Functional Outcomes of Patients Who Underwent Anorectal Malformation Repair Using MRI Guidance.

BACKGROUND: Despite the initiation of minimally invasive laparoscopic techniques, the majority of patients who undergo anorectal malformation repair still experience functional bowel issues in childhood, including constipation and fecal incontinence. In this study, we evaluate the functional outcomes of a procedure in which magnetic resonance imaging guidance is used during initial laparoscopic repair to better locate the epicenter of the sphincter muscle complex and pelvic floor with the goal of more accurate placement of the neoanus and improved functional outcomes. METHODS: A retrospective chart review evaluated demographic, operative, and outcome details for patients who underwent this procedure. A telephone survey was employed to determine levels of social continence using the validated Baylor Continence Scale and to determine what type of bowel management is used. RESULTS: Twenty-six patients were included. Median age at operation was 7 months, and median age at follow-up was 4 years old, with a range of 1-9. Bowel management regimen results revealed that 19 % (n = 5) use no bowel management regimen, 58 % (n = 15) use laxatives only, and 23 % (n = 6) use enemas. Enema use was not associated with different spine or sacral anomalies (p = 0.77). Fifteen patients (58 %) answered the Baylor Continence Scale questions and had a median score of 14. No difference was found in scores when accounting for lesion level (p = 0.43), quality of needle placement (p = 0.46), or quality of sphincter muscles (p = 0.75). CONCLUSIONS: Using MRI guidance in the repair of anorectal malformations shows promise in both the qualitative and quantitative functional outcomes of this complex patient population. LEVEL OF EVIDENCE: Level III.

Understanding Lymphatic Anatomy and Abnormalities at Imaging.

Lymphatic abnormalities encompass a wide range of disorders spanning solitary common cystic lymphatic malformations (LMs) to entities involving multiple organ systems such as lymphangioleiomyomatosis. Many of these disorders are rare, yet some, such as secondary lymphedema from the treatment of malignancy (radiation therapy and/or lymph node dissection), affect millions of patients worldwide. Owing to complex and variable anatomy, the lymphatics are not as well understood as other organ systems. Further complicating this is the variability in the description of lymphatic disease processes and their nomenclature in the medical literature. In recent years, medical imaging has begun to facilitate a deeper understanding of the physiology and pathologic processes that involve the lymphatic system. Radiology is playing an important and growing role in the diagnosis and treatment of many lymphatic conditions. The authors describe both normal and common variant lymphatic anatomy. Various imaging modalities including nuclear medicine lymphoscintigraphy, conventional lymphangiography, and MR lymphangiography used in the diagnosis and treatment of lymphatic disorders are highlighted. The authors discuss imaging many of the common and uncommon lymphatic disorders, including primary LMs described by the International Society for the Study of Vascular Anomalies 2018 classification system (microcystic, mixed, and macrocystic LMs; primary lymphedema). Secondary central lymphatic disorders are also detailed, including secondary lymphedema and chylous leaks, as well as lymphatic disorders not otherwise easily classified. The authors aim to provide the reader with an overview of the anatomy, pathology, imaging findings, and treatment of a wide variety of lymphatic conditions. ©RSNA, 2022.

Conjoined twins: an obstetrician's guide to prenatal care and delivery management.

OBJECTIVE: Obstetricians infrequently encounter conjoined twins. Much of the clinical care literature focuses on postnatal management from a neonatology and pediatric surgery perspective; guidance on obstetrical management is limited. We outline steps for prenatal evaluation, obstetrical care, and delivery planning. STUDY DESIGN: Experiences with two cases of conjoined twins. RESULTS: We identified several points throughout the planning, delivery, and postnatal process that are important to highlight for optimizing clinical outcome, patient safety, and parental satisfaction. CONCLUSION: After diagnosis, patients should be referred to a center experienced in the management of conjoined twins. Specialists in fields including maternal fetal medicine, pediatric surgery, neonatology, and radiology play a vital role in the management of these patients. Early referral allows for timely family counseling and decision-making. Prenatal evaluation beyond the first trimester should include a detailed ultrasound, fetal echocardiogram, and fetal MRI. 3D printed life-sized models can improve delivery planning and patient understanding.

