Intraoperative Hemoadsorption (Cytosorb™) during Open Thoracoabdominal Aortic Repair: A Pilot Randomized Controlled Trial

Strategies to attenuate maladaptive inflammatory response associated with cardiopulmonary bypass

Cardiopulmonary bypass (CPB) initiates an intense inflammatory response due to various factors: conversion from pulsatile to laminar flow, cold cardioplegia, surgical trauma, endotoxemia, ischemia-reperfusion injury, oxidative stress, hypothermia, and contact activation of cells by the extracorporeal circuit. Redundant and overlapping inflammatory cascades amplify the initial response to produce a systemic inflammatory response, heightened by coincident activation of coagulation and fibrinolytic pathways. When unchecked, this inflammatory response can become maladaptive and lead to serious postoperative complications. Concerted research efforts have been made to identify technical refinements and pharmacologic interventions that appropriately attenuate the inflammatory response and ultimately translate to improved clinical outcomes. Surface modification of the extracorporeal circuit to increase biocompatibility, miniaturized circuits with sheer resistance, filtration techniques, and minimally invasive approaches have improved clinical outcomes in specific populations. Pharmacologic adjuncts, including aprotinin, steroids, monoclonal antibodies, and free radical scavengers, show real promise. A multimodal approach incorporating technical, circuit-specific, and pharmacologic strategies will likely yield maximal clinical benefit.

Postoperative bioactive adrenomedullin is associated with the onset of ARDS and adverse outcomes in patients undergoing open thoracoabdominal aortic surgery

Cytokine-mediated systemic inflammation after open thoracoabdominal aortic aneurysm (TAAA) repairs plays a pivotal role in disrupting circulatory homeostasis, potentially leading to organ dysfunction. The bioactive form of adrenomedullin (bio-ADM) is a peptide hormone with immunomodulatory and vasomotor effects, making it a potential diagnostic agent in these cases. This retrospective, bicentric study, conducted between January 2019 and December 2022, recruited 36 elective open TAAA repair patients in two German centres. Serum and plasma samples were collected at multiple time points to measure bio-ADM levels. The primary objective was to evaluate the association of bio-ADM levels with the onset of acute respiratory distress syndrome (ARDS), with secondary endpoints focusing on mortality and SIRS-related morbidity. Results showed a significant association between postoperative bio-ADM levels (12-48 h after surgery) and the onset of ARDS (p < .001), prolonged ventilation (p = .015 at 12h after surgery), atrial fibrillation (p < .001), and mortality (p = .05 at 24h). The biomarker was also strongly associated with sepsis (p = .01 at 12 h) and multi-organ dysfunction syndrome (MODS) (p = .02 at 24 h after surgery). The study underscores the potential utility of bio-ADM as a diagnostic tool for identifying patients at risk of postoperative complications following open TAAA repairs.

The role of hemoadsorption in cardiac surgery - a systematic review

BACKGROUND

Extracorporeal blood purification has been widely used in intensive care medicine, nephrology, toxicology, and other fields. During the last decade, with the emergence of new adsorptive blood purification devices, hemoadsorption has been increasingly applied during CPB in cardiac surgery, for patients at different inflammatory risks, or for postoperative complications. Clinical evidence so far has not provided definite answers concerning this adjunctive treatment. The current systematic review aimed to critically assess the role of perioperative hemoadsorption in cardiac surgery, by summarizing the current knowledge in this clinical setting.

METHODS

A literature search of PubMed, Cochrane library, and the database provided by CytoSorbents was conducted on June 1st, 2023. The search terms were chosen by applying neutral search keywords to perform a non-biased systematic search, including language variations of terms "cardiac surgery" and "hemoadsorption". The screening and selection process followed scientific principles (PRISMA statement). Abstracts were considered for inclusion if they were written in English and published within the last ten years. Publications were eligible for assessment if reporting on original data from any type of study (excluding case reports) in which a hemoadsorption device was investigated during or after cardiac surgery. Results were summarized according to sub-fields and presented in a tabular view.

RESULTS

The search resulted in 29 publications with a total of 1,057 patients who were treated with hemoadsorption and 988 control patients. Articles were grouped and descriptively analyzed due to the remarkable variability in study designs, however, all reported exclusively on CytoSorb® therapy. A total of 62% (18/29) of the included articles reported on safety and no unanticipated adverse events have been observed. The most frequently reported clinical outcome associated with hemoadsorption was reduced vasopressor demand resulting in better hemodynamic stability.

CONCLUSIONS

The role of hemoadsorption in cardiac surgery seems to be justified in selected high-risk cases in infective endocarditis, aortic surgery, heart transplantation, and emergency surgery in patients under antithrombotic therapy, as well as in those who develop a dysregulated inflammatory response, vasoplegia, or septic shock postoperatively. Future large randomized controlled trials are needed to better define proper patient selection, dosing, and timing of the therapy.

