Faculty Bibliography

BACKGROUND: Successful reconstruction of large anterior skull base (ASB) defects after craniofacial resection of malignant skull base tumors is paramount for preventing cerebrospinal fluid (CSF) fistulas. The vascularized pedicled pericranial flap (PCF) has been the gold standard for repairing ASB defects after transbasal transcranial approaches. However, flap necrosis and delayed CSF leaks can occur after adjuvant radiation therapy. We describe a "double flap" reconstruction technique in which the PCF is augmented inferiorly by a secondary vascularized pedicled nasoseptal flap (NSF) that is harvested and rotated using an endoscopic endonasal approach. METHODS: This technique is illustrated in 2 patients who underwent a combined cranionasal (transbasal and endoscopic endonasal) approach for large sinonasal malignancies with significant intracranial extension (1 esthesioneuroblastoma, 1 sinonasal teratocarcinosarcoma). After tumor removal via a combined cranionasal approach, primary repair of the ASB dural defect was performed with a free patch graft. The ASB defect was then repaired using the double flap technique with a vascularized PCF from above and augmented with a vascularized NSF from below. RESULTS: Postoperatively, there were no complications of CSF leakage, meningitis, or tension pneumocephalus in both patients. After subsequent radiation therapy, the double flap repair remained intact at 2 years postoperatively in both patients. CONCLUSION: The double flap skull base reconstruction technique provides an additional barrier of vascularized tissue to prevent CSF leakage, meningitis, tension pneumocephalus, and postradiation necrosis. This technique is a viable option if a combined transcranial and transnasal endoscopic tumor resection is performed and postoperative radiation is anticipated.

PURPOSE: The vascularized pedicled nasoseptal flap (PNSF) represents a successful option for reconstruction of large skull base defects after expanded endoscopic endonasal approaches (EEA). This vascularized flap can be harvested early or late in the operation depending on the anticipation of high-flow CSF leaks. Each harvesting technique (early vs. late) is associated with different advantages and disadvantages. In this study, we evaluate our experience with early harvesting of the PNSF for repair of large skull base defects after EEA. METHODS: A retrospective review was performed at a tertiary care medical center on patients who underwent early PNSF harvesting during reconstruction of intraoperative high-flow CSF leaks after EEA between December 2008 and March 2012. Demographic data, repair materials, surgical approach, and incidence of PNSF usage were collected. RESULTS: Eighty-seven patients meeting the inclusion criteria were identified. In 86 procedures (98.9%), the PNSF harvested at the beginning of the operation was used. In 1 case (1.1%), the PNSF was not used because a high-flow intraoperative CSF leak was not encountered. This patient had recurrence of intradural disease 8months later, and the previously elevated PNSF was subsequent used after tumor resection. CONCLUSION: Based on our data, a high-flow CSF leak and need for a PNSF can be accurately anticipated in patients undergoing EEA for skull base lesions. Because of the advantages of early harvesting of the PNSF and the high preoperative predictive value of CSF leak anticipations, this technique represents a feasible harvesting practice for EEA surgeries.

BACKGROUND: Endoscopic endonasal transcribriform (EET) resection of anterior skull base (ASB) tumors results in large defects that may extend the entirety of the cribriform plate. Endoscopic repair of these cribriform defects can often be challenging. We describe our reconstruction technique for large ASB defects after EET resection of ASB tumors. This triple-layer technique is comprised of autologous fascia lata, acellular dermal allograft, and a vascularized pedicled nasoseptal flap (PNSF). The technique is described and postoperative cerebrospinal fluid (CSF) leak rate is evaluated. METHODS: Retrospective review over a 2-year period identified 10 patients who underwent a purely EET approach for resection of ASB tumors. Patients who underwent combined cranionasal approaches and those treated for ASB encephaloceles were excluded from this study. After tumor resection, patients underwent triple-layer reconstruction using autologous fascia lata inlay, acellular dermal allograft inlay/overlay, followed by a PNSF to reconstruct the cribriform defect. No postoperative lumbar drainage was used. RESULTS: The average cribriform defect size was 9.1 (range, 5.0-13.8) cm(2) . All 10 patients underwent successful reconstruction with a postoperative CSF leak rate of 0% without the use of postoperative lumbar drainage. The mean follow-up period was 7.4 (range, 2-17) months. The mean age was 45.8 (range, 15-81) years with 30% of the patients being females. CONCLUSION: The triple-layer reconstruction technique is effective in reconstructing large ASB defects after endoscopic resection of the cribriform plate. We feel that the use of postoperative lumbar drainage is not necessary when using this repair technique.

