Transcutaneous Retrobulbar Amphotericin B Injection for Invasive Fungal Sinusitis with Orbital Involvement: A Systematic Review.

BACKGROUND: Orbital involvement of invasive fungal sinusitis (IFS) is an ominous prognostic marker that should prompt rapid intervention. Transcutaneous retrobulbar administration of amphotericin B (TRAMB) is an off-label adjunctive treatment that can increase drug penetrance into diseased orbital tissue. To date, there is a lack of consensus regarding the use of TRAMB for treatment of IFS with orbital involvement. OBJECTIVE: This systematic review aims to synthesize the indications, efficacy, and potential complications of TRAMB. METHODS: PubMed, EMBASE, and Web of Science databases were probed for systematic review. Article search was conducted through June 2023 using the keywords "invasive fungal sinusitis," "invasive fungal rhinosinusitis," "rhino-orbital mucormycosis," "rhinosinusitis," "orbital," "retrobulbar," and "amphotericin." RESULTS: In suitable cases as determined by radiologic and clinical evaluation, TRAMB administration has the potential to improve orbital salvage rates and improve versus stabilize visual acuity. Treatment complications are more likely with deoxycholate than with liposomal amphotericin formulations. The existing literature describing use of TRAMB is limited due to its retrospective nature, but the increase in IFS cases since 2020 due to the COVID pandemic has broadened the literature. CONCLUSIONS: TRAMB is an effective adjunctive treatment in IFS with mild-to-moderate orbital involvement when used in combination with standard of care debridement, systemic antifungal therapy, and immunosuppression reversal. Prospective longitudinal studies and multi-institutional randomized trials are necessary to determine the definitive utility of TRAMB.

Combined Direct Tumoral Puncture Embolization with Onyx and Trans-arterial Embolization for JNA.

Onyx is a safe and effective embolic agent to utilize in the treatment paradigm of JNA. We present a tandem approach that combines trans-arterial embolization (TAE) with direct puncture embolization (DPE) with Onyx to limit blood loss and facilitate safe resection. Laryngoscope, 2024.

Anterior-posterior diameter is a key driver of resectability and complications for pituitary adenomas with suprasellar extension in endoscopic transsphenoidal surgery.

BACKGROUND: As endoscopic transsphenoidal approaches are more routinely selected for progressively larger pituitary adenomas with parasellar extension, understanding potential anatomical factors that limit resection and contribute to complications is becoming increasingly important for tailoring a surgical approach. This study aimed to reevaluate existing predictive tools for resectability in pituitary adenomas specifically with suprasellar extension, and furthermore identify any additional measurable features that may be more useful in preoperative planning. METHODS: A single-center retrospective chart review of adult patients who underwent endoscopic transsphenoidal surgery for pituitary adenomas with suprasellar extension from 2015 to 2020 was performed. Preoperative MRIs were systematically assessed to assign a Knosp classification, a Zurich Pituitary Score (ZPS), and for dimensional measurements of the suprasellar aspect of the lesions. Univariate comparisons and multivariate regression models were employed to assess the influence of these factors on extent of resection and postoperative complications. RESULTS: Of the 96 patients with suprasellar pituitary adenomas who underwent endoscopic transsphenoidal surgery, 74 patients (77%) had a gross total resection (GTR). Neither Knosp grade nor ZPS score, even when dichotomized, demonstrated an association with GTR (Knosp 3A-4 versus Knosp 0-2, p = 0.069; ZPS III-IV versus ZPS I-II, p = 0.079). Multivariate regression analysis identified suprasellar anterior-posterior tumor diameter (SSAP) as the only significant predictor of extent of resection in this cohort (OR 0.951, 95% CI 0.905-1.000, p = 0.048*). A higher SSAP also had the strongest association with intraoperative CSF leaks (p = 0.0012*) and an increased overall rate of postoperative complications (p = 0.002*). Further analysis of the regression model for GTR suggested an optimal cut point value for SSAP of 23.7 mm, above which predictability for failing to achieve GTR carried a sensitivity of 89% and a specificity of 41%. CONCLUSIONS: This study is unique in its examination of endoscopic transsphenoidal surgical outcomes for pituitary adenomas with suprasellar extension. Our findings suggest that previously established grading systems based on lateral extension into the cavernous sinus lose their predictive value in lesions with suprasellar extension and, more specifically, with increasing suprasellar anterior-posterior diameter.

