Duration Of Perfusion Research Articles

Efficient decellularization of human fetal kidneys through optimized SDS exposure

Chronic kidney disease poses a significant threat to public health. Renal replacement therapy is the primary treatment option for end-stage kidney disease. However, there is a promising and relatively new method in regenerative medicine for creating a functional organ known as whole kidney decellularization. This method uses the intrinsic vasculature to perfuse the decellularizing agent into the tissue, effectively penetrating and removing cellular material. The regenerated bioscaffolds could serve as a source of organ donation. This study is focused on evaluating the effectiveness of various SDS exposures in decellularizing human fetal kidneys. The study included human fetal kidneys harvested from fetuses terminated before 14 weeks of gestational age. Kidneys were divided into six treatment groups based on SDS concentration and duration of perfusion. Decellularization, scanning electron microscopy, histopathological staining, immunofluorescent staining, and immunohistochemistry staining were performed to evaluate the adequacy of the process. The statistical analysis revealed that the SDS 0.1% treatment group had the highest collagen deposition after 24 h, significantly greater than the SDS 0.5% treatment group at 24 and 48 h. No significant differences were observed among the other treatment groups. The study concludes that the SDS 0.1% treatment group for 24 h was the most effective in terms of ECM content preservation and effective cell removal. This treatment showed better results than the other treatment groups and can be considered for future whole kidney decellularization studies.

A meta-analysis of perfusion parameters affecting weight gain in exvivo perfusion.

Ex vivo machine perfusion (EVMP) has been established to extend viability of donor organs. However, EVMP protocols are inconsistent. We hypothesize that there is a significant relationship between specific parameters during EVMP and perfusion outcomes. A meta-analysis of literature was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) Statement. The search encompassed articles published before July 25, 2023. PubMed, Embase, and CENTRAL databases were screened using search terms "ex-vivo," "ex-situ," "machine," and "perfusion." Weight gain, an indicator of organ viability, was chosen to compare outcomes. Extracted variables included perfused organ, warm and cold ischemia time before perfusion, perfusion duration, perfusate flow, pressure, temperature, perfusate composition (presence of cellular or acellular oxygen carrier, colloids, and other supplements) and percent weight change. Data were analyzed using SPSS statistical software. Overall, 44 articles were included. Red blood cell-based perfusates resulted in significantly lower weight gain compared to acellular perfusates without oxygen carriers (11.3% vs. 27.0%, p < 0.001). Hemoglobin-based oxygen carriers resulted in significantly lower weight gain compared to acellular perfusates (16.5% vs. 27%, p = 0.006). Normothermic perfusion led to the least weight gain (14.6%), significantly different from hypothermic (24.3%) and subnormothermic (25.0%) conditions (p < 0.001), with no significant difference between hypothermic and subnormothermic groups (24.3% vs. 25.0%, p = 0.952). There was a positive correlation between flow rate and weight gain (ß = 13.1, R = 0.390, p < 0.001). Oxygen carriers, low flow rates, and normothermic perfusate temperature appear to improve outcomes in EVMP. These findings offer opportunities for improving organ transplantation outcomes.

Predictive value of early postoperative lactate (

Biomarkers with strong predictive capacity towards transplantation outcome for livers undergoing normothermic machine perfusion (NMP) are needed. We investigated lactate clearing capacity as a basic function of liver viability during the first 6 h of NMP. A trial conducted in 6 high-volume transplant centres in Europe. All centres applied a back-to-base NMP approach with the OrganOx metra system. Perfusate lactate levels at start, 1, 2, 4 and 6 h of NMP were assessed individually and as area under the curve (AUC) and correlated with EAD (early allograft dysfunction), MEAF (model for early allograft function) and modified L-GrAFT (liver graft assessment following transplantation) scores. A total of 509 livers underwent ≥6 h of NMP before transplantation in 6 centres in the UK, Germany and Austria. The donor age was 53 (40-63) years (median, i.q.r.).The total NMP time was 10.8 (7.9-15.7) h. EAD occurred in 26%, MEAF was 4.72 (3.54-6.05) and L-GrAFT10 -0.96 (-1.52--0.32). Lactate at 1, 2 and 6 h correlated with increasing robustness with MEAF. Rather than a binary assessment with a cut-off value at 2 h, the actual 2 h lactate level correlated with the MEAF (P = 0.0306 versus P = 0.0002, Pearson r = 0.01087 versus r = 0.1734). The absolute lactate concentration at 6 h, the AUC of 0-6 h and 1-6 h (P < 0.0001, r = 0.3176) were the strongest predictors of MEAF. Lactate measured 1-6 h and lactate levels at 6 h correlate strongly with risk of liver allograft dysfunction upon transplantation. The robustness of predicting MEAF by lactate increases with perfusion duration. Monitoring lactate levels should be extended to at least 6 h of NMP routinely to improve clinical outcome.

