexpected low-grade infection in spinal pseudarthrosis revision surgery, and to evaluate whether such infection is associated with patient demographics and inflammatory markers.

STUDY DESIGN: Retrospective observational study.

PATIENT SAMPLE: One-hundred-and-twenty-eight patients who underwent thoracolumbar revision surgery due to presumed aseptic pseudarthrosis after spinal instrumentation.

OUTCOME MEASURES: Culture-positive infections or noninfectious pseudarthrosis. METHODS: Samples were routinely taken for microbiological examination from all adults (n=152) who underwent revision surgery for presumed aseptic thoracolumbar pseudarthrosis between 2014 and 2019. A full intraoperative microbiological workup (at least three intraoperative tissue samples) was done for 128 (84%) patients, and these patients were included in further analyses. Patient characteristics, medical history, inflammatory markers, and perioperative data were compared between those with and without microbiologically-confirmed infection based on samples obtained during pseudarthrosis revision.

RESULTS: The microbiological workup confirmed infection in 13 of 128 cases (10.2%). The predominant pathogen was Cutibacterium acnes (46.2%), followed by coagulase-negative staphylococci (38.5%). The presence of infection was associated with the body mass index (30.9§4.7 kg/m2 [infected] vs. 28.2§5.6 kg/m2 [controls], p=.049), surgery in the thoracolumbar region (46% vs. 18%, p=.019), and a slightly higher serum C-reactive protein level on admission (9.4§8.0 mg/L vs. 5.7§7.1 mg/L, p=.031). Occult infection was not associated with age, sex, prior lumbar surgeries, number of fused lumbar levels, American Society of Anesthesiologist score, Charlson Comorbidity Index, presence of diabetes mellitus, and smoking status.

CONCLUSIONS: Occult infections were found in 10% of patients undergoing pseudarthrosis revision after spinal fusion, even without preoperative clinical suspicion. Occult infection was associated with higher body mass index, fusions including the thoracolumbar junction, and slightly higher C-reactive protein levels. Intraoperative microbiological samples should be routinely obtained to exclude or identify occult infection in all revision surgeries for symptomatic pseudarthrosis of the spine, as this information can be used to guide postoperative antibiotic treatment.

The Role of Prophylactic Intraventricular Antibiotics in Reducing the Incidence of Infection and Revision Surgery in Pediatric Patients Undergoing Shunt Placement

Neurosurgery 88(2)2021: 301–305

Ventriculoperitoneal shunt placement remains the primary treatment modality for children with hydrocephalus. However, morbidity and revision surgery secondary to infection remains high, even while using antibiotic-impregnated shunts.

OBJECTIVE: To determine whether intraoperative injection of antibiotics is independently associated with reduced rates of infection and revision surgery in children undergoing shunt placement.

METHODS: This is an analysis of a prospectively collected, multicenter, shunt-specific neurosurgical registry consisting of data from over 100 hospitals collected between 2016 and 2017. All patients under 18 yr of age undergoing first-time shunt placement for the definitive treatment of hydrocephaluswere included. The primary exposure of interest was injection of intraventricular antibiotics into the shunt catheter following shunt placement and prior to closure. The use of additional surgical adjuncts, such as antibiotic-impregnated shunts, stereotactic guidance, and endoscopy was collected. The primary outcome metric was the need for additional intervention because of an infection.

RESULTS: A total of 2007 pediatric patients undergoing shunt placement for hydrocephalus were identified. Postoperatively, 97 (4.8%) patients had additional intervention secondary to infection. In a multivariable regression model controlling for patient characteristics, etiology of hydrocephalus, prior temporizing measures, and placement of an antibiotic-impregnated shunt, injection of intraventricular antibiotics was associated with a significant reduction in postoperative infections (odds ratio = 0.29, 95% CI: 0.04-0.89, P=.038). Of those receiving intraventricular antibiotics, only 2 (0.38%)went on to undergo re-intervention due to infection.

CONCLUSION: These data suggest that for this select group of patients, use of intraventricular antibiotics was associated with decreased rates of re-intervention secondary to infection.

Low-Grade Infection and Implant Failure Following Spinal Instrumentation

Neurosurgery 87:964–970, 2020

Spinal instrumentation can be associated with complications, including implant loosening. Hitherto, implant loosening has mainly been attributed to mechanical overload.

OBJECTIVE: To examine the role of low-grade infections as the cause of implant failure in suspected aseptic implant loosening following spinal instrumentation.

