Laser Treatment of Twin-twin Transfusion Syndrome

ABSTRACT

Objective

Laser ablation of all placental vascular anastomoses is the optimal treatment for twin-twin transfusion syndrome (TTTS). This requires proper endoscopic identification of the anastomoses and adequate photocoagulation. However, two important controversies have recently become apparent—(1) a gap between concept and performance and (2) a question as to whether all the anastomoses can indeed be identified endoscopically and therefore, whether blind lasering of healthy placental tissue between anastomoses is justified. The purpose of this paper is to address the potential source of the gap between concept and performance and to discuss the optimal surgical technique.

Materials and methods

Laser surgery for TTTS can be broken down into two fundamental steps—(1) endoscopic identification of the placental vascular anastomoses and (2) laser ablation of the anastomoses. Regarding the endoscopic identification of the laser targets, the nonselective technique is based upon lasering all vessels crossing the dividing membrane, whether anastomotic or not. The selective technique identifies all anastomoses and occludes only such vessels. The Solomon technique involves lasering healthy areas of the placenta between lasered anastomoses, as it assumes that not all anastomoses are endoscopically visible. Regarding the actual laser ablation process, successful achievement of complete surgical ablation (i.e., lasering all the anastomoses) can be measured by how often the selective technique can be performed, by the rate of postoperative persistent or reverse TTTS (PRTTTS) or postoperative twin anemia-polycythemia sequence (TAPS), and by the rate of residual patent placental vascular anastomoses (RPPVAS) on surgical pathology analysis of the placenta. Articles representing the different techniques are discussed.

Results

The nonselective technique is associated with the lowest double survival rate (35%), compared with 60–75% of the Solomon or the Quintero selective techniques. The Solomon technique is associated with a 20% rate of RPPVAS, compared to 3.5–5% for the Quintero selective technique ( p < 0.05). Both the Solomon and the Quintero selective techniques are associated with a 1% risk of PRTTTS. Adequate placental assessment is highest with the Quintero selective technique (99%) compared with the Solomon (80%) or the “Solomon standard” (60%) techniques ( p < 0.05). A surgical performance index is proposed.

Conclusion

The gap between concept and performance responsible for suboptimal clinical results gave rise to the Solomon technique. Unfortunately, The Solomon technique actually represents a historical backward step in the performance of the surgery, given that it is based on assuming that not all of the anastomoses are visible endoscopically. Furthermore, the Solomon technique is associated with a higher rate of residual patent vascular communications than the Quintero selective technique. The Quintero selective technique is associated with the highest rate of successful ablation of placental vascular anastomoses and with the lowest rate of persistent or reverse TTTS. The reported outcomes of the Quintero selective technique do not lend support to the existence of anastomoses beyond those that can be seen endoscopically that would justify lasering healthy placental tissue.

How to cite this article

Quintero RA, Kontopoulos EV, Chmait RH. Laser Treatment of Twin-twin Transfusion Syndrome. Donald School J Ultrasound Obstet Gynecol 2023;17(2):149–157.