One thousand endoscopic skull base surgical procedures demystifying the infection potential: incidence and description of postoperative meningitis and brain abscesses

Risk Factors for Central Nervous System Infections After Craniotomy

The central nervous system (CNS) is less prone to infection owing to protection from the brain-blood barrier. However, craniotomy destroys this protection and increases the risk of infection in the brain of patients who have undergone craniotomy. CNS infection after craniotomy significantly increases the patient's mortality rate and disability. Controlling the occurrence of intracranial infection is very important for post-craniotomy patients. CNS infection after craniotomy is caused by several factors such as preoperative, intraoperative, and post-operative factors. Craniotomy may lead to postsurgical intracranial infection, which is mainly associated with surgery duration, infratentorial (posterior fossa) surgery, cerebrospinal fluid leakage, drainage tube placement, unregulated use of antibiotics, glucocorticoid use, age, diabetes, and other systemic infections. Understanding the risk factors of CNS infection after craniotomy can benefit reducing the incidence of intracranial infectious diseases. This will also provide the necessary guidance and evidence in clinical practice for planning to control intracranial infection in patients with craniotomy.

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.

Endoscopic Sellar Defect Reconstruction with Avascular Modified Gasket Seal Technique for Sellar Tumors

Watertight repair of the skull base defect is necessary during endonasal skull base surgery to avoid postoperative CSF leak (poCSFl) and consequent intracranial complications. Various techniques have been described for reconstructing sphenoid-sellar defects with varying success rates. We have described the immediate and long-term outcomes following the reconstruction of sphenoid-sellar defects with our technique. A retrospective analysis of the patients following transsphenoidal sellar surgery underwent barrier restoring reconstruction by multi-layered (inlay-overlay) with autologous thigh fat, fascia lata, fibrin glue, knitted collagen, and absorbable gelatin sponge (modified gasket seal technique). A total of 44 patients were included in the study (n = 44). Reconstruction with modified gasket seal technique was done for all patients. 26 (59.1%) had intraoperative CSF leak (ioCSFl), and 9 (20.4%) patients had grade 3 Esposito-Kelly ioCSFl requiring adjunct short-term pressure reducing procedure (Lumbar drain) intraoperatively. 11/44 (25%) had poCSFl, 7/11 patients with poCSFl were managed conservatively, and 4/11 patients required rescue second surgery and ventriculoperitoneal shunting. 1 (2.3%) had severe meningitis and succumbed to it. Pneumocephalus was seen in 6 (13.6%). Multivariate analysis showed that revision surgery, GH-secreting tumors, and defects extending to the suprasellar region had higher chances of poCSFl (p < 0.001). All 43 alive patients had no CSF leak on long-term follow-up. The modified gasket seal technique is a viable technique for endoscopic sellar reconstruction for ioCSFl with an immediate success rate of 79.6% and 97.72% in the long term in preventing the postoperative CSF leak with a 13.6% rate of meningitis.

Patient-specific automated cerebrospinal fluid pressure control to augment spinal wound closure: a case series using the LiquoGuard®

OBJECTIVE

Spinal cerebrospinal fluid (CSF) leaks are common, and their management is heterogeneous. For high-flow leaks, numerous studies advocate for primary dural repair and CSF diversion. The LiquoGuard7® allows automated and precise pressure and volume control, and calculation of patient-specific CSF production rate (prCSF), which is hypothesized to be increased in the context of durotomies and CSF leaks.

METHODS

This single-centre illustrative case series included patients undergoing complex spinal surgery where: 1) a high flow intra-operative and/or post-operative CSF leak was expected and 2) lumbar CSF drainage was performed using a LiquoGuard7®. CSF diversion was tailored to prCSF for each patient, combined with layered spinal wound closure.

RESULTS

Three patients were included, with a variety of pathologies: T7/T8 disc prolapse, T8-T9 meningioma, and T4-T5 metastatic spinal cord compression. The first two patients underwent CSF diversion to prevent post-op CSF leak, whilst the third required this in response to post-op CSF leak. CSF hyperproduction was evident in all cases (mean >/=140ml/hr). With patient-specific CSF diversion regimes, no cases required further intervention for CSF fistulae repair (including for pleural CSF effusion), wound breakdown or infection.

CONCLUSIONS

Patient-specific cerebrospinal fluid drainage may be a useful tool in the management of high-flow intra-operative and post-operative CSF leaks during complex spinal surgery. These systems may reduce post-operative CSF leakage from the wound or into adjacent body cavities. Further larger studies are needed to evaluate the comparative benefits and cost-effectiveness of this approach.

Effect of preoperative hospital stay on surgical site infection in Chinese cranial neurosurgery

OBJECTIVE

Surgical site infection(SSI)after neurosurgical procedure can be devastating. Delayed hospital stay has been identified as a potentially modifiable driver of SSI in general surgery patients. However, the relationship between preoperative length of stay and SSI has not been quantified previously in neurosurgery. This study aimed to clarify the association.

DESIGN

A Cohort study based on STROBE checklist.

METHOD

This observational study focused on cranial neurosurgery patients at a tertiary referral centers in China. Data collection from hospital information system conducted between 1 January 2016 and 31 December 2016 was used to examine the results of interest (n = 600). Logistic regression analysis explored association between preoperative length of stay and SSI, adjusting for potential confounders.

RESULTS

Overall SSI prevalence was 10.8% and was significantly higher in the longer preoperative length of stay group. Besides preoperative length of stay, American Society of Anesthesiologists score, type of surgery, gross blood loss also significantly associated with SSI prevalence. Compared with 1 to 2 days, longer preoperative length of stay was associated with increased SSI prevalence after adjustment for confounders (3 to 4 days: odds ratio[OR], 0.975[95%CI, 0.417 to 2.281]; 5 to 6 days: OR, 2.830[95%CI, 1.092 to 7.332]; 7 or more days: OR, 4.039[95%CI, 1.164 to 14.015]; P for trend < 0.001). On the other hand, we found a positive association between preoperative length of stay to deep/space-organ SSI (OR = 1.404; 95% CI: 1.148 to 1.717; P for trend < 0.001), which was higher than superficial SSI (OR = 1.242; 95% CI: 0.835 to1.848; P for trend= 0.062).

CONCLUSIONS

In a cohort of patients from a single center retrospective surgical registry, a longer preoperative length of stay was associated with a higher incidence of cranial neurosurgical SSI. There is room for improvement in preoperative length of stay. This can be used for hospital management and to stratify patients with regard to SSI risk.

Microbiologic and Clinical Description of Postoperative Central Nervous System Infection After Endoscopic Endonasal Surgery

BACKGROUND

Consensus guidelines for antibiotic prophylaxis in endoscopic endonasal surgery (EES) have not been developed. The study objective was to define the microbiologic and clinical characteristics of post-EES central nervous system (CNS) infections.

METHODS

This was a single-center retrospective study of patients >18 years of age who underwent EES between January 2010 and July 2021 at a high-volume skull base center. Patients with confirmed CNS infection within 30 days of EES were included. During the study period, the standard prophylaxis regimen was ceftriaxone 2 g every 12 hours for 48 hours. For patients with a documented penicillin allergy, vancomycin plus aztreonam was recommended.

