Evaluation of the Feasibility of Transfusing Leucocyte Depletion Filter (LDF) Processed Intra-Operative Cell Salvage (IOCS) Blood in Metastatic Spine Tumour Surgery (MSTS): Protocol for a Non Randomised Study (Preprint)

BACKGROUND Metastatic Spine Tumour Surgery (MSTS) is often complex and extensive leading to significant blood loss. Allogeneic blood transfusion (ABT) is mainstay of blood replenishment but with immune-mediated post-operative complications. Alternative blood management techniques (salvaged blood transfusion (SBT)) allow us to overcome such complications. Despite widespread use of intra-operative cell salvage (IOCS) in oncological and non-oncological surgeries, surgeons remain reluctant to employ IOCS in MSTS. OBJECTIVE This study will analyse the safety of IOCS-LDF processed blood transfusion to patients undergoing MSTS by assessing clinical outcomes – disease progression: tumour progression and overall survival (OS). We will also evaluate whether reinfusion of IOCS-LDF processed blood can reduce the ABT rates in patients undergoing MSTS by comparing the proportion of MSTS patients requiring ABT in those patients who consent to receive SBT, and those who do not consent for SBT. METHODS We aim to recruit 90-patients (minimum)-30 SBT, 30 ABT and 30 with no blood transfusion (NBT). SBT and ABT form the two experimental arms, while NBT forms the control cohort. All available patient data will be reviewed to determine tumour burden secondary to metastasis and post-operative survival and/or disease progression, improvement in pain, neurology and ambulatory status. Collected data will be studied at 3, 6, 12 and 24 months post-operatively, or until demise, whichever occurs first. Collected outcomes of the experimental groups will be compared with that of the control group. Statistical Analysis: Outcomes will be analysed using one-way ANOVA and Fisher’s exact test. OS will be studied by Kaplan-Meier curve and log rank test. Multivariate and competing risk analysis will be used to study the association between blood transfusion type and tumour progression. All statistical analyses will be done using STATA/SE14.0 RESULTS This is the first clinical study on the use of IOCS in MSTS from various primary malignancies. It will provide major clinical evidence regarding safety and applicability of IOCS in MSTS. It will help reduce ABT usage; thus improving overall blood management of MSTS patients. However, limitation of this study is that not all patients undergoing MSTS will survive for the total follow-up period (two years), thereby theoretically leading to under-reporting of disease progression. CONCLUSIONS Results will be disseminated via peer-reviewed publications and will pave the way for future studies CLINICALTRIAL This study did not involve a healthcare intervention and hence, did not need to be registered