Prenatal MRI evaluation of giant neck masses in preparation for the fetal exit procedure

An unusual case of a giant fetal facial tumour and review of the literature

We present the case of a pregnant 32-year-old woman who presented with a giant fetal facial tumour at 22 weeks. The mass, initially 4 × 3.5 × 3 cm in size, was largely cystic with a small solid component. It subsequently increased to 9 × 9 × 10 cm. Significant compression effects on the fetal orbit, temple and infratemporal fossa, with potential compression of the optic nerve, were noted on ultrasound and MRI. The cyst required drainage twice in the pregnancy: firstly to reduce the compression effects and secondly to facilitate caesarean delivery. Postnatally, the baby had significant compression and displacement of the craniofacial skeleton from the mass effect. Postnatal histology revealed a diagnosis of a teratoma. This case highlights the complexities and challenges surrounding the diagnosis and management of a giant fetal facial tumour.

Super-resolution Reconstruction MRI Application in Fetal Neck Masses and Congenital High Airway Obstruction Syndrome

Objective

Reliable airway patency diagnosis in fetal tracheolaryngeal obstruction is crucial to select and plan ex utero intrapartum treatment (EXIT) surgery. We compared the clinical utility of magnetic resonance imaging (MRI) super-resolution reconstruction (SRR) of the trachea, which can mitigate unpredictable fetal motion effects, with standard 2-dimensional (2D) MRI for airway patency diagnosis and assessment of fetal neck mass anatomy.

Study Design

A single-center case series of 7 consecutive singleton pregnancies with complex upper airway obstruction (2013-2019).

Setting

A tertiary fetal medicine unit performing EXIT surgery.

Methods

MRI SRR of the trachea was performed involving rigid motion correction of acquired 2D MRI slices combined with robust outlier detection to reconstruct an isotropic high-resolution volume. SRR, 2D MRI, and paired data were blindly assessed by 3 radiologists in 3 experimental rounds.

Results

Airway patency was correctly diagnosed in 4 of 7 cases (57%) with 2D MRI as compared with 2 of 7 cases (29%) with SRR alone or paired 2D MRI and SRR. Radiologists were more confident (P = .026) in airway patency diagnosis when using 2D MRI than SRR. Anatomic clarity was higher with SRR (P = .027) or paired data (P = .041) in comparison with 2D MRI alone. Radiologists detected further anatomic details by using paired images versus 2D MRI alone (P < .001). Cognitive load, as assessed by the NASA Task Load Index, was increased with paired or SRR data in comparison with 2D MRI.

Conclusion

The addition of SRR to 2D MRI does not increase fetal airway patency diagnostic accuracy but does provide improved anatomic information, which may benefit surgical planning of EXIT procedures.

Risk factor analysis and outcomes of airway management in antenatally diagnosed cervical masses

PURPOSE

To investigate antenatally-determined imaging characteristics associated with invasive airway management at birth in patients with cervical masses, as well as to describe postnatal management and outcomes.

STUDY DESIGN

A retrospective analysis of 52 patients with antenatally diagnosed neck masses was performed using single-center data from January 2008 to January 2019. Antenatal imaging, method of delivery, management, and outcomes data were abstracted from the medical record and analyzed.

RESULTS

Antenatal diagnosis of neck masses in this cohort consisted of 41 lymphatic malformations (78.8%), 6 teratomas (11.5%), 3 hemangiomas (5.8%), 1 hemangioendothelioma (1.9%), and 1 giant foregut duplication cyst (1.9%). Mean gestational age at time of diagnostic imaging was 29 weeks 3 days (range: 19w4d - 37w). Overall, 22 patients (42.3%) required invasive airway management at birth, specifically 18 patients (34.6%) required endotracheal intubation and 4 (7.7%) required tracheostomy. 15 patients (28.8%) underwent ex-utero intrapartum treatment (EXIT) for the purposes of securing an airway. Polyhydramnios, tracheal deviation and compression, and anterior mass location on antenatal imaging were significantly associated with incidence of invasive airway intervention at birth, EXIT procedure, and tracheostomy during the neonatal hospitalization (p < 0.025; Fisher's exact test). Logistic regression analysis demonstrated statistically significant association between increasing antenatally-estimated mass volume and incidence of invasive airway management at birth (p = 0.02). Post-natal cervical mass management involved surgical excision (32.7%), sclerotherapy (50%), and adjuvant therapy with rapamycin (17.3%). Demise in the neonatal period occurred in 4 (7.7%) patients.

CONCLUSION

This series documents the largest single-center experience of airway management in antenatally diagnosed cervical masses. Fetal imaging characteristics may help inform the appropriate method of delivery, airway management strategy at birth, and prenatal counseling.

EXIT (ex utero intrapartum treatment) surgery for the management of fetal airway obstruction: A systematic review of the literature

PURPOSE

To provide a comprehensive overview of the perinatal and maternal outcomes of fetuses undergoing EXIT surgery for the management of fetal airway obstruction secondary to cervical or oral tumors.

METHODS

A comprehensive search from inception to September 2018 was conducted on databases including MEDLINE, EMBASE, Cochrane Library and LILACS. All studies that reported an EXIT surgery in singleton were considered eligible. A descriptive analysis was performed.

RESULTS

Out of the 250 full-text study reports, 120 articles reporting 235 cases of EXIT surgery were included. EXIT surgery was performed at 35.1 weeks of gestation on average. The most frequent diagnosis was teratoma (46.4%, n = 109/235). There were 13 adverse maternal events, and the most frequent one was postpartum hemorrhage (4.7%, n = 11/235). No maternal death was reported. Fetal and neonatal death occurred in 17% (40/235) of the cases. There were 29 adverse fetal events (12.2%), and the most frequent one was the failure of intubation or tracheostomy (3.4%, n = 8/235).

CONCLUSION

EXIT surgery could be considered for the management of an oral or cervical tumor that's highly suspicious of blocking the fetal airway. This systematic review reports that EXIT surgery poses substantial risks of maternal and fetal adverse events, including neonatal death.

