Patient-specific placental vessel segmentation with limited data.

A major obstacle in applying machine learning for medical fields is the disparity between the data distribution of the training images and the data encountered in clinics. This phenomenon can be explained by inconsistent acquisition techniques and large variations across the patient spectrum. The result is poor translation of the trained models to the clinic, which limits their implementation in medical practice. Patient-specific trained networks could provide a potential solution. Although patient-specific approaches are usually infeasible because of the expenses associated with on-the-fly labeling, the use of generative adversarial networks enables this approach. This study proposes a patient-specific approach based on generative adversarial networks. In the presented training pipeline, the user trains a patient-specific segmentation network with extremely limited data which is supplemented with artificial samples generated by generative adversarial models. This approach is demonstrated in endoscopic video data captured during fetoscopic laser coagulation, a procedure used for treating twin-to-twin transfusion syndrome by ablating the placental blood vessels. Compared to a standard deep learning segmentation approach, the pipeline was able to achieve an intersection over union score of 0.60 using only 20 annotated images compared to 100 images using a standard approach. Furthermore, training with 20 annotated images without the use of the pipeline achieves an intersection over union score of 0.30, which, therefore, corresponds to a 100% increase in performance when incorporating the pipeline. A pipeline using GANs was used to generate artificial data which supplements the real data, this allows patient-specific training of a segmentation network. We show that artificial images generated using GANs significantly improve performance in vessel segmentation and that training patient-specific models can be a viable solution to bring automated vessel segmentation to the clinic.

Monochorionic Twin Complications and Fetoscopic Interventions.

Monochorionic twins are at risk for complications due to the presence of placental vascular anastomoses, including twin-twin transfusion syndrome, twin anemia-polycythemia sequence, selective fetal growth restriction, and twin reversed arterial perfusion sequence. While ultrasound is the primary modality to screen for the development of these complications, MRI plays an important role in assessing monochorionic twin pregnancies for the development of other complications, such as neurologic injury. In this article, the authors review the ultrasound imaging findings associated with monochorionic twin complications, management options, and the role for MRI in these pregnancies.

Magnetic resonance imaging of intracranial anomalies in pregnancies complicated by twin anemia-polycythemia sequence.

PURPOSE: To describe fetal brain Magnetic Resonance Imaging (MRI) findings in a large series of monochorionic (MC) pregnancies complicated by Twin Anemia-Polycythemia Sequence (TAPS) prenatally diagnosed, so to characterize the potential intracranial complications associated with this condition, their frequency and potential treatment options. METHODS: This is a retrospective study of MC twin pregnancies complicated by TAPS and undergone fetal MRI in a single institution from 2006 to 2023. MRI control was performed and post-natal ultrasound (US) or MRI were available. RESULTS: 1250 MC pregnancies were evaluated in our institution. 50 pregnancies (4%) were diagnosed with TAPS, 29 underwent a fetal brain MRI. 13/29 pregnancies (44.8%) demonstrated brain findings at MRI in at least a twin. Neuroradiological findings were detected in 14/57 twins (24.6%). We detected four main categories of findings: hemorrhagic lesions, T2-weighted white-matter hyperintensities (WMH), brain edema-swelling and venous congestion. Nineteen findings were present in the anemic and three in the polycythemic twins, with a statistically significant ratio between the two groups (p-value = 0.01). Intrauterine MRI follow-up demonstrated the sequalae of hemorrhagic lesions. A complete regression of brain swelling, veins prominence and T2-WMHs was demonstrated after treatment. Postnatal imaging confirmed prenatal features. CONCLUSIONS: Our work demonstrates that TAPS-related MRI anomalies consisted in edematous/hemorrhagic lesions that occur mostly in anemic rather than in polycythemic twins. Fetoscopic laser surgery could have a potential decongestant role. Therefore, prenatal MRI may help in counselling and management in TAPS pregnancies, especially for the planning of therapy and the monitoring of its efficacy.

Maternal "mirror" syndrome: Evaluating the benefits of fetal therapy.

