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170
I. Mohammad et al.
non-keratinizing carcinoma and basaloid squamous cell carcinoma (Table7.1) [7].
In newly diagnosed NPC, radiotherapy or con-
current chemoradiotherapy has been the standard
Table 7.1 Histopathological types of NPC and their features
Histopathological type of
NPC Features
Keratinizing squamous
cell carcinoma
This is applied to tumours showing obvious or prominent squamous differentiation at the
light microscopic level. Intercellular bridges and/or varying degrees of keratinization are
indicators of squamous differentiation. The tumour grows in irregular islands separated
by desmoplastic stroma [8].
treatment. The use of radiation allows the management of both the primary site and nodal
metastasis, especially the retropharyngeal lymph
nodes as the rst echelon node in
Non-keratinizing
squamous cell
carcinoma
• Differentiated
type
• Undifferentiated
type
Basaloid squamous cell
carcinoma
Keratinizing squamous cell carcinoma (H&E 400×)
As implied by the name, the characteristics of squamous differentiation are ambiguous in
this subtype. Malignant cells are arranged in a variety of ways, ranging from solid to
trabecula to singly. The more prevalent undifferentiated subtype is characterized by large
cells with round-to-oval vesicular nuclei, prominent central nucleoli and sparse
eosinophilic cytoplasm. Indistinct cell borders result in a syncytial appearance. They
coexist with a variable proportion of lymphoplasma cells, and the stroma lacks any
desmoplastic response [8].
Non-keratinizing nasopharyngeal carcinoma, undifferentiated subtype (H&E 400×)
Basaloid squamous cell carcinoma is rare to occur in the nasopharynx. This type is
characterized by the presence of basaloid malignant cells mixed in with squamous cell
carcinoma cells [8].
7 Surgical Management ofNasopharyngeal Carcinoma
Fig. 7.1 General
management outline of
NPC
Suspicious history
Imaging Treatment
Examination and
nasolaryngoscopy
171
Histopathological
diagnosis (HPE)
NPC.Radiotherapy is the loco-regional treatment
for all stages of NPC, without distant metastasis
[9]. General management ow of NPC is as in
Fig.7.1.
7.2 Salvage Neck Dissection
Salvage neck dissection is an approach of choice
for neck residue or recurrent nasopharyngeal carcinoma after primary radiotherapy treatment
(RT). NPC is easily metastasized to cervical
lymph node, and the incidence of residual or
recurrent NPC is 4.6–18% [1].
By denition, a recurrence of disease is when
the cervical lymph nodes reappear 3months after
initial complete regression, while residual of disease is dened as a lymph node without complete
regression by 3 months after primary therapy
[10]. In current practice, the recurrence of
regional NPC is conrmed by ne needle aspiration (FNA) cytology. Before receiving salvage
treatment for regional failure, patients will
receive complete physical examination, nasopharyngoscopy and biopsy of the suspicious nasopharyngeal lesions, repeat imaging and restaging
of the tumour to exclude local disease and distant
metastases.
According to Wang etal., level II is the most
common site of nodal metastasis, followed by
levels V, III, IV and I.From the study, the author
also suggests that if there is no metastasis in level
I and parotid region after careful examination,
routine dissection of level I and parotid gland is
not necessary [11]. In salvage neck dissection,
the operation involves modied radical neck dis-
section, radical neck dissection or extended radical neck dissection (which may include
parotidectomy, skin, phrenic nerve, vagus nerve,
submaxillary and hypoglossal nerve).
7.2.1 Roles ofFlaps inSalvage Neck
Dissection
There are few options for ap reconstructions in
salvage neck dissection. These include anteriorlateral thigh (ALT) free ap and pedicled pectoralis major myocutaneous ap (PMMF) to repair
large facial defects more than 4.0cm in diameter.
However, microsurgical free ap reconstruction
is a challenging procedure in a patient who
received post-operative irradiation because the
treatment depletes the area of potential recipient
neck vessels for microvascular anastomosis [12].
