23.2 Indications

The majority of orbital exenterations are performed to remove malignant tumors, including primary epithelial tumors, such as squamous cell carcinoma, basal cell carcinoma, melanoma, and sebaceous carcinoma, which can arise from eyelid skin, conjunctiva, or the sinonasal cavities. Malignancies arising from the lacrimal gland, such as adenoid cystic carcinoma, are also treated with orbital exenteration. Finally, rhabdomyosarcoma and other rare orbital cancers, as well as intraocular tumors such as retinoblastoma and uveal melanoma with extrascleral orbital invasion, may necessitate orbital exenteration. Once these tumors have gained access to the compartmentalized orbit and have invaded orbital fat, it becomes difficult if not impossible to perform local excision with negative margins without removing the whole orbital unit or a large part of it. Aggressive orbital infection by mucormycoses may also require radical debridement and orbital exenteration. These fungi predispose patients to arterial thrombosis and impede the effective delivery of intravenous antifungal medication to the infected orbit. Other potential indications for orbital exenteration include severe and uncontrollable pain or deformity caused by extreme cases of sclerosing orbital pseudotumor, Grave’s orbital disease, neurofibromatosis, and socket contracture.

23.3 Preoperative Evaluation

Preoperative evaluation for orbital exenteration includes a comprehensive review of the patient’s medical and surgical history. In cases involving cancer, pertinent questions regarding potential manifestations of metastatic disease are addressed. Likewise, physical examination should include inspection for locoregional and metastatic processes rather than focusing only on the orbital disease. Radiographic studies are performed to understand the anatomic extent of the disease process. Histologic examination of the biopsy specimen, when available, can further provide important information about the biologic behavior of the tumor prior to surgery. Both radiographic and histologic studies can influence surgical decision making with regard to the extent of surgical excision and options for reconstruction. However, for some primary ocular adnexal tumors, the exact extent of disease involvement may remain uncertain, despite thorough preoperative evaluation, until intraoperative assessment of the surgical specimen by frozen section histologic analysis.

Patients need to be fully informed about their disease, proposed treatment plan, including the possibility of more radical ablation, and alternatives to orbital exenteration, if any. The preoperative discussion should address psychological aspects of disfigurement resulting from orbital exenteration as well as quality-of-life issues due to loss of vision and facial disfigurement after surgery. The possibility of rehabilitation with an orbital prosthesis should be carefully considered by the clinician and discussed with the patient. Family members and others close to the patients often

are included in the discussion since the surgery can be a psychologically traumatic experience for them as well as for the patients themselves. Showing patients postoperative pictures of patients who have previously undergone orbital exenteration, with and without prosthetic rehabilitation, helps to ease the anxiety experienced by some patients. Depending on the reconstruction planned, a discussion about the appropriate reconstructive flap or graft procedure should also be included.

Orbital exenteration requires the patient to undergo general endotracheal anesthesia. A preanesthetic medical evaluation is conducted to ensure the suitability of the patient to undergo the exenteration procedure as well as the reconstructive procedure. Information about coagulation and cardiopulmonary status, as well as history of allergic reactions, is obtained from the patient’s primary or specialty care physicians if necessary.

23.4 Surgical Techniques of Orbital Exenteration

Generally, orbital exenteration is subclassified into three types: standard, eyelid sparing, and extended orbital exenteration. In standard exenteration, both eyelids and at least the anterior part of the orbit are removed. This technique is used for many adnexal cancers involving the eyelid with orbital extension. In eyelid-sparing exenteration, the anterior lamella of the eyelid (skin or musculocutaneous layer) is spared and used for coverage of the orbital defect. This technique is used when the eyelid skin and orbicularis muscles are not involved in the cancerous process, such as in some palpebral conjunctival and orbital cancers. Extended orbital exenteration is a more radical surgical ablation in which one or more bony orbital walls and neighboring structures, such as the sinuses and facial skin, are resected. This form of exenteration is used for cancers of the paranasal sinuses, nasal cavity, and periorbital and facial soft tissue extending to the orbit. Malignant lacrimal gland cancers, such as adenoid cystic carcinoma, are frequently found to have grossly or, based on intraoperative frozen section analysis, microscopically invaded the bony orbit. In these cases, extended orbital exenteration may be indicated to clear the disease or to remove high-risk tissues near the tumor to decrease the local tumor recurrence rate.

