Release of inflammatory mediators in irradiated cell salvage blood and their biological consequences in human beings following transfusion:

Tumor Necrosis Factor Alpha: Implications of Anesthesia on Cancers

Cancer remains a major public health issue and a leading cause of death worldwide. Despite advancements in chemotherapy, radiation therapy, and immunotherapy, surgery is the mainstay of cancer treatment for solid tumors. However, tumor cells are known to disseminate into the vascular and lymphatic systems during surgical manipulation. Additionally, surgery-induced stress responses can produce an immunosuppressive environment that is favorable for cancer relapse. Up to 90% of cancer-related deaths are the result of metastatic disease after surgical resection. Emerging evidence shows that the interactions between tumor cells and the tumor microenvironment (TME) not only play decisive roles in tumor initiation, progression, and metastasis but also have profound effects on therapeutic efficacy. Tumor necrosis factor alpha (TNF-α), a pleiotropic cytokine contributing to both physiological and pathological processes, is one of the main mediators of inflammation-associated carcinogenesis in the TME. Because TNF-α signaling may modulate the course of cancer, it can be therapeutically targeted to ameliorate clinical outcomes. As the incidence of cancer continues to grow, approximately 80% of cancer patients require anesthesia during cancer care for diagnostic, therapeutic, or palliative procedures, and over 60% of cancer patients receive anesthesia for primary surgical resection. Numerous studies have demonstrated that perioperative management, including surgical manipulation, anesthetics/analgesics, and other supportive care, may alter the TME and cancer progression by affecting inflammatory or immune responses during cancer surgery, but the literature about the impact of anesthesia on the TNF-α production and cancer progression is limited. Therefore, this review summarizes the current knowledge of the implications of anesthesia on cancers from the insights of TNF-α release and provides future anesthetic strategies for improving oncological survival.

Cell Salvage in Oncological Surgery, Peripartum Haemorrhage and Trauma

Oncological surgery, obstetric haemorrhage and severe trauma are the most challenging conditions for establishing clinical recommendations for the use of cell salvage. When the likelihood of allogeneic transfusion is high, the intraoperative use of this blood-saving technique would be justified, but specific patient selection criteria are needed. The main concerns in the case of oncological surgery are the reinfusion of tumour cells, thereby increasing the risk of metastasis. This threat could be minimized, which may help to rationalize its indication. In severe peripartum haemorrhage, cell salvage has not proven cost-effective, damage control techniques have been developed, and, given the risk of fetomaternal alloimmunization and amniotic fluid embolism, it is increasingly out of use. In trauma, bleeding may originate from multiple sites, coagulopathy may develop, and it should be evaluated whether re-transfusion of autologous blood collected from uncontaminated organ cavities would be feasible. General safety measures include washing recovered blood and its passage through leukocyte depletion filters. To date, no well-defined indications for cell salvage have been established for these pathologies, but with accurate case selection and selective implementation, it could become safe and effective. Randomized clinical trials are urgently needed.

Clinical Utility of Autologous Salvaged Blood: a Review

INTRODUCTION

Autologous salvaged blood, commonly referred to as "cell saver" or "cell salvage" blood, is an important method of blood conservation. Understanding the mechanism of action and summarizing the existing evidence regarding the safety, efficiency, and the relative costs of cell salvage may help educate clinicians on how and when to best utilize autotransfusion.

METHODS

This review focuses on issues concerning the quality of red blood cells (RBC), efficiency, and the cost effectiveness relative to autotransfusion. The key considerations of safe use and clinical applicability are described along with the challenges for wider dissemination.

RESULTS

Cell salvage can reduce requirements for allogeneic transfusions, along with the associated risks and costs. Autologous salvaged RBCs provide high-quality transfusion, since the cells have not been subjected to the adverse effects of storage as occurs with banked blood. The risks for RBC alloimmunization and transfusion-related infectious diseases are also avoided. With a careful selection of cases, salvaged blood can be more cost effective than donor blood. Cell salvage may have a role in cardiac, major vascular, orthopedic, transplant, and trauma surgeries. However, there remain theoretical safety concerns in cases with bacterial contamination or in cancer surgery.

CONCLUSION

In addition to other methods of blood conservation used in patient blood management programs, autologous salvaged blood adds value and is cost effective for appropriate surgical cases. Evidence suggests that autologous salvaged blood may be of higher quality and confer a cost reduction compared with the allogeneic banked blood, when used appropriately.

Approaches to Bloodless Surgery for Oncology Patients

Providing optimal care to surgical oncology patients who cannot be transfused for religious or other reasons can be challenging. However, with careful planning, using a combination of blood-conserving methods, these "bloodless" patients have clinical outcomes that are similar to other patients who can be transfused. Bloodless surgery can be accomplished safely for most patients, including those undergoing technically challenging oncologic surgery. This article reviews best practices used in a bloodless program during the preoperative, intraoperative, and postoperative periods, with the aim of achieving optimal outcomes when transfusion is not an option for surgical oncology patients.