Case Report: A Relatively Mild Presentation of Unilateral Congenital Pulmonary Lymphangiectasia.

Pulmonary lymphangiectasia (PL) is a rare congenital disorder of pulmonary lymphatic development. Although it was traditionally a fatal disorder of infancy, some cases in later childhood have been reported, suggesting a spectrum of severity. We present an unusual case of unilateral, congenital pulmonary lymphangiectasia. Our patient presented with neonatal respiratory distress, a chronic wet cough and recurrent episodes of bronchitis. Chest CT revealed thickening of the interlobular septae of the right lung. A lung biopsy confirmed the diagnosis of lymphangiectasia. His clinical course is characterized by chronic coughing and recurrent bronchitis but normal growth and development. This case illustrates a relatively mild presentation of unilateral PL, which, along with other reports, suggests variability in the presentation and severity of this disorder. In the absence of imaging and histological examination, mild presentations may go undiagnosed.

Ultrasound-guided pediatric inguinal hernia repair.

PURPOSE: Inguinal hernias are amongst the most common surgical conditions in children. Typically, these repairs are performed through an open or laparoscopic approach, using a high ligation of the hernia sac. The use of ultrasound has been described in identifying and evaluating hernia contents in children. Our goal was to determine if ultrasound guidance could be used to perform a high ligation of the hernia sac in pediatric patients. METHODS: Following IRB approval, a retrospective review of all female patients at a single center undergoing ultrasound guided inguinal hernia repair between 2017 and 2018 was performed. Pre-operative characteristics, intra-operative outcomes, and post-operative outcomes were all evaluated. Laparoscopy was used to evaluate the repair and evaluate for a contralateral hernia. Male patients did not undergo ultrasound inguinal hernia repair to avoid damage to the vas deferens and vessels. RESULTS: A total of 10 patients with 13 hernias total were found during the study period. A total of one patient was converted to a laparoscopic repair. No patients were found to have an inappropriate repair or a missed contralateral hernia, and there were no vascular injuries or injuries to surrounding structures. No patients had a hernia recurrence during the study period. CONCLUSION: This study demonstrates the safety and feasibility of ultrasound guided inguinal hernia repairs in female pediatric patients. Further study is needed to compare these repairs to existing techniques, evaluate for recurrences over time, and evaluate if these repairs can be performed without general anesthetic in some patients.

Prenatal assessment of congenital diaphragmatic hernia at north american fetal therapy network centers: A continued plea for standardization.

INTRODUCTION: Prenatal work-up for congenital diaphragmatic hernia (CDH) is important for risk stratification, standardization, counseling, and optimal therapeutic choice. To determine current practice patterns regarding prenatal CDH work-up, including prenatal ultrasound and magnetic resonance imaging (MRI) use, and to identify areas for standardization of such evaluation between fetal centers. METHODS: A survey regarding prenatal CDH work-up was sent to each member center of the North American Fetal Therapy Network (NAFTNet) (n = 36). RESULTS: All responded. Sonographic measurement of lung-to-head ratio (LHR) was determined by all, 89% (32/36) of which routinely calculate observed-to-expected LHR. The method for measuring LHR varied: 58% (21/36) used a "trace" method, 25% (9/36) used "longest axis," and 17% (6/36) used an "antero-posterior" method. Fetal MRI was routinely used in 78% (28/36) of centers, but there was significant variability in fetal lung volume measurement. Whereas all generated a total fetal lung volume, the planes, methodology and references values varied significantly. All evaluated liver position, 71% (20/28) evaluated stomach position and 54% (15/28) quantified the degree of liver herniation. More consistency in workup was seen between centers offering fetal intervention. CONCLUSION: Prenatal CDH work-up and management differs considerably among North American fetal diagnostic centers, highlighting a need for its standardization.

Imaged-guided and muscle sparing laparoscopic anorectoplasty using real-time magnetic resonance imaging.

