Impact of Preoperative Cervical Length on Pregnancy Outcome in Twin-Twin Transfusion Syndrome

OBJECTIVE

To evaluate the impact of preoperative cervical length on pregnancy outcome in monochorionic diamniotic twin pregnancies complicated by twin-twin transfusion syndrome that underwent laser surgery or cord occlusion.

MATERIALS AND METHODS

Retrospective study of 330 patients stratified by preoperative cervical length (≥25 mm, 16-24 mm,≤15 mm). Maternal characteristics, operative data, and pregnancy outcomes were compared between the cervical length groups as well as between the subgroups of patients with a cervical length≤15 mm according to management (expectant vs. cerclage).

RESULTS

A preoperative cervical length≥25 mm was observed in 82% (n=271) of cases, 16-24 mm in 9% (n=29), and≤15 mm in 9% (n=30). Patients with a preoperative cervical length≤15 mm showed shorter median procedure-to-delivery interval (5.5 weeks vs. 11.6 (16-24 mm) vs. 13.0 (≥25 mm); p<0.001); lower median gestational age at delivery (29.5 weeks vs. 34.3 (16-24 mm) vs. 33.4 (≥25 mm); p<0.001); higher rate of preterm delivery<32 weeks (78 vs. 20% (16-24 mm) vs. 31% (≥25 mm); p<0.001); and lower neonatal survival rate of at least one twin (70 vs. 88% (16-24 mm) vs. 93% (≥25 mm); p<0.001). Outcome of patients with a preoperative cervical length≤15 mm was similar regardless of management.

CONCLUSION

Monochorionic diamniotic twin pregnancies complicated by twin-twin transfusion syndrome with a preoperative cervical length≤15 mm showed a higher rate of preterm delivery<32 weeks and lower neonatal survival. The role of a cervical cerclage remains unclear.

The heart after surviving twin-to-twin transfusion syndrome

BACKGROUND

The persistent changes in cardiac structure and function in children who survived twin-to-twin transfusion syndrome remain a matter of concern and controversy. Current fetal echocardiographic parameters and their postnatal evolution can help improve our understanding of the subject.

OBJECTIVE

To describe the echocardiographic changes of monochorionic fetuses affected by twin-to-twin transfusion syndrome, the recipient and the donor, before and after laser photocoagulation and to determine their evolution in the third trimester and during their first year of life.

STUDY DESIGN

An observational study was conducted including 55 uncomplicated monochorionic diamniotic twins and 78 pairs with twin-to-twin transfusion syndrome, 44 stage I-II and 34 stage III-IV, prospectively enrolled from 2015 until 2018. Comprehensive echocardiography was performed at 4 time periods: before laser photocoagulation, at 24 to 72 hours after surgery, at 28 to 30 weeks of gestation, and at 6 to 12 months after birth. Echocardiographic parameters were transformed to z-scores or indexed for heart area, estimated fetal weight, or body mass surface.

RESULTS

At diagnosis, recipients in all stages presented larger hearts (cardiothoracic ratio z-score: 2.77 [0.8] vs controls: -0.03 [0.5]; P<.001) and signs of ventricular hypertrophy (left end-diastolic ventricle wall thickness: 2.68 [0.7] vs controls -0.03 [0.7]; P<.001), along with systolic (cardiac index recipients: 317 [114] mL/min/kg vs controls: 400 [120] mL/min/kg, P<.001) and diastolic impairment (isovolumetric relaxation time z-score: 2.76 [0.6] vs controls: 0.05 [0.6]; P<.001). Donors presented smaller ventricular areas and diameters when compared with controls (left end-diastolic ventricle area z-score: -1.48 [1] vs 0.03 [0.9]; P<.001), along with decreased longitudinal motion (tricuspid annular plane systolic excursion z-score: -0.9 [1] vs controls -0.04 [1]; P<.001) and shorter ejection time z-score (-1.5 [0.7] vs controls: 0.0 [0.7]; P<.001). After surgery, an improvement in functional parameters was observed in both fetuses, whereas most morphometric changes prevailed in donors and recipients in the prenatal period. Postnatally, cardiac remodeling persisted in recipients (left relative wall thickness: 0.34 [0.02] vs controls: 0.30 [0.02]; P<.001), whereas donors mainly presented a decreased longitudinal motion in infancy (tricuspid annular plane systolic excursion z-score: -0.72 [0.7] vs controls: 0.23 [0.9]; P<.05).

CONCLUSION

Cardiac remodeling is present in both fetuses at the twin-to-twin transfusion syndrome diagnosis, whereas diastolic dysfunction is only significant in the recipient. Fetal therapy improves most echocardiographic parameters, although postnatally, the echocardiographic changes persist in both fetuses.

Risk Factors Associated with Preterm Prelabor Rupture of Membranes after Cord Occlusion in Monochorionic Diamniotic Twins

INTRODUCTION

Preterm prelabor rupture of membranes (PPROM) is a common complication after fetal surgeries. The aim of this study was to assess risk factors for and outcomes after PPROM following cord occlusion (CO) in monochorionic diamniotic (MCDA) pregnancies.

METHODS

This was a retrospective cohort study of 188 consecutive MCDA pregnancies treated by bipolar or laser CO, either primarily because of discordant malformation (dMF) or severe selective fetal growth restriction (sFGR), or secondarily when complete bichorionization was not possible in case of twin-to-twin transfusion syndrome (TTTS) or sFGR. Intentional septostomy was performed when needed. The procedure-related PPROM was defined as rupture of membranes <32 weeks' gestation (PROM <32 weeks). Selected pre-, intra-, and early postoperative variables were analyzed by univariate and binomial logistic regression to determine they are correlated to PROM <32 weeks after CO.

