From Colposcopy or "Classic Colposcopy" to Actinic Light Colposcopy

 

Introduction

 

The increasing incidence of the diseases of sexual transmission on worldwide scale due Human Papilloma Virus (HPV) is related of very narrow way to the increase of cervical intraepithelial neoplasia (CIN) and cervical cancer (CC) in the woman.

 

In the task for the detection and control of the CIN the gynecologist must resort to laboratory tests to make the diagnosis, the shipment to the laboratory causes pertinent delay and this way the opportunity is postponed to know the results immediately, this process can also cause the increase of negative expectations in the patient and of the degree of uncertainty, in addition that raise the costs.

 

Among the tests sent to the laboratory is the Papanicolaou, which from half of the last century has helped to prevent the cervical cancer at world-wide level, nevertheless, its trustworthiness due to different factors is not sufficiently exact high like we expect.

 

Aim

 

In the clinical environment, in the scope of the doctor's office frequently it is not easy to diagnose the CIN due to lacking procedures, equipment and tests that facilitate of simple form a reliable diagnosis. Therefore, we was reviewed the techniques in the detection of CIN and were detected spaces in which it was possible to improve the colposcopic technique in the detection of the CIN.

 

This way a light source resorted to the use of specific fluorochrome with very exact wave light of luminous band and that fulfilled the fundamental requirements in the illumination.

 

It is considered important to declare that in the design and construction of this colposcope always the optical principles enunciated by Hinselmann of stereoscopy were respected.

 

Although this new colposcope does not have relation with the bands of length of actinic radiation was denominated to him to this system "Actinic Light Colposcope" to differentiate it from the other colposcopes and because the ophthalmologists to visualize the injuries of the cornea use a lamp that commonly call to him of same " Actinic Light" that has a cobalt filter.

 

Exactly, the main intention of the present work is dedicated to present display this new system, the one colposcopy of actinic light, easy use in its application from the clinic for the diagnosis of intraepithelial the physiological and pathological changes in the cervix. It is technique a reliable, non-expensive and fast to apply that no tense to the patient with the delay of the results. That is to say, it takes benefit to the health of the woman in the control of the prevalence of the CIN, its use in the control programs of the reproductive health is ideal and also it is an instrument of routine use for the doctor's office of the gynecologist at public or private level in the control of his patients.

 

The exact appreciation that must be included between the basic concepts understood for of the system of colposcopy of actinic light logically are those of the HPV, the cervical cancer, the histological changes: physiological and pathological of the epithelial tissue of lower female genital reproductive tract, the colposcope and the colposcopic technique.

 

 

Colposcopy or “Classic Colposcopy  and Actinic Light Colposcopy

 

Comparative Techniques

 

Between the limitations that we found in "classic colposcopy" is the trustworthiness degree, the false positives fluctuate between the 4 to 33% and false negatives between the 40 to 62%, fluctuation due mainly to the interpretation of the own one observer.

 

The contrast and the amount of shades of the colors of the reaction of acetic acid in the healthy tissue and the damaged tissue can get to be almost imperceptible because the colors and their contrast are diffuse, the amount of shades of the colors are seen in diverse white tones in the damaged tissue that must be differentiated.

 

In "classic colposcopy" another factor that influences to limit the observer is that a standard as far as the technique of required illumination does not exist, some sources of illumination of the colposcopes are of xenon, others of halogen and others of tungsten still giving as result colors with different brightness, greater or smaller contrast, but or less saturated, if it is added to the lack of uniformity of light intensity on the cervical plane, it still facilitates the existence of diverse diagnostics opinions in a same patient with the same observer, in conclusion the distribution of light and shade on the images will make vary the quality or clearness of observed.

 

According to our studies the colposcope of actinic light displays until a 3% of false positives and a 13% of false negatives, this great difference in the diminution of the error in the observed thing with respect to "classic colposcope" must to that the quality of the image of the colposcope of actinic light uses the fluorescence effect that attracts, this procedure improves the differentiation of color and contrast of the image when existing a dark bottom without white light, with the images of the injuries superposed in green tonalities diminishing this way the error between observers and of the same observer, in addition to other characteristics that are described next.

 

Colposcope of Actinic Light.

 

The colposcope have stayed from the point of view of the optics practically without changes from 1925 although nowadays there is great amount of devices for digital image by means of different equipment from computers or processors of image as well as electronics filters.

 

The colposcope of actinic light, that is specific to see neoplasias, was manufactured with the purpose of correcting the defects in the colposcopic observation, this one uses the knowledge of the optics of the microscopy of fluorescence with episcopic illumination, that is to say, with incident light on the observed focal plane. This technique uses special colorants for fluorescence; fluorochromes called and allow of way specifies to dye the parts of the cells in the tissue that are desired giving like result an image with hi-resolution that is caught by means of systems of specific filters emphasizing therefore the image in a dark bottom (Law of Stokes-Adams).

 

In colposcopy of actinic light the image in a dark bottom discriminating of better way is observed the field observed when diminishing the intensity of unnecessary light. The new system counts on source of illumination similar to call by microscopists illumination according to Kohler in which filament focuses to infinite in the plane of observation, which causes that the different shades are plenty of contrast and color, superposed to a dark bottom reason why an image of greater quality is obtained.

 

 

Technique for Actinic light colposcopy.

 

In the zones of the ill tissue in which the acetic acid acts and that by means of classic colposcopy is an almost transparent target, in colposcopy of actinic light these zones are seen and stood out perfectly in green on a dark bottom.

 

A mordant agent as the acetic acid facilitates the union of fluorochrome to the tissue infected and injured by the HPV. The modification that we made to it’s to the technique of acetic acid allows us for several reasons of visualizing of better way neoplasias. One of them is the absorption to the keratin (protein intra cellular) of acetic acid with fluorochrome and another one by the adsorption of the DNA to fluorochrome of the neoplastic cells because it is in greater proportion than in the healthy cells.

 

By the entire previous one, in the case of having injury by the VPH, this one is stood out by the dark bottom - positive test - and in the case of not having injury - negative test - the only thing that it is seen is a dark field, the differentiation facilitates greater exactitude in the taking of directed biopsy.

 

There are additional, distinct advantages presented by the apparatus and method of the present invention, among them: portability; ergonomical design for the user and patient, ease of use, low heat intensity light source, works dually like a common colposcope and like an actinic light colposcope, and it is specific to detect lesions caused by HPV by virtue of its spectral band with a long-lasting light with a specific wave for the fluorochrome: isothiocyanate of fluoresceine ("FITC"), quick results during the same visit and at the same location where the test is performed.

 

 

Procedure: 

 

• Place the patient comfortably in the gynecological position. 

• Introduce a vaginal specula.

• Locate the cervix.

• Take samples of the endocervix with a citobrush.

• Take samples of the ectocervix with Ayre’s spatula.

• Make uniformly smears of the samples to be sent to the laboratory, only for confirmation of our diagnostic, in case that it most be required.

• Apply acetic acid on the cervix for one minute. This acid solution has two functions: first, it is a bleach of the cells in a Cervical Intraepithelial Noeplasia, and second it is a mordant for couple the fixation of the fluorochrome with the cells.

• Perform an ordinary Colposcopy.

• Introduce the green filter and see the vascular changes as part of the ordinary Colposcopy.

• Make video or pictures, for comparing the results.

• Apply uniform the fluorochrome solution in the cervix uniformly for one minute.

• Introduce the exciter filter of the Colposcope.

• Introduce the suppressor filter of the Colposcope. This is the most important part of the technique, because we will make the diagnostics in this step, this is the “new image”. 

• Make the video records and pictures.

 

Pictures of Method: