Introduction

In the past, autologous red blood cells concentration was the only possible treatment for bleeding in major surgery. [1]. The modern autotransfusion systems use an integrated suction device system that combine the heparinized saline or citrate anticoagulant for blood anticoagulation and centrifugation and washing of blood for RBC concentration and platelets and plasma apheresis [2]. The blood was treated before or after Cardiopulmonary Bypass (CPB) procedures. The role of washing through autotransfusion system is fundamental to eliminate fat micro-emboli, air emboli, and noncellular debris for the microcirculation and organ preservation. Cellular salvage has become a standard of care in cardiac surgery [3]. The autotransfusion system maintain in the washing blood the physiologic levels of 2,3-DPG [4, 5]. Efficiency and safety on suction, filtering, and collecting through autotransfusion reservoir is crucial in the context of cardiothoracic surgery to set up effective aspiration and collection of blood loss from the surgical field with controlled aspiration to prevent hemolysis [6]. In this context, we presented a ten-year single-center retrospective analysis on suction, filtering and blood collection from surgical field through the use of the Cleanfield Autotransfusion Reservoir (Eurosets SRL, Medolla, Italy) in terms of performance, effectiveness, and safety.

Materials and Methods

Study Design

This study was conducted according to the guidelines of the Declaration of Helsinki. The Internal Review Board (Anthea Hospital, GVM Care & Research review board, Bari, Italy) approved this research (September 2023). From January 2013 to January 2023 were collected and analyzed the consecutive uses of Cleanfield Autotransfusion Reservoir in a single cardiothoracic surgery center Anthea Hospital Gvm Care & Research, Bari, Italy.

Criteria for Autotransfusion Reservoir use are as follows: The use of the autotransfusion reservoir is foreseen in all cardiac and vascular surgery procedures for preventive purposes, in case of major bleeding [2]. The Cleanfield reservoir has a capacity of 2800 ml and allows the recovery of even massive blood losses exceeding > 1000 ml.

For single procedure was analyzed

  • the mean number of cleanfield disposable used,

  • the mean maximum blood volume filtered and collected,

  • the mean negative pressure from devices through vacuum meter and the electronic negative pressure measurements in the devices for suctions.

  • the presence and the incidence of adverse events during the use (implosion, clot formation, inability to cell saver use, inability to suction during the use). Adverse events relating to the use of biomedical devices are entered in a register of our institution, with the description and number of the lot, series, and model involved and reported to the relevant company.

Cleanfield Autotransfusion Reservoir Features

Cleanfield autotransfusion reservoir (Eurosets SRL, Medolla, Italy) is a system that improves the blood management through the suction the filtering and collection. The Cleanfield system can be utilized in both blood loss estimation procedures and operations where it is difficult to predict blood loss. The Cleanfield device is cost-effective since it uses less “essential disposable” (the reservoir really resembles a bag); this allows Cleanfield to be utilized in every surgical procedure while still providing the surgeons and the patient with safety. If there are large blood losses during the procedure or after, you might choose to use the washing set.

The cleanfield device is made up of

Reusable part

  • Holder-2800 ml with vacuum regulator and vacuum indicator (Fig. 1A).

Fig. 1
figure 1

A Holder-2800 ml with vacuum regulator and vacuum indicator, B CLEANFIELD (2000 or 2800 ml) Autotransfusion reservoir, C Anticoagulant line for aspiration for intraoperative recovery

Full size image

Disposable part.

  • CLEANFIELD (2000 or 2800 ml) Autotransfusion reservoir (Fig. 1B);

  • Anticoagulant line for aspiration for intraoperative recovery (Fig. 1C).

The Reservoir Holder

The Reservoir Holder is made up of (Fig. 2A) and is intended for unlimited use.

  1. (a)

    The upper half of the vacuum meter is made of aluminum and includes the terminal for a stand.

    The connection for the vacuum font and the vacuum regulator with an ON–OFF switch.

    This is intended to fit tubes with a diameter of 1/4″ and 3/8.″

  2. (b)

    lower portion constructed of sturdy, clear polycarbonate and utilized as a hard container.

Fig. 2
figure 2

A Holder-2800 ml features, B CLEANFIELD (2000 or 2800 ml) Autotransfusion reservoir and Anticoagulant line for aspiration features

Full size image

The Reservoir Disposable Features

The Reservoir is made up of a rigid cover and a soft PVC bag with capacity of 2000 or 2800 ml that contains the filtering system (Fig. 2B).

  • On the cover, we can find two groups of connectors:

  • The SUCTION group contains four connectors that are shielded by red caps. The luer connector is helpful for oxygenators and extracorporeal circulation emptying lines, while the two 1/4″ connectors and the 3/8″ connector are used for connections to aspiration lines.

  • There are three connectors in the OUTLET group: one for 3/8″ tubes that is covered by a blue cap, and one connected to a 1/4″ silicone tube that is also covered by a blue cap. In order to maximize the filtration system, the blood filtration system is made up of two filtering screens with pore sizes of 120 and 40 m that are separated by a distance screen. 700 cm2 is the entire filtering surface. Medical-grade polyester, single thread, is used to make the filtering screens. High-selective screens may be produced with this technology without the risk of particle release and without the sponge effect.