LEVEL OF EVIDENCE

IV case series with no comparison group.

Fetal brain, head, and neck tumors: Prenatal imaging and management

Fetal tumors represent an infrequent pathology when compared to congenital malformations, although their true incidence may be underestimated. A variety of benign and malignant neoplasms may occur anywhere in the neural axis. Imaging plays an important role in the fetal tumor diagnosis and evaluation of their resultant complications. Discovery of a fetal mass on obstetric ultrasound necessitates further evaluation with prenatal magnetic resonance imaging (MRI). New MR sequences and new applications of existing techniques have been successfully implemented in prenatal imaging. A detailed assessment may be performed using a variety of MR. Fetal tumors may be histologically benign or malignant, but their prognosis generally remains poor, especially for intracranial lesions. Unfavorable tumor location or heightened metabolic demands on a developing fetus may result in severe complications and a fatal outcome, even in cases of benign lesions. Nowadays, prenatal treatment focuses mainly on alleviation of secondary complications caused by the tumors. In this article we review congenital tumors of the brain, face, and neck encountered in prenatal life, and discuss diagnostic clues for appropriate diagnosis.

Ex utero intrapartum treatment (EXIT) for fetal neck masses: A tertiary center experience and literature review

OBJECTIVE

Currently no established criteria exist to guide use of ex utero intrapartum treatment (EXIT) for fetal neck mass management. This study aims to correlate prenatal radiographic findings with incidence of ex utero intrapartum treatment and necessity of airway intervention at delivery.

METHODS

We reviewed our EXIT experience between 2012 and 17. Furthermore, we performed a literature review of articles reporting incidences of fetal neck masses considered for EXIT. Articles that were included (1) discussed prenatal radiographic findings such as size, features, and evidence of compression and (2) reported extractable data on delivery outcomes and airway status.

RESULTS

Ten cases at our institution were reviewed. Another 137 cases across 81 studies met inclusion criteria. These studies showed aerodigestive tract compression to be significantly associated with neck masses undergoing EXIT. Additionally, there was significantly higher incidence of airway intervention in cases where polyhydramnios, anatomic compression, and solid masses were seen on prenatal diagnostic imaging, while mass location and size did not correlate with airway intervention.

CONCLUSION

With this data, we propose that any neck mass with anatomic compression on fetal imaging in the 3rd trimester should be considered for EXIT. When radiographic findings do not show compression but do display polyhydramnios or a solid neck mass (regardless of polyhydramnios), an airway surgeon should be available for perinatal airway assistance.

Prenatal diagnosis of congenital head, face, and neck malformations-Is complementary fetal MRI of value?

OBJECTIVES

The aim of this study was to evaluate the role of fetal magnetic resonance imaging (MRI) as a complement to ultrasound (US) in the prenatal diagnosis of craniofacial anomalies.

METHODS

A historical cohort study including all pregnant women who were referred for fetal MRI because of antenatal diagnosis of craniofacial anomalies on screening US. Prenatal diagnostic US, MRI, and postnatal diagnosis were compared for consistencies and discrepancies.

RESULTS

Forty-five pregnant women with 73 suspected fetal craniofacial anomalies diagnosed by US underwent MRI. In 40 out of 73 anomalies (54.8%), US and MRI findings were in complete agreement with postnatal diagnoses. MRI correctly ruled out the diagnosis of 24 anomalies suspected on US and diagnosed four additional pathologies that were not demonstrated by US. Out of the 85 anomalies (suspected by imaging or confirmed postnatally), confident diagnosis could be made by MRI in 68 anomalies (80%), not diagnosed in 10 (11.8%), and over-diagnosed in seven (8.2%). By US, confident diagnosis could be made in 44 anomalies (51.8%), not diagnosed in 11 (12.9%), and over-diagnosed in 30 (35.3%).

CONCLUSION

MRI is valuable in the antenatal evaluation of fetal craniofacial anomalies and may be useful as an adjunct to US in the prenatal work-up of craniofacial anomalies.

Clinical outcomes of ex utero intrapartum treatment for fetal airway obstruction

PURPOSE

The aim of this study was to evaluate the indications and the clinical outcomes of the fetuses managed with ex utero intrapartum treatment (EXIT) procedures.

METHODS

We retrospectively reviewed the medical records of all fetuses who underwent EXIT procedures between 2003 and 2018.

RESULTS

EXIT procedures were performed in nine cases. The prenatal diagnosis of the neonates was congenital high airway obstruction syndrome in four cases, the neck masse in five cases. Although the airway management under the EXIT procedure was successful in eight cases, the airway management failed in one case. During the EXIT procedures, the airway was managed by endotracheal intubation in two cases, whereas six cases underwent tracheostomy. Six cases with fetal airway obstruction survived to discharge, whereas three cases died due to airway management failure or complications of the underlying disease. A case with a cervical teratoma underwent tumor resection the day after birth due to rapid enlargement of the neck mass. Long-term survival was achieved in five cases.

CONCLUSIONS

We concluded that the EXIT procedure was effective and could be performed safely in the airway management of fetuses with suspected airway obstruction. The treatment strategy for the neck masses should be planned before birth.

Prenatal MRI of neck masses with special focus on the evaluation of foetal airway

BACKGROUND

Prenatal magnetic resonance imaging is the best tool to visualize foetal airway.

OBJECTIVE

To evaluate the performance of MRI in the assessment of foetal airway status in the presence of a neck mass.

MATERIALS AND METHODS

Two paediatric radiologists with 12- and 2-year experience in foetal imaging retrospectively analysed 23 foetal MRI examinations, performed between 2001 and 2016, after a second-level ultrasound suspicious for presence of a neck mass. Postnatal imaging, postoperative report, histology, autopsy, and clinical outcomes were the reference standard to calculate sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of prenatal MRI in detecting airway patency. We used the Cohen к statistics to estimate the interobserver agreement. We also assessed MRI performance in the diagnosis of the mass nature.