Do All Patients Benefit From the Soothing Properties of a Conversational Nursing Intervention to Reduce Symptom Burden During Outpatient Chemotherapy?: A Multimethod Secondary Analysis.

Soothing conversation (SC) is particularly promising for symptom management during outpatient chemotherapy. However, we know little about the profile of patients who are most likely to benefit from this intervention. To gain a better understanding of the profile of patients most likely to benefit from SC to reduce symptom burden during outpatient chemotherapy. We performed a multimethod secondary analysis of 2 data sets: the first gathered during a quantitative pilot trial investigating the impact of SC on patients' symptom fluctuations during chemotherapy perfusion (n = 24); the second derived from qualitative interviews about nurses' experiences with SC in this context (n = 6). Secondary quantitative analysis suggests that symptom control with SC is more effective in older patients, reporting lower education, widowed status, work incapacity, advanced cancer, and undergoing chemotherapy perfusion for less than 1 hour. According to nurses' interviews, SC could best benefit patients (1) prone to anxiety and fear, (2) with unalleviated pain, (3) who are unaccompanied during treatment, and contrary to what was shown with quantitative data, (4) undergoing longer perfusion duration. Although this study provides valuable insights, much work remains to be done to fully understand the factors that predispose patients to respond positively to SC during outpatient chemotherapy. This study extends previous research on the effectiveness of SC for symptom management during outpatient chemotherapy by comparing nurses' experience with the intervention to patients' results. Results could be used to inform the assignment and delivery of supportive communication-based interventions during chemotherapy protocols.

Transplantation techniques for liver resections in children

Aim. To carry out a retrospective analysis of the treatment outcomes of the patients who underwent liver resection with angioplasty facilitated by transplantation techniques. Materials and methods. The sample of cases was divided into four groups: liver resection with total vascular isolation of the liver, ante situm liver resection, hepatic artery and portal vein reconstruction, cardiopulmonary bypass resection. The analysis was focused on surgery features and treatment outcomes. Results. The study involved 29 patients. The performed interventions included 11 liver resections with total vascular isolation, 6 ante situm liver resections, 7 resections with angioplasty, and 5 cardiopulmonary bypass resections. 5 patients (17 %) developed complications that required reoperation. Within 90 days, 4 patients (14 %) died. For patients with malignant neoplasms, one-, three-, and five-year overall survival rates accounted for 84.4 %, 58.4 %, and 51.1 %; one-year event-free survival rate comprised 57.1 %, and three- and five-year event-free survival was 41.7 %.The study revealed no significant differences in the complication rates. The groups of ante situm liver resections and cardiopulmonary bypass resections significantly differed from the other groups by the higher incidence of tumor progression, invasion of adjacent organs, hemorrhagic complications, preoperative stay, and duration of cold perfusion of the liver. The cardiopulmonary bypass resections were noted to have higher duration of surgery, vascular isolation, heparin use, and the frequency of anticoagulant therapy before surgery. Conclusion. Liver resections with total vascular isolation, angioplasty and transplantation techniques are considered as the only possible treatment option for a number of patients. Further accumulation of results will reduce the risk of adverse outcomes.

(93) - Longer Duration of Ex-Vivo Perfusion is Associated with Worse Survival in Donation After Circulatory Death Heart Recipients: A National Database Analysis

(93) - Longer Duration of Ex-Vivo Perfusion is Associated with Worse Survival in Donation After Circulatory Death Heart Recipients: A National Database Analysis

Towards Optimizing Sub-Normothermic Machine Perfusion in Fasciocutaneous Flaps: A Large Animal Study.