According to a study by [13], the free ap reconstruction is feasible and safe in patients with prior
irradiation as the failure rate was 6.3% in the
prior irradiation and neck dissection group, 4.8%
in the neck dissection group and 5.2% in the
irradiation group compared to 2.1% in the nonirradiation and neck dissection group.
In the case series of Lin etal., they preferred
ALT ap due to it being a reliable perforator ap
with constant anatomy based on the descending
branch of the lateral circumex femoral artery,
long vascular pedicle that is suitable for microvascular anastomosis to the transcervical recipient vessels and availability of large and long ap
that can be harvested without any complications
[12]. Song etal. had reported the good outcome
of all the aps, which involved PMMFs, free
172
I. Mohammad et al.
forearm ap, free bular bone ap and pedicled
tongue ap, that were used in their salvage surgery in NPC cases. The NPC cases were originally treated with radiotherapy and subsequently
developed neck recurrence or second primary
tumour in the radiated area [14]. In the study, the
PMMF was created in spindle or crescent shape
as required by the donor site and was tunnelled
under the medial one-third of the clavicle, and the
ap was transferred to the cervical area and
sutured to the cervical defect.
7.3 External Access
forNasopharyngectomy: Lip
Split, Maxillary Swing,
Midfacial Degloving
The advent of endoscopic transnasal approaches
has made open approaches to the nasopharynx
less popular. However, it is not entirely obsolete,
especially in the circumstances where an endoscopic approach is deemed unable to adequately
clear the tumour or in centres with facilities
where dedicated skull base team is limited. This
chapter aims to give an idea on the selection criteria, advantages and disadvantages and the brief
surgical steps.
The nasopharynx is bordered anteriorly by
posterior nasal apertures and nasal septum, posteriorly by the buccopharyngeal fascia which lies
anterior to the longus capitis muscle, superiorly
by the pharyngeal mucosa overlying the basisphenoid and inferiorly by the oropharynx at the
level of soft palate. The lateral limit is formed by
the opening of the Eustachian tube (ET). Thus,
the goal of resection is to include the cartilaginous ET medial to the medial pterygoid muscle.
Numerous approaches have been described,
and we would like to classify them as below:
1. Transoral-transpalatine approach
2. Transmandibular-transcervical approach
3. Anterolateral: Maxillary swing approach
4. Lateral: Infratemporal approach type C
5. Combined approach: Subtemporalpreauricular infratemporal fossa approach and
facial translocation
7.3.1 Patient Selection
andPreoperative
consideration
Open nasopharyngectomy unavoidably renders
signicant morbidity to a patient both functionally and aesthetically. It is only reasonable to be
performed should the procedure change the
course of disease either by total eradication of
tumour or by reducing the bulk. Detailed knowledge of the complex anatomy of the nasopharynx
and precise understanding of the vital structures
like skull base and internal carotid artery (ICA)
are therefore indispensable before embarking on
this procedure.
Computed tomography and magnetic resonance imaging are complementary in assessing
the tumour volume and local and intracranialintradural extension, to evaluate the ICA and the
potential damage to it. Angiography and balloon
occlusion test are needed if resection of ICA is
deemed necessary. A pre-procedure tracheostomy is necessary in almost all the open
approaches including the transoral approach.
This is to avoid airway compromise due to
oedema in the immediate post-operative period.
Most patients will require alternative feeding
method in the post-operative period. Therefore,
they need to be counselled on nasogastric tube
feeding or even PEG tube feeding if resection is
anticipated to be extensive, which will signicantly delay the oral feeding. If a transpalatal
approach is used, preoperative designing and
planning for an acrylic palatal splint or obturator
need to be considered.
An honest discussion on the risks of the surgery
with the patient cannot be overemphasized. This
includes potential residual tumour, subsequent
7 Surgical Management ofNasopharyngeal Carcinoma
173
adjuvant chemoradiotherapy, fatal injury to ICA,
haemorrhage from the pterygoid plexus and cerebrospinal uid leak. In patients undergoing nasopharyngectomy as a salvage procedure after
radiotherapy, it is utmost importance to carefully
explain the risk of osteoradionecrosis not only at
the mandible but more dangerously over the sphenoid body. Other risks are injury to the tooth, palatal numbness and velopharyngeal insufciencies.
