Keywords
nasal obstruction - nasal resistance - rhinomanometry - before and after ESS
Introduction
Rhinomanometry and acoustic rhinomanometry, which are used as objective methods to
evaluate nasal airflow, have been published as such in the guideline by the Japanese
Rhinologic Society Committee for the Standardization of Rhinomanometry.[1]
[2]
[3]
[4] Several reports by the committee members have been published on nasal airflow in
nasal septum correction and conchotomy; however, there are few reports of sinus surgery.
Therefore, we evaluated nasal airflow before and after surgery using rhinomanometry
in patients who underwent endoscopic sinus surgery (ESS) and hereby report on the
results of our evaluation.
Material and Methods
The study included 95 patients who underwent ESS for chronic sinusitis between February
2015 and February 2018; in these patients, nasal resistance was evaluated using rhinomanometry
before surgery and at 3 months after surgery. Rhinomanometry was measured using the
active anterior method with a nasal nozzle. Nasal resistance at ΔP = 100 Pa upon inhalation was defined as the representative value. The study comprised
55 male and 40 female patients, aged 13 to 80 years (mean: 54 years). In 49 bilateral
ESS patients and 46 unilateral ESS patients, pre- and postoperative rhinomanometry
data were compared between the two groups. Furthermore, patients were divided into
three groups according to concurrent surgery, i.e., ESS alone group (62 patients),
ESS + septoplasty (11 patients), and ESS + septoplasty + conchotomy (18 patients);
pre- and postoperative nasal resistance were compared in each group, and the amounts
of change in nasal resistance were compared among the groups. Similarly, patients
were classified according to the number of sinuses opened: single sinus surgery group
(32 sides) and polysinus surgery group (108 sides). They were also classified according
to the presence or absence of polyps on the operative side: group without polyps (60
sides) and the group with polyps (85 sides); these groups were then compared. Furthermore,
we conducted the same examination in patients with a preoperative nasal resistance
of ≥0.25 (ESS alone group: 25 patients; ESS + septoplasty group: 4 patients; ESS + septoplasty + conchotomy:
7 patients; single sinus surgery group: 29 sides; polysinus surgery group: 91 sides;
group without polyps: 48 sides; and group with polyps: 76 sides). Moreover, the same
examination was conducted in patients who underwent ESS alone classified into the
group with polyps (45 sides) and the group without polyps (44 sides), after which
the same test was conducted in patients without polyps who underwent ESS alone classified
into the single sinus surgery group (16 sides) and polysinus surgery (28 sides) group.
Pre- and postoperative comparisons were performed using the Wilcoxon signed-rank test,
and intergroup comparisons were performed using the Mann–Whitney test, with p-values of <0.05 considered to indicate significant difference. In 58 patients who
underwent bilateral ESS alone in whom the nasal symptom questionnaire was completed[5] ([Fig. 1]) at the same time that nasal resistance was confirmed, we compared pre- and postoperative
nasal obstruction scores by Wilcoxon signed-rank test. We also assessed the correlation
between nasal obstruction scores and nasal resistance. The present study was approved
by the Institutional Review Board for Clinical Research of the Tokai University School
of Medicine (14R-236).
Fig. 1 Nasal symptom questionnaire. Of the questionnaire items, we investigated “nasal obstruction”
in the present study.
