Metreurysis

METREURYSIS, a method of artificial, forcible (non-bloodless) delivery (accouchement forcé). The essence of metreurysis consists in introducing a special device into the uterus, which partly by purely mechanical means stretches it, and partly through mechanical irritation elicits active contractions. A metreurynter is an instrument that causes such irritation and stretching of the uterus; in appearance it is almost identical to a colpeurynter, the difference being that a colpeurynter is inserted only into the vagina, whereas a metreurynter is inserted directly into the cervix of the uterus and further into its lower segment. Performing artificial dilation of the cervix has long been one of the responsible obstetric operations, especially considering the high maternal morbidity and significant child mortality that it entails. The first to propose this method of dilation was Braun (1851), but he inserted a rubber balloon filled with water only into the vagina. Madurowicz (1864), in the interests of the fetus, used the balloon once in placenta praevia. Only since 1883 did this method gain recognition, ever since Schauta began to widely use it by introducing the device intrauterine; initially, this metreurynter had the appearance of an hourglass-shaped rubber bag; subsequently, it underwent various modifications, and along with this, the indications for its use expanded more and more. At present, there are three types of these devices: one is the aforementioned but somewhat modified by Fehling, the biscuit-shaped Barnes-Fehling metreurynter; the second is the conical Champetier de Ribes; and the third is the ordinary pear-shaped Braun. Method of application of metreurysis: The instrument is boiled for half a minute in water and cooled; then the vaginal part of the cervix is exposed with specula, wiped with gauze soaked in an antiseptic solution, and fixed with bullet forceps; after which the metreurynter is grasped with special forceps (Metreurynter-Zange) in such a way that its tip protrudes by 1-1¹/₂ cm from the latter, rolled up like a cigar, and carefully advanced past the internal os (during rolling, the air from the tube is of course squeezed out). Before using the instrument, it is imperative to check its integrity; when two-thirds of it are already in the uterus, it is held with the fingers of the left hand, while the forceps are removed with the right; then it is filled with sterile water or sterile saline solution (in case of a possible rupture) and clamped with a tap or clamps. The amount of fluid injected at once should not exceed 300-400 cm³. Subsequently, it is necessary to monitor the onset of labor activity, controlling the metreurynter by gently pulling on its end so as not to miss the moment for adding solution, otherwise the device will come out into the vagina before the necessary dilation of the cervix occurs. Filling the metreurynter must be done slowly, as shock may be observed (arising, according to Meyer, on the basis of excessively rapid stretching of the uterus). For faster dilation of the os, a weight of ¹/₂-1 kg can be suspended from the device, thrown over the foot end of the bed, and then either wait for the spontaneous expulsion of the metreurynter or gradually and carefully pull on it. The load should not exceed the weight of the introduced liquid by more than 100 g; its excess can lead to rupture of the cervix, which is observed in 12% of cases. In rare cases, even a detachment of a part of the cervix occurs without suspending a weight (Selitsky) (see figure). If contractions have significantly increased, the suspended weight should be reduced. The introduction of the metreurynter is possible with a cervical dilation of 1-1¹/₂ fingers; in the absence of dilation, it is necessary to perform preliminary cervical dilation using Hegar dilators. The metreurynter is introduced extra- or intra-amniotically and usually without anesthesia. Uterine contractions caused by the metreurynter probably occur due to mechanical irritation of the nerve ganglia of the cervix. Metreurysis as a method of artificial forcible delivery is used 1) for mechanical dilation of the cervix with delayed opening of it and with early rupture of membranes; 2) for inducing artificial premature labor; 3) in umbilical cord presentation, when it is intended to resort to version, but there is not yet the necessary dilation of the os for this operation; 4) in transverse lie, when the waters have broken with small dilation; 5) for preserving the waters as much as possible and enhancing contractions in premature rupture of the membranes; 6) in placenta previa, especially in district medical work, when a major operation cannot be performed for technical reasons or local conditions; in placenta previa, the metreurynter pursues two goals: it is a mechanical irritant contributing to the opening of the cervical canal, and at the same time it presses on the bleeding surface; 7) for the reduction of an incarcerated gravid uterus; the use of the metreurynter, thanks to its gradual and uniform action, is a gentler measure here than manual reduction. In gynecological diseases, it can be used to correct a retroflexed mobile uterus, as well as to stretch adhesions in a retroflexed fixed uterus; then as a combined abdominal-vaginal method for regulating intra-abdominal pressure, significantly altered after the removal of a very large tumor; this is achieved by placing a certain weight on the abdomen and introducing a balloon weighing 1-1¹/₂ kg, pressed directly against the cervix of the uterus. Such mechanical pressure together with counter-pressure is at the same time a hemostatic agent preventing the formation of a hematoma in cases where inadequate hemostasis is suspected. In general, metreurysis is easily performed and technically uncomplicated, but it has its negative sides, namely: 1) it is not always reliable: in some cases, even with its prolonged use, the effect does not occur, i.e., the cervix does not stretch, and the balloon, even if repeatedly introduced, comes out into the vagina; in others, repeated introduction of larger balloons is required to ensure continuous labor activity, since it often happens that labor activity, which started fairly quickly and moreover strongly, soon ceases, and the balloon turns out to be lying freely in the vagina (therefore it is necessary to have several pieces of various sizes). 2) Metreurysis is more effective in multiparae than in primiparae, which is of course explained by the greater compliance of the uterine cervix in the former. The average duration of its action is about 14 hours (Pobedinsky). 3) Its action varies depending on the amount of fluid introduced: in some cases, insufficient stretching of the entire device is obtained, and in others (with an excess of fluid), its rupture may occur. 4) Metreurysis is not always a reliable hemostatic method, because soft balloons do not press tightly enough against the detached placenta, while hard ones do not come into close contact with the uterine wall, due to which free space remains, and bleeding continues. 5) The percentage of child mortality with the use of the metreurynter according to some authors reaches 40. 6) The percentage of maternal morbidity is also relatively large—up to 12. 7) Due to the prolonged and often unsuccessful stay (sometimes more than 10 hours, and counting repeated introductions, even several days) of the metreurynter in the uterus, not to mention the moment of passing it through the birth canal, the introduction of infection is of course always possible; therefore, to accelerate labor activity, it is sometimes necessary to combine the metreurynter with the administration of pituitrin. 8) In dangerous diseases threatening the life of the patient (severe diseases of the heart, lungs, kidneys) requiring rapid but at the same time gentle delivery (e.g., eclampsia), metreurysis is contraindicated (especially in primiparae; Selitsky).

Circular detachment of the cervix.