Association between cerebrospinal fluid leak and meningitis after skull base surgery

Conventional clinical signs and symptoms are poor predictors of postoperative cerebrospinal fluid leak: A single-centre cohort perspective

BACKGROUND

Postoperative cerebrospinal fluid (CSF) leak remains a concerning complication of the endoscopic endonasal approach (EEA) for skull base pathology. Signs and symptoms suggesting CSF leak often trigger additional workup during the postoperative course. We systematically evaluate associations between subjectively reported clinical signs/symptoms noted during the immediate postoperative period and incidence of postoperative CSF leaks.

METHODS

Retrospective chart review was conducted at a tertiary academic medical centre including 137 consecutive patients with intraoperative CSF leak during EEA with primary repair between July 2018 and August 2022. Postoperative CSF leak associations with clinical signs and symptoms were evaluated using positive (PPV) and negative predictive values (NPV), sensitivity, specificity and odds ratio (OR) via univariate logistic regression.

RESULTS

Seventy-nine patients (57.7%) had high-flow leaks repaired and 5 (3.6%) developed CSF leaks postoperatively. Of reported symptoms, rhinorrhea was most common (n = 52, 38.0%; PPV [95% CI] = 7.6% [4.8%, 11.9%]), followed by severe headache (n = 47, 34.3%; 6.3% [3.1%, 12.5%]), dizziness (n = 43, 31.4%; 2.3% [0.4%, 12.1%]), salty or metallic taste (n = 20, 14.6%; 9.9% [3.3%, 25.8%]), and throat drainage (n = 10, 7.3%; 9.9% [1.7%, 41.4%]). Nausea or vomiting constituted the most reported sign concerning for CSF leak (n = 73, 53.3%; PPV [95% CI] = 4.1% [2.0%, 8.1%]). On univariate regression, no sign or symptom, including rhinorrhea (OR [95% CI] = 7.00 [0.76-64.44]), throat drainage (3.42 [0.35-33.86]), salty/metallic taste (4.22 [0.66-27.04]), severe headache (3.00 [0.48-18.62]), dizziness (0.54 [0.06-4.94]), fever (3.16 [0.50-19.99]), and nausea/vomiting (1.33 [0.22-8.21]), associated with postoperative CSF leak.

CONCLUSIONS

A range of subjectively reported symptoms and signs failed to predict postoperative CSF leak. Further investigation is warranted to inform appropriate attention and response.

Profiles of central nervous system surgical site infections in endoscopic transnasal surgery exposing the intradural space

OBJECTIVE

Despite its efficacy and minimal invasiveness, the clean-contaminated nature of endoscopic transnasal surgery (ETS) may be susceptible to central nervous system surgical site infections (CNS-SSIs), especially when involving intradural exposure. However, the profiles of ETS-associated CNS-SSIs are not fully elucidated.

METHODS

The institutional ETS cases performed between May 2017 and March 2023 were retrospectively analysed. The incidences of CNS-SSIs were calculated, and their risk factors examined.

RESULTS

The incidence of CNS-SSIs was 2.3% (7/305) in the entire cohort and 5.0% (7/140) in ETSs with intradural exposure. All the CNS-SSIs were meningitis and developed following ETS with intradural exposure. The incidences were 0%, 5.6% and 5.8% in ETSs with Esposito grade 1, 2 and 3 intraoperative cerebrospinal fluid leakage, respectively. Among the pre- and intra-operative factors, body mass index (unit odds ratio (OR), 0.62; 95% confidence interval (CI), 0.44-0.89; P<0.01), serum albumin (unit OR, 0.03; 95% CI, 0.0007-0.92; P=0.02), and American Society of Anesthesiologists physical status score (unit OR, 20.7; 95% CI, 1.65-259; P<0.01) were significantly associated with CNS-SSIs. Moreover, postoperative cerebrospinal fluid leakage was also significantly associated with CNS-SSIs (OR, 18.4; 95% CI, 3.55-95.0; P<0.01).

CONCLUSIONS

The incidence of ETS-associated CNS-SSIs is acceptably low. Intradural exposure was a prerequisite for CNS-SSIs. Malnutrition and poor comorbidity status should be recognized as important risks for CNS-SSIs in ETS.

Enhanced Dural Repair Using Biodegradable Sealants Based on Photocurable Hyaluronic Acid

Cerebrospinal fluid (CSF) leakage is a common complication of intradural surgery or incidental durotomy in neurosurgery. Dural suturing is a common method for durotomy repair, but this technique requires a long operation time and includes the risk of CSF leakage by incomplete sealing. Glue-type sealants are effective for watertight dural closure. However, unresolved shortcomings include insufficient sealing performance, poor biocompatibility, and excessive swelling. Here, a dural sealant using light-activated hyaluronic acid (HA) with multi-networks (HA photosealant) that provides fast sealing performance and high biocompatibility is reported. The HA photosealants form a watertight hydrogel barrier with multilength networks under low-energy visible light exposure (405 nm, <1 J cm-2) for 5 s and allow firm tissue adhesion on the wet dural surface. In a rabbit model of craniectomy and durotomy, HA photosealants exhibit the faster sealing performance of dural tears and enhance dural repair with accelerated bone formation compared to commercial surgical glues, with no degenerative changes, such as inflammation or necrosis, in histopathological evaluation. This biocompatible HA photosealant can be applied in a variety of clinical settings that require fast wound closure as a promising potential.

Analysis of 3 Surgical Approaches for the Treatment of Cerebrospinal Fluid Otorrhea: A Case Series Report

Background: This case series report aimed to present three surgical approaches used for the treatment of cerebrospinal fluid (CSF) otorrhea, providing less invasive surgical options for managing this condition. Methods: Clinical data of 26 patients with CSF otorrhea, who underwent treatment using three surgical methods between June 2012 and June 2022, were retrospectively analyzed. The study collected information on patients' basic demographic characteristics, chief complaints, location of the defect, results of otorrhea endoscopic examination, findings from skull base thin-slice computed tomography (CT) examination, and causes of CSF otorrhea. Postoperative outcomes of CSF otorrhea were followed up. Results: Among the 26 cases of CSF otorrhea, there were 13 (50%) males and 13 (50%) females who underwent treatment using the three surgical methods. The etiology of CSF otorrhea included 10 (38%) cases of spontaneous CSF otorrhea, including 2 (8%) cases of congenital inner ear deformity and 8 (31%) cases without obvious inducement. Additionally, there were 5 (19%) cases of trauma, 6 (23%) cases of cholesteatoma complications, 3 (12%) cases of postoperative complications of brain tumor, 1 (4%) case of radiotherapy, and 1 (4%) case of a malignant tumor. A total of 12 (46%) cases of CSF otorrhea were treated by local repair of the defect. Furthermore, 3 (12%) cases underwent local repair of the defect combined with sealing of the tympanic sinus entrance, while 11 (42%) cases underwent local repair of the defect combined with sealing of the eustachian tube and the external auditory canal. No recurrence of CSF otorrhea was observed during the 6-month to 10-year follow-up period after surgery. Conclusion: The three methods for CSF otorrhea, including local defect repair, local defect repair combined with sealing of the tympanic sinus entrance, and sealing of the eustachian tube and the external auditory canal, demonstrated successful outcomes in appropriately selected patients.

