Being small for gestational age is not an independent risk factor for mortality in neonates with congenital diaphragmatic hernia: a multicenter study

BACKGROUND

Congenital diaphragmatic hernia (CDH) accounts for 8% of all major congenital anomalies. Neonates who are small for gestational age (SGA) generally have a poorer prognosis. We sought to identify risk factors and variables associated with outcomes in neonates with CDH who are SGA in comparison to neonates who are appropriate for gestational age (AGA).

METHODS

We used the multicenter Diaphragmatic Hernia Research & Exploration Advancing Molecular Science (DHREAMS) study to include neonates enrolled from 2005 to 2019. Chi-squared or Fisher's exact tests were used to compare categorical variables and t tests or Wilcoxon rank sum for continuous variables. Cox model analyzed time to event outcomes and logistic regression analyzed binary outcomes.

RESULTS

589 neonates were examined. Ninety were SGA (15.3%). SGA patients were more likely to be female (p = 0.003), have a left sided CDH (p = 0.05), have additional congenital anomalies and be diagnosed with a genetic syndrome (p < 0.001). On initial single-variable analysis, SGA correlated with higher frequency of death prior to discharge (p < 0.001) and supplemental oxygen requirement at 28 days (p = 0.005). Twice as many SGA patients died before repair (12.2% vs 6.4%, p = 0.04). Using unadjusted Cox model, the risk of death prior to discharge among SGA patients was 1.57 times the risk for AGA patients (p = 0.029). There was no correlation between SGA and need for ECMO, pulmonary hypertensive medication at discharge or oxygen at discharge. After adjusting for confounding variables, SGA no longer correlated with mortality prior to discharge or incidence of unrepaired defects but remained significant for oxygen requirement at 28 days (p = 0.03).

CONCLUSION

Infants with CDH who are SGA have worse survival and poorer lung function than AGA infants. However, the outcome of SGA neonates is impacted by other factors including gestational age, genetic syndromes, and particularly congenital anomalies that contribute heavily to their poorer prognosis.

Rare and de novo variants in 827 congenital diaphragmatic hernia probands implicate LONP1 as candidate risk gene

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly that is often accompanied by other anomalies. Although the role of genetics in the pathogenesis of CDH has been established, only a small number of disease-associated genes have been identified. To further investigate the genetics of CDH, we analyzed de novo coding variants in 827 proband-parent trios and confirmed an overall significant enrichment of damaging de novo variants, especially in constrained genes. We identified LONP1 (lon peptidase 1, mitochondrial) and ALYREF (Aly/REF export factor) as candidate CDH-associated genes on the basis of de novo variants at a false discovery rate below 0.05. We also performed ultra-rare variant association analyses in 748 affected individuals and 11,220 ancestry-matched population control individuals and identified LONP1 as a risk gene contributing to CDH through both de novo and ultra-rare inherited largely heterozygous variants clustered in the core of the domains and segregating with CDH in affected familial individuals. Approximately 3% of our CDH cohort who are heterozygous with ultra-rare predicted damaging variants in LONP1 have a range of clinical phenotypes, including other anomalies in some individuals and higher mortality and requirement for extracorporeal membrane oxygenation. Mice with lung epithelium-specific deletion of Lonp1 die immediately after birth, most likely because of the observed severe reduction of lung growth, a known contributor to the high mortality in humans. Our findings of both de novo and inherited rare variants in the same gene may have implications in the design and analysis for other genetic studies of congenital anomalies.

Likely damaging de novo variants in congenital diaphragmatic hernia patients are associated with worse clinical outcomes

Purpose

Congenital diaphragmatic hernia (CDH) is associated with significant mortality and long-term morbidity in some but not all individuals. We hypothesize monogenic factors that cause CDH are likely to have pleiotropic effects and be associated with worse clinical outcomes.

Methods

We enrolled and prospectively followed 647 newborns with CDH and performed genomic sequencing on 462 trios to identify de novo variants. We grouped cases into those with and without likely damaging (LD) variants and systematically assessed CDH clinical outcomes between the genetic groups.

Results

Complex cases with additional congenital anomalies had higher mortality than isolated cases (P=8×10⁻⁶). Isolated cases with LD variants had similar mortality to complex cases and much higher mortality than isolated cases without LD (P=3×10⁻³). The trend was similar with pulmonary hypertension at 1 month. Cases with LD variants had an estimated 12–17 points lower scores on neurodevelopmental assessments at 2 years compared to cases without LD variants, and this difference is similar in isolated and complex cases.

Conclusion

We found that the LD genetic variants are associated with higher mortality, worse pulmonary hypertension, and worse neurodevelopment outcomes compared to non-LD variants. Our results have important implications for prognosis, potential intervention and long-term follow up for children with CDH.

Establishing best practices for structured NSQIP review

INTRODUCTION

We describe an institutional program (INR- Interval NSQIP Review), to augment NSQIP utility through structured, multidisciplinary review of surgical outcomes in order to create near 'real-time' adverse event (AE) monitoring and improve surgeon awareness.

