Deep learning-based assay for programmed death ligand 1 immunohistochemistry scoring in non-small cell lung carcinoma: Does it help pathologists score?

Several studies have developed various artificial intelligence (AI) models for immunohistochemical analysis of programmed death ligand 1 (PD-L1) in patients with non-small cell lung carcinoma; however, none have focused on specific ways by which AI-assisted systems could help pathologists determine the tumor proportion score (TPS). Herein, we developed an AI model to calculate the TPS of the PD-L1 22C3 assay and evaluated whether and how this AI-assisted system could help pathologists determine the TPS and analyze how AI-assisted systems could affect pathologists' assessment accuracy. We assessed the four methods of the AI-assisted system: 1) and 2) pathologists first assessed and then referred to automated AI scoring results (1, positive tumor cell percentage; 2, positive tumor cell percentage and visualized overlay image) for a final confirmation, and 3) and 4) pathologists referred to the automated AI scoring results (3, positive tumor cell percentage; 4, positive tumor cell percentage and visualized overlay image) while determining TPS. Mixed model analysis was used to calculate the odds ratios (ORs) with 95% confidence intervals for AI-assisted TPS 1) to 4) compared with pathologists' scoring. For all 584 samples of tissue microarray, the OR for AI-assisted TPS 1) to 4) was 0.94-1.07 and not statistically significant. Of them, we found 332 cases of discordant cases, on which the pathologists' judgments were inconsistent; the ORs for AI-assisted TPS 1), 2), 3), and 4) were 1.28 (1.06-1.54, p = 0.012), 1.29 (1.06-1.55, p = 0.010), 1.28 (1.06-1.54, p = 0.012), and 1.29 (1.06-1.55, p = 0.010), respectively, which were statistically significant. For discordant cases, the OR for each AI-assisted TPS compared with the others was 0.99-1.01 and not statistically significant. This study emphasized the usefulness of the AI-assisted system for cases wherein pathologists had difficulty determining the PD-L1 TPS.

Effect of epoprostenol-induced thrombocytopaenia on lung transplantation for pulmonary arterial hypertension.

OBJECTIVES: Preoperative intravenous epoprostenol therapy can cause thrombocytopaenia, which may increase the risk of perioperative bleeding during lung transplantation. This study aimed to determine whether lung transplantation can be safely performed in patients with epoprostenol-induced thrombocytopaenia. METHODS: From June 2008 to July 2022, we performed 37 lung transplants in patients with pulmonary arterial hypertension (PAH), including idiopathic PAH (n = 26), congenital heart disease-associated PAH (n = 7), pulmonary veno-occlusive disease (n = 3) and peripheral pulmonary artery stenosis (n = 1) at our institution. Of these, 26 patients received intravenous epoprostenol therapy (EPO group), whereas 11 patients were treated with no epoprostenol (no-EPO group). We retrospectively analysed the preoperative and postoperative platelet counts and post-transplant outcomes in each group. RESULTS: Preoperative platelet counts were relatively lower in the EPO group than in the no-EPO group (median EPO: 127 000 vs no-EPO: 176 000/µl). However, blood loss during surgery was similar between the 2 groups (EPO: 2473 ml vs no-EPO: 2615 ml). The platelet counts significantly increased over 1 month after surgery, and both groups showed similar platelet counts (EPO: 298 000 vs no-EPO: 284 000/µl). In-hospital mortality (EPO: 3.9% vs no-EPO: 18.2%) and the 3-year survival rate (EPO: 91.4% vs no-EPO: 80.8%) were similar between the 2 groups. CONCLUSIONS: Patients with PAH treated with intravenous epoprostenol showed relatively lower platelet counts, which improved after lung transplantation with good post-transplant outcomes.

Long-term prognosis analysis of surgical therapy for bilateral synchronous multiple primary lung cancer: a follow-up of 293 cases.