RESULTS

We obtained data about postnatal airway status in 19 of 23 patients; prenatal MRI demonstrated a sensitivity of 9/9 [100%, 95% confidence interval (CI) 66-100%], specificity 8/10 (80%, 44-98%), accuracy 17/19 (89%, 67-99%), PPV 9/11 (82%, 48-98%), and NPV 8/8 (100%, 63-100%); the interobserver agreement was perfect. Prenatal MRI correctly identified 21 of 23 masses (к = 0.858); the interobserver agreement was almost perfect (к = 0.851).

CONCLUSION

Prenatal MRI demonstrated high accuracy in assessing foetal airway status and diagnosing mass nature, allowing proper delivery planning.

Fetal Evaluation and Airway Management

Congenital causes of airway obstruction once noted at birth are now diagnosed prenatally. The adoption of ex utero intrapartum treatment has allowed for planned airway stabilization on placental support, dramatically decreasing the incidence of hypoxic injury or peripartum demise related to neonatal airway obstruction. Airway access is gained either through laryngoscopy, bronchoscopy, or a surgical airway. In complete airway obstruction, primary resection of the obstructing lesion may be performed before completion of delivery. This article reviews the current and emerging methods of fetal evaluation, indications for ex utero intrapartum treatment, and provides a detailed description of the procedure and necessary personnel.

Prenatal diagnosis of cervical masses by magnetic resonance imaging and 3D virtual models: perinatal and long-term follow-up outcomes

Objective: To assess perinatal and long-term follow-up outcomes of fetal cervical masses diagnosed by three-dimensional (3D) magnetic resonance imaging (MRI) and 3D virtual models.Methods: This retrospective cohort study evaluated 15 pregnant women (age, 21-38 years) at 29-40 weeks of singleton gestation, whose fetuses exhibited congenital oral and cervical masses. These women were referred to our facility because of suspected fetal malformations on routine obstetric ultrasound, and the cases were confirmed, excluded, or complemented by MRI. Demographic data and perinatal and long-term follow-up outcomes were assessed.Results: Cervical masses were predominant in females (3:2), and the most frequent diagnosis was lymphatic-venous malformation (71%). The masses were cystic in 53.3% of the cases and solid in 46.7%. The esophagus and trachea were displaced in 46.6% of the cases. Associated malformations were diagnosed in 13.3% of the cases. There was complete agreement between prenatal MRI and postnatal diagnoses. Among the newborns, 40% had complications and 46.6% were admitted to the neonatal intensive care unit. Two infants died from complications due to epignathus. Surgical resection was performed in 33.3% of the cases, including complete resection in 26.6%. Sclerotherapy was administered to 53.3% of the cases, with complete remission achieved in 50% of these cases.Conclusion: Cervical masses diagnosed in the prenatal period had good postnatal outcomes except for cases of epignathus, which were associated with high mortality. MRI demonstrated the relationship between cervical masses and adjacent organs and allowed 3D virtual reconstruction of the airways. There was complete agreement between the prenatal diagnosis of cervical masses on MRI and postnatal diagnosis. Surgical treatment was effective in most cases, and sclerotherapy was satisfactory in cases with intrathoracic components.

Fetal Head and Neck Masses: MRI Prediction of Significant Morbidity

OBJECTIVE

The purpose of this study is to determine which MRI parameters of fetal head and neck masses predict high-morbidity neonatal outcomes, including ex utero intrapartum treatment (EXIT) procedure.

MATERIALS AND METHODS

This retrospective study (2004-2016) included parameters of polyhydramnios (based on largest vertical pocket), mass effect on the trachea, mass midline extension, and morphologic grade and size of masses. The morbid cohort included those requiring an EXIT procedure, difficult intubation at delivery, or lethal outcome. Predictive modeling with a multivariable logistic regression and ROC analysis was then performed.

RESULTS

Of 36 fetuses, five were delivered by EXIT procedures, there was one neonatal death within 12 hours after delivery, and another neonate required multiple intubation attempts. The remaining 29 fetuses were delivered at outside institutions with no interventions or neonatal morbidity. The largest vertical pocket and mass effect on the trachea were selected as independent predictors by the logistic regression. The cross-validated ROC AUC was 0.951 (95% CI, 0.8795-1).

CONCLUSION

The largest vertical pocket measurement and mass effect on the trachea were the most contributory MRI parameters that predicted significant morbidity in fetuses with masses of the face and neck, along with other significant parameters. These parameters predict significant morbid neonatal outcomes, including the need for EXIT procedures.

Ex utero intrapartum treatment procedure in two fetuses with airway obstruction

The ex utero intrapartum treatment (EXIT) procedure was introduced to reduce fetal hypoxic damage while establishing an airway in fetuses with upper and lower airway obstruction. Delivery of the fetal head and shoulders while maintaining the uteroplacental circulation offers time to secure the fetal airway. Here, we report two cases of EXIT procedure for fetal airway obstruction, which were successfully managed with extensive preoperative planning by a professional multidisciplinary team.

Infantile hemangiopericytoma of the tongue-Efficacy of ex utero intrapartum treatment procedure and combined-modality therapy

Here we present an extremely rare case of giant infantile hemangiopericytoma (HPC) of the tongue diagnosed prenatally by fetal ultrasonography and MR imaging. Due to airway stenosis, the patient was delivered by the ex utero intrapartum treatment (EXIT) procedure at 36 weeks of pregnancy. Initial diagnosis was infantile hemangioma based on physical examination, diagnostic imaging and the high incidence of hemangioma. The tumor was resistant to conservative treatments. Due to severe tumor hemorrhage, the nutrient vessel was embolized by endovascular treatment on the 73th day after birth. Two days after embolization, a hemiglossectomy was performed. Histological analysis after surgery diagnosed infantile HPC with microscopically positive stumps. After receiving adjuvant chemotherapy, the patient has had no recurrence after 53 months with normal speech and swallowing function resulting in normal growth. Our findings support that infantile HPC is one of the differential diagnosis of infantile hemangioma. The EXIT procedure could be effective for infants with upper respiratory stenosis by head and neck tumor diagnosed prenatally. Though complete resection is required for infantile HPC, our report suggests that a conservative surgical approach followed by adjuvant chemotherapy should be used for giant head and neck infantile HPC.

