Splenic Embolization After Trauma: An Opportunity to Improve Best Immunization Practices

Splenic artery embolization for trauma: a narrative review

The management of traumatic splenic injuries has evolved significantly over the past several decades, with the majority of these injuries now being treated nonoperatively. Patients who exhibit hemodynamic instability upon initial evaluation typically require surgical intervention, while the remainder are managed conservatively. Conservative treatment for traumatic splenic injuries encompasses both medical management and splenic artery angiography, followed by embolization in cases where patients exhibit clinical signs of ongoing splenic hemorrhage. Splenic artery embolization is generally divided into two categories: proximal and distal embolization. The choice of embolization technique is determined by the severity and location of the splenic injury. Patients who retain functioning splenic tissue after trauma do not routinely need immunization. This is in contrast to post-splenectomy patients, who are at increased risk for opportunistic infections.

Prevention and treatment of infection in patients with an absent or hypofunctional spleen: A British Society for Haematology guideline

Guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen were published by the British Committee for Standards in Haematology in 1996 and updated in 2002 and 2011. With advances in vaccinations and changes in patterns of infection, the guidelines required updating. Key aspects included in this guideline are the identification of patients at risk of infection, patient education and information and immunisation schedules. This guideline does not address the non-infective complications of splenectomy or functional hyposplenism (FH). This replaces previous guidelines and significantly revises the recommendations related to immunisation. Patients at risk include those who have undergone surgical removal of the spleen, including partial splenectomy and splenic embolisation, and those with medical conditions that predispose to FH. Immunisations should include those against Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus) and influenza. Haemophilus influenzae type b (Hib) is part of the infant immunisation schedule and is no longer required for older hyposplenic patients. Treatment of suspected or proven infections should be based on local protocols and consider relevant anti-microbial resistance patterns. The education of patients and their medical practitioners is essential, particularly in relation to the risk of serious infection and its prevention. Further research is required to establish the effectiveness of vaccinations in hyposplenic patients; infective episodes should be regularly audited. There is no single group ideally placed to conduct audits into complications arising from hyposplenism, highlighting a need for a national registry, as has proved very successful in Australia or alternatively, the establishment of appropriate multidisciplinary networks.

Preventive Proximal Splenic Artery Embolization for High-Grade AAST-OIS Adult Spleen Trauma without Vascular Anomaly on the Initial CT Scan: Technical Aspect, Safety, and Efficacy-An Ancillary Study

The spleen is the most commonly injured organ in blunt abdominal trauma. Its management depends on hemodynamic stability. According to the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS ≥ 3), stable patients with high-grade splenic injuries may benefit from preventive proximal splenic artery embolization (PPSAE). This ancillary study, using the SPLASH multicenter randomized prospective cohort, evaluated the feasibility, safety, and efficacy of PPSAE in patients with high-grade blunt splenic trauma without vascular anomaly on the initial CT scan. All patients included were over 18 years old, had high-grade splenic trauma (≥AAST-OIS 3 + hemoperitoneum) without vascular anomaly on the initial CT scan, received PPSAE, and had a CT scan at one month. Technical aspects, efficacy, and one-month splenic salvage were studied. Fifty-seven patients were reviewed. Technical efficacy was 94% with only four proximal embolization failures due to distal coil migration. Six patients (10.5%) underwent combined embolization (distal + proximal) due to active bleeding or focal arterial anomaly discovered during embolization. The mean procedure time was 56.5 min (SD = 38.1 min). Embolization was performed with an Amplatzer™ vascular plug in 28 patients (49.1%), a Penumbra occlusion device in 18 patients (31.6%), and microcoils in 11 patients (19.3%). There were two hematomas (3.5%) at the puncture site without clinical consequences. There were no rescue splenectomies. Two patients were re-embolized, one on Day 6 for an active leak and one on Day 30 for a secondary aneurysm. Primary clinical efficacy was, therefore, 96%. There were no splenic abscesses or pancreatic necroses. The splenic salvage rate on Day 30 was 94%, while only three patients (5.2%) had less than 50% vascularized splenic parenchyma. PPSAE is a rapid, efficient, and safe procedure that can prevent splenectomy in high-grade spleen trauma (AAST-OIS) ≥ 3 with high splenic salvage rates.

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.