METHODS

INR is a monthly meeting of quality analysts, surgeons and nursing leadership initiated to validate AE with NSQIP criteria, review data in real-time, and perform in-depth case analyses. Occurrence classification concerns were referred for national NSQIP review. Monthly reports were distributed to surgeons with AE rates and case-specific details.

RESULTS

Since implementation, 377/3,026 AE underwent in-depth review. Of those, 7 occurrences were referred for clarification by central NSQIP review. Overall 37 (1.2%) were not consistent with NSQIP-defined AE after INR. Time from occurrence to surgeon review decreased by 223 days (296 vs. 73 days, p = 0.006).

DISCUSSION

Structured monthly institutional review of AE prior to submission can create greater transparency and confidence of NSQIP data, reduce time from occurrence to surgeon recognition, and improve stakeholder understanding of AE definitions. This approach can be tailored to institutional needs and should be evaluated for downstream improvement in patient outcomes.

Comparative outcomes of right versus left congenital diaphragmatic hernia: A multicenter analysis

BACKGROUND

Congenital diaphragmatic hernia (CDH) occurs in 1 out of 2500-3000 live births. Right-sided CDHs (R-CDHs) comprise 25% of all CDH cases, and data are conflicting on outcomes of these patients. The aim of our study was to compare outcomes in patients with right versus left CDH (L-CDH).

METHODS

We analyzed a multicenter prospectively enrolled database to compare baseline characteristics and outcomes of neonates enrolled from January 2005 to January 2019 with R-CDH vs. L-CDH.

RESULTS

A total of 588, 495 L-CDH, and 93 R-CDH patients with CDH were analyzed. L-CDHs were more frequently diagnosed prenatally (p=0.011). Lung-to-head ratio was similar in both cohorts. R-CDHs had a lower frequency of primary repair (p=0.022) and a higher frequency of need for oxygen at discharge (p=0.013). However, in a multivariate analysis, need for oxygen at discharge was no longer significantly different. There were no differences in long-term neurodevelopmental outcomes assessed at two year follow up. There was no difference in mortality, need for ECMO, pulmonary hypertension, or hernia recurrence.

CONCLUSION

In this large series comparing R to L-CDH patients, we found no significant difference in mortality, use of ECMO, or pulmonary complications. Our study supports prior studies that R-CDHs are relatively larger and more often require a patch or muscle flap for repair.

TYPE OF STUDY

Prognosis study LEVEL OF EVIDENCE: Level II.

De novo variants in congenital diaphragmatic hernia identify MYRF as a new syndrome and reveal genetic overlaps with other developmental disorders

Congenital diaphragmatic hernia (CDH) is a severe birth defect that is often accompanied by other congenital anomalies. Previous exome sequencing studies for CDH have supported a role of de novo damaging variants but did not identify any recurrently mutated genes. To investigate further the genetics of CDH, we analyzed de novo coding variants in 362 proband-parent trios including 271 new trios reported in this study. We identified four unrelated individuals with damaging de novo variants in MYRF (P = 5.3x10(-8)), including one likely gene-disrupting (LGD) and three deleterious missense (D-mis) variants. Eight additional individuals with de novo LGD or missense variants were identified from our other genetic studies or from the literature. Common phenotypes of MYRF de novo variant carriers include CDH, congenital heart disease and genitourinary abnormalities, suggesting that it represents a novel syndrome. MYRF is a membrane associated transcriptional factor highly expressed in developing diaphragm and is depleted of LGD variants in the general population. All de novo missense variants aggregated in two functional protein domains. Analyzing the transcriptome of patient-derived diaphragm fibroblast cells suggest that disease associated variants abolish the transcription factor activity. Furthermore, we showed that the remaining genes with damaging variants in CDH significantly overlap with genes implicated in other developmental disorders. Gene expression patterns and patient phenotypes support pleiotropic effects of damaging variants in these genes on CDH and other developmental disorders. Finally, functional enrichment analysis implicates the disruption of regulation of gene expression, kinase activities, intra-cellular signaling, and cytoskeleton organization as pathogenic mechanisms in CDH.

A definition of gentle ventilation in congenital diaphragmatic hernia: a survey of neonatologists and pediatric surgeons

Ventilation practices have changed significantly since the initial reports in the mid 1980 of successful use of permissive hypercapnia and spontaneous ventilation [often called gentle ventilation (GV)] in infants with congenital diaphragmatic hernia (CDH). However, there has been little standardization of these practices or of the physiologic limits that define GV. We sought to ascertain among Diaphragmatic Hernia Research and Exploration; Advancing Molecular Science (DHREAMS) centers' GV practices in the neonatal management of CDH. Pediatric surgeons and neonatologists from DHREAMS centers completed an online survey on GV practices in infants with CDH. The survey gathered data on how individuals defined GV including ventilator settings, blood gas parameters and other factors of respiratory management. A total of 87 respondents, from 12 DHREAMS centers completed the survey for an individual response rate of 53% and a 92% center response rate. Approximately 99% of the respondents defined GV as accepting higher carbon dioxide (PCO2) and 60% of the respondents also defined GV as accepting a lower pH. There was less consensus about the use of sedation and neuromuscular blocking agents in GV, both within and across the centers. Acceptable pH and PCO2 levels are broader than the goal ranges. Despite a lack of formal standardization, the results suggest that GV practice is consistently defined as the use of permissive hypercapnia with mild respiratory acidosis and less consistently with the use of sedation and neuromuscular blocking agents. GV is the reported practice of surveyed neonatologists and pediatric surgeons in the respiratory management of infants with CDH.

