Prevalence and Outcomes of High versus Low Ratio Plasma to Red Blood Cell Resuscitation in a Multi-Institutional Cohort of Severely Injured Children.

BACKGROUND: The benefit of targeting high ratio fresh frozen plasma (FFP):red blood cell (RBC) transfusion in pediatric trauma resuscitation is unclear as existing studies are limited to patients who retrospectively met criteria for massive transfusion. The purpose of this study is to evaluate the use of high ratio FFP:RBC transfusion and the association with outcomes in children presenting in shock. METHODS: A post-hoc analysis of a 24-institution prospective observational study (4/2018-9/2019) of injured children <18 years with elevated age-adjusted shock index was performed. Patients transfused within 24 hours were stratified into cohorts of low (<1:2) or high (>1:2) ratio FFP:RBC. Nonparametric Kruskal-Wallis and chi-square were used to compare characteristics and mortality. Competing risks analysis was used to compare extended (≥75th percentile) ventilator, intensive care, and hospital days while accounting for early deaths. RESULTS: Of 135 children with median (IQR) age 10 (5,14) years and weight 40 (20,64) kg, 85 (63%) received low ratio transfusion and 50 (37%) high ratio despite similar activation of institutional massive transfusion protocols (MTP; low-38%, high-46%, p = .34). Most patients sustained blunt injuries (70%). Median injury severity score was greater in high ratio patients (low-25, high-33, p = .01); however, hospital mortality was similar (low-24%, high-20%, p = .65) as was the risk of extended ventilator, ICU, and hospital days (all p > .05). CONCLUSION: Despite increased injury severity, patients who received a high ratio of FFP:RBC had comparable rates of mortality. These data suggest high ratio FFP:RBC resuscitation is not associated with worst outcomes in children who present in shock. MTP activation was not associated with receipt of high ratio transfusion, suggesting variability in MTP between centers. LEVEL OF EVIDENCE: Prospective cohort study, Level II.

Injury Patterns and Outcomes at a Single Pediatric Trauma Center During the Coronavirus Disease 19 Pandemic.

INTRODUCTION: The coronavirus disease 19 (COVID-19) pandemic is reported to have changed injury patterns, prevalence, and outcomes across multiple institutions in the United States. Interpretation of aggregate data is difficult because injury patterns vary between urban and rural hospitals and the implementation of locoregional public health policies and guidelines in response to COVID-19 differed. To prepare our trauma system for future societal shutdowns, we compared injury patterns and outcomes of injured children and adolescents at a single pediatric trauma center before and during the first 2 y of the COVID-19 pandemic. METHODS: We abstracted demographic, injury, and outcome data for injured children and adolescents (age <15 y) who required admission using our hospital trauma registry and the electronic medical record. We compared differences prior to and during the COVID-19 pandemic using univariate analysis. To address confounding variables, we also analyzed in-hospital mortality using a multivariable regression. RESULTS: We observed an increase in the number of injured children requiring admission during the first year of the COVID-19 pandemic compared to the prepandemic era. Among injury types sustained, we observed an increase in firearm and nonfirearm related penetrating injuries (P < 0.001) during the first year, but not the second year, of the COVID-19 pandemic. Controlling for several confounding variables, we also observed an increase in in-hospital mortality (P = 0.04) during the first year of the COVID-19 pandemic. CONCLUSIONS: The psychosocial and socioeconomic burden of the COVID-19 pandemic may have contributed to the rise in penetrating injuries and the odds of in-hospital mortality among a cohort of children and adolescents who were admitted to our hospital following injury. This data may be used to prepare our trauma system for future societal shutdowns through data informed resource utilization.

Crystalloid volume is associated with short-term morbidity in children with severe traumatic brain injury: An Eastern Association for the Surgery of Trauma multicenter trial post hoc analysis.

