Laparoscopy-assisted fetoscopy for laser surgery in twin-twin transfusion syndrome with anterior placentation

Development and validation of a flexible fetoscope for fetoscopic laser coagulation

PURPOSE

Fetoscopic laser coagulation for twin-to-twin transfusion syndrome is challenging for anterior placenta due to the rigidity of current tools. The capacity to keep entry port forces minimal is critical for this procedure, as is optimal coagulation distance and orientation. This work introduces technological tools to this end.

METHODS

A novel fetoscope is presented with a rigid shaft and a flexible steerable segment at the distal end. The steerable segment can bend up to 90[Formula: see text] even when loaded with a laser fiber. An artificial pneumatic muscle makes such acute bending possible while allowing for a low-weight and disposable device.

RESULTS

The flexible fetoscope was validated in a custom-made phantom model to measure visual range and coagulation efficacy. The flexible fetoscope shows promising results when compared to a clinical rigid curved fetoscope to reach anterior targets. The new fetoscope was then evaluated in vivo (pregnant ewe) where it successfully coagulated placental vasculature.

CONCLUSION

The flexible fetoscope improved the ability to achieve optimal coagulation angle and distance on anteriorly located targets. The fetoscope also showed the potential to lead fetoscopic laser coagulation and other fetal surgical procedures toward safer and more effective interventions.

Anesthesia for fetal operative procedures: A systematic review

Objective

The anesthetic management of fetal operative procedures (FOP) is a highly debated topic. Literature on fetal pain perception and response to external stimuli is rapidly expanding. Nonetheless, there is no consensus on the fetal consciousness nor on the instruments to measure pain levels. As a result, no guidelines or clinical recommendations on anesthesia modality during FOP are available. This systematic literature review aimed to collect the available knowledge on the most common fetal interventions, and summarize the reported outcomes for each anesthetic approach. Additional aim was to provide an overall evaluation of the most commonly used anesthetic agents.

Methods

Two systematic literature searches were performed in Embase, Medline, Web of Science Core Collection and Cochrane Central Register of Controlled Trials up to December 2021. To best cover the available evidence, one literature search was mostly focused on fetal surgical procedures; while anesthesia during FOP was the main target for the second search. The following fetal procedures were included: fetal transfusion, laser ablation of placental anastomosis, twin-reversed arterial perfusion treatment, fetoscopic endoluminal tracheal occlusion, thoraco-amniotic shunt, vesico-amniotic shunt, myelomeningocele repair, resection of sacrococcygeal teratoma, ligation of amniotic bands, balloon valvuloplasty/septoplasty, ex-utero intrapartum treatment, and ovarian cyst resection/aspiration. Yielded articles were screened against the same inclusion criteria. Studies reporting anesthesia details and procedures’ outcomes were considered. Descriptive statistical analysis was performed and findings were reported in a narrative manner.

Results

The literature searches yielded 1,679 articles, with 429 being selected for full-text evaluation. A total of 168 articles were included. Overall, no significant differences were found among procedures performed under maternal anesthesia or maternal-fetal anesthesia. Procedures requiring invasive fetal manipulation resulted to be more effective when performed under maternal anesthesia only. Based on the available data, a wide range of anesthetic agents are currently deployed and no consistency has been found neither between centers nor procedures.

Conclusions

This systematic review shows great variance in the anesthetic management during FOP. Further studies, systematically reporting intraoperative fetal monitoring and fetal hormonal responses to external stimuli, are necessary to identify the best anesthetic approach. Additional investigations on pain pathways and fetal pain perception are advisable.

Single fetal demise following fetoscopic ablation for twin-to-twin transfusion syndrome-cohort study, systematic review, and meta-analysis

BACKGROUND

Several studies have assessed preoperative and operative factors associated with fetal demise after laser for TTTS, yet these findings are not completely conclusive.

OBJECTIVE

This study aimed to identify risk factors for single fetal demise (recipient and donor twins) after fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome.

STUDY DESIGN

We searched PubMed, Scopus, and Web of Science systematically from the inception of the database to June 2020. We conducted a systemic review on studies investigating risk factors for fetal demise (donor and/or recipient) after fetoscopic laser photocoagulation in monochorionic pregnancies complicated with twin-to-twin transfusion syndrome. Initially, we investigated the cohort of women with twin-to-twin transfusion syndrome that underwent fetoscopic laser photocoagulation at our 2 high-volume fetal centers between 2012 and 2020 to identify risk factors for donor demise and recipient demise. Furthermore, we conducted a systematic review of the literature to better characterize these factors. Among studies that met the entry criteria, multiple preoperative and operative factors were tabulated. The random-effect model was used to pool the standardized mean differences or odds ratios and corresponding 95% confidence intervals. Heterogeneity was assessed using the I² value.

