Echocardiographic evaluation of the fetus with congenital cystic adenomatoid malformation

OBJECTIVES

The development of nonimmune hydrops is a known complication of congenital cystic adenomatoid malformation (CCAM) in the fetus. The aim of this study was to investigate the impact of CCAM on hemodynamics in the fetus and to determine whether cardiac dysfunction contributes to the development of hydrops in this patient population.

METHODS

The echocardiographic data from 41 consecutive fetuses diagnosed prenatally with CCAM were reviewed. The presence or absence of hydrops was noted in each patient. Two-dimensional ultrasonographic and Doppler data were compared between the two groups (with or without hydrops).

RESULTS

The mean gestational age for the study group at the time of imaging was 23.2 +/- 3.0 weeks. Hydrops was noted in 15 of 41 fetuses (36.5%). The fetuses that developed hydrops had a lower cardiac/thoracic ratio than those which did not develop hydrops (0.18 vs. 0.23, P = 0.001). The fetuses with hydrops also demonstrated an increase in early ventricular filling. The ratio of early ventricular filling to atrial contraction (E/A ratio) at both the tricuspid and mitral valves was significantly higher in the fetuses with hydrops (P = 0.005 and P = 0.03, respectively). Doppler interrogation of the inferior vena cava demonstrated a greater degree of reversal with atrial contraction in the hydrops group (29.7% vs. 15.1%, P = 0.003). The development of significant atrioventricular valve insufficiency was rare in the fetuses with hydrops (one of 15 cases).

CONCLUSIONS

Cystic adenomatoid malformation can result in significant cardiac compression in the fetus. This alters hemodynamics and may result in hydrops on the basis of elevated central venous pressure.

Anesthesia for fetoscopic fetal surgery: twin reverse arterial perfusion sequence and twin-twin transfusions syndrome

IMPLICATIONS

Twin reversed arterial perfusion sequence and twin-twin transfusion syndrome can be managed by fetoscopic fetal surgery. It is important to consider the fetal, uteroplacental, and maternal issues when choosing an anesthetic technique. We report on three patients with differing anesthetic issues using fetoscopic surgery for umbilical cord coagulation.

Treatment of severe congenital diaphragmatic hernia by fetal tracheal occlusion: clinical experience with fifteen cases

OBJECTIVE

Our purpose was to determine whether prenatal tracheal occlusion improves survival in a selected population of fetuses affected by severe congenital diaphragmatic hernia.

STUDY DESIGN

Fetuses with isolated congenital diaphragmatic hernia were selected as candidates for fetal intervention by specific criteria designed to predict a 90% mortality rate with conventional postnatal treatment.

RESULTS

Fifteen fetuses underwent tracheal occlusion with 5 survivors (33%). Two fetuses were lost to early preterm labor. In 13 mothers, postoperative gestation ranged from 19 to 68 days, with a mean duration of pregnancy after tracheal occlusion of 38 days. The 5 survivors were hospitalized for an average of 76 days. Despite dramatic lung growth in some fetuses after tracheal occlusion, intensive management was required, and most deaths were caused by respiratory insufficiency.

CONCLUSION

Prenatal tracheal occlusion can result in impressive lung growth in a subset of fetuses with severe congenital diaphragmatic hernia. However, survival remains compromised by pulmonary functional abnormality and the consequences of prematurity.

Adenoviral-mediated gene transfer in wound healing

The application of gene transfer strategies to wound healing is not an obvious use of this technology until one considers the important role of cytokines and growth factors in the normal wound healing response. Several gene transfer strategies have been proposed, from in vitro retroviral-mediated gene transfer with autologous transplantation, to in vivo plasmid based gene transfer as retroviral gene transfer. The limitations of these approaches have been efficiency of gene transfer, transgene expression and biologic response. Adenoviral-mediated gene transfer in wound healing is a relatively new application of this vector. The advantage of the adenovirus as a gene transfer vector lies in its ability to transduce nondividing cells of all types at very high efficiency without integration into the host cell's genome. The disadvantage of adenovirus as a vector is the relatively short duration of transgene expression and the inflammatory response it elicits. In the setting of wound healing brief duration of high levels of transgene may be all that is necessary to favorably influence wound healing. Secondly, as wound healing is fundamentally an inflammatory response, the inflammation elicited by the adenovirus may not be detrimental as long as the transgene is a growth factor with significant vulnerary effects such as platelet-derived growth factor-B. This review summarizes the current state of adenoviral-mediated gene transfer in experimental models of impaired wound healing which have laid the groundwork for proposed phase I clinical trials of adenoviral-mediated gene transfer of platelet-derived growth factor-B in chronic venous leg ulcers and chronic nonhealing diabetic foot ulcers. Adenoviral-mediated gene transfer is a useful tool in the study of the role of specific cytokines and growth factors in normal and impaired wound healing. Adenoviral-mediated gene transfer may hold significant promise for clinical application as a means of efficient growth factor delivery in correcting impaired wound healing.

Assessment of fetal lung volumes and liver herniation with magnetic resonance imaging in congenital diaphragmatic hernia

OBJECTIVE

We evaluated the use of fetal magnetic resonance imaging in predicting outcomes after ultrasonographic diagnosis of left-sided congenital diaphragmatic hernia.

STUDY DESIGN

Forty-one pregnant women carrying fetuses with congenital diaphragmatic hernia underwent 43 magnetic resonance imaging scans. Lung volumes were calculated by summing the areas on 6-mm axial sections. The presence or absence of liver herniation was noted. A liver/diaphragm ratio was obtained by using the distances from the superior aspect of the liver and the diaphragmatic remnant to the apex of the chest.

RESULTS

Mean gestational age was 26 weeks and overall survival was 59%. Neither right, left, nor total lung volume measurements were predictive of survival. Liver herniation into the left side of the chest was predictive of outcome at P<.05. The liver/diaphragm ratio was predictive of outcome at P = .03.

CONCLUSION

Fetal magnetic resonance imaging permits calculation of lung volumes, but these volumes are not predictive of outcome. However, both the presence of liver herniation and the volume of liver within the chest, as reflected by the liver/diaphragm ratio, help predict outcome in left-sided congenital diaphragmatic hernia.

Salvage of a fetus with congenital high airway obstruction syndrome by ex utero intrapartum treatment (EXIT) procedure

A fetus with congenital high airway obstruction syndrome (CHAOS) due to complete tracheal atresia was referred at 31 weeks of gestation after 12 weeks of massive hydrops. The fetus was delivered by the ex utero intrapartum treatment procedure allowing sufficient time while on placental support for bronchoscopy to confirm tracheal atresia and tracheostomy to secure the airway. His postnatal course was complicated by severe capillary leak syndrome secondary to hydrops, diaphragmatic paralysis, tracheobronchial malacia, and the need for chronic ventilatory support. The infant's tracheobronchial malacia resolved by 5 months of age and normal diaphragmatic function was restored at 9 months allowing him to be weaned from mechanical ventilation. He underwent tracheal reconstruction at 17 months of age. At follow up at 32 months of age he has a patent airway and is the first long-term survivor with CHAOS.

