Immediate and Delayed Complications Following Endoscopic Skull Base Surgery

Relation between anterior ethmoidal artery course on computed tomography and supraorbital ethmoid cell and Keros classification

PURPOSE

The anterior ethmoidal artery (AEA) is an important risk area in endoscopic sinus surgery. This study aimed to evaluate the course of AEA according to the Keros classification and the presence of supraorbital ethmoid cell (SOEC) and to prevent possible complications by emphasizing the importance of preoperative paranasal computed tomography (CT) imaging. This approach will increase the effectiveness of endoscopic sinus surgery and improve patient safety.

METHODS

The paranasal CT scan images of patients aged > 18 years between October 2020 and November 2021 from our center were retrospectively analyzed. The images were primarily evaluated in the coronal plane, and the sagittal and axial planes were utilized to evaluate variations in AEA regarding the skull base. Furthermore, the relation of AEA course with Keros classification and SOEC was evaluated. The study included 1000 patients aged 18-80 years (right and left, a total of 2000 samples).

RESULTS

Grade 3 AEA was the most common regarding the skull base. Keros Type 2 was the most common classification. Overall, 48.7% patients had SOEC. The incidence of Grade 3 AEA was higher among patients with SOEC and a higher Keros classification compared with those without SOEC and a lower Keros classification. Furthermore, Keros Type 3 was the most associated with SOEC presence.

CONCLUSION

Consistent with the literature, the probability of Grade 3 AEA in patients with high Keros classification and SOEC was significantly higher in our study. Therefore, we consider that preoperative imaging according to Keros classification and SOEC presence can predict AEA course and guide surgery.

Otolaryngology Considerations of Pituitary Surgery: What an Endocrinologist Should Know

Endoscopic endonasal skull base surgery is the preferred surgical approach for the management of pituitary adenomas. Perioperative management of pituitary lesions requires multidisciplinary care and typically includes a dual surgeon team consisting of a neurosurgeon and an otolaryngologist. The involvement of the otolaryngologist allows for a safe surgical approach with excellent intraoperative visualization of the tumor to enable an effective resection of the tumor by the neurosurgeon. Detection and treatment of sinonasal pathology is essential prior to surgery. Patients may experience sinonasal complaints following endoscopic transsphenoidal surgery, although this is typically temporary. Sinonasal care in the postoperative period can expedite recovery to baseline. Here we discuss the perioperative factors of endoscopic pituitary surgery that endocrinologists should be aware of, ranging from preoperative patient selection and optimization to postoperative care, with a particular emphasis on anatomic and surgical factors.

Endoscope-Assisted Pedicled Maxillary Artery to Middle Cerebral Artery Bypass: An Anatomic Feasibility Study

BACKGROUND

Extracranial to intracranial bypass is used to augment and/or replace the intracranial circulation for various pathologies. The superficial temporal artery is the mainstay donor for pedicled bypasses to the anterior circulation but can be limited by its variable size, low native flow rates, and potential scalp complications. Interposition grafts such as the radial artery or greater saphenous vein are alternatives but are sometimes limited by size mismatch, length needed to reach the extracranial circulation, and loss of inherent vascular elasticity. Interposition grafts between the maxillary artery (IMA) and middle cerebral artery (MCA) address these limitations.

OBJECTIVE

To explore the feasibility of harvesting the IMA through an endoscopic transnasal, transmaxillary approach to perform a direct IMA to MCA bypass.

METHODS

Combined transcranial and endoscopic endonasal dissections were performed in embalmed human cadavers to harvest the IMAs for intracranial transposition and direct anastomosis to the MCA. Donor and recipient vessel calibers were measured and recorded.

RESULTS

A total of 8 procedures were performed using the largest and distal-most branches of the IMA (the sphenopalatine branch and the descending palatine branch) as pedicled conduits to second division of middle cerebral artery (M2) recipients. The mean diameter of the IMA donors was 1.89 mm (SD ± 0.42 mm), and the mean diameter of the recipient M2 vessels was 1.90 mm (SD ± 0.46 mm).

CONCLUSION

Endoscopic harvest of the IMA using a transnasal, transmaxillary approach is a technically feasible option offering an excellent size match to the M2 divisions of the MCA and the advantages of a relatively short, pedicled donor vessel.

