Joy L Graf

Operating on placental support: The ex utero intrapartum treatment procedure

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

The Antegrade Continence Enema Procedure: A Review of the Literature

Since the antegrade continence enema (ACE) was first described in 1990 for fecal incontinence, more than 100 cases have been reported in the literature. This report reviews the indications, operative modifications, outcome, and complications of the procedure.

Fetal Sacrococcygeal Teratoma

Advances in prenatal diagnosis including improvements in ultrasonography have revealed the natural history of fetal sacrococcygeal teratomas, and this natural history differs substantially from that for postnatally diagnosed sacrococcygeal teratoma. A fetal sacrococcygeal teratoma may lead to perinatal morbidity and mortality by a variety of mechanisms. Adverse clinical sequelae of a sacrococcygeal teratoma can be prevented by accurate prenatal assessment and appropriate obstetrical and perinatal management. Development of fetal hydrops and/or placentomegaly predicts fetal demise. Fetal surgical intervention has proven successful in highly selected cases.

A surprising histological evolution of preterm sacrococcygeal teratoma

In fetuses with sacrococcygeal teratomas (SCT), the development of hydrops is a harbinger of imminent fetal demise. In such instances, tumor debulking, either at fetal surgery or postnatally after urgent cesarean section, may prove lifesaving. Definitive SCT resection is carried out in the newborn period when the infant has stabilized. In five such patients, retrospective comparison of the SCT histological findings from the initial debulking procedure and later definitive resection or, in one case, autopsy results, showed a surprising change. After the initial debulking procedure, SCT histology findings from three patients were grade 3 immature teratoma without malignant elements, and in two patients grade 3 immature teratoma with nests of malignant yolk sac elements. In the three patients having grade 3 immature tumor without malignant elements, histological examination after definitive resection (two cases) and autopsy (one case) showed only fibrosis; there was no evidence of the SCT despite the fact that residual tumor had clearly been left at the initial debulking. In the patients in whom the initial histology finding was grade 3 immature with malignant elements, SCT histology results from the definitive resection showed grade 3 immature teratoma without malignancy in one case, and mature, benign tissue in the other. Preterm SCT debulking may induce tumor maturation or, alternatively, maturation of SCT that occurs naturally during gestation may be observed.

Creation of Myelomeningocele in the Fetal Rabbit

Objective: Myelomeningocele is a neural tube defect resulting in an exposed spinal cord, which leads to irreversible neurologic damage at birth. We proposed development of a fetal rabbit model of myelomeningocele to study in utero spinal cord injury and repair strategies. Methods: New Zealand white rabbits (n = 10) at 22 days of gestation (term = 31 days) underwent laparotomy to expose the gravid uterus; a hysterotomy exposed the fetal hindlimbs and back. A three to four level lumbar laminectomy was performed, and the dura over the posterior spinal cord was removed. At 30 days of gestation, the does underwent C-section for fetal harvest, and total fetal number, length, weight, and the presence or absence of a spinal defect were recorded for all viable fetuses. Results: All injured fetuses were smaller and weighed less than the nonoperated littermate controls, and histologic examination confirmed a spina bifida-like lesion of their spinal cords. Conclusions: We successfully created an exposed spinal cord defect in the fetal rabbit model similar to the lesion found in humans. Advantageous because of low animal cost, relatively large fetal size, multiple fetuses per pregnancy, and short total gestation, this model will allow us to study the mechanism of injury to the exposed spinal cord, and perhaps develop strategies to repair human myelomeningoceles.

