Operative sepsis in neurosurgery: a method of classifying surgical cases

Pseudomeningocele Following Posterior Cranial Fossa Surgery Significantly Increases the Risk of Intracranial Infection: A 10-Year Retrospective Analysis

Background: Posterior fossa craniotomy is commonly performed for various pathologies. However, intra-cranial infection following craniotomy causes morbidity. Pseudomeningocele is one of the main complications following posterior fossa operation. This study aimed to test the hypothesis that the risk of intra-cranial infection is increased in patients who undergo posterior fossa craniotomy with pseudomeningocele compared with those without pseudomeningocele. Methods: We retrospectively analyzed the data of patients undergoing posterior fossa craniotomy for the management of neurological pathologies at our institute from 2011 to 2020. A total of 308 craniotomies were included, and the primary outcome of interest was the occurrence of intra-cranial infection. Standard statistical methods were used to explore associations between several parameters, including pseudomeningocele, intra-cranial infection, and wound leak. Results: Of the 308 craniotomies, 41 (13.3%) developed intra-cranial infection and 59 (19.2%) involved pseudomeningocele. Of cases involving pseudomeningocele, 27 (45.8%) developed an intra-cranial infection compared with only 14 of 249 without pseudomeningocele (5.6%; p < 0.001). In the multi-variable analysis, pseudomeningocele was associated with intra-cranial infection (odds ratio [OR] 8.56; 95% confidence interval [CI] 3.145-23.299; p < 0.001) and wound leak (OR 91.339; 95% CI 10.437-799.364; p < 0.001). Conclusion: The findings indicate that patients undergoing posterior fossa craniotomy are at a greater risk of intra-cranial infection if there is pseudomeningocele after the operation.

Association of predictive factors and neurosurgical postoperative infections: A retrospective analysis

OBJECTIVE

To identify the factors that predispose neurosurgical patients to surgical site infections (SSI) as well as assess the risk factors attached to infection by a specific microorganism.

METHODOLOGY

A retrospective case-control study was conducted at University College of Medical Sciences and G.T.B. Hospital, Delhi. Adult patients (>18 years) undergoing a neurosurgical procedure with a diagnosis of SSI in the year 2021 having a minimum follow up of 30 days postoperatively or until death if they survived less than 30 days were included. Statistical analysis was performed using the SPSS 16 software with level of significance at 0.05.

RESULTS

An incidence of 3.15% was observed at our center. Mean age of the study population was 39.2 ± 13.07 years (range 22-70 years) with a male: female ratio of 3:1. Having an underlying infection (p = 0.024), ASA score> 2 (p = 0.041), duration of surgery> 4 h (p = 0.025), diabetes (p = 0.027) and preoperative stay at the hospital (p = 0.036) were found to be statistically significant risk factors in the prediction of SSI in neurosurgical patients which were utilised to create a regression model with an accuracy of 70% and AUC of 0.833. Deep infections were found to have a significant association with positive culture on the collected samples (p = 0.035).

CONCLUSIONS

This study is a starting point to identify which factors could predict the presence of a particular organism isolated from the site of infection in neurosurgical patients, thereby minimizing AMR.

Ventriculitis: Infection or Inflammation

Ventriculitis, or infection of the cerebrospinal fluid, in the presence of external ventricular drains (EVD), is an important complication and associated with substantial mortality, morbidity, and healthcare costs. Further, the conditions that require the insertion of an EVD, such as neurotrauma and subarachnoid hemorrhage, are themselves associated with inflammation of the cerebrospinal fluid. Phenotypically, patients with inflammation of the cerebrospinal fluid can present with very similar symptoms, signs, and laboratory findings to those with infection. This review examines various controversies relating to the definitions, diagnosis, challenges of differentiating infection from inflammation, prevention, and treatment of ventriculitis in patients with EVDs.

Efficacy and safety of decompressive craniectomy with non-suture duraplasty in patients with traumatic brain injury

BACKGROUND

Decompressive craniectomy is an important surgical treatment for patients with severe traumatic brain injury (TBI). Several reports have been published on the efficacy of non-watertight sutures in duraplasty performed in decompressive craniectomy. This study sought to determine the safety and feasibility of the non-suture dural closure technique in decompressive craniectomy.

METHODS

A total of 106 patients were enrolled at a single trauma center between January 2017 and December 2018. We retrospectively collected data and classified the patients into non-suture and suture duraplasty craniectomy groups. We compared the characteristics of patients and their intra/postoperative findings such as operative time, blood loss, imaging findings, complications, and Glasgow Outcome Scale scores.

RESULTS

There were 37 and 69 patients in the non-suture and suture duraplasty groups, respectively. There were no significant differences between the two groups concerning general characteristics. The operative time was significantly lower in the non-suture duraplasty group than in the suture duraplasty group (150 min vs. 205 min; p = 0.002). Furthermore, blood loss was significantly less severe in the non-suture duraplasty group than in the suture duraplasty group (1000 mL vs. 1500 mL; p = 0.028). There were no other significant differences.

CONCLUSION

Non-suture duraplasty involved shorter operative times and less severe blood losses than suture duraplasty. Other complications and prognoses were similar across groups. Therefore, the non-suture duraplasty in decompressive craniectomy is a safe and feasible surgical technique.

Prophylactic antibiotics in pediatric neurological surgery

PURPOSE

Surgical antibiotic prophylaxis (SAP) in pediatric neurosurgery has poorly been characterized until now. This review gives an overview on the current literature extracting recommendations and guidelines.

METHODS

The current literature on SAP with special forcus on pediatric neurosurgerical procedures was reviewed. Further, available recommendations in online databases were checked. Clean neurosurgical, shunt, and implant surgeries are considered separately.

RESULTS

To date, evidence-based data on SAP in pediatric neurosurgery remain sparse and there are no standardized approaches to an adequate use of antimicrobial agents for SSI prevention for this age group.

CONCLUSION

Due to statistical needs, multi-center surveillance studies are needed for implementing SAP recommendations in pediatric neurosurgery.

