Association of bronchopulmonary sequestration with expression of the homeobox protein Hoxb-5.

Bronchopulmonary sequestration (BPS) is caused by the abnormal development of an accessory lung diverticulum from the foregut very early in embryogenesis. The developmental abnormalities seen with BPS suggest that this anomaly is caused by abnormal expression of homeobox genes, which control axial identity and organ-specific patterning during embryogenesis. The authors previously have shown that the homeobox gene Hoxb-5 is necessary for normal airway branching during lung development. The authors now report that BPS is associated with aberrant developmental expression of Hoxb-5 protein, suggesting that this Hox gene is involved in the development of BPS.

Unsuspected splenic rupture in a neonate.

Serious intra-abdominal injuries in neonates are very rare. In addition, the signs and symptoms of hemoperitoneum caused by bleeding from solid viscera are vague and nonspecific and often are not recognized before the onset of hypovolemic shock or death. In this report, we describe a 2-day-old infant who presented with shock and pallor who had a ruptured spleen, presumably from birth. We also review the literature and the importance of recognizing this injury in the emergency department setting.

Multiple spontaneous small bowel anastomosis in premature infants with multisegmental necrotizing enterocolitis.

BACKGROUND/PURPOSE: Fulminant necrotizing enterocolitis (NEC) may result in extensive bowel necrosis. Resection of involved segments may result in short bowel syndrome. Multiple stomas result in complications and further loss of intestinal length with closure. METHODS: Two patients with extensive multisegmental NEC were treated with an intraluminal stent without anastomosis. All necrotic intestine was resected and the remaining viable intestine was lined up over a feeding tube without anastomosis of the intestinal segments. One patient had a diverting jejunostomy and mucous fistula with the tube used to orient the defunctionalized intervening intestinal segments. The second patient had the bowel left in continuity with the tube brought into the jejunem proximal to the first area of resection and distally brought out through the tip of the appendix. Both tubes were brought through the abdominal wall and secured in a loop. RESULTS: Contrast study findings showed that the intestinal segments had auto-anastomosed. In the first case the tube was left in place and intestinal continuity was restored. The patient is now 4 years old and takes full enteral feeds. The latter patient had the enterostomy tube removed at the time of the contrast study, but only tolerated partial feedings and died at 1 year of total parenteral nutrition-related liver failure. CONCLUSION: The technique eliminates nonviable bowel, maximizes length, avoids multiple stomas, and may help avoid reoperation.

Primary laparoscopic placement of peritoneal dialysis catheters in children and young adults.

BACKGROUND: Primary placement of peritoneal dialysis catheters in children often requires suturing of the catheter into the pelvis. We describe our experience with a gasless laparoscopy technique in children and young adults. METHODS: During an 18-month period, 12 patients (mean age, 14 years) underwent primary laparoscopic placement of peritoneal dialysis catheters. A single umbilical port was used for abdominal wall elevation, telescope, and catheter. A needleholder was introduced via an accessory port at the future catheter exit site or through the umbilical port. Omentectomy was performed through the umbilical incision. The catheter was tunneled to the lateral abdominal wall. Follow-up data (>/= 15 months) included time to initiation of dialysis, hospitalization, and outcome. End points were cure, transplantation, or death. RESULTS: Diet was started on the day of surgery and dialysis on the following day. Four patients had seven complications, including leakage and entanglement of the catheter in tubal fimbriae. Long-term revision-free catheter survival was 67% at 24 months. CONCLUSIONS: This minimal access technique for primary placement of peritoneal dialysis catheters includes securing of the catheter tip in a dependent location and omentectomy. It allows nearly immediate use of the catheter, leads to a minimal hospital stay, and has acceptable long-term patency.

Selective use of ultrasonography for acute appendicitis in children.

