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Interventional and Chest Diagnostic Procedures
3D printing and pulmonology
Recent advances in 3D printing has enabled physicians to apply this technology in medical education, procedural planning, tissue modeling, and implantable device manufacturing. This is especially true in the field of pulmonology. Advancements in 3D printing have made personalized airway stents a reality, both by 3D printing-assisted injection molding or direct 3D printing.
Airway stents have significantly evolved over the last half century. With use of silicone, bare metallic, and hybrid stents, pulmonologists have an ever-expanding option to address airway stenosis due to both benign and malignancy etiologies. Personalized airway stents hold the potential for advance customization, minimizing pressure points, and improving airflow dynamics to increase mucus clearance. In January 2020, the US Food and Drug Administration (FDA) cleared patient-specific airway stents developed by Dr. Thomas Gildea of Cleveland Clinic. The patient-specific silicone stents are created using CT scans and 3D visualization software to generate a 3D-printed mold that was subsequently used to inject with medical-grade silicone. Two years earlier, a Duke University startup known as restor3D created the first direct 3D printed airway stent using a compressible biocompatible material with properties similar to that of silicone. Both of these stents have been used in patients with promising response.
As we look into the future, the field of pulmonology will experience significant changes with more adoption of 3D printing (ie, additive manufacturing). We may soon be able to create personalized airway prosthesis of any type (stents, spigots, valves, tracheostomies, t-tubes) for the benefit of our patients.
Disclosure: Dr. George Cheng is a cofounder of restor3D.
George Cheng, MD, PhD, FCCP
Steering Committee Member
Pediatric Chest Medicine
COVID-19: Pediatric story of a new pandemic
In December 2019, an outbreak of pneumonia identified to be caused by 2019 novel coronavirus (2019-nCoV) emerged in Wuhan, China, possibly originating from the local wet market selling many species of live animals. A novel member of enveloped RNA coronavirus was identified in samples of BAL fluid from a patient in Wuhan.
It has since rapidly spread globally to countries across six continents. As of early April, 1,286,409 cases have been reported worldwide with 337,933 cases (9,600 deaths) in the US (https://coronavirus.jhu.edu/map.html) with more cases and deaths every day. Most of these initial reports of COVID-19 (COronaVIrusDisease) in children are from China. Fever (60%) and cough (65%) were the most common symptoms. Procalcitonin elevation (80% and co-infection (80%) were prominent clinical findings. Consolidation with surrounding halo sign (50%) and ground-glass opacities (60%) on CT scan were typical radiologic findings. Almost all children recovered without needing intensive care support.
Increased IgM COVID-19 antibody levels observed in three neonates raise questions of potential in-utero transmission (Kimberlin et al. JAMA 2020 Mar 26. doi: 10.1001/jama.2020.4868). One study provided evidence for persistent fecal shedding and possibility of fecal-oral transmission (Xu et al. Nat Med 2020 Mar 13. doi: 10.1038/s41591-020-0817-4).
Initial reports show that children appear to be at similar risk of infection as adults, though less likely to have severe symptoms. Young children, particularly infants, are more vulnerable to infection (Dong et al. Pediatrics. 2020 Apr. doi: 10.1542/peds.2020-0702); (Bi et al. medRxiv 2020 Mar 27. doi: 10.1101/2020.03.03.20028423v3). Thus far, few deaths have been reported in the pediatric age group. Trials are being conducted on a war footing to find a cure and a vaccine.
Harish Rao, MD, MBBS
Steering Committee Member
Pulmonary Physiology, Function, and Rehabilitation
Controversies and the clinical value of lung volume measurements
Lung volumes are often measured by body plethysmography or gas dilution. Their clinic importance in decision making is unclear. Though measured differently, predicted sets obtained by plethysmography from Caucasian populations are often used for gas dilution measurements (Ruppel GL. Respir Care. 2012 Jan;57[1]:26). Recently the GLI felt lung volume data were insufficient to develop universal reference equations (Cooper B, et al. Breathe (Sheff). 2017 Sep;13[3]:e56-e64). ERS/ATS guidelines recommend adjusting Caucasian predicted values depending on race, without advising how to adjust the confidence limits. Their algorithms show if the VC is normal, lung volumes are unnecessary, though it is not unusual to see a normal VC with reduced TLC. Does this suggest the VC is more important than the TLC, even if lacking predicted volume equations for non-Caucasians? Because combined obstructive and restrictive abnormalities occur simultaneously, recommendations state severity of impairment be determined by the FEV1 percent of predicted rather than TLC (Pellegrino R, et al. Eur Respir J. 2005;26:948). The value of quantifying other volumes such as FRC and ERV in conditions such as obesity and musculoskeletal defects is also not clear. In obstruction, volumes can indicate air trapping or hyperinflation measuring RV and RV/TLC. Though cutoffs of <80% and >120% of predicted are often used, guidelines discourage this practice, recommending using predicted equations based on age, race, height, and sex, with statistical limits of normal (Ruppel GL. Respir Care. 2012 Jan;57(1):26).
