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

Incidence of venous thromboembolism in pediatric orthopedics: A systematic review

BACKGROUNDS

Children undergoing orthopedic procedures often present numerous risk factors for thromboembolism. A recent survey, conducted by the Pediatric Orthopaedic Society of North America (POSNA), indicates that pediatric orthopedic surgeons are unaware of venous thromboembolism (VTE) prevention protocols and feel that certain procedures should require thromboprophylaxis. The aim of this systematic review was to properly assess the incidence of VTE in pediatric orthopedics. By using a thorough and broad search of the literature, the incidence according to different subspecialties of pediatric orthopedics was evaluated.

METHODS

A systematic review on VTE in pediatric orthopedics was conducted. Four databases were searched for articles reporting these events. Three major search concepts: "pediatrics", "orthopedic surgery/trauma" and "VTE complications" were used and broken down in MeSH, EmTree and their free vocabulary synonyms for proper literature review. Two independent authors screened 8467 titles and abstracts. Seventy articles reporting VTE in children treated by orthopedic surgeons were selected for data extraction. We reported median incidences by orthopedic subtypes and by study characteristics with a semi-quantitative review model.

RESULTS

The 70 articles yielded a total of 845,010 participants. Spine articles (33/70) provided 25,2% of the children included in the review. Trauma studies (16/70) accounted for 47.5% of the participants. The overall VTE median incidence was 0.16% [95% CI: 0.0-1.01%]. Musculoskeletal infections had a noticeably higher median incidence of 3.5% [CI: 0.0-13.8%]. Small variations were seen for the other subtypes: trauma, spine and elective surgeries. Subgroups by article characteristics did not differ significantly either.

CONCLUSION

Thrombotic complications are rare events in pediatric orthopedics, but knowledge epidemiologic is important because its potential severity. In this review, VTE median incidence for all orthopedic subtypes was around 0.16% [CI: 0.0-1.01%]. According to subspecialty assessment, musculoskeletal infections were associated with greater risk of VTE occurrence.

LEVEL OF EVIDENCE

III - Systematic review.

Tranexamic acid in hip and spine surgery for children with cerebral palsy - a PRISMA-compliant scoping review

Many children with cerebral palsy (CP) are frail and require major hip and/or spine surgeries associated with substantial blood loss. Tranexamic acid (TXA) is commonly used to reduce blood loss, but there is uncertainty around the optimal dose and timing of administration. There have been reviews in sub-populations and specific dosing regimens, but a broad overview of the available literature is lacking. The aim of this review was to map available evidence on TXA in hip and spine surgery for children with CP. Given the heterogeneous literature, a prospectively registered scoping review was conducted. Eligibility criteria were broad. Three screeners were involved, with the senior author consulted when disagreements were not resolved through discussion.Titles and abstracts of 14,609 records were screened, with 52 records included. Two additional records were obtained from grey literature and citation searching. Cohort studies (50.0%) were the most common. Most records (76.9%) were on spine surgery. TXA dose varied widely. Loading doses range from 5 to 100 mg/kg and intraoperative infusions from 1 to 10 mg/kg/h. Dose was not reported in 35.2% of records. Primary outcome measures included blood loss and transfusion requirements. TXA was generally reported to be safe. None of the included records reported postoperative TXA administration.While TXA is generally considered safe, there was mixed evidence on efficacy. Much of the evidence was drawn from studies in which TXA was used in patients at higher risk of bleeding or with reduced physiological reserve. There was no evidence for TXA being used postoperatively, when a large proportion of transfusions occur.

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

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

Efficacy and Safety of Tranexamic Acid in Resection and Endoprosthetic Reconstruction of Distal Femoral Osteosarcomas in Children: A Retrospective Cohort Study

BACKGROUND

This study aimed to investigate the effect of intravenous tranexamic acid (TXA) on blood loss and transfusion rates in children who underwent resection and endoprosthetic reconstruction of distal femoral osteosarcomas.

