Table 2 Summary of the 2022 WSES consensus on the follow-up strategies for patients with splenic trauma treated with non-operative management (NOM). Statements and recommendations

Research Question: 1. What is the optimal duration of bed-rest for patients treated with NOM for splenic trauma according to the injury grade?

Priority level: High

Statement: Abbreviated bed rest of 24 h is safe and does not increase NOM failure. The panel agrees that early mobilization could be considered in all splenic injury patients according to their general condition and associated injuries [Quality of Evidence: Moderate]. The day on which mobilization was performed is not associated with an increased risk of delayed hemorrhage in adult patients with low (WSES Class I, AAST Grades I–II) and high-grade (WSES Classes II–III, AAST Grades III–V) splenic injuries [Quality of Evidence: Moderate]. Current evidence supports an abbreviated period of bed rest of 24 h or less after splenic injury for hemodynamically stable children whose hemoglobin has been documented to be stable [Quality of Evidence: Moderate]

Recommendation: The panel suggests allowing early mobilization within 24 h in patients with low-grade (WSES Class I, AAST Grades I–II) splenic injuries treated with NOM. Patients with WSES Class II (AAST Grade III) splenic injuries can be mobilized after 2 days from the trauma if no other contraindications exist [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 89.1%]. In patients with high-grade splenic injuries (WSES Class III, AAST Grades IV–V), if no other contraindications to early mobilization exist, the patient can be mobilized safely after 2 days from the trauma when three successive hemoglobins 8 h apart after the first are within 10% of each other, and if clinical parameters remain stable [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 87.2%]. The panel suggests a shortened protocol of one night of bed rest for WSES Class I injuries (AAST Grade II; no need for bed rest for AAST Grade I) and two nights for WSES Classes II–III (AAST Grade ≥ III) in children when clinical parameters remain stable [Strength of Recommendation: Conditional recommendation, based on Moderate quality of evidence, Agreement 82.6%]

Research Question: 2. What is the optimal timing and type of anti-thrombotic prophylaxis for patients with splenic trauma treated with NOM?

Priority level: High

Statement: In the absence of contraindications related to associated injuries or conditions, such as intracranial hemorrhage, hemorrhagic diathesis, or patients under anticoagulation therapy, the best available evidence supports that deep vein thrombosis (DVT) and venous thromboembolism (VTE) prophylaxis can safely be initiated within 48–72 h of admission for blunt splenic trauma, regardless of injury grade, without concern for exacerbation of bleeding, or failure of NOM [Quality of Evidence: Moderate]. Occurrence rates of thrombocytosis in patients after SAE seem comparable to patients who undergo splenectomy, in contrast with average platelet values in those managed with observation alone. So, SAE may be an independent risk factor for thrombotic events in WSES Class II–III (AAST Grades III–V) blunt splenic injuries [Quality of Evidence: Moderate]. Regarding the choice between low molecular weight heparin (LMWH) versus unfractionated heparin (UH), indirect evidence coming from trauma cases in general, and liver trauma specifically, suggests that LMWH is superior to UH for DVT and VTE prevention and may additionally reduce pulmonary embolism (PE) and mortality [Quality of Evidence: Low]

Recommendation: For patients with blunt splenic injuries treated with NOM with/without splenic artery angioembolization (SAE), in the absence of specific complications, the panel suggests that DVT and VTE prophylaxis with LMWH be started within 24 h from hospital admission for patients with WSES Class I (AAST Grades I–II) and within 48–72 h for those with WSES Class II–III (AAST Grades III–V) splenic injuries [Strength of Recommendation: Conditional recommendation, based on Moderate Quality of Evidence, Agreement 91.3%]

Research Question: 3. How long should patients with splenic trauma treated with NOM be followed up in the hospital according to the injury grade?

