Intraoperative myometry relaxation in anesthetic support of intrauterine correction of spina bifida in the fetus via open access

Objective. To improve and optimize a comprehensive approach to anesthetic support and tocolytic therapy following open correction of Spina bifida in the fetus. Material and methods. A prospective randomized comparative study included patients in the second trimester of pregnancy with congenital malformations of central nervous system of the fetus (myelomeningocele, ventriculomegaly, Arnold—Chiari malformation type 2). All patients underwent combined anesthesia (neuroaxial+general anesthesia). In the 1st group, 25% magnesium sulfate solution 16 ml was additionally administered for tocolysis for 15 min before surgery followed by 25% magnesium sulfate solution 4 ml/h throughout surgery. In the 2nd group, atosiban was administered at a rate of 300 μg/min, and nitroglycerin was administered intravenously at a rate of 0.2—0.3 μg/kg/min intraoperatively. Results. Lower dose of inhalation anesthetic in the 2nd group did not increase the frequency of intraoperative myometrial contractions. On the contrary, there was significant difference in registration of increased intraoperative myometrial tone in the 1st group (55% vs. 5%, p<0.001). Lower hemodynamic changes associated with reduced dose of sevoflurane and, consequently, lower doses of norepinephrine administered to maintain stable maternal hemodynamics and uterine perfusion may be additional benefits of avoiding high-dose anesthetic regimen. Conclusion. Intraoperative tocolytic therapy in the 2nd group effectively relaxes myometrium intraoperatively and reduces negative impact of high doses of inhalation anesthetic and sympathomimetic on maternal hemodynamics, uterine-placental blood flow and fetus. The method of multimodal tocolytic therapy reduces the need for high doses of inhalation anesthetics and increases safety of anesthetic support for intrauterine correction of spina bifida in fetus via open access.