Preoperative Embolization Techniques in the Treatment of Juvenile Nasopharyngeal Angiofibroma: A Systematic Review.

OBJECTIVE: Preoperative embolization has proven beneficial in the surgical treatment of juvenile nasopharyngeal angiofibromas (JNA). However, the consensus for the best embolization practices remains unclear. This systematic review seeks to characterize the reporting of embolization protocols throughout the literature and to compare differences in surgical outcomes. DATA SOURCES: PubMed, Embase, and Scopus. REVIEW METHODS: Studies investigating embolization in the treatment of JNA from 2002 to 2021 were selected from defined inclusion criteria. All studies underwent a 2-stage blinded screening, extraction, and appraisal process. Embolization material, time to surgery, and embolization route were compared. Embolization complications, surgical complications, and rate of recurrence were pooled. RESULTS: Of 854 studies, 14 retrospective studies with 415 patients met the criteria for inclusion. A total of 354 patients underwent preoperative embolization. A total of 330 patients (93.2%) underwent transarterial embolization (TAE) and 24 patients had a combination of direct puncture embolization and TAE. Polyvinyl alcohol particles were the most used embolization material (n = 264, 80.0%). The most common reported time to surgery was 24 to 48 hours (n = 8, 57.1%). Pooled results showed an embolization complication proportion of 3.16% (95% confidence interval [CI]: 0.96-6.60) (n = 354), a surgical complication proportion of 4.96% (95% CI: 1.90-9.37) (n = 415), and a recurrence proportion of 6.30% (95% CI: 3.01-10.69) (n = 415). CONCLUSION: The current data on JNA embolization parameters and their effect on surgical outcomes remains too heterogenous to provide expert recommendations. Future studies should use uniform reporting to allow for more robust comparisons of embolization parameters, which, in turn, may lead to optimized patient outcomes.

Reconstruction of the Anterior Skull Base Using the Nasoseptal Flap: A Review.

The nasoseptal flap is a workhorse reconstructive option for anterior skull base defects during endonasal surgery. This paper highlights the versatility of the nasoseptal flap. After providing a brief historical perspective, this review will focus on the relevant primary literature published in the last ten years. We will touch upon new applications of the flap, how the flap has been modified to expand its reach and robustness, and some of the current limitations. We will conclude by discussing what the future holds for improving upon the design and use of the nasoseptal flap in anterior skull base reconstruction.

A Simple Onlay Sellar Reconstruction Does Not Increase the Risk of Postoperative Cerebrospinal Fluid Leak in Well-Selected Patients.

Objective A variety of endonasal sellar repair techniques have been described; many of which are complex, expensive, and carry potential morbidity but are felt to be necessary to prevent postoperative cerebrospinal fluid (CSF) leaks. We propose an effective, technically simple repair for select sellar defects utilizing an onlay of regenerated oxidized cellulose. Design Retrospective review of patients from a single neurosurgeon who underwent endoscopic transsphenoidal surgery for pituitary adenoma and sellar reconstruction with only an onlay of regenerated oxidized cellulose. Patients were selected for this repair technique based on the absence of: (1) intraoperative identification of a CSF leak, (2) patulous diaphragm (expanded diaphragm sella herniating to or through sellar floor defect), and (3) other prohibiting comorbidities. Setting The present study was conducted at a tertiary care center. Participants In this study, pituitary adenoma patients were the participants. Outcome Measures Main outcome measure of the study is postoperative CSF leak. Results A total of 172 patients were identified. Of these, 153 were initial resections of pituitary adenomas. Gross total resection was achieved in 142 (82.6%) cases. Average tumor size was 2.2 ± 1.1 cm. Average tumor volume was 10.4 ± 19.8 cm 3 . No patients had intraoperative CSF leaks. All cases were repaired with only an onlay of regenerated oxidized cellulose. There were two postoperative CSF leaks (1.16%). Pre and postoperative SNOT-22 scores were 12.9 ± 11.9 and 14.3 ± 14.9 ( p = 0.796), respectively. Conclusion The use of an onlay of regenerated oxidized cellulose alone is an effective repair technique for select sellar defects. This technique does not result in increased postoperative CSF leak rates and avoids the higher relative cost and potential morbidity associated with more complex, multilayered closures.

