Outcomes of Extremely Prolonged (> 50 d) Venovenous Extracorporeal Membrane Oxygenation Support.

OBJECTIVES: There has been a sustained increase in the utilization of venovenous extracorporeal membrane oxygenation (ECMO) over the last decade, further exacerbated by the COVID-19 pandemic. We set out to describe our institutional experience with extremely prolonged (> 50 d) venovenous ECMO support for recovery or bridge to lung transplant candidacy in patients with acute respiratory failure. DESIGN: Retrospective cohort study. SETTING: A large tertiary urban care center. PATIENTS: Patients 18 years or older receiving venovenous ECMO support for greater than 50 days, with initial cannulation between January 2018 and January 2022. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred thirty patients were placed on venovenous ECMO during the study period. Of these, 12 received prolonged (> 50 d) venovenous ECMO support. Eleven patients (92%) suffered from adult respiratory distress syndrome (ARDS) secondary to COVID-19, while one patient with prior bilateral lung transplant suffered from ARDS secondary to bacterial pneumonia. The median age of patients was 39 years (interquartile range [IQR], 35-51 yr). The median duration of venovenous ECMO support was 94 days (IQR, 70-128 d), with a maximum of 180 days. Median time from intubation to cannulation was 5 days (IQR, 2-14 d). Nine patients (75%) were successfully mobilized while on venovenous ECMO support. Successful weaning of venovenous ECMO support occurred in eight patients (67%); 6 (50%) were bridged to lung transplantation and 2 (17%) were bridged to recovery. Of those successfully weaned, seven patients (88%) were discharged from the hospital. All seven patients discharged from the hospital were alive 6 months post-decannulation; 83% (5/6) with sufficient follow-up time were alive 1-year after decannulation. CONCLUSIONS: Our experience suggests that extremely prolonged venovenous ECMO support to allow native lung recovery or optimization for lung transplantation may be a feasible strategy in select critically ill patients, further supporting the expanded utilization of venovenous ECMO for refractory respiratory failure.

Simultaneous heart-kidney transplant in patients with borderline estimated glomerular filtration rate without dialysis dependency.

BACKGROUND: Appropriate patient selection for simultaneous heart-kidney transplantation (sHK) in patients with moderate renal dysfunction remains challenging. METHODS: From the United Network for Organ Sharing database (2003-2020), we identified 5678 adults with an estimated pre-transplant glomerular filtration rate (eGFR) between 30 and 45 mL/min/1.73 m2 and no pre-transplant dialysis. Patients undergoing sHK (n = 293) were compared with those undergoing heart transplantation alone (n = 5385) using 1:3 propensity score matching. RESULTS: The sHK utilization rate increased from 1.8% in 2003 to 12.2% in 2020 (p < .001). After matching, 1 and 5-year survival was 87.7% (95% confidence interval [CI] 83.3-91.0) and 80.0% (95% CI 74.2-84.6) after sHK, and 87.3% (95% CI 85.2-89.1) and 71.8% (95% CI 68.4-74.9) after heart transplant alone (p = .04). In the subgroup analysis, sHK was associated with a 5-year survival benefit only in patients with 30 < eGFR ≤ 35 mL/min/1.73 m2 (p = .05) but not in those with 35 < eGFR < 45 mL/min/1.73 m2 (p = .45). Patients who underwent heart transplants alone also had a higher incidence of becoming chronic dialysis-dependent after transplant within 5-year follow-up (10.2%, 95% CI 8.0-12.6 vs. 3.8%, 95% CI 1.7-7.1, p = .004). The 5-year incidence of subsequent kidney waitlisting and transplants after heart transplants alone was 5.6% and 1.9%, respectively. CONCLUSION: Among propensity-matched patients without pre-transplant dialysis, compared to heart transplants alone, sHK had improved 5-year survival in those with 30 < eGFR ≤ 35 but not in those with 35 < eGFR < 45 mL/min/1.73 m2 . One-year survival was similar irrespective of eGFR. Receiving a kidney after a heart transplant alone is rare under the current allocation system.

Long-term outcomes after heart transplantation using ex vivo allograft perfusion in standard risk donors: A single-center experience.

