An indocyanine green-based liquid biopsy test for circulating tumor cells for pediatric liver cancer.

BACKGROUND: Hepatoblastoma and HCC are the most common malignant hepatocellular tumors seen in children. The aim of this study was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide real-time information about tumor response to therapy. METHODS: For this test, we utilized indocyanine green (ICG), a far-red fluorescent dye used clinically to identify malignant liver cells during surgery. We assessed ICG accumulation in cell lines using fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, including ICG, Glypican-3, and DAPI, and tested it with cell lines and noncancer control blood samples. We then used this panel to analyze whole-blood samples for CTC burden with a cohort of 15 patients with hepatoblastoma and HCC and correlated with patient characteristics and outcomes. RESULTS: We showed that ICG accumulation is specific to liver cancer cells, compared to nonmalignant liver cells, non-liver solid tumor cells, and other nonmalignant cells, and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/Glypican-3/DAPI panel showed that it specifically tagged malignant liver cells. Using patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients' responses to therapy. CONCLUSIONS: Our novel ICG-based liquid biopsy test for CTCs can be used to specifically detect and quantify CTCs in the blood of pediatric patients with liver cancer.

Histopathologic and immunophenotypic characterization of patient-derived pediatric malignant hepatocellular tumor xenografts (PDXs).

Advances in targeted therapies for pediatric hepatocellular tumors have been limited due to a paucity of clinically relevant models. Establishment and validation of intrahepatic patient-derived xenograft (PDX) models would help bridging this gap. The aim of this study is to compare the histomorphologic and immunophenotypic fidelity of patient tumors and their corresponding intrahepatic PDX models. Murine PDX models were established by intrahepatic implantation of patient tumors. Pathology slides from both patients and their corresponding PDX models were reviewed and quantitatively assessed for various histologic components and immunophenotypic markers. Ten PDX models were successfully established from nine patients with pre- (n=3) and post- (n=6) chemotherapy samples; diagnosed of hepatoblastoma (n=8) and hepatocellular neoplasm, not otherwise specified (n=1). Two of nine (22.2%) patients showed ≥75% fetal component; however, the corresponding PDX models did not maintain this fetal differentiation. High grade histology was seen in three patients (33.3%) and overrepresented in six PDX models (60%). Within the subset of three PDXs that were further characterized, significant IHC concordance was seen in all 3 models for CK7, CK19, Ki-67, and p53; and 2 of 3 models for Sox9 and Beta-catenin. GPC-3 and GS showed variable to moderate concordance, while Hepar was the least concordant. Our study shows that in general, the PDX models appear to represent the higher-grade component of the original tumor and show significant concordance for Ki-67, making them appropriate tools for testing new therapies for the most aggressive, therapy-resistant tumors.

A novel treatment strategy utilizing panobinostat for high-risk and treatment-refractory hepatoblastoma.

BACKGROUND & AIMS: Patients with metastatic, treatment-refractory, and relapsed hepatoblastoma (HB) have survival rates of less than 50% due to limited treatment options. To develop new therapeutic strategies for these patients, our laboratory has developed a preclinical testing pipeline. Given that histone deacetylase (HDAC) inhibition has been proposed for HB, we hypothesized that we could find an effective combination treatment strategy utilizing HDAC inhibition. METHODS: RNA sequencing, microarray, NanoString, and immunohistochemistry data of patient HB samples were analyzed for HDAC class expression. Patient-derived spheroids (PDSp) were used to screen combination chemotherapy with an HDAC inhibitor, panobinostat. Patient-derived xenograft (PDX) mouse models were developed and treated with the combination therapy that showed the highest efficacy in the PDSp drug screen. RESULTS: HDAC RNA and protein expression were elevated in HB tumors compared to normal livers. Panobinostat (IC50 of 0.013-0.059 µM) showed strong in vitro effects and was associated with lower cell viability than other HDAC inhibitors. PDSp demonstrated the highest level of cell death with combination treatment of vincristine/irinotecan/panobinostat (VIP). All four models responded to VIP therapy with a decrease in tumor size compared to placebo. After 6 weeks of treatment, two models demonstrated necrotic cell death, with lower Ki67 expression, decreased serum alpha fetoprotein and reduced tumor burden compared to paired VI- and placebo-treated groups. CONCLUSIONS: Utilizing a preclinical HB pipeline, we demonstrate that panobinostat in combination with VI chemotherapy can induce an effective tumor response in models developed from patients with high-risk, relapsed, and treatment-refractory HB. IMPACT AND IMPLICATIONS: Patients with treatment-refractory hepatoblastoma have limited treatment options with survival rates of less than 50%. Our manuscript demonstrates that combination therapy with vincristine, irinotecan, and panobinostat reduces the size of high-risk, relapsed, and treatment-refractory tumors. With this work we provide preclinical evidence to support utilizing this combination therapy as an arm in future clinical trials.