The impact of the COVID-19 pandemic on otolaryngologic emergency department visits at two major NYC hospital systems.

PURPOSE: Since the COVID-19 pandemic began, emergency departments (ED) across the country have seen a significant decrease in patient visits. We aim to evaluate the impact of COVID-19 on ED visits for acute otolaryngologic complaints in New York City, one of the first epicenters of the pandemic in the US. MATERIALS AND METHODS: We conducted a retrospective study of patients who presented to the ED with a primary diagnosis of an acute otolaryngologic complaint between March 1 and May 31 in 2019 and 2020. This was a multicenter study, including two tertiary care hospital systems encompassing Manhattan, Bronx, Queens, and Long Island. RESULTS: A total of 10,162 patients were identified. Significantly fewer patients presented to the ED for acute otolaryngologic complaints in 2020 (7332 vs 2830, p < 0.001). The rate of total otolaryngology-related ED visits was decreased by a factor of 0.635 (95% CI 0.6079 to 0.6634). In a subgroup analysis of each individual diagnosis, there was a significant decrease in rate of ED visits for 13 out of 18 diagnoses, including for life-threatening conditions, such as anaphylaxis. There was no significant difference based on which borough in New York City. Pediatric patients (age 0-17) were more significantly impacted by the pandemic compared to other age groups. CONCLUSION: The COVID-19 pandemic has led to a reduction in the utilization of ED for acute otolaryngologic complaints, including those requiring emergent management, and an even more significant reduction in the pediatric population. Healthcare providers should encourage patients to seek appropriate care, particularly for those illnesses with significant associated morbidity and mortality.

Straws Don't Suck: Are Straws Dangerous after Endoscopic Skull Base Surgery?

Objective Patients undergoing endoscopic endonasal surgery have historically been restricted from using straws postoperatively, due to the concern that this activity generates negative pressure. The objective of this study is to evaluate the pressure dynamics in the sinonasal cavity associated with the use of a straw. Methods Intracranial pressure catheters were placed in the nasal cavity of 20 healthy individuals. Pressure measurements were then recorded while participants drank liquids of different viscosities from a cup and from a straw. Measurements were recorded with and without subjects occluding their nose to simulate postoperative nasal obstruction. Results The average pressure in the nasal cavity while drinking water from a cup was -0.86 cmH 2 O, from a straw was -1.09 cmH 2 O, and while occluding the nose and using a straw was -0.81 cmH 2 O. The average pressure in the nasal cavity while drinking a milkshake from a cup was -0.98 cmH 2 O, from a straw was -1.88 cmH 2 O, and while occluding the nose and using a straw was -1.37 cmH 2 O. There was no statistically significant difference in pressure measurements when comparing either task or consistency ( p > 0.05). Conclusion Straw use is not associated with the generation of significant negative pressure in the nasal cavity. The pressure generated when drinking from a straw is not significantly different from that of drinking from a cup. This data suggest that straw use may be safe for patients following endoscopic skull base surgery, but further investigation is warranted.

Loss of SMARCB1 Expression Confers Poor Prognosis to Sinonasal Undifferentiated Carcinoma.

