The role of amicar in decreasing perioperative blood loss in idiopathic scoliosis

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.

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.

Effect of Intravenous Aminocaproid Acid on Blood Loss and Transfusion Requirements After Bilateral Varus Rotational Osteotomy: A Double-blind, Placebo-controlled Randomized Trial

BACKGROUND

ε-Aminocaproic acid (EACA) is an antifibrinolytic agent that has been shown to decrease blood loss and transfusion requirements in several populations undergoing various surgical procedures. However, the efficacy of EACA has not been assessed in pediatric patients with cerebral palsy undergoing bilateral varus rotational femoral osteotomies. The purpose of this study was to assess the efficacy of intravenous EACA in reducing calculated intraoperative blood loss and transfusions in this population.

METHODS

Patients aged 18 years or younger were eligible. Patients were randomized to receive EACA or placebo (saline), and randomization was stratified based on sex and whether or not additional soft tissue or osseous procedures were performed. On the basis of retrospective data, the calculated sample size was 12 patients per arm to detect a difference of 250-mL blood loss. The primary outcome was calculated intraoperative blood loss. Secondary outcomes included transfusion requirements, 24-hour drain output, length of stay, and incidence of complications.

RESULTS

The mean age of patients in this study was 8 years (SD: 2.4 y). There were no differences in age, sex, height, weight, type of anesthesia, operative time, and associated procedures between the EACA and placebo groups (P>0.05). Preoperative hematocrit was lower in the EACA group (37.1 vs. 40.0, P=0.04). Calculated intraoperative blood loss was 536 mL in the EACA group and 628 mL in the placebo group (P=0.45). Transfusions were required in 62% of patients in the EACA group and 67% of patients in the placebo group (P=0.68). Total 24-hour drain output was 72.5 mL in the EACA group and 103.3 mL in the placebo group (P=0.37). Length of stay was similar between both groups, and there were no drug or placebo-related complications in either group.

CONCLUSIONS

There was no difference in blood loss or transfusion requirements associated with EACA compared with placebo; however, this study is underpowered to detect smaller differences in blood loss. Additional studies with larger sample sizes are needed to confirm these findings and further elucidate the indications for antifibrinolytic agents in pediatric patients.

LEVEL OF EVIDENCE

Level I.

The effectiveness of tranexamic acid on operative and perioperative blood loss in long-segment spinal fusions: a consecutive series of 119 primary procedures

OBJECTIVE

The aim of this study was to determine if the use of tranexamic acid (TXA) in long-segment spinal fusion surgery can help reduce perioperative blood loss, transfusion requirements, and morbidity.

METHODS

In this retrospective single-center study, the authors included 119 consecutive patients who underwent thoracolumbar fusion spanning at least 4 spinal levels from October 2016 to February 2019. Blood loss, transfusion requirements, perioperative morbidity, and adverse thrombotic events were compared between a cohort receiving intravenous TXA and a control group that did not.

RESULTS

There was no significant difference in any measure of intraoperative blood loss (1514.3 vs 1209.1 mL, p = 0.29) or transfusion requirement volume between the TXA and control groups despite a higher number of pelvic fusion procedures in the TXA group (85.9% vs 62.5%, p = 0.003). Postoperative transfusion volume was significantly lower in TXA patients (954 vs 572 mL, p = 0.01). There was no difference in the incidence of thrombotic complications between the groups.

CONCLUSIONS

TXA appears to provide a protective effect against blood loss in long-segment spine fusion surgery specifically when pelvic dissection and fixation is performed. TXA also seems to decrease postoperative transfusion requirements without increasing the risk of adverse thrombotic events.

Unexpected higher blood loss associated with higher dose ε-aminocaproic acid in pediatric scoliosis surgery

The purpose of this study was to determine if a higher dosing of ε-aminocaproic acid (EACA) is associated with less perioperative blood loss than a lower dose. A total of 74 patients having scoliosis surgery were analyzed. Of the 74 patients, 36 patients received EACA (10 mg/kg/h) and 38 patients received EACA (33 mg/kg/h). After controlling for key variables, an infusion of 33 mg/kg/h of EACA was associated with an increase in intraoperative blood loss of 8.1 ml/kg compared with an infusion of 10 mg/kg/h of EACA. A 33 mg/kg/h intraoperative infusion is associated with higher intraoperative blood loss than an infusion at 10 mg/kg/h.

Temporary inhibition of the plasminogen activator inhibits periosteal chondrogenesis and promotes periosteal osteogenesis during appendicular bone fracture healing

INTRODUCTION

Aminocaproic acid is approved as an anti-fibrinolytic for use in joint replacement and spinal fusion surgeries to limit perioperative blood loss. Previous animal studies have demonstrated a pro-osteogenic effect of aminocaproic acid in spine fusion models. Here, we tested if aminocaproic acid enhances appendicular bone healing and we sought to uncover the effect of aminocaproic acid on osteoprogenitor cells (OPCs) during bone regeneration.

METHODS

We employed a well-established murine femur fracture model in adult C57BL/6J mice after receiving two peri-operative injections of aminocaproic acid. Routine histological assays, biomechanical testing and micro-CT analyses were utilized to assess callus volume, and strength, progenitor cell proliferation, differentiation, and remodeling in vivo. Two disparate ectopic transplantation models were used to study the effect of the growth factor milieu within the early fracture hematoma on osteoprogenitor cell fate decisions.

RESULTS

Aminocaproic acid treated femur fractures healed with a significantly smaller cartilaginous callus, and this effect was also observed in the ectopic transplantation assays. We hypothesized that aminocaproic acid treatment resulted in a stabilization of the early fracture hematoma, leading to a change in the growth factor milieu created by the early hematoma. Gene and protein expression analysis confirmed that aminocaproic acid treatment resulted in an increase in Wnt and BMP signaling and a decrease in TGF-β-signaling, resulting in a shift from chondrogenic to osteogenic differentiation in this model of endochondral bone formation.

CONCLUSION

These experiments demonstrate for the first time that inhibition of the plasminogen activator during fracture healing using aminocaproic acid leads to a change in cell fate decision of periosteal osteoprogenitor cells, with a predominance of osteogenic differentiation, resulting in a larger and stronger bony callus. These findings may offer a promising new use of aminocaproic acid, which is already FDA-approved and offers a very safe risk profile.

Effect of intraoperative autologous transfusion techniques on perioperative hemoglobin level in idiopathic scoliosis patients undergoing posterior spinal fusion: A prospective randomized trial

BACKGROUND

Massive blood loss during posterior spinal fusion for adolescent idiopathic scoliosis remains a significant risk for patients. There is no consensus on the benefit of acute normovolemic hemodilution (ANH) or intraoperative cell salvage (ICS) in scoliosis surgery.

METHODS

Patients were randomized to one of two groups. Group A received ANH and ICS during operation, while group B received only ICS. Patients' age, sex, height, weight, body blood volume, number of fusion level, Cobb angle, number of screws, duration of surgery, and skin incision length were recorded. Hemoglobin and hematocrit levels were obtained preoperatively and postoperatively (0 h and 24 h).

RESULTS

There were 22 patients in each group. There was no significant difference in total blood loss. The perioperative decrease in hemoglobin levels between preoperation and postoperation 24 h (group A 2.79 ± 1.15 and group B 2.76 ± 1.00) showed no significant difference ( p = 0.93). Group A observed a larger decrease in hemoglobin levels at postoperative 0 h relative to preoperative level (2.57 ± 0.82 g/dl), followed by a smaller decrease within the next 24 h (0.22 ± 1.33 g/dl). Group B showed a continued drop in hemoglobin levels of similar magnitude at postoperation 0 h (1.60 ± 0.67 g/dl) and within the next 24 h (1.16 ± 0.78 g/dl). One patient from group B received 1 unit of allogenic blood transfusion ( p = 0.33).

CONCLUSIONS

The addition of ANH to ICS in posterior spinal fusion surgery for AIS resulted in a similar decrease in hemoglobin levels between preoperative values and at 24 h postoperatively.

