Risk of venous thromboembolism in children after general surgery

Screening and Prophylaxis for Venous Thromboembolism in Pediatric Surgery: A Systematic Review

OBJECTIVE

The American Pediatric Surgical Association Outcomes and Evidence-Based Practice Committee conducted a systematic review to describe the epidemiology of venous thromboembolism (VTE) in pediatric surgical and trauma patients and develop recommendations for screening and prophylaxis.

METHODS

The Medline (Ovid), Embase, Cochrane, and Web of Science databases were queried from January 2000 through December 2021. Search terms addressed the following topics: incidence, ultrasound screening, and mechanical and pharmacologic prophylaxis. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. Consensus recommendations were derived based on the best available literature.

RESULTS

One hundred twenty-four studies were included. The incidence of VTE in pediatric surgical populations is 0.29% (Range = 0.1%-0.48%) and directly correlates with surgery type, transfusion, prolonged anesthesia, malignancy, congenital heart disease, inflammatory bowel disease, infection, and female sex. The incidence of VTE in pediatric trauma populations is 0.25% (Range = 0.1%-0.8%) and directly correlates with injury severity, major surgery, central line placement, body mass index, spinal cord injury, and length-of-stay. Routine ultrasound screening for VTE is not recommended. Consider sequential compression devices in at-risk nonmobile, pediatric surgical patients when an appropriate sized device is available. Consider mechanical prophylaxis alone or with pharmacologic prophylaxis in adolescents >15 y and post-pubertal children <15 y with injury severity scores >25. When utilizing pharmacologic prophylaxis, low molecular weight heparin is superior to unfractionated heparin.

CONCLUSIONS

While VTE remains an infrequent complication in children, consideration of mechanical and pharmacologic prophylaxis is appropriate in certain populations.

TYPE OF STUDY

Systematic Review of level 2-4 studies.

LEVEL OF EVIDENCE

Level 3-4.

Hospital acquired venous thromboembolism in children with sickle cell disease

Sickle cell disease (SCD) is well recognized as a hypercoagulablestate, however, it remains unclear whether a subgroup of children with SCD at higher risk of venous thromboembolic event (VTE) during hospitalization may benefit from thromboprophylaxis. Our objectives were to describe the clinical characteristics, outcomes and recurrence of hospital acquired VTE in patients with SCD younger than 21 years. This was a single center retrospective study. Data regarding demographics, reason for admission, location of VTE, risk factors like central venous catheter (CVC), intensive care unit (ICU) admission among others were extracted from electronic medical records over a 10-year study period (2011-2021). Recurrence of VTE at 1 and 5 years was assessed. Descriptive statistics were used as indicated. We identified a total of 20 VTE events over the 10-year study period. Six of these events occurred in those younger than 12 years of age. Fourteen (70%) VTE events occurred in the HbSS or HbSβThal0 genotypes compared to 6 (30%) in HbSC. Most common VTE was isolated pulmonary embolism (PE) (n = 10, 50%). VTE were most often associated with acute chest syndrome (ACS) (n = 14, 70%), ICU admissions (n = 10, 50%) and CVC (n = 5/9, 55%). One patient died from the VTE event. One patient with additional underlying risk factors had a recurrent VTE at 13 months. Our study suggests that ICU admission, ACS and presence of CVC increases the risk of VTE in children and young adults with SCD, but larger studies are indicated to validate our findings.

Development and validation of a nomogram for catheter-related thrombosis prediction in children with central venous catheter: a retrospective observational study

BACKGROUND

Catheter-related thrombosis (CRT) is a thrombotic complication associated with using central venous catheters (CVCs). Although risk factors for CRT were identified in children, no nomograms or predictive tools are available for the pediatric population with CVCs. This study aimed to develop and validate a prediction model of asymptomatic CRT in children with CVCs.

METHODS

This retrospective observational study included consecutive pediatric patients who admitted to the Children's Hospital Zhejiang University School of Medicine and received CVCs between October and December 2021.

