Pituitary Surgery

I will give you a brief overview of the history of pituitary surgery.

Sir Victor Horsley was the first surgeon to operate on a pituitary adenoma 1889

This is his drawing of the middle fossa approach that was used.Later he also used a subfrontal approach.His mortality rate was 20 % which should be compared to the results of other contemporary surgeons with mortality between 50-80 %

The first successful transsphenoidal removal of a pituitary adenoma was performed a hundred years ago by Herman Schloffer an Austrian ENT surgeon using an extended lateral rhinotomy incision

The transsphenoidal approach as we know it today was initiated by Harvey Cushing .He used an incision under the upper lip get access to nasal septum

The sella was reached through tunnel under the mucosa of the septum

He performed 231 procedures with a mortality of 5,6 % .He returned to the trans cranial approach in spite of this comparatively low mortality figure.

He believed that the transcranial approach enabled a better decompression of the optic apparatus.Due to the enormous influence of Cushing on the neurosurgical community the transsphenoidal approach was more or less abandoned for the transcranial route

A revival of the transsphenoidal approach came with the introduction of fluoroscopy and the operating microscope in the sixties which gave effective light in the deeply situated surgical field

Selective adenomectomy was a milestone . Jules Hardy showed that it was possible to selectively remove a hormone-producing microadenoma

Ninety years after Schloffer a pure endoscopic procedure was into pituitary surgery

Relieve mass effect aim at decompression of nervous structures

Normalize hypersecretion is only possible by the transsphenoidal approach

Later treatment is based on the examination of the surgical specimen

The transsphenoidal approach can be used in a vast majority of the cases

Large size of the tumor is not a problem as long it is situated directly above the sella turcica .The suprasellar portion of the tumor will descend into the sella when the intrasellar part is removed.Parasellar extensions will however not come down into the sella

I some cases the diaframa sellae is incompetent around the pituitary stalk.In such cases the adenoma may extend through the hiatus and expand in the suprasellar region.This part of the tumor will not descend into the sella

A hard and tumor is difficult and risky to remove from below.The consistency of the tumor is however seldom known beforehand

The indications for a transcranial operation are the contraindications for the

Trans sphenoidal approach

The pterion approach is the most frequently used approach for transcranial removal of a tumor of the sellar region.

The incision is made behind the hairline.The plane along the sphenoid wing is used to reach the sellar region.Bone is removed to minimize the need for brain retraction

Splitting the Sylvian Fissure will disengage the frontal lobe from the temporal lobe.The frontal lobe will fall away backward with gravity and open up the space along the sphenoid ridge.This space increases further by removal of CSF

From CSF cisterns on the skull base

The tumor is removed between the optic nerves and between the internal carotid and the optic nerve.The instruments must be handled with care as the

The optic nerve which is stretched by the tumor has little reserve to damage

The traditional transsphenoidal approach is along the nasal septum with an incision under the upper lip or on the columella.

The working space is through a nasal speculum

This picture shows the two main advantages of the transsphenoidal approach

It is possible to spare the normal gland as the adenoma is encountered first

And the optic chiasm is protected by the diafragma sellae so there is no direct contact the between the instruments and the chiasm

The best surgical results are obtained with small tumors .

Pituitary adenomas are benign tumors but they have a potential to grow invasively.A macroadenoma more often have contact with the dura and are consequently more likely to invade the dura and the cavernous sinus.This