INTRODUCTION: The Organ Care System (OCS) is an ex vivo perfusion platform for donor heart preservation. Short/mid-term post-transplant outcomes after its use are comparable to standard cold storage (CS). We evaluated long-term outcomes following its use. METHODS: Between 2011 and 2013, 38 patients from a single center were randomized as a part of the PROCEED II trial to receive allografts preserved with CS (n = 19) or OCS (n = 19). Endpoints included 8-year survival, survival free from graft-related deaths, freedom from cardiac allograft vasculopathy (CAV), non-fatal major adverse cardiac events (NF-MACE), and rejections. RESULTS: Eight-year survival was 57.9% in the OCS group and 73.7% in the CS group (p = .24). Freedom from CAV was 89.5% in the OCS group and 67.8% in the CS group (p = .13). Freedom from NF-MACE was 89.5% in the OCS group and 67.5% in the CS group (p = .14). Eight-year survival free from graft-related death was equivalent between the two groups (84.2% vs. 84.2%, p = .93). No differences in rejection episodes were observed (all p > .5). CONCLUSIONS: In select patients receiving OCS preserved allografts, late post-transplant survival trended lower than those transplanted with an allograft preserved with CS. This is based on a small single-center series, and larger numbers are needed to confirm these findings.

Heart transplantation after total artificial heart bridging-Outcomes over 15 years.

BACKGROUND: Data are limited on outcomes after heart transplantation in patients bridged-to-transplantation (BTT) with a total artificial heart (TAH-t). METHODS: The UNOS database was used to identify 392 adult patients undergoing heart transplantation after TAH-t BTT between 2005 and 2020. They were compared with 11 014 durable left ventricular assist device (LVAD) BTT patients and 22 348 de novo heart transplants (without any durable VAD or TAH-t BTT) during the same period. RESULTS: TAH-t BTT patients had increased dialysis dependence compared to LVAD BTT and de novo transplants (24.7% vs. 2.7% vs. 3.8%) and higher levels of baseline creatinine and total bilirubin (all p < .001). After transplantation, TAH-t BTT patients were more likely to die from multiorgan failure in the first year (25.0% vs. 16.1% vs. 16.1%, p = .04). Ten-year survival was inferior in TAH-t BTT patients (TAH-t BTT 53.1%, LVAD BTT 61.8%, De Novo 62.6%, p < .001), while 10-year survival conditional on 1-year survival was similar (TAH-t BTT 66.8%, LVAD BTT 68.7%, De Novo 69.0%, all p > .20). Among TAH-t BTT patients, predictors of 1-year mortality included higher baseline creatinine and total bilirubin, mechanical ventilation, and cumulative center volume <20 cases of heart transplantation involving TAH-t BTT (all p < .05). CONCLUSION: Survival after TAH-t BTT is acceptable, and patients who survive the early postoperative phase experience similar hazards of mortality over time compared to de novo transplant patients and durable LVAD BTT patients.

Size matching in heart transplantation: Is predicted heart mass the optimal method in a United Kingdom cohort?

Predicted heart mass (PHM) equations have been proposed as an alternative method for size matching in heart transplantation. We assessed association between donor-recipient size mismatch, defined using PHM equations, and survival post-heart transplant in the United Kingdom. Data from all adult patients who received a heart transplant between 1995 and 2017 were obtained from the United Kingdom Transplant Registry. PHM was calculated using published equations. Primary outcome was 1-year survival post-heart transplantation. Recipients of undersized organs had reduced 1-year survival (HR 1.31, 95% CI 1.03-1.67, p = .03). Oversizing had no impact on survival (HR 0.99, 95% CI 0.78-1.26, p = .96). Gender mismatching had no impact on survival in the cohort matched by PHM (HR 1.12, 95% CI 0.86-1.47, p = .4). In recipients without pulmonary hypertension, undersizing by PHM had no impact on 1-year survival (HR 0.95, 95% CI 0.61-1.49, p = .83). In recipients with pulmonary hypertension, oversizing donor RV by using PHM RV equation (PHMRV ) results in improved survival at 1 year (HR 0.65, 95% CI 0.5-0.83, p = .001). In conclusion, receiving an organ undersized by PHM was associated with decreased 1-year survival. Subgroup analyses demonstrated that undersizing only impacted survival in recipients with pulmonary hypertension and that these recipients had improved outcomes if they received an organ with an RV oversized by >10% by PHMRV .

