Cytokines Removal During Ex-Vivo Lung Perfusion: Initial Clinical Experience.

Ex Vivo Lung Perfusion (EVLP) can be potentially used to manipulate organs and to achieve a proper reconditioning process. During EVLP pro-inflammatory cytokines have been shown to accumulate in perfusate over time and their production is correlated with poor outcomes of the graft. Aim of the present study is to investigate the feasibility and safety of cytokine adsorption during EVLP. From July 2011 to March 2020, 54 EVLP procedures have been carried out, 21 grafts treated with an adsorption system and 33 without. Comparing the grafts perfused during EVLP with or without cytokine adsorption, the use of a filter significantly decreased the levels of IL10 and GCSFat the end of the procedure. Among the 38 transplanted patients, the adsorption group experienced a significant decreased IL6, IL10, MCP1 and GCSF concentrations and deltas compared to the no-adsorption group, with a lower in-hospital mortality (p = 0.03) and 1-year death rate (p = 0.01). This interventional study is the first human experience suggesting the safety and efficacy of a porous polymer beads adsorption device in reducing the level of inflammatory mediators during EVLP. Clinical impact of cytokines reduction during EVLP must be evaluated in further studies.

Viability assessment of livers donated after circulatory determination of death during normothermic regional perfusion.

BACKGROUND: Abdominal normothermic regional perfusion (A-NRP) allows in-situ reperfusion and recovery of abdominal organs metabolism in donors after circulatory death (DCD). Besides improving liver transplantation outcomes, liver injury and function can be assessed during A-NRP. METHODS: To refine liver viability assessment during A-NRP, prospectively collected data of controlled DCD donors managed at our Institution between October 2019 and May 2022 were retrospectively analyzed. Baseline characteristics, procedural variables and A-NRP parameters of donors whose liver was successfully transplanted were compared to those of donors whose liver was discarded. RESULTS: Twenty-seven donors were included and in 20 (74%) the liver was accepted (positive outcome). No differences between study groups were observed concerning baseline characteristics and warm ischemia times (WIT). Initial lactate levels were positively correlated with functional WIT (r2 = 0.4, p = 0.04), whereas transaminase levels were not. Blood flow during A-NRP was comparable, whereas oxygen consumption (VO2 ) was significantly higher in the positive outcome group after 1 h. Time courses of lactate, AST and ALT were significantly different between study groups (p < 0.001). Donors whose liver was accepted showed faster lactate clearance, a difference which was amplified by normalizing lactate clearance to oxygen delivery (DO2 ) and VO2 . Lactate clearance was correlated to transaminase levels and DO2 -normalized lactate clearance was the parameter best discriminating between study groups. CONCLUSIONS: DO2 -normalized lactate clearance may represent an element of liver viability assessment during A-NRP.

Awake cardiac surgery using the novel pectoralis-intercostal-rectus sheath (PIRS) plane block and subxiphoid approach.

BACKGROUND: Postoperative pain after cardiac surgery is a very important issue and affects recovery, risk of postoperative complications and quality of life. The pain management has been traditionally based on intravenous opioids with growing evidence suggesting the use of opioid-free and opioid-sparing techniques to reduce its adverse effects. CASE PRESENTATION: We report the case of a 75-year-old frail patient underwent awake mediastinal revision with subxiphoid access due to deep sternal wound infection using a pectoralis-intercostal rectus sheath (PIRS) plane block. During the procedure the patient never reported pain receiving acetaminophen 1 g every 8 h for postoperative pain management without others pain relievers. CONCLUSION: Ultrasound guided PIRS block could be an effective and safe analgesic technique to manage sternal and subxiphoid drainage pain in patients undergoing cardiac surgery via subxiphoid approach.

Is there life on the airway tree? A pilot study of bronchial cell vitality and tissue morphology in the ex vivo lung perfusion (EVLP) era of lung transplantation.

