Andre Hebra

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.

Esophageal Replacement Using the Colon: Is It a Good Choice?

Thirty-eight children (2 months to 26 years of age) underwent esophageal replacement at our institution between 1962 and 1993. Twenty-four patients had esophageal atresia, with the replacement performed at a mean age of 17 months. The remaining patients (37%) had strictures and were older (mean, 7.4 years). Replacement procedures involved the right colon in 61% of cases and the transverse left colon in the others (39%). Sixty-three percent were placed substernally and 37% were done in transthoracic fashion. The average length of stay in the hospital was 34 days (range, 11 to 256 days.) Early complications (within 30 days) included cervical anastomotic leaks (11 patients; 29%) pneumonia (4), would infection (2), pneumothorax/hemothorax (3), wound dehiscence (1), prolonged ventilation (2), vocal cord paralysis (1), Horners syndrome (1), pancreatitis (1), and perforated graft (1). Despite the incidence of early leaks, only two persisted long-term (more than 3 months). Other late complications included significant proximal strictures (5), and cologastric strictures developed in five patients. Seven cases were considered graft failures (18%), and all of these eventually require graft replacement. Additional problems included redundant graft requiring revision (4) and dumping syndrome (2). There were six cases of intestinal obstruction caused by adhesions. Four of these involved intrathoracic obstruction of the graft and two involved small bowel obstruction. There was only one death, which occurred late and was not related to the primary disease or procedure. Long-term follow-up data were available for 20 patients (53%). The follow-up period ranged from 1 to 33 years (mean, 12 years). Fourteen had excellent results after the initial interposition, being able to eat and function well without any further intervention. Seven patients (18%) have had poor results and 17 (45%) required additional procedures to obtain good functional results. In our experience, the colon continues to be a good option for esophageal replacement, but additional procedures frequently are necessary to optimize the functional outcome. Good results can be expected in the majority of cases, but late problems (ie, redundant colon and poor emptying) are not unusual, and careful follow-up is essential in the management of such patients.

Epstein-Barr virus-associated hepatic smooth muscle neoplasm in a cardiac transplant recipient

Host immunosuppression is increasingly recognized as a significant risk factor for the development of a primary neoplasm. Chronic immunosuppressive therapy, as used in organ transplantation, may perturb the immunosurveillance ability of the host, making the patient more susceptible to virus-associated malignancies. We have taken care of a care of a child who received an orthotopic heart transplant and who then developed both a generalized lymphoproliferative disorder and a leiomyoma of the liver a year later. Epstein-Barr virus DNA was detected in a lymph node initially and the hepatic tumor cells subsequently. The former responded to a reduction in the immunosuppressive medications and the latter responded to surgical resection. This is the first report of a hepatic smooth cell neoplasm occurring following cardiac transplant and the development of two sequential Epstein-Barr virus-associated disorders in an immunosuppressed patient.

The effects of ischemia and reperfusion on intestinal motility

The interdigestive migrating motor complex (MMC) has been demonstrated to be a reliable indicator of intestinal motility and function. The effects of low perfusion on the MMC have never been studied. Fourteen newborn Yorkshire piglets (5 to 18 days old, weighing 2.9 +/- 0.4 kg) underwent celiotomy under general anesthesia with placement of four jejunal electrodes (50 cm apart) as well as a superior mesenteric artery (SMA) Doppler flow probe and a pericardial catheter. Group 1 (n = 5) had operation alone. Group 2 (n = 9) had nonocclusive mesenteric ischemia induced by reversible cardiac tamponade for 5 hours between postoperative days 6 to 12. All subjects had MMC phase III electrical activity, cycling time, and propagation velocity recorded daily. In group 2 MMCs were recorded prior to and during ischemia, and during reperfusion. Group 2 animals had 75% +/- 4% decrease in SMA flow during the tamponade period. During the ischemic period, the MMC cycling time (CT) increased from 67 +/- 10 (mean +/- SEM) to 98 +/- 12 minutes (P < .05) and MMC propagation velocity (PV) decreased to 4.2 +/- 2.2 from a baseline value of 10.5 +/- 1.5 cm/min (P < .05). During reperfusion CT and PV values were not significantly different from baseline. The validity of this model is confirmed by the comparable baseline recordings in groups 1 and 2, and by the return of MMC to baseline values within 4 to 7 hours of reperfusion, as seen in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial translocation in mesenteric ischemia-reperfusion injury: Is dysfunctional motility the link?