BACKGROUND: To evaluate the role of ultrasonography in children with equivocal signs of acute appendicitis, and correlate with initial clinical impression and pathological findings. METHODS: This is a prospective evaluation of all children presenting with a possible diagnosis of appendicitis during a 14-month study period. Patients with unequivocal clinical signs of appendicitis underwent appendectomy without ultrasonography. Patients with equivocal signs had documentation of the clinical impression and subsequent abdominal ultrasound. Statistical analysis of results was performed using the chi-square test (P <0.05 significant). RESULTS: Two hundred fifteen consecutive children were enrolled. Signs were unequivocal in 116 and equivocal in 99. Seven patients in the first group had a normal appendix at operation. Of the 99 patients with equivocal signs, there were 28 true positives, 3 false positives, 64 true negatives, and 4 false negatives. In equivocal cases, sensitivity of the initial clinical impression versus ultrasound was 50% and 88%, respectively (P <0.05). Specificity was 85% and 96%, respectively. The positive and negative predictive values improved from 63% to 90% and 78% to 94%, respectively, with the use of ultrasonography. CONCLUSIONS: The low false positive rate (6%) in clinically obvious cases of appendicitis does not, in our opinion, warrant ultrasonography. In clinically equivocal cases, ultrasonography is a fast, sensitive, and specific diagnostic modality to diagnose or rule out appendicitis, avoiding the need for prolonged observation and/or hospitalization.

The changing presentation of pyloric stenosis.

Metabolic abnormalities described in pyloric stenosis are now rare, probably because of prompter recognition of the disease. This report reviews the trend in presentation over three decades. All infants treated for pyloric stenosis during three mid-decade target periods were reviewed. Comparison between the 1975 group and the 1985 group and between the 1995 group and previous decades were designed to identify the impact of ultrasonography, since this modality has only been available in the last decade. Parameters included age at diagnosis and incidence of water and electrolyte imbalance as measures of delay in presentation. Two hundred eighty-three patients were reviewed. Mean age (weeks) at presentation was 5.4+/-3.0 in 1975, 4.6+/-2.0 in 1985, and 3.4+/-1.3 in 1995 (P < .05, ANOVA). Overall, 88% had no electrolyte anomalies on admission. There was no statistical difference in frequency of abnormal results between the three decades. Total and postoperative hospitalization was significantly shorter in the recent period: in 1985, 5.34 and 4.36 days; in 1985, 4.48 and 3.4 days; and in 1995, 3.8 and 2.8 days. These data show that pyloric stenosis is now recognized earlier than in previous decades. The availability of ultrasonography cannot solely be credited for earlier diagnosis, since this trend was already apparent before its introduction. The "classic" metabolic derangements associated with pyloric stenosis have been highly uncommon for the past three decades.

Primary repair of long-gap esophageal atresia by mobilization of the distal esophagus.

Long-gap esophageal atresia remains a difficult problem for the pediatric surgeon. Several strategies for lengthening of the proximal esophageal segment have been used with relative success. Autogenous tissue conduits have resulted in less than optimal long-term results. Five patients since 1991 with long gap esophageal atresia (2 with distal tracheo-esophageal fistula [Type C], and 3 with isolated esophageal atresia [Type A]) underwent mobilization of the distal esophagus to the level of the diaphragm in order to perform a primary anastomosis. A retrospective analysis evaluated the timing of repair, when oral feeds were successfully begun, with particular attention to any ischemic sequelae related to the distal esophageal dissection. Two patients underwent immediate repair, three had delayed repair. There were no anastomotic leaks. Three patients healed without stricture. Of four patients who survived long-term, three patients are eating well and only one still requires jejunoenteric supplementation. Classic teaching dictates that dissection of the distal esophagus should not be done because of disruption of its segmental blood supply. In this series, distal esophageal mobilization was successful in facilitating a primary anastomosis. These results are encouraging as an alternative to the high morbidity and marginal long-term results of interposition grafting or gastric transposition.

Laparoscopic appendectomy and duodenocolonic dissociation (LADD) procedure for malrotation.

The treatment of "asymptomatic" intestinal malrotation remains controversial, particularly beyond the neonatal period. Two cases illustrate the application of laparoscopy for correction of malrotation: one in an older child and another in an asymptomatic infant. Both patients recovered well and were discharged 2 days after surgery. Laparoscopic appendectomy and duodenocolonic dissociation allows excellent visualization of the duodenocolic and Ladd's bands and easily accommodates appendectomy. The availability of this minimal-access technique should encourage correction of malrotation in the asymptomatic patient.

