Faculty Bibliography

OBJECTIVE:There is a shortage of donor lungs relative to need, but overall donor organ utilization remains low. The most common reason for refusal is organ quality, but the standards applied to selection vary. In this study we sought to characterize differences in lung utilization according to quality across several clinically distinct recipient pools. METHODS:Data on donor lungs recovered (April 2006 to September 2019) were extracted from the Scientific Registry of Transplant Recipients database. Organs were classified as ideal, standard, or extended quality according to their poorest metric among selected parameters. Subanalyses were performed on the basis of procedure type, age, lung allocation score, era, and alternative definitions of extended quality. Recipient traits and survival according to organ quality were assessed. RESULTS:Of 156,022 lungs analyzed during the study period, 25,777 (16.5%) were transplanted. There was no difference in quality distribution for single and bilateral transplants. Young candidates were more likely to receive ideal (14.7% vs 12.3%) or standard (9.5% vs 8.2%) lungs, but not extended lungs (75.9% vs 79.5%; all P < .01). Absolute differences in distribution according to lung allocation score quartile were small (<2%). Extended quality donor utilization increased over time. Survival according to donor category was similar at 1 and 3 years post transplant in unadjusted and Cox regression analyses. CONCLUSIONS:Extended quality lungs comprise an increasing share of transplants in a national sample. Organ selection varies according to recipient age and lung allocation score. However, absolute differences in quality distribution are small, and adverse effects on outcomes are limited to organs with multiple extended qualifying characteristics.

Lung transplantation is the only potentially curative treatment for end-stage lung failure and successfully improves both long-term survival and quality of life. However, lung transplantation is limited by the shortage of suitable donor lungs. This discrepancy in organ supply and demand has prompted researchers to seek alternative therapies for end-stage lung failure. Tissue engineering (bioengineering) organs has become an attractive and promising avenue of research, allowing for the customized production of organs on demand, with potentially perfect biocompatibility. While breakthroughs in tissue engineering have shown feasibility in practice, they have also uncovered challenges in solid organ applications due to the need not only for structural support, but also vascular membrane integrity and gas exchange. This requires a complex engineered interaction of multiple cell types in precise anatomical locations. In this article, we discuss the process of creating bioengineered lungs and the challenges inherent therein. We summarize the relevant literature for selecting appropriate lung scaffolds, creating decellularization protocols, and using bioreactors. The development of completely artificial lung substitutes will also be reviewed. Lastly, we describe the state of current research, as well as future studies required for bioengineered lungs to become a realistic therapeutic modality for end-stage lung disease. Applications of bioengineering may allow for earlier intervention in end-stage lung disease and have the potential to not only halt organ failure, but also significantly reverse disease progression.

Objectives/UNASSIGNED:Proning patients with acute respiratory distress syndrome (ARDS) has been associated with increased survival, though little data exists evaluating the safety and feasibility of proning ARDS patients on extracorporeal membrane oxygenation (ECMO). Methods/UNASSIGNED:, 2020 was performed. All proning events were evaluated for complications, as well as change in compliance, sweep, oxygenation and flow. The primary outcome of this study was the rate major morbidity associated with proning while on ECMO. Results/UNASSIGNED:of 86 pre to 103 post (p<0.0001). Mean ECMO flow was unchanged. Conclusions/UNASSIGNED:Proning in patients with ARDS on ECMO is safe with an associated improvement in lung mechanics. With careful planning and coordination, these data support the practice of appropriately proning patients with severe ARDS, even if they are on ECMO.