RESULTS

In total, 2440 EES procedures were performed on 2005 patients; the CNS infection rate was 1.8% (37/2005). CNS infections were more common among patients with a history of previous EES (6.5%; 20/307) compared with those who did not (1%; 17/1698; P < 0.001). The median time from EES to CNS infection was 12 (6-19) days. Thirty-two percent (12/37) of CNS infections were polymicrobic, which was more common among patients without previous EES (52.9%; 9/17) compared with those with previous EES (15%; 3/20; P = 0.03). Across all cases, Staphylococcus aureus (n = 10) and Pseudomonas aeruginosa (n = 8) were commonly isolated pathogens. Among those with confirmed methicillin-resistant Staphylococcus aureus (MRSA) nares colonization before EES, 75% (3/4) developed MRSA CNS infections compared with 6.1% (2/33) of noncolonized patients (P = 0.005).

CONCLUSIONS

CNS infection after EES is rare and causative pathogens vary. Further studies are needed to identify the impact of MRSA nares screening on antimicrobial prophylaxis before EES.

Prediction model of central nervous system infections in patients with severe traumatic brain injury after craniotomy

OBJECTIVE

The aim of this study was to develop and evaluate a nomogram to predict CNS infections in patients with severe traumatic brain injury (sTBI) after craniotomy.

METHODS

This retrospective study was conducted in consecutive adult patients with sTBI who were admitted to the neurointensive care unit (NCU) between January 2014 and September 2020. We applied the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analysis to construct the nomogram, and k-fold cross-validation (k=10) to validate it. The receiver operator characteristic area under the curve (AUC) and calibration curve were applied to evaluate the predictive effect of the nomogram. The clinical usefulness was investigated by decision curve analysis (DCA).

RESULTS

A total of 471 patients with sTBI who underwent surgical treatment were included, of whom 75 patients (15.7%) were diagnosed with CNS infections. The serum level of albumin, cerebrospinal fluid (CSF) otorrhoea at admission, CSF leakage, CSF sampling, and postoperative re-bleeding were associated with CNS infections and incorporated into the nomogram. The results showed that our model yielded satisfactory prediction performance with an AUC value of 0.962 in the training set and 0.942 in the internal validation. The calibration curve exhibited satisfactory concordance between the predicted and actual outcomes. The model had good clinical use since the DCA covered a large threshold probability.

CONCLUSION

We established a straightforward individualized nomogram for CNS infections in sTBI patients in the NCU, which could help physicians screen high-risk patients to perform early interventions to reduce the incidence of CNS infections in sTBI patients.

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.

The 'Maxillary Pull-through' Technique: A Minimally Invasive Endoscopic-Assisted Approach to Nasal Septum Neoformations with Maxillary Bone Infiltration

Study Design

Description and validation of a surgical technique.

Objective

En-bloc maxillectomy with removal of the nasal septum is a rare procedure; preservation of the nasal bones and integrity of the alveolar ridge is even rarer. These procedures traditionally required a combined transfacial-transoral approach based on lateral rhinotomy. We describe a combined endoscopic transnasal-transoral approach for treatment of nasal septal malignancies that involve the hard palate.

Methods

Excision of malignant tumours arising from the nasal septum was achieved in 4 patients using a transnasal-transoral endoscopic approach. Using 4-mm optics angled at 0° and 30°, the septum was freed from the ethmoid and removed en-bloc with the hard palate, by pulling the septum down through the hard palate.

Results

Of the 4 patients, 2 underwent complete removal of septal chondrosarcomas, one removal of a sinonasal undifferentiated carcinoma and one removal of a mucoepidermoid carcinoma. In two cases, the palatal mucosa was spared and repositioned to restore separation between the nose and oral cavity. The remaining two cases underwent complete resection of the hard palate; one palate was reconstructed using a pedicled temporalis muscle flap and the other by employing an obturator. No infection was encountered. Partial ethmoidectomy was performed in all four cases. The mean hospital stay was 5 days. All patients are free of disease after a mean follow-up of 4 years (range: 2-7 years).

Conclusions

Our new approach allows for minimally invasive resection of nasal septal malignancies that extend to the palate. Our maxillary pull-through technique is a valuable new surgical procedure for malignant pathologies of the nasal septum; the only drawback is that endoscopic surgery has a steep learning curve.

A Novel Sublabial Anterior Transmaxillary Approach for Medically Refractory Mesial Temporal Lobe Epilepsy: A Comparative Anatomic Study

BACKGROUND

Current approaches for mesial temporal lobe epilepsy may result in suboptimal seizure control and cognitive decline. An incomplete treatment of the epileptogenic zone and unnecessary violation of functional cortical and subcortical areas may contribute to suboptimal results.

OBJECTIVE

To describe and test the anatomic feasibility of a novel endoscopic anterior transmaxillary (ATM) approach to the temporal lobe and to compare the described technique to other transfacial approaches.

METHODS

Twenty-four cadaveric brain hemispheres fixed in formalin were used to study anterior temporal surface anatomy. Two additional hemispheres were fixed in formalin and then frozen for white matter dissections. Subsequently, bilateral dissections on 4 injected cadaveric heads were used to describe the endoscopic ATM approach and to evaluate various anterior endoscopic corridors for the temporal pole and mesial temporal lobe structures.

RESULTS

The ATM approach was considered superior because of direct visualization of the temporal pole and natural alignment with the mesial temporal structures. The mean exposure corridor covered 49.1° in the sagittal plane and 66.2° in the axial plane. The ATM allowed direct access lateral to the maxillary and mandibular nerves with an anterior-posterior trajectory aligned to the longitudinal axis of the hippocampus formation, allowing for a selective amygdalohippocampectomy with preservation of the trigeminal branches and the lateral temporal neocortex.

CONCLUSION

The ATM approach is anatomically feasible, providing a direct and selective approach for the temporal pole and mesial temporal lobe structures, with a substantial angle of visualization because of its direct alignment with the mesial temporal lobe structures.

CSF rhinorrhoea after endonasal intervention to the skull base (CRANIAL): A multicentre prospective observational study

Objective

Despite progress in endonasal skull-base neurosurgery, cerebrospinal fluid (CSF) rhinorrhoea remains common and significant. The CRANIAL study sought to determine 1) the scope of skull-base repair methods used, and 2) corresponding rates of postoperative CSF rhinorrhoea in the endonasal transsphenoidal approach (TSA) and the expanded endonasal approach (EEA) for skull-base tumors.

Methods

A prospective observational cohort study of 30 centres performing endonasal skull-base neurosurgery in the UK and Ireland (representing 91% of adult units). Patients were identified for 6 months and followed up for 6 months. Data collection and analysis was guided by our published protocol and pilot studies. Descriptive statistics, univariate and multivariable logistic regression models were used for analysis.

Results

A total of 866 patients were included - 726 TSA (84%) and 140 EEA (16%). There was significant heterogeneity in repair protocols across centres. In TSA cases, nasal packing (519/726, 72%), tissue glues (474/726, 65%) and hemostatic agents (439/726, 61%) were the most common skull base repair techniques. Comparatively, pedicled flaps (90/140, 64%), CSF diversion (38/140, 27%), buttresses (17/140, 12%) and gasket sealing (11/140, 9%) were more commonly used in EEA cases. CSF rhinorrhoea (biochemically confirmed or requiring re-operation) occurred in 3.9% of TSA (28/726) and 7.1% of EEA (10/140) cases. A significant number of patients with CSF rhinorrhoea (15/38, 39%) occurred when no intraoperative CSF leak was reported. On multivariate analysis, there may be marginal benefits with using tissue glues in TSA (OR: 0.2, CI: 0.1-0.7, p<0.01), but no other technique reached significance. There was evidence that certain characteristics make CSF rhinorrhoea more likely - such as previous endonasal surgery and the presence of intraoperative CSF leak.