Advances in Fetal Surgery

Advances in prenatal screening and diagnosis, combined with an understanding of the pathophysiology of congenital anomalies, have brought incredible impetus to the field of fetal surgery. Identification of fetal anomalies can lead to counseling of the affected family so that informed decisions can be made on how to proceed with the pregnancy. Counseling may lead to pregnancy termination, changes in the timing or mode of delivery, and, in select cases, prenatal intervention. Open fetal surgery may be considered in severe cases of congenital diaphragmatic hernia, congenital chest lesions, sacrococcygeal teratoma, urinary tract obstruction, and myelomeningocele. The ex utero intrapartum treatment procedure may be lifesaving for fetuses with giant neck masses. Finally, fetoscopic surgery may be offered for select cases of twin-twin transfusion syndrome and twin reversed arterial perfusion sequence. Fetal intervention in all of these cases depends on a team approach to the patient and on the objective comparison of outcomes with and without fetal therapy. In the future, further understanding of the genetic basis of congenital diseases may enable minimally invasive treatments such as stem cell transplantation or gene therapy.

Immediate operative management of the fetus with airway anomalies resulting from congenital malformations

Prenatal diagnosis has transformed the outcome of fetuses with airway obstruction. The thorough evaluation of prenatal imaging allows for categorizing fetuses with airway compromise into those who will require a special mode of delivery and those who can be delivered without any special resources. The ex-utero intrapartum treatment (EXIT) approach allows accessing the airway while the fetus is under placental support, converting a potentially catastrophic situation into a controlled one. An expert multidisciplinary team is the key to success.

Management of Giant Cervical Teratoma with Intracranial Extension Diagnosed in Utero

Cervical teratomas are rare germ cell tumors affecting the fetus that are associated with significant morbidity and mortality due to an increased risk of airway obstruction at delivery. These tumors can commonly produce polyhydramnios that results from the fetus' impaired ability to swallow amniotic fluid. Improved rates of prenatal diagnosis through comprehensive evaluations and imaging have dramatically impacted the perinatal management of infants with this condition. Here, we report a patient diagnosed with polyhydramnios whose fetus was discovered to have a giant cervical teratoma on imaging studies. The child underwent surgical resection after having the airway secured under the uteroplacental support as part of an ex utero intrapartum treatment procedure performed at 37 weeks. The following gross pathological and magnetic resonance images demonstrate this condition and its currently accepted treatment.

[Iconographic imaging (ultrasound/MRI) in prenatal evaluation of cervical cystic lymphatic malformations]

OBJECTIVES

Assess imaging (ultrasound±MRI) in the diagnosis of cervical cystic lymphangioma.

METHODS

Retrospective, descriptive study of the patients who underwent reference ultrasound screening for fetal anterior cervival masses in multidisciplinary prenatal diagnosis center of the Lille Regional University Hospital from 1997 to 2014.

RESULTS

Seventeen lymphangiomas were identified. Seventy-three percent of lymphangiomas (n=12) were diagnosed in the baseline ultrasound and 85% (n=11) in MRI. An extra-cervical extension was identified in 10 (62%) with ultrasound and 11 (85%) with MRI. Main sites of mass extension objectived by ultrasound and MRI were respectively the face (4,23%/6,46%), the base of tongue (3, 18%/2, 15%) and buccal floor (3, 18%/3, 15%). Pharyngeal disease (5,38%) and mandible (4,31%) were detected by MRI and not found on ultrasound. Associated malformations detected with ultrasound were 2 (12%) urogenital malformation, 1 (6%) heart defect and 1 (6%) facial anomalies. Lymphangiomas remained stable in volume in 12 (71%) cases and disappeared before birth in 2 (12%) cases.

CONCLUSION

MRI and ultrasound seem inseparable to assess and optimally manage fetal cervical masses. Detection of associated lesions seems to help in the final lymphangioma diagnosis. Most of the time, lymphangiomas seem to be stable lesion during pregnancy and a good prognosis in cases of uncomplicated cervical lymphatic mass and without pejorative extension.

An Unusual Origin of Fetal Lymphangioma Filling Right Axilla

Fetal lymphangioma is a hamartomatous congenital anomaly of the lymphatic system, which is embracing the fetal skin (sometimes mucous membranes) and the subcutaneous tissue. The general consensus is that it occurs as a result of failure in lymphatic drainage. A 36-year-old pregnant woman was referred to our perinatology clinic at 22 weeks' gestation, because of a fetal right-sided axillary mass revealed by ultrasonography. The mass measuring 5x7x7cm in three dimensions had a multilocular structure without colour Doppler flow and well-circumscribed borders. Amniocentesis revealed a normal constitutional karyotyping. Lymphangioma was considered as prediagnosis. A healthy female baby weighing 3470 grams was delivered at term. Neonatal examination and the postnatal MRI confirmed the diagnosis. The baby is still on follow-up with the medical treatment of Sirolimus an anti-proliferative drug, and the mass got smaller significantly in 8 months after delivery.

Prenatally diagnosed neck masses: long-term outcomes and quality of life

PURPOSE

To determine long-term outcomes of fetuses with neck masses (NM), including functional and cosmetic results.

METHODS

A retrospective review was performed of all fetuses evaluated for NM from November 2001 to March 2014. Quality of life (QOL) was evaluated using the validated PedsQL™ questionnaire.

RESULTS

Of 35 fetuses evaluated, 9 died perinatally and 1 died late from tracheostomy complications. NM ranged from 4 to 20cm (mean, 9.1cm); 18 were delivered by EXIT. Of 25 surviving patients, 22 had mass resection, 7 requiring more than one procedure. Surviving patients with lymphatic malformations (LM) had the highest incidence of moderate and severe disfigurement and a higher rate of persistent/recurrent disease (100% vs. 31%, p=0.002) and cranial nerve dysfunction (50% vs. 0%, p=0.005) compared to those with non-LM diagnoses. Of 9 children attending school, 78% achieve grades of A/B's. QOL for 13 patients revealed a mean score of 83/100 for physical and 78/100 for psychosocial functioning. Median follow-up was 6 years (7 months-17 years).

