CT-scans are obtained for preoperative planning. Diligent examination of the orbital roof in serial multiplanar views is essential to assess possible defects and/or significant malposition.
Displacement of the affected supraorbital ridge is estimated by comparison to the normal side.
A unilateral frontal craniotomy is the standard approach for supraorbital rim osteotomies and secondary orbital roof reconstruction.
For vertical repositioning, a wedge of supraorbital bone may need to be removed. The correction of any posterior rim displacement should also be addressed.
If the planned osteotomy involves the frontal sinus, cranialization and/or obliteration should be considered.
In some exceptional cases, supraorbital rim repositioning may be performed without a craniotomy.
The standard approach is a coronal incision. However, previous craniotomy incisions may also be utilized.
Following exposure of the frontal bone and the superior orbits, a unilateral frontal craniotomy is outlined, trying to avoid the frontal sinuses. If the frontal sinus cannot be avoided, the sinus should be addressed simultaneously. Further details can be found in the section sinus obliteration and cranialization.
Burr holes are made and an epidural dissection is performed.
The craniotomy is completed using a craniotome.
After the bone flap is removed, the frontal dura is elevated in the epidural plane.
The dura is protected with neurosurgical cottonoids and a malleable retractor.
Malleable retractors are used intracranially to protect the brain and intraorbitally to protect the orbital contents.
A superior orbital rim marginotomy is performed starting with the posterior osteotomy behind the lateral rim.
A horizontal osteotomy is performed at the level of the fronto zygomatic suture.
The orbital roof osteotomy is either performed intra cranially or intra orbitally protecting both the brain and orbital contents.
The medial osteotomy is then performed to complete the supraorbital rim marginotomy.
The supraorbital rim should now be completely mobile and removed to give access to the orbital roof.
The planned ostectomy of the supraorbital bone is outlined and performed.
Further subperiosteal dissection of the orbital roof from the orbital and cranial sides is performed.
Malpositioned orbital roof is usually resected with rongeurs. Osteotomy and repositioning of the orbital roof is usually not feasible.
4. Orbital roof reconstruction
Significant orbital roof defects are reconstructed either with autogenous bone or titanium mesh.
If the posterior ledge of the implant is placed along the orbital side of the roof, inferior globe displacement may occur. To avoid this, the posterior ledge of the implant is commonly placed on the cranial side.
An alternative is to place the entire titanium mesh intracranially.
Reconstruction with bone graft
A bone graft is usually harvested from the calvarium. Depending on the size of the defect, segmental bone grafts may be necessary.
Pitfall: If the graft is placed inferior to the orbital roof anatomy, hypoglobus may result.
Reconstruction with titanium mesh
Titanium mesh can be easily trimmed and shaped intraoperatively using a sterile plastic skull or preoperatively using a non-sterile skull followed by implant sterilization.
The mesh should be curved to mimic the normal anatomy of the orbital roof.
The mesh is fixed to either the mobilized rim or the lateral wall with screws.
The plate can also be placed and fixed on the cranial side.
5. Fixation of supraorbital rim
The frontal bone flap is replaced and the mobilized supraorbital rim is repositioned and fixed with miniplates and screws.
Calvarial bone is then used to fill the lateral and medial bone gaps. Burr holes are covered with burr-hole plates.
6. Aftercare following orbitotomy with orbital roof repositioning
Head of bed elevation may significantly reduce edema and pain.
The patient's neurological status should be evaluated as soon as it is feasible. Regular postoperative neurological checks should be performed.
Evaluation of the patient’s vision
Evaluation of the patient’s vision is performed as soon as they are awakened from anesthesia and then at regular intervals until they are discharged from the hospital.
Nose-blowing should be avoided for at least 3 weeks following frontal sinus and skull base repair.
The use of some of the following perioperative medication is controversial.
Analgesia as necessary
Antibiotics (many surgeons use perioperative antibiotics. There is no clear advantage of any one antibiotic, and the recommended duration of treatment is debatable.) The spectrum should be according to the existing bacterial flora, especially in the combined intra and extra cranial procedures.
Corticosteroids may help with postoperative edema.
Ophthalmic ointment should follow local and approved protocol. This is not generally required in case of periorbital edema. Some surgeons prefer it. Some ointments have been found to cause significant conjunctival irritation.
The following signs and symptoms are usually evaluated:
Extraocular motion (motility)
If the patient complains of eye pain, a thorough ophthalmological evaluation should be performed.
A head CT scan is obtained postoperatively to provide a patient baseline and evaluate for intracranial bleeding, dead space, and pneumocephalus.
Remove sutures from skin after approximately 7 days if non resorbable sutures have been used. Moisturizing lotion should be used on the skin wounds to minimize excessive scarring after sutures are removed. Avoid sun exposure and tanning to skin incisions for several months.
Regular patient follow-up after discharge including periodic imaging is recommended.