Conclusions

There is a wide range of skull base repair techniques used across centres. Overall, CSF rhinorrhoea rates across the UK and Ireland are lower than generally reported in the literature. A large proportion of postoperative leaks occurred in the context of occult intraoperative CSF leaks, and decisions for universal sellar repairs should consider the risks and cost-effectiveness of repair strategies. Future work could include longer-term, higher-volume studies, such as a registry; and high-quality interventional studies.

Postoperative protocols following endoscopic skull base surgery: An evidence-based review with recommendations

BACKGROUND

Postoperative management strategies for endoscopic skull base surgery (ESBS) vary widely because of limited evidence-based guidance.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed from January 1990 through February 2022 to examine 18 postoperative considerations for ESBS. Nonhuman studies, articles written in a language other than English, and case reports were excluded. Studies were assessed for levels of evidence, and each topic's aggregate grade of evidence was evaluated.

RESULTS

A total of 74 studies reporting on 18 postoperative practices were reviewed. Postoperative pain management, prophylactic antibiotics, and lumbar drain use had the highest grades of evidence (B). The literature currently lacks high quality evidence for a majority of the reviewed ESBS precautions. There were no relevant studies to address postoperative urinary catheter use and medical intracranial pressure reduction.

CONCLUSION

The evidence for postoperative ESBS precautions is heterogeneous, scarce, and generally of low quality. Although this review identified the best evidence available in the literature, it suggests the urgent need for more robust evidence. Therefore, additional high-quality studies are needed in order to devise optimal postoperative ESBS protocols.

Machine learning driven prediction of cerebrospinal fluid rhinorrhoea following endonasal skull base surgery: A multicentre prospective observational study

Background

Cerebrospinal fluid rhinorrhoea (CSFR) is a common complication following endonasal skull base surgery, a technique that is fundamental to the treatment of pituitary adenomas and many other skull base tumours. The CRANIAL study explored CSFR incidence and related risk factors, particularly skull base repair techniques, via a multicentre prospective observational study. We sought to use machine learning to leverage this complex multicentre dataset for CSFR prediction and risk factor analysis.

Methods

A dataset of 865 cases - 725 transsphenoidal approach (TSA) and 140 expanded endonasal approach (EEA) - with cerebrospinal fluid rhinorrhoea as the primary outcome, was used. Relevant variables were extracted from the data, and prediction variables were divided into two categories, preoperative risk factors; and repair techniques, with 6 and 11 variables respectively. Three types of machine learning models were developed in order to predict CSFR: logistic regression (LR); decision tree (DT); and neural network (NN). Models were validated using 5-fold cross-validation, compared via their area under the curve (AUC) evaluation metric, and key prediction variables were identified using their Shapley additive explanations (SHAP) score.

Results

CSFR rates were 3.9% (28/725) for the transsphenoidal approach and 7.1% (10/140) for the expanded endonasal approach. NNs outperformed LR and DT for CSFR prediction, with a mean AUC of 0.80 (0.70-0.90) for TSA and 0.78 (0.60-0.96) for EEA, when all risk factor and intraoperative repair data were integrated into the model. The presence of intraoperative CSF leak was the most prominent risk factor for CSFR. Elevated BMI and revision surgery were also associated with CSFR for the transsphenoidal approach. CSF diversion and gasket sealing appear to be strong predictors of the absence of CSFR for both approaches.

Conclusion

Neural networks are effective at predicting CSFR and uncovering key CSFR predictors in patients following endonasal skull base surgery, outperforming traditional statistical methods. These models will be improved further with larger and more granular datasets, improved NN architecture, and external validation. In the future, such predictive models could be used to assist surgical decision-making and support more individualised patient counselling.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

Retrospective Review of Surgical Site Infections after Endoscopic Endonasal Sellar and Parasellar Surgery: Multicenter Quality Data from the North American Skull Base Society

Introduction  Transnasal access to the anterior skull base provides a minimally invasive approach for sellar and parasellar masses compared with its open counterparts. The unique microbiome of the sinonasal mucosa provides distinct challenges not encountered with other cranial approaches. The use of antibiotics in these cases has not been standardized, and data remain scarce regarding infectious outcomes. Methods  We conducted a multicenter retrospective analysis of shared quality data points for the endoscopic endonasal approach (EEA) for pituitary adenomas, along with other sellar and parasellar region masses that were included by participating institutions. Patient and operative characteristics, perioperative and postoperative antibiotic regimens and their durations, intraoperative and postoperative cerebrospinal fluid leak, and onset of postoperative meningitis and sinusitis were compared. Results  Fifteen institutions participated and provided 6 consecutive months' worth of case data. Five hundred ninety-three cases were included in the study, of which 564 were pituitary adenomectomies. The incidences of postoperative meningitis and sinusitis were low (0.67 and 2.87% for all pathologies, respectively; 0.35% meningitis for pituitary adenomas) and did not correlate with any specific antibiotic regimen. Immunocompromised status posed an increased odds of meningitis in pituitary adenomectomies (28.6, 95% confidence interval [1.72-474.4]). Conclusions  The results show no clear benefit to postoperative antimicrobial use in EEA, with further larger studies needed.

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.

Complications in Endoscopic Endonasal Pitiuitary Adenoma surgery: An institution experience in 310 patients

Objective: Endoscopic Endonasal approaches (EEA) have shown excellent results for majority of hypophyseal tumors. The aim of this study was to evaluate and report the complications of EEA in patients with Pituitay Adenoma (PA) who underwent surgery between 2013 and 2018. Methods: We performed a retrospective review of 310 consecutive patients/325 procedures with PA treated with an Endoscopic Endonasal (EEA) approach from May 2013 to January 2018. Minor complications including transient diabetes insipidus (DI) or new anterior pituitary hormone insufficiency in one axis and major complications including CSF leakage, hematoma needing reoperation, vascular damage, brain infection, new pan-hypopituitarism permanent DI, new visual impairment, neurological deficits, and mortality were recorded. Results: We encountered 58 complications in 310 patients (18.7%) and in 325 procedures (17.7%). Minor complications were 43 (13.9% and 13.2%) in 310 patients and in 325 procedures respectively; whereas, major complications were 28 (9% and 8.6% respectively). Total complications were associated with diameter group 2 (>30 mm), diaphragm sella violation, suprasellar extension, paraselar involvement, nonfunctional secretory type, intraoperative arachnoid tearing Conclusion: EEA can be considered as a safe surgical treatment with acceptable complications in the management of pituitary adenomas.

[Nosocomial meningitis in endoscopic transsphenoidal surgery]

One of the main problems of transsphenoidal surgery is the risk of infectious complications. Nosocomial meningitis (NCM) can lead to increased length of hospital stay and financial costs, poor treatment outcomes and even mortality. This complication is an indicator of the quality of medical care for patients with neurosurgical diseases. The purpose of the review was to study the main risk factors of NCM, modern schemes for antibiotic prophylaxis and treatment of this complication after endoscopic transsphenoidal surgery. The main risk factors of meningitis are intra- and postoperative CSF leakage, overweight, diabetes mellitus, previous transsphenoidal surgeries and radiotherapy. To date, there are no generally accepted periods for antibiotic prophylaxis in nasal CSF leakage, installed external ventricular / lumbar drains or tampons in nasal cavity. Antibiotic prophylaxis should not exceed 3 postoperative days due to the risk of cultivating the drug-resistant organisms. If NCM is detected, treatment should be initiated immediately with a broad spectrum of antibiotics.