OBJECTIVE: This study examined differences in clinical and resuscitation characteristics between injured children with and without severe traumatic brain injury (sTBI) and aimed to identify resuscitation characteristics associated with improved outcomes following sTBI. METHODS: This is a post hoc analysis of a prospective observational study of injured children younger than 18 years (2018-2019) transported from the scene, with elevated shock index pediatric-adjusted on arrival and head Abbreviated Injury Scale score of ≥3. Timing and volume of resuscitation products were assessed using χ 2t test, Fisher's exact t test, Kruskal-Wallis, and multivariable logistic regression analyses. RESULTS: There were 142 patients with sTBI and 547 with non-sTBI injuries. Severe traumatic brain injury patients had lower initial hemoglobin (11.3 vs. 12.4, p < 0.001), greater initial international normalized ratio (1.4 vs. 1.1, p < 0.001), greater Injury Severity Score (25 vs. 5, p < 0.001), greater rates of ventilator (59% vs. 11%, p < 0.001) and intensive care unit (ICU) requirement (79% vs. 27%, p < 0.001), and more inpatient complications (18% vs. 3.3%, p < 0.001). Severe traumatic brain injury patients received more prehospital crystalloid (25% vs. 15%, p = 0.008), ≥1 crystalloid boluses (52% vs. 24%, p < 0.001), and blood transfusion (44% vs. 12%, p < 0.001) than non-sTBI patients. Among sTBI patients, receipt of ≥1 crystalloid bolus (n = 75) was associated with greater ICU need (92% vs. 64%, p < 0.001), longer median ICU (6 vs. 4 days, p = 0.027) and hospital stay (9 vs. 4 days, p < 0.001), and more in-hospital complications (31% vs. 7.5%, p = 0.003) than those who received <1 bolus (n = 67). These findings persisted after adjustment for Injury Severity Score (odds ratio, 3.4-4.4; all p < 0.010). CONCLUSION: Pediatric trauma patients with sTBI received more crystalloid than those without sTBI despite having a greater international normalized ratio at presentation and more frequently requiring blood products. Excessive crystalloid may be associated with worsened outcomes, including in-hospital mortality, seen among pediatric sTBI patients who received ≥1 crystalloid bolus. Further attention to a crystalloid sparing, early transfusion approach to resuscitation of children with sTBI is needed. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Timing and volume of crystalloid and blood products in pediatric trauma: An Eastern Association for the Surgery of Trauma multicenter prospective observational study.

BACKGROUND: The purpose of this study was to determine the relationship between timing and volume of crystalloid before blood products and mortality, hypothesizing that earlier transfusion and decreased crystalloid before transfusion would be associated with improved outcomes. METHODS: A multi-institutional prospective observational study of pediatric trauma patients younger than 18 years, transported from the scene of injury with elevated age-adjusted shock index on arrival, was performed from April 2018 to September 2019. Volume and timing of prehospital, emergency department, and initial admission resuscitation were assessed including calculation of 20 ± 10 mL/kg crystalloid boluses overall and before transfusion. Multivariable Cox proportional hazards and logistic regression models identified factors associated with mortality and extended intensive care, ventilator, and hospital days. RESULTS: In 712 children at 24 trauma centers, mean age was 7.6 years, median (interquartile range) Injury Severity Score was 9 (2-20), and in-hospital mortality was 5.3% (n = 38). There were 311 patients(43.7%) who received at least one crystalloid bolus and 149 (20.9%) who received blood including 65 (9.6%) with massive transfusion activation. Half (53.3%) of patients who received greater than one crystalloid bolus required transfusion. Patients who received blood first (n = 41) had shorter median time to transfusion (19.8 vs. 78.0 minutes, p = 0.005) and less total fluid volume (50.4 vs. 86.6 mL/kg, p = 0.033) than those who received crystalloid first despite similar Injury Severity Score (median, 22 vs. 27, p = 0.40). On multivariable analysis, there was no association with mortality (p = 0.51); however, each crystalloid bolus after the first was incrementally associated with increased odds of extended ventilator, intensive care unit, and hospital days (all p < 0.05). Longer time to transfusion was associated with extended ventilator duration (odds ratio, 1.11; p = 0.04). CONCLUSION: Resuscitation with greater than one crystalloid bolus was associated with increased need for transfusion and worse outcomes including extended duration of mechanical ventilation and hospitalization in this prospective study. These data support a crystalloid-sparing, early transfusion approach for resuscitation of injured children. LEVEL OF EVIDENCE: Therapeutic, level IV.