OBJECTIVE: To evaluate maternal and perinatal outcomes following fetal intervention in the context of maternal "mirror" syndrome. STUDY DESIGN: A multicenter retrospective study of all cases of fetal hydrops complicated by maternal "mirror" syndrome and treated by any form of fetal therapy between 1995 and 2022. Medical records and ultrasound images of all cases were reviewed. "Mirror" syndrome was defined as fetal hydrops and/or placentomegaly associated with the maternal development of pronounced edema, with or without pre-eclampsia. Fetal hydrops was defined as the presence of abnormal fluid collections in ≥2 body cavities. RESULTS: Twenty-one pregnancies met the inclusion criteria. Causes of fetal hydrops and/or placentomegaly included fetal lung lesions (n = 9), twin-twin transfusion syndrome (n = 6), severe fetal anemia (n = 4), and others (n = 2). Mean gestational age at "mirror" presentation was 27.0 ± 3.8 weeks. Maternal "mirror" syndrome was identified following fetal therapeutic intervention in 14 cases (66.6%). "Mirror" symptoms resolved or significantly improved before delivery in 8 (38.1%) cases with a mean interval from fetal intervention to maternal recovery of 13.1 days (range 4-35). Three women needed to be delivered because of worsening "mirror" syndrome. Of the 21 pregnancies treated (27 fetuses), there were 15 (55.5%) livebirths, 7 (25.9%) neonatal deaths and 5 (18.5%) intra-uterine deaths. CONCLUSION: Following successful treatment and resolution of fetal hydrops, maternal "mirror" syndrome can improve or sometimes completely resolve before delivery. Furthermore, the recognition that "mirror" syndrome may arise only after fetal intervention necessitates hightened patient maternal surveillance in cases of fetal hydrops.

Fetal magnetic resonance imaging, ultrasound, and echocardiography findings in twin reversed arterial perfusion sequence.

BACKGROUND: Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic multiple gestation pregnancies, in which the pump twin provides hemodynamic support to a nonviable co-twin (acardius). Fetal magnetic resonance imaging (MRI) is used to detect pump twin abnormalities, particularly brain ischemia, prior to fetal intervention to interrupt umbilical blood flow to the acardius. OBJECTIVE: To summarize the imaging findings of TRAP sequence pregnancies in a large series. MATERIALS AND METHODS: A single-center retrospective review was performed of all TRAP sequence pregnancies referred for fetal MRI (2004-2021). Fetal MRI, ultrasound, and echocardiography data were collected. RESULTS: Eighty-eight TRAP sequence pregnancies with MRI were included (mean gestational age, 19.8±2.8 weeks). Demise of the pump twin was noted in two pregnancies at the time of MRI. By MRI, 12% (10/86) of live pump twins had abnormalities, including 3% (3/86) with brain abnormalities and 9% (8/86) with extra-cranial abnormalities. By echocardiography, 7% (6/86) of pump twins had structural cardiac abnormalities. Three acardius morphological subtypes were identified by MRI: acephalus (55%, 48/88), anceps (39%, 34/88), and amorphous (7%, 6/88). The mean ultrasound acardius to pump twin ratio A/P ratio, calculated for each twin pair as the ratio of the acardius trunk (and head, if present) plus limb volume to the pump twin estimated fetal weight) differed among the three acardius subtypes (P=.03). The mean A/P ratio moderately correlated with pump twin cardiothoracic ratio and combined cardiac output (Pearson's r=0.45 and 0.48, respectively, both P<.001). CONCLUSION: Fetal MRI of TRAP sequence pregnancies found anomalies in a substantial number of pump twins. The three acardius subtypes differed in A/P ratio, which moderately correlated with the pump twin cardiothoracic ratio and combined cardiac output.

Ultrasonographic Features and Pregnancy Outcomes of Complications in Monochorionic Twin Pregnancy During Various Pregnancy Periods.

