ChatGPT: What Every Pediatric Surgeon Should Know About Its Potential Uses and Pitfalls

ChatGPT - currently the most popular generative artificial intelligence system - has been revolutionizing the world and healthcare since its release in November 2022. ChatGPT is a conversational chatbot that uses machine learning algorithms to enhance its replies based on user interactions and is a part of a broader effort to develop natural language processing that can assist people in their daily lives by understanding and responding to human language in a useful and engaging way. Thus far, many potential applications within healthcare have been described, despite its relatively recent release. This manuscript offers the pediatric surgical community a primer on this new technology and discusses some initial observations about its potential uses and pitfalls. Moreover, it introduces the perspectives of medical journals and surgical societies regarding the use of this artificial intelligence chatbot. As ChatGPT and other large language models continue to evolve, it is the responsibility of the pediatric surgery community to stay abreast of these changes and play an active role in safely incorporating them into our field for the benefit of our patients. LEVEL OF EVIDENCE: V.

Type I and Ir pleuropulmonary blastoma (PPB): A report from the International PPB/DICER1 Registry

BACKGROUND

Pleuropulmonary blastoma (PPB) is the most common lung cancer of infancy and early childhood. Type I PPB is a purely cystic lesion that has a microscopic population of primitive small cells with or without rhabdomyoblastic features and may progress to type II or III PPB, whereas type Ir lacks primitive small cells.

METHODS

Children with suspected PPB were enrolled in the International PPB/DICER1 Registry. Pathology was centrally reviewed, and follow-up was ascertained annually.

RESULTS

Between 2006 and 2022, 205 children had centrally reviewed type I or Ir PPB; 39% of children with type I and 5% of children with type Ir PPB received chemotherapy. Outcomes were favorable, although 11 children (nine with type I and two with type Ir PPB) experienced progression to type II/III (n = 8) or regrowth of type I PPB at the surgical site (n = 3), none of whom received chemotherapy before progression. Age and cyst size in combination were more suitable than either factor alone in predicting whether a particular lesion was type I or Ir PPB.

CONCLUSIONS

For young children with type I PPB, outcomes are favorable, but complete resection is indicated because of the risk for progression. Chemotherapy may be useful in a subset of children at increased risk for recurrence/progression. Efforts to risk stratify children with type I PPB to optimize outcomes while reducing treatment-related side effects are underway.

Outcomes for Children With Type II and Type III Pleuropulmonary Blastoma Following Chemotherapy: A Report From the International PPB/DICER1 Registry

PURPOSE

Pleuropulmonary blastoma (PPB) is the most common primary lung neoplasm of infancy and early childhood. Type II and type III PPB have historically been associated with a poor prognosis.

METHODS

Patients with known or suspected PPB were enrolled in the International PPB/DICER1 Registry. Medical records were abstracted with follow-up ascertained annually. All PPB diagnoses were confirmed by central pathology review. Beginning in 2007, the IVADo regimen (ifosfamide, vincristine, actinomycin-D, and doxorubicin) was recommended as a potential treatment regimen for children with type II and type III PPB. This regimen was compared with a historical control cohort.

RESULTS

From 1987 to 2021, 314 children with centrally confirmed type II and type III PPB who received upfront chemotherapy were enrolled; 132 children (75 with type II and 57 with type III) received IVADo chemotherapy. Adjusted analyses suggest improved overall survival for children treated with IVADo in comparison with historical controls with an estimated hazard ratio of 0.65 (95% CI, 0.39 to 1.08). Compared with localized disease, distant metastasis at diagnosis was associated with worse PPB event-free survival and overall survival with hazard ratio of 4.23 (95% CI, 2.42 to 7.38) and 4.69 (95% CI, 2.50 to 8.80), respectively.

CONCLUSION

The use of IVADo in children with type II and type III PPB resulted in similar-to-improved outcomes compared with historical controls. Inferior outcomes with metastatic disease suggest the need for novel therapies. This large cohort of uniformly treated children with advanced PPB serves as a benchmark for future multicenter therapeutic studies for this rare pediatric tumor.