Bipolar Sealer Devices Used in Posterior Spinal Fusion for Neuromuscular Scoliosis Reduce Blood Loss and Transfusion Requirements

BACKGROUND

Reducing perioperative blood loss and the need for transfusions in patients undergoing spinal surgery is especially important for those with neuromuscular disorders. These patients require extensive spino-pelvic exposure and are often medically fragile. We have used Amicar to decrease blood loss since 2001. As an effort to further reduce blood loss and transfusions, we use a bipolar sealer device (Aquamantys) as an adjunct to electrocautery. We present the results of our first 64 neuromuscular patients to show the efficacy of the device.

METHODS

Using a prospectively maintained database we reviewed the operative time, estimated perioperative blood loss, cell saver use, and intraoperative and postoperative transfusion rate in patients who underwent posterior spinal fusion for neuromuscular scoliosis. Sixty-four patients were identified who fit these criteria since the use of the bipolar sealer device was instituted.We compared these patients with a control group of the preceding 65 patients in whom this device was not used for hemostasis. All patients, including those in the study group, received Amicar (infusion of 100 mg/kg over 15 to 20 min, then 10 mg/kg/h throughout the remainder of the procedure). The surgical technique did not differ between the 2 groups.

RESULTS

Baseline characteristics between the 2 groups were similar except for the number of patients having an all-screw construct which was larger in the investigational group (25% vs. 8%, P=0.03). There were no significant differences in operative time or duration of hospital stay. Intraoperative blood loss was lower in the study group (741 mL) as compared with the control group (1052 mL, P=0.003). Total perioperative blood loss, however, showed no significant difference. Thirty-five (55%) patients in the study group and 50 (77%) patients in the control group required additional intraoperative or postoperative transfusions (P=0.01). The number of packed red cell units transfused per patient was 0.81 in the study group and 1.57 in the control group (P=0.001). Although the intraoperative cell saver transfusion was same, the total blood volume transfused, which includes cell saver and any other transfusions, was significantly lower in the study group, 425 mL versus 671 mL (P=0.002).

CONCLUSIONS

Use of a bipolar sealer device in posterior spinal fusion for neuromuscular scoliosis significantly reduced intraoperative blood loss and transfusion rate when compared with a control group in this retrospective review.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Does a dual attending surgeon strategy confer additional benefit for posterior selective thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis (AIS)? A prospective propensity matching score analysis

BACKGROUND CONTEXT

With an increased cost of adolescent idiopathic scoliosis (AIS) surgery over the past 10 years, improvement of patient safety and optimization of the surgical management of AIS has become an important need. A dual attending surgeon strategy resulted in reduction of blood loss and complication rate.

PURPOSE

This study aimed to investigate the perioperative outcome of posterior selective thoracic fusion in Lenke 1 and 2 AIS patients comparing a single versus a dual attending surgeon strategy.

STUDY DESIGN

A prospective cohort study was carried out.

PATIENT SAMPLE

The study sample comprised 60 patients OUTCOME MEASURE: Operative duration, blood loss, postoperative hemoglobin, need for transfusion, morphine usage, and duration of hospital stay were the outcome measures.

METHODS

A total of 116 patients who underwent posterior selective thoracic fusion from two centers were prospectively recruited. The patients were grouped into Group 1 (single surgeon) and Group 2 (two surgeons). One-to-one matching analysis using "propensity score-matched cohort patient sampling method" was done for age, gender, height, weight, preoperative Cobb angle, number of fusion level, and Lenke classification. The outcome measures included operative duration, blood loss, postoperative hemoglobin, need for transfusion, morphine usage, and duration of hospital stay. This study was self-funded with no conflict of interest.

RESULTS

From 86 patients who were operated by the two surgeons (Group 2), 30 patients were matched with 30 patients who were operated by a single surgeon (Group 1). Group 2 (164.0±25.7 min) has a significantly shorter operation duration (p=.000) compared with Group 1 (257.3±51.4 min). The total blood loss was significantly more (p=.009) in Group 1 (1254.7±521.5 mL) compared with Group 2 (893.7±518.4 mL). There were seven patients (23.3%) in Group 1 who received allogenic blood transfusion (p<.05). The morphine usage and average hospital stay were significantly lower in Group 2, 22.4±10.7 mg and 3.4±0.7 days, respectively (p<.05). In Group 1, there was one patient who developed a superficial wound infection. No other major complications were noted.

CONCLUSIONS

A dual attending surgeon strategy was superior to a single surgeon strategy in posterior selective thoracic fusion in Lenke 1 and 2 AIS patients and will lead to a faster operation, reduced intraoperative blood loss, reduced risk of allogenic transfusion, reduced morphine requirement, and shorter hospital stay.

Antifibrinolytic agents for reducing blood loss in scoliosis surgery in children

BACKGROUND

This is an updated version of the original Cochrane review first published in 2008. Scoliosis surgery is often associated with substantial blood loss and potentially detrimental effects in children. Antifibrinolytic agents are often used to reduce perioperative blood loss. Clinical trials have evaluated their efficacy in children undergoing surgical correction of scoliosis, but no systematic review has been published. This review was first published in 2008 and was updated in 2016.

OBJECTIVES

To assess the efficacy and safety of aprotinin, tranexamic acid and aminocaproic acid in reducing blood loss and transfusion requirements in children undergoing surgery for correction of idiopathic or secondary scoliosis.

SEARCH METHODS

We ran the search for the previous review in June 2007. For this updated version, we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 7), MEDLINE (1946 to August week 1 2015), Embase (1947 to 2015 week 38), Latin American Caribbean Health Sciences Literature (LILACS) (1982 to 14 August 2015), Database of Abstracts of Reviews of Effects (DARE; 2015, Issue 2) and reference lists of reviews and retrieved articles for randomized controlled trials in any language. We also checked the clinical trial registry at http://www.clinicaltrials.gov on 8 October 2015.

SELECTION CRITERIA

We included blinded and unblinded randomized controlled trials (RCTs) that evaluated the effects of antifibrinolytics on perioperative blood loss in children 18 years of age or younger and undergoing scoliosis surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. The primary outcome was total blood loss (intraoperative and postoperative combined). Secondary efficacy outcomes were the number of participants receiving blood transfusion (both autologous and allogeneic) or receiving allogeneic blood transfusion alone, and the total amount of blood transfused. Safety outcomes included the number of deaths, the number of participants reporting any adverse event or a serious adverse event, withdrawals due to adverse events and the number of participants experiencing a specific adverse event (i.e. renal insufficiency, hypersensitivity or thrombosis). We assessed methodological risk of bias for each included study and employed the GRADE approach to assess the overall quality of the evidence.

MAIN RESULTS

We included three new studies (201 participants) in this updated review, for a total of nine studies (455 participants). All but one study employed placebo as the control group intervention. For the primary outcome, antifibrinolytic drugs decreased the amount of perioperative blood loss by 427 mL (95% confidence interval (CI) 251 to 603 mL), for a reduction of over 20% versus placebo. We rated the quality of evidence for our primary outcome as low on the basis of unclear risk of bias for several domains in most studies and the small total number of participants.For secondary outcomes, fewer participants receiving antifibrinolytic drugs received transfusion (allogeneic or autologous) versus those receiving placebo (risk ratio (RR) 0.65, 95% CI 0.50 to 0.85, number needed to treat to prevent one additional harmful outcome (NNTp) 5; very low-quality evidence). Only two studies specifically evaluated the number of participants transfused with only allogeneic blood (risk difference (RD) -0.15, 95% CI -0.26 to -0.03, NNTp 7; very low-quality evidence). Antifibrinolytic drugs decreased the volume of blood transfused by 327 mL (95% CI -186 to -469 mL; low-quality evidence).No study reported deaths in active or control groups. Data were insufficient to allow performance of meta-analysis for any safety outcome. No studies adequately described their methods in assessing safety. The only adverse event of note occurred in one study, when three participants in the placebo group developed postoperative deep vein thrombosis.