Objective: It was to explore the ultrasonic characteristics of complications of twin pregnancies with monochorionic diamniotic (MCDA) during various pregnancy periods and the differences in pregnancy outcomes. Methods: One hundred pregnant women with MCDA were included in the study. They were rolled into a complication group (44 cases) and a non-complication group (56 cases) according to whether they had complications. The pulsatility index (PI), resistance index (RI), and systolic/diastolic (S/D) values of ultrasound in pregnant women and the final neonatal situation at each time period were compared and analyzed. Results: In pregnant women with twin-twin transfusion syndrome (TTTS), there was no significant difference in RI and S/D values between the larger and smaller twin during pregnancy (P > .05). Compared to the group without complications, the incidence of neonatal death was significantly increased in the complication group, and the newborn's weight, length, head circumference, and Apgar score were significantly lower (P < .05). In pregnant women with selective intrauterine growth restriction (sIUGR), the RI and PI values of the larger twin were significantly higher than those of the smaller twin during pregnancy, and S/D values were significantly lower (P < .05). The newborns in the group without complications had significantly higher body weight, length, and head circumference (P < .05). In pregnant women with gestational diabetes mellitus (GDM), there was no significant difference in RI and S/D values between the larger and smaller twin during pregnancy (P > .05), and there were no significant differences in other indicators compared to the group without complications. In pregnant women with premature rupture of membrane (PROM), there was no significant difference in RI and S/D values between the larger and smaller twin during pregnancy (P > .05), but the newborns in the group without complications had significantly higher weight, length, Apgar score, and lower incidence of neonatal death (P < .05). In pregnant women with preeclampsia (PE), there was no significant difference in RI and S/D values between the larger and smaller twin during pregnancy (P > .05), and there were no significant differences in other indicators compared to the group without complications (P > .05). Conclusion: Pregnant women with sIUGR had significantly higher RI and PI values in the larger twin and significantly lower S/D values compared to the smaller twin during pregnancy, while no significant differences were observed for other complications. The combination of TTTS and PROM decreased the birth weight, body length, head circumference, and Apgar score of twins and increased the mortality rate.

Elevated middle cerebral artery peak systolic velocity and risk of death in donor twin affected by twin-twin transfusion syndrome but not twin anemia-polycythemia sequence.

OBJECTIVES: To determine the association between elevated (> 1.5 multiples of the median (MoM)) middle cerebral artery (MCA) peak systolic velocity (PSV) and fetal demise of the donor twin in pregnancies complicated by twin-twin transfusion syndrome (TTTS) in the absence of twin anemia-polycythemia sequence (TAPS). Secondary objectives were to evaluate if donor or recipient MCA-PSV is associated with a risk for their corresponding fetal death, and to compare the proportion of donor fetuses with low MCA pulsatility index (PI) among donor twins with high MCA-PSV and those with normal MCA-PSV to evaluate the contribution of blood-flow redistribution to the fetal brain in donor twins with high MCA-PSV. METHODS: This prospective cohort study included TTTS cases that underwent laser surgery between 2011 and 2022 at a single center. TAPS cases were excluded from the study. Multivariable and Poisson regression analysis were performed to explore the association between isolated elevated donor MCA-PSV and fetal demise, adjusted for TTTS stage, selective fetal growth restriction (sFGR) and other confounders. RESULTS: Of 660 TTTS cases, donor MCA-PSV was not recorded in 48 (7.3%) cases. Of the remaining 612 patients, nine (1.5%) were lost to follow-up and 96 TAPS cases were excluded; thus, 507 cases were included in the study. High donor MCA-PSV was seen in 6.5% (33/507) of cases and was an independent risk factor for donor fetal demise (adjusted relative risk (aRR), 4.52 (95% CI, 2.72-7.50)), after adjusting for confounders. Regression analysis restricted to each Quintero TTTS stage demonstrated that high donor MCA-PSV was an independent risk factor for fetal demise of the donor in Quintero Stage II (aRR, 14.21 (95% CI, 1.09-186.2)) and Quintero Stage III (aRR, 3.41 (95% CI, 1.82-6.41)). Donor MCA-PSV in MoM was associated with fetal demise of the donor (area under the receiver-operating-characteristics curve (AUC), 0.69; P < 0.001), but recipient MCA-PSV in MoM was not associated with fetal demise of the recipient (AUC, 0.54; P = 0.44). A higher proportion of donor twins in the group with high MCA-PSV had a low MCA-PI compared to the group with normal MCA-PSV (33.3% vs 15.5%; P = 0.016). CONCLUSIONS: Elevated donor MCA-PSV without TAPS prior to laser surgery for TTTS is associated with a 4-fold increased risk for donor fetal demise, adjusted for sFGR, TTTS stage and other confounders. Doppler evaluation of donor MCA-PSV prior to laser surgery may help stratify TTTS staging to evaluate the risk of donor fetal demise. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

The changing Doppler patterns and perinatal outcomes of monochorionic diamniotic twins with selective fetal growth restriction.