PURPOSE: Identification and exposure of the frontal sinus recess (FSR) during endoscopic sinus surgery (ESS) are challenging due to the variable anatomy, the narrow opening of the frontal sinus ostium (FSO), and the proximity of vital anatomic structures. Hence, a strong understanding of frontal sinus anatomy is required to prevent intracranial entry. Consistent and easily identifiable landmarks and measurements could assist safe entry into the FSO. In this study, we determine the distances from the columella and anterior nasal spine (ANS) to the nasofrontal beak (NFB) and anterior skull base (ASB) using high-resolution computed tomography (HRCT) scans. METHODS: A radiographic analysis was performed at a tertiary care medical center. Measurements from the ANS to the NFB and ASB, and from the columella to the NFB and ASB were made using sagittal HRCT. Thirty-two HRCT scans were analyzed by three observers, and the mean distances and standard deviations were calculated. RESULTS: The mean distance from the ANS to the NFB was 52.3+/-3.4mm in men and 47.7+/-3.5mm in women (p<0.0001). Mean distance from the ANS to the ASB was 61.8+/-4.1mm in men and 56.5+/-4.1mm in women (p<0.0001). Mean distance from the columella to the NFB was 58.9+/-2.3mm in men and 53.0+/-3.3mm in women (p<0.0001), and from the columella to the ASB was 67.9+/-3.7mm in men and 61.3+/-4.1mm in women (p<0.0001). CONCLUSION: While performing FSR exposure in ESS, it is recommended to stay a distance of less than 66.9mm in men and 60.6mm in women from the columella to minimize intracranial complications.

OBJECTIVE/HYPOTHESIS: The h-index is an objective and easily calculable measure that can be used to evaluate both the relevance and amount of scientific contributions of an individual author. Our objective was to examine how the h-index of academic otolaryngologists relates with academic rank. STUDY DESIGN: A descriptive and correlational design was used for analysis of academic otolaryngologists' h-indices using the Scopus database. METHODS: H-indices of faculty members from 50 otolaryngology residency programs were calculated using the Scopus database, and data was organized by academic rank. Additionally, an analysis of the h-indices of departmental chairpersons among different specialties was performed. RESULTS: H-index values of academic otolaryngologists were higher with increased academic rank among the levels of assistant professor, associate professor, and professor. There was no significant difference between the h-indices of professors and department chairpersons within otolaryngology. H-indices of chairpersons in different academic specialties were compared and were significantly different, suggesting that the use of this metric may not be appropriate for comparing different fields. CONCLUSIONS: The h-index is a reliable tool for quantifying academic productivity within otolaryngology. This measure is easily calculable and may be useful when evaluating decisions regarding advancement within academic otolaryngology departments. Comparison of this metric among faculty members from different fields, however, may not be reliable.

PURPOSE: The aim of this study was to compare the readability of online patient education materials among academic otolaryngology departments in the mid-Atlantic region, with the purpose of determining whether these commonly used online resources were written at a level readily understood by the average American. METHODS: A readability analysis of online patient education materials was performed using several commonly used readability assessments including the Flesch Reading Ease Score, the Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook, Gunning Frequency of Gobbledygook, the New Dale-Chall Test, the Coleman-Liau Index, the New Fog Count, the Raygor Readability Estimate, the FORCAST test, and the Fry Graph. RESULTS: Most patient education materials from these programs were written at or above an 11th grade reading level, considerably above National Institutes of Health guidelines for recommended difficulty. CONCLUSIONS: Patient educational materials from academic otolaryngology Web sites are written at too difficult a reading level for a significant portion of patients and can be simplified.

