Optimal timing for Soave primary pull-through in short-segment Hirschsprung disease: A meta-analysis

BACKGROUND

The optimal age for endorectal pull-through (ERPT) surgery in infants with short-segment Hirschsprung disease varies, with a trend toward earlier surgery. However, it is unclear if the timing of surgery impacts functional outcomes. We undertook the present study to determine the optimal timing of ERPT in infants with short-segment Hirschsprung disease.

METHODS

The NCBI PubMed database was searched for English-language manuscripts published between 2000 and 2019 analyzing functional outcomes for patient following the initial Soave ERPT for short-segment Hirschsprung disease. Raw data from these studies was obtained from the corresponding author for each manuscript. We combined data from these papers with our own institutional data and performed a meta-analysis.

RESULTS

A total of 780 infants were included in our meta-analysis. Constipation occurred in 1.0-31.7%, soiling 1.3-26.0%, anastomotic stricture 0.0-14.6%, and anastomotic leak 0.0-3.4%. Regarding age at ERPT, younger infants at the time of initial corrective surgery had higher rates of soiling, stricture, and leak. On sub-group analysis, patients <2.5 months at their initial corrective surgery had higher rates of soiling (25.9% vs. 11.4%, p<0.01), as well as stricture (10.0% vs 1.7%, p<0.01) and leak (5.5% vs 1.3%, p<0.01).

CONCLUSION

While age at Soave endorectal pull-through for short-segment Hirschsprung disease has decreased over time, functional outcomes associated with this trend have only recently been examined. Our findings suggest that patients <2.5 months old at the time of endorectal pull-through may have worse functional outcomes, emphasizing the need to consider further study of the timing of surgery in this population.

Surgical options in the treatment of ulcerative colitis

Children and young adults with ulcerative colitis tend to present with more extensive colonic disease than an adult population. The need for surgical intervention in the pediatric population with ulcerative colitis occurs earlier after diagnosis and has a greater incidence than a comparably matched adult population with an estimated need for colectomy at 5 years following diagnosis of 14-20%. Perhaps, even more than the adult population, there is a desire to restore intestinal continuity for the pediatric patient to achieve as healthy and normal quality of life as possible. With surgery playing such a prominent role in the treatment of ulcerative colitis in this age group, an understanding of the surgical treatment options that are available is important. The surgeon's awareness of the complexities of the different operations associated with proctocolectomy and reestablishing intestinal continuity may help to avoid early complications and minimize the risk of less than ideal long-term outcomes.

Mutations in TBX18 Cause Dominant Urinary Tract Malformations via Transcriptional Dysregulation of Ureter Development

Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of chronic kidney disease in the first three decades of life. Identification of single-gene mutations that cause CAKUT permits the first insights into related disease mechanisms. However, for most cases the underlying defect remains elusive. We identified a kindred with an autosomal-dominant form of CAKUT with predominant ureteropelvic junction obstruction. By whole exome sequencing, we identified a heterozygous truncating mutation (c.1010delG) of T-Box transcription factor 18 (TBX18) in seven affected members of the large kindred. A screen of additional families with CAKUT identified three families harboring two heterozygous TBX18 mutations (c.1570C>T and c.487A>G). TBX18 is essential for developmental specification of the ureteric mesenchyme and ureteric smooth muscle cells. We found that all three TBX18 altered proteins still dimerized with the wild-type protein but had prolonged protein half life and exhibited reduced transcriptional repression activity compared to wild-type TBX18. The p.Lys163Glu substitution altered an amino acid residue critical for TBX18-DNA interaction, resulting in impaired TBX18-DNA binding. These data indicate that dominant-negative TBX18 mutations cause human CAKUT by interference with TBX18 transcriptional repression, thus implicating ureter smooth muscle cell development in the pathogenesis of human CAKUT.

Management of congenital tracheal anomalies and laryngotracheoesophageal clefts

Congenital obstructions and anomalies of the pediatric airway are rare problems that may be associated with mild symptoms or critical stenoses that may be life threatening in the first few days of life. This review provides an overview of the embryologic development of the airway, different congenital anomalies associated with airway development, and surgical correction that may be associated with good long-term outcome.

Restorative proctocolectomy with and without protective ileostomy in a pediatric population

PURPOSE

This study aim was to review outcomes of pediatric patients after restorative proctocolectomy with or without a protective ileostomy in the treatment of ulcerative colitis and polyposis syndromes.

METHODS

All patients who underwent rectal mucosectomy with ileal pouch reservoir and hand-sewn ileal pouch anal anastomosis (IPAA) during 19-year period were reviewed retrospectively.

RESULTS

Eighty-three patients with ulcerative colitis and 7 patients with polyposis syndromes (ages 2.0-21.8 years) were reviewed. Sixty-eight patients underwent IPAA without diverting ileostomy. Fifty-six patients underwent restorative proctocolectomy as single-stage procedures, and 12 had abdominal colectomy and subsequent definitive IPAA without diverting ileostomy. Nineteen patients had IPAA with diverting ileostomy and subsequent closure of ileostomy. Three-stage procedures were performed in 3 cases. An ileal pouch leak or pelvic abscess occurred in 2 patients. Surgical pouch revision for retraction, efferent limb syndrome, prolapse, pouchitis, or perirectal infections occurred in 19 (6/62 J-pouch, 13/28 S-pouch). Fourteen patients (5/22 with diversion, 9/68 without diversion) developed small bowel obstruction. Overall, daytime and nighttime continence was excellent with rare nocturnal evacuations.

