Management of Gastroschisis: Timing of Delivery, Antibiotic Usage, and Closure Considerations (A Systematic Review From the American Pediatric Surgical Association Outcomes & Evidence Based Practice Committee).

BACKGROUND: No consensus exists for the initial management of infants with gastroschisis. METHODS: The American Pediatric Surgical Association (APSA) Outcomes and Evidenced-based Practice Committee (OEBPC) developed three a priori questions about gastroschisis for a qualitative systematic review. We reviewed English-language publications between January 1, 1970, and December 31, 2019. This project describes the findings of a systematic review of the three questions regarding: 1) optimal delivery timing, 2) antibiotic use, and 3) closure considerations. RESULTS: 1339 articles were screened for eligibility; 92 manuscripts were selected and reviewed. The included studies had a Level of Evidence that ranged from 2 to 4 and recommendation Grades B-D. Twenty-eight addressed optimal timing of delivery, 5 pertained to antibiotic use, and 59 discussed closure considerations (Figure 1). Delivery after 37 weeks post-conceptual age is considered optimal. Prophylactic antibiotics covering skin flora are adequate to reduce infection risk until definitive closure. Studies support primary fascial repair, without staged silo reduction, when abdominal domain and hemodynamics permit. A sutureless repair is safe, effective, and does not delay feeding or extend length of stay. Sedation and intubation are not routinely required for a sutureless closure. CONCLUSIONS: Despite the large number of studies addressing the above-mentioned facets of gastroschisis management, the data quality is poor. A wide variation in gastroschisis management was documented, indicating a need for high quality RCTs to provide an evidence-based approach when caring for these infants. TYPE OF STUDY: Qualitative systematic review of Level 1-4 studies.

ChatGPT: What Every Pediatric Surgeon Should Know About Its Potential Uses and Pitfalls.

ChatGPT - currently the most popular generative artificial intelligence system - has been revolutionizing the world and healthcare since its release in November 2022. ChatGPT is a conversational chatbot that uses machine learning algorithms to enhance its replies based on user interactions and is a part of a broader effort to develop natural language processing that can assist people in their daily lives by understanding and responding to human language in a useful and engaging way. Thus far, many potential applications within healthcare have been described, despite its relatively recent release. This manuscript offers the pediatric surgical community a primer on this new technology and discusses some initial observations about its potential uses and pitfalls. Moreover, it introduces the perspectives of medical journals and surgical societies regarding the use of this artificial intelligence chatbot. As ChatGPT and other large language models continue to evolve, it is the responsibility of the pediatric surgery community to stay abreast of these changes and play an active role in safely incorporating them into our field for the benefit of our patients. LEVEL OF EVIDENCE: V.

Type I and Ir pleuropulmonary blastoma (PPB): A report from the International PPB/DICER1 Registry.

BACKGROUND: Pleuropulmonary blastoma (PPB) is the most common lung cancer of infancy and early childhood. Type I PPB is a purely cystic lesion that has a microscopic population of primitive small cells with or without rhabdomyoblastic features and may progress to type II or III PPB, whereas type Ir lacks primitive small cells. METHODS: Children with suspected PPB were enrolled in the International PPB/DICER1 Registry. Pathology was centrally reviewed, and follow-up was ascertained annually. RESULTS: Between 2006 and 2022, 205 children had centrally reviewed type I or Ir PPB; 39% of children with type I and 5% of children with type Ir PPB received chemotherapy. Outcomes were favorable, although 11 children (nine with type I and two with type Ir PPB) experienced progression to type II/III (n = 8) or regrowth of type I PPB at the surgical site (n = 3), none of whom received chemotherapy before progression. Age and cyst size in combination were more suitable than either factor alone in predicting whether a particular lesion was type I or Ir PPB. CONCLUSIONS: For young children with type I PPB, outcomes are favorable, but complete resection is indicated because of the risk for progression. Chemotherapy may be useful in a subset of children at increased risk for recurrence/progression. Efforts to risk stratify children with type I PPB to optimize outcomes while reducing treatment-related side effects are underway.

Outcomes for Children With Type II and Type III Pleuropulmonary Blastoma Following Chemotherapy: A Report From the International PPB/DICER1 Registry.

