Incidence and impact of perioperative complications in 175 fetoscopy-guided laser coagulations of chorionic plate anastomoses in fetofetal transfusion syndrome before 26 weeks of gestation

Anchoring device to prevent membrane detachment and preterm prelabor rupture of membranes after fetal intervention

OBJECTIVE

To assess the feasibility of using a novel device designed for minimally invasive suturing to anchor fetal membranes to the uterine wall and to close surgical defects after fetoscopy.

METHODS

We tested the WestStitch™ suturing device both ex vivo and in vivo. In the ex-vivo studies, 12-Fr trocar defects were created with a fetoscope in five specimens of human uterine tissue with fetal membranes attached. Specimens were examined for integrity of the anchoring stitch. For the in-vivo studies, trocar defects were created in the two uterine horns of three pregnant ewes, each carrying twins at approximately 79-90 days' gestation. One trocar defect in each ewe was repaired using the suture device, and the other was left unrepaired as a control. The repair sites were examined for membrane-anchoring integrity when the defect was created and at delivery.

RESULTS

Fetal membranes were anchored successfully to the uterine myometrium using the suture-delivery device in all five experiments performed ex vivo. The in-vivo experiments also revealed successful membrane anchoring compared with controls, both at the time of device deployment and 1-9 weeks after the procedure.

CONCLUSIONS

We successfully anchored amniotic membranes to the underlying myometrium using a suturing device, both ex vivo and in vivo. Further studies are needed to evaluate the efficacy of the device and to determine whether it can successfully anchor fetal membranes percutaneously in human patients. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Prevention of preterm birth in twin-to-twin transfusion syndrome: a systematic review and network meta-analysis

OBJECTIVES

We aimed to perform a systematic review and network meta-analysis to evaluate the preventive strategies for preterm birth in twin-to-twin transfusion syndrome.

METHODS

PubMed, Embase and Cochrane Central were searched from inception to December 2023 with no filters. Additionally, the reference lists of the included studies were manually examined to identify any supplementary studies. We selected randomized controlled trials and cohorts comparing interventions to prevent preterm birth in twin pregnancies complicated by twin-to-twin transfusion syndrome. A random-effects frequentist network meta-analysis was performed using RStudio version 4.3.1. Randomized controlled trials and cohorts were assessed respectively using the Risk of Bias in Non-randomized Studies of interventions tool and Cochrane Collaboration's tool for assessing risk of bias in randomized trials.

RESULTS

In this systematic review and meta-analysis, we included eight studies comprising a total of 719 patients. Compared with expectant management, cerclage stood out as the only intervention associated with an increase in the survival of at least one twin (risk ratio 1.12; 95 % confidence interval 1.01-1.23). Our subgroup analysis based on different thresholds for short cervix demonstrated a significant reduction in the risk of preterm birth before 32 weeks with ultrasound-indicated cerclage using a 15 mm criterion (risk ratio 0.65; 95 % confidence interval 0.47-0.92).

CONCLUSIONS

Our study suggests the potential benefit of cerclage as a preventive strategy for preterm birth in pregnancies complicated by twin-to-twin transfusion syndrome. These findings highlight the necessity for further investigation to corroborate our results and address the optimal threshold for ultrasound-indicated cerclage.

Fetoscopic Laser Ablation of Type II Vasa Previa: A Cost Benefit Analysis

OBJECTIVE

We aimed to compare costs of two strategies for third-trimester type II vasa previa management: (1) fetoscopic laser ablation surgery (FLS) referral and (2) standard management (SM).

STUDY DESIGN

A decision analytic model and cost-benefit analysis from a health care perspective were performed. The population included patients with type II vasa previa at approximately 32 weeks. SM entailed 32-week antepartum admission and cesarean at approximately 35 weeks. FLS referral included consultation and possible laser surgery at 32 weeks for willing/eligible candidates. Successful laser surgery allowed the possibility of term vaginal delivery. Outcomes included antepartum admission, preterm birth, cesarean, neonatal transfusion, and death. Sensitivity analyses were performed.

RESULTS

In base case analysis, FLS referral was cost saving compared with SM (total cost per patient $65,717.10 vs. 71,628.16). FLS referrals yielded fewer antepartum admissions, cesareans, premature births, neonatal transfusions, and deaths. Eligible referred patients choosing FLS incurred a total cost of $41,702.46, a >40% decrease compared with SM. FLS referral was cost saving in all one-way sensitivity analyses except when antepartum admission costs were low. In threshold analyses, FLS referral was cost saving unless laser surgery cost was >$39,892 (2.75x expected cost), antepartum admission cost for monitoring of vasa previa or ruptured membranes was <$7,455, <11% patients were eligible for laser surgery, and when <12% of eligible patients chose laser surgery. In two-way sensitivity analysis, FLS referral was cost saving except at very high laser surgery costs and extremely low antepartum admission costs.

CONCLUSION

Referral for FLS for type II vasa previa was cost saving and improved outcomes compared with SM, despite upfront costs, fetoscopy-related risks, and many patients being ineligible or not opting for surgery after referral.

KEY POINTS

· Vasa previa rupture may lead to fetal exsanguination and death.. · Late preterm cesarean is common practice for prenatally diagnosed vasa previa.. · Successful fetoscopic laser ablation for type II vasa previa has been described.. · Laser ablation of vasa previa allows for a safe-term vaginal delivery.. · Referral for laser surgery is cost saving and is associated with improved outcomes..

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.

Twin-twin transfusion syndrome and the definition of recipient polyhydramnios

BACKGROUND

Controversy exists regarding the threshold of recipient twin polyhydramnios required to diagnose twin-twin transfusion syndrome at a gestational age of ≥20 weeks. One criterion set (Quintero staging) requires the amniotic fluid maximum vertical pocket for the recipient twin to measure ≥8 cm, whereas another (European) system uses a maximum vertical pocket for the recipient twin of ≥10 cm.

OBJECTIVE

This study aimed to characterize the patients with twin-twin transfusion syndrome who were treated with laser surgery and would be excluded from laser surgery according to the European criteria.

STUDY DESIGN

A total of 366 monochorionic diamniotic twins diagnosed with twin-twin transfusion syndrome from 20 to 26 weeks' gestation who underwent laser surgery at our center were studied. A maximum vertical pocket for the recipient twin of ≥8 cm was used to diagnose twin-twin transfusion syndrome. Patients were retrospectively divided into the following 2 groups: group A with a maximum vertical pocket for the recipient twin of ≥8 cm and <10 cm and group B with a maximum vertical pocket for the recipient twin of ≥10 cm. The association of each of the groups with the survivorship outcomes was tested. Bivariate associations between the patient characteristics and the 30-day donor twin and dual survivorship outcomes were evaluated. Tests used in the analysis were chi-square or Fisher exact tests as appropriate for categorical variables and Kruskal-Wallis tests for continuous variables. Multiple logistic regression models for each of the survivorship outcomes were then assessed. The results are reported as mean±standard deviation.

RESULTS

Of the 366 studied patients, 53 (14.5%) had a maximum vertical pocket for the recipient twin of ≥8 and <10 cm (group A) and 313 (85.5%) had a maximum vertical pocket for the recipient twin of ≥10 cm (group B). Groups A and B did not differ in the Quintero stage. Notably, 60.4% (32 of 53) of group A patients were stage III or IV. When compared with group B, group A was diagnosed with twin-twin transfusion syndrome at an earlier gestational age (21.7±1.6 vs 22.3±1.6 weeks; P=.0037) and had a higher prevalence of donor growth restriction (81.1% [43 of 53] vs 65.5% [205 of 313]; P=.0260). Rates of at least 1 twin and dual twin survival between group A and B were similar (98.1% [52 of 53] vs 95.8% [300 of 313]; P=.7023, and 79.2% [42 of 53] vs 83.4% [261 of 313]; P=.4369, respectively). Logistic regression models adjusted for perioperative characteristics showed no difference in the outcomes between the groups (group B as reference) (donor twin survival odds ratio, 0.64; 95% confidence interval, 0.29-1.42; P=.2753; and dual survivor odds ratio, 0.90; 95% confidence interval, 0.42-1.91; P=.7757).