Navigating relapsed hepatoblastoma: Predictive factors and surgical treatment strategy.

OBJECTIVE: Hepatoblastoma (HB) is the most common primary hepatic malignancy in childhood. Relapse occurs in more than 50% of high-risk patients with a high mortality due to ineffective salvage therapies. The purpose of this study is to identify risk factors for relapsed HB and predictors of survival in a single tertiary referral center. METHODS: A retrospective chart review showed 129 surgically treated HB patients from October 2004 to July 2020. Of the cohort, 22 patients presented with relapsed HB. Relapse was defined as re-appearance of malignancy after 4 weeks of normalized AFP and disappearance of all tumors on imaging. RESULTS: Patients with relapsed HB had a 5-year overall survival (OS) of 45.4% compared to 93.1% in those without relapse (p = 0.001). When comparing PRETEXT IV, microvascular invasion, metastatic disease, and age on multivariate logistic regression, only PRETEXT IV was an independent risk factor for relapsed HB with an OR of 2.39 (95% CI: 1.16-4.96; p = 0.019). Mixed epithelial and mesenchymal HB (12/19, 63.2%) was the most common histology of primary tumors while pure epithelial HB (13/15, 86.6%) was the most common relapsed histology. Combination of surgical and medical therapy for relapsed disease was predictive of survival with an HR of 16.3 (95% CI: 1.783-149.091; p = 0.013) compared to only chemotherapy. CONCLUSIONS: This study demonstrates that PRETEXT IV staging is an independent predictor of relapsed disease. The most common relapsed histology was epithelial, suggesting a potential selection or resistance of this component. Surgical resection is a critical component of multimodal therapy for relapsed HB.

Pediatric Hepatocellular Adenomas: What Is Known and What Is New?

Current understanding and classification of pediatric hepatocellular adenomas (HCA) are largely based on adult data. HCAs are rare in children and, unlike in adults, are often seen in the context of syndromes or abnormal background liver. Attempts to apply the adult classification to pediatric tumors have led to several "unclassifiable" lesions. Although typically considered benign, few can show atypical features and those with beta-catenin mutations have a risk for malignant transformation. Small lesions can be monitored while larger (>5.0 cm) lesions are excised due to symptoms or risk of bleeding/rupture, etc. Management depends on gender, age, underlying liver disease, multifocality, size of lesion, histologic subtype and presence of mutation, if any. In this review, we summarize the data on pediatric HCAs and highlight our experience with their diagnosis and management.

Development of Iodinated Indocyanine Green Analogs as a Strategy for Targeted Therapy of Liver Cancer.

Liver cancer is one of the leading causes of cancer-related deaths, with a significant increase in incidence worldwide. Novel therapies are needed to address this unmet clinical need. Indocyanine green (ICG) is a broadly used fluorescence-guided surgery (FGS) agent for liver tumor resection and has significant potential for conversion to a targeted therapy. Here, we report the design, synthesis, and investigation of a series of iodinated ICG analogs (I-ICG), which can be used to develop ICG-based targeted radiopharmaceutical therapy. We applied a CRISPR-based screen to identify the solute carrier transporter, OATP1B3, as a likely mechanism for ICG uptake. Our lead I-ICG compound specifically localizes to tumors in mice bearing liver cancer xenografts. This study introduces the chemistry needed to incorporate iodine onto the ICG scaffold and defines the impact of these modifications on key properties, including targeting liver cancer in vitro and in vivo.

An indocyanine green-based liquid biopsy test for circulating tumor cells for pediatric liver cancer.

