Keywords nasal obstruction - computed tomography - septal deviation
Introduction
Symptomatic nasal obstruction is a common complaint [1 ]. It may be attributed to several etiologies, such as severe septal deviation, mucosal
congestion, turbinate hypertrophy, chronic rhinosinusitis, nasal polyps, tumors, and
adenoid hypertrophy. Septoplasty and turbinate reduction are the common surgeries
for non-sinusitis patients with isolated symptomatic nasal obstruction (INO). Preoperative
assessment of patients presenting with isolated nasal airway obstruction might present
a clinical challenge. In current practice, the decision to proceed to surgery and
the extent of surgery in these patients is determined by clinical features, based
on medical history and assessment of the nasal cavity on physical examination (including
anterior rhinoscopy and fiber optic endoscopy). Recent review of long-term results
of septoplasty concluded that it appears to be a far from perfect treatment for nasal
obstruction due to septal deviation. This emphasizes the need for studies that will
help define prognostic factors for nasal obstruction surgical treatment.[1 ]
[2 ]
[3 ] Computed tomography (CT) is widely used in the preoperative assessment of patients
with chronic sinusitis. It is essential for the surgical planning in these patients.
The preoperative evaluation of patients presenting with nasal obstruction and deviated
nasal septum does not routinely include imaging studies; performing a CT scan as part
of the surgical assessment and planning is not currently supported by consensus guidelines.[4 ] Therefore, referral to preoperative CT studies is mainly based on clinical judgment.
The benefits of performing CT in the preoperative setting of nasal obstruction and
deviated nasal septum are unclear, and the relevant literature is scarce. A recent
study by Karatas et al [5 ] demonstrated the possible contribution of CT to the evaluation of other sinonasal
anatomic variants that may contribute to the understanding of patients' sinonasal
complaints and aid in surgical planning.[6 ] However, while CT studies may provide additional information on the status of the
nasal septum and the nasal cavity, the interpretation of this information is not straight-forward,
mainly due to the high frequency of anatomical variations, even in the healthy asymptomatic
population[5 ].
In our outpatient clinic, we encountered patients who were referred to septoplasty
and inferior turbinate reduction due to symptomatic INO who had performed a CT scan
prior to their visit. It was our observation that the imaging performed led to a better
understanding of the patients' condition and affected the surgical plan.
The objective of our study was to investigate the role of CT imaging studies in the
preoperative assessment of patients presenting with INO and septal deviation.
Materials and Methods
Approval for conducting this study and for its design was obtained from the medical
center's Institutional Review Board (0364–16-TLV).
Patient Selection and Evaluation
The present retrospective cohort study was conducted on patients undergoing sinus
surgery in a tertiary medical center between 2006 and 2015. Adult (age [3 ]18 years) patients who underwent endoscopic sinus surgery (ESS), septoplasty or submucosal
resection of septum (SMR), and/or inferior turbinate reduction were considered for
inclusion in the study, and their electronic medical records were reviewed.
We included patients who were referred to our rhinology clinic for surgical treatment
due to INO and septal deviation. Patients whose major complaint was impaired nasal
breathing with anatomical obstruction on clinical evaluation (i.e, septal deviation,
turbinate hypertrophy) without inflammatory findings on physical examination were
defined as suffering from INO. When we felt that the physical examination alone did
not lead to adequate preoperative understanding of obstruction sites, a preoperative
CT scan was performed. Patients with a history of sinus surgery, diagnosis of chronic
sinusitis with or without polyposis, clinical symptoms or findings in physical examination
typical of sinusitis, according to the American Academy of Otolaryngology Head and
Neck Surgery Foundation,[7 ] were excluded from the study. Also excluded were patients with available sinus CT
scans prior to initial intake due to multiple causes.
Data retrieved included demographics (age, gender, allergic symptoms and allergy confirmed
by skin tests), presenting symptoms (INO), clinical findings on physical examination
(septal deviation, middle meatus abnormalities, pale edematous mucosa with appearance
typical of allergy, inferior turbinate hypertrophy), imaging findings detected on
CT scan (concha bullosa, mucosal thickening, inferior turbinate hypertrophy, evidence
of sinus mucosal disease, osteomeatal complex [OMC] obstruction, and septal deviation)
and operative course.
To objectively evaluate the added contribution of CT imaging for the surgeon, CT scans
of 20 patients who had undergone imaging studies as part of their preoperative work-up
were reviewed by a second blinded expert rhinologist, who evaluated the contribution
of the CT scan to the choice of surgical approach (traditional SMR and turbinate reduction
or whether functional endoscopic sinus surgery [FESS] or partial middle turbinectomy
should be considered). The blinded expert only reviewed the patients' medical history,
the documented physical examination in the outpatient clinic visit and the imaging
studies and was unfamiliar with the original surgical plan and the selected surgical
intervention.
