OC116: Trocar‐assisted selective laser photocoagulation of communicating vessels

Abstract

Objectives: Selective laser photocoagulation of communicating vessels (SLPCV) for twin–twin transfusion syndrome (TTTS) in patients with an anterior (ANT) placenta is known to be technically more challenging than in patients with posterior (POST) placentas. We describe a new trocar-assisted (TA) technique to address this issue. Methods: Four surgical techniques were used for SLPCV in ANT placentas: standard, rigid scope; flexible scope; side-firing, twoport; and TA, whereby the anastomoses were lasered from within the trocar sheath after identification with an angled diagnostic endoscope. The protocol was approved by the Institutional Review Board and all patients signed informed consent. Results: SLPCV was performed in 269 patients from February 2003 to May 2005, of which 88 (47.6%) had ANT placentas. Only 7/88 (7.9%) patients with ANT placentas were treated with a flexible scope or a two-port technique and neither of these techniques was used after November 2003. Perinatal survival was independent of placental location (89.7% vs. 85.2%, POST vs. ANT placentas) or ANT placenta techniques. Gestational age at delivery (median 33.1 (range, 17.6–39.4) weeks), and incidence of premature rupture of membranes within 21 days of surgery, was no different between techniques in patients with ANT. However, operating time was significantly less in the TA group (P < 0.05). In 50/88 patients with ANT placentas available for analysis, only one had patent anastomoses in the TA group (2.9%), compared to none in the other techniques (P = 0.7). Conclusions: Laser treatment of TTTS patients with an ANT placenta that requires more than a simple rigid endoscope can be effectively achieved with a TA technique. TA allows orthogonalization of the angle of fire, eliminating the need for a two-port or flexible endoscope technique. TA is also useful in exposing the entire vessel wall in patients with POST placentas with a tangential angle of entry.