Machine perfusion has developed rapidly since its first use in solid organ transplantation. Likewise, reconstructive surgery has kept pace, and ex vivo perfusion appears as a new trend in vascularized composite allotransplants preservation. In autologous reconstruction, fasciocutaneous flaps are now the gold standard due to their low morbidity (muscle sparing) and favorable functional and cosmetic results. However, failures still occasionally arise due to difficulties encountered with the vessels during free flap transfer. The development of machine perfusion procedures would make it possible to temporarily substitute or even avoid microsurgical anastomoses in certain complex cases. We performed oxygenated acellular sub-normothermic perfusions of fasciocutaneous flaps for 24 and 48 h in a porcine model and compared continuous and intermittent perfusion regimens. The monitored metrics included vascular resistance, edema, arteriovenous oxygen gas differentials, and metabolic parameters. A final histological assessment was performed. Porcine flaps which underwent successful oxygenated perfusion showed minimal or no signs of cell necrosis at the end of the perfusion. Intermittent perfusion allowed overall better results to be obtained at 24 h and extended perfusion duration. This work provides a strong foundation for further research and could lead to new and reliable reconstructive techniques.

N-acetylcysteine: a novel approach to methaemoglobinaemia in normothermic liver machine perfusion

Extended duration of normothermic machine perfusion (NMP) provides opportunities to resuscitate suboptimal donor livers. This intervention requires adequate oxygen delivery typically provided by a blood-based perfusion solution. Methaemoglobin (MetHb) results from the oxidation of iron within haemoglobin and represents a serious problem in perfusions lasting > 24 h. We explored the effects of anti-oxidant, N-acetylcysteine (NAC) on the accumulation of methaemoglobin. NMP was performed on nine human donor livers declined for transplantation: three were perfused without NAC (no-NAC group), and six organs perfused with an initial NAC bolus, followed by continuous infusion (NAC group), with hourly methaemoglobin perfusate measurements. In-vitro experiments examined the impact of NAC (3 mg) on red cells (30 ml) in the absence of liver tissue. The no-NAC group sustained perfusions for an average of 96 (range 87–102) h, universally developing methaemoglobinaemia (≥ 2%) observed after an average of 45 h, with subsequent steep rise. The NAC group was perfused for an average of 148 (range 90–184) h. Only 2 livers developed methaemoglobinaemia (peak MetHb of 6%), with an average onset of 116.5 h. Addition of NAC efficiently limits formation and accumulation of methaemoglobin during NMP, and allows the significant extension of perfusion duration.

Incidence of postoperative seizures in neonates following cardiac surgery with regional cerebral perfusion and deep hypothermic circulatory arrest

ObjectivesHistorically, our center has primarily used deep hypothermic circulatory arrest, but in recent years some surgeons have selectively used regional cerebral perfusion as an alternative. We aimed to compare the incidence of postoperative electroencephalographic seizure incidence in neonates undergoing surgery with regional cerebral perfusion and deep hypothermic circulatory arrest. MethodsA retrospective analysis was performed in neonates who underwent surgery between 2012 and 2022 with either deep hypothermic circulatory arrest or regional cerebral perfusion with routine postoperative continuous electroencephalography monitoring for 48 hours. Propensity matching was performed to compare postoperative seizure risk between the 2 groups. ResultsAmong 1136 neonates undergoing cardiac surgery with cardiopulmonary bypass, regional cerebral perfusion was performed in 99 (8.7%) and deep hypothermic circulatory arrest in 604 (53%). The median duration of regional cerebral perfusion was 49 minutes (interquartile range, 38-68) and deep hypothermic circulatory arrest was 41 minutes (interquartile range, 31-49). The regional cerebral perfusion group had significantly longer total support, cardiopulmonary bypass, and aortic crossclamp times. Overall seizure incidence was 11% (N = 76) and 13% (N = 35) in the most recent era (2019-2022). The unadjusted seizure incidence was similar in neonates undergoing regional cerebral perfusion (N = 12, 12%) and deep hypothermic circulatory arrest (N = 64, 11%). After propensity matching, the seizure incidence was similar in neonates undergoing regional cerebral perfusion (N = 12, 12%) and deep hypothermic circulatory arrest (N = 37, 12%) (odds ratio, 0.97; 95% CI, 0.55-1.71; P = .92). ConclusionsIn this contemporary single-center experience, the incorporation of regional cerebral perfusion did not result in a change in seizure incidence in comparison with deep hypothermic circulatory arrest. However, unmeasured confounders may have impacted these findings. Further studies are needed to determine the impact, if any, of regional cerebral perfusion on postoperative seizure incidence.

