Single Lung Transplant Remains a Viable Option for Patients With Severe Secondary Pulmonary Hypertension.

BACKGROUND: Although double lung transplant is recommended in patients with severe secondary pulmonary hypertension (SPH), our institutional experiences suggest a role for single lung transplant in these patients. Here, we review our experience prioritizing single lung transplant in patients with SPH to minimize their surgical burden. METHODS: We conducted a retrospective review of our lung transplant database to identify patients with SPH who underwent single lung transplant. Patients were stratified as either mild SPH (mean pulmonary artery pressure 25-40 mm Hg) or severe SPH (mean pulmonary artery pressure >40 mm Hg). Singe lung recipients without PH transplanted over the same time were also examined. RESULTS: Between January 2017 and December 2019, 318 patients underwent single lung transplantation; 217 had mild SPH (68%), and 59 had severe SPH (18.5%). Forty-two patients without PH underwent single lung transplant. When the groups were compared, significantly higher pulmonary vascular resistance was noted in the severe SPH group, and obesity was noted in both the mild and severe SPH groups. Although the severe SPH group required more intraoperative cardiopulmonary support (37.3% versus 10.3% versus 4.7%, P < 0.05), there were no significant differences in most major postoperative parameters, including the duration of postoperative mechanical ventilation or the incidence of severe primary graft dysfunction. Survival 1 y posttransplant was not significantly different among the groups (93.2% versus 89.4% versus 92.9%, P = 0.58). CONCLUSIONS: Our experience supports the option of single lung transplantation with appropriate intraoperative mechanical circulatory support in patients with SPH. This strategy is worth pursuing, especially with ongoing donor lung shortages.

Anastomotic Suturing Techniques and Their Association With Post-Lung Transplantation Complications.

INTRODUCTION: Currently, standard practice is to use the continuous suturing technique on the bronchial anastomosis during lung transplantation. This study used a large cohort to investigate and contrast continuous and interrupted suturing techniques, comparing survival outcomes and occurrence of postoperative bronchial complications to examine if utilization of interrupted suturing has merit. METHODS: Survival outcomes of 740 single-center lung transplant recipients over 8 y (February 2012-March 2020) were compared by suturing techniques: either continuous or interrupted at the bronchial anastomosis. Clinical parameters and demographics were compared between two suturing groups, with P values < 0.05 considered significant. The groups were compared for postoperative morbidity, including need for bronchial interventions. Survival was compared using Kaplan-Meier curves and log-rank tests. Cox regression analysis was run with statistically significant variables to study association with survival. RESULTS: Of the 740 patients, 462 received the continuous suturing technique and 278 received the interrupted suturing technique. Most demographic and clinical data were not statistically significant between the two groups, and those that were significant were not associated with worse survival outcomes, with the exception of the variable diagnosis. Bronchial complications were comparable between the continuous and interrupted groups (12.6% versus 10.4%, P = 0.382). Extracorporeal membrane oxygenation (ECMO) use did not differ significantly between the two groups (P = 0.12). The Kaplan-Meier curve showed comparable survival between groups (P = 0.98), and Cox regression analysis showed that only diagnosis, bronchial complications, and ECMO utilization were associated with different survival outcomes. Chronic obstructive pulmonary disorder was shown to be associated with more favorable survival outcomes as opposed to idiopathic pulmonary fibrosis and the category "other". The need for ECMO and the occurrence of a bronchial complication were also associated with worse survival outcomes. CONCLUSIONS: Both techniques showed reasonable post-transplant outcomes, as our study demonstrated similar survival outcomes and bronchial complication rates.

Postoperative Bronchial Complications After Lung Transplantation Related to Anastomosis Suture.

BACKGROUND: Postoperative bronchial anastomotic complications are not uncommon in lung transplant recipients. We investigated 2 surgical techniques (continuous and interrupted sutures) during bronchial anastomosis, comparing survival and postoperative bronchial complications. METHODS: We retrospectively analyzed 421 patients who were transplanted in our center (February 2012 to March 2018). Patients were divided according to bronchial anastomotic technique (continuous or interrupted). Demographics and clinical parameters were compared for significance (P < .05). Comparison of postoperative morbidity included bronchial complications, venovenous extracorporeal membrane oxygenation support, and intervention requirements. Survival was assessed using Kaplan-Meier curve and log-rank tests (P < .05). RESULTS: Of the 421 patients, 290 underwent bronchial anastomoses with continuous suture; 44 of these patients had postoperative bronchial complications (15.2%). Contrarily, 131 patients underwent the interrupted suture technique; 9 patients in this group had postoperative bronchial complications (6.9%). Demographics and clinical parameters included age, sex, ethnicity, etiology, lung allocation score, body mass index, donor age, lung transplant type, cardiopulmonary bypass usage, surgical approaches, and median length of stay. Postoperative complications (continuous vs interrupted) were bronchial complications (P = .017), venovenous extracorporeal membrane oxygenation support (P = .41), venoarterial extracorporeal membrane oxygenation support (P = .38), and complications requiring dilatation with stent placement (P = .09). Kaplan-Meier curve showed better survival in the interrupted group (P = .0002). CONCLUSIONS: Our study demonstrated the comparable postoperative results between the continuous and interrupted technique.