FGF2-Targeted adenovirus encoding platelet-derived growth factor-B enhances de novo tissue formation

Gene therapy has yet to achieve reproducible clinical efficacy, due to inadequate gene delivery, inadequate gene expression, or dose-limiting toxicity. We have developed a gene therapy technology for tissue repair and regeneration that employs a structural matrix for DNA delivery. The matrix holds the DNA vector at the treatment site and provides a scaffolding for in-growth and accumulation of repair cells and efficient DNA transfection. We now report, for the first time, matrix-mediated delivery of targeted DNA vectors for soft tissue repair. A collagen matrix was used to deliver an adenoviral vector encoding platelet-derived growth factor-B (AdPDGF-B), resulting in efficient transgene expression in vitro and in vivo. Increases in the overall levels of expression and in the relative amounts of secreted PDGF-BB were achieved when AdPDGF-B was conjugated to fibroblast growth factor (FGF2) such that the virus was targeted for cellular uptake via FGF receptors. Matrix-mediated delivery of AdPDGF-B enhanced wound healing responses in vivo, and FGF2 targeting generated effects comparable to nontargeted vectors at significantly lower doses. Therefore, matrix-mediated delivery in combination with FGF2 targeting overcomes some of the safety and efficacy limitations of current gene therapy strategies and is an attractive therapeutic approach for tissue repair and regeneration.

Diminished interleukin 6 (IL-6) production during scarless human fetal wound repair

Fetal wound healing is characterized by minimal inflammation and scarless repair. IL-6 stimulates inflammation in postnatal wound healing. We hypothesized that fetal skin has a diminished IL-6 response and that exogenous IL-6 will result in scar formation. Human adult or fetal skin was placed subcutaneously in SCID mice and incisionally wounded. Wounds were excised after 4, 12, 24 or 72 h for IL-6 mRNA quantification by RT-PCR. In other grafts, 5 microgram of IL-6 was injected at wounding and then harvested at 7 days for analysis of scar formation. IL-6 production was examined in primary cultures of human fetal or adult dermal fibroblasts incubated for 8 h with 0, 0.1, 1 or 10 ng/ml of PDGF-BB. IL-6 mRNA was detected 4 h after wounding in fetal and adult wounds, but by 12 h there was no IL-6 mRNA in the fetal wounds. Adult wounds had IL-6 mRNA persisting to 72 h. IL-6 administration to fetal wounds resulted in scar formation. Fetal fibroblasts produced less IL-6 protein and mRNA at all points examined (P<0.01 vs adult). Diminished production of inflammatory cytokines such as IL-6 may be responsible for the lack of inflammation seen during fetal wound healing. Diminished inflammation may provide a permissive environment for scarless wound healing.

Fetal wound repair results in scar formation in interleukin-10-deficient mice in a syngeneic murine model of scarless fetal wound repair

BACKGROUND

Fetal dermal wound healing is characterized by minimal inflammation, restoration of normal dermal architecture, and scarless repair. The authors have shown that proinflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8) are diminished during fetal wound repair. Interleukin-10 (IL-10) is an antiinflammatory cytokine that decreases production of IL-6 and IL-8. The authors hypothesized that diminished IL-6 and IL-8 and minimal inflammation may be caused by IL-10.

METHODS

To test this hypothesis, the authors developed a new syngeneic murine model of fetal wound repair in which 15-day-gestation skin from either normal C57BL/6 or transgenic C57BL/6 IL-10 knockout mice was grafted to the back of the same strain adult mice. The grafts were incisionally wounded after 5 days, harvested at 1 week, and analyzed for inflammatory response and scar formation.

RESULTS

Wounds in normal fetal skin grafts showed minimal inflammation and normal dermal reticular collagen pattern at the site of the wound, consistent with scarless repair. In contrast, wounds in IL-10 knockout fetal skin grafts showed significant inflammation and scar formation.

CONCLUSIONS

Fetal skin grafts on adult syngeneic mice heal without inflammation or scar formation. The absence of IL-10 in fetal skin results in scar formation. Intrinsic lack of IL-10 may result in continued amplification of the inflammatory cytokine cascade, continued stimulation of fibroblasts, and abnormal collagen deposition. IL-10 is necessary for scarless wound repair to occur.

Prenatal MRI evaluation of congenital diaphragmatic hernia

The objective of this paper is to evaluate the efficacy of various magnetic resonance imaging (MRI) sequences and the general usefulness of prenatal MRI in determining the position of the fetal liver and visualizing lung tissue in fetuses who have congenital diaphragmatic hernia (CDH). This was a retrospective review of prenatal MRI of fetuses with a confirmed diagnosis by surgery or autopsy of CDH. MRI was performed in a 1.5-Tesla magnet using fast gradient echo, half-Fourier single-shot turbo spin-echo (HASTE) and echo planar images. The presence of a chest mass, position of the stomach and liver and visualization of the lungs by MRI was noted in all fetuses. This was compared to ultrasound studies performed the same day and correlated with postnatal or autopsy studies. The fetuses were 18-36 weeks gestational age (mean 24.5 weeks). MRI diagnosed left CDH (33), right CDH (4), and bilateral CDH (1) and agreed with the postnatal diagnosis in all patients. Ultrasound (US) diagnosed left CDH (33), right CDH (2), and congenital cystic adenomatoid malformation (3). MRI changed the diagnosis in four patients. The fetal liver was easily demonstrated with MRI in all fetuses and was herniated into the chest in 25 of the 38. US diagnosed liver up in 21. Correlation with postnatal studies found MRI correctly diagnosed liver position in 37 out of 38 cases. US correctly diagnosed liver position in 32 out of 38. Both lungs could be visualized in all fetuses with MRI. MRI accurately and easily diagnoses CDH and can differentiate it from other chest masses. MRI was superior to US in demonstrating the position of the fetal liver above or below the diaphragm. MRI reliably visualized fetal lung tissue. These findings are important for counseling parents, selecting fetal surgical candidates, and estimating prognosis.

Superior mesenteric venous thrombosis in malrotation with chronic volvulus

Malrotation can be difficult to diagnose after the newborn period because of intermittent symptoms and vague clinical findings, but malrotation with midgut volvulus is usually quite striking in its presentation. Early diagnosis and surgical treatment are essential to prevent acute ischemic infarction of the bowel, although chronic complications are rare. The authors present an unusual case of mesenteric venous thrombosis secondary to chronic midgut volvulus. A 13-year-old girl presented with an 11-year history of recurrent bouts of abdominal pain evaluated at 3 other institutions without a diagnosis. At the referring hospital, an episode of bilious emesis associated with abdominal pain prompted a computerized tomography scan of the abdomen. This showed a calcified thrombus within the superior mesenteric vein (SMV). At laparotomy, malrotation with chronic 270 degree volvulus was found with evidence of mesenteric venous hypertension. Segmental occlusion was documented on magnetic resonance angiography. SMV thrombosis is an unusual complication of malrotation with chronic midgut volvulus.

Human melanoma progression in skin reconstructs : biological significance of bFGF

Human skin reconstructs are three-dimensional in vitro models consisting of epidermal keratinocytes plated onto fibroblast-contracted collagen gels. Cells in skin reconstructs more closely recapitulate the in situ phenotype than do cells in monolayer culture. Normal melanocytes in skin reconstructs remained singly distributed at the basement membrane which separated the epidermis from the dermis. Cell lines derived from biologically early primary melanomas of the radial growth phase proliferated in the epidermis and the basement membrane was left intact. Growth and migration of the radial growth phase melanoma cells in the dermal reconstruct and tumorigenicity in vivo were only observed when cells were transduced with the basic fibroblast growth factor gene, a major autocrine growth stimulator for melanomas. Primary melanoma cell lines representing the more advanced stage vertical growth phase invaded the dermis in reconstructs and only an irregular basement membrane was formed. Metastatic melanoma cells rapidly proliferated and aggressively invaded deep into the dermis, with each cell line showing typical invasion and growth characteristics. Our results demonstrate that the growth patterns of melanoma cells in skin reconstructs closely correspond to those in situ and that basic fibroblast growth factor is critical for progression.

