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Objectives: This study was designed to examine the outcomes of adult living-donor lobar lung transplants (LDLLTs) using small-for-size grafts., Methods: A calculated graft forced vital capacity of <50% of the predicted forced vital capacity of the recipient was considered to indicate a small-for-size graft. Adult recipients (≥18 years) who underwent LDLLTs between 2008 and 2022 were included in this study., Results: We performed 80 adult LDLLTs, using small-for-size grafts in 15 patients and non-small grafts in 65 patients. Grade 3 primary graft dysfunction developed within 72 h after the transplant in 3 patients (20%) in the small group and in 3 patients (4.6%) in the non-small group (P = 0.0763). The 1- and 5-year survival rates were 86.7% and 69.3% in the small group and 93.8% and 77.1% in the non-small group (P = 0.742). In the small group, the native lungs were spared in 8 patients, whereas 2 lobar grafts were implanted with non-spared native lungs in the other 7 patients. The 1- and 5-year survival rates were significantly better in the spared group (both 100%) than in the non-spared group (71.4% and 23.8%; P = 0.0375). The spared group showed a significantly higher median percent forced vital capacity after the transplant than the non-spared group (68.5% vs 44.9%; P = 0.0027)., Conclusions: Although the use of small-for-size grafts was associated with a higher rate of severe primary graft dysfunction, no differences were found in survival rates. When the graft is small, the native lung should be partially spared if possible., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: Cardiac volume-based estimation offers an alternative to donor-recipient weight ratio (DRWR) in pediatric heart transplantation (HT) but has not been correlated to posttransplant outcomes. We sought to determine whether estimated total cardiac volume (eTCV) ratio is associated with HT survival in infants., Methods: The United Network for Organ Sharing database was used to identify infants (aged <1 year) who received HT in 1987-2020. Donor and recipient eTCV were calculated from weight using previously published data. Patient cohort was divided acc ording to the significant range of eTCV ratio; characteristics and survival were compared., Results: A total of 2845 infants were identified. Hazard ratio with cubic spline showed prognostic relationship of eTCV ratio and DRWR with the overall survival. The cut point method determined an optimal eTCV ratio range predictive of infant survival was 1.05 to 1.85, whereas no range for DRWR was predictive. Overall, 75.6% of patients had an optimal total cardiac volume ratio, while 18.1% were in the lower (LR) and 6.3% in the higher (HR) group. Kaplan-Meier analysis showed better survival for patients within the optimal vs LR (p = 0.0017) and a similar significantly better survival when compared to HR (p = 0.0053). The optimal eTCV ratio group (n = 2,151) had DRWR, ranging from 1.09 to 5; 34.3% had DRWR of 2% to 3%, and 5.0% had DRWR of >3., Conclusions: Currently, an upper DRWR limit has not been established in infants. Therefore, determining the optimal eTCV range is important to identify an upper limit that significantly predicts survival benefit. This finding suggests a potential increase in donor pool for infant recipients since over 40% of donors in the optimal eTCV range include DRWR values >2 that are traditionally not considered for candidate listing., (Copyright © 2024. Published by Elsevier Inc.)

Size-matching donors to recipients in lung transplantation continues to be a clinical challenge. Predicted total lung capacity equations, or more simply, donor and recipient heights, while widely used, are imprecise and may not be representative of the pool of donors and recipients. These inherent limitations may result in size discrepancies. The advent of easily accessible software and the widespread availability of computed tomography (CT) imaging in donor assessments have made it possible to directly measure lung volumes in donors and recipients. As a result, there is a growing interest in adopting personalized CT volumetry as an alternative. This article explores both methods and underscores the potential benefits and precision offered by CT., Competing Interests: Declaration of competing interest The authors of this manuscript have no conflicts of interest to disclose, as described by the American Journal of Transplantation., (Copyright © 2024 American Society of Transplantation & American Society of Transplant Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Preoperative size matching is essential for both allogeneic and xenogeneic heart transplantation. In preclinical pig-to-baboon xenotransplantation experiments, porcine donor organs are usually matched to recipients by using indirect parameters, such as age and total body weight. For clinical use of xenotransplantation, a more precise method of size measurement would be desirable to guarantee a "perfect match." Here, we investigated the use of transthoracic echocardiography (TTE) and described a new method to estimate organ size prior to xenotransplantation., Methods: Hearts from n = 17 genetically modified piglets were analyzed by TTE and total heart weight (THW) was measured prior to xenotransplantation into baboons between March 2018 and April 2022. Left ventricular (LV) mass was calculated according to the previously published method by Devereux et al. and a newly adapted formula. Hearts from n = 5 sibling piglets served as controls for the determination of relative LV and right ventricular (RV) mass. After explantation, THW and LV and RV mass were measured., Results: THW correlated significantly with donor age and total body weight. The strongest correlation was found between THW and LV mass calculated by TTE. Compared to necropsy data of the control piglets, the Devereux formula underestimated both absolute and relative LV mass, whereas the adapted formula yielded better results. Combining the adapted formula and the relative LV mass data, THW can be predicted with TTE., Conclusions: We demonstrate reliable LV mass estimation by TTE for size matching prior to xenotransplantation. An adapted formula provides more accurate results of LV mass estimation than the generally used Devereux formula in the xenotransplantation setting. TTE measurement of LV mass is superior for the prediction of porcine heart sizes compared to conventional parameters such as age and total body weight., (© 2024 The Authors. Xenotransplantation published by John Wiley & Sons Ltd.)