CONCLUSION

Restriction of the definition of twin-twin transfusion syndrome to a maximum vertical pocket for the recipient of ≥10 cm beyond 20 weeks gestational age would potentially exclude 14.5% of patients from laser surgery, the majority of whom had advanced stage twin-twin transfusion syndrome. A unifying criterion of a maximum vertical pocket for the recipient of ≥8 cm regardless of gestational age would allow inclusion of these patients and access to surgical management.

The Future of Fetal Surgery

The field of fetal medicine has evolved significantly over the past several decades. Our ability to identify and treat the unborn patient has been shaped by advancements in imaging technology, genetic diagnosis, an improved understanding of fetal physiology, and the development and optimization of in utero surgical techniques. The future of the field will be shaped by medical innovators pushing for the continued refinement of minimally invasive surgical technique, the application of pioneering technologies such as robotic surgery and in utero stem cell and gene therapies, and the development of innovative ex utero fetal support systems.

Dual demise following laser surgery for twin-twin transfusion syndrome: Analysis of 52 cases at a single fetal surgery center

OBJECTIVE

To evaluate all individual cases of dual twin demise following laser surgery for twin-twin transfusion syndrome (TTTS).

METHOD

This is an analysis of all monochorionic diamniotic twin gestations with TTTS complicated by dual demise following laser surgery from 2006 to 2019. Cases were reviewed by (1) a fetal surgeon researcher and (2) a panel of independent experienced maternal-fetal medicine specialists to code an etiology of demise for the donor and recipient, and to assess for possible preventability.

RESULTS

Of 753 twins that underwent laser surgery for TTTS, 52 (6.9%) had postoperative dual demise. In this subgroup, gestational age at surgery was 19.5 (16.1-24.9) weeks, and 36 (69.2%) patients were Quintero stage III and IV. The most common etiology was the spectrum of disorders leading to preterm delivery, which included cervical insufficiency, preterm premature rupture of membranes, and preterm labor (44.2% and 48.1%, donor and recipient, respectively). Some degree of preventability was estimated for 23.1% of dual demises.

CONCLUSIONS

The most common cause of dual demise post laser surgery for TTTS was preterm birth, reinforcing the need for studies regarding the etiology and prevention of post-fetoscopy prematurity. Nearly one-quarter of dual demise cases were deemed potentially preventable.

Flexible fetoscope in the treatment of twin-to-twin transfusion syndrome

BACKGROUND

Twin-to-twin transfusion syndrome (TTTS) could be treated with fetoscopic laser photocoagulation. For patients with placenta located on the anterior wall of uterus, surgical procedures are difficult. To solve this problem, a flexible fetoscope was designed in our department.

METHODS

The flexible fetoscope was made up of polyurethane, fiberglass and stainless steel coils. The specular body was soft and could bend encountering obstacles, which reduced the possibility of injury to the fetus and placenta. The distal tip of the body could curve from -180° to +270° with the control of the handweel. Three pregnant women of TTTS with anterior placenta was operated with this instrument.

RESULT

All pregnant women were treated smoothly and gave live twins birth at term. Through angiography, it was demonstrated that the vascular connections on the surface had been coagulated.

CONCLUSION

The flexible fetoscope was a novel instrument in treating TTTS, especially for the anterior placenta.

Placental Abruption after Fetoscopic Laser Surgery in Twin-Twin Transfusion Syndrome: The Role of the Solomon Technique

INTRODUCTION

Twin-twin transfusion syndrome (TTTS) is a complication in monochorionic twin pregnancies which is preferably treated with fetoscopic laser surgery. A few small studies suggested a possible association between the Solomon laser technique and placental abruption.

METHODS

The objective of this study is to compare the rate of and to explore potential risk factors for placental abruption in TTTS treated with fetoscopic laser surgery according to the Selective and Solomon laser technique. We conducted a large retrospective cohort study of consecutive TTTS-cases treated with fetoscopic laser surgery in Shanghai, China, and Leiden, The Netherlands treated with either the Selective laser technique (Selective group) or Solomon laser technique (Solomon group).

RESULTS

The rate of placental abruption in the Selective group versus the Solomon group was 1.7% (5/289) and 3.4% (15/441), respectively (p = 0.184). No risk factors for placental abruption were identified. Placental abruption was associated with lower gestational age at birth (p = 0.003) and severe cerebral injury (p = 0.003).

CONCLUSION

The prevalence of placental abruption in TTTS after fetoscopic laser surgery is low, although it appears higher than in the overall population. Placental abruption is associated with a lower gestational age at birth, which is associated with severe cerebral injury. The rate of placental abruption was not significantly increased with the use of the Solomon technique. Continued research of placental abruption in TTTS is necessary to determine why the rate is higher than in the overall population.

Outcomes of fetoscopic laser surgery for twin-to-twin transfusion syndrome between 26 and 27 weeks of gestation in Japan

AIM

The purpose of this study was to investigate the outcomes of fetoscopic laser photocoagulation (FLP) for twin-to-twin transfusion syndrome (TTTS) in Japan.

METHODS

The retrospective cohort study (2012-2018) was conducted in monochorionic twin pregnancies that underwent FLP for TTTS between 26 and 27 weeks from 2012 to 2018. The perioperative data, maternal complications, gestational age (GA) at delivery, neonatal complications, and survival of infants at 28 days of age were analyzed. At term-equivalent age, severe neurological complications were identified by imaging study.

RESULTS

Of 644 patients, 28 (4.3%) underwent FLP between 26 and 27 weeks, and 26 were analyzed. FLP procedures were technically successful in all cases. There were no cases of major maternal complications after surgery. Preterm rupture of membranes occurred in 34.6% of cases, and the mean GA at delivery was 33.2 ± 3.1 weeks. The survival of both twins was found in 23 (88.4%) cases, and the perinatal survival rate of at least one twin at 28 days of age was 100%. Severe neurological complications were found in six (12.2%) cases out of 49.

CONCLUSIONS

FLP for TTTS between 26 and 27 weeks provided a good prognosis and caused no major maternal complications. However, severe neurological findings were found in 12% of infants.

Intrauterine fetoscopic laser surgery versus expectant management in stage 1 twin-to-twin transfusion syndrome: an international randomized trial

BACKGROUND

Selective fetoscopic laser coagulation of the intertwin anastomotic chorionic vessels is the first-line treatment for twin-twin transfusion syndrome. However, in stage 1 twin-twin transfusion syndrome, the risks of intrauterine surgery may be higher than those of the natural progression of the condition.

OBJECTIVE

This study aimed to compare immediate surgery and expectant follow-up in stage 1 twin-twin transfusion syndrome.