Adenoviral-mediated gene transfer in wound healing: acute inflammatory response in human skin in the SCID mouse model

The use of an adenoviral vector as a means of therapeutic protein delivery for the treatment of impaired wound healing is a potentially effective application of current gene transfer techniques. This study was designed to investigate the ability of adenovirus to mediate gene transfer in healing wounds in human skin in vivo. The human skin/severe combined immunodeficient mouse chimera model was used to study both the response of human tissue to adenoviral infection and the nature of the acute inflammatory response. The effects of adenoviral infection and transgene expression on the rate and quality of human wound healing were then investigated. Cell- and species-specific monoclonal antibodies were used to characterize the resident skin cell types participating in wound repair, the inflammatory response, and the proliferative potential of adenovirus-treated compared to control skin. Our studies show that, following wounding, normal skin architecture is restored in the presence of adenoviral infection equivalent to noninfected controls. Despite an increased acute inflammatory response after adenovirus injection, no difference in the healing capabilities of wounded skin was observed, suggesting that adenovirus-mediated gene transfer for growth factor-mediated acceleration of wound healing may be feasible.

Troubles with twins: fetoscopic therapy

Monochorionic twin gestations present challenges in perinatal management not seen in dichorionic twins or singleton pregnancies. Monochorionic twin gestations may be complicated by (1) a monoamniotic presentation, (2) a structurally anomalous cotwin, (3) twin reversed arterial perfusion sequence, (4) and the twin-twin transfusion syndrome. Each of these conditions is associated with increased morbidity and mortality rates. Although a variety of therapeutic interventions are available, fetoscopic surgery is a promising new approach to these conditions. Advances in microinstrumentation have allowed for the wider application of fetoscopy for a variety of prenatally diagnosed conditions, including "troubles with twins." This article examines the natural history, pathophysiology, diagnosis, and indications for fetoscopic surgery in complicated monochorionic twin gestations.

Open fetal surgery for life-threatening fetal malformations

After more than two decades of experimental and clinical work, fetal surgery has become an accepted treatment modality for selected fetuses with life-threatening anomalies. Color Doppler ultrasound and ultrafast fetal magnetic resonance imaging have enhanced the accuracy of prenatal evaluation traditionally made by ultrasound alone. Fetal lung masses associated with hydrops are nearly 100% fatal. These lesions can be resected in utero if they are predominantly solid or multicystic. Thoracoamniotic shunting may be effective in the setting of a single large predominant cyst. Fetuses diagnosed with left congenital diaphragmatic hernia before 26 weeks' gestation with liver herniation and a sonographic right lung to head circumference ratio (LHR) of less than one may benefit from fetal tracheal occlusion. Fetal sacrococcygeal teratoma complicated with placentomegaly, hydrops, or progressive high output heart failure may benefit from in utero resection of the tumor. Although preterm labor still remains the Achilles heel of open fetal surgery, effective tocolysis may, in the future, expand the scope of fetal surgery.

Management of fetal airway obstruction

Fetal airway obstruction can make it difficult if not impossible to secure the airway at birth, before hypoxia, brain injury, or death results. Fetal airway obstruction can result from an intrinsic defect in the airway, such as the congenital high airway obstruction syndrome or extrinsic compression of the airway caused by a cervical mass, most commonly a cervical teratoma or lymphangioma. As fetuses with fetal airway obstruction reach viability, they should be monitored closely for the development or progression of hydrops in intrinsic obstruction cases or polyhydramnios in extrinsic obstruction cases. The fetus should be delivered by using the ex utero intrapartum treatment procedure, with maintenance of uteroplacental circulation and gas exchange. This approach provides time to perform procedures such as direct laryngoscopy, bronchoscopy, or tracheostomy to secure the fetal airway, thereby converting an emergent airway crisis into a controlled situation.

Improvement in hindbrain herniation demonstrated by serial fetal magnetic resonance imaging following fetal surgery for myelomeningocele

CONTEXT

Hindbrain herniation occurs in a large percentage of children with myelomeningocele and is the leading cause of death in this population. The effect of early fetal closure of myelomeningocele on hindbrain herniation is unknown.

OBJECTIVE

To determine whether early fetal closure of myelomeningocele affects hindbrain herniation.

DESIGN

Case series of patients undergoing fetal myelomeningocele closure with serial measurements of hindbrain herniation and a mean follow-up of 182 days.

SETTING

Tertiary care medical center.

PARTICIPANTS

Ten patients undergoing fetal myelomeningocele closure at 22 to 25 weeks' gestation between March 1998 and February 1999.

MAIN OUTCOME MEASURES

Need for shunt placement; degree of hindbrain herniation (grades 0-3) found on magnetic resonance imaging (MRI) performed prior to surgery and 3 and 6 weeks after fetal surgery, as well as shortly after birth; gestational age at delivery.

RESULTS

All initial fetal MRI scans performed at 19 to 24 weeks' gestation showed significant (grade 3) cerebellar herniation and absence of spinal fluid spaces around the cerebellum. Six fetuses were delivered electively at 36 weeks' gestation after lung maturity was established. The other 4 were delivered prematurely, at 25, 30, 30, and 31 weeks of gestation, and the 25-week gestation neonate died. All 9 surviving neonates showed improvement in the hindbrain hernia at the 3-week postoperative fetal scan (grade 2, n = 4; grade 1, n = 5). On the postnatal scan, all patients showed grade 1 hindbrain herniation. Only 1 patient required placement of a ventriculoperitoneal shunt.

CONCLUSION

In this series of patients, fetal myelomeningocele closure resulted in improvement in hindbrain herniation as demonstrated by serial MRI scans.

Adenoviral-mediated overexpression of platelet-derived growth factor-B corrects ischemic impaired wound healing

Chronic wounds represent a major clinical problem with significant morbidity and healthcare expenditures, but no effective therapies. Topical platelet-derived growth factor-BB trials have required large and repeated doses to achieve only a modest effect. We examined the ability of an adenovirus containing the platelet-derived growth factor-B transgene to improve the rate of wound healing through induction of platelet-derived growth factor-B overexpression in cells participating in the wound healing response. We treated excisional wounds in the ischemic rabbit ear, which have a 60% delay in healing, with vehicle, 106, or 108 plaque-forming units of an adenovirus containing the platelet-derived growth factor-B per wound (n = 19). At 7 d this resulted in a decrease in the epithelial gap from 3.4 +/- 1 mm (mean +/- SD) in vehicle-treated wounds to 1.9 +/- 1.8 mm (mean +/- SD, p < 0.05) when treated with 106 plaque-forming units of an adenovirus containing the platelet-derived growth factor-B, and 0.7 +/- 1.1 mm (mean +/- SD, p < 0.001) when treated with 108 plaque-forming units of an adenovirus containing the platelet-derived growth factor-B. Ischemic excisional wounds treated with 108 plaque-forming units of an adenovirus containing the platelet-derived growth factor-B even healed more rapidly than non-ischemic excisional wounds treated with vehicle (p < 0.05). In contrast, 5 microg of platelet-derived growth factor-BB protein (n = 2) resulted in only modest granulation tissue at the margin, but no significant differences in epithelial gap (3 +/- 0.6 mm, mean +/- SD). Plaque-forming units (106 or 108) of an adenovirus containing the beta-galactosidase transgene (n = 4) impaired wound re-epithelialization with an epithelial gap of 5.11 +/- 0.69 mm, mean +/- SD, p < 0.004, and 3.8 +/- 0.57 mm, mean +/- SD, p < 0.07, respectively. Adenoviral-mediated gene transfer of platelet-derived growth factor-B overcame the ischemic defect in wound healing and offers promise in the treatment of chronic nonhealing wounds. The vulnerary effects of platelet-derived growth factor-B overexpression were sufficient to overcome the adverse effects of the adenovirus or transgene on wound healing.