RESULTS

A total of 514 pregnancies with twin-to-twin transfusion syndrome managed with fetoscopic laser photocoagulation were included in the final analysis. Following the logistic regression, factors that remained significant for donor demise were selective fetal growth restriction (odds ratio, 1.9; 95% confidence interval, 1.3-2.8; P=.001) and umbilical artery blood flow with absent or reversed end-diastolic velocity of the donor (odds ratio, 2.06; 95% confidence interval, 1.2-3.4; P=.004). A significant factor associated with recipient demise was absent or reversed a-wave in the ductus venosus of the recipient (odds ratio, 1.74; 95% confidence interval, 1.07-3.13; P=.04). Data from 23 studies and our current cohort were included. A total of 4892 pregnancies with twin-to-twin transfusion syndrome managed with fetoscopic laser photocoagulation were analyzed for risk factors for donor demise, and 4594 pregnancies with twin-to-twin transfusion syndrome were analyzed for recipient demise. Among studies, the overall incidence rates ranged from 10.9% to 35.8% for donor demise and 7.3% to 24.5% for recipient demise. Significant risk factors for donor demise were intertwin estimated fetal weight discordance of >25% (odds ratio, 1.86; 95% confidence interval, 1.44-2.4; I², 0.0%), selective fetal growth restriction (odds ratio, 1.78; 95% confidence interval, 1.4-2.27; I², 0.0%), twin-to-twin transfusion syndrome stage III (odds ratio, 2.18; 95% confidence interval, 1.53-3.12; I², 0.0%), umbilical artery blood flow with absent or reversed end-diastolic velocity of the donor (odds ratio, 2.31; 95% confidence interval, 1.9-2.8; I², 23.7%), absent or reversed a-wave in the ductus venosus of the donor (odds ratio, 1.83; 95% confidence interval, 1.45-2.3; I², 0.0%), and presence of arterioarterial anastomoses (odds ratio, 2.81; 95% confidence interval, 1.35-5.85; I², 90.7%). Sequential selective coagulation was protective against donor demise (odds ratio, 0.31; 95% confidence interval, 0.16-0.58; I², 0.0%). Significant risk factors for recipient demise were twin-to-twin transfusion syndrome stage IV (odds ratio, 2.18; 95% confidence interval, 1.01-4.6; I², 16.5%), umbilical artery blood flow with absent or reversed end-diastolic velocity of the recipient (odds ratio, 2.68; 95% confidence interval, 1.91-3.74; I², 0.0%), absent or reversed a-wave in the ductus venosus of the recipient (odds ratio, 2.37; 95% confidence interval, 1.55-3.64; I², 60.2%), and middle cerebral artery peak systolic velocity of >1.5 multiple of the median (odds ratio, 3.06; 95% confidence interval, 1.36-6.88; I², 0.0%).

CONCLUSION

Abnormal blood flow patterns represented by abnormal Doppler studies and low fetal weight were associated with single fetal demise in women with twin-to-twin transfusion syndrome undergoing laser therapy. Although sequential selective coagulation was protective against donor demise, the presence of arterioarterial anastomoses was considerably associated with donor demise. This meta-analysis extensively investigated the association of a wide range of preoperative and operative factors with fetal demise. These findings may be important inpatient counseling, in further understanding the disease, and perhaps in improving surgical techniques.

Understanding Sociodemographic Disparities in Maternal-Fetal Surgery Study Participation

BACKGROUND/PURPOSE

Although maternal-fetal surgery to treat fetal anomalies such as spina bifida continues to grow more common, potential health disparities in the field remain relatively unexamined. To address this gap, we identified maternal-fetal surgery studies with the highest level of evidence and analyzed the reporting of participant sociodemographic characteristics and representation of racial and ethnic groups.

METHODS

We conducted a systematic review of the scientific literature using biomedical databases. We selected randomized control trials (RCTs) and cohort studies with comparison groups published in English from 1990 to May 5, 2020. We included studies from across the globe that examined the efficacy of fetal surgery for twin-twin transfusion syndrome (TTTS), obstructive uropathy, congenital diaphragmatic hernia (CDH), myelomeningocele (MMC), thoracic lesions, cardiac malformations, or sacrococcygeal teratoma. We determined the frequency of reporting of age, gravidity/parity, race, ethnicity, education level, language spoken, insurance, income level, and relationship status. We identified whether sociodemographic factors were used as inclusion or exclusion criteria. We calculated the racial and ethnic group representation for studies in the USA using the participation-to-prevalence ratio (PPR).