BACKGROUND: Ex vivo lung perfusion (EVLP) is a relevant procedure to increase the lung donor pool but could potentially increase the airway tree ischemic injury risk. METHODS: This study aimed to evaluate the direct effect of EVLP on the airway tree by evaluating bronchial cell vitality and tissue signs of injury on a series of 117 bronchial rings collected from 40 conventional and 19 EVLP-treated lung grafts. Bronchial rings and related scraped bronchial epithelial cells were collected before the EVLP procedure and surgical anastomosis. RESULTS: The preimplantation interval was significantly increased in the EVLP graft group (p < 0.01). Conventional grafts presented cell viability percentages of 47.07 ± 23.41 and 49.65 ± 21.25 in the first and second grafts which did not differ significantly from the EVLP group (first graft 50.54 ± 25.83 and second graft 50.22 ± 20.90 cell viability percentage). No significant differences in terms of histopathological features (edema, inflammatory infiltrate, and mucosa ulceration) were observed comparing conventional and EVLP samples. A comparison of bronchial cell viability and histopathology of EVLP samples retrieved at different time intervals revealed no significant differences. Accordingly, major bronchial complications after lung transplant were not observed in both groups. CONCLUSIONS: Based on these data, we observed that EVLP did not significantly impact bronchial cell vitality and airway tissue preservation nor interfere with bronchial anastomosis healing, further supporting it as a safe and useful procedure.

Validation of a Simple, Rapid, and Cost-Effective Method for Acute Rejection Monitoring in Lung Transplant Recipients.

Despite advances in immunosuppression therapy, acute rejection remains the leading cause of graft dysfunction in lung transplant recipients. Donor-derived cell-free DNA is increasingly being considered as a valuable biomarker of acute rejection in several solid organ transplants. We present a technically improved molecular method based on digital PCR that targets the mismatch between the recipient and donor at the HLA-DRB1 locus. Blood samples collected sequentially post-transplantation from a cohort of lung recipients were used to obtain proof-of-principle for the validity of the assay, correlating results with transbronchial biopsies and lung capacity tests. The results revealed an increase in dd-cfDNA during the first 2 weeks after transplantation related to ischemia-reperfusion injury (6.36 ± 5.36%, p < 0.0001). In the absence of complications, donor DNA levels stabilized, while increasing again during acute rejection episodes (7.81 ± 12.7%, p < 0.0001). Respiratory tract infections were also involved in the release of dd-cfDNA (9.14 ± 15.59%, p = 0.0004), with a positive correlation with C-reactive protein levels. Overall, the dd-cfDNA percentages were inversely correlated with the lung function values measured by spirometry. These results confirm the value of dd-cfDNA determination during post-transplant follow-up to monitor acute rejection in lung recipients, achieved using a rapid and inexpensive approach based on the HLA mismatch between donor and recipient.

HLA-DRB1 mismatch-based identification of donor-derived cell free DNA (dd-cfDNA) as a marker of rejection in heart transplant recipients: A single-institution pilot study.

BACKGROUND: Donor-derived cell-free DNA (dd-cfDNA) is considered a reliable marker of organ damage with potential applications in the follow-up of transplant recipients. METHODS: In this work we present an assay based on the donor-recipient HLA-mismatch (human leukocyte antigen) at the HLA-DRB1 locus to monitor rejection by quantifying the percentage of dd-cfDNA using a droplet digital PCR (polymerase chain reaction) technique. A panel of probes targeting the HLA-DRB1 locus and covering >85% genetic variability was validated and used to assess dd-cfDNA levels in a prospective cohort of 19 adult heart transplant recipients (mean age 50.9±14.8 years). The assay was carried out on a total of 232 liquid biopsies collected at the same time as endomyocardial biopsy (EMB) during routine post-transplant follow-up. RESULTS: Results show a significant increase of dd-cfDNA related to ischemia-reperfusion injury (2.22±2.09%) and to acute cellular rejection (1.71±3.10%) compared to stable conditions (0.43±1.04%, p < 0.0001). On the contrary, no increase was observed during infections or vascular complications, underlining the potential role of this biomarker for rejection monitoring. With a cut-off of 0.11%, the test showed 70.8% specificity (95% CI, 58.17% - 81.40%) and 64.2% sensitivity (95% CI, 49.80% - 76.86%) in discriminating acute rejection from no rejection. CONCLUSIONS: These data demonstrate that this HLA mismatch-based droplet digital PCR method is effective for monitoring rejection in heart transplant recipients. Compared to next generation sequencing approaches, it is far more flexible, less expensive and provides faster results.