Mutations in BMPR2 are not present in patients with pulmonary hypertension associated with congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a prevalent major congenital anomaly with significant morbidity and mortality. Thirty to 40% mortality in CDH is largely attributed to pulmonary hypoplasia and pulmonary hypertension (PH). We hypothesized that the underlying genetic risk factors for hereditary PH are shared with CDH associated PH.

METHODS

Participants were recruited as part of the Diaphragmatic Hernia Research & Exploration; Advancing Molecular Science (DHREAMS) study, a prospective cohort of neonates with a diaphragmatic defect enrolled from 2005 to 2012. PH affected patients with available DNA for sequencing had one of the following: moderate or severe PH on echocardiography at 3months of age; moderate of severe PH at 1month of age with death occurring prior to the 3month echocardiogram; or on PH medications at 1month of age. We sequenced the coding regions of the hereditary PH genes bone morphogenetic protein receptor type II (BMPR2), caveolin 1 (CAV1) and potassium channel subfamily K, member 3 (KCNK3) to screen for mutations.

RESULTS

There were 29 CDH patients with PH including 16 males and 13 females. Sequencing of BMPR2, CAV1, and KCNK3 coding regions did not identify any pathogenic variants in these genes.

TYPE OF STUDY

Prognosis study LEVEL OF EVIDENCE: Level IV.

Abdominal Trauma Evaluation for the Pediatric Surgeon

Trauma is the leading cause of pediatric mortality and abdominal injury is a significant contributor to morbidity. The assessment of abdominal trauma in children must be conducted expeditiously and thoroughly. Physical examination, laboratory testing, and imaging are central to trauma evaluation. In children with minor injury, protocols may help to limit the use of ionizing radiation. Children with significant abdominal injury who are unstable should be resuscitated with blood products and undergo emergent surgical intervention.

Undescended testes: does age at orchiopexy affect survival of the testis?

PURPOSE

The optimal age at which to perform orchiopexy for cryptorchidism has long been debated. The aim of this study was to determine if age at orchiopexy affected testicular atrophy.

METHODS

A retrospective review of patients undergoing orchiopexy from 2000 to 2010 was conducted. An individual testis, rather than patient, was used as the dependent variable. A total of 349 testicles from 1126 charts (ICD-9=752.51) were identified. Primary study outcome was testicular survival without atrophy.

RESULTS

Mean follow up for the study was 25 months. There was postoperative atrophy in 27 testes (7.7%). Intraabdominal testicle was independently associated with increased postsurgical atrophy (p<0.0001). The odds of postsurgical atrophy were 15.66 times higher for an abdominal vs. inguinal location (95% CI: 5.5-44.6). Testicular atrophy was highest for orchiopexy at ages 13-24 months (n=16 of 133, 12%) vs. those less than 13 months (n=3 of 64, 5%), and those greater than 24 months (n=8 of 152, 5%) (p=0.0024). After adjusting for location, age was not statistically significant with postsurgical atrophy (p=0.055).

CONCLUSIONS

From this study we conclude that there is no increase in testicular atrophy in patients less than 13 months.

Risks associated with fresh whole blood and red blood cell transfusions in a combat support hospital

OBJECTIVE

Fresh whole blood (FWB) and red blood cells (RBCs) are transfused to injured casualties in combat support hospitals. We evaluated the risks of FWB and RBCs transfused to combat-related casualties.

DESIGN

Retrospective chart review.

SETTING

Deployed U.S. Army combat support hospitals.

SUBJECTS

Donors of FWB and recipients of FWB and RBCs.

MEASUREMENTS AND RESULTS

The storage age of RBCs at transfusion was measured as an indicator of overall risk associated with the storage lesion of RBCs between January 2004 and December 2004 at one combat support hospital. Between April 2004 and December 2004, FWB was prescreened only at one combat support hospital for human immunodeficiency virus, hepatitis C virus, and hepatitis B surface antigen before transfusion. To estimate the general incidence of infectious agent contamination in FWB units, samples collected between May 2003 and February 2006 were tested retrospectively for human immunodeficiency virus, hepatitis B surface antigen, hepatitis C virus, and human lymphotropic virus. Results were compared between FWB samples prescreened and not prescreened for infectious agents before transfusion. At one combat support hospital in 2004, 87 patients were transfused 545 units of FWB and 685 patients were transfused 5,294 units of RBCs with a mean age at transfusion of 33 days (+/- 6 days). Retrospective testing of 2,831 samples from FWB donor units transfused in Iraq and Afghanistan between May 2003 and February 2006 indicated that three of 2,831 (0.11%) were positive for hepatitis C virus recombinant immunoblot assay, two of 2,831 (0.07%) were positive for human lymphotropic virus enzyme immunoassay, and none of 2,831 were positive for both human immunodeficiency virus 1/2 and hepatitis B surface antigen by Western blot and neutralization methods, respectively. The differences in the incidence of hepatitis C virus contamination of FWB donor units between those prescreened for hepatitis C virus (zero of 406; 0%) and not prescreened (three of 2,425; 0.12%) were not significant (p = .48).

