Learning curves of open and endoscopic fetal spina bifida closure: systematic review and meta-analysis.

OBJECTIVE: The Management of Myelomeningocele Study (MOMS) trial demonstrated the safety and efficacy of open fetal surgery for spina bifida aperta (SBA). Recently developed alternative techniques may reduce maternal risks without compromising the fetal neuroprotective effects. The aim of this systematic review was to assess the learning curve (LC) of different fetal SBA closure techniques. METHODS: MEDLINE, Web of Science, EMBASE, Scopus and Cochrane databases and the gray literature were searched to identify relevant articles on fetal surgery for SBA, without language restriction, published between January 1980 and October 2018. Identified studies were reviewed systematically and those reporting all consecutive procedures and with postnatal follow-up ≥ 12 months were selected. Studies were included only if they reported outcome variables necessary to measure the LC, as defined by fetal safety and efficacy. Two authors independently retrieved data, assessed the quality of the studies and categorized observations into blocks of 30 patients. For meta-analysis, data were pooled using a random-effects model when heterogeneous. To measure the LC, we used two complementary methods. In the group-splitting method, competency was defined when the procedure provided results comparable to those in the MOMS trial for 12 outcome variables representing the immediate surgical outcome, short-term neonatal neuroprotection and long-term neuroprotection at ≥ 12 months of age. Then, when raw patient data were available, we performed cumulative sum analysis based on a composite binary outcome defining successful surgery. The composite outcome combined four clinically relevant variables for safety (absence of extreme preterm delivery < 30 weeks, absence of fetal death ≤ 7 days after surgery) and efficacy (reversal of hindbrain herniation and absence of any neonatal treatment of dehiscence or cerebrospinal fluid leakage at the closure site). RESULTS: Of 6024 search results, 17 (0.3%) studies were included, all of which had low, moderate or unclear risk of bias. Fetal SBA closure was performed using standard hysterotomy (11 studies), mini-hysterotomy (one study) or fetoscopy by either exteriorized-uterus single-layer closure (one study), percutaneous single-layer closure (three studies) or percutaneous two-layer closure (one study). Only outcomes for standard hysterotomy could be meta-analyzed. Overall, outcomes improved significantly with experience. Competency was reached after 35 consecutive cases for standard hysterotomy and was predicted to be achieved after ≥ 57 cases for mini-hysterotomy and ≥ 56 for percutaneous two-layer fetoscopy. For percutaneous and exteriorized-uterus single-layer fetoscopy, competency was not reached in the 81 and 28 cases available for analysis, respectively, and LC prediction analysis could not be performed. CONCLUSIONS: The number of cases operated is correlated with the outcome of fetal SBA closure, and the number of operated cases required to reach competency ranges from 35 for standard hysterotomy to ≥ 56-57 for minimally invasive modifications. Our observations provide important information for institutions looking to establish a new fetal center, develop a new fetal surgery technique or train their team, and inform referring clinicians, potential patients and third parties. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Curvas de aprendizaje del cierre de la espina bífida fetal mediante cirugía abierta y endoscópica: revisión sistemática y metaanálisis OBJETIVO: El ensayo del Estudio sobre la Gestión del Mielomeningocele (MOMS, por sus siglas en inglés) demostró la seguridad y eficacia de la cirugía fetal abierta para la espina bífida aperta (EBA). Las técnicas alternativas recientemente desarrolladas pueden reducir los riesgos de la madre sin comprometer los efectos neuroprotectores del feto. El objetivo de esta revisión sistemática fue evaluar la curva de aprendizaje (CA) de diferentes técnicas de cierre de la EBA fetal. MÉTODOS: Se realizaron búsquedas en las bases de datos de MEDLINE, Web of Science, EMBASE, Scopus y Cochrane, así como en la literatura gris, para identificar artículos relevantes sobre cirugía fetal para la EBA, sin restricción de idioma, publicados entre enero de 1980 y octubre de 2018. Se examinaron sistemáticamente los estudios identificados y se seleccionaron los que informaban de todos los procedimientos consecutivos y con seguimiento postnatal ≥12 meses. Los estudios se incluyeron sólo si informaban sobre las variables de resultado necesarias para medir la CA, definidas por la seguridad y la eficacia para el feto. Dos autores recuperaron los datos de forma independiente, evaluaron la calidad de los estudios y clasificaron las observaciones en bloques de 30 pacientes. Para el metaanálisis, los datos se agruparon mediante un modelo de efectos aleatorios cuando fueron heterogéneos. Para medir la CA, se usaron dos métodos complementarios. En el método de división de grupos, la competencia se definió cuando el procedimiento proporcionó resultados comparables a los del ensayo MOMS para 12 variables de resultados que representaban el resultado quirúrgico inmediato, la neuroprotección neonatal a corto plazo y la neuroprotección a largo plazo a ≥12 meses de edad. Luego, cuando se dispuso de los datos brutos de los pacientes, se realizó un análisis de suma acumulada basado en un resultado binario compuesto que definió el éxito de la cirugía. El resultado compuesto combinó cuatro variables clínicamente relevantes en cuanto a la seguridad (ausencia de parto pretérmino extremo <30 semanas; ausencia de muerte fetal a ≤7 días después de la cirugía) y eficacia (reducción de la hernia del rombencéfalo y ausencia de cualquier tratamiento neonatal de dehiscencia o derrame de líquido cefalorraquídeo en el lugar del cierre). RESULTADOS: De los 6024 resultados de la búsqueda, se incluyeron 17 (0,3%) estudios, todos ellos con un riesgo de sesgo bajo, moderado o incierto. El cierre de la EBA fetal se realizó mediante histerotomía estándar (11 estudios), mini histerotomía (un estudio) o fetoscopia, ya fuera mediante el cierre exteriorizado del útero de una sola capa (un estudio), el cierre percutáneo de una sola capa (tres estudios) o el cierre percutáneo de dos capas (un estudio). Sólo se pudieron metaanalizar los resultados de la histerotomía estándar. En general, los resultados mejoraron significativamente con la experiencia. Se alcanzó la competencia después de 35 casos consecutivos para la histerotomía estándar y se predijo que se alcanzaría después de ≥57 casos para la mini histerotomía y ≥56 para la fetoscopia percutánea de dos capas. En el caso de las fetoscopias percutánea y exteriorizada del útero de una sola capa, no se alcanzó la competencia en los 81 y 28 casos disponibles para el análisis, respectivamente, y no se pudo realizar el análisis de predicción de la CA. CONCLUSIONES: El número de casos operados está correlacionado con el resultado del cierre de la EBA fetal, y el número de casos operados necesarios para alcanzar la competencia estuvo entre 35 para la histerotomía estándar y ≥56-57 para las operaciones con mínima agresividad. Las observaciones realizadas proporcionan información importante para las instituciones que buscan establecer un nuevo centro fetal, desarrollar una nueva técnica de cirugía fetal o entrenar a su equipo, e informar a los médicos que remiten a especialistas a los posibles pacientes y a terceros. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Achilles tendon material properties are greater in the jump leg of jumping athletes.