Gastroschisis increases small bowel nitric oxide synthase activity

In gastroschisis, the eviscerated fetal bowel frequently is damaged and this results in hypoperistalsis and malabsorption. The mechanistic link that ties gastroschisis-induced intestinal damage to dysfunction may be nitric oxide (NO) and the enzyme responsible for producing it, NO synthase. Using a fetal rabbit model, the authors investigated the hypothesis that the hypoperistalsis and malabsorption associated with gastroschisis may be attributable to abnormal small bowel NO synthase activity. Using the 3H-arginine-to-3H-citrulline conversion assay, they measured NO synthase activity in the small bowel of full-term fetal rabbits with and without gastroschisis. The mean total small bowel NO synthase activity of fetal rabbits with gastroschisis was 2.5 times greater than that of control littermates without gastroschisis (n = 6; 5,726 +/- 834 v 2,208 +/- 537 mean pmol/mg protein/min; P = .004). This increased NO synthase activity also was studied by measuring the individual isoforms of NO synthase, and the site of increased NO synthase activity was localized to the small bowel epithelium and neurons. After detecting and localizing the gastroschisis-induced increase in NO synthase activity, the authors explored the mechanism of this increase using NADPH-diaphorase staining. With this histological staining technique, no quantitative increase was found in the small bowel NO synthase of the rabbits with gastroschisis. This suggests that the increased NO synthase activity found in these rabbits is the result of accelerated enzyme kinetics. These findings suggest that the increased NO synthase activity caused by gastroschisis may contribute to the common clinical sequelae of malabsorption and intestinal dysmotility.

Nitroglycerin attenuates the bowel damage of necrotizing enterocolitis in a rabbit model.

Endogenous enteric nitric oxide has multiple functions. Enteric nitric oxide may be diminished in the premature infant and may therefore predispose the immature intestine to injury. The aim of this study was to determine if the infusion of a nitric oxide donor (nitroglycerin) would attenuate intestinal damage in a rabbit model of necrotizing enterocolitis. Transmural injection of rabbit intestinal loops with an acidified solution of casein and calcium gluconate simulates certain aspects of necrotizing enterocolitis. After injection of acidified casein solution into rabbit intestinal loops, twelve rabbits were randomly divided into two groups: six received maintenance fluids only and six received maintenance fluids and a nitroglycerin infusion adjusted to maintain mean arterial pressure 10 mm Hg below baseline (range, 2 to 12 micrograms/kg/min). After 3 hours, the rabbits were killed, and the intestinal tissue graded histologically. Intestinal damage in the nitroglycerin-treated rabbits was significantly less than that of untreated controls (mean histological grade of 0.39 v 1.48, P < .001). In this rabbit model of necrotizing enterocolitis, infusion of the nitric oxide donor nitroglycerin significantly attenuates intestinal damage. We speculate that enteric nitric oxide deficiency, as may exist in the preterm infant, predisposes the intestine to necrotizing enterocolitis.

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).

Neurodevelopmental outcome after open fetal surgery

PURPOSE This study examined the neurological and age-appropriate developmental outcomes of 11 children who underwent open fetal surgery. RESULTS Nine children have normal neurological outcomes, and nine have normal development. CONCLUSION Intensive postnatal care, intracranial hemorrhage, and requirement for prolonged respiratory support were associated with a worse neurological and developmental prognosis.

Complication Avoidance in Miniature Access Pyloromyotomy

Miniature access pyloromyotomy is a well-established procedure for the management of infants with pyloric stenosis. Several studies comparing the miniature access and open approaches have found that the incidence of complications is similar in both. It appears that the miniature access approach offers potential benefits such as superior cosmetic results, earlier feeding, and a shorter hospital stay. We describe our complications and complication avoidance techniques for this procedure. A 2-year period was selected for the study, and 160 infants undergoing miniature access pyloromyotomy at two centers were analyzed. Complications occurred in 7 (4.38%) of the 160 cases: 2 duodenal perforations (1.25%), 2 incomplete myotomies (1.25%), 1 omental evisceration (0.62%), and 2 umbilical wound infections (1.25%). The following measures were taken to prevent complications: avoiding the umbilicus if epithelialization was inadequate, using low flow and moderate pressure carbon dioxide insufflation, careful grasp of t...