Significance and outcome of left heart hypoplasia in fetal congenital diaphragmatic hernia.

OBJECTIVE: In patients with a left-sided congenital diaphragmatic hernia (CDH), the left ventricle (LV) is often compressed and smaller than normal. The objective of this study was to investigate whether small left heart dimensions prenatally normalize after birth in patients with CDH, or whether prenatal indices of left heart size and flow predict postnatal outcome. METHODS: Clinical and echocardiographic data were reviewed for patients diagnosed with left-sided CDH prenatally. Cardiac dimensions and flows were compared with normative data. Among liveborn patients, pre- and postnatal Z-scores of left heart structures were compared, and associations between prenatal indices and outcome were assessed. RESULTS: Of 125 patients diagnosed prenatally with CDH, 111 had a left-sided defect. Of these, 85 were liveborn, including 20 with congenital heart disease. Gestational age-adjusted dimensions of fetal left heart structures, including aortic valve diameter, mitral valve (MV) diameter, LV long-axis, LV short-axis and LV volume, were all smaller than normal (P < 0.001). On average, the LV contributed 33 +/- 8% of combined ventricular output, lower than the normal 40-50%. Z-scores of left heart structures increased from the prenatal echocardiogram to the postnatal study, with average changes ranging from 0.56 +/- 1.68 (aortic valve) to 1.39 +/- 1.85 (LV volume). Among liveborn patients, there was no association between prenatal left heart Z-scores and postnatal survival. CONCLUSIONS: Hypoplasia of and reduced flow through the left heart are common among fetuses with CDH. After birth and CDH repair, left heart dimensions generally normalize, with adequate size to support a biventricular circulation, even when there is very low flow through the left heart in mid- and late-gestation.

Prune belly syndrome.

Prune belly is a lax, wrinkled abdominal wall and frequently is associated with other anomalies. The prune belly syndrome is a specific constellation of anomalies consisting of an abdominal wall deficient in muscular tissue, dilated urinary tract, and bilateral cryptorchidism. This group of anomalies is also called the Eagle-Barrett syndrome and the triad syndrome. In about 3 of 4 patients with the prune belly syndrome, there are associated malformations of the cardiopulmonary, gastrointestinal, and orthopedic systems.

Initial studies of holmium:YAG laser creation of spinal defects in fetal rabbits: model for urologic effects of myelomeningocele.

Myelomeningocele (MMC) is characterized by paraplegia and incontinence, often necessitating surgery. Current models of MMC in sheep and primates create a spinal defect long after anomalous neural tube closure ordinarily occurs. An ideal model of MMC would allow creation of the defect at the earliest age in a low-cost species with a short gestation. We present a method utilizing the holmium laser to create spinal defects in rabbits in utero for the study of the pathophysiology and repair of MMC. Pregnant rabbits of 22 to 23 days' gestational age were prepared and draped in sterile fashion for laparotomy under general anesthesia. The abdomen was opened, and both uterine horns were inspected. Double opposing pursestring sutures were placed to secure the chorioamniotic membranes over the fetal lumbar spine. Amniotic fluid was removed with a needle and saved. Electrocautery was used to open the uterus within the pursestring suture, exposing the fetal dorsum. The spine was exposed by laser dissection of the fetal dorsal musculature. Posterior laminectomy was accomplished with laser incisions of each side of the spinous process, leaving the underlying dura and cord exposed. The pursestring was then cinched, amniotic fluid was returned, and the uterus and trocar sites were closed. Cesarian section was performed at 30 to 31 gestational days, and the pups were examined and then humanely sacrificed for histologic evaluation of the lesion. The rabbit is an inexpensive species with a short gestation (33-35 days), and four or more fetuses may be operated on per litter, with the remainder serving as controls. Utilization of minimally invasive techniques including holmium:YAG laser dissection facilitates creation of spinal defects at an early age in this small-animal model.

Fetal fracture healing in a lamb model.

A large animal model to assess fetal fracture repair and the ability to close excisional bony defects is presented. Incisional and excisional ulnar fractures were made in 14 midgestation fetal lambs, harvested at serial time points, and subjected to high-resolution low-kilovolt magnification radiographs, magnetic resonance imaging scans, and histologic analysis. Fetal fracture healing was characterized by early closure of excisional defects and rapid fracture healing with minimal or no soft-tissue inflammation or callus formation. Magnetic resonance imaging scans of the fractures revealed a characteristic pattern compatible with the histologic findings, namely, minimal inflammation in soft tissue adjacent to the fracture site. Histologic and magnification radiographic findings indicated that complete bony repair occurred within 21 days in incisional defects and within 40 days in excisional defects. In both cases, healed fetal bone resembled normal bone matrix. Excisional defects, including periosteum, of greater than three times the width of the bony cortex closed rapidly with virtually normal-appearing bony matrix and with minimal or no callus formation.

