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1.
J Cardiothorac Vasc Anesth ; 38(3): 610-615, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38228423

ABSTRACT

As the demand for heart allografts for transplantation continues to rise, ex vivo organ perfusion strategies are playing an increasingly important role in the preservation of organs from donation after circulatory death and extended-criteria donors. One such method uses the Organ Care System (TransMedics, Andover, MA). Traditionally, this technique of preservation requires 2 periods of warm ischemia and subsequent cardioplegic arrest. In a novel surgical technique pioneered at the authors' institution, heart allograft implantation no longer requires a second cardioplegic arrest. This article discusses the surgical approach for this procedure, the advantages and disadvantages of this approach, and analogs to current clinical practice to theorize what impact this may have on cardiac transplantation volumes in the future.


Subject(s)
Heart Transplantation , Tissue and Organ Procurement , Humans , Anesthesiologists , Organ Preservation/methods , Heart Transplantation/methods , Tissue Donors , Extracorporeal Circulation , Perfusion/methods
2.
Am J Physiol Gastrointest Liver Physiol ; 320(1): G1-G11, 2021 01 01.
Article in English | MEDLINE | ID: mdl-33174453

ABSTRACT

Gastrointestinal disease burden continues to rise in the United States and worldwide. The development of bioengineering strategies to model gut injury or disease and to reestablish functional gut tissue could expand therapeutic options and improve clinical outcomes. Current approaches leverage a rapidly evolving gut bioengineering toolkit aimed at 1) de novo generation of gutlike tissues at multiple scales for microtissue models or implantable grafts and 2) regeneration of functional gut in vivo. Although significant progress has been made in intestinal organoid cultures and engineered tissues, development of predictive in vitro models and effective regenerative therapies remains challenging. In this review, we survey emerging bioengineering tools and recent methodological advances to identify current challenges and future opportunities in gut bioengineering for disease modeling and regenerative medicine.


Subject(s)
Gastrointestinal Microbiome/physiology , Regeneration/physiology , Regenerative Medicine , Stem Cells/cytology , Animals , Bioengineering/methods , Humans , Organoids/metabolism
3.
Innovations (Phila) ; 19(1): 88-91, 2024.
Article in English | MEDLINE | ID: mdl-38258625

ABSTRACT

Heart transplantation utilizing deceased after circulatory death (DCD) donors has expanded the donor pool through the use of ex vivo normothermic perfusion. Compared with brain death donation, the conventional method of performing DCD heart transplantation includes an additional period of warm and cold ischemia. We have developed a beating heart implantation technique that obliviates the need for a second cardioplegic arrest and the associated reperfusion injury. We hypothesize this reproducible method may improve short-term and long-term outcomes to mirror results seen in brain death donors and provide details on how to perform beating heart transplantation.


Subject(s)
Brain Death , Heart Transplantation , Humans , Heart Transplantation/methods , Tissue Donors , Perfusion/methods
4.
IEEE Trans Biomed Eng ; 71(6): 1958-1968, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38261510

ABSTRACT

OBJECTIVE: Robot-assisted minimally invasive surgery remains limited by the absence of haptic feedback, which surgeons routinely rely on to assess tissue stiffness. This limitation hinders surgeons' ability to identify and treat abnormal tissues, such as tumors, during robotic surgery. METHODS: To address this challenge, we developed a robotic tissue palpation device capable of rapidly and non-invasively quantifying the stiffness of soft tissues, allowing surgeons to make objective and data-driven decisions during minimally invasive procedures. We evaluated the effectiveness of our device by measuring the stiffness of phantoms as well as lung, heart, liver, and skin tissues obtained from both rats and swine. RESULTS: Results demonstrated that our device can accurately determine tissue stiffness and identify tumor mimics. Specifically, in swine lung, we determined elastic modulus (E) values of 9.1 ± 2.3, 16.8 ± 1.8, and 26.0 ± 3.6 kPa under different internal pressure of the lungs (PIP) of 2, 25, and 45 cmH2O, respectively. Using our device, we successfully located a 2-cm tumor mimic embedded at a depth of 5 mm in the lung subpleural region. Additionally, we measured E values of 33.0 ± 5.4, 19.2 ± 2.2, 33.5 ± 8.2, and 22.6 ± 6.0 kPa for swine heart, liver, abdominal skin, and muscle, respectively, which closely matched existing literature data. CONCLUSION/SIGNIFICANCE: Results suggest that our robotic palpation device can be utilized during surgery, either as a stand-alone or additional tool integrated into existing robotic surgical systems, to enhance treatment outcomes by enabling accurate intraoperative identification of abnormal tissue.


