Ivan H. El-Sayed

Learn More
The selection of nanoparticles for achieving efficient contrast for biological and cell imaging applications, as well as for photothermal therapeutic applications, is based on the optical properties of the nanoparticles. We use Mie theory and discrete dipole approximation method to calculate absorption and scattering efficiencies and optical resonance(More)
Open transcranial surgery has long served as the traditional approach for resecting tumors and other lesions in the skull base. However, endoscopic endonasal skull base surgery (EESBS) has emerged as a credible alternative. This paper provides insight on the sinonasal morbidity in patients undergoing EESBS. A literature review was performed by searches of(More)
Recent reports of surgical resection of tuberculum sellae meningiomas through an endoscopic endonasal approach (EEA) have provided an alternative to transcranial approaches in selected cases. However, these published reports have been limited by small sample size from single institutions. We performed a systematic review and meta-analysis to gain insight(More)
Purely suprasellar Rathke's cleft cysts (RCC) treated with a microscopic endonasal approach have increased operative morbidity and poorer outcomes compared to purely sellar RCC. We sought to determine if the extended endoscopic endonasal approach improved outcomes for suprasellar RCC. We retrospectively reviewed RCC patients at our institution over a 10(More)
Esthesioneuroblastoma (EN) is a rare sinonasal tumor with varied aggressiveness and potential for intracranial invasion. EN is staged anatomically with radiographic evaluation using the Kadish staging system (stages A, B, and C) and histologically by using Hyam's criteria (grades 1-4). Here we show that despite radiographic evidence of aggressive features,(More)
BACKGROUND Clival chordomas frequently recur because of their location and invasiveness. OBJECTIVE To investigate clinical, operative, and anatomic factors associated with clival chordoma recurrence. METHODS Retrospective review of clival chordomas treated at our center from 1993 to 2013. RESULTS Fifty patients (56% male) with median age of 59 years(More)
OBJECTIVE To describe otologic manifestations of amyloidosis. STUDY DESIGN Retrospective case review. SETTING Tertiary referral center. PATIENTS Case report of a patient with bilateral external auditory meatal stenosis secondary to amyloidosis. RESULTS The patient is a 60-year-old man who presented with several months' history of bilateral ear(More)
OBJECTIVE Anterior cervical spine decompression and fusion are common neurosurgical operations. Reoperation of the anterior cervical spine is associated with increased morbidity. The authors describe a novel subcricoid approach to protect the recurrent laryngeal nerve in a cuff of tissue while facilitating surgical access to the anterior cervical spine. (More)
OBJECTIVE Aneurysms of the anterior pontine segment of the anterior-inferior cerebellar artery (AICA) are uncommon. Their treatment is challenging because critical neurovascular structures are adjacent to it and the available surgical corridors are narrow and deep. Although endoscopic endonasal approaches are accepted for treating midline skull base(More)