PURPOSE: Pleuropulmonary blastoma (PPB) is the most common primary lung neoplasm of infancy and early childhood. Type II and type III PPB have historically been associated with a poor prognosis. METHODS: Patients with known or suspected PPB were enrolled in the International PPB/DICER1 Registry. Medical records were abstracted with follow-up ascertained annually. All PPB diagnoses were confirmed by central pathology review. Beginning in 2007, the IVADo regimen (ifosfamide, vincristine, actinomycin-D, and doxorubicin) was recommended as a potential treatment regimen for children with type II and type III PPB. This regimen was compared with a historical control cohort. RESULTS: From 1987 to 2021, 314 children with centrally confirmed type II and type III PPB who received upfront chemotherapy were enrolled; 132 children (75 with type II and 57 with type III) received IVADo chemotherapy. Adjusted analyses suggest improved overall survival for children treated with IVADo in comparison with historical controls with an estimated hazard ratio of 0.65 (95% CI, 0.39 to 1.08). Compared with localized disease, distant metastasis at diagnosis was associated with worse PPB event-free survival and overall survival with hazard ratio of 4.23 (95% CI, 2.42 to 7.38) and 4.69 (95% CI, 2.50 to 8.80), respectively. CONCLUSION: The use of IVADo in children with type II and type III PPB resulted in similar-to-improved outcomes compared with historical controls. Inferior outcomes with metastatic disease suggest the need for novel therapies. This large cohort of uniformly treated children with advanced PPB serves as a benchmark for future multicenter therapeutic studies for this rare pediatric tumor.

Management of the undescended testis in children: An American Pediatric Surgical Association Outcomes and Evidence Based Practice Committee Systematic Review.

PURPOSE: Management of undescended testes (UDT) has evolved over the last decade. While urologic societies in the United States and Europe have established some guidelines for care, management by North American pediatric surgeons remains variable. The aim of this systematic review is to evaluate the published evidence regarding the treatment of (UDT) in children. METHODS: A comprehensive search strategy and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were utilized to identify, review, and report salient articles. Five principal questions were asked regarding imaging standards, medical treatment, surgical technique, timing of operation, and outcomes. A literature search was performed from 2005 to 2020. RESULTS: A total of 825 articles were identified in the initial search, and 260 were included in the final review. CONCLUSIONS: Pre-operative imaging and hormonal therapy are generally not recommended except in specific circumstances. Testicular growth and potential for fertility improves when orchiopexy is performed before one year of age. For a palpable testis, a single incision approach is preferred over a two-incision orchiopexy. Laparoscopic orchiopexy is associated with a slightly lower testicular atrophy rate but a higher rate of long-term testicular retraction. One and two-stage Fowler-Stephens orchiopexy have similar rates of testicular atrophy and retraction. There is a higher relative risk of testicular cancer in UDT which may be lessened by pre-pubertal orchiopexy.

Management and outcomes for long-segment Hirschsprung disease: A systematic review from the APSA Outcomes and Evidence Based Practice Committee.

OBJECTIVE: Long-Segment Hirschsprung Disease (LSHD) differs clinically from short-segment disease. This review article critically appraises current literature on the definition, management, outcomes, and novel therapies for patients with LSHD. METHODS: Four questions regarding the definition, management, and outcomes of patients with LSHD were generated. English-language articles published between 1990 and 2018 were compiled by searching PubMed, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar. A qualitative synthesis was performed. RESULTS: 66 manuscripts were included in this systematic review. Standardized nomenclature and preoperative evaluation for LSHD are recommended. Insufficient evidence exists to recommend a single method for the surgical repair of LSHD. Patients with LSHD may have increased long-term gastrointestinal symptoms, including Hirschsprung-associated enterocolitis (HAEC), but have a quality of life similar to matched controls. There are few surgical technical innovations focused on this disorder. CONCLUSIONS: A standardized definition of LSHD is recommended that emphasizes the precise anatomic location of aganglionosis. Prospective studies comparing operative options and long-term outcomes are needed. Translational approaches, such as stem cell therapy, may be promising in the future for the treatment of long-segment Hirschsprung disease.

The effects of early anesthesia on neurodevelopment: A systematic review.

