Surgical technique

Twin-Twin Transfusion Syndrome. Surgical technique

The two methods of cord occlusion performed were umbilical cord ligation (UCL) or umbilical cord photocoagulation (UCP). UCL was performed via a 3.5 mm trocar inserted percutaneously into the amniotic cavity via 1–2 mm skin incision under continuous ultrasound guidance and general or local anesthesia. 

The cord of the target fetus was identified endoscopically with a 2.7–3.3 mm diagnostic or operating endoscope (Richard Wolf, Inc., Vernon Hills, IL, USA). A 3-0 Vicryl suture that had been previously threaded through a custom-designed knot-pusher was passed down the working channel of the endoscope with a semi-automatic grasper (Cook Ob/ Gyn, Spencer, IN, USA), or through a second port, and was laid underneath the target umbilical cord. 

The suture was retrieved out of the amniotic cavity after looping it around the cord, where an extracorporeal knot was tied. The knot was delivered back into the amniotic cavity and tightened with the knot-pusher under continuous ultrasound guidance. 

Cessation of blood flow through the umbilical cord was documented by Doppler sonographically. In those cases in which UCL was not feasible, UCP was performed. Once the umbilical cord of the abnormal twin was identified endoscopically, the cord was photocoagulated by using 20–40 watts of YAG laser energy with a 600 ?m fiber through an operating endoscope until cessation of blood flow was documented sonographically.