Subject(s)
Equipment Design , Minimally Invasive Surgical Procedures , Palpation , Robotic Surgical Procedures , Animals , Swine , Robotic Surgical Procedures/instrumentation , Robotic Surgical Procedures/methods , Rats , Palpation/instrumentation , Palpation/methods , Minimally Invasive Surgical Procedures/instrumentation , Minimally Invasive Surgical Procedures/methods , Phantoms, Imaging , Lung/surgery , Lung/physiology , Elastic Modulus , Liver/surgery , Liver/diagnostic imaging
5.
JAMA Netw Open ; 7(3): e241828, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38466306

ABSTRACT

Importance: The use of ex vivo normothermic organ perfusion has enabled the use of deceased after circulatory death (DCD) donors for heart transplants. However, compared with conventional brain death donation, DCD heart transplantation performed with ex vivo organ perfusion involves an additional period of warm and cold ischemia, exposing the allograft to multiple bouts of ischemia reperfusion injury and may contribute to the high rates of extracorporeal membrane oxygenation usage after DCD heart transplantation. Objective: To assess whether the beating heart method of DCD heart transplantation is safe and whether it has an acceptable rate of extracorporeal membrane oxygenation use postoperatively. Design, Setting, and Participants: This case series includes 10 patients with end-stage heart failure undergoing DCD heart transplantation at a single academic medical center from October 1, 2022, to August 3, 2023. Data were analyzed from October 2022 to August 2023. Interventions: Using a beating heart method of implantation of the donor allograft. Main Outcomes and Measures: The main outcome was primary graft dysfunction necessitating postoperative initiation of mechanical circulatory support. Survival and initiation of mechanical circulatory support were secondary outcomes. Results: In this case series, 10 consecutive patients underwent DCD heart transplantation via the beating heart method. Ten of 10 recipients were male (100%), the mean (SD) age was 51.2 (13.8) years, and 7 (70%) had idiopathic dilated cardiomyopathy. Ten patients (100%) survived, and 0 patients had initiation of extracorporeal membrane oxygenation postoperatively. No other mechanical circulatory support, including intra-aortic balloon pump, was initiated postoperatively. Graft survival was 100% (10 of 10 patients), and, at the time of publication, no patients have been listed for retransplantation. Conclusions and Relevance: In this study of 10 patients undergoing heart transplantation, the beating heart implantation method for DCD heart transplantation was safe and may mitigate ischemia reperfusion injury, which may lead to lower rates of primary graft dysfunction necessitating extracorporeal membrane oxygenation. These results are relevant to institutions using DCD donors for heart transplantation.


Subject(s)
Cardiovascular System , Heart Transplantation , Primary Graft Dysfunction , Humans , Male , Middle Aged , Female , Heart , Tissue Donors
6.
Clin Lung Cancer ; 25(5): 424-430, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38749902

ABSTRACT

INTRODUCTION: Annual low-dose computed tomography (LDCT) screening has been shown to reduce lung cancer mortality in high-risk individuals by detecting the disease at an earlier stage. This study aims to assess the barriers to completing LDCT in a cohort of patients who were determined eligible for lung cancer screening (LCS). METHODS: We performed a single institution, mixed methods, cross-sectional study of patients who had a LDCT ordered from July to December 2022. We then completed phone surveys with patients who did not complete LDCT to assess knowledge, attitude, and perceptions toward LCS. RESULTS: We identified 380 patients who met inclusion criteria, including 331 (87%) who completed LDCT and 49 (13%) who did not. Patients who completed a LDCT and those who did not were similar regarding age, sex, race, primary language, household income, body mass index, median pack years, and quit time. Positive predictors of LDCT completion were: meeting USPSTF guidelines (97.9% vs 81.6%), being married (58.3% vs 44.9%), former versus current smokers (55% vs 41.7%), personal history of emphysema (60.4% vs 42.9%), and family history of lung cancer (13.9% vs 4.1%) (all P < .05). Of the patients who participated in the phone survey, only 7% of respondents thought they were high risk for developing lung cancer despite attending a shared decision-making visit and only 10% wanted to re-schedule their LDCT. CONCLUSION: There exist barriers to completing LDCT even after patients are identified as eligible and complete a shared decision-making visit secondary to knowledge barriers, misperceptions, and patient disinterest.