Total Cardiac Volume (TCV)-based size matching using Computed Tomography (CT) is a novel technique to compare donor and recipient heart size in pediatric heart transplant that may increase overall utilization of available grafts. TCV requires manual segmentation, which limits its widespread use due to time and specialized software and training needed for segmentation. This study aims to determine the accuracy of a Deep Learning (DL) approach using 3-dimensional Convolutional Neural Networks (3D-CNN) to calculate TCV, with the clinical aim of enabling fast and accurate TCV use at all transplant centers. Ground truth TCV was segmented on CT scans of subjects aged 0-30 years, identified retrospectively. Ground truth segmentation masks were used to train and test a custom 3D-CNN model consisting of a DenseNet architecture in combination with residual blocks of ResNet architecture. The model was trained on a cohort of 270 subjects and a validation cohort of 44 subjects (36 normal, 8 heart disease retained for model testing). The average Dice similarity coefficient of the validation cohort was 0.94 ± 0.03 (range 0.84-0.97). The mean absolute percent error of TCV estimation was 5.5%. There is no significant association between model accuracy and subject age, weight, or height. DL-TCV was on average more accurate for normal hearts than those listed for transplant (mean absolute percent error 4.5 ± 3.9 vs. 10.5 ± 8.5, p = 0.08). A deep learning-based 3D-CNN model can provide accurate automatic measurement of TCV from CT images. This initial study is limited as a single-center study, though future multicenter studies may enable generalizable and more accurate TCV measurement by inclusion of more diverse cardiac pathology and increasing the training data., (© 2024. The Author(s).)

Living-donor lobar lung transplantation (LDLLT) is indicated for critically ill patients who would not survive the waiting period in the case of severe brain-dead donor shortage. It is essential to confirm that potential donors are willing to donate without applying psychological pressure from others. In standard LDLLT, the right and left lower lobes donated by 2 healthy donors are implanted into the recipient under cardiopulmonary support. LDLLT can be applied to various lung diseases including restrictive, obstructive, infectious, and vascular lung diseases in both adult and pediatric patients if size matching is acceptable. Functional size matching by measuring donor pulmonary function and anatomical size matching by 3-dimensional computed tomography volumetry are very useful. When 2 donors with ideal size matching are not available, various transplant procedures, such as single lobe, segmental, recipient lobe-sparing, and inverted lobar transplants are valuable options. There seems to be immunological advantages in LDLLT as compared to cadaveric lung transplantation (CLT). Unilateral chronic allograft dysfunction is a unique manifestation after bilateral LDLLT, which may contribute to better prognosis. The growth of adult lung graft implanted into growing pediatric recipients is suggested by radiologic evaluation. Although only 2 lobes are implanted, postoperative pulmonary function is equivalent between LDLLT and CLT. The long-term outcome after LDLLT is similar to or better than that after CLT. The author has performed 164 LDLLTs resulting in 71.6% survival rate at 10 years. All living-donors returned to their previous life styles. Because of possible serious morbidity in donors, LDLLT should be applied only for critically ill patients., (Copyright © 2023 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Total Cardiac Volume (TCV) based size matching using Computed Tomography (CT) is a novel technique to compare donor and recipient heart size in pediatric heart transplant that may increase overall utilization of available grafts. TCV requires manual segmentation, which limits its widespread use due to time and specialized software and training needed for segmentation., Objective: This study aims to determine the accuracy of a Deep Learning (DL) approach using 3-dimensional Convolutional Neural Networks (3D-CNN) to calculate TCV, with the clinical aim of enabling fast and accurate TCV use at all transplant centers., Materials and Methods: Ground truth TCV was segmented on CT scans of subjects aged 0-30 years, identified retrospectively. Ground truth segmentation masks were used to train and test a custom 3D-CNN model consisting of a Dense-Net architecture in combination with residual blocks of ResNet architecture., Results: The model was trained on a cohort of 270 subjects and a validation cohort of 44 subjects (36 normal, 8 heart disease retained for model testing). The average Dice similarity coefficient of the validation cohort was 0.94 ± 0.03 (range 0.84-0.97). The mean absolute percent error of TCV estimation was 5.5%. There is no significant association between model accuracy and subject age, weight, or height. DL-TCV was on average more accurate for normal hearts than those listed for transplant (mean absolute percent error 4.5 ± 3.9 vs. 10.5 ± 8.5, p = 0.08)., Conclusion: A deep learning based 3D-CNN model can provide accurate automatic measurement of TCV from CT images., Competing Interests: Declarations Disclosure / Financial Conflict of Interest Statement Dr. Morales reports contributions from Cormatrix, Inc., personal fees from Syncardia, Inc., personal fees and other contributions from Abbott Medical Inc., personal fees from Xeltis, Inc., personal fees from Azyio, Inc. all outside the submitted work. All other authors have no financial conflicts of interest to disclose. Dr. Zafar is Vice President of Cardiothoracic Clinical Development at Transmedics, Inc, his employment is outside the submitted work. All other authors report no conflicts of interest. Additional Declarations: No competing interests reported.