Spontaneous diaphragmatic rupture as a complication following lung transplantation.

Spontaneous diaphragm rupture is a rare but potentially life-threatening condition, requiring urgent surgical intervention. Here we present two patients who developed spontaneous right hemidiaphragm rupture with abdominal visceral herniation into the thoracic cavity several days following bilateral lung transplantation, as an unusual complication. Both patients' surgeries were performed through bilateral anterior thoracotomies and were uneventful. There may be an association with this complication and patients suffering with emphysema, typically receiving donor lungs smaller than their native lungs, and with significant pretransplant exposure to steroids, factors that when combined may contribute to an increased risk of spontaneous diaphragmatic rupture in the absence of a significant precipitant. If a similar clinical picture is seen, teams managing lung transplant recipients should be aware of this potential complication and recognize the need for urgent intervention.

Transfer of Patients With Cardiogenic Shock Using Veno-Arterial Extracorporeal Membrane Oxygenation.

OBJECTIVES: The authors describe the experience of patient transfer on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) used as a salvage therapy for refractory cardiogenic shock, examining feasibility and long-term outcomes. DESIGN: A retrospective case series. SETTING: A tertiary referral cardiothoracic transplantation center. PARTICIPANTS AND INTERVENTIONS: Since 2012, the authors' multidisciplinary team has traveled to the referring center of 15 patients referred with refractory cardiogenic shock. Of these, 13 were instituted on VA ECMO support (8 peripheral and 5 central) and subsequently transferred to the authors' center. A further 11 patients were transferred to the authors' institution by the referring team, already having been placed on VA-ECMO (8 peripheral and 3 central). MEASUREMENTS AND MAIN RESULTS: All patients were safely transferred. The distance travelled ranged from 16 to 341 miles. The median duration of support on VA-ECMO was 4 days, ranging from 1 to 24 days. The VA-ECMO support was weaned, or the patient underwent a definitive surgical management (including 4 undergoing cardiac transplantation and 3 pulmonary endarterectomy) in 15 (62.5%) patients. The median intensive care unit stay was 15 days (range 1-109). Overall 30-day survival for this patient cohort was 69.6% with 1-year survival of 59.8%. For patients who were weaned from VA-ECMO, the 30-day survival was 100% and 1-year survival 92.9%. CONCLUSIONS: The authors' experience demonstrates the feasibility and survival benefit of a salvage VA-ECMO retrieval service for carefully selected patients with refractory cardiogenic shock. The authors suggest that a system based on the model of nationally commissioned severe respiratory failure services could be organized to support the transfer of these patients.

Catastrophic sickling crisis in patient undergoing cardiac transplantation with sickle cell trait.

There is debate in the literature regarding management of patients with sickle cell trait (SCT) undergoing cardiac surgery, since it is recognized that cardiopulmonary bypass presents many precipitating risk factors for a sickling crisis. Despite this, many report successful outcomes without any modification to perioperative management. A 49-year-old woman with SCT (HbS 38%) with postpartum cardiomyopathy underwent cardiac transplantation. The patient was cooled to 34.0°C and retrograde cold blood cardioplegia was infused continuously. The cold ischemic time was 219 minutes and warm ischemic time 46 minutes. After weaning from bypass, she developed global cardiac dysfunction requiring veno-arterial extracorporeal membrane oxygenation. The circuit suddenly stopped, requiring emergency reinstitution of bypass; the circuit had clotted. Transesophageal-echocardiogram revealed thrombus within the left atrium and ventricle. There was no recovery of cardiac function and the patient developed multiorgan failure. At postmortem there was extensive myocardial infarction with evidence of widespread catastrophic intravascular red-cell sickling. This case highlights the danger of complacency in patients with SCT, offering a learning opportunity for the cardiothoracic community to highlight the most serious complication that can occur in this group of patients. We have learned that SCT and cardiac surgery is not a benign combination.

Three consecutive cases of fatal intraoperative intracardiac thrombosis associated with the initiation of venoarterial extracorporeal membrane oxygenation in the presence of aprotinin.

