The relative efficacy of antifibrinolytics in adolescent idiopathic scoliosis: a prospective randomized trial

The optimal dose of intravenous tranexamic acid for reducing blood loss in spinal surgery: a network meta-analysis

BACKGROUND

This study aims to evaluate the optimal dose of intravenous tranexamic acid (TXA) for reducing blood loss in spinal surgery.

METHODS

A systematic search was conducted in the PubMed, Embase, Cochrane Library database from inception until November 2023. Randomized controlled trials (RCTs) incorporating diverse TXA dosing regimens for spinal surgery were included. The surface under the cumulative ranking curve (SUCRA) analysis was employed to determine ranking order. R software with gemtc package was used for all analyses, with a significance threshold set at P < 0.05.

RESULTS

Twenty-four RCTs were considered eligible and finally included. All TXA treatments demonstrated superior efficacy compared to the placebo, with statistically significant differences (P < 0.05). SUCRA values indicated that Treatment I (100 mg/kg + 10 mg.kg/h) claimed the top rank (SUCRA, 80.3%), followed by Treatment F (15 mg/kg + 2 mg.kg/h) in second place (SUCRA, 76.7%), and Treatment E (10 mg/kg + 2 mg.kg/h) in third place (SUCRA, 75.2%). Conversely, the placebo ranked the lowest (SUCRA, 0.3%). Additionally, Treatment I (100 mg/kg + 10 mg.kg/h) held the top rank (SUCRA, 95.6%), followed by Treatment N (30 mg/kg + 10 mg.kg/h) in second place (SUCRA, 81.0%), and Treatment K (15 mg/kg + 6 mg.kg/h) in third place (SUCRA, 74.8%). Importantly, no statistically significant differences were observed between any TXA treatments and the placebo concerning the occurrence of deep vein thrombosis (DVT) (P > 0.05).

CONCLUSIONS

This network meta-analysis underscores that intravenous TXA is associated with decreased overall blood loss in multilevel spine surgery. Notably, the highest dose in this network meta-analysis (100 mg/kg + 10 mg.kg/h) emerged as the only regimen demonstrating significant benefits in pairwise comparisons with other TXA doses. Although this regimen did not significantly increase DVT risk, careful consideration of safety data for higher doses remains essential.

Efficacy and utility of antifibrinolytics in pediatric spine surgery: a systematic review and network meta-analysis

Antifibrinolytics have gained increasing attention in minimizing blood loss and mitigating the risks associated with massive transfusions, including infection and coagulopathy in pediatric patients undergoing spine surgery. Nevertheless, the selection of optimal agent is still a matter of debate. We aim to review the utility of these agents and compare the efficacy of antifibrinolytics in pediatric and adolescent spine surgeries. A comprehensive search was performed in Scopus, Web of Science, and MEDLINE databases for relevant works. Studies providing quantitative data on predefined outcomes were included. Primary outcome was perioperative bleeding between the groups. Secondary outcomes included transfusion volume, rate of complications, and operation time. Twenty-eight studies were included in the meta-analysis incorporating 2553 patients. The use of Tranexamic acid (RoM: 0.71, 95%CI: [0.62-0.81], p < 0.001, I2 = 88%), Aprotinin (RoM: 0.54, 95%CI: [0.46-0.64], p < 0.001, I2 = 0%), and Epsilon-aminocaproic acid (RoM: 0.71, 95%CI: [0.62-0.81], p < 0.001, I2 = 60%) led to a 29%, 46%, and 29% reduction in perioperative blood loss, respectively. Network meta-analysis revealed higher probability of efficacy with Tranexamic acid compared to Epsilon-aminocaproic acid (P score: 0.924 vs. 0.571). The rate of complications was not statistically different between each two antifibrinolytic agent or antifibrinolytics compared to placebo or standard of care. Our network meta-analysis suggests a superior efficacy of all antifibrinolytics compared to standard of care/placebo in reducing blood loss and transfusion rate. Further adequately-powered randomized clinical trials are recommended to reach definite conclusion on comparative performance of these agents and to also provide robust objective assessments and standardized outcome data and safety profile on antifibrinolytics in pediatric and adolescent pediatric surgeries.

Real-World Effectiveness of Gelatin-Thrombin Matrix Sealant on Blood Loss in Adolescent Idiopathic Scoliosis Patients Undergoing Posterior Spinal Fusion: An Interrupted Time Series Study

STUDY DESIGN

Retrospective cohort study with interrupted time series analysis.

OBJECTIVE

To examine the clinical effectiveness of gelatin-thrombin matrix sealant (GTMS) on blood loss reduction after adolescent idiopathic scoliosis (AIS) surgery.

SUMMARY OF BACKGROUND DATA

The real-world effectiveness of GTMS on blood loss reduction in AIS surgery has not been determined.

PATIENTS AND METHODS

The medical records of patients receiving AIS surgery were retrospectively collected during a period before GTMS approval at our institution (January 22, 2010-January 21, 2015) as well as during a postintroduction period (January 22, 2015-January 22, 2020). The primary outcomes were intraoperative blood loss, drain output over 24 hours, and total blood loss (intraoperative blood loss + drain output over 24 h). Interrupted time series analysis using a segmented linear regression model was used to estimate the effect of GTMS on blood loss reduction.

RESULTS

A total of 179 AIS patients [mean age (range): 15.4 (11-30) yr; 159 females and 20 males; 63 preintroduction patients and 116 postintroduction patients] were included. After its introduction, GTMS was used in 40% of cases. Interrupted time series analysis revealed changes of -340 mL (95% CI: -649 to -31, P = 0.03) for intraoperative blood loss, -35 mL (95% CI: -124 to 55, P = 0.44) for drain output over 24 hours, and -375 mL (95% CI: -698 to -51, P = 0.02) for total blood loss.

CONCLUSIONS

The availability of GTMS was significantly associated with reduced intraoperative and total blood loss in AIS surgery. GTMS use as needed is recommended to control intraoperative bleeding in the setting of AIS surgery.

LEVEL OF EVIDENCE

3.

Utility of postoperative laboratory testing after posterior spinal fusion for adolescent idiopathic scoliosis

PURPOSE

With advancements to blood management strategies, risk of perioperative transfusion following surgical treatment of adolescent idiopathic scoliosis (AIS) has diminished. We hypothesize that routine laboratory testing on postoperative-day 1 (POD1) and beyond is unnecessary. The purpose of this study is to determine necessity of POD1 labs, particularly hematocrit and hemoglobin levels, following surgical management of AIS.

METHODS

We performed a retrospective cohort study of consecutive AIS patients aged 11-19 who underwent posterior spinal fusion (PSF) at a single institution. Univariable logistic regression was utilized to determine factors associated with hematocrit ≤ 22% on POD1 or a postoperative transfusion. Firth's penalized logistic regression was used for any separation in data. Youden's index was utilized to determine the optimal point on the ROC curve that maximizes both sensitivity and specificity.

RESULTS

527 patients qualified for this study. Among the eight total patients with POD1 hematocrit ≤ 22, none underwent transfusion. These patients had lower last intraoperative hematocrit levels compared to patients with POD1 hematocrit > 22% (24.1% vs 31.5%, p < 0.001), and these groups showed no difference in preoperative hematocrit levels (38.2% vs 39.8%, p = 0.11). Four patients underwent postoperative transfusion. Both preoperative hematocrit levels (34.0% vs 39.9%, p = 0.001) and last intraoperative hematocrit levels (25.1% vs 31.4%, p = 0.002) were lower compared to patients without transfusion. Intraoperative hematocrit < 26.2%, operative time of more than 35.8 min per level fused, or cell salvage > 241 cc were significant risk factors for postoperative transfusion.

CONCLUSION

Transfusion after PSF for AIS is exceedingly rare. POD1 labs should be considered when last intraoperative hematocrit < 26%, operative time per level fused > 35 min, or cell salvage amount > 241 cc. Otherwise, unless symptomatic, patients do not benefit from postoperative laboratory screening.

Tranexamic acid can reduce blood loss in adolescent scoliosis surgery: a systematic review and meta-analysis

BACKGROUND

Tranexamic acid (TXA) has been widely used in orthopedic surgery, but its efficacy in adolescent scoliosis (AS) surgery remains unclear in the literature. The purpose of this systematic review and meta-analysis is to evaluate the safety and efficacy of TXA compared to placebo treatment during or after AS surgery, by gathering data from randomized both controlled trials (RCTs) and non-RCTs.

METHODS

English and Chinese electronic databases including PubMed, Web of Science, Embase, Cochrane, CNKI, and Wan Fang database were searched to identify the relevant literature up until August 2022. The primary outcomes were intraoperative blood loss and total blood loss. The secondary outcomes included the need for transfusion, postoperative hemoglobin (Hb) level, and change in Hb level. Stata 17 was used for data analysis and the risk of bias was assessed. We followed the PRISMA checklist to ensure the quality of this article.

RESULTS

Twelve studies (795 participants) were included in the meta-analysis for intraoperative blood loss during surgery. The results suggest that TXA can reduce the intraoperative blood loss of the patients (MD = -306.40ml, 95%CI = -404.04ml to -208.77ml, p < 0.001). Six studies (2027 patients) were included in the meta-analysis for total blood loss. The pooled result shows that the total blood loss of the TXA group was significantly lower than that of the control group (MD = -779.24ml, 95% CI = -1157.10ml to -410.39ml, p < 0.001). Five studies (419 patients) were included in the meta-analysis for postoperative Hb level and shows a non-significant outcome (MD = 5.09 g/l, 95%CI = 2.92 g/l to 7.25 g/l, p = 0.611). Three studies (268 patients) were included in the meta-analysis for the postoperative Hb level. There is a non-significant decrease in the TXA group (MD = -0.23 g/l, 95%CI = -0.48 g/l to 0.01 g/l, p = 0.319). Eight studies (670 patients) reported data on the need for transfusion after surgery. The overall relative risks (RR) showed a significant difference between the TXA and control group, with a lower risk of transfusion in the TXA group (RR = 0.547, 95%CI = 0.308 to 0.972, p = 0.04).

CONCLUSIONS

The meta-analysis of the data reveals that TXA usage is associated with a significant reduction in intraoperative and total blood loss, a lower risk of transfusion, and a non-significant change in postoperative Hb levels in AS surgery However, it should be noted that the surgical operation situations varied across different studies. Therefore, further research is required to investigate the effects of TXA on specific subgroups of gender, operation time, and blood transfusion indicators. Overall, our study provides valuable evidence for the clinical management of AS surgery and may inform the development of practice guidelines and protocols for the use of TXA in this setting.

Comparative efficacy and safety of different hemostatic medications during spinal surgery: A network meta-analysis

BACKGROUND

Significant blood loss is still one of the most frequent issues in spinal surgery. There were different hemostatic methods to prevent blood loss during spinal surgery. However, the optimal hemostatic therapy for spinal surgery is controversial. The purpose of this study was to assess the efficacy and safety of different hemostatic therapies in spinal surgery.