Peritoneal drainage as definitive treatment for intestinal perforation in infants with extremely low birth weight (<750 g).

BACKGROUND: Advances in neonatal intensive care have improved the survival of the extremely premature infant. However, survival at less than 25 weeks' gestational age remains tenuous, with intestinal perforation presenting a significant mortality. METHODS: During an 18-month period from 1995 to 1996, nine patients weighing less than 750 g (range, 485 to 740 g; mean, 615 g) presented with intestinal perforation. All patients were treated with peritoneal drainage. Drains were removed after clinical improvement and the cessation of peritoneal drainage. RESULTS: Seven patients survived the initial drainage procedure (78%). At a mean follow-up of 12 months, the six long-term survivors are all tolerating full enteral feeds, and none developed intestinal strictures or intraabdominal abscess. No patient required subsequent celiotomy. Peritoneal drainage has previously been considered in some centers as temporary therapy in extremely ill neonates deemed unlikely to survive operation. The authors have adopted drainage as the sole treatment in selected patients. CONCLUSION: Peritoneal drainage alone may be considered definitive therapy for intestinal perforation in the majority of micropremature infants.

Carotid artery and jugular vein ligation with and without hypoxia in the rat.

A continuing concern about the use of extracorporeal membrane oxygenation (ECMO) is the cannulation of the common carotid artery or the internal jugular vein. The authors investigated the changes that might occur in the brain with neck vessel ligation in the normal and the hypoxic rat. Two groups of 60 rats each were studied. The first group was divided into three subgroups of 20 animals each. Subgroup 1 (HH) was hypoxic both 24 hours before and 24 hours after operation. Subgroup 2 (HN) (the ECMO model) was hypoxic before operation and recovered for 24 hours in room air. Subgroup 3 (NN) underwent the entire procedure in room air. For each oxygen environment, four different operations were performed: carotid artery ligation, jugular vein ligation, carotid artery and jugular vein ligation, and dissection of the vessels without ligation (sham). Thus each subgroup was further divided into four sub-subgroups based on the operation performed. Rats were again anesthetized after a 24-hour recovery period and killed using low, blunt cervical dislocation. In the first group of 60 rats, the skull was opened and the brain was carefully removed from the cranial vault and placed in a fixative. The brains were placed in a small magnetic resonance imaging (MRI) head coil in groups of five and scans were obtained to provide T1 and T2 images that correlated with histological sections. MRI scans were reviewed in random, blinded fashion by an imager unaware of how these animals had been treated. The brains were then sectioned coronally at six corresponding levels: frontal, mid and posterior cerebrum, midbrain, pons, and medulla. Histological examination was performed in blinded fashion. The number of lesions (usually ischemic as noted by a decrease in the number of neurons) was totaled for each area of the brain. There were no differences that were consistent or statistically significant in the MR images of brains removed from the head, although it would appear that rats with jugular vein and carotid artery ligation were relatively protected. In the HN group jugular vein ligation was worst, and adding carotid artery ligation was best. In the histological studies the NN group had significantly more lesions than the HH group (P < .01). The second group of 60 rats was divided and treated as the first group in all respects except that MRI was conducted immediately after death on intact heads, and no histological studies were performed. This was done to control for lesions that might have been produced by removal of the brains from the skulls. In this group all findings were right sided. One animal in the HN group showed midcerebral white matter edema after jugular and carotid ligation. Focal anterior cerebral edema was seen in another animal (HH) after isolated carotid ligation. An occipital infarct was found in one animal (HH) after both carotid and jugular ligation. The authors conclude that neck vessel ligation in the hypoxic or normoxic rat causes only occasional and sporadic brain injury much as is seen clinically in newborn ECMO patients.

Wandering spleen presenting as duodenal obstruction after repair of congenital diaphragmatic hernia.