Further research is needed to define comprehensive racially appropriate predicted equations for lung volumes to support their clinical applicability in decision making, as well as if predicted values by plethysmography are applicable to values obtained from gas dilution.
Said A. Chaaban, MD
Steering Committee Member
Zachary Q. Morris, MD
NetWork Member
Pulmonary Vascular Disease
Pulmonary hypertension associated with atrial septal defect in adults: closing time?
Up to 10% of adults with atrial septal defects (ASDs) can develop pulmonary arterial hypertension (PAH) according to European Guidelines on pulmonary hypertension (PH) (Galie, et al. Eur Heart J. 2016;37[1]:67). If ASD closure is considered, they propose a pulmonary vascular resistance index (PVRi) <4 Wood units (WU) m² as a safe cutoff. Higher PVRi carries a higher operative risk, warranting evaluation in specialized PH centers.
American guidelines (Stout, et al. Circulation. 2019 Apr 2;139[14]:e698) recommend closure in symptomatic patients with a net shunt (Qp/Qs) of >1.5:1. Closure appears safe if pulmonary artery (PA) systolic pressure is <1/2 systemic blood pressure, and PVR / systemic vascular resistance is <0.3. They recommend specialized evaluation for higher pressures and to avoid closure once a net right to left shunt is present (Qp/Qs <1.0).
However, in severe cases, experienced centers have reported some success with a “treat-and-close” approach if post-therapy PVR reaches <6.5 WU (Bradley, et al. Int J Cardiol. 2019;291:127).
Finally, consider the following when evaluating ASD-associated PAH: 1. A thermodilution cardiac output method should not be used to calculate PVR/PVRi because of confounding recirculation from the intracardiac shunt (Kwan, et al. Clin Cardiol. 2019;42[3]:334). Qp is used instead and is calculated using Fick equation, requiring accurate oxygen saturation measurements. 2. Mixed venous saturation (MvO2) is needed to determine Qs, and PA saturation cannot be used as MvO2 surrogate. MvO2 must be calculated using superior and inferior vena cava saturations. 3. Some patients with idiopathic PAH may have a small coexisting ASD that is not responsible for the abnormal hemodynamics. Closing the ASD in those cases would be contraindicated. 4. Patients may have more than one type of coexistent congenital heart defect.
Francisco J. Soto, MD, MS, FCCP
Steering Committee Member
Interventional and Chest Diagnostic Procedures
3D printing and pulmonology
Recent advances in 3D printing has enabled physicians to apply this technology in medical education, procedural planning, tissue modeling, and implantable device manufacturing. This is especially true in the field of pulmonology. Advancements in 3D printing have made personalized airway stents a reality, both by 3D printing-assisted injection molding or direct 3D printing.
Airway stents have significantly evolved over the last half century. With use of silicone, bare metallic, and hybrid stents, pulmonologists have an ever-expanding option to address airway stenosis due to both benign and malignancy etiologies. Personalized airway stents hold the potential for advance customization, minimizing pressure points, and improving airflow dynamics to increase mucus clearance. In January 2020, the US Food and Drug Administration (FDA) cleared patient-specific airway stents developed by Dr. Thomas Gildea of Cleveland Clinic. The patient-specific silicone stents are created using CT scans and 3D visualization software to generate a 3D-printed mold that was subsequently used to inject with medical-grade silicone. Two years earlier, a Duke University startup known as restor3D created the first direct 3D printed airway stent using a compressible biocompatible material with properties similar to that of silicone. Both of these stents have been used in patients with promising response.
As we look into the future, the field of pulmonology will experience significant changes with more adoption of 3D printing (ie, additive manufacturing). We may soon be able to create personalized airway prosthesis of any type (stents, spigots, valves, tracheostomies, t-tubes) for the benefit of our patients.
Disclosure: Dr. George Cheng is a cofounder of restor3D.