PURPOSE: The Achilles tendon (AT) must adapt to meet changes in demands. This study explored AT adaptation by comparing properties within the jump and non-jump legs of jumping athletes. Non-jumping control athletes were included to control limb dominance effects. METHODS: AT properties were assessed in the preferred (jump) and non-preferred (lead) jumping legs of male collegiate-level long and/or high jump (jumpers; n=10) and cross-country (controls; n=10) athletes. Cross-sectional area (CSA), elongation, and force during isometric contractions were used to estimate the morphological, mechanical and material properties of the ATs bilaterally. RESULTS: Jumpers exposed their ATs to more force and stress than controls (all p≤0.03). AT force and stress were also greater in the jump leg of both jumpers and controls than in the lead leg (all p<0.05). Jumpers had 17.8% greater AT stiffness and 24.4% greater Young's modulus in their jump leg compared to lead leg (all p<0.05). There were no jump versus lead leg differences in AT stiffness or Young's modulus within controls (all p>0.05). CONCLUSION: ATs chronically exposed to elevated mechanical loading were found to exhibit greater mechanical (stiffness) and material (Young's modulus) properties.

Fetal surgery for myelomeningocele: history, research, clinical trials, and future directions.

Myelomeningocele, more commonly known as spina bifida, is the most common neural tube defect worldwide. In the United States, it is the primary cause of lifelong childhood paralysis with approximately four children born daily with this devastating disease. To minimize damage to the exposed spinal cord and prevent ascending central nervous system infections, postnatal closure of the spinal defect has been the standard of care for decades. Research into the mechanism of spinal cord injury in those with spina bifida revealed that damage continues to accrue during the gestational period. Prenatal defect closure via in utero surgery was proposed to prevent this early deterioration of the spinal cord, and early animal research demonstrated that prenatal repair was feasible and promising. This paved the way for the first human prenatal repairs in the mid-to-late 1990s. Following the promising outcomes observed during the first human cases, a randomized controlled trial, the Management of Myelomeningocele Study (MOMS), was conducted comparing postnatal repair of spina bifida to prenatal repair. The MOMS trial demonstrated that to those undergoing prenatal repair of spina bifida had a decreased need for ventriculoperitoneal shunting and improved lower extremity motor function. With the success of the MOMS trial, in utero repair is now considered the standard of care in those who meet the criteria for prenatal repair. This review will provide an overview of spina bifida and its impact, highlight the historical changes in care, describe the early research and theory that made prenatal repair an option, discuss the clinical experiences with human fetal repair and briefly touch on future research directions for those with myelomeningocele.

Subcutaneous endoscopically assisted ligation (SEAL) of the internal ring for repair of inguinal hernias in children: report of a new technique and early results.

BACKGROUND: Open inguinal hernia repair with high ligation is an excellent method of repair in the pediatric population. Advantages of endoscopic repairs include the ability to evaluate the contralateral side, avoidance of access trauma to the vas deferens and gonadal vessels, and decreased operative time. We now report our experience with subcutaneous endoscopically assisted ligation (SEAL),: a novel technique that has proved to be a safe and effective in the treatment of inguinal hernia in the pediatric population. METHODS: The study is based on a retrospective review of 204 pediatric patients with 300 inguinal hernias treated with the SEAL technique from November 2001 to August 2003 at a tertiary referral center. Patient age ranged from 30 days to 16 years at the time of operation, with a mean follow-up of 235 days (median follow-up, 189 days). Statistical analysis was done with chi2 test, with the main outcome measures being intraoperative and postoperative complications including recurrence rate, suture abscesses, and postoperative hydroceles. RESULTS: There were 13 recurrences in 300 SEAL repairs, for a recurrence rate of 4.3% (95% C.I. 2.01%-6.65%), with only two recurrences in the last 100 repairs (2%). There were 10 suture abscesses or granulomas and 7 postoperative hydroceles. There was no statistically significant association between recurrence and gender, age at operation, history of prematurity, bilaterality, or kind of suture used. CONCLUSIONS: Our 4.3% (95% C.I. 2.01-6.65%) recurrence rate is comparable to prior series of laparoscopic repairs citing recurrence rates of 0%-5.7%. The majority of recurrences occurred within the first 4 months of developing this new procedure, with only two recurrences in the last 100 repairs. These pilot data suggest that SEAL is a safe and effective technique for inguinal hernia repair in the pediatric population. A prospective study is planned to compare this laparoscopic technique with open herniorrhaphy.

Gastroschisis: small hole, big cost.

