Cost effectiveness of commercial portable ex vivo lung perfusion at a low-volume US lung transplant center.

BACKGROUND: Portable ex vivo lung perfusion during lung transplantation is a resource-intensive technology. In light of its increasing use, we evaluated the cost-effectiveness of ex vivo lung perfusion at a low-volume lung transplant center in the USA. METHODS: Patients listed for lung transplantation (2015-2021) in the United Network for Organ Sharing database were included. Quality-of-life was approximated by Karnofsky Performance Status scores 1-year post-transplant. Total transplantation encounter and 1-year follow-up costs accrued by our academic center for patients listed from 2018 to 2021 were obtained. Cost-effectiveness was calculated by evaluating the number of patients attaining various Karnofsky scores relative to cost. RESULTS: Of the 13 930 adult patients who underwent lung transplant in the United Network for Organ Sharing database, 13 477 (96.7%) used static cold storage and 453 (3.3%) used ex vivo lung perfusion, compared to 30/58 (51.7%) and 28/58 (48.3%), respectively, at our center. Compared to static cold storage, median total costs at 1 year were higher for ex vivo lung perfusion ($918 000 vs. $516 000; p = 0.007) along with the cost of living 1 year with a Karnofsky functional status of 100 after transplant ($1 290 000 vs. $841 000). In simulated scenarios, each Karnofsky-adjusted life year gained by ex vivo lung perfusion was 1.00-1.72 times more expensive. CONCLUSIONS: Portable ex vivo lung perfusion is not currently cost-effective at a low-volume transplant centers in the USA, being 1.53 times more expensive per Karnofsky-adjusted life year. Improving donor lung and/or recipient biology during ex vivo lung perfusion may improve its utility for routine transplantation.

Comprehensive geriatric assessment predicts listing for kidney transplant in patients with end-stage renal disease: a retrospective cohort study.

BACKGROUND: Comprehensive geriatric assessment (CGA) involves a formal broad approach to assess frailty and creating a plan for management. However, the impact of CGA and its components on listing for kidney transplant in older adults has not been investigated. METHODS: We performed a single-center retrospective study of patients with end-stage renal disease who underwent CGA during kidney transplant candidacy evaluation between 2017 and 2021. All patients ≥ 65 years old and those under 65 with any team member concern for frailty were referred for CGA, which included measurements of healthcare utilization, comorbidities, social support, short physical performance battery, Montreal Cognitive Assessment (MoCA), and Physical Frailty Phenotype (FPP), and estimate of surgical risk by the geriatrician. RESULTS: Two hundred and thirty patients underwent baseline CGA evaluation; 58.7% (135) had high CGA ("Excellent" or "Good" rating for transplant candidacy) and 41.3% (95) had low CGA ratings ("Borderline," "Fair," or "Poor"). High CGA rating (OR 8.46; p < 0.05), greater number of CGA visits (OR 4.93; p = 0.05), younger age (OR 0.88; p < 0.05), higher MoCA scores (OR 1.17; p < 0.05), and high physical activity (OR 4.41; p < 0.05) were all associated with listing on transplant waitlist. CONCLUSIONS: The CGA is a useful, comprehensive tool to help select older adults for kidney transplantation. Further study is needed to better understand the predictive value of CGA in predicting post-operative outcomes.

Barriers and facilitators to smartwatch-based prehabilitation participation among frail surgery patients: a qualitative study.