A challenge when repairing imperforate anus is positioning the neo-rectum into the center of the sphincter muscle complex (SMC) with limited muscle injury and scarring. Unfortunately, the path through the components of the SMC are often non-linear. We have used MRI to delineate the complex and guide the needle through the center using standard MRI-guidance (Raschbaum GR et al. J Pediatr Surg 45:220-223, 2010; Thomas TT et al. J Pediatr Surg 35:927-930, 2000). However, asynchronous scanning requires multiple, time-consuming scans to advance the needle in stepwise fashion. Asynchronous scanning also prevents visualizing the needle as it is advanced. We recently integrated software into the MRI operative suite that allows placement of the needle with real-time MRI. We report the feasibility and utility of real-time MRI-assisted laparoscopic assisted anorectoplasty (RT MRI-LAARP). Needle guidance was performed with Siemens Espree 1.5 T MRI with T1 Flash RT Sequence. After needle placement, laparoscopic mobilization, fistula takedown and pull-through was performed using the needle to guide dilation to create a tract to pull-through the neo-rectum. Charts of patients who underwent RT MRI-LAARP were reviewed. Demographics, anatomy, number of needle passes, OR duration and complications are reported. There were five children that underwent RT MRI-LAARP; one was a redo secondary to a retracted rectovestibular fistula. Operative time ranged from 187-505 min. Average hospital stay was 4.0 ± 1.0 days. There were no intraoperative complications although one patient had temporary urinary retention post-op. Muscle sparring laparoscopic anorectoplasty using real-time MRI is feasible and facilitates needle placement through the SMC.

Discordant prenatal ultrasound and fetal MRI in CDH: wherein lies the truth?

PURPOSE: Prenatal risk assessment of congenital diaphragmatic hernia (CDH) relies on prenatal ultrasound (U/S) and fetal magnetic resonance imaging (MRI). When the modalities differ in prognosis, it is unclear which is more reliable. METHODS: Retrospective chart review identified cases of prenatally diagnosed CDH from 4/2010-6/2018 meeting inclusion criteria. Demographic, radiologic, and postnatal outcomes data were collected. Ultrasound- versus MRI-based prognosis (mild, moderate, and severe) was compared with clinical outcomes. Kappa measures compared congruency in disease severity scaling between imaging modalities, while logistic regression and receiver operating characteristics curves compared the ability of each modality to predict outcomes. RESULTS: Forty-two patients met criteria. Both U/S- and MRI-based prognosis categories differentiated for survival. MRI categories differentiated for ECMO use, surgical repair, and defect type. O/e TFLV better discriminated for survivors and defect type than o/e LHR. Seventeen (40.5%) had discordant prenatal prognostic categories. In 13/17 (76.5%), o/e TFLV predicted higher severity when compared to o/e LHR, but sample size was insufficient to compare accuracy in cases of discordance. CONCLUSIONS: Clinical outcomes suggest fetal MRI may more accurately predict severe pulmonary hypoplasia compared to prenatal ultrasound. Our analysis suggests fetal MRI is a valuable adjunct in the prenatal evaluation of CDH. LEVEL OF EVIDENCE: Level III. TYPE OF STUDY: Retrospective Review.

Calculating Observed-to-Expected Total Fetal Lung Volume in CDH Fetuses in Twin Gestation: Is There a Better Way?

BACKGROUND: Congenital diaphragmatic hernia (CDH) is a potentially lethal birth defect, and identifying prenatal predictors of outcome is important. Observed-to-expected total fetal lung volume (o/e TFLV) has been shown to be a predictor of severity and useful in risk stratification but is variable due to different TFLV formulas. OBJECTIVES: To calculate o/e TFLV for CDH patients part of a twin gestation using the unaffected sibling as an internal control and comparing these values to those calculated using published formulas for TFLV. METHODS: Seven twin gestations with one fetus affected by CDH were identified between 2006 and 2017. The lung volume for each twin was calculated using magnetic resonance imaging (MRI), and o/e TFLV was calculated using the unaffected twin's TFLV. This percentage was then compared to the o/e TFLV calculated using published formulas. RESULTS: Lung volumes in the unaffected twins were within normal ranges at the lower end of the spectrum. No single TFLV formula was found to correlate perfectly. Intraclass correlation coefficient estimate was most consistent for o/e TFLV calculated with the Meyers formula and supported by Bland-Altman plots. CONCLUSIONS: O/e TFLV measured in CDH/non-CDH twin gestations using the unaffected sibling demonstrated agreement with o/e TFLV calculated using the Meyers formula. We urge the fetal community to standardize the method, use, and interpretation of fetal MRI in the prenatal evaluation of CDH.