Congenital chest lesions: diagnosis and characterization with prenatal MR imaging

PURPOSE

To evaluate prenatal magnetic resonance (MR) imaging for diagnosis of fetal chest masses and to determine if MR imaging provides information in addition to that of ultrasonography (US).

MATERIALS AND METHODS

Eighteen pregnant women were referred for MR imaging of possible fetal chest tumors seen at US (16 congenital cystic adenomatoid malformation [CCAM], two bronchopulmonary sequestration [BPS]). The presence, position, size, and characteristics of masses were determined and correlated with postnatal results.

RESULTS

The MR imaging diagnoses were three cases of congenital diaphragmatic hernia, nine of CCAM, two of BPS, and one each of foregut cyst, lung atresia, tracheal atresia, and bronchial stenosis. MR imaging results were in agreement with US results in nine fetuses and in disagreement in nine. MR imaging diagnoses were confirmed at surgery or autopsy in 17 fetuses. MR imaging results led to an error in diagnosis in one fetus with BPS.

CONCLUSION

Fetal chest masses had characteristic MR imaging appearances. MR imaging was accurate for distinguishing congenital diaphragmatic hernia from CCAM and was useful for less common diagnoses and determination of the origin of very large chest tumors. Prenatal diagnosis was changed in some patients owing to MR results and affected treatment and counseling of parents. MR imaging is a valuable adjunct to US for prenatal diagnosis of fetal chest masses.

Recombinant adenoviral mediated gene transfer in ischemic impaired wound healing

Chronic nonhealing wounds represent a large clinical problem resulting in severe disabilities and large healthcare expenditures. Despite the scope of this problem, effective new therapies are lacking. The deficiency of growth factors in chronic wounds has brought attention to the topical application of growth factors, but initial clinical trials have resulted in only modest improvements in healing despite large, repetitive doses. The modest improvement in healing observed in these trials show that growth factors can improve chronic wound healing, but a better means of growth factor delivery is needed. We hypothesized that gene therapy using a recombinant adenoviral vector could be used to induce transgene production directly by cells in the wound. An adenovirus containing the beta-galactosidase reporter transgene (Ad-LacZ) was used in the ischemic rabbit ear model to test this hypothesis. Ad-LacZ resulted in efficient transgene delivery to cells participating in the wound healing response, with expression up to 2 weeks. However, wound reepithelialization was impaired in Ad-LacZ treated wounds compared to vehicle control wounds. Adenoviral mediated gene transfer is a promising efficient means of growth factor delivery to chronic wounds. However, selection of the proper transgene with appropriate biologic activity in wound healing may be essential to overcome the potential adverse effects of adenoviral infection.

Elevated platelet-derived growth factor-B in congenital cystic adenomatoid malformations requiring fetal resection

BACKGROUND

During lung development, platelet-derived growth factor-BB (PDGF-BB) is maximal during the canalicular stage and decreases by the saccular stage. PDGF-BB stimulates lung growth by increasing cell proliferation. Fetal CCAMs have been shown to have an elevated proliferative index, but it is not known why some CCAMs rapidly enlarge in utero and cause fetal hydrops. The authors hypothesized that the high proliferative index and rapid enlargement of some fetal CCAMs may be caused by persistently elevated PDGF-BB production compared with normal fetal lung.

METHODS

To test this hypothesis, tissue was obtained at the time of resection from two fetal CCAMs (22 weeks), three full-term CCAMs, and three normal fetal lungs (21 to 22 weeks). PDGF-BB production by fetal CCAMs was compared with normal age-matched fetal lung using immunohistochemistry, reverse transcriptionase-polymerase chain reaction (RT-PCR), and Western blot analysis.

RESULTS

CCAMs resulting in fetal hydrops and requiring fetal resection had strong mesenchymal immunostaining for PDGF-BB next to epithelial lined cysts, increased PDGF-B gene expression by RT-PCR, and elevated PDGF-BB protein by Western blot, compared with normal age-matched fetal lung. Term CCAMs had minimal PDGF-BB staining, PDGF-B gene expression, and PDGF-BB protein production.

CONCLUSIONS

CCAMs that grew rapidly and progressed to hydrops, requiring in utero resection, demonstrated increased mesenchymal PDGF-B gene expression and PDGF-BB protein production compared with age-matched normal fetal lung, which may, in part, be responsible for the autonomous growth and proliferation seen in hydropic fetal CCAMs.

The ex utero intrapartum treatment procedure for a large fetal neck mass in a twin gestation

BACKGROUND

Large fetal neck masses can make it difficult or impossible to secure airways at birth, with associated risks of hypoxia, brain injury, and death. Based on a MEDLINE search from 1966 to June 1998, using the keywords EXIT procedure, placental support, twins, and neck mass, we report the first ex utero intrapartum treatment procedure performed in a twin gestation complicated by a large fetal neck mass.

CASE

A giant fetal cervical mass was diagnosed in one fetus of a 20-week twin gestation by sonography and magnetic resonance imaging. At 35 weeks' gestation, the ex utero intrapartum treatment procedure was performed successfully for delivery of the normal twin, followed by intrapartum airway access of the twin with the neck mass.

CONCLUSION

Even in twin gestations, the ex utero intrapartum treatment procedure is the delivery method of choice for fetuses with giant neck masses.

The current status and future potential of fetal intervention: image is everything

Fetal imaging is integral to the past, present, and future of fetal intervention. In the early history of fetal intervention, the role of prenatal ultrasound was primarily to identify a fetal lesion, provide a correct anatomic diagnosis, and exclude other anatomic defects. We now depend on ultrasound, and other imaging studies, not only to provide anatomic information, but to provide prognostic, physiologic and functional information prior to, during, and after surgery for optimal selection and management of fetal surgery patients. In the future improvements in imaging and non-invasive technology will drive further expansion of indications and therapeutic options for fetal intervention.

Fetal lung lesions: management and outcome

OBJECTIVE

Our purpose was to review our experience with fetal congenital cystic adenomatoid malformation and extralobar pulmonary sequestration emphasizing natural history, management, and outcome.

STUDY DESIGN

We conducted a retrospective review of 175 fetal lung lesions diagnosed by antenatal ultrasonography at 2 fetal treatment centers.

