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

Have We Made Advancements in Optimizing Surgical Outcomes and Enhancing Recovery for Patients With High-Risk Adult Spinal Deformity Over Time?

BACKGROUND AND OBJECTIVES

The spectrum of patients requiring adult spinal deformity (ASD) surgery is highly variable in baseline (BL) risk such as age, frailty, and deformity severity. Although improvements have been realized in ASD surgery over the past decade, it is unknown whether these carry over to high-risk patients. We aim to determine temporal differences in outcomes at 2 years after ASD surgery in patients stratified by BL risk.

METHODS

Patients ≥18 years with complete pre- (BL) and 2-year (2Y) postoperative data from 2009 to 2018 were categorized as having undergone surgery from 2009 to 2013 [early] or from 2014 to 2018 [late]. High-risk [HR] patients met ≥2 of the criteria: (1) ++ BL pelvic incidence and lumbar lordosis or SVA by Scoliosis Research Society (SRS)-Schwab criteria, (2) elderly [≥70 years], (3) severe BL frailty, (4) high Charlson comorbidity index, (5) undergoing 3-column osteotomy, and (6) fusion of >12 levels, or >7 levels for elderly patients. Demographics, clinical outcomes, radiographic alignment targets, and complication rates were assessed by time period for high-risk patients.

RESULTS

Of the 725 patients included, 52% (n = 377) were identified as HR. 47% (n = 338) had surgery pre-2014 [early], and 53% (n = 387) underwent surgery in 2014 or later [late]. There was a higher proportion of HR patients in Late group (56% vs 48%). Analysis by early/late status showed no significant differences in achieving improved radiographic alignment by SRS-Schwab, age-adjusted alignment goals, or global alignment and proportion proportionality by 2Y (all P > .05). Late/HR patients had significantly less poor clinical outcomes per SRS and Oswestry Disability Index (both P < .01). Late/HR patients had fewer complications (63% vs 74%, P = .025), reoperations (17% vs 30%, P = .002), and surgical infections (0.9% vs 4.3%, P = .031). Late/HR patients had lower rates of early proximal junctional kyphosis (10% vs 17%, P = .041) and proximal junctional failure (11% vs 22%, P = .003).

CONCLUSION

Despite operating on more high-risk patients between 2014 and 2018, surgeons effectively reduced rates of complications, mechanical failures, and reoperations, while simultaneously improving health-related quality of life.

The Statistical Fragility of Tranexamic Acid in Spinal Surgery: A Systematic Review of Randomized Controlled Trials

STUDY DESIGN

Systematic review.

OBJECTIVE

To evaluate the statistical robustness of TXA use in spine surgery as a potential contributor to controversies in this field.

SUMMARY OF BACKGROUND DATA

Tranexamic acid (TXA) is an antifibrinolytic medication administered during spinal surgery to limit blood loss. Existing randomized controlled trials (RCTs) on the efficacy of TXA contain varied results, particularly when reporting outcomes related to blood transfusion rates and thromboembolic events. By calculating the fragility index (FI), reverse fragility index (rFI), and fragility quotient (FQ), statistical robustness was quantified and compared across all included RCTs.

METHODS

PubMed, Embase, and MEDLINE were systematically searched for recent RCTs (January 1, 2000-August 1, 2023) assessing TXA use in patients undergoing spine surgery. The FI and rFI were calculated for each outcome, representing the number of event reversals required to alter statistical significance for significant and nonsignificant outcomes, respectively. The FQ was determined by dividing the FI/rFI by the study sample size.

RESULTS

Of the 297 RCTs screened, 31 studies were included for analysis, yielding 80 dichotomous outcomes. Across these outcomes, the median FI (mFI) was 5.0, with an associated median FQ (mFQ) of 0.060. Nine outcomes were statistically significant (mFQ=0.018), and 71 were nonsignificant (mFQ=0.064). The most common outcome categories included blood/platelet transfusions (38 outcomes), thromboembolic events (15 outcomes), and other adverse events (27 outcomes), resulting in mFQs of 0.056, 0.049, and 0.064, respectively.

CONCLUSIONS

Outcomes examining TXA in spinal surgery demonstrated statistical fragility, with significant and thromboembolic outcomes proving the most fragile. Among all outcomes, there was a lack of significant results. To better guide future research on TXA use in spine surgery, this study recommends RCTs report fragility statistics along with P values and include these metrics when proposing clinical implications.

LEVEL OF EVIDENCE

Level III.

Safety and Efficacy of Tranexamic Acid in Spinal Surgery: A Systematic Review and Meta-Analysis

Background

Tranexamic acid (TXA) has gained popularity in spinal surgery because of its potential to reduce blood loss. However, concerns regarding its safety and efficacy remain. This systematic review and meta-analysis aimed to evaluate the efficacy of TXA in reducing blood loss and its safety profile in spinal surgeries.

