Maxillary Swing/Transpalatal/Midface Degloving With Le Fort I Osteotomy Approach for Nasopharyngectomy

Introduction

Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma of an undifferentiated type. This cancer is endemic among Chinese, having the highest incidence of 10 to 20 per 100,000 for men and 5 to 10 per 100,000 for women. It is sometimes called the “Cantonese Cancer” because of its prevalence as one of the most common cancers of the head and neck among Chinese. The most common site of origin of NPC is from the epithelial lining of the area posteromedial to the medial crura of the Eustachian tube opening in the nasopharynx, which is also called the fossa of Rosenmüller.

Several serologic markers have become useful as a means of screening, diagnosing, and monitoring NPC after establishing that it is closely related to the Epstein-Barr virus (EBV), a double-stranded DNA virus. NPC has since become a model for EBV viral carcinogenesis after studies showed that most NPC cancer cells express EBV proteins and carry the clonal EBV genomes. Screening in the general population can now be done using serologic markers, such as EBV VCA immunoglobulin A (IgA) and DNase, whereas reverse transcription polymerase chain reaction (RT-PCR) methods measure EBV DNA copy numbers in plasma to monitor treatment response and early detection of local recurrence.

To summarize:

• 1.

  For general population screening, serologic diagnosis can be made using EBV VCA IgA.

• 2.

  For early detection of local recurrence, a nasopharyngeal swab should be taken for LMP-1 gene detection.

• 3.

  For monitoring treatment response and to detect possible recurrence, RT-PCR–based plasma cell–free EBV DNA detection should be used.

• 4.

  Currently available therapeutic modalities for NPC are radiation therapy (RT), chemotherapy, or a combination of both. Effective local control is more than 80% using the current RT techniques because of the high radiosensitivity of NPC. A high cure rate is seen among patients with early-stage cancer who undergo RT. Cisplatin-based chemoradiotherapy with or without neoadjuvant chemotherapy has demonstrated significant survival improvement and is currently the standard treatment strategy for patients with advanced locoregional disease.

Despite being a radioresponsive tumor, 10% to 30% of NPC patients develop local failure in the nasopharynx after the initial RT treatment. Whether it is persistence or recurrence after the initial radiation therapy (RT)/concurrent chemoradiation therapy (CCRT), salvage nasopharyngectomy is the treatment of choice. Proceeding with a second course of RT will only expose the patient to the risk of developing osteoradionecrosis (ORN) of the skull base, a potentially fatal complication of high-dose RT, without any assurance that the previously treated NPC cells will respond. Salvage nasopharyngectomy results in better outcomes than most of the published literature on re-radiation.

However, nasopharyngectomy requires skill and training and has posed a real challenge for head and neck surgeons. With the advances in skull base surgery, it is now possible to effectively control NPC recurrence or persistence using salvage nasopharyngectomy with acceptable mortality and morbidity.

Key Operative Learning Points

• Try to preserve or reestablish the blood supply to the bone when performing a facial bone disassembly.

• Perform a medial maxillectomy and posterior septectomy to improve exposure and increase the area of working space.

• During resection, the deep margin is marked by the pharyngobasilar fascia while making sure to remove as lateral as possible including the Eustachian tube cartilage.

• Depending on the extent of the cancer, several different approaches may be used.

• The use of rigid three-point bone segment fixation may prevent nonunion or ORN.

Preoperative Period

Local failure (persistence and recurrence in the nasopharynx) occurs in 16% to 48% of patients with NPC after initial RT. Salvage nasopharyngectomy has become the mainstay of treatment after RT failure, and the key to a successful surgery is proper patient selection. Preoperative period is essential to ensure that the patient is eligible for salvage nasopharyngectomy.

Before proceeding with nasopharyngectomy, all patients require thorough medical history including medical status, physical examination, as well as endoscopic examination. Firstly, it must be established that (1) these patients do have local recurrence or persistent NPC by performing biopsy(s) of the primary site, (2) ultrasound and possible guided fine-needle aspiration biopsy for any suspicious regional recurrence should be used, and (3) there is no distant metastasis. It is advisable to use Positron emission tomography–computed tomography (PET-CT) to exclude the possibility of distant metastasis. MRI with its excellent soft tissue resolution may also be used to evaluate the extent of the cancer and help to plan the surgical approach accordingly.

Other important preoperative preparation includes blood group and matched packed cells and preoperative antibiotic. Patients with pre-existing significant comorbidities should receive special attention. Anticoagulants or antiplatelet medications should be withheld (if possible) before salvage nasopharyngectomy.

Operative Period