George B. Mychaliska

Correction of congenital diaphragmatic hernia in utero IX: Fetuses with poor prognosis (Liver herniation and low lung-to-head ratio) can be saved by fetoscopic temporary tracheal occlusion

BACKGROUND/PURPOSEnFetuses with congenital diaphragmatic hernia (CDH) who have a poor prognosis with postnatal treatment now can be identified on the basis of liver herniation, early diagnosis (before 25 weeks gestation) and a low lung-to-head ratio (LHR). Because complete in utero repair proved unsuccessful for this group, the strategy of temporary tracheal occlusion was developed to gradually enlarge the hypoplastic fetal lung. The purpose of this study is to compare the outcome of patients in the poor-prognosis group treated by one of three methods: (1) standard postnatal care, (2) fetal tracheal occlusion via open hysterotomy, and (3) the recently developed video-fetoscopic (Fetendo) technique of tracheal occlusion without hysterotomy.nnnMETHODSnIn the past 3 years, 34 of 86 fetuses with an isolated left CDH met criteria for the poor-prognosis group. Thirteen families chose postnatal treatment at an extracorporeal membrane oxygenation (ECMO) center, 13 underwent open fetal tracheal occlusion, and eight underwent fetoscopic tracheal occlusion.nnnRESULTSnThe survival rate was 38% in the group treated by standard postnatal therapy, 15% in the open tracheal occlusion group, and 75% in the Fetendo group. There were less postoperative pulmonary complications noted in mothers who underwent the Fetendo procedure versus the open tracheal occlusion. All but one Fetendo clip patient had a striking physiological response demonstrated by sonographic enlargement of the small left lung that was documented postnatally by plain radiographs and its subjective appearance during repair of the CDH. In contrast, only 5 of the 13 open tracheal occlusion patients demonstrated lung growth.nnnCONCLUSIONnFetuses with a left CDH who have liver herniation and a low LHR are at high risk of neonatal demise and appear to benefit from temporary tracheal occlusion when performed fetoscopically, but not when performed by open fetal surgery.

Operating on placental support: The ex utero intrapartum treatment procedure

While treating eight fetuses with predictable airway obstruction, the authors developed a systematic approach, the ex utero intrapartum treatment procedure, to secure the airway during delivery. Six patients had their trachea plugged or clipped in utero for treatment of congenital diaphragmatic hernia, and two patients had prenatally diagnosed cystic hygroma of the neck and oropharynx. The ex utero intrapartum treatment procedure was performed by using high doses of inhaled halogenated agents to facilitate uterine relaxation during cesarean section, securing the fetal airway while feto-placental circulation remained intact, and then dividing the umbilical cord. A variety of procedures were performed during the ex utero intrapartum treatment procedure including bronchoscopy, orotracheal intubation, tracheostomy, tracheostomy with retrograde orotracheal intubation, tracheoplasty, removal of internal tracheal plug, removal of external tracheal clip, central line placement, and instillation of surfactant. There were minimal maternal or fetal complications during the procedure. This approach requires the coordinated efforts of pediatric surgeons, obstetricians, anesthesiologists, sonographers, and neonatologists. The combination of intensive maternal-fetal monitoring, cesarean section with maximal uterine relaxation, and maintenance of intact feto-placental circulation provides a controlled environment for securing the airway in babies with prenatally diagnosed airway obstruction.

In utero hematopoietic stem cell transplants prolong survival of postnatal kidney transplantation in monkeys

The authors hypothesized that in utero transplantation of T-cell-depleted paternal marrow into rhesus monkey fetuses would induce tolerance to postnatal kidney grafts from the marrow donor. T-cell-depleted paternal bone marrow was transplanted intraperitoneally into two female fetal rhesus monkeys at 61 +/- 1 days gestation. Chimeric monkeys (n = 2) received kidney transplants from paternal donors. Control monkeys (n = 2) underwent kidney transplants without prior in utero stem cell transplants. Both chimeric monkeys demonstrated low level (<0.1% donor cells) engraftment in the bone marrow and peripheral blood using the polymerase chain reaction assay for the Y chromosome. The mixed lymphocyte reaction demonstrated hyporeactivity to the donor. Control animals demonstrated severe acute rejection and graft failure 1 week posttransplant. The first chimeric monkey had no significant clinical or sonographic evidence of renal failure until 7 weeks after the transplant. Biopsy findings showed mild rejection 1 week postoperatively, but rejection did not significantly progress until 5 weeks later. The second chimeric monkey had no significant clinical or sonographic changes for 4 weeks, but evidence of moderate rejection was seen on biopsy results. This monkey was given a 10-week course of immunosuppression, and had no clinical or sonographic renal deterioration, although biopsy results showed chronic rejection that was confirmed when electively euthanized 8 months later. Our data suggest that in utero transplantation of hematopoietic stem cells can increase the survival of a kidney allograft in the rhesus monkey.