RESULTS

We included 112 studies (10 RCTs, 102 cohort) published from 1990-1999 (8%), 2000-2009 (30%), and 2010-2020 (62%). Most studies were conducted in the USA (47%) or Europe (38%). The median sample size was 58. TTTS was the most common disease group (37% of studies), followed by MMC (23%), and CDH (21%). The most frequently reported sociodemographic variables were maternal age (33%) and gravidity/parity (20%). Race and/or ethnicity was only reported in 12% of studies. Less than 10% of studies reported any other sociodemographic variables. Sociodemographic variables were used as exclusion criteria in 13% of studies. Among studies conducted in the USA, White persons were consistently overrepresented relative to their prevalence in the US disease populations (PPR 1.32-2.11), while Black or African-American, Hispanic or Latino, Asian, American-Indian or Alaska-Native, and Native-Hawaiian or other Pacific Islander persons were consistently underrepresented (PPR 0-0.60).

CONCLUSIONS

Sociodemographic reporting quality in maternal-fetal surgery studies is poor and inhibits examination of potential health disparities. Participants enrolled in studies in the USA do not adequately represent the racial and ethnic diversity of the population across disease groups.

Interventions to prevent preterm delivery in women with short cervix before fetoscopic laser surgery for twin-twin transfusion syndrome

OBJECTIVE

Preoperative short cervical length (CL) remains a major risk factor for preterm birth after laser surgery for twin-twin transfusion syndrome (TTTS), but the optimal intervention to prolong pregnancy remains elusive. The objective of this study was to compare secondary methods for the prevention of preterm birth in twin pregnancies with TTTS undergoing fetoscopic laser photocoagulation (FLP), in the setting of a short cervix at the time of FLP, in five North American Fetal Treatment Network (NAFTNet) centers.

METHODS

This was a secondary analysis of data collected prospectively at five NAFTNet centers, conducted from January 2013 to March 2020. Inclusion criteria were a monochorionic diamniotic twin pregnancy complicated by TTTS, undergoing FLP, with preoperative CL < 30 mm. Management options for a short cervix included expectant management, vaginal progesterone, pessary (Arabin, incontinence or Bioteque cup), cervical cerclage or a combination of two or more treatments. Patients were not included if the intervention was initiated solely on the basis of having a twin gestation rather than at the diagnosis of a short cervix. Demographics, ultrasound characteristics, operative data and outcomes were compared. The primary outcome was FLP-to-delivery interval. Propensity-score matching was performed, with each treatment group matched (1:1) to the expectant-management group for CL, in order to estimate the effect of each treatment on the FLP-to-delivery interval.

RESULTS

A total of 255 women with a twin pregnancy complicated by TTTS and a short cervix undergoing FLP were included in the study. Of these, 151 (59%) were managed expectantly, 32 (13%) had vaginal progesterone only, 21 (8%) had pessary only, 21 (8%) had cervical cerclage only and 30 (12%) had a combination of treatments. A greater proportion of patients in the combined-treatment group had had a prior preterm birth compared with those in the expectant-management group (33% vs 9%; P = 0.01). Mean preoperative CL was shorter in the pessary, cervical-cerclage and combined-treatment groups (14-16 mm) than in the expectant-management and vaginal-progesterone groups (22 mm for both) (P < 0.001). There was no significant difference in FLP-to-delivery interval between the groups, nor in gestational age at delivery or the rate of live birth or neonatal survival. Vaginal progesterone was associated with a decrease in the risk of delivery before 28 weeks' gestation compared with cervical cerclage and combined treatment (P = 0.03). Using propensity-score matching for CL, cervical cerclage was associated with a reduction in FLP-to-delivery interval of 13 days, as compared with expectant management.