The most common presentation of the wandering spleen in children is torsion with infarction. Duodenal obstruction by the spleen has not been reported previously. Wandering spleen can accompany congenital diaphragmatic hernia (CDH) because of its loss of retroperitoneal fixation. If absence of normal splenic fixation is found during repair of CDH, splenopexy should be performed to eliminate the risk of torsion, infarction, or, as described here, duodenal obstruction.

Extracorporeal membrane oxygenation in pediatric respiratory failure secondary to smoke inhalation injury.

Extracorporeal membrane oxygenation (ECMO) was used successfully in two children who had respiratory failure secondary to smoke inhalation injury. The first involved a 20% body surface area burn with initial carboxyhemoglobin of 26%. The patient developed varicella pneumonia, which complicated his respiratory failure; he was placed on ECMO for 7 days. The second infant had a 35% body surface area burn and carboxyhemoglobin of 30%. He underwent debridement and allografting while on ECMO, and was decannulated after 13 days. Anticoagulation for ECMO did not significantly interfere with dressing changes. Both patients had definitive autografting and were discharged home breathing room air.

Does research during general surgery residency correlate with academic pursuits after pediatric surgery residency?

A study was designed to evaluate whether successful candidates in pediatric surgery have performed laboratory research with publication, and if such preparation leads to continued investigations. We requested a curriculum vitae from the 248 pediatric surgeons who began their pediatric surgery residencies (PSR) between 1979 and 1992. For nonresponders, data were collected from physician directories. Indicators of academic status, personal information, and publication data were obtained. Responders had more publications before, during, and after PSR. Those who published during general surgery residency (GSR) had more research years during their residency. Among responders, 59% had spent time in the laboratory, and the percentage with laboratory time increased over the study period. Those with laboratory experience had more laboratory and clinical papers before PSR. Ninety-four percent were from university-based GSRs and 6% were from community GSRs. University general surgery residents did not have more publications during GSR or PSR but had a greater number of publications after PSR. University general surgery residents had more laboratory publications during GSR and after PSR, but did not have more clinical publications. Publications during GSR and after PSR increased during the study period, but not during PSR. Time in the laboratory during GSR did not independently predict continued laboratory research. Those with laboratory papers during GSR did not publish more basic science papers after PSR. Several surgeons had basic science publications that were initiated only after their PSR. In a recent study that compared successful and unsuccessful PSR candidates, the successful candidates were found to have more publications.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital diaphragmatic hernia with or without extracorporeal membrane oxygenation: are we making progress?

BACKGROUND: Congenital diaphragmatic hernia (CDH) continues to have a high mortality rate (24 to 57 percent) despite changing management schemes, which include extracorporeal membrane oxygenation (ECMO) for treatment of associated persistent pulmonary hypertension of the newborn. STUDY DESIGN: The medical records of 123 acutely symptomatic newborns with CDH treated from 1972 to 1994 were retrospectively reviewed. Patients were divided into three groups to compare historical treatment modalities: group 1, no ECMO available; group 2, postoperative ECMO if necessary; and group 3, delayed repair with preoperative ECMO if necessary. The blood gas values, alveolar-arterial oxygen gradient (A-aDO2), mean airway pressure (MAP), and oxygenation (OI) and ventilation indices (VI) prior to treatment were compared between survivors and nonsurvivors. Chi-square and Student's t tests were used to determine statistical significance. RESULTS: The overall survival rate was 41 percent: 27 percent in group 1, 45 percent in group 2, and 39 percent in groups 3. If those who were not candidates for ECMO were excluded from analysis, the survival rate improved to 35 percent in group 1, 51 percent in group 2, and 50 percent in group 3. No published prognostic scoring system, such as arterial blood gas values, A-aDO2 gradient, MAP, OI, or VI consistently distinguished survivors from nonsurvivors. Extracorporeal membrane oxygenation decreased the mortality rate of patients having large defects. CONCLUSIONS: Prognostic scoring systems do not predict which patients with CDH should be treated. Extracorporeal membrane oxygenation has improved survival in newborns with CDH who present in early respiratory distress. There is no advantage or disadvantage to using ECMO prior to repair of CDH.