ECMO Support and Operator Safety in the Context of COVID-19 Outbreak: A Regional Center Experience.

Since the beginning of the COVID-19 emergency, the referral Intensive Care Unit for the Extracorporeal Membrane Oxygenation (ECMO) support of Piedmont Region (Italy), in cooperation with infectious disease specialists, perfusionists and cardiac surgeons, developed a protocol to guarantee operator safety during invasive procedures, among which the ECMO positioning or inter-hospital transport. The use of powered air-purifying respirators, filtering facepiece particles (FFP) 2-3 masks, protective suits, disposable sterile surgical gowns, and two pairs of sterile gloves as a part of a protocol seemed effective and feasible for trained healthcare workers and allow all the complex activities connected with the positioning of the ECMO support to be completed effectively. The simulation training on donning and doffing procedures and the presence of a dedicated team member to verify the compliance with the safety procedure effectively reassured operators and likely reduced the risk of self-contamination. From 1 March to 31 December 2020, we used the procedure in 35 severe acute respiratory distress syndrome (ARDS) patients and one acute respiratory failure caused by neoplastic total tracheal obstruction, all positive to COVID-19, to be connected to veno-venous ECMO in peripheral hospitals and centralized for ECMO management. This preliminary experience seems to confirm that the use of ECMO during COVID-19 outbreaks is feasible and the risks associated with its positioning and management are sustainable for the health-care workers and safe for patients.

A case series of novel coronavirus infection in heart transplantation from 2 centers in the pandemic area in the North of Italy.

BACKGROUND: Little is known about the coronavirus SARS-CoV-2 disease (COVID-19) in solid organ transplanted patients. We here report a series of heart transplanted patients with COVID-19 from two centers of Italy. METHODS: All heart transplanted patients of Transplant Centers of Bergamo and Torino with a microbiologically confirmed SARS-CoV-2 infection were enrolled. Data collection included clinical presentation, laboratory and radiological findings, treatment and outcome. Follow-up was performed by visit or phone. RESULTS: From February to March 2020 twenty-six heart transplanted patients (age 62±12 years; 77% males; time from transplant 10±10 years; 69% with comorbidities) had a microbiologically confirmed COVID-19. The most frequent symptom was fever, followed by cough. Seventeen patients had a pneumonia, 8 of them severe pneumonia. Seven patients died (27%) and 17 (65%) were hospitalized. Discontinuation of immunosuppression was associated with death (71 vs 21%, p=0.02). Conversely, all patients receiving steroids survived (p<0.001). Patients who received heart transplantation during COVID-19 outbreak survived and no acute graft rejection occurred. Patients who died were older than survivors, had a longer time from transplant and a worse clinical presentation at diagnosis. The current regimen enabled the prolonged survival and function of orthotopic cardiac xenografts in altogether 6 of 8 baboons, of which 4 were now added. These results exceed the threshold set by the Advisory Board of the International Society for Heart and Lung Transplantation. CONCLUSIONS: COVID-19 has a significant impact on long term heart transplanted patients. Conversely, SARS-CoV-2 infection seems to have a limited influence on more recent transplants. Our experience may suggest that heart transplantation programs can be maintained even during the pandemic phase if specific and tailored paths to prevent and to limit virus transmission are provided.

Interventricular Septal Rupture in a 62-Year-Old Man With Familial Amyloid Polyneuropathy.