Orbital exenteration itself starts with marking of the planned incisions on the skin. For a standard exenteration, the orbital rim is outlined. For eyelid-sparing exenteration, the incision mark is made a few millimeters beyond the lash lines on the superior and inferior eyelid skin. Modifications to the incision line are made as needed to ensure a disease-free margin. Next, 4-0 silk traction sutures are placed at the upper and lower eyelid margins. These sutures allow better manipulation and facilitate separation of the orbit from adjacent structures while maintaining the integrity of the surgical specimen. For better hemostasis, lidocaine with epinephrine is injected into the marked lines before skin incision using either a fine-tip cautery or a scalpel.

The initial incision is extended down to the orbital rim with monopolar electrocautery to minimize bleeding. For the eyelid-sparing procedure, the dissection

spares only eyelid skin or skin with orbicularis muscles, and these tissues are separated from the remaining deep and posterior structures with scissors. The dissection is carried out from the skin incision to the orbital rim, with care taken to avoid “buttonholing” the skin flap, and then continues with cutting electrocautery deep down to bony orbital rim.

The periosteum at the orbital rim is incised to gain access to the periorbita with a sharp scalpel or a fine-tip electrocautery. The periosteum is then carefully separated from the orbital bony walls with a periosteal elevator. To avoid excessive and potentially difficult-to-control bleeding, orbital vessels exiting anterior ethmoidal, posterior ethmoidal, and zygomaticotemporal foramina should be carefully identified. These vessels are first cauterized—preferably with bipolar cautery—or ligated before they are severed. The periosteum can be separated with relative ease except for areas of firm attachment between the periosteum and the bony wall at the orbital fissures, medial canthal tendon, and lateral tubercle, where separation often requires using a scalpel or a cutting electrocautery. The nasolacrimal duct is excised distal to the lacrimal sac. Extra caution is exercised while working on the thin medial and inferior orbital walls. Unnecessary violation of the bony orbital walls may lead to sino-orbital fistula, causing chronic infection and/or a nonhealing wound. In cases of extended orbital exenteration, removal of the orbital walls may be intentional and may necessitate reconstruction.

Once the dissection reaches the desired posterior limit at the orbital apex and the orbital content is free of any residual anterior attachment, the orbital specimen can be removed with an appropriate pair of heavy scissors while gentle pulling pressure is applied on the eyelid traction sutures. Although preclamping the orbital apex with a curved clamp before severing the orbital content is an option aimed at achieving good hemostasis, it is not utilized by our team because of the risk of creating crushing artifact at the posterior surgical margin, thereby adversely affecting microscopic study. As soon as the specimen is released posteriorly, the orbital cavity is packed with surgical gauze soaked with cold normal saline or thrombin solution. Light pressure is applied to the packing to facilitate hemostasis. The orbital specimen is then carefully oriented and sent for intraoperative frozen section histologic examination of the surgical margins. Depending on results of the frozen section exam, more resection may be required until a tumor-free margin is obtained.

After a tumor-free margin is established, the orbital cavity is inspected for any gross residual diseased tissue and bleeding. Any bleeding must be adequately controlled with further cauterization of the blood vessels, absorbable hemostatic packing material such as Surgicel (Ethicon Endosurgery, Cincinnati, OH), or bone wax for bone-perforating blood vessels. Additional resection beyond the orbit, as in extended exenteration, is executed according to the tumor location and size and often involves bone removal. Extended resection is frequently performed in collaboration with a head and neck surgeon when the exenteration includes resection of the paranasal sinuses or facial soft tissues or with a neurosurgeon when tumors invade the orbital roof or the orbital apex.