George Cheng, MD, PhD, FCCP
Steering Committee Member
Pediatric Chest Medicine
COVID-19: Pediatric story of a new pandemic
In December 2019, an outbreak of pneumonia identified to be caused by 2019 novel coronavirus (2019-nCoV) emerged in Wuhan, China, possibly originating from the local wet market selling many species of live animals. A novel member of enveloped RNA coronavirus was identified in samples of BAL fluid from a patient in Wuhan.
It has since rapidly spread globally to countries across six continents. As of early April, 1,286,409 cases have been reported worldwide with 337,933 cases (9,600 deaths) in the US (https://coronavirus.jhu.edu/map.html) with more cases and deaths every day. Most of these initial reports of COVID-19 (COronaVIrusDisease) in children are from China. Fever (60%) and cough (65%) were the most common symptoms. Procalcitonin elevation (80% and co-infection (80%) were prominent clinical findings. Consolidation with surrounding halo sign (50%) and ground-glass opacities (60%) on CT scan were typical radiologic findings. Almost all children recovered without needing intensive care support.
Increased IgM COVID-19 antibody levels observed in three neonates raise questions of potential in-utero transmission (Kimberlin et al. JAMA 2020 Mar 26. doi: 10.1001/jama.2020.4868). One study provided evidence for persistent fecal shedding and possibility of fecal-oral transmission (Xu et al. Nat Med 2020 Mar 13. doi: 10.1038/s41591-020-0817-4).
Initial reports show that children appear to be at similar risk of infection as adults, though less likely to have severe symptoms. Young children, particularly infants, are more vulnerable to infection (Dong et al. Pediatrics. 2020 Apr. doi: 10.1542/peds.2020-0702); (Bi et al. medRxiv 2020 Mar 27. doi: 10.1101/2020.03.03.20028423v3). Thus far, few deaths have been reported in the pediatric age group. Trials are being conducted on a war footing to find a cure and a vaccine.
Harish Rao, MD, MBBS
Steering Committee Member
Pulmonary Physiology, Function, and Rehabilitation
Controversies and the clinical value of lung volume measurements
Lung volumes are often measured by body plethysmography or gas dilution. Their clinic importance in decision making is unclear. Though measured differently, predicted sets obtained by plethysmography from Caucasian populations are often used for gas dilution measurements (Ruppel GL. Respir Care. 2012 Jan;57[1]:26). Recently the GLI felt lung volume data were insufficient to develop universal reference equations (Cooper B, et al. Breathe (Sheff). 2017 Sep;13[3]:e56-e64). ERS/ATS guidelines recommend adjusting Caucasian predicted values depending on race, without advising how to adjust the confidence limits. Their algorithms show if the VC is normal, lung volumes are unnecessary, though it is not unusual to see a normal VC with reduced TLC. Does this suggest the VC is more important than the TLC, even if lacking predicted volume equations for non-Caucasians? Because combined obstructive and restrictive abnormalities occur simultaneously, recommendations state severity of impairment be determined by the FEV1 percent of predicted rather than TLC (Pellegrino R, et al. Eur Respir J. 2005;26:948). The value of quantifying other volumes such as FRC and ERV in conditions such as obesity and musculoskeletal defects is also not clear. In obstruction, volumes can indicate air trapping or hyperinflation measuring RV and RV/TLC. Though cutoffs of <80% and >120% of predicted are often used, guidelines discourage this practice, recommending using predicted equations based on age, race, height, and sex, with statistical limits of normal (Ruppel GL. Respir Care. 2012 Jan;57(1):26).
Further research is needed to define comprehensive racially appropriate predicted equations for lung volumes to support their clinical applicability in decision making, as well as if predicted values by plethysmography are applicable to values obtained from gas dilution.
Said A. Chaaban, MD
Steering Committee Member
Zachary Q. Morris, MD
NetWork Member
Pulmonary Vascular Disease
Pulmonary hypertension associated with atrial septal defect in adults: closing time?
Up to 10% of adults with atrial septal defects (ASDs) can develop pulmonary arterial hypertension (PAH) according to European Guidelines on pulmonary hypertension (PH) (Galie, et al. Eur Heart J. 2016;37[1]:67). If ASD closure is considered, they propose a pulmonary vascular resistance index (PVRi) <4 Wood units (WU) m² as a safe cutoff. Higher PVRi carries a higher operative risk, warranting evaluation in specialized PH centers.
