Intracellular cytokine production by fetal and adult monocytes.

BACKGROUND/PURPOSE: In light of the neonate's increased susceptibility to systemic infection, the authors hypothesized that adult and fetal monocytes have different cytokine expression profiles in response to lipopolysaccharide (LPS), and interleukin (IL)-11, a counter-inflammatory cytokine. METHODS: Samples of cord blood (n = 30) and adult blood (n = 30) were obtained and treated as follows: control (baseline expression), LPS exposure, and IL-11 or IL-11+LPS exposure. After incubation with a protein transport inhibitor, mononuclear cells were stained for intracellular tumor necrosis factor (TNF)-alpha, IL-1beta, IL-6, and IL-8. Each sample was then analyzed by flow cytometry for cytokine expression. Cytokine production was measured by the percent positive as well as the fluorescence index for each cytokine. Analysis of variance (ANOVA) and Students t tests were used for statistical analysis. RESULTS: Baseline levels of IL-8 were significantly higher for fetal monocytes (P <.0001). After LPS exposure, fetal monocytes produced less TNF-alpha (P =.0105) and more IL-8 (P <.0007) relative to adult cells. IL-11 treatment reduced baseline production of IL-8 in fetal and adult monocytes (P <.05). CONCLUSIONS: These results suggest that neonatal monocytes portray a different cytokine expression profile compared with adult monocytes. IL-11 treatment appears to alter the IL-8 expression of resting fetal and adult monocytes.

A simple technique for preventing bar displacement with the Nuss repair of pectus excavatum.

BACKGROUND/PURPOSE: The most common complication of the minimally invasive technique for repair of pectus excavatum (MIRPE) is bar displacement, which has been reported to occur in 9.5% of all cases, particularly in teenaged patients. The use of a lateral stabilizing bar has improved stability but has not eliminated the occurrence of this problem. The authors report a new technique added to the standard MIRPE that creates an additional third point of fixation of the pectus bar to prevent displacement. METHODS: The technique requires the simple placement, via a spinal needle, of a nonabsorbable suture next to the sternum, encircling a rib and the bar, using a single 3-mm stab wound and thoracoscopic guidance. The suture simply is buried under the skin. Since 1998, this technique has been applied to 20 patients who underwent MIRPE. RESULTS: The average age was 14 years; 80% were boys. Average operating time was 75 minutes, and all patients had thoracoscopy with the MIRPE. A lateral stabilizing bar also was used in 14 patients. Four patients had 2 struts placed. Average length of stay was 5.5 days. There were no early complications. Mean follow-up was 12 months. Bar displacement occurred in 1 patient early in the series in which an absorbable suture was used for fixation. One patient had a prolonged hospital stay of 7 days because of postoperative pain. CONCLUSIONS: This modification to the original technique of MIRPE creates a 3-point fixation system that minimizes the risk of bar shifting even in teenaged patients. It does not add any significant time or cost to the operation, and it is fairly simple to perform. The authors believe that this technique decreases the occurrence of bar displacement, and they recommend its use for all patients with pectus excavatum considered candidates for the Nuss repair.

Effectiveness of beta-glucan collagen for treatment of partial-thickness burns in children.

