Perioperative blood transfusion: does it influence survival and cancer progression in metastatic spine tumor surgery?

Impact of restrictive versus liberal transfusion strategy on outcomes in patients undergoing surgery for spinal metastasis: a propensity score-matched analysis

BACKGROUND

Spinal metastasis, common in advanced cancer cases, frequently require surgical intervention to improve quality of life by stabilizing the spine and alleviating neural compression. The perioperative transfusion strategies in this setting is under debate. Evidence specific to spinal metastasis surgery remains limited. This study aimed to evaluate the effects of liberal versus restrictive transfusion strategy on postoperative outcomes in patients undergoing surgery for spinal metastasis.

METHODS

A retrospective study was conducted with patients who underwent surgery for spinal metastasis. Using propensity score matching (PSM), patients were matched into restrictive and liberal transfusion groups, adjusting for baseline characteristics. Postoperative outcomes, including 30-day complications, hospital stay, and survival rates at 3 months and 1 year, were compared between the groups.

RESULTS

Among 483 patients, 303 received at least one unit of red blood cells during hospitalization. Of these, 125 (41.3%) were in the restrictive transfusion group, and 178 (58.7%) in the liberal transfusion group. After PSM, 70 patients in each group were matched 1:1, ensuring comparable baseline characteristics. Post-matching analysis revealed no significant differences between the groups in key outcomes: 3-month survival (84% vs. 83%, P = 0.820), 1-year survival (46% vs. 51%, P = 0.499), 30-day postoperative complications (19% vs. 23%, P = 0.532), and median length of stay (15 [IQR, 11-18] days vs. 13 [IQR, 11-17] days, P = 0.316).

CONCLUSIONS

Our study supports using a restrictive transfusion strategy with a target nadir Hb level of 7-8 g/dL for spinal metastasis surgery. This approach ensures adequate oxygen delivery while minimizing unnecessary transfusions and associated risks. Future studies should validate these findings and further explore patient-centered outcomes to refine transfusion strategy in high-risk oncology patients.

CLINICAL TRIAL NUMBER

Not applicable.

Assessing the impact of perioperative allogenic blood transfusion in spinal surgery: a comprehensive systematic review, meta-analysis, and meta-regression analysis

The number of spinal surgeries, including decompression and fusion procedures, has increased significantly. Despite the potential benefits, these surgeries can result in substantial blood loss, requiring perioperative blood transfusions. However, transfusions can pose risks, such as infections and thromboembolic events. This study aimed to compare the outcomes between transfusion and non-transfusion groups in spinal surgery patients, focusing on infection rates, DVT, mortality, and other complications. A systematic search was conducted across PubMed, Medline, Embase, and Scopus from inception to April 1, 2024, yielding 15 studies involving a total of 60,920 patients. These studies focused on adult patients undergoing spinal surgery for conditions such as tumors, trauma, infection, or congenital diseases, comparing those who received blood transfusions (PRBC, FFP, platelets, and allogeneic blood transfusions) to those who did not. Eligible studies reported outcomes such as mortality, ischemic events, surgery duration, pulmonary embolism, surgical site infections (SSI), and urinary tract infections (UTI). Statistical analysis was conducted using Comprehensive Meta-Analysis Version 3.3, applying a random-effects model. Outcomes were expressed as odds ratios (OR) for dichotomous variables and standard differences in means for continuous outcomes. The quality of studies was assessed using the Newcastle-Ottawa quality assessment scale. Heterogeneity was evaluated using I² statistics, and publication bias was assessed using funnel plots. Results indicated no significant difference in surgery duration between transfusion and non-transfusion groups. However, patients receiving transfusions experienced longer hospital stays (SMD: 1.462, p = 0.021) and higher odds of complications (OR: 3.11, p < 0.001). Moreover, the transfusion group exhibited elevated odds of mortality (OR: 3.96, p < 0.001), ischemic events (OR: 3.527, p < 0.001), respiratory complications (OR: 4.18, p < 0.001), renal complications (OR: 2.43, p < 0.001), pulmonary embolism (OR: 2.67, p = 0.012), deep vein thrombosis (OR: 2.737, p < 0.001), and thrombotic complications (OR: 5.232, p < 0.001). Additionally, the transfusion group had higher odds of surgical site infection (OR: 1.951, p < 0.001), while the non-transfusion group had decreased odds of urinary tract infection (OR: 2.960, p < 0.001). No significant difference was observed in respiratory tract infection (OR: 1.936, p = 0.09). Patients receiving blood transfusions had significantly higher odds of complications, including mortality, ischemic events, and thrombotic issues, as well as longer hospital stays. However, no significant difference was found in surgery duration between the transfusion and non-transfusion groups.