Background Due to the diverse histopathologic features and variable survival rates seen in sinonasal undifferentiated carcinoma (SNUC), it is likely that this diagnostic entity is comprised of a heterogonous group of morphologically undifferentiated tumors. As advancements in molecular testing have led to a better understanding of tumor biology, it has become increasingly evident that SNUC may actually encompass several tumor subtypes with different clinical behavior. As a result, it is also likely that all SNUC patients cannot be treated in the same fashion. Recent investigations have identified loss of the tumor suppressor SMARCB1 (INI1) expression in a subset of undifferentiated sinonasal tumors and extrasinonasal tumors and, studies have suggested that this genetic aberration may be a poor prognostic marker. The objective of this study was to identify differential expression of SMARCB1 in SNUC and to analyze and compare the survival outcomes in SNUC patients with and without SMARCB1 expression. Methods All cases of undifferentiated or poorly differentiated neoplasms of the sinonasal tract treated between 2007 and 2018 at a single tertiary care institution were selected. All cases of SNUC were tested for SMARCB1 status by immunohistochemistry (IHC). Clinical parameters were analyzed using Student's t -test and Fischer's test. Kaplan-Meier methods were used to estimate survival durations, while comparison between both the subgroups was done using the log-rank test. Statistical analysis was performed with the use of SPSS software, Version 25 (IBM, New York, NY, United States). Results Fourteen cases of SNUC were identified. Approximately two-thirds (64%; n = 9) of patients were male and the majority (79%; n = 11) were between fifth to seventh decade. Skull base and orbital invasion were seen in 79% ( n = 11) and 93% ( n = 13) of cases, respectively. Fifty-seven percent of tumors ( n = 8) retained SMARCB1 expression by IHC (SR-SNUC), while the remaining 43% ( n = 6) showed loss of SMARCB1 expression and, thus, were considered as SMARCB1 -deficient (SD-SNUC). Although clinicopathological features and treatment modalities were similar, SD-SNUC showed poorer (OS: p = 0.07; disease free survival [DFS]: p = 0.02) overall survival (OS) and DFS on Kaplan-Meier curves. Additionally, SD-SNUC showed higher recurrence (75 vs. 17%) and mortality (67 vs. 14%) (hazard rate = 8.562; p = 0.05) rates. Both OS (28.82 ± 31.15 vs. 53.24 ± 37.50) and DFS durations (10.62 ± 10.26 vs. 43.79 ± 40.97) were consistently worse for SD-SNUC. Five-year survival probabilities were lower for SD-SNUC (0.33 vs. 0.85). Conclusion SNUC represents a heterogeneous group of undifferentiated sinonasal malignancies. Based on the status of SMARCB1 expression, the two subgroups SD-SNUC and SR-SNUC appear to represent distinct clinical entities, with loss of SMARCB1 expression conferring an overall worse prognosis.

The Prevalence of Olfactory and Gustatory Dysfunction in COVID-19 Patients: A Systematic Review and Meta-analysis.

OBJECTIVE: To determine the pooled global prevalence of olfactory and gustatory dysfunction in patients with the 2019 novel coronavirus (COVID-19). DATA SOURCES: Literature searches of PubMed, Embase, and Scopus were conducted on April 19, 2020, to include articles written in English that reported the prevalence of olfactory or gustatory dysfunction in COVID-19 patients. REVIEW METHODS: Search strategies developed for each database contained keywords such as anosmia, dysgeusia, and COVID-19. Resulting articles were imported into a systematic review software and underwent screening. Data from articles that met inclusion criteria were extracted and analyzed. Meta-analysis using pooled prevalence estimates in a random-effects model were calculated. RESULTS: Ten studies were analyzed for olfactory dysfunction (n = 1627), demonstrating 52.73% (95% CI, 29.64%-75.23%) prevalence among patients with COVID-19. Nine studies were analyzed for gustatory dysfunction (n = 1390), demonstrating 43.93% (95% CI, 20.46%-68.95%) prevalence. Subgroup analyses were conducted for studies evaluating olfactory dysfunction using nonvalidated and validated instruments and demonstrated 36.64% (95% CI, 18.31%-57.24%) and 86.60% (95% CI, 72.95%-95.95%) prevalence, respectively. CONCLUSIONS: Olfactory and gustatory dysfunction are common symptoms in patients with COVID-19 and may represent early symptoms in the clinical course of infection. Increased awareness of this fact may encourage earlier diagnosis and treatment, as well as heighten vigilance for viral transmission. To our knowledge, this is the first meta-analysis to report on the prevalence of these symptoms in COVID-19 patients.

