Early Venous Thromboembolism Prophylaxis for Isolated High-Grade Blunt Splenic Injury

When is it safe to start thromboprophylaxis after splenic angioembolization?

BACKGROUND

Thromboprophylaxis after blunt splenic trauma is complicated by the risk of bleeding, but the risk after angioembolization is unknown. We hypothesized that earlier thromboprophylaxis initiation was associated with increased bleeding complications without mitigating venous thromboembolism events.

METHODS

All blunt trauma patients who underwent splenic angioembolization within 24 hours of arrival were identified from the American College of Surgeons Trauma Quality Improvement Program datasets from 2017 to 2019. Cases with <24-hour length of stay, other serious injuries, and surgery before angioembolization were excluded. Venous thromboembolism was defined as deep vein thrombosis or pulmonary embolism. Bleeding complications were defined as splenic surgery, additional embolization, or blood transfusion after thromboprophylaxis initiation. Data were compared with χ2 analysis and multivariate logistic regression at P < .05.

RESULTS

In 1,102 patients, 84% had American Association for the Surgery of Trauma grade III to V splenic injuries, and 73% received thromboprophylaxis. Splenic surgery after angioembolization was more common in those with thromboprophylaxis initiation within the first 24 hours (5.7% vs 1.7%, P = .007), whereas those with the initiation of thromboprophylaxis after 72 hours were more likely to have a pulmonary embolism (2.3% vs 0.2%, P = .001). Overall, venous thromboembolism increased considerably when thromboprophylaxis was initiated after day 3. In multivariate analysis, time to thromboprophylaxis initiation was associated with bleeding (odds ratio 0.74 [95% confidence interval 0.58-0.94]) and venous thromboembolism complications (odds ratio 1.5 [95% confidence interval 1.20-1.81]).

CONCLUSION

This national study evaluates bleeding and thromboembolic risk to elucidate the specific timing of thromboprophylaxis after splenic angioembolization. Initiation of thromboprophylaxis between 24 and 72 hours achieves the safest balance in minimizing bleeding and venous thromboembolism risk, with 48 hours particularly serving as the ideal time for protocolized administration.

When is it safe to start venous thromboembolism prophylaxis after blunt solid organ injury? A prospective American Association for the Surgery of Trauma multi-institutional trial

BACKGROUND

The optimal time to initiate venous thromboembolism (VTE) chemoprophylaxis (VTEp) after blunt solid organ injury remains controversial, as VTE mitigation must be balanced against bleeding promulgation. Evidence from primarily small, retrospective, single-center work suggests that VTEp ≤48 hours is safe and effective. This study was undertaken to validate this clinical practice.

METHODS

Blunt trauma patients presenting to 19 participating trauma centers in North America were screened over a 1-year study period beginning between August 1 and October 1, 2021. Inclusions were age older than 15 years; ≥1 liver, spleen, or kidney injury; and initial nonoperative management. Exclusions were transfers, emergency department death, pregnancy, and concomitant bleeding disorder/anticoagulation/antiplatelet medication. A priori power calculation stipulated the need for 1,158 patients. Time of VTEp initiation defined study groups: Early (≤48 hours of admission) versus Late (>48 hours). Bivariate and multivariable analyses compared outcomes.

RESULTS

In total, 1,173 patients satisfied the study criteria with 571 liver (49%), 557 spleen (47%), and 277 kidney injuries (24%). The median patient age was 34 years (interquartile range, 25-49 years), and 67% (n = 780) were male. The median Injury Severity Score was 22 (interquartile range, 14-29) with Abbreviated Injury Scale Abdomen score of 3 (interquartile range, 2-3), and the median American Association for the Surgery of Trauma grade of solid organ injury was 2 (interquartile range, 2-3). Early VTEp patients (n = 838 [74%]) had significantly lower rates of VTE (n = 28 [3%] vs. n = 21 [7%], p = 0.008), comparable rates of nonoperative management failure (n = 21 [3%] vs. n = 12 [4%], p = 0.228), and lower rates of post-VTEp blood transfusion (n = 145 [17%] vs. n = 71 [23%], p = 0.024) when compared with Late VTEp patients (n = 301 [26%]). Late VTEp was independently associated with VTE (odd ratio, 2.251; p = 0.046).

CONCLUSION

Early initiation of VTEp was associated with significantly reduced rates of VTE with no increase in bleeding complications. Venous thromboembolism chemoprophylaxis initiation ≤48 hours is therefore safe and effective and should be the standard of care for patients with blunt solid organ injury.

LEVEL OF EVIDENCE

Therapeutic and Care Management; Level III.