Intraoperatively, local anaesthesia to the skin
and mucosa can be given with 1% lidocaine with
1:100,000 adrenaline. Patient is positioned in the
standard supine position with neck extension.
Drains are required when the neck is accessed.
Prophylactic antibiotics can be administered to
reduce the risk of infection. Intraoperative steroid
a
(IV dexamethasone) will aid in reducing airway
oedema. Ventilation is best considered using a
tracheostomy as mentioned above.
Image-guided navigation has become almost a
must in recent days.
7.3.2 Transoral-Transpalatine
Approach (Fig.7.2)
This is an approach for malignant tumours
with limited clivus and craniocervical junction extension and size measuring less than 2
cm. This approach is contraindicated for
tumours larger than 2 cm and with
intracranial- intradural involvement, exten-
b
c
Fig. 7.2 Transoral transpalatine approach. (a) Transoral incision. (b) Mucosal incision along the palatal aspect of the
alveolar ridge. (c) Mucosal ap raised and hinged laterally
174
I. Mohammad et al.
sion lateral to the lateral pterygoid muscle,
involvement of cavernous sinus, infratemporal fossa extension and peritubal extension
[15–17].
7.3.2.1 Procedure
1. The patient is placed in the supine position
with their head extended as much as
possible.
2. Mayeld clamp xation is required if imageguided navigation is employed.
3. Tracheostomy is performed.
4. Crockard wide-eld retractors and dissecting
instruments that have been specially designed
for working through narrow long-distance
transoral approach are needed.
5. Mouth gag is inserted, and the oral cavity
and soft and hard palate are inltrated with
1:200,000 adrenaline.
6. The soft palate is split to one side of the
midline.
7. The hard palate mucosa is incised along the
ipsilateral junction of the hard and soft palate
within 5mm of the maxillary dentition.
8. This mucosal incision is extended along the
palatal aspect of the alveolar ridge up to the
level of the rst molar and then taken in an
arc across the palate to the opposite side.
9. A mucoperiosteal ap is elevated exposing
the bony hard palate. The greater palatine
neurovascular bundle is coagulated and
divided.
10. Muscular insertions of the soft palate from
the hard palate are divided to increase
exposure.
11. A self-retaining retractor is then inserted to
keep the two halves of the soft palate out of
the eld.
12. Dissection through the posterior nasopharyngeal wall gives access to the lower clivus.
13. Removal of some palatal vomerine bone
gives access to the sphenoid oor.
14. Perform a Le Fort I osteotomy and then split
the palate in the midline, displacing each
maxilla laterally, known as an ‘open-door
maxillotomy’, which gives access to clivus
and craniocervical junction.
15. A suitable mucosal ap is raised and tucked
laterally or inferiorly.
16. The length of this ap varies according to the
extent of the lesion being removed. The
larger the ap, the better the chance of being
able to approximate it at the end of the
procedure.
17. If access to the clivus is required, the prevertebral fascia and muscles have to be opened
and this is best undertaken in the midline.
The important anatomical landmark is the
anterior arch of the atlas.
18. Most resection is usually performed in a
piecemeal fashion.
19. Dural tears require watertight closure, which
is possible with tissue sealants.
20. The dead space created by tumour resection
can be lled with autograft soft tissue secured
in place by brin glue and covered by pedicled local mucosal or mucoperichondrial
aps.
21. The prevertebral fascia, musculature and
pharyngeal mucosa are reapproximated.
22. The soft palate is approximated in a threelayered closure to minimize a stula.
23. Bone plates and screws are applied if the
maxilla has been split.
24. Removal of the tracheostomy is determined
by the clinical progress of the patient in
terms of swallowing and resolution of
oedema.
7.3.2.2 Advantages
Transoral transpalatine technique is a simple and
direct approach to the nasopharynx.
It is also extendable through the Le Fort
I-palatal split approach.
