CAN INTRA-OPERATIVE CELL SALVAGE (IOCS) BE USED IN METASTATIC SPINE TUMOUR SURGERY? A SYSTEMATIC REVIEW

Summary There is emerging evidence of successful application of IOCS and leucocyte depletion filter in removing tumour cells from blood salvaged during various oncological surgeries. Research on the use of IOCS-LDF in MSTS is urgently needed. Introduction Intra-operative cell salvage (IOCS) can reduce allogeneic blood transfusion requirements in non-tumour related spinal surgery. However, IOCS is deemed contraindicated in metastatic spine tumor surgery (MSTS) due to risk of tumour dissemination. Evidence is emerging from different surgical specialties describing the use of IOCS in cancer surgery. We wanted to investigate if IOCS is really contraindicated in MSTS. We hereby present a systematic literature review to answer the following questions: 1. Has IOCS ever been used in MSTS? 2. Is there any evidence to support the use of IOCS in other oncologic surgeries? Methods A systematic review of the English literature was conducted using computer searching of databases: Medline, Embase, the Cochrane Central Register of Controlled Trials for articles published between 1 January 1986 and 31 Dec 2012. Results Question 1: A comprehensive literature search did not provide any publication describing the use of IOCS in MSTS. The application of IOCS in MSTS has never been described before. Question 2: Our systematic review shows that the use of IOCS has been extensively investigated in patients undergoing surgery for gynaecological, lung, urological, gastrointestinal, and hepatobiliary cancers. The literature review considered 281 abstracts from the initial search. After consideration by consensus, 30 articles were included in the final analysis. We included in our review -prospective, retrospective studies and in vitro studies. The selected articles were then classified according to the surgical specialty: gynaecological, lung, urological, gastrointestinal, and hepatobiliary cancers and type of studies: reinfusion studies, non-reinfusion studies and in vitro studies. 23 Reinfusion studies: Studies where salvaged blood was actually re-infused into patients and analyzed on the basis of clinical outcomes like survival, recurrence, metastasis rates, and transfusion requirements, etc. IOCS has been extensively investigated in several large cohort studies and large case series with considerable follow-up duration across urological, gynaecological, hepatobiliary and gastrointestinal cancers. Patients receiving salvaged blood have been shown to perform as well or better across a variety of clinical outcome measures as mentioned above. 2 in vitro studies and 5 non-reinfusion studies: Studies where salvaged blood was not re-infused into patients but was analyzed for the presence or viability of tumour cells in the processed blood. They consistently demonstrated the utility of LDF in either greatly reducing the number of tumour cells or even completely eradicating tumour cells from blood-tumour admixtures or salvaged blood. This provides the “proof-of-concept” that LDF is able and is effective in removing tumour cells from blood. Discussion/Conclusion There is strong evidence that LDF can safely remove tumour cells from salvaged blood. IOCS in patients undergoing cancer surgery is not associated with any adverse clinical outcomes. The reluctance of spine surgeons to use IOCS in MSTS appears to be unsupported. There is ample evidence supporting the use of IOCS in oncological surgeries. Research is needed to evaluate the application of IOCS in MSTS.