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Biomedical subjects

Russell W Jennings

Publications and source records attributed to Russell W Jennings.

At least 19 recordsLinked to original sources

Ex utero intrapartum treatment with extracorporeal membrane oxygenation for severe congenital diaphragmatic hernia.

PURPOSE: The purpose of this study was to determine whether ex utero intrapartum treatment with extracorporeal membrane oxygenation (EXIT to ECMO) is a reasonable approach for managing patients antenatally diagnosed with severe congenital diaphragmatic hernia (CDH). METHODS: A 6-year retrospective review was performed on fetuses with severe CDH (liver herniation and a lung/head ratio <1.4, percentage of predicted lung volume <15, and/or congenital heart disease). Fourteen of the patients underwent EXIT with a trial of ventilation. Fetuses with poor preductal oxygen saturations despite mechanical ventilation received ECMO before their delivery. Maternal-fetal outcomes were analyzed. RESULTS: There were no maternal-reported complications. Three babies passed the ventilation trial and survived, but 2 of them required ECMO within 48 hours. The remaining 11 fetuses received ECMO before their delivery. Overall survival after EXIT-to-ECMO was 64%. At 1-year follow-up, all survivors had weaned off supplemental oxygen, but 57% required diuretics and/or bronchodilators. CONCLUSION: This is the largest reported experience using EXIT to ECMO in the management of severe CDH. The EXIT-to-ECMO procedure is associated with favorable survival rates and acceptable pulmonary morbidity in fetuses expected to have a poor prognosis under conventional management.

Adult↗

Percent predicted lung volumes as measured on fetal magnetic resonance imaging: a useful biometric parameter for risk stratification in congenital diaphragmatic hernia.

PURPOSE: This study was aimed at determining whether a new method of analyzing lung volumes on fetal magnetic resonance (MR) imaging could be used to predict the degree of pulmonary compromise in congenital diaphragmatic hernia (CDH). METHODS: Seventeen fetuses with CDH were prospectively evaluated by MR. Lung volumes were measured using an established technique and expressed as a percentage of the predicted lung volume (PPLV). Predicted lung volume was determined by subtracting measured mediastinal volume from total measured thoracic volume. The PPLV was correlated with postnatal outcomes. Statistical analyses were performed using the Mann-Whitney, Spearman correlation, or Fisher exact tests (P < .05). RESULTS: Of the 14 liveborn patients, the PPLV was 20.3+/-10.4 (gestational age at MR, 22.3 +/- 5.7 weeks). The PPLV was significantly associated with extracorporeal membrane oxygenation (ECMO) use, hospital length of stay, and survival. All patients with a PPLV of less than 15 required prolonged ECMO support and had a 40% survival rate. In contrast, only 11% of patients with a PPLV of greater than 15 required ECMO, and survival was 100%. CONCLUSION: The PPLV as measured by fetal MR imaging can accurately predict disease severity in CDH. A value of less than 15 is associated with a significantly higher risk for prolonged support and/or death, despite aggressive postnatal management.

Female↗

Bronchial atresia: the hidden pathology within a spectrum of prenatally diagnosed lung masses.

PURPOSE: This study was aimed at determining whether different congenital lung masses represent diverse manifestations of a single developmental abnormality associated with fetal airway obstruction. METHODS: We conducted a 3-year retrospective review of patients who underwent surgical resection of a prenatally diagnosed lung mass. Prenatal imaging was used to define mass position and its effect on adjacent organs. Lung specimens were examined through careful full-specimen microdissections, as well as by plain and contrast roentgenograms. RESULTS: Twenty-five patients underwent lung resection during this study period. Based on the final pathology reports, 56% were congenital cystic adenomatoid malformations, 12% were congenital lobar emphysemas, 8% were bronchopulmonary sequestrations, and 24% had features of both cystic adenomatoid malformation and bronchopulmonary sequestrations. No bronchogenic cysts were present in this series. Overall, bronchial atresia was identified in 77% of the examined specimens (n = 22) and was associated with all types of lung malformations. CONCLUSIONS: Bronchial atresia is a common, unrecognized component of prenatally diagnosed congenital cystic adenomatoid malformations, bronchopulmonary sequestrations, congenital lobar emphysemas, and lesions of mixed pathology. Most congenital lung masses may be part of a spectrum of anomalies linked to obstruction of the developing fetal airway as an underlying component in their pathogenesis.