Prospective Multicenter Surveillance Study of Surgical Site Infection after Intracranial Procedures in Korea : A Preliminary Study

Objective

This study aimed to investigate the rates, types, and risk factors of surgical site infection (SSI) following intracranial neurosurgical procedures evaluated by a Korean SSI surveillance system.

Methods

This was a prospective observational study of patients who underwent neurosurgical procedures at 29 hospitals in South Korea from January 2017 to June 2017. The procedures included craniectomy, craniotomy, cranioplasty, burr hole, and ventriculoperitoneal shunt. Univariate and multivariate logistic regression analyses were performed.

Results

Of the 1576 cases included, 30 showed infection, for an overall SSI rate of 1.9%. Organ/space infection was the most common, found in 21 out of the 30 cases (70%). Staphylococcus aureus was the most common (41%) of all bacteria, and Serratia marcescens (12%) was the most common among gram-negative bacteria. In univariate analyses, the p-values for age, preoperative hospital stay duration, and over T-hour were <0.2. In a multivariate analysis of these variables, only preoperative hospital stay was significantly associated with the incidence of SSI (p<0.001), whereas age and over T-hour showed a tendency to increase the risk of SSI (p=0.09 and 0.06).

Conclusion

Surveillance systems play important roles in the accurate analysis of SSI. The incidence of SSI after neurosurgical procedures assessed by a national surveillance system was 1.9%. Future studies will provide clinically useful results for SSI when data are accumulated.

The Role of Antibiotic Prophylaxis in Clean Neurosurgery

OBJECTIVE

To investigate the efficacy of antibiotic prophylaxis (AP) and the risk factors for postoperative infections in clean neurosurgery.

METHODS

Data were retrospectively collected on all patients who had undergone clean neurosurgical operation at our institution between January 2009 and December 2014. From January 2009 until October 2011, AP was administered to every clean neurosurgical patient. From November 2011 to December 2014, no AP (n-AP) was prescribed for all clean neurosurgical operations. The efficacy of AP and independent risk factors for infection were studied.

RESULTS

A total of 808 clean neurosurgical cases were included. The AP group comprised 360 surgical cases, including 29 meningitis cases and 2 cases of incision infections, whereas the n-AP group consisted of 448 surgical cases, including 35 meningitis cases and 4 cases of incision infections (P = 0.848). Microorganisms were identified in 7 of 29 cases in the AP group compared with their identification in 22 of 35 cases in the n-AP group (P = 0.002). The percentage of patients with multidrug-resistant bacterial meningitis in the AP group was 57.1% compared with 13.6% in the n-AP group (P = 0.038). The risk factors for postoperative infection were cerebrospinal fluid leakage (odds ratio, 27.8; 95% confidence interval, 9.38-28.55) and surgery time (odds ratio, 1.12; 95% confidence interval, 1.02-1.22).

CONCLUSIONS

Our results show that in our data set, AP had no preventive effect on postoperative infections in clean neurosurgery. In addition, AP appeared to decrease the positive bacterial culture rate and to promote the emergence of multidrug-resistant bacteria. Cerebrospinal fluid leakage and surgery time were the risk factors for postoperative infection.

Rapid Time to Positivity of Cerebrospinal Fluid Culture with Coagulase-Negative Staphylococcus Is More Likely to Reflect a True Infection Than Contamination

OBJECTIVE

Cerebrospinal fluid (CSF) culture is the gold standard for diagnosing postoperative central nervous system infection. The time to positivity (TTP) of an automated continuous blood culture system may indicate the original concentration of the organism. Coagulase-negative Staphylococcus (CoNS), the common organism recovered in CSF, poses difficulty in differentiating infection from contamination. This study investigated the TTP of CSF culture with CoNS and its relationship to clinical parameters and prognosis.

METHODS

Adult neurosurgical patients with CoNS who recovered via the use of CSF culture in BacT/ALERT Pediatric FAN blood culture bottles and were admitted from September 2013 to July 2015 were enrolled. The demographics, clinical and microbiological data, and treatment were reviewed, and the TTP of each culture was retrieved.

RESULTS

Thirty-nine adult patients with CoNS recovered from CSF culture were included. The TTP ranged from 7.68 to 57.36 hours. A univariate logistic regression analysis indicated patients with rapid TTP (<21.5 hours) compared with those with longer TTP were more likely to be female, show an effective response to antibiotic therapy within 7 days, have clean-contaminated surgical incisions, and show CSF leak. A multivariate logistic regression analysis indicated that being female, an effective antibiotic therapy within 7 days, and clean-contaminated surgical incisions were independent predictors of rapid TTP.

CONCLUSIONS

Targeted antibiotic therapy was more likely to be beneficial to patients with a rapid TTP within 7 days, which suggested that CoNS with a rapid TTP represents the pathogen of central nervous system infection rather than contamination in neurosurgical patients.

Neuron-Specific Enolase Is Correlated to Compromised Cerebral Metabolism in Patients Suffering from Acute Bacterial Meningitis; An Observational Cohort Study

Introduction

Patients suffering from acute bacterial meningitis (ABM) with a decreased level of consciousness have been shown to have an improved clinical outcome if treated with an intracranial pressure (ICP) guided therapy. By using intracranial microdialysis (MD) to monitor cerebral metabolism in combination with serum samples of biomarkers indicating brain tissue injury, S100B and Neuron Specific Enolase (NSE), additional information might be provided. The aim of this study was to evaluate biomarkers in serum and MD parameters in patients with ABM.

Methods

From a prior study on patients (n = 52) with a confirmed ABM and impaired consciousness (GCS ≤ 9, or GCS = 10 combined with lumbar spinal opening pressure > 400 mmH₂O), a subgroup of patients (n = 21) monitored with intracerebral MD and biomarkers was included in the present study. All patients were treated in the NICU with intracranial pressure (ICP) guided therapy. Serum biomarkers were obtained at admission and every 12 hours. The MD parameters glucose, lactate, pyruvate and glycerol were analyzed. Outcome was assessed at 12–55 months after discharge from hospital. Mann-Whitney U-Test and Wilcoxon matched-pairs signed rank test were applied.

