Abtin Tabaee

Endoscopic cranial base surgery: classification of operative approaches.

OBJECTIVE Endoscopic cranial base surgery is a minimal access, maximally aggressive alternative to traditional transfacial, transcranial, or combined open cranial base approaches. Previous descriptions of endoscopic approaches have used varying terminology, which can be confusing to the new practitioner. Indications for surgery are not well defined. Our objective was to create a comprehensive classification system of the various approaches and describe their indications with case examples. METHODS We prospectively compiled a comprehensive database of our endonasal endoscopic operations, detailing the nasal sinus transgressed, the cranial base approach, and the intracranial target for the first 150 consecutive cases performed at our institution. All cases were performed collaboratively by a neurosurgeon and an otolaryngologist. RESULTS We categorized the endonasal endoscopic cranial base operations into four nasal corridors, nine cranial base approaches, and 13 intracranial targets. Each of the various approaches is described in detail and illustrated with case examples. Pathology encountered included pituitary tumor (50%), meningocele/encephalocele (14%), craniopharyngioma and Rathke cleft cyst (10%), meningioma (8%), chordoma (5%), esthesioneuroblastoma (2%), and other (11%). CONCLUSION Endonasal endoscopic cranial base surgery is a minimal access, maximally invasive alternative to open transcranial cranial base approaches for specific indications. A clear understanding of the possible approaches is facilitated by an awareness of the nasal corridors and intracranial targets.

Three-dimensional endoscopic pituitary surgery.

OBJECTIVE We describe a novel 3-dimensional (3-D) stereoendoscope and discuss our early experience using it to provide improved depth perception during transsphenoidal pituitary surgery. METHODS Thirteen patients underwent endonasal endoscopic transsphenoidal surgery. A 6.5-, 4.9-, or 4.0-mm, 0- and 30-degree rigid 3-D stereoendoscope (Visionsense, Ltd., Petach Tikva, Israel) was used in all cases. The endoscope is based on “compound eye” technology, incorporating a microarray of lenses. Patients were followed prospectively and compared with a matched group of patients who underwent endoscopic surgery with a 2-dimensional (2-D) endoscope. Surgeon comfort and/or complaints regarding the endoscope were recorded. RESULTS The 3-D endoscope was used as the sole method of visualization to remove 10 pituitary adenomas, 1 cystic xanthogranuloma, 1 metastasis, and 1 cavernous sinus hemangioma. Improved depth perception without eye strain or headache was noted by the surgeons. There were no intraoperative complications. All patients without cavernous sinus extension (7of 9 patients) had gross tumor removal. There were no significant differences in operative time, length of stay, or extent of resection compared with cases in which a 2-D endoscope was used. Subjective depth perception was improved compared with standard 2-D scopes. CONCLUSION In this first reported series of purely 3-D endoscopic transsphenoidal pituitary surgery, we demonstrate subjectively improved depth perception and excellent outcomes with no increase in operative time. Three-dimensional endoscopes may become the standard tool for minimal access neurosurgery.

Safety of low-dose intrathecal fluorescein in endoscopic cranial base surgery.

OBJECTIVE Intraoperative identification of cerebrospinal fluid (CSF) leakage is critical in successful closure after endoscopic cranial base surgery. Intrathecal injection of fluorescein is quite useful in identifying CSF leaks. However, complications have been reported with various doses and the technique has fallen out of favor. We explored the safety of low-dose intrathecal fluorescein administered to patients undergoing endoscopic cranial base surgery. METHODS A retrospective chart review and postoperative patient survey were performed. The nature and incidence of complications and subjective complaints were recorded in 54 patients who underwent endoscopic, endonasal approaches to the anterior cranial base and received intrathecal fluorescein after premedication with dexamethasone and diphenhydramine. RESULTS Intraoperative CSF leak was identified with fluorescein in 46.3% of the patients and helped determine the reconstruction technique. Postoperative CSF leak occurred in 9.3% of the patients and resolved with lumbar drainage. There were no seizures. Most side effects were nonspecific, transient, and likely not caused by fluorescein including malaise (57.4%), headache (51.9%), dizziness (31.5%), or nausea/vomiting (24.1%). Three patients (5.6%) experienced persistent subjective lower extremity weakness (n = 2) and numbness (n = 2) postoperatively; however, two of them had undergone lumbar drainage. CONCLUSION Low-dose injection of intrathecal fluorescein after premedication with steroid and antihistamine agents is generally safe. Most symptoms are nonspecific and transient, likely caused by the surgery or lumbar drainage. However, fluorescein should be administered with some caution because it may be responsible for occasional lower extremity weakness and numbness.