Airway Obstruction↗

Hyperoncotic enhancement of fetal pulmonary growth after tracheal occlusion: an alveolar and capillary morphometric analysis.

BACKGROUND/PURPOSE: Previous work has shown that intrapulmonary delivery of oncotic agents enhance overall lung growth after late gestational fetal tracheal occlusion (TO). This study was a post hoc analysis aimed at determining whether actual alveolar and capillary hyperplasias are maximized in this setting. METHODS: Twenty-one near term fetal lambs were evenly divided into 4 groups: group I comprised sham-operated controls; group II had TO alone; and groups III and IV underwent TO and intratracheal infusion of equal amounts of either saline or 25% albumin, respectively. Approximately 2 weeks thereafter, their lungs were examined by detailed alveolar and capillary morphometry before birth. Statistical analysis included analysis of variance and the Bonferroni correction for multiple comparisons (P < .05). RESULTS: Total alveolar and capillary numbers, as well as total alveolar surface area, were significantly higher in group IV and lower in group I compared with all other groups, with no differences between groups II and III. Alveolar capillary load was normal in all groups. CONCLUSIONS: Intrapulmonary delivery of concentrated albumin safely enhances short-term alveolar and capillary hyperplasia in a late gestational model of fetal TO. This therapeutic concept may allow for TO to be effective and predictable when performed late in gestation.

Administration, Inhalation↗

Pulmonary endocrine cells in hypoplastic lungs due to foetal urinary tract obstruction: a microscopic immunohistochemical study.

METHODS: We performed a urinary tract obstruction (UTO) surgical procedure at 93-107 days' gestation in lambs to investigate the relationship between pulmonary hypoplasia and the appearance of pulmonary endocrine cells by quantitative analysis of respiratory tract cells using light microscopic immunohistochemistry. RESULTS: UTO produced a significant reduction in lung weight, lung/body weight ratio, air capacity, air capacity/body weight ratio (p < 0.01) and radial alveolar count (p < 0.05), which indicated the presence of lung hypoplasia. These foetuses also showed a significant increase in the number of neuron-specific enolase (NSE)-positive pulmonary endocrine cells, expressed as the number of NSE-positive cells per bronchus (p < 0.01) or bronchiole (p < 0.05), the number of NSE-positive cells per unit perimeter of bronchus or bronchiole (p < 0.01), and the number of NSE-positive cells per unit bronchial or bronchiolar surface area (p < 0.01). CONCLUSION: These results suggest that UTO significantly retards and modifies the structural growth and functional development of pulmonary endocrine cells in NSE expression. We speculate that pulmonary endocrine cells and their mediators may play a role in the problems associated with UTO during intrauterine life.

Animals↗

Fetal cartilage engineering from amniotic mesenchymal progenitor cells.