An In Vitro Study of Chitosan-Coated Bovine Pericardium as a Dural Substitute Candidate

Defects in the dura matter can be caused by head injury, and many cases require neurosurgeons to use artificial dura matter. Bovine pericardium is an option due to its abundant availability, adjustable size and characteristics, and because it has more collagen than porcine or equine pericardia. Nevertheless, the drawback of bovine pericardium is that it has a higher inflammatory effect than other synthetic dura matters. Chitosan has been shown to have a strong anti-inflammatory effect and has good tensile strength; thus, the idea was formulated to use chitosan as a coating for bovine pericardium. This study used decellularized bovine pericardial membranes with 0.5% sodium dodecyl sulphate and coatings containing chitosan at concentrations of 0.25%, 0.5%, 0.75%, and 1%. An FTIR test showed the presence of a C=N functional group as a bovine pericardium-chitosan bond. Morphological tests of the 0.25% and 0.5% chitosan concentrations showed standard pore sizes. The highest tensile strength percentage was shown by the membrane with a chitosan concentration of 1%. The highest degradation rate of the membrane was observed on the 7th and 14th days for 0.75% and 1% concentrations, and the lowest swelling ratio was observed for the 0.25% concentration. The highest level of cell viability was found for 0.75% chitosan. The bovine pericardium membrane with a 0.75% concentration chitosan coating was considered the optimal sample for use as artificial dura matter.

Closure of small skull base defects with muscle plug napkin ring technique: how I do it

BACKGROUND

Defects through the skull base into the paranasal sinuses can occur during anterior skull base procedures, risking cerebrospinal fluid leak and infection if not repaired.

METHODS

We describe a muscle plug napkin ring technique for closure of small skull base defects, wherein a free muscle graft slightly bigger than the defect is packed tightly in the defect, half extracranially and half intracranially and sealed with fibrin glue. The technique is illustrated in the case of a 58-year-old woman with a large left medial sphenoid wing/clinoidal meningioma.

CONCLUSIONS

The muscle plug napkin ring technique is a simple solution to small skull base defects.

Risk Factors and Management of Incisional Cerebrospinal Fluid Leakage After Craniotomy: A Retrospective International Multicenter Study

BACKGROUND

Incisional cerebrospinal fluid (iCSF) leakage is a serious complication after intradural cranial surgery.

OBJECTIVE

To determine the incidence and risk factors of iCSF leakage after craniotomy. Secondarily, the complications after iCSF leakage and the success rate of iCSF leakage treatment was studied.

METHODS

All patients who underwent an intradural cranial surgery from 2017 to 2018 at 5 neurosurgical centers were retrospectively included. Data were retrieved from medical records with 2 months of follow-up. First, univariate regression analyses were performed. Subsequently, identified risk factors were evaluated in a multivariate regression analysis.

RESULTS

In total 2310 consecutive patients were included. Total iCSF leakage rate was 7.1% (n = 165). Younger age, male, higher body mass index, smoking, infratentorial surgery, and use of a dural substitute were associated with increased iCSF leakage risk, and use of a sealant reduced that risk. The odds for developing a wound infection and/or meningitis were 15 times higher in patients with iCSF leakage compared with patients without leakage. Initial conservative iCSF leakage treatment failed in 48% of patients. In 80% of cases, external cerebrospinal fluid drainage ceased the iCSF leakage. A total of 32% of patients with iCSF leakage required wound revision surgery.

CONCLUSION

iCSF leakage risk increases by younger age, higher body mass index, smoking, infratentorial craniotomy, and dural substitute use, whereas sealant use reduced the risk for iCSF leakage. The leak increases the risk of postoperative infections. When iCSF leakage occurs, immediate external cerebrospinal fluid drainage or wound revision should be considered.

Quality indicators and early adverse in surgery for atypical meningiomas: A 16-year single centre study and systematic review of the literature

Introduction

Atypical meningiomas represent approximately 20% of all intracranial meningiomas and are characterized by distinct histopathological criteria and an increased risk of postoperative recurrence. Recently, quality indicators have been introduced to monitor quality of the delivered care.

Research question

Which quality indicators/outcome measures are being applied in patients being operated for atypical meningiomas? What are risk factors associated with poor outcome? How is the surgical outcome and which quality indicators are reported in the literature?

Material and methods

The primary outcomes of interest were 30-days readmission-, 30-day reoperation-, 30-day mortality-, 30-day nosocomial infection- and the 30-day surgical site infection (SSI) rate, CSF-leakage, new neurological deficit, medical complications, and lengths of stay. The secondary aim was the identification of prognostic factors for the mentioned primary outcomes. A systematic review of the literature was performed screening studies for the mentioned outcomes.

Results

We included 52 patients. 30-days outcomes in terms of unplanned reoperation were 0%, unplanned readmission 7.7%, mortality 0%, nosocomial infection 17.3%, and SSI 0%. Any adverse event occurred in 30.8%. Preoperative C-reactive protein over 5 ​mg/l was independent factor for the occurrence of any postoperative adverse event (OR: 17.2, p ​= ​0.003). A total of 22 studies were included into the review.

Discussion and conclusion

The 30-days outcomes at our department were comparable with reported outcomes in the literature. Currently applied quality indicators are helpful in determining the postoperative outcome but mainly report the indirect outcome after surgery and are influenced of patient, tumor and treatment related factors. Risk adjustment is vital.

Discontinuation of Postoperative Prophylactic Antibiotics for Endoscopic Endonasal Skull Base Surgery

Background  Postoperative prophylactic antibiotic usage for endoscopic skull base surgery varies based on the institution as evidence-based guidelines are lacking. The purpose of this study is to determine whether discontinuing postoperative prophylactic antibiotics in endoscopic endonasal cases led to a difference in central nervous system (CNS) infections, multi-drug resistant organism (MDRO) infections, or other postoperative infections. Methods  This quality improvement study compared outcomes between a retrospective cohort (from September 2013 to March 2019) and a prospective cohort (April 2019 to June 2019) after adopting a protocol to discontinue prophylactic postoperative antibiotics in patients who underwent endoscopic endonasal approaches (EEAs). Our primary end points of the study included the presence of postoperative CNS infection, Clostridium difficile ( C. diff ), and MDRO infections. Results  A total of 388 patients were analyzed, 313 in the pre-protocol group and 75 in the post-protocol group. There were similar rates of intraoperative cerebrospinal fluid leak (56.9 vs. 61.3%, p  = 0.946). There was a statistically significant decrease in the proportion of patients receiving IV antibiotics during their postoperative course ( p  = 0.001) and those discharged on antibiotics ( p  = 0.001). There was no significant increase in the rate of CNS infections in the post-protocol group despite the discontinuation of postoperative antibiotics (3.5 vs. 2.7%, p  = 0.714). There was no statistically significant difference in postoperative C. diff (0 vs. 0%, p  = 0.488) or development of MDRO infections (0.3 vs 0%, p  = 0.624). Conclusion  Discontinuation of postoperative antibiotics after EEA at our institution did not change the frequency of CNS infections. It appears that discontinuation of antibiotics after EEA is safe.

Endonasal skull base repair with a vascularised pedicled temporo-parietal myo-fascial flap

Objective

Expanded endonasal approaches (EEAs) to the skull base have increased the scope and extent of pathologies that can be treated endoscopically. The trade-off is creation of large skull base bone defects requiring reconstruction to re-establish barriers between the sino-nasal mucosa and subarachnoid space to prevent CSF leak and infection. A popular reconstructive technique is the local vascularized pedicled naso-septal flap, an option that may not always be possible when there is disruption of the vascular pedicle from multiple previous surgeries, adjuvant radiotherapy or extensive tumor infiltration. An alternative is the regional temporo-parietal fascial flap (TPFF) transposed via the trans-pterygoid route. We implemented a modification of this technique incorporating contralateral temporalis muscle at the tip of this flap and deeper vascularised pericranial layers within the pedicle to provide a more robust flap in selected cases.