Predicted heart mass ratio (PHMr) has been proposed as an optimal size metric in the selection of a donor heart for transplant; however, it is not known if the same size matching criteria pertains uniformly to all types of cardiomyopathies. Heart transplant recipients in the United Network for Organ Sharing registry database were categorized into 6 groups based on the type of cardiomyopathy, dilated, coronary artery disease, hypertrophic, restrictive, valvular and adult congenital heart disease. Patients in each group of etiology were stratified based on the PHMr into 5 groups: severely undersized <0.86, moderately undersized 0.86 to 0.94, matched 0.95 to 1.04, moderately oversized 1.05 to 1.24, and severely oversized >1.25. The survival and cause of death of patients in each etiology group were reviewed. The United Network for Organ Sharing registry database from January 1987 to July 2021 included 53,573 patients who received a heart transplant. Compared with patients with size matched hearts, recipients with dilated (hazard ratio 1.17, p = 0.001) and valvular (hazard ratio 1.79, p = 0.032) cardiomyopathy who had an undersized heart with PHMr <0.86 had decreased survival. In addition, the survival of patients with hypertrophic or restrictive cardiomyopathy and adult congenital heart disease was not affected by size matching based on the PHMr (0.601 and 0.079, respectively, p = 0.873). In conclusion, our analysis suggests that the size matching criteria based on PHMr may not be uniform to all patients across various etiologies of cardiomyopathy. Therefore, the data can be used to increase the acceptance rate of donor hearts, particularly, for patients with hypertrophic, restrictive cardiomyopathy and congenital heart disease in which size matching is less significant for survival outcome., Competing Interests: Declaration of Competing Interest The authors have no competing interests to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Nano-particles possess desirable attributes such as small particle size, excellent injectivity, and migration performance, making them highly compatible and adaptable for addressing the water flooding requirements of the low-permeability oil reservoir. When selecting an oil displacement agent for enhancing water flooding and improving oil recovery, factors such as injectivity and migration need to be carefully considered. In this study, through a comprehensive analysis of the mechanism and technical characteristics of nano-particle oil displacement agents, the plugging and profile control mechanisms recognized by the mainstream of nano-particles are elucidated. By examining various elements including outcrop fractures, natural micro-fractures, artificial support fractures, and dynamic monitoring data, a reevaluation of the dominant channel scale governing water drive in low permeability reservoirs is conducted, thereby defining the target entities for profile control and flooding operations. Drawing upon Darcy's percolation law and leveraging enhanced oil recovery techniques based on the classical Kozeny equation, a profile control and flooding mechanism is proposed that focuses on increasing the specific surface area of polymer particles while simultaneously reducing reservoir permeability. This innovative approach establishes a novel matching method between nano-polymer particles and the diverse media found within the reservoir. Lastly, the application of nanoparticle flooding technology in Changqing Oilfield is presented, highlighting its practical implementation and benefits., Competing Interests: Author TW was employed by Oil and Gas Technology Research Institute of Changqing Oilfield. Author YHZ was employed by Research Institute of Xi'an Changqing Chemical Group Co., Ltd. Author YCZ was employed by Oil Production Plant NO 11 of Changqing Oilfield. Author ZL was employed Oil Production Plant NO 10 of Changqing Oilfield. The remaining author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wu, Zhao, Zhang, Li and Su.)

Background: Donor/recipient size matching is paramount in heart transplantation. Body weight, height, body mass index, body surface area, and predicted heart mass (PHM) ratios are generally used in size matching. Precise size matching is important to achieve better clinical outcomes. This study aims to determine the donor/recipient ascending aortic diameter (AAoD) ratio as a metric for donor selection and its effect on postoperative clinical outcomes in heart transplant patients., Methods: We retrospectively reviewed all consecutive patients who underwent heart transplantation from January 2015 to December 2018. A cutoff value of 0.8032 for the donor/recipient AAoD ratio (independent variable for the primary endpoint during unmatched cohort analysis) was determined for predicting in-hospital mortality. The patients were divided into two groups based on the cutoff value. Group A, AAoD < 0.8032 ( n  = 96), and Group B, AAoD > 0.8032 ( n  = 265). A propensity score-matched (PSM) study was performed to equalize the two groups comprising 77 patients each in terms of risk. A Cox regression model was developed to identify the independent preoperative variables affecting the primary end-point. The primary endpoint was all-cause in-hospital mortality., Results: A total of 361 patients underwent heart transplantation during the given period. On the multivariate analysis, donor/recipient PHM ratio [HR 16.907, 95% confidence interval (CI) 1.535-186.246, P  = 0.021], donor/recipient AAoD ratio < 0.8032 (HR 5.398, 95% CI 1.181-24.681, P  = 0.030), and diabetes (HR 3.138, 95% CI 1.017-9.689, P  = 0.047) were found to be independent predictors of in-hospital mortality. Group A had higher 3-year mortality than Group B ( P  = 0.022). The surgery time was longer and postoperative RBC, plasma, and platelets transfusion were higher in Group A ( P  < 0.05). Although not statistically significant the use of continuous renal replacement therapy ( P  = 0.054), and extracorporeal membrane oxygenation ( P  = 0.086), was realatively higher, and ventilation time ( P  = 0.079) was relatively longer in Group A., Conclusions: The donor/recipient AAoD ratio is a potential metric for patient matching and postoperative outcomes in heart transplantation. A donor/recipient AAoD ratio > 0.8032 could improve post-heart transplantation outcomes and donor heart utilization., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Masroor, Chen, Wang and Dong.)