Subject(s)
Early Detection of Cancer , Lung Neoplasms , Tomography, X-Ray Computed , Humans , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/diagnosis , Female , Male , Cross-Sectional Studies , Early Detection of Cancer/methods , Tomography, X-Ray Computed/methods , Middle Aged , Aged , Radiation Dosage , Health Knowledge, Attitudes, Practice , Surveys and Questionnaires
7.
J Thorac Cardiovasc Surg ; 167(5): e106-e130, 2024 May.
Article in English | MEDLINE | ID: mdl-37741314

ABSTRACT

OBJECTIVE: Lung transplantation remains limited by the shortage of healthy organs. Cross-circulation with a healthy swine recipient provides a durable physiologic environment to recover injured donor lungs. In a clinical application, a recipient awaiting lung transplantation could be placed on cross-circulation to recover damaged donor lungs, enabling eventual transplantation. Our objective was to assess the ability of recipient swine with respiratory compromise to tolerate cross-circulation and support recovery of donor lungs subjected to extended cold ischemia. METHODS: Swine donor lungs (n = 6) were stored at 4 °C for 24 hours while recipient swine (n = 6) underwent gastric aspiration injury before cross-circulation. Longitudinal multiscale analyses (blood gas, bronchoscopy, radiography, histopathology, cytokine quantification) were performed to evaluate recipient swine and extracorporeal lungs on cross-circulation. RESULTS: Recipient swine lung injury resulted in sustained, impaired oxygenation (arterial oxygen tension/inspired oxygen fraction ratio 205 ± 39 mm Hg vs 454 ± 111 mm Hg at baseline). Radiographic, bronchoscopic, and histologic assessments demonstrated bilateral infiltrates, airway cytokine elevation, and significantly worsened lung injury scores. Recipient swine provided sufficient metabolic support for extracorporeal lungs to demonstrate robust functional improvement (0 hours, arterial oxygen tension/inspired oxygen fraction ratio 138 ± 28.2 mm Hg; 24 hours, 539 ± 156 mm Hg). Multiscale analyses demonstrated improved gross appearance, aeration, and cellular regeneration in extracorporeal lungs by 24 hours. CONCLUSIONS: We demonstrate that acutely injured recipient swine tolerate cross-circulation and enable recovery of donor lungs subjected to extended cold storage. This proof-of-concept study supports feasibility of cross-circulation for recipients with isolated lung disease who are candidates for this clinical application.


Subject(s)
Lung Injury , Lung Transplantation , Swine , Animals , Lung Injury/pathology , Extracorporeal Circulation/methods , Organ Preservation/methods , Lung , Lung Transplantation/adverse effects , Lung Transplantation/methods , Cytokines/metabolism , Oxygen/metabolism , Perfusion/methods
8.
Adv Healthc Mater ; 13(13): e2303026, 2024 05.
Article in English | MEDLINE | ID: mdl-38279961

ABSTRACT

Pulmonary air leak is the most common complication of lung surgery, contributing to post-operative morbidity in up to 60% of patients; yet, there is no reliable treatment. Available surgical sealants do not match the demanding deformation mechanics of lung tissue; and therefore, fail to seal air leak. To address this therapeutic gap, a sealant with structural and mechanical similarity to subpleural lung is designed, developed, and systematically evaluated. This "lung-mimetic" sealant is a hydrofoam material that has alveolar-like porous ultrastructure, lung-like viscoelastic properties (adhesive, compressive, tensile), and lung extracellular matrix-derived signals (matrikines) to support tissue repair. In biocompatibility testing, the lung-mimetic sealant shows minimal cytotoxicity and immunogenicity in vitro. Human primary monocytes exposed to sealant matrikines in vitro upregulate key genes (MARCO, PDGFB, VEGF) known to correlate with pleural wound healing and tissue repair in vivo. In rat and swine models of pulmonary air leak, this lung-mimetic sealant rapidly seals air leak and restores baseline lung mechanics. Altogether, these data indicate that the lung-mimetic sealant can effectively seal pulmonary air leak and promote a favorable cellular response in vitro.