Study design/methods

A retrospective review of two cases is presented with both patients having undergone multiple EEAs to resect skull base tumors with adjuvant radiotherapy, their postoperative courses complicated by recalcitrant CSF leaks resistant to multiple surgeries.

Results

Our patients had their persistent CSF fistulae repaired using infra-temporal transposition of the TPFF modified to include some of the contralateral temporalis muscle with optimisation of a vascular pedicle: a temporo-parietal temporalis myo-fascial flap (TPTMFF). Both CSF leaks resolved without further complication.

Conclusion

In situations where local flap repair to reconstruct skull-base defects following EEA may not be viable or has failed, a modified regional flap incorporating temporo-parietal fascia with a preserved vascular pedicle along with attached temporalis muscle plug may provide a robust alternative option.

Trends in CSF Leakage Associated with Duraplasty in Infratentorial Procedures over the Last 20 Years: A Systematic Review

Cerebrospinal fluid (CSF) leakage is a common postoperative complication of neurosurgical procedures, with iatrogenic causes accounting for 16% of CSF leakages. This complication increases healthcare costs and patient morbidity. The focus of this review is to analyze the rates of CSF leakage of some of the most commonly used xenogeneic and synthetic dural substitutes following surgeries in the infratentorial region of the brain where surgical repair can be most challenging. A systematic literature search was conducted using studies detailing duraplasty procedures performed with nonautologous grafts in the infratentorial region in PubMed. Studies were identified using the following search terms: "posterior fossa" or "infratentorial" were used in combination with "CSF leak," "CSF leakage," "cerebrospinal fluid leakage," "duraplasty" or "dura graft." The outcome of interest was a measure of the prevalence of CSF leakage rates following posterior fossa neurosurgery. Studies that contributed data to this review were published between 2006 and 2021. The dural graft materials utilized included: bovine collagen, acellular dermis, equine collagen, bovine pericardium, collagen matrix, and expanded polytetrafluoroethylene (ePTFE). The number of subjects in studies on each of these grafts ranged from 6 to 225. CSF leak rates ranged from 0% to 25% with the predominance of studies reporting between 3% and 15%. The studies that utilize bovine collagen, equine collagen, and acellular dermis reported higher CSF leakage rates; whereas studies that utilized ePTFE, bovine pericardium, and collagen matrix reported lower CSF leakage rates. Due to the heterogeneity of methodologies used across these studies, it is difficult to draw a direct correlation between the dural patch products used and CSF leaks. Larger prospective controlled studies that evaluate various products in a head-to-head fashion, using the same methods and animal models, are needed to conclude the relative efficacy of these dural patch products.

Collagen-bound fibrin sealant (TachoSil®) for dural closure in cranial surgery: single-centre comparative cohort study and systematic review of the literature

Cerebrospinal fluid (CSF) leakage is a well-known complication of craniotomies and there are several dural closure techniques. One commonly used commercial product as adjunct for dural closure is the collagen-bound fibrin sealant TachoSil®. We analysed whether the addition of TachoSil has beneficial effects on postoperative complications and outcomes. Our prospective, institutional database was retrospectively queried, and 662 patients undergoing craniotomy were included. Three hundred fifty-two were treated with dural suture alone, and in 310, TachoSil was added after primary suture. Our primary endpoint was the rate of postoperative complications associated with CSF leakage. Secondary endpoints included functional, disability and neurological outcome. Systematic review according to PRISMA guidelines was performed to identify studies comparing primary dural closure with and without additional sealants. Postoperative complications associated with CSF leakage occurred in 24 (7.74%) and 28 (7.95%) procedures with or without TachoSil, respectively (p = 0.960). Multivariate analysis confirmed no significant differences in complication rate between the two groups (aOR 0.97, 95% CI 0.53–1.80, p = 0.930). There were no significant disparities in postoperative functional, disability or neurological scores. The systematic review identified 661 and included 8 studies in the qualitative synthesis. None showed a significant superiority of additional sealants over standard technique regarding complications, rates of revision surgery or outcome. According to our findings, we summarize that routinary use of TachoSil and similar products as adjuncts to primary dural sutures after intracranial surgical procedures is safe but without clear advantage in complication avoidance or outcome. Future studies should investigate whether their use is beneficial in high-risk settings.

Comparing Rates of Postoperative Meningitis After Endoscopic Endonasal Procedures Based on Methicillin-Resistant Staphylococcus aureus/Methicillin-Sensitive Staphylococcus aureus Colonization and Antibiotic Prophylaxis

BACKGROUND

Endoscopic endonasal approach (EEA) procedures are inherently contaminated due to direct access through the nasopharyngeal mucosa. The reported rate of postoperative meningitis in EEA procedures is 0.7%-3%. A variety of methods exist to minimize the risk of meningitis with antibiotic prophylaxis, although their value is not completely understood. This study investigated whether there is a difference in rates of postoperative meningitis based on Staphylococcus aureus colonization and use of preoperative antibiotic prophylaxis.

METHODS

All adult patients who underwent EEA resection at our institution from 2013 to 2021 were retrospectively reviewed. Patients with preoperative cerebrospinal fluid infections were excluded. Data including recent preoperative infections, preoperative colonization status, antibiotic administration, and postoperative outcomes were recorded for each patient.

RESULTS

Of 483 patients identified (mean age, 51 years; range, 18-90 years; 274 [56.7%] female), 80 (16.6%) had a positive preoperative methicillin-resistant Staphylococcus aureus (MRSA)/methicillin-sensitive Staphylococcus aureus (MSSA) screening swab. Twenty-one (26.3%) colonized patients were treated with preoperative decolonizing antibiotics. Within 30 days of surgery, 13 (2.7%) patients developed culture-positive meningitis. There was no significant difference in meningitis rates based on MRSA/MSSA colonization status. Among colonized patients, there was no significant difference in rates of MRSA/MSSA meningitis based on preoperative antibiotic decolonization.

CONCLUSIONS

Postoperative rates of meningitis after EEA surgery were not significantly changed based on MRSA/MSSA colonization status of the patient or preoperative decolonization. The utility of preoperative testing of MRSA/MSSA status and antibiotics for decolonization to prevent postoperative meningitis should be further investigated.

Risk Factors in a Pediatric Population for Postoperative Intracranial Infection Following Endoscopic Endonasal Skull Base Surgery and the Role of Antibiotic Prophylaxis

BACKGROUND

Endoscopic endonasal skull base surgery (EESBS) is performed through a non-sterile corridor. Intracranial infection rates in a pediatric population have not been extensively studied and the exact effect of antibiotic prophylaxis on rates of infection after EESBS in pediatric patients remains unclear.

OBJECTIVE

The purpose of our study is to investigate risk factors for postoperative intracranial infection during EESBS in a pediatric population and help elucidate the role of antibiotic prophylaxis.

METHODS

We conducted a retrospective chart review of 99 consecutive patients under the age of 18 who underwent EESBS at our institution from 2013 to 2021. Centers for Disease Control and Prevention/National Healthcare Safety Network criteria for diagnosis of meningitis were used to identify postoperative intracranial infections.

RESULTS

The average age was 12.3 years (range 1.6-18) with 66 male patients and 33 female patients. 49 patients had an intraoperative cerebrospinal fluid (CSF) leak, of which 4 had a postoperative CSF leak. We identified 3 postoperative intracranial infections (3%), which were all meningitis cases. The infection rate was 6% (3/49) among those with intraoperative CSF leaks. All patients with meningitis had a postoperative CSF leak. All infections were transclival approaches (2 chordoma and 1 neurenteric cyst).