OBJECTIVES: To investigate the clinical outcomes and Doppler patterns changes in monochorionic diamniotic (MCDA) twins with selective fetal growth restriction (sFGR). METHODS: We retrospectively analyzed 362 sFGR cases from January 2010 to May 2016 at a single tertiary referral center. The Doppler waveforms of umbilical artery end-diastolic flow were collected, and all neonates were subjected to an early neonatal brain scan. RESULTS: A total of 66/100 (66 %) type I cases were stable, whereas 25/100 (25 %) cases changed to type II and 9/100 (9 %) changed to sFGR complicated twin-twin transfusion syndrome (TTTS). A total of 48.9 % (22/45) sFGR cases were complicated with polyhydramnios and 30.4 % (7/23) sFGR cases were complicated with oligohydramnios, both of which were progressed to sFGR with TTTS. Mild cerebral injury was significantly associated with Doppler flow abnormalities, earlier gestational age at delivery and type of sFGR diagnosis. Severe cerebral injury was significantly associated with gestational age at delivery (31.6 vs. 34.1, p=0.002) and larger birthweight discordance (43.9 vs. 29.3 %, p=0.011). CONCLUSIONS: Doppler patterns in sFGR can gradually change, with important consequences with regard to management and outcomes. Along with abnormal Doppler findings, earlier occurrence of sFGR and delivery are associated with subsequent neonatal cerebral injury.

Fetal and neonatal neuroimaging in twin-twin transfusion syndrome.

OBJECTIVES: To describe the types of brain injury and subsequent neurodevelopmental outcome in fetuses and neonates from pregnancies with twin-twin transfusion syndrome (TTTS). Additionally, to determine risk factors for brain injury and to review the use of neuroimaging modalities in these cases. METHODS: This was a retrospective cohort study of consecutive TTTS pregnancies treated with laser surgery in a single fetal therapy center between January 2010 and January 2020. The primary outcome was the incidence of brain injury, classified into predefined groups. Secondary outcomes included adverse outcome (perinatal mortality or neurodevelopmental impairment), risk factors for brain injury and the number of magnetic resonance imaging (MRI) scans. RESULTS: Cranial ultrasound was performed in all 466 TTTS pregnancies and in 685/749 (91%) liveborn neonates. MRI was performed in 3% of pregnancies and 4% of neonates. Brain injury was diagnosed in 16/935 (2%) fetuses and 37/685 (5%) neonates and all predefined injury groups were represented. Four fetal and four neonatal cases of cerebellar hemorrhage were detected. Among those with brain injury, perinatal mortality occurred in 11/16 (69%) fetuses and 8/37 (22%) neonates. Follow-up was available for 29/34 (85%) long-term survivors with brain injury and the mean age at follow-up was 46 months. Neurodevelopmental impairment was present in 9/29 (31%) survivors with brain injury. Adverse outcome occurred in 28/53 (53%) TTTS individuals with brain injury. The risk of brain injury was increased after recurrent TTTS/post-laser twin anemia-polycythemia sequence (TAPS) (odds ratio (OR), 3.095 (95% CI, 1.581-6.059); P = 0.001) and lower gestational age at birth (OR per 1-week decrease in gestational age, 1.381 (95% CI, 1.238-1.541); P < 0.001). CONCLUSIONS: Based on dedicated neurosonography and limited use of MRI, brain injury was diagnosed in 2% of fetuses and 5% of neonates with TTTS. Adverse outcome was seen in over half of cases with brain injury. Brain injury was related to recurrent TTTS/post-laser TAPS and a lower gestational age at birth. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Predictors of fetal death, neonatal survival and neurological outcomes in severe twin-twin transfusion syndrome treated by laser ablation of placental vessels.