STUDY DESIGN

We conducted a multicentric randomized trial, which recruited from 2011 to 2018 with a 6-month postnatal follow-up. The study was conducted in 9 fetal medicine centers in Europe and the Unites States. Asymptomatic women with stage 1 twin-twin transfusion syndrome between 16 and 26 weeks' gestation, a cervix of >15 mm, and access to a surgical center within 48 hours of diagnosis were randomized between expectant management and immediate surgery. In patients allocated to immediate laser treatment, percutaneous laser coagulation of anastomotic vessels was performed within 72 hours. In patients allocated to expectant management, a weekly ultrasound follow-up was planned. Rescue fetoscopic coagulation of anastomoses was offered if the syndrome worsened as seen during a follow-up, either because of progression to a higher Quintero stage or because of the maternal complications of polyhydramnios. The primary outcome was survival at 6 months without severe neurologic morbidity. Severe complications of prematurity and maternal morbidity were secondary outcomes.

RESULTS

The trial was stopped at 117 of 200 planned inclusions for slow accrual rate over 7 years: 58 women were allocated to expectant management and 59 to immediate laser treatment. Intact survival was seen in 84 of 109 (77%) expectant cases and in 89 of 114 (78%) (P=.88) immediate surgery cases, and severe neurologic morbidity occurred in 5 of 109 (4.6%) and 3 of 114 (2.6%) (P=.49) cases in the expectant and immediate surgery groups, respectively. In patients followed expectantly, 24 of 58 (41%) cases remained stable with dual intact survival in 36 of 44 (86%) cases at 6 months. Intact survival was lower following surgery than for the nonprogressive cases, although nonsignificantly (78% and 71% following immediate and rescue surgery, respectively).

CONCLUSION

It is unlikely that early fetal surgery is of benefit for stage 1 twin-twin transfusion syndrome in asymptomatic pregnant women with a long cervix. Although expectant management is reasonable for these cases, 60% of the cases will progress and require rapid transfer to a surgical center.

Perinatal outcomes and factors affecting the survival rate of fetuses with twin-to-twin transfusion syndrome treated with fetoscopic laser coagulation: a single-center seven-year experience

OBJECTIVES

This single-center study aimed to assess the perinatal outcomes and its associated factors in fetuses with twin-to-twin transfusion syndrome (TTTS) treated by fetoscopic laser coagulation (FLC).

METHODS

In this retrospective study, we included fetuses prenatally diagnosed with TTTS at Asan Medical Center, Seoul, Korea, between October 2011 and December 2018. All patients with TTTS stage II or higher and those with stage I TTTS coupled with symptomatic polyhydramnios or cardiac dysfunction were eligible for FLC.

RESULTS

A total of 172 cases of monochorionic diamniotic twins and one case of dichorionic triamniotic triplets were prenatally diagnosed with TTTS and treated with FLC. The median gestational ages (GAs) at diagnosis and FLC were 20.3 and 20.5 weeks, respectively. The median GA of survivors at delivery was 32.5 weeks. The overall at least one twin- and double-survival rates within 28 days after birth were 82.1% and 55.5%, respectively. The GAs at diagnosis and FLC, Quintero stage, inter-twin weight discordance, associated selective intrauterine growth restriction (sIUGR), procedure time, volume of amnioreduction, preterm prelabor rupture of membranes (PPROM) within one week after FLC, intraoperative intrauterine bleeding, and chorioamnionitis were significant predictive factors of perinatal death. Associated sIUGR, absent end-diastolic flow of umbilical artery, and abnormal cord insertion were significantly associated with donor demise in utero, whereas lower GA at diagnosis and FLC, smaller twins at FLC, pulsatile umbilical vein, and presence of mitral regurgitation were significantly associated with recipient demise in utero. Since the application of the Solomon technique, the survival rate has improved from 75.4% to 88.8%. The FLC before 17 weeks was associated with PPROM within one week after FLC and lower survival rate, whereas that after 24 weeks was associated with twin anemia-polycythemia sequence and higher survival rate. We reached a survival rate of 82% for at least one survival with only 12 procedures.

CONCLUSIONS

FLC is an effective treatment for TTTS. The learning curve reached the acceptable target faster than in previous studies. Several prenatal parameters are identified as predictive factors of fetal survival in TTTS treated with FLC.

A case of total hysterectomy due to massive maternal bleeding immediately after fetoscopic laser surgery for twin-twin transfusion syndrome

Twin-twin transfusion syndrome (TTTS) complicates approximately 10% of monochorionic twin pregnancies and is associated with almost 90% mortality if left untreated. Fetoscopic laser photocoagulation (FLP) is the first-line therapy for TTTS, and an overall twin survival rate of 75% and at least one survival rate of 90% have been established. We report a case of TTTS complicated with bleeding from the uterine wall by inserting the procedure after FLP. The patient consequently underwent emergency caesarean section. The bleeding was uncontrollable due to atonic bleeding and emergency hysterectomy was performed. To detect the possibility of amniotic fluid embolism (AFE), biochemical blood samples demonstrated that there was no inflow of fetal ingredients in blood vessels of uterine tissue. There was no evidence of damage to any specific vessels by histopathological staining. These findings indicated that the cause of massive bleeding was unlikely to have been AFE. It was concluded that atonic bleeding was likely caused by uncontrollable hemorrhage from an injury lesion where an endoscope had been inserted.

Fetoscopic laser ablation in twin-to-twin transfusion syndrome: tips for counselling

Twin-to-twin transfusion syndrome (TTTS) is a serious complication that affects approximately 10-15% of monochorionic twin pregnancies. The most important role for the development of this condition is the presence of an unbalanced flow through the inter-twin vascular anastomoses. Depending on the number, type and direction of the connecting vessels, blood can be transfused disproportionately from one twin (the donor) to the other twin (the recipient). The diagnosis is defined prenatally by ultrasound and involves of two main criteria: the presence of a monochorionic diamniotic (MCDA) pregnancy; and the presence of oligohydramnios in the donor's sac- deep vertical pocket (DVP) 2 cm - and polyhydramnios in the recipient's sac- DVP>8 cm. Once diagnosed, TTTS is usually graded by using the Quintero staging system, that is composed by five stages, from oligohydramnios in the donor and polyhydramnios in the recipient twin to fetal demise in one or both twins. Photocoagulation of the anastomotic vessels, usually followed by equatorial dichorionization, it has currently become the most common fetoscopic operation today and is considered as the gold standard for stage II-IV TTTS. pPROM, chorioamniotic separation and iatrogenic preterm birth are among the most common complications of fetoscopic laser ablation, and the mean gestational age at delivery after laser procedure is about 31 weeks.

Placental Anatomy and Function in Twin Gestations

With an increasing incidence of twin gestations, understanding the inherent risks associated with these pregnancies is essential in modern obstetrics. The unique differences in placentation in twins contribute to the increased risks. Monochorionic twins are susceptible to complications because of their unique placental architecture, including twin-to-twin transfusion syndrome, the twin anemia-polycythemia sequence, selective intrauterine growth restriction, and the twin reversed arterial perfusion sequence. Knowing the clinical correlations of placental anatomy in these gestations helps perinatal pathologists perform a more informed placental evaluation, allowing for better care for the mother and her children.

Renal artery Doppler studies in the assessment of monochorionic, diamniotic twin pregnancies with and without twin-twin transfusion syndrome

BACKGROUND

In monochorionic, diamniotic twin pregnancies complicated by twin-twin transfusion syndrome, imbalanced fetofetal blood shunting and discordant activation of the renin-angiotensin system result in a hypovolemic, oliguric donor twin and a hypervolemic, polyuric recipient twin. Renal artery Doppler assessments have been reported to predict oligohydramnios in singleton pregnancies; however, their value in assessing monochorionic, diamniotic twin gestations, including pregnancies complicated by twin-twin transfusion syndrome, remains unstudied.