Transplantation of a fetus with paternal Thy-1(+)CD34(+)cells for chronic granulomatous disease.

A fetus diagnosed with X-linked chronic granulomatous disease was transplanted with Thy-1+CD34+ cells of paternal origin. The transplant was performed at 14 weeks gestation by ultrasound guided injection into the peritoneal cavity. The fetus was delivered at 38 weeks gestation after an otherwise uneventful pregnancy. Umbilical cord blood was collected and used to determine the level of peripheral blood chimerism as well as levels of functional engrafted cells. Flow cytometry was used to detect donor leukocytes identified as HLA-A2−B7+ cells, whereas recipient cells were identified as HLA-A2+B7− cells. No evidence of donor cell engraftment above a level of 0.01% was found. PCR was used to detect HLA-DRB1*15+ donor cells among the recipients HLA-DRB1*15− cells, but no engraftment was seen with a sensitivity of 1:1000. The presence of functional, donor-derived neutrophils was assessed by flow cytometry using two different fluorescent dyes that measure reactive oxygen species generated by the phagocyte NADPH oxidase. No evidence of paternal-derived functional neutrophils above a level of 0.15% was observed. Peripheral blood and bone marrow samples were collected at 6 months of age. Neither sample showed engraftment by HLA typing using both flow cytometry and PCR. Functional phagocytes were also not observed. Furthermore, no indication of immunological tolerance specific for the donor cells was indicated by a mixed lymphocyte reaction assay performed at 6 months of age. While there appears to be no engraftment of the donor stem cells, the transplant caused no harm to the fetus and the child was healthy at 6 months of age. Analyses of fetal tissues, obtained from elective abortions, revealed that CD3+ T cells and CD56+CD3− NK cells are present in the liver at 8 weeks gestation and in the blood by 9 weeks gestation. The presence of these lymphocytes may contribute to the lack of donor cell engraftment in the human fetus. Bone Marrow Transplantation (2001) 27, 355–364.

Esophageal lung with multiple congenital anomalies: Conundrums in diagnosis and management

BACKGROUND/PURPOSEnCommunicating bronchopulmonary foregut malformations (CBPFM) are a diverse group of potentially devastating congenital anomalies with anatomy that may be difficult to delineate. The authors present a case that illustrates conundrums in the diagnosis and management of these complex disorders.nnnMETHODSnA term baby had esophageal atresia (EA), tracheoesophageal fistula (TEF), and tetralogy of Fallot. Initially, a gastrostomy was performed, and a balloon catheter was inserted through the endotracheal tube to occlude the fistula until the patient was hemodynamically stable. Subsequently, the fistula was ligated. Postoperatively, the left lung collapsed, and bronchoscopy showed an atretic left mainstem bronchus. Repeat thoracotomy showed that the fistula ligation was intact. Air was introduced through the gastrostomy tube, and, surprisingly, the left lung inflated, indicating the left mainstem bronchus arose from the esophagus distal to the ligated TEF.nnnRESULTSnDespite reopening this fistula, ventilation remained poor, and support was withdrawn. Autopsy findings confirmed a unilobed left lung arising from the esophagus, EA, TEF, an atretic left mainstem bronchus, tetralogy of Fallot, and DiGeorge syndrome.nnnCONCLUSIONSnThis is the first report of a combination of EA and distal TEF with a second CBPFM involving the esophagus and the entire left lung. Successful correction of these anomalies will require extensive delineation of the anatomy to plan an operative strategy.

