53 / 412
moderate dysplasia, and 36.4% of the patients with severe dys-
plasia. Type II cordectomy was performed in 35.9% of the pa-
tients with mild dysplasia, 34.6% of the patients with moderate
dysplasia, and 57.6% of the patients with severe dysplasia. Type
III cordectomy was performed in only two (6%) patients with
severe dysplasia.
Recurrence of the disease occurred after 8 months in six
patients, after 9 months in five patients, after 10 months in
four patients, after 11 months in eight patients, and after 12
months in five patients. Most patients with recurrence were in
a group with moderate dysplasia (
Table 5
). Disease progression
was noted in 10 patients with recurrence. Invasive carcinoma
developed in four patients: one from group with moderate dys-
plasia and three from group with severe dysplasia.
Multivariate regression analysis was performed to determine
how factors such as cordectomy type and stroboscopic signs
(glottic occlusion, phase symmetry, periodicity, amplitude of
vibrations, mucosal wave, and nonvibrating segment) corre-
lated with the histopathologic verification of different types
of dysplasia (
Table 6
). Some factors, such as the type of cordec-
tomy and the existence of nonvibrating segment, were set apart
from others and were proven to be significantly different in var-
ious levels of dysplasia (
P
< 0.05).
Logistic regression was used to determine whether the recur-
rence and progression of the disease could be anticipated by
cordectomy type and stroboscopic signs (glottic occlusion,
phase symmetry, periodicity, amplitude of vibrations, mucosal
wave, and nonvibrating segment) (
Table 7
). Of all the analyzed
factors, only the amplitude of vocal fold vibrations in group
with mild dysplasia (
P
¼
0.03) was statistically significant for
recurrent disease. In this group, some factors indicated a higher
risk of recurrence but not statistically significant enough. Pa-
tients with asymmetry in vocal fold vibrations and irregular vo-
cal fold vibrations, with abnormal amplitude of vocal fold
vibrations, and the existing nonvibrating segment were at
higher risk of recurrence. None of the factors was statistically
TABLE 3.
Stroboscopic Signs for Patients With Severe Dysplasia Before Treatment and After 12 Months of Follow-Up or Before
Retreatment
Stroboscopic Signs
Severe Dysplasia
Before Treatment (%)
After 12 Months (%)
Sig.
Glottic occlusion
1.000
Sufficient
25/33 (75.8)
24/33 (72.7)
Insufficient
8/33 (24.2)
9/33 (27.3)
Phase symmetry
—
Symmetrical
0/33 (0)
19/33 (57.6)
Asymmetrical
33/33 (100.0)
14/33 (42.4)
Periodicity
0.000*
Regular
1/33 (3.0)
19/33 (57.6)
Irregular
32/33 (97.0)
14/33 (42.4)
Amplitude
0.000*
Normal
1/33 (3)
19/33 (57.6)
Decreased
29/33 (87.9)
14/33 (42.4)
Increased
3/33 (9.1)
0/33 (0)
Mucosal wave
0.000*
Normal with 30–50% lateral travel
1/33 (3)
19/33 (57.6)
Increased with lateral travel greater than 50%
0/33 (0)
0/33 (0)
Decreased with lateral travel less than 30%
32/33 (97)
14/33 (42.4)
Nonvibratory segment
0.013*
Presence
18/33 (54.5)
8/33 (24.2)
Absence
15/33 (45.5)
25/33 (75.8)
Abbreviation:
Sig., statistical significance.
*
P
< 0.05.
TABLE 4.
Treatment Modalities for the Different Grades of Dysplasia
Cordectomy Types
Mild Dysplasia (%)
Moderate Dysplasia (%)
Severe Dysplasia (%)
All Patients (%)
I
34/53 (64.1)
17/26 (65.4)
12/33 (36.4)
63/112 (56.2)
II
19/53 (35.9)
9/26 (34.6)
19/33 (57.6)
47/112 (42.0)
III
0/53 (0)
0/26 (0)
2/33 (6.0)
2/112 (1.8)
Vojko Djukic,
et al
Stroboscopy in Detection of Laryngeal Dysplasia
33