CONCLUSIONS

The risk of infectious disease transmission with FWB transfusion can be minimized by rapid screening tests before transfusion. Because of the potential adverse outcomes of transfusing RBCs of increased storage age to combat-related trauma patients, the risks and benefits of FWB transfusions must be balanced with those of transfusing old RBCs in patients with life-threatening traumatic injuries.

Pediatric trauma: experience of a combat support hospital in Iraq

BACKGROUND/PURPOSE

The mission of the combat support hospital (CSH) is to evaluate and treat combatants injured during war operations. The 31st CSH in Balad and Baghdad, Iraq, during Operation Iraqi Freedom 2 also treated many injured civilians, including children. The purpose of this article is to report the experience of the 31st CSH treating pediatric trauma patients.

METHODS

A retrospective review of a comprehensive patient database collected in theater was conducted.

RESULTS

From January 1 to December 31, 2004, we treated 99 patients 17 years and younger. The average age of these patients was 10.6 years. Nine died of their wounds. The mean injury severity score was 11.6. Forty-one sustained gunshot wounds, 13 acquired fragment wounds (55% penetrating), and 22 were injured by improvised explosive devices (22%). Seventy-three patients required a total of 191 operations: 18 celiotomies, 8 craniotomies, 23 skeletal fixations, and 75 wound washout/debridements, among others. Predictors of mortality included admission Glasgow Coma Score less than 4 and admission pH less than 7.1.

CONCLUSIONS

The primary mission of the CSH in theater remains unchanged, but its role is evolving. With this study, we can begin to understand the needs of wounded children in urban conflict and help guide training and resource allocation in the future.

Bronchoscopy in the Blast Injury Patient

HYPOTHESIS

Delayed presentation of secondary airway injury is a significant clinical entity following blast injury.

DESIGN

Retrospective review.

SETTING

Combat Support Hospital, Operation Iraqi Freedom.

PATIENTS

Twenty-three blast injury patients with bronchoscopic evidence of secondary airway injury.

MAIN OUTCOME MEASURES

Symptom development and time frame, bronchoscopic findings, and requirement for mechanical ventilation.

RESULTS

All of the 23 patients presented within 12 hours of injury. Eleven patients (48%) arrived at the hospital after prior endotracheal intubation. The majority (17 patients [74%]) of patients had no carbonaceous sputum, singed nasal hair, or thoracic trauma that would suggest possible airway injury. Bronchoscopy revealed mucosal erythema and edema in 16 (70%) of the patients, 6 (23%) had additional airway carbonaceous deposits, and 5 (21%) had normal findings on initial bronchoscopy. Eight patients (35%) initially breathing spontaneously and demonstrating no thoracic trauma required intubation within 12 hours of admission owing to impending loss of airway patency. Bronchoscopy revealed significant airway edema (>50% patency loss) in 6 (75%) of these 8 patients, with additional carbonaceous deposits in 3 patients (38%). Patients requiring delayed intubation had a significantly greater respiratory rate on initial examination.

CONCLUSIONS

Manifestation of secondary airway injury may be delayed up to 12 hours following blast injury. We believe that blast injury patients should be observed for at least 18 hours after injury or until edema has resolved and in a setting amenable to emergent airway support and rapid bronchoscopic evaluation at the earliest indication of possible airway compromise.

Continuous noninvasive monitoring of cardiac performance and tissue perfusion in pediatric trauma patients

PURPOSE

The aim of this study was to assess the accuracy of a continuous survival probability prediction using noninvasive measures of cardiac performance and tissue perfusion in severely injured pediatric patients.

METHODS

Review of all patients entered into a prospective noninvasive monitoring protocol. Cardiac index (CI) was measured using a thoracic bioimpedance device and tissue perfusion was assessed by transcutaneous carbon dioxide (Ptcco(2)) tension and oxygen tension indexed to the fraction of inspired oxygen (Ptco(2)/Fio(2)). Survival probability (SP) was continuously calculated using a stochastic analysis program.

RESULTS

There were 45 patients with a total of 953 data sets. The mean age was 11 years (range, 1-16 years) with a mean Injury Severity Score of 24 (+/-16). There was no difference between survivors (n = 32) and nonsurvivors (n = 13) at study entry for heart rate, blood pressure, CI, or pulse oximetry (all P > .05). However, survivors demonstrated higher Ptcco(2) (45 vs 35), higher Ptco(2)/Fio(2) (236 vs 156), and higher predicted SP (89% vs 62%) compared with nonsurvivors at study entry and throughout the monitoring period (all P < .01). For the entire data set, the strongest independent predictors of survival were Ptco(2)/Fio(2) and SP. The area under the receiver operating characteristic curve for mortality prediction was 0.83 for SP and 0.71 for Ptco(2)/Fio(2), compared with 0.6 for heart rate, 0.51 for blood pressure, and 0.53 for CI. Similar hemodynamic patterns were observed for all injury patterns with the exception of those with severe brain injury.

