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Lungs of donors with high body mass index (BMI) have more atelectasis and a lower PaO 2 /FiO 2 (P/F) ratio than those with normal BMI. This study prospectively evaluated outcomes of a new approach for these lungs in our lung transplant program. From February 2016 to December 2018, 336 lung transplants were performed at Cleveland Clinic. Of these, 58 met criteria for our aggressive approach to donors with a P/F ratio of less than 300 mm Hg at offer and BMI of 25 kg/m2 or greater. In the donor operating room, lung recruitment was performed by positive end-respiratory pressure of 25 to 30 cmH 2 O for 30 seconds and lungs were converted to either straight transplantation or ex vivo lung perfusion (EVLP). Postoperative outcomes of the low P/F–high BMI group were compared with those of recipients receiving lungs meeting standard criteria. Of the 58 donors, 33 were converted to straight lung transplantation because they demonstrated significant improvement in the P/F ratio after lung recruitment compared with the P/F ratio at lung offer (median, 278 versus 420 mm Hg; P <.01). Seventeen lungs with a persistently low P/F ratio underwent EVLP, 8 of which were transplanted. There was no significant difference in primary graft dysfunction grade 3 at 72 hours (n = 3 of 41 [7.5%] versus 31 of 247 [13%]; P =.79) or in 30-day survival (100% versus 97%; P =.60) between low P/F–high BMI and standard groups. These data suggest that atelectasis in high-BMI donors contributes to P/F ratios less than 300 mm Hg and that intraoperative lung recruitment or EVLP can allow the use of lungs from these donors with good outcomes. [ABSTRACT FROM AUTHOR]

Background To determine the value of aortic valve repair rather than replacement for valve dysfunction, we assessed late outcomes of various repair techniques in the contemporary era. Methods From January 2001 to January 2011, aortic valve repair was planned in 1,124 patients. Techniques involved commissural figure-of-8 suspension sutures (n = 63 [6.2%]), cusp repair with commissuroplasty (n = 481 [48%]), debridement (n = 174 [17%]), free-margin plication (n = 271 [27%]) or resection (n = 75) or both, or annulus repair with resuspension (n = 230 [23%]), root reimplantation (n = 252 [25%]), or remodeling (n = 35 [3.5%]). Results Planned repair was aborted for replacement in 115 patients (10%); risk factors included greater severity of aortic regurgitation (AR; p = 0.0002) and valve calcification ( p < 0.0001). In-hospital outcomes for the remaining 1,009 patients included death (12 [1.2%]), stroke (13 [1.3%]), and reoperation for valve dysfunction (14 [1.4%]). Freedom from aortic valve reoperation at 1, 5, and 10 years was 97%, 93%, and 90%, respectively. Figure-of-8 suspension sutures, valve resuspension, and root repair and replacement were least likely to require reoperation; cusp repair with commissural sutures, plication, and commissuroplasty was most likely ( p < 0.05). Survival at 1, 5, and 10 years was 96%, 92%, and 83%. Immediate postoperative AR grade was none-mild (94%), moderate (5%), and severe (1%). At 10 years after repair, AR grade was none (20%), mild (33%), moderate (26%), and severe (21%). Patients undergoing root procedures were less likely to have higher-grade postoperative AR ( p < 0.0001). Conclusions Valve repair is effective and durable for treating aortic valve dysfunction. Greater severity of AR preoperatively is associated with higher likelihood of repair failure. Commissural figure-of-8 suspension sutures and repair with annular support have the best long-term durability. [ABSTRACT FROM AUTHOR]

Background: We present a comparison of porcine bioroot and composite mechanical root replacement in a large series of patients younger than 60 years who required full root replacement for true root pathology. Methods: Between 1997 and 2007, we performed 986 aortic root replacement procedures, including 391 porcine bioroots and 515 composite mechanical roots for true root indications. Of these, 504 patients were younger than 60 years old at time of the operation. Porcine bioroots were placed in 138 patients, including 38 St. Jude Toronto Root (St. Jude Inc, St. Paul, MN), 98 Medtronic Freestyle (Medtronic Inc, Minneapolis, MN), and 2 Edwards Prima (Edwards Lifesciences Inc, Irvine, CA). Standard univariate, logistic regression, Cox regression, and propensity matching techniques were used. Results: To adjust for baseline differences in risk factor profiles, propensity matching yielded a final matched data set of 128 matched pairs, with no differences in preoperative risk factor profile or indication for operation. Overall 30-day operative mortality was 2.3% for porcine bioroot patients vs 1.6% for mechanical root patients (p = 0.6). Root type did not influence early (odds ratio, 0.8; 96% confidence interval, 0.2 to 3.2) or late mortality (hazard risk, 1.4; 95% confidence interval, 0 0.5 to 3.8). Multivariate predictors of late mortality included (hazard ratio, 95% confidence interval) age in years (1.01; 1.01 to 1.03), chronic renal failure (3.6; 1.1 to 12.6), and preoperative bacterial endocarditis (3.6; 1.1 to 11.8). Freedom from reoperation was similar between groups; however, bleeding events were more common among mechanical root patients. Conclusions: Porcine bioroots provide durable midterm to late-term outcomes after aortic root replacement for true root indications and are an appealing alternative in younger patients because they limit morbidity associated with anticoagulant-related bleeding. [Copyright &y& Elsevier]