Living-donor lobar lung transplantation (LDLLT) was first performed in the USA and thereafter it was introduced in Japan in 1998 as an alternative modality to brain-dead donor lung transplantation (BDLT). Although the LDLLT procedure was employed for rapidly deteriorating patients who were hospitalized and mechanically ventilated at the time of transplantation, LDLLT demonstrated better or comparable post-transplant outcomes in comparison to BDLT. Less injured lobar grafts and a significantly shorter graft ischemic time possibly contributed to a significantly lower incidence of severe primary graft dysfunction (PGD) after LDLLT in comparison to BDLT. In standard LDLLT, patients obtained lobar grafts from two different donors, and thus most patients developed chronic lung allograft dysfunction (CLAD) only in the unilateral lung graft. This indicates that the contralateral unaffected lung graft could reserve lung function after the unilateral development of CLAD. In our transplant program, the incidence of CLAD per donor in LDLLT (14.4%) was also significantly lower in comparison to BDLT (24.7%). The 1-, 5- and 10-year survival rates after LDLLT were 90.9%, 75.5% and 57.2%, respectively, which were equivalent to those after BDLT (92.9%, 73.4% and 62.2%). The inherent surgical risk to the living donors should always be considered. In our experience, living-donor surgery was associated with a complication rate of 12.7%, and importantly, all living donors finally returned to their previous social lives. Precise functional and anatomical size matching between donor lobar graft and recipient could provide a favorable pulmonary function after LDLLT. We recently established multimodal surgical approaches, such as native upper lobe-sparing, right-to-left horizontally rotated, segmental, and single-lobe transplantation, in order to resolve the issue of size mismatch between the donor lobar graft and the recipient., Competing Interests: Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-22-1867/coif). The special series “Why is the Outcome Good? Secrets of Lung Transplantation in Japan” was commissioned by the editorial office without any funding or sponsorship. The authors have no other conflicts of interest to declare., (2023 Journal of Thoracic Disease. All rights reserved.)

Background: Appropriate size matching between donor and recipient is critical for successful pulmonary transplantation. Although surrogate measurements such as height and gender are often utilized to approximate predicted lung volume, these methods provide only a gross estimation with wide variability and poor predictive value., Case Description: A single center exploratory study was conducted in which four patients underwent lung transplantation (LT) with pre-operative computed tomography (CT) volumetry obtained in both the donor and recipient to facilitate decision making regarding organ size and suitability. In four cases in which CT volumetry was used, the lung volumes calculated using surrogate measurements significantly overestimated both donor and recipient lung volumes quantified by CT volumetric analysis. All recipients underwent successful LT without necessary graft downsizing., Conclusions: This is an initial report of prospectively utilizing CT volumetry as an adjunct to decision-making regarding suitability of donor lungs. In these cases, CT volumetry facilitated the confident acceptance of donor lungs that were initially predicted to be oversized based on other clinical measures., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-22-1203/coif). DK served as an unpaid editorial board member of Journal of Thoracic Disease from April 2022 to March 2024. RRH reports grants and personal fees from Bristol Myers Squibb, Mallinckrodt, UpToDate, CareDx, Natera, and Transmedics, outside of the submitted work. VP has served on panel discussions for PrecisCa, has a spouse who owns stock in Intuitive Surgical, and reports the following grants: I01 HX002475, R01HL146856, R01CA258681, and MATF. CCF is a board member and owns stock in OpComm, Inc. The other authors have no conflicts of interest to declare., (2023 Journal of Thoracic Disease. All rights reserved.)