BACKGROUND/PURPOSE: Beta glucan collagen matrix (BGC), which combines the carbohydrate beta-glucan with collagen, has been used as a temporary coverage for adult partial thickness burns with reported good results. Observed advantages of BGC coverage include reduction of pain, improved healing, and better scar appearance. Potentially even more important in children is the elimination of painful daily dressing changes to the burned epithelial surface, as well as decreased fluid loss. This report details the authors' 2-year experience with BGC in a pediatric burn center. METHODS: Retrospective chart review of 225 consecutive pediatric patients treated at our institution between 1997 and 1999 identified 43 patients (19%) with suspected partial thickness burns treated with BGC as the primary wound dressing. BGC was applied to a debrided burn wound and secured with steri-strips, kerlix, and an ace wrap. After 24 hours, adherence of the BGC was confirmed and then left open to air. RESULTS: The most common cause of burn injury was scald (61%), followed by flame (37%), and contact (2%). The average age of patients was 5.5 years (range, 6 weeks to 16 years) and mean percent total body surface area burned was 9.3% (1% to 35%). Thirty-four patients (79%) had the BGC remain intact while the wound healed underneath, with excellent cosmetic results, minimal analgesic requirements, and no need for repetitive dressing changes. Nine patients (21%) had the BGC removed before wound healing: 6 patients lost the BGC because of progression of the burn to full thickness, 2 had BGC nonadherence over a joint, and 1 had an unexplained nonadherence. CONCLUSIONS: Partial-thickness burns in children can be effectively treated with BGC with good results, even in infants and toddlers. BGC markedly simplifies wound care for the patient and family and seems to significantly decrease postinjury pain.

Pediatric laparoscopic splenectomy.

BACKGROUND: Lateral laparoscopic splenectomy in adults, first reported in 1991, was begun with children in 1993. METHODS: The authors reviewed records of 59 patients 2 to 17 years old who underwent laparoscopic splenectomy by the lateral approach between 1994 and 1998 at four medical centers. Patients received prophylactic penicillin or vaccinations preoperatively. RESULTS: Of the 59 patients, 51 required splenectomy for one of the following conditions: idiopathic thrombocytopenic purpura, hereditary spherocytosis, or sickle-cell disease. Splenomegaly was found in 86% of the patients, and ten accessory spleens were resected. No deaths or infection occurred, and only three patients had perioperative complications: acute chest crisis, small diaphragmatic injury, and intraoperative hemorrhage. One operation was converted to a minilaparatomy because of difficulty with specimen extraction. CONCLUSIONS: Pediatric laparoscopic splenectomy is safe and effective, resulting in little blood loss, rapid recovery, and a good cosmetic outcome.

Minimally invasive pectus surgery.

The technique of minimally invasive repair of pectus excavatum is a new operation that allows for repair of this deformity without any cartilage resection or sternal osteotomy. The procedure has revolutionized the management of pectus excavatum. The innovative incorporation of thoracoscopic techniques and small but important modifications to the technique have made this operation very effective and safe.

Necrotizing enterocolitis in infants with very low birth weight.

Necrotizing enterocolitis (NEC) is a disease in which the primary risk factor is prematurity. Despite, and partially as a result of, the tremendous strides neonatal care has taken, it is a major cause of morbidity and mortality of the newborn. The infant with very low birth weight is particularly susceptible, and the management of the condition in this group differs somewhat from other neonates. The outcomes continue to improve, but there are significant sequelae. Prevention, which would be the best "cure," is elusive, in no small part because of the multifactorial nature of the etiology of NEC.

Outcome analysis of minimally invasive repair of pectus excavatum: review of 251 cases.

BACKGROUND/PURPOSE: Since the first report in 1997 by Dr Nuss of the technique for minimally invasive repair of pectus excavatum (MIRPE), the popularity and demand for this operation has increased dramatically. Many pediatric surgeons became familiarized with MIRPE and have applied it to a large number of patients. Outcomes and complications have not yet been defined. METHODS: A comprehensive survey of APSA members was conducted to review technical problems, complications, and outcomes of this new technique. RESULTS: Of the 74 survey responders, 31 (42%) currently use the MIRPE as their procedure of choice, and 251 cases were reviewed. A total of 74.2% of surgeons relied on direct observation and written documentation to obtain training in MIRPE. Less than 60% used the chest index in the preoperative assessment. A total of 98% used the Walter Lorenz bar for the MIRPE. The most common complication was bar displacement or rotation requiring reoperation (9.2%). Pneumothorax requiring tube thoracostomy was reported in 4.8%. Less common problems included infectious complications (2%), pleural effusion (2%), thoracic outlet obstruction (0.8%), cardiac injury (0.4%), sternal erosion (0.4%), pericarditis (0.4%), and anterior thoracic artery pseudoaneurysm (0.4%). Three patients (1.2%) required early strut removal. Reoperation using the open modified Ravitch approach was performed in 2 patients (0.8%). Most surgeons indicated that teenaged patients (>15 years old) were at higher risk for complications. Thoracoscopy in combination with MIRPE was used by 61% of the surgeons. Overall patient satisfaction was rated as excellent or good (96.5%). CONCLUSIONS: The relatively high incidence of problems with MIRPE is probably related to the learning curve associated with the introduction of this new technique. Awareness of technical details, careful patient selection, use of a stabilizing bar, and thoracoscopy likely will result in decreased complications. Long-term results are yet to be determined. The development of a national registry is of great importance for further outcome analysis of MIRPE.