Cardiac involvement in familial amyloid polyneuropathy consists of arrhythmias, conduction disturbances, and heart failure. To our knowledge, heart rupture has never been described in association with this condition. We report the case of a 62-year-old man with a 6-year history of refractory familial amyloid polyneuropathy who underwent liver transplantation. The operation was complicated by severe hypotension because the neuropathy involved the autonomic system. Perioperatively, the patient had a myocardial infarction, and during the next 10 days, a complete interventricular septal rupture developed, resulting in a systemic-to-pulmonary shunt. Coronary angiographic findings were normal. However, the shunt caused unstable hemodynamics, resulting in cardiogenic shock. An attempt to close the rupture percutaneously failed. The patient underwent successful heart transplantation 50 days later. Macroscopic examination of the explanted heart showed thickening of both ventricles, septal rupture, and a gray scar in the interventricular septum around the cavity. Histopathologic examination revealed intramural amyloid angiopathy. Our case shows that heart rupture can occur in patients with familial amyloid polyneuropathy who have no history of obstructive coronary artery disease, perhaps as a result of tissue fragility caused by amyloid angiopathy. Therefore, autonomic disturbances should be regarded with concern and promptly treated in the perioperative period.

Vanishing Middle Bronchus in Bilateral Lung Transplant After Ex Vivo Lung Perfusion.

Lung transplant has become the mainstay of therapy for most end-stage lung diseases. Airway complications are one of the most important problems during the first year after lung transplant. In this context, the most severe form of bronchial stenosis reported in the literature is vanishing bronchus syndrome, which is the obliteration with atresia of the ostium of a lobar bronchus, usually related to ischemia and infection. Ex vivo lung perfusion is a novel strategy forlung allograft preservation that keeps the organs at physiologic protective conditions. Nevertheless, many ex vivo systems work with lungs in supine position, and upperregions (middle lobe and lingula) can have lower perfusion supply, increasing the risk of a relative ischemia. We report a case of vanishing middle bronchus after ex vivo reconditioning bilateral lung transplant in a 45-year-old man with nonspecific interstitial pneumonia, whose posttransplant course was complicated by Aspergillusfumigatus infection.

Tailored combined cytomegalovirus management in lung transplantation: a retrospective analysis.

BACKGROUND: There is no univocal prophylactic regimen to prevent cytomegalovirus (CMV) infection/disease in lung transplantation (LT) recipients. The aim of this study is to evaluate short-term clinical outcomes of a tailored combined CMV management approach. METHODS: After 1-year follow up, 43 LT patients receiving combined CMV prophylaxis with antiviral agents and CMV-specific IgG were evaluated in a retrospective observational study. Systemic and lung viral infections were investigated by molecular methods on a total of 1134 whole blood and 167 bronchoalveolar lavage (BAL) and biopsy specimens. CMV immunity was assessed by ELISPOT assay. Clinical and therapeutic data were also evaluated. RESULTS: We found 2/167 cases of CMV pneumonia (1.2%), both in the donor-positive/recipient-positive (D+/R+) population, and 51/167 cases of CMV pulmonary infection (BAL positivity 30.5%). However, only 32/167 patients (19.1%) were treated due to their weak immunological response at CMV ELISPOT assay. Viremia ⩾100,000 copies/mL occurred in 33/1134 specimens (2.9%). Regarding CMV-serological matching (D/R), the D+/R- population had more CMV viremia episodes (p < 0.05) and fewer viremia-free days (p < 0.001). CONCLUSIONS: Compared to previous findings, our study shows a lower incidence of CMV pneumonia and viremia despite the presence of a substantial CMV load. In addition, our findings further confirm the D+/R- group to be a high-risk population for CMV viremia. Overall, a good immunological response seems to protect patients from CMV viremia and pneumonia but not from CMV alveolar replication. The reviews of this paper are available via the supplemental material section.

Extracorporeal membrane oxygenation after lung transplantation: risk factors and outcomes analysis.

