Risk factors for postoperative neurosurgical wound infection. A case-control study

An update on a persisting challenge: A systematic review and meta-analysis of the risk factors for surgical site infection post craniotomy

BACKGROUND

Surgical site infections (SSIs) postcraniotomy continue to impose a significant burden on health care systems and patient outcomes. It is, therefore, important to understand their risk factors in order to promote effective preventative measures. This meta-analysis aims to provide a comprehensive, up-to-date analysis of the risk factors associated with SSIs in neurosurgical procedures.

METHODS

A systematic review was conducted as per preferred reporting items for systematic reviews and meta-analysis guidelines to explore existing primary evidence on the risk factors for SSIs postcraniotomy. A comprehensive search of MEDLINE, EMBASE, and Pubmed was performed from database inception up to June 2023. 43 studies were included in the meta-analysis, encompassing a total of 68,881 patients.

RESULTS

The strongest predictor for SSIs was found to be cerebrospinal fluid (CSF) leak (OR: 8.91, CI: 4.30-18.44). Other significant factors included infratentorial surgery (OR: 0.43, CI: 0.31-0.61), emergency surgery (OR: 1.41, CI: 1.05-1.91), reintervention (OR: 3.19, CI: 1.77-5.75), prolonged operative time (mean difference: 33.25; CI: 18.83-47.67), hospital length of stay (mean difference: 0.60; CI: 0.23-0.98) and intracranial pressure monitor (ICPM) insertion (OR: 1.81; CI: 1.06-3.11). Contrarily, sex, body mass index (BMI), diabetes, antibiotic prophylaxis, immunosuppressive agents, trauma, use of artificial implants did not demonstrate statistical significance.

CONCLUSIONS

This meta-analysis provides an up-to-date and comprehensive evaluation of risk factors for SSIs postcraniotomy. It emphasizes the need for preventive strategies, particularly against CSF leaks, and calls for further research to elucidate the intricate relationships between these factors.

The comparison of the watertight and non-watertight dural closure in supratentorial craniotomy: A single-institute 10-year experience with 698 patients

Watertight dural closure (WTDC) is considered crucial by many neurosurgeons in cranial base surgery, infratentorial craniotomy, and spinal intradural procedure. Whether WTDC also reduce complications remains controversial in supratentorial craniotomy. The objective of this study is to investigate the relationship between WTDC and CSF-related complications in supratentorial craniotomy for the resection of space-occupying lesions. A retrospective analysis of patients who suffered from intracranial space-occupying lesions at Beijing Ditan Hospital between January 2011 and December 2021 was conducted. A total of 698 cases were reviewed with attention to the operative approach, subgaleal fluid collection, wound healing impairment, postoperative infection, and post-craniotomy headaches. The study included a total of 423 patients with WTDC and 275 patients without WTDC. Patients without WTDC had a significantly higher rate of infection (10.9% vs 4.5% with WTDC, P = .001). The rate of subgaleal fluid collection was 9.7% in the WTDC group and 11.3% in the non-WTDC group, but this difference was not statistically significant (P = .502). They suffered from a greater incidence of post-craniotomy headaches in the WTDC group (13.5% vs 9.5% in the non-WTDC group), but without statistical significance (P = .109). We also found no difference in wound healing impairment (P = .719). There is less postoperative infection associated with WTDC during intracranial space-occupying lesion removal than without WTDC in supratentorial craniotomy.

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.

Pictorial review of the post-operative cranium

Imaging evaluation of the brain and cranium after cranial surgery is a routine and significant part of the workflow of a radiology department. Various normal expected findings and early and late complications are associated with the post-operative cranium. In this pictorial review, the authors describe the typical imaging features of the spectrum of various conditions associated with cranial surgery with illustrative cases.

Contribution

A good knowledge and understanding of the spectrum of imaging appearances in the post-operative cranium is vital for the radiologist to accurately diagnose potential complications and distinguish them from normal post-operative findings, improving patient outcomes and guiding further treatment.

Relationship between characteristics of glioma treatment and surgical site infections

PURPOSE

Surgical site infections (SSIs) after neurosurgery are common in daily practice. Although numerous reports have described SSIs in neurosurgery, reports specific to gliomas are limited. This study aimed to investigate the relationship between SSIs and glioma treatment characteristics, such as reoperations, radiation therapy, and chemotherapy.

METHODS

We examined 1012 consecutive patients who underwent craniotomy for glioma between November 2013 and March 2022. SSIs were defined as infections requiring reoperation during the observation period, regardless of their location. We retrospectively analyzed SSIs and patient factors.

RESULTS

During the observation period, SSIs occurred in 3.1% (31/1012). In the univariate analysis, three or more surgeries (P = 0.007) and radiation therapy (P = 0.03) were associated with SSIs, whereas intraoperative magnetic resonance imaging (MRI) was not significantly associated (P = 0.35). Three or more surgeries and radiation therapy were significantly correlated with each other (P < .0001); therefore, they were analyzed separately in the multivariate analysis. Three or more surgeries were an independent factor triggering SSIs (P = 0.02); in contrast, radiation therapy was not an independent factor for SSIs (P = 0.07). Several SSIs localized in the skin occurred more than 1 year after surgery.

CONCLUSIONS

Undergoing three or more surgeries for glioma is an independent risk factor for SSIs. Glioma SSIs can occur long after surgery. These results are considered characteristic of gliomas. We recommend careful long-term observation of patients at a high risk of SSIs.

Outcome after Posterior Vertebral Column Resection in Patients with Severe Osteoporotic Fractures—A Retrospective Analysis from Two Centers

Background and Objectives: In osteoporotic fractures of the spine with resulting kyphosis and threatening compression of neural structures, therapeutic decisions are difficult. The posterior vertebral column resection (pVCR) has been described by different authors as a surgical treatment in a single-stage posterior procedure. The aim of this study is to evaluate midterm outcomes of patients treated by pVCR due to severe osteoporotic fractures. Materials and Methods: Retrospective data analysis of all the patients treated for osteoporotic fractures by pVCR from 2012–2020 at two centers was performed. Demographic data, visual analog scale (VAS), Frankel scale (FS), Karnofsky performance status (KPS), radiological result and spinal fusion rates were evaluated. Results: A total of 17 patients were included. The mean age was 70 ± 10.2 y. The mean VAS decreased significantly from 7.7 ± 2.8 preoperatively to 3.0 ± 1.6 at last follow-up (p < 0.001) and the segmental kyphosis decreased from 29.4 ± 14.1° to 7.9 ± 8.0° (p < 0.001). The neurologic function on the FS did not worsen in any and improved in four of the patients. The median KPS remained stable over the whole observation period (70% vs. 70%). Spinal fusion was observed in nine out of nine patients who received CT follow-up >120 days after index surgery. Conclusions: This study showed that pVCR is a safe surgical technique with few surgical complications and no neurological deterioration considering the cohort. The patients’ segmental kyphosis and VAS improved significantly, while the KPS remained stable.

