Fetal surgery

Trends in research related to fetal therapy from 2012 to 2022: a bibliometric analysis

Background

The development of prenatal diagnosis technology allows prompt detection of severe fetal diseases. To address adverse factors that threaten fetal survival, fetal therapy came into existence, which aims to preserve the function after birth to a higher degree and improve the quality of life.

Objective

To conduct a comprehensive bibliometric analysis of studies on fetal therapy in the past decade and explore the research trends and hotspots in this field.

Methods

We conducted a systematic search on the Web of Science Core Collection to retrieve studies related to fetal therapy published from 2012 to 2022. VOSviewer and CiteSpace were used to analyze the key features of studies, including annual output, countries/regions, institutions, authors, references, research hotspots, and frontiers.

Results

A total of 9,715 articles were included after eliminating duplicates. The annual distribution of the number of articles showed that the number of articles published in fetal therapy had increased in the past decade. Countries and institutions showed that fetal therapy is more mature in the United States. Author analysis showed the core investigators in the field. Keyword analysis showed the clustering and emergence frequency, which helped summarize the research results and frontier hotspots in this field. The cocited references were sorted out to determine the literature with a high ranking of fetal therapy in recent years, and the research trend in recent years was analyzed.

Conclusions

This study reveals that countries, institutions, and researchers should promote wider cooperation and establish multicenter research cooperation in fetal therapy research. Moreover, fetal therapy has been gradually explored from traditional surgical treatment to gene therapy and stem cell therapy. In recent years, fetoscopic laser surgery, guideline, and magnetic resonance imaging have become the research hotspots in the field.

Congenital lung malformations

Congenital lung malformations (CLMs) are rare developmental anomalies of the lung, including congenital pulmonary airway malformations (CPAM), bronchopulmonary sequestration, congenital lobar overinflation, bronchogenic cyst and isolated congenital bronchial atresia. CLMs occur in 4 out of 10,000 live births. Postnatal presentation ranges from an asymptomatic infant to respiratory failure. CLMs are typically diagnosed with antenatal ultrasonography and confirmed by chest CT angiography in the first few months of life. Although surgical treatment is the gold standard for symptomatic CLMs, a consensus on asymptomatic cases has not been reached. Resection, either thoracoscopically or through thoracotomy, minimizes the risk of local morbidity, including recurrent infections and pneumothorax, and avoids the risk of malignancies that have been associated with CPAM, bronchopulmonary sequestration and bronchogenic cyst. However, some surgeons suggest expectant management as the incidence of adverse outcomes, including malignancy, remains unknown. In either case, a planned follow-up and a proper transition to adult care are needed. The biological mechanisms through which some CLMs may trigger malignant transformation are under investigation. KRAS has already been confirmed to be somatically mutated in CPAM and other genetic susceptibilities linked to tumour development have been explored. By summarizing current progress in CLM diagnosis, management and molecular understanding we hope to highlight open questions that require urgent attention.

Minimally Invasive Fetal Surgery and the Next Frontier

Most patients with congenital anomalies do not require prenatal intervention. Furthermore, many congenital anomalies requiring surgical intervention are treated adequately after birth. However, there is a subset of patients with congenital anomalies who will die before birth, shortly after birth, or experience severe postnatal complications without fetal surgery. Fetal surgery is unique in that an operation is performed on the fetus as well as the pregnant woman who does not receive any direct benefit from the surgery but rather lends herself to risks, such as hemorrhage, abruption, and preterm labor. The maternal risks involved with fetal surgery have limited the extent to which fetal interventions may be performed but have, in turn, led to technical innovations that have significantly advanced the field. This review will examine congenital abnormalities that can be treated with minimally invasive fetal surgery and introduce the next frontier of prenatal management of fetal surgical pathology.

Narrative review of congenital lung lesions

This article reviews the contemporary diagnosis and management of antenatally diagnosed congenital lung lesions. These anomalies, which include congenital pulmonary airway malformation (CPAM) (formerly congenital cystic adenomatoid malformation), bronchopulmonary sequestration (BPS), bronchogenic cyst, and congenital lobar emphysema (CLE), are relatively rare but are increasingly encountered by clinicians because of the improved resolution and enhanced sensitivity of fetal ultrasound. Serial assessment of these lesions throughout pregnancy remains the norm rather than the exception. Perinatal management strategies may differ based on initial size and growth patterns of these masses until delivery. Fetal magnetic resonance imaging and other diagnostic testing can sometimes be helpful in providing additional prognostic information. Over the last decade, maternal steroids have become standard of care in the management of larger lesions at risk for nonimmune hydrops. As a result, fetal surgical procedures, including open resection, thoracoamniotic shunting, and ex utero intrapartum treatment (EXIT), are less uncommonly performed. Decisions regarding whether delivery of these fetuses should occur in a tertiary care center with pediatric surgery coverage versus delivery at a local community hospital are now highly relevant in most prenatal counseling discussions with families. Large lung malformations may require urgent surgical removal in the early postnatal period because of respiratory distress. Other complications, such as recurrent pneumonia, pneumothorax, and cancer, are indications for postnatal lung resection on an elective basis. Many children are good candidates for minimally invasive (thoracoscopic) surgical approaches as an alternative to resection by thoracotomy. In the vast majority of cases, the overall prognosis remains excellent.

