Fetoscopic laser coagulation for severe twin-to-twin transfusion syndrome: factors influencing perinatal outcome, learning curve of the procedure and lessons for new centres

Fetal and maternal complications after selective fetoscopic laser surgery for twin-to-twin transfusion syndrome: a single-center experience

OBJECTIVE

To report the incidence of fetal and maternal complications after selective fetoscopic laser surgery for twin-to-twin transfusion syndrome (TTTS).

METHODS

A total of 150 cases of TTTS were treated from January 2004 to June 2009 (period 1, 2004-2006, 62 cases; period 2, 2007 to June 2009, 88 cases). Fetal complications (double and single intrauterine fetal death, recurrence of TTTS, twin anemia-polycythemia sequence (TAPS), reversal of TTTS, cerebral lesions in one twin) and maternal complications were recorded, and retrospectively analyzed.

RESULTS

Nineteen (12.6%), 58 (38.7%), 61 (40.7%) and 12 cases (8.0%) were classified preoperatively as Quintero stage I, II, III and IV, respectively. The anterior placenta was described in 73 cases (48.6%). Double and single fetal death occurred overall in 7.3 and 36.0% of cases, respectively. The rate of recurrence was 11.3%, of TAPS 3.3%, and of reversal of TTTS 1.3%. Cerebral lesions were diagnosed in 3 donors (2.0%). Eighteen cases (12.0%) of fetal complications had a second procedure (6 repeat laser, 4 serial amnioreduction, 8 bipolar cord coagulation). Pregnancies undergoing a second procedure delivered at a median gestational age of 30.2 weeks compared to 32.1 weeks for those not repeating (p = 0.04). Perinatal survival of at least one twin improved from 66.1 to 79.5% (p = 0.06) in the two consecutive periods. For every 10 laser surgeries performed, there was an average improvement of 1.5% in the predicted percentage of survival of at least one twin (OR 1.09, 95% CI 1.00-1.19). Major maternal complications occurred in 9 cases (6.0%), 3 of which required admission to intensive care unit.

CONCLUSIONS

Fetal complications are common after fetoscopic laser surgery. In this experience, an increasing number of procedures improved the performance of a new fetoscopic laser center.

Neonatal outcome using ultrathin fetoscope for laser coagulation in twin-to-twin-transfusion syndrome

OBJECTIVE

To improve neonatal outcome using ultrathin fetoscope for laser treatment of twin-to-twin transfusion syndrome.

METHODS

Retrospective cohort study of a series of 80 cases of twin-to-twin-transfusion syndrome prior to 26-weeks' gestation subjected to laser coagulation by means of a 1.0/1.2 mm fiber fetoscope with a sheath sectional area 2.65 mm(2)/3.34 mm(2) (n=27) and a 2.0 mm classic lens fetoscope with a sheath sectional area: 6.63 mm(2)/11.27 mm(2) (n=53).

RESULTS

The survival rates of at least one twin in the compared groups were 94.4% (classic optic) and 100% (ultrathin optic), for both twins: 75.5% and 83.3%, respectively. By decreasing sheath diameter a pregnancy was prolonged by an average of 21.3 days (P=0.0045), with a resulting increase in the recipient's weight of 389 g (P=0.0049) and an increase in the donor's Apgar score. However, the intervention with ultrathin optic took 11 min longer (P=0.031).

CONCLUSION

The reduction of the iatrogenic damage of the amniotic membrane using ultrathin fetoscope with a small sheath, significantly improves the neonatal outcome after laser treatment of twin-to-twin-transfusion syndrome. The operator should only commence working with the 1 mm fetoscope after the learning curve has been accomplished.

Fetal therapy: practical ethical considerations

Progress in prenatal diagnosis can lead to the diagnosis of severe fetal abnormalities for which natural history anticipates a fatal outcome or the development of severe disability despite optimal postnatal care. Intrauterine therapy can be offered in these selected cases. Prenatal diagnosis is the only field of medicine in which termination is an option in the management of severe diseases. Fetal therapy has therefore developed as an alternative to fatalist expectant prenatal management as well as to termination of pregnancy (TOP). There are few standards of fetal care that have gone beyond the stage of equipoise and even fewer have been established based on appropriate studies comparing pre- and postnatal care. Several ethical questions are being raised as fetal surgery develops, including basic Hippocratic principles of patients' autonomy and doctors' duty of competence moving the boundaries between experimental surgery, therapeutic innovation and standard care. In addition, the technical success of a fetal intervention can only rarely fully predict the postnatal outcome. Managing uncertainty regarding long-term morbidity and the possibility for fetal therapy to change the risk of perinatal death into that of severe handicap remains a critical factor affecting women's choice for TOP as an alternative to fetal therapy.

Laser therapy for twin-to-twin transfusion syndrome (TTTS)

Monochorionic twins are subjected to specific complications which originate in either imbalance or abnormality of the single placenta serving two twins including twin-to-twin transfusion syndrome. The diagnosis is well established in overt clinical forms with the association of polyuric polyhydramnios and oliguric oligohydramnios. The best treatment of cases presenting before 26 weeks of gestion is fetoscopic laser ablation of the intertwin anastomoses on the chorionic plate. Although subjected to subtle variations, the core technique follows robust guidelines which could help understanding and acquiring the required skills and experience to perform this procedure. However appropriate and tailored hands-on training and appropriate perinatal set-up are critical not only for surgical management but also for the follow-up and management of related complications.