METHODS

Two independent reviewers conducted electronic literature searches in 3 electronic databases (PubMed, Embase, and Cochrane library database) as well as a manual search to identify eligible clinical studies from inception to Nov 2022. Studies that including different hemostatic therapy (tranexamic acid [TXA], epsilon-acetyl aminocaproic acid [EACA], and aprotinin [AP]) for spinal surgery were included. The Bayesian network meta-analysis was performed with a random effects model. The surface under the cumulative ranking curve (SUCRA) analysis was performed to determine the ranking order. All analyses were performed by R software and Stata software. P value less than .05 was identified as statistically significant.

RESULTS

Finally, a total of 34 randomized controlled trials met the inclusion criteria and finally included in this network meta-analysis. The SUCRA shows that TXA ranked first (SUCRA, 88.4%), AP ranked second (SUCRA, 71.6%), EACA ranked third (SUCRA, 39.9%), and placebo ranked the last (SUCRA, 0.3%) as for total blood loss. The SUCRA shows that TXA ranked first (SUCRA, 97.7%), AP ranked second (SUCRA, 55.8%), EACA ranked third (SUCRA, 46.2%), and placebo ranked the last (SUCRA, 0.2%) for need for transfusion.

CONCLUSIONS

TXA appears optimal in the reduction of perioperative bleeding and blood transfusion during spinal surgery. However, considering the limitations in this study, more large-scale, well-designed randomized controlled trials are needed to confirm these findings.

Efficacy of high dose tranexamic acid (TXA) for hemorrhage: A systematic review and meta-analysis

BACKGROUND

Standard dose (≤ 1 g) tranexamic acid (TXA) has established mortality benefit in trauma patients. The role of high dose IV TXA (≥2 g or ≥30 mg/kg as a single bolus) has been evaluated in the surgical setting, however, it has not been studied in trauma. We reviewed the available evidence of high dose IV TXA in any setting with the goal of informing its use in the adult trauma population.

METHODS

We searched MEDLINE, EMBASE and unpublished sources from inception until July 27, 2022 for studies that compared standard dose with high dose IV TXA in adults (≥ 16 years of age) with hemorrhage. Screening and data abstraction was done independently and in duplicate. We pooled trial data using a random effects model and considered randomized controlled trials (RCTs) and observational cohort studies separately. We assessed the individual study risk of bias using the Cochrane Risk of Bias for RCTs and the Newcastle-Ottawa Scale for observational cohort studies. The overall certainty of evidence was assessed using the GRADE approach (Grading of Recommendations Assessment, Development and Evaluation).

RESULTS

We included 20 studies with a combined total of 12,523 patients. Based on pooled RCT data, and as compared to standard dose TXA, high dose IV TXA probably decreases transfusion requirements (odds ratio [OR] 0.86, 95% confidence interval [CI] 0.76 to 0.97, moderate certainty) but with possibly no effect on blood loss (mean difference [MD] 43.31 ml less, 95% CI 135.53 to 48.90 ml less, low certainty), and an uncertain effect on thromboembolic events (OR 1.33, 95% CI 0.86 to 2.04, very low certainty) and mortality (OR 0.70, 95% CI 0.37 to 1.32, very low certainty).

CONCLUSION

When compared to standard dose, high dose IV TXA probably reduces transfusion requirements with an uncertain effect on thromboembolic events and mortality.

LEVEL OF EVIDENCE

Systematic review and meta-analysis, level IV.

Perioperative Risk Factors for Bleeding in Adolescents Undergoing Pedicle Screw Instrumentation for Scoliosis

Progressive scoliosis eventually leads to extensive spinal fusion surgery, which carries a risk for significant bleeding. Neuromuscular scoliosis (NMS) patients have an additional inherent risk of major perioperative bleeding. The purpose of our research was to investigate the risk factors for measured (intraoperative, drain output) and hidden blood loss related to pedicle screw instrumentation in adolescents, divided into adolescent idiopathic scoliosis (AIS) and NMS patient groups. A retrospective cohort study with prospectively collected data of consecutive AIS and NMS patients undergoing segmental pedicle screw instrumentation at a tertiary level hospital between 2009 and 2021 was conducted. In total, 199 AIS (mean age 15.8 years, 143 females) and 81 NMS patients (mean age 15.2 years, 37 females) were included in the analysis. In both groups, levels fused, increased operative time, and smaller or larger size of erythrocytes were associated with perioperative blood loss (p < 0.05 for all correlations). In AIS, male sex (p < 0.001) and the number of osteotomies correlated with more drain output. In NMS, levels fused correlated with drain output, p = 0.00180. In AIS, patients' lower preoperative MCV levels (p = 0.0391) and longer operation times, p = 0.0038, resulted into more hidden blood loss, but we did not find any significant risk factors for hidden blood loss in NMS patients.

1,2,3-Triazole Derivatives as Novel Antifibrinolytic Drugs

Fibrinolysis is a natural process that ensures blood fluidity through the removal of fibrin deposits. However, excessive fibrinolytic activity can lead to complications in different circumstances, such as general surgery or severe trauma. The current antifibrinolytic drugs in the market, aminocaproic acid (EACA) and tranexamic acid (TXA), require high doses repetitively to maintain their therapeutic effect. These high doses are related to a number of side effects such as headaches, nasal symptoms, or gastrointestinal discomfort and severely limit their use in patients with renal impairment. Therefore, the discovery of novel antifibrinolytics with a higher specificity and lower dosage could vastly improve the applicability of these drugs. Herein, we synthesized a total of ten compounds consisting of a combination of three key moieties: an oxadiazolone, a triazole, and a terminal amine. The IC₅₀ of each compound was calculated in our clot lysis assays, and the best candidate (1) provided approximately a 2.5-fold improvement over the current gold standard, TXA. Molecular docking and molecular dynamics were used to perform a structure-activity relationship (SAR) analysis with the lysine binding site in the Kringle 1 domain of plasminogen. This analysis revealed that 1,2,3-triazole was crucial for the activity, enhancing the binding affinity through pi-pi stacking and polar interactions with Tyr72. The results presented in this work open the door to further investigate this new family as potential antifibrinolytic drugs.

Randomized, controlled trial of two tranexamic acid dosing protocols in adult spinal deformity surgery

BACKGROUND

Tranexamic acid (TXA) is an anti-fibrinolytic effective in reducing blood loss in orthopedic surgery. The appropriate dosing protocol for adult spinal deformity (ASD) surgery is not known. The purpose of this study was to evaluate two TXA protocols [low dose (L): 10 mg/kg bolus, 1 mg/kg/hr infusion; high dose (H): 50 mg/kg, 5 mg/kg/hr] in complex ASD surgery.

METHODS

Inclusion criteria were ASD reconstructions with minimum 10 fusion levels or planned 3-column osteotomy (3CO). Standard demographic and surgical data were collected. Intraoperative estimated blood loss (EBL) was calculated by suction canisters minus irrigation plus estimated blood lost in sponges, estimated to the nearest 50 mL. Serious adverse events (SAE) were defined a priori as: venothromboembolic event (VTE), cardiac arrhythmia, myocardial infarction, renal dysfunction, and seizure. All SAE were recorded. Simple t tests compared EBL between groups. Mean EBL by total blood volume (TBV), transfusion volume, complications related to TXA were secondary outcomes.

RESULTS

Sixty-two patients were enrolled and 52 patients completed the study; 25 were randomized to H and 27 to L. Demographic and surgical variables were not different between the two groups. EBL was not different between groups (H: 1596 ± 933 cc, L: 2046 ± 1105 cc, p = 0.12, 95% CI: - 1022 to 122 cc). EBL as a percentage of TBV was lower for the high-dose group (H: 29.5 ± 14.8%, L: 42.5 ± 26.2%, p = 0.03). Intraoperative transfusion volume (H: 961 ± 505 cc, L: 1105 ± 808 cc, p = 0.5) and post-operative transfusion volume (H: 513 ± 305 cc, L: 524 ± 245 cc, p = 0.9) were not different. SAE related to TXA were not different (p = 0.7) and occurred in 2 (8%) H and 3 (11%) L. There was one seizure (H), 2 VTE, and 2 arrhythmias.

CONCLUSION

No differences in EBL, transfusion volume, nor SAE were observed between H and L dose TXA protocols. High dose was associated with decreased TBV loss (13%). Further prospective study, with pharmacologic analysis, is required to determine appropriate TXA dosage in ASD surgeries.

LEVEL OF EVIDENCE

Therapeutic Level II.

TRIAL REGISTRATION

The study was registered at Clinicaltrials.gov (NCT02053363) February 3, 2014.

Post-operative tranexamic acid decreases chest tube drainage following vertebral body tethering surgery for scoliosis correction

PURPOSE

Anterior vertebral body tethering (VBT) is a non-fusion surgical treatment for Adolescent Idiopathic Scoliosis requiring chest tube(s) (CT). We sought to assess the efficacy of post-op intravenous tranexamic acid (IV TXA) in reducing CT drainage and retention.

METHODS

35 VBT patients received 24 h of post-op IV TXA (2 mg/kg/h) were compared to 49 who did not. Group comparisons were performed using Wilcoxon rank-sum and chi-squared tests. Multivariate linear regression analysis was used to assess the relationships between TXA and both CT drainage and retention time.

RESULTS

There were no group differences at baseline (Table). CTs placed for thoracic (T) and thoracolumbar (TL) curves were assessed separately. For TH CT, there was less total CT drainage in the TXA group (TXA 569.4 ± 337.4 mL vs. Non-TXA 782.5 ± 338.9 mL; p = 0.003) and shorter CT retention time (TXA 3.0 ± 1.3 vs. Non-TXA 3.9 ± 1.4 days; p = 0.003). For TL CT, there was less total CT drainage in the TXA group (TXA 206.8 ± 152.2 mL vs. Non-TXA 395.7 ± 196.1 mL; p = 0.003) and shorter CT retention time (TXA 1.7 ± 1.3 vs. Non-TXA 2.7 ± 1.0 days; p = 0.001). Following multivariate analysis, use of TXA was the only significant predictor of both drainage in T and TL CTs (p = 0.012 and p = 0.002, respectively) as well as T and TL CT retention time (p = 0.008 and p = 0.009, respectively). There were no differences in LOS (p = 0.863) or ICU stay (p = 0.290).

CONCLUSION

IV TXA results in a significant decrease in CT drainage and retention time. CT retention is decreased by 1 day for those that receive TXA.

LEVEL OF EVIDENCE

III.

Risk Factors of Total Blood Loss and Hidden Blood Loss in Patients with Adolescent Idiopathic Scoliosis: A Retrospective Study

Objectives

To investigate the risk factors of total blood loss (TBL) and hidden blood loss (HBL) in adolescent idiopathic scoliosis (AIS) patients undergoing posterior orthopedic surgery.

Methods

The AIS patients who visited department of spine surgery between January 2015 and December 2020 were retrospectively reviewed. Those with a history of posterior orthopedic surgery for AIS were identified, and their clinical data were collected. Gross formula was used to calculate the TBL and HBL. SPSS 20.0 was used for statistical analysis. The potential risk factors of TBL and HBL were assessed by independent t-test or univariate analysis. The risk factors of TBL and HBL were determined by multiple linear regression.