American guidelines (Stout, et al. Circulation. 2019 Apr 2;139[14]:e698) recommend closure in symptomatic patients with a net shunt (Qp/Qs) of >1.5:1. Closure appears safe if pulmonary artery (PA) systolic pressure is <1/2 systemic blood pressure, and PVR / systemic vascular resistance is <0.3. They recommend specialized evaluation for higher pressures and to avoid closure once a net right to left shunt is present (Qp/Qs <1.0).
However, in severe cases, experienced centers have reported some success with a “treat-and-close” approach if post-therapy PVR reaches <6.5 WU (Bradley, et al. Int J Cardiol. 2019;291:127).
Finally, consider the following when evaluating ASD-associated PAH: 1. A thermodilution cardiac output method should not be used to calculate PVR/PVRi because of confounding recirculation from the intracardiac shunt (Kwan, et al. Clin Cardiol. 2019;42[3]:334). Qp is used instead and is calculated using Fick equation, requiring accurate oxygen saturation measurements. 2. Mixed venous saturation (MvO2) is needed to determine Qs, and PA saturation cannot be used as MvO2 surrogate. MvO2 must be calculated using superior and inferior vena cava saturations. 3. Some patients with idiopathic PAH may have a small coexisting ASD that is not responsible for the abnormal hemodynamics. Closing the ASD in those cases would be contraindicated. 4. Patients may have more than one type of coexistent congenital heart defect.
Francisco J. Soto, MD, MS, FCCP
Steering Committee Member
Interventional and Chest Diagnostic Procedures
3D printing and pulmonology
Recent advances in 3D printing has enabled physicians to apply this technology in medical education, procedural planning, tissue modeling, and implantable device manufacturing. This is especially true in the field of pulmonology. Advancements in 3D printing have made personalized airway stents a reality, both by 3D printing-assisted injection molding or direct 3D printing.
Airway stents have significantly evolved over the last half century. With use of silicone, bare metallic, and hybrid stents, pulmonologists have an ever-expanding option to address airway stenosis due to both benign and malignancy etiologies. Personalized airway stents hold the potential for advance customization, minimizing pressure points, and improving airflow dynamics to increase mucus clearance. In January 2020, the US Food and Drug Administration (FDA) cleared patient-specific airway stents developed by Dr. Thomas Gildea of Cleveland Clinic. The patient-specific silicone stents are created using CT scans and 3D visualization software to generate a 3D-printed mold that was subsequently used to inject with medical-grade silicone. Two years earlier, a Duke University startup known as restor3D created the first direct 3D printed airway stent using a compressible biocompatible material with properties similar to that of silicone. Both of these stents have been used in patients with promising response.
As we look into the future, the field of pulmonology will experience significant changes with more adoption of 3D printing (ie, additive manufacturing). We may soon be able to create personalized airway prosthesis of any type (stents, spigots, valves, tracheostomies, t-tubes) for the benefit of our patients.
Disclosure: Dr. George Cheng is a cofounder of restor3D.
George Cheng, MD, PhD, FCCP
Steering Committee Member
Pediatric Chest Medicine
COVID-19: Pediatric story of a new pandemic
In December 2019, an outbreak of pneumonia identified to be caused by 2019 novel coronavirus (2019-nCoV) emerged in Wuhan, China, possibly originating from the local wet market selling many species of live animals. A novel member of enveloped RNA coronavirus was identified in samples of BAL fluid from a patient in Wuhan.
It has since rapidly spread globally to countries across six continents. As of early April, 1,286,409 cases have been reported worldwide with 337,933 cases (9,600 deaths) in the US (https://coronavirus.jhu.edu/map.html) with more cases and deaths every day. Most of these initial reports of COVID-19 (COronaVIrusDisease) in children are from China. Fever (60%) and cough (65%) were the most common symptoms. Procalcitonin elevation (80% and co-infection (80%) were prominent clinical findings. Consolidation with surrounding halo sign (50%) and ground-glass opacities (60%) on CT scan were typical radiologic findings. Almost all children recovered without needing intensive care support.
Increased IgM COVID-19 antibody levels observed in three neonates raise questions of potential in-utero transmission (Kimberlin et al. JAMA 2020 Mar 26. doi: 10.1001/jama.2020.4868). One study provided evidence for persistent fecal shedding and possibility of fecal-oral transmission (Xu et al. Nat Med 2020 Mar 13. doi: 10.1038/s41591-020-0817-4).