Successful treatment of liver hemorrhage in the premature infant.

Intraoperative neonatal liver hemorrhage usually results in exsanguination and death. The parenchyma of a neonatal liver is fragile, and the capsule is very thin, unlike that in the pediatric and adult patient. This renders the treatment of a neonatal liver fracture almost universally unsuccessful. The current report describes two cases of successful management of intraoperative neonatal liver hemorrhage during surgery for necrotizing enterocolitis (NEC).

One-stage correction of high imperforate anus in the male neonate.

PURPOSE: The aim of this study was to examine the feasibility, safety, and short-term outcome of complete one-stage repair of high imperforate anus in the newborn boy. METHODS: A retrospective review was conducted of five full-term male infants who underwent posterior sagittal anorectoplasty without a colostomy within the first 48 hours of birth. Preoperative imaging was performed to assess associated anomalies. All infants underwent cystoscopy before the perineal operation to determine the level of the urinary tract fistula, if present. After completion of the anoplasty, all were turned supine and the colon irrigated free of meconium. Follow-up ranged from 10 to 24 months. RESULTS: Laparotomy was not required for any patient. Three patients had a rectoprostatic urethral fistula, one a rectovesical fistula, and one no fistula (common wall at level of prostate). Tapering rectoplasty was required for only the one patient with a rectovesical fistula. There were no intraoperative complications. All patients passed stool within 12 hours after operation and took full feeding by 48 hours. The average hospital stay was 7 days. Postoperative and stenosis occurred in one patient secondary to parental noncompliance with the postoperative dilation regimen. There were no perineal wound complications. All patients have a strong urinary stream and defecate spontaneously without the aid of oral medication or rectal stimulation or enemas. CONCLUSIONS: One-stage repair of high imperforate anus in the male neonate is feasible without short-term genitourinary or gastrointestinal morbidity. Whether it is preferable compared with a delayed (two or three stage) repair depends on ultimate long-term anorectal function, which cannot be assessed for several years.

Transabdominal oxygenation using perfluorocarbons.

PURPOSE: Evaluation of the intraabdominal (intraperitoneal and intraluminal) administration of oxygen-saturated perfluorocarbon on both portal and arterial blood oxygenation. METHODS: Eight male rabbits were divided into the test (n = 5) and control (n = 3) groups. Each underwent intrajejunal, intraperitoneal, and intravascular (artery, portal vein) catheter placements along with ligation of the duodenum and the terminal ileum under general anesthesia. The test group received oxygen-saturated perfluorotripropylamine (FTPA), and the control group received oxygen desaturated FTPA. The oxygen delivery was assessed by serial blood gas measurements before and after the administration of FTPA. RESULTS: The administration of oxygen-saturated FTPA significantly increased the partial pressure of oxygen within both the arterial and the portal venous blood (PaO2, PpVO2) without significant changes in PCO2 values. Oxygen desaturated FTPA failed to show any effects on blood gas values. Compared with oxygen desaturated FTPA, oxygen-saturated FTPA increased PaO2, PpVO2, and oxygen saturation (artery, portal vein) significantly at some, but not all of the time-points measured. CONCLUSIONS: The intraabdominal administration of saturated FTPA improved both the portal venous and the arterial oxygenation. This new mode of oxygenation may be helpful as an adjunct to conventional oxygen delivery systems.

Successful fetal sacrococcygeal teratoma resection in a hydropic fetus.

BACKGROUND/PURPOSE: The development of hydrops in a fetus with a sacroccocygeal teratoma (SCT) usually is a predictor of fetal demise; in utero resection may offer the only chance of survival. Although the authors had performed this procedure in 3 previous cases, they had no long-term patient survival. The authors report a successful case of in utero resection of a fetal sacrococcygeal teratoma. METHODS: The authors resected a fetal SCT from a 23-weeks-gestation hydropic fetus, using gradually tightening umbilical tapes at the tumor base, electrocautery, and careful sharp dissection. After a blood transfusion, the fetus suffered cardiac arrest but was resuscitated and returned to the uterus. RESULTS: Postoperatively, residual SCT growth ceased, and hydrops rapidly resolved. Five weeks after the procedure, the infant was delivered because of preterm labor, and, after resection of residual SCT, was discharged home at 3 months of age. She is now a healthy 3 year old. CONCLUSION: This case shows that successful fetal SCT resection and long-term patient survival is possible.