BACKGROUND: For older, frail adults, exercise before surgery through prehabilitation (prehab) may hasten return recovery and reduce postoperative complications. We developed a smartwatch-based prehab program (BeFitMe) for older adults that encourages and tracks at-home exercise. The objective of this study was to assess patient perceptions about facilitators and barriers to prehab generally and to using a smartwatch prehab program among older adult thoracic surgery patients to optimize future program implementation. METHODS: We recruited patients, aged ≥50 years who had or were having surgery and were screened for frailty (Fried's Frailty Phenotype) at a thoracic surgery clinic at a single academic institution. Semi-structured interviews were conducted by telephone after obtaining informed consent. Participants were given a description of the BeFitMe program. The interview questions were informed by The Five "Rights" of Clinical Decision-Making framework (Information, Person, Time, Channel, and Format) and sought to identify the factors perceived to influence smartwatch prehab program participation. Interview transcripts were transcribed and independently coded to identify themes in for each of the Five "Rights" domains. RESULTS: A total of 29 interviews were conducted. Participants were 52% men (n = 15), 48% Black (n = 14), and 59% pre-frail (n = 11) or frail (n = 6) with a mean age of 68 ± 9 years. Eleven total themes emerged. Facilitator themes included the importance of providers (right person) clearly explaining the significance of prehab (right information) during the preoperative visit (right time); providing written instructions and exercise prescriptions; and providing a preprogrammed and set-up (right format) Apple Watch (right channel). Barrier themes included pre-existing conditions and disinterest in exercise and/or technology. Participants provided suggestions to overcome the technology barrier, which included individualized training and support on usage and responsibilities. CONCLUSIONS: This study reports the perceived facilitators and barriers to a smartwatch-based prehab program for pre-frail and frail thoracic surgery patients. The future BeFitMe implementation protocol must ensure surgical providers emphasize the beneficial impact of participating in prehab before surgery and provide a written prehab prescription; must include a thorough guide on smartwatch use along with the preprogrammed device to be successful. The findings are relevant to other smartwatch-based interventions for older adults.

Fair and equitable subject selection in concurrent COVID-19 clinical trials.

Clinical trials emerged in rapid succession as the COVID-19 pandemic created an unprecedented need for life-saving therapies. Fair and equitable subject selection in clinical trials offering investigational therapies ought to be an urgent moral concern. Subject selection determines the distribution of risks and benefits, and impacts the applicability of the study results for the larger population. While Research Ethics Committees monitor fair subject selection within each trial, no standard oversight exists for subject selection across multiple trials for the same disease. Drawing on the experience of multiple clinical trials at a single academic medical centre in the USA, we posit that concurrent COVID-19 trials are liable to unfair and inequitable subject selection on account of scientific uncertainty, lack of transparency, scarcity and, lastly, structural barriers to equity compounded by implicit bias. To address the critical gap in the current literature and international regulation, we propose new ethical guidelines for research design and conduct that bolsters fair and equitable subject selection. Although the proposed guidelines are tailored to the research design and protocol of concurrent trials in the COVID-19 pandemic, they may have broader relevance to single COVID-19 trials.

Organ-specific differences in achieving tolerance.

PURPOSE OF REVIEW: When it comes to tolerance induction, kidney allografts behave differently from heart allografts that behave differently from lung allografts. Here, we examine how and why different organ allografts respond differently to the same tolerance induction protocol. RECENT FINDINGS: Allograft tolerance has been achieved in experimental and clinical kidney transplantation. Inducing tolerance in experimental recipients of heart and lung allografts has, however, proven to be more challenging. New protocols being developed in nonhuman primates based on mixed chimerism and cotransplantation of tolerogenic organs may provide mechanistic insights to help overcome these challenges. SUMMARY: Tolerance induction protocols that are successful in patients transplanted with 'tolerance-prone' organs such as kidneys and livers will most likely not succeed in recipients of 'tolerance-resistant' organs such as hearts and lungs. Separate clinical trials using more robust tolerance protocols will be required to achieve tolerance in heart and lung recipients.

The risk analysis index is an independent predictor of outcomes after lung cancer resection.