Results

A total of 114 patients were included in this study. Operative time (P < 0.001), postoperative platelets (PLT) (P = 0.001), the number of surgical fixation segments (P < 0.001), implanted screws (P < 0.001), hospital stay (P = 0.006), type of scoliosis (P < 0.001), and correction angle of scoliosis (P = 0.063) were the potential risk factors of TBL. Operative time (P < 0.000), postoperative PLT (P = 0.095), the number of surgical fixation segments (P < 0.001), implanted screws (P < 0.001), type of scoliosis (P < 0.001), correction angle of scoliosis (P = 0.073), and total blood volume (P = 0.098) were the potential risk factors of HBL. Multiple linear regression analysis showed that operative time (P = 0.003) and the number of surgical fixation segments (P = 0.014) were risk factors of TBL, while the number of surgical fixation segments (P = 0.004) was a risk factor of HBL.

Conclusions

In AIS patients undergoing posterior internal fixation surgery, the operative time and the number of surgical fixation segments are risk factors of TBL, and the number of surgical fixation segments is a risk factor of HBL. Surgeons need to consider these factors when making surgical strategies for AIS patients.

Epsilon Aminocaproic Acid’s Safety and Efficacy in Pediatric Surgeries Including Craniosynostosis Repair: A Review of the Literature

Craniosynostosis, the premature fusion of skull sutures in children, requires surgical correction. This procedure routinely requires allogeneic blood transfusions, which are associated with multiple risks of their own. Since 2008, antifibrinolytics tranexamic acid (TXA) and epsilon aminocaproic acid (EACA or Amicar) have been widely used. There is literature comparing the two agents in scoliosis and cardiothoracic surgery, but the literature comparing the two agents in pediatric craniofacial surgery (CF) is limited. Tranexamic acid use is more common in pediatric CF surgery and has been thoroughly studied; however, it costs about three times as much as EACA and has been associated with seizures. This study compiles the literature assessing the safety and efficacy of EACA in reducing blood loss and transfusion volumes in children and explores its potential use in pediatric CF surgery.

Papers from 2000 to 2021 regarding the effectiveness and safety of EACA in Pediatric scoliosis, cardiothoracic, and craniosynostosis surgery were reviewed and compiled. Papers were found via searching PubMed and Cochrane databases with the key terms: Epsilon aminocaproic acid, EACA, Amicar, Tranexamic acid, TXA, craniosynostosis, scoliosis, cardiothoracic, and pediatric. Prospective studies, retrospective studies, and meta-analyses were included.

Twenty-nine papers were identified as pertinent from the literature searched. Four were meta-analyses, 14 were retrospective, and 11 were prospective. Of these papers, seven were of cardiac surgery, 12 were of scoliosis, and nine were of craniosynostosis. During our search, EACA has been shown to consistently reduce blood transfusion volumes compared to control. However, it is not as effective when compared to TXA. EACA has a similar safety profile to TXA but has a reduced risk of seizures. There are not many studies of EACA in craniosynostosis repair, but the existing literature shows promising results for EACA's efficacy and safety, warranting more studies. 

Blood loss estimation during posterior spinal fusion for adolescent idiopathic scoliosis

PURPOSE

Blood loss (BL) during posterior spinal fusion for adolescent idiopathic scoliosis (AIS) may be estimated using a variety of unproven techniques. Patient care and research on BL are likely impacted by a lack of standardization. A novel FDA-approved blood volume (BV) analysis system (BVA-100 Blood Volume Analyzer) allows rapid processing with > 97% accuracy. The purpose of this study was to investigate common methods for BL estimation.

METHODS

BV assessment was performed with the BVA-100. After obtaining a baseline sample of 5 mL of blood, 1 mL of I-131-labeled albumin was injected intravenously over 1 min. Five milliliter blood samples were then collected at 12, 18, 24, 30, and 36 min post-injection. Intravenous fluid was minimized to maintain euvolemia. Salvaged blood was not administered during surgery. BL was estimated using several common techniques and compared to the BV measurements provided by the BVA-100 (BVABL).

RESULTS

Thirty AIS patients were prospectively enrolled with major curves of 54° and underwent fusions of 10 levels. BL based on the BVA-100 (BVABL) was 519.2 [IQR 322.9, 886.2] mL. Previously published formulas all failed to approximate BVABL. Multiplying the cell saver volume return by 3 (CS3) approximates BVABL well with a Spearman correlation coefficient and ICC of 0.80 and 0.72, respectively. An extrapolated cell salvage-based estimator also showed high intraclass correlation coefficient (ICC) and Spearman coefficients with less bias than CS3.

CONCLUSION

Published formulaic approaches do not approximate true blood loss. Multiplying the cell saver volume by 3 or using the cell salvage-based estimator had the highest correlation coefficient and ICC.

LEVEL OF EVIDENCE

Prospective cohort Level 2.

Blood Loss and Transfusion in a Pediatric Scoliosis Surgery Cohort in the Antifibrinolytic Era

Children and adolescents undergoing posterior spinal fusion for scoliosis experience high rates of bleeding and blood product transfusion. Antifibrinolytic therapy is one key strategy to decrease blood loss and transfusion in pediatric scoliosis surgery. Here we review 172 pediatric scoliosis patients (birth to 21 y) who underwent posterior spinal fusion at our institution from 2017 to 2018. We reported rates of blood loss and transfusion, compared patients receiving tranexamic acid to a ε-aminocaproic acid, and evaluated antifibrinolytic agent and laboratory parameters as predictors of blood loss and transfusion. Intraoperatively, 62% received tranexamic acid and 38% received ε-aminocaproic acid. Overall, blood loss (mean intraoperative estimated blood loss=14.9±9.7 mL/kg, 22% with clinically significant blood loss [>20 mL/kg], and mean calculated hemoglobin mass loss=175.9±70.1 g) and transfusion rates (15% with intraoperative allogeneic red blood cell transfusion and mean intraoperative allogeneic red blood cell transfusion volume=12.5±7.1 mL/kg) were similar to previous cohorts studying intraoperative antifibrinolytics. There was no difference in intraoperative estimated blood loss, clinically significant blood loss, calculated hemoglobin mass loss, or transfusion rates between the antifibrinolytic groups. Antifibrinolytic choice was not predictive of blood loss or transfusion. Routine hematologic laboratory parameters and antifibrinolytic choice were insufficient to predict blood loss or other outcomes. Future prospective laboratory-based studies may provide a more comprehensive model of surgical-induced coagulopathy in scoliosis surgery and provide a better tool for predicting blood loss and improving outcomes.

Minimally Invasive Scoliosis Surgery Is a Feasible Option for Management of Idiopathic Scoliosis and Has Equivalent Outcomes to Open Surgery: A Meta-Analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVE

To compare outcomes between minimally invasive scoliosis surgery (MISS) and traditional posterior instrumentation and fusion in the correction of adolescent idiopathic scoliosis (AIS).

METHODS

A literature search was performed using MEDLINE, PubMed, EMBASE, Google scholar and Cochrane databases, including studies reporting outcomes for both MISS and open correction of AIS. Study details, demographics, and outcomes, including curve correction, estimated blood loss (EBL), operative time, postoperative pain, length of stay (LOS), and complications, were collected and analyzed.

RESULTS

A total of 4 studies met the selection criteria and were included in the analysis, totaling 107 patients (42 MIS and 65 open) with a mean age of 16 years. Overall there was no difference in curve correction between MISS (73.2%) and open (76.7%) cohorts. EBL was significantly lower in the MISS (271 ml) compared to the open (527 ml) group, but operative time was significantly longer (380 min for MISS versus 302 min for open). There were no significant differences between the approaches in pain, LOS, complications, or reoperations.

CONCLUSION

MISS was associated with less blood loss but longer operative times compared to traditional open fusion for AIS. There was no difference in curve correction, postoperative pain, LOS, or complications/reoperations. While MISS has emerged as a feasible option for the surgical management of AIS, further research is warranted to compare these 2 approaches.

The administration of tranexamic acid for corrective surgery involving eight or more spinal levels: A systematic review and meta-analysis

As the number of fusion levels increases, the complexity of spinal correction surgery also increases. Thus, we conducted this study to determine the safety and efficacy of tranexamic acid (TXA) involving eight or more spinal fusion levels. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Assessing the Methodological Quality of Systematic Reviews (AMSTAR) guidelines, a search of the PubMed, Embase, CENTRAL, Web of Science, and ClinicalTrials.gov databases was conducted for relevant studies published prior to May 30, 2019. The primary outcomes, including blood loss and transfusion requirement, and the secondary outcomes, including general indices, postoperative hemoglobin, and coagulation function, were analyzed using Rev Man 5.3.5 software and STATA version 12.0. Eight randomized controlled trials (473 participants) were included in the study. Compared to the control treatments, TXA reduced intraoperative blood loss, total blood loss, transfusion volume, and prothrombin time. There were no significant differences between the TXA and non-TXA groups in transfusion rate, operative time, hospital stay, complications, hemoglobin level, and other coagulation function parameters. In the pediatric subgroup analysis, TXA additionally improved hemoglobin levels, platelet count, and prothrombin time international normalized ratio. The present meta-analysis showed that TXA reduced blood loss and transfusion volume in both adults and children. In pediatric patients, TXA led to a greater benefit in postoperative hemoglobin levels and coagulation function. Intravenous TXA is safe and effective in children with eight or more spinal corrective levels.

Tranexamic Acid in Pediatric Scoliosis Surgery: A Prospective Randomized Trial Comparing High-dose and Low-dose Tranexamic Acid in Adolescent Idiopathic Scoliosis Undergoing Posterior Spinal Fusion Surgery

STUDY DESIGN

Prospective randomized double-blinded trial.

OBJECTIVE

The objective of this study is to determine the efficacy of high-dose versus low-dose tranexamic acid (TXA) in adolescent idiopathic scoliosis (AIS) corrective surgery.

SUMMARY OF BACKGROUND DATA

Corrective surgery for AIS is associated with significant blood loss. Evidence on the optimum TXA dose to reduce bleeding in pediatric population is scarce.

METHODS

A total of 166 AIS patients aged between 10 and 21 years, of American Society of Anesthesiologists (ASA) physical status I and II, preoperative hemoglobin >10 g/dL, platelet count >150,000 cells/L and Cobb angle of >45° scheduled for elective single-stage posterior spinal fusion (PSF) surgery by two attending surgeons were included between March 2017 and November 2018. Patients were randomized into Group A (High Dose, 30 mg/kg TXA loading dose followed by 10 mg/kg/h infusion) and Group B (Low Dose, 10 mg/kg TXA loading dose followed by 1 mg/kg/h infusion). The primary outcome was total surgical blood loss between both groups. Secondary outcomes were transfusion requirement, perioperative changes in hemoglobin and coagulation profiles, adverse events, and factors that influence total blood loss.