Recursive partitioning analysis of factors determining infection after intracranial tumor surgery

OBJECTIVES

Several factors are commonly associated with the occurrence of post-operative infection after craniotomy. However, the risk factors associated with tumor surgery have been less intensively investigated. The aim of the present study was to analyze the risk factors for infection and categorize patients according to risk rate.

METHODS

In this study, we retrospectively evaluated 987 adult patients consecutively submitted to craniotomy for tumor resection. The primary outcome was the occurrence of infection within 30 days after surgery. The following independent variables were assessed: age, gender, surgery duration, length of hospital stay prior to surgery, reoperation, body mass index, serum albumin, hemoglobin, lactic dehydrogenase, smoking, diabetes, corticoid use, preoperative chemotherapy, previous irradiation, elective or urgent indication for surgery, supra or infratentorial lesion location, and tumor histology. We performed a recursive partitioning analysis to assess the relative importance of these variables in predicting infection.

RESULTS

The model returned a 3-level classification: 1. CSF-leakage (relative contribution 70%), 2. Emergency surgery indication (18%), and 3. Tumor histology (8%). Additionally, partitioning clustered together 3 risk groups: 1. CSF-leakage group (probability of infection 72.5%), 2. No CSF-leakage and urgent surgery (mean probability 18.1%); and 3. no CSF-leakage and no urgent surgery (3.4%). The misclassification rate was 4.5%, the overall specificity and sensitivity were 99.6% and 75.5%, respectively, and the area under the ROC-curve was 0.6908.

CONCLUSION

Our analysis indicates that technical and treatment-related factors are significantly more relevant than patient- or disease-related factors in determining the risk of postoperative infection.

What Isn't a Case-Control Study?

BACKGROUND

Confusion exists among neurosurgeons when choosing and implementing an appropriate study design and statistical methods when conducting research. We noticed particular difficulty with mislabeled and inappropriate case-control studies in the neurosurgical literature.

OBJECTIVE

To quantify and to rigorously review this issue for appropriateness in publication and to establish quality of the manuscripts using a rigorous technique.

METHODS

Following a literature search, pairs drawn from 5 independent reviewers evaluated a complete sample of 125 manuscripts claiming to be case-control studies with respect to basic case-control criteria. Seventy-five papers were then subjected to a more rigorous appraisal for quality using the SIGN Methodology Checklist for case-control studies.

RESULTS

Fifty publications were rejected based on basic criteria used to identify case-control design. Of the 75 subjected to quality analysis, 46 were felt to be acceptable for publication. Only 11 papers (9%) achieved the designation of high quality. Of the original 125 papers evaluated, 79 (63%) were inappropriately labeled case-control studies.

CONCLUSION

Mislabeling and use of inappropriate study design are common in the neurosurgical literature. Manuscripts should be evaluated rigorously by reviewers and readers, and neurosurgical training programs should include instruction on choice of appropriate study design and critical appraisal of the literature.

Effect of Empiric Treatment of Asymptomatic Bacteriuria in Neurosurgical Trauma Patients on Surgical Site and Clostridium difficile Infection

BACKGROUND

Although empiric treatment of urinary tract colonized patients remains a frequent practice in neurosurgery, the value of this practice remains debatable.

OBJECTIVE

To analyze the effect of screening and treatment of bacteriuria on surgical site infections, incidence of Clostridium difficile, and mortality in neurosurgical trauma patients.

METHODS

Database queries and direct patient chart reviews were used to gather patient chart data. T-tests, chi-square tests, binary logistic regressions, and propensity matched cohorts comparisons were performed.

RESULTS

A total of 3563 admitted neurosurgical trauma patients were identified over an 8 yr period (1524 cranial, 1778 spinal, and 261 combined craniospinal diagnoses). Nine hundred ninety-one patients underwent an operative neurosurgical procedure. Urinalysis was significantly associated with antibiotics exposure in both operative and nonoperative patients (P < .001). Operative patients treated with empiric antibiotics did not have a reduced risk of wound infection (P = .21), including in a propensity matched cohort (P = .52). Patients treated with empiric antibiotics had significantly increased rates of C. difficile infection (P < .001). At last follow-up, neurosurgical trauma patients that developed C. difficile had an increased risk of death (P < .005); antibiotic exposure and death were also significantly associated (P = .018). The association of C. difficile with empiric antibiotics remained significant in a propensity-matched cohort (P = .0024).

CONCLUSION

The routine use of urinalysis and empiric urinary antibiotics for bacteriuria in neurosurgical trauma patients without urinary symptoms increases risk of exposure to antibiotics does not decrease rates of wound infection, and is associated with increased rates of C. difficile infection and death.

Cranial flap fixation in sheep using a resorbable bone adhesive

OBJECTIVE

The authors' goal in this study was to investigate the use of a novel, bioresorbable, osteoconductive, wet-field mineral-organic bone adhesive composed of tetracalcium phosphate and phosphoserine (TTCP-PS) for cranial bone flap fixation and compare it with conventional low-profile titanium plates and self-drilling screws.

METHODS

An ovine craniotomy surgical model was used to evaluate the safety and efficacy of TTCP-PS over 2 years. Bilateral cranial defects were created in 41 sheep and were replaced in their original position. The gaps (kerfs) were completely filled with TTCP-PS (T1 group), half-filled with TTCP-PS (T2 group), or left empty and the flaps fixated by plates and screws as a control (C group). At 12 weeks, 1 year, and 2 years following surgery, the extent of bone healing, local tissue effects, and remodeling of the TTCP-PS were analyzed using macroscopic observations and histopathological and histomorphometric analyses. Flap fixation strength was evaluated by biomechanical testing at 12 weeks and 1 year postoperatively.

RESULTS

No adverse local tissue effects were observed in any group. At 12 weeks, the bone flap fixation strengths in test group 1 (1689 ± 574 N) and test group 2 (1611 ± 501 N) were both statistically greater (p = 0.01) than that in the control group (663 ± 385 N). From 12 weeks to 1 year, the bone flap fixation strengths increased significantly (p < 0.05) for all groups. At 1 year, the flap fixation strength in test group 1 (3240 ± 423 N) and test group 2 (3212 ± 662 N) were both statistically greater (p = 0.04 and p = 0.02, respectively) than that in the control group (2418 ± 1463 N); however, there was no statistically significant difference in the strengths when comparing the test groups at both timepoints. Test group 1 had the best overall performance based on histomorphometric evaluation and biomechanical testing. At 2 years postoperatively, the kerfs filled with TTCP-PS had histological evidence of osteoconduction and replacement of TTCP-PS by bone with nearly complete osteointegration.