Subject(s)
Lung , Animals , Humans , Rats , Lung/drug effects , Lung/pathology , Swine , Rats, Sprague-Dawley , Tissue Adhesives/chemistry , Tissue Adhesives/pharmacology , Biomimetic Materials/chemistry , Biomimetic Materials/pharmacology
9.
Article in English | MEDLINE | ID: mdl-38320627

ABSTRACT

OBJECTIVE: The objective of this study is to evaluate survival for combined heart-lung transplant (HLTx) recipients across 4 decades at a single institution. We aim to summarize our contemporary practice based on more than 271 HLTx procedures over 40 years. METHODS: Data were collected from a departmental database and the United Network for Organ Sharing. Recipients younger than age 18 years, those undergoing redo HLTx, or triple-organ system transplantation were excluded, leaving 271 patients for analysis. The pioneering era was defined by date of transplant between 1981 and 2000 (n = 155), and the modern era between 2001 and 2022 (n = 116). Survival analysis was performed using cardinality matching of populations based on donor and recipient age, donor and recipient sex, ischemic time, and sex matching. RESULTS: Between 1981 and 2022, 271 HLTx were performed at a single institution. Recipients in the modern era were older (age 42 vs 34 y; P < .001) and had shorter waitlist times (78 vs 234 days; P < .001). Allografts from female donors were more common in the modern era (59% vs 39%; P = .002). In the matched survival analysis, 30-day survival (97% vs 84%; P = .005), 1-year survival (89% vs 77%; P = .041), and 10-year survival (53% vs 26%; P = .012) significantly improved in the modern era relative to the pioneering era, respectively. CONCLUSIONS: Long-term survival in HLTx is achievable with institutional experience and may continue to improve in the coming decades. Advances in mechanical circulatory support, improved maintenance immunosuppression, and early recognition and management of acute complications such as primary graft dysfunction and acute rejection have dramatically improved the prognosis for recipients of HLTx in our contemporary institutional experience.

10.
J Thorac Dis ; 15(11): 6140-6150, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-38090290

ABSTRACT

Background: Pleural mesothelioma (PM) is rare but portends a poor prognosis. Multimodal treatment, including aggressive surgical resection, may offer the best chance of treatment response and improved survival. Single-center studies suggest that hyperthermic intrathoracic chemotherapy (HITHOC) during surgical resection improves outcomes, but the impact of HITHOC on postoperative morbidity and survival has not been examined on a larger scale. Methods: The National Cancer Database was queried for patients undergoing resection for PM from 2006-2017. Patients were excluded if staging or survival data was incomplete. After propensity-score matching, patients who underwent HITHOC were compared to patients who did not (case-control study). Perioperative outcomes and survival were analyzed. Results: The final cohort consisted of 3,232 patients; of these, 365 patients underwent HITHOC. After propensity-score matching, receipt of HITHOC was associated with increased length of stay (12 vs. 7 days, P<0.001) and increased 30-day readmissions (9.9% vs. 4.9%, P=0.007), but decreased 30-day mortality (3.2% vs. 6.0%, P=0.017) and 90-day mortality (7.5% vs. 10.9%). Kaplan-Meier modeling demonstrated that HITHOC was associated with improved survival in the overall cohort (median 20.5 vs. 16.8 months, P=0.001). In multivariable analysis, HITHOC remained associated with improved overall survival [hazard ratio (HR) =0.80; 95% confidence interval (CI): 0.69-0.92; P=0.002], and this persisted in the propensity-matched analysis (HR =0.73; 95% CI: 0.61-0.88; P=0.001). Conclusions: Using a large national database, we describe the impact of HITHOC on survival in patients with PM. Despite observed increased short-term morbidity, in multivariable analysis HITHOC was associated with an overall survival advantage for patients undergoing surgical resection of PM.