Background: Bilateral synchronous multiple primary lung cancer (BSMPLC) presents significant clinical challenges due to its unique characteristics and prognosis. Understanding the risk factors that influence overall survival (OS) and recurrence-free survival (RFS) is crucial for optimizing therapeutic strategies for BSMPLC patients. Methods: We retrospectively analyzed clinical characteristics and treatment outcomes of 293 patients with BSMPLC who underwent surgical treatment between January 2010 and July 2017. Results: The 10-year OS and RFS rates were 96.1% and 92.8%, respectively. Preoperative forced expiratory volume in 1 second (FEV1) ≥70% [hazard ratio (HR), 0.214; 95% confidence interval (CI): 0.053 to 0.857], identical pathology types (HR, 9.726; 95% CI: 1.886 to 50.151), largest pT1 (HR, 7.123; 95% CI: 2.663 to 19.055), and absence of lymphovascular invasion (LVI; HR, 7.021; 95% CI: 1.448 to 34.032) emerged as independent predictors of improved OS. Moreover, the sum of tumor sizes less than or equal to 3 cm (HR, 6.229; 95% CI: 1.411 to 27.502) and absence of pleural invasion (HR, 3.442; 95% CI: 1.352 to 8.759) were identified as independent predictors of enhanced RFS. The presence or absence of residual nodules after bilateral surgery did not influence patients' OS (P=0.987) and RFS (P=0.054). Conclusions: Patients with BSMPLC who underwent surgery generally had a favorable prognosis. Whether or not to remove all nodules bilaterally does not affect the patient's long-term prognosis, suggesting the need for an individualized surgical approach.

Pulmonary metastasectomy after immune checkpoint inhibitors in malignant melanoma.

The management of malignant melanoma with pulmonary metastases is controversial and occasionally requires multimodality management, including pulmonary metastasectomy after immune checkpoint inhibitors (ICIs). However, limited data are available on these patients. We described a case series of three consecutive patients who underwent pulmonary metastasectomy after ICIs for malignant melanoma and discussed the important characteristics of these patients. After pulmonary metastasectomy, none of the patients had recurrent pulmonary metastases, although extrapulmonary metastases were developed. Our case series suggests that pulmonary metastasectomy after ICIs may control pulmonary metastases in carefully selected patients with malignant melanoma.

Fibrotic progression from acute cellular rejection is dependent on secondary lymphoid organs in a mouse model of chronic lung allograft dysfunction.

Chronic lung allograft dysfunction (CLAD) remains one of the major limitations to long-term survival after lung transplantation. We modified a murine model of CLAD and transplanted left lungs from BALB/c donors into B6 recipients that were treated with intermittent cyclosporine and methylprednisolone postoperatively. In this model, the lung allograft developed acute cellular rejection on day 15 which, by day 30 after transplantation, progressed to severe pleural and peribronchovascular fibrosis, reminiscent of changes observed in restrictive allograft syndrome. Lung transplantation into splenectomized B6 alymphoplastic (aly/aly) or splenectomized B6 lymphotoxin-ß receptor-deficient mice demonstrated that recipient secondary lymphoid organs, such as spleen and lymph nodes, are necessary for progression from acute cellular rejection to allograft fibrosis in this model. Our work uncovered a critical role for recipient secondary lymphoid organs in the development of CLAD after pulmonary transplantation and may provide mechanistic insights into the pathogenesis of this complication.

Various combinations of living and deceased donors for lung retransplantation-a single institutional retrospective study.

OBJECTIVES: Lung retransplantation has been performed as a treatment option mainly for chronic lung allograft dysfunction; however, the outcomes of lung retransplantation have been reported to be worse than those of primary lung transplantation. Because of the scarcity of deceased donors in our country, our lung transplant experience includes both living and deceased donors. Therefore, we have experienced lung retransplantation cases with various combinations of living and deceased donors. The aim of this study was to explore technical pitfalls and outcomes of lung retransplantation in this unique environment. METHODS: We performed 311 lung transplantation procedures between April 2002 and October 2022. Eight lung retransplantation cases (2.6%) were analysed retrospectively. RESULTS: At lung retransplantation, the age of the recipient patients ranged from 11 to 61 years (median, 33 years). The combinations of donor sources (primary lung transplantation/lung retransplantation) were as follows: 2 living/living, 2 deceased/living, 3 living/deceased and 1 deceased/deceased. Seven of 8 patients received lung retransplantation for chronic lung allograft dysfunction. Hospital death occurred in 2 patients (25.0%). The 1-, 3- and 5-year survival rates after lung retransplantation (n = 8) were 75.0%, 75.0% and 75.0%, respectively, while those after primary lung transplantation (n = 303) were 92.8%, 83.4% and 76.4%, respectively (P = 0.162). CONCLUSIONS: Lung retransplantation with various combinations of living and deceased donors is a technically difficult but feasible procedure with acceptable outcomes.