CONCLUSIONS

Thoracic bioimpedance and transcutaneous monitoring give critical real-time hemodynamic and tissue perfusion data that can provide early identification of pathologic flow patterns and accurately predict survival.

Establishing learning curves for surgical residents using Cumulative Summation (CUSUM) Analysis

BACKGROUND

The assessment of technical proficiency is of paramount importance in the training of surgical residents. The fact that technical proficiency is underrepresented in the context of the ACGME outcomes project is evidenced in that proficiency skills comprise less than 5% of all assessments that evaluate residents. In this study, we use Cumulative Summation Analysis (CUSUM) as a visual objective analytic tool to determine performance accuracy and establish learning curves for PGY-1s in surgery.

METHODS

From April 2001 to May 2002, 11 surgical residents completed a 1-month anesthesia rotation. Each resident was asked to complete a preoperative airway assessment followed by endotracheal intubation with induction of anesthesia. Airway assessment was performed independently by a resident and a licensed anesthesiologist or certified anesthetist with the modified Mallampati Score. Data were sequentially collected and plotted for summated successes and failures.

RESULTS

The average intern required approximately 19 intubation attempts to complete the learning curve experience. There was no learning curve for airway assessment.

CONCLUSIONS

The CUSUM analysis is an effective objective tool to define learning curves for technical skills. Vital information is provided for surgical programs that place residents in positions to manage airways, and limitless potential for defining the learning curves for technical skills is provided.

The effect of obesity on bioimpedance cardiac index

BACKGROUND

Cardiac performance may be assessed noninvasively at the patient's bedside by using thoracic bioimpedance. However, it is unclear if this technique can be used reliably in critically injured obese patients because of increased body habitus and chest wall mass.

METHODS

A prospectively maintained database was used to identify all trauma patients admitted to the intensive care unit who underwent simultaneous measurement of cardiac performance by using both thoracic bioimpedance and thermodilution. Patients were divided into 2 groups based on their body mass index (BMI). Patients with a BMI less than 30 kg/m(2) were classified as nonobese, and patients with a BMI of 30 kg/m(2) or greater were categorized as obese.

RESULTS

There were 285 patients who underwent 1,138 simultaneous measurements of cardiac index by using both bioimpedance and thermodilution. There were 211 nonobese patients (BMI = 25 +/- 3 kg/m(2)) and 74 obese patients (BMI = 34 +/- 4 kg/m(2)). Bioimpedance correlated well with thermodilution for the entire population (r = .84, P < .0001), and was reliable equally in obese (r = .85, P < .0001) and nonobese (r = .82, P < .0001) patients. There actually was less test bias in the obese group (-.06 +/- .69) than in the nonobese group (-.16 +/- .75, P = .04).

CONCLUSIONS

Thoracic bioimpedance technology may be used reliably as a noninvasive alternative to pulmonary artery catheterization for assessment of cardiac performance in critically injured obese patients.

Acute lung injury using oleic acid in the laboratory rat: establishment of a working model and evidence against free radicals in the acute phase

OBJECTIVE

To determine the optimal model of acute respiratory distress syndrome (ARDS) using oleic acid in our laboratory and to measure the presence or absence of free radicals in this model.

DESIGN

This protocol consisted of 2 phases. During the first phase, various conditions were tested, to include different doses (30 or 50 microliters) of oleic acid, different levels of support (with and without mechanical ventilation), and different injury time periods (sacrifice 4 or 8 hours after injection). During the second phase, animals were randomly assigned to experimental (injured) and control (noninjured) groups for the measurement of free radicals by nitrotyrosine Western blot and by the conversion of hydroethidine to ethidium bromide by superoxide.

SETTING

Multidisciplinary laboratory and animal surgery suite.

PARTICIPANTS

Twenty-seven male Sprague-Dawley rats.

RESULTS

During the first phase, several animal deaths occurred in the high-dose, ventilated groups, whereas there were no deaths in the nonventilated animals. On hematoxylin and eosin stain, injury was greatest in the animals that received the higher dose of oleic acid and that were sacrificed at 8 hours. In the protocol's second phase, oxygen radical assays were negative for all experimental and control lungs.

CONCLUSIONS

During this study, we successfully established a working animal model of ARDS for our laboratory. Our findings to date suggest that free radicals do not contribute to oleic acid lung injury in the early stages.

Does telomerase activity add to the value of fine needle aspirations in evaluating thyroid nodules?

BACKGROUND

Telomerase replaces DNA sequences that are lost with cell division. Increased activity has been documented in malignant cells. Fine needle aspiration (FNA) has a 90% sensitivity for diagnosis of papillary carcinomas, but a specificity of 52%. This often leads to unnecessary surgery.