Use of intraoperative haemoadsorption in patients undergoing heart transplantation: a proof-of-concept randomized trial

AIMS

The aim of this trial was to compare the clinical effects of intraoperative haemoadsorption versus standard care in patients undergoing orthotopic heart transplantation (OHT).

METHODS AND RESULTS

In a randomized, controlled trial, OHT recipients were randomized to receive intraoperative haemoadsorption or standard care. Outcomes were vasoactive-inotropic score (VIS), frequency of vasoplegic syndrome (VS) in the first 24 h; post-operative change in procalcitonin (PCT) and C-reactive protein (CRP) levels; intraoperative change in mycophenolic acid (MPA) concentration; frequency of post-operative organ dysfunction, major complications, adverse immunological events and length of in-hospital stay and 1-year survival. Sixty patients were randomized (haemoadsorption group N = 30, control group N = 25 plus 5 exclusions). Patients in the haemoadsorption group had a lower median VIS and rate of VS (VIS: 27.2 [14.6-47.7] vs. 41.9 [22.4-63.2], P = 0.046, and VS: 20.0% vs. 48.0%, P = 0.028, respectively), a 6.4-fold decrease in the odds of early VS (OR: 0.156, CI: 0.029-0.830, P = 0.029), lower PCT levels, shorter median mechanical ventilation (MV: 25 [19-68.8] hours vs. 65 [23-287] hours, P = 0.025, respectively) and intensive care unit stay (ICU stay: 8.5 [8.0-10.3] days vs. 12 [8.5-18.0] days, P = 0.022, respectively) than patients in the control group. Patients in the haemoadsorption versus control group experienced lower rates of acute kidney injury (AKI: 36.7% vs. 76.0%, P = 0.004, respectively), renal replacement therapy (RRT: 0% vs. 16.0%, P = 0.037, respectively) and lower median per cent change in bilirubin level (PCB: 2.5 [-24.6 to 71.1] % vs. 72.1 [11.2-191.4] %, P = 0.009, respectively) during the post-operative period. MPA concentrations measured at pre-defined time points were comparable in the haemoadsorption compared to control groups (MPA pre-cardiopulmonary bypass: 2.4 [1.15-3.60] μg/mL vs. 1.6 [1.20-3.20] μg/mL, P = 0.780, and MPA 120 min after cardiopulmonary bypass start: 1.1 [0.58-2.32] μg/mL vs. 0.9 [0.45-2.10] μg/mL, P = 0.786). The rates of cardiac allograft rejection, 30-day mortality and 1-year survival were similar between the groups.

CONCLUSIONS

Intraoperative haemoadsorption was associated with better haemodynamic stability, mitigated PCT response, lower rates of post-operative AKI and RRT, more stable hepatic bilirubin excretion, and shorter durations of MV and ICU stay. Intraoperative haemoadsorption did not show any relevant adsorption effect on MPA. There was no increase in the frequency of early cardiac allograft rejection related to intraoperative haemoadsorption use.

Impact of intraoperative haemoadsorption on outcomes of patients undergoing aortic surgery: a single-centre, prospective, observational study

OBJECTIVES

To investigate the impact of a cytokine haemoadsorption (HA) device (CytoSorb®) on inflammatory markers and patients' outcome during aortic root surgery.

METHODS

Prospective, observational study including all-comers with quasi-randomization by strictly alternating inclusion (1:1 basis). Sixty patients undergoing elective aortic surgery were assigned to either HA group (n = 30) with intraoperative HA, or a control (C) group (n = 30). Primary outcomes were: (i) impact of HA on haemodynamic stability and need for vasopressors (vasoactive-inotropic score) and (ii) sequential organ failure assessment (SOFA) score. Secondary parameters included the impact of HA on the course of hyperinflammation using interleukin-6 and procalcitonin, duration of mechanical ventilation, and lengths of intensive care unit and hospital stay.

RESULTS

Noradrenaline requirement was significantly reduced in the HA group postoperatively compared to the C group (HA: 0.03 µg/kg/min vs C: 0.08 µg/kg/min, P = 0.004 at 2 h, and HA: 0.02 µg/kg/min vs C: 0.04 µg/kg/min, P = 0.004 at 24 h). This translated into a significantly lower vasoactive-inotropic score in the HA group. SOFA score was less in the HA group at all time points and reached statistical significance 2 h postoperatively (HA: 5.77 vs C: 7.43, P < 0.001). Intraoperative HA significantly reduced interleukin-6 levels (P < 0.05) at all time points, and procalcitonin at 2 h after discontinuation from cardiopulmonary bypass (P = 0.005). The duration of ventilation, intensive care unit and hospital stays were shorter in the HA group compared to the C group.

