Intraoperative cell-salvaged autologous blood transfusion is safe in metastatic spine tumour surgery: early outcomes of prospective clinical study

PURPOSE

Allogeneic blood transfusion (ABT) is current standard of blood replenishment despite known complications. Salvaged blood transfusion (SBT) addresses majority of such complications. Surgeons remain reluctant to employ SBT in metastatic spine tumour surgery (MSTS), despite ample laboratory evidence. This prompted us to conduct a prospective clinical study to ascertain safety of intraoperative cell salvage (IOCS), in MSTS.

METHODS

Our prospective study included 73 patients who underwent MSTS from 2014 to 2017. Demographics, tumour histology and burden, clinical findings, modified Tokuhashi score, operative and blood transfusion (BT) details were recorded. Patients were divided based on BT type: no blood transfusion (NBT) and SBT/ABT. Primary outcomes assessed were overall survival (OS), and tumour progression was evaluated using RECIST (v1.1) employing follow-up radiological investigations at 6, 12 and 24 months, classifying patients with non-progressive and progressive disease.

RESULTS

Seventy-three patients [39:34(M/F)] had mean age of 61 years. Overall median follow-up and survival were 26 and 12 months, respectively. All three groups were comparable for demographics and tumour characteristics. Overall median blood loss was 500 mL, and BT was 1000 mL. Twenty-six (35.6%) patients received SBT, 27 (37.0%) ABT and 20 (27.4%) NBT. Females had lower OS and higher risk of tumour progression. SBT had better OS and reduced risk of tumour progression than ABT group. Total blood loss was not associated with tumour progression. Infective complications other than SSI were significantly (p = 0.027) higher in ABT than NBT/SBT groups.

CONCLUSIONS

Patients of SBT had OS and tumour progression better than ABT/NBT groups. This is the first prospective study to report of SBT in comparison with control groups in MSTS.

Reduction of EpCAM-Positive Cells from a Cell Salvage Product Is Achieved by Leucocyte Depletion Filters Alone

Intraoperative cell salvage reduces the need for allogeneic blood transfusion in complex cancer surgery, but concerns about the possibility of it re-infusing cancer cells have hindered its application in oncology. We monitored the presence of cancer cells on patient-salvaged blood by means of flow cytometry; next, we simulated cell salvage, followed by leucodepletion and irradiation on blood contaminated with a known amount of EpCAM-expressing cancer cells, assessing also residual cancer cell proliferation as well as the quality of salvaged red blood cell concentrates (RBCs). We observed a significant reduction of EpCAM-positive cells in both cancer patients and contaminated blood, which was comparable to the negative control after leucodepletion. The washing, leucodepletion and leucodepletion plus irradiation steps of cell salvage were shown to preserve the quality of RBCs in terms of haemolysis, membrane integrity and osmotic resistance. Finally, cancer cells isolated from salvaged blood lose their ability to proliferate. Our results confirm that cell salvage does not concentrate proliferating cancer cells, and that leucodepletion allows for the reduction of residual nucleated cells, making irradiation unnecessary. Our study gathers pieces of evidence on the feasibility of this procedure in complex cancer surgery. Nevertheless, it highlights the necessity of finding a definitive consensus through prospective trials.

Effectiveness of intraoperative cell salvage combined with a modified leucocyte depletion filter in metastatic spine tumour surgery

Background

To compare the effectiveness of intraoperative cell salvage (IOCS) combined with a modified leucocyte depletion filter (MLDF) with IOCS combined with a regular leucocyte depletion filter (RLDF) in eliminating tumour cells from blood salvage during metastatic spine tumour surgery (MSTS).

Methods

Patients with a known primary epithelial tumour who underwent MSTS were recruited for this study. Blood samples were collected in 5 stages: from the patients’ vein before anaesthesia induction (S1), from the operative field at the time of maximum tumour manipulation (S2), and from the operative blood after IOCS processing (S3) and after IOCS+RLDF (S4) and IOCS+MLDF (S5) processing. The polyploids of tumour cells in the blood samples were collected and counted with immunomagnetic separation enrichment and fluorescence in situ hybridization.

Results

We recruited 20 patients. Tumour cells were detected in 14 patients (70%) in S1, 16 patients (80%) in S2, 13 patients (65%) in S3, and 12 patients (60%) in S4. MLDF was added in 8 patients. Tumour cells were detected in only 1 of 8 patients in S5 (12.5%). There were significantly fewer tumour cells in the samples collected after MLDF processing (S5) than in the samples collected after RLDF (S4) and around the tumour (S2) (P = 0.016 and P = 0.039, respectively). Although no significant difference was observed between S4 and S1, a downward trend was observed after IOCS+RLDF processing.

