PRENATAL DIAGNOSIS Prenat Diagn 2010; 30: 482–484. Published online 19 March 2010 in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/pd.2471 RESEARCH LETTER Successful photocoagulation on both sides of inter-twin membrane for twin–twin transfusion syndrome in a case of iatrogenic septostomy after an amnioreduction Efua B. Leke, Ramesha Papanna*, Kenneth J. Moise Jr and Anthony Johnson Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine and the Texas Children’s Fetal Center, Texas Children’s Hospital, Houston, TX, USA KEY WORDS: TTTS; septostomy; laser photocoagulation BACKGROUND Saade et al. (1998) reported that the purposeful punc- ture of the intervening membrane in cases of twin–twin transfusion syndrome (TTTS) could result in the equili- bration of the amniotic fluid in both sacs. These authors proposed that septostomy could be a promising new treatment for TTTS. However, a multicenter randomized trial found that septostomy was associated with a simi- lar rate of perinatal survival as amnioreduction (Moise et al., 2005). Laser ablation of placental anastomoses was subsequently proven to be superior to amniore- duction in both improved perinatal survival as well as prolongation of gestation (Senat et al., 2004). As a result of these trials, iatrogenic septostomy is now rarely indi- cated in the treatment of TTTS (Trevett and Johnson, 2005). Severe polyhydramnios in cases of TTTS results in the displacement of the intervening membrane to the donor side of the placenta. The vascular equator between the twins can then be easily visualized by placing the fetoscope into the recipient twin’s amniotic cavity in order to complete the laser ablation of placental anastomoses. In some cases of amnioreduction, an inadvertent septostomy occurs since the donor sac is collapsed to the uterine wall and is therefore difficult to visualize. This has the potential to complicate a subsequent attempt at laser therapy since the amniotic fluid would be equalized between both twin amniotic cavities (Cooper et al., 2001). We report here a case of TTTS successfully managed by fetoscopic photocoagulation in the setting of an inadvertent septostomy after amnioreduction. A 30-year old female, G2P1-0-0-1 at 22.2 weeks of gestation was referred for persistent TTTS after four successive amnioreductions. Equalization of the amniotic fluid in both the donor and recipient sacs was *Correspondence to: Ramesha Papanna, Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Baylor College of Medicine and the Texas Children’s Fetal Center, Texas Children’s Hospital, 1620 Main Street, Suite #1100, Houston, TX 77030, USA. E-mail: rpapanna@gmail.com noted after the last amnioreduction, but an abnormal venous Doppler changes had appeared in the recipient fetus. Sonographic evaluation at our center revealed a donor fetus with a 10 cm maximum vertical pocket (MVP), no visible bladder and normal Doppler studies. The recipient fetus had a MVP of 8.7 cm, a distended bladder, a reversed a-wave in the ductus venosus and evidence of dilated cardiomyopathy. These findings were consistent with a Quintero stage III-R TTTS. The patient was noted to have a central anterior placenta with no clear vascular-free window for ultrasound-guided percutaneous fetoscopy. After extensive counseling the patient opted to proceed with laser photocoagulation. A laparoscopic-assisted fetoscopic approach was used due to a complete anterior placenta.(Papanna et al., 2010; Middeldorp et al., 2007) Briefly, a laparoscopic port was placed just inferior to the xiphoid process using an open technique. A second port was placed in the midclavicular line using a 5 mm trocar. A blunt device was placed through this port for retraction of the uterus. Using a Seldinger technique, a 12-Fr Teflon cannula (Cook  Medical Inc, Bloomington, IN, USA) loaded with a dilator was introduced through the poste- rior aspect of the uterus into the recipient’s sac under laparoscopic guidance. A 2-mm semi-rigid 0 ◦ fetoscope (Karl Storz GmbH; Tuttlingen, Germany) was then used to map the anastomotic vessels. There were a significant number of vessels crossing to the donor sac which could not be accessed from the recipient cavity. A punctate septostomy was seen in the middle of the interven- ing membrane (Figure 1a). Several attempts were made to advance the fetoscope through this defect, however, these proved unsuccessful due to its small diameter. An attempt to extend the defect using laser coagulation resulted in shrinking of the membrane and a lesser size defect. Subsequently, we passed the laser fiber through the defect and by displacing the fetoscope inferiorly, the defect was extended (Figure 1b). Laser photocoagulation of a total of 11 anastomotic vessels was performed, five sites on the recipient side and six sites on the donor side. The fetoscope was then removed and an amnioreduction performed through the operative cannula. After placing a Copyright  2010 John Wiley & Sons, Ltd. Received: 19 September 2009 Revised: 2 January 2010 Accepted: 5 January 2010 Published online: 19 March 2010