Selective Laser Photocoagulation of Communicating Vessels in Severe Twin–twin Transfusion Syndrome in Women With an Anterior Placenta

Comparison between laparoscopically assisted and standard fetoscopic laser ablation in patients with anterior and posterior placentation in twin‐twin transfusion syndrome: a single center study

“…A distribution plot of the laser time showed no evidence of a skewed pattern. The number of anastomoses ablated was not significantly different between the three groups [7 (5-12) in SAP vs 6 (5-11) in LAP and 8 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) in SPP, p = 0.47]. There were no significant differences seen between the three groups in terms of the amount of fluid either removed or infused during the case.…”

“…In TTTS cases treated before 26 weeks of gestation, laser therapy results in higher survival rates and better neurologic outcomes than non-laser therapies, both in the 16 , and modified LAP. 6,12 Failure to adequately visualize the vascular equator on the placental surface significantly impedes the ability to satisfactorily ablate all of the anastomoses that may exist in a TTTS case. 17,18 The more obtuse the angle of incidence of the fetoscope to the placental surface, the less effective the laser energy will be and the more difficult the visualization becomes because of the semi-rigid nature of the fiber optic fetoscopes we use.…”

“…Because of the relative invasiveness of this method and later developments in endoscopy, they no longer advocate this approach. Quintero et al 6 described two techniques for laser treatment in cases of anterior placenta: the use of a flexible endoscope through a single port and the use of a side-firing laser fiber with a rigid angled-view endoscope. The flexible endoscope technique is associated with difficult visualization of areas close to the entry site of the fetoscope and reduced image quality, and the side firing laser technique requires a second port of entry.…”

“…[2][3][4] Ultrasound-directed percutaneous fetoscopic laser photocoagulation of placental anastomoses has become the standard treatment for TTTS diagnosed before 26 weeks of gestation. [5][6][7] The same percutaneous technique has traditionally been used in cases of both anterior and posterior placentation. When the placenta is posterior, a standard approach works well, but in cases where complete anterior placentation without a 'window' exists, clear placental access for the fetoscope and laser fiber may present a real technical challenge.…”

Re: Intra‐amniotic Doppler measurement of blood flow in placental vascular anastomoses in twin–twin transfusion syndrome

“…Finally, patients with anterior placentae were selected in this study. This may be an additional explanation for missed anastomoses, as the same group have previously described the difficulties with visualization in such cases 6 .…”