AUTHORS' CONCLUSIONS

Since the last published version of this review (2008), we have found three new studies. Additional evidence shows that antifibrinolytics reduce the requirement for both autologous and allogeneic blood transfusion. Limited evidence of low to very low quality supports the use of antifibrinolytic drugs for reducing blood loss and decreasing the risk, and volume, of transfusion in children undergoing scoliosis surgery. Evidence is insufficient to support the use of a particular agent, although tranexamic acid may be preferred, given its widespread availability. The optimal dose regimen for any of these three agents has not been established. Although adverse events appear to occur infrequently, evidence is insufficient to confirm the safety of these agents, particularly for rare but potentially catastrophic events. No long-term safety data are available.

One-step (standard) versus two-step surgical approach in adolescent idiopathic scoliosis posterior spinal fusion: Which is better?

STUDY DESIGN

A retrospective cohort study with IRB approval.

INTRODUCTION

Significant blood loss remains an important concern in terms of the performance of the posterior spinal fusion in adolescent idiopathic scoliosis. Several strategies have been reported to minimize blood loss during surgery. In order to address the need to minimize blood loss without sacrificing the quality of the fusion, in our hospital, we adopted a two-step surgical approach. This surgical approach consist of the exposure and instrumentation of the lumbar region prior to and followed by an extension of the surgical incision to the thoracic region for its subsequent instrumentation. The main purpose of this study was to compare a two-step surgical approach with the one-step (standard) approach.

METHODS

This study was a review of all the data on consecutive posterior spinal fusion surgeries performed by a specific two-surgeon team during 2004-2013. Demographics, surgical variables, radiographic findings, and outcomes regarding blood loss, morbidity, and the duration of the procedure were evaluated.

RESULTS

Eighty-five patients underwent the standard surgical exposure, and 41 patients underwent the two-step surgical technique. With the exception of BMI, neither group showed any statistically preoperative variable significant differences. None of the postoperative outcome variables were statistically significant between both surgical approaches.

CONCLUSIONS

No differences were detected in terms of using a two-step surgical approach versus the one-step standard surgical approach regarding perioperative blood loss, surgical time, or complications.

LEVEL OF EVIDENCE

Level of evidence III.

Assessment of Intraoperative Blood Loss at Different Surgical Stages During Posterior Spinal Fusion Surgery in the Treatment of Adolescent Idiopathic Scoliosis

STUDY DESIGN

Prospective clinical study.

OBJECTIVE

To analyze the amount of blood loss at different stages of Posterior Instrumented Spinal Fusion (PSF) surgery in adolescent idiopathic scoliosis (AIS) patients.

SUMMARY OF BACKGROUND DATA

Knowing the pattern of blood loss at different surgical stages may enable the surgical team to formulate a management strategy to reduce intraoperative blood loss.

METHODS

One hundred AIS patients who underwent PSF from January 2013 to December 2014 were recruited. The operation was divided into six stages; stage 1-exposure, stage 2-screw insertion, stage 3-release, stage 4-correction, stage 5-corticotomies and bone grafting, and stage 6-closure. The duration and blood loss at each stage was documented. The following values were calculated: total blood loss, blood loss per estimated blood volume, blood loss per minute, blood loss per vertebral level fused, and blood loss per minute per vertebral level fused.

RESULTS

There were 89 females and 11 males. The mean age was 17.0 ± 5.8 years old. Majority (50.0%) were Lenke 1 curve type. The mean preoperative major Cobb angle was 64.9 ± 15.0°. The mean number of levels fused was 9.5 ± 2.3 levels. The mean operating time was 188.5 ± 53.4 minutes with a mean total blood loss 951.0 ± 454.0 mLs. The highest mean blood loss occurred at stage 2 (301.0 ± 196.7 mL), followed by stage 4 (226.8 ± 171.2 mL) and stage 5 (161.5 ± 146.6 mL). The highest mean blood loss per minute was at stage 5 (17.1 ± 18.3 mL/min), followed by stage 3 (12.0 ± 10.8 mL/min). The highest mean blood loss per vertebral levels fused was at stage 2 (31.0 ± 17.7 mL/level), followed by stage 4 (23.9 ± 18.1 mL/level) and stage 5 (16.6 ± 13.3 mL/level).

CONCLUSION

All stages were significant contributors to the total blood loss except exposure (stage 1) and closure (stage 6). Blood loss per minute and blood loss per minute per level was highest during corticotomies (stage 5), followed by release (stage 3). However, the largest amount of total blood loss occurred during screw insertion (stage 2).

LEVEL OF EVIDENCE

2.

Tranexamic acid decreases blood loss after total shoulder arthroplasty

BACKGROUND

Tranexamic acid (TXA) significantly decreases blood loss and transfusion rates after total hip and total knee arthroplasty. The purpose of this study was to determine the effects of intravenous TXA on blood loss and patient outcomes after total shoulder arthroplasty (TSA).

METHODS

TXA was used in 106 consecutive patients undergoing primary anatomic and reverse TSA with a dose of 20 mg/kg intravenously (TXA group) and compared with the previous consecutive 88 patients without TXA (non-TXA group). All patients had a blood sample drawn for a hemoglobin and hematocrit determination the morning after surgery. Analysis of variance and χ(2) techniques were used to analyze study hypotheses.

RESULTS

Statistically significant differences in both hemoglobin loss (TXA group Δ = 2.13 vs. non-TXA group Δ = 2.63; P = .01) and hematocrit loss (TXA group Δ = 6.4 vs. non-TXA group Δ = 8.14; P < .01) were seen in the TXA group compared with the non-TXA group. In patients receiving TXA, there were statistically significant decreases in the time spent in the recovery room (mean, TXA group 69 minutes vs. non-TXA group 87 minutes; P < .02) and total length of hospitalization (mean, TXA group 1.18 days vs. non-TXA group 1.4 days; P = .01). Two patients in the TXA group received a blood transfusion, whereas 6 patients in the non-TXA group did.

CONCLUSIONS

TXA 20 mg/kg intravenously given just before primary anatomic and reverse TSA results in statistically significant reductions in blood loss. Patients spent 21% less time in the recovery room and had a 16% shorter hospitalization, resulting in financial savings for the hospital.

A Comparison of Two Different Dosing Protocols for Tranexamic Acid in Posterior Spinal Fusion for Spinal Deformity: A Prospective, Randomized Trial

BACKGROUND

Multilevel spinal fusions have typically been associated with significant blood loss. Previous studies have shown a reduction in blood loss with antifibrinolytics in both adolescent and adult spinal deformity patients. While this has been mirrored in other subspecialties as well, the dosing of TXA remains highly variable. To date, there remains a paucity of data guiding dosing for TXA in spine surgery and orthopedic surgery as a whole.

METHODS/DESIGN

One hundred and fifty patients from 3 institutions (50 each site) will be consecutively enrolled and randomized to either a high dose of TXA (50mg/kg loading followed by 20mg/kg hourly) or a lose dose (10mg/kg, then 1mg/kg hourly). Both surgeons and patients will be blinded to the treatment group. Primary outcomes will be perioperative blood loss, drain output, and transfusion rate. Secondary outcomes will be length of stay, complications, and overall cost.

DISCUSSION

The primary goal of this study is to provide level-1 comparative data for two TXA dosing regimens in adult spinal deformity surgery. Management of blood loss remains a critical factor in reducing complications during spinal deformity surgery. The null hypothesis is that there is no difference between high- and low-dose TXA with respect to any of the primary or secondary outcomes.

Use of Tranexamic Acid (TXA) on reducing blood loss during scoliosis surgery in Chinese adolescents

Background

Many reports had been received on the application of antifibrinolytic medications on spinal corrective surgery and the surgical outcome evaluations of its efficacy on reducing blood loss. This study aimed to assess the efficacy of tranexamic acid (TXA) in reducing operative blood loss during posterior spinal fusion for the treatment of severe adolescent idiopathic scoliosis (AIS).