OBJECTIVES: To identify predictors of outcomes in severe twin oligo-polyhydramnios sequence (TOPS) with or without twin anemia-polycythemia sequence (TAPS) and/or selective fetal growth restriction (SFGR) treated by laser ablation of placental vessels (LAPV). METHODS: Analysis of cases treated from 2011 to 2022. Variables evaluated Prenatal predictors: stages of TOPS, presence of TAPS and/or SFGR; pre-LAPV fetal ultrasound parameters; peri-LAPV variables. Perinatal predictors: GA at birth; birthweight; Apgar scores; transfontanellar ultrasonography (TFUS). OUTCOME VARIABLES: fetal death, neonatal survival, infant's neurodevelopment. Binary logistic regression analyses were performed to detect predictors of outcomes. RESULTS: 265 cases were included. Predictors of post-LAPV donor fetus' death were delta EFW (p:0.045) and absent/reverse end-diastolic flow in the umbilical artery (AREDF-UA) (p < 0.001). The predictor of post-LAPV recipient fetus' death was hydrops (p:0.009). Predictors of neonatal survival were GA at birth and Apgar scores. Predictors of infant's neurodevelopment were TFUS and pre-LAPV middle cerebral artery Doppler (MCAD) for the donor twin; and pre-LAPV ductus venosus' flow and MCAD for the recipient twin. CONCLUSIONS: Prediction of fetal death, neonatal survival and infant's neurodevelopment is possible in cases of TOPS associated or not with SFGR and/or TAPS that were treated by LAPV.

Placental vessel segmentation and registration in fetoscopy: Literature review and MICCAI FetReg2021 challenge findings.

Fetoscopy laser photocoagulation is a widely adopted procedure for treating Twin-to-Twin Transfusion Syndrome (TTTS). The procedure involves photocoagulation pathological anastomoses to restore a physiological blood exchange among twins. The procedure is particularly challenging, from the surgeon's side, due to the limited field of view, poor manoeuvrability of the fetoscope, poor visibility due to amniotic fluid turbidity, and variability in illumination. These challenges may lead to increased surgery time and incomplete ablation of pathological anastomoses, resulting in persistent TTTS. Computer-assisted intervention (CAI) can provide TTTS surgeons with decision support and context awareness by identifying key structures in the scene and expanding the fetoscopic field of view through video mosaicking. Research in this domain has been hampered by the lack of high-quality data to design, develop and test CAI algorithms. Through the Fetoscopic Placental Vessel Segmentation and Registration (FetReg2021) challenge, which was organized as part of the MICCAI2021 Endoscopic Vision (EndoVis) challenge, we released the first large-scale multi-center TTTS dataset for the development of generalized and robust semantic segmentation and video mosaicking algorithms with a focus on creating drift-free mosaics from long duration fetoscopy videos. For this challenge, we released a dataset of 2060 images, pixel-annotated for vessels, tool, fetus and background classes, from 18 in-vivo TTTS fetoscopy procedures and 18 short video clips of an average length of 411 frames for developing placental scene segmentation and frame registration for mosaicking techniques. Seven teams participated in this challenge and their model performance was assessed on an unseen test dataset of 658 pixel-annotated images from 6 fetoscopic procedures and 6 short clips. For the segmentation task, overall baseline performed was the top performing (aggregated mIoU of 0.6763) and was the best on the vessel class (mIoU of 0.5817) while team RREB was the best on the tool (mIoU of 0.6335) and fetus (mIoU of 0.5178) classes. For the registration task, overall the baseline performed better than team SANO with an overall mean 5-frame SSIM of 0.9348. Qualitatively, it was observed that team SANO performed better in planar scenarios, while baseline was better in non-planner scenarios. The detailed analysis showed that no single team outperformed on all 6 test fetoscopic videos. The challenge provided an opportunity to create generalized solutions for fetoscopic scene understanding and mosaicking. In this paper, we present the findings of the FetReg2021 challenge, alongside reporting a detailed literature review for CAI in TTTS fetoscopy. Through this challenge, its analysis and the release of multi-center fetoscopic data, we provide a benchmark for future research in this field.

