Cost-effectiveness analysis of surgical lung volume reduction compared with endobronchial valve treatment in patients with severe emphysema

BACKGROUND Lung volume reduction, either by surgery or bronchoscopically by endobronchial valve treatment have been shown to be a cost-effective alternative compared with conservative therapy. However, there is no comparative analysis of lung volume reduction by surgery and bronchoscopic lung volume reduction using endobronchial valves. OBJECTIVES The aim of this retrospective study was to provide a cost-effectiveness analysis of lung volume reduction by surgery compared with bronchoscopic lung volume reduction using endobronchial valves. METHODS The effectiveness of lung volume reduction was assessed using forced expiratory volume in the first second (FEV1), residual volume (RV) and 6-minute walking distance (6MWD), measured at baseline and at 4 to 12 weeks. Cost unit accounting derived from SwissDRG was used as a surrogate of the costs from the payer's perspective. RESULTS In total, 67 patients (37 men and 30 women) with a mean age of 68.3 ± 7.4 years were included. Both clinical effectiveness and costs were comparable between surgical and bronchoscopic lung reduction. The incremental cost-effectiveness ratios (ICERs) for bronchoscopic compared with lung volume reduction by surgery for FEV1, RV and 6MWD were -101, 4 and 58, respectively. For RV and 6MWD, it could be shown that endobronchial valve treatment is justified as a probably cost-effective alternative to lung volume reduction by surgery. Endobronchial valve treatment resulted in an improvement of 0.25 quality-adjusted life years (QALYs) and an ICER of € 7657 per QALY gained. CONCLUSION A robust statement on the superiority of one of the two procedures in terms of cost-effectiveness cannot be made from the present study. Therefore, the study is not suitable for resource allocation. Two upcoming trials comparing lung volume reduction surgery and endobronchial valve treatment may be able to answer this question

Micro-CT Imaging of Tracheal Development in Down Syndrome and Non-Down Syndrome Fetuses

Objectives: Down syndrome (DS) is associated with airway abnormalities including a narrowed trachea. It is uncertain whether this narrowed trachea in DS is a consequence of deviant fetal development or an acquired disorder following endotracheal intubation after birth. This study aimed to compare the tracheal morphology in DS and non-DS fetuses using microfocus computed tomography (micro-CT). Methods: Twenty fetal samples were obtained from the Dutch Fetal Biobank and divided into groups based on gestational age. Micro-CT images were processed to analyze tracheal length, volume, and cross-sectional area (CSA). Results: Mean tracheal length and tracheal volume were similar in DS and non-DS fetuses for all gestational age groups. Mean, minimum, and maximal tracheal CSA were statistically significantly increased in the single DS fetus in the group of 21–24 weeks of gestation, but not in other gestational age groups. In 90% of all studied fetuses, the minimum tracheal CSA was located in the middle third of the trachea. Conclusion: Tracheal development in DS fetuses was similar to non-DS fetuses between 13 and 21 weeks of gestation. This suggests that the narrowed tracheal diameter in DS children may occur later in fetal development or results from postnatal intubation trauma. The narrowest part of the trachea is in majority of DS and non-DS fetuses the middle third. Level of Evidence: Level 3 Laryngoscope, 2024.</p

Micro-CT Imaging of Tracheal Development in Down Syndrome and Non-Down Syndrome Fetuses

Objectives: Down syndrome (DS) is associated with airway abnormalities including a narrowed trachea. It is uncertain whether this narrowed trachea in DS is a consequence of deviant fetal development or an acquired disorder following endotracheal intubation after birth. This study aimed to compare the tracheal morphology in DS and non-DS fetuses using microfocus computed tomography (micro-CT). Methods: Twenty fetal samples were obtained from the Dutch Fetal Biobank and divided into groups based on gestational age. Micro-CT images were processed to analyze tracheal length, volume, and cross-sectional area (CSA). Results: Mean tracheal length and tracheal volume were similar in DS and non-DS fetuses for all gestational age groups. Mean, minimum, and maximal tracheal CSA were statistically significantly increased in the single DS fetus in the group of 21–24 weeks of gestation, but not in other gestational age groups. In 90% of all studied fetuses, the minimum tracheal CSA was located in the middle third of the trachea. Conclusion: Tracheal development in DS fetuses was similar to non-DS fetuses between 13 and 21 weeks of gestation. This suggests that the narrowed tracheal diameter in DS children may occur later in fetal development or results from postnatal intubation trauma. The narrowest part of the trachea is in majority of DS and non-DS fetuses the middle third. Level of Evidence: Level 3 Laryngoscope, 2024.</p

Microfocus computed tomography for fetal postmortem imaging: an overview

Over the last few years, fetal postmortem microfocus computed tomography (micro-CT) imaging has increased in popularity for both diagnostic and research purposes. Micro-CT imaging could be a substitute for autopsy, particularly in very early gestation fetuses for whom autopsy can be technically challenging and is often unaccepted by parents. This article provides an overview of the latest research in fetal postmortem micro-CT imaging with a focus on diagnostic accuracy, endovascular staining approaches, placental studies and the reversibility of staining. It also discusses new methods that could prove helpful for micro-CT of larger fetuses. While more research is needed, contrast-enhanced micro-CT has the potential to become a suitable alternative to fetal autopsy. Further research using this novel imaging tool could yield wider applications, such as its practise in imaging rare museum specimens

High resolution imaging of human development: shedding light on contrast agents.