CONCLUSIONS

A large proportion of pregnancies with TTTS and a short maternal cervix undergoing FLP were managed expectantly for a short cervix, establishing a high (62%) risk of delivery before 32 weeks in this condition. No treatment that significantly improved outcome was identified; however, there were significant differences in potential confounders and there were also likely to be unmeasured confounders. Cervical cerclage should not be offered as a secondary prevention for preterm birth in twin pregnancies with TTTS and a short cervix undergoing FLP. A large randomized controlled trial is urgently needed to determine the effects of treatments for the prevention of preterm birth in these pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Outcomes of laparoscopy-assisted fetoscopic laser photocoagulation for twin-twin transfusion syndrome: An established alternative for inaccessible anterior placenta

OBJECTIVE

To evaluate laparoscopy-assisted fetoscopic laser photocoagulation (FLPC) of placental anastomoses in the treatment of twin-to-twin-transfusion syndrome (TTTS).

STUDY DESIGN

We performed a retrospective cohort study analyzing pregnancies complicated by TTTS who underwent FLPC in a single university-affiliated tertiary medical-center. Outcomes were compared between patients who received laparoscopy-assisted FLPC (study group) and patients who underwent the conventional FLPC technique (control group). Baseline characteristics, sonographic findings, procedure details, and neonatal outcomes were compared between groups.

RESULTS

The cohort included 278 women with 31 in the study group and 247 in the control group. Sonographic parameters, including fetal biometry and TTTS stage, were comparable between study groups. Gestational age at delivery did not differ between the groups (29.22 ± 4.55 weeks in the study group vs. 30.62 ± 4.3 weeks in the control group, p = 0.09). There were no differences in neonatal survival rates at birth and at 30 days between both groups. A subanalysis comparing the laparoscopy-assisted group to only those patients with anterior placenta in the control group, showed a lower rate of incomplete Solomonization in the laparoscopy-assisted study group (3.4% vs. 33%, p = 0.01).

CONCLUSION

Laparoscopy-assisted FLPC is a reasonable and safe option that may be offered in cases of FLPC where an anterior placenta restricts adequate surgical access.

Early laser surgery is not associated with very preterm delivery or reduced neonatal survival in TTTS

OBJECTIVE

To evaluate the association of laser photocoagulation of placental anastomoses (LPA) prior to 18 weeks' gestation (early LPA) with very preterm delivery and neonatal survival in pregnancies with twin-twin transfusion syndrome (TTTS).

METHODS

This was a retrospective cohort study of monochorionic diamniotic twin pregnancies with TTTS undergoing LPA between 2002 and 2018 at two institutions. The rates of delivery < 28, < 30 and < 32 weeks' gestation, preterm prelabor rupture of membranes (PPROM) and 30-day survival of one or both infants were compared between pregnancies undergoing early LPA and those undergoing LPA ≥ 18 weeks' gestation. Regression analysis was performed to determine the association of early LPA with very preterm delivery and 30-day survival, adjusted for Quintero stage, study phase, selective fetal growth restriction, gestational age at delivery, maternal age ≥ 35 years, body mass index > 35 kg/m² , placental location, use of Seldinger method to place the operative trocar, size of the trocar, participating center, use of Solomon technique, cerclage and PPROM. Survival analysis using the Cox proportional hazard model was applied to examine the LPA-to-delivery interval according to the timing of surgery, adjusted for confounding variables.

RESULTS

A total of 414 TTTS pregnancies were included in the study, of which 68 (16.4%) underwent early LPA. In the total cohort, the incidence of delivery at < 28, < 30 and < 32 weeks' gestation was 22.7%, 39.6% and 53.4%, respectively. Survival of both twins and survival of at least one twin at 30 days were 67.5% and 90.8%, respectively. No significant difference was noted between pregnancies that underwent early LPA and those that had LPA ≥ 18 weeks in the rate of delivery < 28 weeks (19.1% vs 23.4%; P = 0.4), < 30 weeks (38.2% vs 39.9%; P = 0.8) and < 32 weeks (44.1% vs 55.2%; P = 0.1) and PPROM (29.0% vs 24.1%; P = 0.4), or in the incidence of double-twin survival (63.9% vs 68.1%; P = 0.5) and survival of at least one infant (91.8% vs 90.6%; P = 0.7) at 30 days. Early LPA was not associated with very preterm delivery or neonatal survival in the regression analyses. Early LPA was associated with a longer LPA-to-delivery interval compared with LPA performed ≥ 18 weeks (median, 106.9 days (range, 2-164 days) vs median, 69.3 days (range, 0-146 days); P < 0.001) when adjusted for confounding variables (hazard ratio, 2.56 (95% CI, 1.76-3.73); P < 0.001).