Conclusions

Tumour cells could be removed by IOCS combined with RLDF from blood salvaged during MSTS, but residual tumour cells remained. The findings support the notion that MLDF eliminates tumour cells more effectively than RLDF. Hence, this technique can be applied to MSTS.

Trial registration

ChiCTR1800016162 Chinese Clinical Trial Registry.

Removal of EpCAM-positive tumor cells from blood collected during major oncological surgery using the Catuvab device- a pilot study

BACKGROUND

Intraoperative blood salvage (IBS) is regarded as an alternative to allogeneic blood transfusion excluding the risks associated with allogeneic blood. Currently, IBS is generally avoided in tumor surgeries due to concern for potential metastasis caused by residual tumor cells in the erythrocyte concentrate.

METHODS

The feasibility, efficacy and safety aspects of the new developed Catuvab procedure using the bispecific trifunctional antibody Catumaxomab was investigated in an ex-vivo pilot study in order to remove residual EpCAM positive tumor cells from the autologous erythrocyte concentrates (EC) from various cancer patients, generated by a IBS device.

RESULTS

Tumor cells in intraoperative blood were detected in 10 of 16 patient samples in the range of 69-2.6 × 105 but no residual malignant cells in the final erythrocyte concentrates after Catuvab procedure. IL-6 and IL-8 as pro-inflammatory cytokines released during surgery, were lowered in mean 28-fold and 52-fold during the Catuvab procedure, respectively, whereas Catumaxomab antibody was detected in 8 of 16 of the final EC products at a considerable decreased and uncritical residual amount (37 ng in mean).

CONCLUSION

The preliminary study results indicate efficacy and feasibility of the new medical device Catuvab allowing potentially the reinfusion of autologous erythrocyte concentrates (EC) produced by IBS device during oncological high blood loss surgery. An open-label, multicenter clinical study on the removal of EpCAM-positive tumor cells from blood collected during tumor surgery using the Catuvab device is initiated to validate these encouraging results.

Clinical Utility of Autologous Salvaged Blood: a Review

INTRODUCTION

Autologous salvaged blood, commonly referred to as "cell saver" or "cell salvage" blood, is an important method of blood conservation. Understanding the mechanism of action and summarizing the existing evidence regarding the safety, efficiency, and the relative costs of cell salvage may help educate clinicians on how and when to best utilize autotransfusion.

METHODS

This review focuses on issues concerning the quality of red blood cells (RBC), efficiency, and the cost effectiveness relative to autotransfusion. The key considerations of safe use and clinical applicability are described along with the challenges for wider dissemination.

RESULTS

Cell salvage can reduce requirements for allogeneic transfusions, along with the associated risks and costs. Autologous salvaged RBCs provide high-quality transfusion, since the cells have not been subjected to the adverse effects of storage as occurs with banked blood. The risks for RBC alloimmunization and transfusion-related infectious diseases are also avoided. With a careful selection of cases, salvaged blood can be more cost effective than donor blood. Cell salvage may have a role in cardiac, major vascular, orthopedic, transplant, and trauma surgeries. However, there remain theoretical safety concerns in cases with bacterial contamination or in cancer surgery.

CONCLUSION

In addition to other methods of blood conservation used in patient blood management programs, autologous salvaged blood adds value and is cost effective for appropriate surgical cases. Evidence suggests that autologous salvaged blood may be of higher quality and confer a cost reduction compared with the allogeneic banked blood, when used appropriately.

Approaches to Bloodless Surgery for Oncology Patients

Providing optimal care to surgical oncology patients who cannot be transfused for religious or other reasons can be challenging. However, with careful planning, using a combination of blood-conserving methods, these "bloodless" patients have clinical outcomes that are similar to other patients who can be transfused. Bloodless surgery can be accomplished safely for most patients, including those undergoing technically challenging oncologic surgery. This article reviews best practices used in a bloodless program during the preoperative, intraoperative, and postoperative periods, with the aim of achieving optimal outcomes when transfusion is not an option for surgical oncology patients.

Survival analysis of intraoperative blood salvage for patients with malignancy disease: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Intraoperative blood salvage as a blood-saving strategy has been widely used in surgery. Considering its theoretic risk of malignant tumor cells being reinfused and the corresponding blood metastases, the safety of intraoperative blood salvage in cancer surgery remains controversial.

METHODS

Following the Preferred Reporting Items for Systemic Review and Meta-Analysis (PRISMA), we searched the Cochrane Library, MEDLINE and EMBASE to November 2017. We included only studies comparing intraoperative blood salvage with allogeneic blood transfusion.