Impact of Facility Volume on Patient Safety Indicator Events After Transsphenoidal Pituitary Surgery

OBJECTIVES

To investigate the impact of facility volume on Patient Safety Indicator (PSI) events following transsphenoidal pituitary surgery (TSPS).

STUDY DESIGN

Retrospective database review.

SETTING

National Inpatient Sample database (2003-2011).

METHODS

The National Inpatient Sample was queried for TSPS cases from 2003 to 2011. Facility volume was defined by tertile of average annual number of TSPS procedures performed. PSIs, based on in-hospital complications identified by the Agency of Healthcare Research and Quality, and poor outcomes, such as mortality and tracheostomy, were analyzed.

RESULTS

An overall 16,039 cases were included: 804 had ≥1 PSI and 15,235 had none. A greater proportion of male to female (5.8% vs 4.3%) and Black to White (7.0% vs 4.5%) patients experienced PSIs. There was an increased likelihood of poor outcome (odds ratio [OR], 3.1 [95% CI, 2.5-3.7]; P < .001) and mortality (OR, 30.1 [95% CI, 18.5-48.8]; P < .001) with a PSI. The incidence rates of PSIs at low-, intermediate-, and high-volume facilities were 5.7%, 5.1%, and 4.2%, respectively. Odds of poor outcome with PSIs were greater at low-volume facilities (OR, 3.3 [95% CI, 2.4-4.4]; P < .001) vs intermediate (OR, 3.1 [95% CI, 2.1-4.2]; P < .001) and high (OR, 2.5 [95% CI, 1.7-3.8]; P < .001). Odds of mortality with PSIs were greater at high-volume facilities (OR, 43.0 [95% CI, 14.3-129.4]; P < .001) vs intermediate (OR, 40.0 [95% CI, 18.5-86.4]; P < .001) and low (OR, 17.3 [95% CI, 8.0-37.7]; P < .001).

CONCLUSION

PSIs were associated with a higher likelihood of poor outcome and mortality following TSPS. Patients who experienced PSIs had a lower risk of poor outcome but increased mortality at higher-volume facilities.

Closure strategy for endoscopic pituitary surgery: Experience from 3015 patients

Introduction

Effective strategies are required to ensure optimal management of the crucial closure step in endoscopic pituitary surgery. Many surgical techniques have been reported but no significant consensus has been defined.

Methods

Between January 2006 and March 2022, 3015 adult patients with pituitary adenomas were operated on by a single expert neurosurgical team, using a mononostril endoscopic endonasal approach. Based of preoperative risk factors of and operative findings, a detailed closure strategy was used. Body mass index >40, sellar floor lysis, number of surgeries>2, large skull base destruction, prior radiotherapy were considered as preoperative risk factors for closure failure. All patients treated with an expanded endonasal approach were excluded.

Results

Patients were mostly women (F/M ratio: 1.4) with a median age of 50 (range: 18 -89). Intraoperative CSF leak requiring specific surgical management was observed in 319/3015 (10.6%) of patients. If intraoperative leak occurred, patients with predictive risk factors were managed using a Foley balloon catheter in case of sellar floor lysis or BMI>40 and a multilayer repair strategy with a vascularized nasoseptal flap in other cases. Postoperative CSF leak occurred in 29/3015 (1%) of patients, while meningitis occurred in 24/3015 (0.8%) of patients. In patients with intraoperative leak, closure management failed in 11/319 (3.4%) of cases.

Conclusion

Based on our significant 16-year experience, our surgical management is reliable and easy to follow. With a planned and stepwise strategy, the closure step can be optimized and tailored to each patient with a very low failure rate.

Stereotactic radiosurgery for skull base adenoid cystic carcinoma: A report of two cases

Background:

Adenoid cystic carcinoma (ACC) is an uncommon salivary gland tumor with a relatively favorable prognosis. However, treating ACC is potentially challenging because radical resection is usually difficult once the skull base is involved due to the adjacent critical structures. Stereotactic radiosurgery (SRS) is a less invasive alternative for surgically recalcitrant lesions.