CONCLUSION

Unlike those with teratoma or other lesions, children with congenital cervicofacial LM are at high-risk for persistent disease, nerve dysfunction and moderate-severe disfigurement. There is substantial perinatal morbidity for fetuses with neck masses, but for those surviving, the long-term functional and cognitive outcomes are good.

MR imaging of the fetal brain at 1.5T and 3.0T field strengths: comparing specific absorption rate (SAR) and image quality

OBJECTIVES

Our two objectives were to evaluate the feasibility of fetal brain magnetic resonance imaging (MRI) using a fast spin echo sequence at 3.0T field strength with low radio frequency (rf) energy deposition (as measured by specific absorption rate: SAR) and to compare image quality, tissue contrast and conspicuity between 1.5T and 3.0T MRI.

METHODS

T2 weighted images of the fetal brain at 1.5T were compared to similar data obtained in the same fetus using a modified sequence at 3.0T. Quantitative whole-body SAR and normalized image signal to noise ratio (SNR), a nominal scoring scheme based evaluation of diagnostic image quality, and tissue contrast and conspicuity for specific anatomical structures in the brain were compared between 1.5T and 3.0T.

RESULTS

Twelve pregnant women underwent both 1.5T and 3.0T MRI examinations. The image SNR was significantly higher (P=0.03) and whole-body SAR was significantly lower (P<0.0001) for images obtained at 3.0T compared to 1.5T. All cases at both field strengths were scored as having diagnostic image quality. Images from 3.0T MRI (compared to 1.5T) were equal (57%; 21/37) or superior (35%; 13/37) for tissue contrast and equal (61%; 20/33) or superior (33%, 11/33) for conspicuity.

CONCLUSIONS

It is possible to obtain fetal brain images with higher resolution and better SNR at 3.0T with simultaneous reduction in SAR compared to 1.5T. Images of the fetal brain obtained at 3.0T demonstrated superior tissue contrast and conspicuity compared to 1.5T.

Timing of MRI in pregnancy, repeat exams, access, and physician qualifications

This review addresses specific questions regarding performance and utility of fetal MR. The specific issues addressed are (1) physician qualifications; (2) MR safety; (3) access to fetal MR; (4) timing of MRI in pregnancy; (5) repeat exams; and (6) when MRI is most effective for prenatal diagnosis. Fetal MRI is a problem-solving tool used for specific indications that are driven by ultrasound or at times by family history. Fetal MR should always be performed with knowledge of the sonographic findings from prior targeted scan. The best evidence for utility of MR is in assessment of CNS anomalies and assessment of the fetus with airway obstruction requiring decisions regarding mode of therapy. The type of information provided by MR can profoundly impact patient counseling and management. We recommend a team approach including specialists in obstetric imaging, fetal MRI, and postnatal care in interpreting MR so that the best information can be given to the pregnant patient.

The ex utero intrapartum treatment (EXIT) procedure: application of a new therapeutic paradigm

The ex utero intrapartum treatment (EXIT) procedure is a term given to a technique that can transform a potentially fatal neonatal emergency to a controlled intervention with an improved outcome. It has revolutionised the care of prenatally diagnosed congenital malformations in which severe upper airway obstruction is anticipated. An extended period of utero-placental circulation can be utilised to avoid profound cardiopulmonary compromise. Its therapeutic applications have been broadened to include fetuses with congenital diaphragmatic hernia after tracheal plugging, high-risk intrathoracic masses, severe cardiac malformations and conjoined twins. It requires the co-ordination of a highly skilled and experienced multidisciplinary team. The recent enthusiasm for the EXIT procedure needs to be balanced against maternal morbidity. Specific indications and guidelines are likely to be refined as a consequence of ongoing advances in fetal intervention and antenatal imaging.

Fetal magnetic resonance imaging of lymphangiomas

OBJECTIVES

To evaluate the fetal magnetic resonance imaging findings of lymphangiomas.

METHODS

The magnetic resonance scans of eight fetuses with lymphangiomas were evaluated. Magnetic resonance evaluation included: number; size; signal intensities of the lesions; thickness of the septae; configuration of the margins; presence of blood breakdown products; change in size or signal intensity (in four patients with multiple examinations); exact expansion of the lesions to the adjacent anatomical structures; and concomitant pathological findings. Results were compared with postpartum clinical assessment and imaging in seven patients and with autopsy in one patient.

RESULTS

Two retroperitoneal, three thoracic, and three cervical lymphangiomas (diameters between 3.3 and 15.6 cm) were included. All lesions consisted of macrocysts, and additional microcystic parts were found in three lymphangiomas. Blood breakdown products were found in one lesion. Agreement with postpartum imaging was excellent. One patient received intrauterine drainage for chylothorax, and one pregnancy was terminated.

CONCLUSIONS

Fetal lymphangiomas display the same magnetic resonance imaging features as postnatal lymphangiomas. Intrauterine magnetic resonance characterization of lymphangiomas provides the exact delineation, detection of associated and/or concomitant pathologies, and differential diagnosis among other cystic pathologies. Patient management may be altered with respect to the type and/or time of treatment, and with regard to the continuation or termination of pregnancy.

Ex utero intrapartum treatment in the management of giant cervical teratomas

PURPOSE

The purpose of this study is to present the outcome and technical details of the Ex Utero Intrapartum Treatment (EXIT) procedure performed in the management of the fetus with a giant cervical teratoma.

METHODS

A retrospective review of the medical records of patients undergoing the EXIT procedure between September 1995 and September 2010 was performed.

