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Original Article
Combined transnasal and transoral endoscopic
approaches to the craniovertebral junction
I. H. El-Sayed, J-C Wu1,2, C. P. Ames2, G. Balamurali2,3, P. V. Mummaneni2

Department of Otololaryngology-Head and Neck Surgery, 2Department of Neurosurgery, UCSF Spine Center, University of California, San Francisco,
San Francisco, USA, 1Department of Neurosurgery, Taipei Veterans General Hospital, National Yang-Ming University, Taipei, Taiwan, 3Salford Royal
Hospitals, Manchester, England
Corresponding author: Dr. Jau-Ching Wu, UCSF Department of Neurosurgery, 505 Parnassus Avenue M-780, San Francisco, CA 94143, USA. Department of
Neurosurgery, Taipei Veterans General Hospital, National Yang-Ming University, Taipei, Taiwan, E-mail: jauching@gmail.com

DOI: 10.4103/0974-8237.65481 J Craniovert Jun Spine 2010, 1:8

Abstract
Objectives: To describe and evaluate a new technique of a combined endoscope-assisted
transnasal and transoral approach to decompress the craniovertebral junction. Materials
and Methods: A retrospective cohort of patients requiring an anterior decompression at the
craniovertebral junction over a 12-month period was studied. Eleven patients were identified
and included in the study. Eight of the patients had an endoscopic approach [endonasal (2),
endooral (2), and combined (4)]. Four of the 8 patients in the endoscopic group had a prior open
transoral procedure at other institutions.These 8 patients were compared with a contemporary
group of 3 patients who had an open, transoral–transpalatal approach. Charts, radiographic
images, and pathologic diagnosis were reviewed. We evaluated the following issues: airway
obstruction, dysphagia, velopharyngeal insufficiency (VPI), length of hospital stay (LOS), adequate
decompression, and the need for revision surgery. Results: Adequate anterior decompression
was achieved in all the patients.The endoscopic cohort had a reduced LOS (P = 0.014), reduced
need for prolonged intubation/tracheotomy (P =0.024) and a trend toward reduced VPI (P =
0.061) when compared with the open surgery group. None of the patients required a revision
surgery. Conclusion: Proper choice of endoscopic transnasal, transoral, or combined approaches
allows anterior decompression at the craniovertebral junction, while avoiding the need to split
the palate. A combined transnasal–transoral approach appears to reduce procedure-related
morbidity compared with open, transoral, and transpalatal surgeries.
Key words: Craniovertebral junction, endonasal, endoscopic, odontoidectomy, transnasal,
transoral

INTRODUCTION palate is often required for adequate exposure. Mummaneni et al

highlighted a surgical technique variation to avoid the palate split
Several surgical approaches provide anterior access to the by using simple retraction of the soft palate with a red rubber
craniocervical junction and the upper cervical spine, including catheter passed transnasally and secured to the uvula.[12] Despite
transoral,[1,2] high transcervical,[3,4] and endoscopic transnasal– this modification, in some circumstances, invasive approaches
transoral approaches.[5-11] The standard open transoral approach (ie, splitting the soft palate, resecting the hard palate, glossotomy,
has gained wide acceptance by spine surgeons to treat ventral or midline mandibulotomy) are still required to provide surgical
spinal cord compression at the C1–C2 level. However, to access to the craniovertebral junction. Such approaches are often
approach lesions of the craniovertebral junction, splitting of the used for decompression of lesions located high above the level

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J Craniovert Jun Spine 2010, 1:8 El-Sayed, et al.: Combined approach to the craniovertebral junction