CONCLUSIONS

Restorative proctocolectomy without protective ileostomy is not associated with an increased morbidity, even in patients with active colitis, and may be appropriate most patients.

Antegrade colonic enemas and intestinal diversion are highly effective in the management of children with intractable constipation

PURPOSE

Intractable constipation in children is an uncommon but debilitating condition. When medical therapy fails, surgery is warranted; but the optimal surgical approach has not been clearly defined. We reviewed our experience with operative management of intractable constipation to identify predictors of success and to compare outcomes after 3 surgical approaches: antegrade continence enema (ACE), enteral diversion, and primary resection.

METHODS

A retrospective review of pediatric patients undergoing ACE, diversion, or resection for intractable, idiopathic constipation from 1994 to 2007 was performed. Satisfactory outcome was defined as minimal fecal soiling and passage of stool at least every other day (ACE, resection) or functional enterostomy without abdominal distension (diversion).

RESULTS

Forty-four patients (range = 1-26 years, mean = 9 years) were included. Sixteen patients underwent ACE, 19 underwent primary diversion (5 ileostomy, 14 colostomy), and 9 had primary colonic resections. Satisfactory outcomes were achieved in 63%, 95%, and 22%, respectively. Of the 19 patients diverted, 14 had intestinal continuity reestablished at a mean of 27 months postdiversion, with all of these having a satisfactory outcome at an average follow-up of 56 months. Five patients underwent closure of the enterostomy without resection, whereas the remainder underwent resection of dysmotile colon based on preoperative colonic manometry studies. Of those undergoing ACE procedures, age younger than 12 years was a predictor of success, whereas preoperative colonic manometry was not predictive of outcome. Second manometry 1 year post-ACE showed improvement in all patients tested. On retrospective review, patient noncompliance contributed to ACE failure.

CONCLUSIONS

Antegrade continence enema and enteral diversion are very effective initial procedures in the management of intractable constipation. Greater than 90% of diverted patients have an excellent outcome after the eventual restoration of intestinal continuity. Colon resection should not be offered as initial therapy, as it is associated with nearly 80% failure rate and the frequent need for additional surgery.

Botulinum toxin for the treatment of chronic constipation in children with internal anal sphincter dysfunction

Internal anal sphincter (IAS) dysfunction is a cause of refractory constipation in children. The goal of this study was to determine whether intrasphincteric injection of botulinum toxin is effective in the treatment of constipation in pediatric patients with IAS dysfunction. A retrospective review was performed of 24 pediatric patients with intractable constipation. All patients had abnormal anorectal manometry, with either elevated IAS resting pressure (> or =100 mm Hg) or an absent or diminished rectoanal inhibitory reflex. Patients with Hirschsprung's disease were excluded. All patients underwent botox injection into the IAS and were followed for a minimum of 6 months. Of 24 patients, 22 experienced significant improvement in their constipation lasting greater than 2 weeks. The duration of effect was variable, with 12 patients demonstrating benefit lasting at least 6 months. Transient postoperative incontinence occurred in five patients. Intrasphincteric injection of botox is a safe and effective treatment for intractable constipation in children with IAS dysfunction.

Radiographic reduction of intussusception in patients with cystic fibrosis

Cystic fibrosis (CF) is a genetic disorder affecting approximately one in 2,500 births in the United States. Nearly 1% of patients with CF will develop intussusception, which is commonly ileocecal and felt to be secondary to inspissated feces. These patients generally present before the age of ten. Once the diagnosis of intussusception is confirmed on ultrasound or CT, surgery has been the mainstay of treatment in this patient group. We propose the use of air and contrast enemas as effective and beneficial non-operative approach in these patients. Clinical and imaging findings in four children with known CF who presented with intestinal intussusception, average age 13.25 +/- 5.3 years (range 8-18 years) were reviewed. Patients were diagnosed using ultrasound (n = 3) or abdominal CT (n = 1). All patients suffered from an ileocolic intussusception. Air and Gastrografin(R) enemas were used in an attempt to reduce the intussusception. There were six separate successful intussusception reductions in four patients. Three patients required multiple attempts (2.3 +/- 0.6). Air enemas were used initially in all cases. Gastrografin(R) was used successfully following the failure of air enema in one patient. One patient suffered three separate intussusceptions over a period of 18 months, which were all successfully reduced using air. There were no complications and the patients tolerated the procedure well. Intussusception is an uncommon but serious complication in children with CF. While surgical reduction has been the mainstay of treatment for these patients, we demonstrated that reduction of an intussusception using air or contrast can be accomplished safely, without anesthesia, and should be the initial treatment option.

The use of white blood cell count and left shift in the diagnosis of appendicitis in children

BACKGROUND

The use of white blood cell (WBC) count and left shift in the diagnosis of appendicitis in pediatric patients is unproven. It is commonly thought that children with appendicitis have an elevated WBC count with a left shift; however, most data supporting this belief stem from studies conducted on appendicitis in adults, not children. The purpose of this investigation was to determine the value of WBC count and differential in the diagnosis of appendicitis in children presenting to the emergency department (ED) with acute abdominal pain.

METHODS

Seven hundred twenty-two pediatric ED patients with a primary complaint of nontraumatic abdominal pain were identified by prospective and retrospective methods. White blood cell count with differential was performed on patients with history and physical examination findings that were felt to warrant laboratory investigation. Results of WBC counts were determined as low, normal, or high, with or without a left shift, based on normal age-related values per laboratory protocol for pediatric patients.