Methods

A comprehensive search was conducted in electronic databases for randomized controlled trials and prospective studies evaluating the use of TXA in spinal surgery. The primary outcomes were intraoperative and total estimated blood loss (EBL), and the secondary outcomes included the incidence and types of complications associated with TXA use. Meta-analyses were performed using random-effects models.

Results

Thirteen studies involving 1,213 participants were included in the meta-analysis. The use of TXA was associated with significant reductions in both intraoperative (mean difference: -46.56 mL [-73.85, -19.26], p<0.01]) and total EBL (mean difference: -210.17 mL [-284.93, -135.40], p<0.01) while also decreasing the need for blood transfusions (risk ratio: 0.68 [0.51, 0.90], p<0.01). No significant difference was found in the incidence and types of thrombotic complications when TXA was used in spinal surgery. Subgroup analysis showed consistent results in instrumentation and fusion surgery and different doses of TXA.

Conclusions

TXA is effective in reducing intraoperative and overall blood loss in spinal surgery without increasing the risk of complications. These findings support the use of TXA to improve patient outcomes. However, caution should be exercised because of the heterogeneity among the included studies. Further research is needed to confirm these findings and explore potential long-term complications.

Topical Use of Low-dose Tranexamic Acid Has no Effect on Drainage Volume after Medial Open Wedge High Tibial Osteotomy: A Case Control Study

OBJECTIVE

Many studies reported that tranexamic acid (TXA) was effective in reducing surgical blood loss in the perioperative period of medial open wedge high tibial osteotomy (MOWHTO). However, few studies focused on the simple topical use of TXA in MOWHTO, and the modality and dosage of topical use of TXA varied. The purpose of this study was to observe the effect of topical use of low-dose TXA on drainage volume after MOWHTO, and to analyze the related influencing factors.

METHODS

Data of patients who underwent MOWHTO combined with arthroscopic knee surgery in our department from January 2019 to September 2021 were retrospectively analyzed. A total of 105 patients (38 males and 67 females, aged 57.7 ± 7.5 years) were included in this study who received topical TXA or no TXA. The patients were divided into three groups: control group (39 cases), 0.5 g TXA group (40 cases), 1 g TXA group (26 cases). Postoperative drainage volume, wound healing, incidence of hematoma and deep venous thrombosis (DVT) were observed and analyzed in the three groups. The effects of gender, hypertension and diabetes on postoperative drainage volume were analyzed using a t-test. The correlation between age, body mass index (BMI), osteotomy gap and postoperative drainage volume were analyzed using the Pearson correlation coefficient.

RESULTS

The average postoperative drainage volume of the control group was 259.54 ± 226.33 mL, that of the 0.5 g TXA group was 277.18 ± 177.68 mL, and that of the 1 g TXA group was 229.15 ± 219.93 mL. There was no statistically significant difference in postoperative drainage volume among the three groups (F = 0.423, p = 0.656). There was no local hematoma and wound infection in the three groups. The wound fat liquefaction was found in one patient of the control group. The incidence of DVT was 38.9% (7/18) and 57.1% (8/14) in the control group and 0.5 TXA group, respectively. There was no significant difference in the incidence of DVT between the above two groups (p = 0.476). The average postoperative drainage volume of male patients in the three groups was higher than that of female patients, and the differences were statistically significant (p < 0.05). There was no correlation between age, BMI, osteotomy gap and postoperative drainage volume in the three groups (p > 0.05).

CONCLUSION

Topical use of low-dose TXA has no significant effect on drainage volume after MOWHTO. The drainage volume after MOWHTO in male patients was more than that in female patients. Topical administration of low-dose TXA does not increase postoperative complications, such as DVT and hematoma.

Complications and Avoidance in Adult Spinal Deformity Surgery

Adult spinal deformity (ASD) is a complex disease that can result in significant disability. Although surgical treatment has been shown to be of benefit, the complication rate in the perioperative and postoperative periods can be as high as 70%. Some of the most common complications of ASD surgery include intraoperative cerebrospinal fluid leak, high blood loss, new neurologic deficit, hardware failure, proximal junctional kyphosis/failure, pseudarthrosis, surgical site infection, and medical complications. For each of these complications, one or more strategies can be utilized to avoid and/or minimize the consequences.

Characterizing the Current Clinical Trial Landscape in Spinal Deformity: A Retrospective Analysis of Trends in the ClinicalTrials.gov Registry

BACKGROUND

The management of adult spinal deformity (ASD) relies upon retrospective data, but there have been calls for prospective trials to improve the evidentiary base. This study sought to define the state of the spinal deformity clinical trials and highlight trends to guide future research.