Salvage Laparoscopic-Assisted Anorectoplasty after Failed Vestibular Fistula Repair Using Magnetic Resonance Image Guidance.

Patients with vestibular fistula have a good functional outcome after posterior sagittal anorectoplasty (PSARP). While continence is often preserved, close follow-up and management of constipation are often required. Redo anorectal surgery has been associated with worse functional outcomes compared with primary procedures, possibly due to injury and scarring of the pelvic floor musculature and sphincter complex. Our group has a growing experience in the use of intraoperative real-time magnetic resonance imaging (MRI) for anorectal malformation repairs. We present a case of salvage operation of a failed PSARP for vestibular fistula.

Diagnostic accuracy of imaging studies in congenital lung malformations.

BACKGROUND: Although fetal ultrasound, fetal MRI and postnatal CT are now widely used in the evaluation of congenital lung malformations (CLM), their diagnostic accuracy remains undefined. OBJECTIVE: To correlate prenatal and postnatal imaging studies with pathological data after CLM resection. DESIGN: Retrospective, descriptive case series study. SETTING: A North American tertiary care centre. PATIENTS: One hundred and three consecutive lung resections for a suspected CLM between 1 January 2005 and 31 December 2015. MAIN OUTCOME MEASURES: Diagnostic accuracy of imaging diagnosis compared with pathological evaluation. RESULTS: Pathological diagnoses included congenital pulmonary airway malformation ((CPAM) n=45, 44%), bronchopulmonary sequestration (BPS; n=25, 24%), CPAM/BPS hybrid lesions (n=22, 21%) and pleuropulmonary blastoma (n=2, 2%). Fetal ultrasound detected 85 (82.5%) lesions and correctly diagnosed whether or not a lesion was a CPAM in 75% of cases (sensitivity 93%, specificity 32%). Fetal MRI had a similar concordance rate (73%) but was superior in correctly determining whether a systemic feeding vessel was present in 80% of cases (sensitivity 71%, specificity 88%) compared with an ultrasound accuracy rate of 72% (sensitivity 49%, specificity 93%). By comparison, postnatal CT correctly diagnosed whether a CPAM was present in 84% of cases (sensitivity 86%, specificity 77%) and whether a systemic feeding vessel was present in 90% of cases (sensitivity 92%, specificity 88%). CONCLUSIONS: Fetal ultrasound remains an important tool in the detection and evaluation of congenital lung malformations. However, it does not correctly predict histology in approximately 25% of prenatally detected CLMs and remains limited by relatively poor sensitivity for systemic feeding vessels pathognomic for a bronchopulmonary sequestration. These data suggest the importance of obtaining additional cross-sectional imaging, preferably a postnatal CT scan, in all patients to help counsel families and to guide in the optimal management of these lesions.

Neurodevelopmental outcomes in CDH survivors: A single institution's experience.