Management of the undescended testis in children: An American Pediatric Surgical Association Outcomes and Evidence Based Practice Committee Systematic Review

PURPOSE

Management of undescended testes (UDT) has evolved over the last decade. While urologic societies in the United States and Europe have established some guidelines for care, management by North American pediatric surgeons remains variable. The aim of this systematic review is to evaluate the published evidence regarding the treatment of (UDT) in children.

METHODS

A comprehensive search strategy and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were utilized to identify, review, and report salient articles. Five principal questions were asked regarding imaging standards, medical treatment, surgical technique, timing of operation, and outcomes. A literature search was performed from 2005 to 2020.

RESULTS

A total of 825 articles were identified in the initial search, and 260 were included in the final review.

CONCLUSIONS

Pre-operative imaging and hormonal therapy are generally not recommended except in specific circumstances. Testicular growth and potential for fertility improves when orchiopexy is performed before one year of age. For a palpable testis, a single incision approach is preferred over a two-incision orchiopexy. Laparoscopic orchiopexy is associated with a slightly lower testicular atrophy rate but a higher rate of long-term testicular retraction. One and two-stage Fowler-Stephens orchiopexy have similar rates of testicular atrophy and retraction. There is a higher relative risk of testicular cancer in UDT which may be lessened by pre-pubertal orchiopexy.

Management and outcomes for long-segment Hirschsprung disease: A systematic review from the APSA Outcomes and Evidence Based Practice Committee

OBJECTIVE

Long-Segment Hirschsprung Disease (LSHD) differs clinically from short-segment disease. This review article critically appraises current literature on the definition, management, outcomes, and novel therapies for patients with LSHD.

METHODS

Four questions regarding the definition, management, and outcomes of patients with LSHD were generated. English-language articles published between 1990 and 2018 were compiled by searching PubMed, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar. A qualitative synthesis was performed.

RESULTS

66 manuscripts were included in this systematic review. Standardized nomenclature and preoperative evaluation for LSHD are recommended. Insufficient evidence exists to recommend a single method for the surgical repair of LSHD. Patients with LSHD may have increased long-term gastrointestinal symptoms, including Hirschsprung-associated enterocolitis (HAEC), but have a quality of life similar to matched controls. There are few surgical technical innovations focused on this disorder.

CONCLUSIONS

A standardized definition of LSHD is recommended that emphasizes the precise anatomic location of aganglionosis. Prospective studies comparing operative options and long-term outcomes are needed. Translational approaches, such as stem cell therapy, may be promising in the future for the treatment of long-segment Hirschsprung disease.

The effects of early anesthesia on neurodevelopment: A systematic review

BACKGROUND

There is growing concern regarding the impact of general anesthesia on neurodevelopment in children. Pre-clinical animal studies have linked anesthetic exposure to abnormal central nervous system development, but it is unclear whether these results translate into humans. The purpose of this systematic review from the American Pediatric Surgical Association (APSA) Outcomes and Evidence-Based Practice (OEBP) Committee was to review, summarize, and evaluate the evidence regarding the neurodevelopmental impact of general anesthesia on children and identify factors that may affect the risk of neurotoxicity.

METHODS

Medline, Cochrane, Embase, Web of Science, and Scopus databases were queried for articles published up to and including December 2017 using the search terms "general anesthesia and neurodevelopment" as well as specific anesthetic agents. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to screen manuscripts for inclusion in the review. A consensus statement of recommendations in response to each study question was synthesized based upon the best available evidence.

RESULTS

In total, 493 titles were initially identified, with 56 articles selected for full analysis and 44 included for review. Based on currently available developmental assessment tools, a single exposure to general anesthesia does not appear to have a significant effect on general neurodevelopment, although prolonged or multiple anesthetic exposures may have some adverse effects. Exposure to general anesthesia may affect different domains of development at different ages. Regional anesthetic techniques with the addition of dexmedetomidine and/or some intravenous agents may mitigate the risks of neurotoxicity. This approach may be performed safely in some patients and can be considered as an option in selected short procedures.

