Introduction

Orbital exenteration implies the removal of all the orbital contents including the periorbita and eyelids.

An operation similar to modern exenteration was probably described by Bartisch in 1583 (cited by Goldberg et al1). Frezzotti et al2 reviewed the history of exenteration; he attributed the first description to Gooch in 1767.

Modern exenteration aims to achieve local control of the orbital disease. ‘Total’ exenteration as defined above is often needed, but when possible, orbital tissue is conserved and eyelid skin and orbicularis muscle are spared to aid healing.1, 3, 4 If the bone of the orbit is invaded, an ‘extended’ exenteration is required that includes resection of diseased bone.4, 5

Indications

Exenteration surgery is necessary when orbital and periorbital tumours, and occasionally other conditions, that are potentially fatal or relentlessly progressive cannot be treated more effectively in other ways.

About 40–50% of exenterations that present to ophthalmologists are required for tumours originating in the eyelid or periocular skin.1, 4, 6, 7 The remainder originate almost exclusively in the conjunctiva, orbit, or globe. Tumours arising in the paranasal sinuses and nose may also require exenteration to achieve local control, but these tumours usually do not present to an ophthalmologist. The case mix of disease leading to exenteration varies with the special interests of the treatment centre.3

The relative incidence of periocular skin malignancies varies with geographical area and racial group.8, 9, 10 Basal cell carcinoma is universally the most common malignant skin tumour accounting for approximately 90% in most series; squamous cell and sebaceous gland carcinoma occur in approximately 4–6% each. The incidence of all skin malignancy is increasing worldwide.11, 12, 13, 14, 15, 16

Basal cell and squamous cell carcinoma occur most commonly in the lower lid and medial canthus.9, 17, 18 Sebaceous gland carcinoma is most common in the upper lid.19 Other eyelid malignancies are relatively rare.

Any periocular skin malignancy, if neglected, can invade the orbit and raise the probability of exenteration. The incidence of orbital invasion is about 2–4%,20, 21, 22 and the risk factors include multiple recurrences, large size, aggressive histological subtype, perineural spread, canthal location—particularly the medial canthus—, and older patients.22, 23, 24, 25 Exenteration for sebaceous gland carcinoma is more likely to be required if there is intraepithelial (pagetoid) spread of the tumour.26

Perineural invasion occurs in less than 1% of basal cell carcinomas,18, 27 but in about 3–14% of squamous cell carcinomas.17, 28 It is more common in lesions of the forehead and brow29, 30 and with aggressive cell types.23, 24, 28, 31

Clinical signs

There may be no signs of orbital invasion in the early stages, although a mass is almost always palpable.23 As the disease progresses fixation to bone, limitation of ocular motility and globe displacement may occur.22, 23, 29 Spread through the periorbita into bone has been reported in 20–30% of cases.4, 23 Perineural spread is also asymptomatic in the early stages, but eventually results in numbness or, less frequently, pain in the distribution of the trigeminal nerve—especially the supraorbital nerve in periocular tumours. Branches of the facial nerve are also frequently involved.29, 30 As posterior spread continues, the orbital apex and cavernous sinus become involved with predictable accompanying clinical signs.

Investigation

Biopsy of the surface tumour is helpful to establish the cell type and to identify perineural invasion. Biopsy of the supraorbital nerve may be helpful to confirm the presence and extent of perineural invasion in tumours of the forehead or brow.30

CT and MR imaging are useful in assessing the extent of orbital spread. CT is more appropriate for bone destruction, MRI demonstrates the extent of soft tissue invasion and can sometimes detect the integrity of the periorbita—the most effective barrier to tumour spread.22, 23, 32, 33

Management of orbital invasion

Having diagnosed malignant orbital invasion, it is always appropriate to collaborate with a multidisciplinary team in planning management. An oncologist should always be involved and also other disciplines according to the extent and direction of tumour invasion. Radical surgery and adjuvant radiotherapy or chemotherapy may be needed. Occasionally, surgery is not the best management and this can be decided jointly.

Choice of operation

The aim of exenteration is to achieve local control of the disease.

