Long-Term Immune Function Following Splenic Artery Embolisation for Blunt Abdominal Trauma

Splenic artery embolisation for blunt splenic trauma: 10 years of practice at a trauma centre

INTRODUCTION

Splenic artery embolisation (SAE) has transformed the management of splenic trauma. The aim of this study was to review the outcomes and postprocedural management of blunt splenic trauma patients treated with SAE at a trauma centre over a 10-year period.

METHODS

Details of patients undergoing SAE for blunt trauma between January 2012 and January 2022 were acquired from a prospectively maintained database. Patient records were reviewed for demographic information, splenic injury grades, embolisation efficacy, complications, and associated injuries and mortality. Data relating to Injury Severity Scores (ISS) and postprocedural practice (vaccinations, antibiotic prescribing, follow-up imaging) were also obtained.

RESULTS

Thirty-six patients (24 male, 12 female) with a median age of 42.5 years (range 13-97 years) were identified. American Association for the Surgery of Trauma splenic injury grades were III (n = 7), IV (n = 20) and V (n = 9). Seventeen patients had isolated splenic injury and 19 had additional injuries to other organ systems. Median ISS was 18.5 (range 5-50). SAE succeeded first time in 35/36 cases, and upon the second attempt in 1/36 cases. No patients died because of splenic injury or SAE although four patients with polytrauma died owing to other injuries. SAE complications occurred in 4/36 cases. For survivors, vaccinations were administered in 17/32 cases, and long-term antibiotics were initiated in 14/32 cases. Formal follow-up imaging was arranged in 9/32 cases.

CONCLUSIONS

These data show that SAE is an effective means of controlling splenic haemorrhage secondary to blunt trauma with no patient requiring subsequent laparotomy. Major complications occurred in 11% of cases. Follow-up practice varied regarding further imaging, antibiotic and vaccination administration.

A retrospective multi-centre study of splenic volumes measured by CT following splenic artery angioembolisation for high-grade blunt splenic injuries in adults

INTRODUCTION

Splenic artery embolisation is a recognised modality in the management of high grade blunt splenic injury. The impact of embolisation on the spleen in terms of volume and function remains unclear. This results in a lack of clarity regarding post embolisation vaccination policy.

METHODS

This was a two-centre, retrospective observational study over a 24-month period involving all patients who underwent splenic artery embolisation for high grade blunt splenic trauma (AAST grades III-V). Splenic volumes were calculated from an initial CT and a repeat CT at 6 months post embolisation. Subgroup analysis was performed analysing the location of embolisation, AAST grading, and evidence of splenic dysfunction as defined by the presence of altered red cell morphology.

RESULTS

Thirty patients achieved successful splenic salvage with angioembolisation. Mean volume loss was 44.14 cm³ (P = 0.038), with decreased volumes for distal embolisation and increased volumes for proximal embolisation. Three patients had altered red cell morphology; two demonstrated recovery at 6 months, with the third lost to follow up. There were significant associations between, initial splenic volume, AAST grade of injury, and altered red cell morphology. There was no significant association between location of embolisation, initial splenic volumes, or percentage volume change.

CONCLUSION

This study demonstrated a statistically significant change in splenic volume post angioembolisation in trauma, which was associated with AAST grading but not location of embolisation. The low rate of altered red cell morphology appears transient.

Immune Function After Splenic Artery Embolization for Blunt Trauma: Long-Term Assessment of CD27+ IgM B-Cell Levels

Splenic artery embolization (SAE) plays a critical role in the treatment of high-grade splenic injury not requiring emergent laparotomy. SAE preserves splenic tissue, and growing evidence demonstrates preserved short-term splenic immune function after SAE. However, long-term function is less studied. Patients who underwent SAE for blunt abdominal trauma over a 10-year period were contacted for long-term follow-up. Sixteen participants (sex: women, 10, and men, 6; age: median, 34 years, and range, 18-67 years) were followed up at a median of 7.7 years (range, 4.7-12.8 years) after embolization. Splenic lacerations were of American Association for the Surgery of Trauma grades III to V, and 14 procedures involved proximal embolization. All individuals had measurable levels of IgM memory B cells (median, 14.30 as %B cells), splenic tissue present on ultrasound (median, 122 mL), and no history of severe infection since SAE. In conclusion, this study quantitatively demonstrated that long-term immune function remains after SAE for blunt abdominal trauma based on the IgM memory B cell levels.

Immune function and the role of vaccination after splenic artery embolization for blunt splenic injury

The spleen is the most commonly injured solid organ following blunt abdominal trauma. Over recent decades, splenic artery embolization (SAE) has become the mainstay treatment for haemodynamically stable patients with high-grade blunt splenic trauma, with splenectomy the mainstay of treatment for unstable patients. Splenic function is complex but the spleen has an important role in immune function, particularly in protection against encapsulated bacteria. Established evidence suggests that following splenectomy immune function is impaired resulting in increased susceptibility to overwhelming post-splenectomy infection, however, immune function may be preserved following SAE. This review will discuss the current state of the literature on immune function following different treatments of blunt splenic injury, and the controversies surrounding what constitutes a quantitative test of splenic immune function.

SPLEnic salvage and complications after splenic artery EmbolizatioN for blunt abdomINal trauma: the SPLEEN-IN study

BACKGROUND

As an adjunct to non-operative management, splenic artery embolization (SAE) has been increasingly utilized throughout the world and is now the standard of care for hemodynamically stable patients. This study aimed to retrospectively assess the rate of splenic salvage and complications after SAE for blunt trauma at a level 1 trauma center using the 2018 update to the AAST criteria, and further sub-stratify the role of angiography in AAST grade III injuries with significant hemoperitoneum. All patients between 1 January 2009 and 1 January 2019 who underwent blunt trauma and proceeded to embolization were included. Data was collected concerning initial injury grade, location of embolization, type of embolic material used, complications, and need for subsequent splenectomy. Technical success was defined as successful angiographic occlusion of the target artery at the conclusion of embolization. Clinical success was defined as splenic salvage at discharge. Vascular lesions were characterized including those with active bleeding, pseudoaneurysm, and arterio-venous fistula.

RESULTS

Two hundred thirty-two patients were included in the study. Treatments were performed at a median of 0 days (range 0-28 days) and the median AAST grade was IV (range III-V). Technical success was achieved in all patients. There were 13 complications (5.6%) consisting of re-bleed (9, 3.9%), infarction (3, 1.3%), and access site haematoma (1, 0.43%). Clinical success was achieved in 97% of patients with 7 patients requiring splenectomy after SAE (3.0%) at a median time of 4 days (range 0-17 days). Angiography in patients with grade III injuries identified 18 occult vascular injuries not identified at initial CT (p < 0.0001).

CONCLUSIONS

The SPLEEN-IN study shows that treatment of intermediate-high grade blunt force traumatic splenic injuries using SAE resulted in a low rate of complication and splenic salvage in 97% of patients, providing a safe and effective treatment in stable patients. In addition, angiography of grade III injuries identified occult vascular lesions and may warrant treatment of select patients in this cohort.

LEVEL OF EVIDENCE

Level 3.