CONCLUSION

There is no conclusive evidence that a single short anesthetic in infancy has a detectable neurodevelopmental effect. Data do not support waiting until later in childhood to perform general anesthesia for single short procedures. With the complexities and nuances of different anesthetic methods, patients and procedures, the planning and execution of anesthesia for the pediatric patient is generally best accomplished by an anesthesiologist, ideally a pediatric anesthesiologist.

TYPE OF STUDY

Systematic review of level 1-4 studies.

LEVEL OF EVIDENCE

Level 1-4 (mainly level 3-4).

Management of intussusception in children: A systematic review

OBJECTIVE

The goal of this systematic review by the American Pediatric Surgical Association Outcomes and Evidence-Based Practice Committee was to develop recommendations for the management of ileocolic intussusception in children.

METHODS

The ClinicalTrials.gov, Embase, PubMed, and Scopus databases were queried for literature from January 1988 through December 2018. Search terms were designed to address the following topics in intussusception: prophylactic antibiotic use, repeated enema reductions, outpatient management, and use of minimally invasive techniques for children with intussusception. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. Consensus recommendations were derived based on the best available evidence.

RESULTS

A total of 83 articles were analyzed and included for review. Prophylactic antibiotic use does not decrease complications after radiologic reduction. Repeated enema reductions may be attempted when clinically appropriate. Patients can be safely observed in the emergency department following enema reduction of ileocolic intussusception, avoiding hospital admission. Laparoscopic reduction is often successful.

CONCLUSIONS

Regarding intussusception in hemodynamically stable children without critical illness, pre-reduction antibiotics are unnecessary, non-operative outpatient management should be maximized, and minimally invasive techniques may be used to avoid laparotomy.

LEVEL OF EVIDENCE

Level 3-5 (mainly level 3-4) TYPE OF STUDY: Systematic Review of level 1-4 studies.

Severe left diaphragmatic hernia limits size of fetal left heart more than does right diaphragmatic hernia

OBJECTIVES

To assess whether severity of congenital diaphragmatic hernia (CDH) correlates with the degree of left heart hypoplasia and left ventricle (LV) output, and to determine if factors leading to abnormal fetal hemodynamics, such as compression and reduced LV preload, contribute to left heart hypoplasia.

METHODS

This was a retrospective cross-sectional study of fetuses at 16-37 weeks' gestation that were diagnosed with CDH between 2000 and 2010. Lung-to-head ratio (LHR), liver position and side of the hernia were determined from stored ultrasound images. CDH severity was dichotomized based on LHR and liver position. The dimensions of mitral (MV) and aortic (AV) valves and LV were measured, and right and left ventricular outputs were recorded.

RESULTS

In total, 188 fetuses with CDH were included in the study, 171 with left CDH and 17 with right CDH. Fetuses with severe left CDH had a smaller MV (Z = -2.24 ± 1.3 vs -1.33 ± 1.08), AV (Z = -1.39 ± 1.21 vs -0.51 ± 1.05) and LV volume (Z = -4.23 ± -2.71 vs -2.08 ± 3.15) and had lower LV output (26 ± 10% vs 32 ± 10%) than those with mild CDH. MV and AV in fetuses with right CDH (MV, Z = -0.83 ± 1.19 and AV, Z = -0.71 ± 1.07) were larger than those in fetuses with left CDH, but LV outputs were similarly diminished, regardless of hernia side. Severe dextroposition and abnormal liver position were associated independently with smaller left heart, while LHR was not.

CONCLUSION

The severity of left heart hypoplasia correlates with the severity of CDH. Altered fetal hemodynamics, leading to decreased LV output, occurs in both right- and left-sided CDH, but the additional compressive effect on the left heart is seen only when the hernia is left-sided. Improved knowledge of the physiology of this disease may lead to advances in therapy and better risk assessment for use in counseling affected families.

Clinical, biologic, and prognostic differences on the basis of primary tumor site in neuroblastoma: a report from the international neuroblastoma risk group project

PURPOSE

Neuroblastoma (NB) is a heterogeneous tumor arising from sympathetic tissues. The impact of primary tumor site in influencing the heterogeneity of NB remains unclear.