Fetal neuroblastoma: prenatal diagnosis and natural history.

Obstetrical sonography has helped diagnose and define the features of some congenital malformations and tumors. We present five fetal neuroblastomas detected by routine prenatal sonography. All were adrenal tumors diagnosed between 26 and 39 weeks gestation. All 5 tumors were completely resected postnatally and the patients have remained disease free from 2 months to 10 years after resection without adjuvant therapy. A literature review collated 16 other cases of fetal neuroblastoma detected by sonography between 29 and 38 weeks gestation. These cases included 1 cervical, 1 thoracic, and 14 adrenal tumors. Thirteen neonates had Evans stage I or II tumors, and three had more advanced disease. Eleven mothers did not have hypertension or preeclampsia during the pregnancy, and the neonates all had stage I or II disease. Four mothers had hypertension or preeclampsia. Three of these neonates had stage IV or IVS disease with liver metastases, and all three had fetal hydrops. Review of the congenital neuroblastoma literature documented 71 cases diagnosed soon after birth, and several of these cases had unusual features that could have been detected by prenatal ultrasound. Four of the tumors were so large that dystocia resulted and fetal dismemberment was required for delivery. Eight of the tumors metastasized to the placenta, and 1 metastasized to the umbilical cord with subsequent fetal death. We conclude that fetal neuroblastoma can be diagnosed by prenatal sonography. Accurate staging is difficult by sonography, but in mothers with no preeclampsia symptoms the chance of widely disseminated disease is small.(ABSTRACT TRUNCATED AT 250 WORDS)

The CDH two-step: a dance of necessity.

Repair of fetal diaphragmatic hernia has proven technically difficult especially when the left lobe of the fetal liver is incarcerated in the chest. A step-wise approach from both above and below the diaphragm solves several frustrating technical problems.

Anterior cervical approach for repair of laryngotracheoesophageal cleft.

Laryngotracheoesophageal cleft is a very rare congenital malformation characterized by a long midline communication between the esophagus and trachea extending from the larynx down the trachea for a variable distance. The most common repair strategy involves separation of the trachea and esophagus by a lateral approach via both a thoracotomy and a neck incision. The authors report a case of complete repair (without thoracotomy) via a neck incision through the anterior wall of the trachea.

A strategy for primary reconstruction of long gap esophageal atresia using neonatal colon esophagoplasty: a case report.

Treatment options for long gap esophageal atresia without tracheoesophageal fistula generally require several stages over many months. An early neonatal vascularized conduit would allow a tension-free anastomosis, but the precarious blood supply of the neonatal bowel makes mobilization and immediate interposition hazardous. This report describes the successful application of a strategy for primary reconstruction in the neonate using a short piece of colon mobilized into the mediastinum for subsequent delayed anastomosis.

Perineal one-stage pull-through for Hirschsprung's disease.

PURPOSE: The aim of this study was to present the strategy of a one-stage repair of Hirschsprung's Disease (HD) performed via a transanal approach. METHODS: Ten consecutive neonates and one toddler underwent transanal repair for biopsy-proven HD. A rectosigmoid transition zone was suggested by contrast enema in all patients. The mean age at operation for the neonates was 4 days. A mucosal dissection was begun 0.5 cm proximal to the dentate line. Once the correct plane was established, up to 15 cm of bowel can be resected without ligating vessels or performing a transabdominal dissection. The proximal extent of dissection was delineated by the presence of ganglion cells seen on frozen section analysis. RESULTS: The mean operating time was 105 minutes. There were no intraoperative or postoperative complications. All children had the presence of ganglion cells confirmed postoperatively on permanent sections. The mean hospital stay was 2 days. All children averaged three to six bowel movements per day without oral or enema therapy. CONCLUSIONS: The perineal one-stage operative pull-through (POOP) procedure for Hirschsprung's disease is a quick and easy adaptation of a well-described technique of transanal mucosectomy. Long-term follow-up will be required to determine whether bowel function is better that that seen after traditional staged repairs.