Evaluation of Bone Mineral Density in Lung Transplant Recipients by Chest Computed Tomography.

INTRODUCTION: Lung transplantation (LT) recipients are at risk of bone mineral density (BMD) loss. Pre- and post-LT BMD loss has been reported in some cross-sectional studies; however, there are limited studies regarding the serial BMD change in LT recipients. The aim of this study was to investigate the serial BMD changes and the clinical characteristics associated with BMD decline. METHODS: This was a single-center, retrospective observational study. BMD was serially measured in thoracic vertebral bodies (Th4, 7, 10) using computed tomography (CT) before and 3 and 12 months after LT. The frequency of osteoporosis and factors associated with pre-LT osteoporosis and post-LT BMD loss were evaluated. The frequency of post-LT compression fracture and its associated factors were also analyzed. RESULTS: This study included 128 adult LT recipients. LT recipients had decreased BMD (151.8 ± 42.2 mg/mL) before LT compared with age-, sex-, and smoking index-matched controls (176.2 ± 35.7 mg/mL). The diagnosis of COPD was associated with pre-LT osteoporosis. LT recipients experience further BMD decline after transplantation, and the percentage of recipients classified as exhibiting osteoporosis increased from 20% at baseline to 43% at 12 months. Recipients who had been taking no or small doses of glucocorticoids before LT had rapid BMD loss after LT. Early bisphosphonate use (within 3 months) after LT attenuated BMD loss and decreased new-onset compression fracture. CONCLUSION: LT recipients are at high risk for BMD loss and compression fracture after LT. Early bisphosphonate use may decrease BMD loss and compression fracture.

Favorable effect of CD26/DPP-4 inhibitors on postoperative outcomes after lung transplantation: A propensity-weighted analysis.

BACKGROUND: We have shown the efficacy of CD26/dipeptidyl peptidase 4 (CD26/DPP-4) inhibitors, antidiabetic agents, in allograft protection after experimental lung transplantation (LTx). We aimed to elucidate whether CD26/DPP-4 inhibitors effectively improve postoperative outcomes after clinical LTx. METHODS: We retrospectively reviewed the records of patients undergoing LTx at our institution between 2010 and 2021 and extracted records of patients with diabetes mellitus (DM) at 6 months post-LTx. The patient characteristics and postoperative outcomes were analyzed. We established 6 months post-LTx as the landmark point for predicting overall survival (OS) and chronic lung allograft dysfunction (CLAD)-free survival. Hazard ratios were estimated by Cox regression after propensity score weighting, using CD26/DPP-4 inhibitor treatment up to 6 months post-LTx as the exposure variable. We evaluated CLAD samples pathologically, including for CD26/DPP-4 immunohistochemistry. RESULTS: Of 102 LTx patients with DM, 29 and 73 were treated with and without CD26/DPP-4 inhibitors, respectively. Based on propensity score adjustment using standardized mortality ratio weighting, the 5-year OS rates were 77.0% and 44.3%, and the 5-year CLAD-free survival rates 77.8% and 49.1%, in patients treated with and without CD26/DPP-4 inhibitors, respectively. The hazard ratio for CD26/DPP-4 inhibitor use was 0.34 (95% confidence interval (CI) 0.14-0.82, p = 0.017) for OS and 0.47 (95% CI 0.22-1.01, p = 0.054) for CLAD-free survival. We detected CD26/DPP-4 expression in the CLAD grafts of patients without CD26/DPP-4 inhibitors. CONCLUSIONS: Analysis using propensity score weighting showed that CD26/DPP-4 inhibitors positively affected the postoperative prognosis of LTx patients with DM.

Impact of perioperative airway pathogens on living-donor lobar lung transplantation outcomes.