Introduction: In pediatric heart transplantation, donor: recipient weight ratio (DRWR) has long been the sole metric for size matching. Total cardiac volume (TCV)-based size matching has emerged as a novel method to precisely identify an upper limit of donor organ size of a heart transplant recipient while minimizing the risk of complications from oversizing. The clinical adoption of donor: recipient volume ratio (DRVR) to prevent short-term adverse outcomes of oversizing is unknown. The purpose of this single-center study is to determine the relationship of DRWR and DRVR to the risk of post-operative complications from allograft oversizing., Methods: Recipient TCV was measured from imaging studies and donor TCV was calculated from published TCV prediction models. DRVR was defined as donor TCV divided by recipient TCV. The primary outcome was short-term post-transplant complications (SPTC), a composite outcome of delayed chest closure and prolonged intubation > 7 days. A multivariable logistic regression model of DRWR (cubic spline), DRVR (linear) and linear interaction between DRWR and DRVR was used to examine the probability of experiencing a SPTC over follow-up as a function of DRWR and DRVR., Results: A total of 106 transplant patients' records were reviewed. Risk of the SPTC increased as DRVR increased. Both low and high DRWR was associated with the SPTC. A logistic regression model including DRWR and DRVR predicted SPTC with an AUROC curve of 0.74. [95% CI 0.62 0.85]. The predictive model identified a "low-risk zone" of donor-recipient size match between a weight ratio of 0.8 and 2.0 and a TCV ratio less than 1.0., Conclusion: DRVR in combination with DRWR predicts short-term post-transplant adverse events. Accepting donors with high DRWR may be safely performed when DRVR is considered., (Copyright © 2022 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Numerous studies have analyzed the consequences of donor-recipient organ size mismatch within both heart and lung transplantation. However, there is very little data on size matching in combined heart-lung transplantation (HLTx). We reviewed how donor/recipient predicted total lung capacity (pTLC), predicted heart mass (pHM), weight, and height ratios affect HLTx survival and graft rejection outcome., Methods: We performed a retrospective analysis on adult HLTx patients using the UNOS database. Overall survival at 1- and 5-years, as well as 5-years bronchiolitis obliterans syndrome (BOS) and coronary artery vasculopathy (CAV) development, were the outcomes of interest. Each sizing modality was split into 5 groups for survival analysis and 3 groups for graft rejection analysis based on an approximately equal size-matched reference group., Results: In total, 747 patients were analyzed in our study. Of the 4 sizing modalities, only pHM ratio had a significant difference in acute and long-term survival. In particular, a severely undersized pHMr of < 83% was associated with an increased risk of mortality compared to an approximately equally sized match (1-year: HR=1.95, 95% CI=1.30-2.91, p = 0.001; 5-year: HR = 1.47, 95% CI = 1.05-2.06, p = 0.027). No sizing metric was predictive of BOS or CAV development., Conclusion: Our analysis supports the use of pHM ratio for size matching in HLTx. Based on our results, a donor/recipient pHM ratio of >83% should be achieved to minimize mortality risk associated with sizing mismatch., Competing Interests: Disclosure statement Yoshiya Toyoda – Clinical research and grant support from Transmedics Incorporated, Cerus Corporation ReciPe Study, and EvaHeart Incorporated. This had no relationship with the current study and has not affected the integrity of our report. The authors have no conflicts of interest to declare., (Copyright © 2022 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Errors in measuring chest X-ray (CXR) lung heights could contribute to the occurrence of size-mismatched lung transplant procedures., Methods: We first used Bland-Altman analysis for repeated measures to evaluate contributors to measurement error of chest X-ray lung height. We then applied error propagation theory to assess the impact of measurement error on size matching for lung transplantation., Results: A total 387 chest X-rays from twenty-five donors and twenty-five recipients were measured by two raters. Individual standard deviation for lung height differences were independent of age, sex, donor vs. recipient, diagnostic group and race/ethnicity and all were pooled for analysis. Bias between raters was 0.27 cm (±0.03) and 0.22 cm (±0.06) for the right and left lung respectively. Within subject variability was the biggest contributor to error in measurement, 2.76 cm (±0.06) and 2.78 cm (±0.2) for the right and left lung height. A height difference of 4.4 cm or more (95% CI: ±4.2, ±4.6 cm) between the donor and the recipient right lung height has to be accepted to ensure matching for at least 95% of patients with the same true lung height. This difference decreases to ±1.1 cm (95% CI: ±0.9, ±1.3 cm) when the average from all available chest X-rays is used. The probability of matching a donor and a recipient decreases with increasing true lung height difference., Conclusions: Individual chest X-ray lung heights are imprecise for the purpose of size matching in lung transplantation. Averaging chest X-rays lung heights reduced uncertainty., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-21-1755/coif). DK serves as an unpaid editorial board member of Journal of Thoracic Disease. RVG reports that this research was supported by the Washington University Institute of Clinical and Translational Sciences Grant UL1TR002345 from the National Center for Advancing Translational Sciences (NCATS) of the National Institutes of Health (NIH). The content is solely the responsibility of the authors and does not necessarily represent the official view of the NIH. MW reports receiving salary support from Grant UL1TR002345 from the National Center for Advancing Translational Science NCATS of the National Institute of Health (NIH). GFM is the Medical Director at Mid America Transplant. DEB reports receiving research funding from Mid-America Transplant. RH reports receiving research funding from Bristol Myers Squibb and Mallinkrodt, gent funding from Mid America Transplant and personal fees from Transmedics, CareDx, Thevavance, and Vectura. The other authors have no conflicts of interest to declare., (2022 Journal of Thoracic Disease. All rights reserved.)

Living-donor lobar lung transplantation (LDLLT) has become an important life-saving option for patients with severe respiratory disorders, since it was developed by a group in the University of Southern California in 1993 and introduced in Japan in 1998 in order to address the current severe shortage of brain-dead donor organs. Although LDLLT candidates were basically limited to critically ill patients who would require hospitalization, the long-term use of steroids, and/or mechanical respiratory support prior to transplantation, LDLLT provided good post-transplant outcomes, comparable to brain-dead donor lung transplantation in the early and late phases. In Kyoto University, the 5- and 10-year survival rates after LDLLT were reported to be 79.0% and 64.6%, respectively. LDLLT should be performed under appropriate circumstances, considering the inherent risk to the living donor. In our transplant program, all living donors returned to their previous social lives without any major complications, and living-donor surgery was associated with a morbidity rate of <15%. Both functional and anatomical size matching were preoperatively performed between the living-donor lobar grafts and recipients. Precise size matching before surgery could provide a favorable pulmonary function and exercise capacity after LDLLT. Various transplant procedures have recently been developed in LDLLT in order to deal with the issue of graft size mismatching in recipients, and favorable post-transplant outcomes have been observed. Native upper lobe-sparing and/or right-to-left inverted transplantation have been performed for undersized grafts, while single-lobe transplantation has been employed with or without contralateral pneumonectomy and/or delayed chest closure for oversized grafts., Competing Interests: Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/jtd-2021-07). The series “Lung Transplantation: Past, Present, and Future” was commissioned by the editorial office without any funding or sponsorship. Both authors have no other conflicts of interest to declare., (2021 Journal of Thoracic Disease. All rights reserved.)

