By Rebecca H. Allen, MD, MPH, Editor
Associate Professor, Department of Obstetrics and Gynecology, Warren Alpert Medical School of Brown University, Women and Infants Hospital, Providence, RI
SYNOPSIS: In this prospective study, one minute of acetic acid application was found to be sufficient to identify the most severe colposcopic lesion in 96.7% of subjects.
SOURCE: Hilal Z, Tempfer CB, Burgard L, et al. How long is too long? Application of acetic acid during colposcopy: A prospective study. Am J Obstet Gynecol 2020;223:101.e1-101.e8.
The appropriate duration of dilute acetic acid application to identify cervical dysplastic lesions during colposcopy examination is unknown. The authors of this study sought to determine the optimal length of time by video recording the colposcopy and identifying the most severe colposcopic lesion one, three, and five minutes after application.
From September 2018 to May 2019, a total of 300 women were recruited and underwent videocolposcopy for abnormal Pap smear results at two sites in Germany. Dilute acetic acid (5%) was applied to the cervix via a spray can. The colposcopist classified the most severe colposcopic lesion one, three, and five minutes after application. Investigators also documented the time to first appearance of and fading of the most severe colposcopic lesion. A total of 85 videos were randomly selected for a more detailed assessment, with a 1:2:2 ratio (negative for dysplasia:low-grade squamous intra-epithelial lesion [LSIL]:high-grade squamous intra-epithelial lesion [HSIL]) by three blinded colposcopists.
The average age of the participants was 35.2 years. Ninety-eight (37.8%) were smokers. The reason for referral to colposcopy included persistent human papilloma virus in 32 (10.7%), atypical squamous cells of undetermined significance in 11 (3.8%), atypical squamous cells in which HSIL could not be ruled out in 21 (7%), atypical glandular cells in 12 (4.0%), LSIL in 69 (23%), HSIL in 146 (48.6%), adenocarcinoma in-situ in eight (2.7%), and squamous cell carcinoma in one (0.3%). At the end of the colposcopy, five minutes after application of acetic acid, colposcopic assessment found a normal cervix in 61 (23.1%), minor changes in 107 (40.5%), and major changes in 92 (34.9%) cases. After one minute, 290 of 300 subjects (96.7%) were diagnosed with the most severe colposcopic lesion. This did not improve after three or five minutes. The median time from application of acetic acid to the first appearance of the most severe colposcopic lesion was found to be 13.5 seconds (interquartile range [IQR], three to 27.25 seconds), which was significantly lower for HSIL compared to LSIL lesions (P < 0.001). The fading of acetowhite lesions occurred over time, with the median time from application to the start of fading at 191 seconds (IQR, 120 to 295 seconds). Fading started earlier in HSIL compared to LSIL lesions (P = 0.044).
The authors of this study evaluated the optimal duration of acetic acid application to identify colposcopic lesions. Studies that evaluate our current clinical practice are highly interesting. Many times, clinicians practice a certain way because of how they were trained, and the evidence behind these practices often is not examined. Colposcopy practice in the United States is governed by the American Society for Colposcopy and Cervical Pathology (ASCCP). Colposcopy is a technique for the evaluation of cervical and vaginal lesions under magnification to allow for directed biopsies. In 2017, the organization published recommendations for colposcopy practice in the United States, which had been lacking previously.1
These guidelines addressed recommendations for colposcopy practice, including standardizing terminology, reporting, and colposcopy procedures, including the number and types of biopsies. They determined the minimum criteria for reporting should include the following: squamocolumnar junction visibility (fully/not fully), acetowhitening (yes/no), lesion(s) present (acetowhite or other, yes/no), and colposcopic impression (normal/benign, low-grade, high-grade, cancer). They also recommended that, in general, multiple biopsies targeting all areas with acetowhitening, metaplasia, or higher abnormalities are recommended. Usually, at least two, and up to four, targeted biopsies from distinct acetowhite lesions should be taken.1 Furthermore, the guidelines recommend examining the cervix with magnification after application of 3% to 5% acetic acid.2 However, the ASCCP guidelines do not mention how long to wait after the application of the acetic acid.
The authors of this study found that 97% of participants were diagnosed with the most severe colposcopic lesion one minute after acetic acid application. This is important information for colposcopy practice, since the provider should not evaluate the lesion too early or it might be missed, nor too late, since it might fade, as was documented in 78% of cases in this study. It was also noted that HSIL stains very quickly, within seven seconds, but also fades earlier than LSIL. This fading phenomenon has been documented previously, which is why many colposcopists repeat acetic acid application throughout the procedure. I found this study fascinating because I do not remember ever being trained in the optimal duration of acetic acid application. Knowing the majority of lesions will appear after one minute of acetic acid application may help us to not prolong the procedure for the patient.
- Wentzensen N, Massad LS, Mayeaux EJ Jr, et al. Evidence-based consensus recommendations for colposcopy practice for cervical cancer prevention in the United States. J Low Genit Tract Dis 2017;21:216-222.
- Waxman AG, Conageski C, Silver MI, et al. ASCCP Colposcopy Standards: How do we perform colposcopy? Implications for establishing standards. J Low Genit Tract Dis 2017;21:235-241.