OBJECTIVE

This investigation evaluated whether renal artery Doppler parameters are different between sets of monochorionic, diamniotic twins with and without twin-twin transfusion syndrome.

STUDY DESIGN

We conducted a prospective study of women with monochorionic, diamniotic twin pregnancies complicated by twin-twin transfusion syndrome and women with gestational-age matched monochorionic, diamniotic twin control pregnancies without twin-twin transfusion syndrome. For each twin, renal artery Doppler assessment was performed from a coronal view of the fetus, and pulsatility index, resistive index, and peak systolic velocity were measured. In twin pairs complicated by twin-twin transfusion syndrome, renal artery Doppler pulsatility index, resistive index, and peak systolic velocity intertwin ratios were calculated by comparing paired recipient-to-donor values. Similar ratios were calculated for control twin pairs. We compared each measurement between donors and controls and between recipients and controls. Intertwin ratios were compared between twin-twin transfusion syndrome cases and monochorionic, diamniotic controls. Our primary outcome was a comparison of renal artery Doppler pulsatility index measurement between donor fetuses in twin-twin transfusion syndrome cases and matched control twins. Secondary outcomes included comparisons of other renal artery Doppler parameters between twin-twin transfusion syndrome donor twins and controls and between twin-twin transfusion syndrome recipients and controls and comparisons of the renal artery Doppler parameter ratios between twin-twin transfusion syndrome and non-twin-twin transfusion syndrome twin pair groups. Finally, we performed a subgroup analysis involving pregnancies with twin-twin transfusion syndrome that underwent fetoscopic laser therapy and resulted in twin survivors to evaluate if laser therapy influenced renal artery Doppler findings.

RESULTS

We recruited 12 donors and 12 controls. Renal artery Doppler pulsatility index and resistive index did not differ between donors and controls. However, donor renal artery Doppler peak systolic velocity (median, 14.24 [11.51-15.36]) was significantly lower than that of controls (median, 24.79 [22.46-27.03]; P<.0004). When recipient twins were compared with controls, there was no difference in renal artery Doppler pulsatility index, renal artery Doppler resistive index, or renal artery Doppler peak systolic velocity. Renal artery Doppler peak systolic velocity ratios were significantly higher among cases with twin-twin transfusion syndrome (median, 1.70 [1.53-2.02]) than controls (median, 1.06 [1.03-1.15]; P=.002). Applying a renal artery Doppler peak systolic velocity ratio cutoff of >1.35 for the diagnosis of twin-twin transfusion syndrome correctly classified 11 of 12 cases with twin-twin transfusion syndrome and all 12 controls without twin-twin transfusion syndrome (92% sensitivity and 100% specificity). Among donors with twin-twin transfusion syndrome with double survivors after undergoing laser therapy (n=4), prelaser renal artery Doppler peak systolic velocity ratios (mean, 1.46; standard deviation, 0.37) were significantly higher than postlaser renal artery Doppler peak systolic velocity ratios (mean, 0.87; standard deviation=0.37; P=.02). Postlaser intertwin renal artery Doppler peak systolic velocity ratios did not differ from control twin pairs (P=.125).

CONCLUSION

Renal artery Doppler peak systolic velocity ratios differ between monochorionic, diamniotic twins with twin-twin transfusion syndrome and those without twin-twin transfusion syndrome. This effect seems to be driven by altered donor twin renal artery Doppler peak systolic velocity. Laser therapy may normalize renal artery Doppler peak systolic velocity ratios and donor twin renal artery Doppler values to those observed in monochorionic, diamniotic twins without twin-twin transfusion syndrome. Further study is warranted to explore whether renal artery Doppler peak systolic velocity has utility as a tool for twin-twin transfusion syndrome prediction, diagnosis, or staging, and fetal response to laser therapy.

Twin-twin transfusion syndrome in the era of fetoscopic laser surgery: antenatal management, neonatal outcome and beyond

Introduction: Twin-twin transfusion syndrome (TTTS) is a devastating complication of monochorionic twin pregnancy and remains a major challenge for worldwide fetal medicine specialists. In TTTS, intertwin transfusion through vascular anastomoses in the shared placenta leads to severe hemodynamic imbalance. This review summarizes the current knowledge of TTTS.Areas covered: The most recent insights concerning the management of TTTS, as well as fetal and neonatal complications are described. Relevant articles were selected based on a Pubmed search using the keywords below. Understanding of the underlying pathophysiology has improved greatly as a result of placental injection studies. Advancements in antenatal management have led to increased perinatal survival and a decreased incidence of neonatal complications, including brain injury and neurodevelopmental impairment.Expert opinion: Further opportunities for improvement comprise technological innovations in laser procedures and the prevention of preterm rupture of membranes with subsequent prematurity. A noninvasive treatment such as high-intensity focused ultrasound (HIFU) seems to hold promise for the future treatment of TTTS. Fetal MRI studies are important to improve our understanding of fetal brain injury and should relate their findings to long-term neurodevelopment. International collaboration and centralization of care are of paramount importance to ensure the best care for our patients.

Inadvertent Perforation of a Gravid Uterus During Laparoscopy

Background

Laparoscopic surgery is safe in pregnancy, but is not without risk. Inadvertent uterine perforation of the gravid uterus is a rare complication.

Cases

Three pregnant women had inadvertent uterine perforation during laparoscopic surgery. All patients were counseled regarding the risks of an "incidental fetoscopy" and elected to continue the pregnancy. Two delivered after preterm premature rupture of membranes at 32 and 36 weeks' gestation, and one twin pregnancy delivered at 30 weeks due to preeclampsia.

Conclusion

Surgical planning of the gravid patient undergoing laparoscopic surgery should include demarcation of the most superior aspect of the uterine fundus, either via physical examination or, if not conclusive, via preoperative or intraoperative ultrasound.

Reproductive Outcomes following Laser Surgery for Twin-Twin Transfusion Syndrome

BACKGROUND

There are limited studies describing future reproductive outcomes in women who have had selective fetoscopic laser photocoagulation (SFLP) for twin-twin transfusion syndrome (TTTS).

OBJECTIVE

Our study aims to compare reproductive outcomes following monochorionic multiple gestational pregnancies complicated by TTTS requiring SFLP to those not requiring SFLP.

METHODS

This is a retrospective cohort study that analyzed records of patients who were evaluated at the Cincinnati Fetal Center (2007-2014) for monochorionic multiple gestations. A questionnaire regarding reproductive, obstetric, gynecologic, and psychological outcomes following the index pregnancy was administered to consented participants by electronic distribution. The data was compared between pregnancies with prior SFLP versus no prior SFLP.

RESULTS

There was a higher response rate in the SFLP group (219/474, 46.2%) versus the referent group (62/187, 33.2%). The median interval between the index pregnancy and survey completion was 74 months and 46 months in the SFLP and referent groups, respectively. Approximately 38 and 37% of the women in the SFLP and referent groups attempted conception after the index pregnancy with a >90% pregnancy success rate in both groups. Use of assisted reproductive technology was highly prevalent in both the index and subsequent pregnancies, with no significant difference between the groups. Over 60% of the women in each group did not attempt future pregnancy. Of those, approximately 1 in 3 cited the outcome of the index pregnancy as the primary reason for not pursuing future conception. There were no significant differences in selected maternal-fetal complications and new-onset gynecologic problems. More than 1 in 4 women in both groups were diagnosed with a mental health disorder following the index pregnancy.

CONCLUSION

SFLP does not appear to be associated with adverse reproductive, obstetric, or gynecologic outcomes. The data may help facilitate evidence-based counseling for this patient population.