The Impact of the Pandemic on Otolaryngology Patients With Negative COVID-19 Status: Commentary and Insights From Orbital Emergencies.

Efforts aimed at minimizing the spread of COVID-19 and "flattening the curve" may be affecting clinical care delivery for non-COVID-19 cases that include otolaryngologic and orbital conditions. We are witnessing changes in the manner that patients present, as well as modifications in clinical management strategies. An improved understanding of these phenomena and the contributing factors is essential for otolaryngologists to provide sound clinical care during this unprecedented pandemic.

Predicting prolonged length of stay after endoscopic transsphenoidal surgery for pituitary adenoma.

BACKGROUND: Endoscopic transsphenoidal surgery (ETS) for the resection of pituitary adenoma has become more common throughout the past decade. Although most patients have a short postoperative hospitalization, others require a more prolonged stay. We aimed to identify predictors for prolonged hospitalization in the setting of ETS for pituitary adenomas. METHODS: A retrospective chart review as performed on 658 patients undergoing ETS for pituitary adenoma at a single tertiary care academic center from 2005 to 2019. Length of stay (LoS) was defined as date of surgery to date of discharge. Patients with LoS in the top 10th percentile (prolonged LoS [PLS] >4 days, N = 72) were compared with the remainder (standard LoS [SLS], N = 586). RESULTS: The average age was 54 years and 52.5% were male. The mean LoS was 2.1 days vs 7.5 days (SLS vs PLS). On univariate analysis, atrial fibrillation (p = 0.002), hypertension (p = 0.033), partial tumor resection (p < 0.001), apoplexy (p = 0.020), intraoperative cerebrospinal fluid (ioCSF) leak (p = 0.001), nasoseptal flap (p = 0.049), postoperative diabetes insipidus (DI) (p = 0.010), and readmission within 30 days (p = 0.025) were significantly associated with PLS. Preoperative continuous positive airway pressure (CPAP) (odds ratio, 15.144; 95% confidence interval, 2.596-88.346; p = 0.003) and presence of an ioCSF leak (OR, 10.362; 95% CI, 2.143-50.104; p = 0.004) remained significant on multivariable analysis. CONCLUSION: For patients undergoing ETS for pituitary adenomas, an ioCSF leak or preoperative use of CPAP predicted PLS. Additional common reasons for PLS included postoperative CSF leak (10 of 72), management of DI or hypopituitarism (15 of 72), or reoperation due to surgical or medical complications (14 of 72).

Management of Orbital Masses: Outcomes of Endoscopic and Combined Approaches With No Orbital Reconstruction.