Background and Aims: Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common malignant hepatocellular tumors seen in children. The aim of this work was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide information about the real-time state of tumors in response to therapies. Methods: For this test, we utilized indocyanine green (ICG), a far-red fluorescent dye that is used clinically to identify malignant liver cells in the body during surgery. We assessed ICG accumulation in cell lines with fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, ICG, Glypican-3 (GPC3), and DAPI and tested this panel with cell lines and non-cancer control blood samples. We then used this panel to analyze whole blood samples for CTC burden with a cohort of 14 HB and HCC patients and correlated with patient characteristics and outcomes. Results: We showed that ICG accumulation is specific to liver cancer cells, compared to non-malignant liver cells, non-liver solid tumor cells, and non-malignant cells and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/GPC3/DAPI panel showed that it specifically tagged malignant liver cells. With patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients' responses to therapy. Conclusions: Our novel ICG-based liquid biopsy test for CTCs can be used to specifically count CTCs in the blood of pediatric liver cancer patients. Impact and implications: This manuscript represents the first report of circulating tumor cells in the blood of pediatric liver cancer patients. The novel and innovative assay for CTCs shown in this paper will facilitate future work examining the relationship between CTC numbers and patient outcomes, forming the foundation for incorporation of liquid biopsy into routine clinical care for these patients. Graphical abstract: Overview of novel liquid biopsy test for circulating tumor cells for pediatric liver cancer. Figure made with Biorender.

Surgical Management and Outcomes of Patients with Multifocal Hepatoblastoma.

OBJECTIVE: To compare the outcomes of patients with multifocal hepatoblastoma (HB) treated at our institution with either orthotopic liver transplant (OLTx) or hepatic resection to determine outcomes and risk factors for recurrence. BACKGROUND: Multifocality in HB has been shown to be a significant prognostic factor for recurrence and worse outcome. The surgical management of this type of disease is complex and primarily involves OLTx to avoid leaving behind microscopic foci of disease in the remnant liver. METHODS: We performed a retrospective chart review on all patients <18 years of age with multifocal HB treated at our institution between 2000 and 2021. Patient demographics, operative procedure, post-operative course, pathological data, laboratory values, short- and long-term outcomes were analyzed. RESULTS: A total of 41 patients were identified as having complete radiologic and pathologic inclusion criteria. Twenty-three (56.1%) underwent OLTx and 18 (43.9%) underwent partial hepatectomy. Median length of follow-up across all patients was 3.1 years (IQR 1.1-6.6 years). Cohorts were similar in rates of PRETEXT designation status identified on standardized imaging re-review (p = .22). Three-year overall survival (OS) estimate was 76.8% (95% CI: 60.0%-87.3%). There was no difference in rates of recurrence or overall survival in patients who underwent either resection or OLTx (p = .54 and p = .92 respectively). Older patients (>72 months), patients with a positive porta hepatis margin, and patients with associated tumor thrombus experienced worse recurrence rates and survival. Histopathology demonstrating pleomorphic features independently associated with worse rates of recurrence. CONCLUSIONS: Through proper patient selection, multifocal HB was adequately treated with either partial hepatectomy or OLTx with comparable outcome results. HB with pleomorphic features, increased patient age at diagnosis, involved porta hepatis margin on pathology, and the presence of associated tumor thrombus may be associated with worse outcomes regardless of the local control surgery offered. LEVEL OF EVIDENCE: III.

Characterization of Suboptimal Responses to Fetoscopic Endoluminal Tracheal Occlusion in Congenital Diaphragmatic Hernia.

INTRODUCTION: The aim of the study was to characterize the changes in fetal lung volume following fetoscopic endoluminal tracheal occlusion (FETO) that are associated with infant survival and need for extracorporeal membrane oxygenation (ECMO) in congenital diaphragmatic hernia (CDH). METHODS: Fetuses with CDH who underwent FETO at a single institution were included. CDH cases were reclassified by MRI metrics [observed-to-expected total lung volume (O/E TLV) and percent liver herniation]. The percent changes of MRI metrics after FETO were calculated. ROC-derived cutoffs of these changes were derived to predict infant survival to discharge. Regression analyses were done to determine the association between these cutoffs with infant survival and ECMO need, adjusted for site of CDH, gestational age at delivery, fetal sex, and CDH severity. RESULTS: Thirty CDH cases were included. ROC analysis demonstrated that post-FETO increases in O/E TLV had an area under the curve of 0.74 (p = 0.035) for the prediction of survival to hospital discharge; a cutoff of less than 10% was selected. Fetuses with a <10% post-FETO increase in O/E TLV had lower survival to hospital discharge [44.8% vs. 91.7%; p = 0.018] and higher ECMO use [61.1% vs. 16.7%; p = 0.026] compared to those with an O/E TLV increase ≥10%. Similar results were observed when the analyses were restricted to left-sided CDH cases. A post-FETO <10% increase in O/E TLV was independently associated with lower survival at hospital discharge (aOR: 0.073, 95% CI: 0.008-0.689; p = 0.022) and at 12 months of age (aOR: 0.091, 95% CI: 0.01-0.825; p = 0.036) as well as with higher ECMO use (aOR: 7.88, 95% CI: 1.31-47.04; p = 0.024). CONCLUSION: Fetuses with less than 10% increase in O/E TLV following the FETO procedure are at increased risk for requiring ECMO and for death in the postnatal period when adjusted for gestational age at delivery, CDH severity, and other confounders.