The Aspiration Line for Intraoperative Recovery (Anticoagulant Line)

It allows the recovery and anticoagulation of blood suctioned from the surgical field. It consists of a double PVC tube, which serves. The tube used for blood suction has two lines, one line for infusing the solution which converges at the end of the second blood suction line to give anticoagulation. (Fig. 2B):

  1. (a)

    to connect to the suction cannula;

  2. (b)

    Connection to the tank;

  3. (c)

    Connection to the anticoagulant solution tank using a perforator.

Anticoagulant solution: In this study, sodium heparin 25,000 (IU) was used, diluted in one liter of physiological solution, with an infusion rate of 25 ml/hour, which served to thin the blood aspirated from the surgical field to prevent the formation of clots, in the aspiration line and in the venous reservoir. The subsequent washing of the collected blood eliminates heparin, platelets, plasma, and coagulation factors, concentrating only the red blood cells [3].

Methods for Cleanfield Use

Fluid is collected from the operating field via a special double-lumen suction tube and mixed with an anticoagulant solution. The collected fluid is filtered into a sterile cardiotomy reservoir. The tank contains a filter and has a capacity of two to three liters of liquid. Once enough volume has been collected to fill the pond, treatment can begin. The volume required to fill the bowl depends on the hematocrit (HCT) and the size of the centrifuge wash bowl. If the patient's HCT level is normal, the amount required to process the unit is approximately twice the bolus volume. When aspirating blood, it is important to use the following technique whenever possible:

  • Aspirate blood from pools rather than collecting it.

  • Keep the suction tip below the level of the air-blood interface.

  • Avoid blocking the suction tip (e.g., use the suction as a spacer).

The negative pressure in the tank is controlled manually in our experience through vacuum meters for a negative pressure < 40 mmHg.

The use of these techniques helps to reduce red blood cell hemolysis and increase the amount of red blood cells retained.

Statistics

Continuous data are expressed as a mean ± standard deviation or a median for the measured variables in this study. All statistical analyses were performed with SPSS 22.0 (SPSS Inc., Chicago, IL, USA).

Results

In this retrospective analysis, were found 5202 Cleanfield disposable autotransfusion reservoir (Eurosets SRL,Medolla,Italy) use for blood volume suction, filtering, and collection, on 5199 elective cardiac surgery procedures, the maximum blood volume filtered and collected was 1997 ± 123 ml, the mean suction pressure measured from the device with vacuum meter during suction use was 38 ± 3 mmHg, the mean suction pressure measured in the device during suction use was 38 ± 2 mmHg, no presence of adverse event was reported for implosion, clot formation, inability to cell saver use, and inability to suction during the use.

Discussion

In contrast to preoperative autologous donation (PAD) and acute normovolemic hemodilution (ANH), in which the patient's blood is collected before surgical blood loss, intraoperative blood donation (also called blood rescue) focuses on the collection and preservation of already exfoliated or blood lost elsewhere. [7, 8]. The collected blood is washed or filtered and returned to the patient if transfusion is required [9]. Blood sampling is generally safe and has a very low incidence of adverse events. This technique can be used during surgery to compensate for intraoperative blood loss [10, 11]. The benefit is greater in procedures with high blood loss (≥ 1000 ml). In cardiac surgery, re-injection of mediastinal blood after irrigation can be considered as part of a multimodal blood conservation strategy, especially in patients not taking allogeneic blood products [12]. Intraoperative salvage autotransfusion has been reported to affect postoperative renal function [13]. During the process of hematoma collection and transfusion, erythrocytes are aspirated, filtered and separated by vacuum aspiration, resulting in some deterioration of renal function related to hemolysis [14]. Elevated plasma-free hemoglobin levels are associated with multiple organ damage, including severe acute kidney injury. In this study, it was not possible to make a correlation between hemolysis of the suction system and renal function because it is multifactorial and depends on numerous variables, Oxygen delivery during cardiopulmonary bypass (CPB), Mean arterial Pressure (MAP), Transfusion, and Liquids. In the literature to date, many articles have addressed the topic of autotransfusion without specifically addressing the issue of aspiration, filtration, and collection of blood through the autotransfusion reservoir in terms of efficacy and safety [15, 16]. In this context, we have explored this aspect by focusing on the Cleanfield device from Eurosets SRL (Medolla, Italy). The study limitations are as follows: (1) The lack of a comparison group or control group, making it challenging to assess whether the Cleanfield device performs better than other existing autotransfusion systems. A comparative analysis would strengthen the findings and provide a better context for evaluating the device's effectiveness; (2) The study primarily focuses on technical aspects such as blood volume, suction pressure, and adverse events. However, it lacks information on important clinical endpoints such as patient outcomes, postoperative complications, and the overall impact on morbidity and mortality; (3) The study is conducted in a single cardiothoracic surgery center, limiting the generalizability of the findings to a broader population. Including data from multiple centers or diverse settings would enhance the external validity of the study. Despite the major limitations of this research not highlighting clinical endpoints, the accuracy of the measurement of negative aspiration pressure in autotransfusion reservoir lower than 0.03 Mpa is crucial for the prevention of plasma-free hemoglobin as reported by Zeng et al.

Conclusions

In our retrospective report and experience, the use of Cleanfield autotransfusion reservoir (Eurosets SRL, Medolla Italy) in cardiothoracic surgery context was safe and effective for blood volume suction, filtering, and collection. Further investigation is needed to support a clear demonstration of the device's clinical benefits.