Priority level: High

Statement: For patients treated with NOM for splenic injuries, most NOM failures occur early, primarily in the first 24 h. The risk of NOM failure and subsequent splenectomy is highest in the first 24–72 h of admission, with only 3% of splenectomies occurring later in the hospital course. Readmission is relatively rare in patients treated with NOM and most often occurs within 7 days of discharge [Quality of Evidence: Moderate]. Length of hospital stay for children with isolated splenic injuries could be based upon clinical presentation and hemodynamic status, as there is insufficient evidence to support the use of injury grade as the unique determinant of the stay [Quality of Evidence: Moderate]. Family and patient education post-discharge could be considered to reduce the readmission rate [Quality of Evidence: Moderate]

Recommendation: The panel suggests 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–II, AAST Grades III–V) of hospital admission, with the duration of stay based on hemodynamic status, hemoglobin and hematocrit stability, and results of the follow-up CEUS/CT scan at 48–72 h for adult patients [Strength of Recommendation: Conditional recommendation based on Moderate quality of evidence, Agreement 87%]. Admission to a monitored setting (high dependency unit—HDU—or intensive care unit—ICU) is suggested for adult patient with high-grade splenic injuries treated with NOM [Strength of Recommendation: Conditional recommendation based on Low quality of evidence, Agreement 87%]. The panel suggests that early discharge after NOM for blunt splenic injury, especially those with WSES Classes II–III (AAST Grade ≥ III), could be at least accompanied by an explicit patient and caregiver education regarding the risk of outpatient rupture and, in every case, an outpatient clinical follow-up, telephone, GP-follow-up, or community nurse follow-up after 5–7 days is recommended [Strength of Recommendation: Conditional recommendation based on Moderate quality of evidence, Agreement 93.5%]. The panel suggests abandoning strategies according to which the length of hospital stay is injury AAST Grade plus 1 day in children with splenic injuries treated with NOM in favor of an approach based on hemodynamic status, hemoglobin and hematocrit stability [Strength of Recommendation: Conditional recommendation based on Moderate quality of evidence, Agreement 89.1%]

Research Question: 4. What kind of hemodynamic monitoring is indicated during NOM for splenic trauma according to the injury grade?

Priority level: Medium

Statement: No studies focused on hemodynamic monitoring in patients with splenic injuries treated with NOM. No comparative studies focused on the proper monitoring according to the grade of the injury. Consequently, the evidence available is derived from case series and studies designed for other purposes, making the quality of evidence very low. Hemodynamic monitoring in patients with high-grade injuries is performed with continuous monitoring of vital parameters (pulse pressure, cardiac frequency and peripheral O2 saturation), frequent medical and nursing monitoring, and frequent evaluation of serum hemoglobin and hematocrit [Quality of Evidence: Very low]

Recommendation: There is not enough evidence to recommend specific hemodynamic monitoring in patients with splenic injuries treated with NOM. The panel suggests that all patients treated with NOM for high-grade splenic injuries (WSES Classes II–III, AAST Grade ≥ III) might receive continuous hemodynamic monitoring of vital parameters (pulse pressure, cardiac frequency, and peripheral O2 saturation) and frequent serum hemoglobin and hematocrit levels evaluation (every 8 h) [Strength of Recommendation: Conditional recommendation, based on Very low quality of evidence, Agreement 93.5%]. In patients with low-grade splenic injuries and stable hemodynamic status (WSES Class I, AAST Grades I–II) treated with NOM, the panel suggests close medical and nursing monitoring with evaluations of hemoglobin and hematocrit levels every 12–24 h if no complication occurs [Strength of Recommendation: Conditional recommendation, based on Very low quality of evidence, Agreement 91.3%]

Research Question: 5. When is splenic artery embolization (SAE) indicated for patients treated with NOM for splenic trauma?