Results
In bilateral ESS patients, the nasal resistance significantly improved in bilateral,
right-sided, and left-sided procedures (p < 0.05; [Fig. 2]). In unilateral ESS patients, the nasal resistance in the affected side significantly
improved (p < 0.05; [Fig. 3]). In the groups classified by concurrent surgery, those classified by the number
of sinuses opened, and those classified by the presence or absence of polyps, postoperative
nasal resistance was significantly improved ([Fig. 4]). In the groups similarly limited to patients with nasal resistance of ≥0.25, excluding
the ESS + septoplasty group (p = 0.13), the postoperative nasal resistance significantly improved (p < 0.05; [Fig. 5]). The intergroup comparison of the amount of change in nasal resistance revealed
no significant differences between the ESS alone group and ESS + septoplasty group
or between the ESS and ESS + septoplasty + conchotomy group (p = 0.44 and 0.41). The intergroup comparison of the amount of change in nasal resistance
revealed no significant difference between the single sinus surgery group and polysinus
surgery group (p = 0.25). The intergroup comparison of the amount of change in nasal resistance revealed
no significant difference between the group without polyps and the group with polyps
(p = 0.34; [Fig. 4]). When the same comparisons were made on patients after limiting them to those with
nasal resistance of ≥0.25, no significant differences were found (p = 0.99, 0.80, 0.47, and 0.30) ([Fig. 5]). In the examination of the group with polyps and that without polyps among patients
who underwent ESS alone, intergroup comparison of pre- and postoperative data revealed
an improvement with a significant difference (p < 0.05); however, the intergroup comparison of the amount of change in nasal resistance
revealed no significant difference (p = 0.06; [Fig. 6]). In the examination of the single sinus surgery group and polysinus surgery group
among patients who underwent ESS alone without polyps, the comparison of pre- and
postoperative nasal resistance revealed no significant difference in the single sinus
surgery group (p = 0.09); however, a significant improvement was noted in the polysinus surgery group
(p < 0.05). Intergroup comparison of the amount of change in the nasal resistance revealed
no significant difference (p = 0.97; [Fig. 7]).
Fig. 2 Pre- and postoperative comparison in bilateral ESS patients. After surgery, the bilateral
nasal resistance significantly improved. Statistical analysis was performed using
the Wilcoxon signed-rank test. All p-values were <0.05. ESS, endoscopic sinus surgery.
Fig. 3 Pre- and postoperative comparison in unilateral ESS patients. After surgery, the
nasal resistance significantly improved. Statistical analysis was performed using
the Wilcoxon signed-rank test. The p-value was set at <0.05 for all analyses. ESS, endoscopic sinus surgery.
Fig. 4 Pre- and postoperative comparison of nasal airflow rate in each group, and intergroup
comparison of the amount of change in the nasal resistance. Upon comparing the nasal
resistance before and after surgery, we found a significant improvement in all groups
including the ESS alone group, the ESS + septoplasty group, the ESS + septoplasty + conchotomy
group, the single sinus surgery group, polysinus surgery group, the group without
polyps, and the group with polyps. Statistical analysis was performed using the Wilcoxon
signed-rank test. All p-values were <0.05. Upon comparing the amount of change in nasal resistance, we found
no significant difference between the ESS alone group and the ESS + septoplasty group,
between the ESS alone group and the ESS + septoplasty + conchotomy group, between
the single sinus surgery group and polysinus surgery group, and between the group
without polyps and the group with polyps. Statistical analysis was performed using
the Mann–Whitney test. The p-values were 0.44, 0.41, 0.25, and 0.34, respectively. ESS, endoscopic sinus surgery.
Fig. 5 Pre- and postoperative comparison of the nasal resistance in each group, and intergroup
comparison of the amount of change in the nasal resistance in patients with nasal
resistance of ≥0.25. Upon comparing the nasal resistance before and after surgery,
we found a significant improvement in all groups including the ESS alone group, the
ESS + septoplasty + conchotomy group, the single sinus surgery group, polysinus surgery
group, the group without polyps, and the group with polyps. No significant difference
was observed in the ESS + septoplasty group. Statistical analysis was performed using
the Wilcoxon signed-rank test. The p-value was 0.13 in the ESS + septoplasty group, and the p-values in the remaining groups were <0.05. Upon comparing the amount of change in
the nasal resistance, we found no significant difference between the ESS alone group
and the ESS + septoplasty group, between the ESS alone group and the ESS + septoplasty + conchotomy
group, between the single sinus surgery group and polysinus surgery group, and between
the group without polyps and the group with polyps. Statistical analysis was performed
using the Mann–Whitney test. The p-values were 0.99, 0.80, 0.47, and 0.30, respectively. ESS, endoscopic sinus surgery.