We determined whether cartilage could be engineered from mesenchymal progenitor cells (MPCs) normally found in amniotic fluid. Mesenchymal amniocytes were isolated from ovine amniotic fluid samples (n = 5) and had their identity confirmed by immunocytochemistry. Cells were expanded and then cultured as micromass pellets (n = 5) in a chondrogenic medium containing transforming growth factor-beta2 (TGF-beta2) and insulin growth factor-1 (IGF-1) for 6-12 weeks. Pellets derived from fetal dermal fibroblasts (n = 4) were cultured under identical conditions. Additionally, expanded mesenchymal amniocytes were seeded onto biodegradable polyglycolic acid scaffolds (n = 5) and maintained in the same chondrogenic medium within a rotating bioreactor for 10-15 weeks. Engineered specimens were analyzed quantitatively and compared with native fetal hyaline cartilage samples (n = 5). Statistical analysis was by the unpaired Student's t-test (p < 0.05). The isolated cells stained positively for vimentin and cytokeratins-8 and -18, but negatively for CD31. Micromass pellets derived from mesenchymal amniocytes exhibited chondrogenic differentiation by both standard and matrix-specific staining. In contrast, these findings could not be replicated in dermal fibroblast-based pellets. The engineered constructs derived from mesenchymal amniocytes similarly displayed histological evidence of chondrogenic differentiation and maintained their original size and three-dimensional architecture. Quantitative assays of the engineered constructs revealed lower concentrations of collagen type II, but similar amounts of glycosaminoglycans, elastin, and DNA, when compared to native fetal hyaline cartilage. We conclude that mesenchymal amniocytes can be used for the engineering of cartilaginous tissue in vitro. Cartilage engineering from the amniotic fluid may become a practical approach for the surgical treatment of select congenital anomalies.

Amniotic Fluid↗

Reversal of parenteral nutrition-associated liver disease in two infants with short bowel syndrome using parenteral fish oil: implications for future management.

Here we report the reversal of cholestasis in 2 infants with intestinal failure and parenteral nutrition-associated liver disease. Treatment involved the substitution of a conventional intravenous fat emulsion with one containing primarily omega-3 fatty acids. Biochemical tests of liver function improved significantly. One child was removed from the liver transplantation list because of improved hepatic function, and the second child had complete resolution of cholestasis while solely on parenteral nutrition. This suggests that fat emulsions made from fish oils may be an effective means of treating and preventing this often-fatal condition. A randomized, controlled trial is necessary to study the efficacy of this new approach to parenteral nutrition-associated liver disease.

Alanine Transaminase↗

Fetal surgery in otolaryngology: a new era in the diagnosis and management of fetal airway obstruction because of advances in prenatal imaging.

OBJECTIVE: To evaluate the efficacy, safety, and outcome of prenatal imaging and fetal surgery in the diagnosis and management of fetal airway obstruction caused by cervical teratoma or lymphatic malformation. SETTING: Tertiary care medical center. Patients A retrospective study of all consecutive fetal patients with cervical teratoma or lymphatic malformation between January 2001 and December 2003. RESULTS: The indication was potential airway obstruction due to a fetal neck mass in 8 patients. Prenatal images were obtained by ultrasonography and magnetic resonance imaging, and were consistent with teratoma in 4 patients. The mean cervical mass was 8.3 x 7.3 x 6.7 cm, with airway obstruction suspected in all 4 patients. All 4 patients were successfully delivered by ex utero intrapartum treatment, during which 3 newborns required tracheotomy and 1 was successfully intubated. Prenatal images were consistent with lymphatic malformation in the remaining 4 patients. The mean cervical mass was 4.6 x 4.4 x 3.4 cm. There was no indication of airway obstruction based on prenatal images. All 4 patients had an uncomplicated vaginal delivery. CONCLUSIONS: Technological advances in prenatal ultrasonography and magnetic resonance imaging have improved the ability to diagnose congenital abnormalities in utero. This allows for proper assessment of the airway to prevent any unexpected problems at delivery. We believe that many airway emergencies can be avoided by prenatal imaging and initiation of airway management in the prenatal period.

Adult↗

Aortic valvuloplasty in the fetus: technical characteristics of successful balloon dilation.