INTRODUCTION: The endoscopic endonasal approach to management of orbital pathology has expanded. Due to the rarity of these conditions, most reports in the literature consist of small case reports. We report a series from a single institution with a focus on outcomes. METHODS: A retrospective chart review was carried out between 2010 and 2018. RESULTS: Twenty-four patients were identified (average age 58 years, 15 males, 9 females). Average follow-up was 14.9 months. Most common etiologies included cavernous hemangioma (7), metastases (6), idiopathic orbital inflammatory syndrome (6), orbital hematoma/clot (2), and schwannoma (1). Most common presenting symptoms were decreased visual acuity (8), proptosis (8), diplopia (7), and incidental findings (2). All patients underwent endoscopic medial wall orbital decompressions. Sixteen involved a combined open approach by an ophthalmologist. Pathology was either biopsied (15), resected (6), or could not be identified (3). No intraoperative complications were noted. No patients underwent orbital reconstruction of the medial wall. Six patients developed postoperative sinusitis successfully managed with antibiotics. One patient developed epistaxis managed conservatively. In 5 patients, Sino-Nasal Outcome Test-22 scores increased immediately postop and then decreased, whereas scores only decreased in 6 patients. Six patients noted reduced proptosis. There were no new cases of diplopia or worsening visual acuity. CONCLUSIONS: A combined endoscopic endonasal and external approach can be useful for managing orbital lesions. Patients tolerated the procedure well with improvement in ocular symptoms and minimal sinonasal complications. Reconstruction of the medial wall may not be warranted to prevent postoperative diplopia.

Rate of rhinosinusitis and sinus surgery following a minimally destructive approach to endoscopic transsphenoidal hypophysectomy.

BACKGROUND: There remains considerable variation in the extent of sinonasal preservation during the approach for endoscopic transsphenoidal hypophysectomy (TSH). We advocate for a minimally destructive approach utilizing turbinate lateralization, small posterior septectomy, no ethmoidectomy, and preservation of nasoseptal flap (NSF) pedicles bilaterally. Due to these factors, this approach may affect the rates of postoperative rhinosinusitis. The objective of this study is to define the rates of postoperative rhinosinusitis in patients undergoing this approach. METHODS: Single institution, retrospective chart review of patients undergoing TSH from 2005 to 2018. RESULTS: A total of 415 patients were identified and 14% developed an episode of postoperative rhinosinusitis within 3 months. These patients were significantly more likely to have had a history of recurrent acute or chronic rhinosinusitis. Most cases were sphenoethmoidal sinusitis managed with 1 to 2 courses of antibiotics. Of patients with postoperative rhinosinusitis, most did not undergo NSF. Average follow-up was 38 months. Six patients (1.4%) underwent post-TSH functional endoscopic sinus surgery (FESS). Average time from TSH to FESS was 26.3 months. Two of these patients had a history of prior chronic rhinosinusitis without polyposis. Two patients underwent revision TSH for recurrent tumor as the primary indication for surgery at time of FESS. Twenty-two-item Sino-Nasal Outcome Test (SNOT-22) scores generally increased immediately postoperatively, but frequently decreased below preoperative level by the time of last follow-up, regardless of whether patients developed rhinosinusitis. CONCLUSION: Sinonasal preservation during TSH is associated with a low rate of postoperative rhinosinusitis requiring FESS and excellent long-term patient reported outcomes. We continue to advocate for sinonasal preservation during pituitary surgery.

Management of Nonfunctioning Recurrent Pituitary Adenomas.

Pituitary adenomas are typically slow-growing benign tumors. However, 50% to 60% of tumors progress following subtotal resection and up to 30% recur after apparent complete resection. Options for treatment of recurrent pituitary adenomas include repeat surgical resection, radiation therapy, and systemic therapies. There is no consensus approach for the management of recurrent pituitary adenomas. This article reviews the natural history of recurrent adenomas and emerging biomarkers predictive of clinical behavior as well as the outcomes associated with the various treatment modalities for these challenging tumors, with an emphasis on the surgical treatment.

Orientation of the premaxilla in the origin of septal deviation.