CONCLUSION

Laser surgery before 18 weeks is not associated with an increased rate of very preterm delivery and PPROM or with reduced neonatal survival when compared with LPA after 18 weeks. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Perioperative Care of Patients Diagnosed With Twin-to-Twin Transfusion Syndrome Undergoing Laparoscopic-Assisted Fetoscopic Placental Laser Photocoagulation

Twin-to-twin transfusion syndrome (TTTS) is a condition that results in unbalanced blood flow between two fetuses. Patients diagnosed with TTTS can experience maternal or fetal morbidity and mortality. Depending on the severity of TTTS, laser ablation of placental anastomoses may be the most effective treatment. The preferred treatment method requires percutaneous entry to the uterus; however, some patient circumstances (eg, placenta location) require a laparoscopic-assisted procedure. During the preoperative appointments, clinicians assess the condition of the fetuses and patients may participate in genetic counseling. Intraoperative care involves an interdisciplinary team that may include a pediatric general surgeon, maternal-fetal medicine specialists, an RN circulator, a scrub person, and an anesthesia professional. Perioperative nurses should have knowledge of the pathophysiology of TTTS, including its natural progression. They also should understand preoperative and intraoperative patient care requirements to provide safe and effective care for patients undergoing laparoscopic-assisted fetoscopic placental laser photocoagulation procedures.

Distance Traveled to a Fetal Center and Pregnancy Outcomes in Twin-Twin Transfusion Syndrome

BACKGROUND

Fetoscopic laser photocoagulation (FLP) is the definitive treatment for twin-twin transfusion syndrome (TTTS). Due to variability in geographic proximity to high-volume fetal centers, many patients travel great distances to receive experienced care. We sought to determine whether distance traveled (DT) is associated with gestational age (GA) at delivery and neonatal survival.

METHODS

A prospective cohort study of patients within the continental United States referred to our center between September 23, 2011 and July 25, 2018 undergoing planned FLP for TTTS (n = 393; GA 20.6 ± 2.5 weeks; stage I: n = 50; stage II: n = 118; stage III: n = 208; stage IV: n = 17) was performed. The great-circle distance to our center was calculated using patients' home zip codes. DT was stratified into groups containing equal patient numbers and pregnancy outcomes assessed.

RESULTS

A total of 393 patients met the inclusion criteria. The threshold distance from our center was <250 miles (n = 181), 250-499 miles (n= 119), and ≥500 miles (n = 93). There was no significant difference between any of the preoperative variables among the three groups, with the exception of race and rural status. Furthermore, there was no significant association between DT and GA at delivery (p = 0.34), time interval from procedure to delivery (p = 0.37), and the number of neonatal survivors (p= 0.21). Preterm premature rupture of membranes (PPROM) at <34 weeks was highest (47.9%, p = 0.04) in the group traveling 250-499 miles.

CONCLUSION

To our knowledge, this is the largest study to show that in TTTS, DT is not associated with GA at delivery, time interval from procedure to delivery, or neonatal survival. Although PPROM at <34 weeks was higher in the group traveling 250-499 miles, there was no significant difference in GA at delivery. While patients with advanced disease may choose to seek treatment based on proximity, traveling long distances does not adversely affect pregnancy outcomes.

Maternal complications following open and fetoscopic fetal surgery: A systematic review and meta-analysis

OBJECTIVE

To establish maternal complication rates for fetoscopic or open fetal surgery.

METHODS

We conducted a systematic literature review for studies of fetoscopic or open fetal surgery performed since 1990, recording maternal complications during fetal surgery, the remainder of pregnancy, delivery, and after the index pregnancy.

RESULTS

One hundred sixty-six studies were included, reporting outcomes for open fetal (n = 1193 patients) and fetoscopic surgery (n = 9403 patients). No maternal deaths were reported. The risk of any maternal complication in the index pregnancy was 20.9% (95%CI, 15.22-27.13) for open fetal and 6.2% (95%CI, 4.93-7.49) for fetoscopic surgery. For severe maternal complications (grades III to V Clavien-Dindo classification of surgical complications), the risk was 4.5% (95% CI 3.24-5.98) for open fetal and 1.7% (95% CI, 1.19-2.20) for fetoscopic surgery. In subsequent pregnancies, open fetal surgery increased the risk of preterm birth but not uterine dehiscence or rupture. Nearly one quarter of reviewed studies (n = 175, 23.3%) was excluded for failing to report the presence or absence of maternal complications.