BACKGROUND: There is growing concern regarding the impact of general anesthesia on neurodevelopment in children. Pre-clinical animal studies have linked anesthetic exposure to abnormal central nervous system development, but it is unclear whether these results translate into humans. The purpose of this systematic review from the American Pediatric Surgical Association (APSA) Outcomes and Evidence-Based Practice (OEBP) Committee was to review, summarize, and evaluate the evidence regarding the neurodevelopmental impact of general anesthesia on children and identify factors that may affect the risk of neurotoxicity. METHODS: Medline, Cochrane, Embase, Web of Science, and Scopus databases were queried for articles published up to and including December 2017 using the search terms "general anesthesia and neurodevelopment" as well as specific anesthetic agents. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to screen manuscripts for inclusion in the review. A consensus statement of recommendations in response to each study question was synthesized based upon the best available evidence. RESULTS: In total, 493 titles were initially identified, with 56 articles selected for full analysis and 44 included for review. Based on currently available developmental assessment tools, a single exposure to general anesthesia does not appear to have a significant effect on general neurodevelopment, although prolonged or multiple anesthetic exposures may have some adverse effects. Exposure to general anesthesia may affect different domains of development at different ages. Regional anesthetic techniques with the addition of dexmedetomidine and/or some intravenous agents may mitigate the risks of neurotoxicity. This approach may be performed safely in some patients and can be considered as an option in selected short procedures. CONCLUSION: There is no conclusive evidence that a single short anesthetic in infancy has a detectable neurodevelopmental effect. Data do not support waiting until later in childhood to perform general anesthesia for single short procedures. With the complexities and nuances of different anesthetic methods, patients and procedures, the planning and execution of anesthesia for the pediatric patient is generally best accomplished by an anesthesiologist, ideally a pediatric anesthesiologist. TYPE OF STUDY: Systematic review of level 1-4 studies. LEVEL OF EVIDENCE: Level 1-4 (mainly level 3-4).

Management of intussusception in children: A systematic review.

OBJECTIVE: The goal of this systematic review by the American Pediatric Surgical Association Outcomes and Evidence-Based Practice Committee was to develop recommendations for the management of ileocolic intussusception in children. METHODS: The ClinicalTrials.gov, Embase, PubMed, and Scopus databases were queried for literature from January 1988 through December 2018. Search terms were designed to address the following topics in intussusception: prophylactic antibiotic use, repeated enema reductions, outpatient management, and use of minimally invasive techniques for children with intussusception. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. Consensus recommendations were derived based on the best available evidence. RESULTS: A total of 83 articles were analyzed and included for review. Prophylactic antibiotic use does not decrease complications after radiologic reduction. Repeated enema reductions may be attempted when clinically appropriate. Patients can be safely observed in the emergency department following enema reduction of ileocolic intussusception, avoiding hospital admission. Laparoscopic reduction is often successful. CONCLUSIONS: Regarding intussusception in hemodynamically stable children without critical illness, pre-reduction antibiotics are unnecessary, non-operative outpatient management should be maximized, and minimally invasive techniques may be used to avoid laparotomy. LEVEL OF EVIDENCE: Level 3-5 (mainly level 3-4) TYPE OF STUDY: Systematic Review of level 1-4 studies.

Can congenital pulmonary airway malformation be distinguished from Type I pleuropulmonary blastoma based on clinical and radiological features?

BACKGROUND: The management of congenital cystic lung lesions is controversial. Arguments for routine resection during infancy include the possibility of the lesion being Type I pleuropulmonary blastoma (PPB) rather than a cystic congenital pulmonary airway malformation (CPAM). We aimed to identify clinical and radiological features that might distinguish between CPAM and PPB and to develop a diagnostic algorithm based on these features. METHODS: All recorded cases of Type I PPB were retrieved from the International PPB Registry and compared with an institutional cohort of children undergoing resection of CPAM (2002-2013) that was noted at some stage to be at least partially cystic. Regression models were created to identify variables that might differentiate CPAM from PPB. Odds ratio (OR) and positive predictive value (PPV) were calculated for each variable and a decision algorithm developed. RESULTS: In 112 cases of Type I PPB and 103 of CPAM, factors favoring a diagnosis of CPAM included prenatal detection (OR 89.4), systemic feeding vessel (OR 61.7), asymptomatic (OR 8.0), and hyperinflated lung (OR 6.6). Factors favoring a diagnosis of PPB included bilateral or multisegment involvement (OR 2.4). A decision algorithm that helps to identify lesions requiring resection and those which can be safely observed is presented. CONCLUSION: Clinical and radiological features can help to differentiate between CPAM and PPB. Our algorithm allows identification of children at higher risk of PPB in whom we would recommend resection and those at low risk in whom continued close observation is safe.

Clinical, biologic, and prognostic differences on the basis of primary tumor site in neuroblastoma: a report from the international neuroblastoma risk group project.