BACKGROUND: The Risk Analysis Index (RAI) is a frailty assessment tool based on an accumulation of deficits model. We mapped RAI to data from the Society of Thoracic Surgeons (STS) Database to determine whether RAI correlates with postoperative outcomes following lung cancer resection. METHODOLOGY/PRINCIPAL FINDINGS: This was a national database retrospective observational study based on data from the STS Database. Study patients underwent surgery 2018 to 2020. RAI was divided into four increasing risk categories. The associations between RAI and each of postoperative complications and administrative outcomes were examined using logistic regression models. We also compared the performance of RAI to established risk indices (American Society of Anesthesiology (ASA) and Charlson Comorbidity Index (CCI)) using areas under the Receiver Operating Characteristic (ROC) curves (AUC). Results: Of 29,420 candidate patients identified in the STS Database, RAI could be calculated for 22,848 (78%). Almost all outcome categories exhibited a progressive increase in marginal probability as RAI increased. On multivariable analyses, RAI was significantly associated with an incremental pattern with almost all outcomes. ROC analyses for RAI demonstrated "good" AUC values for mortality (0.785; 0.748) and discharge location (0.791), but only "fair" values for all other outcome categories (0.618 to 0.690). RAI performed similarly to ASA and CCI in terms of AUC score categories. CONCLUSIONS/SIGNIFICANCE: RAI is associated with clinical and administrative outcomes following lung cancer resection. However, its overall accuracy as a surgical risk predictor is only moderate and similar to ASA and CCI. We do not recommend routine use of RAI for assessment of individual patient risk for major lung resection.

The association between neighborhood disadvantage and frailty: A retrospective case series.

Background: Frailty predicts poorer outcomes in surgical patients. Recent studies have found socioeconomic status to be an important characteristic for surgical outcomes. We evaluated the association of Area Deprivation Index (ADI) and Social Vulnerability Index (SVI), two geospatial atlases that provide a multidimensional evaluation of neighborhood deprivation, with frailty in a surgery population. Design & methods: A retrospective study of patients undergoing routine frailty screening was conducted 12/2020-8/2022. Frailty was measured using Fried's Frailty Phenotype (FFP) and the five-item Modified Frailty Index (mFI-5). ADI and SVI quartiles were determined using patient residence. Logistic regression models were used to evaluated associations of FFP (frail only vs not frail) and mFI-5 (≥2 vs 0-1) with ADI and SVI (α = 0.05). Results: Of 372 screened patients, 41% (154) were women, median age was 68% (63-74), and 46% (170) identified as non-White. Across ADI and SVI quartiles, higher number of comorbidities, decreasing median income, and frailty were associated with increasing deprivation (p < 0.01). When controlling for age, sex, comorbidities, and BMI category, frailty by FFP was associated with the most deprived two quartiles of ADI (OR 2.61, CI: [1.35-5.03], p < 0.01) and the most deprived quartile of SVI (OR 2.33, [1.10-4.95], p < 0.05). These trends were also seen with mFI-5 scores ≥2 (ADI: OR 1.64, [1.02-2.63], p < 0.05; SVI: OR 1.71, [1.01-2.91], p < 0.05). Conclusions: Surgical patients living in socioeconomically deprived neighborhoods are more likely to be frail. Interventions may include screening of disadvantaged populations and resource allocation to vulnerable neighborhoods.

Metabolite profiling of human renal cell carcinoma reveals tissue-origin dominance in nutrient availability.

The tumor microenvironment is a determinant of cancer progression and therapeutic efficacy, with nutrient availability playing an important role. Although it is established that the local abundance of specific nutrients defines the metabolic parameters for tumor growth, the factors guiding nutrient availability in tumor compared to normal tissue and blood remain poorly understood. To define these factors in renal cell carcinoma (RCC), we performed quantitative metabolomic and comprehensive lipidomic analyses of tumor interstitial fluid (TIF), adjacent normal kidney interstitial fluid (KIF), and plasma samples collected from patients. TIF nutrient composition closely resembles KIF, suggesting that tissue-specific factors unrelated to the presence of cancer exert a stronger influence on nutrient levels than tumor-driven alterations. Notably, select metabolite changes consistent with known features of RCC metabolism are found in RCC TIF, while glucose levels in TIF are not depleted to levels that are lower than those found in KIF. These findings inform tissue nutrient dynamics in RCC, highlighting a dominant role of non-cancer-driven tissue factors in shaping nutrient availability in these tumors.