The optimal balance between achieving the best chance for complete tumor resection and preserving tissue to optimize cosmesis is judged in a highly

individualized way. It may be impossible to surgically eradicate all tumor cells, such as in the case of perineural invasion by tumor cells. In such cases, adjuvant postoperative radiation therapy can be utilized to minimize the chances of locoregional cancer recurrence. In patients with short life expectancy, the goal of orbital exenteration may not be to completely resect the tumor but to achieve palliation.

23.5 Reconstructive Options

When considering available options for reconstructing the exenterated orbit, the reconstructive surgeon must be knowledgeable about advantages and limitations of each technique. The primary goal of reconstruction is to line the orbital cavity with durable tissue and to exclude the nasal or sinus cavities when the medial or the inferior orbital wall has been removed and protect the brain when the orbital roof has been removed. The reconstructed orbit will need to be able to tolerate radiation therapy if radiation therapy is planned and to accommodate an orbital prosthesis if one is desired by the patient. Ultimately, the extent of the oncologic defect as well as whether radiation therapy is planned (preoperatively or postoperatively) determines selection of the reconstructive technique. In addition, the patient’s desire for prosthetic rehabilitation should be considered when planning the reconstruction as a deep cavity facilitates prosthetic fit, while a shallow cavity may not securely hold a prosthesis without osseointegrated implants or may cause the prosthesis to protrude unnaturally.

Healing by secondary intention and granulation may be the simplest treatment after tumor resection. The entire process will take 2–3 months and requires daily wound care with hydrogen peroxide solution and wet-to-dry dressing for infection prevention. The orbital cavity, when completely healed by secondary intention, is only slightly shallow because of granulation tissue, rendering inspection for local tumor recurrence relatively easy. It is our preference to accelerate wound closure by utilizing a meshed or an unmeshed split-thickness skin graft to line the orbital cavity. A bolster dressing is usually applied for 5–7 days after the skin graft is laid into the orbital cavity. Similar to healing by secondary intention, the split-thickness skin grafting of the orbital defect also allows excellent visualization of the orbital cavity for detecting local tumor recurrence. Because skin grafts are thin, skin graft reconstruction usually results in a deep orbital cavity that provides an excellent fit for an orbital prosthesis if one is desired by the patient (Figs. 23.1 and 23.2). When the patient has no history of prior irradiation and no postoperative radiation therapy is planned, a skin graft is usually successful, even on bare orbital bone.

If the orbital cavity is to be irradiated after surgery, thicker lining of the orbital cavity with soft tissue—rather than just spontaneous epithelialization or skin graft coverage—is necessary to prevent failure of the skin engraftment or osteoradionecrosis. Among local vascularized pedicled flaps used, the most common ones are the temporalis muscle flap and the temporoparietal fascia flap because of their proximity to the orbit. The temporalis muscle flap, based on the anterior

Fig. 23.1 Postoperative photograph following exenteration of the orbital cavity and reconstruction with a temporoparietal fascia flap and a full-thickness skin graft. Photo courtesy of Dr. Bita Esmaeli

Fig. 23.2 The same patient as in Fig. 23.1 with his orbital prosthesis in place. Photo courtesy of Dr. Bita Esmaeli

and posterior deep temporal arteries arising from the internal maxillary artery, is thin enough to permit a reasonably secure fit for orbital prostheses, even without osseointegrated implants; however, this results in a depression at the donor site that may be cosmetically unsatisfactory to some patients. The temporoparietal fascia flap covered by a split-thickness skin graft may be preferable because there is no donor site deformity. In both cases, the reach of the flap may be limited, and it may be necessary to remove the lateral orbital wall in order to cover the medial orbital cavity. We tend to avoid large scalp or forehead flaps when other reconstructive options are available because of the donor site disfigurement associated with such flaps.

In extended orbital exenteration in which paranasal sinuses are resected, the size of the cavity usually necessitates soft tissue coverage larger than local or regional