Metastatic spine tumor surgery: does perioperative blood transfusion influence postoperative complications?

Tranexamic Acid Demonstrated a Trend Toward Decreased Perioperative Blood Loss in Posterior Decompression Surgery of Patient with Metastatic Spinal Tumor

Background

To explore the effect of tranexamic acid (TXA) on perioperative blood loss in posterior decompression surgery of patient with metastatic spinal tumor.

Methods

Three hundred sixty-eight consecutive patients between May 2011 and Aug 2022 were retrospectively reviewed. One hundred eighty patients (182 surgeries) met the criteria and were included in the study. Sixty-two surgeries received preoperative intravenous TXA (TXA group), and 120 did not (non-TXA group). The primary outcome was total blood loss. T-test, Mann-Whitney U, and chi-square tests were used to evaluate the difference in baseline data, total blood loss, and other outcome measures between the two groups.

Results

Patients with hyper vascular tumors had significantly more blood loss compared with non-hyper vascular tumors (2002(1531,2792) mL vs 1469(1036,1962) mL, p=0.001). There was no significant different in the postoperative venous thromboembolism of the lower limb between the two groups. For patients with non-hyper vascular tumors, the blood loss (1216(827, 1709) mL vs 1561(1146, 2019) mL, p = 0.012) and postoperative drainage (1-day post-operation: 240(150,290) mL vs 280(150,395) mL, p=0.040; 3-days post-operation: 450(348,630) mL vs 613(398,799) mL, p=0.025) of TXA group were significantly less compared with that of the non-TXA group. Meanwhile, the TXA group had significantly less postoperative hospitalization compared with the non-TXA group (11.0(9.0, 13.3) days vs 12.5(9.0, 16.3) days, p=0.023). For patients with hyper vascular tumors, there were no significant differences in the blood loss and amount of postoperative drainage between the two groups.

Conclusion

Preoperative intravenous TXA demonstrated a trend toward decreased perioperative blood loss in posterior decompression surgery of spinal metastases with non-hyper vascular tumors.

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.

Outcomes and Complications of Surgery for Symptomatic Spinal Metastases; a Comparison Between Patients Aged ≥ 70 and <70

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Physicians may be deterred from operating on elderly patients due to fears of poorer outcomes and complications. We aimed to compare the outcomes of surgical treatment of spinal metastases patients aged ≥70-yrs and <70-yrs.

MATERIALS AND METHODS

This is a retrospective study of patients surgically treated for metastatic epidural spinal cord compression and spinal instability between January-2005 to December-2021. Follow-up was till death or minimum 1-year post-surgery. Outcomes included post-operative neurological status, ambulatory status, medical and surgical complications. Two Sample t-test/Mann Whitney U test were used for numerical variables and Pearson Chi-Squared or Fishers Exact test for categorical variables. Survival was presented with a Kaplan-Meier curve. P < .05 was significant.

RESULTS

We identified 412 patients of which 29 (7.1%) patients were excluded due to loss to follow-up and previous surgical treatment. 79 (20.6%) were ≥70-yrs. Age ≥70-yrs patients had poorer ECOG scores (P = .0017) and Charlson Comorbidity Index (P < .001). No significant difference in modified Tokuhashi score (P = .393) was observed with significantly more ≥ prostate (P < .001) and liver (P = .029) cancer in ≥70-yrs. Improved or maintained normal neurological function (P = .934), independent ambulatory status (P = .171), and survival at 6 months (P = .119) and 12 months (P = .659) was not significantly different between both groups. Medical (P = .528) or surgical (P = .466) complication rates and readmission rates (P = .800) were similar.

CONCLUSION

≥70-yrs patients have comparable outcomes to <70-yr old patients with no significant increase in complication rates. Age should not be a determining factor in deciding surgical management of spinal metastases.

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.

Computed Tomography Perfusion Combined With Preoperative Embolization for Reducing Intraoperative Blood Loss in Separation Surgery for Thoracolumbar Metastases

STUDY DESIGN

A prospective consecutive case study.