Cancer cells convert nutrients into energy differently compared to healthy cells. This difference in metabolism allows them to grow and divide more quickly and sometimes to migrate to different areas of the body. The environment around cancer cells ­ known as the tumor microenvironment ­ contains a variety of different cells and blood vessels, which are bathed in interstitial fluid. This microenvironment provides nutrients for the cancer cells to metabolize, and therefore influences how well a tumor grows and how it might respond to treatment. Recent advances with techniques such as mass spectrometry, which can measure the chemical composition of a substance, have allowed scientists to measure nutrient levels in the tumor microenvironments of mice. However, it has been more difficult to conduct such studies in humans, as well as to compare the tumor microenvironment to the healthy tissue the tumors arose from. Abbott, Ali, Reinfeld et al. aimed to fill this gap in knowledge by using mass spectrometry to measure the nutrient levels in the tumor microenvironment of 55 patients undergoing surgery to remove kidney tumors. Comparing the type and levels of nutrients in the tumor interstitial fluid, the neighboring healthy kidney and the blood showed that nutrients in the tumor and healthy kidney were more similar to each other than those in the blood. For example, both the tumor and healthy kidney interstitial fluids contained less glucose than the blood. However, the difference between nutrient composition in the tumor and healthy kidney interstitial fluids was insignificant, suggesting that the healthy kidney and its tumor share a similar environment. Taken together, the findings indicate that kidney cancer cells must adapt to the nutrients available in the kidney, rather than changing what nutrients are available in the tissue. Future studies will be required to investigate whether this finding also applies to other types of cancer. A better understanding of how cancer cells adapt to their environments may aid the development of drugs that aim to disrupt the metabolism of tumors.

Metabolite profiling of human renal cell carcinoma reveals tissue-origin dominance in nutrient availability.

The tumor microenvironment is a determinant of cancer progression and therapeutic efficacy, with nutrient availability playing an important role. Although it is established that the local abundance of specific nutrients defines the metabolic parameters for tumor growth, the factors guiding nutrient availability in tumor compared to normal tissue and blood remain poorly understood. To define these factors in renal cell carcinoma (RCC), we performed quantitative metabolomic and comprehensive lipidomic analyses of tumor interstitial fluid (TIF), adjacent normal kidney interstitial fluid (KIF), and plasma samples collected from patients. TIF nutrient composition closely resembles KIF, suggesting that tissue-specific factors unrelated to the presence of cancer exert a stronger influence on nutrient levels than tumor-driven alterations. Notably, select metabolite changes consistent with known features of RCC metabolism are found in RCC TIF, while glucose levels in TIF are not depleted to levels that are lower than those found in KIF. These findings inform tissue nutrient dynamics in RCC, highlighting a dominant role of non-cancer driven tissue factors in shaping nutrient availability in these tumors.

Gender Bias in Judging Frailty and Fitness for Lung Surgery.

BACKGROUND: Disparities in surgical care for lung cancer have been well documented, and unconscious bias may be a source of inequity. We assessed whether gender biases exist when nonclinical decision makers render decisions about major lung surgery. METHODS: Amazon Mechanical Turk workers, remotely located "crowdworkers" readily available for hire to perform discrete on-demand tasks on the Amazon Mechanical Turk platform, were each shown 4 videos of different standardized patients (SPs) in a clinic setting, 1 video in each energy level (vigorous or frail) and race category (White or Black), randomized to male or female. Workers scored video characteristics and whether they would support the SP's decision to undergo a major lung operation. RESULTS: A total of 855 workers were recruited. The frail White male SP was more likely to have support to undergo lung surgery than the frail White female SP, while the frail Black male SP was much less likely to have support to undergo lung surgery than the frail Black female SP. There were no significant differences in support for surgery between the vigorous male and female SPs and ratings by male and female workers in their recommendations. CONCLUSIONS: Biases related to patient gender exist in the general population and affect views on surgery, particularly in the setting of frailty. Understanding such differences may aid in educational efforts directed at reducing gender-based biases in treatment recommendations.

