Endoscopic endonasal surgery  Endoscopic endonasal surgery is a minimally invasive technique used mainly in neurosurgery and otolaryngology. A neurosurgeon or an otolaryngologist, using an endoscope that is entered through the nose, fixes or removes brain defects or tumors in the anterior skull base. Normally an otolaryngologist performs the initial stage of surgery through the nasal cavity and sphenoid bone; a neurosurgeon performs the rest of the surgery involving drilling into any cavities containing a neural organ such as the pituitary gland. Antonin Jean Desomeaux, a urologist from Paris, was the first person to use the term, endoscope. However, the precursor to the modern endoscope was invented in the 1800s when a physician in Frankfurt, Germany by the name of Philipp Bozzini, developed a tool to see the inner workings of the body. Bozzini called his invention a Light Conductor, or Lichtleiter in German, and later wrote about his experiments on live patients with this device that consisted of an eyepiece and a container for a candle. Following Bozzini's success, The University of Vienna starting using the device to test its practicality in other forms of medicine. After Bozzini's device received negative results from live human trials, it had to be discontinued. However, Maximilian Nitze and Joseph Leiter used the invention of the light bulb by Thomas Edison to make a more refined device similar to modern day endoscopes. This iteration was used for urological procedures, and eventually otolaryngologists began to use Nitze and Leiter's device for eustachian tube manipulation and removal of foreign bodies. The endoscope made its way to the US when Walter Messerklinger began teaching David Kennedy at Johns Hopkins Hospital. The transsphenoidal and intracranial approaches to pituitary tumors began in the 1800s but with little success. Gerard Guiot popularized the transphenoidal approach which later became part of the neurosurgical curriculum, however he himself discontinued the use of this technique because of inadequate sight. In the late 1970s, the endoscopic endonasal approach was used by neurosurgeons to augment microsurgery which allowed them to view objects out of their line of sight. Another surgeon, Axel Perneczky, is considered to be a pioneer of the use of an endoscope in neurosurgery. Perneczky said that endoscopy, "improved appreciation of micro-anatomy not apparent with the microscope."