Low-concentration ethane capture is crucial for environmental protection and natural gas purification. The ideal physisorbent with strong C 2 H 6 interaction and large C 2 H 6 uptake at low-concentration level has rarely been reported, due to the large pK a value and small quadrupole moment of C 2 H 6 . Herein, we demonstrate the perfectly size matching between the ultramicropore (pore size of 4.6 Å) and ethane (kinetic diameter of 4.4 Å) in a nickel pyridine-4-carboxylate metal-organic framework (IISERP-MOF2), which enables the record-breaking performance for low concentration C 2 H 6 capture. IISERP-MOF2 exhibits the large C 2 H 6 adsorption enthalpy of 56.7 kJ/mol, and record-high C 2 H 6 uptake at low pressure of 0.01-0.1 bar and 298 K (1.8 mmol/g at 0.01 bar). Molecule simulations and C 2 H 6 -loading crystal structure analysis revealed that the maximized interaction sites in IISERP-MOF2 with ethane molecule originates the strong C 2 H 6 adsorption. The dynamic breakthrough experiments for gas mixtures of C 2 H 6 /N 2 (1/999, v/v) and C 2 H 6 /CH 4 (5/95, v/v) proved the excellent low-concentration C 2 H 6 capture performance., (© 2021 Wiley-VCH GmbH.)

Purpose: A difference in the lower body to upper body ratio between similarly heighted individuals could lead to inadequately matched transplants. There has been a perception in clinical circles that body ratio varies between people of different races, and investigating this supposition would prove useful in increasing transplant match accuracy. The investigation's purpose was to derive an equation with a greater correlation to lung length than height alone., Methods: Lung transplantation donor data for 480 adult patients was obtained and divided by ethnicity-Caucasian, African American, and Hispanic. Height, weight, age, sex, right and left lung length were evaluated for significance. The R 2 value of the multiple linear regression with these variables vs. lung length was determined and tested in a separate dataset of 100 patients., Results: Only the distribution of height was significant between the 3 ethnicities ( P = 0.041). None of the ANCOVAs were significant ( P < 0.05) or near significant ( P < 0.10). For the strongest correlation model with lung length, height had a linear fit, weight had a cubic fit, and age had a logistic fit. Multiple regression models were successfully created for right lung (R 2 = 0.202) and left lung (R 2 = 0.213). Independent testing showed a correlation of 0.131 and 0.136, respectively., Conclusion: Using demographic information from the donor and recipient as proxies for estimating lung size should only serve as a rough guide due to their weak correlation with lung length. As a result, for greater accuracy, donor-recipient matching should be individualized by taking donor and recipient chest X-Rays and/or TLC into consideration.

A 16-year-old with new-onset dilated cardiomyopathy underwent VAD placement, later complicated by low flow from outflow graft kinking. To expedite heart transplantation, TCV was calculated and compared with 141 normal patients pinpointing the upper weight threshold. He was transplanted 2 days later within the expanded weight range with no post-transplant complications., (© 2021 Wiley Periodicals LLC.)

Objectives: Lobar lung transplantation (LLTx) from deceased donors is a potential solution for donor-recipient size mismatch for small sized recipients. We reviewed our institutional experience to compare outcomes after LLTx to standard lung transplantation (LTx)., Methods: We retrospectively reviewed transplants in our institution from January 2000 to December 2017. LLTx early- and long-term outcomes were compared with LTx. Additional analysis of outcomes was performed after dividing the cohort into 2 eras (era 1, 2000-2012; era 2, 2013-2017)., Results: Among the entire cohort (1665), 75 were LLTx (4.5%). Compared with LTx, LLTx were more frequently bridged to transplant with extracorporeal life support or mechanical ventilation and were transplanted in a rapidly deteriorating status (respectively, 20% vs 4.4%, P = .001; 22.7% vs 7.9, P < .001; and 41.3% vs 26.5%, P = .013). LLTx had longer intensive care unit and hospital lengths of stay (respectively, median 17 vs 4 days, and 45 vs 23, both P < .001), and greater 30-day mortality (13.3% vs 4.3%, P = .001) and 90-day mortality (17.3% vs 7.2%, P = .003). In era 2, despite a significantly greater 30-day mortality (10.8% vs 2.8%, P = .026), there was no significant difference in 90-day mortality between LLTx and LTx (13.5% vs 5.1%, P = .070). Overall survival at 1, 3, and 5 years was not significantly different between LLTx and LTx (73.2% vs 84.4%, 56.9% vs 68.4% and 50.4% vs 55.8, P = .088)., Conclusions: Although LLTx is a high-risk procedure, both mid- and long-term survival are comparable with LTx in all cohorts in the modern era. LLTx therefore represents a valuable surgical option for small-sized recipients., (Copyright © 2020 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

This work presents an efficient and facile strategy to prepare an α-amylase bioreactor. As enzymes are quite large to be immobilized inside metal-organic frameworks (MOFs), the tertiary and quaternary structures of α-amylase were first disrupted using a combination of urea, dithiothreitol (DTT), and iodoacetamide (IAA). After losing its tertiary structure, the unfolded proteins can now penetrate into the microporous MOFs, affording fragmented α-amylase@MOF bioreactors. Among the different MOFs evaluated, UiO-66 gave the most promising potential due to the size-matching effect of the α-helix of the fragmented α-amylase with the pore size of UiO-66. The prepared bioreactor exhibited high yields of small carbohydrate (maltose) even when reused up to 15 times (>80% conversion).