RESULTS

This study included 669 patients, 553 (314 males, aged 22.00 [0.36, 180.00] months, 62 with CRT) were in the training set, and 116 (62 males, aged 15.00 [1.13, 156.00] months, 16 with CRT) were in the validation set. Multivariate logistic regression showed that a catheter time of 0-3 days (OR = 0.201, 95%CI: 0.081-0.497, P = 0.001), catheter time of 4-7 days (OR = 0.412, 95%CI: 0.176-0.964, P = 0.041), male (OR = 3.976, 95%CI: 1.864-4.483, P < 0.001), congenital heart diseases (OR = 0.277, 95%CI: 0.078-0.987, P = 0.048), postoperative (OR = 0.161, 95%CI: 0.072-0.360, P < 0.001), and femoral CVC (OR = 2.451, 95%CI: 1.129-5.318, P = 0.002) were independently associated with CRT. The nomogram incorporating these variables showed relatively good discrimination (AUC = 0.77, 95%CI: [0.65, 0.90]) and calibration abilities in the validation set, and the decision curve analysis (DCA) yielded a clinical net benefit.

CONCLUSION

A prediction model for CRT in children with CVC was established based on catheter time, sex, diseases, postoperative, and catheter vein. The nomogram based on logistic regression model showed favorable predictive performance.

Proportion and risk factors for hospital-acquired venous thromboembolism in children: a systematic review and meta-analysis of data from 20 million individuals in 22 countries

Background

Hospital-acquired venous thromboembolism (HA-VTE) in children has been widely regarded.

Objectives

We aimed to analyze the proportion and risk factors for HA-VTE in hospitalized children.

Methods

We conducted a comprehensive systematic search across 4 databases from 1990 to 2023. Cochran Q test was used to evaluate the heterogeneity of the effect sizes of study, and I2 statistic was used to quantify the heterogeneity. Pooled estimates were calculated by the inverse-variance weighted method in a fixed-effect model or a random-effect model when heterogeneity was low (I2 < 25%) or high (I2 > 25%), respectively.

Results

In total, 105 original papers and 20,718,294 patients were included in the study, and the proportion of HA-VTE in children was 4.1% (95% CI, 2.9%-5.2%). Although the proportion of venous thromboembolism increased over the various research periods, the differences were not statistically significant. In the subgroup analysis based on country, the proportion of pediatric HA-VTE was lowest in the United Kingdom and highest in Spain, whereas when based on region, the proportion was lowest in Asia and highest in North America. Multiple HA-VTE risk factors were identified, including central venous catheter use, age of >10 years, surgery, injury, infection, obesity, mechanical ventilation, blood transfusion, malignancy, coagulation and hemorrhagic disorders, and length of hospital stay.

Conclusion

In this study, we systematically analyzed the proportion and risk factors of HA-VTE in hospitalized children. Our findings provide valuable insights for the prevention and treatment of HA-VTE in pediatric patients.

Risk of venous thromboembolism in pediatric hospitalized patients undergoing noncardiac surgery: A report from the Children's Hospital-Acquired Thrombosis consortium

Background

Surgery is a known risk factor for hospital-acquired venous thromboembolism (HA-VTE) in children.

Objectives

To assess whether the odds of HA-VTE differs across six anatomic sites of noncardiac surgery and to identify risk factors for HA-VTE in these children.

Methods

This was a multicenter, case-control study. Anatomic sites of surgery and risk factors for HA-VTE were collected on hospitalized pediatric patients who had undergone a single noncardiac surgery and developed HA-VTE (cases), and those who did not develop HA-VTE (controls), via the Children's Hospital-Acquired Thrombosis (CHAT) Registry. Logistic regression estimated the odds ratio (OR) and 95% confidence intervals (CIs) between six anatomic sites of surgery and 16 putative HA-VTE risk factors. Variables with a p value of 0.10 or less in unadjusted analyses were included in adjusted models for further evaluation. The final model used backward selection, with a significance level of 0.05.