Sepsis management and the pediatric surgeon.

Sepsis is a life-threatening condition that requires aggressive, timely, and multi-disciplinary care. Understanding the changes in national guidelines regarding definitions, diagnosis and the management of pediatric sepsis is critical for the pediatric surgeon participating in the care of these patients. The purpose of this article is to review the essential steps for the timely management of pediatric sepsis, including fluid resuscitation, antibiotics, vasopressors, and steroids. This includes a description of the key adjunct modalities of treatment, including renal replacement therapy and extracorporeal life support (ECLS).

Controversies in extracorporeal membrane oxygenation (ECMO) utilization and congenital diaphragmatic hernia (CDH) repair using a Delphi approach: from the American Pediatric Surgical Association Critical Care Committee (APSA-CCC).

PURPOSE: Review current practices and expert opinions on contraindications to extracorporeal membrane oxygenation (ECMO) in congenital diaphragmatic hernia (CDH) and contraindications to repair of CDH following initiation of ECMO. METHODS: Modified Delphi method was employed to achieve consensus among members of the American Pediatric Surgical Association Critical Care Committee (APSA-CCC). RESULTS: Overall response rate was 81% including current and former members of the APSA-CCC. An average of 5-15 CDH repairs were reported annually per institution; 26-50% of patients required ECMO. 100% of respondents would not offer ECMO to a patient with a complex or unrepairable cardiac defects or lethal chromosomal abnormality; 94.1% would not in the setting of severe intracranial hemorrhage (ICH). 76.5% and 72.2% of respondents would not offer CDH repair to patients on ECMO with grade III-IV ICH or new diagnosis of lethal genetic or metabolic abnormalities, respectively. There was significant variability in whether or not to repair CDH if unable to wean from ECMO at 4-5 weeks. CONCLUSIONS: Significant variability in practice pattern and opinions exist regarding contraindications to ECMO and when to offer repair of CDH for patients on ECMO. Ongoing work to evaluate outcomes is needed to standardize management and minimize potentially futile interventions. LEVEL OF EVIDENCE: V (expert opinion).

Routine Bronchoscopy and Fogarty Catheter Occlusion of Tracheoesophageal Fistulas.

INTRODUCTION: Use of a Fogarty catheter for emergent occlusion of tracheoesophageal fistulas (TEFs) has been described for use in unstable neonates. Our purpose was to describe a case series of elective Fogarty catheter occlusion of the TEF. MATERIALS AND METHODS: A formal operative laryngoscopy and rigid bronchoscopy were performed with Fogarty catheter placement into the fistula before surgical intervention. The balloon was inflated and gentle traction provided occlusion of the tract. An endotracheal tube was then placed in a midtracheal location irrespective of fistulous tract location. The Fogarty catheter was removed at the time of fistula ligation. RESULTS: Six patients underwent Fogarty catheter occlusion of the TEF at the time of repair. The average gestational age was 38 ± 2 weeks and birth weight was 2499 ± 399 g. Associated anomalies or comorbidities were present in 2 of 6 patients (33%). Five patients (83%) had an esophageal atresia with distal TEF, all of whom underwent surgical intervention before day of life (DOL) 2. Of these patients, 3 were performed thoracoscopically, 1 was converted from thoracoscopic to open, and 1 was initiated as an open procedure. One patient had an H-type fistula, which was repaired through a cervical approach on DOL 48. Average time required for both bronchoscopy and Fogarty placement was 10 ± 2 minutes. There were no complications associated with Fogarty catheter placement and catheter dislodgement did not occur during any of the procedures. CONCLUSION: Elective Fogarty catheter occlusion of TEF can be performed safely and expeditiously, alleviating many perioperative challenges of TEF.