PURPOSE: Neuroblastoma (NB) is a heterogeneous tumor arising from sympathetic tissues. The impact of primary tumor site in influencing the heterogeneity of NB remains unclear. PATIENTS AND METHODS: Children younger than age 21 years diagnosed with NB or ganglioneuroblastoma between 1990 and 2002 and with known primary site were identified from the International Neuroblastoma Risk Group database. Data were compared between sites with respect to clinical and biologic features, as well as event-free survival (EFS) and overall survival (OS). RESULTS: Among 8,369 children, 47% had adrenal tumors. All evaluated clinical and biologic variables differed statistically between primary sites. The features that were > 10% discrepant between sites were stage 4 disease, MYCN amplification, elevated ferritin, elevated lactate dehydrogenase, and segmental chromosomal aberrations, all of which were more frequent in adrenal versus nonadrenal tumors (P < .001). Adrenal tumors were more likely than nonadrenal tumors (adjusted odds ratio, 2.09; 95% CI, 1.67 to 2.63; P < .001) and thoracic tumors were less likely than nonthoracic tumors (adjusted odds ratio, 0.20; 95% CI, 0.11 to 0.39; P < .001) to have MYCN amplification after controlling for age, stage, and histologic grade. EFS and OS differed significantly according to the primary site (P < .001 for both comparisons). After controlling for age, MYCN status, and stage, patients with adrenal tumors had higher risk for events (hazard ratio, 1.13 compared with nonadrenal tumors; 95% CI, 1.03 to 1.23; P = .008), and patients with thoracic tumors had lower risk for events (HR, 0.79 compared with nonthoracic; 95% CI, 0.67 to 0.92; P = .003). CONCLUSION: Clinical and biologic features show important differences by NB primary site, with adrenal and thoracic sites associated with inferior and superior survival, respectively. Future studies will need to investigate the biologic origin of these differences.

Antenatal maternally-administered phosphodiesterase type 5 inhibitors normalize eNOS expression in the fetal lamb model of congenital diaphragmatic hernia.

PURPOSE: Pulmonary hypertension (pHTN), a main determinant of survival in congenital diaphragmatic hernia (CDH), results from in utero vascular remodeling. Phosphodiesterase type 5 (PDE5) inhibitors have never been used antenatally to treat pHTN. The purpose of this study is to determine if antenatal PDE5 inhibitors can prevent pHTN in the fetal lamb model of CDH. METHODS: CDH was created in pregnant ewes. Postoperatively, pregnant ewes received oral placebo or tadalafil, a PDE5 inhibitor, until delivery. Near term gestation, lambs underwent resuscitations, and lung tissue was snap frozen for protein analysis. RESULTS: Mean cGMP levels were 0.53±0.11 in placebo-treated fetal lambs and 1.73±0.21 in tadalafil-treated fetal lambs (p=0.002). Normalized expression of eNOS was 82%±12% in Normal-Placebo, 61%±5% in CDH-Placebo, 116%±6% in Normal-Tadalafil, and 86%±8% in CDH-Tadalafil lambs. Normalized expression of ß-sGC was 105%±15% in Normal-Placebo, 82%±3% in CDH-Placebo, 158%±16% in Normal-Tadalafil, and 86%±8% in CDH-Tadalafil lambs. Endothelial NOS and ß-sGC were significantly decreased in CDH (p=0.0007 and 0.01 for eNOS and ß-sGC, respectively), and tadalafil significantly increased eNOS expression (p=0.0002). CONCLUSIONS: PDE5 inhibitors can cross the placental barrier. ß-sGC and eNOS are downregulated in fetal lambs with CDH. Antenatal PDE5 inhibitors normalize eNOS and may prevent in utero vascular remodeling in CDH.

Left heart structures in human neonates with congenital diaphragmatic hernia and the effect of fetal endoscopic tracheal occlusion.