RESULTS

The mean total surgical blood loss between the two groups was not significant (Group A: 928.8 ± 406.1 mL [range: 348-1857 mL]; Group B: 918.1 ± 406.2 mL [range: 271-2000 mL], P = 0.865). The median duration of surgery was 120 minutes. One patient in each group received allogenic blood transfusion during the perioperative period. There were no significant changes in hemoglobin and coagulation profile at pre-operation, post-operation 0 hour and 48 hours. Sex, number of vertebral levels fused, and duration of surgery were independently associated with total surgical blood loss. No adverse events were observed perioperatively.

CONCLUSION

Low-dose TXA was as efficacious as high-dose TXA in reducing blood loss and allogenic blood transfusion for AIS patients undergoing PSF surgery.Level of Evidence: 1.

Intravenous Tranexamic Acid Reduces Blood Loss and Transfusion Volume in Scoliosis Surgery for Spinal Muscular Atrophy: Results of a 20-Year Retrospective Analysis

Intravenous tranexamic acid (TXA) has been administered to reduce intraoperative blood loss in scoliosis surgery. However, the therapeutic effect of TXA on spinal muscular atrophy (SMA) scoliosis surgery is not well demonstrated. Therefore, this study aimed to assess the efficacy of intravenous TXA in SMA scoliosis surgery. From December 1993 to August 2020, 30 SMA patients who underwent scoliosis surgery (posterior fusion with fusion level of thoracic second or third to pelvis) were retrospectively enrolled and divided into the TXA group and non-TXA (control) group, with 15 patients in each group. Survey parameters were the amount of blood loss, blood transfusion, crystalloid transfusion volume, intubation time, and associated pulmonary complications (including pneumonia, pulmonary edema, and pulmonary atelectasis). The TXA group had significantly lesser blood loss than the control group (p = 0.011). Compared with the control group, the TXA group had significantly lower blood transfusion (p < 0.001), crystalloid volume (p = 0.041), and total transfusion volume (p = 0.005). In addition, the TXA group had fewer postoperative pulmonary complications, and patients with pulmonary complications were associated with a higher relative crystalloid volume and relative total transfusion volume (p = 0.003 and 0.022, respectively). In conclusion, TXA can be effective in reducing intraoperative blood loss and crystalloid fluid transfusions during scoliosis surgery in SMA patients, which may aid in reducing postoperative pulmonary complications.

The Efficacy and Safety of Epsilon-Aminocaproic Acid for Perioperative Blood Management in Spinal Fusion Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Perioperative blood loss is a major concern in spinal fusion surgery and often requires blood transfusion. A large amount of perioperative blood loss might increase the risks of various perioperative complications. Recent clinical studies have focused on the perioperative administration of epsilon-aminocaproic acid (EACA) in spinal fusion surgery. The aim of this review was to evaluate the efficacy and safety of EACA in spinal fusion surgery.

METHODS

Electronic databases (MEDLINE, EMBASE, PubMed, and Cochrane Central Register of Controlled Trials) were systematically searched up to April 2021. Data on perioperative blood loss, blood transfusion, and complications were extracted and analyzed by RevMan software.

RESULTS

Six randomized controlled studies comprising 398 patients undergoing spinal fusion surgery were included in this systematic review. Compared with the control group, the EACA group had significantly lower total perioperative blood loss, postoperative blood loss, postoperative hemoglobin, postoperative blood transfusion units, total blood transfusion units, and postoperative red blood cell transfusion units. Additionally, no significant differences were observed between the EACA and control groups in intraoperative blood loss, intraoperative blood transfusion units, intraoperative crystalloid administered, hospital stays, operative time, perioperative respiratory complications, and wound bleeding.

CONCLUSIONS

EACA in patients undergoing spinal fusion surgery is effective in perioperative hemostasis without increasing the incidence of postoperative complications. However, more large-scale trials are needed to examine the long-term adverse side effects of EACA in spinal fusion surgery.

Unplanned return to the operating room (UPROR) after surgery for adolescent idiopathic scoliosis

STUDY DESIGN

Retrospective analysis of a prospectively collected multi-center database.

PURPOSE

UPROR (Unplanned Return to the Operating Room) is an inclusive metric for unexpected surgery after the index procedure. Given the many quality and safety improvements in AIS surgery over the past 20 years, it is useful for spine deformity surgeons to understand the current rate of UPROR, the etiologies, and trends over time. A report from a very large data set, including multiple surgeons and centers, with longer follow-up, would provide the clearest picture.

METHODS

We performed a retrospective review of a prospective multi-center database of patients who had AIS deformity correction surgery to analyze all cases of UPROR, using linear regression models, survival analysis, and descriptive statistics.

RESULTS

Among 3464 patients who had surgery (ASF, PSF, or ASF + PSF) for AIS from 1995 to 2017, 4.8% had an UPROR event in one of the following categories: surgical-site-related (43.3%), instrument failures (34.3%), revisions (8.4%), neurologic (5.1%), pulmonary (5.1%), medical (0.6%), and other (3.4%). The average time from initial surgery to UPROR was 734.4 days. 45.5% of UPRORs occurred within 1 year, 12.4% between 1 and 2 years, 30.9% between 2 and 5 years, and 11.2% between 5 and 10 years. In patients with at least 2-year, 5-year, and 10-year follow-up, the UPROR rates were 6.6, 7.3, and 9.2%, respectively. Between 1997 and 2013, the UPROR rate decreased by 0.46% per year (95% CI 0.25-0.68, p < 0.001).

CONCLUSION

UPROR has decreased significantly over time but as expected, increases with increased follow-up.

LEVEL OF EVIDENCE

Level III, therapeutic.

A New Low Dose of Tranexamic Acid for Decreasing the Rate of Blood Loss in Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis

BACKGROUND

Previous studies have demonstrated that the use of tranexamic acid (TXA) reduces blood loss and transfusion requirements in children undergoing scoliosis surgery. Although TXA is safe and effective, significant adverse events have been reported. Using the lowest effective dose of TXA is advisable. We evaluated a new low dosing regimen for TXA based on an improved pharmacokinetic model and therapeutic plasma concentration. The purpose of this study is to evaluate the effectiveness of this new low dosing regimen in reducing blood loss and transfusion requirements in patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion when compared with a control group who did not receive TXA.

METHODS

We retrospectively reviewed 90 consecutive patients with idiopathic scoliosis undergoing posterior spinal fusion at our institution from 2017 to 2020. Forty patients received TXA at the new dosing regimen (10 mg/kg load, 5 mg/kg/h infusion) and 50 patients were in the non-TXA control group. The same 2 orthopaedic surgeons, working as a team, performed all surgical procedures. We assessed the use of TXA as an independent risk factor for estimated blood loss and transfusion requirement after adjusting for age, surgical duration, body mass index, major coronal curve, and sex.

RESULTS

A comparison of the intraoperative cumulative blood loss in the 2 groups showed a significantly lower blood loss in the TXA group. (583.5±272.0 vs. 479.5±288.7 mL, P=0.03) This difference persisted when blood loss was calculated as percent of total blood volume and per vertebral level. Transfusion requirements were lower in the TXA group (4/50 patients vs. 0/40 patients, P=0.13). No patient in the TXA group required a blood transfusion during their hospitalization.

CONCLUSION

This study is the first to provide evidence that a new low dosing regimen of TXA can significantly reduce blood loss and transfusion requirements for idiopathic scoliosis patients and supports the need for a prospective, randomized clinical trial to confirm these findings.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Association of Intravenous Tranexamic Acid With Thromboembolic Events and Mortality: A Systematic Review, Meta-analysis, and Meta-regression

IMPORTANCE

Tranexamic acid (TXA) is an efficient antifibrinolytic agent; however, concerns remain about the potential adverse effects, particularly vascular occlusive events, that may be associated with its use.

OBJECTIVE

To examine the association between intravenous TXA and total thromboembolic events (TEs) and mortality in patients of all ages and of any medical disciplines.

DATA SOURCE

Cochrane Central Register of Controlled Trials and MEDLINE were searched for eligible studies investigating intravenous TXA and postinterventional outcome published between 1976 and 2020.

STUDY SELECTION

Randomized clinical trials comparing intravenous TXA with placebo/no treatment. The electronic database search yielded a total of 782 studies, and 381 were considered for full-text review. Included studies were published in English, German, French, and Spanish. Studies with only oral or topical tranexamic administration were excluded.

DATA EXTRACTION AND SYNTHESIS

Meta-analysis, subgroup and sensitivity analysis, and meta-regression were performed. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

MAIN OUTCOMES AND MEASURES

Vascular occlusive events and mortality.

RESULTS

A total of 216 eligible trials including 125 550 patients were analyzed. Total TEs were found in 1020 (2.1%) in the group receiving TXA and 900 (2.0%) in the control group. This study found no association between TXA and risk for total TEs (risk difference = 0.001; 95% CI, -0.001 to 0.002; P = .49) for venous thrombosis, pulmonary embolism, venous TEs, myocardial infarction or ischemia, and cerebral infarction or ischemia. Sensitivity analysis using the risk ratio as an effect measure with (risk ratio = 1.02; 95% CI, 0.94-1.11; P = .56) and without (risk ratio = 1.03; 95% CI, 0.95-1.12; P = .52) studies with double-zero events revealed robust effect size estimates. Sensitivity analysis with studies judged at low risk for selection bias showed similar results. Administration of TXA was associated with a significant reduction in overall mortality and bleeding mortality but not with nonbleeding mortality. In addition, an increased risk for vascular occlusive events was not found in studies including patients with a history of thromboembolism. Comparison of studies with sample sizes of less than or equal to 99 (risk difference = 0.004; 95% CI, -0.006 to 0.014; P = .40), 100 to 999 (risk difference = 0.004; 95% CI, -0.003 to 0.011; P = .26), and greater than or equal to 1000 (risk difference = -0.001; 95% CI, -0.003 to 0.001; P = .44) showed no association between TXA and incidence of total TEs. Meta-regression of 143 intervention groups showed no association between TXA dosing and risk for venous TEs (risk difference, -0.005; 95% CI, -0.021 to 0.011; P = .53).

CONCLUSIONS AND RELEVANCE

Findings from this systematic review and meta-analysis of 216 studies suggested that intravenous TXA, irrespective of dosing, is not associated with increased risk of any TE. These results help clarify the incidence of adverse events associated with administration of intravenous TXA and suggest that TXA is safe for use with undetermined utility for patients receiving neurological care.

Topical tranexemic acid reduces intra-operative blood loss and transfusion requirements in spinal deformity correction in patients with adolescent idiopathic scoliosis

PURPOSE

To evaluate the effectiveness of the use of topical tranexamic acid (tTXA) in spinal deformity correction in AIS patients METHODS: Sixty consecutive operative AIS patients were reviewed from a single institution and divided into two groups with similar demographics. Standardized peri-operative blood salvage techniques were utilized in all 60 patients. In the latter 30 patients, tTXA soaked sponges (1 g mixed in 500 ml Normal Saline) was utilised for wound packing during the entire surgical procedure compared to dry sponges as used in the former 30 patients. Both the groups were compared for the magnitude of deformity corrected, EBL per level fused, total EBL, blood transfused, drain output and peri-operative events.