Evaluation of the Feasibility of Transfusing Leukocyte Depletion Filter-Processed Intraoperative Cell Salvage Blood in Metastatic Spine Tumor Surgery: Protocol for a Non-Randomized Study

BACKGROUND

Metastatic spine tumor surgery (MSTS) is often complex and extensive leading to significant blood loss. Allogeneic blood transfusion (ABT) is the mainstay of blood replenishment but with immune-mediated postoperative complications. Alternative blood management techniques (salvaged blood transfusion [SBT]) allow us to overcome such complications. Despite widespread use of intraoperative cell salvage (IOCS) in oncological and nononcological surgical procedures, surgeons remain reluctant to use IOCS in MSTS.

OBJECTIVE

This study aims to analyze safety of IOCS-leukocyte depletion filter (LDF)-processed blood transfusion for patients undergoing MSTS by assessing clinical outcomes-disease progression: tumor progression and overall survival. This study evaluates whether reinfusion of IOCS-LDF-processed blood reduces ABT rates in patients undergoing MSTS by sorting patients undergoing MSTS who require ABT into patients who consent to receive or not receive SBT.

METHODS

We aim to recruit a minimum of 90 patients-30 patients for SBT, 30 patients for ABT, and 30 patients with no blood transfusion. SBT and ABT form the 2 experimental arms, whereas no blood transfusion forms the control cohort. Available patient data will be reviewed to determine tumor burden secondary to metastasis and postoperative survival and disease progression, improvement in pain, and neurological and ambulatory status. Data collected will be studied postoperatively at 3, 6, 12, 24, 36, and 48 months or until demise, whichever occurs first. Outcomes of the experimental groups will be compared with those of the control group. Outcomes will be analyzed using 1-way ANOVA and Fisher exact test. The Kaplan-Meier curve and a log-rank test will be used to study overall survival. A multivariate and competing risk analysis will be used to study the association between blood transfusion type and tumor progression. All statistical analyses will be done using Stata Special Edition 14.0 (StataCorp LP).

RESULTS

This is the largest clinical study on use of IOCS in MSTS from various primary malignancies to date. It will provide significant clinical evidence regarding the safety and applicability of IOCS in MSTS. It will help reduce use of ABT, improving overall blood management of patients undergoing MSTS. A limitation of this study is that not all patients undergoing MSTS will survive for the follow-up period (4 years), theoretically leading to underreporting of disease progression. Study commenced in 2016 and patient recruitment continued till 2019. As of September 2019, we have collected operative data on 140 patients. However, the 2-year outcomes of about 40.0% (56/140) of patients are in the process of collection. The study is aimed to be published in the years 2023-2024.

CONCLUSIONS

Results will be disseminated via peer-reviewed publications, paving the way for future studies.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/54609.

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.

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.

Systemic considerations for the surgical treatment of spinal metastatic disease: a scoping literature review

Systemic assessment is a pillar in the neurological, oncological, mechanical, and systemic (NOMS) decision-making framework for the treatment of patients with spinal metastatic disease. Despite this importance, emerging evidence relating systemic considerations to clinical outcomes following surgery for spinal metastatic disease has not been comprehensively summarised. We aimed to conduct a scoping literature review of this broad topic. We searched MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and CINAHL databases from Jan 1, 2000, to July 31, 2021. 61 articles were included, accounting for a total of 22 335 patients. Preoperative systemic variables negatively associated with postoperative clinical outcomes included demographics (eg, older age [>60 years], Black race, male sex, low or elevated body-mass index, and smoking status), medical comorbidities (eg, cardiac, pulmonary, hepatic, renal, endocrine, vascular, and rheumatological), biochemical abnormalities (eg, hypoalbuminaemia, atypical blood cell counts, and elevated C-reactive protein concentration), low muscle mass, generalised motor weakness (American Spinal Cord Injury Association Impairment Scale grade and Frankel grade) and poor ambulation, reduced performance status, and systemic disease burden. This is the first comprehensive scoping review to broadly summarise emerging evidence relevant to the systemic assessment component of the widely used NOMS framework for spinal metastatic disease decision making. Medical, surgical, and radiation oncologists can consider these findings when prognosticating spinal metastatic disease-related surgical outcomes on the basis of patients' systemic condition. These factors might inform a shared decision-making approach with patients and their families.