Statistical Analysis
The statistical analysis was performed using SPSS Statistics for Windows, Version
24.0. (IBM Corp., Armonk, NY, USA). All statistical tests were two-tailed, and a p -value < 0.05 was considered significant. Categorical variants were described as frequency
and percentage. Continuous variables were evaluated for normal distribution and described
as median and interquartile range or mean and standard deviation. Continuous variables
were compared using the Mann-Whitney test, and categorical variables were compared
by the Chi-square test or Fisher exact test. A one-sample binomial test was performed
to compare the independent blinded surgeon assessments of CT benefit to absolute value
to detect significant surgeon-independent benefits.
Results
Of the 843 patients who underwent endoscopic sinonasal procedures between 2006 and
2015, a total of 68 patients met the inclusion criteria, and their medical records
were reviewed by an expert rhinologist ([Fig. 1 ]). The mean age of the patient cohort was 29.65 ± 12.12 years, with male predominance,
50 (73.5%) patients were male ([Table 1 ]). Twenty-one (30.9%) patients reported allergic symptoms, of whom 12 (17.6%) were
diagnosed as having allergy. The physical examination revealed that in addition to
deviated septum, 54 patients (79.4%) had inferior turbinate hypertrophy. In 11 patients
(16.2%), nasal obstruction was attributed also to the middle turbinate ([Table 1 ]).
Table 1
Comparison of anamnestic, preoperative clinical examination and intraoperative findings
of the study group
Variable
Total (N = 68)
No CT (N = 30)
CT (N = 38)
P -value
Male sex
50 (73.5%)
24 (80%)
26 (68.4%)
0.28
Female sex
18 (26.5%)
6 (20%)
12 (31.6%)
0.28
Age
29.65 ± 12.12 [17–69]
29.90 ± 13.55 [18–69]
29.45 ± 11.06 [17–59]
0.61
Known allergies
12 (17.6%)
8 (26.7%)
4(10.5%)
0.08
Snoring
14 (20.6%)
5 (16.7%)
9 (23.7%)
0.47
Physical examination
Middle meatus abnormalities
11 (16.2%)
0 (0%)
11 (28.9%)
0.00
Inferior turbinate hypertrophy
54 (79.4%)
24 (80%)
30 (78.9%)
0.91
Mucosal edema
17 (28.8%)
1 (4.8%)
16 (42.1%)
0.00
Surgery
SMR
66 (97.1%)
29 (96.7%)
37 (97.4%)
< 0.99
Conchotomy
62 (91.2%)
26 (86.7%)
36 (94.7%)
0.39
Surgery extended: ESS/FESS/middle meatus interference
32 (47.1%)
0 (0%)
32 (84.2%)
> 0.00
Abbreviations: CT, computed tomography; ESS, endoscopic sinus surgery; FESS, functional
endoscopic sinus surgery; SMR, submucosal resection of septum.
Categorial variables are described as N = % (and continuous variables as mean and
standard deviation and [] range.
Fig. 1 Flowchart of patient course throughout the study.
Thirty-eight patients (55.88%) underwent a CT scan as part of their preoperative surgical
assessment. The CT findings revealed significant septal deviation in 37/38 patients
(97.4%), as well as middle meatal abnormalities (mainly obstruction due to concha
bullosa) in 18/38 patients (47.4%). Findings on imaging that are typical of chronic
sinusitis, such as sinus opacification, mucosal thickening or OMC obstruction, were
found in 22 patients (57.9%). There was no supporting evidence for these findings
in patients' age, gender, medical history, or physical examination ([Table 2 ]).
Table 2
Computed tomography causing a change in surgical planning: comparison of anamnestic,
preoperative clinical examination, computed tomography findings and intraoperative
findings (N = 38)
Variable
No change
N = 6
Change
N = 32
P -value
Male sex
4 (66.7%)
22 (68.8%)
> 0.99
Female sex
2 (33.3%)
10 (31.2%)
> 0.99
Age
24.5 ± 6.68 (21–38)
30.38 ± 11.54 (18–69)
0.46
Known allergies
0 (0%)
4 (12.5%)
< 0.99
Snoring
1 (16.7%)
8 (25%)
< 0.99
Physical examination
Middle meatus abnormalities
1 (16.7%)
10 (31.3%)
0.65
Inferior turbinate hypertrophy
5 (83.3%)
25 (78.1%)
> 0.99
Mucosal edema
3 (50%)
13 (40.6%)
0.68
CT main findings
Septal deviation
6 (100%)
28 (87.5%)
> 0.99
Concha bullosa
2 (33.3%)
16 (50.0%)
0.66
Compensatory Inferior turbinate
2 (33.3%)
20 (62.5%)
0.21
Sinus shading, decreased ventilation, OMC narrowing
1 (16.7%)
15 (45.9%)
0.37
Abbreviation: OMC, osteomeatal complex.