CONCLUSIONS

TTCP-PS was demonstrated to be safe and effective for cranial flap fixation in an ovine model. In this study, the bioresorbable, osteoconductive bone adhesive appeared to have multiple advantages over standard plate-and-screw bone flap fixation, including biomechanical superiority, more complete and faster bony healing across the flap kerfs without fibrosis, and the minimization of bone flap and/or hardware migration and loosening. These properties of TTCP-PS may improve human cranial bone flap fixation and cranioplasty.

Logistic Regression Analysis of Risk Factors for Intracranial Infection After Multiple Traumatic Craniotomy and Preventive Measures

BACKGROUND AND OBJECTIVE

The aim of this study was to study the risk factors of intracranial infection after traumatic craniotomy in multiple trauma to provide references for clinical prevention and control of intracranial infection.

METHODS

A total of 34 multiple trauma patients treated with craniotomy and complicated with intracranial infection from February 2012 to December 2016 in the department of neurosurgery of our hospital were selected as infection group, and 60 multiple trauma patients who had not been infected after craniotomy during the same period were selected as control group. Related risk factors were screened by univariate analysis at first and analyzed by Logistic regression.

RESULTS

Of the 34 patients in the infection group, 13 cases were cured, 21 cases improved, whereas in the control group, 15 cases were cured and 45 cases improved. There was no significant difference in prognosis between the 2 groups (P > 0.05). Univariate analysis showed that surgical approach, surgical duration, postoperative cerebrospinal fluid leakage, and external drainage were important factors for intracranial infection after craniotomy (P < 0.05). Further Logistic regression analysis showed that postoperative external drainage, cerebrospinal fluid leakage, surgical time, and posterior fossa approaches were independent risk factors for intracranial infection after craniotomy.

CONCLUSION

High attention should be paid to the risk factors of intracranial infection after craniotomy such as postoperative cerebrospinal fluid leakage, external drainage, surgical duration and approach, and taking effective preventive measures to reduce the incidence of intracranial infection after craniotomy in patients with multiple traumatic injuries.

The Importance of Perioperative Prophylaxis with Cefuroxime or Ceftriaxone in the Surgical Site Infections Prevention after Cranial and Spinal Neurosurgical Procedures

Introduction Surgical site infections pose a significant problem in the treatment of neurosurgical procedures, regardless of the application of perioperative prophylaxis with systemic antibiotics. The infection rate in these procedures ranges from less than 1% to above 15%. Different antibiotics and administration regimes have been used in the perioperative prophylaxis so far, and there are numerous comparative studies regarding their efficiency, however, it is generally indicated that the choice thereof should be based on information and local specifics connected to the most probable bacterial causers, which would possibly contaminate the surgical site and cause infection, and moreover, the mandatory compliance with the principles of providing adequate concentration of the drug at the time of the anticipated contamination. Objective Comparing the protective effect of two perioperative prophylactic antibiotic regimes using cefuroxime (second generation cephalosporin) and ceftriaxone (third generation cephalosporin) in the prevention of postoperative surgical site infections after elective and urgent cranial and spinal neurosurgical procedures at the University Clinic for Neurosurgery in Skopje in the period of the first three months of 2016. Design of the study Prospective randomized comparative study. Outcome measures Establishing the clinical outcome represented as prevalence of superficial and deep incision and organ/space postoperative surgical site infections. Material and method We analyzed prospectively 40 patients who received parenteral antibiotic prophylaxis with two antibiotic regimes one hour before the routine neurosurgical cranial and spinal surgical procedures; the patients were randomized in two groups, according to the order of admission and participation in the study, alternately, non-selectively, those persons who fulfilled inclusion criteria were placed in one of the two programmed regimes with cefuroxime in the first, and cefotaxime in the second compared group. All relevant demographic and perioperative patient data were analyzed for both comparative groups, especially the factors known to cause disposition (predisposition) to infections. The prevalence of postoperative infections was evaluated as the primary outcome in both comparative groups, while the secondary outcome was the postoperative infection rate after cranial and spinal neurosurgical procedures at the Neurosurgical clinic in Skopje (having in consideration that so far no data have been published in this context), as well as the prevalence of the risk factors for occurrence of postoperative infections, pre-surgically in patients undergoing neurosurgical interventions locally in the Republic of Macedonia. Results A total of three cases of postoperative infections were registered, two of which classified as superficial incisional, while one case organ/space infection - meningitis (elective intervention) without etiological confirmation. Both comparative groups were statistically similar, without any statistically significant differences in the basic demographic and perioperative characteristics, especially in relation to the incidence of the factors, which, regardless of the antibiotic prophylaxis, show predisposition to postoperative infections. All three cases with infections were registered in the group of persons who received prophylaxis with ceftriaxone preoperatively, with isolated etiological S. aureus agent (elective intervention) in one of them, and methicillin resistant staphylococcus aureus (MRSA) in another (urgent intervention) with superficial incisional SSI. There was no case of SSI in the group of patients who received cefuroxime before surgery. Conclusion Administration of parenteral antibiotics before surgery reduces the incidence of postoperative infections after neurosurgical procedures, especially in cases with increased risk factors for SSI, such as ACA score of ≥ 2/3, the duration of the surgical intervention ≥ 4 hours, contaminated wound and comorbidities. Perioperative antibiotic prophylaxis should be directed to better coverage of the S.aureus arrays.

Scrubbing technique and surgical site infections: an analysis of 14,200 neurosurgical cases

OBJECTIVE

The preoperative scrub has been shown to lower the incidence of surgical site infections (SSIs). Various scrubbing and gloving techniques exist; however, it is unknown how specific scrubbing technique influences SSI rates in neurosurgery. The authors aimed to assess whether the range of scrubbing practice in neurosurgery is associated with the incidence of SSIs.

METHODS

The authors conducted a retrospective review of a prospectively maintained database to identify all 90-day SSIs for neurosurgical procedures between 2012 and 2017 at one of their teaching hospitals. SSIs were classified by procedure type (craniotomy, shunt, fusion, or laminectomy). Surveys were administered to attending and resident physicians to understand the variation in scrubbing methods (wet vs dry, iodine vs chlorhexidine, single vs double glove). The chi-square followed by multivariate logistic regression analyses were utilized to identify independent predictors of SSI.

RESULTS

Forty-two operating physicians were included in the study (18 attending physicians, 24 resident physicians), who performed 14,200 total cases. Overall, SSI rates were 2.1% (296 SSIs of 14,200 total cases) and 2.0% (192 of 9,669 cases) for attending physicians and residents, respectively. Shunts were independently associated with an increased risk of SSI (OR 1.7 [95% CI 1.3-2.1]), whereas laminectomies were associated with a decreased SSI risk (OR 0.4 [95% CI 0.2-0.8]). Wet versus dry scrub (OR 0.9 [95% CI 0.6-1.4]), iodine versus chlorhexidine (OR 0.6 [95% CI 0.4-1.1]), and single- versus double-gloving (OR 1.1 [95% CI 0.8-1.4]) preferences were not associated with SSIs.