CONCLUSIONS

Maternal complications occur in 6.2% fetoscopic and 20.9% open fetal surgeries, with serious maternal complications in 1.7% fetoscopic and 4.5% open procedures. Reporting of maternal complications is variable. To properly quantify maternal risks, outcomes should be reported consistently across all fetal surgery studies.

Impact of cannula size on recurrent twin-twin transfusion syndrome and twin anemia-polycythemia sequence after fetoscopic laser surgery

OBJECTIVE

The optimal outcome after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) depends on the successful ablation of all placental anastomoses. The objective of this study was to determine the incidence of and risk factors for recurrent TTTS (rTTTS) or twin anemia-polycythemia sequence (TAPS) after FLS, focusing on the impact of cannula diameter.

METHODS

This was a secondary analysis of data collected prospectively at two centers from 666 consecutive patients undergoing FLS for TTTS. The main outcomes were rTTTS and TAPS following FLS. Variables assessed included gestational age at intervention, stage of disease, recipient maximum vertical pocket, anterior placenta, number of anastomoses ablated, cannula diameter/operative scopes and use of the Solomon technique. Cannula diameter and corresponding scopes used were as follows: 8 Fr and 1.3 mm/0°; 9 Fr and 2.7 mm/0°; 10 Fr and 3 mm/0°; or 12 Fr and 3.3-3.7 mm/30-70°. Cannula diameter was used as a surrogate for scopes during analysis. Multivariate logistic regression analysis was performed to identify risk factors associated with rTTTS or TAPS after FLS; 'center' was considered an independent variable to account for variations in practice. In a nested cohort of pregnancies in which both fetuses survived, placental dye injection was performed in 315 placentae. Multivariate logistic regression analysis was performed to evaluate variables associated with the presence of residual anastomoses.

RESULTS

rTTTS or TAPS occurred in 61 (9%) cases following FLS (rTTTS in eight (1%) and TAPS in 53 (8%)). Factors associated significantly with the risk of rTTTS/TAPS on multivariate analysis were cannula diameter (when an 8-Fr, 9-Fr, 10-Fr or 12-Fr cannula was used, there was rTTTS/TAPS in 24%, 13%, 2% or 0.8% of cases, respectively (P < 0.001)) and use of the Solomon technique (rTTTS/TAPS occurred in 4.2% of those in which it was used vs 18.1% in those in which it was not (P < 0.001)). Only use of the Solomon technique was associated significantly with no residual anastomoses found after delivery.

CONCLUSIONS

Following FLS for TTTS, a lower incidence of rTTTS/TAPS was seen when the Solomon technique was used, as well as when a 10-Fr or 12-Fr cannula was used. A lower complication rate may be due to the use of a scope with better optics during placental mapping. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Perinatal outcomes of single fetal survivor after fetal intervention for complicated monochorionic twins

OBJECTIVE

To compare perinatal outcomes between acute single fetal demise following fetoscopic laser photocoagulation to planned selective reduction (SR) in complicated monochorionic twin pregnancies.

METHODS

This was a secondary analysis of prospectively collected data in complicated monochorionic twin pregnancies from 2 fetal centers from 2011 to 2016. Group 1 included women undergoing fetoscopic laser photocoagulation for twin-twin transfusion syndrome (TTTS) who experienced a single fetal demise within 24 hours of the procedure. Group 2 consisted of women undergoing planned selective reduction (SR) with TTTS, and Group 3 SR for indications other than TTTS.

RESULTS

Survival of the remaining co-twin at birth was highest in Group 1 (n = 77 patients; 95%) compared with that in Group 2 (n = 15; 80%) and Group 3 (n = 32; 78%; P = .047). The preterm premature rupture of membrane rate was higher in Group 1 (47%) compared with that in Group 2 (33%) and Group 3 (7%; P < .001). Group 1 had a lower gestational age at delivery and shorter procedure-to-delivery interval compared with the other 2 groups (P < .01).

CONCLUSION

When single fetal demise occurs following fetoscopic laser photocoagulation, the surviving co-twin is more likely to survive to delivery but has higher PPROM rates and a shorter latency period compared with planned selective reduction for TTTS or other indications.

Preterm prelabor rupture of membranes after fetoscopic laser surgery for twin-twin transfusion syndrome

OBJECTIVE

To assess the incidence, clinical course, risk factors and outcomes of preterm prelabor rupture of membranes (PPROM) after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS).