Nonoperative management of esophageal perforations in the newborn.

BACKGROUND: Esophageal perforation in neonates occurs most often in cases of extreme prematurity and is commonly due to iatrogenic causes. Treatment over recent decades has become more conservative. The purpose of this study was to review cases of esophageal perforation in neonates and to describe the presentation, management, and outcomes. MATERIALS AND METHODS: A retrospective chart review was performed for patients with International Classification of Diseases, Ninth Revision code for esophageal perforation treated at our institution between the years 2009 and 2015. Data collected included demographic information, etiology of perforation (specifically focusing on cases secondary to orogastric tube placement), treatment course, time to resumption of enteral feeds, length of antibiotic use, time to subsequent radiographic resolution, and mortality. RESULTS: Twenty-five patients met study criteria. The average post-conceptual age at time of diagnosis was 26.5 ± 2.3 wk. All 25 patients were managed nonoperatively with bowel rest, parenteral nutrition, and broad-spectrum antibiotics. Enteral feeds were resumed after a median of 8 d (interquartile range [IQR]: 7-11), the median antibiotic duration was 7 d (IQR: 7-10), and the median time to follow-up esophagram was 7 d (IQR: 7-10). Overall, 24 of 25 patients (96%) demonstrated radiological resolution of perforation on initial follow-up esophagram. Four patients died during the study period, but no deaths were related to the diagnosis of esophageal perforation. CONCLUSIONS: In this largest reported sample of neonates treated for esophageal perforation, nonoperative management with bowel rest, parenteral nutrition, and antibiotics was successful.

Outcomes following neuromuscular blockade in patients receiving tracheostomies.

OBJECTIVE: The purpose of this study is to determine whether the use of neuromuscular blockade agents (NMBAs) in pediatric patients following tracheostomy is associated with increased rates of complications or a prolonged length of stay. METHODS: This was a single-center retrospective chart review of pediatric patients undergoing tracheostomy placement between 2010 and 2013 who were admitted to the pediatric or neonatal intensive care units and did or did not receive NMBA within 7 days post-procedure. RESULTS: Out of 114 included patients, 26 (23%) received NMBAs during the postoperative period. Patients receiving NMBAs were more likely to have cardiac disease and preoperative respiratory failure but less likely to have neurologic disease. Patients receiving NMBAs had a longer median postoperative length of stay (33 vs. 23 days, p=0.043) and were more likely to have postoperative ileus (12% vs. 3%, p=0.037). CONCLUSION: In patients undergoing tracheostomy placement, use of NMBAs is associated with prolonged postoperative hospital courses. NMBAs are not associated with a higher likelihood of postoperative complications.

Single-incision laparoscopic surgery (SILS) for children with Crohn's disease.

PURPOSE: Single-incision laparoscopic surgery (SILS) has been described in adults with Crohn's disease, but its use in pediatric Crohn's patients has been limited. The purpose of this study was to review our experience with SILS in pediatric patients with Crohn's disease. METHODS: A retrospective review was performed for patients diagnosed with Crohn's disease who underwent small bowel resection or ileocecectomy at a freestanding children's hospital from 2006 to 2014. Data collected included demographic data, interval from diagnosis to surgery, operative time, length of stay, and postoperative outcomes. RESULTS: Analysis identified 19 patients who underwent open surgery (OS) and 41 patients who underwent SILS. One patient (2.4 %) within the SILS group required conversion to OS. Demographic characteristics were similar between the 2 cohorts. The most common indication for surgery was stricture/obstruction (SILS 70.7 % vs. OS 68.4 %, p = 0.86), and ileocecectomy was the most common primary procedure performed (SILS 90.2 % vs. OS 100 % OS). Operative times were longer for SILS (135 ± 50 vs. 105 ± 37 min, p = 0.02). However, when the last 20 SILS cases were compared to all OS cases, the difference was no longer statistically significant (SILS 123.3 ± 34.2 vs. OS 105 ± 36.5, p = 0.12). No difference was noted in postoperative length of stay (SILS 6.5 ± 2.2 days vs. OS 7.4 ± 2.2 days, p = 0.16) or overall complication rate (SILS 24.4 % vs. OS 26.3 %, p = 0.16). CONCLUSION: SILS ileocecectomy is feasible in pediatric patients with Crohn's disease, achieving outcomes similar to OS. As experience increased, operative times also became comparable.

