Association of Sociodemographic Factors with Surgical Management of Hepatoblastoma and Hepatocellular Carcinoma in Children.

OBJECTIVE: To evaluate for disparities in surgical care among US children with hepatoblastoma (HB) and hepatocellular carcinoma (HCC). STUDY DESIGN: In this retrospective National Cancer Database study (2004-2015), children aged <18 years with HB or HCC were included. Multivariable mixed-effects logistic regression was used to evaluate the association of sociodemographic factors (age, sex, race and ethnicity, insurance status, income, proximity to treating hospital) with the odds of undergoing surgical treatment after adjusting for disease-related factors (tumor size, metastasis, comorbidities) and hospital-level effects. Subgroup analyses by tumor histology were performed. RESULTS: A total of 811 children were included (HB: 80.9%; HCC: 19.1%), of which 610 (75.2%) underwent surgical treatment. Following adjustment, decreased odds of undergoing surgical treatment were associated with Black race (OR: 0.46 vs White, 95% CI [95% CI]: 0.26-0.80, P = .01), and having Medicaid (OR: 0.58 vs private, 95% CI: 0.38-0.88, P = .01) or no insurance (OR: 0.33 vs private, 95% CI: 0.13-0.80, P = .02). In children with HB, Black race was associated with decreased odds of undergoing surgical treatment (OR: 0.47 vs White, 95% CI: 0.25-0.89, P = .02). In children with HCC, Medicaid (OR: 0.10 vs private, 95% CI: 0.03-0.35, P < .001), or no insurance status (OR: 0.10 vs private, 95% CI: 0.01-0.83, P = .03) were associated with decreased odds of undergoing surgical treatment. Other than metastatic disease, no additional factors were associated with likelihood of surgical treatment in any group. CONCLUSIONS: Black race and having Medicaid or no insurance are independently associated with decreased odds of surgical treatment in children with HB and HCC, respectively. These children may be less likely to undergo curative surgery for their liver cancer.

Operative Complications Following Gastrostomy Tube Placement After Cardiac Surgery During Infancy.

INTRODUCTION: Gastrostomy tube (GT) placement is common in infants following repair of congenital heart defects. We aimed to determine rate of operative complications and predictors of short-term GT use to counsel parents regarding the risks and benefits of GT placement. METHODS: We reviewed infants aged <1 y with congenital heart disease who underwent GT placement after cardiac surgery between 2018 and 2021. Demographics and clinical data were collected and analyzed. Comparisons were made between infants who required the GT for more than 1 y and those who required the GT for less than 1 y. RESULTS: One hundred thirty three infants were included; 35 (26%) suffered one or more complication including wound infection (4, 3%), granulation tissue (3, 2%), tube dislodgement (10), leakage from the tube (9), unplanned emergency department visit (15), and unplanned readmission (1). Thirty-four infants used the GT for feeds for 1 y or less (26%) including 17 (13%) who used it for 3 mo or less. Fifty-six infants had their GT removed during the study period (42%), 20 of whom required gastrocutaneous fistula closure (36%). Thirty-three infants had a GT placed on or before day of life 30, 17 (52%) used the GT for less than 1 y, and 10 (31%) used it for 3 mo or less. CONCLUSIONS: GT placement is associated with a relatively high complication and reoperation rate. GT placement in infants aged less than 30 d is associated with shorter duration of use. Risks, benefits, and alternatives such as nasogastric tube feeds should be discussed in the shared decision-making process for selected infants.

Pneumatosis Intestinalis in Children With Intestinal Failure: The Result of Intestinal Stress From Enteral Feeding?