Initial reports show that children appear to be at similar risk of infection as adults, though less likely to have severe symptoms. Young children, particularly infants, are more vulnerable to infection (Dong et al. Pediatrics. 2020 Apr. doi: 10.1542/peds.2020-0702); (Bi et al. medRxiv 2020 Mar 27. doi: 10.1101/2020.03.03.20028423v3). Thus far, few deaths have been reported in the pediatric age group. Trials are being conducted on a war footing to find a cure and a vaccine.
Harish Rao, MD, MBBS
Steering Committee Member
Pulmonary Physiology, Function, and Rehabilitation
Controversies and the clinical value of lung volume measurements
Lung volumes are often measured by body plethysmography or gas dilution. Their clinic importance in decision making is unclear. Though measured differently, predicted sets obtained by plethysmography from Caucasian populations are often used for gas dilution measurements (Ruppel GL. Respir Care. 2012 Jan;57[1]:26). Recently the GLI felt lung volume data were insufficient to develop universal reference equations (Cooper B, et al. Breathe (Sheff). 2017 Sep;13[3]:e56-e64). ERS/ATS guidelines recommend adjusting Caucasian predicted values depending on race, without advising how to adjust the confidence limits. Their algorithms show if the VC is normal, lung volumes are unnecessary, though it is not unusual to see a normal VC with reduced TLC. Does this suggest the VC is more important than the TLC, even if lacking predicted volume equations for non-Caucasians? Because combined obstructive and restrictive abnormalities occur simultaneously, recommendations state severity of impairment be determined by the FEV1 percent of predicted rather than TLC (Pellegrino R, et al. Eur Respir J. 2005;26:948). The value of quantifying other volumes such as FRC and ERV in conditions such as obesity and musculoskeletal defects is also not clear. In obstruction, volumes can indicate air trapping or hyperinflation measuring RV and RV/TLC. Though cutoffs of <80% and >120% of predicted are often used, guidelines discourage this practice, recommending using predicted equations based on age, race, height, and sex, with statistical limits of normal (Ruppel GL. Respir Care. 2012 Jan;57(1):26).
Further research is needed to define comprehensive racially appropriate predicted equations for lung volumes to support their clinical applicability in decision making, as well as if predicted values by plethysmography are applicable to values obtained from gas dilution.
Said A. Chaaban, MD
Steering Committee Member
Zachary Q. Morris, MD
NetWork Member
Pulmonary Vascular Disease
Pulmonary hypertension associated with atrial septal defect in adults: closing time?
Up to 10% of adults with atrial septal defects (ASDs) can develop pulmonary arterial hypertension (PAH) according to European Guidelines on pulmonary hypertension (PH) (Galie, et al. Eur Heart J. 2016;37[1]:67). If ASD closure is considered, they propose a pulmonary vascular resistance index (PVRi) <4 Wood units (WU) m² as a safe cutoff. Higher PVRi carries a higher operative risk, warranting evaluation in specialized PH centers.
American guidelines (Stout, et al. Circulation. 2019 Apr 2;139[14]:e698) recommend closure in symptomatic patients with a net shunt (Qp/Qs) of >1.5:1. Closure appears safe if pulmonary artery (PA) systolic pressure is <1/2 systemic blood pressure, and PVR / systemic vascular resistance is <0.3. They recommend specialized evaluation for higher pressures and to avoid closure once a net right to left shunt is present (Qp/Qs <1.0).
However, in severe cases, experienced centers have reported some success with a “treat-and-close” approach if post-therapy PVR reaches <6.5 WU (Bradley, et al. Int J Cardiol. 2019;291:127).
Finally, consider the following when evaluating ASD-associated PAH: 1. A thermodilution cardiac output method should not be used to calculate PVR/PVRi because of confounding recirculation from the intracardiac shunt (Kwan, et al. Clin Cardiol. 2019;42[3]:334). Qp is used instead and is calculated using Fick equation, requiring accurate oxygen saturation measurements. 2. Mixed venous saturation (MvO2) is needed to determine Qs, and PA saturation cannot be used as MvO2 surrogate. MvO2 must be calculated using superior and inferior vena cava saturations. 3. Some patients with idiopathic PAH may have a small coexisting ASD that is not responsible for the abnormal hemodynamics. Closing the ASD in those cases would be contraindicated. 4. Patients may have more than one type of coexistent congenital heart defect.
Francisco J. Soto, MD, MS, FCCP
Steering Committee Member