Appraisal of the selectivity index in a cohort of patients treated with laser surgery for twin-twin transfusion syndrome.
OBJECTIVE
The selectivity index (SI) has been proposed as a measure of technical success in laser surgery for twin-twin transfusion syndrome. Surgeries with an index >-0.25 have been considered highly selective. The purpose of this study was to evaluate the applicability of this index in our patient population.


METHODS
The SI was assessed in 314 consecutive laser surgeries and correlated with perinatal survival.


RESULTS
A total of 310 patients (98.7%) underwent a completely selective procedure. The SI was 0.8 in the selective laser photocoagulation of communicating vessels group vs 0.3 in the nonselective laser photocoagulation of communicating vessels group (P = .001). In the selective group perinatal survival of at least 1 twin (92.6% vs 50%) and survival of the donor (75.4% vs 0%) was significantly better (P = .05).


CONCLUSIONS
The SI as originally proposed is misleading and of limited use as it does not differentiate selective from nonselective procedures. We propose instead using a ratio of selective/nonselective procedures, and selectively coagulated/total number of coagulated vessels to appraise center-specific and patient-specific surgical performance of laser surgery for twin-twin transfusion syndrome.
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of South Florida, Miami, FL, USA.
Luminita S
LS
Crisan
Eftichia V
EV
Kontopoulos
Rubén A
RA
Quintero
D015331:Cohort Studies; D005260:Female; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D006801:Humans; D017075:Laser Coagulation / Q000379:methods*; D011247:Pregnancy; D014463:Ultrasonography