OBJECTIVE: The incidence and significance of pneumatosis intestinalis (PI) in children with a diagnosis of intestinal failure is not well understood. The aim of this study was to identify clinical and anatomical factors associated with the imaging findings of PI in patients with intestinal failure. METHODS: We performed a retrospective review of all children with a diagnosis of intestinal failure at Children's Hospital Colorado between January 2019 and April 2022. Patients were stratified and compared based on the incidence of PI on abdominal imaging. Differences were compared using 2-sample Wilcoxon tests, chi-square, or Fisher exact tests. RESULTS: There were 111 patients identified with a diagnosis of intestinal failure and 30.6% (34) developed at least 1 instance of PI. There were no differences in etiology of intestinal failure or anatomy between those who developed PI and those who did not. Patients who developed PI, were less likely to be on total parental nutrition (60.6% vs 98.6%, P < 0.001) and more likely to be receiving any form of enteral feeds (87.9% vs 66.2%, P = 0.035) or tube feeds (75.8% vs 44.2%, P = 0.0045). Of the children with PI, 30.3% (10) were undergoing an enteral feed advancement at time of PI development. Three patients with PI underwent laparotomy for PI treatment, 2 of which were negative laparotomies. CONCLUSIONS: The development of PI in children with intestinal failure is likely a benign finding. It is associated with enteral feeding and may be due to increased intestinal stress.

Trainee educational curriculum to standardize central venous catheter repair.

INTRODUCTION: Children may require durable central venous catheters (CVCs) for various reasons. CVC-related integrity complications are common and can often be repaired at the bedside to increase lifetime. Variability in repair techniques can lead to complications, including the need for repeat repair and Central Line Associated Blood Stream Infection (CLABSI). METHODS: The impact of an educational curriculum to standardize tunneled CVC repairs for trainees on a pediatric surgery service was studied, focusing on comfort level with tunneled CVC repair and to determine the impact on complication rates. Rotating trainees studied a dedicated audiovisual educational curriculum comprised of a video, educational slides, and a practical component from November 2020 through January 2022. Experience and comfort level with tunneled CVC repairs were assessed before and after the rotation. CVCs repaired during the duration of the study were evaluated and compared to the period prior. RESULTS: Forty-nine individuals completed the pre- and post-training survey. Respondents (34.7%, n = 17) most commonly reported one year of surgical experience, and (79.6%, n = 39) had never observed or assisted in a repair previously. Following training, respondents felt more comfortable with all aspects of the CVC repair process (p < 0.001). There were no statistically significant differences in re-repair rates or CLABSI rates following the implementation of the curriculum. CONCLUSIONS: Tunneled CVC procedural repair variability can be standardized with a dedicated educational curriculum for rotating trainees, which improves knowledge and comfort with such procedures.

A benchmark for non-covalent interactions in organometallic crystals.

Organometallic complexes are the basis for homogeneous catalysis, have applications in materials science and are also active pharmaceutical ingredients. The interaction between transition metal complexes in the solid state is determining their thermodynamics and bio-availability. Non-covalent interactions such as hydrogen bonding and van der Waals are stabilizing crystals of transition metal complexes. The variation of ligand field, central metal atoms and their oxidation and spin states are determinants of the magnitude of their inter-molecular interactions. A comparison of a set of 43 manually curated experimental heats of sublimation (the new XTMC43 set) and results from periodic DFT calculations shows that an agreement to within 9% can be achieved using GGA or mGGA functionals with atom-centred Gaussian-type basis functions. The need for careful assessments of consistency, calibration and reproducibility of experimental and computational data is discussed. Results regarding the new XTMC43 benchmark set are suggested to serve as a starting point for further method development, systematic screening and crystal engineering.

Surgeon, patient, and caregiver perspective of pediatric surgical telemedicine in the COVID-19 pandemic era.

PURPOSE: Adoption of telemedicine (TME) in surgical specialties, prior to the COVID-19 pandemic, has previously been slow. The purpose of this prospective, observational, single institution study is to evaluate surgeon and caregiver perspectives of TMEs during the pandemic. METHODS: Surveys were distributed to surgical faculty regarding perceptions of TME early during the pandemic and 2 months later. Caregivers (or patients > 18 years old) were asked after each TME to complete a survey regarding perceptions of TMEs. RESULTS: Surveys were distributed to 73 surgeons. Response rates were 71% initially and 63% at follow-up. Sixty-eight percent reported no prior TME experience. No significant differences were noted in the overall satisfaction. An inverse relationship between surgeon age and satisfaction at the follow-up survey was identified (p = 0.007). Additional surveys were distributed to 616 caregivers or patients (response rate 13%). Seventy-two percent reported no prior experience with TME and 79% described TME as similar to an in-person visit. Audiovisual satisfaction of the TME was higher in greater income households (p = 0.02). CONCLUSIONS: Pre-pandemic experience with TME was low in both groups; however, experiences were perceived as satisfactory. Positive experiences with TME may encourage increased utilization in the future, although demographic variations may impact satisfaction with TME. TRIAL REGISTRATION: Unique identifier NCT04376710 at Clinicaltrials.gov (5/6/2020).

