Charles S. Ebert

Minimally Invasive Pituitary Surgery

Objectives/Hypothesis: Surgical approaches to the pituitary have undergone numerous refinements over the last 100 years. The introduction of the endoscope and the advent of minimally invasive pituitary surgery (MIPS) have revolutionized pituitary surgery. This study aims to compile and evaluate outcomes of all of the MIPS performed at our institution.

Endoscopic skull base reconstruction: a review and clinical case series of 152 vascularized flaps used for surgical skull base defects in the setting of intraoperative cerebrospinal fluid leak.

Endoscopic skull base surgery continues to rapidly evolve, requiring comparable advances in reconstructive techniques. While smaller skull base defects with low intraoperative CSF flow have been successfully managed with a variety of avascular and/or noncellular techniques, larger defects with high CSF flow require more robust repairs often in the form of vascularized flaps, which confer excellent success rates in this setting. Despite these successful outcomes, a paucity of data describing specific patient and operative characteristics and their effects on repair exist. Therefore, a retrospective, consecutive chart review was performed on patients who underwent endoscopic skull base reconstruction with a vascularized flap in the setting of intraoperative CSF leaks. In this series, 151 patients with a mean age of 51 years underwent 152 vascularized flap skull base reconstructions for an array of benign and malignant pathologies. These vascularized flaps included 144 nasoseptal flaps, 6 endoscopic-assisted pericranial flaps, 1 facial artery buccinator flap, and 1 inferior turbinate flap that were used throughout all regions of the skull base. Perioperative (< 3 months) and postoperative (> 3 months) flap complications were assessed and revealed 3 perioperative flap defects (2.0%) defined as a visualized defect within the substrate of the flap and a total of 5 perioperative CSF leaks (3.3%). No patient experienced flap death/complete flap loss in the cohort. Assessed postoperative flap complications included 1 case (0.7%) of mucocele formation, 8 cases (5.3%) of prolonged skull base crusting, and 2 cases (1.3%) of donor-site complication, specifically septal perforation secondary to nasoseptal flap harvest. Among the 152 cases identified, 37 patients received radiation therapy while 114 patients did not undergo radiation therapy as part of the treatment profile. No significant association was found between perioperative complication rates and radiation therapy (p = 0.634). However, a significant association was found between postoperative complication rates and radiation therapy, primarily accounted for by an increased risk for prolonged (> 6 months) skull base crusting (p = 0.025). It is clear that larger skull base defects with high intraoperative CSF flow require thoughtful approach and strong consideration for vascularized repair.

The Impact of Sleep-Disordered Breathing on Cognition and Behavior in Children: A Review and Meta-Synthesis of the Literature

OBJECTIVES: The goal of this review is to provide a synthesis of the current literature addressing the effects of sleep-disordered breathing on cognition and behavior in children aged 2–18. STUDY DESIGN AND SETTING: A computerized search was performed to include studies between 1966 and 2001. Studies were assessed based on research question, sampling, intervention, outcomes, confounding, and statistical methods. Sensitivity analyses were performed for quantitative assessments of selection bias, misclassification, and confounding. RESULTS: Seventeen reports with 5312 patients were reviewed. The majority of these studies demonstrated poor sampling, insufficient consideration of confounders, and imprecise use of statistical tools. However, there was little evidence of bias in two studies when scrutinized using a sensitivity analysis. CONCLUSIONS: Despite suggested links between daytime behavior problems and neurocognitive deficits, there is little certainty for causality based on the quality of the evidence. SIGNIFICANCE: By discussing the quality of the current evidence, we hope to improve study design and contribute to the development of an understanding of this complex topic.

Detection of interaural correlation by neurons in the superior olivary complex, inferior colliculus and auditory cortex of the unanesthetized rabbit

A critical binaural cue important for sound localization and detection of signals in noise is the interaural time difference (ITD), or difference in the time of arrival of sounds at each ear. The ITD can be determined by cross-correlating the sounds at the two ears and finding the ITD where the correlation is maximal. The amount of interaural correlation is affected by properties of spaces and can therefore be used to assess spatial attributes. To examine the neural basis for sensitivity to the overall level of the interaural correlation, we identified subcollicular neurons and neurons in the inferior colliculus (IC) and auditory cortex of unanesthetized rabbits that were sensitive to ITDs and examined their responses as the interaural correlation was varied. Neurons at each brain level could show linear or non-linear responses to changes in interaural correlation. The direction of the non-linearities in most neurons was to increase the slope of the response change for correlations near 1.0. The proportion of neurons with non-linear responses was similar in subcollicular and IC neurons but increased in the auditory cortex. Non-linear response functions to interaural correlation were not related to the type of response as determined by the tuning to ITDs across frequencies. The responses to interaural correlation were also not related to the frequency tuning of the neuron, unlike the responses to ITD, which broadens for neurons tuned to lower frequencies. The neural discriminibility of the ITD using frozen noise in the best neurons was similar to the behavioral acuity in humans at a reference correlation of 1.0. However, for other reference ITDs the neural discriminibility was more linear and generally better than the human discriminibility of the interaural correlation, suggesting that stimulus rather than neural variability is the basis for the decline in human performance at lower levels of interaural correlation.