The authors previously reported that mesenteric ischemia and reperfusion (I/R) in a chronic newborn piglet model creates dysfunctional intestinal motility. Whether this leads to inadequate bacterial clearance and translocation (BT) through the gastrointestinal tract remains unclear. To test this hypothesis the authors used their chronic piglet model (weight, 3.5 +/- 0.3 kg; age, 18 +/- 4 days; on formula feeding); nonocclusive mesenteric ischemia was induced via reversible pericardial tamponade. Mesenteric flow (SMA Doppler measurement via the retroperitoneal approach) was decreased to 25% +/- 5% of baseline for 300 minutes in the ischemia group (n = 7) and followed by 14 hours of reperfusion in the I/R group (n = 6). Control subjects had a sham operation (n = 7). Mesenteric lymph nodes (MLN), liver (L), spleen (S), ileum, peritoneum, and blood were harvested for blind quantitative microbial analysis. Subjects in the control group had no cultures positive for growth. Eighty-five percent of animals in the ischemia group had positive MLN cultures only (P < .05 v control). All piglets in the I/R group had positive MLN cultures (P < .05 v control), and one third of them manifested bacteremia. Histological examination did not show mucosal disruption in any group. The validity of this model is confirmed by the negative cultures in the control group and by the presence of normal ileal flora in all animals. In the ischemia and I/R groups, MLN cultures were consistently positive with gram-negative bacilli (Escherichia coli and/or Klebsiella pneumoniae). When subjects of the I/R group had more than 1,000 colonies in the MLN, bacteremia with the translocating organisms was also identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastroesophageal Reflux in Children

Operations for the control of complicated gastroesophageal reflux in children are commonly performed procedures in large pediatric centers. The comprehensive diagnostic scheme includes radiologic and endoscopic work-up coupled with extended pH probe analysis. Medical therapy remains the principle form of management, with surgery reserved for treatment failure.

Neonatal sternal cleft associated with an extrathoracic cystic mass

This report describes an unusual case of cystic exophytic tumor associated with a complete sternal cleft. The tumor masked the presence of sternal cleft on prenatal ultrasound scan.

Life-threatening complications and mortality of minimally invasive pectus surgery

The prevalence and type of life-threatening complications related to the minimally invasive repair of pectus excavatum (MIRPE) and bar removal are unknown and underreported. The purpose of this communication is to make surgeons aware of the risk of these life threatening complications as well as the modifications which have been developed to prevent them. METHODS Data related to life-threatening complications of Pectus Excavatum (PE) patients was obtained from four sources: 1. A survey of Chest Wall International Group (CWIG) surgeons who specialize in repairing congenital chest wall malformations, 2. Papers and case reports presented at CWIG meetings, 3. Review of medico-legal cases from the USA and 4. A systematic review of the literature related to major complications post MIRPE. RESULTS From 1998 to 2016, we identified 27 published cases and 32 unreported life-threatening complications including: cardiac perforation, hemothorax, major vessel injury, lung injury, liver injury, gastrointestinal problems, and diaphragm injury. There were seven cases of major complications with bar removal (reported and non-reported) with two lethal outcomes. Mortality data with bar placement surgery: Four published death cases and seven unpublished death cases. The overall incidence of minor & major complications post MIRPE has been reported in the literature to be 2-20%. The true incidence of life-threatening complications and mortality is not known as we do not know the overall number of procedures performed worldwide. However, based on data extrapolated from survey information, the pectus bar manufacturer in the USA, literature reports, and data presented at CWIG meetings as to the number of cases performed we estimated that approximately fifty thousand cases have been performed and that the incidence of life-threatening complications is less than 0.1% with many occurring during the learning curve. Analysis of the cases identified in our survey revealed that previous chest surgery, pectus severity and inexperience were noted to be significant risk factors for mortality. CONCLUSIONS Published reports support the safety and efficacy of MIRPE; however major adverse outcomes are underreported. Although major complications with MIRPE and pectus bar removal surgery are very rare, awareness of the risk and mortality of life-threatening complications is essential to ensure optimal safety. Factors such as operative technique, patient age, pectus severity and asymmetry, previous chest surgery, and the surgeons experience play a role in the overall incidence of such events. These preventable events can be avoided with proper training, mentoring, and the use of sternal elevation techniques. TYPE OF STUDY Treatment Study. LEVEL OF EVIDENCE Level IV.