Laryngotracheal Resection After B-Raf Proto-oncogene Inhibition for Anaplastic Thyroid Carcinoma.

Anaplastic thyroid carcinoma is a rare but aggressive neoplasm that often presents as advanced inoperable disease. Patients with B-Raf proto-oncogene (BRAF) v600e mutated anaplastic thyroid carcinoma who receive neoadjuvant dabrafenib/trametinib have improved rates of microscopically margin-negative resection and durable locoregional control. However this has not been evaluated in the setting of tracheal resection and primary reconstruction. Here we demonstrate the safety and efficacy of laryngotracheal resection and reconstruction after dabrafenib/trametinib for locoregionally advanced BRAF v600e mutated anaplastic thyroid carcinoma.

Factors Associated with Health-Related Quality of Life in Lung Transplant Candidates and Recipients.

OBJECTIVES: Health-related quality of life has been well studied across transplantation fields, but factors associated with lung transplant preoperative and postoperative quality of life remain unknown. Here, we determine factors associated with health-related quality of life in lung transplant candidates and recipients to identify patients at risk of lower health-related quality of life. MATERIALS AND METHODS: From January 2021 to May 2022, health-related quality of life was measured in candidates and recipients using the RAND 36-Item Short Form Health Survey questionnaire. We reviewed demographic parameters and clinical information and scored frailty according to the modified 5-item frailty index. We performed Fisher exact test and the Pearson chi-square test and used linear regression models to determine covariate associations on physical component summary, mental component summary, and self-reported health scores (α = 0.05). RESULTS: Eleven candidates and 17 recipients comp-leted the survey. Compared with candidates, transplant recipients reported significantly higher scores in 4 of the 8 health domains and in the physical component summary (P < .01), mental component summary (P = .05), and self-reported health score (P < .01). In candidates, higher body mass index and higher modified 5-item frailty index scores were negatively associated with the physical component summary and mental component summary, respec-tively (P < .05). In recipients, higher body mass index and higher lung allocation scores were associated with lower values for the physical component summary (-2.29; P < .05) and self-reported health score (-0.33; P < .05), respectively. CONCLUSIONS: Body mass index, the modified 5-item frailty index, and the lung allocation score were significantly associated with health-related quality of life in lung transplant recipients. Future interventions should target these modifiable associations to maximize candidate and recipient health-related quality of life.

Technology-assisted behavioral intervention to encourage prehabilitation in frail older adults undergoing surgery: Development and design of the BeFitMe™ Apple Watch app.

Objective: Increasing the physical activity of frail, older patients before surgery through prehabilitation (prehab) can hasten return to autonomy and reduce complications postoperatively. However, prehab participation is low in the clinical setting. In this study, we re-design an existing prehab smartphone application (BeFitMe™) using a novel standalone Apple Watch platform to increase accessibility and usability for vulnerable patients. Methods: Design Science Research Methodology was used to (1) develop an approach to clinical research using standalone Apple Watches, (2) re-design BeFitMe™ for the Apple Watch platform, and (3) incorporate user feedback into app design. In phase 3, beta and user testers gave feedback via a follow-up phone call. Exercise data was extracted from the watch after testing. Descriptive statistics were used to summarize accessibility and usability. Results: BeFitMe™ was redesigned for the Apple Watch with full functionality without requiring patients to have an iPhone or internet connectivity and the ability to passively collect exercise data without patient interaction. Three study staff participated in beta testing over 3 weeks. Six randomly chosen thoracic surgery patients participated in user testing over 12 weeks. Feedback from beta and user testers was addressed with updated software (versions 1.0-1.10), improved interface and notification schemes, and the development of educational materials used during enrollment. The majority of users (5/6, 83%) participated by responding to at least one notification and data was able to be collected for 54/82 (68%) of the days users had the watches. The amount of data collected in BeFitMe™ Watch app increased from 2/11 (16%) days with the first patient tester to 13/13 (100%) days with the final patient tester. Conclusions: The BeFitMe™ Watch app is accessible and usable. The BeFitMe™ Watch app may help older patients, particularly those from vulnerable backgrounds with fewer resources, participate in prehab prior to surgery.

