CHRISTOPHER LOW: This is Christopher Low presenting a case of endoscopic orbital decompression with Dr. Janalee Stokken. The most commonly performed indications for endoscopic orbital decompression are for functional or cosmetic sequelae of thyroid eye disease, also known as Graves' ophthalmopathy. Functional aspects include restrictive myopathy leading to [INAUDIBLE], exposure keratitis, or optic neuropathy.
Cosmetic considerations include an altered appearance secondary to proptosis and exophthalmos. Other indications for endoscopic orbital decompression or for access to the orbit for the removal of benign or malignant orbital tumors, biopsy of indeterminate lesion, decompression of orbital abscesses and hematomas, and as an approach for optic nerve decompression.
This patient is a patient with exophthalmos secondary to thyroid eye disease. Endoscopic orbital decompression is performed under general anesthesia as an outpatient procedure. It first starts with the maxillary antrostomy, total ethmoidectomy with skeletonization of the lamina papyracea and anterior skull base.
Depending on a patient's anatomy, a frontal sinusotomy is often performed. And consideration can be given to performing a sphenoidotomy with the goal of preventing post-operative post-obstructive sinus disease secondary to prolapsed orbital contents in the sinonasal cavity. Further details about endoscopic sinus surgery can be found in other videos in the Surgical Video Atlas.
Once wide exposure has been established, mucosa is first removed from the lamina papyracea. Next, the bony lamina is meticulously removed without fracturing and cutting instruments, carefully preserving the periorbita and skull base. The periorbita is kept intact while removing the lamina to keep orbital fat from obstructing the surgeon's view during dissection.
With the periorbita exposed, an initial posterior periorbita cut is made in an inferior to superior direction. The choice of instrument is as per surgeon preference. Here, an arachnoid knife is used.
Care is taken to ensure only the periorbita's [INAUDIBLE] seeing the tip of the blade through the tissue during the cut. Following this, a superior cut is made in a posterior to anterior direction. Here, an Athro-Lok Retrograde, Beaver Blade is used and care is taken to keep the leading edge of the instrument visible through the periorbita.
An inferior cut is made from a posterior to anterior direction. And the periorbita is peeled away using grasping forceps. Retropulsion of the eye helps to identify facial bands in orbital fat, which are then divided with blunt or sharp instrumentation. The facial band cuts are made in the same orientation as the medial rectus to avoid injury to the muscle fibers underneath. As the facial bands are divided, the globe feels softer to palpation.