7.3.2.3 Disadvantages
The major drawback is narrow working eld
and long working distance and no access laterally to the parapharyngeal and infratemporal
spaces. Apart from this, it requires tracheostomy. The rate of palatal dehiscence and oronasal stula is around 30–40%. Patients are also
prone to the risk of meningitis due to wound
contamination.
7 Surgical Management ofNasopharyngeal Carcinoma
175
7.3.3 Transmandibulartranscervical approach
This approach (Fig.7.3) is suitable for tumours
that are encroaching into the anterior part of the
infratemporal fossa. It is contraindicated if the
tumour has intracranial intradural invasion more
than 2cm or involving the parasellar and posterior infratemporal region [18, 19].
7.3.3.1 Procedure
1. The patient is placed in the supine position
and a tracheostomy is done.
2. Skin incision made from mastoid tip extend-
ing to the midline of the lip to split it.
Subplatysmal ap is raised and directed
beneath the submandibular gland.
3. The tendons of the digastric and stylohyoid
muscles can be released from their hyoid
attachment and reected superiorly along
with the submandibular gland to increase
exposure of the mandible.
4. The great vessels in the carotid sheath and
adjacent cranial nerves are then identied.
5. Dissection is continued as near to the skull
base following the internal and external
carotid arteries.
6. A mandibular osteotomy is performed after
pre-plating is done. The authors prefer a
paramedian mandibulotomy.
7. The floor of the mouth is dissected. The
tongue is retracted to the opposite side, the
mucosa incised and the mylohyoid muscle
divided together with the anterior belly of
the digastric muscle. The lingual and
hypoglossal nerves are identified and
preserved.
8. The mandible is retracted laterally to reach
the parapharyngeal space, which then
becomes continuous between the mouth and
neck. The external carotid artery can be
ligated distal to the lingual artery to increase
the retraction of the mandible.
9. This nally allows an access to the nasopharyngeal part of the parapharyngeal space and
the anterolateral infratemporal fossa.
10. Additionally, the incision can be extended
upward towards the hard palate and pterygoid plates ending about 1cm medial to the
gingival margin should a more median access
be required.
11. Blunt dissection lateral to and behind the
superior and middle constrictor muscles produces a surgical working space.
a
Fig. 7.3 Transmandibular transcervical approach. (a)
Extended incision from the mastoid tip rising anteriorly to
split the lip. (b) A median mandibular osteotomy exposing
b
the oor of the mouth by diving the anterior belly of
digastric and mylohyoid muscle. Lingual and hypoglossal
nerves are in view
176
ac
I. Mohammad et al.
12. Additional posterolateral division of the styloid musculature and glossopharyngeal nerve
and superior dissection along the
retropharyngeal- prevertebral plane release
the oropharynx, making retraction easier to
the contralateral side.
13. Next, to access the cartilaginous part of the
ET, the ICA should be accurately identied
followed by transection of tensor and levator
muscle.
14. Transection of the ET releases the nasopharynx from the skull base at the level of the
pharyngeal tubercle.
15. Access to nasopharynx and upper sphenoid
body can be further increased by removing
the posterior portion of the hard palate. If the
lesion reaches the posterior aspect of the
infratemporal fossa, combination with a lateral approach may be required to allow en
bloc resection.
16. Any dural defect is repaired in watertight
fashion.
17. The remaining pharyngeal sleeve is reattached to the prevertebral muscles at the
skull base; the pharynx is realigned by suturing the ET at intratubal splint. The palatal
muscles are reapproximated, the mucoperiosteal palatal ap is repositioned and the
mucosa is sutured.
18. A pre-planned palatal splint is then applied at
hard palate. The oor of the mouth is recon-
structed, and the mandible is xed with the
pre-tted miniplates.
19. Large drains though a separate stab incision
in the lower neck are placed.
20. The lower lip is closed to achieve accurate
alignment of the vermilion border.
7.3.3.2 Advantages
The transmandibular-transcervical technique
gives good direct access to the epipharynx and
the parapharyngeal and anterior infratemporal
space. It also enables good vascular control.