Maternal Complications and Hemodynamic Changes Following Intrauterine Interventions for Twin-to-Twin Transfusion Syndrome in Monochorionic Diamniotic Twin Pregnancies

Twin-to-twin transfusion syndrome (TTTS) is a challenging complication in monochorionic diamniotic (MCDA) twins. Intrauterine interventions, such as fetoscopic laser ablation and cord occlusion followed by amniodrainage, are established treatments. Little is known about maternal complications and hemodynamics following these interventions. We performed a retrospective analysis of maternal procedure-related complications and the impact of such procedures on maternal hemodynamics and blood characteristics. Within the study period, 100 women with severe TTTS treated by fetoscopic laser ablation (FLA) or cord occlusion (CO) were identified. Clinically relevant maternal complications were reported in four (4%) cases. There was a significant decrease in hemoglobin, hematocrit, and albumin between admission and postoperative measurements (all p < 0.001). Systolic and diastolic blood pressure, as well as maternal heart rate, decreased from time of skin suture to postoperative measurements (all p < 0.001). Within a 24 h interval, there was a positive correlation between hematocrit (Spearman's rho 0.325; p = 0.003), hemoglobin (Spearman's rho 0.379; p < 0.001), and albumin (Spearman's rho 0.360; p = 0.027), and the amount of amniodrainage during the intervention. Maternal procedure-related complications are relatively rare. Significant hemodynamic alterations and maternal hemodilution are common clinical findings following intrauterine interventions.

Quantitative fetal fibronectin to predict spontaneous preterm delivery after laser surgery for twin-twin transfusion syndrome

Our goal was to assess whether quantitative fetal fibronectin (qfFN) is associated with spontaneous preterm birth (sPTB) after laser surgery for twin-twin transfusion syndrome (TTTS). qfFN was collected within 24 hours before and after laser surgery. Aims were: (1) To determine if qfFN changed with operative fetoscopy; and (2) To estimate the number of patients needed to study the predictive value of qfFN for sPTB <28 and <32 weeks. Results are reported as median (range). Among 49 patients, there was no net difference in qfFN levels after laser surgery [0.0 ng/mL (-37 to +400), p = 0.6041]. However, patients with a qfFN increase >10 ng/mL were 19 times more likely to undergo sPTB at <28 weeks (OR = 19.5). We determined that 383 and 160 patients would be needed to achieve adequate statistical power for qfFN to be predictive of sPTB at a GA <28 weeks and <32 weeks, respectively. In conclusion, laser surgery did not alter the qfFN level within the entire cohort, but qfFN may be useful in identifying a subset of patients at increased risk of preterm delivery.

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.

Fetoscopic Release of Amniotic Bands Causing Limb Constriction: Case Series and Review of the Literature

The aim of this study was to review the perioperative complication rates and neonatal outcomes after fetoscopic release of amniotic bands that caused bilateral limb constrictions. We present 5 cases of limb constriction by amniotic bands occurring spontaneously or following fetoscopic surgery and also include a review of 21 previously published cases. The cases were analyzed for indication, surgical technique, and postoperative follow-up. In our population and the literature, the majority of the children acquired a functional limb (75%), with few perioperative complications (15%). Fetal morbidity was mainly linked to the consequences of preterm premature rupture of the membranes (38.4%) and preterm birth (34.7 GW). The mortality rate was low (7.7%). This review only describes amniotic bands causing limb constriction, and illustrates that fetoscopic surgery for their release is technically feasible with an acceptable perioperative complication rate. However, the 75% success rate is very likely to be an overestimation of the true success rate. In view of these observations we cannot recommend treatment for cases where the fetus has been extensively affected by the bands. We believe, however, that we could consider this technique for a fraction of amniotic band syndrome cases isolated to the limb constrictions. This kind of surgery should be proposed as a potential treatment for amniotic band syndrome.

Outcome reporting across randomized trials and observational studies evaluating treatments for twin-twin transfusion syndrome: systematic review

OBJECTIVE

Twin-twin transfusion syndrome (TTTS) is associated with significant mortality and morbidity. Potential treatments for the condition require robust evaluation. The aim of this study was to evaluate outcome reporting across observational studies and randomized controlled trials assessing treatments for TTTS.

METHODS

Cochrane Central Register of Controlled Trials, EMBASE and MEDLINE were searched from inception to August 2016. Observational studies and randomized controlled trials reporting outcome following treatment for TTTS in monochorionic-diamniotic twin pregnancy and monochorionic-triamniotic or dichorionic-triamniotic triplet pregnancy were included. Outcome reporting was systematically extracted and categorized.

RESULTS

Six randomized trials and 94 observational studies were included, reporting data from 20 071 maternal participants and 3199 children. Six different treatments were evaluated. Included studies reported 62 different outcomes, including six fetal, seven offspring mortality, 25 neonatal, six early childhood and 18 maternal/operative outcomes. Outcomes were reported inconsistently across trials. For example, when considering offspring mortality, 31 (31%) studies reported live birth, 31 (31%) reported intrauterine death, 49 (49%) reported neonatal mortality and 17 (17%) reported perinatal mortality. Four (4%) studies reported respiratory distress syndrome. Only 19 (19%) studies were designed for long-term follow-up and 11 (11%) of these reported cerebral palsy.

CONCLUSIONS

Studies evaluating treatments for TTTS have often neglected to report clinically important outcomes, especially neonatal morbidity outcomes, and most are not designed for long-term follow-up. The development of a core outcome set could help standardize outcome collection and reporting in TTTS studies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Outcome after fetoscopic laser coagulation in twin-twin transfusion syndrome - is the survival rate of at least one child at 6 months of age dependent on preoperative cervical length and preterm prelabour rupture of fetal membranes?

Purpose: Twin-to-twin transfusion syndrome (TTTS) complicates 10-15% of all monochorionic twin pregnancies. Selective laser coagulation of placental anastomoses is the only causal therapy. The aim of this study was to analyze the neonatal survival, the survival rate of at least one child at 6 months of age, and maternal outcome after laser therapy in a Swiss cohort.Material and methods: Between 2008 and 2014, 39 women were treated with fetoscopic laser procedure due to TTTS. Two women were excluded from the study because of missing informed consent or loss of follow-up. The women were divided into two groups: group 1 with a cervical length >25 mm and group 2 with a cervical length ≤25 mm. The primary end point was the survival rate of at least one child at 6 months of age and its dependence on maternal preoperative cervical length or the time interval between operation (OP)-preterm prelabour rupture of fetal membranes (PPROM). Secondary outcomes were neonatal complications and maternal complications due to the procedure. Statistical analysis was performed using the program SPSS 22. A p-value of <.05 was considered statistically significant.Results: Mean gestational age (GA) at OP of group 1 (20.3 ± 3 GW) was comparable with group 2 (21.5 ± 2.4 GW; p = .27). The GA at birth was significantly higher in group 1 (31.5 ± 5.9 GW) than in group 2 (27.0 ± 4.7 GW: p = .02). The survival rate of at least one child at 30 days and 6 months of age was 81% in group 1 and only 60% in group 2 (p = .1). PPROM <32 GW occurred in 43%. The survival rate of at least one child was significantly higher if the OP-PPROM interval was >28 days (93 versus 43%; p = .02). Major brain injury was observed in 11% of infants. Severe maternal complications (pulmonary edema) occurred in three cases (8%).Conclusions: Our survival rate of at least one child at 30 days and 6 months of age and the outcome of the mothers is well comparable to other international studies. A preoperative maternal cervical length of >25 mm and an occurrence of PPROM more than 28 days after the laser therapy is associated with a higher survival rate of at least one child at 6 months of age.