RESULTS

The diagnosis of appendicitis was made in 10.2% of all patients presenting to the ED with acute abdominal pain. Thirty percent of toddlers (1-3.9 years) with high WBC counts had appendicitis, whereas 0% of toddlers with low WBC counts and 4.8% of toddlers with normal WBC counts had appendicitis (chi = 6.5, P = 0.04). A normal WBC count did not rule out appendicitis in toddlers; however, the negative predictive value (NPV) for normal or low WBC count was high (NPV = 95.6%). In the child age group (4-11.9 years), high WBC count was both sensitive and specific for the diagnosis of appendicitis in children (sensitivity = 71%, specificity = 72%), and the NPV for normal or low WBC count was high (NPV = 89.5%). Lastly, 43.9% of adolescents (12-19 years) with high WBC counts had appendicitis, whereas 0% of adolescents with low WBC counts and 8.3% of adolescents with normal WBC counts had appendicitis (chi = 37.3, P < 0.001). The NPV for a low or normal WBC count was also high in the adolescent group (NPV = 91.9%). Left shift was also strongly associated with appendicitis. Among toddlers, 40% of patients with a left shift had appendicitis, whereas 1.8% of toddlers without a left shift had appendicitis (chi = 25.7, P < 0.001, NPV = 98.2%). Similarly, left shift was strongly associated with appendicitis in children and adolescents. Among children, 54.3% of patients with a left shift had appendicitis, whereas 5.4% of children without a left shift had appendicitis (chi = 67.8, P < 0.001, NPV = 90.5%). Among adolescents, 53.5% of patients with a left shift had appendicitis, whereas 6.1% of adolescents without a left shift had appendicitis (chi = 72.3, P < 0.001, NPV = 93.9%). In patients with a left shift, 51.2% had appendicitis, whereas 3.7% of patients without a left shift had appendicitis (chi = 226.2; P < 0.001, NPV = 96.3%). In all patients with appendicitis, elevated WBC counts had a sensitivity of 67% and a specificity of 80%. Using left shift alone as an indicator for appendicitis was associated with a sensitivity of 59% and a specificity of 90%. However, when a high WBC count and left shift were combined, the sensitivity climbed to 80%, and specificity remained at 79%. The sensitivity fell to 47% when both a high WBC count and left shift were analyzed, and specificity climbed to 94%. The positive likelihood ratio for a high WBC count and left shift was 9.8.

CONCLUSIONS

The determination of WBC count and differential is useful in the diagnosis of appendicitis in children presenting to the ED with nontraumatic acute abdominal pain, regardless of age. High WBC counts and left shift are independently, strongly associated with appendicitis in children aged 1 to 19 years. In fact, for this subset of patients older than 4 years, the most common diagnosis in the setting of an elevated WBC count was appendicitis. The presence of an increased WBC count or left shift carries with it a high sensitivity (79%), and the presence of both high WBC count and left shift has the highest specificity (94%). These values are, therefore, helpful in the diagnosis and exclusion of appendicitis. Although not absolute, the WBC count and left shift can be helpful in the diagnosis and exclusion of appendicitis.

Malrotation with midgut volvulus: CT findings of bowel infarction

Midgut volvulus, the most common serious complication of malrotation, can be diagnosed using conventional contrast fluoroscopy, US or CT. CT is a quick and comprehensive examination in the evaluation of complex acute abdominal pathology in children. Contrast-enhanced CT can readily help the radiologist recognize perfusion abnormalities of the bowel, which is vital for reducing morbidity and mortality in affected children. Our case emphasizes and demonstrates additional CT features of bowel infarction in a child with a proven malrotation with midgut volvulus.

The diagnosis of acute appendicitis in a pediatric population: to CT or not to CT

PURPOSE

The aim of this study was to determine if focused appendiceal computed tomography with colon contrast (FACT-CC) increases the accuracy of the preoperative diagnosis of acute appendicitis in children.

METHODS

A 5-year retrospective review was conducted of a university hospital database of 283 patients (age 0.8 to 19.3 years; mean, 11.3 years) treated with appendectomy for presumed acute appendicitis.

RESULTS

Of the 283 patients in whom appendectomies were performed, 268 were confirmed by pathologic analysis of the specimen to have acute appendicitis for a diagnostic accuracy in our institution of 94.7%. Ninety-six patients (34%) underwent FACT-CC scans as part of their preoperative evaluation. The sensitivity of the computed tomography (CT) scan was 94.6%, and the positive predictive value was 95.6%. In girls older than 10 years, CT imaging was not significantly more accurate in predicting appendicitis than examination alone (93.9% v. 87.5%; P =.46).

CONCLUSIONS

Preoperative FACT-CC did not increase the accuracy in diagnosing appendicitis when compared with patients diagnosed by history, physical examination and laboratory studies. If there was a strong suspicion of appendicitis, a negative CT scan did not exclude the diagnosis of appendicitis. However, focused appendiceal CT scan is a sensitive test with a high positive predictive value and may be useful in a patient with an atypical history or examination.

Tracheal resection and reanastomosis in the neonatal period

BACKGROUND/PURPOSE

Severe congenital tracheal stenosis is rare. Most of these can be managed conservatively before elective repair. Focal tracheal stenosis has been treated with resection of the involved trachea and primary reanastomosis in older infants. The authors found no reports of repair of this lesion in neonates. Two patients are presented with severe respiratory failure on the first day of life that required extracorporeal life support (ECLS) who underwent successful tracheal resection and reanastomosis (TRR) during the first week of life.

