How long is too long? Application of acetic acid during colposcopy: A prospective study

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.

Publication History

Article published online:
07 October 2020