OBJECTIVES: To describe technical aspects of successful fetal aortic valvuloplasty, with particular attention to balloon size. STUDY DESIGN: We retrospectively reviewed all procedural records and echocardiograms pertaining to 26 attempts at fetal aortic valve dilation performed at a single center over a period of 4 years. We assessed the effect of valvuloplasty as determined by echocardiographic appearance at the time of intervention and in follow-up. RESULTS: In 20 of 26 fetuses who had technically successful aortic valve dilation (median balloon:annulus ratio=1.1), all had improved antegrade flow and 12 had at least mild regurgitation after dilation. Use of an oversized balloon was associated with the onset of moderate or severe aortic regurgitation, seen in 5 fetuses. This aortic regurgitation was well tolerated and improved through the remainder of gestation. CONCLUSIONS: These data imply that fetal aortic valves can be dilated safely with larger balloons than are commonly used for postnatal dilation. The observation of spontaneous improvement in postdilation aortic regurgitation further suggests that fetal valve tissue behaves uniquely.

Aortic Valve Insufficiency↗

Balloon dilation of severe aortic stenosis in the fetus: potential for prevention of hypoplastic left heart syndrome: candidate selection, technique, and results of successful intervention.

BACKGROUND: Preventing the progression of fetal aortic stenosis (AS) to hypoplastic left heart syndrome (HLHS) requires identification of fetuses with salvageable left hearts who would progress to HLHS if left untreated, a successful in utero valvotomy, and demonstration that a successful valvotomy promotes left heart growth in utero. Fetuses meeting the first criterion are undefined, and previous reports of fetal AS dilation have not evaluated the impact of intervention on in utero growth of left heart structures. METHODS AND RESULTS: We offered fetal AS dilation to 24 mothers whose fetuses had AS. At least 3 echocardiographers assigned a high probability that all 24 fetuses would progress to HLHS if left untreated. Twenty (21 to 29 weeks' gestation) underwent attempted AS dilation, with technical success in 14. Ideal fetal positioning for cannula puncture site and course of the needle (with or without laparotomy) proved to be necessary for procedural success. Serial fetal echocardiograms after intervention demonstrated growth arrest of the left heart structures in unsuccessful cases and in those who declined the procedure, while ongoing left heart growth was seen in successful cases. Resumed left heart growth led to a 2-ventricle circulation at birth in 3 babies. CONCLUSIONS: Fetal echocardiography can identify midgestation fetuses with AS who are at high risk for developing HLHS. Timely and successful aortic valve dilation requires ideal fetal and cannula positioning, prevents left heart growth arrest, and may result in normal ventricular anatomy and function at birth.

Aortic Valve Stenosis↗

Creation of an atrial septal defect in utero for fetuses with hypoplastic left heart syndrome and intact or highly restrictive atrial septum.

BACKGROUND: Infants born with hypoplastic left heart syndrome and an intact or highly restrictive atrial septum face a neonatal mortality of at least 48% despite early postnatal left atrial decompression and palliative surgery. Prenatal left atrial decompression has been suggested as a means of improving these outcomes. This study reports the feasibility of fetal catheterization to create an interatrial communication and describes technical considerations. METHODS AND RESULTS: Seven fetuses at 26 to 34 weeks' gestation with hypoplastic left heart syndrome and intact or highly restrictive atrial septum underwent attempted prenatal intervention. Under ultrasound guidance, the atrial septum was approached with a needle introduced percutaneously from the maternal abdominal surface. In 6 of 7 fetuses, the atrial septum was successfully perforated, with balloon dilation of this iatrogenic defect resulting in a small but persistent interatrial communication. There were no maternal complications. One fetus died after the procedure. The remaining fetuses were liveborn at term, although 4 died as neonates. CONCLUSIONS: Ultrasound-guided fetal atrial septoplasty consisting of septal puncture and balloon dilation is feasible and can be performed percutaneously to minimize maternal risk. Although we have not demonstrated any positive clinical impact to date, it is our hope that further technical evolution will ultimately enable prenatal left atrial decompression and improvement of outcomes in fetuses with hypoplastic left heart syndrome and intact atrial septum.

Cardiac Catheterization↗

Contouring buttock reconstruction after sacrococcygeal teratoma resection.