Extended duration of machine perfusion: Maximizing organ utilization.

Extended duration of machine perfusion: Maximizing organ utilization.

Can Hypothermic Oxygenated Perfusion Mitigate Ischemia-Reperfusion Injury in Ex-Situ Split Grafts? – A Comparative Study with Living Donation in Pediatric Liver Transplantation

Abstract Background The gold standard in pediatric split liver transplantation (SLT) is living donation (LD) providing high-quality grafts with short static cold storage (SCS). Aims This study investigates the protective effect of hypothermic oxygenated perfusion (HOPE) on ex-situ partial grafts from deceased donors in comparison to standard ex-situ Static-Split and LD SLT. Methods We included all consecutive HOPE-Split, Static-Split and LD SLT performed from 2018-2022 at a single center. The primary endpoint was early ischemia-reperfusion injury (IRI) based on reperfusion biopsy (graded from none/0 to severe/4), the occurrence of post reperfusion syndrome (PRS, drop≥30% of systolic arterial pressure) and post-LT transaminase release. Results A total of 46 SLT (14 HOPE-Split, 17 Static-Split, and 15 LD) were included. With a median perfusion duration of 100min, HOPE-Split had a significant decrease of SCS compared to Static-Split (473 min vs 538 min; p=0.02) with similar total preservation time (p=0.13). This translated into lower rates of mild to severe IRI (grade≥2; p=0.03) and significantly reduced neutrophilic infiltrate than Static-Split (p=0.04; Fig.1). The PRS was also reduced in HOPE-Split (0% vs 35%, p=0.02) with less transaminase release. Despite prolonged SCS (473 vs 117min, p&amp;lt;0.001), HOPE-Split was comparable to LD regarding grade≥2 IRI (64 vs 40%; p=0.17) and PRS (0 vs 6.7% p=0.34), with however higher transaminase release (571 vs 244 UI/L/100g; p=0.004). Overall, 3-months surgical complications, graft and recipient survival did not differ among groups. Conclusions HOPE allowed improved preservation of ex-situ split grafts compared to static cold storage, resulting in similar early IRI profiles then LD grafts. Preservation with HOPE may offer a promising strategy to improve outcomes and expand selection criteria in split LT for pediatric recipients.

A novel rabbit model of abdominal aortic aneurysm: Construction and evaluation

Prior research has indicated that animal models of abdominal aortic aneurysm (AAA) utilizing porcine pancreatic elastase (PPE) exhibit a perfusion duration of 30 min, and extended perfusion durations are associated with elevated mortality rates. Similarly, the AAA model, which relies solely on balloon dilation (BD), is limited by the occurrence of self-healing aneurysms. Consequently, we constructed a novel AAA model by PPE combined with balloon expansion to shorten the modeling time and improve the modeling success rate. The findings indicated that 5 min was the optimal BD time for rabbits, 3 min BD was ineffective for aneurysm formation, and 10 min BD had a high mortality rate. The model, constructed in combination with PPE and 5 min BD, exhibited a 100% model formation rate and a 244.7% ± 9.83% dilation rate. HE staining exhibited that severe disruption of the inner, middle, and outer membranes of the abdominal aorta, with a marked decrease in smooth muscle cells and elastase, and a marked increase in fibroblasts of the middle membrane, and many infiltrating inflammatory cells were seen in all three layers, especially in the middle membrane. EVG staining displayed that the elastic fibers of the abdominal aortic wall were fractured and degraded, and lost their normal wavy appearance. The protein expression of inflammatory factor (IL-1β, IL-6 and TNF-α) as well as extracellular matrix components (MMP-2 and MMP-9) were significantly increased compared to PPE and 5 min BD alone. In conclusion, PPE combined with BD allows the establishment of a novel AAA model that closely mimics human AAA in terms of histomorphology, inflammatory cell infiltration, and vascular stromal destruction. This model provides an ideal animal model for understanding the pathogenesis of AAA.

