The Atlantic NeuroSurgical Specialists Skull Base Surgery program uses a strategic collection of specialists and the most advanced minimally invasive techniques to assist patients with skull base tumors. Our team includes experts from a variety of interconnected fields, including neurosurgery, otolaryngology, neuro-ophthalmology and radiation oncology to ensure comprehensive care from initial diagnosis through the duration of treatment.
Skull base surgery involves removing hard-to-reach tumors deep within the complex anatomy of the head and neck. Examples of cases our fellowship-trained team might treat include:
- Acoustic neuromas
- Pituitary tumors
- Skull base meningiomas
- Trigeminal neuralgia
- Hemifacial spasm
- Tegmen defects
Diagnosing Skull Base Conditions
Conditions affecting the floor of the cranial cavity can be difficult to diagnosis given the proximity of so many other anatomical areas, including the face, neck, ears, nose and throat. Most patients come to us presenting some or all of the following symptoms:
- Sinus congestion
- Vision changes
- Neck pain
- Hearing loss
- Difficulty swallowing and/or talking
- Endocrine dysfunction
Depending on the area affected, these symptoms may be linked to nerve compression, fluid buildup or interrupted blood flow due to the presence of a tumor or other cranial condition. The type of symptom often tells us which area, or compartment, of the brain is affected.
Final diagnosis involves analysis of patient history, and data gathered using MRIs, CTs, PET scans, blood work, MRA, angiography and/or endoscopy of the sinuses as well as evaluations designed to gauge balance, vision and hearing.
Our Surgical Team In Action
Our Skull Base Surgery program is lead by Dr. Yaron A. Moshel and Dr. Ron Benitez. Together with the rest of their team, these talented ANS physicians perform either endoscopic or traditional open skull base surgery, with assistance from other specialists as indicated.
Skull base surgery refers to surgical techniques required to obtain access to the floor of the cranial cavity. Due to the complexity of this region, the neurosurgeon often works in conjunction with ear, nose, and throat (ENT), or plastic surgeons when performing skull base surgery because of the close proximity of the face and neck to the skull base. Advances in microsurgical techniques, understanding of the skull base anatomy, improvements in neuroimaging, endoscopy, and stereotactic radiosurgery have allowed such lesions to be successfully treated.
Anatomy of the skull base
The skull base is composed of the bones and cartilage that form the face and cranium which surrounds the bottom of the brain. The bones of the skull base also form the eye socket, rood of the nasal cavity, some of the sinuses, and the inner ear. Contained within this region are major blood vessels that supply the brain with essential nutrients and important nerves with their exiting pathways. The floor of the skull is divided into three regions from front to back: the anterior, the middle, and the posterior compartments. The anterior compartment is the region above a person’s eyes and some of the sinuses, the middle compartment is the region behind the eyes and centered around the pituitary gland, an organ required for proper hormonal function. The posterior compartment contains the brainstem and the cerebellum and is centered around the inner ear and the connection of the brain to the spinal column. The brainstem is the connection between the brain and spinal cord, containing the origin of nerves involved in the control of breathing, blood pressure, eye movements, swallowing, etc.
The symptoms and presentation of patients with tumors and conditions of the skull base is highly variable because of the many important structures contained in this area. These symptoms occur due to direct compression of important nerves by a tumor or blood vessels or by blocking the normal flow of fluid around the brain. Tumors of the anterior compartment may produce headache, sinus congestion, or vision changes. Those of the middle compartment may produce endocrine dysfunction or vision changes. Those of the posterior compartment can produce neck pain, dizziness, tinnitus, hearing loss, and difficulties with swallowing and talking.
The diagnosis of growths or abnormalities that may require skull base surgery is based on your symptoms and a physical exam. Imaging studies are an important component of the diagnosis of skull base conditions because this area cannot be seen directly. Brain imaging studies such as magnetic resonance imaging (MRI) and Computed tomography (CT) scans are often used. In some cases, neurological surgeons may employ an MRI or CT scan with frameless stereotactic guidance for preoperative planning purposes. For this study, a high-resolution contrast MRI or CT is performed and then processed by a computer to create a three-dimensional model of the brain and skull base. This can be used in the operating room when performing endoscopic minimally invasive skull base surgery. Special tests such as PET scan, MRA and angiography are sometimes used to help your medical team better see a growth or abnormality and identify its blood supply. If the conditions involves the sinuses or if surgery will traverse the sinuses endoscopy of the sinuses may be performed before surgery by the ENT specialist to evaluate your particular anatomy. Other tests such as balance, vision, and hearing evaluations may also be checked.
Skull base surgery can be done in two main ways. Although the preferred method is endoscopic, open surgery is also an option, depending on the type of growth that needs to be removed and its location:
Endoscopic or Minimally Invasive Skull Base Surgery
An ENT surgeon usually helps approach the tumor through the nose (endonasal) and natural sinuses and together with the neurosurgeon they remove the tumor through a thin tube with a light source at the end called an endoscope. Endoscopic techniques continue to evolve and requires careful analysis by your surgeon to determine if you are a candidate.
Traditional or Open Skull Base Surgery
This type of surgery generally requires an incision behind the hairline and opening of the skull. Advances in neuro-anesthesia and microsurgical techniques (typically an operating microscope is used) have made this surgery safer and less invasive. In this type of surgery, bone surrounding the skull base is removed so that the surgeon can access the skull base with minimal to no brain retraction at all which leads to better outcomes. The bone that is removed is reconstructed at the end of the operation. In some cases this surgery is performed with minimally invasive techniques and combined with an endoscope, which allows for smaller incisions and even surgery through an eye-brow or eyelid incision.
Surgery for Skull Base Tumors and Conditions
The management of skull base tumors and conditions often requires consideration of several factors including the patient’s symptoms, growth of a lesion over time, the suspected pathology and potential for post-operative chemotherapy or radiation. Depending on the particular location and structures involved specialists in ENT, ophthalmology, radiation oncology and medical oncology may need to be involved. Some patients are candidates for non-invasive stereotactic radiosurgery and other patients may benefit from either open or endoscopic surgery. The diversity of skull base tumors and conditions are vast, and they may arise from various sources including the brain, the lining of the brain, the bones making up the skull base, or metastases. Although these tumors and conditions have unique individual characteristics, they may present in a similar fashion due to involvement of similar nervous structures. They can be grouped according to the area of the skull base from which they arise:
Tumors and conditions occurring in the anterior compartment include:
- estheisoneuroblastomas (olfactory neuroblastoma)
- orbital gliomas
- nasopharyngeal carcinomas
- juvenile nasopharyngeal angiofibroma
Those occurring in the middle compartment include:
- pituitary adenomas
- Rathke’s cleft cysts
Those of the posterior compartment include:
- acoustic neuromas
- epidermoid tumors
- Glomus tumors
- Trigeminal neuralgia
- Hemi-facial spasm