Priority level: Urgent

Statement: In stable patients with high-grade splenic injuries (WSES Classes II–III, AAST Grade ≥ III), splenic artery angioembolization (SAE) represents an effective adjunctive tool to NOM, reducing the failure of the conservative approach and the need for surgery. Angiography and SAE should be performed at an early stage when contrast extravasation or vascular injuries (pseudoaneurysm, arteriovenous fistula formation, vessel truncation) are detected on admission CT scan, as well as in high-grade splenic injuries (WSES Class III, AAST Grades IV–V) even if contrast extravasation is not detected. However, small pseudoaneurysms can be safely observed without SAE [Quality of Evidence: High]. Some discrepancies in the management of WSES Class II (AAST Grade III) blunt splenic injury without contrast extravasation still exist among the experts. However, based on the available evidence, SAE in WSES Class II (AAST Grade III) splenic injury without vascular extravasation cannot be currently recommended as routine practice. In children, SAE has not been shown to be efficacious [Quality of Evidence: Low]. The available literature is inconclusive regarding whether proximal or distal embolization should be used to avoid significant re-bleeding, and larger prospective cohort studies are required. However, both techniques have an equivalent rate of post-procedural splenic infarctions and infections. Minor complications occur more often after distal embolization. This is primarily explained by the higher rate of segmental infarctions after distal embolization [Quality of Evidence: Low]

Recommendation: The panel suggests splenic artery angioembolization (SAE) as the first-line intervention in patients with hemodynamic stability and arterial blush on CT scan, irrespective of injury grade, where the expertise and resources required to carry out the procedure are readily available [Strength of Recommendation: Conditional recommendation, based on Moderate quality of evidence, Agreement 93.5%]. A low threshold for SAE is suggested for patients with WSES Class II (AAST Grade III) blunt splenic injury without contrast extravasation in the presence of risk factors for NOM failure (i.e., age above 55 years old, high injury severity score, the need for red cell transfusions in ED or during the first 24 h, patients on anticoagulant therapy, HIV disease, cirrhosis, and drug addiction) [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 89.1%]. The panel suggests angiography and eventual SAE in all hemodynamically stable adult patients with WSES Class III (AAST Grades IV–V) splenic injuries, even in the absence of CT blush, in centers with adequate experience and where SAE is rapidly available, especially when concomitant surgery that requires change of position and that may cause dislodgement of clots and rebleeding (i.e., spinal surgery in the prone position) is needed [Strength of Recommendation: Conditional recommendation, based on Moderate quality of evidence, Agreement 83.7%]. The panel suggests SAE be reserved for children who demonstrate evidence of ongoing bleeding with a vascular blush seen on CT [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence]. The panel suggests preferring proximal SAE over distal SAE when splenic artery angioembolization is needed [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 84.8%]

Research Question: 6. Is there a need for radiological follow-up during the hospital stay for patients treated with NOM for splenic trauma according to the injury grade?

Priority level: Urgent

Statement: A selective re-imaging strategy appears safe, as re-imaging asymptomatic patients rarely results in intervention. Although limited due to the lack of high-quality research, a follow-up CT scan seems to be justified only in patients with WSES Class II (AAST Grade III) or higher splenic injuries to identify vascular abnormalities after splenic trauma. Indeed, 75–90% of adults with pseudoaneurysm or arteriovenous fistula and all such lesions in the pediatric population occur in patients with injuries of such grade [Quality of Evidence: Low]. In higher grade injuries (WSES Classes II–III, AAST Grades III–V), contrast-enhanced ultrasound (CEUS)/CT scan follow-up might be performed in the first 48–72 h to exclude the development of vascular complications [Quality of Evidence: Low]. In literature, most delayed splenic complications are diagnosed in the first 7 days from trauma and rarely in AAST Grade I splenic injuries [Quality of Evidence: Low]