Case Description:

We report two patients with three metastatic skull base ACCs who underwent SRS using the Gamma Knife with a marginal dose of 20 Gy to a 50% isodose line. All tumors were effectively controlled without any adverse events.

Conclusion:

This case report and our review of the literature suggest that SRS can be considered for local control of ACC invading the skull base when surgical resection is unsuitable or a postoperative residual lesion is suspected. Further, investigations on the accumulated subjects are warranted to confirm the role of SRS for the treatment of ACCs.

Exploration of the causes of cerebrospinal fluid leakage after endoscopic endonasal surgery for sellar and suprasellar lesions and analysis of risk factors

Objective

Postoperative cerebrospinal fluid (CSF) leakage following endoscopic endonasal surgery (EES) is a frequent complication. This study aims to identify potential risk factors of postoperative CSF leakage.

Methods

A retrospective review of 360 patients who underwent EES was included. The associations between postoperative CSF leakage and patient demographics, medical history, tumor characteristics, and intraoperative repair techniques were analyzed; the diagnosis and repair of postoperative CSF leakage were also introduced.

Results

Postoperative CSF leakage occurred in 14 patients (3.9%), 2 of them cured by lumbar cistern drainage, 12 underwent endoscopic repair. Among these 12 cases, 3 were repaired twice, and the rest were cured the first time. During the repair surgery, insufficient embedded fat was detected in one case detected, seven with breached inner artificial dura, three had vascularized pedicle nasoseptal flap (VP-NSF) displacement, two with VP-NSF perforation, two with VP-NSF inactivation, and one with imperfect adherence to VP-NSF to the skull base. Eight cases had intracranial infections. Excluding one case who died of severe intracranial infection, the rest were cured and discharged without obvious sequelae. Multivariate analysis revealed that the suprasellar lesion, subarachnoid invasion, and intraoperative grade 3 flow CSF leakage were the risk factors of CSF leakage after operation, while the bone flap was a protective factor.

Conclusion

Bone flap combined with VP-NSF and iodoform gauze for skull base reconstruction is recommended in high-risk patients, while postoperative lumbar cistern drain remains dispensable.

Comparison of Anatomic Exposure After Petrosectomy Using Anterior Transpetrosal and Endoscopic Endonasal Approaches: Experimental Cadaveric Study

OBJECTIVE

Transcranial anterior petrosectomy (AP) is a classic approach; however, it is associated with adverse consequences. The endoscopic endonasal approach (EEA) has been developed as an alternative. We describe surgical techniques for AP and EEA and compare the anatomic exposures of each.

METHODS

Ten cadaveric heads (20 sides) were dissected. Specimens were divided into 4 groups: 1) AP, 2) EEA for medial petrosectomy (MP), 3) EEA for inferior petrosectomy (IP), and 4) EEA for inferomedial petrosectomy (IMP). Outcomes were areas of exposure, angles of attack to neurovascular structures, and bone resection volumes.

RESULTS

AP had a greater area of exposure than did MP and IP (P = 0.30, P < 0.01) and had a higher angle of attack to the distal part of the facial nerve-vestibulocochlear nerve (cranial nerve [CN] VII/VIII) complex than did IP and IMP (P < 0.01). MP had a lower angle of attack than IMP to the midpons (P = 0.04) and to the anterior inferior cerebellar artery (P < 0.01). Compared with IMP, IP had a lower angle of attack to the proximal part of the CN VII/VIII complex (P < 0.01) and the flocculus (P < 0.01). The bone resection volume in AP was significantly less than that in MP, IP, and IMP (P < 0.01).

CONCLUSIONS

AP and all EEA techniques had specific advantages for each specific area. We suggest AP for the ventrolateral pons and the anterior superior internal auditory canal, MP for the midline clivus, IP for the ventrolateral brainstem, and IMP to enhance the lateral corridor of the abducens nerve.

