Hysteroscopic equipment (hysteroscopes)

Hysteroscopy requires expensive equipment. Before starting to perform hysteroscopy, the specialist must undergo special training on the use of apparatus and medical manipulation. Endoscopes and endoscopic instruments are very fragile and require careful treatment to avoid their damage. Before starting work, a specialist should carefully inspect all equipment to identify possible malfunctions.

Currently, hysteroscopic equipment is produced by various companies, but the most widely used machines are Karl Storz (Germany) with optical systems Hopkins and Hamou, Wolf (Germany) with the optical system Lumina-Optic and the company Olympus "(Japan). In recent years hysteroscopes of the firm "Circon-Acmi" (USA) have appeared. There are rigid microhysteroscopes with a small diameter for outpatient hysteroscopy.

Hysteroscopes

The telescope is the main element of the hysteroscopic equipment. More often use hard telescopes with the lens system "Hopkins".

The advantages of this design in front of a conventional optical system are better resolution, contrast and clarity both in the periphery and in the center of the field of view. Different viewing angles (0, 12, 20, 25, 30 and 70 °) allow most of the object to be viewed in one field of view. The use of a telescope with one or another angle of view depends on the preferences of the surgeon.

To conduct a simple diagnostic hysteroscopy, optical tubes with a viewing angle of 30 ° are more convenient, since they make it easier to navigate in the uterine cavity. In surgical interventions, a telescope with a 30 ° angle of view is also preferable.

The Hopkins lens system takes up less space, which allows you to maximally reduce the diameter of instruments (telescope diameters from 2.4 to 4 mm), making entry them safe, less painful and easy to manage.

A simple panoramic telescope magnifies images 3.5 times only with close contact, and with a panoramic view, there is no increase. Despite the fact that telescopes are protected by steel tubes, care must be taken with them. Even a slight displacement of the lens inside the steel case leads to damage to the telescope.

Microlinkowscopes. In 1979, Hamou combined a telescope and a complex microscope. The obtained optical system made it possible to carry out both a panoramic examination of the uterine cavity and a microscopic study of cell architectonics in vivo, using a contact method after intravital staining of the cells. The device was called the microcampohyroscope Hamou.

At present, this type of hysteroscope is produced by the firm "Karl Storz" (Germany). There are two variants of microline gyroscopes - I and II.

The micromolpohysteroscope Hamou I has a diameter of 4 mm and a length of 25 cm, 2 eyepieces - straight and lateral. The device provides the possibility of inspection at different magnifications. A direct eyepiece allows a panoramic inspection with a single, and with a contact method - with a 60-fold increase.

The second (lateral) eyepiece allows panoramic viewing with an increase of 20 times, and when using the contact technique - 150 times. Possible manipulations:

• Ordinary panoramic hysteroscopy (single magnification) with a panoramic view through the direct eyepiece. Viewing depth from infinity to 1 mm (from the distal end of the instrument), viewing angle 90 °. At the general review of a cavity of a uterus mark localization of pathological changes, and then them study with increase.
• Panoramic macrohysteroscopy (20-fold increase) with the use of a side eyepiece is suitable for cervicoscopy, colposcopy and macroscopic evaluation of intrauterine pathology.
• Microhysteroscopy (60-fold increase), the so-called contact hysteroscopy. Use a straight eyepiece, while its distal end is in close contact with the endometrium. Depth of field of 80 microns allows to investigate the structure of normal mucous membrane and atypical sites.
• Microhysteroscopy (150-fold increase) with the use of a side eyepiece, located in contact with the mucosa, allows to conduct studies at the cellular level.

When working with the side eyepiece, focus is performed by rotating a special screw. It should be borne in mind that contact hysteroscopy allows you to inspect the surface having a diameter of 6-8 mm, so to get a full idea of the state of the uterine cavity, you need to repeatedly move the hysteroscope. With a combination of all types of micro-colposcope, you can get the most complete picture, characterizing the state of the uterine cavity.

