The impact of ex vivo lung perfusion location on lung transplant outcomes.

BACKGROUND: Ex vivo lung perfusion (EVLP) conducted outside of the transplant center has increased in recent years to mitigate its limitation by resources and expertise. We sought to evaluate EVLP performed at transplant centers and externally. METHODS: Lung transplant recipients were identified from the United Network for Organ Sharing Database. Recipients were then stratified into two groups based where they were perfused: Transplant Program (TP) or External Perfusion Centers (EPC). The groups were assessed with comparative statistics and long-term survival was assessed by Kaplan-Meier method. The groups were then 1:1 propensity and this process was repeated. RESULTS: EPC use was generally restricted to the Southern United States. Following matching, there were no significant differences in post-operative outcomes to include post-operative stroke, dialysis, airway dehiscence, ECMO use, ventilator use or incidence of primary graft dysfunction Grade 3. Adjusted 3-year survival was 68.9% (95% Confidence Interval [CI]: 60.9%-77.9%) for the TP group and 67.6% (95% CI: 61.0%-74.9%) for the EPC group (p = 0.69). In allografts with extended ischemia (14+ h), those in the TP group had significantly longer length of stay, prolonged ventilation and treated rejection in the 1st year, though no significant difference in mid-term survival (p = 0.66). CONCLUSION: EVLP performed at an EPC can be carried out with results and survival similar to allografts undergoing EVLP at a TP. EPCs will extend the valuable resource of EVLP to lung transplant programs without the resources to perform EVLP.

Extended ischemic times during ex vivo lung perfusion is not associated with increased mortality.

BACKGROUND: The purpose of this study was to identify the association of increasing ischemic times in recipients who receive lungs evaluated by ex vivo lung perfusion (EVLP) and their association with outcomes following lung transplantation. METHODS: Lung transplant recipients who received an allograft evaluated by EVLP were identified from the United Network for Organ Sharing (UNOS) Database from 2016-2023. Recipients were stratified into three groups based on total ischemic time (TOT): short TOT (STOT, 0 to <7 h), medium TOT (MTOT, 7> to <14 h), and long TOT (LTOT, +14 h). The groups were assessed with comparative statistics and Kaplan-Meier methods. A Cox regression was created to determine the association of ischemic time in EVLP donors and long-term mortality. RESULTS: Recipients in the LTOT group had significantly longer length of stay and post-operative extracorporeal membrane use at 72 h (p < 0.05 for both). Additionally, they had nonsignificant increases in rate of stroke (4.7%, p = 0.05) and primary graft dysfunction grade 3 (PGD3, 27.5%, p = 0.082). However, there was no significant difference in hospital mortality or mid-term survival (p > 0.05 for both). On multivariable analysis, ischemic time was not associated with increased mortality whereas increasing recipient age, preoperative ECMO use and donation after circulatory death donors were (p < 0.05 for all). CONCLUSIONS: If EVLP technology is available, under certain circumstances, surgeons should not be dissuaded from using an allograft with extended ischemic time.

The Impact of Bicuspid Aortic Valve on Long-term Outcomes After Bioprosthetic Valve Replacement.

BACKGROUND: There are limited data comparing the outcomes of aortic valve replacement surgery between patients with bicuspid aortic valve (BAV) vs tricuspid aortic valve (TAV) morphology. METHODS: From January 2000 to June 2022, 1122 patients with TAV (n = 562) or BAV (n = 560) underwent surgical aortic valve replacement for aortic stenosis with the same type of bovine pericardial stented bioprosthesis. Propensity score matching identified 350 pairs by matching for age, sex, operative status, chronic lung disease, prior stroke, diabetes, ejection fraction, renal failure on dialysis, coronary artery disease, prior cardiac surgery, and concomitant procedures. The primary end points were long-term survival and reoperation. RESULTS: Perioperative outcomes, including reoperation for bleeding, atrial fibrillation, heart block requiring pacemaker, stroke, need for dialysis, and operative mortality, were similar between the matched groups. Survival at 10 years was 67% (95% CI, 59%-74%) in the BAV group and 54% (95% CI, 46%-61%) in the TAV group (P = .001). BAV valve was a significant protective factor for late mortality, with a hazard ratio of 0.60 (95% CI, 0.45-0.81; P < .001). Risk factors for late mortality included age, chronic lung disease, low ejection fraction, and renal failure on dialysis. Cumulative incidence of aortic valve reintervention at 10 years was similar between the groups at 10% in the BAV group and 4.9% in the TAV group (P = .55). CONCLUSIONS: Patients with BAV likely could not be considered the same as patients with TAV when deciding on the approach of aortic valve intervention.

Ex Vivo Lung Perfusion and Primary Graft Dysfunction Following Lung Transplantation: A Contemporary United Network for Organ Sharing Database Analysis.

Background: Primary graft dysfunction (PGD) has detrimental effects on recipients following lung transplantation. Here, we determined the contemporary trends of PGD in a national database, factors associated with the development of PGD grade 3 (PGD3) and ex vivo lung perfusion's (EVLP) effect on this harmful postoperative complication. Methods: The United Network for Organ Sharing database was queried from 2015 to 2023, and recipients were stratified into No-PGD, PGD1/2, or PGD3. The groups were analyzed with comparative statistics, and survival was determined with Kaplan-Meier methods. Multivariable Cox regression was used to determine factors associated with increased mortality. PGD3 recipients were then stratified based on EVLP use prior to transplantation, and a 3:1 propensity match was performed to determine outcomes following transplantation. Finally, logistic regression models based on select criteria were used to determine risk factors associated with the development of PGD3 and mortality within 1 year. Results: A total of 21.4% of patients were identified as having PGD3 following lung transplant. Those with PGD3 suffered significantly worse perioperative morbidity, mortality, and had worse long-term survival. PGD3 was also independently associated with increased mortality. Matched EVLP PGD3 recipients had significantly higher use of ECMO postoperatively; however, they did not suffer other significant morbidity or mortality as compared to PGD3 recipients without EVLP use. Importantly, EVLP use prior to transplantation was significantly associated with decreased likelihood of PGD3 development, while having no significant association with early mortality. Conclusions: EVLP is associated with decreased PGD3 development, and further optimization of this technology is necessary to expand the donor pool.

Intraoperative Embolization during Inferior Vena Cava Tumor Thrombectomy for Renal Cell Carcinoma.

Intraoperative tumor thrombus embolization is a potentially lethal complication during inferior vena cava (IVC) thrombectomy for renal cell carcinoma (RCC). Intraoperative embolization is uncommonly encountered because IVC thrombectomy surgical technique is focused on avoiding this complication. Nonetheless, early recognition of embolization is essential so that emergent management can be instituted. When available, cardiopulmonary bypass (CPB) and embolectomy should be considered the gold standard for the management of intraoperative embolization. Several novel endovascular techniques are also available for selective use. We present the case of a 71-year-old female with a right renal mass and level II (retrohepatic) IVC tumor thrombus. During cytoreductive nephrectomy and IVC thrombectomy, tumor embolization was diagnosed during a period of hypotension based on transesophageal echocardiographic finding of new thrombus within the right atrium. This prompted sternotomy, CPB, and pulmonary artery embolectomy. The patient survived this embolization event and has a complete response to systemic therapy 9 months postoperatively. This case serves as the framework for a discussion on management considerations surrounding intraoperative embolization during IVC thrombectomy.