The use of ultrasound in establishing COVID-19 infection as part of a trauma evaluation.

PURPOSE: The use of lung ultrasound for diagnosis of COVID-19 has emerged during the pandemic as a beneficial diagnostic modality due to its rapid availability, bedside use, and lack of radiation. This study aimed to determine if routine ultrasound (US) imaging of the lungs of trauma patients with COVID-19 infections who undergo extended focused assessment with sonography for trauma (EFAST) correlates with computed tomography (CT) imaging and X-ray findings, as previously reported in other populations. METHODS: This was a prospective, observational feasibility study performed at two level 1 trauma centers. US, CT, and X-ray imaging were retrospectively reviewed by a surgical trainee and a board-certified radiologist to determine any correlation of imaging findings in patients with active COVID-19 infection. RESULTS: There were 53 patients with lung US images from EFAST available for evaluation and COVID-19 testing. The overall COVID-19 positivity rate was 7.5%. COVID-19 infection was accurately identified by one patient on US by the trainee, but there was a 15.1% false-positive rate for infection based on the radiologist examination. CONCLUSIONS: Evaluation of the lung during EFAST cannot be used in the trauma setting to identify patients with active COVID-19 infection or to stratify patients as high or low risk of infection. This is likely due to differences in lung imaging technique and the presence of concomitant thoracic injury.

Attitudes Affecting Decision-Making for Use of Radiologic Enteral Contrast in the Management of Pediatric Adhesive Small Bowel Obstruction: A Survey Study of Pediatric Surgeons.

BACKGROUND: Pediatric surgeons are often asked to treat clinical problems for which little high-quality data exist. For adults with adhesive small bowel obstruction (ASBO), water soluble contrast-based protocols are used to guide management. Little is known about their utility in children. We aimed to better understand key factors in clinical decision-making processes and integration of adult based data in pediatric surgeon's approach to ASBO. METHODS: We administered a web-based survey to practicing pediatric surgeons at institutions comprising the Western Pediatric Surgery Research Consortium. RESULTS: The response rate was 69% (78/113). Over half of respondents reported using contrast protocols to guide ASBO management either routinely or occasionally (n = 47, 60%). Common themes regarding the incorporation of adult-based data into clinical practice included the need to adapt protocols for pediatric patients, the dearth of pediatric specific data, and the quality of the published adult evidence. CONCLUSIONS: Our findings demonstrate that pediatric surgeons use contrast-based protocols for the management of ASBO despite the paucity of pediatric specific data. Furthermore, our survey data help us understand how pediatric surgeons incorporate adult based evidence into their practice.

Infantile myofibromatosis: multiple firm nodules in a premature newborn.

Infantile myofibromatosis is a rare myofibroblastic proliferative disorder characterized by firm, skin-colored to red-purple cutaneous and subcutaneous nodules; these are the most prevalent fibrous tumors observed in infancy. A premature male infant presented at birth with multiple subcutaneous firm skin-colored nodules measuring about 1-2cm each. Full body MRI and excisional biopsy of the right chest nodule confirmed the diagnosis. We review the case of infantile myofibromatosis and discuss its highly heterogeneous presentation and clinical course, as well as histopathology, genetic testing, and approaches to management.

Left main coronary artery dissection in pediatric sport-related chest trauma.