RESULTS

There were 134 congenital cystic adenomatoid malformation cases. Fourteen women underwent elective abortion, 101 women were managed expectantly, 13 women had fetal surgery, and 6 women had placement of a thoracoamniotic shunt. For the congenital cystic adenomatoid malformation lesions that were not associated with nonimmune hydrops, all babies survived. Of 25 large congenital cystic adenomatoid malformations that had associated hydrops that were followed expectantly, all fetuses died before or shortly after birth. Fetal surgical resection of the tumor (fetal lobectomy) was performed at 21 to 29 weeks' gestation in 13 hydropic fetuses with 8 fetuses continuing gestation with subsequent hydrops resolution, impressive in utero lung growth, and neonatal survival. Six fetuses with a very large solitary cyst underwent thoracoamniotic shunting and 5 survived. There were 41 extralobar pulmonary sequestration cases. Twenty-eight extralobar pulmonary sequestrations dramatically regressed on serial prenatal sonography, were asymptomatic after birth, and were only detectable by imaging studies postnatally (no resection required). Of the remaining 13 extralobar pulmonary sequestration cases, 2 underwent elective abortion, 7 symptomatic lesions were resected after birth with survival, 1 hydropic fetus died, and 3 fetuses had an associated tension hydrothorax with secondary hydrops that was successfully treated by either fetal thoracenteses or thoracoamniotic shunting followed by postnatal resection.

CONCLUSIONS

The natural history of prenatally diagnosed lung masses is variable, and associated anomalies are rare. Most congenital cystic adenomatoid malformation lesions can be managed with maternal transport, planned term delivery, and postnatal resection. Many extralobar pulmonary sequestrations dramatically decrease in size before birth and may not need treatment after birth. Fetal therapy is now an option for lung lesions associated with nonimmune hydrops.

Tracheal occlusion reverses the high impedance to flow in the fetal pulmonary circulation and normalizes its physiological response to oxygen at full term

PURPOSE

The authors hypothesized that in utero tracheal occlusion would reverse the high impedance to pulmonary blood flow associated with congenital diaphragmatic hernia (CDH) and normalize the fetal physiological response to oxygen at term.

METHODS

Three experimental groups were studied. Six fetal lambs (CDH group) underwent creation of a left CDH at 80 days' gestation, an additional six fetal lambs underwent left CDH creation at 80 days' gestation followed by fetal tracheal occlusion performed at 108 days' gestation (CDH + TO group), and four control fetal lambs (control group) underwent a sham procedure at 80 days gestation. All lambs were followed up at 2-week intervals by pulse wave Doppler echocardiography. At each time-point the pulsatility index (PI) was calculated for the left branch pulmonary artery from the Doppler blood velocity waveform. Near term (term, 145 days gestation) at 136 days gestation, measurements were repeated under maternal normoxia and hyperoxia. The fetal lungs were harvested and processed for morphometric analysis by radial alveolar counts (RAC) and lung-to-body-weight ratios (LBWR) as measures of lung growth.

RESULTS

At 136 days' gestation the PI of the CDH + TO group (2.88 +/- 0.29) and control group (3.97 +/- 0.37) were significantly lower compared with the PI of the CDH group (9.02 +/- 0.50). There was a significant decrease in the PI of both the CDH + TO group and the control group with maternal hyperoxia at term, whereas the CDH group showed no change. The lungs of the CDH group fetuses were significantly smaller by LBWR and RAC than both CDH + TO and control fetuses.

CONCLUSIONS

An elevated PI is associated with pulmonary hypoplasia, fetal tracheal occlusion reverses this finding, and results in a normal fetal physiological response to changes in oxygen tension at term.

Increased cell proliferation and decreased apoptosis characterize congenital cystic adenomatoid malformation of the lung

BACKGROUND/PURPOSE

Congenital cystic adenomatoid malformations (CCAM) are lung lesions that demonstrate abnormalities of both mesenchymal and epithelial tissues. The pathogenesis of these tumors remains unknown. Because normal organogenesis requires a balance between cell proliferation and programmed cell death (apoptosis), the authors hypothesized that CCAM results from an increase in cell proliferation or a decrease in apoptosis within the developing lung, possibly mediated by keratinocyte growth factor (KGF).

METHODS

To examine cell cycle control in CCAM, we measured indices of cell proliferation and apoptosis in lesions requiring fetal (n = 4) or neonatal (n = 8) resection compared with those of normal fetal (14 to 28 weeks' gestation; n = 14) and neonatal (n = 3) human lung. Cell proliferation was analyzed by immunostaining for a proliferation marker (Ki-67). Apoptosis was examined using an in situ digoxigenin end-labeling technique to localize apoptotic bodies. The expression of KGF protein and KGF mRNA in CCAM and normal lung was examined using immunohistochemistry and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

CCAM lesions in general showed a twofold increase in cell proliferation index (19.2% +/- 1.4% v 9.6% +/- 0.7%, P < .00005) and a fivefold decrease in apoptotic bodies (0.9 +/- 0.2 v 4.5 +/- 0.5, P < .0005) compared with age-matched normal lung. CCAMs that required resection before birth had the highest cell proliferation index. There were no differences in the expression of KGF protein or KGF mRNA in CCAM and normal lung.

CONCLUSIONS

These results demonstrate that CCAM differs from normal lung by increased cell proliferation and decreased apoptosis. The increased proliferation does not appear to be mediated by the pneumocyte mitogen KGF. An examination of factors that control cell proliferation and apoptosis in CCAM may provide further insight into the pathogenesis of this tumor.

Hyaluronan receptor expression increases in fetal excisional skin wounds and correlates with fibroplasia

BACKGROUND/PURPOSE

The midgestation fetus heals incisional skin wounds scarlessly, whereas large excisional wounds scar. High concentrations of hyaluronan (HA) are associated with scarless fetal as opposed to scar-forming adult wound repair. Because expression of the HA receptors, CD44 and RHAMM (Receptor for HA-Mediated Motility), has been associated with adult wound fibroplasia, the authors postulated that fetal excisional wounds would show increased expression of CD44 and RHAMM as compared with incisional wounds.

METHODS

Two models of fetal wound healing were examined. Fetal skin from human abortuses was heterotransplanted subcutaneously into severe combined immunodeficient (SCID) mice. Fourteen days after grafting, incisional or 2-mm excisional wounds were created (n = 6 per time-point). In addition, incisional and excisional (6 to 10 mm) wounds (n = 5 per time-point) were created on the backs of 70- to 75-day fetal lambs (term, 145 days). Tissue from both models was harvested at sequential time-points after injury. Wounds were studied histologically for fibroplasia and assayed for their HA content. CD44 and RHAMM expression were analyzed by immunohistochemistry and immunoblotting.

RESULTS

As expected, in both models, incisional wounds healed scarlessly, whereas excisional wounds showed fibroplasia. Incisional wounds of fetal lambs maintained a significantly higher HA content than excisional wounds 3 days after injury. Between 1 and 7 days in either human or sheep fetal wounds, immunostaining for CD44 and RHAMM markedly increased along the margins of excisional wounds as compared with incisional wounds and unwounded skin. Immunoblot analysis confirmed this increased HA receptor expression in both models.

CONCLUSIONS

HA receptor expression increased in both human and sheep fetal excisional wounds and correlated with fibroplasia and a reduced HA content. The authors speculate that strategies to limit the expression or function of HA receptors during postnatal wound repair may modify the development of scar.

Diminished interleukin-8 (IL-8) production in the fetal wound healing response

BACKGROUND

Fetal skin wound healing results in scarless repair with minimal cellular inflammatory response. Interleukin-8 (IL-8) stimulates inflammation in postnatal wound healing but little is known about its role in fetal wounds. We hypothesized that fetal tissues have diminished IL-8 during wound repair and in response to platelet-derived growth factor (PDGF), a growth factor central to wound healing.

