Interpretation
The literature about laser ablation for the treatment of VaIN lacked
detailed description of the procedure and led to large fluctuation of
effective rate and relapse rate of the disease. MTLA was proposed in
this study and we obtained high pathological cure rate under this
treatment mode. We expected to maintain the high efficacy in the long
term.
Because laser ablation is a destructive procedure with no
histopathological examination, malignancy should be excluded if we
choose laser ablation for VaIN. The punch biopsy-proven VaIN could not
exclude microinvasion, and the incidence of coexisting malignancy was
1.0~30.3% as the literature reported [10,14,15,38].
All patients in our study received colposcopic and pathological
examinations. Patients were excluded if the lesions observed by
colposcopy were suspicious of malignancy with the indications such as
widespread or bulging lesions, or if the pathological examinations
suspected of invasive lesions. The incidence of coexisting cancer rises
in widespread VaIN3 or carcinoma in situ.
The MTLA method was decided according to the overall assessment of
patients’ status during the treatment. Firstly, colposcopic examination
played a key role. Colposcopic examination could not only assess the
severity of the lesions, but also guide multiple biopsies to exclude
invasive lesions and evaluate the efficacy in follow-up period. The
accuracy rate of colposcopic examination diagnosing VaIN was 52.17% and
the risk rate of HSIL(VaIN2,3) missed diagnosis was about 35.71%
[39]. Experienced practitioners predominantly elevated the accuracy
rate. Secondly, MTLA method emphasized sufficient exposure of lesions
and precise targeting at the lesions when ablating. VaIN was usually
detected in the upper third of the vagina and sheltered by the cervix
which might lead to missed diagnosis and treatment. For patients
received hysterectomy, VaIN usually arose in the mucosal folds
especially the bilateral apex of vagina. MTLA required flattening
wrinkles and overlapping ablation scanning. Thirdly, surveillance was
important for the individual decision-making of MTLA. The results of
cytologic tests, HR-HPV tests, colposcopic and pathological examinations
were key factors to decide whether to repeat laser ablation in follow-up
phase. Persistent HPV infection was a high-risk factor for relapse of
VaIN [14,16]. Repeat laser ablation was preferred if any of below
appeared: abnormal results of cytologic tests, positive results of HPV
tests, proliferative lesions found by colposcopic examinations
indicating VaIN, or biopsy-proven VaIN. Excisional procedure was
preferred if any signs indicated malignancy. The incidence of VaIN
progressing to malignant tumors after treatment was
3.4~12% [5,8,10,15,18].
The high-risk factors for VaIN included menopause, HR-HPV infection,
CIN/CC history, vaginal intracavity radiotherapy, immunosuppression and
so on as reported [40~44]. Larger VaIN areas and
hysterectomy were independent risk factors for pathological persistence
in this study. Patients with larger areas of VaIN might have a higher
rate of suffering high-grade lesions, multifocal lesions, CIN/VIN and
other risk factors, which increased the difficulty of laser procedures.
The indications of hysterectomy in this study were mainly past diseases
of CIN/CC. The patients with the history of hysterectomy experienced
more adverse factors like older age, a more complicated history of
HPV-associated diseases, vaginal atrophy and local immunosuppression. In
a report, 2/3 VaIN patients had the history of hysterectomy mainly
indicated by cervical HSIL [45]. It was known that VaIN might share
the same etiology with CIN. And VaIN might have occurred but missed
diagnosis when hysterectomy was done. Menopause and no-use of condemns
were independent risk factors for HPV persistence in the study. For
postmenopausal females, insufficient estrogen leads to vaginal atrophy
and local immunosuppression which result in a low capacity to eliminate
viruses. Doctors can publicize the benefit of condemn use to protect our
patients from HPV infection. HPV vaccine could also prevent HPV-related
VaIN [46,47].