Analysis of Short-Term versus Long-Term Readmission-Free Survival After Metastatic Spine Tumor Surgery

BACKGROUND

Readmission-free survival (ReAFS) is a novel clinical and quality metric after metastatic spine tumor surgery (MSTS). We believe that factors influencing ReAFS after index MSTS vary based on time. We considered 2 time frames and defined short-term ReAFS as survival without an unplanned hospital readmission up to 90 days and long-term ReAFS as survival without unplanned hospital readmission up to 1 year after MSTS.

METHODS

We retrospectively analyzed 266 patients who underwent MSTS between 2005 and 2016. All relevant oncologic, surgical and follow-up data were collected. Multivariate logistic regression analysis was used to analyze prognostic factors associated with higher probability of short-term ReAFS and long-term ReAFS.

RESULTS

Multivariate analysis showed that Eastern Cooperative Oncology Group score ≤2 (P = 0.011), preoperative hemoglobin (Hb) level >12 g/dL (P = 0.008), ≤3 comorbidities (P = 0.052), shorter index length of stay ≤10 days (P = 0.007), and absence of neurologic/hematologic complications during index stay (P = 0.015) significantly increased the probability of short-term ReAFS, whereas preoperative Hb level >12 g/dL (P = 0.003) or tumor primaries with advanced treatment modalities such as breast (P = 0.012), hematologic (P = 0.006), prostate (P = 0.004), and renal/thyroid (P = 0.038) as opposed to aggressive lung tumor primaries were associated with significantly higher probability of long-term ReAFS.

CONCLUSIONS

Patient and treatment factors predominantly influence ReAFS up to 90 days, whereas primary tumor-related factors alongside general health influence ReAFS beyond 90 days after index MSTS. Awareness of these factors may help oncologists and surgeons optimize treatment planning. The clinical significance of this study will continue to evolve, because we have been witnessing over the past decade that patients are becoming more involved in both their general health and understanding the natural history of the diseases that affect them.

Transfusion‑related immunomodulation in patients with cancer: Focus on the impact of extracellular vesicles from stored red blood cells (Review)

Red blood cell (RBC) transfusions may have a negative impact on the prognosis of patients with cancer, where transfusion‑related immunomodulation (TRIM) may be a significant contributing factor. A number of components have been indicated to be associated with TRIM. Among these, the impact of extracellular vesicles (EVs) has been garnering increasing attention from researchers. EVs are defined as nano‑scale, cell‑derived vesicles that carry a variety of bioactive molecules, including proteins, nucleic acids and lipids, to mediate cell‑to‑cell communication and exert immunoregulatory functions. RBCs in storage constitutively secrete EVs, which serve an important role in TRIM in patients with cancer receiving a blood transfusion. Therefore, the present review aimed to first summarize the available information on the biogenesis and characterization of EVs. Subsequently, the possible mechanisms of TRIM in patients with cancer and the impact of EVs on TRIM were discussed, aiming to provide an outlook for future studies, specifically for formulating recommendations for managing patients with cancer receiving RBC transfusions.

Thirty-day Outcomes After Surgery for Metastatic Bone Disease of the Extremities: An Analysis of the NSQIP Database

INTRODUCTION

Metastatic bone disease of the extremities is a notable cause of morbidity and mortality. Surgical management is not curative; therefore, risks and benefits of surgery must be carefully considered. Previous studies of surgical outcomes are limited by small sample sizes because of the rare incidence of these procedures. In this study, we aim to describe the rates of complications and mortality in the first 30 days after surgical treatment of metastatic bone disease of the femur and humerus.

METHODS

A retrospective review of patients in the National Surgical Quality Improvement Program database who underwent surgery between 2005 and 2016 was performed. Demographics, comorbidities, preoperative factors, surgical parameters, and postoperative complications were extracted. The cohort was also partitioned by surgical site and surgical modality.