CONCLUSION

This investigation represents one of the largest pediatric endoscopic skull base surgery cohorts. EESBS is safe to perform in pediatric populations, but transclival approaches and postoperative CSF leaks are risk factors for postoperative meningitis.

Reconstructive Outcomes of Multilayered Closure of Large Skull Base Dural Defects Following Open Anterior Craniofacial Resection

Introduction Standardized reconstruction protocols for large open anterior skull base defects with dural resection are not well described. Here we report the outcomes and technique of a multilayered reconstructive algorithm utilizing local tissue, dural graft matrix, and microvascular free tissue transfer (MVFTT) for reconstruction of these deformities.

Design This study is a retrospective review.

Results Eleven patients (82% males) met inclusion criteria, with five (45%) having concurrent orbital exenteration and eight (73%) requiring maxillectomy. All patients required dural resection with or without intracranial tumor resection, with the average dural defect being 36.0 ± 25.9 cm2. Dural graft matrices and pericranial flaps were used for primary reconstruction of the dural defects, which were then reinforced with free fascia or muscle overlay by means of MVFTT. Eight (73%) patients underwent anterolateral thigh MVFTT, with the radial forearm, fibula, and vastus lateralis comprising the remainder. Average total surgical time of tumor resection and reconstruction was 14.9 ± 3.8 hours, with median length of hospitalization being 10 days (IQR: 9.5, 14). Continuous cerebrospinal fluid drainage through a lumber drain was utilized in 10 (91%) patients perioperatively, with an average length of indwelling drain of 5 days. Postoperative complications occurred in two (18%) patients who developed asymptomatic pneumocephalus that resolved with high-flow oxygen therapy.

Conclusion A standardized multilayered closure technique of dural graft matrix, pericranial flap, and MVFTT overlay in the reconstruction of large open anterior craniofacial dural defects can assist the reconstructive team in approaching these complex deformities and may help prevent postoperative complications.

Postoperative Early Lumbar Drainage Can Reduce the Duration of Fever or Infection in Patients with Complicated Intracranial Tumors after a Long Operation Time

Background

Intracranial fever or infection is one of the common complications after craniotomy, especially for complicated intracranial tumors such as deep skull base tumors.

Objective

We used early cerebrospinal fluid (CSF) drainage with a preplaced lumbar drainage (LD) tube after surgery and observed whether this procedure could reduce the rate and duration of fever or infection.

Material and Methods

The authors conducted a retrospective study of 142 patients who underwent complicated intracranial tumor surgery with no less than four hours of dural opening at the Center of Neurosurgery of Tangdu Hospital. The LD group underwent preoperative LD placement, intraoperative CSF release and postoperative continuous drainage, but the control group received routine craniotomy without preoperative LD. The primary outcomes included the rate, duration, and hospital length of stay (LOS) for patients with fever or infection after surgery, as compared between the two groups. The second outcome included complications related to LD and the rate of postoperative CSF leakage.

Results

There were 22 patients in the LD group and 23 patients in the control group who presented with delayed fever, which was supposed to be caused by intracranial infection or aseptic inflammation. The median duration of delayed fever in the LD group was obviously lower than that in the control group (7.762 ± 3.129 days vs 11.73 ± 5.239 days), and there was a statistically significant difference (P = 0.0046). In addition, there was a significant reduction in the median postoperative LOS (12 [8,10,15,21] days in the LD group vs 15 [9,13,20,28] days in the controls). Moreover, there was no significant difference in complications related to LD between the two groups. Three patients with brain herniation were observed in the LD group compared with one patient in the control group. All four patients had contemporary mild-to-moderate neurologic disorders after surgery or conservative treatment. Additionally, the rate of CSF leakage in the LD group was 5.41% (4/74), which was lower than that in the control group (8/68, [11.76%]), although there was no significant difference (P = 0.174).

Conclusions

For patients receiving complicated intracranial lesions following a long operation time, postoperative early LD was beneficial for the treatment of patients with fever or infection. It not only reduced the duration of infection or fever in postoperative patients but also decreased the postoperative LOS. We should minimize the complications related to LD by careful and standardized LD and management processes, and ensure the effectiveness and safety of this treatment.

Antibiotic Use in Lateral Skull Base Surgery: A Survey of the North American Skull Base Society

Objectives  Antibiotic use in lateral skull base surgery (LSBS) has not been thoroughly investigated in the literature. There is wide variability in antibiotic use and insufficient data to guide management. This study aims to describe the factors and patterns influencing antibiotic use in LSBS among the membership of the North American Skull Base Society (NASBS). Design  An online-based survey was designed and distributed to the membership of the NASBS. Data was analyzed using bivariate analysis and logistic regression modeling. Setting  Online-based questionnaire. Participants  NASBS membership. Main Outcome Measures  Use of intraoperative antibiotics and use of postoperative antibiotics. Results  The survey response rate was 26% (208 respondents). Of the 208 total respondents, 143 (69%) respondents performed LSBS. Most respondents are neurosurgeons (69%) with the remaining being otolaryngologists (31%). The majority of respondents (79%) are fellowship-trained in skull base surgery. Academic or government physicians make up 69% of respondents and 31% are in private practice with or without academic affiliations. Bivariate analysis showed that practice setting significantly influenced intraoperative antibiotic use ( p  = 0.01). Geographic location significantly affected postoperative antibiotic use ( p  = 0.01). Postoperative antibiotic duration was significantly affected by presence of chronic otitis media, cerebrospinal fluid leak, and surgeon training ( p  = 0.02, p  = 0.01, and p  = 0.006, respectively). Logistic regression modeling showed that the motivation to reduce infection significantly impacted postoperative antibiotic use ( p  = 0.03). Conclusion  This study demonstrates significant variations in intraoperative and postoperative antibiotic use in LSBS among the NASBS membership. Appropriate guidelines for optimal perioperative antibiotic use patterns should be determined with randomized studies in the future.

Diagnostic Value of Non-Contrast CT in Cerebrospinal Fluid Leakage After Endoscopic Transnasal Surgery for Sellar and Suprasellar Tumors

We aimed to study the relationship between pneumocephalus on non-contrast CT (NCCT) and post-operative cerebrospinal fluid leakage (p-CFL) after endoscopic transsphenoidal sellar and suprasellar tumor surgeries. Data from patients who underwent endoscopic treatment for sellar or suprasellar tumors from January 2018 to March 2020 were consecutively collected and reviewed. The NCCT pneumocephalus (NP) was measured the first day after operation and the first day after the expansive sponge was extracted. p-CFL was determined according to post-operative clinical symptoms, high resolution CT and glucose test, and expert consensus. Of the 253 patients enrolled in this study, 32 (12.6%) had p-CFL. Compared with patients without p-CFL, patients with p-CFL had a higher occurrence of intra-operative CFL, a longer operation time, a higher rate of pneumocephalus on first-day NCCT after operation (i.e., first-day NP), and a higher rate of NP volume change between two NCCT measurements (referred to as the NP change) (all p < 0.05). In multivariate regression analysis, first-day NP was independently associated with p-CFL occurrence [odds ratio (OR)=6.395, 95% confidence interval (CI)=2.236-18.290, p=0.001). After adding the NP change into the regression model, first-day NP was no longer independently associated with p-CFL, and NP change (OR = 19.457, 95% CI = 6.095–62.107, p<0.001) was independently associated with p-CFL. The receiver operating characteristic curve comparison analysis showed that NP change had a significantly better predicting value than first-day NP (area under the curve: 0.988 vs. 0.642, Z=6.451, p=0.001). NP is an effective imaging marker for predicting p-CFL after endoscopic sellar and suprasellar tumors operation, and the NP change has a better predicting value.