METHODS

A retrospective review was conducted.

RESULTS

Both babies had severe pulmonary hypertension and carbon dioxide retention despite maximal therapy and were placed on ECLS shortly after transfer. One had an isolated stenosis of the upper trachea, and the other had agenesis of the right lung, esophageal atresia with tracheoesophageal fistula, and a tracheal stenosis at the end of a short trachea with a long, narrow left bronchus. Both underwent diagnostic studies and had surgical repair while on ECLS at day 3 and 7 of life without bleeding complications. They were weaned off ECLS 1 and 8 days after surgery. One patient was extubated and did well. The other was extubated transiently, but required a tracheostomy because of left mainstem bronchomalacia. Both are alive and well at 18 and 38 months of age, with no narrowing of the repairs.

CONCLUSION

In the setting of severe respiratory failure requiring ECLS support, TRR can be performed safely and successfully in the neonate with focal tracheal stenosis.

Diltiazem reduces pulmonary arterial pressures in recurrent pulmonary hypertension associated with pulmonary hypoplasia

BACKGROUND/PURPOSE

Recurrent pulmonary hypertension in the neonatal population is an unusual event with dire consequences. Pulmonary hypertension seen in association with pulmonary hypoplasia may be refractory to conventional medical management. The effect of the calcium channel antagonist diltiazem was studied in five patients with severe pulmonary hypertension.

METHODS

A retrospective review of the hospital records was performed to determine the efficacy of diltiazem for refractory pulmonary hypertension. All five patients experienced and did not respond to maximal conventional therapy, which included inhaled nitric oxide, intravenous nitrates, and extracorporeal membrane oxygenation (ECMO). Right ventricular pressures were determined by transthoracic echocardiograms and were used to document improvement in the pressure gradients. Statistical analyses were performed using a paired Student's ttest. A P value of less than .05 was considered significant.

RESULTS

Diltiazem significantly reduced the right ventricular systolic pressure (RVSP) from 82 +/- 8.4 mm Hg to 58.4 +/- 7 mm Hg (P = .008). Two patients died; one had a large ventricular septal defect, and the other suffered multisystem organ failure secondary to sepsis. The surviving patients were weaned off diltiazem and did not experience recurrent pulmonary hypertension.

CONCLUSIONS

In cases of pulmonary hypoplasia with recurrent pulmonary hypertension, diltiazem may be considered as a therapy. A multicenter prospective trial is advocated.

Extracorporeal membrane oxygenation for nonneonatal acute respiratory failure

HYPOTHESIS

Extracorporeal membrane oxygenation (ECMO) is effective in nonneonatal acute respiratory failure under certain circumstances.

DESIGN

Retrospective medical record review.

SETTING

The intensive care unit of a tertiary care hospital.

PATIENTS

Thirty-four nonneonatal patients (mean age, 22 years; range, 8 days to 56 years), with ratios of the PaO2 to the fraction of inspired oxygen persistently below 70, who were treated with ECMO after maximal ventilator therapy had failed (mean time of ventilator therapy, 6.9 days; range, 1-41 days). The mean ECMO duration was 304 hours (range, 56-934 hours). Patients were grouped into 7 categories based on their diagnosis: sepsis or sepsis syndrome (n = 3), bacterial or fungal pneumonia (n = 10), viral pneumonia (n = 5), trauma or burn (n = 2), inhalation injury without burn (n = 1), immunocompromised state (due to transplantation or chemotherapy) (n = 8), and acute respiratory failure of unknown origin (n = 5).

MAIN OUTCOME MEASURE

Survival to hospital discharge following ECMO therapy.

RESULTS

Overall survival was 53% (18 patients). All 6 patients (100%) with viral pneumonias or isolated inhalation injuries survived. Of 13 patients with bacterial pneumonia, sepsis, or sepsis syndrome not complicated by multiorgan failure, 10 (77%) survived. In contrast, all but 1 of the immunocompromised patients died. Survival in patients who were intubated for less than 9 days before ECMO was 64%, whereas survival fell precipitously to 22% for patients who experienced mechanical ventilation for 9 or more days before the implementation of ECMO. Finally, the proportion of patients who died while receiving ECMO therapy was greater when the ECMO duration exceeded 300 hours (62% vs. 38%; P<.05).

CONCLUSIONS

Nonneonatal survival with ECMO therapy is strongly dependent on the diagnosis. Pre-ECMO intubation for less than 9 days had little effect on survival. Survival rates decreased when the length of time of receiving ECMO exceeded 300 hours.

Prenatal glucocorticoids improve pulmonary morphometrics in fetal sheep with congenital diaphragmatic hernia

PURPOSE

Prenatal glucocorticoids reverse pulmonary immaturity in rodents with pharmacologically induced congenital diaphragmatic hernia (CDH). The authors applied quantitative stereologic morphometric techniques to test whether these effects could be reproduced in large animals (sheep) with surgically created CDH.

METHODS

Diaphragmatic hernias were created surgically in fetal lambs at gestational day 80. The fetuses were treated with intravenous cortisol (n = 6) or normal saline control (n = 5) from days 133 to 135. Lungs distended at 15 cm pressure from each group were harvested at day 136, processed histologically, and studied by brightfield microscopy at 400 x using a 42-point equidistant counting grid. Ten morphometric parameters (Mean +/- SEM) were measured by point-counting 60 fields/lung, and analysis of variance was performed.