BACKGROUND: Small left heart structures are observed in fetuses with left-sided congenital diaphragmatic hernia (CDH). Fetoscopic tracheal occlusion (FETO) in mid-gestation promotes lung growth in fetuses with CDH, however cardiac effects of FETO are poorly described. We studied the effects of FETO on cardiac structure size at birth, hypothesizing that left heart structures would be larger in neonates who had undergone fetal intervention. METHODS/RESULTS: We performed retrospective measurements of atrioventricular and semilunar valve and pulmonary artery diameters, ventricular lengths, left ventricular end-diastolic volume indexed (LVEDVi) to body surface area. 35 patients were studied (9 FETO, 26 controls). All fetuses had liver herniation and a lung-to-head ratio <1 at fetal presentation. At birth the intervention group had larger LVEDVi (16.8 vs. 12.76 ml/m(2), p < 0.05), LV length Z-score (-2.05 vs. -4, p < 0.01), LV:RV length ratio (1.43 vs. 1.04, p < 0.05), LPA diameter Z-score (+1.71 vs. -1.04, p < 0.05), and better growth of aortic valve (-2.18 FETO, -3.3 controls, p < 0.01). There was a trend toward higher LV output in the FETO group. CONCLUSIONS: Left heart structures and LPA were larger postnatally in patients with CDH who underwent FETO than in those who did not. Hemodynamic alterations are introduced with tracheal occlusion that are associated with alterations in ventricular loading and may influence growth.

Aberrant pulmonary lymphatic development in the nitrofen mouse model of congenital diaphragmatic hernia.

PURPOSE: Many infants develop a postsurgical chylothorax after diaphragmatic hernia repair. The pathogenesis remains elusive but may be owing to dysfunctional lymphatic development. This study characterizes pulmonary lymphatic development in the nitrofen mouse model of CDH. METHODS: CD1 pregnant mice were fed nitrofen/bisdiamine (N/B) or olive oil at E8.5. At E14.5 and E15.5, lung buds were categorized by phenotype: normal, N/B without CDH (N/B - CDH), or N/B with CDH (N/B+CDH). Anti-CD31 was used to localize all endothelial cells, while anti-LYVE-1 was used to identify lymphatic endothelial cells in lung buds using immunofluorescence. Differential protein expression of lymphatic-specific markers was analyzed. RESULTS: Lymphatic endothelial cells localized to the mesenchyme surrounding the airway epithelium at E15.5. CD31 and LYVE-1 colocalization identified lymphatic endothelial cells. LYVE-1 expression was upregulated in N/B+CDH lung buds in comparison to N/B - CDH and normal lung buds by immunofluorescence. Western blotting shows that VEGF-D, LYVE-1, Prox-1, and VEGFR-3 expression was upregulated in N/B+CDH lung buds in comparison to N/B - CDH or control lung buds at E14.5. CONCLUSIONS: Lung lymphatics are hyperplastic in N/B+CDH. Upregulation of lymphatic-specific genes suggests that lymphatic hyperplasia plays an important role in dysfunctional lung lymphatic development in the nitrofen mouse model of CDH.

Tumor metrics and morphology predict poor prognosis in prenatally diagnosed sacrococcygeal teratoma: a 25-year experience at a single institution.

PURPOSE: Some fetuses with sacrococcygeal teratoma (SCT) develop hydrops, but there is no consensus on an appropriate prognostic marker for poor prognosis. The purpose of this study is to establish predictors of poor prognosis in fetuses with SCT. METHODS: A retrospective review of patients with prenatally diagnosed SCT from 1986 to 2011 was performed. Patients with outcome data and ultrasound exams before 32 weeks gestational age (GA) were included (n=37). Tumor volume-to-fetal weight ratio (TFR) and tumor morphology were assessed as sonographic predictors of poor prognosis. RESULTS: Twelve patients (32%) had good prognosis, and twenty-five patients (68%) had poor prognosis. All patients with poor prognosis had a morphology score ≥ 3, which is a significant predictor of poor prognosis (p <0.0001). TFR was assessed, and a receiver operating characteristic (ROC) analysis identified a cutoff value of 0.12 before 24 weeks GA and 0.11 before 32 weeks GA as predictors for poor prognosis. TFR is a significant predictor of poor prognosis (p<0.0001). CONCLUSIONS: Patients with cystic SCT all had good prognosis. TFR >0.12 was validated as a sonographic predictor of poor prognosis. TFR and tumor morphology can be used to counsel expectant families with prenatally diagnosed SCT regarding prognosis.

Fetal production of growth factors and inflammatory mediators predicts pulmonary hypertension in congenital diaphragmatic hernia.