OBJECTIVE

This study aimed to assess the accuracy of computed tomography perfusion (CTP) in evaluating the vascularity of thoracolumbar metastases and to determine the impact of combining CTP with preoperative embolization on reducing intraoperative blood loss during separation surgery.

SUMMARY OF BACKGROUND DATA

Surgery for thoracolumbar metastases is a complex procedure with the potential for substantial blood loss. Therefore, assessing tumor vascularity before surgery and taking measures to minimize intraoperative blood loss is essential.

METHODS

A total of 62 patients with thoracolumbar metastases were prospectively enrolled. All patients underwent separation surgery using the posterior approach. Before surgery, the vascularity of the metastases was evaluated using CTP. On the basis of the CTP results, patients were categorized into hypervascular and hypovascular groups. Preoperative angiography and embolization were performed for the hypervascular group. Clinical data were abstracted, including intraoperative blood loss, perioperative complications, visual analog scale score, neurological status, and the accuracy of vascularity evaluation by CTP confirmed by angiography. χ 2 testing was used to compare categorical variables, whereas independent sample t tests were used to compare continuous variables, with paired t tests used to assess differences from preoperative to postoperative time points.

RESULTS

The mean intraoperative blood loss was 485±167 and 455±127.6 mL in the two groups, respectively. The accuracy of vascularity evaluation by CTP was 100%. In the hypervascular group, 80.6% of the patients experienced at least one level of improvement in neurological status, while the hypovascular group had 81.5% of patients with similar improvement. None of the patients experienced neurological deterioration. There was a significant reduction in visual analog scale scores in both groups after the operation.

CONCLUSIONS

The vascularity of thoracolumbar metastases could be accurately evaluated using noninvasive CTP. When combined with preoperative embolization, this approach effectively and safely reduced intraoperative blood loss in the setting of separation surgery.

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.

Nomogram for predicting postoperative pulmonary complications in spinal tumor patients

OBJECTIVES

Although several independent risk factors for postoperative pulmonary complications (PPCs) after spinal tumor surgery have been studied, a simple and valid predictive model for PPC occurrence after spinal tumor surgery has not been developed.

PATIENTS AND METHODS

We collected data from patients who underwent elective spine surgery for a spinal tumor between 2013 and 2020 at a tertiary hospital in China. Data on patient characteristics, comorbidities, preoperative examinations, intraoperative variables, and clinical outcomes were collected. We used univariable and multivariable logistic regression models to assess predictors of PPCs and developed and validated a nomogram for PPCs. We evaluated the performance of the nomogram using the area under the receiver operating characteristic curve (ROC), calibration curves, the Brier Score, and the Hosmer-Lemeshow (H-L) goodness-of-fit test. For clinical use, decision curve analysis (DCA) was conducted to identify the model's performance as a tool for supporting decision-making.

RESULTS

Among the participants, 61 (12.4%) individuals developed PPCs. Clinically significant variables associated with PPCs after spinal tumor surgery included BMI, tumor location, blood transfusion, and the amount of blood lost. The nomogram incorporating these factors showed a concordance index (C-index) of 0.755 (95% CI: 0.688-0.822). On internal validation, bootstrapping with 1000 resamples yielded a bias-corrected area under the receiver operating characteristic curve of 0.733, indicating the satisfactory performance of the nomogram in predicting PPCs. The calibration curve demonstrated accurate predictions of observed values. The decision curve analysis (DCA) indicated a positive net benefit for the nomogram across most predicted threshold probabilities.

CONCLUSIONS

We have developed a new nomogram for predicting PPCs in patients who undergo spinal tumor surgery.

Is perioperative blood transfusion associated with postoperative thromboembolism or infection after metastatic spinal tumor surgery?

STUDY DESIGN

Retrospective cohort.