METHODS

This was a prospective observational cohort study of 154 consecutive cases of TTTS. PPROM was defined as rupture of membranes before 34 weeks' gestation. Procedure-to-PPROM and PPROM-to-delivery intervals were determined. Relevant preoperative and intraoperative variables were analyzed by univariate and multivariate logistic regression to determine their impact on PPROM after FLS.

RESULTS

The incidence of PPROM was 39% (n = 60), occurring at a mean gestational age of 27.2 ± 4.6 weeks. Median procedure-to-PPROM interval was 46 (range, 1-105; interquartile range (IQR), 13-66) days and median PPROM-to-delivery interval was 1 (range, 0-93; IQR, 0-13) day. Mean gestational age at delivery in cases with PPROM was 29.0 ± 4.5 weeks compared with 32.6 ± 3.9 weeks in cases without PPROM (P < 0.0001). Insertion of a collagen plug was the only significant factor found on both univariate and multivariate analysis to be associated with an increased rate of PPROM (odds ratio, 3.1 (95% CI, 1.2-8.0); P = 0.006). There was no statistically significant difference in fetal (P = 0.07) or neonatal (P = 0.08) survival between those with and those without PPROM.

CONCLUSIONS

PPROM after FLS increases prematurity by 3.6 weeks. The latency period after PPROM was 2 weeks; 50% of patients delivered within 24 h. No variable thought to be associated with PPROM after FLS was found to be significantly associated with this complication. Other etiologies and mechanisms for PPROM after FLS should be explored. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Preterm delivery after fetoscopic laser surgery for twin-twin transfusion syndrome: etiology and risk factors

OBJECTIVE

Preterm delivery after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) is a major complication. The causative factors leading to preterm delivery continue to be elusive and a better understanding of the risk factors could reduce complications. The objective of this study was to determine the etiology of preterm delivery after FLS for TTTS and its associated risk factors.

METHODS

This was a secondary analysis of a prospective study of 203 patients with TTTS who underwent FLS at a single center between September 2011 and December 2014. Preoperative, operative, postoperative, delivery and neonatal data were reviewed. Preterm delivery was categorized according to etiology into three groups: spontaneous (SPT), indicated (IND) and elective (ELC). Comparisons between groups were performed by ANOVA. Kaplan-Meier survival analysis was performed to compare the procedure-to-delivery interval between groups. To identify risk factors for preterm delivery, logistic regression, with calculation of relative risks (RR), was performed, with P < 0.05 considered statistically significant.

RESULTS

Mean gestational age at time of FLS was 20.6 ± 2.4 weeks and mean gestational age at delivery was 30.9 ± 4.7 weeks. Iatrogenic preterm prelabor rupture of membranes (iPPROM) occurred in 39% of cases. SPT preterm delivery occurred in 97 (48%) patients, IND preterm delivery in 65 (32%) and ELC preterm delivery in 41 (20%). In the IND group, 30 (46%) patients delivered for fetal indications, 31 (48%) for maternal indications and four (6%) for combined fetal and maternal indications. The overall chorioamnionitis rate was 6.4%; of these, nine (9%) were in the SPT group and four (6%) were in the IND group, with no case occurring in the ELC group. There was a significant difference in procedure-to-delivery interval between groups (P < 0.0001). Using variables from the ELC group as a baseline, significant risk factors for SPT preterm delivery were iPPROM (RR, 16.2 (95% CI, 4.5-57.7)), preoperative cervical length (RR, 0.96 (95% CI, 0.92-0.998)) and number of anastomoses (RR, 1.14 (95% CI, 1.02-1.27)). Significant risk factors for IND preterm delivery were iPPROM (RR, 9.6 (95% CI, 2.6-35.0)) and number of ablated anastomoses (RR, 1.13 (95% CI, 1.02-1.30)).

CONCLUSION

iPPROM and an increased number of ablated placental anastomoses were associated independently with SPT and IND preterm deliveries. A shorter preoperative cervical length was associated with SPT preterm delivery. Strategies to prevent iPPROM and for management of cervical length shortening are needed urgently in these pregnancies. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Comparison between laparoscopically assisted and standard fetoscopic laser ablation in patients with anterior and posterior placentation in twin-twin transfusion syndrome: a single center study

BACKGROUND

The objective of our study was to compare outcomes following laparoscopically assisted procedure (LAP group) with those seen following a standard approach used in patients with either an anterior placenta (SAP group) or posterior placenta (SPP group).

METHOD

This was a retrospective review of all the cases of twin-twin transfusion syndrome treated in our fetal center from October 2011 to July 2013. Technical characteristics of the procedure, perinatal survival outcome, and maternal morbidity were compared.