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.

Metastatic efficiency of tumour cells can be impaired by intraoperative cell salvage process: truth or conjecture?

The use of salvaged blood in oncological surgery has been a matter of controversy over the years. This is due to the concern of systemic dissemination of reinfused tumour cells. Recent literature, across disciplines, has shed considerable light on its safety in terms of tumour recurrence, progression and overall survival rates. This clinical safety demonstrates the apparent metastatic inefficiency of reinfused tumour cells. The proof of this concept comes from various studies that have shown that salvaged blood has no tumour cells, or has a significantly lower count as compared to the patient's original circulatory tumour load. Recently, we took a step further and found that the tumour cells in the salvaged blood lose the capacity to replicate. In this review, we revisited the safety of salvaged blood from the point of view of metastatic potential. We have presented basic and applied science evidence regarding the innocuous nature of tumour cells that have been subjected to the cell salvage process. The understanding of the metastatic efficiency or the lack of it in tumour cells subjected to salvage process is key to allay the concerns conventionally associated with the use of salvaged blood in tumour surgery. Based on the available literature, we surmise that the prevalent apprehensions on the usage of salvaged blood are ill-founded and further substantiate why tumour cells in the salvaged blood could be regarded as cells with non-metastatic potential.

Are we ready for the use of intraoperative salvaged blood in metastatic spine tumour surgery?

PURPOSE

To evaluate the feasibility of using intraoperative cell salvage (IOCS) in combination with leucocyte depletion filter (LDF) in eliminating tumour cells from blood salvaged during metastatic spine tumour surgery (MSTS). This is with the view to pave the path for use of IOCS-LDF in MSTS and musculoskeletal oncological surgery.

METHODS

Sixty consecutive patients with known primary epithelial tumour, who were offered surgery for metastatic spine disease at our university hospital, were recruited. Blood samples were collected at three different stages during surgery: from operative field prior to IOCS processing, after IOCS processing and after IOCS-LDF processing. Three separate samples (5 ml each) were taken at each stage. Samples were examined by cell block technique using immunohistochemical monoclonal antibodies to identify tumour cells of epithelial origin in the samples.

RESULTS

Of 60 patients, ten were excluded for not fulfilling the inclusion criteria leaving 50 patients. Malignant tumour cells were detected in the samples from operative field prior to IOCS processing in 24 patients and in the samples from the transfusion bag post-IOCS processing in 4 patients. No viable malignant cells were detectable in any of the blood samples after passage through both IOCS and LDF.

CONCLUSIONS

The findings support the notion that IOCS-LDF combination works effectively in eliminating tumour cells from salvaged blood so this technique can possibly be applied in MSTS and even musculoskeletal oncological surgery. This concept can then be extended to other oncological surgeries in general with further appropriate clinical studies.

Alternative procedures for reducing allogeneic blood transfusion in elective orthopedic surgery

Perioperative blood loss is a major problem in elective orthopedic surgery. Allogeneic transfusion is the standard treatment for perioperative blood loss resulting in low postoperative hemoglobin, but it has a number of well-recognized risks, complications, and costs. Alternatives to allogeneic blood transfusion include preoperative autologous donation and intraoperative salvage with postoperative autotransfusion. Orthopedic surgeons are often unaware of the different pre- and intraoperative possibilities of reducing blood loss and leave the management of coagulation and use of blood products completely to the anesthesiologists. The goal of this review is to compare alternatives to allogeneic blood transfusion from an orthopedic and anesthesia point of view focusing on estimated costs and acceptance by both parties.

Alternatives to allogeneic blood transfusions

Inherent risks and increasing costs of allogeneic transfusions underline the socioeconomic relevance of safe and effective alternatives to banked blood. The safety limits of a restrictive transfusion policy are given by a patient's individual tolerance of acute normovolaemic anaemia. latrogenic attempts to increase tolerance of anaemia are helpful in avoiding premature blood transfusions while at the same time maintaining adequate tissue oxygenation. Autologous transfusion techniques include preoperative autologous blood donation (PAD), acute normovolaemic haemodilution (ANH), and intraoperative cell salvage (ICS). The efficacy of PAD and ANH can be augmented by supplemental iron and/or erythropoietin. PAD is only cost-effective when based on a meticulous donation/transfusion plan calculated for the individual patient, and still carries the risk of mistransfusion (clerical error). In contrast, ANH has almost no risks and is more cost-effective. A significant reduction in allogeneic blood transfusions can also be achieved by ICS. Currently, some controversy regarding contraindications of ICS needs to be resolved. Artificial oxygen carriers based on perfluorocarbon (PFC) or haemoglobin (haemoglobin-based oxygen carriers, HBOCs) are attractive alternatives to allogeneic red blood cells. Nevertheless, to date no artificial oxygen carrier is available for routine clinical use, and further studies are needed to show the safety and efficacy of these substances.