Fig. 6 Pre- and postoperative comparison of the nasal resistance in the group with polyps
and the group without polyps, and intergroup comparison of the amount of change in
the nasal resistance in patients who underwent ESS alone. A significant improvement
was observed in postoperative nasal resistance compared with preoperatively in the
group without polyps and the group with polyps. Statistical analysis was performed
using the Wilcoxon signed-rank test. All p-values were <0.05. In the intergroup comparison of the amount of change in the degree
of nasal resistance between the group without polyps and the group with polyps, no
significant difference was observed. Statistical analysis was performed using the
Mann–Whitney test, and the p-value was 0.06. ESS, endoscopic sinus surgery.
Fig. 7 Pre- and postoperative comparison of the nasal resistance in patients who underwent
ESS alone without polyps in the single sinus surgery group and polysinus surgery group,
and intergroup comparison of the amount of change in the nasal resistance. Upon comparing
the nasal resistance before and after surgery in patients in the single sinus surgery
group, there was no significant difference observed; however, the nasal resistance
significantly improved in the polysinus surgery group. Statistical analysis was performed
using the Wilcoxon signed-rank test. The p-value was 0.09 in the single sinus surgery group, and <0.05 in the polysinus surgery
group. Upon comparing the amount of change in the nasal resistance between the single
sinus surgery group and polysinus surgery group, there was no significant difference
observed. Statistical analysis was performed by Mann–Whitney test, and the p-value was 0.97. ESS, endoscopic sinus surgery.
The nasal obstruction scores significantly improved from a preoperative mean of 2.0
to a postoperative mean of 0.5 (p < 0.05), and all postoperative scores were <2. A weak correlation with a Spearman
rank correlation coefficient of 0.3 was observed between preoperative nasal obstruction
scores and resistance rate ([Fig. 8]); however, the postoperative correlation coefficient of 0.1 ([Fig. 9]) indicated that there was no correlation. Between the amount of pre-to-postoperative
change in nasal obstruction scores and amount of pre-to-postoperative change in nasal
resistance, the Spearman rank correlation coefficient was 0.203, indicating no significant
correlation ([Fig. 10]).
Fig. 8 Scatter diagram of the nasal resistance and nasal symptoms scores (preoperative).
A weak correlation was observed with a Spearman rank correlation coefficient of 0.3.
Fig. 9 Scatter diagram of the nasal resistance and nasal obstruction scores (postoperative).
A significant correlation was not observed with a Spearman rank correlation coefficient
of 0.1.
Fig. 10 Scatter diagram of the amount of pre-to-postoperative change in the nasal resistance,
and the amount of pre-to-postoperative change in nasal obstruction scores. A significant
correlation was not observed with a Spearman rank correlation coefficient of 0.203.
Discussion
In the Japan Rhinologic Society, the evaluation of subjective symptoms and quality
of life (QOL), evaluation using endoscopy, evaluation using computed tomography imaging,
and evaluation using rhinomanometry have been proposed as a functional assessment
of ESS. In the present study, before and after ESS, we evaluated the nasal resistance,
which is believed to strongly correlate with nasal obstruction, i.e., the primary
symptom of chronic sinusitis. Furthermore, as influencing factors, we examined the
presence or absence of concurrent surgery such as septoplasty and conchotomy, the
presence of any differences depending on whether single sinus surgery or polysinus
surgery was performed, as well as the difference according to the presence or absence
of polyps.
In the pre- and postoperative comparison, excluding the ESS + septoplasty group with
nasal resistance of ≥0.25, the nasal airflow rate improved with a significant difference.
One group showed no significant difference; this was considered to be owing to the
fact that the group had a small sample size (four patients). We believe that the reason
for the improvement in the nasal resistance is direct changes resulting from surgery
and indirect changes such as alleviation of paranasal sinusitis and reduction in mucosal
swelling.[6]
According to the criteria reported by Takeuchi et al, to evaluate ESS when the preoperative
nasal resistance is 100, the postoperative nasal airflow rate is approximately 70.[6] Based on this criterion, in the present study, the postoperative nasal resistance
was found to be 63.4 in bilateral patients and 44.9 in the affected side of unilateral
patients, indicating a sufficient improvement.