Background: The pediatric heart transplant community uses weight-based donor-to-recipient size matching almost exclusively, despite no evidence to validate weight as a reliable surrogate of cardiac size. Donor size mismatch is the second most common reason for the refusal of donor hearts in current practice (∼30% of all refusals). Whereas case-by-case segmentation of total cardiac volume (TCV) by computed tomography (CT) for direct virtual transplantation is an attractive option, it remains limited by the unavailability of donor chest CT. We sought to establish a predictive model for donor TCV on the basis of anthropomorphic and chest X-ray (CXR) cardiac measures., Methods: Banked imaging studies from 141 subjects with normal CT chest angiograms were obtained and segmented using 3-dimensional modeling to derive TCV. CXR data were available for 62 of those subjects. A total of 3 predictive models of TCV were fit through multiple linear regression using the following variables: Model A (weight only); Model B (weight, height, sex, and age); Model C (weight, height, sex, age, and 1-view anteroposterior CXR maximal horizontal cardiac width)., Results: Model C provided the most accurate prediction of TCV (optimism corrected R 2  = 0.99, testing set R 2  = 0.98, mean absolute percentage error [MAPE] = 8.6%) and outperformed Model A (optimism corrected R 2  = 0.94, testing set R 2  = 0.94, MAPE = 16.1%) and Model B (optimism corrected R 2  = 0.97, testing set R 2  = 0.97, MAPE = 11.1%)., Conclusions: TCV can be predicted accurately using readily available anthropometrics and a 1-view CXR from donor candidates. This simple and scalable method of TCV estimation may provide a reliable and consistent method to improve donor size matching., (Copyright © 2020 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Heart transplant waitlist mortality remains high in infants <1 year of age and among those with CHD. Currently, the median accepted donor-to-recipient weight percentage is approximately 130% of the recipient's weight. We hypothesized that patients with CHD may accept a larger organ using novel 3D-derived imaging data to estimate donor and recipient TCV., Methods: A single-center, retrospective study was performed using CT data for 13 patients with CHD and 94 control patients. 3D visualization software was used to create digital 3D heart models that provide an estimate of TCV. In addition, echocardiograms obtained prior to cross-sectional imaging were reviewed for presence of ventricular chamber dilation., Results: Sixty-two percent (8/13) of patients with CHD had 3D-derived TCV resulting in a weight that was >130% larger than their actual weight. This was seen in single-ventricle patients following Blalock-Taussig shunt and Fontan palliation, and patients with biventricular repair. Of those, 75% (6/8) had reported moderate-to-severe ventricular chamber dilation by echocardiogram or cardiac magnetic resonance imaging., Conclusions: In a large portion of patients with CHD, 3D-derived TCV place the recipient at a higher listing weight than their actual weight. We propose obtaining cross-sectional imaging to better assess TCV in a recipient, which may increase the donor range for CHD recipients and improve organ utilization in pediatrics., (© 2019 Wiley Periodicals, Inc.)

Traumatic injury and idiopathic avascular necrosis of the talus bone can result in osteochondral lesions of the talus leading to pain, motion loss, and disability. Treatment with osteochondral allografting currently requires the donor talus to be size matched to the recipient talus to ensure precise fits. Eliminating or reducing the need for size matching would lessen costs and the delay between diagnosis and treatment. 3D models of 12 tali of varying sizes were used to analyze curvatures and profiles of select areas on the talar dome. The allograft procedure was mimicked to compare the results between using 20mm and 30mm osteochondral allografts with, and without, donor size matching. The observed curvatures and profiles on the talar dome were found to be consistent between tali of different sizes. Size matching was not required to have acceptable levels of deviation between donor and recipient tali when using 20mm length segments. Deviations without size matching were found to be very similar to the deviations with size matching with only 14.8% of the fits without size matching having larger deviations (although less than 1.5mm) than those with size matching. Using the 30mm segments, there was a significant difference between the small female tali and the largest male tali. Thus, donor size matching is not necessary when treating large osteochondral lesions of the talus with an osteochondral allograft taken from the central 20mm of the donor talar dome, and only sex matching may be necessary for 30mm grafts., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Living-donor lobar lung transplantation (LDLLT) was developed to deal with the severe shortage of brain dead door for patients who would not survive the long waiting period. In standard LDLLT, right and left lower lobes removed from two healthy donors are implanted into a recipient after right and left pneumonectomies using cardiopulmonary bypass (CPB). The number of LDLLT has decreased in the USA due to the recent change in allocation system for cadaveric donor lungs. For the past several years, most of the reports on LDLLT have been from Japan, where the average waiting time for a cadaveric lung is exceeding 800 days. LDLLT has been performed both for adult and pediatric patients suffering from various end-stage lung diseases including restrictive, obstructive, vascular and infectious lung diseases. Since only two lobes are implanted, size matching is a very important issue. Functional size matching by measuring donor pulmonary function and anatomical size matching by three-dimensional computed tomography (3D-CT) volumetry are very useful. For oversize graft, we have employed several techniques, including single lobe transplantation, delayed chest closure, downsizing the graft, and middle lobe transplantation. In cases of undersize mismatch, native upper lobe sparing transplant or right-left inverted transplant was performed. The 5-, 10- and 15-year survivals were 80.8%, 72.6% and 61.7%, respectively. There was no difference in survival between standard LDLLT and non-standard LDLLT such as single, sparing and inverted transplant. All donors have been discharged without any restrictions. LDLLT is a viable option for very ill patients who would not survive a long waiting time for cadaveric lungs. We have successfully developed various surgical techniques to overcome size mismatching with favorable outcome., Competing Interests: Conflicts of Interest: The author has no conflicts of interest to declare.