RESULTS

This meta-analysis included 9 studies with 4354 patients with 1346 patients in the intraoperative blood salvage group and 3008 patients in the allogeneic blood transfusion group. There were no significant differences in the 5-year overall survival outcome (odds ratio [OR] 1.12; 95% confidence interval [CI], 0.80-1.58), 5-year disease-free survival outcome (OR 1.08; 95% CI 0.86-1.35), or 5-year recurrence rate (OR 0.86; 95% CI 0.71-1.05) between the 2 study groups. Subgroup analysis also showed no significant differences in the 5-year overall survival outcome (OR 0.97; 95% CI 0.57-1.67) of hepatocellular carcinoma patients in liver transplantation.

CONCLUSIONS

For patients with malignant disease, intraoperative blood salvage did not increase the tumor recurrence rate and had comparable survival outcomes with allogeneic blood transfusion.

Current Status of the Use of Salvaged Blood in Metastatic Spine Tumour Surgery

To review the current status of salvaged blood transfusion (SBT) in metastatic spine tumour surgery (MSTS), with regard to its safety and efficacy, contraindications, and adverse effects. We also aimed to establish that the safety and adverse event profile of SBT is comparable and at least equal to that of allogeneic blood transfusion. MEDLINE and Scopus were used to search for relevant articles, based on keywords such as "cancer surgery," "salvaged blood," and "circulating tumor cells." We found 159 articles, of which 55 were relevant; 20 of those were excluded because they used other blood conservation techniques in addition to cell salvage. Five articles were manually selected from reference lists. In total, 40 articles were reviewed. There is sufficient evidence of the clinical safety of using salvaged blood in oncological surgery. SBT decreases the risk of postoperative infections and tumour recurrence. However, there are some limitations regarding its clinical applications, as it cannot be employed in cases of sepsis. In this review, we established that earlier studies supported the use of salvaged blood from a cell saver in conjunction with a leukocyte depletion filter (LDF). Furthermore, we highlight the recent emergence of sufficient evidence supporting the use of intraoperative cell salvage without an LDF in MSTS.

Metastatic efficiency of tumour cells can be impaired by intraoperative cell salvage process: truth or conjecture?

The use of salvaged blood in oncological surgery has been a matter of controversy over the years. This is due to the concern of systemic dissemination of reinfused tumour cells. Recent literature, across disciplines, has shed considerable light on its safety in terms of tumour recurrence, progression and overall survival rates. This clinical safety demonstrates the apparent metastatic inefficiency of reinfused tumour cells. The proof of this concept comes from various studies that have shown that salvaged blood has no tumour cells, or has a significantly lower count as compared to the patient's original circulatory tumour load. Recently, we took a step further and found that the tumour cells in the salvaged blood lose the capacity to replicate. In this review, we revisited the safety of salvaged blood from the point of view of metastatic potential. We have presented basic and applied science evidence regarding the innocuous nature of tumour cells that have been subjected to the cell salvage process. The understanding of the metastatic efficiency or the lack of it in tumour cells subjected to salvage process is key to allay the concerns conventionally associated with the use of salvaged blood in tumour surgery. Based on the available literature, we surmise that the prevalent apprehensions on the usage of salvaged blood are ill-founded and further substantiate why tumour cells in the salvaged blood could be regarded as cells with non-metastatic potential.

Flow cytometric evaluation of the safety of intraoperative salvaged blood filtered with leucocyte depletion filter in spine tumour surgery

BACKGROUND

Intraoperative cell salvage (IOCS) has not been widely adopted in oncological surgery due to the hypothetical concern of reinfusion of malignant cells. We evaluated the feasibility of IOCS in combination with leucocyte depletion filter (LDF) in metastatic spine tumour surgery (MSTS).

METHODS

Patients with known primary epithelial tumour, operated for metastatic spinal disease, were recruited. Blood samples were collected at five different stages during surgery: 2 stages from patient vein during induction and at the time of maximum tumour manipulation, 3 stages from the operative blood prior to IOCS processing, after IOCS processing, and after IOCS-LDF processing. Of the samples taken at each stage, 5 ml were analyzed for tumour cells using flow cytometry.

RESULTS

Of 12 patients recruited, only 11 could be finally analyzed. Flow cytometry analysis of their samples showed that 8 of 11 patients had tumour cells in the unfiltered salvaged blood. In filtered salvaged blood, the tumour cell count was zero in the majority of samples (8/11 patients), whereas three patients' samples had a few tumour cells. The mean difference between the tumour cell quantity in the samples from the patient vein and filtered salvaged blood was significant.

CONCLUSIONS

IOCS-LDF was shown to be effective in removing tumour cells from the blood salvaged during MSTS. If there were any tumour cells found, the quantity was significantly less than that in the patient's circulation. The results of this study reiterates the conclusions of our previous published work where we showed that IOCS-LDF treated blood in MSTS is safe for transfusion.