Non-operative management of blunt splenic trauma: evolution, results and controversies

ABSTRACT The spleen is one of the most frequently affected organs in blunt abdominal trauma. Since Upadhyaya, the treatment of splenic trauma has undergone important changes. Currently, the consensus is that every splenic trauma presenting with hemodynamic stability should be initially treated nonoperatively, provided that the hospital has adequate structure and the patient does not present other conditions that indicate abdominal exploration. However, several topics regarding the nonoperative management (NOM) of splenic trauma are still controversial. Splenic angioembolization is a very useful tool for NOM, but there is no consensus on its precise indications. There is no definition in the literature as to how NOM should be conducted, neither about the periodicity of hematimetric control, the transfusion threshold that defines NOM failure, when to start venous thromboembolism prophylaxis, the need for control imaging, the duration of bed rest, and when it is safe to discharge the patient. The aim of this review is to make a critical analysis of the most recent literature on this topic, exposing the state of the art in the NOM of splenic trauma.


Meira Júnior
Non-operative management of blunt splenic trauma: evolution, results and controversies conduction of NOM 15  Until the 1980s, splenic lesions were routinely treated with splenectomy 19 . According to Upadhyaya, it was mistakenly believed that the spleen had no function, that nonoperative treatment was lethal, that there was an imminent risk of rupture if the organ was preserved, and that the spleen could not be sutured 9 21 , leading to a discussion about the harm of traumatic asplenia also in adults 22 and the potential benefit of preserving this organ.
The first reports of NOM for splenic injuries came from studies with children 19,23 , and since then the incidence of splenectomy in the context of splenic trauma has dropped significantly 24 9.6% of wich are from hollow viscera [28][29][30] . The operative care of splenic injury associated with hollow viscus injury affords contemporaneous operative care of the splenic injury, whether by splenectomy, splenorraphy, or simply by packing the spleen with hemostatic gauze. However, lesions that result in perforation and leakage of these viscera contents are rare in blunt abdominal trauma, with incidence around 0.3% 29 , which guarantees certain safety in the adoption of NOM. With regard to penetrating mechanisms, few studies address the NOM of splenic lesions, and currently there is insufficient evidence to suggest a broad incorporation of this practice safely into victims of penetrating spleen injury.
As NOM was increasingly instituted, cases of failure of NOM began to become more evident. In order to identify which patients were most at risk, several studies sought to determine the predictors of failure of NOM.

Predictors of failure of nonoperative management
Most patients with low-grade splenic injuries (I to III according to AAST) are successfully submitted to NOM. However, even patients with high-grade lesions (IV-V AAST) may initially undergo NOM, provided they are hemodynamically stable 12,31 . It is noteworthy that even patients who meet the criteria for NOM Once decided by splenic embolization, the results regarding proximal (splenic artery trunk) or distal (also called selective) embolization must be analyzed.
Proximal embolization is usually used when bleeding is diffuse, when the patient's hemodynamic condition is Meira Júnior Non-operative management of blunt splenic trauma: evolution, results and controversies borderline, or when vascular anatomy is unfavorable. In cases where bleeding is focal, distal embolization is used.
It is noteworthy that, although there are no prospective studies, proximal embolization is faster, and has lower failure and complication rates compared to distal 45  Most studies referring to hematimetric control discuss the frequency with which hemoglobin and hematocrit levels should be obtained. In fact, there is currently not enough evidence to guide a specific regimen 5 .
In a consensus of experts 32 , most agreed that it was necessary to collect hemoglobin or hematocrit every 4 or 6 hours within the first 24 hours of onset of NOM or until level stability. After this period, it was recommended that the measurements should be performed once or twice a day. Despite being a controversial concept, studies seem to agree that hematimetric stability is defined by a fall of less than 0.5mg/dL in two consecutive measurements, and that the measurements of hematimetric levels should be frequent in the first day of NOM (at least every 6 hours), and further apart in the following days (once or twice every day).
The relationship between early patient mobilization and failure of NOM is discussed as well.
In a recent study, Teichman et al. 47   There is also discussion about the need for control imaging after the onset of NOM of splenic injury.
It is currently accepted that vascular abnormalities may appear later than the first CT scan. One study showed that pseudoaneurysms can appear even in grade II and III 55 injuries on a control tomography between 1 and 8 days of trauma in 15% of the cases, half of which evolved with spontaneous pseudoaneurysm occlusion, without the need of any intervention. As such, repeat imaging appears to be an unnecessary practice because it did not influence the treatment 18 . However, it is noteworthy that data regarding the long term evolution of these patients are lacking, especially regarding the need for angioembolization of the lesions identified in the control CT 56,57 . In a recent review 57,58 , patients submitted to NOM were followed with routine imaging examination (either ultrasound or CT scan), between zero (within 24h) and 11 days from the initial CT scan.