METHODS: A prospective single center observational study was performed. All patients who had revision surgery following spinal instrumentation between August 2015 and February 2018 were screened. Patients with revision surgery due to screw loosening on the computed tomograhy scan constituted the study group. Patients in which the screws where not loosened but removalwas performed for other reasons formed the comparison group. Intraoperative swabswere taken and sonicationwas performedwith the explanted material. Results of microbiological cultivation were analyzed.

RESULTS: A total of 59 patients were included in the study group and 34 in the comparison group. In the study group in 42.4% of the cultures a bacterium was detected, while in the comparison group only in 17.6%. 84%, and 83.3% of these germs were detected by sonication in the study and comparison group, respectively. The rate of positive cultures was significantly higher in the study group compared to the comparison group (P= .001). The most frequent bacterium cultivated in both groups was Propionibacterium acnes, followed by Staphylococcus species.

CONCLUSION: For patients with screw loosening a high level of suspicion for a low-grade infection should be raised. Cultures should be performed from the sonication fluid of the explanted devices in all patients with symptomatic screw loosening.

Double-blind randomized clinical trial of vancomycin in spinal arthrodesis: no effects on surgical site infection

J Neurosurg Spine 32:473–480, 2020

Surgical site infection (SSI) results in high morbidity and mortality in patients undergoing spinal fusion. Using intravenous antibiotics in anesthesia induction reduces the rate of postoperative infection, but it is not common practice to use them topically, despite recent reports that this procedure helps reduce infection. The objective of this study was to determine whether the topical use of vancomycin reduces the rate of postoperative SSI in patients undergoing thoracolumbar fusion.

METHODS A randomized, double-blind clinical trial in a single hospital was performed comparing vancomycin and placebo in thoracolumbar fusion patients.

RESULTS A total of 96 patients were randomized to placebo or vancomycin treatment. The mean patient age was 43 ± 14.88 years, 74% were male, and the most common etiology was fall from height (46.9%). The overall rate of postoperative SSI was 8.3%, and no difference was found between the groups: postoperative infection rates in the vancomycin and placebo groups were 8.2% and 8.5% (relative risk [RR] of SSI not using vancomycin 1.04, 95% confidence interval [CI] 0.28–3.93, p = 0.951), respectively. Patients with diabetes mellitus had higher SSI rates (RR 8.98, 95% CI 1.81–44.61, p = 0.007).

CONCLUSIONS This is the first double-blind randomized clinical trial to evaluate the effects of topical vancomycin on postoperative infection rates in thoracolumbar fusion patients, and the results did not differ significantly from placebo. Clinical trial registration no.: RBR-57wppt (ReBEC; http://www.ensaiosclinicos.gov.br/)

 

Greening the Operating Room: Results of a Scalable Initiative to Reduce Waste and Recover Supply Costs

Neurosurgery 85:432–437, 2019

Operating rooms generate 42% of a hospital’s revenue and 30% of hospital waste. Supply costs are 56% of a total operating room (OR) budget. US academic medical centers use 2 million pounds ($15 million) of recoverable medical supplies annually. Forming a multidisciplinary leadership team, we analyzed sources of waste focusing on our Department of Neurosurgery. We developed an 8-wk pilot project to recycle “blue wrap,” the number 5 plastic polypropylene material that is ubiquitously used in ORs across the country to wrap instrument pans and implant trays for sterilization. Blue wrap can be baled and sold to recyclers where the material is pelletized and transformed into plastic products.

During the 39 d of the pilot, we collected 1247 pounds of blue wrap (32 lbs collected daily). The cost of the pilot was $14987 that includes a new baler ($11200) and 5 transport carts ($3697). The revenue received from baled blue wrap was 8 cents per pound. Cost avoidance yielded $31680.00 in savings. Implementation of this pilot across our main hospital would yield $5000 in revenue annually and $174.240 in cost avoidance.

This project can be replicated at other centers and not only reduces the environmental footprint, but also helps generate additional revenue by recycling a necessary packing material that would otherwise require payment for disposal.

 

Evaluation of neurosurgical implant infection rates and associated pathogens: evidence from 1118 postoperative infections

Neurosurg Focus 47 (2):E6, 2019

Various implanted materials are used in neurosurgery; however, there remains a lack of pooled data on infection rates (IRs) and infective bacteria over past decades. The goal of this study was to investigate implant infections in neurosurgical procedures in a longitudinal retrospective study and to evaluate the IRs of neurosurgically implanted materials and the distribution of pathogenic microorganisms.