Central venoarterial extracorporeal membrane oxygenation has been used since the 1970s to support patients with cardiogenic shock following cardiac surgery. Despite this, in-hospital mortality is still high, and although rare, thrombus within the cardiac chambers or within the extracorporeal membrane oxygenation circuit is often fatal. Aprotinin is an antifibrinolytic available in Europe and Canada, though not currently in the United States. Due to historical safety concerns, use of aprotinin is generally limited and is commonly reserved for patients with the highest bleeding risk. Given the limited availability of aprotinin over the last decade, it is not surprising to find a complete absence of literature describing the use of venoarterial extracorporeal membrane oxygenation in the presence of aprotinin. We present three consecutive cases of rapid fatal intraoperative intracardiac thrombosis associated with post-cardiotomy central venoarterial extracorporeal membrane oxygenation in patients receiving aprotinin.

Robotic-assisted lung transplantation: First in man.

Lung transplantation remains the best option for patients with end-stage lung disease. However, this operation has historically carried significant potential morbidity. To improve near-term patient outcomes, attempts have been made to decrease invasiveness, but this is limited by the complex nature of the operation and the anatomy of the chest. To facilitate further reduction in incision size and augment our existing minimally invasive approach, we developed a novel technique utilizing the Da Vinci robotic system to implant a right lung in a 69-year-old recipient.

Heart transplantation in patients from socioeconomically distressed communities.

BACKGROUND: Studies examining heart transplantation disparities have focused on individual factors such as race or insurance status. We characterized the impact of a composite community socioeconomic disadvantage index on heart transplantation outcomes. METHODS: From the Scientific Registry of Transplant Recipients (SRTR), we identified 49,340 primary, isolated adult heart transplant candidates and 32,494 recipients (2005-2020). Zip code-level socioeconomic disadvantage was characterized using the Distressed Community Index (DCI: 0-most prosperous, 100-most distressed) based on education, poverty, unemployment, housing vacancies, median income, and business growth. Patients from distressed communities (DCI ≥ 80) were compared to all others. RESULTS: Patients from distressed communities were more often non-white, less educated, and had public insurance (all p < 0.01). Distressed patients were more likely to require ventricular assist devices at listing (29.4 vs 27.1%) and before transplant (44.8 vs 42.0%, both p < 0.001), and they underwent transplants at lower-volume centers (23 vs 26 cases/year, p < 0.01). Distressed patients had higher 1-year waitlist mortality or deterioration (12.3% [95% confidence interval (CI) 11.6-13.0] vs 10.9% [95% CI 10.5-11.3]) and inferior 5-year survival (75.3% [95% CI 74.0-76.5] vs 79.5% [95% CI 79.0-80.0]) (both p < 0.001). After adjustment, living in a distressed community was independently associated with an increased risk of waitlist mortality or deterioration hazard ratio (HR 1.10, 95% CI 1.02-1.18) and post-transplant mortality (HR 1.13, 95% CI 1.06-1.20). CONCLUSIONS: Patients from socioeconomically distressed communities have worse waitlist and post-transplant mortality. These findings should not be used to limit access to heart transplantation, but rather highlight the need for further studies to elucidate mechanisms underlying the impact of community-level socioeconomic disparity.

Limited cumulative experience with ex vivo lung perfusion is associated with inferior outcomes after lung transplantation.

OBJECTIVE: Ex vivo lung perfusion (EVLP) allows for prolonged preservation and evaluation/resuscitation of donor lungs. We evaluated the influence of center experience with EVLP on lung transplant outcomes. METHODS: We identified 9708 isolated, first-time adult lung transplants from the United Network for Organ Sharing database (March 1, 2018-March 1, 2022), 553 (5.7%) involved using donor lungs after EVLP. Using the total volume of EVLP lung transplants per center during the study period, centers were dichotomized into low- (1-15 cases) and high-volume (>15 cases) EVLP centers. RESULTS: Forty-one centers performed EVLP lung transplants, including 26 low-volume and 15 high-volume centers (median volume, 3 vs 23 cases; P < .001). Recipients at low-volume centers (n = 109) had similar baseline comorbidities compared with high-volume centers (n = 444). Low-volume centers used numerically more donation after circulatory death donors (37.6 vs 28.4%; P = .06) and more donors with Pao2/Fio2 ratio <300 (24.8 vs 9.7%; P < .001). After EVLP lung transplants, low-volume centers had worse 1-year survival (77.8% vs 87.5%; P = .007), with an adjusted hazard ratio of 1.63 (95% CI, 1.06-2.50, adjusting for recipient age, sex, diagnosis, lung allocation score, donation after circulatory death donor, donor Pao2/Fio2 ratio, and total annual lung transplant volume per center). When compared to non-EVLP lung transplants, 1-year survival of EVLP lung transplants was significantly worse at low-volume centers (adjusted hazard ratio, 2.09; 95% CI, 1.47-2.97) but similar at high-volume centers (adjusted hazard ratio, 1.14; 95% CI, 0.82-1.58). CONCLUSIONS: The use of EVLP in lung transplantation remains limited. Increasing cumulative EVLP experience is associated with improved outcomes of lung transplantation using EVLP-perfused allografts.