METHODS

Telomeric repeat amplification protocol assays were performed on FNA specimens of thyroid nodules in 19 patients. These results were compared with the surgical pathology using chi-square analysis.

RESULTS

There were 5 malignant and 14 benign nodules. Telomerase activity was found in 3 of 5 malignant (60%) and 9 of 14 benign (64%): sensitivity was 60%, specificity was 36%.

CONCLUSION

Telomerase assays did not add any additional information to FNA alone. Inflammatory changes associated with benign and malignant lesions can possess telomerase activity independent of the malignant state.

Bioabsorption qualities of chitosan-absorbable vascular templates(1)

PURPOSE:The scope of endovascular surgical techniques has expanded to include the treatment of diseases considered at one time to be amenable only to surgical treatment. The development of the biodegradable template follows as an extension of current permanent stent technology. The goal of our project is to develop and test chitosan as an absorbable template for the vascular system.Ultrapure chitosan, heparin sodium salt and lysozyme, and contrast agents MD-76R and Oxilan-350 were used to give radioopaque quality. Prototype chitosan vascular templates were obtained by a dip coating method in which alternate layers of chitosan were coagulated with nonsolvents or heparin. The amount of loaded and released heparin was determined using Azure II colorimetric assay. In vitro enzymatic degradation of templates was evaluated using lysozyme solutions in phosphate buffered saline. Mechanical properties were analyzed using the Dynamic Mechanical Analyzer, DMA-7 (Perkin Elmer, Foster City, Calif.). The microstructure of freeze-dried templates was investigated by field emission scanning electron microscopy (FE SEM) using an LEO 982 electron microscope (Zeiss, Thornwood, NY).In vivo deployment of the templates was undertaken in 10 full-sized pigs (Sus scrofa). After open expose and control of the iliac artery, a closed balloon catheter technique was used to advance and place the balloon catheter and template. The balloon was then expanded, deploying a Palmaz stent with a chitosan template anchored distally. Patency and deployment of the stent-template complex was confirmed by an arteriogram. The animals were sacrificed at 1, 2, 3, 4, and 5 weeks poststent placement, and arterial sections were taken for microscopic analysis. The amount of chitosan remaining was estimated to determine an in vivo rate of absorption.On hematoxilyn and eosin staining of the section arterial samples, a marked inflammatory response was noted and progressed with duration of in vivo contact. A giant cell foreign body reaction coupled with intense intimal hyperplasia and organized thrombus was also noted and progressed with duration of time in vivo. Also noted was the degradation of the template material with only small remnants of material noted within the giant cell by week 4. Clinically, none of the pigs developed limb ischemia or evidence of thromboembolic events.In this in vivo study, the chitosan template proved to be biodegradable but elicited an intense thrombotic and foreign body reaction despite heparin bonding. Further investigation is ongoing as to decreasing the thrombogenic and antigenic qualities of the template materials by either alteration of the base material or addition of bioactive side chains.

Trauma experience comparison of army forward surgical team surgeons at Ben Taub Hospital and Madigan Army Medical Center(2)(2)

Far forward life-saving surgical care is the mission of an army forward surgical team (FST). Trauma skill maintenance is necessary to complete that mission. A new program has been developed for FST training using the resources of a Level 1 trauma center. We sought to compare the experience of FST surgeons at a major urban trauma center with the yearly trauma experience at an army Level 2 trauma center.General surgeons of the 250th FST prospectively tabulated data for trauma patients during a September 1999 unit deployment to Ben Taub Hospital (Houston, Texas). Data collected included nature and location of injury, hospital admission, and surgical intervention. During 1999, similar data were collected at Madigan Army Medical Center (MAMC) (Ft. Lewis, Washington), home station of the 250th and Level 2 trauma center since November 1998.The FST general surgeons observed 319 injuries. Of those injured, 104 were admitted and 19 underwent urgent operation. Direct participation by FST general surgeons in the operative procedures varied. In 1999, MAMC general surgeons treated 455 trauma victims in direct supervision of Army general surgery residents. Madigan Army Medical Center general surgeons admitted 304 and urgently operated on 57 trauma patients, while 107 patients were transferred to another institution for definitive management of orthopedic and nonoperative neurosurgical injuries.CONCLUSIONS:The volume of trauma surgical cases at MAMC during 1999 was 3 times that seen in the 1-month rotation at Ben Taub. General surgeons performed more trauma and abdominal surgery at MAMC with significantly more direct involvement in patient care and operative procedures. The experience of the 250th FST does not justify trauma sustainment deployments for surgeons from military trauma centers.

