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].