RESULTS

One thousand one hundred fifty-four patients were identified, 13.1 percent of patients experienced one or more complications within 30 days of surgery. The most common complications were urinary tract infection (2.9%), deep vein thrombosis (2.5%), pneumonia (2.4%), pulmonary embolism (2.0%), and surgical site infections (1.9%). In addition, intraoperative or postoperative bleeding requiring transfusion occurred in 32.9% of cases. The rates of unplanned readmission and unplanned revision surgery were 12.7% and 4.1%, respectively. The 30-day mortality rate was 7.1%. Femur and arthroplasty cases were associated with a higher risk of bleeding requiring transfusion. Prophylactic stabilization was associated with a lower risk of unplanned revision surgery (P = 0.015) and a lower overall complication rate (P < 0.0001).

CONCLUSION

Our study demonstrates a higher 30-day mortality rate than previously reported. In additon, prophylactic stabilization of impending pathologic fractures may be associated with a lower risk of complications and unplanned revision surgery. The National Surgical Quality Improvement Program or other large database reports can help surgeons counsel patients appropriately regarding the risks and benefits of surgery.

Asymptomatic Construct Failure after Metastatic Spine Tumor Surgery: A New Entity or a Continuum with Symptomatic Failure?

Study Design

Retrospective cohort study.

Purpose

To study the incidence, onset, underlying mechanism, clinical course, and factors leading to asymptomatic construct failure (AsCF) after metastatic spinal tumor surgery (MSTS).

Overview of Literature

The reported incidence rates for implant and/or construct failure after MSTS are low (1.9%–16%) and based on clinical presentations and revisions required for symptomatic failures (SFs). AsCF after MSTS has not been reported.

Methods

We conducted a retrospective analysis of 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological AsCF were defined as presentation before and after 3 months, respectively. We analyzed patients with AsCF for risk factors and survival duration by performing competing risk regression analyses where AsCF was the event of interest, with SF and death as competing events.

Results

We observed AsCF in 41/246 patients (16.7%). The mean time to onset of AsCF after MSTS was 2 months (range, 1–9 months). Median survival of patients with AsCF was 20 and 41 months for early and late failures, respectively. Early AsCF accounted for 80.5% of cases, while late AsCF accounted for 19.5%. The commonest radiologically detectable AsCF mechanism was angular deformity (increase in kyphus) in 29 patients. Increasing age (p<0.02) and primary breast (13/41, 31.7%) (p<0.01) tumors were associated with higher AsCF rates. There was a non-significant trend towards AsCF in patients with a spinal instability neoplastic score ≥7, instrumentation across junctional regions, and construct lengths of 6–9 levels. None of the patients with AsCF underwent revision surgery.

Conclusions

AsCF after MSTS is a distinct entity. Most patients with early AsCF did not require intervention. Patients who survived and maintained ambulation for longer periods had late failure. Increasing age and tumors with a better prognosis have a higher likelihood of developing AsCF. AsCF is not necessarily an indication for aggressive/urgent intervention.

Prognostic Differences in Patients with Solitary and Multiple Spinal Metastases

Objectives

To investigate the association between the number of metastases to the spine and survival in patients with metastatic spinal cord compression (MSCC), as well as the prognosis difference between patients with solitary spinal metastasis (SSM) and multiple spinal metastases (MSM).

Methods

Three institutional databases were searched to identify all patients who had undergone spinal surgery for metastatic spinal tumors between March 2002 and June 2010. As well as age and gender, preoperative medical conditions were collected from medical records, including primary tumor, preoperative Frankel score, other bone metastases, preoperative Karnofsky performance status (KPS), number of involved vertebrae, pathological fracture metastasis site, serum albumin, sphincter dysfunction and the time of developing motor deficits before surgery. Survival data were obtained from medical records or via telephone follow‐ups. Univariate and multivariate predictors of overall survival for each group were assessed using the Cox proportional hazards model.

Results

The median postoperative survival time was 6.0 ± 0.6 months (95% confidence interval [CI] 4.8–7.2) in patients with SSM and 7.0 ± 1.0 months (95% CI 5.1–8.9) in patients with MSM (P = 0.238). The difference in survival was not significant between groups. Furthermore, univariate analysis showed that the number of spinal metastases had no significant association with survival (P = 0.075). Primary tumor (P = 0.004) and preoperative KPS (P < 0.001) were independent prognostic factors in the whole cohort; primary tumor (P = 0.020), time of developing motor deficit (P = 0.041) and preoperative KPS (P = 0.038) were independent prognostic factors in patients with SSM; while preoperative KPS (P = 0.001) and serum album level (P < 0.001) were independent prognostic factors in patients with MSM.