of the palate. In addition, these invasive open approaches may junction decompression
also be needed in patients with atypical oral anatomy, or severe The patients were positioned supine and were intubated
trismus (inability to distract the jaw open). orally and given general anesthesia. Neuromonitoring with
somatosensory-evoked potentials was used throughout the
Palatal splitting has been reported to increase patient morbidity,
procedure. Spinal traction was applied as needed to get the
especially velopharyngeal insufficiency (VPI), dysphonia, and
odontoid process into a more normal position. Flouroscopy and
dysphagia.[13] VPI occurs when there is incomplete closure of the
neuronavigation were used for surgical guidance.
nasopharynx with resultant escape of air and food into the nose
during speech and swallow. Whereas dysphagia often resolves The endoscopic transnasal approach (endonasal approach)
within 12 months following surgery, VPI often persists for a long consisted of a bilateral approach through the nostrils. In the
term. We have recently referred 2 patients for pharyngoplasty expanded form, as described by Kassam et al,[5] a nasal septal
after 1 year of persistent, significant VPI following an open flap was first elevated for closure and then a corridor was
transoral approach. prepared with a maxillary antrostomy, ethmoidectomy, middle
turbinate resection on the right, posterior septectomy, and
In order to avoid splitting the soft palate (and glossotomy/ a wide sphenoidectomy. However, not all patients required
mandibulotomy, etc), we have used endoscopic transnasal– sphenoidectomy or middle turbinectomy, and dissection was
transoral techniques to decompress the craniovertebral junction tailored to the individual’s anatomy. Depending on the location
in patients with challenging anatomic features. of the lesion, the sphenoid floor and clival bone were drilled to
access the craniocervical junction pathology. A midline incision
MATERIALS AND METHODS was made with an extended needlepoint cautery through the
posterior nasopharygeal mucosa down to the preveterbral fascia.
A retrospective chart review was performed to review all the The prevertebral muscles were dissected vertically in the midline
patients who underwent surgery of the craniovertebral junction and elevated laterally off the spine, which allowed exposure
during a 12-month period at our hospital (UCSF). We included of the anterior tubercle of the atlas. Decompression was then
only those with lesions located between the clivus and the body performed using a drill, currettes, and/or Kerrison Rongeur.
of C2. Eleven patients were identified and included. The medical
records were reviewed for demographics and disease-specific The endosocopic transoral approach (endooral approach) was
information, including age, sex, diagnosis, surgical approach, performed with soft palate retraction using 1 or 2 red rubber
length of hospital stay (LOS) after surgery, and surgery-related catheters tied to the uvula and pulled cranially through the
complications. The median age was 54 years (18–64 years). nostrils.[12] The oral cavity and tongue were retracted open
Eight of the patients had an endoscopic approach [endonasal with a Spetzler–Sonntag oral retractor. The endoscope was
(2), endooral (2), and combined endoscopic transnasal– guided under the retracted soft palate to visualize the posterior
pharyngeal wall, and the pharyngeal incision was created and
transoral (4) approaches]. These 8 patients were compared with
continued in the midline to the desired height to expose the
a contemporary group of 3 patients who had an open, transoral–
C1–C2 area [Figure 1a, b]. The soft tissue and bony structures
transpalatal approach for lesions of the craniovertebral junction.
causing ventral cord compression were resected in a similar
Diagnoses for the endoscopic group included infection (2), fashion to a transnasal decompression, described above [Figure
tumor (2), rheumatoid arthritis (1), and basilar impression (3). 1c–e]. The endoscope allowed us to “look” cranially above the
Four of the endoscopic patients had prior transoral surgery at level of the soft palate to complete the decompression.
another hospital in the past. All the 3 patients having an open
For a combined transnasal and transoral approach, the exposure
approach had rheumatoid arthritis. None of these 3 had prior
was a combination of the above-mentioned steps in both routes.
C1–C2 surgery.
Then the endoscope and surgical instruments were brought
Early and late postoperative complications were recorded, into the surgical field alternatively through the nose and
including documented VPI, dysphagia, need for insertion of mouth, in order to maximize the exposure with less dissection.
percutaneous gastric feeding tube, and airway complications Decompression was straightforward because visualization
defined as need for endotracheal intubation longer than 24 h, was gained from 2 different angles (from above and below
or a tracheotomy as a result of the surgery. Preoperative and the palate). The most favorable feature gained via combined
postoperative images [computed tomography (CT) and/or transnasal and transoral approach is the ability to visualize
magnetic resonance imaging (MRI)] were carefully reviewed for laterally beyond the confines of the nasal cavity. Such lateral
evaluation of the adequacy of resection or decompression. visualization is restricted by the nasal cavity/pterygoid plates
in the transnasal-only approach. The addition of the transoral
The data were stored in an excel spreadsheet and transferred to endoscopic approach increased the ability to reach out laterally
SAS (SAS Institute Inc., Cary, NC, USA) for data analysis by beyond the confines of the transnasal approach.
the UCSF Department of Biostatistics, using Fisher’s exact test
and the Mann–Whitney U test where appropriate. CT-based image guidance navigation was typically used for the
endoscopic cases. After the pharyngeal incision was completed,
Surgical technique for endoscopic craniovertebral surgical dissection was performed with 2 surgeons working