BACKGROUND: Traumatic coronary artery dissection (CAD) after blunt chest trauma (BCT) is extremely rare, particularly in children. Among coronary dissections, left main coronary artery (LMCA) dissection is the least common, with only two pediatric cases reported previously. Manifestations of coronary dissections can range from ST segment changes to sudden death. However, these manifestations are not specific and can be present with other cardiac injuries. To our knowledge we present the first pediatric case of traumatic LMCA dissection after sport-related BCT that was treated successfully with coronary stenting. CASE REPORT: A 14-year-old child sustained BCT during a baseball game. Early in the clinical course, he had episodes of ventricular dysrhythmias, diffuse ST changes, rising troponin I, and hemodynamic instability. Emergent cardiac catheterization revealed an LMCA dissection with extension into the proximal left anterior descending artery (LADA). A bare metal stent was placed from the LMCA to the LADA, which improved blood flow through the area of dissection. He has had almost full recovery of myocardial function and has been managed as an outpatient with oral heart failure and antiplatelet medications. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Our case highlights that CAD, although rare, can occur after pediatric BCT. Pediatric emergency responders must have a heightened awareness that evidence of ongoing myocardial ischemia, such as evolving and focal myocardial infarction on electrocardiogram, persistent elevation or rising troponin I, and worsening cardiogenic shock, can represent a coronary event and warrant further evaluation. Cardiac catheterization can be both a diagnostic and therapeutic modality in such cases. Early recognition and management is vital for myocardial recovery.

Management and Outcomes of Hepatoblastoma in Patients With Trisomy 18: A Systematic Review and Pooled Analysis of 70 Patients.

INTRODUCTION: Predicted 1-year survival of children with trisomy 18 (T18) has increased to 59.3%. We aimed to systematically review the characteristics, management, and outcomes of children with T18 and hepatoblastoma. METHODS: A systematic literature review of the PubMed, Embase, Scopus, Web of Science, and Cochrane Library databases was performed according to the PRISMA 2020 statement (end-of-search date: 03/03/2024). RESULTS: Fifty studies reporting on 70 patients were included. The median age at diagnosis was 11.5 months, 85.9% were female (n = 55/64), and 15.0% had mosaic T18 (n = 6/40). Diagnosis was made during symptom evaluation (most commonly hepatomegaly or abdominal mass) in 45.5% (n = 15/33), incidentally in 24.2% (n = 8/33), during surveillance with abdominal ultrasound in 18.2% (n = 6/33), and at autopsy in 12.1% (n = 4/33). The median tumor size was 6.4 cm, 33.3% had multiple tumors (n = 14/42), and metastasis was present in one patient (3.8%; n = 1/26). Neoadjuvant chemotherapy was administered in 42.6% (n = 26/61) and adjuvant chemotherapy in 31.6% (n = 18/57). Surgical treatment was performed in 64.2% (n = 43/67). Of the patients not diagnosed on autopsy, overall mortality was 35.5% (n = 22/62) over a median follow-up of 11.0 months. Among the 26 deceased patients (including those diagnosed on autopsy), the most common causes of death were cardiopulmonary disease (38.5%, n = 10/26) and tumor progression (30.8%, n = 8/26). CONCLUSIONS: T18 does not preclude resection with curative intent for hepatoblastoma. Combination of surgery and chemotherapy should be considered in children on an individualized basis depending on tumor characteristics and underlying cardiopulmonary comorbidities. Locoregional modalities may have a role in the setting of severe comorbidities. LEVEL OF EVIDENCE: Level IV evidence.

Variation in cost of disposable operating room supplies at a children's hospital.

BACKGROUND: Operating room (OR) costs account for 40% of hospital costs. Disposable supplies make up a portion of OR costs and are the only cost that is under control of the surgeon. There are little data to explain how surgeons select surgical supplies and what factors predict supply selection. Our goal with the current work was to assess variation in cost of disposable OR supplies at the surgeon level, hypothesizing high variability would be observed. STUDY DESIGN: Cost data were reviewed for the most common procedures performed by five surgical divisions at a single children's hospital over a six-month period in 2021. For each procedure, the average disposable OR costs for each surgeon were tabulated and compared to the median supply cost for a given procedure at the group level. RESULTS: For each procedure, the variation ranged from 149% (gastrostomy tube placement) to 758% (tonsillectomy and adenoidectomy). The median supply cost for an individual surgeon was not always above or below the median supply cost for that procedure for the group. No relationship was observed between whether the supply cost was above or below the median for a given case and a surgeon's case volume, years in practice, or operative length. There was also no relationship between surgeon volume and median cost, surgery length, and years of experience. CONCLUSION: These data demonstrate variation in the cost of disposable OR supplies at the individual surgeon level at a single institution. This variation is not explained by case volume, years in practice, or operative length.