RESULTS

The CDH-cortisol-treated lungs showed striking significant maturational improvements when compared with lungs of CDH-normal saline controls by seven of ten morphometric parameters.

CONCLUSIONS

(1) Prenatal glucocorticoids accelerate lung maturity in fetal lambs with CDH by seven quantitative morphometric parameters. (2) The observation that prenatal glucocorticoid therapy improves measures of maturity for both CDH rodent and sheep models encourages proceeding with a Phase I human clinical trial in ultrasound-confirmed CDH.

Infantile intestinal leiomyosarcoma: surgical resection (without adjuvant therapy) for cure

A 7-week-old boy presented with a 6-week history of failure to thrive, acute intestinal obstruction, and an apparently irreducible intussusception (noted on contrast enema). He underwent abdominal exploration, during which a cecal mass was identified and resected. The mass proved to be a leiomyosarcoma. Histologically, it was an intermediate-grade malignancy with a predicted 5-year survival rate of 16% to 23% based on data from the adult experience. Three years after resection and without having received adjuvant therapy, he is healthy and free of disease. A review of the literature showed that in infants these tumors are predominantly colonic, compared with the predilection for small intestinal lesions found in the older pediatric and adult populations. Infantile intestinal leiomyosarcomata are rare malignancies that do well if complete surgical excision of the disease can be accomplished. The histological prognostic indicators proposed for intestinal leiomyosarcomas in the adult population cannot be extrapolated to infants because when they occur in infants, they appear to be less aggressive, and these patients do well without adjuvant therapy.

Prenatal glucocorticoid therapy reverses pulmonary immaturity in congenital diaphragmatic hernia in fetal sheep

OBJECTIVE

To assess the feasibility of conducting clinical trials of prenatal steroid therapy for congenital diaphragmatic hernia (CDH) in humans, the authors tested whether prenatal glucocorticoid, currently the standard treatment to minimize respiratory distress syndrome in premature infants, might improve the pulmonary immaturity in severe CDH in a large animal model.

SUMMARY BACKGROUND DATA

The authors have used the nitrofen-induced rat model of CDH, which demonstrates immature lungs by biochemical, morphometric, and molecular biologic criteria. They also have shown that the lethally immature lungs of the full-term CDH rats can be improved by biochemical, morphometric, physiologic, and molecular criteria by treating the mothers with parenteral steroids at doses extrapolated from the current therapy used to accelerate lung development of premature human babies.

METHODS

During a 3-year period in 88 fetal sheep, 1) left-sided diaphragmatic hernias were created surgically at varying gestational ages (day 78-90; term = 142-145 days) and size to maximize severity (n = 45), 2) placement and design of indwelling fetal intravenous catheters were optimized (n = 13), and 3) timing and dosage of cortisol administration were determined (n = 17). As a result, diaphragmatic hernias were created on day 80, intravenous catheters were placed on day 120, and twice-daily intravenous cortisol injections (n = 8) or saline as the control (n = 5) were administered (days 133-135). Lambs were delivered on day 136 via cesarean section to avoid steroid-induced abortion; vascular access was obtained, and the fetuses were ventilated at standard settings. Physiologic data were collected, and lungs were harvested for biochemical and histologic analysis.

RESULTS

Significant improvements were measured in postductal arterial oxygen pressure ([PaO2] 38 +/- 6 mmHg after cortisol therapy compared with 20 +/- 3 mmHg for saline controls; p = 0.002) and in dynamic compliance (0.42 +/- 0.05 mL/cm H2O vs. 0.29 +/- 0.01 mL/cm H2O; p = 0.01). Lung glycogen levels in the right lung of the cortisol group were significantly better than controls (4.6 +/- 0.3 mg/g lung vs. 6.8 +/- 0.4 mg/g; p = 0.002), as were protein/DNA levels (8.3 +/- 0.9 mg/mg vs. 14.5 +/- mg/mg; p < 0.05). Striking morphologic maturation of airway architecture was observed in the treated lungs.

CONCLUSIONS

Prenatal glucocorticoids correct the pulmonary immaturity of fetal sheep with CDH by physiologic, biochemical, and histologic criteria. These data, combined with previous small animal studies, have prompted the authors to initiate a prospective phase I/II clinical trial to examine the efficacy of prenatal glucocorticoids to improve the maturation of hypoplastic lungs associated with CDH.

Surgical evaluation and management of refractory constipation in older children

Chronic constipation is a common childhood problem that accounts for 3% to 5% of pediatric visits and 10% to 25% of referrals to pediatric gastroenterologists. The etiology of constipation can be elusive, and extensive investigation often fails to identify a specific cause. The authors conducted a 5-year retrospective review of the patients referred for deep transanal rectal biopsy to determine the usefulness of this procedure in the evaluation and subsequent surgical management of refractory constipation. Specimens obtained by transanal rectal biopsy established a diagnosis for 30 of the 70 patients, and 17 of these 30 had subsequent procedures in the treatment of their constipation. The authors conclude that transanal rectal biopsy identifies a significant number of patients with previously unidentified neuroenteric disorders who may benefit from additional surgery in the treatment of constipation refractory to medical management.

Type IV laryngotracheoesophageal clefts: surgical management for long-term survival

Complete laryngotracheoesophageal clefts (types III and IV) are rare congenital anomalies that occur when the primitive foregut fails to separate into the tracheobronchial tree and the esophagus. This article summarizes a 10-year institutional experience with six infants who had type IV clefts, presents a modification of the authors' surgical approach, and identifies pitfalls in the management of these infants. Three of the six children are long-term survivors. The recognition of specific complicating issues leads to a standardized approach, which can result in successful repair and long-term survival.