BACKGROUND: Lung transplantation is the treatment of choice for end-stage pulmonary disease in selected patients. However, severe primary graft dysfunction is a significant complication of transplant and requires the implantation of an extracorporeal support. The aim of the study is to evaluate the impact of extracorporeal membrane oxygenation (ECMO) after transplant in our center. METHODS: From January 2008 till June 2018, 195 consecutive unselected patients receiving a lung transplant were considered. Mean age was 49±15 years. Main indications for transplant were idiopathic pulmonary fibrosis in 72 patients, chronic obstructive pulmonary disease in 60 patients, and cystic fibrosis in 40 patients. Prior to transplant, 18 patients were on mechanical ventilation and 14 were on ECMO. RESULTS: Twenty-five patients required venous-venous ECMO after transplant. Vascular disease as cause of transplant [relative risk (RR) 7.8, 95% CI: 1.5-41, P=0.02], donor age (RR 1.6, 95% CI: 1.03-2.3, P=0.03) and need for cardiopulmonary by-pass during transplant (RR 3.1, 95% CI: 1.02-9, P=0.04) were associated with ECMO implantation. Patients requiring post-transplant ECMO received more transfusions (P<0.01), had a longer mechanical ventilation (P<0.01) and ICU stay (P<0.01) and had a higher hospital mortality (P<0.01). Post-transplant ECMO significantly influenced one- and five-year survival [hazard ratio (HR) 5.5, 95% CI: 3-10, P<0.001 and HR 3.5, 95% CI: 2-6, P<0.001, respectively]. However, conditional survival after t months is similar for patients with or without post-transplant ECMO. CONCLUSIONS: In our experience, although ECMO is a reliable and effective strategy to support pulmonary function, severe graft dysfunction after lung transplantation still has a significant impact on early and late results.

Feasibility of lung microdialysis to assess metabolism during clinical ex vivo lung perfusion.

BACKGROUND: Lung metabolism during ex vivo lung perfusion (EVLP) is increasingly studied. Microdialysis (MD) allows metabolic monitoring by sampling parenchymal interstitial fluid. This study investigated lung metabolism using MD during EVLP and evaluated whether microdialysate metabolites could improve selection and discriminate outcome of donor lungs. METHODS: MD monitoring was used during 14 clinical EVLP procedures. Paired microdialysate and perfusate samples were analyzed for glucose, lactate, pyruvate, glutamate, and the lactate/pyruvate (L/P) ratio, and values that best discriminated an unfavorable outcome were determined. Outcome was defined as unfavorable (lungs not transplanted or transplanted with primary graft dysfunction at 72 hours ≥ 2) or favorable (lungs transplanted with primary graft dysfunction < 2). RESULTS: Microdialysate markers and the perfusate L/P ratio could discriminate unfavorable outcome with sensitivity and specificity of 0.85 and 0.81 for MD glutamate > 18.4 µmol/liter, 0.81 and 0.74 for MD lactate > 685 µmol/liter, 0.92 and 0.75 for MD glucose > 530 µmol/liter, 0.85 and 0.65 for MD pyruvate > 25 µmol/liter, and 0.73 and 0.67 for perfusate L/P ratio > 24.17. All microdialysate markers, perfusate and microdialysate L/P ratio, and perfusate lactate discriminated outcome when we limited analysis only to transplanted lungs. CONCLUSIONS: We report the use of MD to evaluate lung metabolism during clinical EVLP, demonstrating that MD metabolites can contribute to selection of reconditioned lungs and discriminate early outcome after transplantation. Furthermore, glutamate as a marker of lung injury during EVLP is proposed and could hence be used as a potential target for future therapies.

Left Ventricular Unloading during Peripheral Extracorporeal Membrane Oxygenator Support: A Bridge To Life In Profound Cardiogenic Shock.

A limit of peripheral veno-arterial Extracorporeal Membrane Oxigenator (VA-ECMO) is the inadequate unloading of the left ventricle. The increase of end-diastolic pressure reduces the possibility of a recovery and may cause severe pulmonary edema. In this study, we evaluate our results after implantation of VA-ECMO and Transapical Left Ventricular Vent (TLVV) as a bridge to recovery, heart transplantation or long-term left ventricular assit devices (LVAD). From 2011 to 2014, 24 consecutive patients with profound cardiogenic shock were supported by peripheral VA-ECMO as bridge to decision. In all cases, TLVV was implanted after a mean period of 12.2 ± 3.4 hours through a left mini-thoracotomy and connected to the venous inflow line of the VA-ECMO. Thirty-day mortality was 37.5% (9/24). In all patients, hemodynamics improved after TLVV implantation with an increased cardiac output, mixed venous saturation and a significant reduced heart filling pressures (p < .05). Recovery of the cardiac function was observed in 11 patients (11/24; 45.8%). Three patients were transplanted (3/24; 12.5%) and three patients (3/24; 12.5%) underwent LVAD implantation as destination therapy, all these patients were discharged from the hospital in good clinical conditions. In these critical patients, systematic TLVV improved hemodynamic seemed to provide better in hospital survival and chance of recovery, compared to VA-ECMO results in the treatment of cardiogenic shock reported in the literature . TLVV is a viable alternative to standard VA-ECMO to identify the appropriate long-term strategy (heart transplantation or long-term VAD) reducing the risk of treatment failure. A larger and multicenter experience is mandatory to validate these hypothesis.

