Optical Vaginal Biopsy Using Optical Coherence Tomography

Lasers in Gynecology

The first published reports on the use of laser for cervical pathology date back to 1973. Technical advancements in flexible and rigid laser fibers revolutionized video laser laparoscopy in the 1990s. Fractionated lasers have been used to treat vulvovaginal symptoms associated with genitourinary syndrome of menopause, lichen sclerosus, and urinary incontinence. Review of available data suggests that fractionated lasers can improve both subjective and objective signs of vaginal atrophy and lichen sclerosus, but the evidence is weak because most of the trials are underpowered, are at risk for bias, and lack long-term follow-up. There is no strong evidence to support fractionated laser therapy for urinary incontinence or low-level laser therapy for chronic pelvic pain. Although short-term, single-arm trials suggest benefit of fractionated laser therapy for genitourinary syndrome of menopause, lichen sclerosus, and urinary incontinence, additional adequately powered, prospective, randomized, and longer-term comparative trials are needed before lasers can be recommended for these specific conditions. The purpose of this Clinical Expert Series is to review basic laser biophysics and the mechanism of action for modern fractionated lasers as relevant to the gynecologist. We also summarize safety and effectiveness data for lasers used for some of the most commonly studied gynecologic conditions: the vulvovaginal atrophy component of genitourinary syndrome of menopause, lichen sclerosus, and urinary incontinence.

OCT angiography in the monitoring of vaginal health

Fractional-pixel CO2 laser therapy shows promise for treating the genitourinary syndrome of menopause (GSM). Nevertheless, it remains controversial in the field of female pelvic medicine. This is due to the inherent difficulties in obtaining noninvasive biopsies to evaluate the treatment's efficacy and safety objectively. To address this challenge, we developed a noninvasive intravaginal optical coherence tomography (OCT)/OCT angiography (OCTA) endoscopic system, whose probe features a shape identical to the laser treatment probe. This system can provide high-resolution OCT images to identify the microstructure of vaginal tissue and visualize the vasculature network in vivo. We conducted clinical research on 25 post-menopausal patients with GSM. OCT/OCTA scans were acquired at four different locations of the vagina (distal anterior, distal posterior, proximal anterior, and proximal posterior) during the whole laser treatment session. A U-Net deep learning model was applied to segment the vaginal epithelium for assessing vaginal epithelial thickness (VET). Blood vessel density and VET were quantified to monitor the efficacy of fractional-pixel CO2 laser therapy. Statistical correlation analyses between these metrics and other clinical scores were conducted, validating the utility of our system. This OCT/OCTA endoscopic system has great potential to serve as a noninvasive biopsy tool in gynecological studies to screen, evaluate, and guide laser treatment for GSM.

Depth-Resolved Attenuation Mapping of the Vaginal Wall under Prolapse and after Laser Treatment Using Cross-Polarization Optical Coherence Tomography: A Pilot Study

Vaginal wall prolapse is the most common type of pelvic organ prolapse and is mainly associated with collagen bundle changes in the lamina propria. Neodymium (Nd:YAG) laser treatment was used as an innovative, minimally invasive and non-ablative procedure for the treatment of early-stage vaginal wall prolapse. The purpose of this pilot study was to assess connective tissue changes in the vaginal wall under prolapse without treatment and after Nd:YAG laser treatment using cross-polarization optical coherence tomography (CP OCT) with depth-resolved attenuation mapping. A total of 26 freshly excised samples of vaginal wall from 26 patients with age norm (n = 8), stage I-II prolapses without treatment (n = 8) and stage I-II prolapse 1-2 months after Nd:YAG laser treatment (n = 10) were assessed. As a result, for the first time, depth-resolved attenuation maps of the vaginal wall in the B-scan projection in the co- and cross-polarization channels were constructed. Two parameters within the lamina propria were target calculated: the median value and the percentages of high (≥4 mm-1) and low (<4 mm-1) attenuation coefficient values. A significant (p < 0.0001) decrease in the parameters in the case of vaginal wall prolapse compared to the age norm was identified. After laser treatment, a significant (p < 0.0001) increase in the parameters compared to the normal level was also observed. Notably, in the cross-channel, both parameters showed a greater difference between the groups than in the co-channel. Therefore, using the cross-channel achieved more reliable differentiation between the groups. To conclude, attenuation coefficient maps allow visualization and quantification of changes in the condition of the connective tissue of the vaginal wall. In the future, CP OCT could be used for in vivo detection of early-stage vaginal wall prolapse and for monitoring the effectiveness of treatment.