RESULTS

Between 2006 and 2017, 188 cases underwent CO. Diagnosis was TTTS in 28.2% (n = 53), severe sFGR in 49.5% (n = 93), and dMF in 22.3% (n = 42). PROM <32 weeks occurred in 21.3% (n = 40), resulting in worse perinatal outcomes, as preterm birth <32 weeks occurred in 80.7% (vs. 8.3%, p = 0.000), procedure-to-delivery interval was 47.5 days (vs. 125, p = 0.000), gestational age (GA) at birth 30.0 weeks (vs. 37.7 weeks, p = 0.000), and survival 65.0% (vs. 91.1%, p = 0.000). In univariate analysis, indication, anterior placenta, cervical length, GA at surgery, operation time, amniodistention and drainage fluid volumes, chorioamniotic membrane separation, and septostomy were selected as relevant factors to be included in the regression model. In a multivariate analysis, TTTS was the only factor associated to PROM <32 weeks (OR 3.5 CI 95% 1.5-7.9).

CONCLUSIONS

PROM <32 weeks after CO increases the risk of preterm delivery. In this cohort, the membrane rupture was more likely when CO was done in the context of TTTS.

Ex-vivo mechanical sealing properties and toxicity of a bioadhesive patch as sealing system for fetal membrane iatrogenic defects

Preterm prelabor rupture of membranes (PPROM) is the most frequent complication of fetal surgery. Strategies to seal the membrane defect created by fetoscopy aiming to reduce the occurrence of PPROM have been attempted with little success. The objective of this study was to evaluate the ex-vivo mechanical sealing properties and toxicity of four different bioadhesives integrated in semi-rigid patches for fetal membranes. We performed and ex-vivo study using term human fetal membranes to compare the four integrated patches composed of silicone or silicone-polyurethane combined with dopaminated-hyaluronic acid or hydroxypropyl methylcellulose (HPMC). For mechanical sealing properties, membranes were mounted in a multiaxial inflation device with saline, perforated and sealed with the 4 combinations. We measured bursting pressure and maximum pressure free of leakage (n = 8). For toxicity, an organ culture of membranes sealed with the patches was used to measure pyknotic index (PI) and lactate dehydrogenase (LDH) concentration (n = 5). All bioadhesives achieved appropriate bursting pressures, but only HPMC forms achieved high maximum pressures free of leakage. Concerning toxicity, bioadhesives showed low PI and LDH levels, suggesting no cell toxicity. We conclude that a semi-rigid patch coated with HPMC achieved ex-vivo sealing of iatrogenic defects in fetal membranes with no signs of cell toxicity. These results warrant further research addressing long-term adhesiveness and feasibility as a sealing system for fetoscopy.

[Informatics in cardiology: proposal for standardized terminology in clinical records and in permanent cardiac electrostimulation]

To make operative two medical computerized programs, one dedicated to the cardiological clinical record (PAC) and the other to permanent cardiac stimulation (PGP), we codified about 4000 terms concerning the general medical field and particularly the cardiological area. The importance of standardization of the medico-cardiological language is emphasized, specially in relation to the systematization of the information, necessary to work with computerized systems.

[Clinical electrophysiological evaluation of mexiletine]

We studied sixteen patients (pts), seven men and nine women (mean age 35 years) with sustained tachyarrhythmias, for acute therapeutic trial with mexiletine (3 mg/kg IV). The arrhythmias were: ventricular tachyarrhythmia in eight pts supra-ventricular tachycardia (SVT) in eight pts, seven due to abnormal tracts (43%) and one to nodal reentry. After mexiletine administration, the sinusal cycle length was reduced in 12.7% (P less than 0.05) and the H-V interval decreased 6.1% (P less than 0.05). The nodal conduction (A-H) didn't show any substantial change, neither the atrial nor the ventricular refractory periods (RP). In two pts with complex premature ventricular beats it was not possible to induce the ventricular tachycardia(VT) six had sustained VT. After mexiletine administration, three of them (37.5%) showed self limited VT with a greater R-R cycle. Another case was complicated by ventricular fibrillation, In the pts with SVT, the retrograde RP of the abnormal tracts shortened in 27% (P less than 0.05), while the antegrade was not modified. Mexiletine showed to be efficient for the VT treatment. Its efficacy was very limited in pts with SVT. There was no evidence of any deleterious effect over the His-Purkinje conduction.

Meteorological influences on myocardial infarction in the metropolitan area of Milan

We attempted to relate admission rate for acute myocardial infarction with some meteorological variables in a region having a temperate climate. We used 2830 consecutive episodes collected over a 2-year (1979-1980) period. The temperatures, atmospheric pressure, relative humidity, front passage, rain and snow and foehn wind have been associated in the past with acute myocardial infarction. No significant association with any of them was found in our study, nor any correlation over the time between admission rates in six different Coronary Care Units (at the time the only ones active in the area) which participated in the study.

[Comparative evaluation of mexiletine and propafenone by dynamic electrocardiography]

We have compared the efficacy of Propafenon and Mexiletine in 12 subjects (7 males and 5 females, age range of 22-61 year) affected by chronic ventricular extrasystolic beats. Propafenon and Mexiletine were orally administered in doses of 900 mg/day and 600 mg/day respectively in a single blind, cross-over fashion. Our results show that: Propafenon is better tolerated; Propafenon has caused a statistically significant reduction of the total number of ventricular ectopic beats/24 hours; the efficacy of Propafenon has been greater than that of Mexiletine (66% and 25% respectively); with both drugs, in 2 cases, there was an increase of the total number of ventricular ectopic beats/24 hours; Propafenon has induced clear-cut electrocardiogram changes (statistically significant lengthening of P-Q and Q-T intervals).