Methods

A retrospective cohort study was carried out on 90 (TXA = 55, Control = 35) AIS girls undergoing posterior spinal surgery. Patients in TXA group used TXA as an antifibrinolytic agent to reduce blood loss, while control group did not. Blood loss, haemoglobin change and amount of blood transfused was estimated from intraoperative measurement by anaesthesiologists. Demographics were compared using Student’s T-test or Chi-square test where appropriate. Linear regression modelling was carried out between the use of TXA and total blood loss with controlling of confounding factors.

Results

Mean age and mean maximum major curve were 15.2 and 73°, and 15.3 and 63° in TXA and control groups respectively. TXA group showed significantly less intra-operative blood loss than the control group from intraoperative measurement (1.8 L vs. 3.9 L, p < 0.01) and volume of cell saver blood transfused back to patients (0.6 L vs. 1.7 L, p < 0.01). TXA group also showed significantly shorter total time taken for surgery (437 min vs. 502 min, p < 0.01), and total blood loss per surgical segment level (0.1 L vs. 0.3 L, p < 0.01). Regression models showed that the use of TXA decreased total blood loss by 794.3 ml after adjusting for maximum major curve, age, number of segments fused, bone graft, clotting capability, and infusion of coagulation factors.

Conclusions

Patients undergoing posterior spinal corrective surgery with the use of TXA showed much reduced total blood loss, reduced use of transfused blood, much less cell saver blood transfused back to the patient. The total blood loss was decreased by after using TXA after controlling for maximum major curve, age, surgical parameters, clotting capability, and infusion of coagulation factors.

Population pharmacokinetics of ϵ-aminocaproic acid in adolescents undergoing posterior spinal fusion surgery

BACKGROUND

Despite demonstrated efficacy of ϵ-aminocaproic acid (EACA) in reducing blood loss in adolescents undergoing spinal fusion, there are no population-specific pharmacokinetic data to guide dosing. The aim of this study was to determine the pharmacokinetics of EACA in adolescents undergoing spinal fusion surgery and make dosing recommendations.

METHODS

Twenty children ages 12-17 years were enrolled, with 10 children in each of two groups based on diagnosis (idiopathic scoliosis or non-idiopathic scoliosis). Previously reported data from infants undergoing craniofacial surgery were included in the model to enable dosing recommendations over a wide range of weights, ages, and diagnoses. A population non-linear mixed effects modelling approach was used to characterize EACA pharmacokinetics.

RESULTS

Population pharmacokinetic parameters were estimated using a two-compartment disposition model with allometrically scaled weight and an age effect on clearance. Pharmacokinetic parameters for the typical patient were a plasma clearance of 153 ml min(-1) 70 kg(-1) (6.32 ml min(-1) kg(-0.75)), intercompartmental clearance of 200 ml min(-1) 70 kg(-1) (8.26 ml min(-1) kg(-0.75)), central volume of distribution of 8.78 litre 70 kg(-1) (0.13 litre kg(-1)), and peripheral volume of distribution of 15.8 litre 70 kg(-1) (0.23 litre kg(-1)). Scoliosis aetiology did not have a clinically significant effect on drug pharmacokinetics.

CONCLUSIONS

The following dosing schemes are recommended according to patient weight: weight <25 kg, 100 mg kg(-1) loading dose and 40 mg kg(-1) h(-1) infusion; weight ≤25 kg-<50 kg, 100 mg kg(-1) loading dose and 35 mg kg(-1) h(-1) infusion; and weight ≥50 kg, 100 mg kg(-1) loading dose and 30 mg kg(-1) h(-1) infusion. An efficacy trial employing this dosing strategy is warranted.

CLINICAL TRIAL REGISTRATION

NCT01408823.

The effects of Amicar and TXA on lumbar spine fusion in an animal model

STUDY DESIGN

Animal model.

OBJECTIVE

To determine whether aminocaproic acid (Amicar) and tranexamic acid (TXA) inhibit spine fusion volume.

SUMMARY OF BACKGROUND DATA

Amicar and TXA are antifibrinolytics used to reduce perioperative bleeding. Prior in vitro data showed that antifibrinolytics reduce osteoblast bone mineralization. This study tested whether antifibrinolytics Amicar and TXA inhibit spine fusion.

METHODS

Posterolateral L4-L6 fusion was performed in 50 mice, randomized into groups of 10, which received the following treatment before and after surgery: (1) saline; (2) TXA 100 mg/kg; (3) TXA 1000 mg/kg; (4) Amicar 100 mg/kg; and (5) Amicar 1000 mg/kg. High-resolution plane radiography was performed after 5 weeks and micro-CT (computed tomography) was performed at the end of the 12-week study. Radiographs were graded using the Lenke scale. Micro-CT was used to quantify fusion mass bone volume. One-way analysis of variance by ranks with Kruskal-Wallis testing was used to compare the radiographical scores. One-way analysis of variance with least significant difference post hoc testing was used to compare the micro-CT bone volume.

RESULTS

The average±standard deviation bone volume/total volume (%) measured in the saline, TXA 100 mg/kg, TXA 1000 mg/kg, Amicar 100 mg/kg, and Amicar 1000 mg/kg groups were 10.8±2.3%, 9.7±2.2%, 13.4±3.2%, 15.5±5.2%, and 17.9±3.5%, respectively. There was a significant difference in the Amicar 100 mg/kg (P<0.05) and Amicar 1000 mg/kg (P<0.001) groups compared with the saline group. There was greater bone volume in the Amicar groups compared with the TXA group (P<0.001). There was more bone volume in the TXA 1000 mg/kg group compared with TXA 100 mg/kg (P<0.05) but the bone volume in neither of the TXA groups was different to saline (P=0.49). There were no between-group differences observed using plane radiographical scoring.

CONCLUSION

Amicar significantly "enhanced" the fusion bone mass in a dose-dependent manner, whereas TXA did not have a significant effect on fusion compared with saline control.These data are in contrast to prior in vitro data that antifibrinolytics inhibit osteoblast bone mineralization.

LEVEL OF EVIDENCE

N/A.

The effect of surgeon experience on outcomes of surgery for adolescent idiopathic scoliosis

BACKGROUND

Single-surgeon series investigating the learning curve involved in surgery for spinal deformity may be confounded by changes in technology and techniques. Our objective with this multicenter, prospective study was to present a cross-sectional analysis of the impact of surgeon experience on surgery for adolescent idiopathic scoliosis.

METHODS

All posterior-only surgical procedures for adolescent idiopathic scoliosis performed in the 2007 to 2008 academic year, with a minimum of two years of patient follow-up, were included. Two groups were created on the basis of surgeon experience: a young surgeons' group, which included patients of surgeons with less than five years of experience, and an experienced surgeons' group, which included patients of surgeons with five or more years of experience.

RESULTS

Nine surgeons (four young and five experienced) operated on a total of one hundred and sixty-five patients with adolescent idiopathic scoliosis. The surgeons' experience ranged from less than one year to thirty-six years in practice. The two groups had similar preoperative curve-magnitude measurements, SRS-22 (Scoliosis Research Society-22) scores, and distribution by Lenke curve type. There were significant operative and postoperative differences. The young surgeons fused an average of 1.2 levels more than the experienced surgeons (p = 0.045). The mean intraoperative estimated blood loss (EBL) of the young surgeons' group was more than twice that of the experienced surgeons' group (2042 mL compared with 1013 mL; p < 0.001). The duration of surgery was 458 minutes for the young surgeons compared with 265 minutes for the experienced surgeons (p < 0.001). The overall SRS-22 scores were significantly worse in the young surgeons' group (a mean of 4.1 compared with 4.5; p = 0.001). The difference between groups was also significant for the domains of pain (p = 0.016), self-image (p = 0.008), and function (p < 0.001). Complication rates did not differ significantly between the groups.

CONCLUSIONS

Operative results and health-related quality of life following surgery for adolescent idiopathic scoliosis were significantly and positively correlated with surgeon experience.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Efficacy of Amicar Versus Tranexamic Acid in Pediatric Spinal Deformity Surgery: A Prospective, Randomized, Double-Blinded Pilot Study

STUDY DESIGN

Single-center, prospective, randomized, double-blinded trial.