Thrombosis in left ventricular assistance device with centrifugal technology: is early thrombolysis a better solution?

BACKGROUND: Continuous flow left ventricular assistance devices (CF-LVADs) have revolutionized the treatment of advanced heart failure. Pump replacement for thrombosis is a high-risk procedure with a high perioperative mortality rate with possible recurrence. We aim to summarize our experience using a conservative approach with medical therapy. METHODS: We retrospectively reviewed records of patients who experienced pump thrombosis after LVAD implantation with HeartWare HVAD at our institution, from November 2010 to March 2016. Device thrombosis (DT) was divided into suspected (SDT) and confirmed (CDT). A conservative approach using thrombolysis and heparin was used in all patients. RESULTS: A total of 32 HeartWare HVAD pumps were implanted. Mean age was 59 ± 10 years and the mean time on mechanical support was 19.29 months (±14.06). Pump thrombosis occurred in 7 patients (0.14 patients/year) after a mean time of 733 (231-1,606) days after LVAD implantation. Three out of 7 cases had thrombosis recurrence (43%). Overall 19 episodes were recorded (0.38 event per patient/year). Eighteen out of 19 thrombolytic treatments were successful (94.7%). No patient required LVAD replacement or transfusion of blood products. There was no significant difference in terms of survival between patients who experienced thrombotic events and patients who did not. No major complications related to thrombolysis were recorded. CONCLUSIONS: Systemic thrombolysis plus heparin was an excellent therapeutic option. Early intervention in clinically stable patients without signs of heart failure but with indirect signs of device thrombosis has led to better outcomes.

Dabigatran etexilate in a vitamin-K antagonist non responder patient during Heartware HVAD support.

We report a case of a patient supported with a HeartWare left ventricular assist device for idiopathic cardiomyopathy who was resistance to vitamin-K antagonists three months after implantation. The patient initially started low-molecular-weight heparin therapy and then, after the onset of an ischemic stroke, switched to dabigatran etexilate (DE). The patient had progressive recovery of cardiac function for which the device was explanted. No thrombotic or bleeding events occurred during DE therapy.

A simple device to secure ventricular assist device driveline and prevent exit-site infection.

OBJECTIVES: Driveline infections are one of the most common and important complications in patients with left ventricular assist device (LVAD). One of the causes favouring the development of this complication is the traumatism of the exit site, which occurs in response to movement of the driveline. In this work, we present a simple and feasible method to immobilize the driveline at the level of the exit site. METHODS: From April 2013 until November 2013, 6 patients underwent implantation of HeartWare LVAD (HVAD) for an end-stage heart failure. When the patient has begun to mobilize after the implantation of the device, we have combined the use of two components with the aim of securing the driveline to the patient's skin: a StatLock system and a silicone suture. RESULTS: No case of local traumatism and no case of local infection at the driveline were observed during the follow-up. No patient reported pain or swelling at the driveline exit site. All patients were satisfied with their quality-of-life and they do not report any limitations in their daily activities. CONCLUSIONS: One of the major long-term complications in patients with LVAD is the development of infections of the exit site of the driveline. The trauma of this skin region promotes the onset and maintenance of an inflammatory process and local infectious. Avoiding excessive mobilization of the driveline is likely to reduce the incidence of infections of the exit site and improve the quality-of-life.