MATERIALS AND METHODS

To examine the IL-8 response of fibroblasts to PDGF, cultures of human fetal (17-18 weeks) and adult dermal fibroblasts were incubated 8 h with PDGF (0, 0.1, 1, or 10 ng/mL) and supernatants and cells were collected for IL-8 ELISA and IL-8 RT-PCR. To evaluate the IL-8 response to wounding, human adult and fetal skin was placed subcutaneously in the SCID mouse, wounded, and the wound cleft excised after 4, 12, 24, or 72 h for IL-8 RT-PCR.

RESULTS

Fetal fibroblasts produced less IL-8 protein at baseline (50 +/- 6 pg/mL versus 450 +/- 115 pg/mL, P < 0.001) and in response to all concentrations of PDGF examined (P < 0.001). IL-8 mRNA was detected in unstimulated adult fibroblasts but not in fetal fibroblasts. Much less IL-8 mRNA was detected in stimulated fetal fibroblasts than in adult fibroblasts. IL-8 mRNA was detected 4 h after wounding in fetal and adult wounds. By 12 h no IL-8 mRNA was detected in fetal wounds, whereas adult wounds had IL-8 mRNA persisting to 72 h.

CONCLUSIONS

Diminished inflammatory cytokine response by fetal tissues may be responsible for the lack of cellular recruitment and inflammation seen in fetal wound healing and may contribute to scarless wound repair.

Prenatal MRI evaluation of giant neck masses in preparation for the fetal exit procedure

Airway compromise at birth can be anticipated with giant neck masses, so that as much anatomic information as possible is necessary prior to delivery to establish a diagnosis and assess the airway. With this study, we evaluated the usefulness of prenatal magnetic resonance imaging (MRI) for evaluation of giant fetal neck masses prior to operating on placental support, the Ex Utero Intrapartum Treatment (EXIT) procedure, performed to secure the neonatal airway. Three pregnant women with an ultrasound (US) diagnosis of fetal giant neck mass were referred for prenatal MRI. As this was our initial experience performing prenatal MRI, a variety of imaging sequences were used including spin-echo, fast gradient-echo, half-fourier single shot turbo spin-echo (Haste), and echo-planar imaging (EPI). All sequences performed were able to demonstrate the fetal airway relative to the mass. In addition, the images were able to give a more global definition of the mass because of the larger field of view than could be obtained with MRI compared to US. The Haste sequence provided the best definition of a mass because of decreased motion artifacts. The prenatal diagnosis on MRI was teratoma in two and lymphangioma in one and was confirmed at birth. MRI provided essential information about the diagnosis and the anatomy of the giant neck masses and adjacent airway in three fetuses prior to selection for the EXIT surgical procedure.

Anomalies and malformations affecting the fetal/neonatal chest

Although significant anomalies of the fetal thorax are uncommon, with improvement in high-resolution ultrasonography, more of these lesions are being diagnosed prenatally. Accurate and specific prenatal diagnosis is important because different lesions have different natural histories and prognosis. Prenatal MRI is an increasingly important adjunct for identification and differentiation of these lesions and may help determine in selected cases when and if in utero fetal intervention is indicated.

Intrapartum airway management for giant fetal neck masses: the EXIT (ex utero intrapartum treatment) procedure

OBJECTIVE

Our goal was to review our experience with the EXIT (ex utero intrapartum treatment) procedure in the management of five cases with life-threatening fetal neck masses.

STUDY DESIGN

We present a retrospective review of prenatal presentation and course, diagnostic accuracy of imaging studies, intraoperative management, complications, and outcomes.

RESULTS

Polyhydramnios was the initial presenting symptom in three of five fetuses with a mean gestational age of 25 +/- 6 weeks. Preterm labor occurred in two patients. Fetal magnetic resonance imaging provided accurate diagnosis in all four cases whereas conventional ultrasonography led to the diagnosis in four of five cases. The mean duration of EXIT was 28 +/- 22 minutes. The mean venous cord blood gas values were pH 7.22 +/- 0.05, PCO2 61 +/- 11 mm Hg, and PO2 42 +/- 8 mm Hg. In four of five cases an airway was successfully secured.

CONCLUSIONS

The EXIT procedure provides up to 1 hour of good uteroplacental support and is the procedure of choice to secure an airway in the fetus with a giant neck mass.

Fetal ovarian cyst decompression to prevent torsion

BACKGROUND/PURPOSE

Neonates who have ovarian torsion caused by an ovarian cyst often lose their ovary because the torsion and infarction occurred antenatally. Because ultrasound scan has been so effective in diagnosing ovarian cysts in utero, we have a better understanding of their natural history and can select appropriate cases for cyst decompression in utero to prevent torsion. The authors reviewed experience with seven fetuses who had fetal ovarian cyst.

METHODS

During a 26-month period, seven patients were referred for the evaluation of fetal ovarian cyst. The mean gestational age at presentation was 31.9 +/- 3.6 weeks (+/-SD; range, 27 to 37 weeks). There was no history of maternal risk factors such as diabetes mellitus or fetal risk factors such as hyperthyroidism or placentomegally. All seven cases involved isolated unilateral cysts without associated anomalies or chromosomal abnormalities. Mean initial cyst diameter was 3.4 +/- 1.7 cm (+/-SD; range, 1 to 6.1). Indications used for ovarian cyst decompression included anechoic cysts with a diameter > or =4 cm, a cyst "wandering" about the abdomen on serial sonograms, or demonstrating rapid enlargement (>1 cm/wk).

RESULTS

All but one cyst progressed in size during observation. One fetal ovarian cyst (diameter, 2 cm) subsequently regressed spontaneously and another (diameter, 2.1 cm) stabilized during prenatal ultrasound surveillance. One "cyst" observed with a diameter of 3.5 cm proved to be a persistent cloaca. Four fetal ovarian cysts met criteria for decompression. Because of fetal position, decompression could not be performed in one. One cyst (seen before defining criteria for decompression) with a diameter of 5 cm was observed only and underwent torsion. Two cysts (diameters, 6.1 cm and 4 cm) were decompressed in utero under local anesthesia with ultrasound guidance, of 95 mL and 35 mL, respectively. High cyst fluid progesterone (12,041 and 1,990 ng/dL, respectively) and testosterone (1,298 and 2,900 ng/dL, respectively) confirmed the etiology of the cyst as ovarian. Neither cyst recurred, and postnatal ultrasound scan confirmed resolution. There was no maternal or fetal morbidity or mortality and only the patient observed before development of criteria for decompression lost her ovary because of torsion.

CONCLUSIONS

Fetal ovarian cysts tend to present as isolated unilateral lesions in normal fetuses in the third trimester. Spontaneous regression of fetal ovarian cysts may occur. Fetal ovarian cyst decompression, in select cases, may preserve ovaries at risk for torsion.

Pitfalls of the 'double bubble' sign: a case of congenital duodenal duplication

The 'double bubble' sign in prenatal diagnosis is most often associated with duodenal atresia. However, other causes of upper intestinal obstruction and cystic abdominal masses need to be considered. One possible diagnosis that can mimic the 'double bubble' sign of duodenal atresia is duodenal duplication, but little information is available to guide sonologists in the prenatal diagnosis of this rare congenital anomaly. In this case report we describe the successful prenatal diagnosis of duodenal duplication, by relying on the early gestational age of presentation, the lack of polyhydramnios, the failure to consistently demonstrate a 'double bubble' on transverse images, and the presence of a normal distal bowel pattern.