PURPOSE: Massive sacrococcygeal teratomas are typically resected and closed in a "chevron" fashion. The resultant scar may leave protuberant "dog ears" and extend across and below the infragluteal creases down onto the posterior thighs, causing undesirable buttock deformity. Given the redundant skin often available, the authors sought to develop a closure technique to minimize deformity and unpleasant scars. METHODS: At the time of resection of 2 sacrococcygeal teratomas, attention was directed to minimizing redundant skin, restoring normal buttock contour, and avoiding scars crossing the infragluteal crease. After properly securing the anal location, serial polygonal skin excisions were performed, working the excess tissue centrally rather than peripherally, leaving 2 right-angled scars on each buttock. RESULTS: Each infant underwent successful reconstruction with a normal buttock contour without redundancy. All scars on the buttocks can be easily covered by bathing attire. CONCLUSIONS: The excess skin expanded by large sacrococcygeal teratomas affords an opportunity to apply straightforward tissue rearrangement principles to reconstruct the buttocks with a normal contour and hidden scars.

Buttocks↗

Diaphragmatic reconstruction with autologous tendon engineered from mesenchymal amniocytes.

PURPOSE: This study examined the effects of amniocyte-based engineered tendons on partial diaphragmatic replacement. METHODS: Ovine mesenchymal amniocytes were labeled with green fluorescent protein (GFP), expanded, and seeded into a collagen hydrogel. Composite grafts (20 to 25 cm2) based on acellular dermis (group I), or acellular small intestinal submucosa (group II) received either a cell-seeded or an acellular hydrogel within their layers. Newborn lambs (n = 20) underwent partial diaphragmatic replacement with either an acellular or a cellular autologous construct from either group. At 3 to 12 months' postoperatively, implants were subjected to multiple analyses. RESULTS: Diaphragmatic hernia recurrence was significantly higher in animals with acellular grafts (5 of 5) then in animals with cellular ones (1 of 4) in group I (P <.05) but not in group II (3 of 6 and 4 of 5, respectively). Cellular grafts had higher modular (5.27 +/- 1.98 v. 1.27 +/- 0.38 MPa) and ultimate (1.94 +/- 0.70 v. 0.29 +/- 0.05 MPa) tensile strength than acellular implants in group I (P <.05), but not in group II. Quantitative analyses showed no differences in extracellular matrix components between cellular and acellular implants in either group. All cellular implants showed GFP-positive cells. CONCLUSIONS: Diaphragmatic repair with an autologous tendon engineered from mesenchymal amniocytes leads to improved mechanical and functional outcomes when compared with an equivalent acellular bioprosthetic repair, depending on scaffold composition. The amniotic fluid may be a preferred cell source for engineered diaphragmatic reconstruction.

Amniotic Fluid↗

Quantitative study of pulmonary endocrine cells in fetal, postnatal and adult sheep.

Using light microscopic immunohistochemistry, neuron-specific enolase (NSE)-positive endocrine cells were quantitatively analyzed in the sheep lung during different stages of development from the canalicular stages to adulthood. In all stages, NSE-positive endocrine cells were usually located in the bronchi and bronchioles as solitary cells, although a few NSE-positive cell clusters, the so-called neuroepithelial bodies, were found in some places. The number of NSE-positive endocrine cells decreased with advanced stages of gestation. In the late alveolar stage, the number of NSE-positive endocrine cells reached its bottom during the fetal period. There was a gradual upturn after birth. The overall pattern of growth and differentiation of the endocrine cells is most likely species-related and depends on the state of airway development; the number of the endocrine cells of almost all animals, excluding the sheep, in relation to the size of the lung reaches a peak in the late fetal and early neonatal periods and decreases shortly thereafter. NSE-positive endocrine cells were also predominantly located in the large airways during the early stage of development (canalicular stage), and were found more frequently in the small peripheral airways towards the term. These results show the number of NSE-positive endocrine cells in the sheep to be different from that seen in other species.