Anatomical considerations for endoscopic endonasal skull base surgery in pediatric patients

Pediatric skull base surgery is limited by several boney sinonasal landmarks that must be overcome prior to tumor dissection. When approaching a sellar or parasellar tumor, the piriform aperture, sphenoid sinus pneumatization, and intercarotid distances are areas of potential limitation. Quantitative pediatric anatomical measurements relevant to skull base approaches are lacking. Our goal was to use radio‐anatomic analysis of computed tomography scans to determine anatomical limitations for trans‐sphenoidal approaches in pediatric skull base surgery.

Clear cell odontogenic carcinoma: A comprehensive analysis of treatment strategies

Odontogenic neoplasms of predominately clear cells are unusual. They represent a diagnostic dilemma, and as a result, treatment strategies are diverse. Our goal is to present two new cases, summarize reported cases of clear cell odontogenic carcinoma (CCOC), assess potential risk factors for recurrence, and propose definitive surgical and therapeutic strategies.

Radiation Dose to the Eyes and Parotids during CT of the Sinuses

OBJECTIVE: To measure the radiation dose to the lens and parotid during high-resolution computed tomography scan of the sinuses. STUDY DESIGN AND SETTING: Nine cadaver heads were scanned in the axial plane by means of a fine-cut (0.75 mm) protocol. Images were then reconstructed in the coronal and sagittal planes for use with the image guidance software. Thermoluminescent dosimeters were taped over the eyes and parotids and used to measure the radiation dose absorbed by these organs. RESULTS: Doses obtained were 29.5 mGy for the lens and around 30 mGy for the parotid. CONCLUSION: The measured doses are lower than the reported acute thresholds of 500-2000 mGy for lens opacities and well below the threshold of 2500 mGy for damage to the parotid. SIGNIFICANCE: These results demonstrate minimal risk from radiation through the use of high-resolution computed tomography and support the use of such a protocol for diagnosis and preoperative planning.

Concordance of middle meatal swab and maxillary sinus aspirate in acute and chronic sinusitis: a meta-analysis.

Background The medical management of acute and chronic sinusitis is a therapeutic challenge. The use of endoscopic middle meatal cultures as a noninvasive method to determine the bacteriology of the maxillary sinus has not accurately been established. The aim of this study was to review the literature that compares cultures obtained by endoscopic middle meatal swabs with those obtained from maxillary sinus aspirates (MSAs). Methods We reviewed studies published between January 1966 and October 2003 that were identified from searches of multiple databases, bibliographies, and original articles. Studies were included for analysis if they compared the results of endoscopic middle meatal cultures to aspirate cultures. All clinical variables and test performances were independently extracted by two reviewers. Results Middle meatal culture had a per isolate accuracy of 82% (95% confidence interval, 0.64, 0.92) compared with MSA (excluding coagulase negative staphylococcus and fungal cultures). Conclusion Endoscopic middle meatal cultures have a high concordance with MSAs.

Staged Endoscopic and Combined Open/Endoscopic Approach in the Management of Inverted Papilloma of the Frontal Sinus

Background The endoscopic management of inverted papilloma has gained increasing popularity over the last 10 years. Although early concerns over an increased risk of recurrence seem to have been allayed, the appropriate management of lesions involving the frontal sinus and frontal recess still has to be determined. Methods We performed a retrospective review of the results of all patients with inverted papilloma from 2000 to 2004. Results A total of 18 patients were treated between October 2000 and January 2004. Six patients had frontal sinus involvement at the time of initial evaluation. One of these patients had isolated frontal sinus involvement. These patients were managed with either initial endoscopic resection with determination for the need for an additional procedure at the time of endoscopic resection (n = 5) or open/endoscopic approach for isolated frontal sinus involvement (n = 1). Of the five patients who had their disease managed endoscopically, three patients were determined at the initial procedure to need an osteoplastic flap and, subsequently, were managed successfully with a combined approach. One other patient was initially successfully managed endoscopically but ultimately required an osteoplastic flap for definitive management. The fifth patient was managed entirely endoscopically with multiple procedures. All patients treated with this protocol remain disease free with an average follow-up of 13.3 months. Conclusion The limitations of endoscopic resection of inverted papilloma of the frontal recess can be managed with staged procedures. Initial endoscopic resection of ethmoid/maxillary disease with subsequent open treatment of the frontal sinus has been successful in our experience.

Quantification of airflow into the maxillary sinuses before and after functional endoscopic sinus surgery.

The effects of increases in maxillary sinus (MS) airflow following functional endoscopic sinus surgery (FESS) are unknown. The goal of this study was to quantify the effects of FESS on airflow into the MS in a cohort of patients with chronic rhinosinusitis, and compare MS flow rate with patient‐reported outcome measures.