Management

In 1954, Parsons and Lewis9 reported their landmark paper on en bloc subtotal resection of the temporal bone and introduced the present day concept for management of the temporal bone malignancies. Conley and Novack,1,4 in 1960, described an operation for malignancies limited to the external canal, with preservation of the facial nerve. Before this, piecemeal removal followed by radiation was advocated with poor 5-year survival rates.10 With the advent of skull base surgery, many previously unresectable tumors have become amenable to en bloc surgical extirpations. In addition, free tissue transfers have decreased wound complications and made postoperative radiotherapy more feasible. Before the introduction of free tissue transfers, the temporal bone defect was dressed with only a split-thickness skin graft. This precluded resection of dura and would on occasion result in CSF leaks and ascending meningitis.

Treatment of SCC of the external canal is determined by accurate preoperative clinical, CT, and MRI staging of this disease. Complete surgical resection followed by radiation yields the highest cure rate, and incomplete surgical removal almost certainly will result in death or recurrence within a few years.11

In T1 SCC (limited to the ear canal without bone involvement), the lateral temporal bone resection as described by Con-ley and Novack4 with preservation of the facial nerve is the treatment of choice. I always include the parotid gland (in a retrograde dissection of the facial nerve) as part of the specimen because of possible migration of tumor through the fissures of Santorini. Postoperative radiotherapy in stage 1 disease is determined by the final pathologic findings. For stages 2 and 3, a subtotal temporal bone resection, as described by Parsons and Lewis,9 is the treatment of choice, followed by radiation. The technique for subtotal temporal bone resection has been described extensively by many investigators; it is not be described here, except to state that the medial osteotomies are directed just lateral to the petrous ICA and medial to the arcu-

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ate eminence.

For T4a and T4b, a total en bloc resection is necessary along with a neck dissection including the soft tissues, dura, and the ICA, if necessary. Sekhar et al.13 use a saphenous vein interposition graft to reconstruct the petrous ICA. Malata et al.14 describe their techniques for total enbloc resection with preservation of the ICA. This procedure invariably results in multiple cranial nerve palsies and their sequelae. Curtin and Som15 have described the air cell system in the petrous apex and other anatomic feature of the petrous apex with which surgeons should be familiar. Total temporal bone resection will invariably result in CSF leaks and STSG are not adequate to reconstruct the defect. Various myocutaneous flaps and local muscle flaps have been used, but large defects are ideally reconstructed with free tissue transfers because they are free of reach limitation. The rectus abdominus flap is the ideal flap to use because the patient does not have to be repositioned, its bulk obliterates the cavity, and the rectus sheath can be used for dural repair, avoiding CSF leaks and ascending meningitis.14 Temporal bone resection and free flap reconstruction require the skills of the ablationist, the neurosurgeons, and a microvascular surgeon, not to mention the skills of a neuro-surgical anesthesiologist.

Postop radiotherapy is mandatory but is of no benefit if the tumor has not been completely resected.11 Facial reanimation is accomplished by either a cable graft or a hypoglossal facial crossover. However, the latter is not indicated when a total temporal bone resection is done and IX and X nerve paralysis are anticipated, because a XII nerve palsy would further complicate the swallowing function. However, in subtotal temporal bone resection, a hypoglossal to facial nerve neurarraphy serves well. Some do not recommend a neck dissection because of the low incidence of metastasis (10 to 15%). However, a suprahyoid dissection affords good exposure and access for recipient vessels for free tissue transfer. I subscribe to this approach because a suprahyoid dissection takes very little time and gives excellent exposure.

The operative and perioperative mortality has decreased markedly from 10% in 1954 to less than 5%, but the morbidity associated with cranial nerve palsies has not decreased. Free tissue transfers have significantly decreased the morbidity due to CSF leaks and meningitis.14

Cure rate reports by many investigators range from 28% to 50%.17 These are difficult to interpret because of differences in histology, sites of origin, and staging systems in addition to different surgical approaches (including piecemeal removal as advocated by Kinney and Wood),16 and the use of postoperative radiotherapy. The small number of cases in each report study is statistically insignificant.

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