Prenatal treprostinil improves pulmonary arteriolar hypermuscularization in the rabbit model of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a congenital malformation characterized by pulmonary hypoplasia, pulmonary hypertension, and cardiac dysfunction. Pulmonary hypertension represents the major cause of neonatal mortality and morbidity. Prenatal diagnosis allows assessment of severity and selection of foetal surgery candidates. We have shown that treprostinil, a prostacyclin analogue with an anti-remodelling effect, attenuates the relative hypermuscularization of the pulmonary vasculature in rats with nitrofen-induced CDH. Here we confirm these observations in a large animal model of surgically-created CDH. In the rabbit model, subcutaneous maternal administration of treprostinil at 150 ng/kg/min consistently reached target foetal concentrations without demonstrable detrimental foetal or maternal adverse effects. In pups with CDH, prenatal treprostinil reduced pulmonary arteriolar proportional medial wall thickness and downregulated inflammation and myogenesis pathways. No effect on alveolar morphometry or lung mechanics was observed. These findings provide further support towards clinical translation of prenatal treprostinil for CDH.

Long-term pulmonary and neurodevelopmental impairment in a fetal growth restriction rabbit model

Fetal growth restriction (FGR) remains one of the main obstetrical problems worldwide, with consequences beyond perinatal life. Animal models with developmental and structural similarities to the human are essential to understand FGR long-term consequences and design novel therapeutic strategies aimed at preventing or ameliorating them. Herein, we described the long-term consequences of FGR in pulmonary function, structure, and gene expression, and characterized neurodevelopmental sequelae up to preadolescence in a rabbit model. FGR was induced at gestational day 25 by surgically reducing placental blood supply in one uterine horn, leaving the contralateral horn as internal control. Neonatal rabbits born near term were assigned to foster care in mixed groups until postnatal day (PND) 21. At that time, one group underwent pulmonary biomechanical testing followed by lung morphometry and gene expression analysis. A second group underwent longitudinal neurobehavioral assessment until PND 60 followed by brain harvesting for multiregional oligodendrocyte and microglia quantification. FGR was associated with impaired pulmonary function and lung development at PND 21. FGR rabbits had higher respiratory resistance and altered parenchymal biomechanical properties in the lungs. FGR lungs presented thicker alveolar septal walls and reduced alveolar space. Furthermore, the airway smooth muscle content was increased, and the tunica media of the intra-acinar pulmonary arteries was thicker. In addition, FGR was associated with anxiety-like behavior, impaired memory and attention, and lower oligodendrocyte proportion in the frontal cortex and white matter. In conclusion, we documented and characterized the detrimental pulmonary function and structural changes after FGR, independent of prematurity, and beyond the neonatal period for the first time in the rabbit model, and describe the oligodendrocyte alteration in pre-adolescent rabbit brains. This characterization will allow researchers to develop and test therapies to treat FGR and prevent its sequelae.

Diaphragmatic hernia repair porcine model to compare the performance of biodegradable membranes against Gore-Tex®

BACKGROUND

Patch repair of congenital diaphragmatic hernia (CDH) using Gore-Tex® is associated with infection, adhesions, hernia recurrence, long-term musculoskeletal sequels and poor tissue regeneration. To overcome these limitations, the performance of two novel biodegradable membranes was tested to repair CDH in a growing pig model.

METHODS

Twelve male pigs were randomly assigned to 3 different groups of 4 animals each, determined by the type of patch used during thoracoscopic diaphragmatic hernia repair (Gore-Tex®, polycaprolactone electrospun membrane-PCLem, and decellularized human chorion membrane-dHCM). After 7 weeks, all animals were euthanized, followed by necropsy for diaphragmatic evaluation and histological analysis.

RESULTS

Thoracoscopic defect creation and diaphragmatic repair were performed without any technical difficulty in all groups. However, hernia recurrence rate was 0% in Gore-Tex®, 50% in PCLem and 100% in dHCM groups. At euthanasia, Gore-Tex® patches appeared virtually unchanged and covered with a fibrotic capsule, while PCLem and dHCM patches were replaced by either floppy connective tissue or vascularized and floppy regenerated membranous tissue, respectively.

