High-energy CO2 laser radiation may be effectively used in the treatment of the external and internal genitalia. In gynecological surgery, the carbon-dioxide laser may be used at uterine amputation and extirpation, wedge ovariectomy, conservative myomectomy, in endometriosis. The application of carbon-dioxide laser is an aid in lessening the traumatism of an operation, improving hemostasis, enhancing the reliability of sutures, relieving pain sensations, accelerating laser wound healing to form a more delicate cicatrix, in reducing the incidence of complications and the time of recovery (N.M.Pobedinsky, 1992).
Laser use is used at the stages of resection of the uterus during its amputation or extirpation, of resection of a cyst during wedge ovariectomy. It is best to apply continuous laser radiation: 20 W, a 0.5-mm light spot. The resection gives rise to a sterile surface, good hemostasis, without the margins overhanging, which facilitates and accelerates the performance of the following stage: wound surface peritonization.
In conservative myomectomy, CO2 laser radiation is used to cut off myomatous nodes or to vaporize minor subserous nodes. It is wise to apply continuous laser radiation: 20 W, a 0.5-mm light spot. To vaporize minor subserous nodes, it is reasonable to use the pulsed radiation mode: 10 W, a 0.5-mm light spot, a pulse duration of 0.3-0.6 sec, a pause duration of 0.05 sec. Exposure to the laser beam is started with the border of the node, by moving the beam smoothly, resecting or vaporizing the abnormally changed tissues.
In endometriosis, CO2 laser radiation is used to vaporize small endometrioid cysts or to treat the bed of a large cyst after its removal to prevent recurrences. It is best to apply the pulsed laser radiation mode: 5-10 W, a 0.5-mm light spot, a pulse duration of 0.3-0.5 sec, a pause duration of 0.05 sec. The energy density should be at least 1000 J/cm2. The doses are recommended to calculate by Tables 4 and 5. The application of carbon-dioxide laser reduces the time of an operation, facilitates surgical techniques, lessens the bleeding of the wound surface and leads to wound healing to form a more delicate cicatrix without complications.
CO2 laser radiation is effective in treating the diseases of the external genitalia. Pointed condylomas, papillomas, and polyps are excised using the laser beam by the procedure described in item 6.5 (Treatment of wounds). Benign diseases of the cervix uteri, vagina, and vulva are treated by taking into account their nosological entity. CO2 laser radiation in indicated in the following processes: mild, moderate, and severe dysplasias of the cervix uteri; in leukoplasias of the cervix uteri, particularly when the process extends into the vaginal vaults wherein the application of other treatments is difficult; erythroplasias of the cervix uteri; recurrent background diseases (pseudoerosions, ectopias, erosive ectropions) occurring after other treatments; in ineffective conservative and surgical treatments; retention cysts of the cervix uteri and vagina; cicatricial deformity of the cervix uteri; craurosis vulva.
There are no contraindications to treatment with CO2 laser. It is not recommended in inflammations of the adnexa uteri, in discharges of pathogenic and opportunistic microbes in the secretion before antibiotic therapy and infection eradication. The optimum period of CO2 laser radiation is the first phase of a menstrual cycle (days 5-7).
First, the posterior surface of the cervix uteri to the ostium uteri, then the anterior surface, and finally the area of the ostium uteri and the posterior third of the cervical canal of the uterus (the area of a further epithelial joint) should be irradiated. This sequence is due to the decreased risk of hemorrhage at the beginning of an operation. In rare instances when hemorrhage occurs after vaporization of rather large tissues volumes, the operation should be completed by packing of the cervix uteri tightly.
The indications for conization of the vaginal portion of the cervix uteri are moderate and severe dysplasias, ectropion, deformity of the cervix uteri. Depending on the de-gree of an injury, the tissue is removed from 1 to 3 cm high. After treating the genitalia and vagina with antisep-tics, the cervix uteri is exposed in the speculas. After de-fining the required scope of conization, the injured tissues of the cervix uteri are vaporized. It is best to apply the pulsed laser radiation mode: 5-10 W, a 0.5-mm light spot, a pulse duration of 0.1-0.3 sec, a pause duration of 0.05 sec. The energy density adequate for tissue evaporation and co-agulation should be 700-1000 J/cm2.
Exposed to the laser radiation, the cervical surface becomes whitish, coated with a thin film of the coagulated tissues. Long-term exposure may give rise to a carbonized crust which, in this case, easily comes off, which may promote the occurrence of hemorrhage from minor arteries. Here the crust is removed, the cervical surface is drained and exposed to the beam at an energy density of 600-800 J/cm2, i.e. by increasing the diameter of a light spot and the duration of a pulse until a thin coagulation film appears. After the termination of vaporization of pathological tissues, the operation is completed by putting a methyluracil ointment tampon into the defect. If there is bleeding from the large arterial trunks, it is arrested via 3- and 9-o'clock ligation with the uterine arterial branches.