RESULTS

Sixty AIS patients (mean age 14.4 yrs, 43 females, mean BMI 21.5, mean levels 10.7) were included. Both groups achieved similar change in Coronal Cobb correction. The EBVL (Estimated blood volume loss) % lost in the topical TXA group was 38% less than the control group (11.2 vs. 18.3%, p = 0.006). Similarly, the EBL/level was significantly lower in the topical TXA group (41 ± 30 ml vs. 57 ± 26 ml, p = 0.03). Three of 30 patients in the control group required at least 1 unit of blood transfusion, whereas only 1 patient in the topical TXA group required transfusion (10 vs. 3.3%, p = 0.001). No differences were noted in post-operative drain output, change in hemoglobin levels, and peri-operative complication rates.

CONCLUSION

When used as an adjunct to the conventional blood salvage techniques in spinal deformity correction procedures, the use of tTXA resulted in reduced operative blood loss, and blood transfusion requirements.

Safe and effective performance of pediatric spinal deformity surgery in patients unwilling to accept blood transfusion: a clinical study and review of literature

BACKGROUND

Pediatric deformity surgery traditionally involves major blood loss. Patients refusing blood transfusion add extra clinical and medicolegal challenges; specifically the Jehovah's witnesses population. The objective of this study is to review the safety and effectiveness of blood conservation techniques in patients undergoing pediatric spine deformity surgery who refuse blood transfusion.

METHODS

After obtaining institutional review board approval, we retrospectively reviewed 20 consecutive patients who underwent spinal deformity surgery and refused blood transfusion at a single institution between 2014 and 2018. We collected pertinent preoperative, intraoperative and most recent clinical and radiological data with latest follow-up (minimum two-year follow-up).

RESULTS

Twenty patients (13 females) with a mean age of 14.1 years were identified. The type of scoliotic deformities were adolescent idiopathic (14), juvenile idiopathic (1), neuromuscular (3) and congenital (2). The major coronal Cobb angle was corrected from 55.4° to 11.2° (80% correction, p <  0.001) at the latest follow-up. A mean of 11.4 levels were fused and 5.6 levels of Pontes osteotomies were performed. One patient underwent L1 hemivertebra resection and three patients had fusion to pelvis. Estimated blood loss, percent estimated blood volume loss, and cell saver returned averaged 307.9 mL, 8.5%, and 80 mL, respectively. Average operative time was 214 min. The average drop in hemoglobin after surgery was 2.9 g/dL. The length of hospital stay averaged 5.1 days. There were no intraoperative complications. Three postoperative complications were identified, none related to their refusal of transfusion. One patient had in-hospital respiratory complication, one patient developed a late infection, and one patient developed asymptomatic radiographic distal junctional kyphosis.

CONCLUSIONS

Blood conservation techniques allow for safe and effective spine deformity surgery in pediatric patients refusing blood transfusion without major anesthetic or medical complications, when performed by an experienced multidisciplinary team.

LEVEL OF EVIDENCE

Level IV.

The effect of multiple-dose oral versus intravenous tranexamic acid in reducing postoperative blood loss and transfusion rate after adolescent scoliosis surgery: a randomized controlled trial

BACKGROUND CONTEXT

Tranexamic acid (TXA) is widely used in surgery for adolescent idiopathic scoliosis (AIS) and has been proved to be efficacious in reducing intraoperative blood loss (IBL) and the transfusion rate. However, the routine TXA regimen was intraoperative administration alone, in which the concentration of TXA could not cover the whole process of hyperfibrinolysis. And, its ability to control the massive postoperative blood loss (PBL) may be insufficient. Thus, we promoted a multiple-dose regimen of TXA for patients with AIS who underwent surgical correction.

PURPOSE

The primary aims were (1) to determine whether the multiple-dose regimen of TXA could reduce PBL and the postoperative transfusion rate, and (2) to compare the efficacy of oral administration with intravenous administration. The secondary aims were (3) to evaluate whether this regimen could alleviate inflammatory response, and (4) to assess the occurrence of drug-related side effects.

STUDY DESIGN

Prospective, double-blinded, randomized controlled trial.

PATIENT SAMPLE

A total of 108 patients with AIS who underwent posterior scoliosis correction and spinal fusion (PSS) were enrolled in this study.

OUTCOME MEASURES

The primary parameters were PBL and postoperative transfusion rate. Other parameters such as total blood loss (TBL), maximum hemoglobin (Hb) decrease, volume of drainage, inflammation markers (interleukin-6 [IL-6] and C-reactive protein [CRP]), and occurrence of complications were also collected and compared. Multiple regression analysis was used to examine the variables that affected PBL.

METHODS

Patients were randomized into three groups. All patients received intravenous TXA 50 mg/kg loading dose and 10 mg/kg/h maintenance dose during surgery. Group A received 1 g oral TXA at 4 hours, 10 hours, and 16 hours postoperatively; group B received 0.5 g intravenous TXA at 6 hours, 12 hours, and 18 hours postoperatively; group C received placebo.

RESULTS

The mean PBL and postoperative transfusion rate in group A (957.8±378.9 mL, 13.89%) and B (980.3±491.8 mL, 11.11%) were significantly lower than those in group C [1,495.9±449.6 mL, mean differences=538.1 mL, 95% confidence interval (CI), 290.1-786.1 mL, p<0.001; 515.6 mL, 95% CI, 267.6-763.6 mL, p<.001]; (36.11%, p=.029, p=.013). Meanwhile, the mean TBL, maximum Hb decrease, and volume of drainage were also significantly lower in group A and B than in group C. IL-6 and CRP in group A and B were significantly lower than in group C from postoperative days 1 to 3. All these differences were not significant between groups A and B. No drug-related complications were observed in any patient. Multiple regression showed that the application of postoperative TXA and number of screws were significant parameters affecting PBL.

CONCLUSIONS

A multiple-dose regimen of TXA, either by oral or intravenous application, could be a safe and effective means of controlling PBL and decreasing the postoperative transfusion rate in patients with AIS who underwent scoliosis surgery. In addition, it could inhibit postoperative inflammatory response.

Different Dose Regimens of Intravenous Tranexamic Acid in Adolescent Spinal Deformity Surgery: A Systematic Review and Meta-Analysis

Objective

To evaluate the efficacy and safety of different dose regimens of intravenous (IV) tranexamic acid (TXA) in adolescent spinal deformity surgery.

Methods

Two researchers independently searched multiple databases, including PubMed, Embase, Cochrane Library, and Web of Science to find studies that met the inclusion criteria. A meta-analysis was performed based on the guidelines of the Cochrane Reviewer's Handbook.

Results

Six randomized controlled trials (RCTs) and eleven non-RCTs were identified, including 1148 patients. According to different dose regimens of IV TXA, the included studies were divided into the high-dose group and the low-dose group. Compared with placebo, both groups had less total blood loss (TBL) (high dose: WMD = -1737.55, 95% CI: (-2247.16, -1227.94), P < 0.001, I ² = 0%; low dose: WMD = -528.67, 95% CI: (-666.06, -391.28), P < 0.001, I ² = 0%), intraoperative blood loss (IBL) (high dose: WMD = -301.48, 95% CI: (-524.3, -78.66), P = 0.008, I ² = 60.3%; low dose: WMD = -751.14, 95% CI: (-967.21, -535.08), P < 0.001, I ² = 0%), and blood transfusion rates (high dose: RR = 0.19, 95% CI: (0.1, 0.37), P < 0.001, I ² = 0%; low dose: RR = 0.4, 95% CI: (0.18, 0.91), P = 0.029, I ² = 57%). High-dose IV TXA use was associated with more vertebral fusion segments (WMD = 0.53, 95% CI: (0.23, 0.82), P < 0.001, I ² = 31.2%). Low-dose IV TXA use was associated with shorter operative time (WMD = -18.43, 95% CI: (-26.68, -10.17), P < 0.001, I ² = 0%).

Conclusion

High-dose and low-dose IV TXA were effective in reducing TBL, IBL, and blood transfusion rates without increasing complications in adolescent patients undergoing spinal deformity surgery. Low-dose IV TXA was effective in reducing the operative time. Both the high-dose and low-dose groups had similar preoperative and postoperative Hb levels compared to the control group.

[Progress on the application of tranexamic acid in adolescent spine corrective surgery]

OBJECTIVE

To review the advances in the application of tranexamic acid (TXA) in adolescent spinal corrective surgery.

METHODS

The mechanism of action and pharmacokinetic, effectiveness, dosage, safety as well as methods of administration were comprehensively summarized by consulting domestic and overseas related literature about the application of TXA in adolescent spinal corrective surgery in recent years.

RESULTS

TXA efficaciously reduce intraoperative blood loss, transfusion rate and volume, postoperative drainage volume in adolescent spinal corrective surgery. At present, the most common method of administration in adolescent spinal corrective surgery is that a loading dose is given intravenously before skin incision or induction of anesthesia, followed by a maintenance dose until the end of the surgery. The range of loading dose and maintenance dose is 10-100 mg/kg and 1-10 mg/(kg·h), respectively. No drug related adverse event has been reported in this range.

CONCLUSION

The effectiveness and safety of TXA in adolescent spinal surgery have been basically confirmed. However, further studies are needed to determine the optimal dosage, method of administration as well as whether it could reduce blood loss after surgery.

Impact of Pediatric Subspecialty Training on Perioperative Complications in Adolescent Idiopathic Scoliosis Surgery

This was a retrospective study of data prospectively collected from 2012 to 2016 from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database. The objective was to evaluate the effect of pediatric fellowship training on 30-day perioperative morbidity and mortality following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). Several pathways exist in North America by which physicians acquire the clinical and technical skills to manage AIS surgically. Previous work has noted that surgeons with pediatric fellowship training tend to perform the bulk of pediatric spine surgeries. However, no study has been performed that examines if pediatric fellowship training (PFT) has an impact on early postoperative outcomes. A total of 14,194 AIS surgical patients were identified from the ACS NSQIP database. A cohort receiving isolated PSF was abstracted from this group and separated into 3 groups according to surgeon training: (1) ped+ (with PFT, n=4455); (2) ped-(without PFT, n=325); and (3) ped+match (patients selected from ped+ matched to ped- for age, sex, and fusion levels, n=325). The groups were compared for 30-day perioperative morbidity and mortality. No significant differences were noted for the 3 groups in terms of wound infections, length of hospital stay, readmissions, and unplanned returns to the operating room. Ped+match and ped- groups had no difference in neurologic injury rates. However, the ped+ and ped+match groups had significantly lower rates of blood transfusion and average volume of blood lost compared with the ped- group. Surgeons with pediatric fellowship training have a significantly lower average blood loss volume and blood transfusion rate in PSF for AIS than surgeons without such training. Understanding that different training pathways for surgeons may directly impact operative outcomes invites further examination of surgical education in North America to improve training consistency. [Orthopedics. 2020;43(5):e454-e459.].

Do Antifibrinolytic Agents Reduce the Risk of Blood Transfusion in Children Undergoing Spinal Fusion?: A Propensity Score-matched Comparison Using a National Database

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To evaluate the effectiveness and safety of antifibrinolytic (AF) agents in reducing perioperative blood transfusion in pediatric patients undergoing spinal fusion.