Risk factors impacting intra- and postoperative cerebrospinal fluid rhinorrhea on the endoscopic treatment of pituitary adenomas: A retrospective study of 250 patients

We aimed to identify the risk factors associated with intra- and postoperative cerebrospinal fluid (CSF) leakage in pituitary adenomas treated with endoscopic transsphenoidal surgery.This study is a retrospective analysis of 250 pituitary adenoma cases from January 2017 to December 2019 at our hospital. All patients underwent endoscopic endonasal transsphenoidal surgeries. Univariate and multivariate analyses were performed to investigate the risk factors associated with intra- and postoperative CSF rhinorrhea.Eighty (32.0%) and nine (3.6%) patients had intra- and postoperative CSF leakage, respectively. Tumor size was an independent risk factor for intraoperative CSF leakage (odds ratio [OR], 1.229; 95% confidence interval [CI], 1.133-1.334; P < .001); intraoperative CSF leakage was an independent risk factor for postoperative CSF leakage (OR, 7.707; 95% CI, 1.336-44.455; P = .022). Chronic respiratory disease (OR, 57.500; 95% CI, 8.031-411.682; P < .001) was also an independent risk factor for postoperative CSF leakage. Vascularized septal mucosal flap was a protective factor (OR, 0.107; 95% CI, 0.013-0.894; P = .039).Intraoperative CSF leakage is more likely to occur in large pituitary adenomas. In the presence of intraoperative CSF leakage, postoperative CSF rhinorrhea is very likely to occur. Patients with chronic respiratory disease are also more likely to develop postoperative CSF leakage. The sellar base reconstructed using vascularized nasal septal flaps can significantly decrease the risk. The Knosp grade, degree of tumor resection, and postoperative use of a lumbar subarachnoid drain did not have any effects on postoperative CSF rhinorrhea.

Perioperative Antibiotic Use in Endoscopic Endonasal Skull Base Surgery

Background Improved evidence-based guidelines on the optimal type and duration of antibiotics for patients undergoing endoscopic endonasal transsphenoidal surgery (EETS) are needed. We analyze the infectious complications among a large cohort of EETS patients undergoing a standardized regimen of cefazolin for 24 hours, followed by cephalexin for 7 days after surgery (clindamycin if penicillin/cephalosporin allergic).

Methods A retrospective review of 132 EETS patients from 2018 to 2020 was conducted. Patient, tumor, and surgical characteristics were collected, along with infection rates. Multivariate logistic regression determined the variable(s) independently associated with infectious outcomes.

Results Nearly all patients (99%) received postoperative antibiotics with 78% receiving cefazolin, 17% receiving cephalexin, 3% receiving clindamycin, and 2% receiving other antibiotics. Fifty-three patients (40%) had an intraoperative cerebrospinal fluid (CSF) leak, and three patients (2%) developed a postoperative CSF leak requiring surgical repair. Within 30 days, no patients developed meningitis. Five patients (4%) developed sinusitis, two patients (3%) developed pneumonia, and one patient (1%) developed cellulitis at a peripheral intravenous line. Two patients (2%) developed an allergy to cephalexin, requiring conservative management. After adjustment for comorbidities and operative factors, presence of postoperative infectious complications was independently associated with increased LOS (β = 3.7 days; p = 0.001).

Conclusion Compared with reported findings in the literature, we report low rates of infectious complications and antibiotic intolerance, despite presence of a heavy burden of comorbidities and high intraoperative CSF leak rates among our cohort. These findings support our standardized 7-day perioperative antibiotic regimen.

Skull base repair following endonasal pituitary and skull base tumour resection: a systematic review

PURPOSE

Postoperative cerebrospinal fluid rhinorrhoea (CSFR) remains a frequent complication of endonasal approaches to pituitary and skull base tumours. Watertight skull base reconstruction is important in preventing CSFR. We sought to systematically review the current literature of available skull base repair techniques.

METHODS

Pubmed and Embase databases were searched for studies (2000-2020) that (a) reported on the endonasal resection of pituitary and skull base tumours, (b) focussed on skull base repair techniques and/or postoperative CSFR risk factors, and (c) included CSFR data. Roles, advantages and disadvantages of each repair method were detailed. Random-effects meta-analyses were performed where possible.

RESULTS

193 studies were included. Repair methods were categorised based on function and anatomical level. There was absolute heterogeneity in repair methods used, with no independent studies sharing the same repair protocol. Techniques most commonly used for low CSFR risk cases were fat grafts, fascia lata grafts and synthetic grafts. For cases with higher CSFR risk, multilayer regimes were utilized with vascularized flaps, gasket sealing and lumbar drains. Lumbar drain use for high CSFR risk cases was supported by a randomised study (Oxford CEBM: Grade B recommendation), but otherwise there was limited high-level evidence. Pooled CSFR incidence by approach was 3.7% (CI 3-4.5%) for transsphenoidal, 9% (CI 7.2-11.3%) for expanded endonasal, and 5.3% (CI 3.4-7%) for studies describing both. Further meaningful meta-analyses of repair methods were not performed due to significant repair protocol heterogeneity.

CONCLUSIONS

Modern reconstructive protocols are heterogeneous and there is limited evidence to suggest the optimal repair technique after pituitary and skull base tumour resection. Further studies are needed to guide practice.

Complications after 1002 endoscopic endonasal approach procedures at a single center: lessons learned, 2010-2018

OBJECTIVE

The endoscopic endonasal approach (EEA) has evolved into a mainstay of skull base surgery over the last two decades, but publications examining the intraoperative and perioperative complications of this technique remain scarce. A prior landmark series of 800 patients reported complications during the first era of EEA (1998-2007), parallel to the development of many now-routine techniques and technologies. The authors examined a single-institution series of more than 1000 consecutive EEA neurosurgical procedures performed since 2010, to elucidate the safety and risk factors associated with surgical and postoperative complications in this modern era.

METHODS

After obtaining institutional review board approval, the authors retrospectively reviewed intraoperative and postoperative complications and their outcomes in patients who underwent EEA between July 2010 and June 2018 at a single institution.

RESULTS

The authors identified 1002 EEA operations that met the inclusion criteria. Pituitary adenoma was the most common pathology (n = 392 [39%]), followed by meningioma (n = 109 [11%]). No patients died intraoperatively. Two (0.2%) patients had an intraoperative carotid artery injury: 1 had no neurological sequelae, and 1 had permanent hemiplegia. Sixty-one (6.1%) cases of postoperative cerebrospinal fluid leak occurred, of which 45 occurred during the original surgical hospitalization. Transient postoperative sodium dysregulation was noted after 87 (8.7%) operations. Six (0.6%) patients were treated for meningitis, and 1 (0.1%) patient died of a fungal skull base infection. Three (0.3%) patients died of medical complications, thereby yielding a perioperative 90-day mortality rate of 0.4% (4 deaths). High-grade (Clavien-Dindo grade III-V) complications were identified after 103 (10%) EEA procedures, and multivariate analysis was performed to determine the associations between factors and these more serious complications. Extradural EEA was significantly associated with decreased rates of these high-grade complications (OR [95% CI] 0.323 [0.153-0.698], p = 0.0039), whereas meningioma pathology (OR [95% CI] 2.39 [1.30-4.40], p = 0.0053), expanded-approach intradural surgery (OR [95% CI] 2.54 [1.46-4.42], p = 0.0009), and chordoma pathology (OR [95% CI] 9.31 [3.87-22.4], p < 0.0001) were independently associated with significantly increased rates of high-grade complications.