Conclusion

The number of spinal metastases has not proven to be useful in predicting the prognosis for patients with MSCC. Consequently, more aggressive operations should be considered for patients with multiple spinal metastases.

Allogeneic red cell transfusion and its influence on relevant humoral and cellular immunological parameters: A prospective observational trial

BACKGROUND

It is assumed that transfusion of allogeneic red cells is associated with increased peri-operative mortality and morbidity. Also assumed is the theory of transfusion-related immunomodulation.

OBJECTIVE

The aim of this study was to investigate the hypothesis that red cell transfusion specifically leads to an immunological response in surgical patients.

DESIGN

Prospective observational study.

SETTING

Departments of Orthopedic Surgery and Anaesthesia, University Hospital, Thailand.

PATIENTS

Low-risk, noncancer patients, aged 18 to 75 years undergoing elective major spine surgery, with and without red cell transfusion therapy.

INTERVENTIONS

Blood specimens were withdrawn four times (prior to surgery and on days 1, 3 and 5).

MAIN OUTCOME MEASURES

Assessment of immunocompetent cells and cytokines in transfused and nontransfused patients using flow cytometry and multiplex ELISA.

RESULTS

From a total of 78 patients, 61 met the requirements and were analysed in three groups: 19 with no transfusion and 26 and 16 transfused intra-operatively and on day 1 or 2, respectively. No patient experienced peri-operative haemorrhage. Postoperative infection or thrombosis occurred in 5.5% of nontransfused patients and 16.6% of transfused patients; the difference was not significant. There was no significant immunomodulatory effect of red cell transfusion: of 45 immunological parameters, only five little-relevant cytokines were significantly affected, although slightly and nonspecifically.

CONCLUSION

Our data indicate that red cell transfusion alone does not create an immunological response in otherwise healthy surgical patients. Our findings do not generally contradict the transfusion-related immunomodulation phenomenon, which has, however, primarily been observed in patients with an already weakened or procedure-deteriorated immune system, such as from malignant disease, significant comorbidity, extensive abdominal/thoracic surgery and cardiopulmonary bypass.

TRIAL REGISTRATION

The study was registered on 15 May 2014, before enrolment of the first patient, at www.ClinicalTrials.gov, NCT02140216.

Clinical Outcomes Associated With Allogeneic Red Blood Cell Transfusions in Spinal Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The objectives of this systematic review were to report the available clinical evidence on patient outcomes associated with perioperative allogeneic red blood cell (RBC) transfusions in adult patients undergoing spinal surgery and to determine whether there is any evidence to support an association between transfusion timing and clinical outcomes.

METHODS

A systematic review of the PubMed, EMBASE, and Cochrane Library databases was performed to identify all articles examining outcomes of adult spinal surgery patients who received perioperative allogeneic RBC transfusions. The level of evidence for each study was assessed using the "Oxford Levels of Evidence 2" classification system. Meta-analysis was not performed due to the heterogeneity of reports.

RESULTS

A total of 2759 unique citations were identified and 76 studies underwent full-text review. Thirty-four studies were selected for analysis. All the studies, except one, were retrospective. Eleven studies investigated intraoperative or postoperative transfusions. Only one article compared outcomes related to intraoperative versus postoperative transfusions.

CONCLUSIONS

Perioperative transfusion is associated with increased rates of postoperative complications, especially infectious complications, and prolonged length of stay. Some evidence suggests that a dose-response relationship may exist between morbid events and the number of RBC units administered, but these findings are inconsistent. Because of the heterogeneity of reports and inconsistent findings, the incidence of specific complications remains unclear. Limited research activity has focused on intraoperative versus postoperative transfusions, or the effect of transfusion on functional outcomes of spine surgery patients. Further research is warranted to address these clinical issues.

