Introduction
Exenteration is a surgical procedure where the entire orbital contents and nearby structures are removed down to the bone. Depending on the ailment being treated, the surrounding structures removed include fatty tissue adjacent to the eye, eyelids, muscles, and nerves. George Bartisch first described the procedure with the modern form later described by Arlt.
Exenteration is often used to cure the body of cancer or malignant orbital tumors. The most common orbital malignant tumors addressed by exenteration include sebaceous cell carcinoma, basal cell carcinoma, squamous cell carcinoma among others. It can also be performed in painful conditions or life-threatening infections and inflammations. The procedure may be done with associated procedures like craniofacial resection (removal of tumors, especially nasal and paranasal sinus) or maxillectomy (removal of primary tumor).
Preparation & Expectation Before Surgery
The patient will be adequately counselled because exenteration is a mutilating operation that may have psychological implications. The doctor will take the patient through the details of the procedure, such as the pros and cons. The patient undergoes extensive examination, which may include a biopsy to establish the exact diagnosis. Ocular history is taken, and an ophthalmic examination conducted. The patient also goes through standard preoperative procedures like avoiding food, drink, cigarettes, and alcohol several days or weeks before the surgery.
Types, Purpose & Procedure
Exenteration is a very extensive surgery that is only undertaken when all other options to leave the eyeball intact for vision have failed. These other options do not offer the best chance of completely ridding the orbit of cancer and may compromise the patient’s life.
The three types of exenteration include total where the entire orbital contents are removed (the eyelids may or may not be removed. The second type is called ‘subtotal’ marked by partial removal of orbital contents but with the ocular bulb sacrificed. The third type is extended exenteration, a procedure that removes the paranasal sinuses and adjacent bone walls.
The patient is put under general anesthesia with endotracheal intubation (placing a tube through the windpipe). In the procedure, the surgeon:
- Makes an incision down the bone along the line of the orbital rim.
- Injects extremely dilute adrenaline into the tissues prior to the procedure because of the possibility of excessive bleeding. The surgeon can also apply firm pressure on the edge of the wound to control bleeding.
- Secures the bleeding points using artery forceps and either uses ligation (ties up arteries) or diathermy (uses heat to cause a clot).
- Makes an incision on the periosteum, right around the rim of the orbit, to enable a dissection on the bare bone.
- Strips and separates the periosteum from the bone, passing back towards the orbit’s apex.
- Closely attaches the periosteum to the bone at the orbital rim. S/he completes the dissection stretching back to the orbital apex.
- Uses a scalpel blade or heavy, curved scissors to divide the tissues at the orbit's apex.
- Apply very firm pressure for about five or more minutes to control profuse bleeding or a hot pack if bleeding persists. However, hot packs should be avoided because they can delay healing by causing thrombosis of the vessels in the bone.
- May leave the orbit for granulation with the skin progressively covering it from the edge. Alternatively, the surgeon can leave the orbit packed and perform a delayed skin graft.
- Apply a split skin graft if the body's ability to respond to blood vessel injury and bleeding is good. The surgeon uses a few small skin patches or a mesh graft with holes to allow for drainage. S/he applies the graft over a damp pack which is pushed into the orbit.
- Stitches the graft’s edges to the skin at the orbital rim.
In modified exenteration, the surgeon can preserve one or both eyelids. S/he may also preserve some of the eyelid skin and turn it inwards to cover the plain orbital bone.
Following exenteration, the surgeon reconstructs the cavity of the orbit. S/he may coat the orbital cavity using skin flaps or temporal muscle transposition. The surgeon may alternatively allow healing by spontaneous granulation.
Risks, Side Effects & Complications
In the case of infections, antibiotics can be used. It is also possible for a patient to develop intracranial infections, which can be addressed by the surgeon obliterating the entire cavity using soft-tissue free-flaps. This action protects the cranium from a likely infection.
One risk that can occur preoperatively is that it is possible to misdiagnose malignant tumors requiring exenteration because of several different tumor types, whether malignant or benign. Some orbital inflammatory masses and cysts may pass for malignant tumors. Proptosis (abnormal protrusion) may be confused with a tumor since it may occur with some cases of pseudotumor (inflammatory condition of the orbit) or endophthalmitis (inflammation of interior of the eye). Therefore, the doctor needs to be as sure as possible that s/he has made the correct diagnosis. Orbital diseases are almost always difficult to carry out and manage.
Orbital exenteration has few major complications. These may include bleeding that may require a blood transfusion. The procedure may leave the ethmoid bones fractured, creating an opening between the nasal cavity and orbit. The cavity created may facilitate the leakage of cerebrospinal fluid.
After Care, Recovery & Results
The patient is patched and given instructions on how they can remove keratin accumulated in the socket. Systemic antibiotics and regular postoperative analgesia are prescribed. The skin surrounding the incision must be cleaned with cool, boiled water. The patient should limit sneezing and nose blowing for at least six weeks after surgery to prevent secondary infection. To alleviate bruising and swelling, the patient’s head is elevated on extra pillows during sleep for a fortnight.
The surgeon leaves the orbit for about ten days until the pack is removed. Pack removal should be done carefully to avoid pulling off any skin graft, which may provoke bleeding from granulation tissue. The donor site can be covered for up to 10 days.The patient may stay in the hospital for one day.
The patient is required to attend a review clinic after seven days, where the dressing and superficial skin stitches will be removed. Patients will need regular clinical review for up to five years after the procedure.
Full recovery is expected after many months. To improve aesthetics, the patient can be fitted with a prosthesis which is attached to the now hollow-looking socket using specialized magnetic implants.If possible, secondary skin grafting may be applied. Later, when the socket has settled, the patient may require adjunctive local radiotherapy or chemotherapy. The purpose is to help clear any remaining tumor cells.
The challenge with many malignant tumors is that they spread very early to other body parts. Hence, exenteration will not save a patient’s life if the cancer has metastasized (spread). However, the procedure may be performed to afford comfort in a patient’s last phase of life if orbital mass emits a hideous fungating smell. In the case of advanced basal cell carcinoma or conjunctival carcinoma, exenteration may completely cure the tumor.