CONCLUSIONS

The authors have reported a large 1002-operation cohort of EEA procedures and associated complications. Modern EEA surgery for skull base pathologies has an acceptable safety profile with low morbidity and mortality rates. Nevertheless, significant intraoperative and postoperative complications were correlated with complex intradural procedures and meningioma and chordoma pathologies.

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.

Transnasal endoscopic skull base surgery in the COVID-19 era: Recommendations for increasing the safety of the method

Transnasal endoscopic skull base surgery (eSBS) has been adopted in recent years, in great part to replace the extended procedures required by external approaches. Though sometimes perceived as "minimally invasive", eSBS still necessitates extensive manipulations within the nose/paranasal sinuses. Furthermore, exposure of susceptible cerebral structures to light and heat emanated by the telescope should be considered to comprehensively evaluate the safety of the method. While the number of studies specifically targeting eSBS safety still remains scarce, the problem has recently expanded with the SARS-CoV-2 pandemic, which also has implications for the safety of the surgical personnel. It must be stressed that eSBS may directly expose the surgeon to potentially high volumes of virus-contaminated aerosol. Thus, the anxiety of both the patient and the surgeon must be taken into account. Consequently, safety requirements must follow the highest standards. This paper summarizes current knowledge on SARS-CoV-2 biology and the peculiarities of human immunology in respect of the host-virus relationship, taking into account the latest information concerning the SARS-CoV-2 worrisome affinity for the nervous system. Based on this information, a workflow proposal is offered for consideration. This could be useful not only for the duration of the pandemic, but also during the unpredictable timeline involving our coexistence with the virus. Recommendations include technical modifications to the operating theatre, personal protective equipment, standards of testing for SARS-CoV-2 infection, prophylactic pretreatment with interferon, anti-IL6 treatment and, last but not least, psychological support for the patient.

Ultra-short antibiotic prophylaxis guided by preoperative microbiological nasal swabs in endoscopic endonasal skull base surgery

PURPOSE

Endoscopic endonasal skull base surgery (EESBS) is a clean-contaminated procedure. Guidelines regarding the antibiotic prophylaxis in EESBS have not been developed yet, and today, there are no universally accepted protocols. In this article, we investigated the efficacy of our new ultra-short antibiotic prophylaxis protocol for EESBS guided by the cultural results of preoperative microbiological nasal swabs.

METHODS

We defined as "nasal swab-related antibiotic protocol" the administration of a first-generation cephalosporin (cefazolin 2 g) in patients whose nasal swabs revealed the presence of normal nasal flora or methicillin-sensitive Staphylococcus aureus (MSSA), and the administration of vancomycin 1 g intravenously in patients whose nasal swabs revealed the presence of methicillin-resistant Staphylococcus aureus (MRSA) or with reported cephalosporin/penicillin allergy. This case-control study included 120 patients who underwent EESBS. The case group included 60 cases who received the "nasal swab-related antibiotic protocol," while the control group included 60 cases who received the "standard hospital antibiotic protocol" used in neurosurgery (cefazolin 2 g plus metronidazole 500 mg at induction, and 2 g of cefazolin repeated after 180 min).

RESULTS

The preoperative microbiological nasal swabs showed normal nasal flora in 42 patients (70%), MSSA in 17 patients (28.3%), and MRSA in 1 patient (1.6%). During the study period, no cases of meningitis or sinusitis occurred in the case group ("nasal swab-related antibiotic protocol"), while two infections (3.3%, 1 sinusitis and 1 meningitis) were reported in the control group ("standard hospital antibiotic protocol"). Mean length of hospitalization was 6.5 days for the case group and 8.5 days in the control group. "Standard hospital antibiotic protocol" is less expensive (range, 2.88-5.42 euros) compared with our new "nasal swab-related antibiotic protocol" (range, 10.02-32.56 euros), but in line with other antibiotic prophylaxis protocols reported in literature.

DISCUSSION

The low complication rates of our case series (0%) is comparable to complication rates reported in literature (1.6% for meningitis and 8% for sinusitis). Compared with other perioperative antibiotic regimens reported in literature, the "nasal swab-related antibiotic protocol" is cheap and at least equally effective. We discuss the rationale on which we based the choice of chemoprophylaxis, the timing, and the length of our regimen.

CONCLUSIONS

Our study confirmed the safety and efficacy of our easily applicable and low-cost antibiotic prophylaxis protocol.

CSF Rhinorrhoea After Endonasal Intervention to the Skull Base (CRANIAL) - Part 1: Multicenter Pilot Study

Background

CRANIAL (CSF Rhinorrhoea After Endonasal Intervention to the Skull Base) is a prospective multicenter observational study seeking to determine 1) the scope of skull base repair methods used and 2) corresponding rates of postoperative cerebrospinal fluid (CSF) rhinorrhea in the endonasal transsphenoidal approach (TSA) and the expanded endonasal approach (EEA) for skull base tumors. We sought to pilot the project, assessing the feasibility and acceptability by gathering preliminary data.

Methods

A prospective observational cohort study was piloted at 12 tertiary neurosurgical units in the United Kingdom. Feedback regarding project positives and challenges were qualitatively analyzed.

Results

A total of 187 cases were included: 159 TSA (85%) and 28 EEA (15%). The most common diseases included pituitary adenomas (n = 142/187), craniopharyngiomas (n = 13/187). and skull base meningiomas (n = 4/187). The most common skull base repair techniques used were tissue glues (n = 132/187, most commonly Tisseel), grafts (n = 94/187, most commonly fat autograft or Spongostan) and vascularized flaps (n = 51/187, most commonly nasoseptal). These repairs were most frequently supported by nasal packs (n = 125/187) and lumbar drains (n = 20/187). Biochemically confirmed CSF rhinorrhea occurred in 6/159 patients undergoing TSA (3.8%) and 2/28 patients undergoing EEA (7.1%). Four patients undergoing TSA (2.5%) and 2 patients undergoing EEA (7.1%) required operative management for CSF rhinorrhea (CSF diversion or direct repair). Qualitative feedback was largely positive (themes included user-friendly and efficient data collection and strong support from senior team members), demonstrating acceptability.

Conclusions

Our pilot experience highlights the acceptability and feasibility of CRANIAL. There is a precedent for multicenter dissemination of this project, to establish a benchmark of contemporary practice in skull base neurosurgery, particularly with respect to patients undergoing EEA.