PURPOSE: To elucidate the clinical impact of pathogenic organism (PO) positivity early after transplantation, we evaluated the impact of perioperative airway POs on outcomes after living-donor lobar lung transplantation (LDLLT), where the graft airway is supposed to be sterile from a healthy donor. METHOD: A retrospective review of 67 adult LDLLT procedures involving 132 living donors was performed. Presence of POs in the recipients' airways was evaluated preoperatively and postoperatively in intensive-care units. RESULTS: POs were detected preoperatively in 13 (19.4%) recipients. No POs were isolated from the donor airways at transplantation. POs were detected in 39 (58.2%) recipients postoperatively; most were different from the POs isolated preoperatively. Postoperative PO isolation was not associated with short-term outcomes other than prolonged postoperative ventilation. The 5-year overall survival was significantly better in the PO-negative group than in the PO-positive group (89.1% vs. 63.7%, P = 0.014). In the multivariate analysis, advanced age (hazard ratio [HR]: 1.041 per 1-year increase, P = 0.033) and posttransplant PO positivity in the airway (HR: 3.684, P = 0.019) significantly affected the survival. CONCLUSIONS: The airways of the living-donor grafts were microbiologically sterile. PO positivity in the airway early after transplantation negatively impacted long-term outcomes.

Convolutional neural network-based program to predict lymph node metastasis of non-small cell lung cancer using 18F-FDG PET.

PURPOSE: To develop a convolutional neural network (CNN)-based program to analyze maximum intensity projection (MIP) images of 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) positron emission tomography (PET) scans, aimed at predicting lymph node metastasis of non-small cell lung cancer (NSCLC), and to evaluate its effectiveness in providing diagnostic assistance to radiologists. METHODS: We obtained PET images of NSCLC from public datasets, including those of 435 patients with available N-stage information, which were divided into a training set (n = 304) and a test set (n = 131). We generated 36 maximum intensity projection (MIP) images for each patient. A residual network (ResNet-50)-based CNN was trained using the MIP images of the training set to predict lymph node metastasis. Lymph node metastasis in the test set was predicted by the trained CNN as well as by seven radiologists twice: first without and second with CNN assistance. Diagnostic performance metrics, including accuracy and prediction error (the difference between the truth and the predictions), were calculated, and reading times were recorded. RESULTS: In the test set, 67 (51%) patients exhibited lymph node metastases and the CNN yielded 0.748 predictive accuracy. With the assistance of the CNN, the prediction error was significantly reduced for six of the seven radiologists although the accuracy did not change significantly. The prediction time was significantly reduced for five of the seven radiologists with the median reduction ratio 38.0%. CONCLUSION: The CNN-based program could potentially assist radiologists in predicting lymph node metastasis by increasing diagnostic confidence and reducing reading time without affecting diagnostic accuracy, at least in the limited situations using MIP images.

Thoracoscopic precision excision technique for small lung lesions using radiofrequency identification marking.

With the introduction of multi-detector computed tomography (CT), the number of incidentally detected small lung nodules has dramatically increased. Determination of lung nodule malignancy is crucial, and an early diagnosis of these indeterminate lesions can lead to subsequent potentially curative treatment. However, there are some limitations to excising these nodules with sublobar resection in a minimally invasive thoracoscopic setting. Under thoracoscopy, although stapler-based wedge resection seems to be the preferred technique, particularly in patients whose lesions are located far from the edge of the lobe, the stapler can unexpectedly sacrifice normal pulmonary parenchyma. To overcome this issue, we have developed a wireless excision precision technique using cone-beam CT-guided electromagnetic navigation bronchoscopy in a minimally invasive thoracoscopic setting. Our technique is implemented in a hybrid operating room, and small tumors can be removed using a radiofrequency identification microchip without intraoperative fluoroscopy and do not require lung palpation under thoracoscopy.