Recommendation: The panel suggests radiological follow-up to be based on clinical findings in WSES Class I (AAST Grades I–II) splenic trauma treated with NOM and suggests against routine imaging follow-up in these patients [Strength of Recommendations: Conditional recommendation based on Low quality of evidence, Agreement 91.3%]. The panel suggests repeating imaging with contrast-enhanced ultrasound (CEUS)/CT scan in 48 h to 72 h post-admission and, eventually, at 5–7 days of trauma (only if remarkable changes in CT scan at 72 h are detected, or new signs/symptoms related to the trauma occur) in adult patients with WSES Class II splenic injuries (AAST Grade III) or higher treated with NOM, regardless of whether SAE has been performed or not [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 82.6%]

Research Question: 7. What is the best imaging method to follow-up patients treated with NOM for high-grade splenic injures in the acute phase during NOM (Ultrasound without contrast, Contrast-enhanced ultrasound, CT-Angio)?

Priority level: High

Statement: Although contrast-enhanced CT scan is the gold standard modality for imaging abdominal organ traumatic injury, contrast-enhanced ultrasound (CEUS) has developed a role in the follow-up of traumatic injuries, including splenic trauma. CEUS is a valuable tool for detecting post-traumatic lesions; it is comparable to CT after splenic embolization and may replace CT in follow-up studies in expert hands [Quality of Evidence: Low]. CEUS may be considered in children, although repeat imaging in children is rarely needed [Quality of Evidence: Low]

Recommendation: The panel suggests, in expert hands and dedicated institutions, using CEUS as an alternative imaging modality in the follow-up of conservatively managed splenic trauma to reduce the number of CT examinations, especially in children [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 91.3%]

Research Question: 8. Should patients treated with NOM for splenic trauma (with or without splenic artery embolization) receive vaccinations?

Priority level: Medium

Statement: Most patients with splenic injuries treated with NOM, including those treated with splenic artery embolization (SAE), present a significantly lower rate of post-traumatic infections than those who undergo splenectomy [Quality of Evidence: Moderate]. SAE does not show higher rates of early and delayed infective complications compared with NOM without SAE [Quality of Evidence: Low]. There is insufficient evidence to advise mandatory vaccination in patients treated with NOM for splenic trauma, either with or without SAE [Quality of Evidence: Moderate]

Recommendation: The panel suggests against routine vaccination for overwhelming post-splenectomy infection (OPSI) from encapsulated bacteria in patients treated with NOM for splenic injury with or without SAE [Strength of Recommendation: Conditional recommendation, based on Moderate quality of evidence, Agreement 89.1%]. The panel suggests a tailored approach driven by the immunologic state of the patient before the splenic injury and taking into account possible effects of SAE in losing 50% or more of spleen mass. If 50% or more of the splenic mass is lost, and in every case of WSES Class III (AAST Grade V) injury, patients might be considered as asplenic and potentially more susceptible to OPSI; therefore, they could receive immunization against encapsulated organisms [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 93.5%]

Research Question: 9. For how long should patients with splenic trauma treated with NOM be followed up after hospital discharge according to the injury grade?

Priority level: Medium

Statement: Risk factors for late failure of NOM and hospital readmission include hemoperitoneum with signs of blush at first contrast-enhanced CT and high (WSES Class III, AAST IV–V) grade injuries [Quality of Evidence: Low]. There is neither agreement nor sufficient evidence to recommend the optimal length of follow-up after hospital discharge in patients with splenic trauma treated with NOM. The role of imaging has not been cleared out in the post-discharge follow-up [Quality of Evidence: Very low]. Imaging follow-up, either by CEUS or CT scan, does not seem to provide clinical benefits in the post-discharge period, and it might be considered in severe injuries (WSES Class III, AAST Grades IV–V) and depending on the level of activity (professional athletes, those practicing high-impact sports, heavy lifting) [Quality of Evidence: Very low]. Before returning to major physical activity, imaging follow-up with a contrast-enhanced CT scan or CEUS seems to be indicated to assess the status of the healing process after WSES Class II–III (AAST Grades III–V) splenic injuries treated with NOM [Quality of Evidence: Low]. The panel suggests that patients with blunt splenic injuries treated with NOM (with or without SAE) and families be informed of long-term complications and the possibility of NOM failure [Quality of Evidence: Low]