7.3.3.3 Disadvantages
This approach places the wound at a hazard of
potential infection through oral contamination,
possible mandibular non-union and prolonged
need for tracheostomy. Apart from that, restoration of normal or adequate swallowing is often
signicantly delayed (mean 7weeks). Therefore,
temporary PEG is often needed.
7.4 Anterolateral Approach:
Maxillary Swing
This approach (Fig.7.4) is suitable for nasopharyngeal tumours with limited extension to the
anterior infratemporal region. However, it is contraindicated for tumours encroaching the petrous
ICA, petrous apex, parasellar and/or posterior
b
Fig. 7.4 Anterolateral: Maxillary swing approach. (a)
Weber-Ferguson-Longmire incision made, extending laterally to the zygoma. (b) Osteotomy site to separate maxilla from zygoma, medially along the inferior orbital rim
and in midline. (c) Transoral view showing palatal split.
Entire maxilla swung laterally together with cheek ap
and masseter muscle
7 Surgical Management ofNasopharyngeal Carcinoma
177
infratemporal region (combination with lateral
approach required) [20].
7.4.1 Procedure
1. Patient is placed in a supine position and
draped.
2. The authors prefer a preliminary
tracheostomy.
3. Skin incision: Weber-Ferguson-Longmire
incision is made.
4. The vertical incision limb is through the
upper lip and is continued between the central incisors and onto the hard palate until the
junction of hard and soft palate.
5. The incision is then curved laterally to run
behind the maxillary tuberosity.
6. The facial incision is made through the subcutaneous, muscular and periosteal layers to
expose the planned osteotomy line.
7. The osteotomy is begun by separating the
zygoma from the maxilla, moving medially
along the infraorbital rim until the frontal
process is divided from the anterior maxillary wall. Then the medial maxillary wall is
separated from the midline nasal complex in
an antero-posterior fashion.
8. The posterior wall is released using an osteotome inserted through the antrum.
9. The palatal bone is incised, and a midline
osteotomy is fashioned.
10. The pterygoid plates are separated from
maxillary tuberosity by using a curved
osteotome.
11. Finally, the maxilla can be swung laterally
attached to the cheek ap and the masseter
muscle.
12. The nasopharynx including the cartilaginous
ET bilaterally becomes well exposed. This
allows en bloc resection of the lesion.
13. Additional ipsilateral turbinectomy gives tissue for free graft that can be placed on
exposed bone in the epipharynx. Nasal packing keeps the graft in place.
14. Maxilla is returned to its anatomical position
and xed to the zygoma and contralateral
maxilla with miniplates.
15. Alveolar ridges are approximated by using a
preoperatively fashioned dental splint.
16. The facial and intraoral incisions are closed
in layers.
17. A grommet should be inserted if cartilaginous ET was resected.
18. Oral feeding can be started after 72h.
19. Any non-resorbable nasal packs should be
removed on the seventh post-operative day
and the dental plate after about a month or
when all the mucosal wounds have healed.
7.4.2 Advantages
Maxillary swing is relatively a simple technique,
which gives wide exposure and good cosmetic
and functional results.
7.4.3 Disadvantages
However, it gives very limited parapharyngeal
and infratemporal exposure. Lack of access to the
neck renders lack of vascular control. Patient will
also suffer from post-operative trismus from pterygoid myositis or brosis. In some patients, the
maxilla can become necrosed.
7.5 Lateral Infratemporal Fossa
Approach Type C
This procedure (Fig.7.5) is indicated in infratemporal fossa (ITF) tumours that extend into the
temporal bone with involvement of the epipharynx such as juvenile angiobroma class III b–IV
(Fisch) and nasopharyngeal carcinoma (NPC).
This procedure is contraindicated in lesions
extending into the sella, contralateral middle
fossa or anterior skull base [21, 22].
7.5.1 Procedure
1. A postauricular C-shaped incision is made
that extends superiorly into the temporal
region and inferiorly into the neck.
178
I. Mohammad et al.
a
Fig. 7.5 Lateral infratemporal fossa approach, type C.