Temperature management during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

In addition to attaining complete or near complete cytoreduction, the instillation of select heated chemotherapeutic agents into the abdominal cavity has offered a chance for cure or longer survival inpatients with peritoneal surface malignancies. While the heating of chemotherapeutic agents enhances cytotoxicity, the resulting systemic hyperthermia has been associated with an increased risk of severe hyperthermia and its associated complications. Factors that have been associated with an increased risk of severe hyperthermia include intraoperative blood transfusions and longer perfusion duration. However, the development of severe hyperthermia still remains largely unpredictable. Thus, at several institutions, cooling protocols are employed during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Cooling protocols for CRS-HIPEC are not standardized and may be associated with episodes of severe hyperthermia or alternatively hypothermia. In theory, excessive cooling could result in a decreased effectiveness of the intraperitoneal chemotherapeutic agents. This presumption has been supported by a recent study of 214 adults undergoing CRS-HIPEC, where failure to attain a temperature of 38° C at the end of chemo-perfusion was associated with worse survival. Although not statistically significant, failure to maintain a temperature of 38° C for at least 30 minutes was associated with worse survival. Although studies are limited in this regard, the importance of maintaining a steady state of temperature during the hyperthermic phase of intraperitoneal chemotherapy administration cannot be disregarded. The following article describes the processes and physiological mechanisms responsible for hyperthermia during CRS-HIPEC. The challenges associated with temperature management during CRS-HIPEC and methods to avoid severe hypothermia and hyperthermia are also described.

Sequential hypothermic and normothermic perfusion preservation and transplantation of expanded criteria donor livers

BackgroundThe purpose of this study was to assess the safety and feasibility of sequential hypothermic oxygenated perfusion and normothermic machine perfusion and the potential benefits of graft viability preservation and assessment before liver transplantation. MethodsWith the Food and Drug Administration and institutional review board approval, 17 expanded criteria donor livers underwent sequential hypothermic oxygenated perfusion and normothermic machine perfusion using our institutionally developed perfusion device. ResultsExpanded criteria donor livers were from older donors, donors after cardiac death, with steatosis, hypertransaminasemia, or calcified arteries. Perfusion duration ranged between 1 and 2 hours for the hypothermic oxygenated perfusion phase and between 4 and 9 hours for the normothermic machine perfusion phase. Three livers were judged to be untransplantable during normothermic machine perfusion based on perfusate lactate, bile production, and macro-appearance. One liver was not transplanted because of recipient issue after anesthesia induction and failed reallocation. Thirteen livers were transplanted, including 9 donors after cardiac death livers (donor warm ischemia time 16–25 minutes) and 4 from donors after brain death. All livers had the standardized lactate clearance >60% (perfusate lactate cleared to <4.0 mmol/L) within 3 hours of normothermic machine perfusion. Bile production rate was 0.2 to 10.7 mL/h for donors after brain death livers and 0.3 to 6.1 mL/h for donors after cardiac death livers. After transplantation, 5 cases had early allograft dysfunction (3 donors after cardiac death and 2 donors after brain death livers). No graft failure or patient death has occurred during follow-up time of 6 to 13 months. Two livers developed ischemic cholangiopathy. Compared with our previous normothermic machine perfusion study, the bile duct had fewer inflammatory cells in histology, but the post-transplant outcomes had no difference. ConclusionSequential hypothermic oxygenated perfusion and normothermic machine perfusion preservation is safe and feasible and has the potential benefits of preserving and evaluating expanded criteria donor livers.