Categorial variables are described as N = % (and continuous variables ad mean and
standard deviation and [] range.
Both patient groups (the group of patients that was sent for imaging and the group
that was not) were similar in demographics and clinical findings, with the exception
of one main finding; patients who did undergo a CT scan had higher rates of mucosal
findings (mainly hypertrophy and edema) on physical examination (4.8% vs 42.1%, p = 0.002) ([Table 1 ]).
Of the patients who underwent CT scan, 32 (84.2%) required a modification of the initial
preoperative planning (endoscopic septoplasty and turbinoplasty procedure) based on
radiological findings, such as concha bullosa and findings typical of chronic sinusitis.
To identify patients more likely to benefit from imaging studies prior to surgery,
those whose operative plans were changed due to CT findings were compared with those
whose operative plans remained unchanged. There were no significant differences between
the two groups, nor were there any group differences in demographics and clinical
findings. Due to the small size of the group of patients who did not benefit from
CT scans, we matched the cohort according to gender and age (up to 3 years of age
difference). The matching revealed 21 pairs of patients. However, no significant differences
were detected in this analysis as well.
Sixty-two patients (91.2%) underwent septoplasty and inferior turbinate reduction.
Additional surgical interventions were performed only among patients that had undergone
CT scans that revealed obstructive concha bullosa (requiring resection) or findings
suggesting chronic sinusitis (ESS).
To further determine the benefit of CT scanning, a second expert rhinologist, who
was blinded to the patients' surgical course, assessed the medical records and CT
scans of 20 patients. The assessment was first made without the imaging studies and
again with the imaging studies taken under consideration. A change in the preoperative
surgical plan was noted in 12 cases (58%). We defined 3 contribution values (10%,
20%, and 30%) as the minimal threshold values to perform a CT. A comparison of the
need for change in the surgical plan (58%) to the defined values revealed that it
was significantly higher than the minimal threshold for statistical significance (p < 0.001, p = 0.003, and p = 0.048, respectively). Thus, the contribution of CT scans carried a 30% (p = 0.048) chance for a change in the surgical plan from classical SMR and inferior
turbinate reduction to a more extended surgical procedure for patients presenting
with INO and deviated nasal septum.
Discussion
Nasal congestion and obstruction are common complaints, and a deviated nasal septum
is a common pathology in the rhinology outpatient clinic. The routine methods of assessment
of nasal obstruction severity and causes are medical history, anterior rhinoscopy,
and flexible fiber optic endoscopy, and their effectiveness is dependent upon physician
skills and experience. None of these methods, however, can provide the comprehensive
information on the status of the nasal spaces or 3-dimensional understanding of the
nasal airflow that is needed for a thorough preoperative evaluation. One large-scale
model demonstrated the importance of the physiological airflow of the middle meatus,
emphasizing that ∼ 50% of the nasal airflow passes through the middle meatus, while
35% of it only flows through the inferior meatus.[8 ]
A CT of the paranasal sinuses is the gold standard imaging for anatomy and pathology
of the nasal and paranasal structures. It is not, however, routinely performed for
patients presenting with INO. Moreover, the role of the CT scan in the setting of
nasal obstruction and septal deviation has not been established in the literature.
Several publications failed to demonstrate good correlation between CT findings and
the severity of nasal symptoms. Ardeshirpour et al noted that CT findings of septal
deviation severity do not necessarily correlate with patient-reported complaints as
assessed by the nasal obstruction symptom evaluation (NOSE) scale.[9 ] Others observed that CT findings did not always correlate with those related to
the nasal septum assessment on physical examination.[10 ] On the other hand, Cho et al[11 ] reported some correlation between the cross-sectional area of the nasal airway as
well as the presence of septal deviation on sinus CT scans and patient-reported nasal
obstruction symptoms.
The relationship between the appearance of the nasal airflow passage on CT scans in
comparison to a thorough physical examination that includes anterior rhinoscopy and
nasal fiber optic endoscopy remains unclear. The advantages of preoperative CT imaging
before endoscopic sinus surgery are undisputable, to the point that it is considered
malpractice to perform sinus surgery without it.[7 ] A CT scan is an objective assessment that produces a clear anatomical image that
is of utmost importance to the planning and safety of the surgery, as well as being
associated with better results.[12 ] Yet, when surgery is planned for the alleviation of INO related to septal deviation
or other non-inflammatory causes, the role of preoperative CT remains unclear.