Fetoscopic gene therapy for congenital lung disease

Fetal gene therapy offers the promise of cure for certain genetic diseases, like cystic fibrosis and surfactant protein B deficiency. The authors hypothesized that a fetoscopic approach could attain a high level of organ-specific gene transfer to the fetal lung late in gestation. To test this hypothesis the authors examined the efficacy, specificity, and toxicity of recombinant adenovirus-mediated transfer of the beta-galactosidase marker gene to the lung of late gestation fetal sheep using a fetoscopic technique. Twelve fetal sheep of 125 to 135 days' gestation (term, 145 days) underwent fetoscopic bronchoscopy and intratracheal administration of a replication-deficient adenoviral vector that transduces the beta-galactosidase marker gene. Escape of administered virus was prevented by the fetoscopic deployment of a detachable silicone balloon in the fetal trachea. All fetuses survived until being killed at 2 days after vector delivery for the histopathologic assessment of vector efficacy and specificity. Optimal beta-galactosidase transgene expression was observed at a viral titer of 2 x 10(12) particles per milliliter of administered volume. Expression was greatest in the distal pulmonary parenchyma, particularly in type II pneumocytes, and extended out to the pleura. There was no evidence of gene transfer in either the large conducting airways or in any other fetal organ. The authors have developed a minimally invasive technique for the specific pulmonary delivery of gene therapy vectors to the fetus with no associated acute toxicity. Gene transfer to the late gestation fetus for the treatment of congenital pulmonary disease may be feasible through fetoscopy.

Differential collagen I gene expression in fetal fibroblasts

PURPOSE

Fetal wound healing is characterized by the regeneration of normal dermis and the absence of scar. Transforming growth factor beta-1 (TGF-beta1) is a ubiquitous cytokine with potent fibrogenic effects in both postnatal and fetal wounds. Supplementing fetal wounds with TGF-beta1 results in increased fibrosis consisting primarily of collagen I. We hypothesized that the lack of scar formation in fetal wounds may be caused by differential collagen I gene (COL1A1) expression. The authors examined basal collagen Ia gene expression in human fetal, newborn, and adult dermal fibroblasts after stimulation with exogenous TGF-beta1.

METHODS

Subconfluent human dermal fibroblasts from fetal, newborn, and adult cell lines were incubated for 24 hours, then stimulated by incubation for 4 hours with 1 ng/mL of human recombinant TGF-beta1, or with media alone for basal collagen gene expression, and then placed in guanidium isothyocyanate buffer. To quantitate COL1A1 gene expression, total cellular RNA was extracted and subjected to northern and slot blot hybridization analysis with Dig-labeled COL1A1 probes. The membrane was exposed to x-ray film for 15 minutes and developed.

RESULTS

Scant COL1A1 gene transcript was detected in control fetal fibroblasts. Brief stimulation with of TGF-beta1 upregulated the COL1A1 gene transcription in fetal fibroblasts. Gene expression for COL1A1 in both postnatal cell lines appeared similar in treated and untreated cells. Housekeeping control (GAPDH) confirmed no difference in total amount of RNA at the start or end of the experiment.

CONCLUSION

COL1A1 gene expression is notably absent in unstimulated fetal fibroblasts, but is upregulated by TGF-beta1. In contrast, postnatal fibroblasts demonstrate significant constitutive COL1A1 gene expression at baseline and unchanged after TGF-beta1 stimulation. This differential regulation may contribute to the ability of fetal wounds to regenerate without scar and explain the effect of exogenous TGF-beta1 to increase fibroplasia in fetal dermal incisional wounds.

Myofibroblast persistence in fetal sheep wounds is associated with scar formation

The scarless repair capabilities of the fetus are influenced by the size of the wound and the gestational age of the fetus. Whereas small wounds heal scarlessly, large wounds in the same fetus heal with scar. Myofibroblasts are specialized fibroblasts that express alpha-smooth muscle actin (alpha-SMA), a contractile cytoskeletal protein. The authors hypothesized that small fetal wounds that heal scarlessly will have a relative absence of myofibroblasts, whereas large wounds that heal with scar will have abundant myofibroblasts. In this study, an incisional wound and four punch biopsy wounds of 2, 4, 6, and 10 mm diameter were placed on the backs of 60- to 90-day-gestation fetal sheep (term, 145 days). Fourteen days after wounding, the healed fetal wounds were harvested, the repair morphology was determined (scarless, transitional repair, or scar), and the expression of alpha-SMA was analyzed by immunohistochemistry. In the second part of this study the authors analyzed the temporal expression of alpha-SMA in fetal wounds at 1, 2, 3, and 7 days after wounding in 70-day-gestation fetal sheep. In the 14-day wounds, the authors found that alpha-SMA was not expressed in any incisional or 2-mm wound that healed scarlessly, but it was expressed in all wounds that healed with scar. Overall, alpha-SMA expression strongly correlated with increasing wound size (P < .005). Myofibroblasts were seen as early as 24 hours after wounding, and at 3 and 7 days all wounds showed strong expression of alpha-SMA. These results demonstrate that although myofibroblasts are induced early in fetal wound repair, by 14 days there is a notable lack of myofibroblasts in wounds that heal scarlessly and an abundance of myofibroblasts in those wounds that scar. By determining the factors that regulate the disappearance of the myofibroblast in scarless fetal wounds, the authors hope to gain new insights into the mechanisms of scarless fetal repair.

Cystic lung lesions with systemic arterial blood supply: a hybrid of congenital cystic adenomatoid malformation and bronchopulmonary sequestration

Congenital cystic adenomatoid malformation and bronchopulmonary sequestration are congenital lung tumors that are classically described as having distinct embryology, pathology, and natural history. The authors treated six patients who had prenatally diagnosed lung masses that displayed clinicopathologic features of both lesion types. At prenatal diagnosis (19 to 30 weeks' gestation), all six lesions were classified sonographically as congenital cystic adenomatoid malformation, and none of the masses appeared to have a systemic arterial blood supply as seen by color flow Doppler study. Two of the six masses showed size regression antenatally. At the time of surgery, all six lesions had a systemic vessel directly from the aorta--five cases were consistent grossly with an intralobular bronchopulmonary sequestration, and one case was consistent with an extralobular bronchopulmonary sequestration. However, all six lesions displayed congenital cystic adenomatoid malformation histology. Hydrops developed in one fetus with a huge mass, and that fetus underwent successful fetal surgical resection (left lower lobectomy) at 22 weeks' gestation with delivery at 35 weeks' gestation. One neonate with a large extralobular bronchopulmonary sequestration was treated with resection and extracorporeal membrane oxygenation (ECMO) but died of pulmonary hypoplasia. Four other patients who had much smaller masses underwent elective lower lobectomy after birth. These findings emphasize the importance of seeking an anomalous blood supply in patients who have congenital lung lesions. These "hybrid" cases suggest a similar embryological origin for congenital cystic adenomatoid malformation and bronchopulmonary sequestration.

Left-sided congenital diaphragmatic hernia: value of prenatal MR imaging in preparation for fetal surgery

PURPOSE

To evaluate the usefulness of prenatal magnetic resonance (MR) imaging in determination of the position of the fetal liver and amount of lung tissue in left-sided congenital diaphragmatic hernia.

MATERIALS AND METHODS

In three pregnant women, MR imaging was performed with a 1.5-T magnet and fast gradient-echo, half-Fourier single-shot turbo spin-echo, and echo-planar sequences. MR imaging findings were compared with those from ultrasound (US) performed the same day. The fetuses were 20, 23, and 32 weeks gestational age.

