Suboccipital Craniectomy for Acoustic Neuroma
An acoustic neuroma is a benign tumor found on the nerves that lead from the brain to the inner ear and control balance and hearing. When surgery to remove an acoustic neuroma is necessary, a suboccipital craniectomy is most frequently the procedure chosen.
Treatment for an Acoustic Neuroma
Treatment for an acoustic neuroma depends on the size and growth rate of the tumor, and may include observation, radiation or surgical removal. Small tumors can be monitored regularly through regular imaging and hearing tests to determine how fast and how much they are growing. Radiosurgery, a non-invasive procedure known as “Gamma Knife” surgery, may be used to deliver radiation therapy to the tumor to stop its growth without the need for an incision. This procedure is most often used for tumors that cannot be removed without damaging brain tissue. Larger or more aggressive tumors may need to be removed through surgery to prevent permanent damage from occurring.
The Suboccipital Craniectomy Procedure
When surgery is required, a suboccipital craniectomy is often the best method of treatment. This procedure involves removing a portion of skull bone to access and remove the acoustic neuroma. The term suboccipital refers to the location of the craniectomy, which is performed at the base of the skull. This allows the surgeon to directly reach the cranial nerves near the back of the brain where the acoustic neuroma has formed.
A suboccipital craniectomy is performed under general anesthesia. The patient’s hair is shaved at the site and the surgeon makes an incision in the scalp behind the ear. A specialized drill is used to create a hole in the skull bone and a portion of bone is removed. Through this opening, the surgeon can access the auditory canal and nerves and carefully cut out the acoustic neuroma. As the tumor is removed, the surgeon will stimulate the nerves involving hearing and facial movement, as well as the brainstem, to ensure that no damage occurs during the procedure. In some cases, it is safer to leave a small portion of the tumor behind than to remove it in its entirety and risk permanent loss of some function.
After the tumor removal, the skull bone is not replaced. If the hole is large enough to warrant it, the area will be covered with a precisely fitted synthetic substance. The incision in is then sutured closed.
Transsphenoidal Surgery For Tumor
Transsphenoidal surgery is performed to treat tumors of the pituitary gland. Because the pituitary gland produces hormones affecting many systems of the body, patients with pituitary tumors may suffer from a great variety of symptoms include headaches, vision loss and seizures.
Although pituitary tumors are usually benign, successful treatment of their disturbing symptoms almost always requires surgical removal of the tumor, often accompanied by medication and radiation therapy. Such surgery may be performed through the skull (craniotomy) or as transsphenoidal surgery, crossing through the sphenoid sinus at the back of the nose.
Types of Transsphenoidal Surgery
Transsphenoidal surgery may be performed either as an open procedure or endoscopically, depending on the size and location of the tumor. Both operations are performed under general anesthesia. The endoscopic procedure, using miniature surgical tools, computer magnification, and guided imaging, is usually the preferred method of treatment since it is minimally invasive, accessing the pituitary tumor through the nostrils. Not only does endoscopic surgery require no incisions, it results in shorter recovery time, less scarring and a lower risk of complications.
When endoscopic surgery is not possible because of the size or location of the tumor, open surgery is performed through an incision in the nose or below the lip inside the mouth. The goal of either surgical procedure is to remove the entire tumor by sections, but if the growth is too close to a nerve or major blood vessel this may not be possible. In such cases, partial removal of the tumor, which leaves healthy tissue intact, is considered safer.
The Transsphenoidal Procedure
Either type of transsphenoidal surgery involves the creation of a hole in the bone behind the nose since this allows the surgeon access to the pituitary gland. Once the tumor is sectioned and removed, the region will be carefully examined to make sure there are no remaining hidden portions of diseased tissue. In some cases, a small amount of fatty tissue is transplanted from another part of the patient’s body, such as the abdomen, to fill the space left by the tumor’s removal. Either a bone graft from the patient’s septum, the partition between the nostrils, or a piece of synthetic mesh will be used to support the portion of removed skull bone. This helps to prevent the leakage of cerebrospinal fluid.