Hypophysectomy
Hypophysectomy or hypophysis is the removal of the pituitary gland.
Why a Hypophysectomy is performed
The pituitary gland is in the middle of the head. Removing this master gland is a
drastic step that was taken in the extreme circumstance of two cancers that had escaped
all other forms of treatment. Cancers of the female breast and male prostate grow faster
in the presence of sex hormones. It used to be that sex hormones could be suppressed only
by removing their source, the glands that made them. After the gonads were removed, some
cancers continued to grow, so other stimulants to their growth had to removed. At this
point, some cancer specialists turned to the pituitary.
With the development of new therapeutic agents and methods, especially new ways to
manipulate hormones without removing their source, this type of endocrine surgery has been
largely relegated to history. However, tumors develop in the pituitary gland that require
removal. Here, the idea is to remove the tumor but partially preserve the gland.
General information about a Hypophysectomy
There are several surgical approaches to the pituitary. The surgeon will choose the
best one for the specific procedure. The pituitary lies directly behind the nose, and
access through the nose or the sinuses is often the best approach. Opening the skull and
lifting the frontal lobe of the brain will expose the delicate neck of the pituitary
gland. This approach works best if tumors have extended above the pituitary fossa (the
cavity in which the gland lies).
Newer surgical methods using technology have made other approaches possible.
Stereotaxis is a three-dimensional aiming technique using x rays or scans for guidance.
Instruments can be placed in the brain with pinpoint accuracy through tiny holes in the
skull. These instruments can then manipulate brain tissue, either to destroy it or remove
it. Stereotaxis is also used to direct radiation with similar precision using a gamma
knife. Access to some brain lesions can be gained through the blood vessels using tiny
tubes and wires guided by x rays. |