Brain Protection in Patients with Aortic Dissection and Coronary Artery Disease

The aim. To compare the effectiveness of methods of protecting the brain and visceral organs during operations for aortic aneurysms combined with coronary artery lesions.&#x0D; Materials and methods. In the period from 2012 to 2020, 23 patients with Stanford type A and non-A non-B aortic dissection with damage to the coronary arteries were operated at the National Amosov Institute of Cardiovascular Surgery of the NAMS of Ukraine using the brain protection techniques. Out of 23 surgical interventions, 16 were performed for Stanford type A acute aortic dissection, 3 for Stanford type A chronic aortic dissection, 1 for Stanford type A subacute aortic dissection, and 3 for Stanford non-A non-B aortic dissection. The main causes of aortic dissection were hypertension (16 patients), Marfan syndrome (3 patients), bicuspid aortic valve (4 patients).&#x0D; Results. The most threatening postoperative complication in this group of patients is neurological damage, which was observed in 4 (17%) patients after surgery, with gradual recovery of brain function. Also, the complications observed were respiratory failure in 3 (13%) patients, which required long-term artificial ventilation (more than 72 hours), and multiple organ failure in 1 (4.3%) patient, which caused a fatal outcome.Complications such as kidney and liver failure were not observed (most likely due to the small sample size). Heart failure was not noted as well. Hospital mortality was 4.3% (1 fatal case). In our study, among the entire group of operated patients, symptoms of neurological damage occurred in 4 (17.4%) patients, hemorrhagic stroke was present in 1 (4.3%) patient with a complicated medical history, 2 (8.6%) patients had hemiparesis and in 1 case (4.3%) there were cognitive disorders.&#x0D; Conclusions. Comparing brain protection techniques, taking into account the prolongation of aortic clamping time due to coronary artery shunting compared to isolated aortic dissection, it can be concluded that longer duration of selective brain perfusion (retrograde or antegrade) or duration of circulatory arrest more often lead to postoperative complications, namely neurological lesions.&#x0D; On the other hand, the small number of observations does not make it possible to fully assess the impact of each of the techniques. Further follow-up with a larger sample will provide opportunities for a more complete evaluation of brain protection techniques in operations for dissecting aortic aneurysms and coronary artery lesions.

P11.14: The Use of Ex Vivo Normothermic Perfusion to ‘Pause’ Cold Ischaemic Time to Allow for Third Recipient to Be Selected And Undergo Kidney Transplant

Introduction: On arrival to the hospital on receipt of a transplant offer, recipients can be found to be unfit precluding transplantation. In this instance, the graft is offered back to NHS Blood and Transplant. Grafts often, however, remain locally to reduce cold ischaemic time inherent in further relocation. When another suitable recipient is not found, and cold ischaemic time (CIT) increases to undesirable levels, grafts can unfortunately be deemed unusable. Case Presentation: Herein we describe a case in which ex vivo normothermic perfusion (EVNP) facilitated the admittance of a third potential recipient for a 66yo DCDkidney. The first two allocated recipients who were deemed unfit: the first recipient was found to have an infected lower limb ulcer; the second patient was found to have raised inflammatory markers in the context of an aorto-bifemoral graft. At the time a third recipient (55yo, pre-dialysis) was selected the CIT on the graft was 19 hours. The patient was admitted to the ward and EVNP was used to ‘pause’/limit CIT in order for the patient to be prepared, assessed and consented for transplantation. Outcome: EVNP assessment score = 1 (one hour perfusion duration), with excellent perfusion demonstrated and good urine output (>100ml); total CIT was 23 hours at in situ reperfusion. The patient was successfully transplanted and the graft achieved primary function with a creatinine of 166µmol at time of discharge. At 5 months the creatinine is 151µmol and eGFR 32mls/min/m2. Discussion: Without EVNP this graft would have likely been discarded. Cold ischaemic time was effectively paused by the perfusion technology allowing the graft to be assessed and utilised, and ultimately prevented graft discard. EVNP offers a technique to improve organ utilisation.

