Recovery of platelet-rich red blood cells and acquisition of convalescent plasma with a novel gravity-driven blood separation device

The Importance of Cell Saver Usage in Complex Endovascular Repair of Thoraco-Abdominal Aortic Aneurysms

AIM

The use of the cell-saver is well established in open aneurysm repair, however, its role in endovascular repair is yet to be determined. The aim of this study was to analyze the effects of cell-saver usage in patients undergoing complex endovascular procedures.

MATERIALS AND METHODS

Single-center retrospective cohort study including consecutive patients undergoing fenestrated and/or branched repair for the treatment of thoracoabdominal and complex abdominal aortic aneurysms between January 2019 and December 2022. The cell-saver was a standard part of the intraoperative setup of these procedures and its use was readily available. The primary endpoint was the percentage of patients in which autologous blood collected was transfused (CSBT), alongside the usable amount obtained. Secondary endpoints included mean blood loss, postoperative haemoglobin levels and 30-day mortality.

RESULTS

A total of 170 patients (77.1% male, mean age 71.2 ± 9.2 years) were included, with a median blood loss of 700mL (IQR 400-1200mL). A total of 96 patients received some kind of blood transfusion (BT) (56.5%): 35 (20.6%) allogenic BT, 31 (18.2%) CSBT only and 30 (17.6%) a combination of both. In total, 61 patients (35.9%, or 63.5% of all patients requiring BTs) received CSBT, with a median usable blood volume of 282mL (IQR, 194.5 - 508mL). Thirty-day mortality was similar in both groups. Although the CSBT group had lower intraoperative hemoglobin values (9.25 ± 1.55 vs. 10.36 ± 1.88 mg/dL; p<0.001), both groups presented similar postoperative hemoglobin levels.

CONCLUSION

Blood loss during complex endovascular repair is not insignificant. In this cohort, over 50% of included patients required some kind of BT, 32.3% of which received exclusively CSBT while 31.3% had supplementary CSBT alongside allogenic BT. This data showcases its potential role in these repairs, paving the way for its standardization in the intraoperative setup of these complex procedures.

Reduced Mortality among COVID-19 ICU Patients after Treatment with HemoClear Convalescent Plasma in Suriname

Convalescent plasma is a promising therapy for coronavirus disease 2019 (COVID-19), but its efficacy in intensive care unit (ICU) patients in low- and middle-income country settings such as Suriname is unknown. Bedside plasma separation using the HemoClear device made convalescent plasma therapy accessible as a treatment option in Suriname. Two hundred patients with severe SARS-CoV-2 infection requiring intensive care were recruited. Fifty eight patients (29%) received COVID-19 convalescent plasma (CCP) treatment in addition to standard of care (SOC). The CCP treatment and SOC groups were matched by age, sex, and disease severity scores. Mortality in the CCP treatment group was significantly lower than that in the SOC group (21% versus 39%; Fisher's exact test P = 0.0133). Multivariate analysis using ICU days showed that CCP treatment reduced mortality (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.18 to 0.66; P = 0.001), while complication of acute renal failure (creatinine levels, >110 mol/L; HR, 4.45; 95% CI, 2.54 to 7.80; P < 0.0001) was independently associated with death. Decrease in chest X-ray score in the CCP treatment group (median -3 points, interquartile range [IQR] -4 to -1) was significantly greater than that in the SOC group (median -1 point, IQR -3 to 1, Mann-Whitney test P = 0.0004). Improvement in the PaO₂/FiO₂ ratio was also significantly greater in the CCP treatment group (median 83, IQR 8 to 140) than in the SOC group (median 35, IQR -3 to 92, Mann-Whitney P = 0.0234). Further research is needed for HemoClear-produced CCP as a therapy for SARS-CoV-2 infection together with adequately powered, randomized controlled trials. IMPORTANCE This study compares mortality and other endpoints between intensive care unit COVID-19 patients treated with convalescent plasma plus standard of care (CCP), and a control group of patients hospitalized in the same medical ICU facility treated with standard of care alone (SOC) in a low- and middle-income country (LMIC) setting using bedside donor whole blood separation by gravity (HemoClear) to produce the CCP. It demonstrates a significant 65% survival improvement in HemoClear-produced CCP recipients (HR, 0.35; 95% CI, 0.19 to 0.66; P = 0.001). Although this is an exploratory study, it clearly shows the benefit of using the HemoClear-produced CCP in ICU patients in the Suriname LMIC setting. Additional studies could further substantiate our findings and their applicability for both LMICs and high-income countries and the use of CCP as a prepared readiness method to combat new viral pandemics.

Comparison of Washing Efficiency and Recovery of Blood Cells Between Centrifugation, Coarse Filtration and Microfiltration Techniques to Prepare Autologous Blood for Transfusion

Purpose

Cell salvage is the process by which blood lost in surgery is collected and washed or filtered to produce autologous blood for re-transfusion to the patient. Cell salvage aims to reduce the need for donor blood. Centrifugal cell salvage washing technique is a preferred medical treatment in order to retain lost red blood cells (RBCs) without contaminants. Although this technology very efficiently collects and washes shed blood, it is costly and often impractical or unavailable, especially in middle- or low-income countries. This study assessed two innovative filter devices as an alternative to centrifugal cell salvage technology: a coarse collection filter device (Hemafuse) and a microfiltration device (HemoClear). In contrast to centrifugal technology, both filter devices do not require electricity, nor costly equipment and extensive training. We compared the effectiveness of these filtration technologies to remove plasma constituents and recover and concentrate the cellular components with centrifugal technology (autoLog^® device).

Methods

Whole blood was processed with each technology according to the device manufacturer’s instructions. Before and after processing, the blood products were analyzed for supernatant solutes and cellular composition.

Results

The centrifugal technology confirmed its efficacy to remove potentially harmful solutes and capture red blood cells. The microfiltration technology (HemoClear) reached comparable levels of removal of solutes, with a potential advantage over centrifugal technology in the ability to also recover platelets. The coarse filtration technology (Hemafuse) had no washing capacity but, like the microfiltration technology, has the advantage of recovering platelets.

Conclusion

Innovative filtration devices represent an alternative to centrifugal technology in the preparation of autologous blood for reinfusion. The HemoClear technology for the first time enables the recovery of washed platelets and red blood cells. Clinical trials will have to be performed to investigate the clinical value of this new autologous blood product.