Results

The included patients had a mean GCS of 8 (range, 3–10) on admission and increased ICP (>20 mmHg) was observed in 62% (n = 13/21) of the patients. Patients with a lactate:pyruvate ratio (LPR) >40 (n = 9/21, 43%) had significantly higher peak levels of serum NSE (p = 0.03), with similar, although non-significant observations made in patients with high levels of glycerol (>500 μmol/L, p = 0.11) and those with a metabolic crisis (Glucose <0.8 mmol/L, LPR >25, p = 0.09). No associations between serum S100B and MD parameters were found. Furthermore, median MD glucose levels decreased significantly between day 1 (0–24h) and day 3 (48–72h) after admission to the NICU (p = 0.0001). No correlation between MD parameters or biomarkers and outcome was found.

Conclusion

In this observational cohort study, we were able to show that cerebral metabolism is frequently affected in patients with ABM. Furthermore, patients with high LPR (LPR>40) had significantly higher levels of NSE, suggesting ongoing deterioration in compromised cerebral tissue. However, the potential clinical impact of MD and biomarker monitoring in ABM patients will need to be further elaborated in larger clinical trials.

Complications of glioma surgery

Even with current advances in adjunctive therapies, including radiation, chemotherapy, and various clinical trials of gene therapy and immunotherapy, surgical resection remains one of the most effective treatment for intra-axial gliomas. Survival in these patients has been shown to be related to the extent of resection. In some cases, it can provide cures of long-term remission; in others, it can provide disease control when combined with the above adjunctive treatments. However, surgical resection carries its own risks and complications. These complications can be broadly divided into neurologic, regional, and systemic, including direct cortical and vascular injury, surgical wound complications, and postsurgical medical complications. Certain patient characteristics, including Karnofsky performance status score (KPS) and pathology of the tumor, have been shown to have an impact on the risk of postsurgical complications. Advancement in preoperative and intraoperative adjunct technology such as cortical mapping and navigation has improved the surgeon's ability to safely and maximally resect the tumors. It is therefore important to understand the perioperative complications after craniotomy and tumor resection and factors affecting morbidity and mortality in order for surgeons to optimally select and counsel patients who will benefit the most from surgical resection. This chapter will focus on the complications associated with craniotomy for intrinsic glioma and ways of avoiding these events.

Risk factors for meningitis after craniotomy in patients with subarachnoid hemorrhage due to anterior circulation aneurysms rupture

OBJECTIVES

Postoperative meningitis is a serious complication occurring after neurosurgical interventions. However, few investigations have focused specifically on the risk factors that predispose patients to meningitis after major craniotomy. This study identified the risk factors for postoperative meningitis after neurovascular surgery, and investigated the relationship between postoperative meningitis and clinical outcome.

PATIENTS AND METHODS

A total of 148 consecutive patients with subarachnoid hemorrhage (SAH) who underwent clipping surgery through a pterional approach within 72 h between January 2007 and September 2011 were retrospectively analyzed. The treatment strategy of our hospital for patients with SAH was based on the findings of digital subtraction angiography in the acute phase. Coil embolization was firstly considered, and clipping through craniotomy if indicated was performed as soon as possible. Prophylactic antibiotics were administered before beginning craniotomy and for at least 3 days after. Hydrocortisone was used to prevent hyponatremia if allowed by the medical condition of the patient. Intrathecal administration of nicardipine hydrochloride was given if required for vasospasm treatment. Meningitis was clinically diagnosed from the blood samplings and cerebrospinal fluid (CSF) examinations. Data were collected from the electronic and paper charts. The status of modified Rankin scale (mRS) 0-2 at discharge was defined as favorable outcome.

RESULTS

A total of 14 patients (9.5%) had meningitis during this study period. Symptomatic vasospasm was detected in 33 patients (22.3%), and 12 patients (8.1%) had permanent neurological deficits caused by vasospasm. Overall, 109 patients (73.6%) had favorable outcome. The longer duration of drainage placement, presence of CSF leakage, and intrathecal administration of vasodilatory agent showed significantly higher incidence of postoperative meningitis in univariate analysis (p=0.0093, 0.0017, and 0.0090, respectively). The proportion of favorable outcome patients at discharge (mRS 0-2) was significantly lower in patients with postoperative meningitis (35.7%) than in patients without it (77.6%) (p=0.0004). The duration of in-hospital stay was significantly longer in patients with postoperative meningitis (median 58.5, range 28-115 days) than in patients without it (median 38.5, range 19-149 days) (p<0.001). Multivariate logistic regression analysis showed that only presence of CSF leakage was associated with postoperative meningitis (p=0.0299).

CONCLUSION

Meningitis after surgery is still a serious complication that requires preventative intervention. The clinical outcome of patients with postoperative meningitis after neurovascular surgery is not still satisfactory.

Efficacy of ultra-short single agent regimen antibiotic chemo-prophylaxis in reducing the risk of meningitis in patients undergoing endoscopic endonasal transsphenoidal surgery

OBJECTIVES

The study aims to evaluate the incidence of infectious complications (namely meningitis) within 30 days after endoscopic endonasal transspheinodal neurosurgery (EETS) in patients receiving an ultra-short peri-operative chemo-prophylaxis regimen with 2 doses of 1st generation cephalosporin or macrolide.

PATIENTS AND METHODS

We retrospectively analyzed the clinical records of 145 patients who received an ultra-short chemoprophylaxis with two doses of an antibiotic, given 30 min before and 8h after EETS, over a 30-month time-frame. Ninety-seven patients (66.89%) received endovenous cefazolin, a 1st generation cephalosporin, administered at a dosage of 1000 mg, and 48 patients (33.10%) with an history of allergy to various agents, received endovenous clarithromycin at a dosage of 500 mg.

