Role of intraoperative red cell salvage and autologus transfusion in metastatic spine surgery: a pilot study and review of literature

Does Patient Blood Management Affect Outcomes in Metastatic Spine Tumour Surgery? A Review of Current Concepts

STUDY DESIGN

Narrative review.

OBJECTIVE

The spine is the most common site of metastases, associated with decreased quality of life. Increase in metastatic spine tumour surgery (MSTS) has caused us to focus on the management of blood, as blood loss is a significant morbidity in these patients. However, blood transfusion is also not without its own risks, and hence this led to blood conservation strategies and implementation of a concept of patient blood management (PBM) in clinical practise focusing on these patients.

METHODS

A narrative review was conducted and all studies that were related to blood management in metastatic spine disease as well as PBM surrounding this condition were included.

RESULTS

A total of 64 studies were included in this review. We discussed a new concept of patient blood management in patients undergoing MSTS, with stratification to pre-operative and intra-operative factors, as well as anaesthesia and surgical considerations. The studies show that PBM and reduction in blood transfusion allows for reduced readmission rates, lower risks associated with blood transfusion, and lower morbidity for patients undergoing MSTS.

CONCLUSION

Through this review, we highlight various pre-operative and intra-operative methods in the surgical and anaesthesia domains that can help with PBM. It is an important concept with the significant amount of blood loss expected from MSTS.

LEVEL OF EVIDENCE

Not applicable.

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.

Efficacy of Intraoperative Blood Salvage in Cerebral Aneurysm Surgery

Background. The use and effectiveness of intraoperative cell salvage has been analyzed in many surgical specialties. Until now, no data exist evaluating the efficacy of intraoperative cell salvage in cerebral aneurysm surgery. Aim. To evaluate the efficacy and cost effectiveness of intraoperative cell salvage in cerebral aneurysm surgery. Methods. Data were collected retrospectively for all the patients who underwent cerebral aneurysm surgery at our institution between 2013 and 2019. Routinely, we apply blood salvage through autotransfusion. The cases were divided into a ruptured cerebral aneurysm group and a unruptured cerebral aneurysm group. Results. A total of 241 patients underwent cerebral aneurysm clipping. Of all the cerebral aneurysms, 116 were ruptured and 125 were unruptured and clipped electively. Age, location of the aneurysm, postoperative red blood cell count, intraoperative blood loss, and number of allogenic blood cell transfusions were statistically significantly different between the groups. The autotransfusion of salvaged blood could only be facilitated in eight cases with ruptured cerebral aneurysms and in none with unruptured cerebral aneurysms clipped electively (p < 0.01). Additionally, 35 patients with ruptured cerebral aneurysms and one patient with unruptured cerebral aneurysm required allogenic red blood cell transfusion after surgery, and 71 vs. 2 units of blood were transfused (p < 0.0001). In terms of cost effectiveness, a total of EUR 45,189 in 241 patients was spent to run the autotransfusion system, while EUR 13,797 was spent for allogenic blood transfusion. Conclusions. The use of cell salvage in patients with unruptured cerebral aneurysm, undergoing elective surgery, is not effective.

[Safety of cell salvage in tumor surgery : Systematic review with meta-analysis]

BACKGROUND

Allogeneic blood transfusion is avoidable in many oncological interventions by the use of cell salvage or mechanical autotransfusion (MAT). As irradiation is elaborate and expensive, the safety of leucocyte depletion filters (LDF) for autologous blood from the surgical field might be a more acceptable alternative for the prevention of cancer recurrences. A previous meta-analysis could not identify an increased risk of cancer recurrence. The aim of this review article is to provide an update of a previous meta-analysis from 2012 as well as a safety analysis of cell salvage with LDF due to the improved data situation.

MATERIAL AND METHODS

This systematic review included all studies in PubMed, Cochrane, Cochrane Reviews and Web of Science on cell salvage or autotransfusion combined with outcomes, e.g. cancer recurrence, mortality, survival, blood transfusion, length of hospital stay (LOS) after the use of MAT without irradiation and with or without LDF. The grades of recommendations (GRADE) assessment of underlying evidence was applied.

RESULTS

A total of seven new observational studies and seven meta-analyses were found that compared unfiltered or filtered cell salvage with autologous predeposition, allogeneic transfusion or without any transfusion. No randomized controlled trials have been completed. A total of 27 observational and cohort studies were included in a meta-analysis. The evidence level was low. The risk of cancer recurrence in recipients of autologous salvaged blood with or without LDF was reduced (odds ratio, OR 0.71, 95% confidence interval, CI 0.58-0.86) as compared to non-transfused subjects, allogeneic or predeposited autologous transfusion. The transfusion rate could not be assessed due to the substantial selection bias and large heterogeneity. Cell salvage does not change mortality and LOS. Leucocyte depletion studies reported a removal rate of cancer cells in the range of 99.6-99.9%.

CONCLUSION

Randomized controlled trials on a comparison of MAT and allogeneic blood transfusion as well as LDF and irradiation would be desirable but are not available. From observational trials and more than 6300 subjects and various tumors, cell salvage in cancer surgery with or without LDF appears to be sufficiently safe. The efficacy of leucocyte depletion of autologous salvaged blood is equivalent to irradiation. Unavailability of radiation is not a contraindication for cell salvage use in cancer surgery. By usage of leucocyte depleted salvaged autologous blood, the risks of allogeneic transfusion can be avoided.