Microcampohyroscope Hamou II. Possible manipulations:

• Panoramic hysteroscopy (single magnification).
• Macrohysteroscopy (20-fold increase).
• Microhysteroscopy (80-fold increase).

This hysteroscope does not allow you to study the structure of the cell, it is intended for intrauterine surgery.

Diagnostic and operational hysteroscopes. The telescope for hysteroscopy is placed in an outer metal casing. There are two types of housing: for diagnostic and operating hysteroscopes.

• The case of the diagnostic hysteroscope has a diameter of 3-5.5 mm (depending on the manufacturer), is equipped with a crane for fluid or gas, sometimes a second tap for their removal. There are also two-lumen tubes for separate feeding and outflow of liquid (Figures 2-6).
• The hysteroscope case has a diameter of 3.7-9 mm (depending on the manufacturer), more often double-lumen. Access to this channel is through a rubber valve to create a seal.

There are cases equipped with a special deflection device located at the distal end (albarran) and serving to facilitate access of auxiliary instruments to hard-to-reach areas of the uterine cavity.

Optical operating instruments (a rector) are a metal case with a diameter of 7 mm (21 Fr). At its distal end there are rigid scissors or various shapes of bites and forceps. A telescope is inserted inside the case.

The telescope, together with the resector, is inserted into the outer casing, provided with cranes for insertion and outflow of liquid. This outer body is equipped with an obturator. In the process of working, the latter is removed and a telescope with a tool is placed instead.

Optical operating tools are not widely used due to the danger and complexity of working with them. When working with optics at a viewing angle of 30 ° (used most often), the cutting part of the tool partially or completely (depending on the type of working part) closes the view and makes it difficult to work with this tool.

Fibrogysteroscope

1. Diagnostic fibrogysteroscope - a flexible hysteroscope with fiber optics (Figure 2-10) - has several advantages.
   • The small diameter (from 2.5 mm) of the distal end of the fibrohysteroscope allows hysteroscopy without expansion of the cervical canal, without anesthesia, in outpatient conditions.
   • The flexibility of the tip of the device allows you to inspect the uterine corners. Depth of inspection from 1 to 50 mm, a large viewing angle due to the displacement of the distal end.

Fibrohysteroscope deficiency is a honeycomb structure of the image due to the peculiarities of light transmission through an optical cable consisting of a number of optical fibers, which degrades the quality and accuracy of the image. Because of this, there may be errors in the interpretation of the hysteroscopic picture.

2. In addition to the diagnostic, there is an operational fibrogysteroscope with a working diameter of 4.5 mm and an operating channel of 2.2 mm. Depth of inspection 2-50 mm, viewing angle 120 °. However, the operational capabilities of this hysteroscope are small, since the narrow operating channel allows the introduction of only a few types of fine instruments, with which it is possible to perform only targeted endometrial biopsy, removal of small endometrial polyps and dissection of tender intrauterine synechia.

Due to small operational capabilities and high cost, the fibrogysteroscope has not yet found wide application in our country. Abroad, it is widely used for outpatient diagnostic hysteroscopy.

Resectoscope - the main tool of electrosurgical operations, produced in the uterine cavity. Resectoscopes are produced by manufacturers under various names: a resectoscope (Karl Storz), a myomarezectoscope (Wolf), a hysteresisectoscope (Olympus, Circon-Acmi).

Resectoscope consists of 5 parts: telescope, external and internal tubes, working element and electrode.

The telescope is represented by panoramic rigid optics "Hamou" and "Hopkins" with a diameter of 4 mm, the viewing angle can be different. The most popular telescope with a view angle of 30 °.

