Janet L. Meller

Surgical and genetic aspects of persistent müllerian duct syndrome

Persistent müllerian duct syndrome (PMDS) is characterized by the presence of a uterus, cervix, and fallopian tubes in an otherwise normally differentiated 46.XY male. During embryogenesis, regression of müllerian structures in normal males is mediated by antimüllerian hormone (AMH), also called müllerian inhibiting substance (MIS), produced by fetal Sertolis cells. PMDS has been attributed to deficient AMH activity or to abnormalities in the AMH receptor. The authors report on two patients with PMDS in whom the abnormalities were discovered during surgery for inguinal hernia and cryptorchidism. During the initial operations in each case, testicular biopsies were obtained, and the gonads and müllerian elements were replaced in the pelvis. A second operative procedure, performed several months later, included proximal salpingectomies with dissection of the vasa deferentia on pedicles of myometrium. This permitted excision of the vestigial uterine corpus, leaving a tiny remnant of cervix with the vasa deferentia. The testes were further mobilized so that bilateral orchidopexies could be completed. In the first case, a molecular abnormality was present at position 377 of the first exon of the AMH gene. Thymine replaced cytosine, which altered a CGG arginine codon to a TGG tryptophan codon, rendering the AMH molecule unstable. The molecular abnormality in the first case differs from the first abnormality in AMH reported by Knebelmann et al, thus indicating heterogeneity in this condition. The molecular basis for deficient AMH activity in the second patient has not yet been defined. No molecular abnormalities were found in the exons of this patients AMH gene.

Penetrating zone-II neck injuries in children

Over a 4-year period, 1,237 children under 16 years of age were managed at our level-I pediatric trauma center, of which 24 (1.9%) had zone-II penetrating neck injuries. Six of these 24 children (25%) were explored surgically with positive findings in four and negative findings in two neck explorations; five children (21%) underwent radiologic or endoscopic studies and were observed; 13 (54%) were observed only and did not require studies or exploration. Nonoperative observation of penetrating zone-II neck injuries is safe and the procedure of choice if active observation can be performed and the facilities for immediate operative intervention are available.

A variant of the split notochord syndrome

Split notochord syndrome has been described in several previous case reports; however, we recently treated a patient with a previously undescribed variant of this syndrome. A 2.5-g baby girl was admitted to the neonatal intensive care unit with a skin-covered mass on the back, and a portion of intestine, with meconium being passed, attached to it. The legs were equino varus, and the anus was anteriorly displaced. Radiographs were consistent with a lumbar split notochord, and the patient was taken to the operating room for closure. During surgery, the skin-covered mass was opened and found to contain loops of small intestine leading to an intussuscepted cecum and an open ended duplication of the cecum attached to the end of the spinal cord. The small intestinal loops exited the abdomen from a peritoneal-lined opening to the back. The loops were returned to the abdomen after releasing the duplication from the cord. The peritoneal connection was closed with a purse string suture, and the abdomen was opened. The duplication of the cecum was partially amputated and the rest was used to create a chimney-type stoma. The intraabdominal exploration was significant for nonrotation as well as a normal rectum. The postoperative course was uneventful. This case is unique because most cases of split notochord only involve a fistula to the rectum. In this case, a major part of the small bowel had herniated. Moreover, there was an open duplication similar to that found in extrophy. In approaching such a situation, it is also important to have the neurosurgeon available to provide adequate closure of the back similar to a myelomeningocele.

Ideal treatment for total colonic Hirschsprung's disease*

Five children were treated for total colonic Hirschsprungs disease between 1982 and 1986. Three girls and two boys underwent total colectomy and straight ileoanal endorectal pull-through, with creation of a suprapelvic side-to-side anastomosis of 10 cm of cecum and ascending colon to ileum (Boley procedure). All patients have been followed for periods of greater than 1 year, and they have been free of any postoperative complication. Stool frequency on an unrestricted diet has been between one and five semiformed per day. Their growth and development have been excellent. An advantage of this procedure is excellent water absorption without the risks of mechanical problems encountered with a variety of pelvic pouch creations in the young growing child.

