The goal of the Endonasal Approach is to reach tumors and lesions from the inside out using precise surgical corridors – “inside out surgery.” It is like eating an apple from the core--leaving the key outer structures intact. Surgeons place an endoscope (telescope) directly inside the nasal and sinus cavities creating an up- close, “flashlight” effect. This provides a panoramic, magnified view of the skull base and brain structures. Once a small window is created in the base of the skull, surgeons have a clear view of the tumor and it is removed through the nose. The Endonasal Approach can be performed using either a fully endoscopic (telescope) or endoscope-assisted technique. It is useful to think of the brain as a soft delicate structure like a sponge surrounded by a circle of fixed walls (the skull). The objective is to enter the skull with minimal disruption to critical tissues.

Advantages of Endonasal Approach

The potential advantages of the Endonasal Approach include:

     •   Reduced complication rate
     •   Less pain
     •   Improved recovery and outcomes

Why was Endonasal Approach was Developed?

It is useful to think of the brain as a soft delicate structure like a spone surrounded by a circle of fixed walls (the skull).  The objective is to enter the skull with minimal disruption to critical tissues. 

Conditions Treated with Endonasal Approach

In general, the Endonasal Approach allows surgeons access to the intracranial space above and behind the nasal cavities and air sinuses behind the nose. This broad region of the skull base provides a corridor to many skull base tumors and brain tumors. The Endonasal Approach is the preferred route for removal of: 

1. Pituitary adenomas  
2. Rathke’s cleft cysts 
3. Midline meningiomas  
4. Craniopharyngiomas  
5. Chordomas 
6. Chondrosarcomas
7. Petrous apex cholestetomas
8. Cholesterol granulomas 
9. Olfactory neuroblastomas (esthesioblastoma)

It is also used for performing odontoid resection in patients with rheumatoid arthritis. The specific tumor type has not proven to be prohibitive to the approach. More fibrous tumors or those attached to or surrounding critical nerves or blood vessels can still often be accessed via the Endonasal Approach but they require a surgeon with greater experience and familiarity with the technique. Additionally some invasive or highly adherent tumors may not be able to be removed completely. For some tumors that are located more laterally (away from the midline of the nasal and sinus cavities) or lateral to the optic or other nerves, then a different approach (e.g. eyebrow craniotomy or retro-mastoid craniotomy) may be best suited.

Experience and Breakthroughs 

It is important that the surgeon chosen have progressive and incremental experience specifically with Endonasal Approach; however, it is also equally important the surgeon be versed in all minimally invasive 360º and conventional neurosurgical techniques. This allows for a tailored and specific approach unique to each individual, rather than basing the approach on familiarity with one technique over another.

Breakthrough Medicine

Dr. Kelly has helped establish several critical breakthroughs in endonasal surgery. They were among the first in the world to undertake a variety of procedures through the nose and have added significantly to the understanding of the technical and anatomic aspects, as well as, the outcomes (risks, benefits and limits) of Endonasal Approach.