Permissive hypercapnia as a ventilatory strategy in burned children: effect on barotrauma, pneumonia, and mortality

OBJECTIVE

To document the incidence of barotrauma, pneumonia, and respiratory death associated with a mechanical ventilation protocol based on permissive hypercapnia in pediatric burn patients.

DESIGN

Retrospective review.

MATERIALS AND METHODS

Patients were managed using a mechanical ventilation protocol based on permissive hypercapnia, tolerating moderate (pH > 7.20) respiratory acidosis to keep inflating pressures below 40 cm H2O.

MAIN RESULTS

Over a 2.5-year interval, 54 burned children (11% of 495 acute admissions) with an average age of 6.5 years (range 5 weeks to 17 years), average burn size of 44% (range 0 to 98%), and median burn size of 46% required mechanical ventilatory support for an average of 12.5 days (range 1 to 56 days). Inhalation injury was diagnosed in 34 (63%) of the children and 72% percent were admitted within 24 hours of injury. Overt barotrauma occurred in 5.6% of the patients, pneumonia in 32%, and respiratory death in 0%.

CONCLUSIONS

A conventional ventilation protocol based on permissive hypercapnia is associated with acceptable rates of barotrauma and pneumonia. The low incidence of respiratory death associated with this strategy suggests that it also minimizes ventilator-induced lung injury.

Left ventricular failure complicating severe pediatric burn injuries

PURPOSE

Despite improvements in the overall survival rates for critically burned children, failed resuscitation may account for 54% of deaths following burn injuries. Clinical and experimental studies have implicated failure of the right side of the heart in adults, biventricular failure in elderly patients, and inadequate resuscitation as causes of refractory burn shock. This retrospective study of resuscitation at a tertiary pediatric burn center showed that myocardial depression is a complicating factor in the treatment of the pediatric burn victim.

METHODS

From 1989 to 1992, 28 critically burned children (> or = 60% total burn surface area) were resuscitated primarily at our center (admission within 24 hours of injury). Twenty-seven children had central lines, nine of whom underwent pulmonary artery catheterization for intensive hemodynamic monitoring because standard resuscitative therapy had failed. The average amount of fluid received at 8 and 24 hours after injury was within 10% of the calculated volume based on the Parkland formula.

RESULTS

Indexes of a failing rescue attempt included respiratory distress (PaO2/FlO2 < or = 200), central venous pressure of greater than 10 mm Hg, and urine output of less than 1 mL/kg/h. Filling pressures were found to be normal or elevated in all children, indicating adequate volume replacement. Evaluation of cardiac function was performed using a thermodilution technique and showed that 100% of the study group had depressed left ventricular function, with an average left ventricular stroke work index (LVSWI) of 19.9 g.m/m2 (normal, 44 to 68 g.m/m2), whereas only 38% had concomitant right ventricular failure. This left-sided dysfunction persisted throughout the acute resuscitation period but was improved after appropriate modification of fluid resuscitation and initiation of vasopressors (average final LVSWI, 38.0 g.m/m2). There were no complications from placement of the Swan-Ganz catheters in this group.

CONCLUSION

Cardiogenic failure is a major determinant of a failing pediatric burn resuscitation, and, contrary to the adult burn patient, the myocardial depression is predominantly left-sided. Information from pulmonary artery catheters can help direct therapy by providing indications for vasopressors and modifying fluid resuscitation.

The burn unit as a resource for the management of acute nonburn conditions in children

Burn units bring together resources to manage large complex wounds, organ failures, and the hypermetabolic response to injury. These resources can also facilitate management of other problems such as purpura fulminans, toxic epidermal necrolysis, staphylococcal scalded skin syndrome, and major mechanical soft-tissue injuries. During a recent 10-year interval 2.4% of all acute admissions to a regional pediatric burn facility were in this category and form the basis for this review.

Immunologically nonspecific mechanisms of tissue destruction in the rejection of skin grafts

When mice are lethally irradiated and reconstituted with allogeneic bone marrow cells, their skin is repopulated over a period of several months with Langerhans cells (LC) of marrow donor origin. Skin from such mice, when transplanted to unirradiated syngeneic recipients, became in many cases the sites of intense inflammatory responses that led to varying degrees of destruction of the transplanted skin and in some instances, to rejection of the entire graft. The frequency and intensity of these responses were influenced by the nature of the immunogenetic disparity between the donors and recipients of the marrow cells. Chimeric skin placed on hybrid mice derived from crosses between the marrow donors and recipients behaved in all respects as syngeneic grafts or autografts. When the recipients of the chimeric skin were presensitized to the antigens of the marrow donor, the responses were especially intense, and resulted in all cases in complete rejection. Thus the immunologically mediated attack on the allogeneic LCs was accompanied by widespread and nonspecific destruction of bystander cells. In all cases, the inflammation and tissue damage were confined sharply to the grafted skin, showing clearly that nonspecific or indirect tissue destruction is entirely consistent with highly selective destruction of grafted tissues. This finding removes a major objection to postulated mechanisms of rejection that involve indirect destruction of grafted tissues.