SUMMARY OF BACKGROUND DATA

The potential for AF to decrease bleeding and reduce exposure to allogenic transfusions has led to widespread off-label use in a number of major pediatric surgical procedures. Recent reviews call for improving the body of evidence for their effectiveness and safety in pediatric spinal fusion.

METHODS

Children undergoing spinal fusion were identified in the American College of Surgeons National Surgical Quality Improvement Program Pediatric (NSQIP-P) 2016 and 2017 databases. Univariate analyses of patient and perioperative characteristics informed the creation of a propensity score model predicting treatment with AF, followed by 1:1 matching to allow comparison of allogenic red blood cell transfusion rates and secondary outcomes between treated and untreated patients.

RESULTS

Of 6626 total patients, 5434 (81%) received AF and 1533 (23%) received a blood transfusion. Analysis of data for 1192 propensity score-matched pairs revealed that treatment with AF was associated with a statistically nonsignificant 16% reduction in perioperative transfusion (OR 0.84, 95% confidence interval 0.68-1.05, P = 0.119) and a statistically significant 43% reduction in postoperative transfusion (OR 0.57, 95% confidence interval 0.39-0.81, P = 0.002). No differences in the incidences of postoperative seizure or thrombosis were observed, with overall rates of 7.5 and 22.5 events per 10,000 patients, respectively.

CONCLUSION

AF agents appear to reduce postoperative allogenic transfusion in children undergoing spinal fusion surgery. Adverse drug effects such as thromboembolic complications and seizure were extremely rare and warrant continued monitoring, though this is the largest study to date providing evidence for the safety profile of these drugs.

LEVEL OF EVIDENCE

3.

Cost-benefit analysis of tranexamic acid and blood transfusion in elective lumbar spine surgery for degenerative pathologies

OBJECTIVE

Blood transfusions are given to approximately one-fifth of patients undergoing elective lumbar spine surgery, and previous studies have shown that transfusions are accompanied by increased complications and additional costs. One method for decreasing transfusions is administration of tranexamic acid (TXA). The authors sought to evaluate whether the cost of TXA is offset by the decrease in blood utilization in lumbar spine surgery patients.

METHODS

The authors retrospectively reviewed patients who underwent elective lumbar or thoracolumbar surgery for degenerative conditions at a tertiary care center between 2016 and 2018. Patients who received intraoperative TXA (TXA patients) were matched with patients who did not receive TXA (non-TXA patients) by age, sex, BMI, ASA (American Society of Anesthesiologists) physical status class, and surgical invasiveness score. Primary endpoints were intraoperative blood loss, number of packed red blood cell (PRBC) units transfused, and total hemostasis costs, defined as the sum of TXA costs and blood transfusion costs throughout the hospital stay. A subanalysis was then performed by substratifying both cohorts into short-length (1-4 levels) and long-length (5-8 levels) spinal constructs.

RESULTS

Of the 1353 patients who met inclusion criteria, 68 TXA patients were matched to 68 non-TXA patients. Patients in the TXA group had significantly decreased mean intraoperative blood loss (1039 vs 1437 mL, p = 0.01). There were no differences between the patient groups in the total costs of blood transfusion and TXA (p = 0.5). When the 2 patient groups were substratified by length of construct, the long-length construct group showed a significant net cost savings of $328.69 per patient in the TXA group (p = 0.027). This result was attributable to the finding that patients undergoing long-length construct surgeries who were given TXA received a lower amount of PRBC units throughout their hospital stay (2.4 vs 4.0, p = 0.007).

CONCLUSIONS

TXA use was associated with decreased intraoperative blood loss and significant reductions in total hemostasis costs for patients undergoing surgery on more than 4 levels. Furthermore, the use of TXA in patients who received short constructs led to no additional net costs. With the increasing emphasis put on value-based care interventions, use of TXA may represent one mechanism for decreasing total care costs, particularly in the cases of larger spine constructs.

Antifibrinolytic Drugs and Allogeneic Transfusion in Pediatric Multilevel Spine Surgery: A Propensity Score Matched Cohort Study

STUDY DESIGN

Observational cohort study with propensity score matching.

OBJECTIVE

Determine whether antifibrinolytic drug use is associated with decreased allogeneic blood transfusion in multilevel pediatric spine surgery.

SUMMARY OF BACKGROUND DATA

Antifibrinolytic drugs are commonly used in adult multilevel spine surgery to reduce blood loss and allogeneic transfusion; however, only small studies have examined their efficacy in pediatric patients having multilevel spine surgery.

METHODS

Pediatric patients who had posterior multilevel spine surgery between 2016 and 2017 were identified in the national surgery quality improvement program participant use file. Propensity score matching was used to reduce bias from confounding and the rate of intraoperative allogeneic transfusion was compared between patients who received antifibrinolytic drugs and those who did not. Secondary outcomes included intraoperative cell saver volume, postoperative allogeneic transfusion, massive intraoperative transfusion, and adverse events including venous thromboembolism and seizure.

RESULTS

A total of 6904 patients underwent posterior multilevel spine surgery during the study period and 83% received antifibrinolytics. The matched cohort included 604 patients. Antifibrinolytic use had no association with reduced intraoperative allogeneic transfusion: odds ratio (OR) = 0.71 (99% confidence interval [CI] = 0.40-1.26, P = 0.12) or cell saver volume, median volume = 114 mL (0, 250 mL) in antifibrinolytic group versus 100 mL (0, 246 mL) in control group, P = 0.04. There was also no association with reduced postoperative allogeneic transfusion OR = 1.23 (99% CI = 0.54-2.81, P = 0.52) or massive transfusion OR = 1.0 (99% CI = 0.34-2.92, P = 1.0). No patient in the matched cohort had a venous thromboembolism or seizure.

CONCLUSION

Antifibrinolytic drugs are commonly used in pediatric multilevel spine surgery in the United States, but no efficacy was demonstrated in our study. There were no venous thromboembolisms or seizures implying an excellent safety profile in pediatric patients.

LEVEL OF EVIDENCE

3.

Safety and Effectiveness of Antifibrinolytics in Posterior Scoliosis Surgery for Adolescent Idiopathic Scoliosis: An Analysis of the NSQIP-Pediatric Database

STUDY DESIGN

This was a retrospective study of prospectively collected data.

OBJECTIVE

To utilize a large national database with prospectively collected data [National Surgical Quality Improvement Program Pediatric (NSQIP-Pediatric)] to study the safety and effectiveness of antifibrinolytic use during multilevel posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

There is currently a lack of consensus and evidence regarding the safety and effectiveness of antifibrinolytic use for pediatric patients undergoing corrective surgery for AIS.

MATERIALS AND METHODS

Patients who underwent multilevel PSF for AIS in the 2016 NSQIP-Pediatric database were identified. Preoperative and procedural characteristics were compared between patients who received antifibrinolytics versus those who did not. Multivariate regressions were used to compare perioperative transfusion rates and postoperative outcomes, such as rate of return to the operating room, 30-day readmission, and intensive care unit and hospital length of stay between the 2 treatment groups.

RESULTS

This study included 975 patients who received antifibrinolytics and 223 patients who did not. Patients who received these agents tended to have more levels fused, osteotomies performed, and longer operative times. After controlling for these variances, there were no statistical differences in rate and volume of transfusion, rate of return to the operating room, 30-day readmission, 30-day postoperative complications, or intensive care unit or hospital length of stay between the 2 treatment groups.

CONCLUSIONS

This study did not demonstrate transfusion reduction in the group that received antifibrinolytics. This finding may be, in part, secondary to nonoptimized or nonstandardized protocols for antifibrinolytic use in pediatric deformity surgery or the inability to adequately control for selection bias, as those with greater surgical invasiveness may be more likely to receive antifibrinolytics. Nonetheless, using antifibrinolytics in this population appears safe and not associated with increased perioperative complications.

LEVEL OF EVIDENCE

Level III.

Safety and efficacy of tranexamic acid in spinal canal tumors: a retrospective cohort study

Objective: The use of tranexamic acid (TXA) has become popular in spinal surgery, the purpose of this study is to investigate the effectiveness and safety of intraoperative TXA used to reduce surgical bleeding and transfusion requirements in spinal canal tumor resection.Methods: The data for patients with spinal canal tumors treated in our hospital from June 2014 to June 2017 were collected. The patients (≥18 years of age) were divided into a TXA group (group A, n = 30) and a non-TXA group (group B, n = 30). The TXA dose regimen in group A comprised a loading dose of 10 mg/kg 30 minutes before the operation, followed by a maintenance dose of 1 mg/kg per hour during the operation. Group B was not given TXA. The operation time, intraoperative blood loss, postoperative drainage, postoperative complications, coagulation function such as plasma thrombin time(PT), prothrombin time(TT), activated thromboplastin time(APTT), fibrinogen (Fib) were statistically analyzed.Results: The intraoperative blood loss and postoperative drainage volume were significant lower in group A than in group B (p<.05). There were no significant differences in the operation time, plasma thrombin time, prothrombin time, activated thromboplastin time, or fibrinogen between the two groups before and after the operation (p>.05), and no thrombotic complications occurred.Conclusion: TXA used during spinal tumor surgery can reduce the amount of intraoperative blood loss and postoperative drainage without increasing the risk of deep vein thrombosis and related complications.

Efficacy of antifibrinolytics in pediatric orthopedic surgery: a systematic review and meta-analysis

Antifibrinolytics (AFs) stabilize blood clot formation and reduce bleeding. The purpose of this systematic review and meta-analysis was to determine the impact of AF use on intraoperative blood loss and the need for blood transfusion in pediatric orthopedic surgery. A systematic review was performed using Medline and Embase to identify studies that utilized AFs during pediatric orthopedic surgery. The primary outcome measure was intraoperative blood loss in ml. Secondary outcomes included blood transfusion and thromboembolic events. Pooled estimates were derived from a random-effects model. Heterogeneity was assessed using the Cochrane Q and I statistic. Meta-regression assessed if age or study quality modified the effect of AFs on blood loss. Publication bias was assessed using a funnel plot, Egger regression analysis, and the Kendall τ-test. Twenty studies, with a total of 1356 patients, were included. The mean difference in intraoperative blood loss was 653 ml [95% confidence interval (CI): 464-842 ml, P < 0.001]. Similarly, the mean difference in percent of blood volume lost was 22% less in patients treated with AFs compared with controls (95% CI: 12-32, P < 0.001). Patients treated with AFs had a lower odds of transfusion compared to controls (OR: 0.324; 95% CI: 0.105-0.997, P = 0.049). The use of AF in pediatric orthopedic surgery results in decreased intraoperative blood loss and a lower risk of blood transfusion. The majority of studies included involve spine surgery; the benefits of AFs in extremity surgery in the pediatric population have yet to be delineated. Level of Evidence: Level II.

Comparison of the Coagulation Profile of Adolescent Idiopathic Scoliosis Patients Undergoing Posterior Spinal Fusion With and Without Tranexamic Acid

STUDY DESIGN

Prospective, observational cohort study.

OBJECTIVE

To improve the understanding of coagulation and bleeding mechanisms during spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

Fibrinolysis is the mechanism of bleeding for adolescent idiopathic scoliosis undergoing posterior spinal fusion. Antifibrinolytics have become popular; however, literature to support their use remains mixed. The mechanism of action has not been demonstrated.