PATIENTS AND METHODS

Children younger than age 21 years diagnosed with NB or ganglioneuroblastoma between 1990 and 2002 and with known primary site were identified from the International Neuroblastoma Risk Group database. Data were compared between sites with respect to clinical and biologic features, as well as event-free survival (EFS) and overall survival (OS).

RESULTS

Among 8,369 children, 47% had adrenal tumors. All evaluated clinical and biologic variables differed statistically between primary sites. The features that were > 10% discrepant between sites were stage 4 disease, MYCN amplification, elevated ferritin, elevated lactate dehydrogenase, and segmental chromosomal aberrations, all of which were more frequent in adrenal versus nonadrenal tumors (P < .001). Adrenal tumors were more likely than nonadrenal tumors (adjusted odds ratio, 2.09; 95% CI, 1.67 to 2.63; P < .001) and thoracic tumors were less likely than nonthoracic tumors (adjusted odds ratio, 0.20; 95% CI, 0.11 to 0.39; P < .001) to have MYCN amplification after controlling for age, stage, and histologic grade. EFS and OS differed significantly according to the primary site (P < .001 for both comparisons). After controlling for age, MYCN status, and stage, patients with adrenal tumors had higher risk for events (hazard ratio, 1.13 compared with nonadrenal tumors; 95% CI, 1.03 to 1.23; P = .008), and patients with thoracic tumors had lower risk for events (HR, 0.79 compared with nonthoracic; 95% CI, 0.67 to 0.92; P = .003).

CONCLUSION

Clinical and biologic features show important differences by NB primary site, with adrenal and thoracic sites associated with inferior and superior survival, respectively. Future studies will need to investigate the biologic origin of these differences.

Antenatal maternally-administered phosphodiesterase type 5 inhibitors normalize eNOS expression in the fetal lamb model of congenital diaphragmatic hernia

PURPOSE

Pulmonary hypertension (pHTN), a main determinant of survival in congenital diaphragmatic hernia (CDH), results from in utero vascular remodeling. Phosphodiesterase type 5 (PDE5) inhibitors have never been used antenatally to treat pHTN. The purpose of this study is to determine if antenatal PDE5 inhibitors can prevent pHTN in the fetal lamb model of CDH.

METHODS

CDH was created in pregnant ewes. Postoperatively, pregnant ewes received oral placebo or tadalafil, a PDE5 inhibitor, until delivery. Near term gestation, lambs underwent resuscitations, and lung tissue was snap frozen for protein analysis.

RESULTS

Mean cGMP levels were 0.53±0.11 in placebo-treated fetal lambs and 1.73±0.21 in tadalafil-treated fetal lambs (p=0.002). Normalized expression of eNOS was 82%±12% in Normal-Placebo, 61%±5% in CDH-Placebo, 116%±6% in Normal-Tadalafil, and 86%±8% in CDH-Tadalafil lambs. Normalized expression of β-sGC was 105%±15% in Normal-Placebo, 82%±3% in CDH-Placebo, 158%±16% in Normal-Tadalafil, and 86%±8% in CDH-Tadalafil lambs. Endothelial NOS and β-sGC were significantly decreased in CDH (p=0.0007 and 0.01 for eNOS and β-sGC, respectively), and tadalafil significantly increased eNOS expression (p=0.0002).

CONCLUSIONS

PDE5 inhibitors can cross the placental barrier. β-sGC and eNOS are downregulated in fetal lambs with CDH. Antenatal PDE5 inhibitors normalize eNOS and may prevent in utero vascular remodeling in CDH.

Tumor metrics and morphology predict poor prognosis in prenatally diagnosed sacrococcygeal teratoma: a 25-year experience at a single institution

PURPOSE

Some fetuses with sacrococcygeal teratoma (SCT) develop hydrops, but there is no consensus on an appropriate prognostic marker for poor prognosis. The purpose of this study is to establish predictors of poor prognosis in fetuses with SCT.