RESULTS

Eighty-seven EXIT procedures were performed. In 20% of cases (17/87), the indication was giant cervical teratoma. There were 10 females and 7 males. Polyhydramnios was present in 82%. Median gestational age at EXIT was 35 weeks (range, 30-39 weeks). Median birth weight was 2.5 kg (range, 1.7-3.7 kg). Access to the airway under placental support was established in all cases via direct laryngoscopy/bronchoscopy in 8 patients (47%) and via surgical exploration (tracheostomy or retrograde intubation) in 9 patients (53%). The mortality rate under placental support was zero. Seven patients had the tumors resected immediately after the EXIT, 6 patients had the resection later, and 4 patients died before resection. The neonatal mortality rate was 23% (4/17 patients). Patients who died had severe pulmonary hypoplasia that resulted from the upward traction by the giant cervical mass on the airway and compression of the lungs against the thoracic apex.

CONCLUSIONS

We conclude that the EXIT procedure continues to be the optimal delivery strategy for patients with prenatally diagnosed giant cervical teratomas and potential airway obstruction at birth. A thorough evaluation of the prenatal images and an experienced multidisciplinary team are key factors for an effective approach to the obstructed fetal airway.

Fetal neuroimaging

Although ultrasound remains the screening modality of choice in evaluation of the fetal nervous system, magnetic resonance imaging with its multiplanar imaging ability and high signal-to-noise ratio is highly accurate in illustrating the morphologic changes of the developing brain and fetal brain abnormalities. Fetal magnetic resonance imaging is an established powerful tool for obtaining additional information in evaluation of anomalies of the fetal face, neck, and spine. It is helpful to patients and their health care professionals in making vital management decisions and aids in genetic counseling for future pregnancies.

Tracheoesophageal displacement index and predictors of airway obstruction for fetuses with neck masses

PURPOSE

There are no established selection guidelines to determine which fetuses with giant neck masses may benefit from delivery using an ex utero intrapartum treatment procedure. The purposes of this study were to describe the tracheoesophageal displacement index (TEDI), a novel measurement of fetal airway displacement, and to correlate this measurement and other prenatal findings to the extent of airway obstruction at birth.

METHODS

The medical records of all fetuses with giant neck masses evaluated between 2001 and 2011 were reviewed. At birth, each infant's airway was categorized as uncomplicated or complicated. Prenatal variables were correlated with airway difficulty.

RESULTS

There were 24 fetuses with large neck masses (11 lymphatic malformations, 10 teratomas, 3 others). One fetus died in utero, and 3 underwent pregnancy termination. Variables associated with a complicated airway at birth included polyhydramnios, teratoma diagnosis, and tracheoesophageal displacement index. Tracheoesophageal displacement index greater than 12 correlated strongly with a complicated airway (area under the curve = 0.80). All fetuses classified with an uncomplicated airway (n = 7) had a diagnosis other than teratoma and normal amniotic fluid volume.

CONCLUSION

In fetuses with giant neck masses, the presence of polyhydramnios, teratoma diagnosis, or tracheoesophageal displacement index greater than 12 are predictive of a complicated airway at birth. Our data suggest that fetuses without any of these findings may be delivered safely without an ex utero intrapartum treatment approach.

Prenatal sonographic diagnosis of congenital epulis

Congenital epulis is a benign gingival tumor that has rarely been diagnosed prenatally. We report a fetus with congenital epulis diagnosed by ultrasound at 37 weeks' gestation. The mass was diagnosed as originating from the inferior alveolar ridge prenatally. After birth, it was completely removed by simple excision under general anesthesia. Histologic examination revealed a congenital granular cell tumor.

Ex-utero intrapartum treatment procedure for giant neck masses--fetal and maternal outcomes

BACKGROUND/PURPOSE

For fetuses with giant neck masses and tracheal obstruction, an ex-utero intrapartum treatment (EXIT) procedure allows for safe nonemergent airway management while on placental support. Our objective was to examine fetal and maternal outcomes after EXIT procedure specifically for giant neck masses.

METHODS

The medical records of all patients referred to a comprehensive fetal center for a giant neck mass between 2001 and 2010 were reviewed retrospectively.

RESULTS

Among 24 patients referred, an EXIT procedure was performed in 12 with evidence of tracheal compression. An EXIT procedure was not performed because of minimal tracheal involvement (n = 8), elective abortion (n = 2), fetal demise (n = 1), or obstetric complication (n = 1). In all fetuses, the airway was successfully secured; tracheal intubation was achieved with rigid bronchoscopy (n = 10), direct laryngoscopy (n = 1), and tracheostomy (n = 1). Eleven patients survived to discharge, whereas 1 patient with significant pulmonary hypoplasia died 8 days after emergency EXIT procedure. Of 11 surviving infants, 10 are neurodevelopmentally intact. All mothers who desired future pregnancies have subsequently had uncomplicated deliveries (n = 6).

CONCLUSIONS

Ex-utero intrapartum treatment procedure for giant neck mass can be performed safely for both mother and child. Most fetuses can be orotracheally intubated with minimal long-term morbidity. The potential for future pregnancies is preserved.

Approaches to the management of antenatally diagnosed congenital tumours

Congenital fetal tumours are rare, but current imaging modalities including US and MRI facilitate antenatal diagnosis and investigation, allowing a presumptive diagnosis and management strategy. Although the prevalence of fetal tumours is difficult to ascertain, an incidence of 7.2 per 100,000 live births has previously been reported, with the incidence of neonatal malignancy estimated at 36.5 per million births. Teratomas and neuroblastomas are the most common solid tumours described. Tumours may be very large or associated with severe hydrops leading to significant dystocia with the potential for difficult vaginal or caesarean delivery. Once the diagnosis of a fetal tumour is made, optimal management incorporates a multidisciplinary approach including obstetrician, neonatologist, paediatric surgeon and paediatric oncologist so that counselling is appropriate and a clear management plan is in place for parents.

MRI of the fetal central nervous system and body

MRI is being increasingly used to assess for fetal abnormalities. Although significant progress in the field of fetal MRI has occurred during the past 20 years, continued technical advances will likely contribute to significant growth of the field. Moreover, with continued hardware and software improvements, additional MRI sequences will likely become available. Prenatal MRI complements ultrasound because of larger field-of-view, superior soft tissue contrast, easier and more precise volumetric measurement, and greater accuracy in the demonstration of intracranial and spinal abnormalities. While ultrasound remains the primary modality for fetal imaging, these advantages of MRI make it a valuable adjunct to fetal surgery. Because fetal MRI involves many disciplines, the future of fetal MR will best be achieved through collaborative efforts.