A new method of treatment for complete tracheal rings in an infant: endoscopic laser division and balloon dilation.

PURPOSE: The authors describe a new technique for management of complete tracheal rings in infants. METHODS: The procedure consists of rigid bronchoscopy with KTP laser division, in the posterior midline, of the complete rings and gradual advancement of the bronchoscope aided by endoscopic balloon dilation. CONCLUSIONS: The laser division, coupled with balloon dilation, allows for controlled separation of the cartilages posteriorly. The anterior esophageal wall buttresses the posterior tracheal separation.

Primary laparoscopic-assisted endorectal colon pull-through for Hirschsprung's disease: a new gold standard.

OBJECTIVE: To describe the surgical technique and early clinical results after a one-stage laparoscopic-assisted endorectal colon pull-through for Hirschsprung's disease. SUMMARY BACKGROUND DATA: Recent trends in surgery for Hirschsprung's disease have been toward earlier repair and fewer surgical stages. A one-stage pull-through for Hirschsprung's disease avoids the additional anesthesia, surgery, and complications of a colostomy. A laparoscopic-assisted approach diminishes surgical trauma to the peritoneal cavity. METHODS: The technique uses four small abdominal ports. The transition zone is initially identified by seromuscular biopsies obtained laparoscopically. A colon pedicle preserving the marginal artery is fashioned endoscopically. The rectal mobilization is performed transanally using an endorectal sleeve technique. The anastomosis is performed transanally 1 cm above the dentate line. This report discusses the outcome of primary laparoscopic pull-through in 80 patients performed at six pediatric surgery centers over the past 5 years. RESULTS: The age at surgery ranged from 3 days to 96 months. The average length of the surgical procedure was 2.5 hours. Almost all of the patients passed stool and flatus within 24 hours of surgery. The average time for discharge after surgery was 3.7 days. All 80 patients are currently alive and well. Most of the children are too young to evaluate for fecal continence, but 18 of the older children have been reported to be continent. CONCLUSION: Laparoscopic-assisted colon pull-through appears to reduce perioperative complications and postoperative recovery time dramatically. The technique is quickly learned and has been performed in multiple centers with consistently good results.

"One-stop" surgery: implications for anesthesiologists of an expedited pediatric surgical process.

BACKGROUND: "One-stop surgery" (OSS) allows pediatric patients to undergo initial surgical evaluation, anesthesia, surgery, and discharge home, on the same day. METHODS: Patients referred for umbilical hernia repair, circumcision, or central venous catheter removal completed a screening questionnaire, after which they were scheduled for initial surgical and anesthesia evaluation if eligible and had surgery if indicated on the same day. RESULTS: Three patients had comorbidity precluding OSS, two patients refused indicated surgery, two patients did not require surgery, and 12 patients did not keep their appointment. Eighty patients had surgery without complications. Average total time was significantly shorter for OSS than non-OSS for circumcision (120 vs 142 min) and umbilical hernia repair (139 vs 165 min) but similar for catheter removal (100 vs 109 min). All families were satisfied with OSS. CONCLUSIONS: One-stop surgery appears to be a safe, efficient, and convenient alternative to the traditional process for patients and their families.

Detection of intracellular tumor necrosis factor alpha in stimulated fetal cells.