RESULTS

No case of peri- and post-operative meningitis occurred in patients receiving the 2 doses of antibiotic. Only one patient (0.68%) developed cerebral fluid leakage on the 7th postoperative day, which required the switching to a broad-spectrum antibiotic prophylaxis for one week; this patient received the ultrashort prophylaxis with a macrolide. In addition, 7 patients (4.82%) developed minor infectious complications such as low-grade fever (3 cases, all of them receiving cefazolin), enlarged submandibular and cervical lymphnodes (3 cases, all of them receiving cefazolin), and upper and lower respiratory tract infection (1 case receiving clarithromycin). The cost of this prophylaxis regimen ranged from 7.76 Euro (cefazolin) to 39.54 Euro (clarithromycin).

CONCLUSIONS

This study suggested that an ultra-short single-antibiotic prophylaxis is a safe, cheap and effective regimen to prevent post-operative meningitis in patients undergoing EETS and who do not require lumbar drainage after surgery. In these patients also the rate of minor infective complications was acceptable when compared with the previous more expensive regimen based on 3rd generation cephalosporin plus aminoglycoside or alone, that could be suitable only for at-risk patients (e.g. smokers, cerebrospinal leak or Cushing's diseases).

Population pharmacokinetics of vancomycin in adult Chinese patients with post-craniotomy meningitis and its application in individualised dosage regimens

PURPOSE

Vancomycin (VCM) is a first-line antibacterial drug used to treat post-craniotomy meningitis (PCM). VCM pharmacokinetic parameters are altered in PCM patients, compared to those in other patients. Although VCM population pharmacokinetics (PPK) has been reported, changes in VCM PPK in adult Chinese PCM patients remain unknown. We developed a VCM PPK model in adult Chinese PCM patients and proposed a new strategy for individualising VCM administration using this model.

METHODS

Data was obtained from a prospective study of 100 adult PCM patients in the Neurosurgery Department of the First Affiliated Hospital of Fujian Medical University. The trough concentrations at steady state were determined by enzyme multiplied immunoassay. Nonlinear mixed-effect model software was employed to develop the PPK model. The final model was evaluated using the bootstrap method and normalised prediction error distribution and through the testing of 20 independent adult PCM patients.

RESULTS

VCM clearance in PCM patients was higher than that observed in other patients. Creatinine clearance affected VCM clearance, whereas no co-administered drugs influenced VCM pharmacokinetics. Trough concentrations were accurately predicted by the final model, while the prediction errors were less than ±32 %. Moreover, a new strategy for individualising VCM regimens using the PPK model was proposed and validated.

CONCLUSIONS

A PPK model was developed to estimate the individual clearance in inpatients receiving intravenously infused VCM and could be used to develop individualised dosing of adult Chinese PCM patients.

Impact of resident involvement in neurosurgery: an analysis of 8748 patients from the 2011 American College of Surgeons National Surgical Quality Improvement Program database

OBJECT

This study evaluates the impact of resident presence in the operating room on postoperative outcomes in neurosurgery.

METHODS

The authors retrospectively reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) and identified all cases treated in a neurosurgery service in 2011. Propensity scoring analysis and multiple logistic regression models were used to reduce patient bias and to assess independent effect of resident involvement.

RESULTS

Of the 8748 neurosurgery cases identified, residents were present in 4529 cases. Residents were more likely to be involved in complex procedures with longer operative duration. The multivariate analysis found that resident involvement was not a statistically significant factor for overall complications (OR 1.116, 95% CI 0.961-1.297), surgical complications (OR 1.132, 95% CI 0.825-1.554), medical complications (OR 1.146, 95% CI 0.979-1.343), reoperation (OR 1.250, 95% CI 0.984-1.589), mortality (OR 1.164, 95% CI 0.780-1.737), or unplanned readmission (OR 1.148, 95% CI 0.946-1.393).

CONCLUSIONS

In this multicenter study, the authors demonstrated that resident involvement in the operating room was not a significant factor for postoperative complications in neurosurgery service. This analysis also showed that much of the observed difference in postoperative complication rates was attributable to other confounding factors. This is a quality indicator for resident trainees and current medical education. Maintaining high standards in postgraduate training is imperative in enhancing patient care and reducing postoperative complications.

Infections in patients undergoing craniotomy: risk factors associated with post-craniotomy meningitis

OBJECT The authors performed a prospective study to define the prevalence and microbiological characteristics of infections in patients undergoing craniotomy and to clarify the risk factors for post-craniotomy meningitis. METHODS Patients older than 18 years who underwent nonstereotactic craniotomies between January 2006 and December 2008 were included. Demographic, clinical, laboratory, and microbiological data were systemically recorded. Patient characteristics, craniotomy type, and pre- and postoperative variables were evaluated as risk factors for meningitis RESULTS Three hundred thirty-four procedures were analyzed (65.6% involving male patients). Traumatic brain injury was the most common reason for craniotomy. Almost 40% of the patients developed at least 1 infection. Ventilator-associated pneumonia (VAP) was the most common infection recorded (22.5%) and Acinetobacter spp. were isolated in 44% of the cases. Meningitis was encountered in 16 procedures (4.8%), and CSF cultures were positive for microbial growth in 100% of these cases. Gram-negative pathogens (Acinetobacter spp., Klebsiella spp., Pseudomonas aeruginosa, Enterobacter cloaceae, Proteus mirabilis) represented 88% of the pathogens. Acinetobacter and Klebsiella spp. demonstrated a high percentage of resistance in several antibiotic classes. In multivariate analysis, the risk for meningitis was independently associated with perioperative steroid use (OR 11.55, p = 0.005), CSF leak (OR 48.03, p < 0.001), and ventricular drainage (OR 70.52, p < 0.001). CONCLUSIONS Device-related postoperative communication between the CSF and the environment, CSF leak, and perioperative steroid use were defined as risk factors for meningitis in this study. Ventilator-associated pneumonia was the most common infection overall. The offending pathogens presented a high level of resistance to several antibiotics.