Recommendation: The panel suggests selective imaging follow-up at one, three, and (unless imaging confirms healing at 3 months) 6 months after discharge for patients with blunt splenic injuries treated with NOM only in the presence of risk factors for long-term complications and depending on the level of activity (professional athletes, those practicing high-impact sports, heavy lifting). The choice to perform imaging follow-up after discharge includes several considerations, such as the presence of severe splenic injuries (WSES Class III, AAST Grades IV–V); the association with other injuries that would warrant other specific follow-up; the age and expected activity level of the patient post-discharge; the type of NOM utilized (e.g., strictly observational or including interventional radiology); the duration of the hospital stay (with earlier discharge at risk of higher readmission rates) [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 86.0%]. The panel suggests performing contrast-enhanced imaging follow-up (CT/CEUS) before returning to major physical activity (2–4 months in high-grade injuries) in adult patients with WSES Class II–III (AAST Grades III–V) splenic injuries treated with NOM [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 89.1%]. Pediatric patients could be offered follow-up as outpatient consultation focusing on psychological response to injury and pain management, with further radiological examinations only if clinically indicated [Strength of Recommendation: Conditional recommendation, based on Very low quality of evidence, Agreement 95.7%]. The panel suggests imaging follow-up with CEUS before return to major physical activity in children with WSES Class II–III (AAST Grades III–V) splenic injuries treated with NOM [Strength of Recommendation: Conditional recommendation, based on Low quality of evidence, Agreement 82.6%]

Research Question: 10. How long should patients treated with NOM for splenic trauma abstain from major physical activities based on the grade of the splenic injury?

Priority level: High

Statement: Although there is a lack of high-quality research on the duration and intensity of restricted activity and return to play after blunt spleen injuries treated with NOM, the current trend is toward shorter post-discharge follow-up with earlier return to daily activity. Specifically, physical activity restrictions limited to 4 weeks after the injury, irrespective of injury grade on CT, seem safe in pediatric patients. Non-contact activity, including school, can be allowed safely after discharge [Quality of Evidence: Low]

Recommendation: The panel suggests that major activity restrictions (athletic activities, no-contact sports, heavy lifting) in adults with splenic trauma treated with NOM might be prescribed for 3–5 weeks in low-grade splenic injuries (WSES Class I, AAST Grades I–II) and up to 2–4 months in high-grade injuries (WSES Classes II–III, AAST Grades III–V). A follow-up imaging with contrast-enhanced CT/CEUS is suggested before return to full activities to confirm healing [Strength of Recommendation: Conditional recommendation based on Low quality of evidence, Agreement 89.1%]. The panel suggests that major activity restrictions in children with splenic trauma treated with NOM could be limited to 4 weeks after the injury, irrespective of injury grade on CT scan [Strength of Recommendation: Conditional recommendation based on Low quality of evidence, Agreement 87%]

Research Question: 11. Which is the best treatment of post-splenic artery embolization (SAE) necrosis of the spleen for patients with splenic trauma treated with NOM? Surgery or radiological drainage?

Priority level: High

Statement: Splenic abscess following NOM for splenic injuries is an infrequent complication. In the case of a splenic abscess, surgery and percutaneous drainage seem similar in safety and efficacy, but the quality of supporting evidence is poor [Quality of Evidence: Low]

Recommendation: The panel suggests considering percutaneous drainage as the first-line treatment of splenic abscesses after NOM in case of availability of the interventional radiology technique, adequate skills, and technical feasibility [Strength of Recommendation: Conditional recommendation based on Low quality of evidence, Agreement 95.7%]. In case of failure of percutaneous drainage (intense and persistent pain in patients with sepsis) or unavailability, the panel suggests performing splenectomy, open or laparoscopic, according to local expertise [Strength of Recommendation: Conditional recommendation based on very Low quality of evidence, Agreement 97.8%]