Mortality and respiratory failure in a pediatric burn population

A 9-year retrospective review of 1,242 admissions to a tertiary burn center identified 137 patients who were intubated and ventilated for a critical airway or pulmonary problem. These patients varied in age from 2 months to 18 years with an average total body surface area (TBSA) burn of 55%. We evaluated this group for evidence of respiratory failure (ARF) as defined by the respiratory failure index (RFI) (PaO2/FIO2 < or = 300). While only 23% of admissions to the burn center were related to flame burns, these injuries accounted for 82% of children who had ARF. Forty-two percent of these intubated children had abnormalities on their admission chest x-ray and 61% of this cohort developed evidence of ARF as defined by the RFI. The development of sepsis along with ARF regardless of TBSA involvement doubles the mortality of ARF alone. Early burn wound excision and grafting is critically important to prevent the late complication of sepsis. We carefully monitor ventilator settings to insure low peak inspiratory pressures, allowing relative hypercapnia and avoiding hyperoxia. Despite an increased number of admissions and critically injured children, we have not seen an increase in morbidity and have had a 53% reduction in mortality in the last 2 years with these techniques. We believe this management offers the best outcome for the pediatric burn victim and would recommend this strategy to other centers dealing with these severely injured children.

A case of a closed partial cloacal septation defect with a patent urachus

A boy with a closed partial cloacal septation defect with a patent urachus is reported. He had an intact abdominal wall, a patent urachus, a colovesical fistula, intact genitalia and urethra, imperforate anus, and a lipomyelocystocoele. Patients with similar constellation of findings have been reported as cloacal exstrophy variants. What distinguishes this case from the other reported variants is the intact abdominal wall with the patent urachus, the small and normally formed phallus and urethra, and the presence of a lipomyelocystocoele. We discuss the possible embryologic mechanism responsible for this boy's findings and possible relationship with the cloacal exstrophy spectrum. We also discuss new terminology for the epispadias-exstrophy spectrum. Furthermore this case reminds us that there is considerable variability within the epispadias-exstrophy spectrum.

Treatment of acute pulmonary failure with extracorporeal support: 100% survival in a pediatric population

Since February 1990, five children, aged 10 days to 6.5 years, were treated with extracorporeal lung support at our hospital for acute, unrelenting pulmonary failure. Two had viral pneumonia: one with respiratory syncytial virus (RSV) bronchiolitis, and one with herpes simplex virus pneumonia, encephalitis, and disseminated intravascular coagulation. One presented with a febrile illness followed by a pulmonary hemorrhage. Two patients had adult respiratory distress syndrome (ARDS) complicating severe systemic illnesses, toxic epidermal necrolysis in one and cat scratch disease with encephalitis in the other. All children had diffuse parenchymal lung disease by chest x-ray. On maximum medical management all patients were developing carbon dioxide retention and progressive hypoxemia, exceeding previously established NIH study criteria for extracorporeal treatment. Three children (10 days, 2 months, 13 months) were placed on venoarterial support and two children (20 months and 6.5 years) were placed on venovenous extracorporeal support (ECCO2R). Three of the five had open lung biopsies performed, which showed findings consistent with a moderate to severe cellular phase of ARDS. No viral inclusions were found in the patient with RSV infection. One hundred percent immediate survival was achieved in this patient population. Average duration of support was 330 hours (range, 89 to 840). Following completion of extracorporeal support, all children were successfully weaned from the ventilator with an average time to extubation of 23.2 days (range, 2 to 58 days). One child died of congestive heart failure following palliative surgery for a complex noncyanotic congenital cardiac lesion 35 days after successfully weaning from extracorporeal support for an acute febrile illness and pulmonary hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)

Ectopic class II major histocompatibility antigens in Hirschsprung's disease and neuronal intestinal dysplasia

Although the etiology of Hirschsprung's disease and neuronal intestinal dysplasia remains obscure, both have histological abnormalities involving ganglion cells and neuronal elements. Searching for a common pathway that may inhibit normal maturation of neurogenic precursors, we examined the possible role of an immune mechanism in the maldevelopment of the enteric neural network. Six patients with Hirschsprung's disease were studied by comparing biopsy specimens from diseased colon with ones taken from proximal ganglionic colon in the same patients. These were similarly compared with colonic biopsy specimens from patients studied with chronic constipation or bowel removed at the time of operation for other disorders. Biopsies were taken from four other patients with neuronal intestinal dysplasia. Each was examined by hematoxylin & eosin staining, acetylcholinesterase histochemistry, and immunohistochemistry of major histocompatibility complex (MHC) class I and class II antigens. All rectal samples from Hirschsprung's disease patients exhibited elevated acetylcholinesterase histochemistry and absent ganglia to confirm the diagnosis. These findings were correlated with marked elevation of class II MHC in the aganglionic area, whereas the proximal normal ganglionic segments showed no elevation. Rectal biopsy specimens from patients with chronic constipation exhibited no such elevation. A similar elevation of class II MHC was detected in the mucosa and submucosa of all four patients with the rare neuronal intestinal dysplasia disorder whose diagnosis was confirmed by giant ganglia in Auerbach's plexuses, aberrant Meissner's ganglia in the lamina propria mucosa, and giant neurofibrils in the mucosa and submucosa. The correlation of elevated class II MHC in these two neuronal dysfunction disorders may indicate an underlying autoimmune mechanism as is seen in thyroiditis and insulin dependent diabetes mellitus.(ABSTRACT TRUNCATED AT 250 WORDS)

Laryngotracheoesophageal cleft (type IV): management and repair of lesions beyond the carina