Timing of venous thromboembolism prophylaxis initiation after injury: Findings from the consensus conference to implement optimal VTE prophylaxis in trauma

ABSTRACT

Optimizing prophylaxis against venous thromboembolic events (VTEs) is a critical issue in the care of injured patients. Although these patients are at significant risk of developing VTE, they also present competing concerns related to exacerbation of bleeding from existing injuries. Especially after high-risk trauma, including injuries to the abdominal solid organs, brain, and spine, trauma providers must delineate the time period in which VTE prophylaxis successfully reduces VTE rates without encouraging bleeding. Although existing data are primarily retrospective in nature and further study is required, literature supports early VTE chemoprophylaxis initiation even for severely injured patients. Early initiation is most frequently defined as <48 hours from admission but varies from <24 hours to 72 hours and occasionally refers to time from initial trauma. Prior to chemical VTE prophylaxis initiation in patients at risk for bleeding, an observation period is necessary during which injuries must show themselves to be hemostatic, either clinically or radiographically. In the future, prospective examination of optimal timing of VTE prophylaxis is necessary. Further study of specific subsets of trauma patients will allow for development of effective VTE mitigation strategies based upon collective risks of VTE and hemorrhage progression.

Thromboprophylaxis Timing After Blunt Solid Organ Injury: A Systematic Review and Meta-analysis

INTRODUCTION

Trauma patients with blunt abdominal solid organ injuries are at high risk for venous thromboembolism (VTE), but the optimal time to safely administer chemical thromboprophylaxis is controversial, especially for patients who are managed nonoperatively due to increased risk of hemorrhage. We sought to compare failure of nonoperative management (NOM) and VTE events based on timing of chemical thromboprophylaxis initiation.

METHODS

A systematic review was conducted in PubMed and Embase databases. Studies were included if they evaluated timing of initiation of chemical thromboprophylaxis in trauma patients who underwent NOM of blunt solid organ injuries. Outcomes included failure of NOM and incidence of VTE. A random-effects meta-analysis was performed comparing patients who received late (>48 h) versus early thromboprophylaxis initiation.

RESULTS

Twelve retrospective cohort studies, comprising 21,909 patients, were included. Three studies, including 6375 patients, provided data on adjusted outcomes. Pooled adjusted analysis demonstrated no difference in failure of NOM in patients receiving late versus early thromboprophylaxis (odds ratio [OR] 0.92, 95% confidence interval [CI]:0.4-2.14). When including all unadjusted studies, even those at high risk of bias, there remained no difference in failure of NOM (OR 1.16, 95% CI:0.72-1.86). In the adjusted analysis for VTE events, which had 6259 patients between two studies, patients receiving late chemical thromboprophylaxis had a higher risk of VTE compared with those who received early thromboprophylaxis (OR 1.89, 95% CI:1.15-3.12).

CONCLUSIONS

Based on current observational evidence, initiation of prophylaxis before 48 h is associated with lower VTE rates without higher risk of failure of NOM.

Follow-up strategies for patients with splenic trauma managed non-operatively: the 2022 World Society of Emergency Surgery consensus document

Background

In 2017, the World Society of Emergency Surgery published its guidelines for the management of adult and pediatric patients with splenic trauma. Several issues regarding the follow-up of patients with splenic injuries treated with NOM remained unsolved.

Methods

Using a modified Delphi method, we sought to explore ongoing areas of controversy in the NOM of splenic trauma and reach a consensus among a group of 48 international experts from five continents (Africa, Europe, Asia, Oceania, America) concerning optimal follow-up strategies in patients with splenic injuries treated with NOM.

Results

Consensus was reached on eleven clinical research questions and 28 recommendations with an agreement rate ≥ 80%. Mobilization after 24 h in low-grade splenic trauma patients (WSES Class I, AAST Grades I–II) was suggested, while in patients with high-grade splenic injuries (WSES Classes II–III, AAST Grades III–V), if no other contraindications to early mobilization exist, safe mobilization of the patient when three successive hemoglobins 8 h apart after the first are within 10% of each other was considered safe according to the panel. The panel suggests adult patients to be admitted to hospital for 1 day (for low-grade splenic injuries—WSES Class I, AAST Grades I–II) to 3 days (for high-grade splenic injuries—WSES Classes II–III, AAST Grades III–V), with those with high-grade injuries requiring admission to a monitored setting. In the absence of specific complications, the panel suggests DVT and VTE prophylaxis with LMWH to be started within 48–72 h from hospital admission. The panel suggests splenic artery embolization (SAE) as the first-line intervention in patients with hemodynamic stability and arterial blush on CT scan, irrespective of injury grade. Regarding patients with WSES Class II blunt splenic injuries (AAST Grade III) without contrast extravasation, a low threshold for SAE has been suggested in the presence of risk factors for NOM failure. The panel also suggested angiography and eventual SAE in all hemodynamically stable adult patients with WSES Class III injuries (AAST Grades IV–V), even in the absence of CT blush, especially when concomitant surgery that requires change of position is needed. Follow-up imaging with contrast-enhanced ultrasound/CT scan in 48–72 h post-admission of trauma in splenic injuries WSES Class II (AAST Grade III) or higher treated with NOM was considered the best strategy for timely detection of vascular complications.