Perspective review on applications of optics in skull base surgery

The use of optic technology in skull base surgeries has the potential to revolutionize the field of medicine, particularly neurosurgery and neurology. Here, we briefly present the past, present, and future of skull-base surgery, with an emphasis on the applications of optical topography techniques. We discuss optical topography techniques such as functional near-infrared spectroscopy, optical diffusion tomography, and optical topographical imaging. Optical topography techniques are particularly advantageous when combined with other imaging methods. For instance, optical topography can be combined with techniques such as functional magnetic resonance imaging (fMRI) to combine the temporal resolution of optical topography with the spatial resolution of fMRI. Multimodal approaches will be critical to advance brain-related research as well as medicine. Structured light imaging techniques are also writing the future of 3-dimensional imaging. In short, optical topography can allow for non-invasive, high-resolution imaging that will provide real-time visualizations of the brain that are ideal for neurosurgery. From the limitations of traditional skull base surgeries to the newest developments in optical neuroimaging, here we will discuss the potential applications of optics in skull base procedures.

Heterogeneity in Outcome Reporting in Endoscopic Endonasal Skull Base Reconstruction: A Systematic Review

Objective  Presently, there are no standards for reporting outcomes of endoscopic endonasal skull base reconstruction (ESBR). This is problematic as a lack of consistent reporting makes synthesizing findings in systematic reviews and meta-analysis challenging. Thus, the aim of this study was to systematically review and describe the patterns of reporting outcomes in ESBR as a foundation for developing reporting guidelines. Study Design  Present study is a systematic review. Methods  Embase, PubMed, CINAHL, Cochrane Library, and Web of Science were searched for all publications with ≥25 patients and a focus on ESBR. The reporting patterns of each study's variables and outcomes were assessed. Results  A total of 112 studies were included in the review. The most commonly reported demographic variables were the number of included patients ( n  = 112, 100%) and types of pathologies treated ( n  = 104, 92.9%). Meanwhile, the most routinely described preoperative variable was history of prior treatment ( n  = 48, 42.9%). Type of reconstruction was a commonly reported intraoperative variable ( n  = 110, 98.2%), though the rate of intraoperative cerebrospinal fluid (CSF) leak was noted in only 76 studies (67.9%). With regard to postoperative outcomes, postoperative CSF leak rate was routinely provided ( n  = 101, 90.2%), but reporting of other surgical complications was more inconsistent. Ultimately, of the 43 variables and outcomes reviewed, a median of 12 (range: 4-22) was reported in each study. Conclusion  There is significant heterogeneity in the outcomes reported in studies relating to ESBR. This highlights the need for the development of standard reporting guidelines to minimize bias and improve interstudy comparability.

Predictors of surgical complications in patients with sinonasal malignancy

OBJECTIVES

Sinonasal and skull base tumors are rare, making it difficult to identify trends in surgical outcome. This study examines complications in a large cohort of patients undergoing surgery for sinonasal malignancy.

METHODS

Following IRB approval, an institutional database was reviewed to identify patients who underwent surgery for sinonasal or skull base malignancies from 1973 to 2016 at our institution. Charlson comorbidity index score and Clavien-Dindo grade were calculated. The main study endpoint was subgroup analysis of Clavien-Dindo Grade 0, Grades 1-2, and Grades 3-5 complications. An ordinal logistic regression model was constructed to assess the association between comorbidities, demographics, tumor characteristics, and surgical complications.

RESULTS

In total, 448 patients met inclusion criteria. Perioperative mortality rate at 30 days was 1.6% (n = 7). The rate of severe complications (Clavien-Dindo 3 or higher) was 13.6% (n = 61). Multivariate analysis using an ordinal logistic regression model showed no association between Charlson comorbidity index score and Clavien-Dindo grade of postoperative complication. Advanced T-stage was significantly associated with complications (p = 0.0014; odds ratio: 3.442 [95% confidence interval: 1.615, 7.338]).

CONCLUSION

Surgery for sinonasal and skull base tumors is safe with a low mortality rate. Advanced T-stage is associated with postoperative complications. These findings have implications for preoperative risk stratification. Key Points Surgery for sinonasal malignancy is safe with a 30 mortality of 1.6% and rate of severe complications of 12.8%. There is no association between patient comorbidity and post operative complication. On multivariate analysis, only advanced T stage was associated with increased rate of surgical complication.

Surgical approach is associated with complication rate in sinonasal malignancy: A multicenter study

BACKGROUND

Management of sinonasal malignancy (SNM) often includes surgical resection as part of the multimodality treatment. Treatment-related surgical morbidity can occur, yet risk factors associated with complications in this population have not been sufficiently investigated.