Differential Approach to Surgical and Endovascular Treatments of Pulmonary Thromboembolism in Patients with Neurological and Neurosurgical Problems

INTRODUCTION: Pulmonary embolism (PE) is one of the most threatening complications in patients with neurological and neurosurgical problems. The high epidemiological threshold values and mortality in the considered group of patients attracted the interest of researchers in the methods of early diagnosis and selection of methods of reperfusion of the pulmonary arterial bed.&#x0D; AIM: To analyze clinical and hemodynamic results of the surgical and endovascular treatment of PE of the high and intermediatehigh risks in the group of patients with neurological and neurosurgical problems.&#x0D; MATERIALS AND METHODS: This study involved 24 patients with PE of high and intermediate high-risks. The first group involved seven patients with neurosurgical problems who underwent thromboembolectomy from the main and lobular branches of the pulmonary artery in conditions of parallel perfusion of the artificial circulation. The duration of perfusion was 26.0 7.4 min. The second group consisted of 17 patients with acute hemorrhagic stroke, in whom endovascular mechanical fragmentation of thromboemboli was performed using a modified Pig-Tail type catheter introduced by puncture through the subclavian or jugular vein. The first clinical manifestations of PE appeared 4.78 2.02 days after the neurosurgical intervention and 8.45 2.6 days after the onset of stroke. The initial systolic pressure in the pulmonary artery was 67.24 5.15 mm Hg in the first group and 70.53 4.53 mm Hg in the second group. Both groups had American Society of Anesthesiologist physical status IV and V classes of surgical risk and Pulmonary Embolism Severity Index class V (130174 points).&#x0D; RESULTS: The hospital survival rates were 100% and 82.36% in the first and second groups, respectively (three lethal cases due to progressing right-ventricular failure in the first 18 h after the procedure). On discharge, signs of reverse remodeling of the right heart chambers and reduction of the mean and systolic pressure in the pulmonary artery to 21 2.16 and 31 4.12 mm Hg, respectively, were noted in the first group and to 46 5.23 and 57 3.16 mm Hg, respectively, in the second group.&#x0D; CONCLUSION: Surgical treatment of PE is effective and safe with predictable results. Endovascular catheter induced destruction of the thromboembolus substrate is an alternative to the surgical treatment of patients with a high-risk of open surgery and absolute contraindications for thrombolytic therapy.

Dynamic Metabolic Changes During Prolonged Ex Situ Heart Perfusion Are Associated With Myocardial Functional Decline.

Ex situ heart perfusion (ESHP) was developed to preserve and evaluate donated hearts in a perfused beating state. However, myocardial function declines during ESHP, which limits the duration of perfusion and the potential to expand the donor pool. In this research, we combine a novel, minimally-invasive sampling approach with comparative global metabolite profiling to evaluate changes in the metabolomic patterns associated with declines in myocardial function during ESHP. Biocompatible solid-phase microextraction (SPME) microprobes serving as chemical biopsy were used to sample heart tissue and perfusate in a translational porcine ESHP model and a small cohort of clinical cases. In addition, six core-needle biopsies of the left ventricular wall were collected to compare the performance of our SPME sampling method against that of traditional tissue-collection. Our state-of-the-art metabolomics platform allowed us to identify a large number of significantly altered metabolites and lipid species that presented comparable profile of alterations to conventional biopsies. However, significant discrepancies in the pool of identified analytes using two sampling methods (SPME vs. biopsy) were also identified concerning mainly compounds susceptible to dynamic biotransformation and most likely being a result of low-invasive nature of SPME. Overall, our results revealed striking metabolic alterations during prolonged 8h-ESHP associated with uncontrolled inflammation not counterbalanced by resolution, endothelial injury, accelerated mitochondrial oxidative stress, the disruption of mitochondrial bioenergetics, and the accumulation of harmful lipid species. In conclusion, the combination of perfusion parameters and metabolomics can uncover various mechanisms of organ injury and recovery, which can help differentiate between donor hearts that are transplantable from those that should be discarded.