BACKGROUND/PURPOSE: This study was designed to assess the outcome and financial costs incurred for the treatment of gastroschisis. METHODS: A retrospective analysis was conducted of all patients with gastroschisis at a single institution over the past decade (n = 69). Hospital costs were determined and standardized to December 2001 dollars. RESULTS: Of the 69 patients, average gestational age at delivery was 35.9 weeks. Thirty-six patients had a primary fascial closure; 33 had a silo placed. The mean time to first feeding was 22 days and full feeding, 33 days. Average length of stay was 47 days. There were 3 deaths (2 shortly after birth, and one 131 days later owing to sepsis). The average cost of hospitalization and physician fees for patients with gastroschisis was $123,200. Using multivariate regression analysis, significant variables (P <.05) associated with cost of hospitalization were number of operative procedures, ventilatory days, male gender, and length of stay. Room expenses (43%), physician fees (15%), respiratory and pulmonary care (10%), and supply and devices (10%) made up the majority of costs. CONCLUSIONS: Cost of care associated with treatment for gastroschisis is high. Strategies designed to reduce cost must limit gastrointestinal, respiratory, and operative complications and reduce length of stay.

Congenital diaphragmatic hernia and hydrops: a lethal association?

BACKGROUND/PURPOSE: Nonimmune hydrops in the fetus is a finding that often portends death. The association and prognosis of fetuses with congenital diaphragmatic hernia (CDH) and hydrops is not known. METHODS: A retrospective review of all prenatally diagnosed cases and referrals of CDH was performed. Variables analyzed included gestational age at diagnosis and delivery, side of hernia, presence of associated anomalies and hydrops, and neonatal outcome. RESULTS: Since 1993, 474 prenatal referrals for CDH have been made. One hundred seventy-five were evaluated; 15 fetuses had hydrops (9%). Five patients had CDH, hydrops, and associated lethal anomalies. In the remaining 10 patients, 6 of the diaphragmatic defects were right-sided and 4 were left-sided. All except one had a major portion of the liver herniated into the chest. Six fetuses had prenatal intervention. Five neonates died shortly after birth. There were 5 long-term survivors; all received prenatal intervention. CONCLUSIONS: The association of CDH and hydrops is rare but often results in fatality. Hydrops appears to be associated with liver in the hernia, right-sided lesions, and lethal anomalies. Fetal intervention can be performed successfully in patients with CDH and hydrops, and may improve long-term survival rate in this group.

Fetoscopic treatment for discordant twins.

BACKGROUND/PURPOSE: In rare instances in monochorionic twin pregnancies, one twin can have a discordant anomaly (eg, cystic hygroma). If this twin dies in utero, neurologic injury and death can occur in the surviving cotwin. To protect the normal twin, the authors developed an approach to separate the circulations and ablate the umbilical cord of the abnormal twin. METHODS: From September 1998 to February 2001, 6 cases of discordant anomalous twins were diagnosed by prenatal ultrasound scan in which the anomaly was lethal or parents desired prenatal termination for this abnormal twin. All underwent surgical intervention with gestational ages varying from 19 to 24 weeks. RESULTS: Depending on cord insertion site and placental anatomy, blood flow was interrupted to the anomalous fetus by either radiofrequency ablation (RFA; 2 cases), cord transection (1 case), or cord transection after laser ablation of communicating vessels (3 cases). Fetal death occurred in one normal twin 4 days postoperatively. Average age at delivery for the 5 surviving fetuses was 34.5 weeks' gestation. On follow-up, all surviving infants are neurologically intact. CONCLUSION: An otherwise normal monochorionic twin threatened by an anomalous cotwin can be salvaged successfully with a strategy tailored to interrupt the vascular connections between the 2 twins.

Fetal intervention for myelomeningocele: effect on postnatal bladder function.