Fetal MRI of the central nervous system: clinical relevance

OBJECTIVE

Specific conditions of the mother sometimes reduce the quality of ultrasound. In these cases, fetal magnetic resonance imaging (MRI) can be performed after gestational week (GW) 18. Interpretation of subtle disorders or malformations becomes safe not before GW 23. Clinical development of children with central nervous system (CNS) disorders is not predictable with imaging alone. Statistical evidence and personal experience of the medical team are essential in counseling, but optimized imaging is helpful in being more precise. The value of fetal MRI (fMRI) is evaluated.

MATERIALS AND METHODS

Twenty-five pregnant women (30.5 +/- 4.5 years) were investigated by additional fMRI.

TECHNIQUE

Breath-hold technique with T2 half-Fourier acquisition single-shot turbo spin-echo and T1 FLASH-2D images in three dimensions with field of view of 350 x 400 mm. All cases have been correlated with postnatal MRI, ultrasound, and clinical follow-up.

RESULTS

In all fetuses, diagnostic MRI was performed 3-10 days after ultrasound between GW 22 and 34 (GW 26.1 +/- 3.6). Sedation was not necessary. In eight cases of suspicious ultrasound, fMRI confirmed ultrasound findings. In 13 cases, additional diagnoses or exclusions of suspected findings could be established. Complete revision of diagnosis was realized in four cases. Findings could be confirmed by postnatal MRI in 11 patients. The clinical course was not predictable in cases with ambivalent prognosis.

CONCLUSIONS

Prenatal diagnosis of CNS pathologies should result in parental counseling. Sufficient diagnostic information, statistical data, and experience of the involved professionals are essential. These results show that in detecting congenital CNS abnormalities fMRI is superior to ultrasound and should be considered in difficult cases.

Fetal surgery

Fetal surgery has emerged from the realm of medical curiosity into an exciting, multidisciplinary specialty now capable of improving patient outcomes for a wide variety of diseases. Recent advances allow prenatal providers to both accurately diagnose and treat many fetal anomalies while maintaining maternal safety. As the initial postnatal health care providers to the majority of these newborns, neonatologists need to be familiar with some of the more recent state-of-the-art procedures currently being used. In this review, the authors discuss the prenatal evaluation process and various operative approaches (ie, open hysterotomy, fetoscopy, and percutaneous) to conduct fetal surgery. They then analyze the effectiveness of some of the more established and experimental prenatal therapies that are being performed for a number of fetal anomalies, including twin-twin transfusion syndrome, thoracic malformations, airway obstruction, congenital diaphragmatic hernia, myelomeningocele, and aortic valve stenosis.

Four cases of congenital airway obstruction: optimising perinatal management

Congenital anomalies causing airway obstruction in the newborn are potentially fatal. However if an effective airway can be maintained the long-term prognosis is often excellent. We present four cases of airway obstruction, three of which were diagnosed antenatally. We discuss the role of antenatal imaging and review delivery options including the need for a multidisciplinary team approach. In conclusion, we recommend antenatal imaging with both ultrasound scan and magnetic resonance to inform perinatal management. Polyhydramnios, in association with suspected neonatal airway obstruction, should alert clinicians to a high-risk situation. We recognize that even in skilled hands, securing an airway can be very difficult and alternatives such as maintenance of the fetomaternal circulation or extra-corporeal life support should be considered.

The usefulness of fetal MRI for prenatal diagnosis

PURPOSE

Fast MRI has provided detailed and reproducible fetal anatomy. This study was performed to evaluate the usefulness of fetal MRI for prenatal diagnosis.

MATERIALS AND METHODS

Fifty-six fetuses with congenital abnormalities on ultrasonography were evaluated by fetal MRI from 2001 to 2004 in Severance Hospital. Final diagnosis was made by postnatal pathology, postnatal MRI, and other modalities (such as ultrasound, retrograde pyelogram). A 1.5-Tesla superconductive MR imaging unit was used to obtain half-Fourier acquisition single-shot turbo spin images.

RESULTS

Of the 56 fetuses, intracranial abnormalities were found in 26 fetuses, intraabdominal abnormalities in 17 fetuses, intrathoracic in 6 fetuses, head and neck in 5 fetuses, and other sites in 2 fetuses. There were six cases in which the diagnoses of fetal MRI and ultrasonography differed. In such cases, fetal MRI provided more exact diagnosis than ultrasonography (5 vs. 0). Three fetuses with intracranial abnormalities on ultrasonography were diagnosed as normal by fetal MRI and in postnatal diagnosis.

CONCLUSION

Although ultrasonography is known as a screening modality of choice in the evaluation of fetus because of the cost-effectiveness and safety, the sonographic findings are occasionally inconclusive or insufficient for choosing the proper management. Thus, in this study, we suggest that fetal MRI is more useful than ultrasonography for the evaluation of intracranial abnormalities in some instances. For prenatal counseling and postnatal treatment planning, fetal MRI can be informative when prenatal ultrasonography is inadequate and doubtful.

Prenatal diagnosis of congenital epulis by three-dimensional ultrasound and magnetic resonance imaging

Congenital epulis is a benign intraoral tumor that has rarely been diagnosed prenatally. We report a fetus with congenital epulis diagnosed by three-dimensional (3-D) ultrasound and fetal magnetic resonance imaging (MRI) at 35 weeks' gestation. We show an image of congenital epulis using a new ultrasound technique, the 3-D multislice view, which shows images similar to CT or MRI. This is a short case report of congenital epulis diagnosed prenatally by 3-D ultrasound using multislice view and MRI.