OBJECTIVES/HYPOTHESIS: The endoscopic endonasal transcribriform approach (EETA) is a viable alternative option for resection of selected anterior skull base (ASB) tumors. However, this technique results in the creation of large cribriform defects. Some have reported the use of a rigid substitute for ASB reconstruction to prevent postoperative frontal lobe sagging. We evaluate the degree of frontal lobe sagging using our triple-layer technique [fascia lata, acellular dermal allograft, and pedicled nasoseptal flap (PNSF)] without the use of rigid structural reconstruction for large cribriform defects. STUDY DESIGN: Retrospective analysis. METHODS: Nine patients underwent an EETA for resection of large ASB tumors from August 2010 to November 2011. The degree of frontal lobe displacement after EETA, defined as the ASB position, was calculated based on the most inferior position of the frontal lobe relative to the nasion-sellar line defined on preoperative and postoperative imaging. A positive value signified upward displacement, and a negative value represented inferior displacement of the frontal lobe. RESULTS: The average cribriform defect size was 9.3 cm(2) (range, 5.0-13.8 cm(2) ). The average distance of postoperative frontal lobe displacement was 0.2 mm (range, -3.9 to 2.9 mm) without any cases of significant brain sagging. The mean follow-up period was 10.1 months (range, 4-19 months). There were no postoperative CSF leaks. CONCLUSIONS: Rigid structural repair may not be necessary for ASB defect repair after endoscopic endonasal resection of the cribriform plate. Our technique for multilayer cranial base reconstruction appears to be satisfactory in preventing delayed frontal lobe sagging.

PURPOSE: Persistent cerebrospinal fluid (CSF) rhinorrhea after open skull base surgery can be challenging to manage due to the risk of meningitis, brain abscess, surgical morbidity associated with revision craniotomy, and the lack of available healthy autologous tissue after failure of a pericranial flap. Given the recent success of the vascularized pedicled nasoseptal flap (PNSF) for reconstruction after endoscopic skull base surgery, we have adopted this technique as a salvage method to treat recalcitrant CSF rhinorrhea after previous open skull base surgery in order to avoid revision craniotomy. To our knowledge, use of the PNSF in this setting has not been previously described in the literature. METHODS: A retrospective analysis was performed on 4 patients who underwent endoscopic endonasal PNSF repair of persistent CSF rhinorrhea after having undergone previous open transcranial skull base operation. Pathologies consisted of one sinonasal anterior skull base squamous cell carcinoma, one recurrent petrosal skull base meningioma, and 2 traumatic gunshot wounds to the head. RESULTS: All 4 patients underwent successful repair of CSF rhinorrhea without complications using the salvage endoscopic endonasal PNSF technique after a mean follow-up of 21.5 months. CONCLUSIONS: In patients who have undergone previous open skull base surgery as the primary approach, persistent CSF rhinorrhea can be safely repaired using the vascularized PNSF via an endoscopic endonasal approach. This minimally invasive strategy has the advantage of providing new healthy vascularized tissue for skull base reconstruction while avoiding revision craniotomy.

BACKGROUND: High-grade dural arteriovenous fistulas (DAVFs) with retrograde cortical leptomeningeal drainage are formidable lesions because of their risk for intracranial hemorrhage. Treatment is aimed at occluding venous outflow to achieve obliteration of the fistula. In DAVFs that involve a large dural venous sinus (transverse sigmoid sinus or superior sagittal sinus), occluding venous outflow can be accomplished endovascularly with transvenous embolization. However, in some cases of DAVFs with reflux into cortical leptomeningeal veins, there may be venous restrictive disease downstream, such as occlusive thrombosis, which can prohibit endovascular access via the transfemoral or transjugular routes. In these instances, a transcranial approach can be performed to expose the large dural venous sinus distal to the site of occlusion for direct catheterization of the venous outflow for transvenous embolization. This combined surgical and endovascular strategy provides direct access to the venous outflow and bypasses the site of thrombotic obstruction. METHODS: In this report, we describe our technique of single stage surgically-assisted transvenous embolization in three patients with high-grade DAVFs involving a large dural sinus. RESULTS: All patients achieved complete obliteration of their DAVFs without any venous related complications. CONCLUSION: Our technique of surgically-assisted direct transvenous embolization of high-grade DAVFs can be successfully performed as a single stage in the operating room with intraoperative angiography and stereotactic image guidance.