Management of fetal teratomas

Fetal teratomas are the most common tumors diagnosed prenatally. The majority of these tumors are benign and cured by complete resection of the mass during the neonatal period. Prenatal diagnosis has improved the perinatal management of these lesions and especially for the teratomas that might benefit from fetal intervention. A comprehensive prenatal evaluation including conventional ultrasounds, Doppler, echocardiography and fetal MRI, is essential for an effective counseling and perinatal management. Antenatal counseling helps the parents to better understand the natural history, fetal intervention, and perinatal management of these tumors, which differ dramatically depending on their size and location. Fetal surgical debulking improves survival in cases of sacrococcygeal teratoma with cardiac decompensation. Additionally, the use of an EXIT procedure reduces the morbidity and mortality if a complicated delivery in cases of cervical and mediastinal teratomas. Here, we offer an overview of all fetal teratomas and their recommended management, with emphasis on in utero treatment options.

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.

Urologic management of spina bifida

The urologist plays an important role in the multidisciplinary team of physicians who provide care for patients with spina bifida. We review common strategies for managing the urinary tract in these patients. The primary objective in all phases of life is protecting kidney function by minimizing bladder hostility and establishing a good capacity, low-pressure urinary reservoir. Ensuring adequate bladder and bowel continence is also paramount for enhancing self-esteem and independence. Medical therapy incorporating clean intermittent catheterization and antimuscarinic medication is the cornerstone of neurogenic bladder management and often the only intervention required to achieve the above goals. Others may require formal lower urinary tract reconstruction to prevent urinary tract deterioration. As will be shown, current management, while effective, is not supported by strong evidence-based protocols; and the impact of any intervention upon quality of life, while subjectively seen as positive, does not have objective validation. These limitations are recognized and currently the subject of urologic investigation.

The urologist's role in the management of spina bifida: a continuum of care

Caring for the child with spina bifida necessitates lifelong care by a coordinated team of health care providers, and the urologist plays a vital role in this team. The most important management goal of the urologist is the early establishment and consistent maintenance of a lower pressure urinary reservoir. Ensuring social continence along with its attendant social independence provides some of the greatest management challenges. In those patients who fail medical therapy, surgeons, caregivers, and patients must understand the scope of lower urinary tract reconstruction, the need for strict compliance, and the possibility of future surgery. In this article, we review the recent advances in spina bifida management.

A large animal model of the fetal tracheal stenosis/atresia spectrum

BACKGROUND

Treatment of congenital tracheal stenosis/atresia remains essentially unresolved. Previous models of this disease entity have been restricted to rodents and the chick. We sought to establish the principles of a large, surgical animal model of this spectrum of fetal anomalies.

METHODS

Fetal lambs (n = 8) underwent open surgery at 90-112 days gestation. Their cervical tracheas were encircled by a biocompatible polytetrafluoroethylene wrap, so as to extrinsically restrict their external diameter by 25%. Survivors (n = 7) were killed at different time points post-operatively before term. The manipulated tracheal segments were compared with their respective proximal portions (controls). Analyses included morphometry, histology and quantitative extracellular matrix measurements.

RESULTS

At necropsy, the typical gross appearance of tracheal stenosis/atresia was present in all manipulated tracheal segments. Histological findings included the virtual disappearance of the membranous portion of the trachea, along with infolding, fragmentation, and/or posterior fusion of cartilaginous rings, often with disappearance of the airway mucosa. There were significant decreases in diameter (P < 0.001) and total collagen levels (P = 0.005) on the manipulated trachea compared with the control portions. No significant differences were observed in overall elastin or glycosaminoglycan contents. A significant time-dependent increase in elastin was noted on the control, but not the experimental side.

CONCLUSIONS

In a surgical ovine model, controlled extrinsic compression of the fetal trachea leads to morphological and biochemical findings compatible with the congenital tracheal stenosis/atresia spectrum. This simple and easily reproducible prenatal model can be instrumental in the development of emerging therapies for these congenital anomalies.

The role of fetal echocardiography in fetal intervention: a symbiotic relationship

In this review, the authors explore the role of noninvasive and invasive fetal interventions in fetal cardiovascular disease guided by observations at fetal echocardiography. They first review fetal cardiac lesions that may be ameliorated by fetal intervention and then review noncardiac fetal pathologic findings for which fetal echocardiography can provide important insight into the pathophysiology and aid in patient selection for and timing of intervention and postintervention surveillance.

Congenital malformations of the central nervous system: clinical approach

Central nervous system (CNS) malformations represent important factor of morbidity and mortality in children. The aim of the study was to determine the incidence, type and clinical features of CNS malformations in children who were admitted at the Neonatal and Child Neurology Department, Neonatal Intensive Care Unit and Paediatric Intensive Care Unit of Paediatric Clinic, University of Sarajevo Clinics Centre, from January 1st, 2002 to December 31st, 2006. There were total of 16520 admissions at the Paediatric Clinic over the studied period. CNS malformations, solitary or multiple, have been diagnosed in 100 patients (0,61%). The total number of various CNS malformations was 127. Lethal outcome was established in 9/100 cases (9%). The most frequent CNS malformations were neural tube defects 49/127 (38,6%). Hydrocephalus was seen in 34/127 (26,8%), microcephaly in 24/127 (18,9%), agenesis of corpus callosum in 10/127 (7,9%), Dandy Walker malformation in 6/127 (4,7%) and other CNS malformations in 4/127 (3,1%). In 20/100 of patients neural tube defect was associated with hydrocephalus (20%). CNS malformations were prenatally diagnosed in 13/100 of patients (13%). Primary prevention of CNS malformations can be improved in our country by better implementation of preconceptional folic acid therapy for all women of childbearing age. Secondary prevention by prenatal diagnosis requires advanced technical equipment and adequate education of physicians in the field of foetal ultrasonography. In our circumstances, prenatal diagnostics of CNS malformations is still not developed enough.