Microdialysis Monitoring of CSF Parameters in Severe Traumatic Brain Injury Patients: A Novel Approach

Background: Neuro-intensive care following traumatic brain injury (TBI) is focused on preventing secondary insults that may lead to irreversible brain damage. Microdialysis (MD) is used to detect deranged cerebral metabolism. The clinical usefulness of the MD is dependent on the regional localization of the MD catheter. The aim of this study was to analyze a new method of continuous cerebrospinal fluid (CSF) monitoring using the MD technique. The method was validated using conventional laboratory analysis of CSF samples. MD-CSF and regional MD-Brain samples were correlated to patient outcome.

Materials and Methods: A total of 14 patients suffering from severe TBI were analyzed. They were monitored using (1) a MD catheter (CMA64-iView, n = 7448 MD samples) located in a CSF-pump connected to the ventricular drain and (2) an intraparenchymal MD catheter (CMA70, n = 8358 MD samples). CSF-lactate and CSF-glucose levels were monitored and were compared to MD-CSF samples. MD-CSF and MD-Brain parameters were correlated to favorable (Glasgow Outcome Score extended, GOSe 6–8) and unfavorable (GOSe 1–5) outcome.

Results: Levels of glucose and lactate acquired with the CSF-MD technique could be correlated to conventional levels. The median MD recovery using the CMA64 catheter in CSF was 0.98 and 0.97 for glucose and lactate, respectively. Median MD-CSF (CMA 64) lactate (p = 0.0057) and pyruvate (p = 0.0011) levels were significantly lower in the favorable outcome group compared to the unfavorable group. No significant difference in outcome was found using the lactate:pyruvate ratio (LPR), or any of the regional MD-Brain monitoring in our analyzed cohort.

Conclusion: This new technique of global MD-CSF monitoring correlates with conventional CSF levels of glucose and lactate, and the MD recovery is higher than previously described. Increase in lactate and pyruvate, without any effect on the LPR, correlates to unfavorable outcome, perhaps related to the presence of erythrocytes in the CSF.

Collagen matrix duraplasty for posterior fossa surgery: evaluation of surgical technique in 52 adult patients

Object

Complete dural closure is not always possible following posterior fossa surgery, often requiring a graft to secure complete closure. The authors report their experience of using a collagen matrix as an onlay dural graft for repair of a posterior fossa dural defect.

Methods

A retrospective analysis was performed in 52 adult patients who had undergone collagen matrix duraplasty for the posterior fossa. Complications directly related to the dural graft, the presence or absence of hydrocephalus, and the role of closed suction wound drainage in relation to postsurgical pseudomeningoceles were analyzed.

Results

The indication for posterior fossa surgery was tumors in 32 patients, vascular abnormalities in 9 patients, and spontaneous cerebellar hemorrhage in 11 patients. Closed suction wound drainage was used in 23 patients (44.2%). Forty-eight (92.3%) of 52 patients had a dural defect > 2 cm. Nine (81.8%) of 11 patients with hydrocephalus required ventriculoperitoneal shunts. Complications of the surgery included pseudomeningoceles in 2 patients (3.8%; no closed suction wound drainage); superficial wound infections in 1 patient (1.9%; with closed suction wound drainage); and unexplained eosinophilia in 1 patient.

Conclusions

Duraplasty using a collagen matrix is safe and effective in the posterior fossa, and is easy to use and time efficient. Meticulous layered wound closure, the detection and effective control of hydrocephalus, and the use of closed suction wound drainage reduces complications related to collagen matrix duraplasty for the posterior fossa.

Risk factors for neurosurgical site infections: an 18-month prospective survey

OBJECT

The purpose of this study was to determine the incidence rate and risk factors of surgical site infections (SSIs) in neurosurgery for any type of surgery and any American Society of Anesthesiologists class.

METHODS

The authors undertook an exhaustive 18-month prospective survey including patients who underwent neurosurgery. In particular, a 30-day follow-up was completed in patients whose surgery did not involve placement of a prosthesis or implant, and 1-year follow-up was completed for patients who underwent surgery to place a prosthesis or implant. The Centers for Disease Control definition of SSI was used. Univariate and multivariate analyses were conducted; all dependent variables found in univariate analysis were entered in the multiple regression model. A stepwise multiple logistic regression method was used.

RESULTS

Of the 844 patients studied, 35 SSIs were diagnosed, yielding an incidence rate of 4.1% (95% confidence interval 3.6-4.5). Independent predictive risk factors for infection were cerebrospinal fluid leakage, external shunt, Altemeier class, and further neurosurgery. A lack of antibiotic prophylaxis was not found to be a risk factor.

CONCLUSIONS

Infection risk factors occur mainly during the postoperative period.

Polymicrobial skull osteomyelitis: a rare complication of subdural hematoma evacuation

BACKGROUND

Osteomyelitis of the skull (SO) is a rare condition. The infection may complicate community-acquired sinusitis, otitis, or mastoiditis, in which case, the skull base is affected most commonly. The flora typically seen in these conditions, such as Streptococcus pneumoniae and Haemophilus influenzae, tends also to be responsible for the SO. Osteomyelitis also may follow neurosurgical procedures that breach the skull, in which case, the pathogens frequently are typical cutaneous flora such as Staphylococcus aureus or coagulase-negative staphylococci.

METHODS

A case report of post-neurosurgical SO and a review of the relevant English-language literature.

RESULTS

We report a delayed presentation of SO after craniotomy for the evacuation of a chronic subdural hematoma. Cranial tissue cultures grew Staphylococcus aureus, Corynebacterium spp., and Escherichia coli.

CONCLUSIONS

The isolation of Escherichia coli as an infecting organism in SO has been reported rarely and may reflect a unique pathogenesis.