BACKGROUND: It is unknown if immature fetal cells produce tumor necrosis factor (TNF) alpha in the same manner that adult cells do. The aim of this study was to determine the feasibility of early detection of intracellular TNF produced by circulating human monocytes (Mo) and lymphocytes (Ly) using flow cytometry and to compare the stimulation profiles of mature and fetal cells. MATERIAL AND METHODS: Fetal umbilical cord blood (n = 10) and adult volunteer blood (n = 10) were obtained. In vitro stimulation with endotoxin (LPS) and ionomycin-PMA was performed. Brefeldin A was added to prevent extracellular transport of TNF. Cell type was determined by using CD-14 marker separating monocyte and lymphocyte populations. Anti-human TNF monoclonal antibody was used to detect intracellular TNF by flow cytometry analysis. RESULTS: Thirty to sixty thousand cells were analyzed per sample. Average TNF expression of stimulated fetal Mo was 28.2%, and that of fetal Ly was only 1.1%. Adult stimulated Ly had an average TNF expression of 31.9%, and adult Mo, 29.6% (P < 0.05 for adult Ly vs fetal Ly). CONCLUSION: TNF flow cytometry analysis allows assessment of individual cell types and their ability to produce that cytokine. Fetal cells are able to produce TNF when stimulated, but the stimulation profile of Ly differs from that of adult samples. This observation may be of clinical importance in evaluating the response of immature cells to a septic stimulus. Flow cytometry is reliable, reproducible, quick, and easily obtained from a small sample of peripheral blood. Clinical use will be applicable once appropriate controls are developed, as reported in this study.

Impact of segmental grafts on pediatric liver transplantation--a review of the United Network for Organ Sharing Scientific Registry data (1990-1996).

PURPOSE: The aim of this study was to assess the relative impact of segmental grafts from cadaveric and living donors on outcomes in 3,409 pediatric transplants (<18 years) between 1990 and 1996. METHODS: Analysis of the United Network for Organ Sharing (UNOS) Scientific registry data from 1990 to 1996 was performed. RESULTS: Liver grafts consisted of 2,636 whole grafts (WLG), 246 liver donor grafts (LDG), 89 split liver graft (SLG), and 438 reduced-size grafts (RSG). Although the number of pediatric transplants were unchanged between 1990 and 1996, segmental grafts made up an increasing proportion from 14.5% to 29.2%, and WLG decreased proportionately. The increase among segmental grafts occurred for LDG (threefold), followed by SLG (53%) and RSG (50%). One-year graft and patient survival rates for 3,409 transplants were 69.7% and 81.9%, respectively and were significantly higher (P<.001) in nonhospitalized patients than in hospitalized patients (79.8% and 91.3% v 61.0% and 73.7%). LDG graft survival (75.9%) was comparable with WLG(70.9%) but significantly better at 1 year than SLG (60.3%, P = .007) and RSG (61.1%, P = .001), even after excluding retransplants and ICU patients. Patient survival rates were not different statistically between groups. A separate analysis of outcomes in recipients less than 1 year of age suggested significantly better graft and patient survivals for LDG (83.3% and 89.4%) than for WLG (62.3% and 76.5%) and RSG (62.7% and 75%). CONCLUSIONS: Segmental liver grafts from cadaveric and living donors constitute an increasing proportion of pediatric transplants. Survival rates of cadaveric segmental graft are inferior to those of live donor segmental grafts even after adjustment for medical condition. Live donor grafts demonstrate consistently superior graft and patient outcomes in pediatric recipients less than 1 year of age, and should be promoted aggressively as a solution to the critical shortage of size matched grafts in small recipients.

One-stop surgery: evolving approach to pediatric outpatient surgery.