METHODS A systematic literature search was conducted using PubMed and Web of Science databases for the time period between 1968 and 2018. Neurosurgical implant infections were studied in 5 subgroups, including operations or diseases, implanted materials, bacteria, distribution by country, and time periods, which were obtained from the literature and statistically analyzed. In this meta-analysis, statistical heterogeneity across studies was tested by using p values and I2 values between studies of associated pathogens. Egger’s test was used for assessing symmetries of funnel plots with Stata 11.0 software. Methodological quality was assessed to judge the risk of bias according to the Cochrane Handbook.

RESULTS A total of 22,971 patients from 227 articles satisfied the study’s eligibility criteria. Of these, 1118 cases of infection were reported, and the overall IR was 4.87%. In this study, the neurosurgical procedures or disorders with the top 3 IRs included craniotomy (IR 6.58%), cranioplasty (IR 5.89%), and motor movement disorders (IR 5.43%). Among 13 implanted materials, the implants with the top 3 IRs included polypropylene-polyester, titanium, and polyetheretherketone (PEEK), which were 8.11%, 8.15%, and 7.31%, respectively. Furthermore, the main causative pathogen was Staphylococcus aureus and the countries with the top 3 IRs were Denmark (IR 11.90%), Korea (IR 10.98%), and Mexico (IR 9.26%). Except for the low IR from 1998 to 2007, the overall implant IR after neurosurgical procedures was on the rise.

CONCLUSIONS In this study, the main pathogen in neurosurgery was S. aureus, which can provide a certain reference for the clinic. In addition, the IRs of polypropylene-polyester, titanium, and PEEK were higher than other materials, which means that more attention should be paid to them. In short, the total IR was high in neurosurgical implants and should be taken seriously.

Comparing the diagnostic accuracies of F-18 FDG PET and MRI for the detection of spondylodiscitis: A meta-analysis

Spine. 44(7):E414-E422, April 1, 2019

The aim of this study was to compare the diagnostic accuracies of F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET) and magnetic resonance imaging (MRI) for the detection of spondylodiscitis through a meta-analysis.

Summary of Background Data. There is no meta-analysis study that compares the diagnostic accuracies of F-18 FDG PET and MRI for the detection of spondylodiscitis.

Methods. The MEDLINE and EMBASE databases were searched from the earliest available date of indexing to January 10, 2018 for studies comparing the diagnostic performance F-18 FDG PET with that of MRI for the detection of spondylodiscitis. We determined the sensitivities and specificities across studies, calculated the positive and negative likelihood ratios (LR+ and LR-), and constructed the summary receiver operating characteristic curves.

Results. In the seven studies (212 patients) selected, the pooled sensitivity and specificity of F- 18 FDG PET were 0.95 (95% confidence interval [CI]: 0.87-0.98) and 0.88 (95% CI: 0.73-0.95), respectively. The LR syntheses showed an overall LR+ of 7.6 (95% CI: 3.4-17.2) and LR- of 0.05 (95% CI: 0.02-0.14). The pooled diagnostic odds ratio (DOR) was 141 (95% CI: 44-444). The pooled sensitivity and specificity of MRI were 0.85 (95% CI: 0.65-0.95) and 0.66 (95% CI: 0.48-0.80), respectively. The LR syntheses showed an overall LR+ of 2.5 (95% CI: 1.5-4.2) and LR- of 0.22 (95% CI: 0.08-0.60). The pooled DOR was 11 (95% CI: 3-42). In the metaregression analysis, no variable was identified as the source of the study heterogeneity.

Conclusions. The current meta-analysis shows that F-18 FDG PET has better diagnostic accuracy than MRI for the detection of spondylodiscitis. Further large multicenter studies would be necessary to substantiate the diagnostic accuracies of F-18 FDG PET and MRI for spondylodiscitis.

Level of Evidence: 2

Immediate Cranioplasty for Postcranioplasty Infection in Patients with Ventriculoperitoneal Shunt

World Neurosurg. (2018) 119:311-314

Patients with a ventriculoperitoneal (VP) shunt tend to develop epidural fluid accumulation after cranioplasty and also have a higher frequency of syndrome of the trephined after bone flap removal. Thus treatment of patients with postcranioplasty infection and a VP shunt is often challenging.

CASE DESCRIPTION: We treated 2 patients with postcranioplasty infection and a VP shunt. One patient had undergone decompressive craniectomy for cerebral hemorrhage, and the other patient had a large frontal dead space following resection of a brain tumor. Both patients were treated by immediate cranioplasty with obliteration of the epidural dead space by using a vascularized free latissimus dorsi muscle flap. In both of them, the postoperative course was uneventful without any complications.