Racial differences in phenotypic frailty assessment among general thoracic surgery patients.

Objectives: The American Association for Thoracic Surgery recommends using frailty assessments to identify patients at higher risk of perioperative morbidity and mortality. We evaluated what patient factors are associated with frailty in a thoracic surgery patient population. Methods: New patients aged more than 50 years who were evaluated in a thoracic surgery clinic underwent routine frailty screening with a modified Fried's Frailty Phenotype. Differences in demographics and comorbid conditions among frailty status groups were assessed with chi-square and Student t tests. Logistic regressions performed with binomial distribution assessed the association of demographic and clinical characteristics with nonfrail, frail, prefrail, and any frailty (prefrail/frail) status. Results: The study population included 317 patients screened over 19 months. Of patients screened, 198 (62.5%) were frail or prefrail. Frail patients undergoing thoracic surgery were older, were more likely single or never married, had lower median income, and had lower percent predicted diffusion capacity of the lungs for carbon monoxide and forced expiratory volume during 1 second (all P < .05). More non-Hispanic Black patients were frail and prefrail compared with non-Hispanic White patients (P = .003) and were more likely to score at least 1 point on Fried's Frailty Phenotype (adjusted odds ratio, 3.77; P = .02) when controlling for age, sex, number of comorbidities, median income, diffusion capacity of the lungs for carbon monoxide, and forced expiratory volume during 1 second. Non-Hispanic Black patients were more likely than non-Hispanic White patients to score points for slow gait and low activity (both P < .05). Conclusions: Non-Hispanic Black patients undergoing thoracic surgery are more likely to score as frail or prefrail than non-Hispanic White patients. This disparity stems from differences in activity and gait speed. Frailty tools should be examined for factors contributing to this disparity, including bias.

Screening in serum-derived medium reveals differential response to compounds targeting metabolism.

A challenge for screening new anticancer drugs is that efficacy in cell culture models is not always predictive of efficacy in patients. One limitation of standard cell culture is a reliance on non-physiological nutrient levels, which can influence cell metabolism and drug sensitivity. A general assessment of how physiological nutrients affect cancer cell response to small molecule therapies is lacking. To address this, we developed a serum-derived culture medium that supports the proliferation of diverse cancer cell lines and is amenable to high-throughput screening. We screened several small molecule libraries and found that compounds targeting metabolic enzymes were differentially effective in standard compared to serum-derived medium. We exploited the differences in nutrient levels between each medium to understand why medium conditions affected the response of cells to some compounds, illustrating how this approach can be used to screen potential therapeutics and understand how their efficacy is modified by available nutrients.

Smartphone-Based Gait Cadence to Identify Older Adults with Decreased Functional Capacity.