Retrospective analysis of a new antibiotic chemoprophylaxis regimen in 170 patients undergoing endoscopic endonasal transsphenoidal surgery

BACKGROUND

The aim of this study is to evaluate the rate of infectious complications post endoscopic transspheinodal neurosurgery in patients receiving a new antibiotic chemoprophylaxis regimen.

METHODS

Clinical records of 170 patients who received prophylaxis with a third-generation cephalosporin plus aminoglycoside (160 cases) or alone (10 cases) were retrospectively analyzed. Twenty-eight patients (16.4%) had CSF leakage. The postsurgical follow-up ranged from 3 months to 4 years.

RESULTS

Of 170 patients, 2 (1.17%) developed infectious complications: 1 case of meningitis by Staphylococcus epidermidis and 1 case of sphenoid sinusitis (without microbiological diagnosis). In addition, asymptomatic sphenoid sinusitis was diagnosed in 2 other patients. The cost ranged from 22.50 to 33.34 euros/d.

CONCLUSIONS

The rate of infectious complications was very low in patients receiving prophylaxis with a third-generation cephalosporin plus aminoglycoside or alone; because of the broad-spectrum of antibiotics and their high cost, this regimen could be used in at-risk patients (eg, smokers, patients with cerebrospinal leak, or patients with Cushing diseases).

Efficacy of Prophylactic Antibiotics Against Meningitis after Craniotomy: A Meta-Analysis

OBJECTIVE

Although prophylactic antibiotics have been shown by randomized clinical trials (RCTs) to help prevent deep infection after craniotomies, recent reports have suggested that antibiotics are not effective in preventing postcraniotomy meningitis.

METHODS

Data on meningitis as an end point from RCTs on prophylactic antibiotics for craniotomies were pooled in a random-effects meta-analysis.

RESULTS

Six prospective randomized trials or trial subgroups enrolling 1729 patients or operations were identified. Antibiotics reduced postoperative infection rates in five of the six RCTs; no trial individually showed a statistically significant benefit from antibiotics. The pooled odds ratio for meningitis with antibiotic treatment in the six RCTs was 0.43 (95% confidence interval, 0.20–0.92; P = 0.03). Subgroup analyses showed no detectable difference in antibiotic efficacy if antibiotics, with or without gram- negative coverage, were used or if the trial was single or double blinded. A sensitivity analysis showed modest dependence of the results of the analysis on the specific definition of postoperative meningitis used in interpreting trial results.

CONCLUSION

Prophylactic antibiotics administered before craniotomy reduce rates of postoperative meningitis by approximately one-half, a statistically and clinically significant benefit.

Risk factors associated with postcraniotomy meningitis

OBJECTIVE

The authors conducted a retrospective cohort study to determine the incidence, bacteriological features, and risk factors for postcraniotomy meningitis.

METHODS

Patients older than 18 years who underwent nonstereotactic craniotomies between January 1996 and March 2000 and who survived for more than 7 days were included. Operations for placement of burr holes and shunts were excluded. Records of the first 30 postoperative days were abstracted. Host factors, types of craniotomy, and pre- and postoperative variables were evaluated as risk factors for meningitis

RESULTS

Among 453 patients, there were 25 cases of meningitis. Eight out of 12 culture-positive cases were the result of gram-positive cocci. Four hundred twenty (92%) patients received antibiotic prophylaxis, most commonly a first-generation cephalosporin. In multivariate analysis, the risk of meningitis was increased by surgery that entered a sinus (odds ratio [OR], 4.49; P = 0.018), an increase in the American Society of Anesthesiologists score (OR, 1.72; P = 0.023), and increases in the number of days of external ventricular drainage (OR, 1.21; P = 0.049) and intracranial pressure monitoring (OR, 1.24; P = 0.002).

CONCLUSION

Access of upper airway bacteria to the surgical wound, host factors as expressed by the American Society of Anesthesiologists score, and duration of device-related postoperative communication of the cerebrospinal fluid and the environment are major risk factors for postoperative meningitis after craniotomy.

Free flap transfer for the treatment of intractable postcraniotomy subdural empyemas and epidural abscesses

OBJECTIVE

Postcraniotomy subdural empyemas and epidural abscesses are uncommon, potentially lethal, complications of neurosurgery. Patients with these complications may be difficult to manage, and mortality can occur.

METHODS

Between 1997 and 2006, the authors treated eight patients with recalcitrant postcraniotomy subdural empyema and epidural abscess with combinations of myocutaneous free flap transfer. The free flap transfer was intended for patients who could not be cured with conventional surgical debridement and bone flap removal. Patient ages ranged from 15 to 67 years (mean, 41.5 yr). There were six men and two women. Treatment was required for cranial base tumors (n = 3), the result of trauma (n = 2), malignant tumors (n = 2), and cerebral hematoma (n = 1). In six patients (75%), an expanded polytetrafluoroethylene sheet was used as a dural substitute at the original surgery. We used three rectus abdominis myocutaneous flaps and five latissimus dorsi myocutaneous flaps. In six patients (75%), surgery was performed in the chronic stage of infection, and the other two patients were in the acute stage of infection.

RESULTS

Among all the patients, two failures occurred because of flap ischemia, but these were resolved after an additional procedure. However, one of these two patients, in whom surgery was performed at the acute stage of infection, died 4 weeks after the surgery. The postoperative course of the other six patients was uneventful. Isolated microorganisms were methicillin-resistant Staphylococcus aureus (four patients), Pseudomonas aeruginosa (three patients), and methicillin-sensitive Staphylococcus aureus (one patient).

CONCLUSION

Myocutaneous free flap transfer allows sufficient blood circulation and dead space control and is resistant to infection. Therefore, free flap transfer is useful for eliminating intractable empyema and abscess; however, it is important that the procedure be considered in the chronic stage of infection.

Safety and efficacy of a novel polyethylene glycol hydrogel sealant for watertight dural repair

Object

The authors prospectively evaluated the safety and efficacy of a novel polyethylene glycol (PEG) hydrogel sealant in patients undergoing elective cranial surgery with documented cerebrospinal fluid (CSF) leakage after sutured dural repair.