CONCLUSIONS

There is no evidence to suggest that perioperative infection is associated with personal scrubbing or gloving preference in neurosurgical procedures.

Risk factors for surgical site infection after craniotomy: a prospective cohort study

Background

Although surgical site infection after craniotomy (SSI-CRAN) is a serious complication, risk factors for its development have not been well defined. We aim to identify the risk factors for developing SSI-CRAN in a large prospective cohort of adult patients undergoing craniotomy.

Methods

A series of consecutive patients who underwent craniotomy at a university hospital from January 2013 to December 2015 were prospectively assessed. Demographic, epidemiological, surgical, clinical and microbiological data were collected. Patients were followed up in an active post-discharge surveillance programm e for up to one year after surgery. Multivariate analysis was carried out to identify independent risk factors for SSI-CRAN.

Results

Among the 595 patients who underwent craniotomy, 91 (15.3%) episodes of SSI-CRAN were recorded, 67 (73.6%) of which were organ/space. Baseline demographic characteristics were similar among patients who developed SSI-CRAN and those who did not. The most frequent causative Gram-positive organisms were Cutibacterium acnes (23.1%) and Staphylococcus epidermidis (23.1%), whereas Enterobacter cloacae (12.1%) was the most commonly isolated Gram-negative agent. In the univariate analysis the factors associated with SSI-CRAN were ASA score > 2 (48.4% vs. 35.5% in SSI-CRAN and no SSI-CRAN respectively, p = 0.025), extrinsic tumour (28.6% vs. 19.2%, p = 0.05), and re-intervention (4.4% vs. 1.4%, p = < 0.001). In the multivariate analysis, ASA score > 2 (AOR: 2.26, 95% CI: 1.32–3.87; p = .003) and re-intervention (OR: 8.93, 95% CI: 5.33–14.96; p < 0.001) were the only factors independently associated with SSI-CRAN.

Conclusion

The risk factors and causative agents of SSI-CRAN identified in this study should be considered in the design of preventive strategies aimed to reduce the incidence of this serious complication.

Electronic supplementary material

The online version of this article (10.1186/s13756-019-0525-3) contains supplementary material, which is available to authorized users.

Post-operative complications of craniotomy and craniectomy

Craniotomy and craniectomy are widely performed emergent neurosurgical procedures and are the prescribed treatment for a variety of conditions from trauma to cancer. It is vital for the emergency radiologist to be aware of expected neuroimaging findings in post-craniotomy and craniectomy patients in order to avoid false positives. It is just as necessary to be familiar with postsurgical complications in these patients to avoid delay in lifesaving treatment. This article will review the commonly encountered normal and abnormal findings in post-craniotomy and craniectomy patients. The expected postoperative CT and MRI appearance of these procedures are discussed, followed by complications. These include hemorrhage, tension pneumocephalus, wound/soft tissue infection, bone flap infection and extradural abscesses. Complications specifically related to craniectomies include extracranial herniation, external brain tamponade, paradoxical herniation, and trephine syndrome.

Oyster calcification of infected bone flap: A rare complication

An extremely rare case of chronic epidural empyema after cranioplasty is presented. It derives its extreme rareness from its association with calcification. This patient when presented to our department had a complaint of swelling with on and off discharging sinus for 2 months adjacent to old incision scar mark. The patient had a history of decompressive craniectomy and evacuation of acute subdural hematoma, in some other institution, 8 years back. Following that, the patient underwent cranioplasty with the exteriorized and preserved bone flap. In the meantime, he was asymptomatic. It is a unique interesting case of chronic epidural empyema with calcified walls after 8 years of long duration following cranioplasty.

Frontal Sinus Breach During Routine Frontal Craniotomy Significantly Increases Risk of Surgical Site Infection: 10-Year Retrospective Analysis

BACKGROUND

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 outcome of 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 was much 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.

Development of a prediction rule for diagnosing postoperative meningitis: a cross-sectional study

OBJECTIVE

Diagnosing nosocomial meningitis (NM) in neurosurgical patients is difficult. The standard CSF test is not optimal and when it is obtained, CSF cultures are negative in as many as 70% of cases. The goal of this study was to develop a diagnostic prediction rule for postoperative meningitis using a combination of clinical, laboratory, and CSF variables, as well as risk factors (RFs) for CNS infection.

METHODS

A cross-sectional study was performed in 4 intensive care units in Medellín, Colombia. Patients with a history of neurosurgical procedures were selected at the onset of febrile symptoms and/or after an increase in acute-phase reactants. Their CSF was studied for suspicion of infection and a bivariate analysis was performed between the dependent variable (confirmed/probable NM) and the identified independent variables. Those variables with a p value ≤ 0.2 were fitted in a multiple logistic regression analysis with the same dependent variable. After determining the best model according to its discrimination and calibration, the β coefficient for each selected dichotomized variable obtained from the logistic regression model was used to construct the score for the prediction rule.

RESULTS

Among 320 patients recruited for the study, 154 had confirmed or probable NM. Using bivariate analysis, 15 variables had statistical associations with the outcome: aneurysmal subarachnoid hemorrhage (aSAH), traumatic brain injury, CSF leak, positioning of external ventricular drains (EVDs), daily CSF draining via EVDs, intraventricular hemorrhage, neurological deterioration, age ≥ 50 years, surgical duration ≥ 220 minutes, blood loss during surgery ≥ 200 ml, C-reactive protein (CRP) ≥ 6 mg/dl, CSF/serum glucose ratio ≤ 0.4 mmol/L, CSF lactate ≥ 4 mmol/L, CSF leukocytes ≥ 250 cells, and CSF polymorphonuclear (PMN) neutrophils ≥ 50%. The multivariate analysis fitted a final model with 6 variables for the prediction rule (aSAH diagnosis: 1 point; CRP ≥ 6 mg/dl: 1 point; CSF/serum glucose ratio ≤ 0.4 mmol/L: 1 point; CSF leak: 1.5 points; CSF PMN neutrophils ≥ 50%: 1.5 points; and CSF lactate ≥ 4 mmol/L: 4 points) with good calibration (Hosmer-Lemeshow goodness of fit = 0.71) and discrimination (area under the receiver operating characteristic curve = 0.94).

CONCLUSIONS

The prediction rule for diagnosing NM improves the diagnostic accuracy in neurosurgical patients with suspicion of infection. A score ≥ 6 points suggests a high probability of neuroinfection, for which antibiotic treatment should be considered. An independent validation of the rule in a different group of patients is warranted.

Risk Factors Associated with Meningitis after Neurosurgery: A Retrospective Cohort Study in a Chinese Hospital

BACKGROUND

Meningitis is a serious complication occurring after neurosurgical operations, which can result in severe morbidity and high mortality. This retrospective cohort study aimed to determine the risk factors of postoperative meningitis in a large clinical center of neurosurgery in China.