CONCLUSION

Gore-Tex® was associated with a higher survival rate and lower recurrence. Nevertheless, the proposed biodegradable membranes were associated with better tissue integration when compared with Gore-Tex®.

Minimally Invasive Neck Surgery: An Animal Model Study

Background: Minimally invasive surgery (MIS) is replacing conventional surgery as the "gold standard" in different surgical areas. Although cervical MIS is already accepted in the adult population, its use in children is still new and controversial. The natural obstacles to this approach are the absence of a natural cavity, with the inherent complications of creating one artificially, and the limited existing workspace especially in pediatric patients. All endoscopic techniques in the field of neck surgery try to live up to the high cosmetic expectations and the transoral cervical approach as a natural orifice surgery technique excels at it. Aim: Besides the goal of feasibility, we aim to report on the pitfalls of this approach, by using an experimental rabbit model for minimally invasive thyroidectomy. Materials and Methods: Transoral endoscopic thyroidectomies using a vestibular approach were performed in 10 anesthetized rabbits. All surgeries were video recorded. The surgical time, anatomy identified, difficulties, and intraoperative complications were documented. Results: Through one trocar in the vestibular area and two lateral stab incisions, it was possible to create a working space and to reach the peritracheal area. Total thyroidectomies were completed in the 10 animals with a mean operative time of 51 minutes. In all of them we were able to identify the fascial spaces of the neck and the major vessels. During surgery, the lack of space required surgical gestures to be very precise, soft, and gentle. There were 2 cases with a small amount of bleeding and one mild trachea laceration during the procedure, but none of them required suspension or conversion to an open procedure. Animals were euthanized immediately after the surgical procedure. Conclusions: The vestibular approach seems to be a feasible technique to access pediatric neck pathology. Despite the differences in the cervical anatomy, the limited workspace of the rabbit model perfectly matches the requirements of a pediatric training model.

Operative Management of Neonatal Lymphatic Malformations: Lesson Learned From 57 Consecutive Cases

Aim of the study: Lymphatic malformations (LMs) are rare entities, sometimes difficult to treat, that may be life-threatening when intricately connected to airway structures. Invasive treatments are occasionally required, with sclerotherapy considered the treatment of choice and surgery as a second-line approach. The aim of the present study was to evaluate our multidisciplinary team experience in treating newborns affected by LMs requiring operative management, while defining early outcomes. Methods: Retrospective review of all consecutive patients admitted for LMs requiring operative management between January 2000 and January 2019. Patients were mainly characterized based on anatomical district of the LM (and further stratified based on the development of respiratory distress), need for tracheostomy, number of sclerotherapies, indication for surgery, and residual disease beyond the 1st year. Morbidity and mortality were also evaluated. Fisher exact test and Mann-Whitney test were used as appropriate. Statistical significance was set at p < 0.05. Results: Fifty-seven patients were included in the study, 36 with cervicofacial and/or mediastinal LMs and 21 with LMs of other anatomical districts. Due to the risk of developing respiratory distress at birth, patients with cervicofacial and/or mediastinal LMs were divided into two groups (8/36 group A vs. 28/36 group B). Group A patients are at higher risk for tracheostomy (7/8 group A vs. 1/28 group B, p = 0.0001) and more often require surgical reduction of the residual lymphatic abnormality (5/8 group A vs. 4/28 group B, p = 0.013). They also require sclerotherapies more often, but the difference is not statistically significant (8/8 group A vs. 19/28 group B, p = 0.15). Patients with cervicofacial/mediastinal LMs frequently suffer from persistent residual disease beyond the 1st year of life, significantly more often in group A (7/8 group A vs. 12/28 group B, p = 0.043). Conclusion: LMs are rare conditions with potential life-threatening behavior. Their intrinsic clinical complexity requires a multidisciplinary approach to the affected patients. Planning a long-term follow-up is essential because of the late-term problems those patients may experience.

Urethral duplication in male epispadias: a very uncommon association

BACKGROUND

Urethral duplication associated with epispadias is a rare malformation. Few cases are described in Literature. We report the experience of two centers to add to the literature.