Age Factors↗

Analysis of an improved survival rate for congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Congenital diaphragmatic hernia (CDH) is a condition associated with significant mortality. This study examines the survival rate of neonates with CDH treated by a multidisciplinary team in a single pediatric hospital. Actual survival rate is compared with predicted outcome based on severity of illness. METHODS: A consecutive series of neonates with CDH was evaluated beginning January 1, 2000. There were no excluded patients. A treatment protocol emphasizing minimal barotrauma and control of pulmonary hypertension was used. Predicted survival rate was estimated using birth weight and Apgar score at 5 minutes per the logistic regression equation published by the CDH Study Group. Actual survival rates were calculated and compared with predicted values using a one sample binomial test with significance deemed to be present at P less than.05. RESULTS: Thirty-six of 39 (93%) neonates with CDH survived, whereas the predicted survival rate for this cohort was 68% (P <.001). Twelve of 14 (86%) neonates requiring extracorporeal membrane oxygenation (ECMO) survived, despite a predicted survival rate of 52% for this subset (P <.01). Twenty-five percent of survivors required supplemental oxygen at home. CONCLUSIONS: Using a simple analysis, centers may now objectively compare their CDH survival rates with predicted outcomes adjusted for disease severity. This technique confirmed that a consecutive series of neonates with CDH, treated in one hospital, had a significantly higher than predicted survival rate. Thus, it may be possible to identify other centers with higher than expected survival rates and to define common therapeutic strategies associated with decreased mortality.

Actuarial Analysis↗

Fetal tissue engineering from amniotic fluid.

BACKGROUND: We have recently shown, in an animal model, that amniotic fluid can be a source of cells for fetal tissue engineering. This study was aimed at determining whether fetal tissue constructs could also be engineered from cells normally found in human amniotic fluid. STUDY DESIGN: Cells obtained from the amniotic fluid of pregnant women at 15 to 19 weeks of gestation (n=6) were cultured in Dulbecco's Modified Eagle's medium (Sigma Chemical, St Louis, MO) containing 20% fetal bovine serum and 5 ng/mL basic fibroblast growth factor in a 95% humidified, 5% CO(2) chamber at 37 degrees C. A subpopulation of morphologically distinct cells was then mechanically isolated from the rest and selectively expanded. The lineage of this subpopulation of amniocytes was determined by immunofluorescent staining with antibodies against standard intermediate filaments and surface antigens. Cell proliferation rates were determined by oxidation assay. After cell expansion, colonies of amniocytes were statically and dynamically seeded onto both unwoven, 1-mm-thick polyglycolic acid polymer scaffold and acellular human dermis for 72 hours. The resulting constructs were analyzed by scanning electron microscopy. RESULTS: Amniocytes stained positively for smooth muscle actin, vimentin, cytokeratin 18, and fibroblast surface protein, and negatively for desmin, cluster of differentiation 31, and von Willebrand's factor (Dako, Carpenteria, CA). These findings are consistent with a mesenchymal, fibroblast-myofibroblast cell lineage. Mesenchymal amniocytes could be rapidly expanded in culture, based on results of the proliferation assay. Scanning electron microscopy of amniocyte constructs revealed dense, confluent layers of cells surrounding the polymer matrices and firm cell adhesion to both PGA and Alloderm (Lifecell Corp, Branchburg, NJ) scaffolds. No evidence of cell death was observed. CONCLUSIONS: Subpopulations of fetal mesenchymal cells can be consistently isolated from human amniotic fluid and rapidly expanded in vitro. Human mesenchymal amniocytes attach firmly to both polyglycolic acid polymer and acellular human dermis. The amniotic fluid can be a valuable and practical cell source for fetal tissue engineering.

Amniotic Fluid↗

Prenatal diagnosis of vascular anomalies.