PURPOSE: Survivors of congenital diaphragmatic hernia (CDH) face high morbidity. We studied the neurodevelopmental outcomes of CDH survivors at a single institution. METHODS: CDH survivors born July 2006-March 2016 at a free-standing children's hospital were reviewed. Neurodevelopment was assessed using the Peabody Developmental Motor Scales (PDMS-2) broken into gross, fine, and total motor quotients. Data collected included prenatal variables (liver herniation, defect laterality, observed:expected total fetal lung volume (o:eTFLV) on MRI), birth demographics (sex, race, estimated gestational age (EGA), birth weight (BtWt), 5 min APGAR, associated anomalies), and therapies/hospital course (HFOV/HFJV, ECMO, timing of repair, pulmonary hypertension (PHTN) severity, length of stay, ventilator days). Variables were analyzed using mixed linear modeling. RESULTS: Sixty-eight children were included. Most patients had left-sided CDH (55/68, 81%) without liver herniation (42/68, 62%). ECMO utilization was 25/68 (37%). The mean [95% confidence interval] gross motor quotient for the entire cohort was 87 [84-91], fine motor quotient was 92 [88-96], and total motor quotient was 88 [84-93], representing below average, average, and below average functioning, respectively. o:eTFLV predicted fine motor quotient among prenatal variables. Associated anomalies and ECMO use predicted all quotients in the final model. CONCLUSIONS: Associated anomalies and ECMO use predict neurodevelopmental delay in CDH survivors. TYPE OF STUDY: Retrospective observational study; Prognostic. LEVEL OF EVIDENCE: II.

Early Delivery of Sacrococcygeal Teratoma with Intraspinal Extension.

Sacrococcygeal teratoma (SCT) with intraspinal extension is rare. There is a risk of paraplegia associated with prolonged spinal cord compression. We present the case of an infant with a prenatal diagnosis of an SCT with a large intraspinal component that was causing compression of the lower spinal cord. Ultrasound at 33 weeks showed bilateral lower extremity and foot movement without hydrops or cardiac failure. Multidisciplinary decision was made to administer betamethasone and proceed with Cesarean delivery at 34 weeks. A vigorous live-born female was delivered and a multilevel laminectomy was performed at day of life 4. The pelvic resection was performed at 4 months. Pathology revealed mature teratoma. She had an uncomplicated postoperative course, is ambulatory, continent of stool, and has no evidence of recurrence. We conclude that intraspinal extension of SCT should be evaluated prenatally with ultrasound and fetal MRI. If there is concern for spinal cord compression, early delivery and urgent decompressive laminectomy may diminish the neurologic sequelae of prolonged spinal cord compression. Since these cases are rare, risks of prematurity need to be weighed against the neurologic risks. These infants should be treated with a multidisciplinary approach.

Pulmonary Hypertension in Patients with Congenital Diaphragmatic Hernia: Does Lung Size Matter?

PURPOSE: The relationship between pulmonary hypoplasia and pulmonary arterial hypertension (PHTN) in patients with congenital diaphragmatic hernia (CDH) remains ill-defined. We hypothesized that prenatal estimates of lung size would directly correlate with PHTN severity. METHODS: Infants with isolated CDH (born 2004-2015) at a single institution were included. Estimates of lung size included observed-to-expected LHR (o:eLHR) and %-predicted lung volumes (PPLV = observed/predicted volumes). The primary outcome was severity of PHTN (grade 0-3) on echocardiography performed between day of life 3 and 30. RESULTS: Among 62 patients included, there was 32% mortality and 65% ECMO utilization. PPLV (odds ratio [OR] = 0.94 per 1 grade in PHTN severity, 95% confidence interval [CI] = 0.89-0.98, p < 0.01) and o:eLHR (OR = 0.97, 95% CI = 0.94-0.99, p < 0.01) were significantly associated with PHTN grade. Among patients on ECMO, PPLV (OR = 0.92, 95% CI = 0.84-0.99, p = 0.03) and o:eLHR (OR = 0.95, 95% CI = 0.92-0.99, p = 0.01) were more strongly associated with PHTN grade. PPLV and o:eLHR were significantly associated with the use of inhaled nitric oxide (iNO) (OR = 0.90, 95% CI = 0.83-0.98, p = 0.01 and OR = 0.94, 95% CI = 0.91-0.98, p < 0.01, respectively) and epoprostenol (OR = 0.91, 95% CI = 0.84-0.99, p = 0.02 and OR = 0.93, 95% CI = 0.89-0.98, p < 0.01, respectively). CONCLUSION: Among infants with isolated CDH, PPLV, and o:eLHR were significantly associated with PHTN severity, especially among patients requiring ECMO. Prenatal lung size may help predict postnatal PHTN and associated therapies.