OBJECTIVES

To compare blood loss, allogenic transfusion requirements, and coagulation parameters between pediatric spinal deformity patients receiving aminocaproic acid (Amicar) or tranexamic acid (TXA) during posterior spinal fusion.

SUMMARY OF BACKGROUND DATA

Amicar and TXA have been shown to decrease blood loss in pediatric spinal deformity cases compared with controls. The difference in efficacy between these medications in this population has not been reported.

METHODS

Enrolled patients were randomized to receive either Amicar or TXA during scoliosis surgery. Baseline demographic and deformity comparisons were collected. Intraoperative comparisons included estimated and calculated blood loss, number of levels instrumented, number of osteotomies, operative time, and allogenic transfusion requirements. Preoperative and postoperative hemoglobin, platelets, prothrombin time, partial prothrombin time (PTT), international normalized ratio (INR), and fibrinogen were recorded.

RESULTS

A total of 47 patients were enrolled with data available for review (N = 25, Amicar; N = 22, TXA). No difference in cohorts was found in demographics, preoperative hemoglobin, platelets, prothrombin time, PTT, INR, initial Cobb angle, average number of: levels fused, patients with osteotomies and osteotomies, operative time, and final Cobb angles. Estimated blood loss was significantly less (about 221 mL) than the calculated blood loss in both groups (p = .003). Estimated blood loss (1,088 vs. 726 mL; p = .055) and calculated blood loss (1,366 vs. 903 mL; p = .13) trended higher in the Amicar group. Although no difference in allogenic transfusion rates (20% vs. 14%) was observed, average volumes transfused were significantly higher in the Amicar cohort (1,014 vs. 461 mL; p = .03). The TXA cohort demonstrated a statistically significant smaller change in INR, a lower PTT, and greater fibrinogen levels postoperatively.

CONCLUSIONS

Compared with Amicar, TXA use was associated with a lower allogenic transfusion requirement, less alteration in postoperative clotting studies, and a trend toward lower blood loss in pediatric posterior spinal fusion patients.

Topical tranexamic acid in total knee replacement: a systematic review and meta-analysis

BACKGROUND

To examine the safety and efficacy of topical use of tranexamic acid (TA) in total knee arthroplasty (TKA).

METHODS

An electronic literature search of PubMed Medline; Ovid Medline; Embase; and the Cochrane Library was performed, identifying studies published in any language from 1966 to February 2013. The studies enrolled adults undergoing a primary TKA, where topical TA was used. Inverse variance statistical method and either a fixed or random effect model, depending on the absence or presence of statistical heterogeneity were used; subgroup analysis was performed when possible.

RESULTS

We identified a total of seven eligible reports for analysis. Our meta-analysis indicated that when compared with the control group, topical application of TA limited significantly postoperative drain output (mean difference: -268.36ml), total blood loss (mean difference=-220.08ml), Hb drop (mean difference=-0.94g/dL) and lowered the risk of transfusion requirements (risk ratio=0.47, 95CI=0.26-0.84), without increased risk of thromboembolic events. Sub-group analysis indicated that a higher dose of topical TA (>2g) significantly reduced transfusion requirements.

CONCLUSIONS

Although the present meta-analysis proved a statistically significant reduction of postoperative blood loss and transfusion requirements with topical use of TA in TKA, the clinical importance of the respective estimates of effect size should be interpreted with caution.

LEVEL OF EVIDENCE

I, II.

Population pharmacokinetics of epsilon-aminocaproic acid in infants undergoing craniofacial reconstruction surgery

BACKGROUND

Understanding the clinical pharmacology of the antifibrinolytic epsilon-aminocaproic acid (EACA) is necessary for rational drug administration in children. The aim of this study is to determine the pharmacokinetics (PKs) of EACA in infants aged 6-24 months undergoing craniofacial reconstruction surgery.

METHODS

Cohorts of six infants were enrolled sequentially to one of the three escalating loading dose-continuous i.v. infusion (CIVI) regimens: 25 mg kg(-1), 10 mg kg(-1) h(-1); 50 mg kg(-1), 20 mg kg(-1) h(-1); 100 mg kg(-1), 40 mg kg(-1) h(-1). Plasma EACA concentrations were determined using a validated high-performance liquid chromatography-tandem mass spectrometry assay. A population non-linear mixed effects modelling approach was used to characterize EACA PKs.

RESULTS

Population PK parameters of EACA were estimated using a two-compartment disposition model with weight expressed as an allometric covariate and an age effect. The typical patient in this study had an age of 38.71 weeks and a weight of 8.82 kg. PK parameters for this typical patient were: pre-/postoperative plasma drug clearance of 32 ml min(-1) (3.6 ml kg(-1) min(-1)), inter-compartmental clearance of 42.4 ml min(-1) (4.8 ml min(-1) kg(-1)), central volume of distribution of 1.27 litre (0.14 litre kg(-1)), and peripheral volume of distribution of 2.53 litre (0.29 litre kg(-1)). Intra-operative clearance and central volume of distribution were 89% and 80% of the pre-/postoperative value, respectively.

CONCLUSIONS

EACA clearance increased with weight and age. The dependence of clearance on body weight supports weight-based dosing. Based on this study, a loading dose of 100 mg kg(-1) followed by a CIVI of 40 mg kg(-1) h(-1) is appropriate to maintain target plasma EACA concentrations in children aged 6-24 months undergoing these procedures.

The preoperative and intraoperative risk factors for early postoperative mechanical ventilation after scoliosis surgery: A retrospective study

BACKGROUND

Patients undergoing corrective surgery for scoliosis of spine are commonly ventilated in our institute after the operation. Postoperative mechanical ventilation (PMV) and subsequent prolongation of intensive care unit stay are associated with increase in medical expenditure and complications such as ventilator-associated pneumonia. Identification of factors which may contribute to PMV and their modification may help in allocation of resources effectively. The present study was performed to identify preoperative and intraoperative factors associated with early PMV after scoliosis surgery.

METHODS

One hundred and two consecutive patients who underwent operation for scoliosis correction between January 2006 to July 2011 were reviewed retrospectively. Patients requiring PMV included patients who were not extubated in the operating room and were continued on mechanical ventilation. Preoperative and intraoperative factors which were analysed included age, gender, weight, cardiorespiratory function, presence of kyphosis, number and level of vertebrae involved, surgical approach, whether thoracoplasty was done, duration of surgery, blood loss, fluids and blood transfused, hypothermia and use of antifibrinolytics.

RESULTS

The average age of the patients was 14.31±3.78 years with female preponderance (57.8%). Univariate analysis found that longer fusions of vertebrae (more than 8), blood loss, amount of crystalloids infused, blood transfused and hypothermia were significantly associated with PMV (P<0.05). Independent risk factors for PMV were longer fusion (Odds Ratio (OR), 1.290; 95% confidence interval (CI), 1.038-1.604) and hypothermia (OR, 0.096; 95% CI, 0.036-0.254; P<0.05).

CONCLUSION

The authors identified that longer fusions and hypothermia were independent risk factors for early PMV. Implementation of measures to prevent hypothermia may result in decrease in PMV.

Antifibrinolytic agents reduce blood loss during pediatric vertebral column resection procedures

STUDY DESIGN

Retrospective multicenter review.

OBJECTIVE

To evaluate the effect of intraoperative antifibrinolytic (AF) agents on blood loss associated with vertebral column resection (VCR) procedures for pediatric patients.

SUMMARY OF BACKGROUND DATA

VCR procedures may be associated with substantial blood loss.

METHODS

A multicenter review of 147 patients (aged <21 yr) who underwent VCR as part of their spinal deformity correction was conducted. Estimated blood loss (EBL) was calculated as percentage of blood volume (BV) (EBL/BV × 100), which was normalized on the basis of the number of vertebral levels removed (%BV/level). The use of AF agents was noted (tranexamic acid [TXA], aminocaproic acid, aprotinin, none) and based on surgeons' choice. EBL was compared using analysis of covariance (controlling for deformity magnitude) (P < 0.05).