BACKGROUND: Congenital diaphragmatic hernia (CDH) represents a spectrum of lung hypoplasia, and consequent pulmonary hypertension (PH) is an important cause of postnatal morbidity and mortality. We studied biomarkers at the maternal-fetal interface to understand factors associated with the persistence of PH. METHODS: Maternal and cord blood samples from fetuses with CDH and unaffected controls were analyzed using a human 39plex immunoassay kit. Cellular trafficking between the mother and the fetus was quantified using quantitative real-time PCR for nonshared alleles. Biomarker profiles were then correlated with CDH severity on the basis of the degree of PH. RESULTS: Cord blood levels of epidermal growth factor, platelet-derived growth factor, and several inflammatory mediators increased significantly as the severity of CDH increased, whereas maternal levels of growth factors and mediators decreased significantly with CDH severity. Maternal cells were increased in fetuses with severe CDH as compared with controls, with elevated levels of the CXC chemokine ligand-10 in patients with the highest trafficking. CONCLUSION: Patients with CDH demonstrate proinflammatory and chemotactic signals in fetal blood at the time of birth. Because some of these molecules have been implicated in the development of PH, prenatal strategies targeting specific molecular pathways may be useful adjuncts to current fetal therapies.

Hepatic portocholecystostomy for biliary atresia: a 25-year follow-up and review.

We report the successful salvage of a patient's native liver 25 years after hepatic portocholecystostomy for biliary atresia. Our case demonstrates the effectiveness of biliary specific, high-resolution CT imaging in the diagnosis of, and operative planning for complex cases of biliary obstruction. We also report the longest-term pathologic follow-up of biliary atresia after hepatic portocholecystostomy. Life-long follow-up of patients with biliary atresia is important to prevent life-threatening complications of biliary stasis/obstruction.

Implantable ultra-low pulmonary pressure monitoring system for fetal surgery.

Congenital pulmonary hypoplasia is a devastating condition affecting fetal and newborn pulmonary physiology, resulting in great morbidity and mortality. The fetal lung develops in a fluid-filled environment. In this work, we describe a novel, implantable pressure sensing and recording device which we use to study the pressures present in the fetal pulmonary tree throughout gestation. The system achieves 0.18 cm H2O resolution and can record for twenty one days continuously at 256 Hz. Sample tracings of in vivo fetal lamb recordings are shown.

Advances in prenatal diagnosis and treatment of congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) is a common birth anomaly. Absence or presence of liver herniation and determination of lung-to-head ratio are the most accurate predictors of prognosis for fetuses with CDH. Though open fetal CDH repair has been abandoned, fetal endoscopic balloon tracheal occlusion promotes lung growth in fetuses with severe CDH. Although significant improvements in lung function have not yet been shown in humans, reversible or dynamic tracheal occlusion is promising for select fetuses with severe CDH. This article reviews advances in prenatal diagnosis of CDH, the experimental basis for tracheal occlusion, and its translation into human clinical trials.

Synchronous ipsilateral Bochdalek and Morgagni diaphragmatic hernias: a case report.

The etiology of congenital diaphragmatic hernia (CDH) is unknown. Phenotypic patterns of CDH defects provide clues about normal diaphragm development and the pathophysiology of CDH. We report a case of a patient who was diagnosed with CDH postnatally and was found on imaging to have simultaneous Bochdalek and Morgagni hernias on the right side. During the operative repair of these defects, an additional left-sided Morgagni-type defect was also found. To the best of our knowledge, this form of CDH has not been previously reported.

Dynamic tracheal occlusion improves lung morphometrics and function in the fetal lamb model of congenital diaphragmatic hernia.

BACKGROUND: Congenital diaphragmatic hernia (CDH) is associated with significant neonatal morbidity and mortality. Although prenatal complete tracheal occlusion (cTO) causes hypoplastic CDH lungs to enlarge, improved lung function has not been demonstrated. Furthermore, cTO interferes with the dynamic pressure change and fluid flow associated with fetal breathing. PURPOSE: The purpose of the study was to assess a novel dynamic tracheal occlusion (dTO) device that preserves pressure changes and fluid flow. METHODS: In this pilot study, CDH was created in fetal lambs at 65 days of gestational age (GA). At 110 days GA, a cTO device (n = 3) or a dTO device (n = 4) was placed in the fetal trachea. At 135 days GA, lambs were delivered and resuscitated. Unoperated lamb co-twins (n = 5), sham thoracotomy lambs (n = 2), and untreated CDH lambs (n = 3) served as controls. RESULTS: Tracheal opening pressure, lung volume, lung fluid total protein, and phospholipid were significantly higher in the cTO group than in the dTO and unoperated control groups. Maximal oxygenation and lung compliance were significantly lower in the cTO group when compared with the unoperated control and dTO groups. CONCLUSION: Preliminary results suggest that in the fetal lamb CDH model, dTO restores normal lung morphometrics and function, whereas cTO leads to enlarged but less functional lungs.