Twin-twin transfusion syndrome - What we have learned from clinical trials

Monochorionic twin pregnancies are at increased risk for adverse outcome compared to dichorionic twin pregnancies and singletons. Monochorionic-specific complications include twin-twin transfusion syndrome (TTTS), twin anemia-polycythemia sequence, single intrauterine fetal demise and its consequences on the co-twin, and selective intrauterine growth restriction. Whereas the natural history of monochorionic-specific complications carries a high risk of fetal death or severe neurologic disability, a framework now exists, based on well-designed clinical trials, for optimal treatment of these entities. Fetoscopic selective laser coagulation of anastomotic vessels on the chorionic plate has been clearly demonstrated to improve survival and neurologic outcomes for Quintero stage ≥2 TTTS. However, many challenges remain unsolved, the most important of which is preterm premature rupture of membranes. Further improvement in the outcomes of monochorionic pregnancies will require improvements in the rate of premature delivery, and improved diagnosis and treatment strategies for early and late onset TTTS.

Arabin cervical pessary for prevention of preterm birth in cases of twin-to-twin transfusion syndrome treated by fetoscopic LASER coagulation: the PECEP LASER randomised controlled trial

Background

Fetoscopic LASER coagulation of the placental anastomoses has changed the prognosis of twin-twin transfusion syndrome. However, the prematurity rate in this cohort remains very high. To date, strategies proposed to decrease the prematurity rate have shown inconclusive, if not unfavourable results.

Methods

This is a randomised controlled trial to investigate whether a prophylactic cervical pessary will lower the incidence of preterm delivery in cases of twin-twin transfusion syndrome requiring fetoscopic LASER coagulation. Women eligible for the study will be randomised after surgery and allocated to either pessary or expectant management. The pessary will be left in place until 37 completed weeks or earlier if delivery occurs. The primary outcome is delivery before 32 completed weeks. Secondary outcomes are a composite of adverse neonatal outcome, fetal and neonatal death, maternal complications, preterm rupture of membranes and hospitalisation for threatened preterm labour. 352 women will be included in order to decrease the rate of preterm delivery before 32 weeks’ gestation from 40% to 26% with an alpha-error of 0.05 and 80% power.

Discussion

The trial aims at clarifying whether the cervical pessary prolongs the pregnancy in cases of twin-twin transfusion syndrome regardless of cervical length at the time of fetoscopy.

Trial registration

ClinicalTrials.gov Identifier: NCT01334489. Registered 04 December 2011.

Case report of myometrial window following fetoscopic treatment of twin-twin transfusion syndrome: indications of underlying collagen vascular disease?

Intraperitoneal amniotic fluid leak is a known complication of fetoscopic procedures that usually resolves spontaneously with expectant management. Intraperitoneal amniotic fluid leak may persist after fetoscopic procedures due to a myometrial window as well as to persistent chorioamniotic membrane disruption, which may be amenable to surgical repair.

Histologic Chorioamnionitis and Funisitis After Laser Surgery for Twin-Twin Transfusion Syndrome

OBJECTIVE

To estimate the incidence of histologic chorioamnionitis and funisitis after fetoscopic laser surgery for the management of twin-twin transfusion syndrome.

METHODS

A case-control study was performed at the Leiden University Medical Center from 2013 to 2014. All patients with twin-twin transfusion syndrome managed with laser surgery during the study period were included and compared with a control group of all monochorionic twins not treated with laser surgery. We excluded patients with fetal demise or higher order pregnancies. Placentas were reviewed for the presence and degree of chorioamnionitis and presence or absence of fetal inflammatory response. The primary outcome was the incidence of histologic chorioamnionitis and funisitis after laser surgery. Odds ratios (ORs) and 95% confidence intervals (CIs) for primary outcomes were calculated. A P value of <.05 was considered as statistical significance.

RESULTS

Sixty-two patients treated with laser surgery were included in the study group and compared with 64 patients in the control group. The incidence of histologic chorioamnionitis was 13% (8/62) in the laser group compared with 5% (3/64) in the control group (OR 3.0, 95% CI 0.8-11.9, P=.12). Funisitis occurred in 8% (10/124) in the laser group compared with 0% in the control group (OR 11.1, 95% CI 1.3-96.9, P=.03). Histologic chorioamnionitis with or without funisitis after laser surgery was associated with a shorter laser-to-delivery interval (median 6.6 [range 3.4-14.1] compared with 13.6 [4.4-20.1] weeks, P<.01) and lower gestational age at birth (median 28.1 [range 23.1-32.6] compared with 32.7 [24.4-37.0] weeks, P<.01).

CONCLUSION

These findings suggest that laser surgery for twin-twin transfusion syndrome is associated with an increased risk of funisitis.

Is intrauterine surgery justified? Report from the working group on ultrasound in obstetrics of the World Association of Perinatal Medicine (WAPM)

Fetal surgery involves a large number of heterogeneous interventions that vary from simple and settled procedures to very sophisticated or still-in-development approaches. The overarching goal of fetal interventions is clear: to improve the health of children by intervening before birth to correct or treat prenatally diagnosed abnormalities. This article provides an overview of fetal interventions, ethical approaches in fetal surgery, and benefits obtained from antenatal surgeries.

Amniopatch treatment of iatrogenic preterm premature rupture of membranes (iPPROM) after fetoscopic laser surgery for twin-twin transfusion syndrome

OBJECTIVES

Amniopatch is a proposed treatment of iatrogenic preterm premature rupture of membranes (iPPROM). We studied characteristics associated with successful amniopatch treatment of iPPROM after fetoscopic laser surgery for twin-twin transfusion syndrome.

METHODS

Patients with iPPROM within 15 days of laser surgery treated with an amniopatch were studied. Factors associated with amniopatch success (i.e. cessation of leakage with normalization of amniotic fluid volume) were tested univariately and in multivariate logistic regression models. Continuous variables are expressed as median (range).

RESULTS

Of 1124 patients undergoing laser surgery, 19 (1.7%) had iPPROM and subsequent amniopatch. Twelve (63.2%) were successful. Latency in days from iPPROM to delivery was greater in the successful group (114.0 [87.0-141.0]) versus (44.0 [3.9-88.0], p = 0.0005), which translated into greater gestational age (GA) (weeks) at delivery (35.1 [30.9-39.4] versus 28.1 [22.0-31.0], p = 0.0005). The 30-day survival of the affected recipient twin was improved (100% versus 57.1%, p = 0.0361). After multivariate testing, GA < 20 weeks at the time of the amniopatch placement was the only variable that remained associated with successful sealing of the membranes.

CONCLUSIONS

Treatment of iPPROM via amniopatch was successful in almost two-thirds of cases and was associated with higher GA at delivery and improved perinatal survival.

Increased Risk Of Early-Onset Neonatal Sepsis After Laser Surgery For Twin-to-Twin Transfusion Syndrome

OBJECTIVE

To investigate the occurrence of early-onset neonatal sepsis (EOS) in twin-twin transfusion syndrome (TTTS) managed with laser surgery.

STUDY DESIGN

We performed a prospective cohort study of all consecutive TTTS cases treated with laser surgery (TTTS group) delivered at the Leiden University Medical Center. We recorded the occurrence of EOS, defined as a positive blood culture ≤72 hours postpartum (proven sepsis) or administration of a full course of antibiotics due to risk factors or signs of sepsis, in the absence of a positive blood culture (suspected sepsis). Perinatal variables in the TTTS group were compared with uncomplicated monochorionic twins (no-TTTS group). A multivariate model was generated, examining the association between EOS and gestational age at birth, interval between laser surgery and birth, anterior placenta, laser period (first study period: 2002-2008; second study period: 2009-2015), and preterm premature rupture of membranes (PPROM).