METHODS

The coagulation profile of 88 adolescent idiopathic scoliosis patients undergoing posterior spinal fusion was analyzed. Standard coagulation laboratory investigations and thromboelastograms were drawn hourly through the case. Fifty-eight patients received no antifibrinolytic, whereas 30 patients received tranexamic acid by standardized protocol. The coagulation parameters, estimated blood loss, and transfusion requirements were compared in the two groups.

RESULTS

The two cohorts had no differences in demographic or surgical characteristics. Mean age was 13.6 years, 83% were female, a mean of 11.1 levels were fused, and the mean duration of surgery was 209 minutes. The tranexamic acid cohort did not demonstrate a decrease in blood loss. The transfusion rate, however, dropped from 47% in the non-tranexamic acid cohort to 23% in the tranexamic acid cohort (p = .03). Standard coagulation parameters did not differ between the groups. Fibrinolysis was diminished in the tranexamic acid cohort as measured by a Fibrinolysis score (mean maximum value 2.0 without tranexamic acid vs. 0.7 with tranexamic acid, p < .0001) and the lysis percent at 30 minutes by thromboelastogram (elevated to 3.9% without tranexamic acid vs. 1.2% with tranexamic acid at the 3-hour mark, p = .05).

CONCLUSIONS

This study provides confirmation of antifibrinolytic activity during posterior spinal fusion for adolescent idiopathic scoliosis. The presented data of fibrinolysis are proposed as standard measurements for future work on controlling blood loss during scoliosis surgery.

LEVEL OF EVIDENCE

Level 2, prospective comparative study.

The use of tranexamic acid in adult spinal deformity: is there an optimal dosing strategy?

BACKGROUND CONTEXT

ASD (Adult spinal deformity) surgery often entails complex osteotomies and realignment procedures, particularly in the setting of rigid deformities. Although previous studies have established the efficacy of tranexamic acid (TXA), data evaluating the widely variable dosing regimens remains sparse.

PURPOSE

To improve understanding of blood loss and transfusion requirements for low-dose and high-dose TXA regimens for adult spinal deformity (ASD) surgery.

STUDY DESIGN/SETTING

This is a retrospective cohort study of 318 ASD patients who received TXA. Outcome measures include estimated blood loss (EBL), perioperative transfusion requirement, and complications.

METHODS

A retrospective review was conducted on 318 ASD patients: 258 patients received a low-dose regimen of TXA (10 or 20 mg/kg loading dose with a 1 or 2 mg/kg/h maintenance dose) and 60 patients received a high-dose regimen of TXA (40 mg/kg loading dose with a 1 mg/kg/h maintenance dose, 30 mg/kg loading dose with a 10 mg/kg/h maintenance dose, or 50 mg/kg loading dose with a 5 mg/kg/h maintenance dose).

RESULTS

Compared with the low-dose TXA group, the high-dose TXA group had significantly decreased EBL (1402 vs. 1793 mL, p=.009), blood volume lost (30.3 vs. 39.4%, p=.01), intraoperative packed red blood cell (pRBC) transfusion (0.9 vs. 1.6 U, p<.0001), and intraoperative platelet transfusion (0 vs. 0.1 U, p<.0001). High-dose TXA was predictive of 515 cc less EBL (p=.002), 11.4% less blood volume lost (p=.004), and 1 U pRBC less transfused intraoperatively (p<.0001) than the low-dose TXA group. The high-dose TXA group had a higher incidence of postop atrial fibrillation (5 vs. 0%, p<.0001) and myocardial infarction (1.7 vs. 0%, p=.04).

CONCLUSIONS

Varying dosing regimens of TXA are utilized for ASD surgery, with a prevailing theme of dosing ambiguity. These data demonstrate that high-dose TXA is more effective than low-dose TXA in reducing blood loss and blood product transfusion requirement in ASD surgery. Importantly, rates of MI and postop AF were higher in the high-dose TXA group.

Correction of adult spinal deformity with a minimally invasive fusionless bipolar construct: Preliminary results

INTRODUCTION

Fusion in adult spinal deformity has a high rate of complications. Fusionless constructs in children and percutaneous fixation in adults are now being used routinely. The aim of this study was to evaluate the preliminary results of a minimally invasive fusionless surgical technique used to correct adult spinal deformity.

MATERIALS AND METHODS

Thirty-eight patients with an average age of 45 years (15-76) with major spinal deformity requiring extensive arthrodesis from the upper thoracic region to the pelvis were operated consecutively and followed prospectively. Two hooks were implanted at the top and two iliosacral screws at the bottom. Two large rods connected by dominos to two small rods joined the upper hooks to the lower screws. The surgical data (operative time and bleeding), the radiological findings (Cobb angle, sagittal parameters, C7-plumbline AP and lateral), the complication rate and the morbidity were evaluated at the last follow-up visit.

RESULTS

The primary curvature was reduced by 40% from a mean of 58.5° (26-146) to 35.2° (3-109) (p<0.001). A clear decrease in operating time (270min) and blood loss (50cc/level) were observed. The length of hospitalization averaged 18 days (6-66), including an 8-15 day long preoperative traction period for 11 patients. We found 7 infectious complications, 11 early mechanical complications and one case of paraplegia due to severe kyphoscoliosis.

CONCLUSION

The corrections obtained are comparable to those reported in the literature for standard constructs. Most patients had an uneventful postoperative course. The early complications observed led us to very carefully select the indications. Long-term follow-up is essential.

Use of an Accelerated Discharge Pathway in Patients With Severe Cerebral Palsy Undergoing Posterior Spinal Fusion for Neuromuscular Scoliosis

BACKGROUND

Implementation of a coordinated multidisciplinary postoperative pathway has been shown to reduce length of stay after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis. This study sought to compare the outcomes of nonambulatory cerebral palsy (CP) patients treated with PSF and cared for using an accelerated discharge (AD) pathway with those using a more traditional discharge (TD) pathway.

METHODS

A total of 74 patients with Gross Motor Function Classification System (GMFCS) class 4/5 CP undergoing PSF were reviewed. Thirty consecutive patients were cared for using a TD pathway, and 44 patients were subsequently treated using an AD pathway. The cohorts were then evaluated for postoperative complications and length of stay.

RESULTS

Length of stay (LOS) was 19% shorter in patients managed with the AD pathway (AD 4.0 days [95% CI 2.5-5.5] vs. TD 4.9 days [95% CI 3.5-6.3], p = .01). There was no difference between groups with respect to age at surgery, GMFCS class, preoperative curve magnitude, pelvic obliquity, kyphosis, postoperative curve correction, fusion to the pelvis, or length of fusion between groups. Length of stay remained significantly shorter in the AD group by 0.9 days when controlling for estimated blood loss (EBL) and length of surgery. Complication rates trended lower in the AD group (33% AD vs. 52% TD, p = .12), including pulmonary complications (21% AD vs. 38% TD, p = .13). There was no significant difference in wound complications, return to the operating room, or medical readmissions between groups.

CONCLUSIONS

Adoption of a standardized postoperative pathway reduced LOS by 19% in nonambulatory CP patients. Overall, complications, including pulmonary, trended lower in the AD group. Early discharge appears to be possible in this challenging patient population. Although the AD pathway may not be appropriate for all patients, the utility of the AD pathway in optimizing care for more routine PSF for this patient subset appears to be worthwhile.

LEVEL OF EVIDENCE

Level III, therapeutic.

The use of tranexamic acid in spine surgery

Patients undergoing surgical procedures of the spine with associated large volume blood loss often require perioperative blood conservation strategies. Synthetic antifibrinolytic medications such as tranexamic acid (TXA) may reduce blood transfusion requirements and postoperative complications following spinal procedures. Studies investigating the role of TXA in spine surgery have presented promising results and have proven its safety and efficacy. However, further investigation is needed to determine the optimal dosing regimen of TXA. In this article, we provide an overview of the basic science and pharmacology of TXA. A comprehensive summary of the findings from clinical trials and a review of the literature that demonstrate the risks and benefits of TXA in spine surgery are also presented.

Origins, Courses, and Distributions of the Lumbar Arterial Branches in Relation to the Spinal Nerves: An Anatomical Study

STUDY DESIGN

Observational, anatomical, cadaveric study.

OBJECTIVE

To investigate the origins, courses, and distributions of the lumbar arterial branches in relation to the spinal nerves using Japanese cadavers.

SUMMARY OF BACKGROUND DATA

Lumbar arterial branches to the spinal nerves can be damaged during posterior lumbar column osteotomy, leading to neurological complications. Spinal cord ischemia via arterial ligation has been reported to be a major cause of neurological complications in anterior thoracolumbar surgery. Although neurological deficits have been considered the most common complications in lumbar pedicle subtraction osteotomy, there is little information on the possible neurological deficits due to spinal nerve ischemia caused by damage to the lumbar arterial branches.

METHODS

In total, 111 lumbar arteries (1 lumbar artery was damaged) from 14 embalmed cadavers (28 sides, L1-L4) were investigated. We examined the branching patterns and measured their diameter and length. Branches to the spinal nerves were classified as follows: radicular branch (Rb), spinal nerve branch (SNb), and plexus branch (Pxb).

RESULTS

The Rb was identified most frequently at L1 (21.4%) and included the main branch to supply the spinal cord. The SNb diverged from the dorsal branch (59.4%) and was mainly detected at L2 (85.7%) and L3 (85.2%). The Pxb originated from the lumbar artery (56.1%) and was found most frequently at L4 (75%). The Pxb had a larger diameter and a longer length at L3 and L4 than the SNb. Both the L3 and L4 Pxbs were the main blood suppliers to the femoral nerve.

CONCLUSION

The L3 and L4 Pxbs mainly supplied the femoral nerve. The Pxb is likely to exist in the medial side of the spinal nerve in the extraforaminal region. Thus, the Pxb should be recognized as a very important arterial branch during operation procedures.

LEVEL OF EVIDENCE

5.

Efficacy and safety of antifibrinolytic agents in spinal surgery: a network meta-analysis

Background:

Significant blood loss is still one of the most frequent complications in spinal surgery, which often necessitates blood transfusion. Massive perioperative blood loss and blood transfusion can create additional risks. Aprotinin, tranexamic acid (TXA), and epsilon-aminocaproic acid (EACA) are antifibrinolytics currently offered as prophylactic agents to reduce surgery-associated blood loss. The aim of this study was to evaluate the efficacy and safety of aprotinin, EACA, and low/high doses of TXA in spinal surgery, and assess the use of which agent is the most optimal intervention using the network meta-analysis (NMA) method.

Methods:

Five electronic databases were searched, including PubMed, Cochrane Library, ScienceDirect, Embase, and Web of Science, from the inception to March 1, 2018. Trials that were randomized and compared results between TXA, EACA, and placebo were identified. The NMA was conducted with software R 3.3.2 and STATA 14.0.