CONCLUSIONS: Immediate cranioplasty and obliteration of the epidural dead space with a vascularized free latissimus dorsi muscle flap is an alternative for patients with postcranioplasty infection who are unfavorable candidates for temporary bone flap removal because of the risk of neurologic deterioration

Topical Vancomycin Reduces Surgical-Site Infections After Craniotomy: A Prospective, Controlled Study

Neurosurgery 83:761–767, 2018

Surgical-site infections (SSIs) are an important cause of morbidity and mortality in neurosurgical patients. Topical antibiotics are one potential method to reduce the incidence of these infections.

OBJECTIVE: To examine the efficacy of topical vancomycin applied within the wound during craniotomy in a large prospective cohort study at a major academic center.

METHODS: Three hundred fifty-five patients were studied prospectively in this cohort study; 205 patients received 1 g of topical vancomycin powder in the subgaleal space while 150 matched control patients did not. Patients otherwise received identical care. The primary outcome variable was SSI rate factored by cohort. Secondary analysis examined cost savings from vancomycin usage estimated from hospital costs associated with SSI in craniotomy patients.

RESULTS: The addition of topical vancomycinwas associated with a significantly lower rate of SSI than standard of care alone (0.49% [1/205] vs 6% [9/150], P=.002). Based on the costs of revision surgery for infections, topical vancomycin usage was estimated to save $1367 446 per 1000 craniotomy patients. No adverse reactions occurred.

CONCLUSION: Topical vancomycin is a safe, effective, and cost-saving measure to prevent SSIs following craniotomy. These results have broad implications for standard of care in craniotomy.

Management of spinal infection: a review of the literature

Acta Neurochirurgica (2018) 160:487–496

Spinal infection (SI) is defined as an infectious disease affecting the vertebral body, the intervertebral disc, and/or adjacent paraspinal tissue and represents 2–7% of all musculoskeletal infections. There are numerous factors, which may facilitate the development of SI including not only advanced patient age and comorbidities but also spinal surgery. Due to the low specificity of signs, the delay in diagnosis of SI remains an important issue and poor outcome is frequently seen. Diagnosis should always be supported by clinical, laboratory, and imaging findings, magnetic resonance imaging (MRI) remaining the most reliable method. Management of SI depends on the location of the infection (i.e., intraspinal, intervertebral, paraspinal), on the disease progression, and of course on the patient’s general condition, considering age and comorbidities. Conservative treatment mostly is reasonable in early stages with no or minor neurologic deficits and in case of severe comorbidities, which limit surgical options. Nevertheless, solely medical treatment often fails. Therefore, in case of doubt, surgical treatment should be considered. The final result in conservative as well as in surgical treatment always is bony fusion. Furthermore, both options require a concomitant antimicrobial therapy, initially applied intravenously and administered orally thereafter. The optimal duration of antibiotic therapy remains controversial, but should never undercut 6 weeks. Due to a heterogeneous and often comorbid patient population and the wide variety of treatment options, no generally applicable guidelines for SI exist and management remains a challenge. Thus, future prospective randomized trials are necessary to substantiate treatment strategies.

Intrawound Vancomycin Decreases the Risk of Surgical Site Infection After Posterior Spine Surgery: A Multicenter Analysis

Spine 2018;43:65–71

Study Design. Secondary analysis of data from a prospective multicenter observational study.

Objective. The aim of this study was to evaluate the occurrence of surgical site infection (SSI) in patients with and without intrawound vancomycin application controlling for confounding factors associated with higher SSI after elective spine surgery.

Summary of Background Data. SSI is a morbid and expensive complication associated with spine surgery. The application of intrawound vancomycin is rapidly emerging as a solution to reduce SSI following spine surgery. The impact of intrawound vancomycin has not been systematically studied in a welldesigned multicenter study.

Methods. Patients undergoing elective spine surgery over a period of 4 years at seven spine surgery centers across the United States were included in the study. Patients were dichotomized on the basis of whether intrawound vancomycin was applied. Outcomes were occurrence of SSI within postoperative 30 days and SSI that required return to the operating room (OR). Multivariable random-effect log-binomial regression analyses were conducted to determine the relative risk of having an SSI and an SSI with return to OR.