METHODS

The medical records of 56 patients who underwent resection and endoprosthetic reconstruction for distal femoral osteosarcomas between 2017 and 2019 were retrospectively reviewed. Patients were divided into 2 groups: group 1 consisted of 25 patients (11 male and 14 female, mean age 15.2±3 y) who received preoperative 15 mg/kg intravenous TXA, and group 2 consisted of 31 control patients (18 male and 13 female, mean age 14.3±2.6 y) who did not receive TXA. The groups were compared based on their total blood loss, intraoperative blood loss, hidden blood loss, postoperative drain output, transfusion requirements, preoperative and postoperative hemoglobin (Hb) and hematocrit (Htc) difference, length of hospital stays, operative time, and complications.

RESULTS

The mean total blood loss was lower in intravenous TXA group (1247.5±300.9 mL) when compared with control group (1715.7±857.0 mL) (P=0.018). The mean intraoperative blood loss in intravenous TXA group (386±109 mL) was lower than that in control group (977.4±610.7 mL) (P<0.001). Postoperative drain output at 24 and 48 hours was 198.0±61.8 and 72.4±27.4 mL in intravenous TXA group, respectively, and was low compared with 268.4±118.2 and 117.1±67.8 mL in control group (P=0.028 and 0.006). The rate of patients requiring transfusion was significantly lower in intravenous TXA group (56%) than in control group (83.9%). Preoperative and postoperative 6, 24, and 72 hours Hb and Htc differences were significantly lower in intravenous TXA group [(-1.7±1.8 g/dL P<0.001; -2.0±1.5 g/dL P<0.001; -2.3±1.7 g/dL P<0.001, for Hb) (-5.7±4.6, P<0.001; -6.9±4.0, P<0.001; -9.6±9.1, P<0.001, for Htc)]. Intravenous TXA group had shorter hospital stay time in comparison to control group (P<0.001). The operative time was significantly longer in the control group (P<0.05). No increase in pulmonary embolism or venous thromboembolism rate was observed with intravenous TXA use.

CONCLUSION

We conclude that administration of intravenous TXA reduces intraoperative and postoperative blood loss, transfusion rates, and hospital stay in resection and endoprosthetic reconstruction of the distal femoral osteosarcomas in children.

TYPE OF STUDY

This was a retrospective comparative study.

LEVEL OF EVIDENCE

Level III.

Efficacy of antifibrinolytics in reducing blood loss during hip reconstruction surgery in cerebral palsy children. A systematic review and meta-analysis

BACKGROUND

Cerebral palsy (CP) children undergoing hip reconstruction are more prone to blood loss during surgery due to poor nutritional status, antiepileptic medication intake, depletion of clotting factors, and the extent of surgery involved. We conducted this present review to analyze whether antifibrinolytics during hip surgery in CP children would reduce surgical blood loss and transfusion requirements.

METHODS

Three databases (PubMed, EMBASE, and Cochrane library) were searched independently for publications mentioning the use of antifibrinolytics during hip reconstruction surgery in CP children. The primary outcome was to compare the surgical blood loss with and without antifibrinolytics use. Secondary outcomes were transfusion requirements, drop in hemoglobin level, length of hospital stay, and complication rates.

RESULTS

All five studies (reporting 478 patients) published on this topic were found eligible based on inclusion criteria and were included for final analysis. Primary outcome: In three of the included studies, antifibrinolytics use resulted in a significant reduction in total blood loss with a mean difference (MD) of -151.05 mL (95% CI -272.30 to -29.80, p = 0.01). In the other two studies although statistically not significant, antifibrinolytics use reduces estimated blood loss (MD: 3.27, 95% CI -21.44 to 14.91, p = 0.72). Secondary outcomes: We observed that in the antifibrinolytics group, there was a reduction in total blood transfusion requirements (OD: 0.70, 95% CI 0.35 to 1.37, p = 0.29), and a drop in haemoglobin level (MD: 0.16, 95% CI -0.62 to 0.30, p = 0.49) but statistically not significant. No adverse effects related directly to antifibrinolytics were noticed in all five studies.

CONCLUSION

Only two out of five included studies favored the use of antifibrinolytics in CP children undergoing hip reconstruction. The evidence synthesized on this meta-analysis is also not sufficient enough to support its routine use in this cohort of children for hip reconstruction surgery. High-quality studies with adequate sample size to determine the effective and safe dosage, timing, and cost involved of different antifibrinolytics are the need of the hour.

LEVEL OF EVIDENCE

Ⅲ.