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J Craniovert Jun Spine 2010, 1:8 El-Sayed, et al.: Combined approach to the craniovertebral junction

a b sutures [Figure 1f]. Tissue sealant and a transnasal merocel

sponge were packed in the nose. A transoral feeding tube was
then passed under endoscopic guidance. Postoperative CT
scans or MRI were performed and adequate decompression was
assured in every patient. If the clivus was resected as part of the
dissection, a pedicled nasal septal flap was harvested and rotated
over the clival defect for closure. This was held in place with an
absorbable tissue sealant (DuraSeal, Covidien, Mansfield, MA,
c USA) and 2 transnasal merocel sponges.
d
RESULTS

The outcomes of the 3 patients who underwent standard open

transoral/transpalatal decompression of the craniovertebral
junction were compared with those of the 8 patients who
had endoscope-assisted decompression of the craniovertebral
e f junction to evaluate the differences in the techniques. Issues
such as postoperative airway obstruction, LOS, development
of VPI, dysphagia requiring a nasogastric tube for more than
7 days, or the need for a percutaneous gastric feeding tube are
detailed in Table 1. The hospital LOS was significantly reduced
for patients undergoing the purely endoscopic approach to the
craniovertebral junction compared with the open approach (P
= 0.014). Furthermore, patients undergoing an open transoral
Figure 1: Intraoperative view of the anterior craniovertebral approach had a statistically significant higher incidence of airway
junction, using an endoscopic transoral approach. (a) Linear obstruction and tracheotomy (P = 0.024).
incision of the pharyngeal mucosa made by Bovie electrocautery.
(b) Dissection and exposure of the underlying C1 anterior arch. (c) In the endoscopic group, 4 of the 8 patients had an open transoral
Drilling of the C1 anterior arch. (d) Drilling of the odontoid process. approach in the past. When these 4 patients were grouped with
(e) Kerrison Rongeur used to remove the remnants of the odontoid
those having an open approach currently and compared with the
and decompress the dura. (f) Closure of the pharyngeal wall
following the decompression. (arrow indicates the suture needle) patients who had only an endoscopic approach, there was a trend
toward reduction of VPI and dysphagia (P = 0.061) in patients who
in tandem (otolaryngologist and neurosurgeon), one holding underwent a virgin endoscopic approach. [Table 1, right side]
the endoscope and retraction while the other performed the
dissection and decompression. Visualization of the pulsating DISCUSSION
dural sac and intraoperative fluoroscopic imaging of instruments
placed at the borders of decompression confirmed the extent of This study presents our early experience with a combined
the resection. endonasal–endooral approach. While the approaches reported
earlier include purely endonasal[5,6] or endoscopic transcervical
Closure of the pharyngotomy was performed with absorbable
approach,[3] our approach uses a flexible strategy with an
Table 1: Summary of results
Approach of craniovertebral surgery Ever palate split
Endo (n = 8) Open (n = 3) P Yes No (n = 4) P
LOS 7 (7–11) 15 (12–20) 0.014 [1]

Airway 1/8 3/3 0.024[2] 4/7 0/4 0.19[2]

VPI 2/8 3/3 0.061[2] 5/7 0/4 0.061[2]
Dysphagia > 7 days 2/8 3/3 0.061[2] 5/7 0/4 0.061[2]
PEG 0/8 1/3 0.061[2] 1/7 0/4 1.0[2]
The left side of the table demonstrates our experience with patients undergoing surgery for craniovertebral junction decompression with either a purely endoscopic approach
or an open approach. Patients undergoing endoscopic procedures had a statistically lower rate of airway complications and a lower length of stay. The right side of the table
(“Ever Palate Split”) is shown since 4 patients in the endoscopic group had prior open surgery with palatal splitting. In this portion of the table, patients undergoing anterior
decompression of the craniocervical junction with a history of prior palatal splitting were grouped with patients having a virgin open approach and compared with patients who
had a virgin endoscopic-only approach. These data demonstrate that VPI and dysphagia tended to be lower in the virgin endoscopic surgery patients (P = 0.061). LOS = length of
hospital stay (in days). Airway = patients requiring intubation for more than 24 h after surgery or requiring a tracheotomy as a result of the surgery.VPI = development of new
onset velopharyngeal insufficiency occurring or lasting more than 2 months after surgery. Dysphagia = patients requiring supplemental feeding for more than 7 days after surgery.
PEG = patients who required a percutaneous feeding tube after surgery. (1 = Mann–Whitney U test, 2 = Fisher’s exact test).