(a) Skin incision from the temporal region extending inferiorly to the neck. (b) Skin ap together with pinna
2. The temporalis muscle, mastoid and zygoma
are exposed. A periosteal ap is elevated, and
the external auditory canal is transected and
closed in a blind sac.
3. The pinna and skin ap are reected
anteriorly.
4. For vascular control, the neck is dissected so
that carotid and jugular vessels are accessible.
5. The main trunk of the facial nerve is identied together with its frontal branch.
6. The zygomatic arch is exposed and divided
anterior to the temporomandibular joint
(TMJ) and just behind the orbital rim preserving the frontal branch.
7. The zygomatic arch is reected inferiorly
attached to masseter muscle.
8. The temporalis muscle and fascia are elevated from the temporal fossa and reected
inferiorly, exposing the superolateral quadrant of ITF.
9. A subtotal petrosectomy is done in which the
sigmoid sinus, ICA and middle fossa dura
are skeletonized with preservation of the
labyrinth.
10. The TMJ capsule is exposed followed by
excision of the articular disc and displacing
the condyle inferiorly.
b
reected anteriorly and the main trunk of facial nerve is
identied to divide zygomatic branch anterior to the temporomandibular joint without damaging frontal branch
11. Additional space can be established by
release of the sphenomandibular and stylomandibular ligament.
12. The glenoid fossa is resected to give extensive exposure of ITF, and this can be enlarged
further by division of the mandibular nerve
and middle meningeal artery.
13. The pterygoid process with lateral and
medial plates is removed, giving access to
the anterior third of the ET and
nasopharynx.
14. The nasopharyngeal cavity is entered
through incision of the pharyngobasilar
membrane and nasopharyngeal mucosa.
Subsequent dissection is done to complete
the resection.
15. To close the defect, the temporalis muscle
can be rotated into it. The alternative is to use
the latissimus dorsi ap.
16. The TMJ is reconstructed by interposing
temporalis muscle between the condyle of
the mandible and the middle fossa dura.
17. The skin and subcutaneous tissue are closed
in layers.
18. Drain is placed and secured.
19. Normal oral feeding can be started on the
rst post-operative day.
ac
7 Surgical Management ofNasopharyngeal Carcinoma
179
7.5.2 Advantages
The type C lateral ITF approach gives a wide and
direct access to the infratemporal region, including the parasellar and temporal regions. It also
provides short working distance.
7.5.3 Disadvantages
The drawbacks of this procedure are transient
post-operative trismus, malocclusion and hypaesthesia of the lower half of the face and ipsilateral
tongue (V3). As the ET is resected, it results in
permanent conductive hearing loss. Temporary
frontal facial paresis occurs in 30%.
7.6 Subtemporal-Preauricular Infratemporal Fossa Approach
This is a combined approach (Fig.7.6) requiring
an established team comprising a lateral skull
base ENT surgeon and a neurosurgeon. This
approach is not often performed, but it is done for
large ITF tumours (T4) encroaching the nasopharynx, the cavernous sinus and the middle
cranial fossa. It is contraindicated in bilateral
optic chiasm or ICA involvement, or in lesions
extending to the posterior cranial fossa for which
a combination with a retrosigmoid or transotic
approach is necessary [23].
7.6.1 Procedure
1. This procedure requires preoperative
tracheostomy.
2. The ipsilateral scalp, face, neck, lower
abdomen and thigh are prepared and
draped.
3. An extended Blair incision is made and a
cervico-facial ap raised.
4. The facial nerve trunk is identied, and its
major branches are dissected peripherally.
5. The parotid gland is raised from the masseteric fascia.
6. The temporal branches of external carotid
are ligated.
b
Fig. 7.6 Subtemporal preauricular infratemporal fossa
approach. (a) An extended Blair incision. (b) Osteotomy
site for the zygomatic arch including in a fronto-temporal
craniotomy; also to include glenoid fossa and oor of the
middle fossa lateral to the foramen spinosum and ovale.
(c) Removal of more bone medial to glenoid fossa and
greater wing of the sphenoid giving access to the
Eustachian tube. Removal of the pterygoid process giving
access to the anterior Eustachian tube and posterolateral
aspect of nasopharynx