A population-based assessment of metastatic hepatoblastoma in Texas reveals ethnic disparities.

Background: Hepatoblastoma (HB) is the most common primary liver cancer in children with emerging evidence that incidence is increasing globally. While overall survival for low risk hepatoblastoma is >90%, children with metastatic disease have worse survival. As identifying factors associated with high-risk disease is critical for improving outcomes for these children, a need for a further understanding of the epidemiology of hepatoblastoma is warranted. Therefore, we conducted a population-based epidemiologic study of hepatoblastoma in Texas, a large state characterized by ethnic and geographic diversity. Methods: Information on children diagnosed with hepatoblastoma at 0-19 years of age for the period of 1995-2018 was obtained from the Texas Cancer Registry (TCR). Demographic and clinical variables including sex, race/ethnicity, age at diagnosis, urban-rural status, and residence along the Texas-Mexico border were evaluated. Multivariable Poisson regression was used to calculate adjusted incidence rate ratios (aIRRs) and 95% confidence intervals (CIs) for each variable of interest. Joinpoint regression analysis was used to determine the trend in incidence of hepatoblastoma, overall and by ethnicity. Results: Overall, 309 children diagnosed with hepatoblastoma in Texas for the period of 1995-2018. Joinpoint regression analysis showed no joinpoints in the overall or the ethnic-specific analyses. Over this period, the incidence increased at 4.59% annually; with the annual percent change higher among Latinos (5.12%) compared to non-Latinos (3.15%). Among these children, 57 (18%) had metastatic disease at diagnosis. Factors associated with hepatoblastoma included male sex (aIRR = 1.5, 95% CI: 1.2-1.8, p = 0.002); infancy (aIRR = 7.6, 95% CI: 6.0-9.7, p < 0.001); and Latino ethnicity (aIRR = 1.3, 95% CI: 1.0-1.7, p = 0.04). Additionally, children living in rural areas were less likely to develop hepatoblastoma (aIRR = 0.6, 95% CI: 0.4-1.0, p = 0.03). While residence on the Texas-Mexico border association with hepatoblastoma approached statistical significance (p = 0.06) in unadjusted models, this finding did not remain significant after adjusting for Latino ethnicity. The two factors associated with being diagnosed with metastatic hepatoblastoma included Latino ethnicity (aIRR = 2.1, 95% CI: 1.1-3.8, p = 0.02) and male sex (aIRR = 2.4, 95% CI: 1.3-4.3, p = 0.003). Conclusions: In this large population-based study of hepatoblastoma, we found several factors associated with hepatoblastoma and metastatic disease. The reasons for a higher burden of hepatoblastoma among Latino children is unclear but could be due to differences in geographic genetic ancestry, environmental exposures, or other unmeasured factors. Additionally, it is notable that Latino children were also more likely to be diagnosed with metastatic hepatoblastoma compared to non-Latino white children. To our knowledge, this has not been previously reported and warrants further study to delineate the causes of this disparity and identify interventions to improve outcomes.

Association of Intercostal Nerve Cryoablation During Nuss Procedure With Complications and Costs.