Treatment, complications, and outcomes of metastatic disease of the spine: from Patchell to PROMIS

Spinal metastases are common in patients with cancer. As cancer treatments improve and these patients live longer, the number who present with metastatic spine disease will increase. Treatment strategies for these patients continues to evolve. In particular, since the prospective randomized controlled study in 2005 by Patchell et al. showed increased survival with decompressive surgical treatment of spinal metastases, there is a growing body of literature focusing on surgical management and complications of surgery for this disease. Surgery is often one component of a multimodal treatment approach with chemotherapy and radiation, which makes it difficult to parse the benefits of each individual treatment in outcome studies. Additionally, there has been more recent emphasis placed on patient-reported outcomes (PRO) after treatment for metastatic spine disease. In this review, we summarize treatments of metastatic spinal disease, possible perioperative complications, and validated tools used to assess outcomes for these patients.

Red blood cell transfusion and its alternatives in oncologic surgery-A critical evaluation

Although blood transfusions have been used for more than 100 years and their potential to save lives is indisputable, there is still limited data on medium- and long-term outcomes after hemotherapy. Until recently, red blood cell transfusions represented the most commonly employed treatment for cancer anemia. As transfusions have been related to worse patient outcome in oncologic surgery, preventive strategies and alternative treatment approaches in the perioperative setting are warranted. This review aims to evaluate the evidence concerning the impact of transfusion on the course of malignant diseases with a focus on oncologic surgery and to provide a bundle of measures to improve patient care. The perioperative period is pivotal in determining long-term cancer outcome. An increasingly recognized area for improvement during this highly sensitive period is the treatment of anemia for three main reasons: Firstly, anemia has been recognized as an independent predictor of poor prognosis in cancer patients. Secondly, anemia is largely undertreated. Thirdly and probably most importantly, anemia therapy relied and often still relies heavily on red blood cell (RBC) transfusions, which may be an often suboptimal stopgap treatment. Perioperative RBC transfusions should be kept to a minimum due to growing concerns regarding the associated risks, which this review tries to clarify by providing an update of recent literature. This review furthermore discusses treatments for anemia and provides best-practice approaches to improve perioperative management of oncology patients undergoing surgery.

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.

Transfusion-related immunomodulation: a reappraisal

PURPOSE OF REVIEW

This review summarizes current and prior observations regarding transfusion-related immunomodulation (TRIM) and puts these ideas into a modern immunological context, incorporating concepts from innate, adaptive, and nutritional immunity. We propose that TRIM research focus on determining whether there are specific, well-defined immunosuppressive effects from transfusing 'pure' red blood cells (RBCs) themselves, along with the by-products produced by the stored RBCs as a result of the 'storage lesion.' Macrophages are a key cell type involved in physiological and pathological RBC clearance and iron recycling. The plasticity and diversity of macrophages makes these cells potential mediators of immune suppression that could constitute TRIM.

RECENT FINDINGS

Recent reports identified the capacity of macrophages and monocytes to exhibit 'memory.' Exposure to various stimuli, such as engulfment of apoptotic cells and interactions with ß-glucan and lipopolysaccharide, were found to induce epigenetic, metabolic, and functional changes in certain myeloid cells, particularly macrophages and monocytes.

SUMMARY

Macrophages may mediate the immunosuppressive aspects of TRIM that arise as a result of transfused RBCs and their storage lesion induced by-products.

Red blood cell transfusion in surgical cancer patients: Targets, risks, mechanistic understanding and further therapeutic opportunities

Anemia is present in more than half of cancer patients and appears to be an independent prognostic factor of short- and long-term adverse outcomes. It increases in the advanced period of cancer and perioperatively, in patients with solid tumors who undergo surgery. As a result, allogeneic red blood cell (RBC) transfusion is an indispensable treatment in cancer. However, its safety remains controversial, based on several laboratory and clinical data reporting a linkage with increased risk for cancer recurrence, infection and cancer-related mortality. Immunological, inflammatory and thrombotic reactions mediated by the residual leukocytes and platelets, the stored RBCs per se, the biological response modifiers and the plasticizer of the unit may underlie infection and tumor-promoting effects. Although the causality between transfusion and infection has been established, the effects of transfusion on cancer recurrence remain confusing; this is mainly due to the extreme biological heterogeneity that characterizes RBC donations and cancer context. In fact, the functional interplay between donation-associated factors and recipient characteristics, including tumor biology per se, inflammation, infection, coagulation and immune activation state and competence may synergistically and individually define the clinical impact of each transfusion in any given cancer patient. Our understanding of how the potential risk is mediated is important to make RBC transfusion safer and to pave the way for novel, promising and highly personalized strategies for the treatment of anemia in surgical cancer patients.