11.
Ann Thorac Surg ; 115(3): 719-724, 2023 03.
Article in English | MEDLINE | ID: mdl-35618049

ABSTRACT

BACKGROUND: The sensitivity of fluoroscopic esophagography with oral administration of contrast material to exclude anastomotic leak after esophagectomy is not well documented, and the consequences of missing a leak in this setting have not been previously described. METHODS: We performed a retrospective cohort study of a prospectively maintained institutional database of patients undergoing esophagectomy with esophagogastric anastomosis from 2008 to 2020. Relevant details of leaks, management, and outcomes were obtained from the database and formal chart review. Statistical analysis was performed to compare patients with and without leaks and those with false-negative vs positive esophagrams. RESULTS: There were 384 patients who underwent esophagectomy with gastric reconstruction; the majority were Ivor-Lewis (82%), and 51% were wholly or partially minimally invasive. By use of a broad definition of leak, 55 patients (16.7%) developed an anastomotic leak. Of the 55 patients, 27 (49%) who ultimately were found to have a leak initially had a normal esophagram result (performed on average on postoperative day 6). Those with a normal initial esophagram result were more likely to have an uncontained leak (81% vs 29%; P < .01), to require unplanned readmission (70% vs 39%; P = .02), and to undergo reoperation (44% vs 11%; P < .01). CONCLUSIONS: Early postoperative esophagrams intended to evaluate anastomotic integrity have a low sensitivity of 51%, and leaks missed on the initial esophagram have greater clinical consequences than those identified on the initial esophagram. These findings suggest that a high index of suspicion must be maintained even after a normal esophagram result and call into question the common practice of using this test to triage patients for diet advancement.


Subject(s)
Anastomotic Leak , Esophageal Neoplasms , Humans , Anastomotic Leak/surgery , Esophagectomy , Retrospective Studies , Esophageal Neoplasms/surgery , Anastomosis, Surgical , Postoperative Complications/surgery
12.
Bioeng Transl Med ; 8(1): e10322, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36684064

ABSTRACT

Pulmonary air leak is the most common complication of lung surgery, with air leaks that persist longer than 5 days representing a major source of post-surgery morbidity. Clinical management of air leaks is challenging due to limited methods to precisely locate and assess leaks. Here, we present a sound-guided methodology that enables rapid quantitative assessment and precise localization of air leaks by analyzing the distinct sounds generated as the air escapes through defective lung tissue. Air leaks often present after lung surgery due to loss of tissue integrity at or near a staple line. Accordingly, we investigated air leak sounds from a focal pleural defect in a rat model and from a staple line failure in a clinically relevant swine model to demonstrate the high sensitivity and translational potential of this approach. In rat and swine models of free-flowing air leak under positive pressure ventilation with intrapleural microphone 1 cm from the lung surface, we identified that: (a) pulmonary air leaks generate sounds that contain distinct harmonic series, (b) acoustic characteristics of air leak sounds can be used to classify leak severity, and (c) precise location of the air leak can be determined with high resolution (within 1 cm) by mapping the sound loudness level across the lung surface. Our findings suggest that sound-guided assessment and localization of pulmonary air leaks could serve as a diagnostic tool to inform air leak detection and treatment strategies during video-assisted thoracoscopic surgery (VATS) or thoracotomy procedures.

13.
Article in English | MEDLINE | ID: mdl-37360840

ABSTRACT

BACKGROUND: Severe Coronavirus Disease 2019 (COVID-19) infection is associated with prolonged intubation and its complications. Tracheal stenosis is one such complication that may require specialized surgical management. We aimed to describe the surgical management of post-COVID-19 tracheal stenosis. METHODS: This case series describes consecutive patients with tracheal stenosis from intubation for severe COVID-19 infection at our single, tertiary academic medical center between January 1st, 2021, and December 31st, 2021. Patients were included if they underwent surgical management with tracheal resection and reconstruction, or bronchoscopic intervention. Operative through six-month, symptom-free survival and histopathological analysis of resected trachea were reviewed. RESULTS: Eight patients are included in this case series. All patients are female, and most (87.5%) are obese. Five patients (62.5%) underwent tracheal resection and reconstruction (TRR), while three patients (38.5%) underwent non-resection-based management. Among patients who underwent TRR, six-month symptom free survival is 80%; one patient (20%) required tracheostomy after TRR due to recurrent symptoms. Two of the three (66.7%) of patients who underwent non-resection-based management experienced durable relief from symptoms of tracheal stenosis with tracheal balloon dilation, and the remaining patient required laser excision of tracheal tissue prior to experiencing symptomatic relief. CONCLUSIONS: The incidence of tracheal stenosis may increase as patients recover from severe COVID-19 infection requiring intubation. Management of tracheal stenosis with TRR is safe and effective, with comparable rates of success to TRR for non-COVID-19 tracheal stenosis. Non-resection-based management is an option to manage tracheal stenosis in patients with less severe stenosis or in poor surgical candidates.