The incidence of postoperative cerebrospinal fluid leakage after elective cranial surgery: a systematic review

Cerebrospinal fluid (CSF) leakage is a major complication after elective neurosurgical procedures. The aim of this systematic literature review is to summarize the incidence rates of postoperative cerebrospinal fluid leakage for neurosurgical procedures, classified by surgical approach. The Pubmed, Cochrane, Embase, and Web of Science databases were searched for studies reporting the outcome of patients undergoing elective neurosurgical procedures. The number of patients, surgical approach, and indication for surgery were recorded for each study. Outcomes related to CSF leakage such as clinical manifestation and treatment were reported as well. One hundred and thirteen studies were included, reporting 94,695 cases. Overall, CSF leaks were present in 3.8% of cases. Skull base surgery had the highest rate of CSF leakage with 6.2%. CSF leakage occurred in 5.9% of anterior skull base procedures, 6.4% of middle fossa, and 5.2% of transpetrosal surgeries. 5.8% of reported infratentorial procedures were complicated by CSF leakage versus 2.9% of supratentorial surgeries. CSF leakage remains a common serious adverse event after cranial surgery. There exists a need for standardized procedures to reduce the incidence of postoperative CSF leakage, as this serious adverse event may lead to increased health care costs.

Ex vivo evaluation of a multilayered sealant patch for watertight dural closure: cranial and spinal models

Cerebrospinal fluid leakage is a frequent complication after cranial and spinal surgery. To prevent this complication and seal the dura watertight, we developed Liqoseal, a dural sealant patch comprising a watertight polyesterurethane layer and an adhesive layer consisting of poly(DL-lactide-co-ε-caprolactone) copolymer and multiarmed N-hydroxylsuccinimide functionalized polyethylene glycol. We compared acute burst pressure and resistance to physiological conditions for 72 h of Liqoseal, Adherus, Duraseal, Tachosil, and Tisseel using computer-assisted models and fresh porcine dura. The mean acute burst pressure of Liqoseal in the cranial model (145 ± 39 mmHg) was higher than that of Adherus (87 ± 47 mmHg), Duraseal (51 ± 42 mmHg) and Tachosil (71 ± 16 mmHg). Under physiological conditions, cranial model resistance test results showed that 2 of 3 Liqoseal sealants maintained dural attachment during 72 hours as opposed to 3 of 3 for Adherus and Duraseal and 0 of 3 for Tachosil. The mean burst pressure of Liqoseal in the spinal model (233 ± 81 mmHg) was higher than that of Tachosil (123 ± 63 mmHg) and Tisseel (23 ± 16 mmHg). Under physiological conditions, spinal model resistance test results showed that 2 of 3 Liqoseal sealants maintained dural attachment for 72 hours as opposed to 3 of 3 for Adherus and 0 of 3 for Duraseal and Tachosil. This novel study showed that Liqoseal is capable of achieving a strong watertight seal over a dural defect in ex vivo models.

Bacterial Flora in the Sphenoid Sinus Changes with Perioperative Prophylactic Antibiotic Administration

The complications of endonasal transsphenoidal surgery (ETSS) include meningitis and sinusitis, and these complications are troublesome. Some reports have investigated the type of bacteria and the susceptibility of sphenoid sinus mucosal flora to drugs. However, most specimens can be collected after perioperative antibiotic administration. In this study, 95 and 103 sphenoid sinus mucosal samples collected during ETSS from September 2013 to February 2015 and from June 2017 to January 2019, respectively, were examined for bacterial culture. Sphenoid sinus mucosal samples were collected after antibiotic administration in the first period, whereas samples were collected before antibiotic administration in the second period. Hence, the specimens in the second period were not affected by antibiotics. Moreover, drug susceptibility tests for the detected bacteria were performed. Overall, 52 and 51 bacterial isolates were collected during both periods. Gram-positive cocci (GPCs), including Staphylococcus aureus and Staphylococcus epidermidis, were more common in the non-antibiotic group than in the antibiotic group (p <0.01). However, the proportion of gram-negative rods (GNRs) did not significantly differ between the two groups (p = 0.54). The antibiotic group had a significantly higher proportion of bacteria resistant to ampicillin (p <0.01) and first-generation cephalosporin (p = 0.01) than the non-antibiotic group. In conclusion, there was a difference in bacterial flora in the sphenoid sinus mucosal samples collected before and after intraoperative antibiotic administration.

Spontaneous cerebrospinal fluid leaks of the temporal bone - clinical features and management outcomes

OBJECTIVE

METHODS: A retrospective cohort study over seven-years from 2013 to 2020 was conducted at five tertiary referral centres. Patients identified with biochemically confirmed spontaneous cerebrospinal fluid leaks of the temporal bone manifesting as middle ear fluid with no other obvious cause were included. Demographics (age, gender, body-mass-index), symptomatology, past medical history, examination, investigation (biochemical and radiological), management and outcomes were recorded.

RESULTS

90 adult patients with spontaneous cerebrospinal fluid otorrhoea were identified. Right sided leaks were most common (58%), and a majority of the cohort overweight (mean body-mass-index = 29.2 kg/m²). Unilateral hearing loss was the commonest presenting symptom (81%). Two patients presented to hospital with meningitis presumed secondary to spontaneous cerebrospinal fluid otorrhoea. Over half (54%) of patients were observed who tended to be older (mean age of 71 years vs 62 years) whilst the remainder underwent surgical repair with middle-fossa craniotomy the most common approach (87%). Eight patients managed surgically had recurrent leaks (21%).

CONCLUSIONS

This is one of the largest cohorts of spontaneous cerebrospinal fluid otorrhoea reported in the literature and reiterates the importance for clinicians to have a high index of suspicion for this condition in patients presenting with a unilateral middle ear effusion, especially in those who are overweight. Surgical intervention carries a risk of recurrence and further studies are needed to determine the risk of intra-cranial infection in order to guide management.

Endoscopic Anterior Skull Base Reconstruction: A Meta-Analysis and Systematic Review of Graft Type

OBJECTIVE

The influence of graft type (nonautologous vs. autologous) on surgical outcomes in endoscopic anterior skull base (EASB) reconstruction is not well understood. This review systematically evaluated rates of postoperative complications of EASB repairs that utilized autologous or nonautologous grafts.

METHODS

Original studies reporting EASB reconstruction outcomes were extracted from PubMed, Ovid, and the Cochrane Library from database inception to 2019. Risk ratios, risk differences, χ² tests, and multivariate logistic regression were used to evaluate outcome measures: postoperative cerebrospinal fluid (CSF) leaks, meningitis, and other major complications (OMCs).

RESULTS

A total of 2275 patients from 29 studies were analyzed. Rates of postoperative CSF leaks, meningitis, and OMCs were 4.0%, 1.6%, and 2.3%, respectively, using autologous grafts, and 5.0%, 0.3%, and 1.0%, respectively, using nonautologous grafts. Multivariate analysis of 118 patients demonstrated no significant differences in age, CSF flow rate, single or multilayer reconstruction, and presence of intraoperative CSF leak or lumbar drain. Meta-analyses of 6 studies yielded a risk ratio of 0.64 (95% confidence interval [CI], 0.19-2.14; P = 0.47) for postoperative CSF leakage, and risk differences of -0.01 (95% CI, -0.06 to 0.05; P = 0.80) and -0.02 (95% CI, -0.09 to 0.05; P = 0.51) for postoperative meningitis and OMCs, respectively. There were no significant differences in postoperative CSF leakage (P = 0.95) and OMCs (P = 0.41) between graft types among cases with intraoperative CSF leaks. However, meningitis rates were lower (P = 0.04) in the nonautologous group.