METHODS

A retrospective study was conducted in two Italian Centers. All patients with urethral duplication associated with epispadias, treated from 1997 to 2017 were included. The preoperative work-up included renal-urinary ultrasonography and voiding cystourethrogram. All patients underwent surgery according to the Mitchell-Caione technique. Cosmetic result, urinary continence and satisfaction degree of patients at the last follow-up were evaluated as outcomes. Six male patients with urethral duplication in epispadias were included. Two patients presented penile epispadias and four penopubic epispadias. Only one patient had urinary incontinence as presenting symptomatology. The diagnosis of urethral duplication was accidental during preoperative evaluation in the remaining five patients.

RESULTS

At last follow-up (mean 8.3 years) all patients but one presented good cosmetic result, one patient presented mild stress urinary incontinence, one presented nocturnal enuresis. The physical genital appearance was improved in all patients. Urethral duplication in association with epispadias is a rare urogenital abnormality. No classification is universally accepted.

CONCLUSIONS

Based on our experience, we believe that the presence of any duplication should be carefully searched during surgery for male epispadias.

Laryngotracheal Abnormalities in Esophageal Atresia Patients: A Hidden Entity

Importance: Presence of laryngotracheal abnormalities is associated with increased morbidity and higher mortality rate in esophageal atresia patients. Objective: Determine the prevalence of laryngotracheal abnormalities (LTA) in a prospectively collected cohort of patients treated for esophageal atresia and/or tracheoesophageal fistula (EA/TEF). Analysis of the impact of those airway anomalies in early post-operative outcomes was performed. Patients and Methods: This was a review of a prospectively collected database, including patients from January 2008 to December 2017. Patients enrolled in the present study were treated in a high-volume referral center. Present study included all newborn-infants consecutively treated for EA/TEF. All patients were evaluated by flexible laryngotracheoscopy performed under local anesthesia in spontaneous breathing. In case of airway malformation suspected during flexible endoscopy, a rigid endoscopy was performed to complete airway assessment. If post-operative respiratory symptoms (noisy breathing, respiratory difficulty, failure to extubate, or difficulty feeding) were noted, a second laryngotracheoscopy was performed. Primary study outcome was to evaluate the prevalence of LTA in EA/TEF infants, characterizing of LTA, and their impact on early post-operative outcomes. Those primary study outcomes were planned before data collection began. Results: During the study period 207 patients with EA/TEF were treated. LTA had a period prevalence of 40.1% (83/207). Although no differences were recorded in terms of demographics and clinical presentation, LTA+ infants more frequently required tracheostomy (12/52, 23% vs. 0/124, 0%; p 0.0001) and were at increased risk of death (12/83, 14% vs. 5/124, 4%; p 0.009) in comparison with EA/TEF without LTA. Conclusions: Present data suggest a high prevalence of congenital LTA in patients affected by EA. Most of the abnormalities are congenital and a high proportion of patients with LTA require a tracheostomy. Mortality significantly correlates with the presence of LTA. Systematic airway endoscopic preoperative evaluation has to be pushed forward to minimize LTA-related morbidity and mortality.

Embryological and clinical implications of the association between anorectal malformations and spinal dysraphisms

PURPOSE

To describe the association of anorectal malformation (ARM) and spinal dysraphism (SD) in terms of impact on the management of SD and embryogenetic implications.

METHODS

Patients with SD associated with (A) or without (B) ARM were included. The two groups were further divided into operated on (A1/B1) or not (A2/B2) for SD. Groups A and B were compared for type of SD (embryogenetic classification) and prevalence of neurosurgery; Groups A1 vs. A2 for type of ARM (Wingspread classification); Groups A1 vs. B1 for age at neurosurgery, neurophysiology, and clinical symptoms.

MAIN RESULTS

One hundred twenty-one patients with SD, 83 with and 38 without ARM were consecutively treated (1999-2015). Group A was associated only with SDs developing after primary neurulation, corresponding to the period of cloacal septation and organogenesis (p = 0.0007). Untethering surgery was significantly less frequent in Group A (p < 0.0001 and p = 0.04, respectively). Higher ARMs were not associated with increased risk for neurosurgery. No other significant differences were detected.

CONCLUSIONS

In our series, ARMs were associated only with SD developing after primary neurulation, suggesting a single insult leading to both SD and the associated ARM. Neurosurgery is indicated less frequently in patients with ARM-associated SD, despite the similar preoperative clinical features.