METHODS

Patients who underwent a neurosurgical procedure between January 2014 and December 2015 were selected, and 1016 cases were included our final analysis. On the basis of propensity scores, 84 patients with postoperative meningitis were successfully matched to 84 patients without postoperative meningitis.

RESULTS

After propensity score matching, age, hospitalization duration, intraoperative use of corticoids, intraoperative use of antibiotics, external ventricular drainage, lumbar drainage, enteral nutrition, duration of surgery, major craniotomy, and transsphenoidal surgery were associated with postoperative meningitis. Furthermore, preoperative use of corticoids, intraoperative use of corticoids, intraoperative use of antibiotics, external ventricular drainage, lumbar drainage, and major craniotomy were independent predictors of postoperative meningitis in propensity score-matched cohort. A prediction model including these 6 independent predictors was established. Finally, receiver operating characteristic curve and discriminant analysis confirmed that this model has strong predictive power for evaluating postoperative meningitis.

CONCLUSIONS

The prediction model built in our study can be an excellent tool for predicting meningitis after neurosurgical procedures.

Cutibacterium (formerly Propionibacterium) acnes infections associated with implantable devices

INTRODUCTION

Cutibacterium acnes (C. acnes), a Gram-positive biofilm-forming rod implicated in acne vulgaris, is increasingly recognized for its role in implant-associated infections. The diagnosis of C. acnes implant-associated infections remains challenging. The optimal treatment is a combination of both surgical intervention and antibiotic therapy. Areas covered: In this review, we discuss the different types of implant-associated infections caused by C. acnes. We also highlight the clinical manifestations pertaining to the various sites of infection, and identify several risk factors previously reported in the literature. We then cover the diagnostic laboratory markers, such as IL-6 and AD-1, optimizing C. acnes recovery in culture, and the specific molecular techniques. Finally, we examine the various effective antibiotic regimens and identify some preventive methods against C. acnes infections. Expert commentary: Biomarkers such as IL-6 and AD-1 should be further investigated for the diagnosis of C. acnes implant-associated infections. The use of 16S rRNA gene sequencing and other molecular techniques should be further explored in this setting. Longer incubation periods should be requested whenever C. acnes infection is suspected. If the clinical suspicion is high, sonication of the excised implant should be encouraged. Research should focus on developing effective anti-biofilm agents. Finally, preventive methods such as hair removal prior to surgery should be further explored.

The Association Between Operating Room Personnel and Turnover With Surgical Site Infection in More Than 12 000 Neurosurgical Cases

BACKGROUND

Surgical site infection (SSI) contributes significantly to postoperative morbidity and mortality and greatly increases the cost of care.

OBJECTIVE

To identify the impact of workflow and personnel-related risk factors contributing to the incidence of SSIs in a large sample of neurological surgeries.

METHODS

Data were obtained using an enterprisewide electronic health record system, operating room, and anesthesia records for neurological procedures conducted between January 1, 2009, and November 30, 2012. SSI data were obtained from prospective surveillance by infection preventionists using Centers for Disease Control and Prevention definitions. A multivariate model was constructed and refined using backward elimination logistic regression methods.

RESULTS

The analysis included 12 528 procedures. Most cases were elective (94.5%), and the average procedure length was 4.8 hours. The average number of people present in the operating room at any time during the procedure was 10.0. The overall infection rate was 2.3%. Patient body mass index (odds ratio, 1.03; 95% confidence interval [CI], 1.01-1.04) and sex (odds ratio, 1.36; 95% CI, 1.07-1.72) as well as procedure length (odds ratio, 1.19 per additional hour; 95% CI, 1.15-1.23) and nursing staff turnovers (odds ratio, 1.095 per additional turnover; 95% CI, 1.02-1.21) were significantly correlated with the risk of SSI.

CONCLUSION

This study found that patient body mass index and male sex were associated with an increased risk of SSI. Operating room personnel turnover, a modifiable, work flow-related factor, was an independent variable positively correlated with SSI. This study suggests that efforts to reduce operating room turnover may be effective in preventing SSI.

ABBREVIATIONS

OR, operating roomSSI, surgical site infection.

Risk factors of neurosurgical site infection after craniotomy: A systematic review and meta-analysis

BACKGROUND

Neurosurgical site infection (SSI) is a complication related to craniotomy, which may lead to severe morbidity and higher hospital costs during the postoperative period.

METHODS

Retrospective cohorts, case-control studies, or prospective investigations addressing risk factors of SSI updated until January 2017 were systematically searched in 2 databases (PubMed and Embase). The Newcastle-Ottawa Scale was used to evaluate quality of the included studies, heterogeneity was assessed by I² tests, and a funnel plot and Egger test were used for the evaluation of publication bias.

RESULTS

There were 26 studies in total enrolled in this review. The results showed that the risk factors which had relation with SSI were other infection (odds ratio [OR], 5.42; 95% confidence interval [CI], 2.8-10.49), number of operations (>1) (OR, 2.352; 95% CI, 1.142-4.847), cerebrospinal fluid (CSF) leak (OR, 7.817; 95% CI, 2.573-23.751), CSF drainage (OR, 2.55; 95% CI, 1.58-4.11), duration of operation (>4 hours) (as for retrospective cohort studies) (OR, 1.766; 95% CI, 1.110-2.809), venous sinus entry (OR, 4.015; 95% CI, 1.468-10.982), American Society of Anesthesiologists score (>2) (OR, 1.398; 95% CI, 1.098-1.78), sex (male) (as for prospective investigations) (OR, 1.474; 95% CI, 1.013-2.145), and surgical reasons (nontraumatic) (OR, 2.137; 95% CI, 1.106-4.129).

CONCLUSIONS

According to the current analysis, all the factors mentioned were the risk factors for SSI after craniotomy. Patients with these risk factors should be paid more attention to prevent SSI. More evidence provided by high-quality studies is still needed to further investigate the risk factors of SSI.

Risk factors for surgical site infections and assessment of vancomycin powder as a preventive measure in patients undergoing first-time cranioplasty