METHODS

A retrospective review of patients with prenatally diagnosed SCT from 1986 to 2011 was performed. Patients with outcome data and ultrasound exams before 32 weeks gestational age (GA) were included (n=37). Tumor volume-to-fetal weight ratio (TFR) and tumor morphology were assessed as sonographic predictors of poor prognosis.

RESULTS

Twelve patients (32%) had good prognosis, and twenty-five patients (68%) had poor prognosis. All patients with poor prognosis had a morphology score ≥ 3, which is a significant predictor of poor prognosis (p <0.0001). TFR was assessed, and a receiver operating characteristic (ROC) analysis identified a cutoff value of 0.12 before 24 weeks GA and 0.11 before 32 weeks GA as predictors for poor prognosis. TFR is a significant predictor of poor prognosis (p<0.0001).

CONCLUSIONS

Patients with cystic SCT all had good prognosis. TFR >0.12 was validated as a sonographic predictor of poor prognosis. TFR and tumor morphology can be used to counsel expectant families with prenatally diagnosed SCT regarding prognosis.

Aberrant pulmonary lymphatic development in the nitrofen mouse model of congenital diaphragmatic hernia

PURPOSE

Many infants develop a postsurgical chylothorax after diaphragmatic hernia repair. The pathogenesis remains elusive but may be owing to dysfunctional lymphatic development. This study characterizes pulmonary lymphatic development in the nitrofen mouse model of CDH.

METHODS

CD1 pregnant mice were fed nitrofen/bisdiamine (N/B) or olive oil at E8.5. At E14.5 and E15.5, lung buds were categorized by phenotype: normal, N/B without CDH (N/B - CDH), or N/B with CDH (N/B+CDH). Anti-CD31 was used to localize all endothelial cells, while anti-LYVE-1 was used to identify lymphatic endothelial cells in lung buds using immunofluorescence. Differential protein expression of lymphatic-specific markers was analyzed.

RESULTS

Lymphatic endothelial cells localized to the mesenchyme surrounding the airway epithelium at E15.5. CD31 and LYVE-1 colocalization identified lymphatic endothelial cells. LYVE-1 expression was upregulated in N/B+CDH lung buds in comparison to N/B - CDH and normal lung buds by immunofluorescence. Western blotting shows that VEGF-D, LYVE-1, Prox-1, and VEGFR-3 expression was upregulated in N/B+CDH lung buds in comparison to N/B - CDH or control lung buds at E14.5.

CONCLUSIONS

Lung lymphatics are hyperplastic in N/B+CDH. Upregulation of lymphatic-specific genes suggests that lymphatic hyperplasia plays an important role in dysfunctional lung lymphatic development in the nitrofen mouse model of CDH.

Hepatic portocholecystostomy for biliary atresia: a 25-year follow-up and review

We report the successful salvage of a patient's native liver 25 years after hepatic portocholecystostomy for biliary atresia. Our case demonstrates the effectiveness of biliary specific, high-resolution CT imaging in the diagnosis of, and operative planning for complex cases of biliary obstruction. We also report the longest-term pathologic follow-up of biliary atresia after hepatic portocholecystostomy. Life-long follow-up of patients with biliary atresia is important to prevent life-threatening complications of biliary stasis/obstruction.

The new low-toxic histone deacetylase inhibitor S-(2) induces apoptosis in various acute myeloid leukaemia cells