Gran feto acardio: diagnóstico tardío de gestacion gemelar monocorial biamniótica complicada por secuencia TRAP: reporte de un caso y revisión de la literatura / Great acardiac fetus: late diagnosis of monochorionic diamniotic twin pregnancy complicated by sequence TRAP: case report and review of the literature

OBJETIVOS: reportar el caso de una paciente con gestación gemelar monocorial-biamniótica complicada por secuencia TRAP que dio lugar al nacimiento de un feto bomba de 1932 gramos sin malformaciones anatómicas y de un feto acardio anceps de 1800 gramos, y realizar una revisión sobre esta patología y la importancia de su diagnóstico y tratamiento precoces. MATERIALES Y MÉTODOS: se presenta el caso de un feto acardio en una gestante con embarazo sin control estricto en el Hospital San Pedro de Logroño en el año 2019, de interés por su diagnóstico tardío y elevado peso al nacimiento del feto acardio. Se realizó una búsqueda de la literatura en las bases de datos Medline vía PubMed, OVID, Embase y SciE-LO con las palabras clave DeCS y términos MeSH. Como criterios de inclusión se consideraron artículos tipo series y reportes de casos y artículos de revisión desde enero de 1950 hasta enero de 2020. RESULTADOS: la búsqueda incluyó 39 referencias bibliográficas sobre las que se repasaron las principales cuestiones teóricas a exponer. El peso del feto acardio de nuestro caso fue muy elevado sin provocar repercusión en el feto sano, en comparación con la bibliografía, lo que aporta singularidad al caso, siendo sólo equiparable la serie de casos de Brassard et al (1999), con pesos de los fetos acardio por encima de 1700 gramos y diferenciándose en 100 gramos del feto bomba. CONCLUSIONES: el feto acardio es una complicación infrecuente de embarazos gemelares monocoriales. Se requiere la presencia de anastomosis vasculares placentarias entre ambas circulaciones. El diagnóstico precoz es importante para disminuir la morbilidad y usar, en la medida de lo posible, técnicas terapéuticas no invasivas.

OBJECTIVES: to report the case of a patient with a monochorionic-biamniotic twin gestation complicated by TRAP sequence that gave rise to the birth of a pump fetus without anatomical malformations (1932 g) and an acardiac anceps fetus (1800 g), and to review this pathology and the importance of its early diagnosis and management. MATERIAL AND METHODS: the case of an acardiac fetus is presented in a pregnant woman without strict control at the Hospital San Pedro de Logroño in 2019, worthwhile because of its late diagnosis and high birth weight. A search of the literature was carried out in the Medline databases via PubMed, OVID, Embase and SciELO with the MeSH terms. As inclusion criteria, we considered series-type articles and case reports, cohorts and review articles from January 1950 to January 2020. RESULTS: 39 bibliographic references were included with the main theoretical questions to be reviewed. Our acardiac fetus weight was very high comparing with the bibiography and without causing repercussion in the healthy fetus, which contributes to the uniqueness of the case, only the series report by Brassard et al (1999) is comparable, with weights of the acardiac fetus above 1700 grams and differing by 100 grams from the pump fetus. CONCLUSIONS: the acardiac fetus is an infrequent complication of monochorionic twin pregnancies. The presence of placental vascular anastomoses between both circulations is required. Early diagnosis is important to decrease morbidity and to use, as far as possible, non-invasive therapeutic techniques.

Acardius mylacephalus: un diagnóstico poco frecuente / Acardius mylacephalus: an infrequent diagnosis

Se presenta el caso clínico de una primigesta de 21 años de edad, a quien se le detectó un embarazo gemelar monoamniótico y monocigótico en el examen ecográfico en el Centro Provincial de Genética de Santiago de Cuba. El primer feto presentaba hidronefrosis bilateral predominantemente en el lado izquierdo, y el segundo estructura fetal rudimentaria y deforme, área cardíaca mal estructurada y latidos cardíacos solo arrítmicos y bradicárdicos, además de que no se definieron los órganos internos y todo se encontraba rodeado de linfangioma quístico grave con grandes quistes paravertebrales y un solo cordón umbilical con tres vasos. Lo descrito en la ecografía se corroboró con los resultados de la necropsia, lo cual se correspondió con la variedad Acardius mylacephalus