Inter-radiologist agreement for CT scoring of pediatric splenic injuries and effect on an established clinical practice guideline.

BACKGROUND: The American Pediatric Surgical Association (APSA) advocates for the use of a clinical practice guideline to direct management of hemodynamically stable pediatric spleen injuries. The clinical practice guideline is based on the CT score of the spleen injury according to the American Association for the Surgery of Trauma (AAST) CT scoring system. OBJECTIVE: To determine the potential effect of radiologist agreement for CT scoring of pediatric spleen injuries on an established APSA clinical practice guideline. MATERIALS AND METHODS: We retrospectively analyzed blunt splenic injuries occurring in children from January 2007 to January 2012 at a single level 1 trauma center (n = 90). Abdominal CT exams performed at clinical presentation were reviewed by four radiologists who documented the following: (1) splenic injury grade (AAST system), (2) arterial extravasation and (3) pseudoaneurysm. Inter-rater agreement for AAST injury grade was assessed using the multi-rater Fleiss kappa and Kendall coefficient of concordance. Inter-rater agreement was assessed using weighted (AAST injury grade) or prevalence-adjusted bias-adjusted (binary measures) kappa statistics; 95% confidence intervals were calculated. We evaluated the hypothetical effect of radiologist disagreement on an established APSA clinical practice guideline. RESULTS: Inter-rater agreement was good for absolute AAST injury grade (kappa: 0.64 [0.59­0.69]) and excellent for relative AAST injury grade (Kendall w: 0.90). All radiologists agreed on the AAST grade in 52% of cases. Based on an established clinical practice guideline, radiologist disagreement could have changed the decision for intensive care management in 11% (10/90) of children, changed the length of hospital stay in 44% (40/90), and changed the time to return to normal activity in 44% (40/90). CONCLUSION: Radiologist agreement when assigning splenic AAST injury grades is less than perfect, and disagreements have the potential to change management in a substantial number of pediatric patients.

Prenatally diagnosed severe CDH: mortality and morbidity remain high.

PURPOSE: This study sought to evaluate prenatal markers' ability to predict severe congenital diaphragmatic hernia(CDH) and assess this subgroup's morbidity and mortality. METHODS: A retrospective review was performed between 2006 and 2014. Prenatal criteria for severe CDH included: liver herniation, lung-to-head ratio (LHR) <1 on prenatal ultrasound and/or observed-to-expected LHR (o/eLHR) <25%, and/or observed-to-expected total lung volume (o/eTLV) <25% on fetal MRI. Postnatal characteristics included: mortality, ECMO utilization, patch closure, persistent suprasystemic pulmonary hypertension (PHtn), O2 requirement at discharge, and few ventilator-free days in the first 60. Statistics performed used unpaired t-test, p<0.05 significant. RESULTS: Overall, 47.5%(29/61) of patients with prenatally diagnosed, isolated CDH met severe criteria. Mean LHR: 1.04±0.35, o/eLHR: 31±10% and o/eTLV: 20±7%. Distribution was 72% LCDH, 24% R-CDH. Overall survival: 38%. ECMO requirement: 92%. Patch rate: 91%. Mean ventilator-free days in 60: 7.1±14. Supplemental oxygen at discharge was required in 27%. In this prenatally diagnosed severe cohort, 58%(15/26) had persistent PHtn post-ECMO requiring inhaled nitric oxide±epoprostenol. Comparing patients with and without PHtn: mean ECMO duration 18±10 days versus 9±7 days (p=0.01) and survival 20% versus 72% (p=0.006). CONCLUSION: A combination of prenatal markers accurately identified severe CDH patients. Outcomes of this group remain poor and persistent PHtn contributes significantly to mortality.

Spine ultrasound imaging in the newborn.

Ultrasound of the spine in the neonate is widely used as the initial modality to evaluate spinal canal anatomy, anatomical variants, and congenital malformations. The spinal canal and its contents are best visualized in the newborn and young infant owing to incomplete ossification of the posterior vertebral elements.