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J Craniovert Jun Spine 2010, 1:8 El-Sayed, et al.: Combined approach to the craniovertebral junction

endonasal approach or an endooral approach or a combined the palate to the posterior pharynx (the nasopalatal line) serves
endonasal–endooral approach.[12] The combination of an as an excellent reference point to assess the lesion location.[14]
endoscopic transnasal and transoral route appears to be a The lesions can be categorized as types A (high above
pragmatic way to conserve the advantages of endoscopic the nasopalatal NP line= nasopalatal line [Figure 2], B
visualization via different corridors, while minimizing procedure- (intermediate location above the NP line), and C (at the level
related morbidity due to splitting of the soft palate. We found of (or below) the NP line). For intermediately located lesions
that the endooral approach was advantageous in providing (Type B), either an endoscopic transnasal or an endoscopic
access to lesions that extended too far inferiorly to be reached by transoral approach may be adopted for decompression. Such
a purely endonasal approach.[6] lesions may also be easily accessed using a standard, open
transoral approach without a palate split as reported by several
Moreover, in standard open transoral approaches with
authors.[1,2,12,15-17] Finally, for low lying lesions or lesions
microscope visualization, the hard palate sometimes still
extending to the midbody of C2 (Type C, at or below the NP
obstructs visualization of the upper extent of the compressive
line), an endoscopic transoral approach may be used [Figure 3].
lesion. The use of the endoscope overcame this obstacle with
ease as it could be navigated to look around the palate. We found that the endoscopic approach significantly reduced
the LOS and postoperative airway compromise when compared
Previously reported endoscopic transnasal odontoidectomy
with a standard transoral/transpalatal open approach. The
reports mentioned the most caudal limiting extent of the
increased airway obstruction and LOS in the open transoral
transnasal route to be the C1 rim (due to the position of the
group was probably related to the increased oropharyngeal
hard palate and the size of the nostril).[6] By combining the edema and muscular dysfunction caused by the incision of the
endonasal approach with a transoral endoscopic approach, we palate and posterior pharynx as well as by prolonged retraction
overcame this limitation and were able to reach lesions that on the tongue.
extended into the mid-body of C2.
Limitations to the endoscopic approach include 2-dimensional
Appropriate utilization of the combined transnasal and visualization, a relatively small working space, and the learning
transoral endoscopic approach allowed for a minimally curve associated with endoscopic technology. Consequently,
invasive surgery with full exposure for anterior decompression open transoral surgery continues to be our primary choice
at the craniovertebral junction while avoiding a split of the of approach in cases that have an intermediate position of the
soft palate. The optimal choice of a transnasal, transoral, or odontoid (not blocked by the position of the hard palate).
combined endoscopic approach should be tailored according
to each individual’s anatomy. Physical examination of the There are several drawbacks to our study. First, variables in
patient will reveal anatomic factors, such as trismus that would the patient’s disease and anatomy were not controlled in
prevent oral exposure of the pharynx. We have also found this retrospective analysis. The open procedures were done
during the earlier phase of the study time period, whereas the
that a careful review of the preoperative CT or MRI scan to
endoscopic procedures were done during the later phase of
evaluate the relative location of the hard palate and the target
the study. The data represented our early experience with the
for decompression allows us to pick the optimal choice for a
surgical approach. A radiographic line drawn along the floor of

Figure 3: Schematic illustration of our algorithm to select the

optimal choice of surgical approach. The relative position of the
lesion to a line drawn from the hard palate to the posterior pharynx
(the nasopalatal line) dictates the choice of approach. Lesions are
defined as types A (well above NP line), B (intermediate location
above the NP line), or C (at or below NP line). Left (Type A): For
lesions located well above the hard palate, an endoscopic transnasal
approach is optimal. Middle (Type B): For intermediately located
compressive lesions of the craniovertebral junction that protrude
Figure 2: This patient had ventral brainstem compression at the above the hard palate, either a transnasal or a transoral endoscopic
tip of the odontoid. Note the extremely high location of odontoid, route may be used. Also, we found that a combination of both
significantly above the palate in this patient with congenital approaches was often quite helpful. Right (Type C): For lesions
platybasia. We used an endonasal approach alone to decompress located at the level of the hard palate (or below) a standard open,
this lesion transoral approach is preferred