Total exenteration removes all orbital tissue, including the periorbita, posterior to the orbital rim. The eyelids may be preserved in tumours placed posteriorly within the orbit and even some arising in periocular skin. Most anteriorly placed tumours, however, require removal of all anterior orbital tissue and periorbita together with the eyelids, but the posterior orbital tissues may be preserved. If there are macroscopic changes at operation suspicious of bone invasion, it is helpful to have a frozen section examination of the periorbita. If it is positive, bone should be removed and sent for decalcification and pathological analysis.

Shields et al3 reported 56 exenterations. Four of the nine skin tumours allowed some eyelid sparing; in 22 of the 24 conjunctival tumours and all of the 11 orbital tumours, the eyelids were spared. Ben Simon et al4 reported 34 exenterations: 13 were subtotal, 14 were total, and seven were extended.

In planning the surgery, the extent of orbital invasion—which may have been underestimated by the investigations—the biological behaviour of the tumour, and the presence of perineural spread must be taken into account. Aggressive cell types and in particular the possibility of perineural invasion should prompt generous margins of excision.

Techniques

Exenteration including the eyelids34, 35

The orbital rim is marked and the skin and tissues are incised down to the periosteum. The periosteum is incised for 360° and reflected from the orbital rim then posteriorly within the orbit to behind the globe. Special care is taken along the thin medial wall and orbital roof. The orbital tissues are transected at a point posteriorly that allows safe clearance of the tumour. The lacrimal sac is removed with the exenterated orbital tissues. The nasolacrimal duct is tied off. If there is macroscopic evidence of bone involvement, the affected bone is removed with rongeurs or a saw. The skin and muscle are approximated medially and laterally at the orbital rim to reduce the skin aperture.

Management of the exenterated orbit without lid sparing

The exposed bone of the exenterated orbit may be treated in a variety of ways.

The orbit heals by granulation in 3–4 months.3, 4, 36 Frequent dressings with antibacterial packs are needed. Healing by granulation results in a shallower socket than with split skin grafting.

Split skin, with or without meshing, generally heals well.1, 35, 37 Full-thickness skin grafts should not be used, as the secretions can be profuse and unpleasant.

The transposed forehead flap is one of a number of vascularised flaps, which have been described to fill the orbit.38, 39, 40 Free tissue transfers have also been used. These are particularly effective if large defects in the orbital walls have to be covered or if radiotherapy has been used or is planned. Temporalis muscle flaps are covered with a split skin graft. Shallow sockets result with these techniques and a prosthesis may be difficult or impossible to wear.

Lid sparing exenteration1, 3, 4

Incisions are made 1 mm from the lashes in the upper and lower lids. Dissection is preferably deep to the orbicularis muscle, but it can be at a more superficial level between the skin and orbicularis muscle if tumour clearance would be compromised by a deeper level of dissection. At the orbital rim, the periosteum is incised 360° and the exenteration proceeds as above.

Management of the exenterated orbit with lid sparing

The skin–muscle flaps preserved from the eyelids are sutured together, with local undermining if necessary. A drain is not usually needed. Local advancement or other flaps may be needed to achieve closure without excess tension. Separation of the sutured flaps occurs occasionally; they can be resutured with further undermining or allowed to heal by granulation. Healing is significantly shorter following lid sparing than with simple granulation.3

Clearance of tumours

It is not always possible to achieve complete clearance of a tumour despite radical surgery. Incomplete clearance was found in 38% of total and 17% of subtotal exenterations by Goldberg et al.1 Perineural invasion may indicate more extensive spread than anticipated, the risk of incomplete clearance is higher and the prognosis is worse.21, 29

Complications

Ben Simon et al4 reported complications in 23.5% of 34 exenterations. These include fistula formation into a sinus, the nose or the nasolacrimal duct, tissue necrosis with eschar formation, chronic drainage, infection, chronically exposed bone, cerebrospinal fluid leak, and pain. Large fistulae and exposed bone can be managed with a temporalis muscle flap38 or other local flap. The time taken for healing with granulation can occasionally far exceed the usual 3–4 months.3 Split skin usually takes well but occasionally some skin is lost owing to infection or haematoma or following irradiation.41 Crusting and general cleanliness of the socket can be a problem. Careful attention to daily hygiene is necessary. Crusting can be managed with dilute potassium permanganate (1 : 10 000) packs supplemented with Trimovate ointment (clobetasone butyrate 0.05%, oxytetracycline, nystatin). Less commonly, a cerebrospinal fluid leak may result from cautery or other trauma to the orbital roof.42, 43

Patch or prosthesis?