RESULTS

Average preoperative major deformity (kyphosis or scoliosis) was 97° ± 31°. The average number of levels excised was 1.6 (range, 1-5). Total EBL averaged 1317 mL (range, 50-6026 mL). Eleven patients were excluded: 7 with incomplete data and 4 who received aminocaproic acid (too few to compare). This resulted in 136 cases; 64 with no AF, 42 received TXA, and 30 received aprotinin. Overall %BV/level EBL was 41% ± 39% (range, 6%-162%) and was significantly higher in the no-AF group (52% ± 37%) than the TXA (30% ± 34%; P < 0.01) and aprotinin (32% ± 24%; P < 0.05) groups. The effect of the AFs varied by site.

CONCLUSION

EBL associated with VCR was highly variable and in many cases exceeded the patient's BV. AF agents were not routinely used and we had insufficient data to assess the efficacy of aminocaproic acid. Both aprotinin and TXA resulted in less EBL than when no AF was used; however, the effect of the reduction varied by site. Aprotinin has since been removed from the market. When normalized to patient size and levels excised, the use of TXA resulted in a reduction in intraoperative EBL.

Does the intraoperative tranexamic acid decrease operative blood loss during posterior spinal fusion for treatment of adolescent idiopathic scoliosis?

STUDY DESIGN

Retrospective, observational study.

OBJECTIVE

To assess the efficacy and safety of tranexamic acid (TXA) in decreasing operative blood loss and the need for transfusion during posterior spinal fusion for the treatment of idiopathic scoliosis in adolescents.

SUMMARY OF BACKGROUND DATA

Blood loss associated with spinal surgery is a common potential cause of morbidity and often requires a blood transfusion, which subjects patients to the known risks of blood transfusion including transmission of diseases. Since the 1990s, intraoperative administration of antifibrinolytics has gained popularity. This study assesses the efficacy and safety of TXA in controlling blood loss during posterior spinal fusion for the treatment of idiopathic scoliosis in adolescents at 1 institution.

METHODS

A retrospective comparative analysis of 106 consecutive adolescents undergoing posterior spinal fusion procedures at 1 institution was performed. Patients were analyzed according to treatment group: controls (63) and TXA (43). There were no significant differences in demographic (age, sex, and comorbidities) or surgical traits (surgical time, number of fused vertebrae, preoperative hematocrit and hemoglobin) between the 2 groups.

RESULTS

TXA group had significantly less intraoperative blood loss (613 ± 195 mL) than the control group (1079 ± 421 mL; P < 0.001) as well as postoperative blood loss (155 ± 86 mL and 263 ± 105 mL, respectively; P < 0.001). TXA group received significantly less blood during the surgical procedure than the control group (258 ± 246 mL and 377 ± 200 mL, respectively; P < 0.001). There were no major intraoperative complications for any of the treatment groups.

CONCLUSION

TXA treatment group lost significantly less blood and received significantly fewer blood transfusions than the control group without significant differences in intra- and postoperative complications. A multicenter randomized prospective analysis would provide additional information of the efficacy and safety of TXA.

Does patient diagnosis predict blood loss during posterior spinal fusion in children?

STUDY DESIGN

A retrospective review.

OBJECTIVE

To assess the relationship between diagnosis and blood loss in children undergoing posterior spinal fusion surgery for deformity correction.

SUMMARY OF BACKGROUND DATA

To our knowledge, this relationship is not well established. It has important implications for understanding the mechanisms for blood loss and planning for surgery.

METHODS

Clinical records were reviewed for all patients 10 to 18 years of age who underwent spinal fusion surgery (at least 5 levels) by the senior author from 2001 through 2011. Patients were excluded for antifibrinolytic use, vertebral column resections, history of spinal surgery, nonpedicle screw instrumentation, cervical spine fusion, or anterior approaches. The 617 patients (with 37 diagnoses) were categorized into 5 groups: idiopathic scoliosis (IS), Scheuermann kyphosis (SK), cerebral palsy, other neuromuscular disorders, and genetic and syndromic disorders. Analysis of covariance was used to assess differences in blood loss across the diagnostic groups. Normalized blood loss (NBL) was calculated by dividing blood loss by number of levels fused and by patient's weight; NBL differences between groups were analyzed using Bonferroni correction method. Significance was set at P < 0.05.

RESULTS

Blood loss differed significantly by diagnostic group, adjusting for extent of fusion and patient weight (P < 0.001). Patients with cerebral palsy had a significantly higher NBL than patients with IS (P < 0.001), SK (P < 0.001), other neuromuscular disorders (P = 0.049), or genetic and syndromic disorders (P = 0.006). Patients with other neuromuscular disorders had a significantly higher NBL than patients with IS (P < 0.001) or SK (P < 0.001). Patients with genetic and syndromic disorders also had a significantly higher NBL than patients with IS (P < 0.001) or SK (P < 0.001).

CONCLUSION

There is a significant relationship between patient diagnosis and blood loss during posterior spinal fusion surgery in children.

Are antifibrinolytics helpful in decreasing blood loss and transfusions during spinal fusion surgery in children with cerebral palsy scoliosis?

STUDY DESIGN

Therapeutic comparative study.

OBJECTIVE

To evaluate the safety and efficacy of antifibrinolytic (AF) agents in reducing blood loss and transfusions during posterior spinal fusion (PSF) in children with cerebral palsy (CP) scoliosis.

SUMMARY OF BACKGROUND DATA

Scoliosis surgery in CP children is associated with substantial blood loss. Few reports on the role of AFs exist.

METHODS

A multicenter, retrospective review of a prospectively collected database of 84 consecutively enrolled patients with CF (age < 18 years) with spinal deformity who underwent PSF and instrumentation. The use of AFs, tranexamic acid (TXA), epsilon-aminocaproic acid (EACA), or none was based on the surgeon preference. Estimated blood loss (EBL), transfusion requirements, and length of stay were recorded. Analysis was performed with the independent-samples t test and 1-way analysis of variance with post hoc Bonferroni analysis.

RESULTS

The average age at the time of surgery was 14.4 ± 2.6 years. The groups were well matched in preoperative major deformity, age, levels fused, and operating time. Forty-four patients received AFs (30 TXA and 14 EACA), and 40 received no antifibrinolytics (NAF). The EBL averaged 1684 mL for the AFs group and 2685 mL for the NAF group (P = 0.002). There was more cell salvage transfusion in the NAF group. No significant differences were found in total transfusion requirements. There was a trend for decreased hospital stay in the AFs group. No adverse effects were seen. On comparison of the 3 groups (NAF, TXA, and EACA), a significant difference was observed between the TXA and the other groups with respect to EBL and cell salvage transfusion.

CONCLUSION

AFs significantly reduced intraoperative EBL associated with PSF, with no adverse effects; however, we could not demonstrate significant differences in total transfusion, except in cell salvage. TXA was more effective than EACA in decreasing the EBL and cell salvage transfusion.

Idiopathic intracranial hypertension following spinal deformity surgery in children

Idiopathic intracranial hypertension (IIH) after pediatric spinal deformity surgery has not been previously reported. The authors conducted a retrospective analysis of more than 1500 pediatric spinal surgeries performed between 1992 and 2011. From their analysis, they report on 3 adolescent patients who underwent uncomplicated segmental spinal instrumentation for pediatric spinal deformity correction and subsequently developed features of IIH. The common variables in these 3 patients were adolescent age, spinal deformity, being overweight, symptom onset within 2 weeks postoperatively, significant estimated blood loss, and intraoperative use of ε-aminocaproic acid (antifibrinolytic) injection. The authors postulate that the development of IIH could be the result of venous outflow obstruction due to derangement of the epidural venous plexus during surgery. The use of ε-aminocaproic acid could potentially have the risk of causing IIH, probably mediated through hyperfibrinogenemia, although there have not been published cases in the neurosurgical, orthopedic, cardiac, or general surgical literature. Idiopathic intracranial hypertension after spinal deformity correction is a condition that should be recognized by neurosurgeons and orthopedic surgeons, because appropriate intervention with early medical therapy can lead to a satisfactory clinical outcome.