Impact of minimally invasive lung transplantation on early outcomes and analgesia use: A matched cohort study.

BACKGROUND: Minimally invasive (MI) approaches to lung transplantation (LTx) offer the prospect of faster recovery compared to traditional incisions, however, little data exist describing the impact of surgical technique on early outcomes and analgesia use. METHODS: A prospectively maintained institutional registry identified 170 patients who underwent LTx between January, 2017 and June, 2022. Post-COVID acute respiratory distress syndrome, repeat, and multiorgan transplants were excluded (n = 27) leaving 37 MILTx and 106 traditional LTx patients. Propensity score matching by age, sex, body mass index, diagnosis, lung allocation score, double vs. single lung, hypertension, diabetes, and hospitalization status created 37 pairs. RESULTS: Before matching, MILTx patients were more often male (70% vs 43%) and more likely to receive grafts from younger (31 vs 42 years), circulatory death donors (19% vs 6%) compared with traditional LTx patients (all p < 0.05). After matching, there were no differences in graft warm ischemia or operative duration (both p > 0.05). Postoperatively, MILTx experienced shorter intensive care unit (ICU) (4.3 [IQR 3.1-5.5] vs 8.2 [IQR 3.7-10.8] days) and hospital lengths of stay (LOS) (13 [IQR 11-15] vs 17 [IQR 12-25] days) (both p < 0.05). Among patients surviving to discharge, MILTx patients required fewer opioid prescriptions at discharge (38% vs 66%, p = 0.008) and had improved pulmonary function at 3 months (Forced expiratory volume in 1 second 82 [IQR 72-102] vs 77 [IQR 52-88]% predicted; forced vital capacity 78 [IQR 65-92] vs 70 [IQR 62-80]% predicted] (both p < 0.05). CONCLUSION: Minimally invasive LTx techniques demonstrate potential advantages over traditional approaches, including reduced ICU and hospital LOS, lower opioid use on discharge, and improved early pulmonary function.

Temporary Left Ventricular Support Device as a Bridge to Heart-Liver or Heart-Kidney Transplant: Pushing the Boundaries of Temporary Support.

In patients with severe cardiogenic shock, temporary mechanical circulatory support has become a viable strategy to bridge patients to heart transplantation. However, end-stage heart failure is often associated with progressive organ dysfunction of the liver or kidney. This can require a dual organ transplant for definitive management (combined heart-liver [HL] or heart-kidney [HK] transplantation). We evaluated temporary mechanical support to bridge patients to HL or HK transplant at a single, high-volume center. All patients who underwent Impella 5.0 placement from January 2014 to October 2018 were identified. From this dataset, patients who underwent placement as a bridge to dual organ transplant were selected, as were those who underwent Impella as a bridge to isolated heart transplant. Over the 5 years of evaluation, 104 patients underwent Impella 5.0 placement. Of these, 14.3% (n = 15) were identified as potential dual organ recipients (11 HK, 4 HL). In total, 80% (12/15) successfully underwent dual organ transplant (8 HK, 4 HL), with a 1-year survival of 100% in both transplanted groups. Among patients undergoing Impella 5.0 placement as a bridge to isolated heart transplant (n = 33), 78.8% (26) were successfully bridged, and 1-year survival was 92% after transplantation. Impella 5.0 is a viable bridge to dual organ transplantation and should be considered as a management strategy in these complex patients at experienced institutions.