SUMMARY OF BACKGROUND DATA

Patients with metastatic spine disease who undergo surgical intervention have a high risk of requiring red blood cell (RBC) transfusion. Perioperative transfusion has been independently associated with increased risk of venous thromboembolic (VTE) and infectious complications following orthopedic procedures and degenerative spinal intervention; however, literature within spine oncology is limited.

OBJECTIVE

To determine the association between perioperative RBC transfusion and postoperative VTE or infection following spinal tumor surgery.

METHODS

A total of 153 patients who underwent surgery for spinal metastases between April 2012 and April 2022 were included. Medical records were reviewed to identify RBC transfusion administered either intraoperatively or within 96 h following surgery. The primary endpoints were: 1) development of any VTE or 2) development of any infection within 30 days following surgery. Any VTE was defined as deep vein thrombosis or pulmonary embolism, and any infection was defined as pneumonia, meningitis, Clostridium difficile infection, urinary tract infection, surgical site infection, or sepsis. Logistic regression analyses were performed.

RESULTS

Of the 153 patients included in the study, 43 % received a perioperative RBC transfusion. The overall incidence of postoperative VTE and infection was 15 % and 22 %, respectively. In univariate analysis, perioperative transfusion was not associated with postoperative VTE (odds ratio [OR] 2.41; 95 % confidence interval [CI] 0.97-6.00; p = 0.058) but was associated with infection (OR 3.02; 95 % CI 1.36-6.73; p = 0.007). After adjusting for confounders such as performance status, operative time, and surgical extent, transfusion was not associated with both VTE (OR 1.25; 95 % CI 0.36-4.32; p = 0.727) or infection (OR 1.86; 95 % CI 0.70-4.92; p = 0.210). While not statistically significant, sub-analyses demonstrated a trend towards increased VTE incidence in patients requiring transfusion earlier (within 24 h) as opposed to later postoperatively.

CONCLUSIONS

We found that perioperative transfusion was not an independent predictor of 30-day postoperative VTE or infection in patients undergoing metastatic spinal surgery. Further exploration of time-dependent transfusion outcomes is warranted.

The severity of preoperative anemia escalates risk of poor short-term outcomes after lumbar spine fusion

OBJECTIVE

To evaluate how preoperative anemia severity affects 90-day outcomes of spinal fusion surgery.

METHODS

A retrospective cohort study was conducted on adult lumbar fusion patients at a tertiary medical center. Patients were classified by World Health Organization anemia severity definitions for comparisons. Multivariate regression models were created to control for confounding variables, for all primary outcomes of transfusion requirements, non-home discharge, readmissions, complications, and length of stay.

RESULTS

A total of 2582 patients were included: 2.7% with moderate-severe anemia, 11.0% with mild anemia, and 86.3% without anemia. Moderate-severe patients had the longest hospital stay (5.03 days vs 4.14 and 3.59 days, p < 0.001) and highest risk of transfusion (52.2% vs 13.0% vs 2.69%, p < 0.001), non-home discharge (39.1% vs 27.8% vs 15.4%, p < 0.001), readmission (7.25% vs 5.99% vs 3.36%, p = 0.023), and complications (13.0% vs 9.51% vs 6.20%, p = 0.012). On multivariable logistic regression, both patients with mild and moderate-severe anemia had an increased risk of transfusion (OR: 37.3, p < 0.001; OR: 5.25, p < 0.001, respectively) and non-home discharge (OR: 2.00, p = 0.021; OR: 1.71, p = 0.001, respectively) compared to patients without anemia. Anemia severity was not independently associated with complications or 90-day readmission. On multivariable linear regression, mild anemia (β: 0.37, p = 0.001) and moderate-severe anemia (β: 1.07, p < 0.001) were independently associated with length of hospital stay.

CONCLUSION

Patients with moderate-severe preoperative anemia are at increased risk for longer length of stay, transfusions, and non-home discharge. Improved optimization of preoperative anemia may significantly reduce healthcare utilization, and surgeons should consider these risks in preoperative planning.

LEVEL OF EVIDENCE

III.

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.

