Randomized Controlled Trial of Twin-Twin Transfusion Syndrome Laser Surgery: The Sequential Trial.

BACKGROUND

Intraoperative blood transfer between twins during laser surgery for twin-twin transfusion syndrome (TTTS) can vary by surgical technique and has been proposed to explain differences in donor twin survival.

OBJECTIVE

This trial compared donor twin survival with 2 laser techniques: the sequential technique, in which the arteriovenous communications from the volume-depleted donor to the volume-overloaded recipient are laser-occluded before those from recipient to donor; and the selective technique, in which the occlusion of the vascular communications is performed in no particular order.

STUDY DESIGN

A single-center, open-label, randomized controlled trial was conducted in which TTTS patients were randomized to sequential versus selective laser surgery. Nested within the trial, a second trial randomized patients with superficial anastomoses (arterioarterial and venovenous) to ablation of these connections first (before ablating the arteriovenous anastomoses) versus last. The primary outcome measure was donor twin survival at birth.

RESULTS

A total of 642 patients were randomized. Overall donor twin survival was similar between the 2 groups (85.6% [274/320] versus 84.2% [271/322], OR 1.12 [0.73-1.73], P=.605). Superficial anastomoses occurred in 27.6% (177/642) of cases. Donor survival was lower in the superficial anastomosis group versus those with only arteriovenous communications (70.6% [125/177] versus 90.3% [420/465], aOR 0.33 [0.20-0.54], P<.001). In cases with superficial anastomoses, donor survival was independent of timing of ablation or surgical technique. The postoperative mean middle cerebral artery (MCA) peak systolic velocity (PSV) was lower in the sequential vs selective group (1.00 ± 0.30 versus 1.06 ± 0.30 MoM, P=.003). Post hoc analyses showed 2 factors that were associated with poor overall donor twin survival: the presence/absence of donor twin preoperative critical abnormal Doppler (CAD) parameters and the presence/absence of arterioarterial anastomoses (AA). Depending on these factors, 4 categories of patients resulted: (1) Category 1 (54%, 347/642), no donor twin CAD + no AA: donor twin survival was 91.2% in the sequential and 93.8% in the selective groups; (2) Category 2 (22%, 143/642), CAD present + no AA: donor survival was 89.9% versus 75.7%; (3) Category 3 (11%, 73/642), no CAD + AA present: donor survival was 94.7% versus 74.3%; and (4) Category 4 (12%, 79/642), CAD present + AA present: donor survival was 47.6% versus 64.9%.

CONCLUSION

Donor twin survival did not differ between the sequential versus selective laser techniques, and did not differ if superficial anastomoses were ablated first versus last. The donor twin's postoperative MCA PSV was improved with the sequential versus the selective approach. Post hoc analyses suggest that donor twin survival may be associated with the choice of laser technique according to high-risk factors. Further study is needed to learn if using these categories to guide the choice of surgical technique will improve outcomes.

TRIAL REGISTRATION

NCT02122328 with no external funding.

Informations de copyright

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