PURPOSE: Myelomeningocele is the most common congenital malformation of the central nervous system noted on prenatal ultrasound. Due to its significant postnatal sequelae, treatment in utero could potentially have a profound impact on the newborn. Others have reported fetal surgical techniques for in utero repair of myelomeningocele and its potential benefits on motor and neurological function. We report our urodynamic findings in the newborn after in utero repair of spina bifida in an effort to characterize postnatal bladder function. MATERIALS AND METHODS: A retrospective review of the fetal surgery database at University of California San Francisco was performed identifying patients with a diagnosis of myelomeningocele. Prenatal surgical repair of myelomeningocele was considered if a normal karyotype was present, no other significant congenital anomalies were evident and gestational age was less than 24 weeks. The spinal defects were in the lumbar or lumbosacral region. All surgery was performed before 24 weeks of gestations. RESULTS: Fetal surgery to correct myelomeningocele was performed in 6 patients. All patients were born premature at 32 weeks of gestation or less. Videourodynamics performed at age 1 month in 4 patients indicated decreased bladder capacity for weight, increased detrusor storage pressures and significant post-void residual. Hydronephrosis was demonstrated in 4 patients on renal/bladder ultrasound, and moderate vesicoureteral reflux was seen in 3. CONCLUSIONS: Patients with spinal bifida treated in utero appear to have the same changes in urodynamic parameters and anatomical abnormalities in the urinary tract as other children with spinal defects who have undergone standard postnatal care. In utero treatment of spinal bifida may expose the newborn to the effects of prematurity. The long-term effects on bladder function in the fetus after in utero repair of myelomeningocele remain unknown. A randomized controlled trial is necessary to evaluate long-term bladder function as well as other outcome variables in this experimental approach to patients with myelomeningocele.

The surgical airway.

Traumatic airway injuries are rare in children, partly due to their unique anatomy. The larynx is well protected from direct blows behind the mandibular arch, and only a small portion of the trachea is unprotected above the manubrium due to the relatively short neck. Furthermore, the tracheobronchial tree is less prone to injuries as compared with adults due to its elasticity. A high index of suspicion is thus needed to adequately diagnose and manage pediatric airway injuries. Laryngotracheal injuries in particular may present with discreet initial symptoms that if undiagnosed may rapidly progress to loss of airway. The most important signs of laryngeal injury include hoarseness and subcutaneous emphysema. Tracheobronchial injuries often present with dramatic symptoms, the most common being pneumothorax, which does not resolve after placement of chest tube, or large persistent air leaks. Endoscopy is mandatory on suspicion of injury to the larynx, trachea, or bronchi. CT scan may be helpful in determining the extent of injury to the larynx. Correct management of the airway in laryngotracheal injuries has a direct impact on morbidity and mortality. Endotracheal intubation over a flexible bronchoscope during spontaneous ventilation and in halothane anesthesia is the method of choice in children, but it should be performed in the operating room with the possibility of emergency tracheotomy. Cricothyroidotomy should be avoided in all laryngotracheal injuries because this method may aggravate the injury. Most laryngotracheal injuries in children can be conservatively managed. Extensive injuries, including displaced fractures of the cartilage, injuries to the recurrent nerves, and laryngotracheal separation, require surgical intervention. Injuries to bronchi and the thoracic trachea that do not cause a persistent air leak, and where the lungs expand completely after insertion of chest tubes, may be managed conservatively. All other injuries to the tracheobronchial tree should be repaired surgically as soon as feasible. Induction of anesthesia and opening of the chest may make ventilation difficult and are best managed by selective intubation of the contralateral lung. Long-term outcome after laryngeal, tracheal, and bronchial injuries in children, if managed swiftly and accurately, is usually excellent unless other injuries are present. The final result is improved by early recognition and early surgical intervention. These children need to be followed endoscopically for months and sometimes years in order to diagnose and treat stenoses as soon as they occur. Long-term pulmonary function has been shown to be excellent. Children with bilateral recurrent nerve paralysis may not fully recover voice or airway.

Fetoscopic temporary tracheal occlusion by means of detachable balloon for congenital diaphragmatic hernia.

Occlusion of the fetal trachea blocks the egress of fetal lung fluid and stimulates the growth of hypoplastic lungs in fetuses with diaphragmatic hernia. Accomplishing temporary and reversible occlusion of the fetal trachea has proven difficult without invasive fetal surgery. Using simultaneous real-time ultrasonography and fetal bronchoscopy through a single uterine port, we placed a detachable balloon in the trachea of 2 fetuses with severe diaphragmatic hernia. In both fetuses the fetal lung subsequently enlarged, allowing survival after birth.

Pylephlebitis, portal-mesenteric thrombosis, and multiple liver abscesses owing to perforated appendicitis.