RESULTS

The rates of combined suspected and proven EOS in the TTTS group and no-TTTS group were 16% (68/416) and 10% (55/542), respectively (relative ratio [RR] 1.74, 95% confidence interval [CI] 1.19-2.55). Multivariate analysis showed that EOS in the TTTS group was independently associated with lower gestational age at birth (odds ratio [OR] 0.75, 95% CI 0.63-0.88), first study period (OR 2.25, 95% CI 1.08-4.67) and PPROM (OR 2.47, 95% CI 1.28-4.75).

CONCLUSION

The rate of EOS in the TTTS group is low, but increased compared to the no-TTTS group. EOS in TTTS is independently associated with premature delivery, earlier laser period, and PPROM.

Balancing Patient Access to Fetoscopic Laser Photocoagulation for Twin-to-Twin Transfusion Syndrome With Maintaining Procedural Competence: Are Collaborative Services Part of the Solution?

The benefits of fetoscopic laser photocoagulation (FLP) for treatment of twin-to-twin transfusion syndrome (TTTS) have been recognized for over a decade, yet access to FLP remains limited in many settings. This means at a population level, the potential benefits of FLP for TTTS are far from being fully realized. In part, this is because there are many centers where the case volume is relatively low. This creates an inevitable tension; on one hand, wanting FLP to be readily accessible to all women who may need it, yet on the other, needing to ensure that a high degree of procedural competence is maintained. Some of the solutions to these apparently competing priorities may be found in novel training solutions to achieve, and maintain, procedural proficiency, and with the increased utilization of 'competence based' assessment and credentialing frameworks. We suggest an under-utilized approach is the development of collaborative surgical services, where pooling of personnel and resources can improve timely access to surgery, improve standardized assessment and management of TTTS, minimize the impact of the surgical learning curve, and facilitate audit, education, and research. When deciding which centers should offer laser for TTTS and how we decide, we propose some solutions from a collaborative model.

The Impact of Entry Technique and Access Diameter on Prelabour Rupture of Membranes Following Primary Fetoscopic Laser Treatment for Twin-Twin Transfusion Syndrome

Objective: To evaluate the impact of entry method and access diameter at fetoscopic surgery for twin-twin transfusion syndrome in twin pregnancies with at least one survivor. The outcomes evaluated were prelabour rupture of membranes (PROM) and birth <4 weeks, preterm birth (PTB) <28 weeks, and latency to birth. Methods: A retrospective analysis of prospectively collected data of consecutive laser procedures from 6 centers was performed. Three entry methods (sheath + trocar; cannula + trocar; cannula + Seldinger) and 6 access diameters (2.3, 3.0, 3.3, 3.5, 3.8, 4.0 mm) were used. Exclusion criteria were subsequent invasive interventions, termination of pregnancy or double fetal death after laser. Multivariate analysis was performed to determine risk factors for the study outcomes. Results: Six hundred seventy three fetoscopic laser cases were analyzed. The use of different entry methods and access diameters did not affect PROM or birth <4 weeks, or latency from laser to birth. Access diameter was associated with PTB <28 weeks. Cervical length was associated with PROM and birth <4 weeks, and latency from laser to birth. Conclusion: Instrument choice at fetoscopic laser procedures did not affect outcomes <4 weeks. Access diameter may affect the likelihood for PTB <28 weeks. Cervical length is critically associated with obstetrical outcomes following laser surgery.

Twin Anemia Polycythemia Sequence: Current Views on Pathogenesis, Diagnostic Criteria, Perinatal Management, and Outcome

Monochorionic twins share a single placenta and are connected with each other through vascular anastomoses. Unbalanced inter-twin blood transfusion may lead to various complications, including twin-to-twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS). TAPS was first described less than a decade ago, and the pathogenesis of TAPS results from slow blood transfusion from donor to recipient through a few minuscule vascular anastomoses. This gradually leads to anemia in the donor and polycythemia in the recipient, in the absence of twin oligo-polyhydramnios sequence (TOPS). TAPS may occur spontaneously in 3-5% of monochorionic twins or after laser surgery for TTTS. The prevalence of post-laser TAPS varies from 2% to 16% of TTTS cases, depending on the rate of residual anastomoses. Pre-natal diagnosis of TAPS is currently based on discordant measurements of the middle cerebral artery peak systolic velocity (MCA-PSV; >1.5 multiples of the median [MoM] in donors and 8 g/dL), and at least one of the following: reticulocyte count ratio >1.7 or minuscule placental anastomoses. Management includes expectant management, and intra-uterine blood transfusion (IUT) with or without partial exchange transfusion (PET) or fetoscopic laser surgery. Post-laser TAPS can be prevented by using the Solomon laser surgery technique. Short-term neonatal outcome ranges from isolated inter-twin Hb differences to severe neonatal morbidity and neonatal death. Long-term neonatal outcome in post-laser TAPS is comparable with long-term outcome after treated TTTS. This review summarizes the current knowledge after 10 years of research on the pathogenesis, diagnosis, management, and outcome in TAPS.

Postnatal survival after endoscopic equatorial laser for the treatment of twin-to-twin transfusion syndrome

BACKGROUND

Endoscopic laser coagulation of placental anastomoses is the first-line treatment for severe twin-to-twin transfusion syndrome. A recent randomized controlled trial reported that laser coagulation along the entire vascular equator was associated with a similar dual survival and survival of at least 1 twin compared with the group that was treated with the selective technique. In addition, there was a significantly lower incidence of postoperative recurrence of twin-to-twin transfusion syndrome and the development of twin anemia-polycythemia sequence in the equatorial group.

OBJECTIVE

The purpose of this study was to report on neonatal survival in twin-to-twin transfusion syndrome pregnancies that were treated with endoscopic laser therapy with the use of the equatorial technique and to examine the relationship between preoperative factors and twin loss.

STUDY DESIGN

Endoscopic equatorial laser therapy was carried out as the primary treatment for twin-to-twin transfusion syndrome in all consecutive monochorionic diamniotic twin pregnancies that were referred at a single fetal surgery Center over a 4-year period. All visible placental anastomoses were coagulated; additional laser ablation of the placental tissue between the coagulated vessels was carried out. Pre-laser ultrasound data, periprocedural complications, pregnancy outcome, and postnatal survival at hospital discharge were recorded and analyzed.

RESULTS

A total of 106 pregnancies were treated during the study period. Median gestational age at laser therapy was 19.7 weeks (range, 15.1-27.6 weeks). There was postoperative recurrence of twin-to-twin transfusion syndrome or the development of twin anemia-polycythemia sequence in 2 (1.9%) and 2 (1.9%) cases, respectively. The survival rates of both and at least 1 twin were 56.6% and 83.0%, respectively. Donor survival was significantly lower compared with the recipient co-twin (64.2% vs 75.5%, respectively; P < .05). The rate of fetal death, which was the most common cause of twin loss, was significantly higher in donors compared with recipient fetuses (23.6% vs 10.4%, respectively; P < .05). In cases with absent or reversed end-diastolic velocity in the donor umbilical artery, dual and donor survival rates were significantly lower compared with the remaining twin-to-twin transfusion syndrome pregnancies (40.0% vs 64.8% and 40.0% vs 76.1%, respectively; P < .05). There were no significant differences between the 2 groups in the survival of at least 1 twin and in the recipient survival.