Methods

The PEG hydrogel sealant was used at 11 different study sites in 111 patients with documented intraoperative CSF leakage after neurosurgical dural repair for a variety of conditions. Intraoperative CSF leakage was either spontaneous or induced by a Valsalva maneuver. Patients were monitored for 3 months postoperatively with physical examinations, clinical laboratory analyses, and diagnostic imaging.

The PEG hydrogel sealant was 100% effective in stopping CSF leakage in all patients. There were no sealant-related adverse events and all clinical outcomes were consistent with expectations for seriously ill patients undergoing prolonged neurosurgical procedures.

Conclusions

The PEG hydrogel sealant provides a safe and effective watertight closure when used as an adjunct to sutured dural repair during cranial surgery.

Collagen matrix duraplasty for cranial and spinal surgery: a clinical and imaging study

Object

The repair of dural defects is controversial in contemporary neurosurgery. To date, collagen-based products remain a continued area of interest in the development of dural grafts. The authors conducted a prospective case–control study in which they evaluated collagen matrix in the repair of dural defects following cranial and spinal surgery by using specific clinical and magnetic resonance (MR) imaging outcome measures.

Methods

Enrolled in the study were 79 patients, 36 male (45.6%) and 43 female (54.4%), with a mean age of 53 ± 15.8 years. The pathological diagnosis was brain tumor in 49 cases (62%), vascular conditions in 16 (20.2%), degenerative spine in 10 (12.7%), trauma in two (2.5%), and other in two (2.5%). Most of the patients underwent supratentorial craniotomy (57; 72.2%), whereas 11 patients (13.9%) each underwent posterior fossa and spinal surgery. Sixty-three patients (79.7%) completed the study, which included clinical and MR imaging evaluations at 3 months postsurgery. There were no cerebrospinal fluid (CSF) leaks or delayed hemorrhages. The neurosurgical wound infection rate was 3.8%: superficial wound infection in two cases and deep infection and brain abscess in one case (recurrent brain tumor following radiation therapy).

Among the 63 patients in whom 3-month postsurgery imaging data were available, asymptomatic small pseudomeningoceles were detected on MR imaging in two (3.2%); a minor subgaleal fluid collection, which resolved spontaneously, was apparent in another patient (1.6%). Nonspecific dural enhancement was demonstrated on images obtained in seven patients (11.1%), and asymptomatic spinal epidural enhancement was observed on images obtained in two of three patients who had undergone lumbar laminectomy for spinal stenosis.

Conclusions

When used as a dural onlay graft, collagen matrix had a 100% CSF containment rate but might be associated with occult radiological abnormalities.

Risk Factors for Adult Nosocomial Meningitis After Craniotomy Roleof Antibiotic Prophylaxis

OBJECTIVE

To evaluate incidence and risk factors of postoperative meningitis, with special emphasis on antibiotic prophylaxis, in a series of 6243 consecutive craniotomies.

METHODS

Meningitis was individualized from a prospective surveillance database of surgical site infections after craniotomy. Ventriculitis related to external ventricular drainage or cerebrospinal fluid shunt were excluded. From May 1997 until March 1999, no antibiotic prophylaxis was prescribed for scheduled, clean, lasting less than 4 hours craniotomies, whereas emergency, clean-contaminated, or long-lasting craniotomies received cloxacillin or amoxicillin-clavulanate. From April 1999 until December 2003, prophylaxis was given to every craniotomy. Independent risk factors for meningitis were studied by a multivariate analysis. Efficacy of antibiotic prophylaxis in preventing meningitis was studied as well as consequences on bacterial flora.

RESULTS

The overall meningitis rate was 1.52%. Independent risk factors were cerebrospinal fluid leakage, concomitant incision infection, male sex, and surgical duration. Antibiotic prophylaxis reduced incision infections from 8.8% down to 4.6% (P < 0.0001) but did not prevent meningitis: 1.63% in patients without antibiotic prophylaxis and 1.50% in those who received prophylaxis. Bacteria responsible for meningitis were mainly noncutaneous in patients receiving antibiotics and cutaneous in patients without prophylaxis. In the former, microorganisms tended to be less susceptible to the prophylactic antibiotics administered. Mortality rate was higher in meningitis caused by noncutaneous bacteria as compared with those caused by cutaneous microorganisms.

CONCLUSION

Perioperative antibiotic prophylaxis, although clearly effective for the prevention of incision infections, does not prevent meningitis and tends to select prophylaxis resistant microorganisms.

Evaluation of an antibiotic-impregnated shunt system for the treatment of hydrocephalus

Object. Staphylococcus species are the most common organisms responsible for infection following implantable cerebrospinal fluid (CSF) diversionary procedures. The role of an antibiotic-impregnated shunt (AIS) system in the prevention of shunt infection has remained unclear because no human clinical trial has been reported on thus far. In this study, the authors assess an AIS system with respect to its prevention of shunt infection.

Methods. Patients were prospectively randomized into groups to evaluate the efficacy of an AIS system against an identical control shunt system. The data accrued were subjected to a detailed statistical analysis. Logistic regression analysis was performed to determine the independent association between outcome and predictor variables. Shunt function analysis was also performed to compare the average time to infection between the two groups.

One hundred ten patients were recruited; 60 received control shunt systems and 50 received AIS systems. Thirteen shunt infections were recorded (10 in the control group and three in the AIS group). Nine (69%) of 13 infections occurred within 2 months after shunt implantation (eight of 10 in the control group and one of three in the AIS group). Apart from one patient in whom no organism was identified, a total of 14 organisms (12 patients) were cultured from either the CSF (nine) or the shunt apparatus (three). Staphylococcus species accounted for the majority of shunt infections (83%): all 10 control shunts were found to have a positive culture of staphylococci, whereas none of the AISs had any staphylococci (p = 0.038).