14.
JTCVS Open ; 16: 919-928, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38204675

ABSTRACT

Background: Radiotherapy (RT) is integral to breast cancer treatment, especially in the current era that emphasizes breast conservation. The aim of our study was to determine the incidence of subsequent primary lung cancer after RT exposure for breast cancer over a time span of 3 decades to quantify this risk over time as modern oncologic treatment continues to evolve. Methods: The SEER (Surveillance, Epidemiology, and End Results) database was queried from 1988 to 2014 for patients diagnosed with nonmetastatic breast cancer. Patients who subsequently developed primary lung cancer were identified. Multivariable regression modeling was performed to identify independent factors associated with the development of lung cancer stratified by follow up intervals of 5 to 9 years, 10 to 15 years, and >15 years after breast cancer diagnosis. Results: Of the 612,746 patients who met our inclusion criteria, 319,014 (52%) were irradiated. primary lung cancer developed in 5556 patients (1.74%) in the RT group versus 4935 patients (1.68%) in the non-RT group. In a multivariable model stratified by follow-up duration, the overall HR of developing subsequent ipsilateral lung cancer in the RT group was 1.14 (P = .036) after 5 to 9 years of follow-up, 1.28 (P = .002) after 10 to 15 years of follow-up, and 1.30 (P = .014) after >15 years of follow-up. The HR of contralateral lung cancer was not increased at any time interval. Conclusions: The increased risk of developing a primary lung cancer secondary to RT exposure for breast cancer is much lower than previously published. Modern RT techniques may have contributed to the improved risk profile, and this updated study is important for counseling and surveillance of breast cancer patients.

15.
JTCVS Open ; 16: 855-872, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38204720

ABSTRACT

Objective: Failure to rescue (FTR), defined as in-hospital death following a major complication, has been increasingly studied in patients who undergo cardiothoracic surgery. This study tested the hypothesis that elderly patients undergoing lung cancer resection have greater rates of FTR compared with younger patients. Methods: Patients who underwent surgery for primary lung cancer between 2011 and 2020 and had at least 1 major postoperative complication were identified using the National Surgical Quality Improvement Program database. Patients who died following complications (FTR) were compared with those who survived in an elderly (80+ years) and younger (<80 years) cohort. Results: Of the 2823 study patients, the younger cohort comprised 2497 patients (FTR: n = 139 [5.6%]), whereas the elderly cohort comprised 326 patients (FTR: n = 39 [12.0%]). Pneumonia was the most common complication in younger (877/2497, 35.1%) and elderly patients (118/326, 36.2%) but was not associated with FTR on adjusted analysis. Increasing age was associated with FTR (adjusted odds ratio [AOR], 1.55 per decade, P < .001), whereas unplanned reoperation was associated with reduced risk (AOR, 0.55, P = .01). Within the elderly cohort, surgery conducted by a thoracic surgeon was associated with lower FTR risk (AOR, 0.29, P = .028). Conclusions: FTR following lung cancer resection was more frequent with increasing age. Pneumonia was the most common complication but not a predictor of FTR. Unplanned reoperation was associated with reduced FTR, as was treatment by a thoracic surgeon for elderly patients. Surgical therapy for complications after lung cancer resection and elderly patients managed by a thoracic specialist may mitigate the risk of death following an adverse postoperative event.