Clinical and laboratory results in vaginal wall restoration using a fractional-pixel-CO2 laser: histological findings and changes in the Ki67 protein and telomere length

Thermal deposition of laser energy in the vaginal epithelium in genitourinary syndrome of menopause (GSM) results in clinical and biological effects, but many cellular and molecular changes indicating cell proliferation or senescence inhibition are unknown. The aim of this study is to evaluate the clinical efficacy of the fractional-pixel-CO2 laser in the possible improvement of GMS signs and symptoms that can be correlated with histological changes or with cellular or molecular indicators of restoration. A detailed prospective study was designed to assess 17 women diagnosed with GSM who were treated intravaginally with two laser sessions. Seven non-treated women diagnosed with GSM were used as controls. Three validated outcome questionnaires for assessment of quality of sexual life and urinary incontinence were performed. Vaginal biopsies were collected before the first laser treatment and 4 months following the second session. Histological status, elastin, collagen, and hyaluronic acid content of the biopsies were also evaluated. Cell proliferation was assessed by Ki67 staining. Telomere length (TL) was measured by qPCR. The results show an improvement of the clinical symptoms of GSM (p < 0.05), vaginal epithelium recovery and enhancement of collagen (p < 0.05), elastic fibers (p < 0.005), and hyaluronic acid (p < 0.0005) content in the lamina propria after fractional-pixel-CO2 laser treatment. The laser treatment induced a significant rise on the TL of vaginal epithelial cells (VECs), and a positive correlation was found between the improvements of the collagen and hyaluronic acid content and TL changes (r = 0.82, p < 0.05; r = 0.38, p < 0.05). The percentage of proliferative Ki67-positive VECs was increased in patients whose vaginal TL lengthened after laser treatment (p < 0.05). In conclusion, the results indicate that laser treatment may induce restoration of the vaginal epithelium which is associated to increased TL and proliferation in the VECs. Performing a TL assay could be a suitable tool to evaluate the efficacy of vaginal laser treatment.

Optical coherence tomography evaluation of vaginal epithelial thickness during CO2 laser treatment: A pilot study

Genitourinary syndrome of menopause (GSM) negatively affects more than half of postmenopausal women. Energy-based therapy has been explored as a minimally invasive treatment for GSM; however, its mechanism of action and efficacy is controversial. Here, we report on a pilot imaging study conducted on a small group of menopause patients undergoing laser treatment. Intravaginal optical coherence tomography (OCT) endoscope was used to quantitatively monitor the changes in the vaginal epithelial thickness (VET) during fractional-pixel CO2 laser treatment. Eleven patients with natural menopause and one surgically induced menopause patient were recruited in this clinical study. Following the laser treatment, 6 out of 11 natural menopause patient showed increase in both proximal and distal VET, while two natural menopause patient showed increase in VET in only one side of vaginal tract. Furthermore, the patient group that showed increased VET had thinner baseline VET compared to the patients that showed decrease in VET after laser treatment. These results demonstrate the potential utility of intravaginal OCT endoscope in evaluating the vaginal tissue integrity and tailoring vaginal laser treatment on a per-person basis, with the potential to monitor other treatment procedures.