OBJECTIVE Craniectomy is often performed to decrease intracranial pressure following trauma and vascular injuries. The subsequent cranioplasty procedures may be complicated by surgical site infections (SSIs) due to prior trauma, foreign implants, and multiple surgeries through a common incision. Several studies have found that intrawound vancomycin powder (VP) is associated with decreased risk of SSIs after spine operations. However, no previously published study has evaluated the effectiveness of VP in cranioplasty procedures. The purpose of this study was to determine whether intrawound VP is associated with decreased risk of SSIs, to evaluate VP's safety, and to identify risk factors for SSIs after cranioplasty among patients undergoing first-time cranioplasty. METHODS The authors conducted a retrospective cohort study of adult patients undergoing first-time cranioplasty for indications other than infections from January 1, 2008, to July 31, 2014, at an academic health center. Data on demographics, possible risk factors for SSIs, and treatment with VP were collected from the patients' electronic health records. RESULTS During the study period, 258 patients underwent first-time cranioplasties, and 15 (5.8%) of these patients acquired SSIs. Ninety-two patients (35.7%) received intrawound VP (VP group) and 166 (64.3%) did not (no-VP group). Patients in the VP group and the no-VP group were similar with respect to age, sex, smoking history, body mass index, and SSI rates (VP group 6.5%, no-VP group 5.4%, p = 0.72). Patients in the VP group were less likely than those in the no-VP group to have undergone craniectomy for tumors and were more likely to have an American Society of Anesthesiologists physical status score > 2. Intrawound VP was not associated with other postoperative complications. Risk factors for SSI from the bivariable analyses were diabetes (odds ratio [OR] 3.65, 95% CI 1.07-12.44), multiple craniotomy procedures before the cranioplasty (OR 4.39, 95% CI 1.47-13.18), prior same-side craniotomy (OR 4.73, 95% CI 1.57-14.24), and prosthetic implants (OR 4.51, 95% CI 1.40-14.59). The multivariable analysis identified prior same-side craniotomy (OR 3.37, 95% CI 1.06-10.79) and prosthetic implants (OR 3.93, 95% CI 1.15-13.40) as significant risk factors for SSIs. After adjusting for potential confounders, patients with SSIs were more likely than those without SSIs to be readmitted (OR 7.28, 95% CI 2.07-25.60). CONCLUSIONS In this study, intrawound VP was not associated with a decreased risk of SSIs or with an increased risk of complications. Prior same-side craniotomy and prosthetic implants were risk factors for SSI after first-time cranioplasty.

Free-style Deepithelialized Propeller Flaps: An Ideal Local Flap to Obliterate Wounds with Dead Space

BACKGROUND

The reconstruction of the posterior trunk, especially with large dead spaces, remains challenging. Regional muscle flaps may lack adequate volume and reach. The purpose of this report was to evaluate the efficacy of deepithelialized free-style perforator-based propeller flaps to obliterate defects with large dead space.

METHODS

A total of 7 patients with defects on the posterior trunk with large dead spaces were evaluated. After complete debridement or resection, all flaps were designed on a single perforator adjacent to the defect, deepithelialized, and then rotated in a propeller fashion. Flaps were further modified in some cases such as folding the flap after deepithelialization to increase bulk and to obliterate the dead space.

RESULTS

The flap dimension ranged from 10 × 5 × 1 to 15 × 8 × 2.5 cm based on a single perforator. The rotation arch of the flap ranged from 90 to 180 degrees. Uneventful healing was noted in all cases. One case showed latent redness and swelling at 7 months after falling down, which resolved with medication. During the average follow-up of 28 months, there were no other flap and donor site complications.

CONCLUSION

The deepithelialized propeller flap can be used efficiently to obliterate dead spaces in the posterior trunk and retains advantages such as having a good vascular supply, adequate bulk, sufficient reach without tension, and minimal donor site morbidity.

Analysis on the risk factors of intracranial infection secondary to traumatic brain injury

OBJECTIVE

To discuss the characteristics and risk factors for intracranial infection post traumatic brain injury to prevent and better the clinical care.

METHODS

Retrospective study of 520 patients with traumatic brain injury were included, 308 male and 212 female. The risky factors of intracranial infection were identified.

RESULTS

Thirty two cases (6.54%, 32/520) of intracranial infection were diagnosed. Intracranial infection most likely happened 4-10 days after injury. Cerebrospinal fluid leakage, drainage, multiple craniotomies were significant related to intracranial infection. Logistic regression predicted cerebrospinal fluid leakage and drainage as independent factors.

CONCLUSION

Intracranial infection is a serious complication after traumatic brain injury. Patients with drainage or cerebrospinal fluid leakage are more risky for intracranial infection. Aggressive precaution should be taken to better outcome.

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.

Analysis of neurosurgical reoperations: use of a surgical checklist and reduction of infection-related and preventable complication-related reoperations

OBJECT

Use of the WHO surgical checklist has been proven to reduce surgical morbidity and mortality, but its effect on surgical complications requiring reoperation has not been previously studied. The aim of this study was to determine whether the use of the WHO surgical checklist would have an impact on the number and causes of neurosurgical complications leading to a reoperation.

METHODS

The authors retrospectively gathered information on all neurosurgical reoperations using hospital discharge data as well as the operations and procedures registry, and tracked all primary neurosurgical operations (n = 175) preceding a complication-related reoperation from 2007 to 2011. There were a total of 5418 neurosurgical operations during the study period. For further analysis of electronic patient records, the primary operations were divided into 2 groups based on the time of the WHO surgical checklist implementation in the authors' unit: 103 operations before and 72 after the introduction of the checklist. Observed adverse events and reoperations were categorized as preventable or unpreventable, and the actual use of the checklist during each operation was recorded.

RESULTS

The overall rate of preventable complication-related neurosurgical reoperations decreased from 3.3% (95% CI 2.7%–4.0%) to 2.0% (95% CI 1.5%–2.6%) after the checklist implementation. The reoperations were mainly due to wound infections, 46% before and 39% after the checklist. All infection-related reoperations proportioned to all neurosurgical operations (2.5% before vs 1.6% after checklist implementation) showed a significant reduction (p = 0.02) after the implementation of the checklist. In particular, there was a significant decrease (p = 0.006) in the rate of preventable infections associated with reoperations, i.e., 2.2% before versus 1.2% after checklist implementation. The overall adherence to checklist use (the “time out” phase) in neurosurgical operations was 78%, and adherence was 70% in primary operations preceding a complication-related reoperation regarded as preventable.

CONCLUSIONS

The implementation of the WHO surgical checklist in neurosurgery was associated with a decrease in complication-related reoperations, especially those due to preventable infection complications, the majority of which were wound infections. The adherence to checklist use in individual operations after the checklist implementation did not appear to have an impact on the results.

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.

Predictors of infections following cranioplasty: a retrospective review of a large single center study

Introduction. The variables that predispose to postcranioplasty infections are poorly described in the literature. We formulated a multivariate model that predicts the risk of infection in patients undergoing cranioplasty. Method. Retrospective review of all patients who underwent cranioplasty following craniectomy from January, 2000, to December, 2011. Tested predictors were age, sex, diabetic status, hypertensive status, reason for craniectomy, urgency status of craniectomy, location of cranioplasty, reoperation for hematoma, hydrocephalus postcranioplasty, and material type. A multivariate logistic regression analysis was performed. Results. Three hundred forty-eight patients met the study criteria. Infection rate was 26.43% (92/348). Of these cases with infection, 56.52% (52/92) were superficial (supragaleal), 43.48% (40/92) were deep (subgaleal), and 31.52% (29/92) were present in both the supragaleal and subgaleal spaces. The predominant pathogen was coagulase-negative staphylococcus (30.43%) followed by methicillin-resistant Staphylococcus aureus (22.83%) and methicillin-sensitive Staphylococcus aureus (15.22%). Approximately 15.22% of all cultures were polymicrobial. Multivariate analysis revealed convex craniectomy, hemorrhagic stroke, and hydrocephalus to be associated with an increased risk of infection (OR = 14.41; P < 0.05, OR = 4.33; P < 0.05, OR = 1.90; P = 0.054, resp.). Conclusion. Many of the risk factors for infection after cranioplasty are modifiable. Recognition and prevention of the risk factors would help decrease the infection's rate.