METHODS

Adult patients with histologically confirmed SNM whose primary treatment included surgical resection were prospectively enrolled into an observational, multi-institutional cohort study from 2015 to 2020. Sociodemographic, disease, and treatment data were collected. Complications assessed included cerebrospinal fluid leak, orbital injury, intracranial injury, diplopia, meningitis, osteoradionecrosis, hospitalization for neutropenia, and subsequent chronic rhinosinusitis. The surgical approach was categorized as endoscopic resection (ER) or open/combined resection (O/CR). Associations between factors and complications were analyzed using Student's t test, Fisher's exact test, and logistic regression modeling.

RESULTS

Overall, 142 patients met the inclusion criteria. Twenty-three subjects had at least 1 complication (16.2%). On unadjusted analysis, adjuvant radiation therapy was associated with developing a complication (91.3% vs 65.5%, p = 0.013). Compared with the ER group (n = 98), the O/CR group (n = 44) had a greater percentage of higher T-stage lesions (p = 0.004) and more frequently received adjuvant radiation (84.1% vs 64.4%, p = 0.017) and chemotherapy (50.0% vs 30.6%, p = 0.038). Complication rates were similar between the ER and O/CR groups without controlling for other factors. Regression analysis that retained certain factors showed O/CR was associated with increased odds of experiencing a complication (odds ratio, 3.34; 95% confidence interval, 1.06-11.19).

CONCLUSIONS

Prospective, multicenter evaluation of SNM treatment outcomes is feasible. Undergoing O/CR was associated with increased odds of developing a complication after accounting for radiation therapy. Further studies are warranted to build upon these findings.

A caroticocavernous fistula without vascular injury following endoscopic transsphenoidal excision of a tuberculum sellae meningioma-A case report

Caroticocavernous fistulae can occur following transsphenoidal surgery even without evidence of carotid artery injury. A role of vascularized flap reconstruction may be contributory.

Complications in Skull Base Surgery and Subsequent Repair

Over the past several decades, endoscopic sinus surgery has revolutionized the approach to skull base surgery. Open skull base approaches remain a viable option for advanced skull base tumors. Complications have gone down with increased reliability of vascularized tissue transfer. In this article, the authors explore the various complications that can present following skull base surgery and review the approaches for repair when such issues are encountered.

Risk Factors for Rhinosinusitis After Endoscopic Transsphenoidal Adenomectomy

OBJECTIVE

Patients undergoing endoscopic transsphenoidal adenomectomy (eTSA) for pituitary tumors are at risk for postoperative complications, including rhinosinusitis. We aimed to determine if preoperative sinonasal disease is a risk factor for postoperative rhinosinusitis (PRS).

STUDY DESIGN

Retrospective review.

SETTING

Tertiary academic center in U.S.

SUBJECTS AND METHODS

Patients with a diagnosis of pituitary adenoma who underwent eTSA between 2007-2016. PRS patients were matched to non-PRS patients or sex, age, tumor size, skull base reconstruction with intranasal tissue grafting, and concurrent septoplasty. Groups were statistically analyzed for potential preoperative risk factors of sinonasal disease (patient-reported, radiographic, endoscopic).

RESULTS

49 of 987 patients who underwent eTSA developed PRS (44.9% male, 71.4% Caucasian, mean age 49.3y). On analysis of individual risk factors, there was a significantly higher proportion of patients with a history of prior sinonasal surgery in the PRS group than the non-PRS group (25.5% vs. 6.5%, p = 0.01); however, this group difference became insignificant on multivariate analysis. There were no significant group differences with regard to history of sinus infections, nasal symptoms, seasonal allergies, radiographic abnormalities, or sinonasal disease on endoscopy.

CONCLUSION

This is the first study to investigate preoperative sinonasal disease as a risk factor for PRS after eTSA. The risk factors considered did not demonstrate definitive risk for PRS, although a history of prior sinonasal surgery should be investigated further.

Cribriform Plate, Crista Galli, Olfactory Fossa and Septal Deviation

OBJECTIVES

In the present study, we investigated the relationship between olfactory fossa, cribriform plate, crista galli and nasal Septal Deviation (SD). Keros classification of olfactory fossa was also performed.