BACKGROUND: Intercostal nerve cryoablation with the Nuss procedure has been shown to decrease opioid requirements and hospital length of stay; however, few studies have evaluated the impact on complications and hospital costs. METHODS: A retrospective cohort study was performed for all Nuss procedures at our institution from 2016 through 2020. Outcomes were compared across 4 pain modalities: cryoablation with standardized pain regimen (n = 98), patient-controlled analgesia (PCA; n = 96), epidural (n = 36), and PCA with peripheral nerve block (PNB; n = 35). Outcomes collected included length of stay, opioid use, variable direct costs, and postoperative complications. Univariate and multivariate hierarchical regression analysis was used to compare outcomes between the pain modalities. RESULTS: Cryoablation was associated with increased total hospital cost compared with PCA (cryoablation, $11 145; PCA, $8975; P < .01), but not when compared with epidural ($9678) or PCA with PNB ($10 303). The primary driver for increased costs was operating room supplies (PCA, $2741; epidural, $2767; PCA with PNB, $3157; and cryoablation, $5938; P < .01). With multivariate analysis, cryoablation was associated with decreased length of stay (-1.94; 95% CI, -2.30 to -1.57), opioid use during hospitalization (-3.54; 95% CI, -4.81 to -2.28), and urinary retention (0.13; 95% CI, 0.05-0.35). CONCLUSIONS: Cryoablation significantly reduces opioid requirements and length of stay relative to alternative modalities, but it was associated with an increase in total hospital costs relative to PCA, but not epidural or PCA with PNB. Cryoablation was not associated with allodynia or slipped bars requiring reoperation.

Quantitative ctDNA Detection in Hepatoblastoma: Implications for Precision Medicine.

Hepatoblastoma is characterized by driver mutations in CTNNB1, making it an attractive biomarker for a liquid biopsy approach utilizing circulating tumor DNA (ctDNA). This prospective observational study sought to ascertain the feasibility of ctDNA detection in patients with hepatoblastoma and explore its associations with established clinical indicators and biomarkers, including serum Alpha-fetoprotein (AFP). We obtained 38 plasma samples and 17 tumor samples from 20 patients with hepatoblastoma. These samples were collected at various stages: 10 at initial diagnosis, 17 during neoadjuvant chemotherapy, 6 post-operatively, and 5 at disease recurrence. Utilizing a bespoke sequencing assay we developed called QUENCH, we identified single nucleotide variants and deletions in CTNNB1 ctDNA. Our study demonstrated the capability to quantitate ctDNA down to a variant allele frequency of 0.3%, achieving a sensitivity of 90% for patients at initial diagnosis, and a specificity of 100% at the patient level. Notably, ctDNA positivity correlated with tumor burden, and ctDNA levels exhibited associations with macroscopic residual disease and treatment response. Our findings provide evidence for the utility of quantitative ctDNA detection in hepatoblastoma management. Given the distinct detection targets, ctDNA and AFP-based stratification and monitoring approaches could synergize to enhance clinical decision-making. Further research is needed to elucidate the interplay between ctDNA and AFP and determine the optimal clinical applications for both methods in risk stratification and residual disease detection.

HepT1-derived murine models of high-risk hepatoblastoma display vascular invasion, metastasis, and circulating tumor cells.

Hepatoblastoma (HB) is the most common pediatric primary liver malignancy, and survival for high-risk disease approaches 50%. Mouse models of HB fail to recapitulate hallmarks of high-risk disease. The aim of this work was to generate murine models that show high-risk features including multifocal tumors, vascular invasion, metastasis, and circulating tumor cells (CTCs). HepT1 cells were injected into the livers or tail veins of mice, and tumor growth was monitored with magnetic resonance and bioluminescent imaging. Blood was analyzed with fluorescence-activated cell sorting to identify CTCs. Intra- and extra-hepatic tumor samples were harvested for immunohistochemistry and RNA and DNA sequencing. Cell lines were grown from tumor samples and profiled with RNA sequencing. With intrahepatic injection of HepT1 cells, 100% of animals grew liver tumors and showed vascular invasion, metastasis, and CTCs. Mutation profiling revealed genetic alterations in seven cancer-related genes, while transcriptomic analyses showed changes in gene expression with cells that invade vessels. Tail vein injection of HepT1 cells resulted in multifocal, metastatic disease. These unique models will facilitate further meaningful studies of high-risk HB. This article has an associated First Person interview with the first author of the paper.

Fetal endoscopic tracheal occlusion and pulmonary hypertension in moderate congenital diaphragmatic hernia.