Debunking Myths of Gender Informed Care: What Every Pediatric Surgeon Should Know.

As the transgender population in the United States grows, gender-affirming care is becoming increasingly relevant to the practice of pediatric surgery. Medical care for the transgender and gender diverse population is a politically charged topic with significant complexity and opportunities for clarification. It is important for providers to better understand this population's unique health and social needs. This review aims to debunk long-standing myths regarding gender-affirming care and highlight the current therapeutic and legislative landscapes within the scope of pediatric surgical practice. LEVEL OF EVIDENCE: IV.

Practice patterns in the management of pediatric iliofemoral arterial thrombosis.

BACKGROUND: Acute arterial thrombosis can be life- and limb-threatening. Most pediatric patients with iliofemoral arterial thrombosis are treated successfully with medical therapy; however, expert consensus is limited, and many recommendations are based on the extrapolation of adult data. We aim to understand treatment patterns and long-term outcomes after pediatric acute iliofemoral arterial thrombosis, from which management recommendations can be informed. METHODS: A single-institution retrospective study of pediatric patients diagnosed with iliofemoral arterial thrombosis from 2009 to 2018 was performed. Multiple parameters of management and follow-up were evaluated. Children anticoagulated for ≤28 days versus >28 days were compared. Data analysis used Fisher exact and Mann-Whitney U tests. RESULTS: Two hundred thirty-six children were included. Median age at diagnosis was 65 days (interquartile range 17-163), with 207 diagnosed as infants, 15 diagnosed between 1 to 2 years, and 14 diagnosed between 2 to 16 years. The median treatment duration was 28 days (interquartile range 13-42); patients treated for >28 days had a longer time for thrombus resolution, and more follow-up ultrasounds were performed. Limb length discrepancy did not differ between the groups (1.0% vs 6.3%, P = .06), and no patients were documented to have developed peripheral arterial disease over a median 6.5-year follow-up. Multiple treatment strategies were employed, the most common being heparin bridged to enoxaparin (25.0%) and enoxaparin monotherapy (21.6%). Eight patients (3.4%) underwent surgical intervention. CONCLUSION: Pediatric iliofemoral arterial thrombosis is primarily a disease of infants treated adequately with heparin or enoxaparin, infrequently requires surgical intervention, and is rarely associated with long-term complications. When guided by thrombus resolution on ultrasound, a four-week or shorter course of anticoagulation does not increase the need for surgical intervention or long-term complications.

Quality Improvement Campaign Improved Utilization of Rapid Sequence MRI for Diagnosis of Pediatric Appendicitis.

INTRODUCTION: Appendicitis is the most common indication for emergency general surgery in the pediatric population. Computed tomography (CT) or magnetic resonance imaging (MRI) may be used for diagnosis when ultrasound findings are equivocal. However, CT involves unnecessary radiation exposure if MRI is available. After introducing a rapid sequence MRI (rsMRI) appendicitis protocol at our institution, CT was still preferentially used. We therefore implemented a quality improvement (QI) campaign to reduce the rate of CTs and increase the rate of rsMRI. Here, we assess the effectiveness of the QI campaign while evaluating potential barriers to using rsMRI. METHODS: We conducted a mixed methods study, first performing stakeholder interviews which informed the design of a QI campaign initiated in May 2021 and a midway feedback survey in December 2021. A retrospective cohort study was then performed of children evaluated for appendicitis at our institution between January 1, 2016, and April 30, 2022. CT and rsMRI rates were compared before and after QI campaign implementation. RESULTS: There was a significant decrease in rate of CTs and increase in rate of rsMRIs performed following the initiation of the QI campaign (p < 0.0001). The rate of CT scans decreased by a factor of 0.4 while the rate of rsMRI increased by a factor of 9.5. CONCLUSION: A successful QI campaign was initiated at our institution, resulting in decreased utilization of CT and increased use of rsMRI for the evaluation of suspected appendicitis. These results highlight the potential impact of QI projects. LEVEL OF EVIDENCE: III.