Comparing outcomes in patients with end-stage chronic obstructive pulmonary disease: single versus bilateral lung transplants.

OBJECTIVES: Debate continues on whether a bilateral (BLT) or a single lung transplantation (SLT) is preferred for patients with end-stage chronic obstructive pulmonary disease (COPD). The purpose of this study is to examine the interplay between patient age and transplant type on survival outcomes. METHODS: We performed a retrospective study of lung transplants for COPD at our centre from February 2012 to March 2020 (n = 186). Demographics and clinical parameters were compared between patients based on their age (≤65 vs >65 years old) and type of transplant (single vs bilateral). Cox proportional hazards regression was also performed. P-values <0.05 were considered significant. RESULTS: Of the 186 patients with COPD who received lung transplants, 71 (38.2%) received BLTs and 115 (61.8%) received SLTs. There was no significant difference in survival outcomes when looking at patients with single versus BLTs (P = 0.870). There was also no difference in survival between the 2 age groups ≤65 versus > 65 years (P = 0.723). The Cox model itself also did not show a statistically significant improvement in survival outcomes (P = 0.126). CONCLUSIONS: Lung transplant outcomes in patients with end-stage COPD demonstrated non-inferior results in patients with an SLT compared to patients with a BLT. When we compared the age groups, neither transplant type showed superior survival benefits, suggesting there may be some utility in an SLT in younger recipients.

Prior and Perioperative Revascularization Does Not Affect Survival in Lung Transplant Patients.

BACKGROUND: Coronary artery disease is common in lung transplant patients and has historically been viewed as a contraindication to the procedure. Although this mindset is changing, the effect of prior or perioperative revascularization on lung transplant survival outcomes is not adequately established. METHODS: We performed a single-center retrospective analysis of all single and double lung transplant patients from 2012 to 2018 (n = 468). Patients were split into 4 groups: (1) patients who received a preoperative percutaneous coronary intervention (n = 34), (2) those who received coronary artery bypass grafting (CABG) before transplantation (n = 25), (3) those that received concomitant CABG during transplantation (n = 29), and (4) those who had lung transplantation with no need for revascularization (n = 380). Groups were compared for demographics, surgical procedure, and survival outcomes. RESULTS: The no-revascularization group was statistically younger than the rest (P = .001). The lung allocation score trended toward being higher in the concomitant coronary artery bypass group (P = .03). All groups were predominantly diagnosed with idiopathic pulmonary fibrosis. The proportion of patients with chronic obstructive pulmonary disease was greatest in the group not requiring revascularization (P = .001). Patients with previous CABG were more likely to receive a single lung transplant than a double one (21 versus 4; P = .054). Length of stay, posttransplant survival, and postoperative adverse events were similar among all groups. CONCLUSIONS: Results suggest that preoperative or intraoperative revascularization does not negatively affect survival in lung transplant patients; lung recipients with coronary artery disease have comparable survival when adequately revascularized.

Examining ABO compatible donors in double lung transplants during the era of lung allocation score.

BACKGROUND: The short-term and long-term effect of using ABO compatible donors in the era of lung allocation score is unknown. This study determined if carefully selected ABO compatible donors could be used in double lung transplantation (DLT) with good outcomes. METHODS: The United Network for Organ Sharing database was retrospectively reviewed for adult DLT from May 2005 to December 2011. RESULTS: Of 6,655 double lung transplants, 493 (7.4%) were with ABO compatible donors and 6,162 (92.6%) were with ABO identical donors. In multivariate analysis, use of ABO compatible donors was not associated with mortality at 30 days (HR, 1.16; 95% CI, 0.76 to 1.79, p = 0.49), 1 year (HR, 1.10; 95% CI, 0.86 to 1.42, p = 0.46), and 5 years (HR, 1.06; 95% CI, 0.83 to 1.34, p = 0.65). Variables associated with mortality at 5 years were donor female sex, donor age 60 years or greater, prolonged ischemic time, increasing recipient creatinine, recipient age, race mismatch, and mechanical ventilation or extracorporeal membrane oxygenation as a bridge to transplantation. Length of stay was longer in the ABO compatible group (30.9 vs 25.9 days, p = 0.001). Acute rejection episodes on index hospitalization (8.8 vs. 8.9%, p = 1.00), peak posttransplant forced expiratory volume in 1 second (FEV1) (82.7 vs 79.7%, p = 0.053), and decrement in FEV1 over time were not different (p = 0.13). Freedom from bronchiolitis obliterans syndrome was similar (1,475 vs 1,454 days, p = 0.17). CONCLUSIONS: The use of ABO compatible donors in the era of lung allocation score was not associated with short-term or long-term mortality and resulted in equivalent posttransplant lung function. A DLT with carefully selected ABO compatible donors can result in excellent outcomes.