OBJECTIVE: To study the role of fetal endoscopic tracheal occlusion (FETO) on resolution of pulmonary hypertension (PH) in fetuses with isolated moderate left-sided diaphragmatic hernia (CDH). METHODS: This retrospective study included fetuses with CDH evaluated between February 2004 and July 2017. Using the tracheal occlusion to accelerate lung growth (TOTAL) trial definition, we classified fetuses into moderate left CDH if O/E-LHR (observed/expected-lung head ratio) was 25-34.9% regardless of liver position or O/E-LHR of 35-44.9% if liver was in the chest. Postnatal echocardiograms were used to diagnose PH. Logistic regression analyses were performed to determine the relationship of FETO with study outcomes. RESULTS: Of 184 cases with no other major anomalies, 30 (16%) met criteria. There were nine FETO and 21 non-FETO cases. By hospital discharge, a higher proportion of infants in the FETO group had resolution of PH (87.5 (7/8) vs. 40% (8/20); p=.013). FETO was associated with adjusted odds ratio of 17.3 (95% CI: 1.75-171; p=.015) to resolve PH by hospital discharge. No significant differences were noted in need for ECMO or survival to discharge between groups. CONCLUSIONS: Infants with moderate left-sided CDH according to O/E-LHR, FETO is associated with resolution of PH by the time of hospital discharge.

Variations in Nuss Procedure Operative Techniques and Complications: A Retrospective Review.

INTRODUCTION: The Nuss procedure is the most common and preferred operative correction of pectus excavatum. Surgeon preference and patient factors can result in variations in Nuss procedure technique. We hypothesize that certain techniques are associated with increased risk of complications. MATERIALS AND METHODS: We performed a single-center retrospective review of Nuss operations from 2016 to 2020. Variations in intraoperative techniques included sternal elevator (SE) use, number of bars placed, and usage of bilateral stabilizing sutures. Patient demographics, intraoperative data, and postoperative outcomes were reported as median with interquartile ranges or percentages. Statistical significance (p < 0.05) was determined with Wilcoxon's rank-sum and chi-square tests. Multivariate analysis was performed to control for introduction of intercostal nerve cryoablation and surgeon volume, and reported as odds ratio with 95% confidence interval. RESULTS: Two hundred and sixty-five patients were identified. Patients repaired with two bars were older with a larger Haller index (HI). Patient demographics were not significantly different for SE or stabilizing suture use. Placement of two bars was associated with significantly increased risk of readmission. Similarly, SE use was associated with increased risk of pleural effusion and readmission. Finally, the use of bilateral stabilizing sutures resulted in less frequent slipped bars without statistical significance. CONCLUSION: Older patients with a larger HI were more likely to need two bars placed to repair pectus excavatum. Placement of multiple bars and SE use are associated with significantly higher odds of certain complications.

Intertwin differences in umbilical artery pulsatility index are associated with infant survival in twin-to-twin transfusion syndrome.

OBJECTIVES: To evaluate the association of intertwin differences in umbilical artery pulsatility index (DUAPI) and infant survival in twin-to-twin transfusion syndrome (TTTS). METHODS: Absolute DUAPI was calculated prior to laser surgery. Receiver-operating characteristics (ROC) curve analysis provided an intertwin DUAPI cutoff of 0.4 for the prediction of double twin survival to 30 days of life. Infant survival was compared between women with an intertwin DUAPI <0.4 and ≥0.4 in the whole cohort, in TTTS cases with Quintero stages I/II and in those with Quintero stages III/IV. Regression analyses were performed to evaluate the association of intertwin DUAPI <0.4 and infant survival adjusted for confounders. RESULTS: In total, 349 TTTS cases were included. Double twin survival to 30 days was observed in 67% (234/349) of cases. Significant differences in double twin survival was seen between intertwin DUAPI groups in the whole cohort (76.8 vs. 52.2%; p<0.001), in women with TTTS Quintero stage I or II (77.8 vs. 58.5%; p=0.015) as well as in women with TTTS Quintero stage III or IV (75 vs. 49.5%; p=0.001). Intertwin DUAPI <0.4 conferred a threefold increased chance for double twin survival. CONCLUSIONS: Small intertwin DUAPI is associated with increased double infant survival in early and advanced TTTS stages.

Intercostal cryoablation during Nuss procedure: A large volume single surgeon's experience and outcomes.