APSA Members experience bias and discrimination in training and practice.

INTRODUCTION: Bias and discrimination remain pervasive in the medical field and increase the risk of burnout, mental health disorders, and medical errors. The experiences of APSA members with bias and discrimination are unknown, therefore the APSA committee on Diversity, Equity and Inclusion conducted a survey to characterize the prevalence of bias and discrimination. METHODS: 1558 APSA members were sent an anonymous survey, of which 423 (27%) responded. Respondents were asked about their demographics, knowledge of implicit bias, and experience of bias and discrimination within their primary workplace, APSA, and APSA committees. Data were analyzed using Fisher's Exact test, Kruskal-Wallis test, and multivariable logistic regression as appropriate with significance defined as p<0.05. RESULTS: Discrimination was reported across all levels of practice, academic appointments, race, ethnicity, and gender identities. On multivariable analysis, surgical trainees (OR 3.6) as well as Asian American and Pacific Islander (OR 4.8), Black (OR 5.2), Hispanic (OR 8.2) and women (OR 8.7) surgeons were more likely to experience bias and discrimination in the workplace. Community practice surgeons were more likely to experience discrimination within APSA committees (OR 3.6). Members identifying as Asian (OR 0.4), or women (OR 0.6) were less likely to express comfort reporting instances of bias and discrimination. CONCLUSION: Workplace discrimination exists across all training levels, academic appointments, and racial and gender identities. Trainees and racial- and gender-minority surgeons report disproportionately high prevalence of bias and discrimination. Improving reporting mechanisms and implicit bias training are possible initiatives in addressing these findings.

Diversity and demographics of APSA members: Understanding our identity.

INTRODUCTION: There are existing healthcare disparities in pediatric surgery today. Identity and racial incongruity between patients and providers contribute to systemic healthcare inequities and negatively impacts health outcomes of minoritized populations. Understanding the current demographics of the American Pediatric Surgical Association and therefore the cognitive diversity represented will help inform how best to strategically build the organization to optimize disparity solutions and improve patient care. METHODS: 1558 APSA members were sent an anonymous electronic survey. Comparative data was collected from the US Census Bureau and the Association of American Medical Colleges. Results were analyzed using standard statistical tests. RESULTS: Of 423 respondents (response rate 27%), the race and ethnicity composition were 68% non Hispanic White, 12% Asian American and Pacific Islander, 6% Hispanic, 5% multiracial, and 4% Black/African American. Respondents were 35% women, 63% men, and 1% transgender, androgyne, or uncertain. Distribution of sexual identity was 97% heterosexual and 3% LGBTQIA. Religious identity was 50% Christian, 22% Agnostic/Atheist, 11% Jewish, 3% Hindu, and 2% Muslim. 32% of respondents were first-generation Americans. Twenty-four different primary languages were spoken, and 46% of respondents were conversational in a second language. These findings differ in meaningful ways from the overall American population and from the population of matriculants in American medical schools. CONCLUSION: There are substantial differences in the racial, gender, and sexual identity composition of APSA members compared with the overall population in the United States. To achieve excellence in patient care and innovate solutions to existing disparities, representation, particularly in leadership is essential. TYPE OF STUDY: Survey; original research. LEVEL OF EVIDENCE: Level IV.

Effect of MDM2 and vascular endothelial growth factor inhibition on tumor angiogenesis and metastasis in neuroblastoma.