The incidence and risk factors of meningitis after major craniotomy in China: a retrospective cohort study

Background

Meningitis after neurosurgery can result in severe morbidity and high mortality. Incidence varies among regions and limited data are focused on meningitis after major craniotomy.

Aim

This retrospective cohort study aimed to determine the incidence, risk factors and microbiological spectrum of postcraniotomy meningitis in a large clinical center of Neurosurgery in China.

Methods

Patients who underwent neurosurgeries at the Department of Neurosurgery in Huashan Hospital, the largest neurosurgery center in Asia and the Pacific, between 1^stJanuary and 31^st December, 2008 were selected. Individuals with only shunts, burr holes, stereotactic surgery, transsphenoidal or spinal surgery were excluded. The complete medical records of each case were reviewed, and data on risk factors were extracted and evaluated for meningitis.

Results

A total of 65 meningitides were identified among 755 cases in the study, with an incidence of 8.60%. The risk of meningitis was increased by the presence of diabetes mellitus (odds ratio [OR], 6.27; P = 0.009), the use of external ventricular drainage (OR, 4.30; P = 0.003) and the use of lumbar drainage (OR, 17.23; P<0.001). The isolated microorganisms included Acinetobacter baumannii, Enterococcus sp, Streptococcus intermedius and Klebsiella pneumonia.

Conclusions

Meningitis remains an important source of morbidity and mortality after major craniotomy. Diabetic patients or those with cerebral spinal fluid shunts carry significant high risk of infection. Thus, identification of the risk factors as soon as possible will help physicians to improve patient care.

Management of fractures of the nasofrontal complex

Repair of fractures involving the nasofrontal region remains a mainstay of contemporary oral and maxillofacial surgery. This article discusses the epidemiology of these injuries, anatomy of the area, and management of these fractures with insight into potential complications. These include fractures of the frontal sinus, naso-orbital-ethmoidal region, root of the nose, and associated adjacent structures.

Case-control studies in neurosurgery

OBJECT

Observational studies, such as cohort and case-control studies, are valuable instruments in evidence-based medicine. Case-control studies, in particular, are becoming increasingly popular in the neurosurgical literature due to their low cost and relative ease of execution; however, no one has yet systematically assessed these types of studies for quality in methodology and reporting.

METHODS

The authors performed a literature search using PubMed/MEDLINE to identify all studies that explicitly identified themselves as "case-control" and were published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Each paper was evaluated for 22 descriptive variables and then categorized as having either met or missed the basic definition of a case-control study. All studies that evaluated risk factors for a well-defined outcome were considered true case-control studies. The authors sought to identify key features or phrases that were or were not predictive of a true case-control study. Those papers that satisfied the definition were further evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist.

RESULTS

The search detected 67 papers that met the inclusion criteria, of which 32 (48%) represented true case-control studies. The frequency of true case-control studies has not changed with time. Use of odds ratios (ORs) and logistic regression (LR) analysis were strong positive predictors of true case-control studies (for odds ratios, OR 15.33 and 95% CI 4.52-51.97; for logistic regression analysis, OR 8.77 and 95% CI 2.69-28.56). Conversely, negative predictors included focus on a procedure/intervention (OR 0.35, 95% CI 0.13-0.998) and use of the word "outcome" in the Results section (OR 0.23, 95% CI 0.082-0.65). After exclusion of nested case-control studies, the negative correlation between focus on a procedure/intervention and true case-control studies was strengthened (OR 0.053, 95% CI 0.0064-0.44). There was a trend toward a negative association between the use of survival analysis or Kaplan-Meier curves and true case-control studies (OR 0.13, 95% CI 0.015-1.12). True case-control studies were no more likely than their counterparts to use a potential study design "expert" (OR 1.50, 95% CI 0.57-3.95). The overall average STROBE score was 72% (range 50-86%). Examples of reporting deficiencies were reporting of bias (28%), missing data (55%), and funding (44%).

CONCLUSIONS

The results of this analysis show that the majority of studies in the neurosurgical literature that identify themselves as "case-control" studies are, in fact, labeled incorrectly. Positive and negative predictors were identified. The authors provide several recommendations that may reverse the incorrect and inappropriate use of the term "case-control" and improve the quality of design and reporting of true case-control studies in neurosurgery.

The incidence of complications in elective cranial neurosurgery associated with dural closure material

OBJECT

Dural closure with synthetic grafts has been suggested to contribute to the incidence of infection and CSF leak. The objective of this study was to assess the contribution of choice of dural closure material, as well as other factors, to the incidence of infection and CSF leak.

METHODS

A retrospective, consecutive cohort study of adult patients undergoing elective craniotomy was established between April 2010 and March 2011 at a single center. Exclusion criteria consisted of trauma, bur hole placement alone, and temporary CSF fluid diversion.

RESULTS

Three hundred ninety-nine patients were included (mean follow-up 396.6 days). Nonautologous (synthetic) dural substitute was more likely to be used (n = 106) in cases of reoperation (p = 0.001). Seventeen patients developed a surgical site infection and 12 patients developed a CSF leak. Multivariate logistic regression modeling identified estimated blood loss (OR 1.002, 95% CI 1.001-1.003; p < 0.001) and cigarette smoking (OR 2.198, 95% CI 1.109-4.238; p = 0.019) as significant predictors of infection. Synthetic dural graft was not a predictor of infection in multivariate analysis. Infratentorial surgery (OR 4.348, 95% CI 1.234-16.722; p = 0.024) and more than 8 days of postoperative corticosteroid treatment (OR 3.886, 95% CI 1.052-16.607; p = 0.048) were significant predictors for the development of CSF leak. Synthetic dural graft was associated with a lower likelihood of CSF leak (OR 0.072, 95% CI 0.003-0.552; p = 0.036).

CONCLUSIONS

The use of synthetic dural closure material is not associated with surgical site infection and is associated with a reduced incidence of CSF leak. Modifiable risk factors exist for craniotomy complications that warrant vigilance and further study.

Immediate titanium cranioplasty after debridement and craniectomy for postcraniotomy surgical site infection

BACKGROUND

For postcraniotomy surgical site infection (SSI) involving the bone, typical management involves craniectomy, debridement, and delayed cranioplasty. Disadvantages to delayed cranioplasty include cosmetic deformity, vulnerability of unprotected brain, and risks and costs associated with an additional operation. Many authors have attempted bone flap salvage by using various techniques.