Assessment of thermally stabilized electrospun poly(vinyl alcohol) materials as cell permeable membranes for a novel blood salvage device

The use of Intraoperative Cell Salvage (ICS) is currently limited in oncological surgeries, due to safety concerns associated with the ability of existing devices to successfully remove circulating tumour cells. In this work, we present the first stages towards the creation of an alternative platform to current cell savers, based on the extremely selective immunoaffinity membrane chromatography principle. Non-woven membranes were produced via electrospinning using poly(vinyl alcohol) (PVA), and further heat treated at 180 °C to prevent their dissolution in aqueous environments and preserve their fibrous morphology. The effects of the PVA degree of hydrolysis (DH) (98 % vs 99 %), method of electrospinning (needleless DC vs AC), and heat treatment duration (1-8 h) were investigated. All heat treated supports maintained their cytocompatibility, whilst tensile tests indicated that the 99 % hydrolysed DC electrospun mats were stronger compared to their 98 % DH counterparts. Although, and at the described conditions, AC electrospinning produced fibres with more than double the diameter compared to those from DC electrospinning, it was not chosen for subsequent experiments because it is still under development. Evidence of unimpeded passage of SY5Y neuroblastoma cells and undiluted defibrinated sheep's blood in flow-through filtration experiments confirmed the successful creation of 3D networks with minimum resistance to mass transfer and lack of non-specific cell binding to the base material, paving the way for the development of novel, highly selective ICS devices for tumour surgeries.

Transfusion guidelines in adult spine surgery: a systematic review and critical summary of currently available evidence

BACKGROUND CONTEXT

Red blood cell transfusion can be associated with complications in medical and surgical patients. Acute anemia in ambulatory patients undergoing surgery can also impede wound healing and independent self-care. Current transfusion threshold guidelines are still based on evidence derived from critically-ill intensive care unit medical patients and may not apply to spine surgery candidates.

PURPOSE

We aimed to provide the reader with a synthesis of the best available evidence to recommend transfusion trigger thresholds and guidelines in adult patients undergoing spine surgery.

STUDY DESIGN/SETTING

This is a systematic review.

OUTCOME MEASURES

Physiological measure: Blood transfusion thresholds and associated posttransfusion complications (morbidity, mortality, length of stay, infections, etc) of the published articles.

PATIENT SAMPLE

Adult spine surgery patients.

METHODS

A systematic review of the literature using the PubMed, Google Scholar, and Web of Science electronic databases was made according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Focus was set on papers discussing thresholds for blood transfusion in adult surgical spine patients, as well as complications associated with transfusion after acute surgical blood loss in the operating room or postoperative period. Publications discussing pediatric cases, blood type analyses, blood loss prevention strategies and protocols, systematic reviews and letters to the editor were excluded.

RESULTS

A total of 22 articles fitting our search criteria were reviewed. Patients who received blood transfusion in these studies were older, of female gender, had more severe comorbidities except for smoking, and had prolonged surgical time. Blood transfusion was associated with multiple adverse postoperative complications, including a higher rate of superficial or deep surgical site infections, sepsis, urinary and pulmonary infections, cardiovascular complications, return to the operating room, and increased postoperative length of stay and 30 day readmission. Analysis of transfusion thresholds from these studies showed that a pre-operative hemoglobin (Hb) of > 13 g/dL, and an intraoperative and post-operative Hb nadir above 9 and 8 g/dL, respectively, were associated with better outcomes and fewer wound infections than lower thresholds (Level B Class III). Additionally, it was generally recommended to transfuse autologous blood that was < 28 days old, if possible, with a limit of 2 to 3 units to minimize patient morbidity and mortality.

CONCLUSIONS

Blood transfusion thresholds in surgical patients may be specialty-specific and different than those used for critically-ill medical patients. For adult spine surgery patients, red blood cell transfusion should be avoided if Hb numbers remain > 9 and 8 g/dL in the intraoperative and direct post-operative periods, respectively.

