Evaluation of the safety of Intraoperative Salvaged Blood by using Microwell based Culture
Authors: Kumar Naresh , Zaw Aye Sandar , Khoo Bee Luan , Thiery Jean Paul 
Published: April 2016

Introduction Intraoperative cell salvage (IOCS) in metastatic spine tumor surgery (MSTS) is a novel alternative for addressing the potential side effects related to ABT. However, it has not been widely adopted in oncological surgery due to the hypothetical concern of reinfusing tumor cells to the patients. Despite the emerging evidence of the safety of IOCS especially in combination with leucocyte depletion filter (LDF), most surgeons are still doubtful about using IOCS during oncological surgery. We aimed to evaluate the feasibility of using intraoperative cell salvage (IOCS) in combination with leucocyte depletion filter (LDF) in eliminating cancer cells from blood salvaged during metastatic spine tumor surgery (MSTS). We hypothesized that tumor cells, even if left in the salvaged blood, are incapable of seeding and replicating due to potential damage to the cell membrane or the contents during suction, centrifugation and filtration during cell saver processing and hence, making the salvaged blood safe to be reinfused. Methods Patients with known primary epithelial tumor, who were offered surgery for metastatic spine disease at our university hospital, were recruited. Blood samples were collected at five different stages during surgery: Stage A: venous blood from the patient during induction by anaesthetist, Stage B: venous blood from the patient during maximum tumor manipulation by the surgeons, Stage C:blood from operative field prior to IOCS processing, Stage D: salvaged blood after IOCS processing and stage E: salvaged blood after IOCS-LDF processing. Blood samples(5 ml) were taken at each stage. Samples were sent for preparation of microwell-based culture assay for detection of primary circulating tumor cells (CTCs). Results We recruited 13 patients of which 12 were included in final analysis. There were 7 females and 5 males. The median age of the patients was 61 years (range: 48 - 76 years). The commonest primary tumor was lung, followed by breast, hepatocellular and renal cell carcinoma. The median blood loss was 800 ml (range: 300 – 1500 ml). Analysis of the cultured samples showed that clusters or CK+ CTCs (cytokeratin positive CTCs) were found in the samples taken from stage A in three patients, stage B in three patients and stage C in one patient. However, none of the samples D and E from any patients generated viable tumor clusters or CK+ CTCs after culture. Conclusions The present study proved that our hypothesis was correct. The findings supported the notion that IOCS-LDF combination works effectively in eliminating/destroying tumor cells from salvaged blood. The absence of viable CTCs in the samples taken from salvaged blood (stage D) provided the fact that salvaged blood even without filtration is safe for reinfusion in cancer patients. This IOCS technique can be applied in MSTS and even musculoskeletal oncological surgery. The concept can then be extended to other oncological surgeries in general with further appropriate clinical studies.