Background: Functional capacity assessment is a critical step in the preoperative evaluation to identify patients at increased risk of cardiac complications and disability after major noncardiac surgery. Smartphones offer the potential to objectively measure functional capacity but are limited by inaccuracy in patients with poor functional capacity. Open-source methods exist to analyze accelerometer data to estimate gait cadence (steps/min), which is directly associated with activity intensity. Here, we used an updated Step Test smartphone application with an open-source method to analyze accelerometer data to estimate gait cadence and functional capacity in older adults. Methods: We performed a prospective observational cohort study within the Frailty, Activity, Body Composition and Energy Expenditure in Aging study at the University of Chicago. Participants completed the Duke Activity Status Index (DASI) and performed an in-clinic 6-min walk test (6MWT) while using the Step Test application on a study smartphone. Gait cadence was measured from the raw accelerometer data using an adaptive empirical pattern transformation method, which has been previously validated. A 6MWT distance of 370 m was used as an objective threshold to identify patients at high risk. We performed multivariable logistic regression to predict walking distance using a priori explanatory variables. Results: Sixty patients were enrolled in the study. Thirty-seven patients completed the protocol and were included in the final data analysis. The median (IQR) age of the overall cohort was 71 (69-74) years, with a body mass index of 31 (27-32). There were no differences in any clinical characteristics or functional measures between participants that were able to walk 370 m during the 6MWT and those that could not walk that distance. Median (IQR) gait cadence for the entire cohort was 110 (102-114) steps/min during the 6MWT. Median (IQR) gait cadence was higher in participants that walked more than 370 m during the 6MWT 112 (108-118) versus 106 (96-114) steps/min; p = 0.0157). The final multivariable model to identify participants that could not walk 370 m included only median gait cadence. The Youden's index cut-point was 107 steps/min with a sensitivity of 0.81 (95% CI: 0.77, 0.85) and a specificity of 0.57 (95% CI: 0.55, 0.59) and an AUCROC of 0.69 (95% CI: 0.51, 0.87). Conclusions: Our pilot study demonstrates the feasibility of using gait cadence as a measure to estimate functional capacity. Our study was limited by a smaller than expected sample size due to COVID-19, and thus, a prospective study with preoperative patients that measures outcomes is necessary to validate our findings.

Pulmonary Parenchymal Changes in COVID-19 Survivors.

BACKGROUND: As the COVID-19 pandemic moves into the survivorship phase, questions regarding long-term lung damage remain unanswered. Previous histopathologic studies are limited to autopsy reports. We studied lung specimens from COVID-19 survivors who underwent elective lung resections to determine whether postacute histopathologic changes are present. METHODS: This multicenter observational study included 11 adult COVID-19 survivors who had recovered but subsequently underwent unrelated elective lung resection for indeterminate lung nodules or lung cancer. We compared these against an age- and procedure-matched control group who never contracted COVID-19 (n = 5) and an end-stage COVID-19 group (n = 3). A blinded pulmonary pathologist examined the lung parenchyma focusing on 4 compartments: airways, alveoli, interstitium, and vasculature. RESULTS: Elective lung resection was performed in 11 COVID-19 survivors with asymptomatic (n = 4), moderate (n = 4), and severe (n = 3) COVID-19 infections at a median 68.5 days (range 24-142 days) after the COVID-19 diagnosis. The most common operation was lobectomy (75%). Histopathologic examination identified no differences between the lung parenchyma of COVID-19 survivors and controls across all compartments examined. Conversely, patients in the end-stage COVID-19 group showed fibrotic diffuse alveolar damage with intra-alveolar macrophages, organizing pneumonia, and focal interstitial emphysema. CONCLUSIONS: In this study to examine the lung parenchyma of COVID-19 survivors, we did not find distinct postacute histopathologic changes to suggest permanent pulmonary damage. These results are reassuring for COVID-19 survivors who recover and become asymptomatic.

Evaluation of Release Maneuvers After Airway Reconstruction.

BACKGROUND: Airway release (AR) maneuvers performed during airway resection to reduce anastomotic tension have not been thoroughly studied. METHODS: This study retrospectively analyzed consecutive resections for postintubation stenosis (PITS) and primary tracheal neoplasms (PTNs) at Massachusetts General Hospital (Boston, MA). Anastomotic complications were defined as stenosis, separation, necrosis, granulation tissue, and air leak. Logistic regression modeling was used to identify factors associated with AR and adverse outcome. RESULTS: From 1993 to 2019, 545 patients with PITS (375; 68.8%) and PTNs (170; 31.2%) underwent laryngotracheal, tracheal, or carinal (resections and reconstructions; 5.7% (31 of 545) were reoperations. AR was performed in 11% (60 of 545): in 3.8% of laryngotracheal resections (6 of 157; all laryngeal), in 9.8% of tracheal resections (34 of 347; laryngeal, 12, and hilar, 22), and in 49% of carinal resections (20 of 41; laryngeal, 1, and hilar, 19). Mean resected length was 3.5 cm (range, 1to- 6.3 cm) with AR and 3.0 cm (range, 0.8 to 6.5 cm) without AR (P < .01). Operative mortality was 0.7% (4 of 545); all 4 anastomoses were intact until death. Anastomotic complications were present in 5% of patients who underwent AR (3 of 60) and in 9.3% (45 of 485) of patients who did not. AR was associated with resection length of 4 cm or longer (odds ratio [OR], 6.15; 95% confidence interval [CI], 1.37 to 27.65), PTNs (OR, 7.81; 95% CI, 3.31 to 18.40), younger age (OR, 0.96; 95% CI, 0.94 to 0.98), and lung resection (OR, 6.09; 95% CI, 1.33 to 27.90). Anastomotic complications in patients with tracheal anastomoses were associated with preexisting tracheostomy (OR, 2.68; 95% CI, 1.50 to 4.80), but not release. CONCLUSIONS: Tracheal reconstruction succeeds, even when anastomotic tension requires AR. Because intraoperative assessment may underestimate tension, lowering the threshold for AR seems prudent, particularly in patients with diabetes.