The authors report a case of a ruptured retrocecal appendix presenting with pylephlebitis, portal-mesenteric thrombosis, and multiple liver abscesses in an 8-year-old boy. A right hemicolectomy was performed, and liver abscesses were drained. The patient was treated with long-term antibiotics and anticoagulation. This the only case of perforated appendicitis associated with these 3 morbid complications in the modern literature.

Outcome of prenatally diagnosed solid fetal tumors.

BACKGROUND/PURPOSE: In the last 10 years, the ability to diagnose fetal tumors in the prenatal period has improved greatly because of technical advances in imaging. Early diagnosis and determination of tumor may affect prognosis. METHODS: The authors retrospectively reviewed the records of 1316 fetuses who underwent sonographic evaluation for congenital defects at University of California-San Francisco over a 6-year period. Of these, 16 had fetal tumors and were followed up at our institution. There were solid or predominantely solid with small cystic component masses in one of 3 locations: cervical, mediastinal, or abdominal. Excluded from our study were those fetuses with either sacrococcygeal teratoma, congenital cystic adenomatoid malformation of the lung, or ovarian cyst, because these defects have been extensively reviewed elsewhere. In addition, masses that were primarily cystic also were excluded. Data collected included diagnosis, gestational age at diagnosis and at delivery, mode of delivery, fetal and neonatal survival, and disease confirmation. RESULTS: Of the 16 fetuses, 4 had mediastinal tumors: 2 with pericardial teratomas (both of whom died in utero) and 2 with cardiac rhabdomyomas (1 died; the other presented tuberous sclerosis and is alive at 2 years of age). Four patients had cervical tumors (3 died; 1 survived and is alive and well), and 8 had abdominal tumors (3 with liver tumors, 4 with a left adrenal mass, and 1 with retroperitoneal teratoma). All eight patients with an abdominal tumor are alive and well. CONCLUSIONS: Fetal tumors are rare, and the prognosis seems to depend on their location and size. Although easier to detect, cervical and mediastinal tumors have a worse prognosis. Abdominal masses are more difficult to detect but have a better prognosis.

Fetal surgery for myelomeningocele.

Myelomeningocele is a devastating birth defect affecting a significant number of live births worldwide. Prenatal repair of myelomeningocele has been performed in the United States for 5 years with mixed results. The initial intent was to preserve distal neurological function by covering the exposed spinal cord. Although there has been relatively little effect on distal sensorimotor function, prenatal repair serendipitously led to an apparent reduction in hindbrain herniation and a possible decreased need for ventriculoperitoneal shunting. The long-term clinical consequences of these findings are not clear. What is clear, however, is that further study in the form of a prospective, randomized trial is mandatory.

Congenital diaphragmatic hernia associated with a gastroesophageal duplication cyst: a case report.

Severe left congenital diaphragmatic hernia was diagnosed in a baby prenatally, and she underwent hernia repair on the sixth postnatal day of life. She was found to have a huge symptomatic gastroesophageal duplication cyst on day 24 of life. A thoracoabdominal dissection allowed successful cyst excision. J Pediatr Surg 36:626-628.

Radiofrequency ablation of human fetal sacrococcygeal teratoma.

OBJECTIVE: Fetuses with solid, highly vascularized sacrococcygeal teratomas can die as a result of the vascular steal syndrome. This is the first report in which a percutaneous technique, radiofrequency ablation, was used to interrupt blood flow to a sacrococcygeal teratoma in 4 human fetuses. STUDY DESIGN: A radiofrequency ablation probe was percutaneously inserted into the fetal tumor under ultrasonographic guidance. In 2 fetuses a significant portion of the tumor mass was ablated, whereas in the other 2 fetuses only the major feeding vessels were targeted. RESULTS: Two infants were delivered at 28 and 31 weeks' gestation, respectively, and are doing well. In 2 other cases hemorrhage into the tumor led to an unfavorable fetal outcome. CONCLUSION: Ablation of a majority of the tumor tissue in sacrococcygeal teratoma is not necessary and proved fatal in two instances. Targeted ablation of the feeding tumor vessels diminishes blood flow sufficiently to reverse high-output fetal heart failure.

Safety of chronic fetal vascular access in the sheep model.