Resectoscope tube consists of two parts (external and internal, made of stainless steel); flows of flow and outflow of liquid are separated. The diameter of the outer shell varies from 6.3 to 9 mm (19-27 Fr), the working length is 18-35 cm. The outer tube at the distal end has numerous holes intended for aspiration of fluid from the uterine cavity. The internal tube in resectoscopes of the latest generation is equipped with a rotational mechanism that allows rotational movements of the working element in relation to the tube. Such a construction facilitates the operation, does not create difficulties with the bends of numerous connecting hoses when the position of the working element changes.

Electrodes of various shapes, sizes and diameters are connected to the working element: cutting loops (straight and curved), knife, rake-shaped, needle-shaped, spherical and cylindrical electrodes, as well as evaporation electrodes.

The larger the diameter of the cutting loop, the safer and more efficient it is. Small loops increase the duration of the operation and increase the risk of perforation of the uterus. Cutting loops with an angle of inclination from the surgeon are used for resection of the endometrium in the angular and uterine fundus, the hinge with the angle of inclination to the surgeon for resection of the endometrium of the walls of the uterine cavity.

The large dimensions of a spherical or cylindrical electrode are preferable for rapid completion of the operation, but they make it difficult to survey. Consequently, with normal size of the uterus, smaller electrodes are preferable.

The working element of the resectoscope is controlled by pressing the trigger on the trigger. There are two working mechanisms: active and passive. With the active mechanism, the electrode is pulled out of the body by pressing the trigger. With a passive mechanism, the electrode automatically returns to the body after the pressure is released on the trigger, cutting the tissues or coagulating. The passive mechanism is safer in operation. In the design of the operating element, the electrode is placed in such a way that when the probe is extended beyond the limits of the tube, the working surface of the electrode is constantly in the zone of visibility.

Auxiliary tools

To perform operative intrauterine interventions, hysteroscopes are equipped with sets of rigid, semi-rigid and flexible instruments: biopsy forceps, biopsy dentate, grasping forceps, scissors, endoscopic catheters and probes for bougie tubal ligation. These instruments are conducted through the operating channel of the hysteroscope and used for intrauterine manipulation. These tools are quite fragile, easily broken and deformed. Scissors can be used to cut off small polyps and myomas, sometimes for dissecting the thin intrauterine septum and gentle intrauterine synechia. Biopsy forceps allow you to perform a targeted endometrial biopsy, excise polyps of small size or legs of polyps in the area of uterine corners.

Through the operating channel of the hysteroscope, it is also possible to conduct an electrical conductor in an isolated housing for coagulation of the uterine tubes to sterilize. A laser conductor can be conducted through the same channel.

Most often gynecologists use an Nd-YAG laser having a wavelength of 1.064 nm and destroying tissue to a depth of 4-6 mm. The laser is used for ablation of the endometrium, myomectomy, dissection of the intrauterine septum.

Equipment used to expand the uterine cavity

The uterine cavity can be expanded by introducing a liquid or gas.

For the supply of liquid to the uterine cavity, various simple devices as well as complex electronic devices are used.

Fluid into the uterine cavity can be injected with a syringe of Janet. You can place a container (jar or bag) with a liquid at a height of 1 m (74 mm Hg) or 1.5 m (110 mm Hg) above the patient, in which case the liquid enters the uterine cavity under gravity . Another option is to attach a rubber pear or a pressure cuff to the container with a liquid (manual or automatic). In this case, a certain pressure is maintained in the uterine cavity, and excess fluid, washing the cavity, flows through the enlarged cervical canal. These are cheap and affordable methods that provide good image quality.

However, when carrying out long-term intra-uterine operations, in order to avoid serious complications, it is preferable to use different pumps supplying fluid at a certain rate and pressure into the uterine cavity. The most sophisticated in this regard is the complex electronic apparatus endomat.

Endomat is a combined device used for washing and aspiration in both hysteroscopic and laparoscopic surgery. The selection of the appropriate parameters for the installation takes place automatically according to the attached set of tubes. Their display on the monitor allows the surgeon to monitor the flow rate and pressure in the uterine cavity during the intervention. The electronic safety system interrupts the rinsing / aspiration in case of a long deviation of the parameters from the predetermined ones. The use of endomatome in intrauterine operations can significantly reduce the likelihood of complications. The only drawback of this device is its high cost.