Intrathecal Fluorescein in Endoscopic Skull Base Surgery

OBJECTIVES: Reconstruction following endoscopic skull base surgery requires a high degree of success to avoid the morbidity of postoperative cerebrospinal fluid (CSF) leak. The impact on outcomes of CSF visualization with intrathecal fluorescein, however, is unknown. STUDY DESIGN: A retrospective review of patients undergoing endoscopic skull base surgery with intrathecal fluorescein. A possible correlation between intraoperative fluorescein identification and postoperative CSF leak was analyzed. RESULTS: 61 patients underwent surgery for a variety of lesions including pituitary adenoma (55.7%), encephalocele (14.8%), and meningioma (9.8%). Seven (19.4%) of the 37 patients with intraoperative fluorescein leak experienced postoperative CSF leak compared to 0 of the 24 patients who did not have intraoperative fluorescein leak (P = 0.02). All cases of CSF leak resolved with lumbar drainage alone. CONCLUSIONS: The lack of intraoperative fluorescein leak-age correlates strongly with a low risk for postoperative CSF leak. This can be used to stratify the extent of skull base reconstruction required during endoscopic skull base surgeries.

Three-dimensional endoscopic sinus surgery: Feasibility and technical aspects

The development of endoscopic techniques for a variety of sinonasal disorders has paralleled advances in technology and instrumentation including angled endoscopes, multi-chip cameras, and image guidance. Despite the progressive technological innovations in modern endoscopic surgery, the visualization that is currently used remains 2-dimensional (2D). This is associated with significant limitations, notably a lack of depth perception. Although visual and haptic cues allow for a surgeon to understand the spatial relationships of the various structures, current visualization technology fails to provide the 3-dimensional (3D) perspective that is available in open and microscopic surgery. The development of a miniature stereoscopic camera and its adaptation to rigid endoscopes allows for performance of 3D endoscopic sinus surgery. It is hypothesized that incorporation of 3D visualization may enhance the spatial resolution required in advanced endoscopic approaches with a theoretical potential to improve outcomes. TECHNOLOGY Following Institutional Review Board approval and a trial in a cadaver laboratory, a prospective study of 3D endoscopic sinus surgery with a miniature stereoscopic camera (Visionsense Ltd, Petach Tikva, Israel) was carried out. All patients underwent fully endoscopic, endonasal approaches to the anterior skull base with a 6.5 mm, 3D 0 degree stereoscopic endoscope (Figs 1 and 2). The procedures were performed by the senior authors (VKA, THS). The endoscope was used for the entire sinonasal approach and select portions of the intracranial aspect of the procedure. At the time of the study, only a 0 degree 3D endoscope was available. Angled 2D endoscopes were, therefore, also used for suprasellar and lateral visualization. Twelve patients underwent endoscopic, endonasal, transsphenoidal surgery during this study. The indication for surgery included pituitary lesions in nine cases, cerebrospinal fluid leaks in two patients, and craniopharyngioma in one patient. Bilateral transnasal sphenoidotomies were carried out in each patient with the 3D endoscope. One patient additionally underwent a complete ethmoidectomy for further visualization of a spheno-ethmoidal encephalocele. There were no intraoperative or postoperative complications noted during the study. Qualitative assessments by the surgical team revealed improved depth perception and improved recognition of anatomic structures especially the carotid artery and optic nerve prominences in the lateral sphenoid wall. There was no subjective increase in the operative time with the incorporation of the 3D endoscopes.