A prospective, randomized, double-blinded single-site control study comparing blood loss prevention of tranexamic acid (TXA) to epsilon aminocaproic acid (EACA) for corrective spinal surgery

BACKGROUND

Multilevel spinal fusion surgery has typically been associated with significant blood loss. To limit both the need for transfusions and co-morbidities associated with blood loss, the use of anti-fibrinolytic agents has been proposed. While there is some literature comparing the effectiveness of tranexamic acid (TXA) to epsilon aminocaproic acid (EACA) in cardiac procedures, there is currently no literature directly comparing TXA to EACA in orthopedic surgery.

METHODS/DESIGN

Here we propose a prospective, randomized, double-blinded control study evaluating the effects of TXA, EACA, and placebo for treatment of adolescent idiopathic scoliosis (AIS), neuromuscular scoliosis (NMS), and adult deformity (AD) via corrective spinal surgery. Efficacy will be determined by intraoperative and postoperative blood loss. Other clinical outcomes that will be compared include transfusion rates, preoperative and postoperative hemodynamic values, and length of hospital stay after the procedure.

DISCUSSION

The primary goal of the study is to determine perioperative blood loss as a measure of the efficacy of TXA, EACA, and placebo. Based on current literature and the mechanism by which the medications act, we hypothesize that TXA will be more effective at reducing blood loss than EACA or placebo and result in improved patient outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT00958581.

Effect of epsilon aminocaproic acid on red-cell transfusion requirements in major spinal surgery

STUDY DESIGN

: Randomized, placebo-controlled trial.

OBJECTIVE

: To evaluate the efficacy of epsilon aminocaproic acid (EACA) to reduce the number of red-cell (RBC) transfusions in adult patients undergoing major spinal surgery.

SUMMARY OF BACKGROUND DATA

: Reconstructive spinal surgery is associated with significant blood loss. The number of studies evaluating the efficacy of EACA in adult patients undergoing spinal surgery remains scarce and limited.

METHODS

: EACA (100 mg/kg) or placebo was administered to 182 adult patients after the induction of anesthesia followed by an infusion that was continued for 8 hours after surgery. Primary end points included total allogeneic RBC transfusions through postoperative day 8 and postoperative allogeneic plus autologus RBC transfusions through postoperative day 8.

RESULTS

: Mean total allogeneic RBC transfusions were not statistically different between the groups (5.9 units EACA vs. 6.9 units placebo; P = 0.17). Mean postoperative RBC transfusions in the EACA group was less (2.0 units vs. 2.8 units placebo; P = 0.03). There was no significantdifference in mean estimated intraoperative estimated-blood loss (2938 cc EACA vs. 3273 cc placebo; P = 0.32). Mean intensive care unit length of stay was decreased (EACA: 1.8 days vs. 2.8 days placebo; P = 0.04). The incidence of thromboembolic complications was similar (2.2% EACA vs. 6.6% placebo; P = 0.15).

CONCLUSION

: The difference in total allogeneic RBC transfusions between the groups was not statistically significant. EACA was associated with a 30% (0.8 units) reduction in postoperative RBC transfusions and a 1-day reduction in ICU LOS, without an increased incidence of thromboembolic events. EACA may be considered for patients undergoing major spinal surgery. Larger studies are needed to evaluate the relationship between EACA and total RBC requirements.

Perioperative blood transfusion requirements in pediatric scoliosis surgery: the efficacy of tranexamic acid

BACKGROUND

Previous studies have noted that the use of antifibrinolytic medications can help reduce blood loss and transfusion requirements during cardiac, total joint arthroplasty, and spine surgery. Tranexamic acid (TXA) has been investigated in these patient groups but consensus with respect to the dosing regimen has not been achieved, especially in the pediatric scoliosis literature. The purpose of this study was to compare the effects of 2 TXA dosing regimens on reducing transfusion requirements.

METHODS

A retrospective chart review was performed on all idiopathic scoliosis patients undergoing posterior spinal instrumentation and fusion from 2005 to 2006 to determine total perioperative transfusion requirements. Transfusion requirements for those patients receiving either a low (10 mg/kg loading, 1 mg/kg/h infusion) or high (20 mg/kg loading, 10 mg/kg/h infusion) dose of TXA were compared.

RESULTS

High-dose TXA (n = 11) showed a trend toward a reduction in transfusion requirements compared with the low dose (n = 15) for idiopathic scoliosis patients undergoing posterior only instrumentation and fusion (687.9 +/- 778.1 mL vs 1372.6 +/- 1077.3 mL; P = 0.07; 95% confidence interval for the mean difference, -66.3 mL to 1435.7 mL). Although substantial, this difference was underpowered to show a difference.

CONCLUSIONS

The use of the higher dose of TXA resulted in a 50% reduction in transfusion requirements for idiopathic scoliosis patients. Given previous studies, there appears to be a dose-response effect. A prospective dose-ranging study is now required to determine the optimal dose for pediatric patients with idiopathic scoliosis.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Blood conservation techniques in spinal deformity surgery: a retrospective review of patients refusing blood transfusion

STUDY DESIGN

A retrospective review.

OBJECTIVE

To review the effectiveness of blood conservation techniques in the spinal fusion of patients that refuse blood transfusion; specifically the Jehovah's witnesses population.

SUMMARY OF BACKGROUND

Spinal surgery can be challenging in patients refusing blood transfusion. There is paucity in the literature examining blood conservation techniques in spinal surgery.

METHODS

The radiographic and medical records of 19 Jehovah's witnesses patients who underwent spinal deformity surgery at a single institution between 2000 and 2003 were reviewed. Patients were assessed for excessive blood loss (EBL), deformity correction, operative time, perioperative complications, and hospital stay. At latest follow-up (mean, 40 months; range, 8-76) the patients were examined for radiographic fusion, progression and complications.

RESULTS

Spinal fusion was attempted in 19 patients, with a mean age of 17 years (range, 10-36 years). All 19 patients were identified through the "Bloodless Surgery Program." Hypotensive anesthesia, hemodilution, and cell saver was employed for all 19 cases. Erythropoietin with supplemental iron was used in 15 patients. Aprotinin was used in 3 patients. EBL and blood returned by cell saver averaged 855 and 341 mL, respectively. Operative times average 315 minutes. The average drop in hemoglobin from after surgery was 3.1 g/dL. There were 2 intraoperative complications: (i) transient loss of somatosensory evoked potential/motor evoked potential signals; and (ii) one surgery abandoned due to EBL. The average spinal deformity correction was 58%. There were 3 postoperative complications, none related to their refusal of a transfusion. 17 patients were available for radiographic and clinic follow-up of at least 24 months. All displayed radiographic fusion without progression.

CONCLUSION

These blood conservation techniques allow satisfactory completion of deformity surgery on those patients not willing to be transfused and without major anesthetic or medical complications.

The role of Amicar in same-day anterior and posterior spinal fusion for idiopathic scoliosis

STUDY DESIGN

A retrospective study of the effectiveness of Amicar (epsilon aminocaproic acid).

OBJECTIVE

Evaluate the effectiveness of Amicar in decreasing perioperative blood loss and transfusion requirements in same-day anterior (ASF) and posterior spinal fusion (PSF) with segmental spinal instrumentation (SSI) for idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Preliminary prospective, prospective randomized double-blind, and fibrinogen studies have demonstrated Amicar to be effective in decreasing perioperative blood loss in patients with idiopathic scoliosis undergoing PSF with SSI. Increased fibrinogen secretion is a possible explanation.

METHODS

There were 73 consecutive patients divided into 3 study groups based on the administration of Amicar: Group 1 (n = 16), no Amicar; Group 2 (n = 18), Amicar for the PSF with SSI only; and Group 3 (n = 39), Amicar for both ASF and PSF with SSI. All patients were managed using the same general anesthesia technique, intraoperative procedure, postoperative care path, and indications for transfusion (hemoglobin <7 g/dL). Total perioperative blood loss (estimated intraoperative blood loss for both procedures and measured postoperative chest tube and PSF wound suction drainage) and total transfusion requirements between groups were compared using one-way ANOVA.