Slide tracheoplasty for congenital tracheal stenosis: a case report.

BACKGROUND/PURPOSE: A variety of techniques have been used to manage pediatric congenital tracheal stenosis. The authors report the technique of slide tracheoplasty for a child with long congenital tracheal stenosis. METHODS: A 2-year-old male presented with a history of stridor with feeding. Bronchoscopy findings showed 50% stenosis from complete cartilaginous rings, extending from 2.5 cm below the vocal cords to 2 cm above the carina. Through a neck incision, the trachea was exposed from the cricoid to both bronchi and transected at the midpoint of the stenosis. The upper trachea was split anteriorly to the area of stenosis just below the cricoid. The lower trachea was split posteriorly in the midline. Posterior dissection allowed sliding and anastomosis of both tracheal segments while the lateral vascular supply was left intact. A brace was placed to maintain cervical flexion, and the patient underwent extubation in the operating room. RESULTS: He recovered without complication and was dis charged on postoperative day 4. CONCLUSION: Slide tracheoplasty offers several advantages for tracheal reconstruction because it is performed with the native tracheal tissues, can be accomplished through a transverse collar incision, and can repair long stenoses without significant tracheal shortening.

Prospective analysis of lung-to-head ratio predicts survival for patients with prenatally diagnosed congenital diaphragmatic hernia.

BACKGROUND: Accurate prenatal prediction of outcome for fetuses who have congenital diaphragmatic hernia (CDH) is very difficult. The authors previously reported a retrospective analysis of risk factors for fetal CDH and proposed a new index of severity: the lung-to-head ratio (LHR). The authors now report a prospective study to test whether this new index predicts neonatal outcome. METHODS: Fifteen patients who had left-sided CDH were sonographically evaluated at the University of California, San Francisco (UCSF) and followed prenatally and postnatally. LHR was measured at 24 to 26 weeks' gestation. Outcome variables included survival and the need for extracorporeal membrane oxygenation (ECMO). RESULTS: Overall survival was 47%. LHR ranged from 0.62 to 1.86. No patient with an LHR of less than 1.0 (n = 3) survived despite ECMO, whereas all patients with an LHR greater than 1.4 survived (n = 4), one requiring ECMO. LHR values between 1.0 to 1.4 were associated with 38% survival (n = 8), 75% requiring ECMO. Overall, survivors had a mean LHR of 1.4 +/- 0.33 and nonsurvivors, 1.05 +/- 0.3 (P < .05). CONCLUSION: The LHR is a useful index to help predict neonatal outcome in patients who have left-sided CDH.

Ontogeny of fetal sheep polymorphonuclear leukocyte phagocytosis.

Premature infants and neonates are vulnerable to bacterial sepsis. This susceptibility may be due to the relative immaturity of their immune systems. To determine if neonates and, in particular, premature infants have decreased polymorphonuclear leukocyte (PMN) phagocytosis, we tested PMN phagocytosis of Staphylococcus aureus as a function of gestational age in the fetal lamb model. Because phagocytosis is made more efficient by the presence of opsonins in plasma, fetal and postnatal PMN phagocytosis were also measured after exposure to fetal and adult plasma. PMNs were isolated from fetal lambs at 104, 114, 124, and 141 days' gestation (term gestation for the fetal lamb is 145 days), as well as from 10-day-old neonatal sheep and adult sheep. Labeled S aureus were opsonized by incubation in either fetal or adult plasma, or left unopsonized for baseline values. Phagocytosis was measured as a percent of adult PMN phagocytosis after adult plasma opsonization. It was found that fetal PMN function is limited by two factors during the early third trimester: a primary defect in the ability of the PMN to phagocytose S aureus despite adequate opsonization, and the diminished ability of autologous fetal plasma to opsonize bacteria. The defect in PMN phagocytosis disappears late in the third trimester, but the inability of the fetal plasma to opsonize effectively continues until after birth.

Midgestational excisional fetal lamb wounds contract in utero.