METHODS

This study was performed retrospectively. Computerized Tomography (CT) images of 200 adult subjects were observed. Unilateral nasal Septal Deviation (SD) cases were included into the study. On coronal CT scans, SD side and location, SD angle, cribriform plate width, olfactory fossa depth (Keros classification) and width, area of the olfactory fossa, crista galli length, width and pneumatization were evaluated.

RESULTS

Anterior and anteroposterior deviations were detected mainly. In females, 64.0% and in males, 45.3% of the SDs were located anteriorly. In males, anteroposterior SDs (40.0%) were detected more than females. In anteroposterior SDs, SD angle was higher than anterior SDs. With higher SD angle, crista galli width and height decreased. Cribriform plate width, olfactory fossa height, width and area values of contralateral side were significantly higher than those of the ipsilateral side. For Keros classification, in male group, type 1 (53.3%) and in females, type 2 (57.6%) was detected at ipsilateral side. For contralateral side, type 2 Keros was detected in both genders. Complete crista galli pneumatization was observed in 4.0% and partial pneumatization was detected in 12.0%. In 84% of the patients, there is no Crista galli pneumatization. With the presence of pneumatized crista galli, contralateral Keros values decreased. Crista galli height and contralateral olfactory fossa width showed positive correlation. In older patients, cribriform plate width decreased.

CONCLUSION

In our study, there was no Keros type 3 olfactory fossa. In males' contralateral side of SD; and in females both ipsilateral and contralateral side of SD, Keros type 2 olfactory fossa were detected. Therefore, during sinus surgery, surgeons should work carefully not to made intracranial penetration.

Perioperative Considerations in Endoscopic Skull Base Surgery

Purpose of the Review

Present an overview of perioperative considerations specific to endoscopic skull base surgery necessary to maximize successful outcomes.

Recent Findings

The majority of perioperative considerations for endoscopic skull base surgery lack strong supporting evidence and frequently have varied use or implementation amongst institutions. A notable exception comes from a recent randomized controlled trial demonstrating the benefit of lumbar drainage in high-risk cerebrospinal fluid leaks.

Summary

Skull base surgeons must consider a multitude of perioperative factors. While many components of perioperative management are extrapolated from related fields such as endoscopic sinus surgery or open cranial base surgery, additional high-quality studies are needed to delineate best practices specific to endoscopic skull base surgery.

Rapid Diagnostic Test Kit for Point-of-Care Cerebrospinal Fluid Leak Detection

Cerebrospinal fluid (CSF) leaks can occur when there is communication between the intracranial cavities and the external environment. They are a common and serious complication of numerous procedures in otolaryngology, and if not treated, persistent leaks can increase a patient's risk of developing life-threatening complications such as meningitis. As it is not uncommon for patients to exhibit increased secretions postoperatively, distinguishing normal secretions from those containing CSF can be difficult. Currently, there are no proven, available tests that allow a medical provider concerned about a CSF leak to inexpensively, rapidly, and noninvasively rule out the presence of a leak. The gold standard laboratory-based test requires that a sample be sent to a tertiary site for analysis, where days to weeks may pass before results return. To address this, our group recently developed a semiquantitative, barcode-style lateral-flow immunoassay (LFA) for the quantification of the beta-trace protein, which has been reported to be an indicator of the presence of CSF leaks. In the work presented here, we created a rapid diagnostic test kit composed of our LFA, a collection swab, dilution buffers, disposable pipettes, and instructions. Validation studies demonstrated excellent predictive capabilities of this kit in distinguishing between clinical specimens containing CSF and those that did not. Our diagnostic kit for CSF leak detection can be operated by an untrained user, does not require any external equipment, and can be performed in approximately 20 min, making it well suited for use at the point of care. This kit has the potential to transform patient outcomes.

Sphenoid Sinus Mucocele Caused by Complications After Transsphenoidal Pituitary Surgery

OBJECTIVE

The purpose of this study was to review the clinical characteristics, treatment methods, and surgical outcomes of sphenoid sinus mucocele after transsphenoidal pituitary surgery.