PURPOSE: Maximizing patient satisfaction is of prime importance in today's competitive outpatient surgery market. The authors recently devised a system, one-stop surgery, which simplifies outpatient surgery for pediatric patients and their families by combining the traditionally separate preoperative evaluation and subsequent operation into one visit. This report describes our initial experience with one-stop surgery. METHODS: Umbilical hernia repair, circumcision, and portacath removal were considered surgical procedures appropriate for our one-stop surgery pilot study. Medical information obtained by phone or fax from referring physicians was used to identify potential candidates. Families were contacted, precertified for their surgical procedure, and given nothing by mouth instructions. The day of surgery the child was evaluated by the attending pediatric surgeon. If the diagnosis was confirmed, and no contraindications to surgery were identified, the child immediately underwent the prescheduled surgical procedure. RESULTS: From April through October 1997, 61 children were scheduled for one-stop surgery. Nine patients (15%) were no shows, and one additional family opted not to proceed with circumcision. The remaining 51 children (83%) underwent their one-stop surgical procedure: umbilical hernia repair (n = 23), circumcision (n = 19), portacath removal (n = 8), and inguinal hernia repair (n = 1). No child had an anesthetic contraindication to surgery, and only one minor postoperative complication (wound hematoma) occurred. CONCLUSIONS: This pilot study has demonstrated that with appropriate patient screening and cooperation of the entire surgical team, a variety of outpatient surgical procedures can be handled using this one-stop surgery method. By combining one-stop surgery with our previously reported phone follow-up system, many minor surgical procedures can be managed with only one visit to the hospital. Decreasing the "hassle factor" of outpatient surgery for children and their families, who frequently live far from their closest children's hospital, while providing the highest quality of specialized surgical and anesthetic care, may potentially be a very powerful marketing tool for pediatric surgical specialists.

Acute chest syndrome in the postoperative sickle cell patient.

BACKGROUND/PURPOSE: Acute chest syndrome (ACS), a phenomenon of pulmonary sequestration in sickle cell disease (SCD) patients, is frequently missed in the postoperative SCD child. The constellation of symptoms range from fever and respiratory distress to abdominal discomfort. In its most fulminate state, the syndrome has been reported in some series to carry almost a 25% to 50% mortality rate in the postoperative patient. The incidence in pediatric patients in the era of minimally invasive surgery is unknown. METHODS: Since December 1995, 63 episodes of ACS have been documented in the nearly 500 SCD children seen at our institution. Six of 63 episodes occurred within 2 weeks after a surgical procedure under general anesthesia. During this period, 59 operations were performed by the pediatric surgery service on SCD patients with an ACS incidence of 10.2%. Careful review of the preoperative, intraoperative, and postoperative management of these patients was performed. RESULTS: All six received preoperative oxygen saturation monitoring and intravenous fluid (IVF) hydration. One half of these patients required transfusion to achieve a hemoglobin level of greater than 10 mg/dL. Documentation of intraoperative temperature, hypoxia, volume status, and hypercarbia as well as any atypical perioperative events were monitored and reviewed. All patients received postoperative oxygen supplementation and IVF hydration. Onset of ACS ranged from 1 hour to 7 days postoperatively. Only one of six was thought to be of microbial etiology (elevated mycoplasma titers), and all patients received prophylactic antibiotic and aggressive pulmonary therapy. Overall length of hospitalization was increased with an average stay of 6.1 days. There were no postsurgical ACS deaths. CONCLUSIONS: Despite close attention and avoidance of known risk factors for development of postoperative SCD complications, ACS occurred with an incidence much higher than previously reported in the literature (0.4% v 10.2%). Interestingly, five of six cases were after laparoscopic procedures suggesting that the advantages of laparoscopy, such as reduced postoperative pain, do not extrapolate to decreased incidence of ACS.

Persistent pulmonary hypertension in a neonate with cystic adenomatoid malformation of the lung following lobectomy: survival with prolonged extracorporeal membrane oxygenation therapy.

A full-term neonate is reported with congenital cystic adenomatoid malformation of the lung treated by lobectomy with development of pulmonary hypertension. The infant was successfully treated with extracorporeal membrane oxygenation (ECMO) for persistent pulmonary hypertension, which developed postoperatively. An 18-day course of venovenous ECMO was necessary to effectively reverse the severe pulmonary hypertension. This was probably a result of significant pulmonary hypoplasia of the compressed lung. Although not all congenital cystic adenomatoid malformations of the lung are associated with pulmonary hypoplasia and persistent pulmonary hypertension, this is one case where severe pulmonary hypertension developed secondary to a mass effect by a large lesion in the chest.