Histone deacetylase inhibitors (HDACi) induce tumour cell cycle arrest and/or apoptosis, and some of them are currently used in cancer therapy. Recently, we described a series of powerful HDACi characterized by a 1,4-benzodiazepine (BDZ) ring hybridized with a linear alkyl chain bearing a hydroxamate function as Zn(++)--chelating group. Here, we explored the anti-leukaemic properties of three novel hybrids, namely the chiral compounds (S)-2 and (R)-2, and their non-chiral analogue 4, which were first comparatively tested in promyelocytic NB4 cells. (S)-2 and partially 4--but not (R)-2--caused G0/G1 cell-cycle arrest by up-regulating cyclin G2 and p21 expression and down-regulating cyclin D2 expression, and also apoptosis as assessed by cell morphology and cytofluorimetric assay, histone H2AX phosphorylation and PARP cleavage. Notably, these events were partly prevented by an anti-oxidant. Moreover, novel HDACi prompted p53 and α-tubulin acetylation and, consistently, inhibited HDAC1 and 6 activity. The rank order of potency was (S)-2 > 4 > (R)-2, reflecting that of other biological assays and addressing (S)-2 as the most effective compound capable of triggering apoptosis in various acute myeloid leukaemia (AML) cell lines and blasts from patients with different AML subtypes. Importantly, (S)-2 was safe in mice (up to 150 mg/kg/week) as determined by liver, spleen, kidney and bone marrow histopathology; and displayed negligible affinity for peripheral/central BDZ-receptors. Overall, the BDZ-hydroxamate (S)-2 showed to be a low-toxic HDACi with powerful anti-proliferative and pro-apototic activities towards different cultured and primary AML cells, and therefore of clinical interest to support conventional anti-leukaemic therapy.

Implantable ultra-low pulmonary pressure monitoring system for fetal surgery

Congenital pulmonary hypoplasia is a devastating condition affecting fetal and newborn pulmonary physiology, resulting in great morbidity and mortality. The fetal lung develops in a fluid-filled environment. In this work, we describe a novel, implantable pressure sensing and recording device which we use to study the pressures present in the fetal pulmonary tree throughout gestation. The system achieves 0.18 cm H2O resolution and can record for twenty one days continuously at 256 Hz. Sample tracings of in vivo fetal lamb recordings are shown.

Advances in prenatal diagnosis and treatment of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common birth anomaly. Absence or presence of liver herniation and determination of lung-to-head ratio are the most accurate predictors of prognosis for fetuses with CDH. Though open fetal CDH repair has been abandoned, fetal endoscopic balloon tracheal occlusion promotes lung growth in fetuses with severe CDH. Although significant improvements in lung function have not yet been shown in humans, reversible or dynamic tracheal occlusion is promising for select fetuses with severe CDH. This article reviews advances in prenatal diagnosis of CDH, the experimental basis for tracheal occlusion, and its translation into human clinical trials.

Synchronous ipsilateral Bochdalek and Morgagni diaphragmatic hernias: a case report

The etiology of congenital diaphragmatic hernia (CDH) is unknown. Phenotypic patterns of CDH defects provide clues about normal diaphragm development and the pathophysiology of CDH. We report a case of a patient who was diagnosed with CDH postnatally and was found on imaging to have simultaneous Bochdalek and Morgagni hernias on the right side. During the operative repair of these defects, an additional left-sided Morgagni-type defect was also found. To the best of our knowledge, this form of CDH has not been previously reported.

Long-term surgical outcomes in congenital diaphragmatic hernia: observations from a single institution

BACKGROUND/PURPOSE

Surgical complications are common in survivors of congenital diaphragmatic hernia (CDH), but little is known about long-term incidence patterns and associated predictors.

METHODS

A cohort of 99 CDH survivors was prospectively followed at a single-institution multidisciplinary clinic. Data were gathered regarding the adverse surgical outcomes of hernia recurrence, chest and spinal deformity, and operative small bowel obstruction (SBO), and then were retrospectively analyzed in relation to perinatal and perioperative markers of disease severity to determine significant predictors. Statistical methods used included univariate and multivariate regression analysis, hazard modeling, and Kaplan-Meier analysis.

RESULTS

At a median cohort age of 4.7 (range, 0.2-10.6) years, 46% of patients with patch repairs and 10% of those with primary repairs had a hernia recurrence at a median time of 0.9 (range, 0.1-7.3) years after repair. Chest deformity was detected in 47%. Small bowel obstruction and scoliosis occurred in 13%. Recurrence and chest deformity were significantly more common with patch repair, liver herniation, age at neonatal extubation greater than 16 days, oxygen requirement at discharge, and prematurity. The strongest predictor of SBO was patch repair. Multivariate analysis showed that patch repair was independently predictive of recurrence and early chest deformity (odds ratios of 5.0 and 4.8, confidence intervals of 1-24 and 1-21, P < .05). Use of an absorbable patch was associated with the highest risk of surgical complications.