Since the first successful repair of a complete laryngotracheoesophageal cleft (LTEC) to the carina in 1982, three newborn infants were observed with a particularly difficult variant in which the cleft extends beyond the carina into the mainstem bronchi. This type IV LTEC creates a long common tracheoesophagus, whose successful separation requires meticulous preoperative, operative, and postsurgical care. Three infants had complete surgical repair at our institution at 29, 49, and 225 days old and survived a minimum of 8 months. Recurrent tracheoesophageal fistulae at the thoracic inlet occurred in two infants, but was not observed in one patient when sternocleidomastoid muscle was interposed between the trachea and esophagus in the neck. Microgastria is an associated finding in each infant with the tracheoesophageal cleft extending beyond the carina. The small stomach is problematic as it is anatomically inadequate for any antireflux procedure and has not grown well, even with prolonged feeding. Early cleft repair is essential to prevent the development of chronic lung disease secondary to recurrent aspiration. The techniques to make the diagnosis, the preferred treatment to initially protect the airway, a single-stage operation performed simultaneously through the chest and neck to definitively repair the cleft, and finally the intraoperative and postoperative management critical for an optimal outcome are described.

Aberrant colonic expression of MHC class II antigens in Hirschsprung's disease

The major histocompatibility complex (MHC) Class I and II cell surface antigens responsible for the recognition of self vs non-self were studied in patients with documented Hirschsprung's disease. Monoclonal antibodies reactive with monomorphic determinants of human lymphocyte antigen (HLA)-A,B,C (Class I) and HLA-DR (Class II) were used to demonstrate immunohistochemically the expression of MHC antigens in 27 biopsy specimens from a variety of colorectal disorders. The rectal specimens examined from patients with Hirschsprung's disease showed an unexpected, marked elevation of Class II antigens with abnormal localization in the mucosa and lamina propria. This ectopic expression was not seen in any portion of the small or large bowel of patients who did not have Hirschsprung's disease. Furthermore, proximal normal colon of children with Hirschsprung's disease failed to show increased expression of Class II antigen. In an attempt to better define the effector arm at a cellular level, the distribution of helper T cells (CD4+), cytotoxic/suppressor T cells (CD8+) and natural killer cells (NK; CD16+) was examined in 5 cases. In Hirschsprung's disease, rectal infiltration of CD8+ and CD16+ cells was found, but not CD4+ cells. Ectopic expression of Class II antigen with increased numbers of rectal T cells and NK cells suggested that an early immunologic event may be causal in Hirschsprung's disease.

Bilateral Wilms' tumors: changing concepts in management

Bilaterality is uncommon in Wilms' tumor, being present in 4% to 8% of the cases. We report the combined experience of two children's hospitals in one city over a 20-year period. We encountered nine cases of synchronous bilateral nephroblastoma (National Wilms' Tumor Study 3, stage V). Age at diagnosis ranged from 9 to 41 months (mean 23 months). There were five girls and four boys. Associated findings include nephroblastomatosis in three cases (33%), one of which also had a familial history; undescended testis in two cases; and minor anomalies in two other cases. Surgical treatment consisted of unilateral nephrectomy with contralateral partial nephrectomy or tumorectomy in six cases, nephrectomy with contralateral biopsy only in two cases, and the other patient had bilateral biopsies initially, followed at a later date by partial nephrectomy on one side. All patients received chemotherapy; actinomycin D (AMD) only was used in the oldest case, vincristine and AMD in five cases, to which was added cyclophosphamide in one case and adriamycin in two. Seven patients received radiation therapy. Seven out of the nine patients survived more than 2 years (77%); five are well, off chemotherapy, with no evidence of disease from 4 to 11 years after diagnosis. Two patients suffered from chronic renal failure and one died from complications after renal transplantation more than 19 years after diagnosis. The two patients who died from their disease presented with more advanced tumor. Therefore, the agressiveness of multimodal therapy can be tailored according to stage and histology, and effective chemotherapy allows maximal preservation of renal parenchyma in patients with stage I and II tumors.

Zipper closure of the abdominal wall in the treatment of recurrent intra-abdominal abscesses

Diffuse retroperitoneal soilage following rectal laceration with a blunt object resulted in significant morbidity despite prompt recognition, parenteral antibiotic administration, and early surgical intervention. A septic postoperative course was complicated by perforation of the third portion of the duodenum and a diffuse suppurative peritonitis with multiple intra-abdominal abscesses. Closure of the incision at reexploration was facilitated by sewing Marlex to the fascia while a centrally located nylon zipper allowed access to the peritoneal cavity for further explorations and eventual ablation of the septic process.

Changes in the phenotype of T-cell subset determinants following murine cytomegalovirus infection

The murine model provides a particularly apt experimental system in which to evaluate the effects of cytomegalovirus (CMV) infection. CMV exerts a profound "suppression" of the immune response in the mouse and in humans; the infected animal is no longer able to mediate an appropriate response to mitogens or alloantigens. Using fluorocytometry and fluoresceinated monoclonal antibodies directed against the Thy-1.2, Lyt-1, and Lyt-2 cell membrane determinants following a nonlethal intraperitoneal inoculation of weanling BALB/c mice with Smith strain murine cytomegalovirus, significant changes in T-cell subsets were found that are consistent with findings described in the clinical situation. These ratio changes are temporally consistent with the cytotoxic T-lymphocyte population described by others. Finally, novel changes in the antigenic determinant distribution is found which may reflect the appearance of an antigen-committed cytotoxic T-lymphocyte population. This population which peaks at the ninth postinfection day may consist of 20-47% of the T-lymphocyte population and may offer an explanation for the cellular hyporesponsiveness seen following CMV infection.