Alternative technique for Nd : YAG laser coagulation in twin-to-twin transfusion syndrome with anterior placenta
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Nd: YAG laser coagulation is used to treat severe twin-to-twin transfusion syndrome (TTS). Success of the technique depends on visualization of the placenta, the fetal membranes and the targeted vessels, as well as obtaining an optimal inclination angle for laser coagulation. In the rare case of an extensive anterior placenta, it may be difficult to achieve these conditions using the percutaneous approach. Here, we propose an alternative to the percutaneous procedure. Modifications involve an open access and the use of a flexible cannula and bent scope. An extraplacental area, usually at the fundus, is identified by B-mode and color Doppler imaging. A mini-laparotomy is made under general anesthesia. The viscera are retracted and the cannula is inserted under direct view and ultrasound control by the Seldinger technique. The curved fiberscope is passed through the flexible cannula, allowing adequate inspection of the placenta, and target vessels can be coagulated at an angle close to 90 degrees. After the procedure, the uterus is closed primarily to prevent postoperative leakage of amniotic fluid or hemorrhage. This technique has been successfully used in six patients with TTS and a completely anterior placenta, with a gestational age between 18.5 and 22.0 weeks. In all patients, the amniotic cavity was accessed without hemorrhage. The outcomes are similar to those published previously for laser coagulation. The mean interval from intervention until delivery was 10.5 weeks. All 12 fetuses were live born but four died from complications of extreme prematurity. No maternal complications occurred.