RESULTS

There were statistically significant decreases in mean estimated intraoperative PSF with SSI, total perioperative blood loss, and transfusion requirements in the 2 Amicar groups. However, Amicar had no significant effect on estimated intraoperative ASF blood loss, chest tube drainage, or PSF wound suction drainage. Total perioperative blood loss and transfusion requirements (cell saver, autologous, directed, and allogeneic blood) were: 3442.8 +/- 1344.0 mL and 1537.1 +/- 905.1 mL in Group 1; 2089.8 +/- 684.0 mL and 485.2 +/- 349.8 mL in Group 2; and 2184.1 +/- 1163.7 mL and 531.5 +/- 510.5 mL in Group 3. There were no Amicar related complications.

CONCLUSION

Amicar was highly effective in decreasing total perioperative blood loss and transfusion requirements in same-day ASF and PSF with SSI for idiopathic scoliosis. It results in less preoperative autologous blood donation, perioperative blood transfusion, costs, and potential transfusion-related complications. It was most effective in decreasing intraoperative estimated PSF with SSI blood loss. It had no significant effect during the ASF, postoperative chest tube, or PSF wound suction drainage. We now recommend that it be used for the PSF with SSI procedure only.

Antifibrinolytic agents for reducing blood loss in scoliosis surgery in children

BACKGROUND

Scoliosis surgery is often associated with substantial blood loss and potential detrimental effects in children. Antifibrinolytic agents are often used to reduce perioperative blood loss. Clinical trials have evaluated their effect in children undergoing surgical correction of scoliosis but no systematic review has been published. We performed a systematic review on the efficacy and safety of antifibrinolytic drugs in children undergoing scoliosis surgery.

OBJECTIVES

To assess the efficacy and safety of aprotinin, tranexamic acid and aminocaproic acid in reducing blood loss and transfusion requirements in children undergoing scoliosis surgery.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2007, Issue 3), OVID MEDLINE (1950 to September 3rd 2007), LILACS (1992 to June 20th 2007) and EMBASE (1980 to July 23rd 2007). We also searched conference proceedings from 2003 to 2007 and the clinicaltrials.gov registry. No language restriction was applied.

SELECTION CRITERIA

We included blinded or unblinded randomized controlled trials that evaluated the effect of antifibrinolytics on perioperative blood loss in children that were 18 years of age or younger and undergoing scoliosis surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently performed the data extraction. Primary outcomes were mortality and number of patients transfused. Secondary outcomes were number of patients transfused with allogeneic blood, amount of total blood transfused, total blood loss and adverse events. To assess heterogeneity we used the I(2) test and for the quantitative analysis we used a fixed-effect model.

MAIN RESULTS

Six studies fulfilled the inclusion criteria. The total number of participants was 254, of whom 127 were allocated to placebo and 127 to antifibrinolytic drugs. Aprotinin, tranexamic acid and aminocaproic acid were evaluated in two studies each. All studies had placebo as the control group intervention. There were no deaths or any serious adverse events in any study, in either the active or the control group. The risk of being transfused was similar in patients receiving antifibrinolytic drugs or placebo. Antifibrinolytics drugs decreased the amount of blood transfused by 327 ml (95% CI -469.04 to -185.78) and the amount of blood loss by 427 ml (95% CI -602.51 to -250.56). There was no indication of publication bias, however, we cannot rule it out due to the small number of studies included.

AUTHORS' CONCLUSIONS

The effect of antifibrinolytic drugs on mortality could not be assessed. Antifibrinolytic drugs reduced blood loss and the amount of blood transfused in children undergoing scoliosis surgery; however, their effect on the number of children requiring blood transfusion remains unclear. Aprotinin, tranexamic acid and aminocaproic acid seem to be similarly effective.

Video-assisted thoracoscopic surgery in idiopathic scoliosis: evaluation of the learning curve

STUDY DESIGN

Retrospective review of patients with idiopathic scoliosis who underwent same-day or staged anterior and posterior spinal fusion and segmental spinal instrumentation.

OBJECTIVE

Evaluation of our learning curve with video-assisted thoracoscopic surgery (VATS) with respect to operative time, blood loss, and complications in patients with idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

VATS is a minimally invasive alternative to thoracotomy in the management of idiopathic scoliosis. An increased or steep learning curve has been described in the initial application of this technique.

METHODS

We began performing VATS in 1998. We compared our first 25 consecutive VATS patients (Group 2) and subsequent 28 consecutive VATS patients (Group 3) to our previous 16 consecutive patients (Group 1) with a thoracotomy (1991-1998) for idiopathic scoliosis. Training at a sponsored regional course was obtained before performing our first VATS procedure.

RESULTS

VATS allowed more disc to be excised in Group 2 (4.5 +/- 1, 5.7 +/- 1, and 4.4 +/- 1 discs in Group 1, Group 2, and Group 3, respectively) and significantly decreased the anterior operative time (215 +/- 33, 260 +/- 56, and 177 +/- 47 minutes) and time per individual disc excision (50 +/- 13, 47 +/- 12, and 41 +/- 12 minutes), while providing comparable correction of the thoracic deformity (67% +/- 12%, 66% +/- 10%, and 70% +/- 13% correction). There was no increase in estimated intraoperative anterior blood loss (228 +/- 213, 183 +/- 136, and 211 +/- 158 mL), estimated blood loss per disc excised (51 +/- 42, 34 +/- 29 and 48 +/- 37 mL), or complications in the VATS groups. Complications were primarily pulmonary and resolved with medical therapy. Postoperative chest tube drainage (855 +/- 397, 462 +/- 249, and 561 +/- 261 mL) and total perioperative anterior blood loss (1083 +/- 507, 647 +/- 309, and 773 +/- 308 mL) were significantly decreased in the VATS groups, but this was attributed to the use of Amicar.

CONCLUSIONS

VATS is an effective procedure for anterior spinal fusion in idiopathic scoliosis. The learning curve is short, provided appropriate training is obtained.

Fibrinogen levels following Amicar in surgery for idiopathic scoliosis

STUDY DESIGN

Prospective evaluation of fibrinogen levels before surgery and after surgery in patients with idiopathic scoliosis undergoing posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI) who received Amicar to decrease perioperative blood loss.

OBJECTIVES

To assess a possible association between postoperative fibrinogen levels and Amicar administration.

SUMMARY OF BACKGROUND DATA

Our previous randomized, double-blind (Amicar and control) study demonstrated a rise in fibrinogen levels on the first postoperative day in the Amicar group, but not in the control group. Fibrinogen levels were not measured on the remaining postoperative days. We subsequently measured fibrinogen levels on all postoperative days in 21 consecutive patients with idiopathic scoliosis and found a dramatic increase throughout the postoperative hospitalization. This study is a continuation of our analysis of postoperative fibrinogen levels.

METHODS

We analyzed fibrinogen levels before surgery and on all postoperative days (4 or 5 days) until discharge in 51 consecutive patients, including our 21 previously reported patients, who received Amicar and underwent a PSF and SSI. We also analyzed the same factors with respect to perioperative blood loss as in our previous Amicar studies.

RESULTS

There were 41 females and 10 males with a mean age at surgery of 14.2 +/- 1.8 years. Their mean hospitalization was 4.6 +/- 0.8 days. Their mean estimated intraoperative blood loss was 766 +/- 308 mL and postoperative suction drainage 532 +/- 186 mL for a total perioperative blood loss of 1297 +/- 311 mL. The perioperative transfusion requirements were 0.5 +/- 0.6 U per patient. The preoperative fibrinogen was 255.5 +/- 58.3 mg/dL, and it rose steadily throughout the postoperative period to 680.9 +/- 111.9 mg/dL on the fifth postoperative day. There were no complications related to the use of Amicar.

CONCLUSIONS

Fibrinogen levels rise steadily throughout the postoperative period. The significance of this increase is unknown. Was it due to the use of Amicar or just the effects of surgery itself? Further investigations will be necessary.