Minimally Invasive Ileal Pouch-Anal Anastomosis with Rectal Eversion Allows for Equivalent Outcomes in Continence in Pediatric Patients.

BACKGROUND: Different techniques for ileal pouch-anal anastomosis (IPAA) following total proctocolectomy (TPC) have been described in patients with ulcerative colitis (UC), including rectal eversion (RE). RE allows for precise identification of the dentate line, but concerns have been raised regarding continence rates. No studies have specifically evaluated RE in the pediatric population. The purpose of this study was to evaluate the outcomes and continence rates for pediatric patients undergoing minimally invasive surgery (MIS) TPC and IPAA with RE for UC. MATERIALS AND METHODS: All patients who underwent TPC and IPAA were reviewed at our institution. Data collected included demographics, proctocolectomy technique (open without RE versus MIS with RE), operative time, postoperative data, and continence outcomes following ileostomy closure. RESULTS: Thirty-three patients were identified who underwent TPC and IPAA between July 2006 and October 2014. Thirty of these patients underwent ileostomy takedown and were evaluated for continence. Of these, 17 (56.7%) patients had a laparoscopic procedure, 5 (16.7%) had a robotic-assisted procedure, and 8 (26.7%) had an open procedure. There were no statistically significant differences in regard to demographics, operative time, or length of stay when comparing the two groups. There were no differences in the two groups as measured at 1, 6, and 12 months in terms of number of daily stools (P = .93, .09, and .87, respectively), nighttime stooling (P = .29, .10, and .25, respectively), soiling (P = .43, .36, and .52, respectively), or stool-altering medication usage (P = .26, 1.00, and .37, respectively). CONCLUSIONS: The RE technique can be used safely and effectively during MIS TPC and IPAA in children without altering continence rates.

Delaying Appendectomy Does Not Lead to Higher Rates of Surgical Site Infections: A Multi-institutional Analysis of Children With Appendicitis.

OBJECTIVES: To investigate the association between time to appendectomy and the risk of surgical site infections (SSIs) in children with appendicitis across multiple NSQIP-Pediatrics institutions. BACKGROUND: Several recently published single institution retrospective studies have reported conflicting relationships between delaying appendectomy and the risk of increasing surgical site infections (SSI) in both children and adults. This study combines data from NSQIP-Pediatrics with institutional data to perform a multi-institutional analysis to examine the effects of delaying appendectomy on surgical site infections. METHODS: Data from NSQIP-Pediatrics between January 2010 and June 2012 for cases of appendectomy for appendicitis at 6 institutions (preoperative characteristics, time of operation, and postoperative occurrences) were combined with data from medical record review (length of symptoms; times of initial presentation, emergency department (ED) triage, and admission; and diagnosis as simple appendicitis (SA, acute) or complicated appendicitis (CA, gangrenous/ruptured)). Cochran-Armitage tests for trend and multivariable logistic regression models were used to evaluate associations between time to appendectomy and SSI. RESULTS: Of the 1338 patients included, 70% had SA and 30% had CA. Postoperative SSIs were more common in CA (5.7% vs 1.2%, P < 0.001). SSI rates did not differ significantly across hospitals (P = 0.17). Compared with patients who did not develop an SSI, patients who developed an SSI had similar times between ED triage and appendectomy (median (interquartile range) 11.5 hours (6.4-14.7) versus 9.7 hours (5.8-15.6, P = 0.36), and similar times from admission to appendectomy (5.5 hours (1.9-10.2) versus 4.3 hours (1.4-9.9), P = 0.36). Independent risk factors for SSI were CA (Odds Ratio (95% CI): 3.46 (1.48-8.10), P = 0.004), longer symptom duration (OR for a 10-hour increase: 1.05 (1.01-1.10), P = 0.02), and presence of sepsis/septic shock (2.70 (1.17-6.28), P = 0.02). CONCLUSIONS: A 16-hour delay from ED presentation or a 12-hour delay from hospital admission to appendectomy was not associated with an increased risk for SSI.