Evolution of materials for implants in metastatic spine disease till date - Have we found an ideal material?

"Metastatic Spine Disease" (MSD) often requires surgical intervention and instrumentation with spinal implants. Ti6Al4V is widely used in metastatic spine tumor surgery (MSTS) and is the current implant material of choice due to improved biocompatibility, mechanical properties, and compatibility with imaging modalities compared to stainless steel. However, it is still not the ideal implant material due to the following issues. Ti6Al4V implants cause stress-shielding as their Young's modulus (110 gigapascal [GPa]) is higher than cortical bone (17-21 GPa). Ti6Al4V also generates artifacts on CT and MRI, which interfere with the process of postoperative radiotherapy (RT), including treatment planning and delivery. Similarly, charged particle therapy is hindered in the presence of Ti6Al4V. In addition, artifacts on CT and MRI may result in delayed recognition of tumor recurrence and postoperative complications. In comparison, polyether-ether-ketone (PEEK) is a promising alternative. PEEK has a low Young's modulus (3.6 GPa), which results in optimal load-sharing and produces minimal artifacts on imaging with less hinderance on postoperative RT. However, PEEK is bioinert and unable to provide sufficient stability in the immediate postoperative period. This issue may possibly be mitigated by combining PEEK with other materials to form composites or through surface modification, although further research is required in these areas. With the increasing incidence of MSD, it is an opportune time for the development of spinal implants that possess all the ideal material properties for use in MSTS. Our review will explore whether there is a current ideal implant material, available alternatives and whether these require further investigation.

Intraoperative blood loss in oncological spine surgery

OBJECTIVE

Intraoperative blood loss in patients undergoing oncological spine surgery poses a major challenge for vulnerable patients. The goal of this study was to assess how the surgical procedure, tumor type, and tumor anatomy, as well as anesthesiological parameters, affect intraoperative blood loss in oncological spine surgery and to use this information to generate a short preoperative checklist for spine surgeons and anesthesiologists to identify patients at risk for increased intraoperative blood loss.

METHODS

The authors performed a retrospective analysis of 430 oncological patients who underwent spine surgery between 2013 and 2018 at the university medical spine center. Enrolled patients had metastatic tumor of the spine requiring surgical decompression of neural structures and/or stabilization including tumor biopsy using an open, percutaneous, and/or combined dorsoventral approach. Patients requiring vertebro- and kyphoplasty or biopsy only were excluded. Statistical analyses performed included a multiple linear regression analysis.

RESULTS

The mean intraoperative blood loss in the study patient cohort was 1176 ± 1209 ml. In total, 33.8% of patients received intraoperative red blood cell transfusions. The statistical analyses showed that tumor histology indicating myeloma, operative procedure length, epidural spinal cord compression (ESCC) score, tumor localization, BMI, and surgical strategy were significantly associated with increased intraoperative blood loss or risk of needing allogeneic blood transfusions. Anesthesiological parameters such as the American Society of Anesthesiologists (ASA) Physical Status classification score were not associated with blood loss. Multiple linear regression analysis demonstrated good predictive value (r = 0.437) for a five-item preoperative checklist to identify patients at risk for high intraoperative blood loss.

CONCLUSIONS

The analyses performed in this study demonstrated key factors affecting intraoperative blood loss and showed that a simple preoperative checklist including these factors can be used to identify patients undergoing surgery for metastatic spine tumors who are at risk for increased intraoperative blood loss.

ABBREVIATIONS

ABT = allogeneic blood transfusion; ASA = American Society of Anesthesiologists; ESCC = epidural spinal cord compression; KW = Kruskal-Wallis; MET = metabolic equivalent of task; RBC = red blood cell.

The "Spinal Metastasis Invasiveness Index": A Novel Scoring System to Assess Surgical Invasiveness

STUDY DESIGN

Retrospective review.

OBJECTIVE

The aim of this study was to develop a surgical invasiveness index for metastatic spine tumor surgery (MSTS) that can serve as a standardized tool in predicting intraoperative blood loss and surgical duration; for the purpose of ascertaining resource requirements and aiding in patient education.