Octreotide does not prevent bacterial translocation in an infant piglet model of intestinal ischemia-reperfusion☆

The process of bacterial translocation (BT) after ischemia/reperfusion (I/R) injury is reported to be mediated by local mucosal factors, the effects of pancreatic enzymes, epithelial disruption, and by dysfunctional intestinal motility. Octreotide (OCT), a somatostatin analog, has been postulated to protect against BT by influencing one or more of these factors. Twenty-two formula-fed piglets (weight, 3.5 +/- 0.5 kg; age, 20 +/- 5 days) were divided into four groups: control (no drug given; no I/R; n = 6), I/R (no drug given; n = 5), I/R plus low-dose OCT (LD OCT, 0.08 microgram/kg; n = 6), and I/R plus high-dose OCT (HD OCT, 8 micrograms/kg; n = 5). All experimental subjects had nonocclusive mesenteric ischemia induced by reversible pericardial tamponade with mesenteric flow decreased to 25 +/- 5% of baseline for 5 hours followed by 15 +/- 5 hours of reperfusion. Mesenteric lymph nodes (MLN), liver, spleen, blood, and peritoneum were harvested for blind microbial analysis. None of the animals in the control group experienced translocation to the tissues tested. All of the animals in the I/R group experienced BT to the MLN. The subjects in the LD OCT and HD OCT groups experienced BT to the MLN 66% and 80% of the time, respectively. Despite the reported clinical evidence that OCT can protect the intestinal mucosa from injury and increase the clearance of bacteria from the gastrointestinal tract, in this study in which variables other than I/R known to promote bacterial translocation were eliminated, OCT failed to modify or prevent the occurrence of translocation to the MLN after I/R injury.

Ovarian masses in children: A review of 91 cases

Ovarian masses in children are uncommon. We reviewed all cases of ovarian masses presenting to this hospital from 1979 to 1990. Ninety-one patients fulfilled the criteria and had medical records available. All patients were less than 18 years old. Four were diagnosed antenatally. Thirty-four tumors presented prior to 8 years of age and 1 (2.9%) was malignant. Fifty-eight tumors presented after 8 years of age and 18 (33%) were malignant. Seventy-two patients had benign disease and 19 had malignant tumors. Of those with benign disease 22 had simple or epithelial cysts, 25 had teratomas, 13 had torsion with cyst formation, 3 had granulosa cell tumors, and 9 had other less common lesions. Analysis of symptoms could not distinguish between benign and malignant lesions; however, age was less (P < .03) and tumor size smaller (P < .001) in patients with benign lesions. Benign lesions presented at a mean age of 8.8 years. Fifty-four patients had an ultrasound, all were diagnostic: simple mass (14), complex mass (8), or cyst (32). Mean size of the masses was 9.5 x 7.7 cm. Fourteen patients had a contralateral ovarian cyst. The malignant lesions included 14 germ cell tumors (4 endodermal sinus, 4 teratoma, 2 choriocarcinoma, 2 dysgerminoma, 1 embryonal, and 1 mixed), 4 epithelial tumors (1 mucinous cystadenocarcinoma, papillary cystadenocarcinoma, papillary serous cystadenocarcinoma, and endometrioid adenocarcinoma), and one patient with leukemic infiltration (ALL). Germ cell tumors presented at a mean age of 11.8 years. Eight of these patients had an ultrasound and all showed a mass (7) or cyst (1).(ABSTRACT TRUNCATED AT 250 WORDS)