Person-to-Person Cancer Transmission via Allogenic Blood Transfusion

Despite the recognized capability of Circulating Tumor Cells (CTCs) to seed tumors, allogenic blood transfusions are not presently screened for the presence of CTCs. Previous research has examined blood transfusions and the associated risk of cancer recurrence, but not cancer of unknown primary (CUP) occurrence. The Hypothesis explored in this paper proposes that there is potential for cancers to be transmitted from donor-to-patient via CTCs in either blood transfusions or organ transplants or both. This proposed haematogenic tumor transmission will be discussed in relation to two scenarios involving the introduction of donor-derived CTC's from allogeneic blood transfusions into either known cancer surgery patients or into non-cancer patients. The source of CTCs arises either from the donor with a 'clinically dormant cancer' or a 'pre-clinical cancer' existing as yet undiagnosed, in the donor. Given the significant number of allogenic blood transfusions that occur worldwide on a yearly basis, allogenic blood transfusions have the potential to expose a substantial number of non-cancer recipients to the transmission of CTCs and associated tumor risk. This risk is greatly amplified in the low-income nations where the blood collection and processing protocols, including exclusion and screening criteria are less stringent than those in high-income countries.

A clinical calculator for predicting intraoperative blood loss and transfusion risk in spine tumor patients

BACKGROUND CONTEXT

Surgery for vertebral column tumors is commonly associated with intraoperative blood loss (IOBL) exceeding 2 liters and the need for transfusion of allogeneic blood products. Transfusion of allogeneic blood, while necessary, is not benign, and has been associated with increased rates of wound complication, venous thromboembolism, delirium, and death.

PURPOSE

To develop a prediction tool capable of predicting IOBL and risk of requiring allogeneic transfusion in patients undergoing surgery for vertebral column tumors.

STUDY DESIGN/SETTING

Retrospective, single-center study.

PATIENT SAMPLE

Consecutive series of 274 patients undergoing 350 unique operations for primary or metastatic spinal column tumors over a 46-month period at a comprehensive cancer center OUTCOME MEASURES: IOBL (in mL), use of intraoperative blood products, and intraoperative blood products transfused.

METHODS

We identified IOBL and transfusions, along with demographic data, preoperative laboratory data, and surgical procedures performed. Independent predictors of IOBL and transfusion risk were identified using multivariable regression.

RESULTS

Mean age at surgery was 57.0±13.6 years, 53.1% were male, and 67.1% were treated for metastatic lesions. Independent predictors of IOBL included en bloc resection (p<.001), surgical invasiveness (β=25.43 per point; p<0.001), and preoperative albumin (β=-244.86 per g/dL; p=0.011). Predictors of transfusion risk included preoperative hematocrit (odds ratio [OR]=0.88 per %; 95% confidence interval [CI, 0.84, 0.93]; p<0.001), preoperative MCHgb (OR=0.88 per pg; 95% CI [0.78, 1.00]; p=0.048), preoperative red cell distribution width (OR=1.32 per %; 95% CI [1.13, 1.55]; p<0.001), en bloc resection (OR=3.17; 95%CI [1.33, 7.54]; p=0.009), and surgical invasiveness (OR=1.08 per point; [1.06; 1.11]; p<0.001). The transfusion model showed a good fit of the data with an optimism-corrected area under the curve of 0.819. A freely available, web-based calculator was developed for the transfusion risk model (https://jhuspine3.shinyapps.io/TRUST/).

CONCLUSIONS

Here we present the first clinical calculator for intraoperative blood loss and transfusion risk in patients being treated for primary or metastatic vertebral column tumors. Surgical invasiveness and preoperative microcytic anemia most strongly predict transfusion risk. The resultant calculators may prove clinically useful for surgeons counseling patients about their individual risk of requiring allogeneic transfusion.

Evaluation of riboflavin photochemical treatment for inactivation of HCT116 tumor cells mixed in simulative intraoperative salvage blood

BACKGROUND

Radiation and filtration have achieved satisfactory results in inactivation or removal of tumor cells mixed in salvage blood, but some drawbacks remain. This study evaluated the inactivation on HCT116 cells mixed in simulative salvage blood by riboflavin photochemical treatment.

METHODS

HCT116 cells were added to the whole blood to simulate contaminated salvaged blood. The mixed blood was added with riboflavin of 50 μmol/L final concentration and illuminated by ultraviolet light. The samples were divided into control group and Experimental Groups 1 (18 J/cm² ), 2 (23.4 J/cm² ), and 3 (28.8 J/cm² ). An autotransfusion system (Cell Saver Elite, Haemonetics) was used to simulate the intraoperative blood salvage procedure to deal with whole blood. The apoptosis rate and tumorigenicity of HCT116 cells and the superimposed damage to red blood cells (RBCs) were evaluated.

RESULTS

The apoptosis rates of HCT116 in Experimental Groups 1, 2, and 3 were much higher than that in the control group. Tumor growth was found in the control group, but no tumor growth was found in the three experimental groups. The hemolysis rates in the three experimental groups were significantly higher than that in the control group, but much lower than the quality standard of RBCs at the end of preservation. The concentration of adenosine triphosphate in RBCs was comparable in the control and experimental groups.

CONCLUSION

Riboflavin at a 50 μmol/L final concentration and 18 J/cm² ultraviolet illumination can effectively inactivate HCT116 cells in salvaged blood, with minimum damage to the structure and function of RBCs, and the main quality indexes of salvaged RBCs were within the standard range.