SUMMARY OF BACKGROUND DATA

Magnitude of surgery is important in the metastatic spine disease (MSD) population since these patients have a continuing postoperative oncological process; a consideration that must be taken into account to maintain or improve quality of life. Surgical invasiveness indices have been established for general spine surgery, adult deformity, and cervical deformity, but not yet for spinal metastasis.

METHODS

Demographic, oncological, and procedural data were collected from consecutive patients that underwent MSTS. Binary logistic regression, using median values for surgical duration and intraoperative estimated blood loss (EBL), was used to determine statistical significance of variables to be included in the "spinal metastasis invasiveness index" (SMII). The corresponding weightage of each of these variables was agreed upon by experienced spine surgeons. Multivariable regression analysis was used to predict operative time and EBL while controlling for demographical, procedural, and oncological characteristics.

RESULTS

Two hundred and sixty-one MSD patients were included with a mean age of 59.7-years and near equal sex distribution. The SMII strongly predicted extended surgical duration (R2 = 0.28, P < 0.001) and high intraoperative blood loss (R2 = 0.18, P < 0.001). When compared to a previously established surgical invasiveness index, the SMII accounted for more variability in the outcomes. For every unit increase in score, there was a 42-mL increase in mean blood loss (P < 0.001) and 5-minute increase in mean operative time (P < 0.001).

CONCLUSION

Long surgical duration and high blood loss were strongly predicted by the newly developed SMII. The use of the SMII may aid in preoperative risk assessment with the goal of improving patient outcomes and quality of life.Level of Evidence: 4.

A clinical calculator for predicting intraoperative blood loss and transfusion risk in spine tumor patients

BACKGROUND CONTEXT

Surgery for vertebral column tumors is commonly associated with intraoperative blood loss (IOBL) exceeding 2 liters and the need for transfusion of allogeneic blood products. Transfusion of allogeneic blood, while necessary, is not benign, and has been associated with increased rates of wound complication, venous thromboembolism, delirium, and death.

PURPOSE

To develop a prediction tool capable of predicting IOBL and risk of requiring allogeneic transfusion in patients undergoing surgery for vertebral column tumors.

STUDY DESIGN/SETTING

Retrospective, single-center study.

PATIENT SAMPLE

Consecutive series of 274 patients undergoing 350 unique operations for primary or metastatic spinal column tumors over a 46-month period at a comprehensive cancer center OUTCOME MEASURES: IOBL (in mL), use of intraoperative blood products, and intraoperative blood products transfused.

METHODS

We identified IOBL and transfusions, along with demographic data, preoperative laboratory data, and surgical procedures performed. Independent predictors of IOBL and transfusion risk were identified using multivariable regression.

RESULTS

Mean age at surgery was 57.0±13.6 years, 53.1% were male, and 67.1% were treated for metastatic lesions. Independent predictors of IOBL included en bloc resection (p<.001), surgical invasiveness (β=25.43 per point; p<0.001), and preoperative albumin (β=-244.86 per g/dL; p=0.011). Predictors of transfusion risk included preoperative hematocrit (odds ratio [OR]=0.88 per %; 95% confidence interval [CI, 0.84, 0.93]; p<0.001), preoperative MCHgb (OR=0.88 per pg; 95% CI [0.78, 1.00]; p=0.048), preoperative red cell distribution width (OR=1.32 per %; 95% CI [1.13, 1.55]; p<0.001), en bloc resection (OR=3.17; 95%CI [1.33, 7.54]; p=0.009), and surgical invasiveness (OR=1.08 per point; [1.06; 1.11]; p<0.001). The transfusion model showed a good fit of the data with an optimism-corrected area under the curve of 0.819. A freely available, web-based calculator was developed for the transfusion risk model (https://jhuspine3.shinyapps.io/TRUST/).