Gastrin-releasing peptide: a potential growth factor expressed in human neuroblastoma tumors(1)

PURPOSE:Gastrin-releasing peptide (GRP) is a 27-amino acid neuropeptide that has been identified in the cytoplasm of many neuroendocrine tumors. Gastrin releasing peptide has been labeled as an autocrine growth factor in small cell lung carcinomas. Recent work has also shown this to be true in the growth of neuroblastoma cells in vitro. The purpose of this study was to demonstrate GRP and its receptor (GRP-R) in resected human neuroblastomas and to correlate the presence or absence with other known predictors of poor prognosis.To demonstrate the presence of GRP and GRP-R mRNA, total RNA was extracted from human neuroblastoma cells. A reverse transcription-polymerase chain reaction (RT-PCR) was then performed using specific primers. The products of the RT-PCR were then confirmed to be GRP and GRP-R cDNA by Southern blot analysis. The RT-PCR products were then sequenced, and these sequences were compared with the know sequences of GRP and GRP-R DNA.N = 19. GRP and GRP-R mRNA were present in all neuroblastoma specimens. Although no correlation with other known predictors of poor prognosis existed, transcripts of four different sizes (400, 450, 500, and 950 bp) were seen in the GRP-R transcripts. The sequences of the 950 bp-sized transcript reverse transcription PCR products were identical to the known GRP-R.We conclude that gastrin releasing peptide and gastrin releasing peptide receptor mRNA are present in all human neuroblastomas. Although qualitatively it appears to lack prognostic significance, its ubiquitous nature in the tumor suggests it may be a useful target on which to base future treatment modalities.

Pulmonary barotrauma in congenital diaphragmatic hernia: a clinicopathological correlation

BACKGROUND/PURPOSE

The high mortality rate in congenital diaphragmatic hernia (CDH) has been ascribed to pulmonary hypoplasia and persistent pulmonary hypertension of the newborn (PPHN). One of the principal treatment strategies has been the use of hyperventilation to reverse ductal shunting, but the wisdom of this approach is being questioned because of parenchymal lung injury from high inflation pressures. The authors hypothesize that the use of hyperventilation to reverse or prevent ductal shunting would result in ventilator-induced lung injury, which would be evident on postmortem examination. A retrospective review of clinical and autopsy information was conducted.

METHODS

Clinical and autopsy information gathered for a previously published series of 223 infants with CDH presenting in the first 24 hours of life was reviewed. Autopsy and clinical data were analyzed from 68 of 101 nonsurvivors who died with severe hypoxemia.

RESULTS

Sixty-two of 68 cases (91%) had evidence of diffuse alveolar damage and hyaline membrane formation, which was more evident in the ipsilateral lung. Forty-four (65%) infants had pneumothoraces, and 4 infants had interstitial fibrosis. Pulmonary hemorrhage was seen in 35 cases (50 maximum peak inspiratory pressure [mean +/- SD] was 40.4+/-7.9 cm H2O and lowest modified ventilatory index [respiratory rate x peak airway pressure] was 2323+/-836). The degree of pulmonary hypoplasia was evaluated by lung weight with the ratio of the observed combined lung weight to the expected lung weight based on birth weight and gestational age. The ratio based on birth weight was 57%+/-25%, and the ratio based on gestational age was 60%+/-26%. Twenty-one infants (35%) had nonpulmonary anomalies. The most significant was a 10% incidence of congenital heart disease. Apart from this, lethal nonpulmonary anomalies were rare.

CONCLUSION

These results suggest that lung injury secondary to mechanical ventilation plays an important role in the mortality rate of patients with CDH, which may become increasingly significant when there is underlying pulmonary hypoplasia.

Multidisciplinary evaluation of the distended abdomen in critically ill infants and children: the role of bedside sonography

Abdominal distention and metabolic acidosis are common in critically ill infants and children, and can be manifestations of an intra-abdominal catastrophe. This series demonstrates the value of bedside sonography (US) in this difficult assessment. Eight infants and children presented with the above situation. Seven were immediately post-cardiopulmonary resuscitation and none had antecedent histories of abdominal pain or bilious vomiting. Abdominal radiographs could not rule out intra-abdominal pathology such as ischemic bowel. Review of all laboratory and radiological data showed US to be a discerning modality for acute bowel pathology. A characteristic pattern of echogenic ascites, thickened bowel wall, dilated, fluid-filled bowel lumen, and lack of peristalsis was seen in those children with gangrenous bowel. Sonographic examination accurately predicted the status of the bowel in all patients. Four patients survived: two had segmental ileal necrosis, one had localized gangrene of the jejunum (twice), and one had necrotic bowel from a closed-loop obstruction. The four who died had malrotation with volvulus (two), superior mesenteric venous thrombosis, and one was immunocompromised with pulmonary aspiration. We conclude that bedside US can be extremely valuable as an adjunct in assessing the abdomen and diagnosing gangrenous bowel in critically ill infants and children.

Congenital thymic cysts in children--mostly misdiagnosed

BACKGROUND/PURPOSE

Thymic cysts are rare lesions of the neck and mediastinum that are difficult to diagnose. Often considered inconsequential, these lesions can frequently be symptomatic. In this report the authors contrast their experience with that of the literature.

METHODS

From 1984 through 1997, the authors encountered 14 patients with this lesion. All cysts were completely excised. Patients that had an acquired cyst of the thymus were excluded from this series.