The biology and ethics of banking fetal liver hematopoietic stem cells for in utero transplantation

BACKGROUND/PURPOSEnTransplantation of fetal liver hematopoietic stem cells (HSCs) in utero has the potential to treat a variety of hematologic, immunologic, and metabolic diseases. One prerequisite for broad clinical application is the establishment of a bank of fetal liver HSC tissue. The authors describe their methods for processing fetal liver free of known human pathogens while maximizing HSC activity after cryopreservation.nnnMETHODSnThe authors developed a protocol that separates the abortion decision from the donation decision and preserves confidentiality between donor and recipient. Human fetal livers (12 to 14 weeks gestation) were procured from aborted specimens and the light-density hematopoietic cells isolated by density centrifugation. Total viable cell count increased with gestational age and averaged from 4.36 x 10(7) cells for 12-week livers to 2.0 x 10(8) cells for 14-week livers.nnnRESULTSnFlow cytometric analysis demonstrated the presence of early progenitors in fresh and thawed specimens and a low number of T cells in each group. The functional capacity of fetal liver progenitors was assessed with colony-forming assays before and after cryopreservation. Thawed specimens showed an average 63% recovery rate for the high-proliferative potential colony-forming cells, a primitive subset of progenitors thought to include HSC. However, the more mature fraction of low-proliferative potential colony-forming cells had a recovery rate of only 35%. These data suggest that fetal liver HSC maybe more resistant to the detrimental effects of cryopreservation than mature progenitors. The fetal liver was screened for bacterial, fungal, and viral contaminates and the serum from donor mothers was screened for human immunodeficiency virus (HIV), hepatitis A, B, and C, human T-cell lymphoma virus (HTLV I/II), rapid plasma reagent (RPR), cytomegalovirus (CMV), and toxoplasmosis IgM. The bacterial contamination rate was 14% (n = 28). The maternal serum was positive for CMV in 78% of cases, and positive for hepatitis C in 0.7% of cases (n = 28). However, all fetal liver specimens were culture negative for CMV.nnnCONCLUSIONSnThese findings demonstrate that human fetal liver HSCs can be procured ethically and processed to ensure a safe graft with a small number of T-cells, and a high yield of progenitors after cryopreservation. A bank of fetal liver HSC will prove useful in treating a variety of genetic diseases before birth by in utero HSC transplantation.

Early Delivery of Sacrococcygeal Teratoma with Intraspinal Extension

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

Novel Application of Laparoscopic Ultrasound for Fetoscopic Laser Ablation in Twin-Twin Transfusion Syndrome with Complete Anterior Placenta

Fetoscopic laser coagulation of the placental communicating vessels has become the standard treatment for monochorionic/diamniotic twin pregnancies complicated by severe twin-twin transfusion syndrome. Fetoscopic trocar placement can be performed with transabdominal ultrasound guidance with a posterior placenta and most anterior placentas that have a safe avascular window for entry. However, trocar insertion is challenging in cases of a complete anterior placenta without an avascular window. Current techniques to deal with this situation include mini-laparotomy with exteriorization to allow for dorsal entry, percutaneous lateral entry under transabdominal ultrasound/Doppler guidance, and laparoscopic assisted access with direct visualization of trocar entry. We describe a modified technique of laparoscopic assisted fetoscopic trocar placement using a laparoscopic ultrasound probe, which allows for precise, real-time guidance of trocar placement.

Effects of an artificial placenta on brain development and injury in premature lambs

PURPOSEnWe evaluated whether brain development continues and brain injury is prevented during Artificial Placenta (AP) support utilizing extracorporeal life support (ECLS).nnnMETHODSnLambs at EGA 118days (term=145; n=4) were placed on AP support (venovenous ECLS with jugular drainage and umbilical vein reinfusion) for 7days and sacrificed. Early (EGA 118; n=4) and late (EGA 127; n=4) mechanical ventilation (MV) lambs underwent conventional MV for up to 48h and were sacrificed, and early (n=5) and late (n=5) tissue control (TC) lambs were sacrificed at delivery. Brains were harvested, formalin-fixed, rehydrated, and studied by magnetic resonance imaging (MRI). The gyrification index (GI), a measure of cerebral folding complexity, was calculated for each brain. Diffusion-weighted imaging was used to determine fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in multiple structures to assess white matter (WM) integrity.nnnRESULTSnNo intracranial hemorrhage was observed. GI was similar between AP and TC groups. ADC and FA did not differ between AP and late TC groups in any structure. Compared to late MV brains, AP brains demonstrated significantly higher ADC (0.45±0.08 vs. 0.27±0.11, p=0.02) and FA (0.61±0.04 vs. 0.44±0.05; p=0.006) in the cerebral peduncles.nnnCONCLUSIONSnAfter 7days of AP support, WM integrity is preserved relative to mechanical ventilation.nnnTYPE OF STUDYnResearch study.

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

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