PATIENTS AND METHODS

A total of 404 patients who underwent transsphenoidal pituitary surgery between January 2010 and December 2016 were identified. Among them, 5 patients with sphenoid sinus mucocele were included in this study. In our hospital, a single-nostril endonasal endoscopic wide sphenoidotomy is routinely used for pituitary tumor surgery.

RESULTS

The occurrence rate of sphenoid sinus mucocele was 1.2% (5/404). Of the 5 patients, 2 were males and 3 were females. Four lesions (80.0%) were located in the right sphenoid sinus and 1 lesion (20.0%) was located in the left sphenoid sinus. Endoscopic marsupialization for sphenoid sinus mucocele was performed under local anesthesia in all patients. There were no major complications resulting from the surgical intervention, and there was no recurrence at the time of the last follow-up.

CONCLUSION

Sphenoid sinus mucocele after endonasal transsphenoidal pituitary surgery is an extremely rare complication. Nasal endoscopy and MRI are useful for diagnosing this lesion. Endoscopic marsupialization is a safe and effective procedure for sphenoid sinus mucocele after endonasal transsphenoidal pituitary surgery.

Development of Chronic Sphenoid Sinusitis After Sellar Reconstruction with Medpor Porous Polyethylene Implant

OBJECTIVE

The Medpor porous polyethylene implant is reported to be safe and effective for sellar reconstruction after transsphenoidal surgery (TSS). However, we have observed several cases of delayed chronic sphenoid sinusitis related to the implant. The purpose of this study is to describe the presentation and management of implant-related sphenoid sinusitis after sellar reconstruction.

METHODS

This is a retrospective study of patients who underwent endonasal TSS with Medpor sellar reconstruction between December 2008 and January 2013 at a tertiary care institution. Patient demographics, initial surgical management, sinonasal symptoms, postoperative imaging, sinusitis management, and resulting outcomes were analyzed.

RESULTS

From 2008-2013, 139 patients underwent sellar reconstruction using Medpor. Five patients (3.6%) presented between 8 and 60 months after surgery with chronic sphenoid sinusitis that required surgical management. All 5 patients presented as outpatients for management of headaches and nasal drainage, 4 patients experienced chronic nasal congestion, and 3 patients noted recurrent sinusitis. At the time of revision surgery, all 5 patients were found to have mucosal inflammation and edema surrounding the implant, and 4 of the 5 had an exposed or partially extruded implant that was removed.

CONCLUSIONS

Reconstruction of the sellar floor may be performed after TSS to prevent postoperative complications. Although porous polyethylene implants have previously been described as safe and effective for this purpose, surgeons should be aware of the risk of subsequent implant extrusion and chronic sphenoid sinusitis that can occur in a delayed manner.

Avoiding complications in endoscopic skull base surgery

PURPOSE OF REVIEW

Endoscopic skull base surgery has become an established approach for the removal of tumors and cerebrospinal fluid fistulae repair. Compared with external approaches, it provides better aesthetic results and quality of life postoperatively. However, as it becomes popular and expands its indications possible complications should be reassessed in terms of incidence and variability in order to confirm its efficacy and safety. This article reviews the recent literature describing the main categories of possible complications suggesting strategies to minimize their incidence.

RECENT FINDINGS

Detailed preoperative planning based on imaging and histology can prevent major complications. Intraoperative use of image guidance and meticulous hemostasis provide the surgical field needed to avoid complications. Postoperative patient counseling, along with close and detailed nasal postoperative care are significant factors for an optimal outcome.

SUMMARY

Monitoring of complications after endoscopic skull base surgery is necessary in order to standardize protocols of management and improve our surgical techniques. The presence of late onset complications underlines the need of a special focus in postoperative care and follow-up.

Point-of-Care Cerebrospinal Fluid Detection

OBJECTIVE

A cerebrospinal fluid leak is one of the most serious complications in otolaryngology. It may occur as a result of injury to the skull base, typically traumatic or iatrogenic. While the presence of a leak is often discerned in the emergent setting, distinguishing normal secretions from those containing cerebrospinal fluid can be difficult during postoperative visits in the clinic. As most current laboratory-based assays are labor intensive and require several days to result, we aim to develop a more user-friendly and rapid point-of-care cerebrospinal fluid detection device.