Abstract 285: Organ chip culture of vascularized triple negative breast cancer explant tissues with validated pathological and clinically-targetable properties of tumor vasculature

Abstract Triple negative breast cancer (TNBC) is an aggressive subtype characterized by a lack of the classic targetable receptors. Targeting the TNBC microenvironment via the biophysical properties of the tumor vasculature is a promising approach. The objective of this study was to engineer a microphysiological model of vascularized TNBC with validated pathological properties of tumor vasculature for in vitro modeling of selective drug delivery via the enhanced permeability and retention effect. We engineered a method for standardized production of milliscale tissues housed in fluidic culture devices that are accessible only via a fully anastomosed and perfusable internal vasculature comprised of endothelial cells and organ specific fibroblasts. We first established a baseline of vascular morphometry, endothelial barrier function, inflammatory activation, and perivascular extracellular matrix (ECM) composition in vascularized tissues devoid of cancer cells. In parallel, we developed a novel approach for processing patient-derived TNBC tissues into injectable explants of disaggregated tumor imbibed in ECM hydrogel in less than one hour. These explant tissues cultured in our devices consistently maintain high viability and a Ki67 index around 70%, on par with the Ki67 indexes of source TNBC tumors. We hypothesized that TNBC derivatives would induce the formation of a pathological vasculature in our model. The TNBC derivatives were mixed with exogenous fibroblasts and endothelial cells at optimized ratios and the same workflow described above was used to form vascularized TNBC explant tissues. TNBC-associated vasculature exhibited a significantly altered vascular morphometry relative to cancer-free control tissues across multiple quantitative metrics including vessel length, vessel diameter, and network branch points. These morphological changes were consistent with known dysmorphic features of tumor vasculature. Twofold or greater increases in endothelial ICAM-1 expression in TNBC-associated vasculature was measured by multiple methods of analysis. Increased inflammatory adhesion molecule expression was accompanied by disorganized VE-cadherin junctions and disrupted patterns of perivascular cell coverage that suggested TNBC-associated vasculature should be significantly more permeable. FITC-dextran perfusion studies revealed widespread macromolecular leakage from TNBC-associated vasculature into the TNBC explant tissue interstitium by 5 minutes, whereas no leakage was observed from control vasculature for the duration of perfusion up to one hour. Ongoing work to be presented is focused on validating our model as a platform for studying drug delivery via the enhanced permeability and retention effect using Abraxane nanoparticles. Citation Format: Kevin M. Conrad, Charles E. Byrne, Matthew R. Burow, Mark Mondrinos. Organ chip culture of vascularized triple negative breast cancer explant tissues with validated pathological and clinically-targetable properties of tumor vasculature [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 285.

The Effect of Normothermic Machine Perfusion on the Immune Profile of Donor Liver.

BackgroundNormothermic machine perfusion (NMP) allows viability assessment and potential resuscitation of donor livers prior to transplantation. The immunological effect of NMP on liver allografts is undetermined, with potential implications on allograft function, rejection outcomes and overall survival. In this study we define the changes in immune profile of human livers during NMP.MethodsSix human livers were placed on a NMP device. Tissue and perfusate samples were obtained during cold storage prior to perfusion and at 1, 3, and 6 hours of perfusion. Flow cytometry, immunohistochemistry, and bead-based immunoassays were used to measure leukocyte composition and cytokines in the perfusate and within the liver tissue. Mean values between baseline and time points were compared by Student’s t-test.ResultsWithin circulating perfusate, significantly increased frequencies of CD4 T cells, B cells and eosinophils were detectable by 1 hour of NMP and continued to increase at 6 hours of perfusion. On the other hand, NK cell frequency significantly decreased by 1 hour of NMP and remained decreased for the duration of perfusion. Within the liver tissue there was significantly increased B cell frequency but decreased neutrophils detectable at 6 hours of NMP. A transient decrease in intermediate monocyte frequency was detectable in liver tissue during the middle of the perfusion run. Overall, no significant differences were detectable in tissue resident T regulatory cells during NMP. Significantly increased levels of pro-inflammatory and anti-inflammatory cytokines were seen following initiation of NMP that continued to rise throughout duration of perfusion.ConclusionsTime-dependent dynamic changes are seen in individual leukocyte cell-types within both perfusate and tissue compartments of donor livers during NMP. This suggests a potential role of NMP in altering the immunogenicity of donor livers prior to transplant. These data also provide insights for future work to recondition the intrinsic immune profile of donor livers during NMP prior to transplantation.