RESULTS

Of the 14 patients ranging in age from 2 weeks to 16 years, seven patients had cervical masses, five had mediastinal masses, and two children had both sites involved. Seven children were symptomatic with wheezing and upper respiratory infection, with cough and fever being the most common clinical features. Investigations included chest radiograph, contrast esophagram, sonography (US) and computerized tomography (CT). Displacement of vital mediastinal or neck structures was observed in eight patients. Only two patients received correct diagnosis before surgery. Successful and complete excision of all cysts was achieved. The cysts were benign and ranged in size from 2 to 22 cm in diameter.

CONCLUSION

Often forgotten, thymic cysts are rare benign lesions that should be considered in the differential diagnosis of cervical and mediastinal masses in children.

Congenital diaphragmatic hernia--a tale of two cities: the Toronto experience

PURPOSE

The optimal therapy for congenital diaphragmatic hernia (CDH) is evolving. This study analyzes the results of treatment of CDH in a large tertiary care pediatric center using conventional and high-frequency oscillatory ventilation (HFOV) without extracorporeal membrane oxygenation (ECMO) contrasting these with a parallel study from a similar large urban center using conventional ventilation with ECMO.

METHODS

Between 1981 and 1994, 223 consecutive neonates who had CDH diagnosed in the first 12 hours of life were referred for treatment before repair. Conventional ventilation was used with conversion to HFOV for refractory hypoxemia or hypercapnia, and a predicted near 100% mortality rate. ECMO was used in only three patients, all of whom died. A retrospective database was collected. Thirty-one clinical variables were tested for their association with the outcome. Common ventilatory and oxygenation indices were tested for their prognostic capability.

RESULTS

Apgar scores, birth weight, right-sided defects, pneumothorax, total ventilatory time, and the use of high frequency oscillatory ventilation were the only variables associated with outcome. A modified ventilatory index and postductal A-aDo2 were strong prognostic indicators. From 1981 to 1984 surgery was performed on an emergency basis. Since 1985 surgery was deferred until stabilization had been achieved. This resulted in a shift in the mortality from postoperative to preoperative with no change in total survival. HFOV did not alter the overall survival. Results of autopsies performed (70%) showed significant pulmonary hypoplasia and barotrauma as the primary causes of death. The survival was 54.7%.

CONCLUSION

Conventional ventilation with HFOV produced equal survival to conventional ventilation with ECMO in two comparable series. Pulmonary hypoplasia was the principle cause of death. This continued high mortality at both centers suggests that new therapies are required to improve outcomes.

A 45-year experience with surgical treatment of peptic ulcer disease in children

Peptic ulcer disease (PUD) requiring surgical treatment has become rare with the availability of modern medical management. A retrospective study of all patients who required operations for PUD between 1949 and 1994 (n = 43) was done. The patients were classified into 3 groups: A (n = 38): pre-histamine-2 (H2) blocker era (1949-1975); B (n = 3): pre-hydrogen-potassium (H-K+) ATPase inhibitor era (1976-1988); C (n = 2): H-K+ ATPase inhibitor era (1989-1994). Data, analyzed using X2 analysis (P < .01), included preoperative medical therapy, surgical indications, type of operation performed, complications, and postoperative medical therapy. The indication for surgery in group A was bleeding (26), perforation (8), or obstruction (4); in group B the indication was obstruction (2) or perforation (1); in group C the indication was obstruction (1) or bleeding (1). The incidence of obstruction as an indication for surgery did not differ among the groups (P < .01). Two of the three patients who had surgery for obstruction in groups B and C had biopsy-proven Helicobacter pylori. The postoperative morbidity rate was lower for groups B and C, although not significantly. The relative mortality among the groups did not change (P > .01). Children with PUD can have complications similar to those of adults with PUD. Since the introduction of H2 antagonists, the recognition and treatment of H pylori, and the use of H-K+ ATPase inhibition, the incidence of operations for bleeding and perforation has decreased dramatically. However, the incidence of surgery for obstruction remains the same.

Enhanced detection of preinvasive breast cancer: combined role of mammography and needle localization biopsy

Several recent reports have described an increase in the incidence of preinvasive carcinoma of the breast. To determine the incidence of preinvasive breast cancer at our institution, the results of 469 consecutive outpatient breast biopsies performed at Walter Reed Army Medical Center between July 1, 1985, and January 1, 1987, were reviewed. During this time period, 256 biopsies were performed on palpable masses, and 213 needle localization biopsies were performed on mammographically suspicious lesions. The overall incidence of cancer was 15.4%. Needle localization biopsies yielded a diagnosis of cancer in 17.8% of cases, as did 13.3% of biopsies performed on palpable masses. Eight of 38 (21.1%) carcinomas identified by mammography were preinvasive at the time of diagnosis. Only one of 34 (2.9%) cancers identified because of a breast mass was preinvasive. We conclude that screening mammography is an invaluable tool for the detection of preinvasive carcinoma of the breast and that the increased use of mammography will result in an increase in the incidence of detection of this lesion.