The reliability of CT scanning in assessing the nasal septum is undetermined. We observed
that CT scans made a major contribution by changing the preoperative plans, and that
the surgeon subsequently considered anatomical structures other than the septum and
inferior turbinate in most of the cases. There was agreement between two expert rhinologists
that the CT scan modified the scope of the operation in almost 60% of cases, and that
it contributed to better understanding of the surgical anatomical field in 55% of
cases. Even when there were no inflammatory findings, CT imaging offered better delineation
of site of obstruction; for instance, turbinate hypertrophy mainly because of bony
thickening, septal thickening and obstructing middle turbinate ([Fig. 2 ].). In 2013, Karatas et al[5 ] assessed the possible contribution of CT to surgery for nasal obstruction related
to septal deviation. Their retrospective study included 76 patients that were assigned
to one group of 40 patients who arrived with prior CT scans and 36 patients who had
not undergone CT scans beforehand. Their patients were assessed for the detection
of pathologies and subjective postoperative relief in nasal airflow. The authors also
described a large percentage of patients with concha bullosa (35%) and chronic sinusitis
(17.5%). Computed tomography was found capable of recognizing pathologic findings
that could not be found on physical examination. It was described as being helpful
in deciding the location as well as the required type of surgery. Karatas et al found
that the additional surgical interventions that were indicated by CT scans that were
performed before a planned septoplasty were very helpful in relieving the patient's
nasal airway obstruction. However, it is important to highlight that patients with
allergic rhinitis were not included in their study, and the authors did not provide
their opinion about patients with atopic background and suspected atopic complaints
without an established diagnosis of rhinitis.
Fig. 2
Representative images of a patient who underwent a computed tomography scan (A ) Images of the middle and (B ) inferior meatus obtained after application of topical vasoconstrictors and decongestants
just prior to surgery. (C ) A computed tomography scan demonstrating a very narrow nose due to inferior turbinate
hypertrophy (blue arrow) and a severely deviated septum (orange arrow) with high deviation
and a concha bullosa (red arrow) that further narrows the passage of air on the right
side.
It should be emphasized that CT is complementary to a thorough clinical assessment
among patients with nasal obstruction that may benefit from surgery. We believe that
it should be considered especially when obstruction is not anterior to the nasal valve,
when it is difficult to assess the middle meatus, and in patients with severe septal
deviation that does not allow adequate inspection.
We are aware that CT scans performed in young populations may result in excessive
exposure to radiation. The head and neck region is sensitive to radiation, mainly
due to accumulation of the radiation in two of the most radiation-sensitive organs
encompassed by the scanning field, the thyroid gland and the eye lens, which is at
risk for radiation-induced cataract.[13 ] There are ongoing attempts to decrease the radiation dose per CT scan,[14 ] and the cone beam CT, which requires less radiation, can now serve as an alternative.
As surgical treatment is not free of risks and complications, we believe that optimizing
the preoperative evaluation benefits surgical results, thus minimizing risks of further
treatments. Moreover, multiple operations may carry additional financial costs.
Our study has several limitations. It is retrospective and includes a relatively small
number of patients, which can lead to a biased selection of patients. The main possible
bias is that patients were selected to perform a CT scan based on an expert rhinologist
clinical judgment. While physical examination is subjective, we believe that the fact
that in 32/38 patients (84%) an objective assessment with CT imaging was found beneficial
overcomes this bias.
We did, however, find significant differences between the two groups of patients and
believe that our findings demonstrate several specific advantages of preoperative
CT in patients planned for surgery due to nasal obstruction. Our study aimed to investigate
the effect of preoperative CT scan on the surgical treatment. The effect on QoL and
objective measurement of nasal air flow were not addressed. These are aimed to be
further addressed in future prospective studies. Reviewing postoperative follow-up
visits, all patients expressed satisfaction from the operation results and none required
a revision surgery or additional procedures.
Patients were allocated to CT according to the clinical presentation in our study.
Some may suggest that an experienced rhinologist may understand the surgical anatomy
only by clinical judgment. However, this subjective examination may also lead to misevaluation,
while CT is an objective measurement that gives the most reliable anatomical information
relating to the nasal cavity.[12 ]
Conclusions
In this series, the initial preoperative planning that was based on physical examination
alone was modified in 84.2% of patients who underwent preoperative imaging for nasal
obstruction. Our findings indicate that CT is a valuable complementary tool for detecting
pathological findings that are difficult to detect on physical examination alone.
Computed tomography scan may play a pivotal role in assessing septal deviation, especially
when the physical examination is limited due to obstruction of one or both nares.