Magnetic resonance imaging of pediatric pelvic masses.

Both benign and malignant pelvic masses are encountered in the pediatric population. Although ultrasonography remains the modality of choice for initial evaluation of a pediatric pelvic mass, in selected cases magnetic resonance (MR) imaging can add important diagnostic information. MR imaging has several advantages over ultrasonography and computed tomography, including superior contrast resolution and an ability to characterize abnormalities based on unique tissue characteristics. MR evaluation assists in lesion characterization, presurgical planning, and staging when a malignancy is suspected. MR imaging also offers a nonionizing imaging modality for long-term follow-up of patients undergoing therapy for malignant pelvic masses.

Another dimension to survival: predicting outcomes with fetal MRI versus prenatal ultrasound in patients with congenital diaphragmatic hernia.

PURPOSE: A major determinant of survival in patients with congenital diaphragmatic hernia (CDH) is severity of pulmonary hypoplasia. This study addresses the comparative effectiveness of prenatal methods of lung assessment in predicting mortality, extracorporeal membrane oxygenation (ECMO), and ventilator dependency. METHODS: We retrospectively reviewed all patients born with isolated CDH between 2004 and 2008. Lung-to-head ratio (LHR) and observed-to-expected LHR (OELHR) were obtained from prenatal ultrasounds. Percent-predicted lung volume (PPLV) was obtained from fetal MRI (fMRI). Postnatal data included in-hospital mortality, need for ECMO, and ventilator dependency at day-of-life 30. RESULTS: Thirty-seven patients underwent 81 prenatal ultrasounds, while 26 of this sub-cohort underwent fMRI. Gestational age during imaging study was associated with LHR (p=0.02), but not OELHR (p=0.12) or PPLV (p=0.72). PPLV, min-LHR, and min-OELHR were each associated with mortality (p=0.03, p=0.02, p=0.01), ECMO (p<0.01, p<0.01, p=0.03), and ventilator dependency (p<0.01, p<0.01, p=0.02). For each outcome, PPLV was a more discriminative measure, based on Akaike's information criterion. Using longitudinal analysis techniques for patients with multiple ultrasounds, OELHR remained associated with mortality (p=0.04), ECMO (p=0.03), and ventilator dependency (p=0.02), while LHR was associated with ECMO (p=0.01) and ventilator dependency (p=0.02) but not mortality (p=0.06). CONCLUSION: When assessing fetuses with CDH, OELHR and PPLV may be most helpful for counseling regarding postnatal outcomes.

Developmental impact and lesion maturation of histotripsy-mediated non-invasive tissue ablation in a fetal sheep model.

Non-invasive histotripsy therapy has previously been used to achieve precise fetal tissue ablation in a sheep model. To further assess the clinical viability of the technique, this study investigated potential effects of histotripsy therapy during the remaining gestation and its local impact on fetal development. Five ewes (six lambs) at 95-107 d of gestation were treated and allowed to complete the full gestation period of 150 d. A 1-MHz focused transducer was used to treat the fetal kidney and liver with 5-µs pulses at 500-Hz repetition rates and 10- to 16-MPa peak negative pressures; ultrasound imaging provided real-time treatment guidance. The lambs were euthanized after delivery and treated organs were harvested. Samples were examined by magnetic resonance imaging and histopathologic analysis. These data were compared with results from four other ewes (four lambs) that underwent similar treatments but were sacrificed immediately after the procedure. The sheep tolerated the treatment well, and acute lesion samples displayed well-defined ablated regions characterized by the presence of fractionated tissue and hemorrhage. All fetuses that were allowed to continue gestation survived and were delivered at full term. The lambs were healthy on delivery, with no signs of external injury. A minor indentation was observed in each of the treated kidneys with minimal presence of fibrous tissue, while no discernible signs of lesions were detected in treated livers. In a sheep model, histotripsy-mediated fetal tissue ablation caused no acute or pregnancy-related complications, supporting the potential safety and effectiveness of histotripsy therapy as a tool in fetal intervention procedures.