Conclusion

This consensus document could help guide future prospective studies aiming at validating the suggested strategies through the implementation of prospective trauma databases and the subsequent production of internationally endorsed guidelines on the issue.

Optimal timing of venous thromboembolic chemoprophylaxis initiation following blunt solid organ injury: meta-analysis and systematic review

PURPOSE

The need to prevent venous thromboembolism (VTE) following blunt solid organ injury must be balanced against the concern for exacerbation of hemorrhage. The optimal timing for initiation of VTE chemoprophylaxis is not known. The objective was to determine the safety and efficacy of early (≤ 48 h) VTE chemoprophylaxis initiation following blunt solid organ injury.

METHODS

An electronic search was performed of medical libraries for English language studies on timing of VTE chemoprophylaxis initiation following blunt solid organ injury published from inception to April 2020. Included studies compared early (≤ 48 h) versus late (> 48 h) initiation of VTE chemoprophylaxis in adults with blunt splenic, liver, and/or kidney injury. Estimates were pooled using random-effects meta-analysis. Odds ratios were utilized to quantify differences in failure of nonoperative management, need for blood transfusion and rates of VTE.

RESULTS

The search identified 2,111 studies. Of these, ten studies comprising 14,675 patients were included. All studies were non-randomized and only one was prospective. The overall odds of failure of nonoperative management were no different between early and late groups, OR 1.09 (95%CI 0.92-1.29). Similarly, there was no difference in the need for blood transfusion either during overall hospital stay, OR 0.91 (95%CI 0.70-1.18), or post prophylaxis initiation, OR 1.23 (95%CI 0.55-2.73). There were significantly lower odds of VTE when patients received early VTE chemoprophylaxis, OR 0.51 (95%CI 0.33-0.81).

CONCLUSIONS

Patients undergoing nonoperative management for blunt solid organ injury can be safely and effectively prescribed early VTE chemoprophylaxis. This results in significantly lower VTE rates without demonstrable harm.

Timing of thromboprophylaxis in patients with blunt abdominal solid organ injuries undergoing nonoperative management

BACKGROUND

Decision making regarding the optimal timing for initiating thromboprophylaxis in patients with blunt abdominal solid organ injuries (BSOIs) remains ill-defined, with no guidelines defining optimal timing. In this study, we aimed to evaluate the relationship of the timing of thromboprophylaxis with thromboembolic and bleeding complications in the setting of BSOIs.

METHODS

A retrospective analysis of the Trauma Quality Improvement Program database was performed between 2013 and 2016. All patients with isolated BSOIs (liver, spleen, pancreas, or kidney, Abbreviated Injury Scale score, <3 in other regions) who underwent initial nonoperative management (NOM) were included. Patients were divided into three groups (early, <48 hours; intermediate, 48-72 hours; and late, >72 hours) based on timing of thromboprophylaxis initiation. Primary outcomes were rates of thromboembolism and bleeding after thromboprophylaxis initiation.

RESULTS

Of the 25,118 patients with isolated BSOIs, 3,223 met the inclusion criteria (age, 38.7 ± 17.3 years; males, 2.082 [64.6%]), among which 1,832 (56.8%) received early thromboprophylaxis, 703 (21.8%) received intermediate thromboprophylaxis, and 688 (21.4%) received late thromboprophylaxis. Late thromboprophylaxis initiation was independently associated with a higher likelihood of both deep vein thrombosis (odds ratio [OR], 3.15; 95% confidence interval [CI], 1.68-5.91, p < 0.001) and pulmonary embolism (OR, 4.29; 95% CI, 1.95-9.42; p < 0.001). Intermediate thromboprophylaxis initiation was independently associated with a higher likelihood of deep venous thrombosis (OR, 2.38; 95% CI, 1.20-4.74; p = 0.013), but not pulmonary embolism (p = 0.960) compared with early initiation. Early (but not intermediate) thromboprophylaxis initiation was independently associated with a higher likelihood of bleeding (OR, 2.05; 95% CI, 1.11-2.18; p = 0.023), along with a history of diabetes mellitus, splenic, and high-grade liver injuries.

CONCLUSION

Early thromboprophylaxis should be considered in patients with BSOIs undergoing nonoperative management who are at low likelihood of bleeding. An intermediate delay (48-72 hours) of thromboprophylaxis should be considered for patients with diabetes mellitus, splenic injuries, and Grades 3 to 5 liver injuries.

LEVEL OF EVIDENCE

Therapeutic, Level IV.