Results. A total of 2056 patients were included in the analysis. Intrawound vancomycin was utilized in 47% (n=966) of patients. The prevalence of SSI was higher in patients with no vancomycin use (5.1%) than those with use of intrawound vancomycin (2.2%). The risk of SSI was higher in patients in whom intrawound vancomycin was not used (relative risk (RR) – 2.5, P<0.001), increased number of levels exposed (RR -1.1, P=0.01), and those admitted postoperatively to intensive care unit (ICU) (RR -2.1, P=0.005). Patients in whom intrawound vancomycin was not used (RR -5.9, P<0.001), increased number of levels were exposed (RR-1.1, P=0.001), and postoperative ICU admission (RR -3.3, P<0.001) were significant risk factors for SSI requiring a return to the OR.

Conclusion. The intrawound application of vancomycin after posterior approach spine surgery was associated with a reduced risk of SSI and return to OR associated with SSI.

Level of Evidence: 2

Frontal Sinus Breach During Routine Frontal Craniotomy

Neurosurgery 81:504–511, 2017

Frontotemporal craniotomies are commonly performed for a variety of neurosurgical pathologies. Infections related to craniotomies cause significant morbidity. We hypothesized that the risk of cranial surgical site infections (SSIs) may be increased in patients whose frontal sinuses are breached during craniotomy.

OBJECTIVE: To compare the rate of cranial SSIs in patients undergoing frontotemporal craniotomies with and without frontal sinus breach (FSB).

METHODS: We performed a retrospective analysis of all patients undergoing frontotemporal craniotomies for the management of cerebral aneurysms from 2005 to 2014. This study included 862 patients undergoing 910 craniotomies. Primary outcomeof interest was occurrence of a cranial SSI. Standard statistical methods were utilized to explore associations between a variety of variables including FSB, cranial SSI, and infections requiring reoperation.

RESULTS: Of the 910 craniotomies, 141 (15.5%) involved FSB. Of those involving FSB, 22 (15.6%) developed a cranial SSI, compared to only 56 of the 769 without FSB (7.3%; P = .001). Cranial SSI requiring reoperation wasmuch more likely in patients with FSB compared to those without a breach (7.8% vs 1.6%; P < .001). In those presenting with cranial SSIs, epidural abscess formation was more common with FSB compared to no FSB (27.3% vs 5.4%; P = .006). In multivariate analysis, breach of the frontal sinus was significantly associated with cranial SSI (OR 2.16; 95% CI 1.24-3.78; P = .01) and reoperation (OR 4.20; 95% CI 1.66-10.65; P = .003).

CONCLUSION: Patients undergoing frontotemporal craniotomies are at significantly greater risk of serious cranial SSIs if the frontal sinus has been breached.

Does Intrawound Vancomycin Application During Spine Surgery Create Vancomycin-Resistant Organism?

Neurosurgery (2017) 80 (5): 746-753

Surgical site infection (SSI) following spine surgery is a morbid and expensive complication. The use of intrawound vancomycin is emerging as a solution to reduce SSI. The development of vancomycin-resistant pathogens is an understandable concern.

OBJECTIVE: To determine the occurrence of vancomycin-resistant SSI in patients with and without use of intrawound vancomycin.

METHODS: Patients undergoing elective spine surgery were dichotomized based on whether intrawound vancomycin was applied. Outcome was occurrence of SSI requiring return to the operating room within postoperative 90 days. The intrawound culture and vancomycin minimal inhibitory concentrations (MIC) were reviewed. Analyses were conducted to compare the pathogen profile and MIC for vancomycin in patients who received vancomycin and those who did not.

RESULTS: Of the total 2802 patients, 43% (n = 1215) had intrawound vancomycin application during the index surgery. The use of vancomycin was associated with significantly lower deep SSI rates (1.6% [n = 20] vs 2.5% [n = 40], P = .02). The occurrence of Staphylococcus aureus SSI was significantly lower in the patients who had application of intrawound vancomycin (32% vs 65%, P = .003). None of the patients who had application of intrawound vancomycin powder, and subsequently developed an S aureus SSI, demonstrated pathogens with resistance to vancomycin. All patients had MIC < 2 μg/mL, the vancomycin susceptibility threshold. The occurrence of gram-negative SSI (28% vs 7%) and culture negative fluid collection (16% vs 5%) was higher in the vancomycin cohort.

CONCLUSIONS: The use of intrawound vancomycin during the index spine surgery was protective against SSI following spine surgery. The application of intrawound vancomycin during index surgery does not appear to create vancomycin-resistant organisms in the event of an SSI.