Hysteroflator is a complex electronic device necessary for gas supply to the uterine cavity. The gas flow rate is from 0 to 100 ml / min, the pressure in the uterine cavity reaches 100 or 200 mm Hg. (depending on the manufacturer).

Equipment for hysteroscopy

The light source is needed for endoscopy. To improve the quality of work, you need to use very intense light sources. When carrying out diagnostic hysteroscopy, a halogen light source with a power of 150 W is sufficient. But for performing complex operations using a video camera, it is preferable to use a halogen light source with a power of 250 W or a xenon light source with a power of 175-300 watts. The Xenon NOVA Xenon light source ("Karl Storz") is the most ideal. The spectrum of the xenon lamp is close to the spectrum of sunlight, so the quality of photos is the best. Immediately after switching on the lamp, the intensity of the illumination becomes maximum. In addition, the intensity of the light flux in the xenon light source can be automatically controlled by an endoscopic video camera or manually adjusted.

The supply of light from the light source to the endoscope is carried out through flexible fibers of fiber optics, the diameter of the light guides is 3.6 and 4.8 mm.

High-frequency voltage generator. When carrying out electrosurgical operations, a high-frequency voltage generator is required.

Due to the high concentration of electrolytes biological tissues have sufficient electrical conductivity. To cut and coagulate tissues, use an electric current of high frequency. Low frequency current can not be used, as it causes muscle contraction. At a frequency of more than 100 kHz, this effect is negligible. Current generators have a frequency of 475-750 kHz.

When carrying out operations using high-frequency current, the following types of equipment are used:

1. Monopolar operating technique. The electric current goes from the active small electrode to the passive or neutral large electrode. The patient's body is always part of a closed electrical circuit. Cutting of tissue or coagulation occurs on the active electrode.
2. Bipolar operational technique. An electric current passes between two connected electrodes. Depending on the type of surgical procedure (cutting or coagulation), the electrodes are of the same or different size. In this case only a small part of the tissue between the electrodes is included in the electrical circuit.

In operative hysteroscopy, monopolar coagulation is used.

High-frequency surgery is associated with a certain risk to the personnel and the patient (for example, unintentional thermal damage to the tissue). Knowing the possible causes and observing the safety instructions, you can reduce the risk to a minimum.

The most advanced generators of high-frequency voltage are "Autocon-200" and "Autocon-350". There is a function of automatic control and regulation of the depth of the incision and the degree of coagulation, in addition, these apparatuses provide a high degree of safety for the surgeon and the patient.

Camcorder and monitor. Significantly facilitates the work of the surgeon using an endoscopic video camera with a video monitor. The camcorder allows you to record the progress of the research on videotape and to take photographs, which creates an opportunity to demonstrate the procedure to colleagues in the operating room and further training.

The video monitor provides greater magnification, freedom of manipulation, reduces the burden on the surgeon's eyes, allows the doctor to take a comfortable pose. Some types of intrauterine operations are possible only with the use of a video monitor.

In recent years, endovideo cameras have been significantly improved, as a result of their increased resolution and increased photosensitivity. For hysteroscopy, you can use high-quality single-chip video cameras Endovision HYSTEROCAM SL and Endovision TELECAM SL ("Karl Storz"). The most advanced video camera is Endovision TRICAM SL ("Karl Storz") with even greater resolution.

Application of the latest achievements of computer technology allows you to currently perform image correction on the monitor screen during the operation - to detail the structure of the object (DIGIVIDEO), to create a picture in the picture (TWINVIDEO), to rotate the image in various planes and projections ("Karl Storz" ),

Endoscopic cameras and video monitors are produced by various companies, including domestic ones.

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