Upon examining the effect of septoplasty with bilateral submucosal inferior turbinectomy
on patients with sleep-related sleeping disorders and/or snoring habit, it has been
reported that the nasal resistance significantly improved after surgery.[7]
[8] In the present study, we conducted an intergroup comparison of the amount of change
in nasal resistance in patients classified according to concurrent surgery into the
ESS alone group, the ESS + septoplasty group, and the ESS + septoplasty + conchotomy
group. Compared with the ESS alone group, we predicted that the amount of pre-to-postoperative
change in nasal resistance would be greater in the concurrent surgery groups. However,
the results revealed no difference between groups in the amount of change. This could
be attributed to a sufficient improvement in postoperative nasal resistance as a result
of appropriate choice of surgery for each individual patient. Numminen et al compared
middle meatus antrostomy and ethmoidectomy using rhinomanometry, and reported that
patients who underwent ethmoidectomy showed a greater improvement in nasal resistance.[9] To examine the effect of the number of sinuses opened on nasal airflow rate, we
classified patients into the single sinus surgery group and polysinus surgery group;
however, an intergroup comparison of the amount of change in nasal resistance revealed
no significant difference. To exclude the effect of concurrent surgery and the effect
of polyps, we conducted the same examination in patients limited to those who underwent
ESS alone and did not have polyps; however, no significant difference was found. It
is conceivable that the effect on nasal resistance differs depending on the site of
the opened sinus, which we believe could have been the reason why there was no difference
found in the study limited to the number of opened sinuses alone. We also investigated
the presence or absence of polyps, which is believed to greatly affect nasal resistance
but found no difference between the groups. To exclude the effect of concurrent surgery,
we conducted the same examination with patients limited to those who underwent ESS
alone; however, there was no significant difference. The effect of polyps on nasal
resistance differs depending on their size and location, which therefore could have
prevented a significant difference from being found in our comparison according to
the presence or absence of polyps alone. In patients with normal preoperative nasal
resistance, the amount of pre-to-postoperative change is small; therefore, we conducted
the same examination with patients limited to those with nasal resistance of ≥0.25;
however, no significant difference was found in any of the intergroup comparisons.
In addition to the items examined in the present study, the nasal resistance is affected
by multiple factors such as the state of the nasal mucosa, the amount of nasal discharge,
and the nasal cycle. In the future, multivariate analyses need to be performed on
a larger subject sample with factors classified in more detail.
Naito et al evaluated nasal airflow and nasal obstruction pre- and postoperatively
using rhinomanometry and acoustic rhinomanometry in 50 patients who underwent nasal
sinus and paranasal sinus surgery, and reported an improvement with a significant
difference.[10] At our hospital, we evaluate subjective symptoms and QOL using a questionnaire in
conjunction with pre- and postoperative rhinomanometry. In the present study, nasal
obstruction scores significantly improved after surgery, and all postoperative scores
were <2. Furthermore, we examined the correlation between nasal obstruction scores
and nasal airflow rates. As a result, a weak correlation was found preoperatively;
however, no correlation was noted postoperatively. A weak correlation both preoperatively
and postoperatively has been reported between nasal resistance and the sinonasal outcome
test-20 (SNOT-20), which is an evaluation tool for subjective symptoms and QOL.[11] In the present study, we only examined nasal obstruction items. In the future, correlations
with subjective evaluations and nasal resistance combined with other questionnaire
items need to be investigated.
Conclusions
We compared the nasal resistance before and after ESS. The nasal resistance adequately
improved after surgery for most evaluation items. Intergroup comparison between the
single surgery group and the concurrent surgery group revealed no difference in the
amount of change in nasal resistance. Intergroup comparison between the single sinus
surgery group and the polysinus surgery group as well as that between the group without
polyps and the group with polyps revealed no difference in the amount of change in
nasal resistance. Intergroup comparison between the group without polyps and the group
with polyps in patients who underwent ESS alone revealed no difference in the amount
of change in nasal resistance, and in patients without polyps who underwent ESS alone,
intergroup comparison between the single sinus surgery group and polysinus surgery
group also revealed no difference in the amount of change in nasal resistance. In
future, the effect of other factors on nasal resistance should be examined. Furthermore,
while a weak correlation was found between preoperative nasal resistance and nasal
obstruction, there was no correlation observed between the postoperative nasal resistance
and the amount of pre-to-postoperative change. In future studies, we intend to examine
the relationship of subjective evaluations other than nasal obstruction with nasal
resistance.