Lung transplantation outcomes in patients from socioeconomically distressed communities.

BACKGROUND: Previous studies have demonstrated racial and gender disparities in lung allocation, but contemporary data regarding socioeconomic disparities in post-transplant outcomes are lacking. We evaluated the impact of a composite socioeconomic disadvantage index on post-transplant outcomes. METHODS: The Scientific Registry of Transplant Recipients identified 27,763 adult patients undergoing isolated primary lung transplantation between 2005 and 2020. Zip code-level socioeconomic distress was characterized using the Distressed Communities Index (DCI: 0-no distress, 100-severe distress) based on education level, poverty, unemployment, housing vacancies, median income, and business growth, and patients were stratified into high (DCI ≥60) or low (DCI <60) distressed groups. RESULTS: Recipients from high-distress communities (n = 8006, 28.8%) were younger (59years [interquartile range {IQR} 50-64] vs 61years [IQR 52-66]), less often white (73 vs 85%), less likely to have a college degree (45 vs 59%), and more likely to have public insurance (57 vs 49%, all p < 0.001) compared to those from low-distress communities. Additionally, high-distress recipients were more likely to have group A diagnoses (32 vs 27%) and undergo bilateral lung transplants (72.4 vs 69.3%, all p < 0.001). Post-transplant survival at 5years was 55.7% (95% confidence interval [CI]: 54.4-56.9) in high-distress recipients and 58.2% (95% CI: 57.4-58.9) in low-distress recipients (p = 0.003). After adjustment, high distress level was independently associated with an increased risk of 5-year mortality (hazard ratio:1.09, 95% CI:1.04-1.15). CONCLUSIONS: Recipients from distressed communities are at increased mortality risk following lung transplantation. Efforts should be focused on increased resource allocation and further study to better understand factors which may mitigate this disparity.

Real-time transcription polymerase chain reaction cycle threshold values as criteria for utilization of incidental COVID-19 positive lung donors.

Shortage of organ donors is an ongoing limiting factor in lung transplantation (LT). Despite increasing prevalence of asymptomatic COVID-19 infection, positive COVID-19 testing from a potential donor remains a contraindication at many LT centers. In this report, we present the outcomes of LT utilizing an algorithm based on donor clinical presentation, and COVID-19 real-time reverse transcription polymerase chain reaction (RT-PCR) with cycle threshold (Ct) values evaluation. The Ct value threshold for organ acceptance was >35. A total of 8 COVID-positive donors were included. No donor-to-recipient transmissions of COVID-19 were observed. Short-term outcomes were comparable to those reported in pre-COVID literature. Survival-to-date is 100% with median POD of 161 days. Our findings support the safety and efficacy of utilizing our algorithm including Ct value threshold for selection of donors with incidental COVID-19 positive testing.

Risk of prolonged ischemic time linked to use of cardiopulmonary bypass during implantation for lung transplantation in the United Kingdom.

BACKGROUND: Some degree of ischemia is inevitable in organ transplantation, and for most, if not all organs, there is a relationship between ischemic time and transplant outcome. The contribution of ischemic time to lung injury is unclear, with conflicting recent data. In this study, we investigate the impact of ischemia time on survival after lung transplantation in a large national cohort. METHODS: We studied the outcomes for 1,565 UK adult lung transplants over a 12-year period, for whom donor, transplant, and recipient data were available from the UK Transplant Registry. We examined the effect of ischemia time (defined as donor cross-clamp to recipient reperfusion) and whether standard cardiopulmonary bypass was used using Cox proportional hazards models, adjusting for other risk factors. RESULTS: The total ischemic time increased from a median under 5 hours in 2003 to over 6.2 hours in 2013. Our findings show that, when the cardiopulmonary bypass was used, there was an increase in the hazard of death (of 13% [95% CI: 5%-21%] for 1-year patient survival) for each hour of total ischemic time. However, if the cardiopulmonary bypass was not used for implantation, this link disappeared-there was no statistically significant change in mortality with increasing ischemic time. CONCLUSIONS: We document that avoidance of bypass may remove ischemic time, within the limits of our observed range of ischemic times, as a risk factor for poor outcomes. Our data add to the evidence that bypass may be harmful to the donor lung.