Endoscopic endonasal surgery for anterior cranial fossa meningiomas

Meningiomas along the anterior skull base arise from the midline but have historically been resected via open cranial approaches with lateral to medial trajectories. The endoscopic endonasal approach (EEA) offers a direct, inferomedial approach which has demonstrated several superior qualities for their resection. These meningiomas include tuberculum sellae, planum sphenoidale, and olfactory groove meningiomas. While early gross total resection (GTR) was lower than open approaches, EEA has currently achieved comparable rates of GTR and significantly improved postoperative visual outcomes. Rate of cerebrospinal fluid (CSF) leak was one of the early complicating features preventing widespread use of EEA. However, CSF leak rates have dramatically fallen into a tolerable range with introduction of the vascularized nasoseptal flap. Olfactory groove meningiomas often present with anosmia which is persistent after endonasal approach. Rates of other complications have proven similar between EEA and open approaches and include: vascular injury, infection, morbidity, and mortality. With the appropriate team and experience, EEA for anterior skull base meningiomas is increasingly becoming the standard for resection of these lesions. However, there are certain anatomic considerations, patient features, and other aspects which may favor the open approach over EEA, and vice versa; these must be carefully and judiciously evaluated preoperatively. Overall, resection and recurrence rates are comparable, complication rates fall within a very acceptable range, and patients experience superior cosmesis and improved visual outcome with this approach.

CSF rhinorrhoea after endonasal intervention to the anterior skull base (CRANIAL): proposal for a prospective multicentre observational cohort study

BACKGROUND

The endonasal transsphenoidal approach (TSA) has emerged as the preferred approach in order to treat pituitary adenoma and related sellar pathologies. The recently adopted expanded endonasal approach (EEA) has improved access to the ventral skull base whilst retaining the principles of minimally invasive surgery. Despite the advantages these approaches offer, cerebrospinal fluid (CSF) rhinorrhoea remains a common complication. There is currently a lack of comparative evidence to guide the best choice of skull base reconstruction, resulting in considerable heterogeneity of current practice. This study aims to determine: (1) the scope of the methods of skull base repair; and (2) the corresponding rates of postoperative CSF rhinorrhoea in contemporary neurosurgical practice in the UK and Ireland.

METHODS

We will adopt a multicentre, prospective, observational cohort design. All neurosurgical units in the UK and Ireland performing the relevant surgeries (TSA and EEA) will be eligible to participate. Eligible cases will be prospectively recruited over 6 months with 6 months of postoperative follow-up. Data points collected will include: demographics, tumour characteristics, operative data), and postoperative outcomes. Primary outcomes include skull base repair technique and CSF rhinorrhoea (biochemically confirmed and/or requiring intervention) rates. Pooled data will be analysed using descriptive statistics. All skull base repair methods used and CSF leak rates for TSA and EEA will be compared against rates listed in the literature.

ETHICS AND DISSEMINATION

Formal institutional ethical board review was not required owing to the nature of the study - this was confirmed with the Health Research Authority, UK.

CONCLUSIONS

The need for this multicentre, prospective, observational study is highlighted by the relative paucity of literature and the resultant lack of consensus on the topic. It is hoped that the results will give insight into contemporary practice in the UK and Ireland and will inform future studies.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Efficacy of simultaneous pericranial and nasoseptal "double flap" reconstruction of anterior skull base defects after combined transbasal and endoscopic endonasal approaches

BACKGROUND

The "double flap" reconstruction technique, comprised of a simultaneous vascularized pedicled pericranial flap (PCF) and pedicled nasoseptal flap (NSF), can be used to repair anterior skull base defects after a combined cranionasal or transbasal-endoscopic endonasal approach (EEA) has been performed to remove malignant anterior skull base tumors. The use of two vascularized flaps may potentially decrease the incidence of post-radiation flap necrosis and postoperative cerebrospinal fluid (CSF) leaks after radiation therapy.

METHODS

We conducted a retrospective review of a prospective skull base database on patients who underwent the double flap reconstruction technique after a combined transbasal-EEA approach. Data collected for each patient included demographics, method of tumor resection and repair, complications, tumor recurrence, and follow-up.

RESULTS

Nine patients who underwent a combined transbasal-EEA approach for resection of anterior skull base tumors with significant intracranial extension followed by reconstruction of the cranial base using the double flap technique. Four were men and five were women, with a mean age of 49 years (range, 15-68 years). There was no postoperative CSF leakage detected or complications of infection, meningitis, mucocele, or tension pneumocephalus after a mean follow-up of 35.7 months (range, 4.5-98 months). Seven of the nine patients underwent adjuvant radiation without flap necrosis. Local tumor recurrence was not observed in any of the patients at last follow-up; however, one patient developed distant brain metastasis.

CONCLUSION

The simultaneous PCF and NSF double flap reconstruction is an effective technique in preventing postoperative CSF leakage and post-radiation necrosis when repairing anterior skull base defects after combined transbasal-EEA approaches. This technique may be useful in patients anticipated to undergo postoperative radiation therapy.

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.

Infectious Complications of Expanded Endoscopic Transsphenoidal Surgery: A Retrospective Cohort Analysis of 100 Cases

Objective  To identify perioperative factors that may predict postoperative cerebrospinal fluid (CSF) leak and meningitis following expanded endoscopic transsphenoidal surgery (EETS). Study Design  This is a retrospective study. This study was set at the Cedars-Sinai Medical Center, Los Angeles. A total of 78 patients who underwent EETS between January 2007 and November 2018 were participated. The main outcome measures were CSF leak and meningitis. Results  A total of 78 patients underwent a total of 100 EETS procedures; 17.9 and 10.3% of patients developed postoperative CSF leaks and meningitis, respectively. Out of eight, three patients with meningitis did not develop an observable CSF leak. The risk of developing meningitis in patients with a CSF leak was significantly higher than those without a leak, with an odds ratio (OR) of 11.48 (95% confidence interval, 2.33-56.47; p  = 0.004). Pituicytomas were significantly associated with meningitis compared with other pathologies. No other patient-specific factors were identified as risks for leak or meningitis, including method of skull base repair, sex, tumor volume, or body mass index, although there was a strong trend toward reduced CSF leak rates in patient with nasoseptal flaps used for skull base repair, compared with those without (9.5 vs. 25%). CSF protein was consistently elevated on the first CSF values obtained when meningitis was suspected. Conclusion  CSF leak and meningitis are common complications of expanded endonasal surgery No statistically significant risk factors for developing a postoperative leak other than the pathology of pituicytoma were identified, including method of skull base repair, although the use of a vascularized nasoseptal flap did trend toward a reduced CSF leak rate. CSF protein is the most sensitive marker for the presumptive diagnosis and timely treatment of meningitis.

Risk factors for postoperative intracranial infections in patients with pituitary adenoma after endoscopic endonasal transsphenoidal surgery: pneumocephalus deserves further study

OBJECTIVE

The authors sought to identify the relevance between pneumocephalus and postoperative intracranial infections, as well as bacteriological characteristics and risk factors for intracranial infections, in patients with pituitary adenomas after endoscopic endonasal transsphenoidal surgery.

METHODS

In total, data from 251 consecutive patients with pituitary adenomas who underwent pure endoscopic endonasal transsphenoidal surgeries from 2014 to 2018 were reviewed for preoperative comorbidities, intraoperative techniques, and postoperative care.

RESULTS

This retrospective study found 18 cases of postoperative pneumocephalus (7.17%), 9 CNS infections (3.59%), and 12 CSF leaks (4.78%). Of the patients with pneumocephalus, 5 (27.8%) had CNS infections. In patients with CNS infections, the culture results were positive in 7 cases and negative in 2 cases. The statistical analysis suggested that pneumocephalus (maximum bubble diameter of ≥ 1 cm), diaphragmatic defects (intraoperative CSF leak, Kelly grade ≥ 1), and a postoperative CSF leak are risk factors for postoperative CNS infections.