Results

From January 2012 to March 2020, 163 cases (median age, 5.7 years; interquartile range [IQR], 0.3-14.2) and 208 controls (median age of 7.5 years; IQR, 3.7-12.9) met our criteria. There was no statistically significant increased odds of VTE among the types of noncardiac surgery. In the final adjusted model, central venous catheter (CVC; OR, 14.69; 95% CI, 7.06-30.55), intensive care unit (ICU) stay (OR, 5.31; 95% CI, 2.53-11.16), and hospitalization in the month preceding surgery (OR, 2.75; 95% CI, 1.24-6.13) were each independently significant risk factors for HA-VTE.

Conclusion

In children undergoing noncardiac surgery, placement of CVCs, admission/transfer to the ICU, or hospitalization in the month prior to surgery were positively associated with HA-VTE.

Anti-Xa levels in critically ill children receiving enoxaparin for venothromboembolism prophylaxis

Venothrombolism (VTE) prophylaxis is increasingly utilized in pediatric intensive care units (PICUs). Enoxaparin, a low-molecular weight heparin, is frequently used for this purpose. Enoxaparin can also be used for therapeutic anticoagulation in cases of known thrombus. In such cases, monitoring involves obtaining serum anti- Xa levels with a target value of 0.5-1 units/mL. No monitoring recommendations currently exist for enoxaparin when intended for pediatric VTE prophylaxis. We hypothesize that a clinically important number of patients on VTE prophylaxis with enoxaparin have serum anti-Xa levels consistent with values targeted for therapeutic anticoagulation. We found that over 20% of patients on VTE prophylaxis with enoxaparin had serum anti-Xa levels consistent with true therapeutic anticoagulation (anti-Xa level 0.5-1 units/mL) during their enoxaparin course and 5% achieved values of supratherapeutic anticoagulation (anti-Xa level >1 units/mL). Serum anti-Xa level did not correlate with once versus twice daily dosing, body mass index (BMI), or creatinine level. Blood urea nitrogen (BUN) was found to have a positive odds ratio for an anti-Xa level ≥ 0.5 units/mL. We believe that this incidence of unintended therapeutic anticoagulation indicates a clinically significant number and therefore routine anti-Xa evaluation while on VTE prophylaxis is warranted within our population.

Venous thromboembolism in children undergoing surgery: incidence, risk factors and related adverse events

Background

Although less common in adults, venous thromboembolism (VTE) in children is a highly morbid, preventable adverse event. While VTE has been well studied among pediatric hospitalized and trauma patients, limited work has been done to examine postoperative VTE in children undergoing surgery.

Methods

Using data from National Surgical Quality Improvement Project Pediatric database (NSQIP-P) from 2012 to 2016, a retrospective cohort analysis was performed to determine the incidence of, and risk factors for, VTE in children undergoing surgery. Additionally, the relationships between VTE and other postoperative adverse outcomes were evaluated.

Results

Of 361 384 pediatric surgical patients, 378 (0.10%) were identified as experiencing postoperative VTE. After controlling for patient and surgical factors, we found that American Society of Anesthesiologists (ASA) class of II or greater, aged 16–18 years, non-elective surgery, general surgery (compared with several other surgical specialties), cardiothoracic surgery (compared with general surgery) and longer operative time were significantly associated with VTE in pediatric patients (p<0.001 for each comparison). Furthermore, a majority of adverse events were found to be associated with increased risk of subsequent VTE (p<0.001).

Conclusion

In a large pediatric surgical population, an incidence of postoperative VTE of 0.10% was observed. Defined patient and surgical factors, and perioperative adverse events were found to be associated with such VTE events.

Venous thromboembolism following inpatient pediatric surgery: Analysis of 153,220 patients

PURPOSE

To evaluate venous thromboembolism (VTE) rates and risk factors following inpatient pediatric surgery.

