optic nerve decompression

The optic nerve is divided into the inner segment of the ball, the inner segment of the ankle, the inner segment of the optic canal (the inner segment of the bone tube), and the intracranial segment. The inner segment of the optic canal is located in the narrow optic canal and is about 5 to 6 mm long. The bone tube is formed by the upper and lower sides of the sphenoid winglet, and is covered by three layers of meninges. The dura mater is divided into two layers, the outer layer is fused with the periosteum, and the inner layer is connected with the arachnoid and pia mater, which has the function of fixing the optic nerve. The small blood vessels on the pia mater provide this segment of neurotrophy, and the ophthalmic artery is also performed in the tube segment, and the entire optic canal is located at the tip of the palate. Treating diseases: optic neuritis Indication 1. Zagara believes that it is only suitable for those with a slower vision loss. Walsh advocates that the eyesight or pupillary light-reactive positive can still be operated after the injury. The operation time is 7-10 days after the injury, and no more than 2 weeks at the latest. 2, Convese advocates conservative treatment, but when there are broken bone fragments, whether or not with or without periosteal detachment, surgery should be timely reset, absolutely preserved bone fragments; broken bone through the brain or X-ray shows that there is intracranial In the case of air, a craniotomy should be performed. Contraindications 1. The visual acuity was completely lost after the injury, and the pupil was negative for light. 2, vision loss immediately after injury, but there is a trend of recovery, general contraindication surgery (Zygora). 3, the optic nerve has been severely damaged, it is not suitable for surgery (Duke-Elder). Surgical procedure 1. From the sacral sinus surgery (1) A curved skin incision along the inner and lower edges of the eyebrow arch, 5 mm from the medial malleolus, up to the medial end of the eyebrow arch, and the tear cyst area, about 40 mm long, cut the skin directly to the surface of the periosteum, and pressure to stop bleeding. (2) along the incision, the periosteum together with the medial malleolus ligament, the lacrimal sac is peeled off from the bone wall, and gradually peeled off to the deep part of the iliac crest. Carefully expose the sieving board until it is close to the inferior border of the sacral optic canal. Anterior and posterior arteries, if necessary, electrocoagulation to stop bleeding. (3) Pull the periosteum and tendon to the outside with a thin plate, expose the inner wall of the ankle, and carefully detect the presence or absence of a fracture. Partially distracting part of the maxillary frontal process, frontal bone nose and part of the tear bone, and cutting off part of the inner wall of the iliac crest board and part of the anterior and posterior sieving rooms under the suture of the sieving board, and then proceeding to the deep part of the sac, until the posterior group The posterior wall of the sinus. During the operation, pay attention to retain the inner side wall of the sieve room, do not hurt the beginning of the middle turbinate, and do not make the operation area communicate with the nasal cavity. (4) In the posterior wall of the posterior ethmoid sinus, the lateral part of the anterior wall of the sphenoid sinus, open the sphenoid sinus cavity, remove the mucosa of the anterior and lateral wall of the sphenoid sinus, and the semi-tubular iliac crest is visible above the sphenoid wall. The inferior border (pre-lower margin) of the optic canal can be seen 0.5 to 1.0 cm posterior to the posterior ethmoid artery. Here, the special inferior bone wall, the curette, the callus, etc. are used to carefully remove the inferior wall of the bone tube for about 1/2 week. The diameter is 4 to 6 mm long, and the general open bone can be 2/3. In the open decompression, the oozing and clot should be removed by the aspirator, and the optic canal and its surroundings should be carefully explored. If the fracture piece compresses the optic nerve, it will be removed. After the optic canal is opened, observe whether there is blood in the tube, whether the sheath is swollen or changed in color, whether the sheath and optic nerve are torn or damaged, and the optic nerve sheath is not normally cut. (5) After the optic canal is opened and decompressed, the local should be carefully treated to stop bleeding. Rinse with 1:4000 units of gentamicin physiological saline. Subsequently, the periosteum membrane was replaced with the lacrimal sac and the medial malleolus ligament, and the periosteum, soft tissue, and skin were layered and sutured, and the flow strip was not placed, and the dressing was pressure-wrapped. Intraoperative attention: 1 During the ethmoid sinus surgery, do not damage the nasal nails, and do not make the operation area communicate with the nasal cavity. 2 Intraoperative attention to continue to remove the oozing and blood clots in the bone tube area by suction, and add 1:5000 adrenaline solution (mixed with gentamicin) in the washing solution. 2, from the lateral side of the sinus surgery through the sinus (1) The skin incision, from the inside of the eyebrow to the lacrimal sac, and cut vertically at a length of 40 mm. (2) Cut the periosteum, continue to separate with the periosteal separator, and cut the medial malleolar ligament with 4-0 gut. When the periosteum is separated to the inside of the eyelid, as shown in the previous section, make a 15mm×40mm bone window and expose the sieve. The posterior hole opens the ethmoid hole and identifies the optic nerve. The rest of the operations are as described in the previous section. (3) Surgery through the forehead craniotomy: 1 Coronal incision in the forehead area, for the unilateral forehead bone flap, along the anterior cranial fossa, lift the frontal lobe outside the dura, expose the pterygoid of the dome. 2 Find the inner side of the anterior bed, ie the optic nerve tube. 3 Use a small long chisel to cut a hole in the dome, and then use a small bite clamp to bite the upper wall of the optic canal. 4 Open the posterior and lateral bone wall of the optic canal and cut the periosteum of the optic canal to relieve oppression of the optic nerve. complication 1, occasionally broken bone into the brain tissue, no early removal, causing brain abscess. 2, the optic nerve due to other factors rather than the fracture itself caused by necrosis, such as optic nerve sheath and adjacent cavity bleeding caused by necrosis, such as blood vessel compression and vascular necrosis caused by embolism or paralysis. 3, local infection, can be complicated by sinusitis.