BACKGROUND Visualizing (micro)vascular structures remains challenging for researchers and clinicians due to limitations in traditional radiological imaging methods. Exploring the role of vascular development in craniofacial malformations in experimental settings can enhance understanding of these processes, with the effectiveness of high-resolution imaging techniques being crucial for successful research in this field. Micro-CT imaging offers 3D microstructural insights, but requires contrast-enhancing staining agents (CESAs) for visualizing (micro)-vascular tissues, known as contrast-enhanced micro-CT (CECT). As effective contrast agents are crucial for optimal visualization, this review focuses on comparative studies investigating such agents for micro-vascular tissue imaging using micro-CT. Furthermore, we demonstrate the utilization of B-Lugol solution as a promising contrast agent for acquiring high-quality micro-CT images of (micro)vascular structures in human embryonic samples. METHOD This scoping review followed Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols. PubMed database provided relevant articles, screened initially by title and abstract. Inclusion and exclusion criteria defined outcomes of interest. RESULTS From an initial search, 273 records were identified, narrowed down to 9 articles after applying our criteria. Additionally, two articles were added through citation searching. This, a total of 11 articles were incorporated in this study. CONCLUSION This micro-CT contrast agent review underscores the need for tailored choices based on research goals. Both Barium sulfate and Iodine-based agents showing excellent results, providing high resolution (micro) vascular content, especially in ex-vivo specimens. However, careful consideration of protocols and tissue characteristics remains imperative for optimizing the effectiveness of micro-CT imaging for the study of cranio-facial vascular development

Pulse oximetry training landscape for healthcare workers in low- and middle-income countries: A scoping review

Background Pulse oximetry has been used in medical care for decades. Its use quickly became standard of care in high resource settings, with delayed wide-spread availability and use in lower resource settings. Pulse oximetry training initiatives have been ongoing for years, but a map of the literature describing such initiatives among health care workers in low- and middle-income countries (LMICs) has not previously been conducted. Additionally, the coronavirus disease 2019 (COVID-19) pandemic further highlighted the inequitable distribution of pulse oximetry use and training. We aimed to characterise the landscape of pulse oximetry training for health care workers in LMICs prior to the COVID-19 pandemic as described in the literature. Methods We systematically searched six databases to identify studies reporting pulse oximetry training among health care workers, broadly defined, in LMICs prior to the COVID-19 pandemic. Two reviewers independently assessed titles and abstracts and relevant full texts for eligibility. Data were charted by one author and reviewed for accuracy by a second. We synthesised the results using a narrative synthesis. Results A total of 7423 studies were identified and 182 screened in full. A total of 55 training initiatives in 42 countries met inclusion criteria, as described in 66 studies since some included studies reported on different aspects of the same training initiative. Five overarching reasons for conducting pulse oximetry train?ing were identified: 1) anaesthesia and perioperative care, 2) respiratory support programme expansion, 3) perinatal assessment and monitoring, 4) assessment and monitoring of children and 5) assessment and monitoring of adults. Educational programmes varied in their purpose with respect to the types of patients being targeted, the health care workers being instructed, and the depth of pulse oximetry specific training. Conclusions Pulse oximetry training initiatives have been ongoing for decades for a variety of purposes, utilising a multitude of approaches to equip health care workers with tools to improve patient care. It is important that these initiatives continue as pulse oximetry availability and knowledge gaps remain. Neither pulse oximetry provision nor training alone is enough to bolster patient care, but sustainable solutions for both must be considered to meet the needs of both health care workers and patients.</p

Human embryonic and fetal biobanking:Establishing the Dutch Fetal Biobank and a framework for standardization

Recent studies of human embryos and fetuses have advanced our understanding not only of basic biology but also of health and disease, through a combination of detailed three-dimensional (3D) morphology and processes such as gene expression, cellular decision-making and differentiation, and epigenetics during the various phases of human development and growth. Large-scale research initiatives focusing on these topics have been initiated during the last decade, all of which depend on biobanks that provide high-quality images of human embryonic and fetal morphology, as well as on high-quality collections of tissue samples that are obtained and stored appropriately. In this perspective, we describe our experience in establishing the Dutch Fetal Biobank to present the framework and workflow of the biobank, provide a brief discussion of the main legal and ethical aspects involved in establishing a pre-natal tissue bank, and present the preliminary data on the first 329 donated specimens.</p

Human embryonic and fetal biobanking:Establishing the Dutch Fetal Biobank and a framework for standardization

Recent studies of human embryos and fetuses have advanced our understanding not only of basic biology but also of health and disease, through a combination of detailed three-dimensional (3D) morphology and processes such as gene expression, cellular decision-making and differentiation, and epigenetics during the various phases of human development and growth. Large-scale research initiatives focusing on these topics have been initiated during the last decade, all of which depend on biobanks that provide high-quality images of human embryonic and fetal morphology, as well as on high-quality collections of tissue samples that are obtained and stored appropriately. In this perspective, we describe our experience in establishing the Dutch Fetal Biobank to present the framework and workflow of the biobank, provide a brief discussion of the main legal and ethical aspects involved in establishing a pre-natal tissue bank, and present the preliminary data on the first 329 donated specimens.</p

Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low-risk and unselected populations

Background: Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies. Objectives: To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeks’ gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeks’ gestation. Search methods: We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts &amp; Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies. Selection criteria: Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeks’ gestation, respectively. The reference standard was detection of anomalies at birth or postmortem. Data collection and analysis: Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity. Main results: Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons. Authors' conclusions: A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeks’ gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeks’ gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeks’ gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.</p

Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low-risk and unselected populations

Background: Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies. Objectives: To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeks’ gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeks’ gestation. Search methods: We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts &amp; Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies. Selection criteria: Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeks’ gestation, respectively. The reference standard was detection of anomalies at birth or postmortem. Data collection and analysis: Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity. Main results: Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons. Authors' conclusions: A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeks’ gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeks’ gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeks’ gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.</p