CONCLUSIONS

In pituitary adenoma patients who underwent pure endoscopic endonasal transsphenoidal surgeries, intraoperative saddle reconstruction has a crucial role for patients with postoperative intracranial infections. Additionally, postoperative pneumocephalus plays an important role in predicting intracranial infections that must not be neglected. Therefore, neurosurgeons should pay close attention to the discovery of postoperative intracranial pneumocephalus because this factor is as important as a postoperative CSF leak. Pneumocephalus (maximum bubble diameter of ≥ 1 cm), diaphragmatic defects (an intraoperative CSF leak, Kelly grade ≥ 1), and a postoperative CSF leak were risk factors predictive of postoperative intracranial infections. In addition, it is essential that operative procedures be carefully performed to avoid diaphragmatic defects, to reduce exposure to the external environment, and to decrease patients’ suffering.

A Systematic Review of Prophylactic Antibiotic Use in Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Lesions

BACKGROUND

The benefit of prophylactic antibiotic use in endoscopic endonasal transsphenoidal surgery (EETS) for pituitary lesions is controversial. Many surgeons administer antibiotics perioperatively not based on clear guidelines but to be safe. The purpose of this study was to determine if antibiotic prophylaxis use reduces the risk of infection (e.g., meningitis, sinusitis) within 30 days after the surgery in adult patients with pituitary lesions undergoing EETS.

METHODS

A systematic review was performed to assess the effectiveness of perioperative antibiotic use in preventing infectious complications in patients undergoing EETS. Data sources included Ovid Databases, Scopus, PubMed, Cochrane Library, and Grey Literature. The inclusion criteria were randomized controlled trials, systematic reviews, observational studies, and case series of prophylactic antibiotic perioperative use for EETS. The study end points were the rates of meningitis and sinusitis as infectious complications after EETS.

RESULTS

A total of 282 articles were identified by the initial literature search. Four studies met the inclusion criteria: 3 retrospective cohort and 1 prospective case series studies. All patients included in each study received different antibiotic regimens perioperatively. The quality of studies did not permit performance of a meta-analysis.

CONCLUSIONS

Even though there are no clear practice guidelines regarding the antibiotic prophylaxis need in EETS, various antibiotic regimens have been used by surgeons. Our systematic review identified a limited number of published studies assessing this question, all observational. Randomized controlled trials are needed to evaluate the effectiveness of prophylactic antibiotic use in patients with pituitary lesions undergoing EETS.

Epidemiology of central nervous system infectious diseases: a meta-analysis and systematic review with implications for neurosurgeons worldwide

OBJECTIVE

Central nervous system (CNS) infections cause significant morbidity and mortality and often require neurosurgical intervention for proper diagnosis and treatment. However, neither the international burden of CNS infection, nor the current capacity of the neurosurgical workforce to treat these diseases is well characterized. The objective of this study was to elucidate the global incidence of surgically relevant CNS infection, highlighting geographic areas for targeted improvement in neurosurgical capacity.

METHODS

A systematic literature review and meta-analysis were performed to capture studies published between 1990 and 2016. PubMed, EMBASE, and Cochrane databases were searched using variations of terms relating to CNS infection and epidemiology (incidence, prevalence, burden, case fatality, etc.). To deliver a geographic breakdown of disease, results were pooled using the random-effects model and stratified by WHO region and national income status for the different CNS infection types.

RESULTS

The search yielded 10,906 studies, 154 of which were used in the final qualitative analysis. A meta-analysis was performed to compute disease incidence by using data extracted from 71 of the 154 studies. The remaining 83 studies were excluded from the quantitative analysis because they did not report incidence. A total of 508,078 cases of CNS infections across all studies were included, with a total sample size of 130,681,681 individuals. Mean patient age was 35.8 years (range: newborn to 95 years), and the male/female ratio was 1:1.74. Among the 71 studies with incidence data, 39 were based in high-income countries, 25 in middle-income countries, and 7 in low-income countries. The pooled incidence of studied CNS infections was consistently highest in low-income countries, followed by middle- and then high-income countries. Regarding WHO regions, Africa had the highest pooled incidence of bacterial meningitis (65 cases/100,000 people), neurocysticercosis (650/100,000), and tuberculous spondylodiscitis (55/100,000), whereas Southeast Asia had the highest pooled incidence of intracranial abscess (49/100,000), and Europe had the highest pooled incidence of nontuberculous vertebral spondylodiscitis (5/100,000). Overall, few articles reported data on deaths associated with infection. The limited case fatality data revealed the highest case fatality for tuberculous meningitis/spondylodiscitis (21.1%) and the lowest for neurocysticercosis (5.5%). In all five disease categories, funnel plots assessing for publication bias were asymmetrical and suggested that the results may underestimate the incidence of disease.

CONCLUSIONS

This systematic review and meta-analysis approximates the global incidence of neurosurgically relevant infectious diseases. These results underscore the disproportionate burden of CNS infections in the developing world, where there is a tremendous demand to provide training and resources for high-quality neurosurgical care.

The 3F (Fat, Flap, and Flash) Technique For Skull Base Reconstruction After Endoscopic Endonasal Suprasellar Approach

BACKGROUND

Endoscopic endonasal surgery is a rapidly evolving field that offers the possibility of treating a wide variety of skull base lesions. Reconstruction of the osteodural defect is of utmost importance, as an effective and watertight closure is mandatory. Over the years, various techniques and materials have been adopted in an effort of providing a resilient and reliable method of closure.

MATERIALS AND METHODS

We retrospectively analyzed data from a series of 25 patients who underwent skull base reconstruction according to a novel paradigm following endoscopic endonasal transtuberculum-transplanum approaches for tumor removal between June 2017 and June 2018. The 3F strategy involves autologous fat grafting, nasoseptal flap coverage, and flash mobilization out of the bed following the operation.

RESULTS

The 3F technique achieved successful watertight closure in 24 of 25 cases (96%). One case of postoperative cerebrospinal fluid rhinorrhea developed on postoperative day 10, which did not require reoperation. No perioperative complications related to the 3F strategy (e.g., overpacking, infections, or hematomas) occurred. No donor graft site infections or hematomas developed.

CONCLUSIONS

The 3F skull base reconstruction is a safe and effective method in achieving watertight closure after extended endoscopic endonasal approaches. Despite this study reporting a preliminary experience in a small series of patients, it seems that the 3F technique can be considered as a viable solution among the wide kaleidoscope of available skull base reconstruction methods.

Endoscopic endonasal surgery for epidermoid and dermoid cysts: a 10-year experience

OBJECTIVE

Epidermoid and dermoid cysts may be found along the cranial base and are commonly resected via open transcranial approaches. The use of endoscopic endonasal approaches for resection of these tumors has been rarely reported.

METHODS

The authors retrospectively reviewed the medical records of 21 patients who underwent endoscopic endonasal surgery for epidermoid and dermoid cyst resection at the University of Pittsburgh Medical Center between January 2005 and June 2014. Surgical outcomes and variables that might affect the extent of resection and complications were analyzed.