Results:

Thirty randomized controlled trial (RCT) studies were analyzed. Aprotinin (standardized mean difference [SMD]=−0.65, 95% credibility intervals [CrI;−1.25, −0.06]), low-dose TXA (SMD = −0.58, 95% CrI [−0.92, −0.25]), and high-dose TXA (SMD = −0.70, 95% CrI [−1.04, −0.36]) were more effective than the respective placebos in reducing intraoperative blood loss. Low-dose TXA (SMD = −1.90, 95% CrI [−3.32, −0.48]) and high-dose TXA (SMD = −2.31, 95% CrI [−3.75, −0.87]) had less postoperative blood loss. Low-dose TXA (SMD = −1.07, 95% CrI [−1.82, −0.31]) and high-dose TXA (SMD = −1.07, 95% CrI [−1.82, −0.31]) significantly reduced total blood loss. However, only high-dose TXA (SMD = −2.07, 95% CrI [−3.26, −0.87]) was more effective in reducing the amount of transfusion, and was significantly superior to low-dose TXA in this regard (SMD = −1.67, 95% CrI [−3.20, −0.13]). Furthermore, aprotinin (odds ratio [OR] = 0.16, 95% CrI [0.05, 0.54]), EACA (OR = 0.46, 95% CrI [0.22, 0.97]) and high dose of TXA (OR = 0.34, 95% CrI [0.19, 0.58]) had a significant reduction in transfusion rates. Antifibrinolytics did not show a significantly increased risk of postoperative thrombosis. Results of ranking probabilities indicated that high-dose TXA had the greatest efficacy and a relatively high safety level.

Conclusions:

The antifibrinolytic agents are able to reduce perioperative blood loss and transfusion requirement during spine surgery. And the high-dose TXA administration might be used as the optimal treatment to reduce blood loss and transfusion.

The Perioperative Efficacy and Safety of Tranexamic Acid in Adolescent Idiopathic Scoliosis

OBJECTIVE

To evaluate the efficacy and safety of tranexamic acid (TXA) in patients with adolescent idiopathic scoliosis undergoing corrective surgery.

METHODS

A literature search of PubMed, Embase, and Cochrane Library was performed to identify studies published from inception to February 2019. After study selection and data extraction, statistical analysis was performed. Odds ratios and weighted mean differences (WMDs) with 95% confidence intervals (CIs) for all available clinical outcomes were analyzed using fixed-effects or random-effects models.

RESULTS

Twelve studies comprising 2500 patients were included. Intravenous TXA use was associated with significantly fewer patients received blood transfusions (odds ratio, 0.12; 95% CI, 0.06 to 0.22; P < 0.001), less intraoperative estimated blood loss (WMD, -470.07; 95% CI, -645.23 to -294.90; P < 0.001), less intraoperative estimated blood loss per segment (WMD, -27.40; 95% CI, -32.80 to -22.00; P < 0.001), less cell salvage blood transfusion (WMD, -106.02; 95% CI, -170.84 to -41.20; P = 0.001), and shorter surgical time (WMD, -26.18; 95% CI, -46.91 to -5.46; P = 0.010). No significant difference was found in postoperative hemoglobin (WMD, 0.39; 95% CI, -0.07 to 0.86; P = 0.100) and hemoglobin change (WMD, -0.92; 95% CI, -2.90 to 1.07; P = 0.360) between TXA and control groups. No renal, thromboembolic, or other major complications associated with TXA were noted in included studies.

CONCLUSIONS

TXA was effective in reducing surgical time, intraoperative estimated blood loss, and blood transfusion without increasing complications in patients undergoing corrective surgery for adolescent idiopathic scoliosis. TXA had no influence on postoperative hemoglobin and hemoglobin change.

The Efficacy and Safety of Epsilon-Aminocaproic Acid for Blood Loss and Transfusions in Spinal Deformity Surgery: A Meta-Analysis

OBJECTIVE

To assess the efficacy and safety of epsilon-aminocaproic acid (EACA) in reducing the blood loss and transfusion volume during open spinal deformity surgery.

METHODS

A systematic search was conducted for all studies written in English published on or before October 2018 in PubMed, EMBASE, and the Cochrane Library that compared antifibrinolytic agents with placebos for open spinal deformity surgeries. The primary outcomes included the total blood loss, intraoperative, and postoperative blood loss, transfusions volume and complication rate.

RESULTS

Seven studies that included 525 patients who were diagnosed with spinal deformity. Compared with placebo, the patients who received EACA showed a reduction in the postoperative blood loss (mean difference [MD] -249.80; 95% confidence interval [CI] -375.65 to -123.95; P = 0.0001) and total blood loss (MD -670.30; 95% CI -1142.63 to -197.98; P = 0.005). Furthermore, the patients treated with EACA received approximately 1.67 fewer units of blood (MD -1.67; 95% CI -3.10 to -0.24; P = 0.02). However, in this cohort, no statistically significant differences were observed in the intraoperative blood loss (MD -452.19; 95% CI -1082.21 to 177.83; P = 0.16) and complication rate (odds ratio 0.73; 95% CI 0.16-3.24; P = 0.68).

CONCLUSIONS

This meta-analysis demonstrated that EACA could be safe and potentially efficacious for reducing blood loss and transfusions volume in patients with spinal deformity surgeries when compared with placebo. In light of the significant heterogeneity, the findings of this meta-analysis should be confirmed in methodologically rigorous and adequately powered clinical trials.

The Use of Tranexamic Acid to Reduce Surgical Blood Loss: A Review Basic Science, Subspecialty Studies, and The Evolution of Use in Spine Deformity Surgery

Significant blood loss is often seen in orthopedic surgeries, especially complex spinal procedures that constitute long surgical times, large incisions, and rich blood supplies. Tranexamic acid (TXA), a synthetic analog of the amino acid lysine, has proven to be a cost-effective method in decreasing transfusion rates and avoiding complications associated with low blood volume. Recent data on TXA's use in spine surgery suggest that TXA remains both efficacious and safe, although the ideal dosing and timing of administration is still a point of disagreement. The purpose of this study is to review the literature for the use of TXA in spine surgery to better understand its safety profile and ideal dosage. This narrative review on TXA was conducted on prospective orthopedic studies that used TXA in spine deformity surgery. TXA in adult and pediatric spine surgery has decreased intraoperative and postoperative blood loss, decreasing the need for blood transfusions. The most common dose in the literature is a 10 mg/kg loading dose, followed by 1 mg/kg per hour. Although the proper dosing of TXA for spine surgery remains debatable, studies have proven that TXA is effective at reducing blood loss without increasing the risk of thrombotic events.

Antifibrinolytic agents for paediatric scoliosis surgery: a systematic review and meta-analysis

STUDY DESIGN

Systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE

The purpose of this study is to perform a systematic review and meta-analysis of antifibrinolytic agents for paediatric spine surgery.

BACKGROUND

Bleeding is an important consideration in paediatric scoliosis surgery; blood loss leads directly to higher morbidity and mortality. Antifibrinolytics are an attractive non-invasive method of reducing bleeding as evidenced in arthroplasty, cardiac surgery and adult scoliosis surgery.

METHODS

A thorough database search of Medline, PubMed, EMBASE and Cochrane was performed according to PRISMA guidelines, and a systematic review was performed.

RESULTS

Five randomised controlled trials were identified in this meta-analysis, consisting of a total of 285 spine surgery patients with subgroups of tranexamic acid (n = 101), epsilon aminocaproic acid (n = 61) and control (n = 123). This meta-analysis found that antifibrinolytics lead to statistically significant reductions in peri-operative blood loss (MD - 379.16, 95% CI [- 579.76, - 178.57], p < 0.001), intra-operative blood loss (MD - 516.42, 95% CI [- 1055.58, 22.74], p < 0.001), reduced fresh frozen plasma requirements (MD - 307.77, 95% CI [- 369.66, - 245.88], p < 0.001) and reduced post-operative blood loss (MD -  185.95, 95% CI [- 336.04, - 35.87], p = 0.02).

CONCLUSION

This meta-analysis concludes that antifibrinolytics lead to statistically significant reductions in peri-operative blood loss, intra-operative blood loss, reduced fresh frozen plasma requirements and reduced post-operative blood loss with TXA. These slides can be retrieved under Electronic Supplementary Material.

What's New in Pediatric Orthopaedic Quality, Safety, and Value? A Systematic Review With Results of the 2016 POSNA Quality, Safety, and Value Initiative (QSVI) Challenge

BACKGROUND

Enhancing the safety, quality, and value of care provided is a point of emphasis for modern health care systems. We performed a review of recent literature to highlight those efforts relevant to pediatric musculoskeletal care.

METHODS

We searched the PubMed database for all papers related to quality improvement, patient safety, and/or value in pediatric orthopaedics published from October 1, 2012 to October 31, 2017, yielding 193 papers.

RESULTS

A total of 36 papers were selected for review based upon new findings. Papers were selected based on significant contributions in the following categories: casting safety, antibiotic stewardship/infection prevention, perioperative care pathways, blood conservation, venous thromboembolic disease prevention, and imaging safety/appropriateness.

CONCLUSIONS

There have been numerous advances in safety, quality, and value in pediatric orthopaedic care. Quality improvement efforts emphasizing provider education and safety monitoring can lead to a decrease in cast-related complications. Perioperative care pathways and bundles are associated with a decrease risk of surgical site infection and decreased length of stay in pediatric spinal deformity surgery. Increased scrutiny has been placed on the value of routine follow-up radiographs in pediatric fracture and spinal deformity care.

LEVEL OF EVIDENCE

Level 4-literature review.

Exclusion criteria and adverse events in perioperative trials of tranexamic acid: a systematic review and meta-analysis

BACKGROUND

Tranexamic acid (TXA) is an inexpensive therapy effective at minimizing perioperative blood loss and transfusion. However, it remains underutilized due to safety concerns. To date, no evidence-based guidelines exist identifying which patients should not receive TXA therapy. This study determined patient groups for whom safety information regarding TXA is lacking due to common exclusion from perioperative TXA trials.

STUDY DESIGN AND METHODS

A systematic review searching the databases Medline, EMBASE, CENTRAL, and Clinicaltrials.gov was performed. Randomized controlled trials (RCTs) administering systemic TXA perioperatively to elective or emergent surgery patients were eligible. Our primary outcome was to describe exclusion criteria of RCTs, and the secondary outcome was TXA safety. A descriptive synthesis of exclusion criteria was performed, and TXA safety was assessed by meta-analysis.

RESULTS

A total of 268 eligible RCTs were included. Meta-analysis showed that systemic TXA did not increase risk of adverse events compared to placebo or no intervention (relative risk, 1.05; 95% confidence interval, 0.99-1.12). Patient groups commonly excluded from perioperative TXA trials, and thus potentially lacking TXA safety data, were those with major comorbidities, a history of thromboembolism, medication use affecting coagulation, TXA allergy, and coagulopathy. Exclusion of patients with major comorbidities may not be necessary; we showed that the risk of adverse events was similar in studies that excluded patients with major comorbidities and those that did not.

CONCLUSION

Sufficient evidence exists to develop perioperative guidelines for TXA use in many populations. Further studies evaluating perioperative TXA use in patients with a history of thromboembolism are warranted.