INTRODUCTION: While most people believe the nasal septum to have intrinsic deviation and overgrowth in patients seeking rhinoplasty, an alternative concept is that a mal-oriented premaxilla causes extrinsic septal buckling and external extrusion of the septal cartilage. In this sense, the premaxillary bone plays a significant role in the pathogenesis of septal deviation. This study was performed to determine if non-traumatically acquired septal/nasal functional and aesthetic pathology or septal deviation may be related to the orientation of the premaxilla relative to the skullbase. METHODS: A retrospective, single-center study of patients in the general population who underwent maxillofacial CT scans and presented for the evaluation of nasal obstruction. CT scans were used to measure features of both pathologic and non-pathologic nasal septums. RESULTS: A total of 68 subjects were evaluated. When comparing patients with a premaxillary-skullbase angle of greater than 81° (the mean of the study group) to those of less than 81°, and a more obtuse nasolabial angle was observed (p = 0.0269). When comparing the extremes of premaxillary rotation, specifically, greater than 87° (mean 91.7°, SD 5.1) and less than 77° (mean 70.7°, SD 3.6), the differences were more pronounced with regard to caudal septal excess (p = 0.0451) and septal deviation in the axial plane (p = 0.0150). CONCLUSION: Septal developmental changes may involve an overly rotated or more vertically oriented premaxillary bone relative to the skull base. An understanding of the cause of septal deformity may provide insight into the design of improved treatments.

Adenosine-induced transient hypotension for carotid artery injury during endoscopic skull-base surgery: case report and review of the literature.

BACKGROUND: As the management of ventral skull-base pathology has transitioned from open to endonasal treatment, there has been an increased focus on the prevention and endoscopic endonasal management of internal carotid artery (ICA) and major vascular injury. The use of adenosine to induce transient hypotension or flow arrest has been previously described during intracranial aneurysm surgery; however, there have been no reports of the technique being used during endonasal skull-base surgery to achieve hemostasis following major vascular injury. METHODS: Case report (n = 1) and literature review. RESULTS: A 25-year-old female underwent attempted endoscopic endonasal resection of an advanced right-sided chondrosarcoma. During resection of the tumor, brisk arterial bleeding was encountered consistent with focal injury to the right cavernous ICA. Stable vascular hemostasis could not be achieved with tamponade. An intravenous bolus dose of adenosine was administered to induce a transient decrease in systemic blood pressure and facilitate placement of the muscle patch over the direct site of vascular injury. The patient subsequently underwent endovascular deconstruction of the right ICA. CONCLUSION: This is the first reported use of adenosine to induce transient hypotension for a major vascular injury sustained during endonasal skull-base surgery. Based on well-established safety data from neurosurgical application, adenosine has the potential to be used as a safe and effective adjunctive technique in similar endonasal circumstances and may represent an additional tool in the armamentarium of the skull-base surgeon. Surgeons should consider having adenosine available when a risk of ICA injury is anticipated.

Evaluation of cranial base repair techniques utilizing a novel cadaveric CPAP model.

BACKGROUND: Although recent guidelines for obstructive sleep apnea recommend early postoperative use of continuous positive airway pressure (CPAP) after endonasal skull base surgery, the time of initiation of CPAP is unclear. In this study we used a novel, previously validated cadaveric model to analyze the pressures delivered to the cranial base and evaluate the effectiveness of various repair techniques to withstand positive pressure. METHODS: Skull base defects were surgically created in 3 fresh human cadaver heads and repaired using 3 commonly used repair techniques: (1) Surgicel™ onlay; (2) dural substitute underlay with dural sealant onlay; and (3) dural substitute underlay with nasoseptal flap onlay with dural sealant. Pressure microsensors were placed in the sphenoid sinus and sella, both proximal and distal to the repair, respectively. The effectiveness of each repair technique against various CPAP pressure settings (5-20 cm H2 O) was analyzed. RESULTS: Approximately 79%-95% of positive pressure administered reached the sphenoid sinus. Sellar pressure levels varied significantly across the 3 repair techniques and were lowest after the third technique. "Breach" points (CPAP settings at which sellar repair was violated) were lowest for the first group. All 3 specimens showed a breach after the first repair technique. For the second repair technique, only a single breach was created in 1 specimen at 20 cm H2 O. No breaches were created in the third group. CONCLUSION: Different skull base repair techniques have varying ability to withstand CPAP. Both second and third repair techniques performed in a nearly similar fashion with regard to their ability to withstand positive pressure ventilation.