RESULTS

The fetal liver was demonstrated in the chest in all three fetuses with MR imaging and in only one fetus with US. The best images of the fetal liver were obtained with a T1-weighted gradient-echo sequence. The best images of the entire fetus were obtained with a half-Fourier single-shot turbo spin-echo sequence.

CONCLUSION

In these fetuses, MR imaging proved important by clearly demonstrating herniation of fetal liver into the chest, thereby changing family counseling and prenatal care.

Early prenatal diagnosis of choledochal cyst

Unrecognized biliary tract obstruction due to choledochal cysts or biliary atresia can result in significant morbidity and mortality. Diagnosis in utero of choledochal cyst allows prompt postnatal diagnostic evaluation and appropriate surgical therapy to be instituted early in life. This may minimize the potential complications of cholangitis, cirrhosis, and liver failure in infants with choledochal cysts.

Effect of fetal serum on fibroblast pericellular matrix formation

Hyaluronic acid (HA)-dependent pericellular matrices (PCM) play a role in embryonic differentiation of mesodermal cells. Fetal fibroblasts have significantly larger PCMs than postnatal fibroblasts. To determine if this property is intrinsic to fetal fibroblasts or induced by factors in the fetal environment, we studied the effect of fetal bovine serum (FBS) of varying gestational age on human fetal, newborn, and adult fibroblast PCM formation. Cultured human fetal, newborn, and adult fibroblasts were plated in triplicate at a density of 1 x 10(5) cells and incubated in medium alone, medium containing 10% pooled FBS, or FBS from the first, second, or third trimesters. The cells were photographed and morphometric analysis of PCM was performed by the erythrocyte exclusion technique. PCM size was expressed as a ratio of the maximal width of the cell matrix to the maximal width of the cell. The unpaired Student's t test was used for statistical analysis. The earlier the gestational age of FBS used, the larger the PCM observed in fetal and newborn fibroblasts. The PCM of fetal fibroblasts was significantly larger (P < 0.001) than that of newborn and adult fibroblasts at each gestational age of FBS tested (fetal >> newborn > adult). Medium containing pooled FBS caused a significant (P < 0.001) increase in PCM size in all cell lines compared with serum-free medium. There are both intrinsic and extrinsic factors which affect PCM size. These factors which affect HA-dependent PCM size may contribute to a permissive microenvironment for cell migration, proliferation, and development which may be important for scarless fetal wound repair.

Desmoplastic small cell tumor: a report of three cases and a review of the literature

PURPOSE

Desmoplastic round cell tumor (DSCT) is a highly malignant abdominal tumor first described in 1991, with subsequent cases predominantly noted in pathologic case reports. The authors evaluated response to alternating, intensive chemotherapy in three patients with DSCT, and reviewed the clinical experience with this newly described tumor as reported in the literature.

PATIENTS AND METHODS

Three adolescent boys with DSCT were treated intravenously with vincristine 2 mg/m2, doxorubicin 75 mg/m2, cyclophosphamide 1.8 g/m2, alternating with 5-day cycles of etoposide 100 mg/m2/day, ifosfamide 1.8 g/m2/day for a total of 11-15 courses.

RESULTS

Each patient showed initial tumor regression during chemotherapy, but developed progressive disease within 8-18 months. One patient subsequently showed a transient response to doxorubicin 45 mg/m2 plus 5-fluorouracil 500-600 mg/m2. All three patients died of disease within 20 months of diagnosis. A comprehensive literature review of clinical data on 101 reported cases of DSCT is presented. The median age was 21 years (range 6-38 years) with 78 male patients and 23 female patients. Ninety-nine cases involved tumor mass in the abdominal-pelvic cavity in proximity to the mesentery. Metastatic seeding to the omentum was most common, followed by spread of disease to liver, distant lymph nodes, lung, and occasionally to scrotum or to ovary. Tumor response to chemotherapy was noted in approximately 50% of 40 patients who received combinations of doxorubicin, cisplatin, cyclophosphamide, etoposide, and/or 5-fluorouracil. Four of 13 patients who received additional radiotherapy were alive at 24-48 months. Median survival was 17 months (range: 3-72 months), with only two patients reported disease free beyond 2 years at 40 and 48 months.

CONCLUSION

DSCT should be included in the differential diagnosis of small round cell tumors in children and young adults. Tumor regression has been noted during multiagent chemotherapy, but prolonged survival is rare with current therapies.

Hyaluronic acid-dependent pericellular matrices in fetal fibroblasts: implication for scar-free wound repair

Fetal fibroblasts are intrinsically different from postnatal fibroblasts. We studied the differences in expression, size, and assembly of pericellular matrices in human fetal and postnatal fibroblasts, as well as the effect of fetal fibroblast-conditioned media as a source of migration stimulating factor on pericellular matrix formation. Fibroblasts in their fifth to fifteenth passages were cultured for 24 hours before analysis. Streptomyces hyaluronidase (0.1 U/ml), monoclonal mouse anti-human CD-44std, or anti-human CD-4 antibodies were added and incubated for 1 hour (at 4 degrees and 37 degrees C) before analysis of the pericellular matrices with the use of a particle exclusion technique. The pericellular matrix/cell body ratio of fetal fibroblasts was significantly larger than that of newborn (p < 0.002) and adult (p < 0.001) fibroblasts. Hyaluronidase disrupted the pericellular matrices in all three cell lines. Assembly of the pericellular matrices was blocked by anti-human CD-44std antibody but not by anti-human CD-4 antibody at both 4 degrees and 37 degrees C. Incubation of fibroblast cell lines in fetal fibroblast-conditioned media did not increase pericellular matrix/cell body ratio but did increase the percentage of fibroblasts expressing a detectable pericellular matrix in adult (p < 0.01), newborn (p < 0.001), and fetal (p < 0.005) fibroblasts. We conclude that fibroblasts produce hyaluronic acid-dependent pericellular matrices which require interaction with a hyaluronic acid-binding protein for assembly. Large pericellular matrices are one intrinsic factor characterizing a unique fetal fibroblast phenotype.

Minimal hydronephrosis in the fetus: clinical significance and implications for management

PURPOSE

We further define the natural history and management of minimal fetal hydronephrosis.

MATERIALS AND METHODS

Experience with minimal fetal hydronephrosis (renal pelvic diameter 4 to 10 mm. before 20 weeks of gestation and 5 to 10 mm. from 20 to 24 weeks) was reviewed for 18 months at New England Medical Center.

RESULTS

The incidence of minimal fetal hydronephrosis was 2.2% in the 5,900 fetuses screened by ultrasound. In 63% of cases prenatal ultrasound was done more than once, and revealed that dilatation of the urinary tract was stable during gestation in 31 (25%), and became normal in 35 (29%) and worse in 11 (9%). A total of 63 patients (103 renal units) followed for up to 1 year underwent postnatal sonography. Those with abnormalities were screened with a voiding cystourethrogram and renal scan, including 40 with normal postnatal ultrasound and no changes on subsequent evaluation. Of the 23 patients with abnormal findings 4 had functionally significant ureteropelvic junction obstruction and 1 had severe vesicoureteral reflux. A retrospective analysis of the sonograms of patients with minimal fetal hydronephrosis and persistence or progression of hydronephrosis revealed calicectasis, progression of minimal fetal hydronephrosis in utero and/or abnormal renal echogenicity in each fetus.

CONCLUSIONS

Our study shows that in a small but significant number of fetuses minimal fetal hydronephrosis will progress, whereas in most it will resolve.