Pediatric laparoscopic biliary tract surgery.

Laparoscopic cholecystectomy is being performed with increasing frequency in children. The authors discuss the presentation, surgical technique, overall results, and potential complications associated with pediatric laparoscopic biliary tract surgery, citing a large personal experience as well as that reported in the literature.

A new technique for laparoscopic splenectomy with massively enlarged spleens.

Splenectomy is indicated in several hematological disorders and it can be particularly challenging in children with sickle cell disease, splenomegaly, and recurrent sequestration. Over the last 6 months, we have developed a new technique for laparoscopic splenectomy (LS) for hypersplenism and splenomegaly in five children with sickle cell disease. The average age of our patients was 6 years (range, 2-11), and the average weight was 18.7 kg (range, 13.2-30.1). On preoperative ultrasound, spleen size index ranged from 0.42 to 0.76. For the LS, four trochars were placed. One patient, who also underwent a laparoscopic cholecystectomy, had six trochars placed, two of which were used for both cholecystectomy and splenectomy. After laparoscopic mobilization of the spleen and hilar vascular stapling, a Steiner electromechanical morcellator was inserted through the 12-mm port to extract cores of splenic tissue until complete splenectomy was achieved. No patient required conversion to an open procedure or creation of a larger incision to remove the massively enlarged spleen. Operative time averaged 190 minutes; the combined LS and cholecystectomy took 245 minutes. Postoperative length of stay was <2 days for all patients. There were no complications, and no patient required postoperative transfusion. Based on these early findings, we conclude that intracorporeal coring of splenic tissue allows for safe and complete laparoscopic removal of very large spleens in small children. It provides expedient recovery and minimal postoperative pain and scarring. This new technique should enable surgeons to perform LS even in patients with massive splenomegaly, eliminating the need for large and cumbersome intracorporeal bags or the creation of additional incisions to remove the spleen.

Enteric defensin expression in necrotizing enterocolitis.

Immaturity of local innate defenses has been suggested as a factor involved in the pathophysiology of necrotizing enterocolitis (NEC). The mRNA of enteric human defensins 5 (HD5) and 6 (HD6), antibiotic peptides expressed in Paneth cells of the small intestine, have significantly lower levels of expression in fetal life compared with the term newborn and adult. In the current study, intracellular HD5 was demonstrated by immunohistochemistry at 24 wk of gestation, but at low levels, consistent with findings at the mRNA level. These data suggest that the low level enteric defensin expression, characteristic of normal intestinal development, may contribute to the immaturity of local defense, which predisposes the premature infant to NEC. To test if levels of defensin expression are altered in NEC, specimens from six cases of patients with NEC and five control subjects (four patients with atresia and one with meconium ileus) were analyzed to determine HD5 and HD6 mRNA levels by in situ hybridization. Compared with the control group, the level of enteric defensin expression per Paneth cell assessed by image analysis was increased 3-fold in cases of NEC (p = 0.02, analysis of variance and covariance). In addition, the number of Paneth cells was increased 2-fold in the small intestinal crypts of NEC specimens compared with those of control subjects (p < 0.01, covariance analysis). In healthy tissue, peptide levels within Paneth cells paralleled mRNA levels through development. In tissue from infants with NEC, the steady state level of intracellular peptide was not increased in conjunction with the observed rise in defensin mRNA. A straightforward interpretation of this finding is that HD5 is actively secreted in this setting and the Paneth cells maintain a constant steady state level of intracellular peptide, but the possibility of translational regulation of peptide expression is also consistent with these data. The associations between NEC and enteric defensin expression reported here offer support for future studies to address the role of these endogenous host defense factors in the pathophysiology of this disease.