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J Craniovert Jun Spine 2010, 1:8 El-Sayed, et al.: Combined approach to the craniovertebral junction

endoscopic procedure (for which there is a learning curve). 4. McGirt MJ, Attenello FJ, Sciubba DM, Gokaslan ZL, Wolinsky JP. Endoscopic
The other issue was that this series was based on our referral transcervical odontoidectomy for pediatric basilar invagination and cranial
settling. Report of 4 cases. J Neurosurg Pediatr 2008;1:337-42.
patterns at a major tertiary care center, which might be biased 5. Kassam AB, Snyderman C, Gardner P, Carrau R, Spiro R.The expanded endonasal
toward more complicated patients. This was evidenced by the approach:A fully endoscopic transnasal approach and resection of the odontoid
fact that 4 of the 8 patients undergoing the purely endoscopic process: Technical case report. Neurosurgery 2005;57:E213; discussion E213.
procedure had a prior open transoral procedure in the past at 6. Wu JC, Huang WC, Cheng H, Liang ML, Ho CY, Wong TT, et al. Endoscopic
an outside hospital. Although revision surgeries might lead transnasal transclival odontoidectomy: A new approach to decompression:
Technical case report. Neurosurgery 2008;63:ONSE92-4; discussion ONSE94.
to a higher complication rate, our ability to perform adequate 7. Cappabianca P, Cavallo LM, Esposito F, De Divitiis O, Messina A, De Divitiis
resections endoscopically after a prior open procedure further E. Extended endoscopic endonasal approach to the midline skull base:
demonstrates the feasibility of the endoscopic approach. The evolving role of transsphenoidal surgery. Adv Tech Stand Neurosurg
2008;33:151-99.
8. Cavallo LM, Cappabianca P, Messina A, Esposito F, Stella L, de Divitiis E, et
CONCLUSION al. The extended endoscopic endonasal approach to the clivus and cranio-
vertebral junction: Anatomical study. Childs Nerv Syst 2007;23:665-71.
The combined endonasal–endooral approach is a useful 9. Frempong-Boadu AK, Faunce WA, Fessler RG. Endoscopically assisted
approach offering a wide access to the anterior craniovertebral transoral-transpharyngeal approach to the craniovertebral junction.
junction. This approach appears to reduce airway obstruction Neurosurgery 2002;51:S60-6.
10. Messina A, Bruno MC, Decq P, Coste A, Cavallo LM, de Divittis E, et al. Pure
and LOS after surgery when compared with a standard open endoscopic endonasal odontoidectomy: Anatomical study. Neurosurg Rev
transoral/transpalatal approach. 2007;30:189-94; discussion 194.
11. Pillai P, Baig MN, Karas CS, Ammirati M. Endoscopic image-guided transoral
ACKNOWLEDGMENTS approach to the craniovertebral junction: An anatomic study comparing
surgical exposure and surgical freedom obtained with the endoscope and
the operating microscope. Neurosurgery 2009;64:437-42; discussion 442-4.
The authors thank Erin Madden, MPH, UCSF Department of 12. Mummaneni PV, Haid RW. Transoral odontoidectomy. Neurosurgery
Biostatistics, for help with statistical analysis. This publication 2005;56:1045-50; discussion 1045-50.
was supported by NIH/NCRR UCSF-CTSI Grant Number UL1 13. Jones DC, Hayter JP, Vaughan ED, Findlay GF. Oropharyngeal morbidity
following transoral approaches to the upper cervical spine. Int J Oral
RR024131. Its contents are solely the responsibility of the authors and
Maxillofac Surg 1998;27:295-8.
do not necessarily represent the official views of the NIH. 14. de Almeida JR, Zanation AM, Snyderman CH, Carrau RL, Prevedello DM,
Gardner PA, et al. Defining the nasopalatine line: The limit for endonasal
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Conflict of Interest: None declared.
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