BACKGROUND/PURPOSE: Vascular anomalies are diagnosed prenatally with increasing frequency. The authors reviewed a group of children treated at their center who had an abnormal prenatal diagnosis to determine (1) fetal age at which the vascular anomaly was detected, (2) general diagnostic accuracy, and (3) impact on ante- and postnatal care. Their findings are compared with reported cases and series. The authors clarify appropriate terminology and underscore the need for interdisciplinary participation of specialists in the field of vascular anomalies. METHODS: Patients referred during prenatal life and children with a history of abnormal antenatal findings seen at our vascular anomalies center during a 1-year period (September 1999 through August 2000) were included in this study. The fetal age at diagnosis, pre- and postnatal diagnoses, antenatal course, and neonatal outcome were obtained from the parents, through chart reviews, and through telephone interviews with the treating obstetricians. RESULTS: Twenty-nine patients with vascular anomalies were identified: 17 had a correct prenatal diagnosis, and 12 had an incorrect diagnosis, an overall diagnostic accuracy of 59%. Capillary-lymphatic-venous malformations (CLVM) most often were correctly diagnosed (67%), followed by lymphatic malformation (LM, 62%) and hemangioma (59%). In the infants who received correct diagnoses in utero, there were no fetal deaths and there was no neonatal morbidity. Maternal steroids were administered for a fetus with an intrahepatic hemangioma and deteriorating cardiac function, with subsequent stabilization and successful delivery of a healthy neonate. Among infants with incorrect diagnoses, there was 1 postnatal death, 1 case of erroneous gender assignment, 1 case of unnecessary fetal surgical intervention, 1 unnecessary neonatal laparotomy, and 1 delay in diagnosis of a malignancy. Cesarean section was done for 65% of correctly diagnosed cases, (including 2 ex utero intrapartum [Exit] procedures) and for 33% of incorrectly diagnosed cases. Most diagnoses were made during the mid- to late second trimester and third trimester; only 4 cases (14%) were detected before 20 weeks. CONCLUSIONS: In this series, accurate diagnosis optimized antenatal care by providing an opportunity for planning deliveries, for pharmacologic fetal intervention in 1 case, and for appropriate parental counselling. Inaccurate diagnosis was associated with significantly increased morbidity and mortality. Finally, the intrauterine diagnosis of LM should be distinguished from posterior nuchal translucency, an obstetric term applied to fetal lymphatic abnormalities detected in the first and second trimesters that do not manifest as postnatal LM.

Arteriovenous Malformations↗

Ultrasound-guided fetal tracheal occlusion.

BACKGROUND/PURPOSE: This study was aimed at examining the feasibility of fetal tracheal occlusion guided exclusively by ultrasonography and at establishing the technical principles of this procedure based on current instrumentation and ultrasound technology. METHODS: Time-dated pregnant ewes underwent a small laparotomy and partial uterine exposure. Under real-time ultrasound guidance, a steerable guide wire was fed into the fetal tracheal lumen. An 8F catheter then was fed around the guide wire into the trachea. This was followed by intratracheal placement of a 2F coaxial angiographic catheter, connected to a detachable silicone balloon at its extremity, which then was inflated with saline and delivered locally. Euthanasia was performed at term. RESULTS: Complete tracheal occlusion was achieved in all fetuses (n = 7) intraoperatively. Operating time needed for tracheal occlusion, once access to the amniotic cavity was established, varied widely, but could be as short 1 minute. Tracheal lumen dimensions outgrew balloon diameter in 57.1% of fetuses (4 of 7), resulting in balloon dislodgment in those animals. No balloon rupture was observed. CONCLUSIONS: (1) Accurate access to the fetal trachea and local delivery of an occlusive detachable silicone balloon are consistently feasible exclusively under real-time ultrasound guidance with commercially available instrumentation. (2) Balloon dimensions are determining factors of displacement risk and must be selected carefully before tracheal delivery. Ultrasound-guided fetal tracheal occlusion may be a preferable alternative to surgical intervention for treatment of fetal pulmonary hypoplasia.

Animals↗