CONCLUSIONS

EASB reconstructions utilizing autologous and nonautologous grafts are associated with similar rates of postoperative CSF leakage and OMCs. In cases with intraoperative CSF leakage, nonautologous grafts were associated with reduced postoperative meningitis.

Acellular dermal matrix as an alternative to autologous fascia lata for skull base repair following extended endoscopic endonasal approaches

BACKGROUND

Skull base reconstruction after extended endoscopic endonasal approaches (EEAs) can be challenging. In addition to the nasoseptal flap, which has been adopted by most centers, autologous fascia lata is also often utilized. Harvesting of fascia lata requires a separate thigh incision, may prolong recovery, and results in a visible scar. In principal, the use of non-autologous materials would be preferable to avoid a second incision and maintain the minimally invasive nature of the approach, assuming the CSF leak rate is not compromised.

OBJECTIVE

To assess the efficacy of acellular dermal matrix (ADM) as a non-autologous alternative to autologous fascia lata graft for watertight closure of the cranial base following EEAs.

METHODS

A retrospective chart review of extended EEAs performed before and after the transition from fascia lata to ADM was performed. Cases were frequency matched for approach, pathology, BMI, use of lumbar drainage, and tumor volume. Power analysis was performed to estimate the sample size needed to demonstrate non-inferiority.

RESULTS

ADM was used for watertight closure of the cranial base in 19 consecutive extended endoscopic endonasal approaches (16 gasket-seals and 3 buttons) with 1 postoperative CSF leak at the last follow-up (median 5.3, range 1.0-12.6 months). All patients had high-flow intraoperative leaks. The cohort included 8 meningiomas, 8 craniopharyngiomas, 2 chordomas, and 1 pituicytoma ranging in size from 0.2 to 37.2cm³ (median 5.5, IQR 2.8-13.3 cm³). In 19 historical controls who received fascia lata, there were 2 postoperative CSF leaks.

CONCLUSIONS

Preliminary results suggest that ADM provides a non-inferior non-autologous alternative to fascia lata for watertight gasket-seal and button closures following extended EEAs, potentially reducing or eliminating the need to harvest autologous tissue.

Perioperative nasal and paranasal sinus considerations in transsphenoidal surgery for pituitary disease

Endoscopic endonasal skull base surgery has emerged as the treatment modality of choice for a range of skull base lesions, particularly pituitary adenomas. However, navigation and manipulation of the nasal corridor and paranasal sinuses requires that surgeons are aware of effective techniques to maximize patient outcomes and avoid sinonasal morbidity postoperatively. This paper is a narrative review aimed to provide an updated and consolidated report on the perioperative management of the nasal corridor and paranasal sinuses in the setting of endoscopic skull base surgery for pituitary disease. Anatomic variants and common surgical techniques are discussed. Post-operative complications are evaluated in detail. Understanding the structural implications of the endonasal approach to the sphenoid is crucial to optimization of the surgical outcomes. We propose guidelines for perioperative management of endoscopic endonasal skull base surgery for pituitary diseases. Standardized treatment algorithms can improve patient satisfaction, and increase the comparability and the quality of reported information across research studies.

Soft tissue grafts for dural reconstruction after meningioma surgery

The meninges are involved in various pathologies and are often directly or indirectly severed during surgical procedures, especially the dura mater. This can pose a real challenge for the surgeon, as a proper reconstruction of the meninges is important to prevent complications such as cerebrospinal fluid leak (CSF). A variety of techniques for dural reconstruction have been described, employing natural and artificial materials. A novel technique for dural reconstruction involves soft tissue grafts in the form of fibrous or fibromuscular flaps, which are placed on the dural defects to seal the gaps. These soft tissue grafts represent an appropriate scaffold for cell ingrowth and fibrosis, thus preventing CSF. In this pilot study, we described the application of soft tissue grafts for dural reconstruction in 10 patients who underwent convexity meningioma surgery.

Predictive Factors, 30-Day Clinical Outcomes, and Costs Associated with Cerebrospinal Fluid Leak in Pituitary Adenoma Resection

Cerebrospinal fluid (CSF) leak is a complication of endoscopic endonasal pituitary adenoma resection. Previous studies examining complications of pituitary adenoma resection have not examined associations of an exhaustive list of clinical and financial variables with CSF leak. We designed a retrospective analysis of 334 consecutive patients that underwent endoscopic endonasal pituitary adenoma resection at a single institution over 5 years, analyzing associations between CSF leak and demographic data, operative data, comorbidities, clinical complications and outcomes, costs, charges, and payments. Of the 20 preoperative variables studied, none were positively associated with CSF leak in between-groups comparison, although multivariate analysis revealed an association with a history of radiation to the skull base (odds ratio [OR], 8.67; 95% confidence interval [CI], 0.94-57.03; p  < 0.05). CSF leak was associated with a significantly higher rate of postoperative diabetes insipidus (Δ = 33.4%, p  = 0.040) and increased length of stay after operation in between-groups comparison. Multivariate analysis on postoperative variables revealed significant associations between CSF leak and intracerebral hemorrhage (OR, 17.44; 95% CI, 0.65-275.3; p  < 0.05) and postoperative intracranial infection (OR, 28.73; 95% CI, 2.04-438.7; p  < 0.05). Also, CSF leak was associated with significantly higher costs (Δ = $15,643, p  < 0.05) and hospital charges (Δ = $46,026, p  < 0.05). Operating room time, room and board, and supplies and implants were the strongest cost drivers. This study highlights the difficulty of utilizing preoperative variables to predict CSF leak, the clinical complications and outcomes of leak, and the financial subcategories that drive the costs, charges, and payments associated with this complication.

Clinical Experience with Hemopatch® as a Dural Sealant in Cranial Neurosurgery

Background: Herein, we report our clinical experience with the novel polyethylene glycol-covered matrix dural onlay, Hemopatch® (Baxter Deutschland GmbH, Unterschleißheim, Germany) for the prevention of postoperative cerebrospinal fluid (CSF) fistulas.

Methods: Retrospectively, 22 consecutive patients (11 females, 11 males, mean age: 49.8 years, range: 15–77 years) with oncological and vascular intracranial lesions were included in this study. In all patients, the Hemopatch was applied as the dural onlay. The accuracy of the primary dural sutures was distinguished into 1) no visible gaps, 2) small gaps < 3 mm, and 3) large gaps > 3 mm. We evaluated the patient charts, surgical reports, and postoperative images. The median follow-up was three months. We recorded any wound healing disorder, such as infection or CSF fistula, and postoperative hemorrhage resulting in surgical revision.

Results: Supratentorial, infratentorial, and transsphenoidal approaches were conducted in 17, four, and one patient, respectively. Accurate sutures without visible gaps, small gaps, and large gaps were covered with the Hemopatch in 11, eight, and three patients. One patient developed a CSF fistula (4.5%), one patient had a wound infection (4.5%), and in one patient, a remote cerebellar hemorrhage occurred (unrelated to the dural closure) (4.5%). Thus, the surgical revision rate due to wound healing disorders was 9% (2/22).

Conclusion: It is safe and feasible to use the Hemopatch as a dural sealant. The rate of postoperative wound healing disorders in our population was in the lower range of reported surgical revision rates after supra-/infratentorial craniotomies. However, prospective and controlled clinical trials are still warranted.