Combination therapy with EGFR tyrosine kinase inhibitors and TEAD inhibitor increases tumor suppression effects in EGFR mutation-positive lung cancer.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the first-line therapies for EGFR mutation-positive lung cancer. EGFR-TKIs have favorable therapeutic effects. However, a large proportion of patients with EGFR mutation-positive lung cancer subsequently relapse. Some cancer cells survive the initial treatment with EGFR-TKIs, and this initial survival may be associated with subsequent recurrence. Therefore, we aimed to overcome the initial survival against EGFR-TKIs. We hypothesized that yes-associated protein 1 (YAP1) is involved in the initial survival against EGFR-TKIs, and we confirmed the combined effect of EGFR-TKIs and a YAP1-TEAD pathway inhibitor. The KTOR27 (EGFR kinase domain duplication [KDD]) lung cancer cell lines established from a patient with EGFR mutation-positive lung cancer and commercially available PC-9 and HCC827 (EGFR exon 19 deletions) lung cancer cell lines were used. These cells were used to evaluate the in vitro and in vivo effects of VT104, a TEAD inhibitor. Additionally, YAP1 involvement was investigated in pathological specimens. YAP1 was activated by short-term EGFR-TKI treatment in EGFR mutation-positive lung cancer cells. In addition, inhibiting YAP1 function using small interfering RNA increased the sensitivity to EGFR-TKIs. Combination therapy with VT104 and EGFR-TKIs showed better tumor-suppressive effects than EGFR-TKIs alone, in vitro and in vivo. Moreover, the combined effect of VT104 and EGFR-TKIs was observed regardless of the localization status of YAP1 before EGFR-TKI exposure. These results suggest that combination therapy with the TEAD inhibitor and EGFR-TKIs may improve the prognosis of patients with EGFR mutation-positive lung cancer.

M2-like tumor-associated macrophages promote epithelial-mesenchymal transition through the transforming growth factor ß/Smad/zinc finger e-box binding homeobox pathway with increased metastatic potential and tumor cell proliferation in lung squamous cell carcinoma.

Epithelial-mesenchymal transition (EMT) promotes primary tumor progression toward a metastatic state. The role of tumor-associated macrophages (TAMs) in inducing EMT in lung squamous cell carcinoma (LUSC) remains unclear. We aimed to clarify the significance of TAMs in relation to EMT in LUSC. We collected 221 LUSC specimens from patients who had undergone surgery. Immunohistochemistry was performed to evaluate M1-like and M2-like TAM distribution and EMT by E-cadherin and vimentin staining. Human LUSC cell lines (H226 and EBC-1) and a human monocyte cell line (THP-1) were used for in vitro experiments. M2-like polarization of TAMs and EMT marker expression in LUSC cells were evaluated by western blotting. The biological behavior of LUSC cells was evaluated by migration, invasion, and cell proliferation assays. Immunohistochemical analysis showed that 166 (75.1%) tumors were E-cadherin-positive and 44 (19.9%) were vimentin-positive. M2-like TAM density in the tumor stroma was significantly associated with vimentin positivity and worse overall survival. Western blotting demonstrated higher levels of CD163, CD206, vascular endothelial growth factor, and transforming growth factor beta 1 (TGF-ß1) in TAMs versus unstimulated macrophages. Furthermore, increased TGF-ß1 secretion from TAMs was confirmed by ELISA. TAM-co-cultured H226 and EBC-1 cells exhibited EMT (decreased E-cadherin, increased vimentin). Regarding EMT-activating transcriptional factors, phosphorylated Smad3 and ZEB-family proteins were higher in TAM-co-cultured LUSC cells than in parental cells. TAM-co-cultured H226 and EBC-1 cells demonstrated enhanced migration and invasion capabilities and improved proliferation. Overall, the present study suggests that TAMs can induce EMT with increased metastatic potential and tumor cell proliferation in LUSC.

Novel intrathoracic irrigation using ultrafine ozone bubbles in a rat empyema model.

Dissolved ozone is generally used for sanitization, but it has not been used for thoracic cavity sanitization because of its short half-life (< 20 min) and possible toxicity. We developed a novel solution containing ultrafine ozone bubbles (ozone-UFB) with a fivefold longer half-life than non-UFB ozone. Using an in vitro model, Staphylococcus aureus colonies were counted after exposure to ozone-UFB or non-UFB ozone at the same ozone concentration (0.4 mg/L). The colony count was significantly lower in the ozone-UFB group than in the non-UFB ozone group (p = 0.034). The effect of repeated pleural irrigation using ozone-UFB and saline was compared in a rat empyema model of S. aureus infection. The bacterial count in the pleural effusion was decreased by at least fivefold following intrathoracic lavage with ozone-UFB (3 mg/L). To examine the safety of ozone-UFB for intrathoracic use, ozone-UFB with a higher ozone concentration (10 mg/L) was injected into the thoracic cavities of normal rats. The treatment did not result in any specific pleural damage or elevated serum interleukin-6 concentrations. The findings highlighted the efficacy and safety of ozone-UFB for intrathoracic sanitization, but further studies are needed to determine the optimal therapeutic ozone concentration with appropriate safety margins.