BACKGROUND: Recent studies have shown intercostal cryoablation(IC) during the Nuss procedure decreases hospital length of stay(LOS) and opioid administration. However, few studies have also evaluated the risk of postoperative complications related to IC. METHODS: We performed a single center retrospective analysis of all patients who underwent Nuss procedure by one surgeon from 2/2016 to 2/2020, comparing intraoperative IC to other pain management modalities(non-IC). Primary outcomes were postoperative complications, hospital LOS, and opioid administration. Multivariate analysis was performed with outcomes reported as regression coefficients(RC) or odds ratios(OR) with 95% confidence interval. RESULTS: IC was associated with decreased hospital LOS (RC -1.91[-2.29 to -1.54], less hospital opioid administration (RC -4.28[-5.13 to -3.43]), and less discharge opioid administration (RC -3.82[-5.23 to -2.41]). With respect to postoperative complications, IC decreased the odds of urinary retention (OR 0.16[0.06 to 0.44]); however, increased the odds of slipped bars requiring reoperation (OR 36.65[5.04-266.39]). CONCLUSIONS: Our single surgeon experience controls for surgeon variability and demonstrates intraoperative IC for the Nuss procedure is an effective pain management modality that decreases hospital LOS and opioid use during hospitalization and at discharge; however, it is associated with increased odds of slipped bars requiring reoperation. LEVEL OF EVIDENCE: III.

Detecting the Dark Matter of Unpublished Clinical Cancer Studies: An Analysis of Phase 3 Randomized Controlled Trials.

Unpublished randomized controlled trial (RCT) frequency, correlates, and financial impact are not well understood. We sought to characterize the nonpublication of peer-reviewed manuscripts among interventional, therapeutic, multi-arm, phase 3 oncology RCTs. Trials were identified by searching ClinicalTrials.gov, while publications and abstracts were identified through PubMed and Google Scholar. Trial data were extracted from ClinicalTrials.gov and individual publications. Publication was defined as a peer-reviewed manuscript addressing the primary endpoint. Patient accrual cost was extrapolated from experimental data; investigators/sponsors were contacted to determine nonpublication reasons. Six hundred eighty-four completed RCTs met inclusion criteria, which accrued 434,610 patients from 1994 to 2015; 638 were published (93.3%) and 46 were unpublished (6.7%). Among the unpublished trials, the time difference from primary endpoint maturity to data abstraction was a median of 6 years (interquartile range, 4 to 8 years). On multiple binary logistic regression analysis, factors associated with unpublished trials included lack of cooperative group sponsorship (odds ratio, 5.91, 95% CI, 1.35 to 25.97; P=.019) and supportive care investigation (odds ratio, 2.90; 95% CI, 1.13 to 7.41; P=.027). The estimated inflation-adjusted average cost of patient accrual for all unpublished trials was $113,937,849 (range, $41,136,883 to $320,201,063). Direct contact with sponsors/investigators led to a 50.0% response rate (n=23 of 46); manuscript in preparation and/or in submission (n=10 of 23) was the most commonly cited reason for nonpublication. In conclusion, approximately 1 in 15 clinical oncology RCTs are unpublished and this has a profound impact on the research enterprise. The cooperative group infrastructure may serve as a blueprint to reduce nonpublication.

Umbilical Artery Doppler Patterns and Right Ventricular Outflow Abnormalities in Twin-Twin Transfusion Syndrome.

OBJECTIVES: To evaluate the association of abnormal Doppler velocimetric patterns in the umbilical arteries (UAs) and right ventricular outflow tract abnormalities (RVOTAs) in twin- twin transfusion syndrome (TTTS) cases. METHODS: This retrospective study involved women who had laser surgery for TTTS between January 2012 and May 2018 at a single institution. The prevalence of an RVOTA in either twin was compared among TTTS cases in which both twins had positive end-diastolic flow (EDF) in the UA and those in which either twin had intermittent or persistent absent/reversed UA EDF. Nonparametric tests were used for comparisons. Logistic regression was performed to identify variables associated with an RVOTA in either twin, adjusted for moderate or severe tricuspid regurgitation, right ventricular hypertrophy, right ventricular systolic or diastolic dysfunction, the Quintero stage, and other confounders. P < .05 was considered significant. RESULTS: A total of 126 consecutive TTTS cases were included. Right ventricular outflow tract abnormalities were seen in 8.7% (11of 126) of cases, all in recipient twins. Significant differences in the rate of RVOTAs in the recipient twin were seen between TTTS cases with intermittent absent/reversed UA EDF and those with positive UA EDF (26.9% [7 of 26] versus 3.7% [3 of 82]; P = .002]. However, no significant differences were noted among the other study groups. Intermittent absent/reversed UA EDF was associated with a significantly increased risk for an RVOTA (adjusted odds ratio, 20.6 [95% confidence interval, 3.1-138]; P = .002) after adjusting for confounders. CONCLUSIONS: Intermittent changes in vascular impedance to UA flow may contribute to the pathogenesis of acquired right-sided cardiac lesions in the recipient twin affected with TTTS.