Laser conization of the cervix uteri is ablastic, aseptic, virtually bloodless; hemorrhage is observed rarely; healing generally takes place without complications; stenoses and cicatrices are absent. So laser conization may be employed both in the in- and outpatient settings.
Laser conization in combination with laser vaporization is used to treat leukoplakias, erythroplasias, pseudoerosions of the cervix uteri, retention cysts of the cervix uteri and vagina. It is best to apply the pulsed laser radiation mode: 5-10 W, a 0.5-mm light spot, a pulse duration of 0.1-0.5 sec, a pause duration of 0.1 sec. The most effective vaporization is observed at an energy density of above 1000 J/cm2, yet tissue coagulation being less pronounced, the optimum doses for tissue coagulation are 600-800 J/cm2.
The parameters of laser radiation are individually chosen by Tables 4, 5, and 6. The recommended depth of tissue vaporization is 1-3 mm, the magnitude of removal of abnormally changed tissues is colposcopically controlled; only the ostia of the cervical glands, which are a source of cervical epithelial regeneration are left. If the cervical ostia are preserved, complete epithelization occurs within 21-28 days, their removal prolongs epithelization up to 1.5-2 months.
To treat cervical endometriosis with carbon-dioxide laser is also highly effective. For vaporization and coagulation it is reasonable to use the pulsed laser radiation mode: 5-10 W, a 0.5-mm light spot, a pulse duration of 0.1-0.5 sec, a pause duration of 0.1 sec, an energy density of 600 to 1200 J/cm2. The depth of tissue vaporization is 1.0-4.0 and 1.0-2.0 mm in the cervix uteri and vagina, respectively.
In cicatricial deformities of the cervix uteri, either conization or dissection of the existing commissures and cicatrices is made using laser radiation. For commissural dissection, it is wise to use the pulsed laser radiation mode: 10 W, a 0.2-mm light spot, a pulse duration of 0.3-0.5 sec, a pause duration of 0.05 sec.
Craurosis vulva well responds to CO2 laser treatment. It is best to use pulsed laser radiation: 10 W, a 0.5-1.0-mm light spot, a pulse duration of 0.4-0.6 sec, a pause duration of 0.01 sec. After tissue vaporization at a depth of 1-2.5 mm, the operation is completed with the application of an ointment bandage.
As the cervix uteri exposed to laser radiation heals, the colposcopic picture shows some specific features. After removal of a pathological focus at the boundary of normal tissue, there is an area of a superficial coagulation crust whose depth is no greater than 0.3-0.5 mm. Unlike diathermocoagulation and cryotherapy, this treatment vaporizes the whole abnormal tissue, coagulation necrosis is arranged within the normal tissues. The peculiarity of laser wound healing consists in the reduced phase of exudation, insignificant neutrophilic infiltration, stimulated regeneration and epithelization so the laser wounds of the cervix uteri and vagina heal in the minimum periods of time, providing a good functional result. On days 2-3, the coagulation surface shows a grey film 1 mm thick. The wound surface becomes clean from day 4 and on, there is epithelization from day 8 on. In a fortnight, the areas of marginal and focal epithelization are seen onto the clean wound surface. Epithelization generally comes to a close by days 21 to 28. Epithelization of the cervix uteri brings about a fresh epithelial joint accessible for colposcopic examination. Control examination should be made 1, 2, and 6 weeks after laser radiation.
High-energy CO2 laser radiation of the cervix uteri has a great impact on the me-chanisms of neuroendocrine control. The papers by N.M.Pobedinsky et al. (1990, 1993) indicate that exposure of the cervix uteri to CO2 laser radiation shows 1.5-1.7- and nearly 2-fold increases in the levels of estrogens and progesterone, respectively. This is likely to be associated with the excitation of cervical receptors and the stimulation of the hypothalamic reflex of the cervix uteri. In this connection, the optimum time of surgical intervention is the first phase of a menstrual cycle, i.e. days 5 to 7.
After exposure of the cervix uteri to CO2 laser, restoration of a regular menstrual cycle is observed in many investigations. Due to the normalization of menstrual function and the activation of the hypothalamohypophyseal system, ovulation is also stimulated therefore the likelihood of pregnancy increases. This also exerts a beneficial effect on the central nervous system in the menopausal syndrome. On long-term exposure of the cervix uteri to CO2 laser radiation, there may be not only its local negative effect as a thick carbonized tissue crust, but overirritation of cervical receptors and the hypothalamo-hypophyseal system, which may be followed by menoschesis. From the above reasoning, the duration of exposure of the cervix uteri to laser radiation should be limited to 3 minutes and it is also best to apply the pulsed mode that causes a less thermal damage to the adjacent tissues.
By and large, the use of a carbon-dioxide laser in the surgical treatment of a great deal of gynecological diseases is highly effective and available both in the in- and outpatient settings; this may improve the immediate and late outcomes of treatment.