BACKGROUND:Our objective was to report the incidence, management, and outcomes of patients who developed a secondary pneumothorax while admitted for coronavirus disease 2019 (COVID-19). METHODS:A single-institution, retrospective review of patients admitted for COVID-19 with a diagnosis of pneumothorax between March 1, 2020, and April 30, 2020, was performed. The primary assessment was the incidence of pneumothorax. Secondarily, we analyzed clinical outcomes of patients requiring tube thoracostomy, including those requiring operative intervention. RESULTS:From March 1, 2020, to April 30, 2020, 118 of 1595 patients (7.4%) admitted for COVID-19 developed a pneumothorax. Of these, 92 (5.8%) required tube thoracostomy drainage for a median of 12 days (interquartile range 5-25 days). The majority of patients (95 of 118, 80.5%) were on mechanical ventilation at the time of pneumothorax, 17 (14.4%) were iatrogenic, and 25 patients (21.2%) demonstrated tension physiology. Placement of a large-bore chest tube (20 F or greater) was associated with fewer tube-related complications than a small-bore tube (14 F or less) (14 vs 26 events, P = .011). Six patients with pneumothorax (5.1%) required operative management for a persistent alveolar-pleural fistula. In patients with pneumothorax, median hospital stay was 36 days (interquartile range 20-63 days) and in-hospital mortality was significantly higher than for those without pneumothorax (58% vs 13%, P < .001). CONCLUSIONS:The incidence of secondary pneumothorax in patients admitted for COVID-19 is 7.4%, most commonly occurring in patients requiring mechanical ventilation, and is associated with an in-hospital mortality rate of 58%. Placement of large-bore chest tubes is associated with fewer complications than small-bore tubes.

BACKGROUND:Severe coronavirus disease 2019 (COVID-19) can cause acute respiratory failure requiring mechanical ventilation. Venovenous (VV) extracorporeal membrane oxygenation (ECMO) has been used in patients in whom conventional mechanical ventilatory support has failed. To date, published data have focused on survival from ECMO and survival to discharge. In addition to survival to discharge, this study reports 1-year follow-up data for patients who were successfully discharged from the hospital. METHODS:A single-institution, retrospective review of all patients with severe COVID-19 who were cannulated for VV-ECMO between March 10, 2020 and May 1, 2020 was performed. A multidisciplinary ECMO team evaluated, selected, and managed patients with ECMO support. The primary outcome of this study was survival to discharge. Available 1-year follow-up data are also reported. RESULTS:A total of 30 patients were supported with VV-ECMO, and 27 patients (90%) survived to discharge. All patients were discharged home or to acute rehabilitation on room air, except for 1 patient (3.7%), who required supplemental oxygen therapy. At a median follow-up of 10.8 months (interquartile range [IQR], 8.9-14.4 months) since ECMO cannulation, survival was 86.7%, including 1 patient who underwent lung transplantation. Of the patients discharged from the hospital, 44.4% (12/27) had pulmonary function testing, with a median percent predicted forced expiratory volume of 100% (IQR, 91%-110%). For survivors, a 6-minute walk test was performed in 59.3% (16/27), with a median value of 350 m (IQR, 286-379 m). CONCLUSIONS:A well-defined patient selection and management strategy of VV-ECMO support in patients with severe COVID-19 resulted in exceptional survival to discharge that was sustained at 1-year after ECMO cannulation.

BACKGROUND:Our objective is to assess the feasibility and safety of discharging patients by postoperative day one (POD1) after robotic segmentectomy and lobectomy, and to describe outcomes for patients. METHODS:A retrospective analysis was made of a prospectively collected database of a quality improvement initiative by a single surgeon. Factors associated with discharge by POD1 were evaluated using a multivariate logistic regression model. RESULTS:From January 2018 to July 2020, of 253 patients who underwent robotic anatomic pulmonary resection, 134 (53%) were discharged by POD1, 67% after segmentectomy and 41% after lobectomy. Discharge by POD1 improved with experience and was achieved in 97% of patients after segmentectomy and 68% after lobectomy in the final quartile. Thirty-one patients (12%) were discharged home with a chest tube, including 7 (2.8%) on POD1. On multivariate analysis, never smokers and segmentectomy were associated with discharge by POD1. Conversely, decreased baseline performance status and perioperative complications were associated with discharge after POD1. There were 10 minor morbidities (4%), 6 major morbidities (2.4%), and no 30- or 90-day mortality. There were 4 readmissions (1.6%), of which 1 (0.4%) was after POD1 discharge. Patient satisfaction remained high throughout the study period. CONCLUSIONS:With experience and communication, select patients can be discharged home on POD1 after robotic segmentectomy and lobectomy with excellent outcomes and high satisfaction. Discharge by POD1 was associated with never smokers and segmentectomy, and inversely associated with decreased baseline performance status and perioperative complications.