2.17\ Orbital Exenteration

2.17.1\ Discussion

Orbital exenteration is performed for treatment of primary orbital malignancies and periorbital malignancies that invade the orbit. Several types of orbital exenteration procedures can be performed with various degrees of dissection, ranging from extended enucleation, subtotal exenteration with sparing of the eyelid, total exenteration with removal of the eyelid in addition to orbital contents, and radical exenteration

with removal of structures surrounding the orbit, such as paranasal sinuses and skull base (Figs. 2.60, 2.61, 2.62, and 2.63). The socket created by more extensive exenteration procedures can either heal by granulation or lined with skin graft or tissue flap. Since patients who undergo exenterations for malignant neoplasms typically receive radiation therapy, complications may include necrosis (Fig. 2.64), infection, tumor recurrence (Fig. 2.65), and radiation-induced neoplasms (Fig. 2.66), which can occur many years after treatment.

Fig. 2.61  Orbital exenteration with maxillectomy and flap reconstruction. The patient has a history of recurrent stage IV left face squamous cell carcinoma treated with radical exenteration with myocutaneous flap reconstruction in addition to chemoradiation. Axial CT image (a) shows the normal-appearing muscle (M) and fat (F) components of the myocutaneous thigh flap within the left orbit and maxillectomy defect. The vascular supply to the

graft is derived from the left facial artery and vein. Sagittal (b) T1-weighted, axial T2-weighted (c), and fat-sup- pressed coronal contrast-enhanced T1-weighted (d) MRI sequences show the subcutaneous fat (F) portion of the graft, which loses signal with fat suppression. There is normal enhancement of the muscle component of the graft (M), which suggests viability

Fig. 2.65  Tumor recurrence. The patient has a history of exenteration of the left orbit for squamous cell carcinoma. Axial CT image shows a nodular lesion in the medial aspect of the left orbit (arrow)

Fig. 2.66  Radiation-induced osteosarcoma. Axial fat-­ suppressed post-contrast T1-weighted MRI shows a heterogeneously enhancing mass (arrow) arising medal to the right orbit, which contains an ocular implant and prosthesis