Prediction of dual survival following fetoscopic laser photocoagulation for twin-twin transfusion syndrome

OBJECTIVE

To develop a model based on factors available at the time of diagnosis of twin-twin transfusion syndrome (TTTS) for predicting the probability of dual twin survival following fetoscopic laser photocoagulation (FLP) using a machine-learning algorithm.

METHODS

This was a retrospective study of data collected at two university-affiliated tertiary fetal centers between 2012 and 2021. The cohort included monochorionic diamniotic twin pregnancies complicated by TTTS that underwent FLP. Data were stratified based on survival 30 days after delivery, and cases with dual survival were compared to those without dual survival. A random forest machine-learning algorithm was used to construct a prediction model, and the relative importance value was calculated for each parameter that presented a statistically significant difference between the two study groups and was included in the model. The holdout method was applied to check overfitting of the random forest algorithm. A prediction model for dual twin survival 30 days after delivery was presented based on the test set.

RESULTS

The study included 537 women with monochorionic diamniotic twin pregnancy, of whom 346 (64.4%) had dual twin survival at 30 days after delivery and were compared with 191 (35.6%) cases that had one or no survivors. Univariate analysis demonstrated no differences in demographic parameters between the groups. At the time of diagnosis, the dual-survival group had lower rates of estimated fetal weight (EFW) < 10th centile for gestational age in the donor twin (56.4% vs 69.4%; P = 0.004), intertwin EFW discordance > 25% (40.8% vs 56.5%; P = 0.001) and anterior placenta (40.5% vs 50.0%; P = 0.034). Comparison of Doppler findings between the two groups demonstrated significant differences in the donor twin, with a lower rate of pulsatility index (PI) > 95th centile in the umbilical artery and ductus venosus and a lower rate of PI < 5th centile in the fetal middle cerebral artery in the dual-survival group. Relative importance values for each of these six parameters were calculated, allowing the construction of a prediction model with an area under the receiver-operating-characteristics curve of 0.916 (95% CI, 0.887-0.946).

CONCLUSIONS

We developed a predictive model for dual survival in monochorionic twin pregnancies following FLP for TTTS, which incorporates six variables obtained at the time of diagnosis of TTTS, including donor EFW < 10th centile, intertwin EFW discordance > 25%, anterior placenta and abnormal PI in the umbilical artery, ductus venosus and middle cerebral artery of the donor twin. This clinically applicable tool may improve treatment planning and patient counseling. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Iatrogenic chorioamniotic separation and septostomy following fetoscopic laser photocoagulation for twin-twin transfusion syndrome

OBJECTIVE

To compare the perinatal outcomes of pregnancies complicated by chorioamniotic separation (CAS) vs septostomy following fetoscopic laser photocoagulation (FLP) for twin-twin transfusion syndrome (TTTS).

METHODS

This was a retrospective cohort analysis of monochorionic diamniotic twin pregnancies with TTTS that underwent FLP at one of two university-affiliated tertiary medical centers between January 2012 and December 2020. CAS and septostomy were diagnosed either during the procedure or by ultrasonography within 24-48 h after FLP. Data on procedure and postprocedure parameters, pregnancy outcomes and survival were collected from the patients' electronic medical records. Pregnancies were stratified according to the presence of CAS, septostomy or neither. Patients diagnosed with both CAS and septostomy were analyzed separately.

RESULTS

Of the 522 women included in the cohort, 38 (7.3%) were diagnosed with CAS, 68 (13.0%) with septostomy and 23 (4.4%) with both CAS and septostomy. The remaining 393 (75.3%) women comprised the control group. Groups did not differ in demographic characteristics. The septostomy group had a lower rate of selective fetal growth restriction than did the CAS and control groups (24.2% vs 36.8% vs 42.7%, respectively; P = 0.017). Moreover, intertwin size discordance was lower in the septostomy group (15.1% vs 23.4% in the CAS group and 25.5% in the control group; P = 0.001). Median gestational age at FLP was significantly lower in the CAS group (19.3 weeks vs 20.4 weeks in controls and 20.9 weeks in the septostomy group; P = 0.049). The rate of delivery prior to 34 weeks was significantly higher in the CAS group (89.2%), followed by the septostomy group (80.9%), compared with the control group (69.0%) (P = 0.006). A secondary analysis demonstrated that patients with both CAS and septostomy presented the highest rates of delivery prior to 34 weeks (100%) and 32 weeks (68.2%).