Deep Learning for Predicting Effect of Neoadjuvant Therapies in Non-Small Cell Lung Carcinomas With Histologic Images.

Neoadjuvant therapies are used for locally advanced non-small cell lung carcinomas, whereby pathologists histologically evaluate the effect using resected specimens. Major pathological response (MPR) has recently been used for treatment evaluation and as an economical survival surrogate; however, interobserver variability and poor reproducibility are often noted. The aim of this study was to develop a deep learning (DL) model to predict MPR from hematoxylin and eosin-stained tissue images and to validate its utility for clinical use. We collected data on 125 primary non-small cell lung carcinoma cases that were resected after neoadjuvant therapy. The cases were randomly divided into 55 for training/validation and 70 for testing. A total of 261 hematoxylin and eosin-stained slides were obtained from the maximum tumor beds, and whole slide images were prepared. We used a multiscale patch model that can adaptively weight multiple convolutional neural networks trained with different field-of-view images. We performed 3-fold cross-validation to evaluate the model. During testing, we compared the percentages of viable tumor evaluated by annotator pathologists (reviewed data), those evaluated by nonannotator pathologists (primary data), and those predicted by the DL-based model using 2-class confusion matrices and receiver operating characteristic curves and performed a survival analysis between MPR-achieved and non-MPR cases. In cross-validation, accuracy and mean F1 score were 0.859 and 0.805, respectively. During testing, accuracy and mean F1 score with reviewed data and those with primary data were 0.986, 0.985, 0.943, and 0.943, respectively. The areas under the receiver operating characteristic curve with reviewed and primary data were 0.999 and 0.978, respectively. The disease-free survival of MPR-achieved cases with reviewed and primary data was significantly better than that of the non-MPR cases (P<.001 and P=.001), and that predicted by the DL-based model was almost identical (P=.005). The DL model may support pathologist evaluations and can offer accurate determinations of MPR in patients.

The first successful case of ABO-incompatible living-donor lobar lung transplantation following desensitization therapy.

ABO-incompatible (ABO-I) living-donor lobar lung transplantation (LDLLT) was successfully performed in a 14-year-old girl who suffered from bronchiolitis obliterans due to graft-versus-host disease following hematopoietic stem cell transplantation. In the ABO-I LDLLT procedure, the blood type O patient received a right lower lobe donated from her blood type B father and a left lower lobe donated from her blood type O mother. Desensitization therapy, using rituximab, immunosuppressants, and plasmapheresis, was implemented for 3 weeks prior to transplantation to reduce the production of anti-B antibodies in the recipient and prevent acute antibody-mediated rejection after ABO-I LDLLT.

One-year change in the health status predicts the subsequent hospitalization and mortality in patients waitlisted for lung transplantation in Japan.

BACKGROUND: Poor health-related quality of life (HRQL) at the registration for lung transplantation is related to waitlist mortality. We investigated the relationship between 1-year change in HRQL and subsequent outcomes in patients waitlisted for lung transplantation. METHODS: In a 5-year longitudinal study, we analyzed the factors related to waitlist mortality in 197 lung transplant patients registered on the Japan Organ Transplant Network. HRQL was assessed using St. George's Respiratory Questionnaire (SGRQ), and factors related to changes in SGRQ scores were evaluated after 1 year. We assessed the relationship between the 1-year change in SGRQ score and subsequent mortality or hospitalization. RESULTS: Among 197 patients, 108 remained waitlisted during the first-year assessment. During the median follow-up period of 469 d, 28 patients died, and 54 underwent lung transplantation. Univariate Cox proportional hazards analysis revealed that the changes in all components and total score of the SGRQ after 1 year were associated with waitlist mortality (p < 0.05). Stepwise multivariate analysis revealed that the 1-year changes in SGRQ scores were significantly related to waitlist mortality. Forty-three patients with worsened HRQL after 1 year had higher likelihoods of hospitalization (p = 0.038) and mortality (p = 0.026) after 1 and 4 years of follow-up, respectively, than 61 patients without worsened HRQL. CONCLUSIONS: Patients with worsened health status during the first year after registration had higher likelihoods of hospitalization and mortality after 1 and 4 years of follow-up, respectively, than those without worsened HRQL. Strategies to improve health status while waiting are needed to reduce waitlist hospitalization or mortality.

