May 05, 2015
Let's review the basics for resection of "Hypothalamic hamartomas" via the supraorbital approach. This is a 23 year-old male with multifocal seizures included several different semiologies as well as gelastic seizures. MRI evaluation revealed a hyperintense mass on T2 weighted images at the floor of the third ventricle. A hamartoma leading to gelastic seizures was suspected. Patient on the way resection of this hamartoma via a supraorbital craniotomy. A left sided approach was used so that I can reach the slightly larger part of the tumor on the right side, through the cross-core trajectory. Patient positioning is demonstrated next. You can see minimal rotation of the head, minimal flection of the neck, and a relatively sizable suitor incision. So that, the super orbital area can be generously exposed. Here's the craniotomy. A relatively small one. Alternatively, an eyebrow incision may be used. The craniotomy is reduced to the level of the orbital roof. Let's go ahead and review the intradural events. A piece of rubber there, a of glove is placed underneath the catenoid to slide the catenoid around the sub frontal area and expose the optic nerve. Gentle elevation of the frontal lobe, exposes the optic nerve, optical carotid cisterns. These cisterns are dissected. So, CSF is drained. Sharp dissection is continued using an arachnoid knife. The optic nerves are both dissected away from the subfrontal area until lamina terminalis is exposed. We're essentially using a supra-orbital subfrontal trans-lamina terminalis route to reach the floor of the third ventricle. Sharp arachnoid dissection continues. You can see the use of dynamic retraction. Chiasm is almost in view. The ICA and A1 branches should be carefully protected during sharp dissection. Here's the chiasm. Here's the area of the lamina terminalis. Lamina terminals is incised, so the lesion at the floor of the third ventricle is exposed. Here's this grayish tissue, consistent with a tumor or the hamartoma. Gross removal of the mass is not necessary. And in fact, it's unsafe. I coagulate the surface of the hamartoma and debulk, much of it, and gently separate it from the surrounding gliotic margins. I do not look for absolute normal margins during resection of this hamartoma. You can see the grayish texture of this hamartoma at the anterior base of the third ventricle. I'm essentially completing more of a disconnective procedure at this stage, after the hamartomata has been debulked. Additional small pieces may be removed since they appear quite discolored. Here are the gliotic margins of the hamartoma. Tissue is very fibrous. Can see the margins of the resection. Postoperative MRI revealed reasonable removal of the hamartoma. No complicating features is evident. This patient enjoyed relief of his gelastic seizures. There was also some decrease in frequency of his other type of seizures as well. Thank you.
Please login to post a comment.