CONCLUSIONS

CAS and septostomy following laser surgery for TTTS are independently associated with higher rates of preterm delivery. The presence of these two findings in the same patient enhances the risk of prematurity. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

The clinical value of the delta finger to palm distance in systemic sclerosis

Systemic sclerosis (SSc) is a collagen-vascular disorder characterized by fibrosis and vasculopathy. Delta finger to palm distance (delta FTP) is an index measuring the distance between the tip of the third finger to the distal palmar crease in the flexed and extended position. The present study aimed to evaluate the clinical value of delta FTP and to assess the correlation of delta FTP with modified Rodnan skin score (mRSS) and forced vital capacity (FVC) over the 12-month follow-up. This prospective longitudinal study began with 50 participants who were followed for twelve months. Lowess smoothing and linear regression were applied to detect and assess the relationship between delta FTP and mRSS. p-values were adjusted by the Benjamini-Hochberg method (BHM) as a control for false discovery rate. Delta FTP was lower among patients with higher disease duration (p-valueadj: 0.008), diffuse cutaneous SSc (p-valueadj: 0.006), digital ulcers (p-valueadj: 0.003), telangiectasia (p-valueadj: 0.006) and dysphagia (p-valueadj: 0.036). The mRSS has a significant negative linear effect on the delta FTP at the baseline and the end of the follow-up (r: -0.31 and -0.40, respectively). Moreover, changes of mRSS and delta FTP showed a negative linear association over time (r: -0.22). These linear effects remained significant after regrouping the patients based on their SSc subtype. Delta FTP and FVC were not correlated either at the baseline or at the end. It seems that the delta FTP can be a valuable clinical index, supported by its correlated changes with mRSS and other SSc clinical manifestations over the one-year follow-up.

Eligibility assessment for intravenous thrombolytic therapy in acute ischemic stroke patients; evaluating barriers for implementation

Background:

Intravenous thrombolysis is an approved treatment method for patients with acute ischemic stroke (AIS) and is recommended by multiple guidelines. However, it seems that it is less frequently used in the developing countries compared to the developed countries.

Objectives:

The purpose of this study was to estimate the percentage of patients with AIS, eligible for intravenous thrombolytic therapy, at the main referral center in Northwest Iran and to determine the main barriers for implementation of this method.

Patients and Methods:

Over one year, 647 patients who were admitted to the emergency department and met the Cincinnati Stroke Scale were enrolled into the study. The center to which patients were admitted, is a tertiary university hospital that has the required infrastructure for thrombolytic therapy in AIS. Factors recorded were neurological examinations and time between onset of symptoms and hospital arrival, hospital arrival and performance of brain computed tomography (CT) scanning, and hospital arrival to complete the investigations. Patients eligible for intravenous thrombolytic therapy were identified according to the American Heart Association (AHA) guidelines.

Results:

Mean time interval between hospital arrival and completion of brain CT scanning was 91 minutes (range: 20–378 minutes) and mean time from hospital arrival to completion of investigations was 150 minutes (range: 30–540 minutes). A total of 159 (31.3%) patients arrived at hospital within 3 hours of the onset of symptoms (early enough for intravenous thrombolytic therapy). However, 81.7% (130/159) of these patients missed thrombolytic therapy due to delayed performance of brain CT scanning and laboratory tests and 38.3% (61/159) had contraindications. The remaining 16 patients (10% of those who arrived within 3 hours and 3.1% of all cases) were eligible for thrombolytic therapy.

Conclusions:

The major barriers for thrombolytic therapy for patients with AIS in this setting were delays in the provision of in-hospital services, like initial patient assessment, CT scans or laboratory studies. These results were in contrast with previous reports.