The case report of a 21 years primigravida woman is presented to whom a monoamniotic and monochorial twin pregnancy was detected in the echographic exam at the Genetic Provincial Center of Santiago de Cuba. The first fetus presented bilateral hydronephrosis predominantly in the left side, and the second rudimentary and deformed fetal structure, not well structured heart area and just arrhythmic and bradycardiac heart beats besides that the internal organs were not defined and everything was surrounded by severe cystic lymphangioma with big paravertebral cysts and a single umbilical cord with three vessels. Everything described in the echogram was corroborated with the results of the autopsy, which corresponded with Acardius mylacephalus variety

Complicaciones intestinales en el síndrome de trasfusión feto fetal (STFF) / Intestinal complications in twin-to-twin transfusion syndrome (TTTS) treated by laser coagulation (LC)

Introducción: El desequilibrio hemodinámico secundario a la presencia de anastomosis vasculares placentarias en el STFF así como los cambios hemodinámicos generados durante y tras su tratamiento mediante fotocoagulación con láser (FC) puede dar lugar a complicaciones hipóxico-isquémicas en distintos sistemas. Revisamos nuestra experiencia en el tratamiento del STFF con FC y presentamos las complicaciones intestinales encontradas. Material y métodos: Estudio retrospectivo de casos tratados intraútero entre 2012 y 2015. Recogimos datos sociodemográficos, terapia fetal, pruebas diagnósticas prenatales (ecografía, RM) y resultados perinatales. Expresamos las medidas en medianas y rangos. Resultados: Se procedió al tratamiento intraútero de 29 gestaciones monocoriales complicadas con STFF (23 FC, 4 oclusiones de cordón y 2 FC seguidas de oclusión). La edad gestacional en el procedimiento fue 19 (16-26) semanas y en el 86% de los casos se trataba de un estadio de Quintero ≥ II. El 70% de las madres tuvieron al menos 1 recién nacido vivo, con mediana de edad gestacional al parto de 31 (24-37) semanas. Presentaron problemas intestinales 4 pacientes (1 atresia yeyunal, 2 atresias ileales, 1 enterocolitis necrotizante con perforación), con sospecha prenatal diagnóstica en 2 de ellos. Postnatalmente se realizó resección del segmento afecto y ostomía. Actualmente se ha restablecido el tránsito intestinal en todos sin secuelas digestivas graves tras 21(8-38) meses de seguimiento. Conclusiones: Hemos descrito distintos tipos de complicaciones intestinales asociadas al STFF y/o su tratamiento con FC. Es posible hacer el diagnóstico prenatal de dichas complicaciones mediante ecografía y RM. Su conocimiento pone al cirujano en alerta y es importante en la toma de decisiones postnatales

Aim of the study: The hemodynamic imbalance due to placental vascular anastomoses in TTTS but also vascular changes generated after intrauterine treatment may lead to hypoxic-ischemic complications. Different intestinal complications in TTTS are reviewed in this paper. Methods: Retrospective review of TTTS cases treated by laser coagulation (LC) from 2012-2015. Demographic data, fetal therapy, prenatal diagnosis (US, MRI) and perinatal outcome were recorded. We describe cases with intestinal complications and their postnatal management. Results are expressed by median and range. Results: 29 monochorionic pregnancies with TTTS were treated (23 LC, 4 cord occlusions and 2 cord occlusions after LC). The diagnosis was made at 19(16-26) weeks and 86% presented stage of Quintero ≥ II. In 70% of mothers survived at least one fetus with a median of 31 (24-37) weeks at birth. Four patients had intestinal complications (1 jejunal atresia, 2 ileal atresia, 1 perforated necrotizing enterocolitis), half of them had prenatal diagnosis. Postnatal resections of the affected segments and ostomies were performed. Intestinal transit was restored and there were no severe digestive sequelae after 21 (8-38) months of follow up. Conclusions: Different types of intestinal complications were associated with TTTS and LC. US and MRI enable prenatal diagnosis of these complications and this allows prompt decisions after birth

Manejo del síndrome de transfusión feto fetal en gestaciones gemelares monocoriales / Management of twin-twin transfusion syndrome in monochorionic twin gestations