Development of novel layered polyglycolic acid sheet for regeneration of critical-size defect in rat trachea.

OBJECTIVES: Polyglycolic acid (PGA) sheets are difficult to adapt to the central airway because of poor durability against high air pressure. Therefore, we developed a novel layered PGA material to cover the central airway and examined its morphologic traits and functional performance as a potential tracheal replacement. METHODS: A critical-size defect in rat cervical tracheas was covered with the material. Morphologic changes were bronchoscopically and pathologically evaluated. Functional performance was evaluated by regenerated ciliary area, ciliary beat frequency and ciliary transport function determined by measuring the moving distance of microspheres dropped onto the trachea (µm/s). The evaluation time points were 2 weeks, 1 month, 2 months and 6 months after surgery (n = 5, respectively). RESULTS: Forty rats underwent implantation, and all survived. Histological examination confirmed ciliated epithelization on the luminal surface after 2 weeks. Neovascularization was observed after 1 month, tracheal glands after 2 months and chondrocyte regeneration after 6 months. Although the material was gradually replaced by self-organization, tracheomalacia was not bronchoscopically observed at any time point. The area of regenerated cilia significantly increased between 2 weeks and 1 month (12.0% vs 30.0%; P = 0.0216). The median ciliary beat frequency significantly improved between 2 weeks and 6 months (7.12 vs 10.04 Hz; P = 0.0122). The median ciliary transport function was significantly improved between 2 weeks and 2 months (5.16 vs 13.49 µm/s; P = 0.0216). CONCLUSIONS: The novel PGA material showed excellent biocompatibility and tracheal regeneration both morphologically and functionally 6 months after tracheal implantation.

Impact of Spousal Donation on Postoperative Outcomes of Living-donor Lobar Lung Transplantation.

BACKGROUND: The effect of human leukocyte antigen mismatches between donors and recipients on postoperative outcomes of lung transplantation remains controversial. We retrospectively reviewed adult recipients receiving living-donor lobar lung transplantation (LDLLT) to examine the difference in de novo donor-specific antibody (dnDSA) development and clinically diagnosed unilateral chronic lung allograft dysfunction per graft (unilateral CLAD) between lung grafts donated by spouses (nonblood relatives) and nonspouses (relatives within the third degree). We also investigated the difference in prognoses between recipients undergoing LDLLTs including spouse donors (spousal LDLLTs) and not including spouse donors (nonspousal LDLLTs). METHODS: In this study, 63 adult recipients undergoing LDLLTs (61 bilateral and 2 unilateral LDLLTs from 124 living donors) between 2008 and 2020 were enrolled. The cumulative incidence of dnDSAs per lung graft was calculated, and prognoses were compared between recipients undergoing spousal and nonspousal LDLLTs. RESULTS: The cumulative incidence of both dnDSAs and unilateral CLAD in grafts donated by spouses was significantly higher than that in grafts donated by nonspouses (5-y incidence of dnDSAs: 18.7% versus 6.4%, P = 0.038; 5-y incidence of unilateral CLAD: 45.6% versus 19.4%, P = 0.011). However, there were no significant differences in the overall survival or chronic lung allograft dysfunction-free survival between recipients undergoing spousal and nonspousal LDLLTs ( P > 0.99 and P = 0.434, respectively). CONCLUSIONS: Although there were no significant differences in prognoses between spousal and nonspousal LDLLTs, more attention should be paid to spousal LDLLTs because of the higher development rate of dnDSAs and unilateral CLAD.