Managing moderately injured pediatric patients without immediate surgeon presence: 10 years later.

PURPOSE: Beginning in 2003, the pediatric emergency medicine (PEM) physician replaced the surgeon as the team leader for all level II trauma resuscitations at a busy pediatric trauma center. The purpose was to review the outcomes 10 years after implementing this practice change. METHODS: Trauma registry data for all level II activations requiring admission were extracted for the 21 months (April 1, 2001-December 31, 2002) prior to policy change (period 1, **n=627) and compared to the admitted patients from the 10 subsequent years (2003-2013; period 2, n=2694). Data included demographics, length of stay (LOS), injury severity score (ISS), readmissions, complications, and mortality. RESULTS: Mean ISS scores for admitted patients during period 1 (8.5) were higher than during period 2 (7.8). During period 1, 53.6% of patients underwent abdominal CT versus 41.8% in period 2 (p<.001), and the median ED LOS was 135 versus 191 minutes in period 2. From 2000 to 2003, 91% of patients seen as level II trauma alerts were admitted compared to 56.6% of patients in period 2 (p<0.001). There were no missed abdominal injuries identified, and readmission rate was low. CONCLUSIONS: We conclude that level II trauma resuscitations can be safely evaluated and managed without immediate surgeon presence. Although ED LOS increased, admission rate and CT scan usage decreased significantly without an increase in missed injuries.

An unusual case of foreign body pulmonary embolus: case report and review of penetrating trauma at a pediatric trauma center.

PURPOSE: Penetrating thoracic trauma is relatively rare in the pediatric population. Embolization of foreign bodies from penetrating trauma is very uncommon. We present a case of a 6-year-old boy with a penetrating foreign body from a projectile dislodged from a lawn mower. Imaging demonstrated a foreign body that embolized to the left pulmonary artery, which was successfully treated non-operatively. METHODS: We reviewed the penetrating thoracic trauma patients in the trauma registry at our institution between 1/1/03 and 12/31/12. Data collected included demographic data, procedures performed, complications and outcome. RESULTS: Sixty-five patients were identified with a diagnosis of penetrating thoracic trauma. Fourteen of the patients had low velocity penetrating trauma and 51 had high velocity injuries. Patients with high velocity injuries were more likely to be older and less likely to be Caucasian. There were no statistically significant differences between patients with low vs. high velocity injuries regarding severity scores or length of stay. There were no statistically significant differences in procedures required between patients with low and high velocity injuries. CONCLUSIONS: Penetrating thoracic trauma is rare in children. The case presented here represents the only report of cardiac foreign body embolus we could identify in a pediatric patient.

Does delay in appendectomy affect surgical site infection in children with appendicitis?

PURPOSE: The purpose of this study was to investigate the association between time from diagnosis to operation and surgical site infection (SSI) in children undergoing appendectomy. METHODS: Pediatric patients undergoing appendectomy in 2010-2012 were included. We collected data on patient demographics; length of symptoms; times of presentation, admission and surgery; antibiotic administration; operative findings; and occurrence of SSI. RESULTS: 1388 patients were analyzed. SSI occurred in 5.1% of all patients, 1.4% of simple appendicitis (SA) patients, and 12.4% of complex appendicitis (CA) patients. SSI did not increase significantly as the length of time between ED triage and operation increased (all patients, p=0.51; SA patients, p=0.91; CA patients, p=0.44) or with increased time from admission to operation (all patients, p=0.997; SA patients, p=0.69; CA patients, p=0.96). However, greater length of symptoms was associated with an increased risk of SSI (p<0.05 for all, SA and CA patients). In univariable analysis, obesity, and increased admission WBC count were each associated with significantly increased SSI. In multivariable analysis, only CA was a significant risk factor for SSI (p<0.0001). CONCLUSION: We found no significant increase in the risk of SSI related to delay in appendectomy. A future multi-institutional study is planned to confirm these results.