Background: The International Society for Heart and Lung Transplantation (ISHLT) guidelines advise against inappropriate weight match (IWM) for heart transplant, defined as donor weight <70% of recipient's weight. Few studies have explored in detail this size-matching recommendation, especially with regard to body mass index (BMI) and gender matching. We aimed to determine whether any difference could be observed between size-matching in obese and non-obese recipients with regard to mortality after cardiac transplantation., Methods: Data from 52,455 adult heart transplants (recipients ≥18 years of age) between 1994 and 2013 were obtained from the ISHLT Registry. We defined the following subgroups of patients based on BMI: underweight, BMI <18.5; non-obese, BMI 18.5 to 30; and obese, BMI >30. The end-points were all-cause 30-day mortality and cumulative mortality., Results: IWM was associated with increased 30-day mortality (odds ratio [OR] = 1.20, 95% confidence interval [CI] 1.01 to 1.43, p = 0.041) and cumulative mortality (hazard ratio [HR] = 1.14, 95% CI 1.07 to 1.22, p < 0.001). In non-obese recipients, IWM was associated with increased 30-day mortality (OR = 1.89, 95% CI 1.48 to 2.41, p < 0.001) as well as cumulative mortality (HR = 1.27, 95% CI 1.15 to 1.41, p < 0.001), whereas, for obese recipients, IWM was not associated with 30-day or cumulative mortality. Male recipients of female allografts (HR = 1.08, 95% CI 1.04 to 1.12, p < 0.001) as well as female recipients of male allografts (HR = 1.07, 95% CI 1.02 to 1.13, p = 0.003) had increased cumulative mortality compared with gender-matched transplants. There was no interaction between IWM and gender mismatch., Conclusions: Our results indicate that donor weight <70% of recipient weight increases mortality in non-obese heart transplant recipients, but not in obese transplant recipients. Gender mismatch increases mortality independently of weight match., (Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Objectives: In standard living-donor lobar lung transplantation (LDLLT), the right and left lower lobes from 2 healthy donors are implanted. Because of the difficulty encountered in finding 2 donors with ideal size matching, various transplant procedures have been developed in our institution. The purpose of this retrospective study was to compare outcomes of nonstandard LDLLT with standard LDLLT., Methods: Between June 2008 and January 2016, we performed 65 LDLLTs for critically ill patients. Functional size matching was performed by estimating graft forced vital capacity based on the donor's measured forced vital capacity and the number of pulmonary segments implanted. For anatomical size matching, 3-dimensional computed tomography volumetry was performed. In cases of oversize mismatch, single-lobe transplant or downsizing transplant was performed. In cases of undersize mismatch, native upper lobe sparing transplant or right-left inverted transplant was performed. In right-left inverted transplants, the donor's right lower lobe was inverted and implanted into the recipient's left chest cavity., Results: Twenty-nine patients (44.6%) received nonstandard LDLLT, including 12 single-lobe transplants, 7 native upper lobe sparing transplants, 6 right-left inverted transplants, 2 sparing + inverted transplants, and 2 others. Thirty-six patients (57.4%) received standard LDLLT. Three- and five-year survival rates were similar between the 2 groups (89.1% and 76.6% after nonstandard LDLLT vs 78.0% and 71.1% after standard LDLLT, P = .712)., Conclusions: Various transplant procedures such as single, sparing and inverted transplants are valuable options when 2 donors with ideal size matching are not available for LDLLT., (Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

An impedimetric sensor for persistent toxic substances, including organic pollutants and toxic inorganic ions is presented. The persistent toxic substances are detected using an ultrasensitive technique that is based on electron-transfer blockage. This depends on the formation of guest-host complexes, hydrogen bonding, or a cyclodextrin (CD)-metal complex (M m (OH) n -β-CD) structure between the target pollutants and β-CD.

The field of lung transplantation has seen an exciting evolution recently, with novel approaches to increasing the number of organs available for patients with end-stage lung disease. We review 2 recent reports describing the approach of lobar lung transplant as a successful and viable option for those recipients who are challenged by size mismatch and clinical course decline while on the transplant waiting list., (© 2013 Elsevier Inc. All rights reserved.)

Interactions among granivores and seeds depend on the foraging behaviour and morphology of the granivores and on the attributes and availability of seeds. We investigated seed selection by the seed harvesting ant Messor bouvieri in three adjacent plant communities in Spain by relating the harvested seeds to those in the seed rain. Preference was positively correlated with seed size and abundance which accounted for 43% and 20% of the variance respectively. Contrary to predictions of central place foraging theory, the size of seeds harvested did not increase with distance from the nest. Inclusion of a less-preferred item in the diet was more strongly related to the abundance of more-preferred items (60% of the variance) than the abundance of the less-preferred item (14% of the variance). Worker size accounted for 20-30% of the variance in the size of harvested seeds, although small workers did not appear to be constrained by load size for the range of seeds available. The body size of ants was significantly larger in the community with the greatest proportion of large seeds, although this was not due to their ability to carry larger loads or due to the greater force required to crush these seeds. The strong preference of M. bouvieri for large seeds may have important consequences for the plant communities in which they forage.