Effectiveness of Dural Sealants in Prevention of Cerebrospinal Fluid Leakage After Craniotomy: A Systematic Review

OBJECTIVE

Cerebrospinal fluid (CSF) leakage is one of the most challenging complications in neurosurgery. We sought to evaluate the efficacy of dural sealants in preventing CSF leakage after cranial surgery.

METHODS

A literature search was performed in the PubMed, Embase, and Cochrane databases. The inclusion criteria were defined to include articles describing regular cranial procedures combined with the use of any dural sealant reporting CSF leakage. The primary outcome was CSF leakage (pseudomeningocele formation or incisional CSF leakage), secondary outcomes were pseudomeningocele formation, incisional CSF leakage, and surgical-site infection.

RESULTS

Twenty articles were included. Ten of these were comparative studies (sealant vs. no sealant) including 3 randomized controlled trials. In the 20 articles, a total of 3682 surgical procedures were reported. The number of CSF leakages in general did not differ between the sealant group (8.2%) and control group (8.4%), risk ratio (RR) 0.84 (0.50-1.42), I² = 56%. Exclusion of non-randomized controlled trials did not alter the results. Meta-analyses for secondary outcomes showed no difference between number of incisional CSF leakage, RR 0.30 (0.05-1.59), I² = 38%. Also, no difference was found in the pseudomeningocele formation, RR 1.50 (0.43-5.17), I² = 0%. Surgical-site infection was seen less in the sealant group (1.0%) compared with the control group (5.6%), RR 0.25 (0.13-0.48), I² = 0%.

CONCLUSIONS

This systematic review showed that dural sealants did not reduce the number of CSF leaks in general, the number of incisional CSF leaks alone, or the number of pseudomeningocele formations alone. However, dural sealants reduced the risk of surgical-site infection.

Nasoseptal flap necrosis: a rare complication of endoscopic endonasal surgery

OBJECTIVE The vascularized nasoseptal flap (NSF) has become the workhorse for skull base reconstruction during endoscopic endonasal surgery (EES) of the ventral skull base. Although infrequently reported, as with any vascularized flap the NSF may undergo ischemic necrosis and become a nidus for infection. The University of Pittsburgh Medical Center's experience with NSF was reviewed to determine the incidence of necrotic NSF in patients following EES and describe the clinical presentation, imaging characteristics, and risk factors associated with this complication. METHODS The electronic medical records of 1285 consecutive patients who underwent EES at the University of Pittsburgh Medical Center between January 2010 and December 2014 were retrospectively reviewed. From this first group, a list of all patients in whom NSF was used for reconstruction was generated and further refined to determine if the patient returned to the operating room and the cause of this reexploration. Patients were included in the final analysis if they underwent endoscopic reexploration for suspected CSF leak or meningitis. Those patients who returned to the operating room for staged surgery or hematoma were excluded. Two neurosurgeons and a neuroradiologist, who were blinded to each other's results, assessed the MRI characteristics of the included patients. RESULTS In total, 601 patients underwent NSF reconstruction during the study period, and 49 patients met the criteria for inclusion in the final analysis. On endoscopic exploration, 8 patients had a necrotic, nonviable NSF, while 41 patients had a viable NSF with a CSF leak. The group of patients with a necrotic, nonviable NSF was then compared with the group with viable NSF. All 8 patients with a necrotic NSF had clinical and laboratory evidence indicative of meningitis compared with 9 of 41 patients with a viable NSF (p < 0.001). Four patients with necrotic flaps developed epidural empyema compared with 2 of 41 patients in the viable NSF group (p = 0.02). The lack of NSF enhancement on MR (p < 0.001), prior surgery (p = 0.043), and the use of a fat graft (p = 0.004) were associated with necrotic NSF. CONCLUSIONS The signs of meningitis after EES in the absence of a clear CSF leak with the lack of NSF enhancement on MRI should raise the suspicion of necrotic NSF. These patients should undergo prompt exploration and debridement of nonviable tissue with revision of skull base reconstruction.

Complication Avoidance in Endoscopic Skull Base Surgery

Endoscopic endonasal approaches to the skull base pathology have developed and evolved dramatically over the past 2 decades, particularly with collaboration between neurosurgery and otolaryngology physicians. These advances have increased significantly the use of such approaches beyond just resection of pituitary adenomas, including a variety of skull base pathologies. As the field has evolved, so has our understanding of the complications accompanying endoscopic skull base surgery, as well as techniques to both avoid and manage these complications. These are discussed here.

Systematic Review of the Effectiveness of Perioperative Prophylactic Antibiotics for Skull Base Surgeries

Background

Perioperative antibiotics are commonly used in endoscopic skull base surgeries as prophylaxis for infectious complications, e.g., meningitis. The role of perioperative prophylactic antibiotics in endoscopic sinus surgery is unclear, and the routine use of prophylactic antibiotics in endoscopic skull base surgery is also highly debated. Currently, there is no formal recommendation for perioperative antibiotic use in skull base surgery, and regimens vary greatly from one institution to the next.

Objective

To assess perioperative antibiotics as prophylaxis against infectious complications in patients who underwent endoscopic skull base surgery.

Data Sources

PubMed, Ovid EMBASE, and the Cochrane Library.

Methods

A systematic review that examined perioperative antibiotic use in endoscopic skull base and craniofacial surgeries was conducted. Inclusion criteria were prospective or retrospective study design and clinical trials related to the use of antibiotics within 30 days of skull base surgery. End points included infectious complications such as (1) meningitis and (2) sinusitis.

Results

A total of 2543 articles were identified by the initial search, and 5 articles met inclusion criteria. The five eligible trials were all observational and involved different types of skull base surgical procedures and antibiotic regimens.

Conclusions

Despite institutional variability in antibiotic regimens, meningitis rarely occurs after skull base procedures and seems to be encountered most frequently in open craniofacial surgeries. A systematic review revealed a limited number of published studies, all observational in study design, which precluded a formal meta-analysis. A novel large-scale randomized-controlled clinical trial is needed to evaluate antibiotic selection and need in endoscopic skull base surgery.

Postoperative Low-Flow Cerebrospinal Fluid Leak of Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Adenoma--Wait and See, or Lumbar Drain?

To assess the effectiveness of continuous lumbar drainage (LD) for management of postoperative cerebrospinal fluid leaks after endoscopic endonasal transsphenoidal approach for resection of pituitary adenoma. Three hundred eighty-four medical records of patients who were admitted to our institute during a 2.5-year period were retrospectively reviewed, 33 of them experienced low-flow cerebrospinal fluid leak postoperatively. If LD was used, all patients with low-flow cerebrospinal fluid leak were classified into 2 groups, lumbar drained group and conservatively treated group. The age, sex, management of cerebrospinal fluid leaks, and related complications were reviewed. Statistical comparisons between the 2 groups were made using SPSS 19.0 (IBM Corp, Armonk, NY). The differences were considered statistically significant if the P value was less than 0.05.Thirty-three of 384 (8.6%) experienced low-flow postoperative cerebrospinal fluid leaks. Cured rate of cerebrospinal fluid leak was 94.4% (17/18) in continuous lumbar drained group, and 93.3% (14/15) in control group. There were 2 (11.2%) patients who developed meningitis in the LD group and 1 (5.6%) patient in the control group. One patient required endoscopic repair of skull base because of persistent cerebrospinal fluid leak in both groups, with the rates of 5.6% and 6.7%, respectively. There was no significant difference noted in each rate in both groups.Placement of LD may not be necessary for the management of low-flow postoperative cerebrospinal fluid leak after using endoscopic endonasal transsphenoidal approach to pituitary adenoma.