Background: Surgical techniques have been developed for mitral valve repair for a wide range of pathologies. However, excessive tissue stress and damage have been identified as etiologic factors limiting long-term durability. Before computational models to optimize valve repair can be realistically developed, in-vivo dynamic mitral valve leaflet strain data are required. However, these data do not presently exist. In the present study, a sheep model and sonomicrometry were used to compute the in-surface Eulerian strain tensor of the anterior leaflet over the cardiac cycle at varying afterloads. Methods: The anterior leaflet of nine Dorsett sheep (35 kg to 45 kg) was instrumented with nine 1-mm hemispherical piezoelectric transducers in a 15-mm square array. Three-dimensional crystal spatial positions were recorded at 250 Hz over several cardiac cycles, with peak left ventricular pressures varying from 90 mm Hg to 200 mm Hg. The in-surface Eulerian strain tensor was computed from the crystal displacements. Results: The mitral valve anterior leaflet experiences large anisotropic strains and peak strain rates of 400%/s, followed by an absolute cessation of any deformation during systole. Increasing left ventricular pressure also increased the effective leaflet stiffness but not the peak strains. Conclusions: We report the first data on the dynamic in-vivo strain tensor of a functioning mitral valve anterior leaflet, which indicated large anisotropic strains and very high strain rates. Our observations also suggest that changes in left ventricular pressure and annular geometry result in altered effective leaflet stiffness, and may be an important factor in reducing leaflet stress and as such potentially affect mitral valve repair longevity. [Copyright &y& Elsevier]

Background: Early infarct expansion initiates adverse remodeling, leads to left ventricular dilatation and portends a poor long-term outcome. Early mechanical prevention of infarct expansion has been proposed as a method to improve remodeling, but the extent of ventricular restraint necessary to optimize the salutary effect is not known. We tested the hypothesis that left ventricular restraint (wrap) is superior to infarct stiffening (patch). Methods: Infarction of 20% to 25% of the left ventricle was induced by coronary ligation in 69 sheep. Infarcts were either anteroapical (n = 33) or posterobasal (n = 36). Animals with each infarct received either no treatment (anteroapical, n = 26; posterobasal, n = 17), infarct stiffening with a localized Marlex mesh patch (posterobasal, n = 9) or left ventricular wrapping with Merseline mesh (anteroapical, n = 7; posterobasal, n = 10). End-systolic volume, end-diastolic volume, end-systolic muscle to cavity area ratio, left ventricular sphericity, ejection fraction, and degree of mitral regurgitation as determined by quantitative echocardiography were assessed before infarction and at 2, 5, and 8 weeks after infarction to evaluate the extent of left ventricular remodeling. Results: Control animals in both groups experienced adverse remodeling. Anteroapical infarct animals developed large left ventricular aneurysms and the posterobasal infarct animals developed severe mitral regurgitation. Early infarct stiffening did not significantly improve any aspect of remodeling due to the posterobasal infarct. Early left ventricular wrapping significantly improved remodeling after both types of infarctions. Conclusions: Early left ventricular wrapping attenuates infarct expansion and has a salutary effect on remodeling. Simple infarct stiffening alone is not effective. [Copyright &y& Elsevier]

Background: Lungs of donors with high body mass index (BMI) have more atelectasis and a lower PaO 2 /FiO 2 (P/F) ratio than those with normal BMI. This study prospectively evaluated outcomes of a new approach for these lungs in our lung transplant program., Methods: From February 2016 to December 2018, 336 lung transplants were performed at Cleveland Clinic. Of these, 58 met criteria for our aggressive approach to donors with a P/F ratio of less than 300 mm Hg at offer and BMI of 25 kg/m 2 or greater. In the donor operating room, lung recruitment was performed by positive end-respiratory pressure of 25 to 30 cmH 2 O for 30 seconds and lungs were converted to either straight transplantation or ex vivo lung perfusion (EVLP). Postoperative outcomes of the low P/F-high BMI group were compared with those of recipients receiving lungs meeting standard criteria., Results: Of the 58 donors, 33 were converted to straight lung transplantation because they demonstrated significant improvement in the P/F ratio after lung recruitment compared with the P/F ratio at lung offer (median, 278 versus 420 mm Hg; P < .01). Seventeen lungs with a persistently low P/F ratio underwent EVLP, 8 of which were transplanted. There was no significant difference in primary graft dysfunction grade 3 at 72 hours (n = 3 of 41 [7.5%] versus 31 of 247 [13%]; P = .79) or in 30-day survival (100% versus 97%; P = .60) between low P/F-high BMI and standard groups., Conclusions: These data suggest that atelectasis in high-BMI donors contributes to P/F ratios less than 300 mm Hg and that intraoperative lung recruitment or EVLP can allow the use of lungs from these donors with good outcomes., (Copyright © 2020 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)