Splenic trauma: endovascular treatment approach

The spleen is a commonly injured organ in blunt abdominal trauma. Splenic preservation, however, is important for immune function and prevention of overwhelming infection from encapsulated organisms. Splenic artery embolization (SAE) for high-grade splenic injury has, therefore, increasingly become an important component of non-operative management (NOM). SAE decreases the blood pressure to the spleen to allow healing, but preserves splenic perfusion via robust collateral pathways. SAE can be performed proximally in the main splenic artery, more distally in specific injured branches, or a combination of both proximal and distal embolization. No definitive evidence from available data supports benefits of one strategy over the other. Particles, coils and vascular plugs are the major embolic agents used. Incorporation of SAE in the management of blunt splenic trauma has significantly improved success rates of NOM and spleen salvage. Failure rates generally increase with higher injury severity grades; however, current management results in overall spleen salvage rates of over 85%. Complication rates are low, and primarily consist of rebleeding, parenchymal infarction or abscess. Splenic immune function is felt to be preserved after embolization with no guidelines for prophylactic vaccination against encapsulated bacteria; however, a complete understanding of post-embolization immune changes remains an area in need of further investigation. This review describes the history of SAE from its inception to its current role and indications in the management of splenic trauma. The endovascular approach, technical details, and outcomes are described with relevant examples. SAE is has become an important part of a multidisciplinary strategy for management of complex trauma patients.

Effect of Prophylactic Embolization on Patients With Blunt Trauma at High Risk of Splenectomy: A Randomized Clinical Trial

Importance

Splenic arterial embolization (SAE) improves the rate of spleen rescue, yet the advantage of prophylactic SAE (pSAE) compared with surveillance and then embolization only if necessary (SURV) for patients at high risk of spleen rupture remains controversial.

Objective

To determine whether the 1-month spleen salvage rate is better after pSAE or SURV.

Design, Setting, and Participants

In this randomized clinical trial conducted between February 6, 2014, and September 1, 2017, at 16 institutions in France, 133 patients with splenic trauma at high risk of rupture were randomized to undergo pSAE or SURV. All analyses were performed on a per-protocol basis, as well as an intention-to-treat analysis for specific events.

Interventions

Prophylactic SAE, preferably using an arterial approach via the femoral artery, or SURV.

Main Outcomes and Measures

The primary end point was an intact spleen or a spleen with at least 50% vascularized parenchyma detected on an arterial computed tomography scan at 1 month after trauma, assessed by senior radiologists masked to the treatment group. Secondary end points included splenectomy and pseudoaneurysm, secondary SAE after inclusion, complications, length of hospital stay, quality-of-life score, and length of time off work or studies during the 6-month follow-up.

Results

A total of 140 patients were randomized, and 133 (105 men [78.9%]; median age, 30 years [interquartile range, 23-47 years]) were retained in the study. For the primary end point, data from 117 patients (57 who underwent pSAE and 60 who underwent SURV) could be analyzed. The number of patients with at least a 50% viable spleen detected on a computed tomography scan at month 1 was not significantly different between the pSAE and SURV groups (56 of 57 [98.2%] vs 56 of 60 [93.3%]; difference, 4.9%; 95% CI, -2.4% to 12.1%; P = .37). By the day 5 visit, there were significantly fewer splenic pseudoaneurysms among patients in the pSAE group than in the SURV group (1 of 65 [1.5%] vs 8 of 65 [12.3%]; difference, -10.8%; 95% CI, -19.3% to -2.1%; P = .03), significantly fewer secondary embolizations among patients in the pSAE group than in the SURV group (1 of 65 [1.5%] vs 19 of 65 [29.2%]; difference, -27.7%; 95% CI, -41.0% to -15.9%; P < .001), and no difference in the overall complication rate between the pSAE and SURV groups (19 of 65 [29.2%] vs 27 of 65 [41.5%]; difference, -12.3%; 95% CI, -28.3% to 4.4%; P = .14). Between the day 5 and month 1 visits, the overall complication rate was not significantly different between the pSAE and SURV groups (11 of 59 [18.6%] vs 12 of 63 [19.0%]; difference, -0.4%; 95% CI, -14.4% to 13.6%; P = .96). The median length of hospitalization was significantly shorter for patients in the pSAE group than for those in the SURV group (9 days [interquartile range, 6-14 days] vs 13 days [interquartile range, 9-17 days]; P = .002).

Conclusions and Relevance

Among patients with splenic trauma at high risk of rupture, the 1-month spleen salvage rate was not statistically different between patients undergoing pSAE compared with those receiving SURV. In view of the high proportion of patients in the SURV group needing SAE, both strategies appear defendable.

Trial Registration

ClinicalTrials.gov Identifier: NCT02021396.