RESULTS

The laser procedure time was significantly longer in the SAP group (44 ± 10 min) in contrast with SPP (19.3 ± 13.9 min, p < 0.001) and LAP group (32 ± 11 min, p: 0.012). Preterm premature rupture of membranes (PPROM) before 32 and 34 weeks of pregnancy was significantly more common with LAP versus SAP and SPP (90 vs 33.3 and 70.8% for 32 weeks respectively, p: 0.015; 100 vs 50 and 79.1% for 34 weeks respectively, p: 0.021). In terms of maternal morbidity and neonatal outcome, there were no significant differences between the three groups.

CONCLUSION

LAP may be useful in cases where SAP is not feasible. Despite the increased risk of PPROM with LAP, perinatal survival and maternal outcomes are similar to that seen in SAP and SPP patients.

Risk factors associated with preterm delivery after fetoscopic laser ablation for twin-twin transfusion syndrome

OBJECTIVE

Despite improved perinatal survival following fetoscopic laser ablation (FLA) for twin-twin transfusion syndrome (TTTS), prematurity remains an important contributor to perinatal mortality and morbidity. The objective of the study was to identify risk factors for complicated preterm delivery after FLA.

METHODS

Retrospective cohort study of prospectively collected data on maternal/fetal demographics and pre-operative, operative and postoperative variables of 459 patients treated with FLA in three USA fetal centers. Multivariate linear regression was performed to identify significant risk factors associated with preterm delivery, which were cross-validated using the k-fold method. Multivariate logistic regression was performed to identify risk factors for early compared with late preterm delivery based on median gestational age at delivery of 32 weeks.

RESULTS

There were significant differences in case selection and outcomes between the centers. After controlling for the center of surgery, multivariate analysis indicated that a lower maternal age at procedure, a history of previous prematurity, shortened cervical length, use of amnioinfusion, a cannula diameter of 12 French (Fr), lack of a collagen plug placement and iatrogenic preterm premature rupture of membranes (iPPROM) were significantly associated with a lower gestational age at delivery.

CONCLUSIONS

Specific fetal/maternal and operative variables are associated with preterm delivery after FLA for the treatment of TTTS. Further studies to modify some of these variables may decrease the perinatal morbidity after laser therapy.

Fetal membrane patch and biomimetic adhesive coacervates as a sealant for fetoscopic defects

Iatrogenic preterm premature rupture of membranes after fetoscopic procedures affects 10-47% of patients, secondary to the non-healing nature of membranes and the separation of layers during the entry. In this study we developed an in vitro model to mimic the uterine wall-fetal membrane interface using a water column with one end sealed with human fetal membranes and poultry breast, and a defect was created with an 11 French trocar. Further, a fetal membrane patch in conjunction with multiphase adhesive coacervates modeled after the sandcastle worm bioadhesive was tested for sealing of an iatrogenic defect. The sealant withstood an additional traction of 12 g for 30-60 min and turbulence of the water column without leakage of fluid or slippage. The adhesive is non-toxic when in direct contact with human fetal membranes in an organ culture setting. A fetal membrane patch with multiphase adhesive complex coacervates may help to seal the defect and prevent iatrogenic preterm premature rupture of the membranes.

Use of the Learning Curve-Cumulative Summation test for quantitative and individualized assessment of competency of a surgical procedure in obstetrics and gynecology: fetoscopic laser ablation as a model

OBJECTIVE

We sought to determine the learning curve (LC) for fetoscopic laser photocoagulation (FLP) as a model for the evaluation of training in surgical procedures.

STUDY DESIGN

A retrospective review of consecutive case series of FLP from 2 centers with 3 operators (operator I [O-I], observer trained; operator II [O-II], hands-on trained; and operator III [O-III], clinical fellow) was performed and the LC-cumulative summation (CUSUM) test was plotted.

RESULTS

The acceptable and unacceptable success rates for at least 1 fetus survival after FLP were set at 82% and 70%, respectively, from a systematic review. A total of 171 consecutive cases were performed by the 3 operators (O-I, 91; O-II, 49; and O-III, 31). From LC-CUSUM test O-I needed 60 procedures, O-II needed 20 procedures, and O-III needed 20 procedures to reach an acceptable performance rate for at least 1 survivor.

CONCLUSION

The LC-CUSUM test can be used to accurately assess the LC in a surgical procedure in obstetrics and gynecology. Hands-on trained operators exhibit a shorter LC.