METHODS

The ClinicalTrials.gov database was queried for all ASD trials initiated since 2008. ASD was defined as adults (>18 years) and defined by the trial. All identified trials were categorized by enrollment status, study design, funding source, start and completion dates, country, outcomes examined, among many other study characteristics.

RESULTS

Sixty trials were included, of which 33(55.0%) started within the past 5 years of the query date. Most trials were sponsored by academic centers (60.0%) followed by industry (48.3%). Notably, 16 (27%) trials had multiple funding sources, all included collaboration with an industry entity. Only one trial had funding from a government agency. There were 30 (50%) interventional and 30 (50%) observational studies. The average time to completion was 50.8 ± 49.1 months. A total of 23 (38.3%) studies investigated a new procedural innovation, while 17 (28.3%) studies examined the safety or efficacy of a device. Study publications were associated with 17 (28.3%) trials in the registry.

CONCLUSIONS

The number of trials has increased significantly over the past 5 years, with the bulk of trials being funded by academic centers and industry and a notably lack by government agencies. Most trials focused on device or procedural investigation. Despite growing interest in ASD clinical trials, there remain many points for improvement in the current evidentiary base.

Surgeon-Specific Treatment Selection Bias and Heterogeneous Perioperative Practices in an Observational Spine Surgery Study. A Statistical Tutorial with Implications for Analysis of Observational Studies of Perioperative Interventions

BACKGROUND

It is essential that treatment effects reported from retrospective observational studies are as reliable as possible. In a retrospective analysis of spine surgery patients, we obtained a spurious result: tranexamic acid (TXA) had no effect on intraoperative blood loss. This statistical tutorial explains how this result occurred and why statistical analyses of observational studies must consider the effects of individual surgeons.

METHODS

We used an observational database of 580 elective adult spine surgery patients, supplemented with a review of perioperative medication records. We tested whether common statistical methods (multivariable regression or propensity score-based methods) could adjust for surgeons' selection bias in TXA administration.

RESULTS

Because TXA administration (frequency, timing, and dose) and surgeon were linked (collinear), estimating and testing the independent effect of TXA on outcome using multivariable regression without including surgeon as a variable would provide biased (spurious) results. Likewise, because of surgeon/TXA linkage, assumptions of propensity score-based analysis were violated, statistical methods to improve comparability between groups failed, and spurious blood loss results were worsened. Others numerous differences among surgeons existed in intraoperative and postoperative practices and outcomes.

CONCLUSIONS

In observational studies in which individual surgeons determine whether their patients receive the treatment of interest, consideration must be given to inclusion of surgeon as an independent variable in all analyses. Failure to include the surgeon in an analysis of observational data carries a substantial risk of obtaining spurious results, either creating a spurious treatment effect or failing to detect a true treatment effect.

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.

The Effect of Tranexamic Acid on Operative and Postoperative Blood Loss in Transforaminal Lumbar Interbody Fusions

OBJECTIVE

The purpose of this retrospective cohort study was to evaluate the effect of tranexamic acid (TXA) on reducing perioperative blood loss and length of stay after transforaminal lumbar interbody fusion (TLIF). Spine surgery is associated with the potential for significant blood loss, and adequate hemostasis is essential to visualizing crucial structures during the approach and procedure. Although TXA use has been extensively studied in the pediatric and adult spinal deformity literature, there is a dearth of literature on its efficacy in reducing blood loss for patients who undergo 1- to 3-level TLIF.

METHODS

All patients requiring 1- to 3-level TLIF who received a preoperative loading dose of TXA were grouped and compared with patients who didn't receive TXA. Demographic, surgical, and laboratory values were collected and analyzed. Continuous and categorical variables were analyzed with χ², Kruskal-Wallis, or analysis of variance tests, depending on normality and data type. Multiple linear regressions were developed to determine independent predictors of the estimated blood loss (EBL), total blood loss, drain output, and length of stay. Statistical significance was set at P < 0.05.

RESULTS

Patients who received preoperative TXA had more comorbidities (P = 0.006), longer surgery length (P < 0.001), and longer length of stay (P = 0.004). TXA was independently associated with a decreased day 0, 1, 2, and total drain output (P < 0.001, P = 0.001, P = 0.007, P < 0.001, respectively), but was not associated with a change in EBL, total blood loss, or length of stay.

CONCLUSIONS

The application of preoperative TXA for patients undergoing 1- to 3-level TLIF reduced drain output in the first 2 postoperative days, but it did not affect hospital length of stay, total blood loss, or EBL.