STUDY DESIGN

Our laboratory developed a barcode-style lateral-flow immunoassay utilizing antibodies for beta-trace protein, a protein abundant in and specific for cerebrospinal fluid, with a concentration of 1.3 mg/L delineating a positive result.

SETTING

Tertiary medical center.

SUBJECTS AND METHODS

Tests with known concentrations of resuspended beta-trace protein and the contents of discarded lumbar drains (presumed to contain cerebrospinal fluid) were performed to validate our novel device.

RESULTS

Our results demonstrate the ability of our device to semiquantitatively identify concentrations of beta-trace protein from 0.3-90 mg/L, which is within the required range to diagnose a leak, thus making beta-trace protein an excellent target for rapid clinical detection.

CONCLUSION

Herein we detail the creation and initial validation of the first point-of-care cerebrospinal fluid detection device. This device is a feasible method to more efficiently and cost-effectively identify cerebrospinal fluid leaks, minimize costs, and improve patient outcomes.

Complications of Skull Base Surgery

Approaches to surgical management of skull base pathology and reconstruction of skull base defects have evolved over the past several decades. The goal, however, remains the same-to effectively address the pathology with minimal complications. In this article, the authors try to explore multiple complications of skull base surgery, discussing their incidence, natural course, and prevention. This will prove beneficial in optimal management of patients with a myriad of skull base disorders.

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.

Endoscopic Endonasal Approach for Suprasellar Lesions in Children: Complications and Prevention

The endoscopic endonasal approach (EEA) has been popularized in adults and has been applied to an expanding range of surgical modules and indications in this population. However, its clinical application in pediatric neurosurgery has been impeded by the differences in anatomical features and the relatively low incidence of diseases to which it is applicable. In this review article, we mainly discuss the surgical indications, feasibility, and complications of EEA for suprasellar lesions in children based on a review of the literature, focusing especially on the age-related anatomical features of the nasal cavity, various pathologic entities, and the impact of EEA on long-term craniofacial growth.

Analysis of the Relationship between the Location of the Anterior Ethmoid Artery and Keros Classification

Objective We sought to identify a relationship between skull base height and anterior ethmoid artery (AEA) anatomy. Study Design Retrospective radiologic chart review. Setting University of Arkansas for Medical Sciences. Subjects Patients seen in a tertiary rhinology clinic between September 2014 and October 2015. Methods Review of 101 maxillofacial computed tomography scans with institutional review board approval. Skull base height and AEA locations were measured on each side. Prevalence of the AEA outside of the skull base and distance of the AEA from skull base were calculated and compared with Keros classification using χ² testing. Comparisons of skull base height between sexes and age and distance between skull base and the AEA among Keros 2 and Keros 3 patients were made using an unpaired, 2-tailed t test. Results The AEA was located below the skull base in 25.7% of cases and more often in Keros type 3 (55%) than in Keros type 2 (29.5%) or Keros type 1 (0%) ( P < .05). Male patients were significantly more likely to have a greater average skull base height (5.25 vs 4.28 mm) and to have AEAs below the skull base (38.4% vs 14.8%). In addition, the distance of the AEA from the skull base was significantly higher in Keros type 3 patients compared with Keros type 2 patients (4.55 vs 3.42 mm, P = .001). Conclusions Variations in the AEA pathway occur more in male patients and those with higher Keros classifications. The distance between the variant AEA and the skull base increases with higher Keros classification. Keros classification can yield insight to the location of the AEA.

Imaging of Cerebrospinal Fluid Rhinorrhea and Otorrhea

As the obesity epidemic grows in the United States, rhinorrhea and otorrhea from spontaneous cerebrospinal fluid (CSF) leaks secondary to untreated idiopathic intracranial hypertension are increasing in prevalence. CSF rhinorrhea and otorrhea should also be carefully evaluated in posttraumatic and postsurgical settings, because untreated CSF leaks often have serious consequences. The work-up, diagnosis, and characterization of a CSF leak can be complex, often requiring a multimodality approach to optimize surgical planning. This article reviews the causes of CSF leaks, describes the methodology used to work up a suspected leak, and discusses the challenges of making an accurate diagnosis.