Conclusions. The AIS afforded antistaphylococcal protection, especially during the early postoperative period when most shunt infections are known to occur and throughout the follow-up period (median 9 months). The AIS system represents another important tool to enable the neurosurgeon to prevent shunt infections.

Surgical treatment of tinea capitis in childhood

Fungal infections of the scalp can cause kerion, pus-filled swellings, that may look like bacterial abscesses. We report on two children who underwent incision and drainage of their kerions under local and general anesthesia. This treatment was inappropriate: it carried the risk associated with general anesthesia and surgery without providing the therapeutic chance linked to adequate antimicrobial chemotherapy. We recommend that children who are present at emergency departments with pus-filled swellings on the scalp should be referred to a dermatology unit where appropriate clinical and laboratory investigations and antifungal treatment can be provided, if considered adequate.

Controversies in the prevention of neurosurgical infection

Amongst post-operative infections, those associated with neurosurgery are of particular significance in view of their proximity to, or location within, the central nervous system. Superficial surgical site infections may be complicated by osteomyelitis of the calvarium and deeper extension to the meninges and cerebral parenchyma. The prevention, diagnosis and management of infections associated with implant devices provide similar challenges to those faced in orthopaedic and cardiac surgery. Whilst some consensus exists regarding the need for antimicrobial prophylaxis in the latter two disciplines, its place in neurosurgery remains controversial. When prophylaxis is considered, choice of antimicrobial agents should take account of up-to-date local information in relation to the relevant microbial ecology in hospitals and in the community setting. The potential for spread of blood-borne virus infections and transmissible spongiform encephalopathies in relation to neurosurgery must also be considered and it should be ensured that appropriate preventive strategies are in place.

[Nosocomial meningitis in the adult]

Cerebrospinal fluid (CSF) has anti-infectious defense abilities similar to those of the serum of a neutropenic patient. A septic inoculation as in case of nosocomial meningitis (NM), results rapidly in microbial proliferation with major alterations to the blood brain barrier, cerebral oedema and loss of autoregulation of the cerebral blood flow. Arterial hypotension during NM may induce focal or global cerebral ischaemia. The incidence of NM is increasing, staphylococci and Gram negative bacilli being the most frequent pathological agents. Clinical symptoms are not specific in this postoperative and post-traumatic context. In this context, the analysis of pleocytosis and the increased protein content of CSF is disturbing. Numerous clinical conditions may cause NM. Among them, NM from spinal puncture is an important issue for anaesthetists, while combined epidural and spinal anaesthesia carry the highest risks. Cutaneous contamination plays a major role. Half of the post-operative infections after neurosurgery are due to NM, and CSF leakage, iterative operations and surgery in contaminated conditions are the main risk factors. Antibioprophylaxis for postoperative NM is validated for clean and clean-contaminated surgery. Some consider that only procedures of more than two hours require this prophylaxis. Prophylaxis is targeted on staphylococci. Other preventive measures (drainage of less than 24 h, head shaving and prevention of CSF leakage) are of major importance. Antibiotherapy should be guided by the same considerations as for community acquired meningitis, associated with specific issues in the surgical context (presence of foreign material and CSF blockage).

Risk factors for neurosurgical site infections after craniotomy: a prospective multicenter study of 2944 patients. The French Study Group of Neurosurgical Infections, the SEHP, and the C-CLIN Paris-Nord. Service Epidémiologie Hygiène et Prévention

OBJECTIVE

To determine the incidence and risk factors of surgical site infections (SSIs) after craniotomy and to test the risk index score proposed by the National Nosocomial Infections Surveillance (NNIS) system, which, to our knowledge, has not been validated in neurosurgery to date.

METHODS

During a 15-month period, every adult patient undergoing craniotomy in 10 neurosurgical units was prospectively evaluated for development and risk factors of SSI. The follow-up period was at least 30 days. SSIs were defined according to the Center for Disease Control definitions. Incidence was calculated per patient. Multivariate analyses were conducted at first to include all significant risk factors of univariate analysis and then only those known preoperatively. Finally, the NNIS risk index was tested in this population.

RESULTS

Of a total of 2944 patients, 117 patients (4%) with SSIs were observed, including 30 with wound infections, 14 with bone flap osteitis, 56 with meningitis, and 17 with brain abscesses. Independent risk factors for SSIs were postoperative cerebrospinal fluid leakage (odds ratio, 145; 95% confidence interval, 72-293) and subsequent operation (odds ratio, 7; 95% confidence interval, 4-12). Independent predictive risk factors were emergency surgery, clean-contaminated and dirty surgery, an operative time longer than 4 hours, and recent neurosurgery. Absence of antibiotic prophylaxis was not a risk factor. The NNIS risk index was effective in identifying at-risk patients.

CONCLUSION

Independent risk factors for SSIs after craniotomy involve postoperative events. However, the NNIS risk index is effective in identifying at-risk patients.

A clinicopathological study of collagen sponge as a dural graft in neurosurgery

There is frequently a need for dural grafts to cover defects resulting from retraction, shrinkage, or excision following neurosurgical procedures. Several materials have been evaluated both experimentally and clinically, and then discarded. Collagen, in its various forms, continues to be an area of intense interest. In this study the authors examined the suitability of collagen sponge to effect dural repair. In a 5-year clinical study 102 collagen sponge implants were examined macroscopically and histologically. Graft encapsulation, neomembrane formation, delayed hemorrhage, and foreign body reactions were not found. The porous nature of the collagen sponge encouraged fibroblastic ingrowth and dural repair. Meningocerebral adhesions were present in 11 patients, all of whom had required significant cortical resection or had pia-arachnoid disruption during the initial surgery. Inflammatory cells were seen only in response to infection. Postoperative cerebrospinal fluid leaks developed in only three of 67 patients who underwent an intradural posterior fossa procedure. In a prospective arm of the study involving 459 patients, the wound infection rate using collagen sponge was 6.1%, which compared favorably (p = 0.67) with the 5.7% rate in a similar group of 637 patients in whom collagen sponge had not been used.