A new multilayer reconstruction using nasal septal flap combined with fascia graft dural suturing for high-flow cerebrospinal fluid leak after endoscopic endonasal surgery

This study aimed to evaluate the usefulness and reliability of a new endoscopic multilayer reconstruction using nasal septal flap (NSF) to prevent high-flow cerebrospinal fluid leak after endoscopic endonasal surgery. This study was a retrospective review on 97 patients who underwent multilayer reconstructions using NSF combined with fascia graft dural suturing after endoscopic endonasal surgery between July 2012 and March 2014. Patients were divided into two groups, third ventricle opening group and nonopening group, based on the presence of a direct connection between the third ventricle and the paranasal sinus after tumor removal. Furthermore, we compared this procedure with our previous reconstruction after resection of craniopharyngioma. Finally, we checked the patients who had postoperative prolonged discomfort of the nasal cavity for over a year. Postoperative cerebrospinal fluid (CSF) leak occurred in three patients (3.1 %): one from the third ventricle opening group and the remaining two from the nonopening group. External lumbar drain was performed after surgery in only seven patients (7.2 %). The incidence of postoperative CSF leak was similar in both groups, whereas the rate of craniopharyngioma in the third ventricle opening group was significantly higher. The incidence of postoperative CSF leak after resection of craniopharyngioma was not statistically significant but obviously higher in the previous group (12.2 %) compared with that in the present group (2.3 %). Twelve patients (12.4 %) had postoperative nasal discomfort of the nasal cavity for over a year. Multilayer reconstruction using NSF combined with fascia graft dural suturing is a more reliable method for preventing postoperative high-flow CSF leakage after endoscopic endonasal surgery even if there is a direct connection between the third ventricle and the paranasal sinus. However, we should pay close attention especially to prolonged discomfort of the nasal cavity after harvesting NSF.

A multicentre, prospective, randomized, controlled study to evaluate the use of a fibrin sealant as an adjunct to sutured dural repair

BACKGROUND

Obtaining intra-operative watertight closure of the dura is considered important in reducing post-operative cerebrospinal fluid (CSF) leak. The purpose of this study was to evaluate a fibrin sealant as an adjunct to sutured dural repair to obtain intra-operative watertight closure in cranial neurosurgery.

METHODS

This randomized, controlled multicenter study compared a fibrin sealant (EVICEL^® Fibrin Sealant [Human]) to sutured dural closure (Control). Subjects underwent supratentorial or posterior fossa procedures. Following primary dural repair by sutures, the closure was evaluated for intra-operative CSF leak by moderately increasing the intracranial pressure. If present, subjects were randomized to EVICEL^® or additional sutures (2:1 ratio), stratified by surgical approach. Following treatment, subjects were successful if no CSF leaks were present during provocative challenge. Safety was assessed to 30 days post-surgery, including incidence of CSF leakage.

RESULTS

One hundred and thirty-nine subjects were randomized: 89 to EVICEL^® and 50 to Control. Intra-operative watertight closure was achieved in 92.1% EVICEL^®-treated subjects versus 38.0% controls; a treatment difference of 54.1% (p < 0.001). The treatment differences in the supratentorial and posterior fossa strata were 49.1% and 75.7%, respectively (p < 0.001). The incidence of adverse events was similar between treatment groups. No deaths or unexpected serious adverse drug reactions were reported. CSF leakage within 30 days post-operatively was 2.2% and 2.0% in EVICEL^® and control groups, respectively. In addition, 2 cases of CSF rhinorrhoea were observed in the EVICEL^® group. Although not associated with the suture line where EVICEL^® was applied, when combined with the other CSF leaks, the observed leak rate in the EVICEL^® group was 4.5%.

CONCLUSIONS

These results indicate that EVICEL^® is effective as an adjunct to dural sutures to provide watertight closure of the dura mater in cranial surgery. The study confirmed the safety profile of EVICEL^®.

Impact of Chemoradiotherapy on CSF Leak Repair after Skull Base Surgery

Background Transnasal endoscopic resection (TER) has become the treatment of choice for many skull base tumors. A major limitation of TER is the management of large dural defects and the need for repair of cerebrospinal fluid (CSF) leaks, particularly among patients who are treated with chemotherapy (CTX) or radiotherapy (RT). The objective of this study is to determine the impact of CTX and RT on the success of CSF leak repair after TER. Methods We performed a retrospective chart review of a single-institution experience of TER from 1992 to 2011. Results We identified 28 patients who had endoscopic CSF leak repair after resection of malignant skull base tumors. Preoperative RT was utilized in 18 patients, and 9 had undergone CTX. All patients required CSF leak repair with rotational flaps after cribriform and/or dural resection. CSF leak repair failed in three patients (11%). A history of RT or CTX was not associated with failed CSF leak repair. Conclusion Adjuvant or neoadjuvant CTX or RT is not associated with failed CSF leak repair. Successful CSF leak repair can be performed in patients with malignant skull base tumors with an acceptable risk profile.

Subcranial craniotomy approach for frontobasal fracture correction

OBJECTIVE

Frontobasilar fracture types and the outcome of patients after management with the subcranial approach technique were evaluated.

MATERIAL AND METHODS

A retrospective analysis of 48 patients (45 males, mean age 38,5 years; range 16-82 years) who had a subcranial approach for frontal base fracture correction between April 1996 and April 2011 at a tertiary care academic hospital in Turku, Finland.

RESULTS

Sixteen (33%) patients had fractures including all frontobasilar fracture types (Type I-IV) i.e. fractures that involved frontal sinuses, orbital roofs, ethmoidal region, cribriform plate and sphenoidal region. Twenty-seven (56%) patients were considered to have had brain damage at presentation. Forty percent of patients were suffering from synchronous trauma. Peroperatively, 31 (65%) patients had exposure or defect of the dura due to bone dehiscence but only two patients suffered from cerebrospinal fluid (CSF) fistula following surgery. CSF fistulae were covered by pericranium in most of the cases (68%). There was no postoperative meningitis. Thirty-eight percent of the patients needed further operation with a subcranial craniotomy following primary reconstruction. At the last follow-up visit 35% were suffering from permanent neurological problems following brain injury.

CONCLUSIONS

Subcranial approach seemed successful in the management of all frontobasilar fractures in this series with reasonably low complication rate. Therefore, we would recommend it as the technique of choice in multiple and even in the most complicated frontal base fractures.

The risk of acquiring bacterial meningitis following surgery in Denmark, 1996-2009: a nationwide retrospective cohort study with emphasis on ear, nose and throat (ENT) and neurosurgery

SUMMARY

This paper estimates the risk of bacterial meningitis following surgery between 1996 and 2009 in Denmark. We conducted two retrospective nationwide cohort studies; first by linking notified bacterial meningitis cases to the National Patient Registry to see how many had undergone a surgical procedure; second, we scrutinized notified bacterial meningitis cases to see if the clinician suspected a surgical procedure to be the aetiology. We found that ear, nose and throat surgery had an 11-fold, and neurosurgery a sevenfold, increased risk compared to the reference group in the first 10 days following surgery. Streptococcus pneumoniae was the pathogen most often involved. Operation procedures involving penetration of dura mater was associated with increased risk for post-operative bacterial meningitis. In absolute numbers we found few bacterial meningitis cases after surgery; however, patients undergoing certain surgical procedures are at-risk and should be considered when national vaccination guidelines are revised.