OBJECTIVE

We evaluate our experience with immediate titanium mesh cranioplasty at the time of craniectomy and debridement.

METHODS

We retrospectively reviewed SSIs in patients that underwent craniotomy for treatment of a brain tumor. These patients were treated with craniectomy, debridement, and immediate titanium mesh cranioplasty followed by antibiotics. The primary outcome was recurrent infection.

RESULTS

Twelve patients met the inclusion criteria. Risk factors for infection included preoperative radiation therapy (33%), prior craniotomy (33%), and postoperative CSF leak (25%). Median follow-up was 14 months. Ten (83%) patients had long-term resolution without recurrent infection. One patient required additional surgical debridement for persistent infection with successful placement of new titanium mesh. Another patient developed recurrent infection but opted for hospice care because of tumor progression.

CONCLUSION

This series demonstrates the safety and feasibility of performing immediate titanium cranioplasty at the time of craniectomy and debridement in patients with postcraniotomy infections. This has been shown in patients with risk factors for poor wound healing. Immediate cranioplasty avoids the drawbacks, risks, and costs of delayed cranioplasty.

Surgical mortality at 30 days and complications leading to recraniotomy in 2630 consecutive craniotomies for intracranial tumors

BACKGROUND

In order to weigh the risks of surgery against the presumed advantages, it is important to have specific knowledge about complication rates.

OBJECTIVE

To study the surgical mortality and rate of reoperations for hematomas and infections after intracranial surgery for brain tumors in a large, contemporary, single-institution consecutive series.

METHODS

All adult patients from a well-defined population of 2.7 million inhabitants who underwent craniotomies for intracranial tumors at Oslo University Hospital from 2003 to 2008 were included (n = 2630). The patients were identified from our prospectively collected database and their charts studied retrospectively. Follow-up was 100%.

RESULTS

The overall surgical mortality, defined as death within 30 days of surgery, was 2.3% (n = 60). The mortality rates for high- and low-grade gliomas, meningiomas, and metastases were 2.9%, 1.0%, 0.9%, and 4.5%, respectively. Age >60 (odds ratio 1.84, P < 0.05) and biopsy compared with resection (odds ratio 4.67, P < 0.01) were significantly positively associated with increased surgical mortality. Hematomas accounted for 35% of the surgical mortality. Postoperative hematomas needing evacuation occurred in 2.1% (n = 54). Age >60 was significantly correlated to increased risk of postoperative hematomas (odds ratio 2.43, P < 0.001). A total of 39 patients (1.5%) were reoperated for postoperative infection. Meningiomas had an increased risk of infections compared with high-grade gliomas (odds ratio 4.61, P < 0.001).

CONCLUSION

The surgical mortality within 30 days of surgery was 2.3%, with age >60 and biopsy vs resection being the 2 factors significantly associated with increased mortality. Postoperative hematomas caused about one third of the surgical mortality.

Central nervous system infection in the pediatric population

Infection of the central nervous system is a life-threatening condition in the pediatric population. Almost all agents can cause infection within the central nervous system and the extent of infection ranges from diffuse involvement of the meninges, brain, or the spinal cord to localized involvement presenting as a space-occupying lesion. Modern imaging techniques define the anatomic region infected, the evolution of the disease, and help in better management of these patients. Acute bacterial meningitis remains a major cause of mortality and long-term neurological disability. Fortunately, the incidence of infection after clean craniotomy is < 5%, but it leads to significant morbidity as well as fiscal loss. The most significant causative factor in postcraniotomy infections is postoperative CSF leak. Cerebral abscess related to organic congenital heart disease is one of the leading causes of morbidity and mortality in the pediatric population. The administration of prophylactic antibiotics is indicated for contaminated and clean-contaminated wounds.

Reconstruction of scalp and cranium defect utilizing latissimus dorsi musculocutaneous and serratus anterior muscle free flaps with interpositional anastomosis of T-shaped flap artery: case report

The use of a combination musculocutaneous free flap, consisting of a latissimus dorsi flap and a serratus anterior flap, for reconstruction of a large scalp and cranium defect is described. The recipient artery, the superficial temporal artery (STA), was anastomosed to the flap artery, without sacrificing blood flow, by means of a special technique: forming the end of the flap artery into a T shape and interposing it between the two stumps of the transected STA, because the STA was crucial for tissue adjacent to the defect. The flap vein was anastomosed to the external jugular vein with a vein graft. The extensive defect was immediately closed with sutures, and there were no remarkable complications.

Surgical site infection associated with the use of bovine serum albumine-glutaraldehyde surgical adhesive (BioGlue) in cranial surgery: a case-control study

PURPOSE

To enhance the water tightness of dura mater closure in cranial surgery, an organic glue called BioGlue was used in our neurosurgical department between January 2006 and June 2007. During this period of time, we noticed an important increase in the surgical site infection (SSI) incidence. We conducted a case-control study to identify risk factors for these infections. Our objective was to test the hypothesis that BioGlue was one of the risk factors.

METHODS

Cases with infection were defined retrospectively. We included two controls per case. Study data were age, sex, time of year, in stay hospital preoperative time, length of surgery, type of surgery, surgeon, use of BioGlue, and use of duraplasty. We first performed a univariate analysis and then the significant variables were introduced in a logistic regression model.

RESULTS

Thirty patients were defined as cases (60 controls). In multivariate analysis, risk factors were young age (p = 0.04), extended operative length (p = 0.02) and the use of BioGlue (p = 0.007). The combined use of BioGlue and Neuropatch appeared to be a significant risk factor for SSI (p = 0.002).

CONCLUSIONS

BioGlue seems to increase the risk of SSI for patients who underwent craniotomy, especially when associated with synthetic dural graft. BioGlue triggers an intense inflammatory response, which causes wound breaches allowing bacteria to spread down in the wound, and then creates an ideal environment for bacterial growth.

Imaging of the post-operative cranium

Imaging plays an essential role in the evaluation of patients after cranial surgery. It is important to be familiar with the normal anatomy of the cranium; the indications for different surgical techniques such as burr holes, craniotomy, craniectomy, and cranioplasty; their normal postoperative appearances; and complications such as tension pneumocephalus, infection, abscess, empyema, hemorrhage, hematoma, herniation, hygroma, and trephine syndrome. Postoperative infection and hemorrhage are common to all neurosurgical procedures, where-as other complications are peculiar to certain procedures (eg, drill "plunging" during burr hole creation and sinking skin flap after craniec-tomy). Recognizing life-threatening complications such as tension pneumocephalus and paradoxical herniation, which require urgent intervention, is important for a better clinical outcome. Computed tomography is fast, cost effective, and easily accessible for first-line imaging. Magnetic resonance imaging has higher sensitivity for detecting postoperative infection and ischemia, but diffusion-weighted imaging may be less reliable for detecting postoperative infections.