OBJECTIVE: Long-term access to the fetal circulation has the potential to open up new perspectives in the treatment of numerous fetal anomalies. The purpose of this study was to investigate the safety of long-term catheterization of fetal placental vessels. METHODS: A midline laparotomy was performed in 4 time-mated pregnant ewes at 125 days' gestation (term 145 days). Placental vessels were exposed by a small uterine incision. A specially designed catheter was inserted into a placental vessel over a length of 3 cm, the distal end of the catheter was tunneled underneath the maternal skin and attached to a subcutaneous port implanted in the maternal flank. All pregnancies were allowed to go to term. RESULTS: Ewes and fetuses tolerated the placement of the catheter and port without complications. The catheter remained patent in all cases. All lambs were delivered vaginally at term and did not require resuscitation after birth. No fetal anomalies or growth restriction were noted. CONCLUSION: The ovine placental vessel can be accessed long term without complication.

Congenital diaphragmatic hernia without herniation of the liver: does the lung-to-head ratio predict survival?

The purpose of the present study was to determine the ability of lung-to-head ratio to predict survival and need for extracorporeal membrane oxygenation support in fetuses with left congenital diaphragmatic hernia without herniation of the liver into the chest. The perinatal records of 20 fetuses with isolated left congenital diaphragmatic hernia without herniation of the left lobe of the liver into the chest were reviewed. Fetuses were stratified into two groups depending on lung-to-head ratio: those with a ratio of less than 1.4 (historically a poor prognosis group) and those with a ratio of greater than 1.4. The outcome of both groups was compared with chi-square analysis. Eight of 11 fetuses with a lung-to-head ratio greater than 1.4 survived, whereas 8 of 9 fetuses with a ratio of less than 1.4 survived. No differences were noted in the need for extracorporeal membrane oxygenation support or survival between the two groups. Fetuses with a prenatally diagnosed left congenital diaphragmatic hernia without herniation of liver into the chest have a favorable prognosis even in the presence of a low lung-to-head ratio.

Hindbrain herniation develops in surgically created myelomeningocele but is absent after repair in fetal lambs.

OBJECTIVE: The purpose of our study was to determine whether prenatal repair of myelomeningocele prevents or reverses hindbrain herniation in the sheep model. STUDY DESIGN: A myelomeningocele was surgically created in fetal sheep. One group was repaired later in utero; the others were delivered without repair. After delivery, lambs were assessed for the presence of hindbrain herniation. RESULTS: In all lambs that had not undergone repair of the myelomeningocele, severe hindbrain herniation developed, whereas the brains of all lambs that had undergone fetal repair were normal. CONCLUSION: Prenatal repair of myelomeningocele prevents or reverses development of hindbrain herniation in the fetal lamb model.

Balloon tracheal occlusion for congenital diaphragmatic hernia: experimental studies.

PURPOSE: Temporary tracheal occlusion is an effective strategy to enlarge fetal lungs, but the optimal technique to accomplish occlusion is unknown. External clips are effective when applied fetoscopically (Fetendo clip), but require a difficult fetal neck dissection. This study was undertaken to assess the feasibility of intratracheal balloon occlusion, revisiting the internal occlusion strategy. METHODS: (1) The internal diameter (ID) of human fetal trachea (53 fetuses; 14 to 41 weeks' gestation) was compared using a computer-assisted image analyzer and sonography, ex vivo. (2) Volume to diameter relationship of the balloon (balloon configuration curve) was defined using an image analyzing computer. (3) Using the trachea of fetal sheep, pressures that break balloon tracheal seal (seal pressure) were investigated. RESULTS: (1) Between 16 and 41 weeks' gestation, tracheal ID (range, 0.7 to 5.4 mm) correlates significantly with gestational age. (2) Balloon volume required to achieve tracheal seal could be determined based on the tracheal growth curve and the balloon configuration curve. (3) Tracheal seal breaking points varied depending on the tracheal specimen tested. CONCLUSION: Internal tracheal occlusion using a balloon is feasible with minimal tracheal damage if the balloon volume is adjusted to fetal tracheal growth.