Pixel-CO2 laser for the treatment of stress urinary incontinence

Abstract

The aim of this study was to assess the safety and efficacy of a minimally invasive pixel-CO₂ laser procedure for the treatment of stress urinary incontinence (SUI). This was a prospective, open-label study with a cohort of 59 women. Patients were treated intravaginally with a fractional/pixel CO₂ laser every 4–6 weeks for a total of three treatments and assessed at 3, 6, and 12 months. Evaluation tools included a Sandvik severity score based on a validated questionnaire, 1-h pad test, vaginal health index score (VHIS), validated female sexual function index (FSFI), patient’s impression of disease severity (PGI-S), global impression of improvement (PGI-I), and the short-term pelvic floor impact questionnaire (PFIQ-7) to assess improvements in quality of life. Reduction in SUI severity was noticed throughout the duration of the study, as compared to the baseline in which 2% of the patients were defined as “slight,” 73% “moderate,” and 25% “severe.” Gradual improvement of symptoms resulted in redistribution of severity score and the best outcome observed between 3 and 6 months. Sanitary pad weight declined from an average of 35.45 g per day at baseline to 12.47 g at the 3rd treatment, and increased to 23.06 g at 12 months. Vaginal acidity changes showed a similar pattern. No serious adverse events were reported. Pixel-CO₂ laser is safe and effective for treating SUI. Additional maintenance treatments should be considered during the 6–12-month post-treatment period in order to maintain the beneficial effects.

Brief summary

Pixel-CO₂ laser is a safe and effective treatment for SUI. Maintenance treatments should be considered at 6–12 months.

Vaginal laser therapy for genitourinary syndrome of menopause - systematic review

BACKGROUND

Genitourinary syndrome of menopause (GSM) can have a great impact on the quality of life (QOL), and affects between 53.8% and 90% of postmenopausal women. The literature suggests that vaginal laser therapy could be an effective treatment for GSM symptoms, but its efficacy and safety have not been established and international societies do not endorse its use. Despite that, there has been an increase in the use of vaginal laser therapy globally over the last decade.

OBJECTIVE

The objective of this review is to evaluate the literature which assesses the efficacy and safety of the vaginal laser therapy in the treatment of GSM.

METHODS

A comprehensive literature search was conducted electronically using Embase and PubMed to retrieve studies assessing evidence for the efficacy and safety of vaginal laser therapy for GSM or vulvovaginal atrophy up to June 2021.

RESULTS

A total of 64 studies were finally included in the review. There were 10 controlled intervention studies, 7 observational cohort and cross-sectional studies and 47 before-after studies without a control group.

CONCLUSION

Vaginal laser seems to improve scores on the Visual Analogue Scale (VAS), Female Sexual Function Index (FSFI) and Vaginal Health Index (VHI) in GSM over the short term. Safety outcomes are underreported and short-term. Further well-designed clinical trials with sham-laser control groups and evaluating objective variables are needed to provide the best evidence on efficacy.

Investigations on the potential of optical coherence tomography as an imaging tool for eustachian tube

The purpose of this study was to explore the feasibility of eustachian tube optical coherence tomography (ET-OCT) for imaging the pharyngeal region of the eustachian tube (ET). Ten subjects with ear complaints underwent ET-OCT guided by nasal endoscopy, and ET-OCT examination was performed on both sides of each subject's ETs. The process and resulting images were analysed. Ten subjects ranging from 21 to 73 years old (45 ± 14.77) were enrolled in this study. Eighteen ET-OCT imaging examinations were completed. The mean duration of each examination was 2.80 ± 1.62 min (ranging from 2 to 7 min). There were no adverse events or complications. In some subjects, the ET-OCT images clearly presented the microstructures of the ET wall, including the lumen, mucosa, submucosa, cartilage and plica. However, in some subjects, it showed different characteristics, such as an unclear hierarchy and secretions in the lumen. ET-OCT may help to distinguish the structural composition of the ET and elucidate related pathophysiological mechanisms. It is a valuable imaging tool suited for the ET, with potential diagnostic value in determining the morphology of the lumen, intraluminal mucosa and submucosal tissue in the pharyngeal region of the ET.