16.
J Heart Lung Transplant ; 42(3): 335-344, 2023 03.
Article in English | MEDLINE | ID: mdl-36456408

ABSTRACT

BACKGROUND: Xenogeneic cross-circulation (XC) is an experimental method for ex vivo organ support and recovery that could expand the pool of donor lungs suitable for transplantation. The objective of this study was to establish and validate a standardized, reproducible, and broadly applicable technique for performing xenogeneic XC to support and recover injured human donor lungs ex vivo. METHODS: Human donor lungs (n = 9) declined for transplantation were procured, cannulated, and subjected to 24 hours of xenogeneic XC with anesthetized xeno-support swine (Yorkshire/Landrace) treated with standard immunosuppression (methylprednisolone, mycophenolate mofetil, tacrolimus) and complement-depleting cobra venom factor. Standard lung-protective perfusion and ventilation strategies, including periodic lung recruitment maneuvers, were used throughout xenogeneic XC. Every 6 hours, ex vivo donor lung function (gas exchange, compliance, airway pressures, pulmonary vascular dynamics, lung weight) was evaluated. At the experimental endpoint, comprehensive assessments of the lungs were performed by bronchoscopy, histology, and electron microscopy. Student's t-test and 1-way analysis of variance with Dunnett's post-hoc test was performed, and p < 0.05 was considered significant. RESULTS: After 24 hours of xenogeneic XC, gas exchange (PaO2/FiO2) increased by 158% (endpoint: 364 ± 142 mm Hg; p = 0.06), and dynamic compliance increased by 127% (endpoint: 46 ± 20 ml/cmH2O; p = 0.04). Airway pressures, pulmonary vascular pressures, and lung weight remained stable (p > 0.05) and within normal ranges. Over 24 hours of xenogeneic XC, gross and microscopic lung architecture were preserved: airway bronchoscopy and parenchymal histomorphology appeared normal, with intact blood-gas barrier. CONCLUSIONS: Xenogeneic cross-circulation is a robust method for ex vivo support, evaluation, and improvement of injured human donor lungs declined for transplantation.


Subject(s)
Lung Transplantation , Humans , Swine , Animals , Lung Transplantation/methods , Lung , Perfusion/methods , Tissue Donors , Organ Preservation/methods
18.
J Vis Exp ; (182)2022 04 06.
Article in English | MEDLINE | ID: mdl-35467661

ABSTRACT

Repeated injury to airway tissue can impair lung function and cause chronic lung disease, such as chronic obstructive pulmonary disease. Advances in regenerative medicine and bioreactor technologies offer opportunities to produce lab-grown functional tissue and organ constructs that can be used to screen drugs, model disease, and engineer tissue replacements. Here, a miniaturized bioreactor coupled with an imaging modality that allows in situ visualization of the inner lumen of explanted rat trachea during in vitro tissue manipulation and culture is described. Using this bioreactor, the protocol demonstrates imaging-guided selective removal of endogenous cellular components while preserving the intrinsic biochemical features and ultrastructure of the airway tissue matrix. Furthermore, the delivery, uniform distribution, and subsequent prolonged culture of exogenous cells on the decellularized airway lumen with optical monitoring in situ are shown. The results highlight that the imaging-guided bioreactor can potentially be used to facilitate the generation of functional in vitro airway tissues.


Subject(s)
Biomedical Engineering , Tissue Engineering , Animals , Bioreactors , Rats , Tissue Engineering/methods
19.
JACC Case Rep ; 4(14): 839-843, 2022 Jul 20.
Article in English | MEDLINE | ID: mdl-35912321

ABSTRACT

We describe surgical repair of a Stanford Type A aortic dissection with concurrent aortic valve Streptococcus equi endocarditis in the setting of subarachnoid hemorrhage and disseminated intravascular coagulation. Multidisciplinary collaboration among specialists from a variety of disciplines is essential when treating acutely ill cardiovascular patients with multisystem involvement. (Level of Difficulty: Beginner.).

20.
ACS Biomater Sci Eng ; 8(1): 82-88, 2022 01 10.
Article in English | MEDLINE | ID: mdl-34874712

ABSTRACT

Injured or diseased airway epithelium due to repeated environmental insults or genetic mutations can lead to a functional decline of the lung and incurable lung diseases. Bioengineered airway tissue constructs can facilitate in vitro investigation of human lung diseases and accelerate the development of effective therapeutics. Here, we report robust tissue manipulation modalities that allow: (i) selective removal of the endogenous epithelium of in vitro cultured airway tissues and (ii) spatially uniform distribution and prolonged cultivation of exogenous cells that are implanted topically onto the denuded airway lumen. Results obtained highlight that our approach to airway tissue manipulation can facilitate controlled removal of the airway epithelium and subsequent homogeneous distribution of newly implanted cells. This study can contribute to the creation of innovative tissue engineering methodologies that can facilitate the treatment of lung diseases, such as cystic fibrosis, primary ciliary dyskinesia, and chronic obstructive pulmonary disease.


Subject(s)
Hydrogels , Trachea , Animals , Epithelial Cells , Lung , Rats , Tissue Engineering
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