CONCLUSIONS

For long-term survivors of CDH, specific perinatal and operative variables, particularly patch repair, are associated with subsequent adverse surgical outcomes.

Constitutively active endothelial Notch4 causes lung arteriovenous shunts in mice

Lung arteriovenous (AV) shunts or malformations cause significant morbidity and mortality in several distinct clinical syndromes. For most patients with lung AV shunts, there is still no optimal treatment. The underlying molecular and cellular etiology for lung AV shunts remains elusive, and currently described animal models have insufficiently addressed this problem. Using a tetracycline-repressible system, we expressed constitutively active Notch4 (Notch4*) specifically in the endothelium of adult mice. More than 90% of mice developed lung hemorrhages and respiratory insufficiency and died by 6-7 wk after gene expression began. Vascular casting and fluorescent microsphere analysis showed evidence of lung AV shunts in affected mice. Cessation of Notch4* expression reversed these pathophysiological effects. Assessment of the vascular morphology revealed enlarged, tortuous vessels in the lungs that resembled arteriovenous malformations. By using whole lung organ culture, we demonstrated the effects of constitutively active Notch4 on the lung vasculature to be a primary lung phenomenon. Together, our results indicate the importance of Notch signaling in maintaining the lung vasculature and offer a new, reliable model with which to study the pathobiology of lung arteriovenous shunts and malformations.

Intrauterine umbilical cord hemorrhage with associated jejunal atresia captured by real-time ultrasound

The presence of unexplained umbilical cord ulceration and hemorrhage has been sporadically reported in fetuses with antenatally suggested intestinal atresia. This case report illustrates a patient with spontaneous intrauterine umbilical cord hemorrhage, captured by real-time ultrasonography, in the setting of jejunal atresia with volvulus of the distal jejunal segment.

Imaging accuracy and incidence of Wilms' and non-Wilms' renal tumors in children

PURPOSE

The purpose of this study is to determine the actual incidence, age distribution, and preoperative imaging accuracy of non-Wilms' tumors (nWT) in children with renal masses.

METHODS

Pathologic reports from all tumor nephrectomies or open renal biopsies performed at a single institution from September 1999 to June 2005 were analyzed. Patient demographics, pathologic findings, specific imaging study descriptors, and differential diagnoses were tabulated. Accuracy of imaging studies in identifying specific tumors was calculated.

RESULTS

Ninety-two patients were identified. Sixty-eight had Wilms' tumor (WT) and 24 had an nWT. The nWT group included congenital mesoblastic nephroma (5), clear cell sarcoma (4), neuroblastoma (4), renal cell carcinoma (4), lymphoma (2), angiomyolipoma (2), teratoma (1), hemangioma (1), and renal epithelial tumor (1). When grouped by ages, the incidence of nWT was between 0% and 83%. Sensitivity, specificity, positive predictive value, and negative predictive value for computed tomography (CT) determining a diagnosis of WT were 0.92, 0.55, 0.84, and 0.73, respectively. The CT reports explicitly stated a potential diagnosis in 89% of cases, with a diagnostic accuracy of 82%.

CONCLUSIONS

Non-Wilms' tumors may represent a significant proportion of renal tumors in children, especially in children aged less than 6 months or greater than 12 years. Preoperative imaging is of limited value in differentiating these tumors. These data have significant implications for parental counseling, surgical plan, and the choice of neoadjuvant chemotherapy and argue in favor of obtaining a tissue diagnosis before instituting therapy.

Thoracoscopic versus open resection for congenital cystic adenomatoid malformations of the lung

PURPOSE

This study evaluated the potential advantages of thoracoscopy compared to thoracotomy for resection of congenital cystic adenomatoid malformations (CCAM).

METHODS

We conducted a retrospective chart review of consecutive cases of CCAM resection at University of California San Francisco Children's Hospital from January 1996 to December 2006.