RESULTS

Total resection (total removal of cyst contents and capsule) was achieved in 8 patients (38.1%), near-total resection (total removal of cyst contents, incomplete removal of cyst capsule) in 9 patients (42.9%), and subtotal resection (incomplete removal of cyst contents and capsule) in 4 patients (19%). Larger cyst volume (≥ 3 cm3) and intradural location (15 cysts) were significantly associated with nontotal resection (p = 0.008 and 0.0005, respectively). In the whole series, surgical complications were seen in 6 patients (28.6%). No complications were observed in patients with extradural cysts. Among the 15 patients with intradural cysts, the most common surgical complication was postoperative CSF leak (5 patients, 33.3%), followed by postoperative intracranial infection (4 patients, 26.7%). Larger cysts and postoperative CSF leak were associated with intracranial infection (p = 0.012 and 0.028, respectively). Subtotal resection was marginally associated with intracranial infection when compared with total resection (p = 0.091). All patients with neurological symptoms improved postoperatively with the exception of 1 patient with unchanged abducens nerve palsy.

CONCLUSIONS

Endoscopic endonasal approaches may be effectively used for resection of epidermoid and dermoid cysts in carefully selected cases. These approaches are recommended for cases in which a total or near-total resection is possible in addition to a multilayer cranial base reconstruction with vascularized tissue to minimize the risk of intracranial infection.

Endoscopic Resection of Pediatric Skull Base Tumors: An Evidence-Based Review

Objectives  To perform a systematic review examining experiences with endoscopic resection of skull base lesions in the pediatric population, with a focus on outcomes, recurrence, and surgical morbidities. Methods  PubMed/MEDLINE, Cochrane Library, Embase, and Web of Science databases were evaluated. Studies were assessed for level of evidence. Bias risk was evaluated using the Cochrane Bias tool, Grades of Recommendation, Assessment, Development and Evaluation (GRADE), and Methodological Index for Non-Randomized Studies (MINORS) criteria. Patient characteristics, pathology, site of primary disease, presenting symptoms, stage, procedure specific details, and complications were evaluated. Results were reported using the Preferred Reporting Systems for Systematic Reviews and Meta-Analysis guidelines. Results  Ninety-three studies met criteria for inclusion, encompassing 574 patients with skull base tumors. The GRADE and MINORS criteria determined the overall evidence to be moderate quality. The most common benign and malignant pathologies included juvenile nasopharyngeal angiofibromas ( n  = 239) and chondrosarcomas ( n  = 11) at 41.6 and 1.9%, respectively. Of all juvenile nasopharyngeal angiofibroma tumors, most presented at stage IIIa and IIIb (25.8 and 27.3%, respectively). Nasal obstruction (16.5%) and headache (16.0%) were common symptoms at initial presentation. Surgical approaches included endoscopic endonasal ( n  = 193, 41.2%) and endoscopic extended transsphenoidal ( n  = 155, 33.1%). Early (< 6 weeks) and late (>6 weeks) complications included cerebrospinal fluid leak ( n  = 36, 17.3%) and endocrinopathy ( n  = 43, 20.7%). Mean follow-up time was 37 months (0.5-180 months), with 86.5% showing no evidence of disease and 2.1% having died from disease at last follow-up. Conclusion  Endoscopic skull base surgery has been shown to be a safe and effective method of treating a variety of pediatric skull base tumors. If appropriately employed, the minimally invasive approach can provide optimal results in the pediatric population.

Delayed complications from expanded endonasal surgery for intracranial tumors

PURPOSE OF REVIEW

Delayed complications after endoscopic endonasal approaches to the skull base, defined as complications greater than 1 month postoperatively, are uncommon. These complications are divided into categories including sinonasal, neuroanatomic, endocrine and vascular. This review highlights the most up-to-date advancements and reviews the management of delayed complications for skull base patients.

RECENT FINDINGS

Over the last 10 years, the field of endoscopic endonasal skull base surgery has expanded with new data highlighting the long-term patient outcomes. The majority of patients experience increased quality of life (QOL) after these interventions. However, delayed complications including alterations to sinonasal function, delayed encephaloceles from the bony skull base defect and resulting endocrinopathies can significantly impact patient's QOL. Awareness of these complications and their current management is valuable for endoscopic surgeons.

SUMMARY

Endonasal approaches to the skull base are safe and well tolerated in properly selected patients. This article highlights the delayed complications that require recognition and management by skull base surgeons to ensure the best possible care for patients.

Survey of endoscopic skull base surgery practice patterns among otolaryngologists

Background

Endoscopic skull base surgery (ESBS) is a rapidly expanding field. Despite divergent reported preferences for reconstructive techniques and perioperative management, limited data exist regarding contemporary practice patterns among otolaryngologists performing ESBS. This study aims to elucidate current practice patterns, primarily the volumes of cases performed and secondarily a variety of other perioperative preferences.

Methods

An anonymous 32‐item electronic survey examining perioperative ESBS preferences was distributed to the American Rhinologic Society membership. Statistical significance between variables was determined utilizing Student t, chi‐square, and Fisher exact tests.

Results

Seventy otolaryngologists completed the survey. The effective response rate was approximately 22.5%. Sixty percent of respondents were in full‐time academic practice and 70% had completed rhinology/skull base fellowships. Annually, 43.3 mean ESBS cases were performed (29.1 private practice vs. 52.9 academic practice, P = .009). Academic practice averaged 24.1 expanded cases versus only 11 in private practice (P = .01). Of respondents, 55.7% stood on the same side as the neurosurgeon and 72.9% remained present for the entire case. Current procedural terminology coding and antibiotic regimens were widely divergent; 31.4% never placed lumbar drains preoperatively, while 41.4% did so for anticipated high‐flow cerebrospinal fluid leaks. While considerable variation in reconstructive techniques were noted, intradural defect repairs utilized vascularized flaps 86.3% of the time versus only 51.3% for extradural repairs (P < 0.001). Major complications were rare. Postoperative restrictions varied considerably, with most activity limitations between 2–8 weeks and positive airway pressure use for 2–6 weeks. Most respondents started saline irrigations 0–2 weeks postoperatively.

Conclusions

Based on responses from fellowship‐ and non‐fellowship‐trained otolaryngologists in various practice settings, there remains considerable variation in the perioperative management of patients undergoing ESBS.

Level of Evidence

5

Nasoseptal Flap for Skull Base Reconstruction in Children

Objective  The endoscopic endonasal approach is being increasingly used for the resection and reconstruction of anterior skull base (ASB) lesions. Vascularized nasoseptal flaps (NSF) have become the workhorse for the reconstruction of ASB defects, resulting in a significant decrease in the incidence of cerebrospinal fluid (CSF) leaks. The objective of this study was to investigate the efficacy and safety of NSF in children. Methods  This is a retrospective analysis of the medical records of all patients under the age of 18 years who underwent endoscopic repair of ASB lesions with the use of NSF at our tertiary medical center between 1/2011 and 8/2016. Results  Twelve children underwent ASB defect repair for both benign and malignant neoplasms using the endoscopic endonasal NSF technique. Four children had previously undergone ASB surgery. The male-to-female ratio was 1:1, the average age was 12.3 years, the average hospitalization time was 8.3 days, and the maximum follow-up period was 24 months, during which craniofacial growth appeared to be unimpaired. A lumbar drain was used postoperatively in six cases. Crust formation and synechia were observed in two cases. There was one case of a major long-term complication (a CSF leak followed by meningitis). Conclusions  Endoscopic endonasal NSF was both an effective and a safe technique for ASB defect reconstruction in 12 children for both benign and malignant neoplasms. It had a high success rate and a low complication rate. No apparent negative influence on craniofacial growth was observed in our series.