El síndrome de transfusión feto fetal es una complicación grave de las gestaciones gemelares monocoriales. Su etiología se debe a la transfusión crónica de sangre del feto donante, al feto receptor; a través de las anastomosis vasculares entre los territorios placentarios de ambos. El cuadro clínico característico se evidencia en ambos fetos: receptor y donante, lo cual es consecuencia directa de las alteraciones en la volemia que padece cada uno. En el feto receptor, se observa un polihidramnios relacionado con la poliuria derivada de un estado de hipervolemia constante, que evoluciona hacia una insuficiencia cardiaca congestiva. En el feto donante, el cuadro es inverso; caracterizado por oligoamnios, oliguria, crecimiento intrauterino retardado e hipovolemia, con tasas de mortalidad sin tratamiento de entre 80-100 por ciento de los casos, que varían en función del grado de transfusión. El diagnóstico se basa en el estudio ecográfico exhaustivo de ambos fetos, procurando un diagnóstico precoz y un estadiaje correcto, ya que el pronóstico se verá muy influenciado por la actuación temprana. El tratamiento de elección es la coagulación láser de las anastomosis vasculares por fetoscopia, idealmente entre la semana 18 y 26 de embarazo. El pronóstico es variable, en función de la disponibilidad de terapia fetal y de la edad gestacional en el momento del diagnóstico; al ser, en general, de muy mal pronóstico sin tratamiento efectivo(AU)

Twin-twin transfusion syndrome is one of the most serious complications of monochorionic multiple gestations. Its etiology is due to a chronic blood transfusion from de donor twin to the recipient twin through the vascular anastomoses between the placental territories of both fetuses. The characteristic clinical presentation appears in both donor and recipient fetuses, as a direct consequence of altered volemia in each one. Polyhydramnios related to polyuria resulting from a state of constant hypervolemia is observed in the recipient twin, finally evolving into congestive heart failure. The clinical presentation in the donor twin is reversed and characterized by oligoamnios, oliguria, retarded intrauterine growth and hypovolemia, with untreated mortality rates ranging 80-100 percent of all cases, which may vary depending on the severity of the transfusion. The diagnosis is based on exhaustive echographic examination of both fetuses to make an early diagnosis and correct staging, since the prognosis depends very much on early action. The treatment of choice is fetoscopic laser coagulation of vascular anastomoses between 18 and 26 weeks of gestation. The prognosis is variable, depending on the availability of fetal therapy and the gestational age at diagnosis, being prognosis generally very poor without an effective treatment(AU)

Sequência anemia-policitemia em gêmeos: definição, classificação e tratamento / Twin anemia-polycythemia sequence: definition, classification and treatment

A presença de anastomoses vasculares placentárias nas gestações gemelares monocoriônicas favorece o surgimento de complicações graves como a Síndrome de Transfusão Feto-Fetal (STFF) e a Sequência Anemia-Policitemia em Gêmeos (TAPS). STFF e TAPS são ambas formas crônicas de transfusão feto-fetal. TAPS, descrita em 2007, é caracterizada por anemia crônica no gêmeo doador e policitemia no gêmeo receptor, na ausência de discordância no volume de líquido amniótico, característica da STFF clássica. O diagnóstico pode ser feito pré- e pós-natal. O critério diagnóstico pré-natal é baseado na discordância intergemelar da medida do Doppler do pico de velocidade sistólica da artéria cerebral média (PSV-ACM). O diagnóstico pós-natal é baseado na grande diferença da hemoglobina intergemelar, ao nascimento, e reticulocitose no gêmeo doador.(AU)

The presence of placental vascular anastomoses in monochorionic twins favors the development of several complications like Twin-Twin Transfusion Syndrome (TTTS) and Twin Anemia-Polycythemia Sequence (TAPS). TTTS and TAPS are both chronic forms of fetofetal transfusion. TAPS, described on 2007, is characterized by chronic anemia in the donor twin and polycythemia in the recipient twin, in the absence of amniotic fluid volume discordances, characteristic of classical TTTS. The diagnostic can be made pree posnatally. The prenatal diagnostic criteria is based on the inter-twin discordance in Doppler measurement of peak systolic velocity in the middle cerebral artery (MCA-PSV). The postnatal diagnosis is based on large intertwin hemoglobin difference at birth and retoculocytosis in the donor twin.(AU)