CONCLUSIONS

Intraoperative HA has the potential to mitigate hyperinflammatory response leading to improved haemodynamics after aortic root surgery, thereby shortening the duration of ventilation, and lengths of intensive care unit and hospital stay. However, it must be evaluated in larger cohorts.

The Effect of CytoSorb on Inflammatory Markers in Critically Ill Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

The effectiveness of CytoSorb at removing inflammatory mediators in critically ill patients is controversial.

DATA SOURCES

Electronic databases were searched from inception to May 2023.

STUDY SELECTION

Randomized controlled trials reporting the effects of CytoSorb therapy on inflammatory parameters in critically ill patients with hyperinflammatory conditions were included.

DATA EXTRACTION

Two authors screened articles for eligibility, extracted data, and assessed the risk of bias, conflicts of interest, and certainty of evidence (CoE). The primary outcome was interleukin (IL)-6 at 1 day after initiation of the therapy. Secondary outcomes included various inflammatory markers at 1, 2, 3, and 5 days and mortality. Data were pooled if at least three trials reported the outcome of interest. We conducted meta-analyses of the data using a random-effects model.

DATA SYNTHESIS

Seventeen trials ( n = 855) were included. Fourteen trials were judged to have notable concern about conflicts of interest. Seven trials were performed in medical ICU patients with hyperinflammatory conditions and 10 in complex cardiovascular surgery under cardiopulmonary bypass. Hemoadsorption with CytoSorb was not associated with lower IL-6 at 1 day (mean difference -5.98 [95% CI, -30.44 to 18.48] pg/mL), 2 days, 3 days, or 5 days after initiation of the treatment, as well as the concentration of procalcitionin. The levels of C-reactive protein were not lower with CytoSorb at 1, 2, and 3 days. The use of CytoSorb was associated with higher mortality at latest follow-up (relative risk = 1.22 [95% CI, 1.02-1.45]) and at 30 days. CoE ranged from low to very low.

CONCLUSIONS

The use of CytoSorb hemoadsorption in a mixed population of critically ill patients with hyperinflammatory conditions does not exhibit a consistent decrease in IL-6 and other inflammatory parameters within the first 5 days of treatment. The significant uncertainty surrounding these findings highlights the need for further investigations.

Successful Extracorporeal Cytokine Hemoadsorption in a Marfan Syndrome Patient with COVID-19 Undergoing Redo Bentall Procedure

BACKGROUND Patients with COVID-19 undergoing emergency or complex surgical procedures are at increased risk of developing perioperative complications. CytoSorb is a blood purification therapy used to remove circulating cytokines in conditions of hyperinflammation. This report is of a patient with COVID-19 requiring redo replacement of the aortic valve and aorta due to aortic aneurysm of the ascending aorta (Bentall procedure) associated with Marfan syndrome. The patient was successfully treated with extracorporeal cytokine hemoadsorption. CASE REPORT A 34-year-old man with Marfan syndrome, who had undergone a Bentall procedure in 2018, was admitted with symptoms of worsening dyspnea, tachycardia, fever, and confirmed COVID-19. Further diagnostic workup revealed dehiscence of the aortic root as well as moderate aortic regurgitation, in the context of a hyperinflammatory state. Anti-infective treatment was initiated. Given the severity of symptoms, COVID-19, echocardiography findings, and risk of aortic rupture, urgent Bentall surgery was performed. Additionally, a CytoSorb hemoadsorber was integrated into the cardiopulmonary bypass circuit to attenuate the anticipated systemic hyperinflammation. Intraoperatively, several blood products were administered due to excessive bleeding from the friable tissues and the pre-existing anemia and thrombocytopenia. Treatment was associated with marked improvements in vital parameters and inflammatory markers, and weaning from the ventilator and inotropes was possible after 48 hours. The remaining time in hospital was uneventful. CONCLUSIONS This report supports the findings from recent studies and reports that extracorporeal cytokine hemoadsorption has a role to play in reducing the systemic effects of cytokine storm associated with complex surgery involving cardiopulmonary bypass alongside severe infections, including COVID-19.

Intraoperative immunomodulation during left heart bypass in open thoracoabdominal aortic aneurysm repair

Despite the technical innovations introduced in the previous decades, open thoracoabdominal aortic aneurysm repair still represents an enormous challenge for patients and surgeons. Logically, the systemic inflammatory response resulting from these massive operations appears considerable; however, the response has never been thoroughly investigated. In addition, intraoperative adjuncts to modulate the postoperative activation of the immune system have not yet been introduced into clinical practice. We report a case of intraoperative hemadsorption during open repair of a thoracoabdominal aortic aneurysm through the introduction of a CytoSorb device (CytoSorbents Corp) in the left heart bypass circuit. The technique appeared feasible and safe and probably contributed to the good clinical outcomes.