CONCLUSIONS

Endoscopic equatorial laser therapy was associated with a survival of both and at least 1 twin of approximately 55% and 83%, respectively, with a low rate of recurrent twin-to-twin transfusion syndrome and twin anemia-polycythemia sequence. In addition, the preoperative finding of abnormal donor umbilical artery Doppler on ultrasound identified a subgroup of twin-to-twin transfusion syndrome pregnancies with a lower dual survival rate caused by increased intrauterine deaths of donor twins.

Audit of immediate outcomes for MCDA twins following laser therapy for twin-twin transfusion syndrome at the NSW Fetal Therapy Centre

OBJECTIVE

To audit immediate pregnancy and neonatal outcomes of selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS) at the New South Wales Fetal Therapy Centre.

METHODS

Retrospective cohort study of 151 TTTS cases undergoing SLPCV between July 2003 and May 2013, evaluating procedural details, delivery and perinatal outcomes.

RESULTS

The majority of cases were Stage III at SLPCV (56.9%), although proportion of Stage II SLPCV increased over time (P = 0.03). Survival to hospital discharge of at least one baby was 85.6% and dual survival was 52.5%. Median gestational age at delivery was 32.6 weeks (IQR 29.0-35.0 weeks) with a median of 11.4 weeks (IQR 8.3-14.7) from laser to delivery. Median birthweight was 1792 g (IQR 1288-2233 g), with 75% of babies admitted to the nursery, predominantly secondary to prematurity. Immediate SLPCV complications were in utero fetal demise <1 week postprocedure in 27 fetuses (19.6%) and/or ruptured membranes <1 week postprocedure in 9 fetuses (6.6%).

CONCLUSIONS

This Australian series shows that local outcomes after SLPCV for stages II-IV TTTS remain equal to the international published literature and have remained stable after an initial learning curve. Women were more likely to be Stage II rather than III in the more recent years. However, this does not appear to be attributable to altered referral patterns.

Twenty-Five Years of Fetoscopic Laser Coagulation in Twin-Twin Transfusion Syndrome: A Systematic Review

Objective: The aim of this study was to assess the perinatal outcome of pregnancies with twin-twin transfusion syndrome (TTTS) treated with laser therapy over the past 25 years, and in relation to different techniques used in this time period. Methods: A systematic review of studies reporting on perinatal outcome according to the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines was conducted. The MEDLINE, Embase and Cochrane Library databases were systematically searched. Comparisons were made in respect to time period and laser technique and Quintero stages. Results: In total, 34 studies reporting on 3,868 monochorionic twin pregnancies were included. The mean survival of both twins increased from 35 to 65% (p = 0.012) and for at least one twin from 70 to 88% (p = 0.009) over the past 25 years. Mean gestational age at birth remained stable over the years at 32 weeks gestation. Also, we showed a significantly improved perinatal survival with the evolution of the laser technique from non-selective to selective, selective sequential and the Solomon technique (p = 0.010). Discussion: Since the introduction of laser therapy for TTTS more than two decades ago, perinatal survival improved significantly. Improved outcome is probably associated with several factors, including evolution of the laser technique, learning curve effect, better referral and improved early neonatal care.

Outcome following selective fetoscopic laser ablation for twin to twin transfusion syndrome: an 8 year national collaborative experience

OBJECTIVE

With the recognition of the role of fetoscopic laser ablation for twin to twin transfusion syndrome (TTTS), there is a requirement for auditable standards for this technically challenging and specialized treatment. The purpose of this study is to report on the perinatal and medium-term neurodevelopmental outcomes following an 8-year national single center experience in the management of TTTS using the selective fetoscopic laser ablation technique.

STUDY DESIGN

An audit of all cases of TTTS treated with selective laser ablation by a single national fetal medicine team was performed. Overall perinatal survival and medium-term neurodevelopmental outcomes were reported and correlated with gestational age at diagnosis, placental location, volume of amnio-reduction, Quintero staging and percentage inter-twin growth discordance. Procedure-related complications were recorded.

RESULTS

The overall fetal survival for the first 105 consecutive cases of TTTS was 61% (128/210 fetuses). Dual survival occurred in 47% (49/105) of cases, and with a single survival rate of 28% (30/105), perinatal survival of least one infant was achieved in 75% (79/105) of cases. No correlation was found between any clinical or sonographic marker and perinatal outcome, although dual survival was noted to be significantly decreased with increasing Quintero stage (p=0.041). Currently, 86% of survivors have been reported to have a normal medium-term neurological outcome.

CONCLUSION

Fetoscopic laser ablation is the established optimal treatment for severe twin to twin transfusion syndrome (TTTS). We report comparable short and medium-term outcomes following the selective fetoscopic technique comparing results from our national program with internationally published single-center outcomes, supporting the efficacy and safety of this treatment at our center.

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.

High-intensity focused ultrasound applied to the placenta using a toroidal transducer: a preliminary ex-vivo study

OBJECTIVE

To demonstrate in an ex-vivo model the feasibility of applying high-intensity focused ultrasound (HIFU) using a toroidal transducer for the creation of placental lesions.

METHODS

In this study we used a toroidal transducer, composed of 32 ring-shaped emitters with an ultrasound probe at the center, operating at a frequency of 2.5 MHz. We examined 45 human placentae, following either normal vaginal delivery or medical termination of pregnancy between 17 and 40 gestational weeks. First, the attenuation coefficients of 12 human placentae were measured and integrated into a numerical model for simulating HIFU lesions. Then, using acoustic parameters from this preliminary study, we performed ex-vivo experiments with 33 human placentae, each overlain with an animal abdominal wall to simulate the maternal wall. We created single HIFU lesions in 25 of these placentae, and a series of six juxtaposed lesions in eight, studying these both sonographically and macroscopically.

RESULTS

Human placental attenuation coefficients of the 12 human placentae ranged from 0.072 to 0.098 Np/cm/MHz, according to gestational age. The 25 single HIFU lesions created had an average diameter of 7.1 ± 3.2 mm and an average depth of 8.2 ± 3.1 mm. The average diameter of the eight series of six juxtaposed HIFU lesions was 23.0 ± 5.0 mm and the average depth was 11.0 ± 4.7 mm. The average thickness of the abdominal walls was 10.5 ± 1.8 mm. No lesions or damage were observed in intervening tissues.

CONCLUSION

This study demonstrates, using an ex-vivo model, the feasibility, reproducibility, harmlessness and effectiveness of HIFU applied to the human placenta.

Stage-related outcome after fetoscopic laser ablation in twin-to-twin transfusion syndrome

AIM

To review the perinatal outcome of twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser coagulation in a developing country with detailed analysis according to the stage of the syndrome.

METHODS

This was a retrospective study of 85 TTTS cases treated with fetoscopic laser coagulation at the Fetal Diagnosis and Treatment Unit of Istanbul Faculty of Medicine between January 2006 and March 2013.

RESULTS

The surgical failure rate was 5.8% (5/85). Among all the cases of the total cohort, only 1 fetus survived in 27 pregnancies (31.8%), and both fetuses survived in 22 pregnancies (25.9%). In 49 pregnancies (57.6%) at least one fetus survived at the end of the neonatal period. The overall survival and live birth rates were 41.8% (71/170) and 56.4% (96/170), respectively, and they significantly decreased as the stage of disease increased. Delivery occurred before 32 weeks of gestation in 54 (63.5%) pregnancies. Logistic regression analysis showed that gestational age at delivery was the only independent factor, and the risk of nonsurvival significantly decreased with increasing age.

CONCLUSION

Based on our experience, the outcome of fetoscopic laser coagulation of the placental anastomoses for TTTS became worse as the Quintero stage of the disease advanced.