Clinical observations and experimental data suggest that fetal wound healing is very different from adult wound healing. An understanding of the biology of scarless fetal wound healing has tremendous clinical potential for modulating postnatal wound problems. In this study, the fetal lamb model was used to assess excisional fetal skin wound contraction in utero. Full-thickness 9-mm punch biopsy wounds were created on fetal lambs at 100 days' gestation (term, 145 days). Half of the wounds remained exposed to amniotic fluid, whereas the other half were covered by a silastic patch to exclude amniotic fluid. Wounds were harvested 3, 7, or 14 days later and wound areas were calculated. Exposure to amniotic fluid retarded wound contraction significantly at 3 days, but by 14 days all wounds had completely contracted and reepithelialized. Myofibroblasts are an important cellular element of wound contraction. The presence of wound myofibroblasts was documented by both transmission electronmicroscopy and immunocytochemistry with antimuscle actin antibody. It is concluded that fetal lamb wounds contract in utero and exposure to amniotic fluid appears to retard fetal skin wound contraction only during the early healing process.

Adult-to-neonate lung transplantation: anatomic considerations.

Babies born with severe pulmonary hypoplasia are unsalvageable despite maximal therapy including extracorporeal membrane oxygenation (ECMO). Using ECMO as a bridge to transplantation, reduced-size lung grafts (pulmonary lobe or segment) could expand the pool of cadaver donors and may allow for HLA-matched living-related transplants. We tested this concept first in the piglet model and developed the technical maneuvers necessary to perform lobar and segmental lung transplants from adult pigs into neonatal piglets. Prior to clinical application, a systematic evaluation of anatomic considerations for reduced-size human lung transplantation was needed. A series of human adult and neonatal cadaver thoracic dissections were performed to determine the adult pulmonary lobe or segment with the proper size, orientation, and vascular and bronchial anatomy for use as a neonatal lung transplant. The adult right middle lobe (RML) is the best candidate for neonatal left lung replacement. The adult RML, once removed, can be rotated 180 degrees around its superior-inferior axis and the vessels and bronchus align well in the left chest of the neonate. The RML may require further reduction to fit into the neonatal left chest. Selective arterial perfusion of the RML showed the anterior segment to be a near-perfect match for fit and anatomy. This technique may eventually permit living-related lung transplantation.

New techniques in fetal surgery.

Optimal fetal management during and after fetal surgery has been limited by an inability to reliably monitor the fetal heart rate and temperature, and by a lack of access to the fetal circulation. In order to solve these problems, we used early third trimester fetal sheep to develop: (1) an implantable radiotelemetry device that transmits the fetal electrocardiogram and temperature, and (2) an intraosseous access technique. A miniaturized radiotelemeter was implanted subcutaneously in the axilla of four fetal sheep. Safe implantation of the radiotelemeter was technically feasible and the device reliably recorded the fetal electrocardiogram and temperature both intraoperatively and postoperatively. Although many possible routes for access to the fetal circulation have been tried experimentally and clinically for both resuscitation and blood sampling, none have proven satisfactory. We assessed the use of intraosseous access in fetal sheep (n = 6) for both infusion and blood sampling. Access with an intraosseous needle was obtained in both sheep fetuses and human fetal cadavers. Blood gas values (pH, PCO2, and PO2) obtained from the medullary cavity of fetal sheep accurately reflected peripheral venous values. Resuscitation drugs reached the fetal circulation via the intraosseous route: sodium bicarbonate elevated venous bicarbonate levels from 28.4 +/- 1.7 to 31.8 +/- 2.1 mEq/dL (P < .05); injected glucose increased venous glucose levels by 520 +/- 108 mg/dL (P < .01); and injection of calcium chloride elevated venous calcium levels from 11.8 +/- 0.7 to 15.2 +/- 2.2 mEq/dL (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Vascular changes with in utero correction of diaphragmatic hernia.

In utero surgical correction of fetal diaphragmatic hernia is a new therapeutic alternative for selected prenatally diagnosed patients. With increasing experience, the authors have found that fetuses with herniation of the liver through the diaphragmatic defect have a high incidence of perioperative death. The hypothesis was that reduction of the liver during fetal diaphragmatic hernia repair caused distortion of fetal vascular anatomy resulting in fetal demise. To study this, the authors performed angiograms through the umbilical vein in fetal and neonatal cadavers, with and without diaphragmatic hernias, and simulated in utero repair. Large fetal congenital diaphragmatic hernias can be associated with dramatic changes in the vascular anatomy of the liver. The liver does not simply rotate up into the chest through a diaphragmatic defect; instead, the liver more likely develops in the chest, with its vascular anatomy situated accordingly. Attempts to reduce a herniated liver can result in significant distortion of the fetal vasculature, leading to fetal death. Techniques to prevent vascular compromise during hepatic manipulation may improve the outcome for fetuses during in utero repair of diaphragmatic hernias.