The history of the endoscope in skull base surgery is de facto the history of pituitary surgery. The first pituitary operation was likely performed by Sir Victor Horsley in 1889 via a transfrontal approach though he did not publish his results 1).
His compatriots, Caton and Paul, were the first to publish the results of this operation in 1893 2) in which they reported that their patient was cured of his headaches for the three months he survived post operatively.
Transsphenoidal surgery was overlooked until 1894, when an anatomical study by Davide Giordano (1864-1954), head of surgery at Venice Hospital, provided an approach to the sella turcica through an extracranial transsphenoidal approach, after a transfacial exposure 3) 4) 5).
Hermann Schloffer is widely regarded as the father of modern pituitary surgery. In 1906 he published a seminal paper discussing the possibility of pituitary surgery via a transsphenoidal approach 6) and performed this operation on March 16, 1907 in a procedure performed in three phases 7)
The operation was performed via nasal translocation and lasted about 75 min. Though there were no intraoperative complications, the patient died two months later and on autopsy was found to have hydrocephalus as a result of residual tumor blocking the foramen of Monro 8)
Markus Hajek elegantly described the surgical approach to the posterior ethmoids and sphenoid sinus in 1904 using a transnasal route.
Building on this foundation, Oskar Hirsch described the fully extracranial endonasal transethmoid transsphenoidal approach in 1909. He was first to describe surgical entrance to the sella using this exclusively unilateral endonasal route, which he demonstrated on a cadaver. He reports performing this procedure on a live patient in April, 1910, under local anesthesia in stages over 5 weeks. For better exposure, Hirsch consolidated his method with Killian's submucosal window resection of the posterior nasal septum allowing for bilateral access to the sphenoid sinus and sella, and completed a single stage procedure on a patient in June 1910
Oskar Hirsch was the first to describe and perform a stepwise surgical approach to the sella using an exclusively extracranial, endonasal, transethmoid, and transsphenoidal approach. He built upon his mentor Markus Hajek's approaches to the posterior ethmoid cells and sphenoid sinus 9) 10)
Cushing performed his first pituitary operation in 1909 11) using Schloffer's method but then rapidly adopted Hirsh's approach adding a sublabial incision and a headlamp to improve visualization of the sella. Using this approach he performed 231 operations with a 5.6% mortality rate 12) 13).
Hirsch continued to perform transphenoidal hypophysectomy and by 1937 had performed the operation on 277 patients with a mortality rate of 5.4% 14). After being displaced from Austria by the Nazis shortly thereafter, he emigrated to the US and continued to operate at Massachusetts General Hospital in collaboration with a neurosurgeon, Hannibal Hamlin. The other surgeon who kept the technique alive was Norman Dott, a British neurosurgeon who learned the approach in 1923 from Cushing and by 1956 had performed 80 procedures with no deaths 15).
The modern advent of the transsphenoidal approach as the preferred approach to the pituitary began in 1956 when a French neurosurgeon, Gerard Guiot, learned the technique from Dott and brought it back to Paris and reintroduced it to skeptical colleagues. He ultimately performed over 1,000 transsphenoidal hypophysectomies and also introduced the use of intraoperative fluoroscopy 16) 17) 18).
A student of Giuot, Jules Hardy revolutionized the transsphenoidal pituitary approach when he introduced the use of the operating microscope and microsurgical instrumentation in 1967. The microscope with increased illumination and magnification permitted a more thorough and safer resection without deaths or major morbidities 19) 20).
Indeed, Hardy's contributions led to a paradigm shift in pituitary tumor surgery. Previously, the operation was performed to debulk large tumors off the optic apparatus, but now microsurgical techniques were introduced allowing for surgical cure of hormonal disease in microadenomas.
Although the procedure described by Hardy underwent numerous modifications (including extended approaches to other skull base sites: clival and suprasellar tumors as well as cavernous sinus lesions), it was the main procedure performed by neurosurgeons for removal of pituitary tumors from the 1960's through the early 1990's 21).
Although Griffith and Veerapen reported a case of endonasal approach to the sellar region in 1987, the transsphenoidal endonasal approach did not gain popularity. 22).
There has been a paradigm shift linked to developing endoscopic technologies with the introduction of completely endoscopic endonasal approaches to the ventral skull base.
Endoscopic endonasal skull base surgery has dramatically changed and expanded over recent years due to significant advancements in instrumentation, techniques, and neuroanatomy understanding. With these advances, the need for more robust skull base reconstructive techniques was vital 23)
Since 1995 there is a remarkable advancement in endonasal approach by endoscope. Refinements in camera definition, neurosurgical instruments, neuronavigation, and surgical technique.
Since 2000s, Endoscopic endonasal approach has become the most popular choice of neurosurgeons and otolaryngologists to treat lesions of the skull base, with minimal invasiveness, lower incidence of complications, and lower morbidity and mortality rates compared with traditional approaches.
The dual surgeon team, have facilitated purely endonasal endoscopic approaches to the majority of the midline skull base that were previously difficult to access through the transsphenoidal approach via microscope.