Hematoma of the maxillary sinus presenting as a mass— a case report and review of literature

We report a case of an organized hematoma of the maxillary sinus presenting with proptosis, facial numbness and a maxillary sinus mass. A review of the literature highlights potential etiologic factors. A diagnostic and therapeutic approach to this uncommon lesion is also discussed.

Patient-controlled comparison of flexible endoscopic evaluation of swallowing with sensory testing (FEESST) and videofluoroscopy.

Objective: The objective of this study was to compare the results of videofluoroscopy (VFS) with flexible endoscopic evaluation of swallowing with sensory testing (FEESST) in dysphagia testing.

The efficacy of computer assisted surgery in the endoscopic management of cerebrospinal fluid rhinorrhea

OBJECTIVE: To determine the outcome of endoscopic repair of cerebrospinal fluid (CSF) rhinorrhea with and without computer assisted surgery. STUDY DESIGN: A review of all patients undergoing endoscopic closure of CSF rhinorrhea at a tertiary care medical center between 1994 and 2003. Charts from the 24 patients were reviewed for indications, location of leak, type of surgical closure, number of prior closure attempts, graft materials, use of computer assisted surgery, complications, and need for revision surgery. Analysis was performed to determine a possible correlation between success of CSF leak repair and use of computer assisted surgery. RESULTS: The etiology of the leak was previous sinus surgery in 10 patients (41.7%), trauma in 5 patients (20.8%), spontaneous leak in 5 patients (20.8%), and skull base surgery in 4 patients (16.7%). The most common sites of leak were the fovea ethmoidalis in 10 patients (41.7%), cribriform plate in 8 patients (33.3%), and sphenoid sinus in 6 patients (25%). Image guidance was employed in 66.7% (16 patients) of our first attempted repairs. Six patients underwent a total of 9 revision procedures. At last follow-up, 96% of patients had no evidence of CSF rhinorrhea. A comparison of patients in the 2 groups failed to reveal a statistically significant difference in the rate of CSF leak closure. CONCLUSION: Endoscopic closure of CSF rhinorrhea represents a minimally invasive and highly successful procedure. The use of computer assistance may improve the confidence of the surgeon and is a valuable adjunct in this procedure. Our study, however, did not demonstrate an improvement in the rates of successful closure with the use of computer assistance. EBM RATING: C

Flexible Endoscopic Evaluation of Swallowing With Sensory Testing in Patients With Unilateral Vocal Fold Immobility: Incidence and Pathophysiology of Aspiration

Objectives/Hypothesis: The objective was to examine the incidence and pathophysiology of aspiration in patients with unilateral vocal fold immobility presenting with dysphagia.

Outcome of computer-assisted sinus surgery: a 5-year study.

Background The aim of this work was to study the outcome and rate of complications in a cohort of patients who underwent computer-assisted surgery (CAS). A retrospective study was performed of all patients undergoing CAS at a tertiary care teaching hospital over a 5-year period. Methods All patients who underwent computer-assisted sinus surgery with at least 1 year of follow-up were included in the study. Charts were reviewed for indication of CAS, incidence of major complications, and need for revision surgery after CAS. Results A total of 120 patients underwent CAS in the 5-year period. Ten patients were lost to follow-up and were not included in the analysis. Indications for the use of CAS were revision surgery in 85 patients, sphenoid sinus disease in 12 patients, isolated frontal sinus disease in 4 patients, combined sphenoid and frontal disease in 2 patients, and cerebrospinal fluid leak (CSF) leak in 7 patients. The mean postoperative follow-up was 2.6 years. There were no major complications. Fifteen (16.5%) patients required revision surgery: 10 patients required revision endoscopic sinus surgery (1–5 revisions using CAS), 3 patients required an external open procedure, and 3 patients required revision CSF leak closure (one patient required both revision sinus surgery and an external procedure). There were no cases of major intra- or postoperative bleeding, central nervous system damage, CSF leak, or orbital trauma in this study. Conclusion CAS helps in avoiding trauma to the orbit and anterior skull base and has a low incidence of major complications. The need for revision surgery may occur in patients with frontal sinus disease, nasal polyposis, or recurrent CSF leak.