Single-lung transplantation with ABO-compatible donors results in excellent outcomes.

BACKGROUND: The goal of this study was to determine if carefully selected ABO-compatible donors in single-lung transplantation results in acceptable outcomes. METHODS: The United Network for Organ Sharing database was reviewed for adult single-lung transplant recipients from May 2005 to December 2011. Recipients of lungs from ABO-compatible donors were compared with those of ABO-identical donors. Mortality was examined with risk-adjusted multivariable Cox proportional hazards regression using significant univariate predictors. RESULTS: Of 3,572 single-lung transplants, 342 (9.6%) were from ABO-compatible donors. The two groups were evenly matched in recipient age (60.8 vs 60.2 years, p = 0.28), male gender (61.8% vs 58.2%, p = 0.10), lung allocation score (43.4 vs 42.6, p = 0.32), forced expiratory volume in 1 second (FEV1; 41.2% vs 40.8%, p = 0.32), and ischemic time (4.2 vs 4.0 hours, p = 0.09), and donor age (34.4 vs 32.9, p = 0.07) and male gender (61.5 vs 65.5, p = 0.14). ABO-compatible donors were less likely to be race mismatched (58.3% vs 50.9%, p = 0.01). Median survival was not different (1,284.0 vs 1,540 days, p = 0.39). On multivariate analysis, lungs from ABO-compatible donors were not associated with mortality (hazard ratio, 1.02; 95% confidence interval, 0.85-1.22; p = 0.86). Prolonged ischemic time, increasing recipient creatinine, increasing recipient age, race mismatch, class I plasma reactive antigen panel > 10%, and the use of mechanical ventilation or extracorporeal membrane oxygenation were associated with mortality. Peak post-transplant FEV1 (64.5% vs 64.0%, p = 0.69) and decrement in FEV1 over time were similar (p = 0.82). CONCLUSIONS: This large multi-institutional analysis of ABO-compatible donors in single-lung transplantation demonstrates that careful selection of ABO-compatible donors results in excellent outcomes.

Gene therapy with adenovirus-mediated myocardial transfer of vascular endothelial growth factor 121 improves cardiac performance in a pacing model of congestive heart failure.

BACKGROUND: Myocardial ischemia is the most common cause of congestive heart failure. Angiogenic therapy has recently been demonstrated to enhance myocardial perfusion in the ischemic setting. We therefore hypothesized that administration of adenovirus encoding for vascular endothelial growth factor could be used to enhance myocardial function in a pacing-induced model of heart failure. METHODS: Yorkshire swine underwent a left thoracotomy with placement of a ventricular epicardial pacing system. Animals received adenovirus coding either for the 121-amino-acid isoform of vascular endothelial growth factor (Ad(CU)VEGF121.1 group, n = 8) or a null vector coding for no genes (AdNull group, n = 8). The adenovirus was administered in the left ventricular free wall as 10 transepicardial injections of 100 microL each (total dose of 10(11) particle units). After a 1-week recovery period, animals were paced at a rate of 230 beats/min for 7 days to induce heart failure. Transthoracic echocardiographic and sonomicrometric measurements were performed before pacing (baseline), on termination of pacing (day 0), and then weekly for 3 weeks. RESULTS: The fractional area change was significantly decreased in AdNull animals at day 0 after pacing compared with the Ad(CU)VEGF121.1 animals (29% +/- 14% vs 46% +/- 8%, P =.02). The fractional area change recovered to baseline values within 7 days in the Ad(CU)VEGF121.1 animals (62% +/- 7%) but remained significantly impaired in the AdNull group compared with that in the Ad(CU)VEGF121.1 animals up to day 21 (P =.04). Similarly, fractional wall thickening demonstrated a decrease at day 0 after pacing that was greater (P <.05) in the AdNull group compared with that in the Ad(CU)VEGF121.1 group in 5 of 6 segments. Fractional wall thickening returned to levels approximating prepacing values in all segments within 7 days in the Ad(CU)VEGF121.1 group but remained significantly impaired compared with prepacing fractional wall thickening (P <.05) in the AdNull group in 5 of 6 segments up to day 21 after pacing. Segmental shortening, as measured by sonomicrometry, also was significantly decreased at day 7 in the AdNull group compared with that in the Ad(CU)VEGF121.1 group (10% +/- 4% vs 16% +/- 3%, P =.004) and remained significantly impaired (P <.05) in the AdNull group at day 14 and 21 when compared with baseline values. CONCLUSION: Preservation of cardiac performance and a more rapid recovery of myocardial function can be achieved in a model of pacing-induced cardiomyopathy with adenovirus-mediated administration of vascular endothelial growth factor compared with that seen in a null virus control group. These data suggest that angiogenic therapy may be useful clinically in treating cardiomyopathy.