Background Applying acetic acid (AA) to the cervix followed by colposcopic assessment is the
standard test used to detect dysplastic lesions of the cervix. However, there is no
evidence-based common standard defining how to exactly perform this test.
Methods Consecutive women referred to our colposcopy unit were recruited. Using a standardized
colposcopy protocol, we recorded the most severe colposcopic lesion (MSCL) 1, 3, and
5 minutes after application of AA (primary study end point). The time to first appearance
of the MSCL and highest staining intensity were video-documented.
Results 300 women were included. After 1 minute, 290/300 (96.7 %) of patients were diagnosed
with the MSCL. This proportion did not improve after 3 minutes (290/300 [96.7 %])
nor after 5 minutes (233/264 [88.3 %]). The proportion of minor and major changes
continuously declined over time from 142/300 (47.3 %; 1 minute) to 107/264 (40.5 %;
5 minutes) and from 110/300 (36.7 %) to 91/264 (34.5 %), respectively. The median
time until the first appearance of the MSCL was 13.5 (interquartile range [IQR] 3
to 27.25) seconds and was significantly lower in HSIL (7 [IQR 1 to 20] seconds) compared
to LSIL (19 [IQR 9 to 39.5] seconds; p< 0.001). Overall, the net difference between
colposcopic assessments at 3 minutes versus at 1 minute was one more HSIL and one
less LSIL.
Conclusion It is reasonable to conclude that the best time to identify lesions is 1 minute after
the application of AA. Continued evaluation for up to 3 minutes may be considered
reasonable for an optimal HSIL yield.