METHODS

153,220 inpatient pediatric surgical patients were selected from the 2012-2015 NSQIP-P database. Demographic and perioperative variables were documented. Primary outcome was VTE requiring treatment within 30 postoperative days. Secondary outcomes included length of stay (LOS) and 30-day mortality. Prediction models were generated using logistic regression. Mortality and time to VTE were assessed using Kaplan-Meier survival analysis.

RESULTS

305 patients (0.20%) developed 296 venous thromboses and 12 pulmonary emboli (3 cooccurrences). Median time to VTE was 9 days. Most VTEs (81%) occurred predischarge. Subspecialties with highest VTE rates were cardiothoracic (0.72%) and general surgery (0.28%). No differences were seen for elective vs. urgent/emergent procedures (p = 0.106). All-cause mortality VTE patients was 1.2% vs. 0.2% in patients without VTE (p < 0.001). After stratifying by American Society of Anesthesiologists (ASA) class, no mortality differences remained when ASA < 3. Preoperative, postoperative, and total LOSs were longer for patients with VTE (p < 0.001 for each). ASA ≥ 3, preoperative sepsis, ventilator dependence, enteral/parenteral feeding, steroid use, preoperative blood transfusion, gastrointestinal disease, hematologic disorders, operative time, and age were independent predictors (C-statistic = 0.83).

CONCLUSIONS

Pediatric postsurgical patients have unique risk factors for developing VTE.

LEVEL OF EVIDENCE

Level II.

Pediatric Acute Paradoxical Cerebral Embolism with Pulmonary Embolism Caused by Extremely Small Patent Foramen Ovale

Herein, we report a pediatric case of acute paradoxical cerebral embolism complicated by serious acute pulmonary embolism that was caused by an extremely small patent foramen ovale (PFO). The patient had no medical history suggestive of any other reason.

Paradoxical cerebral embolism may occur even with an extremely small PFO because of the increased right-side pressure of the heart and a resulting right-to-left shunt from the acute pulmonary embolism. Although pediatric cases of pulmonary embolism are rare, when diagnosed, clinicians should consider the risk of a concurrent paradoxical cerebral embolism resulting from a latent PFO. The possibility of PFO should be assessed extremely carefully in pediatric critical care by checking for a thrombogenesis tendency and the existence of deep vein thrombosis in the patient.

Incidence and risk factors associated with 30-day post-operative venous thromboembolism: A NSQIP-pediatric analysis

INTRO

Venous thromboembolism (VTE) is a rare event in children, but can cause significant morbidity and mortality. The majority of research on pediatric VTE has been in the trauma and critical care populations. The incidence of VTE after surgery in children is not well-established.

OBJECTIVE

The objective was to evaluate the incidence of VTE in the 30 days after surgery, as well as associated risk factors.

STUDY DESIGN

All cases in the National Surgical Quality Improvement Program Pediatric (NSQIPP) database from 2012 to 2015 were assessed for presence of post-operative VTE. Demographic, clinical, and peri-operative characteristics were collected. Descriptive statistics were performed, and multiple logistic regression models were created to estimate associated risk of VTE.

RESULTS

In a cohort of 267,299 surgical cases, the 30-day incidence of post-operative VTE was 12 per 10,000 cases (0.12%). VTE incidence followed a bi-modal distribution, highest in infants and adolescents (Figure). Malignancy, pre-operative illness, and greater anesthetic times were associated with increased risk of VTE.

DISCUSSION

The incidence of post-operative VTE in NSQIPP is similar to that seen in pediatric trauma and critical care populations. Risk factors are also consistent, including baseline illness, immobility, and prolonged anesthetic time.

CONCLUSION

Post-operative VTE in children occurs infrequently, yet certain individuals are at increased risk and thus guidelines for prophylaxis and treatment are needed.