Evolving Indications for the EXIT Procedure: The Usefulness of Combining Ultrasound and Fetal MRI

The EXIT procedure (EX utero Intrapartum Treatment) encompasses a multidisciplinary approach to situations in which airway obstruction is anticipated. Uteroplacental circulation is maintained to avoid neonatal hypoxemia while intubation is attempted. Not only is it useful in congenital diaphragmatic hernia with intrauterine tracheal occlusion, but new indications have been proposed. We present two cases in which EXIT procedure was adopted (huge cervical mass with tracheal compression and a highly vascularized cephalocervical mass) for the same purpose on different grounds. Our two cases stress once more the importance of combining fetal ultrasound and magnetic resonance imaging in the characterization of cervical masses and its usefulness in programming the procedure with a multidisciplinary team.

Teratomas of the neck and mediastinum in children

This retrospective study reviews a series of teratomas of the neck and mediastinum aiming at defining the features of these particular locations. We recorded prenatal diagnosis, perinatal management, clinical and radiologic features, pathology, surgical strategies and results in cervical and mediastinal teratomas treated over the last 10 years. During this period we treated 66 children with teratoma of which 11 (6 male and 5 female) had cervicomediastinal locations. Five babies had cervical teratomas extended into the anterior mediastinum in two cases. Prenatal diagnosis was made in three (two with polyhydramnios). Four babies were born by C-section and only one had a successful EXIT procedure. The diagnosis was confirmed by imaging and increased AFP. Surgical treatment involved total tumor removal and in one case subsequent removal of lymph node metastases. All children survived except one in whom airway could not be cleared at birth. Two children bear mild hypothyroidism. During the same period six patients aged 0-17 years were treated for mediastinal teratoma. Only one was prenatally diagnosed and only two had some dyspnea. Removal was performed either by median sternotomy, thoracotomy, or thoracoscopy. They all survive and are free of disease. Teratomas of the neck may cause fetal disease and unmanageable neonatal airway obstruction. Prenatal diagnosis and planned multidisciplinary management are mandatory at birth. In contrast, only some mediastinal tumors cause respiratory embarrassment. Although benign, these tumors are sometimes immature and may metastasize to regional lymph nodes. Total surgical removal is curative. Thyroid insufficiency may be present at birth in cervical teratomas and may be aggravated by surgery.

The EXIT procedure: principles, pitfalls, and progress

Although performing procedures on a fetus before severing the umbilical cord has previously been reported, the principles of the ex utero intrapartum treatment (EXIT) procedure were first fully developed for reversing tracheal occlusion in fetuses with severe congenital diaphragmatic hernia. The EXIT procedure offers the advantage of insuring uteroplacental gas exchange while on placental support. The lessons learned in the development of the principles that underlie the EXIT procedure have improved outcomes when applied in other conditions, most notably in cases of airway obstruction. The range of indications for the EXIT procedure has expanded and currently includes giant fetal neck masses, lung or mediastinal tumors, congenital high airway obstruction syndrome, and EXIT to ECMO (extracorporeal membrane oxygenation), among others. This review summarizes the underlying principles of the EXIT procedure, the expanding indications for its use, the pitfalls of management, and the progress that has been made in its successful application.

Fetal MRI in experimental tracheal occlusion

Congenital diaphragmatic hernia (CDH) is associated with a high mortality, which is mainly due to pulmonary hypoplasia and secondary pulmonary hypertension. In severely affected fetuses, tracheal occlusion (TO) is performed prenatally to reverse pulmonary hypoplasia, because TO leads to accelerated lung growth. Prenatal imaging is important to identify fetuses with pulmonary hypoplasia, to diagnose high-risk fetuses who would benefit from TO, and to monitor the effect of TO after surgery. In fetal imaging, ultrasound (US) is the method of choice, because it is widely available, less expensive, and less time-consuming to perform than magnetic resonance imaging (MRI). However, there are some limitations for US in the evaluation of CDH fetuses. In those cases, MRI is helpful because of a better tissue contrast between liver and lung, which enables evaluation of liver herniation for the diagnosis of a high-risk fetus. MRI provides the ability to determine absolute lung volumes to detect lung hypoplasia. In fetal sheep with normal and hyperplastic lungs after TO, lung growth was assessed on the basis of cross-sectional US measurements, after initial lung volume determination by MRI. To monitor fetal lung growth after prenatal TO, both MRI and US seem to be useful methods.

Obstetric MRI

Ultrasound is the imaging modality of choice for pregnant patients. However, MRI is increasingly utilized in patients in whom the sonographic diagnosis is unclear. These include maternal conditions unique to pregnancy such as ectopic pregnancy, placenta accreta, and uterine dehiscence. MRI is also being increasingly utilized in the assessment of abdominopelvic pain in pregnancy, in particular in assessment for appendicitis. Fetal MRI is performed to assess central nervous system (CNS) abnormalities and patients who are considering fetal surgery for conditions such as neural tube defects, congenital diaphragmatic hernia, and masses that obstruct the airway. In the future, functional MRI and fetal volumetry may provide additional information that can aid in our care of complicated pregnancies.

Severe pulmonary hypoplasia associated with giant cervical teratomas

BACKGROUND

The use of the ex utero intrapartum treatment (EXIT) procedure has salvaged many fetuses with giant neck masses. Despite an adequate airway, a subset of these patients die from an inability to achieve adequate gas exchange.

METHODS

We reviewed our experience with the EXIT procedure from 1996 to 2004. The EXIT was used to deliver 23 fetuses with giant neck masses.

RESULTS

Three fetuses with giant cervical teratomas died of severe pulmonary hypoplasia. On postmortem, these patients had severe airway distortion by the mass. The carina was retracted superiorly to the first or second rib resulting in compression of the lungs in the apices of the chest and pulmonary hypoplasia. Hypoplasia was reflected in the lung weights of 24 vs 38 g and 17 vs 34 g for age-matched normal lung.

CONCLUSIONS

Unsuspected obstructive fetal neck masses can be fatal because of an inability to secure an airway. Prenatal ultrasonography can identify fetuses at risk, allowing the fetus to be salvaged using the EXIT procedure. Despite obtaining airway control, a subset of these patients will die because of pulmonary hypoplasia. When counseling patients with large cervical masses it is important to discuss potential pulmonary hypoplasia in these patients.