CONCLUSIONS

Here we present the first clinical calculator for intraoperative blood loss and transfusion risk in patients being treated for primary or metastatic vertebral column tumors. Surgical invasiveness and preoperative microcytic anemia most strongly predict transfusion risk. The resultant calculators may prove clinically useful for surgeons counseling patients about their individual risk of requiring allogeneic transfusion.

Readmission-Free Survival Analysis in Metastatic Spine Tumour Surgical Patients: A Novel Concept

BACKGROUND

Outcomes commonly used to ascertain success of metastatic spine tumour surgery (MSTS) are 30-day complications/mortality and overall/disease-free survival. We believe a new, effective outcome indicator after MSTS would be the absence of unplanned hospital readmission (UHR) after index discharge. We introduce the concept of readmission-free survival (ReAFS), defined as 'the time duration between hospital discharge after index operation and first UHR or death'. The aim of this study is to identify factors influencing ReAFS in MSTS patients.

PATIENTS AND METHODS

We retrospectively analysed 266 consecutive patients who underwent MSTS between 2005 and 2016. Demographics, oncological characteristics, procedural, preoperative and postoperative details were collected. ReAFS of patients within 2 years or until death was reviewed. Perioperative factors predictive of reduced ReAFS were evaluated using multivariate regression analysis.

RESULTS

Of 266 patients, 230 met criteria for analysis. A total of 201 had UHR, whilst 1 in 8 (29/230) had no UHR. Multivariate analysis revealed that haemoglobin ≥ 12 g/dL, ECOG score of ≤ 2, primary prostate, breast and haematological cancers, comorbidities ≤ 3, absence of preoperative radiotherapy and shorter postoperative length of stay significantly prolonged the time to first UHR.

CONCLUSIONS

Readmission-free survival is a novel concept in MSTS, which relies on patients' general condition, appropriateness of interventional procedures and underlying disease burden. Additionally, it may indicate the successful combination of a multi-disciplinary treatment approach. This information will allow oncologists and surgeons to identify patients who may benefit from increased surveillance following discharge to increase ReAFS. We envisage that ReAFS is a concept that can be extended to other surgical oncological fields.

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.

Rates, Risk Factors, and Complications of Red Blood Cell Transfusion in Metastatic Spinal Tumor Surgery: An Analysis of a Prospective Multicenter Surgical Database

OBJECTIVE

To identify rates, risks, and complications of red blood cell (RBC) transfusion in metastatic spinal tumor surgery.

METHODS

The multicenter prospective American College of Surgeons National Quality Improvement Program database was queried for the years 2012-2016. Adult patients with disseminated cancer who underwent metastatic spinal tumor surgery were identified. Transfusion was defined as having received at least 1 intraoperative/postoperative RBC transfusion within the first 72 hours of surgery start time. A stepwise multiple logistic regression model with backward elimination was used.

RESULTS

Of 1601 patients identified, 623 patients (38.9%) received a RBC transfusion. Independent predictors of RBC transfusion included higher American Society of Anesthesiologists class (odds ratio [OR] = 1.54), preoperative anemia (OR = 3.10), instrumentation (OR = 1.63), and longer operative time (OR = 1.52). The overall complication rate was significantly higher in patients who received a transfusion compared with patients who did not receive a transfusion (22.3% vs. 15.0%, P < 0.001). Individual complications that were more common in patients who received a transfusion were sepsis (3.5% vs. 1.9%, P = 0.050), deep vein thrombosis (6.1% vs. 3.3%, P = 0.007), and prolonged ventilation (3.9% vs. 1.3%, P = 0.001). RBC transfusion (OR = 1.65), hypoalbuminemia (OR = 1.53), and anterior/anterolateral approaches for corpectomy (OR = 2.11) were independent risk factors for developing a postoperative complication.

CONCLUSIONS

RBC transfusion after metastatic spinal tumor surgery may increase the risk of early postoperative complications. Future research into preoperative patient optimization and decreasing intraoperative blood loss is needed.

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.

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.