Neuroblastoma is the most common pediatric abdominal tumor and principally a p53 wild-type, highly vascular, aggressive tumor, with limited response to anti-VEGF therapies alone. MDM2 is a key inhibitor of p53 and a positive activator of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) activity with an important role in neuroblastoma pathogenesis. We hypothesized that concurrent inhibition of both MDM2 and VEGF signaling would have cooperative anti-tumor effects, potentiating anti-angiogenic strategies for neuroblastoma and other p53 wild-type tumors. We orthotopically implanted SH-SY5Y neuroblastoma cells into nude mice (n = 40) and treated as follows: control, bevacizumab, Nutlin-3a, combination of bevacizumab plus Nutlin-3a. Expression of HIF-1α and VEGF were measured by qPCR, Western blot, and ELISA. Tumor apoptosis was measured by immunohistochemistry and caspase assay. Angiogenesis was evaluated by immunohistochemistry for vascular markers (CD-31, type-IV collagen, αSMA). Both angiogenesis and metastatic burden were digitally quantified. In vitro, Nutlin-3a suppresses HIF-1α expression with subsequent downregulation of VEGF. Bevacizumab plus Nutlin-3a leads to significant suppression of tumor growth compared to control (P < 0.01) or either agent alone. Combination treated xenograft tumors display a marked decrease in endothelial cells (P < 0.0001), perivascular basement membrane (P < 0.04), and vascular mural cells (P < 0.004). Nutlin-3a alone and in combination with bevacizumab leads to significant tumor apoptosis (P < 0.0001 for both) and significant decrease in incidence of metastasis (P < 0.05) and metastatic burden (P < 0.03). Bevacizumab plus Nutlin-3a cooperatively inhibits tumor growth and angiogenesis in neuroblastoma in vivo with dramatic effects on tumor vascularity. Concomitantly targeting VEGF and p53 pathways potently suppresses tumor growth, and these results support further clinical development of this approach.

Epithelial IGF1R is dispensable for IGF2 mediated enhanced intestinal adaptation in retinoblastoma-deficient mice.

PURPOSE: Previously, we demonstrated enhanced adaptation after small bowel resection (SBR) in intestinal-specific retinoblastoma (Rb)-deficient mice along with elevated levels of insulin-like growth factor 2 (IGF2) expression within the villi. The purpose of this study was to verify that the insulin-like growth factor 1 receptor (IGF1R) plays a role in this phenomenon. METHODS: Inducible and intestinal specific Rb and IGF1R double knockout mice (iRb/IGF1R-IKO) (n=4) and Rb single knockout mice (iRb-IKO) (n=5) underwent 50% mid SBR. On post-operative day 28, mice were harvested, and structural adaptation was measured as changes in crypt depth and villus height. Rates of enterocyte proliferation were recorded. IGF2 expression within the remnant villi was measured via RT-PCR. RESULTS: Both iRb-IKO and iRb/IGF1R-IKO mice demonstrated enhanced adaptation with at least a 45% increase in both crypt depth and villus height in the proximal and distal remnant bowel. Both groups showed elevation of IGF2 expression in the remnant villi, but there were no differences between the two groups. CONCLUSION: Epithelial IGF1R is dispensable for IGF2-mediated enhanced intestinal adaptation in retinoblastoma-deficient mice. Our findings suggest that IGF2 signals for enhanced adaptation in cells outside of the epithelium. Further investigation is needed to study the IGF2/IGF1R signaling interaction within the mesenchyme. LEVEL OF EVIDENCE: Animal study - not clinical.

Both epidermal growth factor and insulin-like growth factor receptors are dispensable for structural intestinal adaptation.

PURPOSE: Intestinal adaptation structurally represents increases in crypt depth and villus height in response to small bowel resection (SBR). Previously, we found that neither epidermal growth factor receptor (EGFR) nor insulin-like growth factor 1 receptor (IGF1R) function was individually required for normal adaptation. In this study, we sought to determine the effect of disrupting both EGFR and IGF1R expression on resection-induced adaptation. METHODS: Intestinal-specific EGFR and IGF1R double knockout mice (EGFR/IGF1R-IKO) (n=6) and wild-type (WT) control mice (n=7) underwent 50% proximal SBR. On postoperative day (POD) 7, structural adaptation was scored by measuring crypt depth and villus height. Rates of crypt cell proliferation, apoptosis, and submucosal capillary density were also compared. RESULTS: After 50% SBR, normal adaptation occurred in both WT and EGFR/IGF1R-IKO. Rates of proliferation and apoptosis were no different between the two groups. The angiogenic response was less in the EGFR/IGF1R-IKO compared to WT mice. CONCLUSION: Disrupted expression of EGFR and IGF1R in the intestinal epithelial cells does not affect resection-induced structural adaptation but attenuates angiogenesis after SBR. These findings suggest that villus growth is driven by receptors and pathways that occur outside the epithelial cell component, while angiogenic responses may be influenced by epithelial-endothelial crosstalk.