Most patients prefer to wear a patch after exenteration, rather than a prosthesis, especially with the larger reconstructions.1, 3, 4, 35, 40

Attempts have been made to preserve more of the orbital tissues including palpebral and bulbar conjunctiva to achieve reconstruction of a socket, which allows retention of a standard ocular prosthesis (simple artificial eye) using mucosal grafts in addition if needed.1 This is feasible in only a small minority of exenterated patients.

If a standard postexenteration facial-type prosthesis is preferred to a patch, good cosmesis can be achieved. The prosthesis is moulded to the underlying socket and may include components to close any communication with the nose or sinuses. Fixation of the prosthesis may be with tissue glue or it may be mounted on spectacles. Tissue glue is inefficient and glue deposits are left on the prosthesis, which may discolour. Spectacle-mounted prostheses prevent the spectacles ever being removed in public. Patients often lose confidence with these methods and tend to abandon their prosthesis for a patch.

An alternative method of prosthesis fixation is the use of titanium osseointegrated implants to which the prosthesis is attached by magnets or clips.44 The technique was pioneered by Brånemark in Sweden and it has proven to be a very successful method of fixation for facial and other prostheses.

The implants are usually placed once the orbit is healed. The procedure is in two stages. Three or four titanium fixtures are implanted into the bony orbital rim and covered again with skin while osseointegration occurs. About 4 months later, the skin over the implants is opened, healing of the skin around the implant is allowed to occur, and then the final magnets or framework for prosthesis fixation are fitted (Figure 1). The mould of the socket is taken at this stage and the prosthesis is made44, 45 (Figure 2). Osseointegration also occurs in irradiated orbits, but it is less reliable and it is advisable to delay implantation for at least a year following irradiation.44, 46 Patient satisfaction with implant-retained prostheses is generally high45 (Figures 3 and 4).

Figure 1
figure 1

Exenteration with Branemark implants.

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Figure 2
figure 2

Facial prosthesis.

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Figure 3
figure 3

Facial prosthesis fitted.

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Figure 4
figure 4

Oblique view of facial prosthesis in place.

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Prognosis

Mohr and Esser5 reported a 1-year survival of 89%, a 5-year rate of 63%, and a 10-year rate of 48% in 77 exenterations, 58% of whom required simultaneous bone removal.

Bartley et al47 reported 5-year recurrence and survival rates in patients with and without known residual tumour. Eighty-two per cent had no residual tumour at operation, and in this group, the 1-year survival was 88.6%, the 5-year survival was 56.8%, and at 5 years, 48.3% remained clear of local recurrence and metastases. Eighteen per cent had known residual local tumour or metastasis at operation. The 1-year survival in this group was 55.0% and the 5-year survival was 25.8%.

Savage25 reported 11 exenterations in patients with large squamous or basal cell carcinomas of the skin. The recurrence rate was 60% and the 5-year survival was 56%.

Perineural tumour spread has a worse prognosis. McNab et al29 reported 21 patients with perineural spread of squamous cell carcinoma. The primary tumour was most commonly found in the forehead or brow; 95.2% had altered or reduced sensation, 42.9% had pain, 66.7% had ophthalmoplegia. 66.7% had involvement of the facial nerve, and 66.7% died between 9 months and 5 years, one was alive at 3 years but with recurrent disease. Two were alive at 14 and 18 years. Four had no recurrence at 2, 3, 4, and 12 months.

Williams et al33 reported 35 patients with clinical perineural spread. 51.4% had positive evidence of perineural spread on imaging. The 5-year survival in this group was 50%. In the group without CT or MR confirmation of perineural spread, the 5-year survival was 86%.

Conclusion

Exenteration is a radical operation for potentially fatal or relentlessly progressive disease that has invaded the orbital tissues. Clearance is achieved in more than 60% of total exenterations and more than 80% of subtotal exenterations. The 5-year survival is about 55–65% for exenterations that present to ophthalmologists:tumours arising in the skin, globe, or orbital tissues. Survival is significantly lower if there is perineural spread of the tumour. Good cosmetic rehabilitation can be achieved with a facial prosthesis, but most patients still prefer to wear a patch.