Enteric nervous system abnormalities are present in human necrotizing enterocolitis: potential neurotransplantation therapy.

INTRODUCTION: Intestinal dysmotility following human necrotizing enterocolitis suggests that the enteric nervous system is injured during the disease. We examined human intestinal specimens to characterize the enteric nervous system injury that occurs in necrotizing enterocolitis, and then used an animal model of experimental necrotizing enterocolitis to determine whether transplantation of neural stem cells can protect the enteric nervous system from injury. METHODS: Human intestinal specimens resected from patients with necrotizing enterocolitis (n = 18), from control patients with bowel atresia (n = 8), and from necrotizing enterocolitis and control patients undergoing stoma closure several months later (n = 14 and n = 6 respectively) were subjected to histologic examination, immunohistochemistry, and real-time reverse-transcription polymerase chain reaction to examine the myenteric plexus structure and neurotransmitter expression. In addition, experimental necrotizing enterocolitis was induced in newborn rat pups and neurotransplantation was performed by administration of fluorescently labeled neural stem cells, with subsequent visualization of transplanted cells and determination of intestinal integrity and intestinal motility. RESULTS: There was significant enteric nervous system damage with increased enteric nervous system apoptosis, and decreased neuronal nitric oxide synthase expression in myenteric ganglia from human intestine resected for necrotizing enterocolitis compared with control intestine. Structural and functional abnormalities persisted months later at the time of stoma closure. Similar abnormalities were identified in rat pups exposed to experimental necrotizing enterocolitis. Pups receiving neural stem cell transplantation had improved enteric nervous system and intestinal integrity, differentiation of transplanted neural stem cells into functional neurons, significantly improved intestinal transit, and significantly decreased mortality compared with control pups. CONCLUSIONS: Significant injury to the enteric nervous system occurs in both human and experimental necrotizing enterocolitis. Neural stem cell transplantation may represent a novel future therapy for patients with necrotizing enterocolitis.

Cholangiocyte apoptosis is an early event during induced metamorphosis in the sea lamprey, Petromyzon marinus L.

BACKGROUND: Research in biliary atresia has been hindered by lack of a suitable animal model. Lampreys are primitive vertebrates with distinct larval and adult life cycle stages. During metamorphosis the biliary system of the larval lamprey disappears. Lamprey metamorphosis has been proposed as a model for biliary atresia. We have begun to explore cellular events during lamprey metamorphosis by assessing for cholangiocyte apoptosis. MATERIALS AND METHODS: Sea lamprey larvae were housed under controlled environmental conditions. Premetamorphic larvae were induced to undergo metamorphosis by exposure to 0.01% KClO(4). Animals were photographed weekly, and the stage of metamorphosis was assigned based upon external features. Livers were harvested and processed for routine histology and immunohistochemistry. DNA fragmentation was detected using deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assays and cholangiocytes were identified with antibodies to cytokeratin-19. Percent TUNEL+ cholangiocytes at different stages of metamorphosis was determined. RESULTS: The percentage of TUNEL+ cholangiocytes was 10% in premetamorphic (stage 0) lamprey (n = 6), 51% at stage 1 (n = 6), 40% at stage 2 (n = 5), 18% at stage 3 (n = 5), and 9% stage 4 (n = 4). Routine hemotoxylin and eosin stained paraffin-embedded tissue sections revealed frequent apoptotic bodies at stages 3 and 4 of metamorphosis without histologic evidence of necrosis. CONCLUSIONS: DNA fragmentation is identified at the earliest stages of metamorphosis during induced metamorphosis in lampreys. Additional studies are necessary to validate this potentially valuable animal model.