Multi-disciplinary management of patients with benign airway strictures: A review.

Histologically benign airway strictures are frequently misdiagnosed as asthma or COPD and may present with severe symptoms including respiratory failure. A clear understanding of pathophysiology and existing classification systems is needed to determine the appropriate treatment options and predict clinical course. Clinically significant airway strictures can involve the upper and central airways extending from the subglottis to the lobar airways. Optimal evaluation includes a proper history and physical examination, neck and chest computed tomography, pulmonary function testing, endoscopy and serology. Available treatments include medical therapy, endoscopic procedures and open surgery which are based on the stricture's extent, location, etiology, morphology, severity of airway narrowing and patient's functional status. The acuity of the process, patient's co-morbidities and operability at the time of evaluation determine the need for open surgical or endoscopic interventions. The optimal management of patients with benign airway strictures requires the availability, expertise and collaboration of otolaryngologists, thoracic surgeons and interventional pulmonologists. Multidisciplinary airway teams can facilitate accurate diagnosis, guide management and avoid unnecessary procedures that could potentially worsen the extent of the disease or clinical course. Implementation of a complex airway program including multidisciplinary clinics and conferences ensures that such collaboration leads to timely, patient-centered and evidence-based interventions. In this article we outline algorithms of care and illustrate therapeutic techniques based on published evidence.

Surgical intervention for late gastric conduit obstruction.

OBJECTIVES: Gastric emptying delay after oesophagectomy may occur in conduits exposed to pleural forces of respiration or anatomic obstruction. Remedial operations addressing both causes are rarely reported. The study aim was to categorize severe gastric conduit obstruction (GCO) and report the outcome of surgical revision. METHODS: A single-institution, retrospective study of gastric conduit revision following oesophagectomy for oesophageal cancer investigated incidence, risk factors and categories of conduit obstruction. Evaluation consisted of contrast studies, computed tomogram and endoscopy. Interventions were categorized according to obstructive cause and included pyloroplasty, hiatal hernia reduction and thoraco-abdominal conduit repositioning. RESULTS: Among 1246 oesophagectomies over a 17-year period, 14 patients (1.1%) required post-oesophagectomy relief of GCO. Two additional patients presented after oesophagectomy elsewhere. Before oesophagectomy, 18.8% (3/16) and 62.5% (10/16) of patients were on chronic opioid and psychotropic medications, respectively. Distinct anatomic features separated obstruction into 3 categories: pyloric in 31% (5/16), extrinsic in 12.5% (2/16) and combined in 56.3% (9/16). Operative revision led to complete symptom resolution in 50% (8/16) of patients and symptom improvement in 43.8% (7/16) of patients. One patient (1/16, 6.25%) in the combined obstruction group did not improve with surgical revision. CONCLUSIONS: GCO after oesophagectomy rarely requires surgical revision. Potential association with medications affecting oesophageal and gastric motility requires further investigation. Classification of obstruction identifies a patient subset with lower success after surgical revision.