Arteriography in the Evaluation of Penetrating Pediatric Extremity Injuries

The routine use of arteriography for evaluating penetrating extremity injuries is undergoing reevaluation in the adult literature. Its role in children is less clear. Eighty-seven children treated for penetrating extremity trauma over a 5-year period were studied retrospectively to define the usefulness of arteriography. The ages ranged from 2 to 16 years. Twenty-four arteriograms were performed. Twelve were for patients who exhibited physical signs of vascular injury (diminished pulse, distal ischemia, expanding hematoma, or bruits/thrills over the wound). The other 12 were performed on asymptomatic children with wounds in proximity to major vessels. Two other patients with ongoing hemorrhage were taken directly to the operating room. Of the 12 arteriograms performed for abnormal physical signs, eight (67%) showed vascular injuries. None of the studies performed for proximity alone had abnormal results (P < .01). Ten of 10 patients with vascular injuries had abnormal physical findings, whereas only four of 77 patients without vascular injuries had abnormal findings (sensitivity 100%, specificity 95%). Eighty-five percent of patients have had follow-up in the pediatric surgery clinic, and no missed injuries or complications have been discovered. Timely diagnosis and repair is the cornerstone for successful management of vascular injuries. While the arteriogram is an important adjunct in patients who have abnormal physical findings, proximity to major vessels alone fails to identify patients at risk for significant injuries. Angiography may not be warranted in patients whose physical examination results are normal. Noninvasive modalities such as B-mode ultrasound and Doppler may have future application in the evaluation of these cases.

Bile Flow and Composition in Preterm, Term and Infant Baboons

UNLABELLED We studied the maturational changes in bile composition, bile flow and choleretic effects of sodium taurocholate and secretin in preterm (160 +/- 2 days, n = 4, group I), term (184 +/- 2 days, n = 4, group II), 7-day postnatal age (n = 5, group III) and 60-day-old (n = 5, group IV) baboons. The canalicular bile flow was determined by 14C-erythritol clearance. RESULTS Gall bladder volume increased from group I to group III (0.08 +/- 0.06 to 1.06 +/- 0.93 ml). Bile flow increased significantly from group I to IV (0.13 +/- 0.05 to 0.34 +/- 0.07 microliter/min/g liver weight, p < 0.05). This was associated with significant increases in total bile acid excretion (16 +/- 3.6 to 31 +/- 2.5 mEq/l, p < 0.05). The composition of bile also showed maturational changes with increasing postnatal age. Sodium taurocholate and secretin increased the bile flow significantly in all groups. CONCLUSION Data from these studies clearly demonstrate that the bile flow and bile acid excretion is immature in preterm and term baboons when compared to 7- and 60-day-old baboons. The present studies also suggest that baboons can be used as a model to study the postnatal maturation of hepatic excretory function.

Transduodenal feedings: A superior route of enteral nutrition*†

Our recent study comparing gastric with jejunal feedings in neonatal piglets demonstrated better weight gain, less diarrhea, and less fat malabsorption in animals fed gastrically. These differences were postulated to be due either to loss of duodenal osmoregulation and absorption, and/or to loss of the combined effects of salivary enzymes, gastric emptying, and gastric secretions on jejunal feedings. The objective of this investigation was to determine the relative contributions of gastric and duodenal function to the differences between gastric and jejunal feedings. Seven piglets (3 to 5 days old, 1.5 to 2.0 kg) underwent operative transgastric insertion of a duodenostomy tube placed just distal to the pylorus. Intravenous fluids and antibiotics were administered for two days postoperatively, then Premature Enfamil Formula (24 kcal/oz; Mead Johnson, Evansville, IN) was administered continuously through the feeding tube. The animals were maintained on 115 kcal/kg/d as in the previous study. Weight, fecal fat analysis, and stool characteristics were determined throughout the 2-week period. The resulting data were compared with data from our previous study comparing gastric with jejunal feedings. These data suggest the vital importance of gastroduodenal contributions of absorption, osmoregulation, and regulation of nutrient concentrations in improving the nutritional status of experimental animals. Duodenal feedings may be preferred to either gastric or jejunal feedings because they provide equivalent nutritional support without the gastroesophageal reflux and aspiration reported with gastric feedings in the neonatal population.