RESULTS

Thirty-six cases of postnatal CCAM resections were done over the past 10 years; 12 patients had thoracoscopic resections, whereas 24 patients had open resections. Patients in the thoracoscopic group had significantly longer operative time (mean difference of 61.3 minutes; 95% confidence interval [CI], 30.5-92.1) but shorter postoperative hospital stay (mean difference of 5.7 days; 95% CI, 0.9-10.4) and duration of tube thoracostomy (mean difference of 2.6 days; 95% CI, 0.7-4.5) and lower odds of postoperative complications (odds ratio of 9.0 x 10(-4); 95% CI, 8.0 x 10(-6)-0.1). In the subgroup analysis of only asymptomatic patients, the thoracoscopy group still had a significantly shorter hospital stay (mean difference of 2.8 days; 95% CI, 0.7-4.8). There was also a pattern for reduced complications in the thoracoscopy group (OR, 0.13; 95% CI, 0.02-1.0; P = .05). The average hospital costs were similar in both groups. With a conversion rate of 33% (6/18), patients with a history of preoperative respiratory symptoms had a higher incidence of conversion than those who were asymptomatic (66.7% vs 0%, P = .005). These four patients had a history of pneumonia.

CONCLUSION

Minimally invasive resection of CCAM results in longer operative time but shorter hospital stay, potentially reduced complications, and no additional hospital costs. Thoracoscopic lobectomy in patients with a history of pneumonia is challenging and a risk factor for conversion to thoracotomy.

Pulmonary vascular remodeling

The maladaptive response of the pulmonary vasculature that occurs in patients with congenital diaphragmatic hernia significantly impacts outcome. Muscularized distal pulmonary arterioles inhibit the ability of the neonate to adjust to extrauterine circulation, resulting in severe pulmonary hypertension. This review summarizes the current state of knowledge regarding normal and abnormal development of the lung vascular system and identifies current and potential therapies directed toward preserving or restoring proper pulmonary vascular function.

L-arginine polymers inhibit the development of vein graft neointimal hyperplasia

OBJECTIVE

We sought to determine whether L -arginine polymer treatment of vein grafts enhances vascular production of nitric oxide and inhibits the development of neointimal hyperplasia.

METHODS

External jugular veins of New Zealand White rabbits (n = 42) were harvested; treated intraluminally for 15 minutes with phosphate-buffered saline solution or L -arginine polymer 5, 7, or 9 at either 10 or 100 micromol/L; and then grafted into the contralateral carotid artery. Rabbits were killed after 28 days, and 5-microm sections of vessels were stained with hematoxylin and scored for intima/media ratio by using computerized morphometric analysis. Separate veins were treated in a similar fashion with biotinylated polymers and phosphate-buffered saline solution to assess for translocation efficiencies. Finally, vein segments pretreated with either phosphate-buffered saline solution or L -arginine polymers were cultured in Dulbecco's modified Eagle's medium containing lipopolysaccharide (100 microg/mL) and interferon gamma (200 U/mL) for 48 hours before measuring nitric oxide levels by means of the Griess reaction.

RESULTS

Biotinylated L -arginine polymers demonstrated a dose- and length-dependent uptake into intimal and medial cells of treated vessels. Nitric oxide levels were significantly higher in vein segments treated with 100 micromol/L of L -arginine polymer 9 compared with control segments. Finally, the intima/media ratio also reflected both length- and concentration-dependent inhibition of neointimal hyperplasia.intima/media ratio PBS R5 R7 R9 10 micromol/L 0.909 +/- 0.072 0.920 +/- 0.073 0.861 +/- 0.138 0.710 +/- 0.122 100 micromol/L 0.924 +/- 0.061 0.581 +/- 0.089* 0.529 +/- 0.093* PBS, Phosphate-buffered saline solution; R, L -arginine polymer. *P <.001 versus phosphate-buffered saline solution and L -arginine polymer 5 controls (Bonferroni-corrected value).

CONCLUSIONS

Arginine polymers of sufficient length and concentration were effective in increasing nitric oxide levels and reducing neointimal hyperplasia in this vein graft model.