Quick reference algorithm

Splenic Injury Management

Patients with blunt splenic injury · October 2026 edition

Blunt splenic injuryNOM pathwayAAST gradingAAST grades ↓

Blunt splenic injury identified

ATLS primary survey
FAST exam
CT abdomen/pelvis with IV contrast

Hemodynamically stable?After initial resuscitation

NOUnstable ↓YESStable · NOM ↓

Hemodynamically unstable

Non-responder or transient responder

Emergent laparotomy

Splenorrhaphy

Splenic salvage if feasible

Splenectomy

If DCS required

Vaccines after splenectomy (CDC 2025)

Pneumococcal, if no prior PCV: PCV20 or PCV21 × 1 (or PCV15 then PPSV23 ≥ 8 weeks later); prior PCV20/21: none needed
MenACWY: 2 doses ≥ 8 weeks apart; booster every 5 years
MenB: series per product (same brand for all doses); booster at 1 year, then every 2–3 years
Hib × 1 if not previously vaccinated
Annual influenza
Timing (WSES 2017): day 14 after splenectomy, or before discharge if follow-up is uncertain (CDC: as soon as stable after surgery)
OPSI prophylaxis counseling

After angioembolization: routine vaccination not recommended (EAST 2022); consider if grade V or ≥ 50% of splenic mass lost (WSES 2022).

YES

Hemodynamically stable

Non-operative management (NOM) candidate

Grade I–II

Floor

Vital signs q4h
H/H q12h until stable × 2
Serial abdominal exams
Early mobilization — no routine bed rest
Repeat CT only for clinical change

Grade III–V

ICU ≥ 24 h

Continuous HR; BP q1–2h for the first 24 h
H/H q6h × 24 h → q12h × 24 h → daily; step down only while stable
Serial abdominal exams; type & screen / crossmatch
Mobilize once H/H stable
Repeat CT (or contrast US) at 48–72 h to screen for pseudoaneurysm
Grade IV–V: consider prophylactic angioembolization

Selected stable grade III without active bleeding may go to step-down.

Monitoring follows WTA (H/H q12h until stable × 2 for grade I–II; q6h until stable × 2 with ICU ≥ 24 h for grade III–V). The q12h → daily step-down is institutional practice; no guideline specifies a taper.

VTE prophylaxis

Mechanical prophylaxis (SCDs) for all from admission
Chemoprophylaxis: grade I–III within 24 h if no active bleeding; grade IV–V 24–48 h once hemodynamically stable and H/H stable
After angioembolization: chemoprophylaxis ≈ 48 h after embolization (spleen-specific; takes precedence over the timing above)

Timing per the site VTE chart (WTA 2020 VTE; AAST/ACS-COT 2022). Spleen-specific guidelines start grade III later (WTA 2023: 24–72 h once H/H stable; WSES 2022: 48–72 h).

Active extravasation?Blush, PSA, AVF on CT

YESAngioembolization ↓NOContinue NOM ↓

Yes

Angioembolization

IR consult emergently
Proximal vs. selective embolization
Also consider for Grade IV–V even without blush (prophylactic)
VTE prophylaxis ≈ 48 h after embolization; vaccines not routinely needed (see vaccines)

Continue NOM monitoring

Serial H/H, abdominal exams
Mobilization per grade card (I–II early; III–V once H/H stable)

NOM failure triggers → operative intervention

Hemodynamic instability despite resuscitation
> 4 units pRBC in 24h
Peritonitis
Falling H/H despite transfusion
Escalating vasopressor need

Age > 55 and anticoagulated patients have higher NOM failure rates

Discharge — Grade I–II

Minimum: ≥ 24 h from injury, stable H/H, tolerating diet
No routine follow-up imaging
Normal activity at 2 weeks; all sports and strenuous activity (incl. heavy lifting) at 6 weeks

Discharge — Grade III–V

Minimum: ≥ 72 h from injury, stable H/H, tolerating diet, stable repeat CT
Normal activity at 4 weeks; all sports and strenuous activity ≥ 6 weeks by clinical judgment

Discharge — all grades

Clinic or phone follow-up 5–7 days after discharge
Return precautions

Abbreviations

AAST: American Association for the Surgery of Trauma
ATLS: Advanced Trauma Life Support
AVF: Arteriovenous fistula
CDC: Centers for Disease Control and Prevention
DCS: Damage control surgery
EAST: Eastern Association for the Surgery of Trauma
FAST: Focused assessment with sonography for trauma
H/H: Hemoglobin / hematocrit
Hib: Haemophilus influenzae type b vaccine
IR: Interventional radiology
MenACWY: Meningococcal conjugate vaccine (serogroups A, C, W, Y)
MenB: Meningococcal serogroup B vaccine
NOM: Non-operative management
OPSI: Overwhelming post-splenectomy infection
PCV: Pneumococcal conjugate vaccine; the number is the valency (PCV15, PCV20, PCV21)
PPSV23: 23-valent pneumococcal polysaccharide vaccine
pRBC: Packed red blood cells
PSA: Pseudoaneurysm
SCD: Sequential compression device
US: Ultrasound
VTE: Venous thromboembolism
WSES: World Society of Emergency Surgery
WTA: Western Trauma Association

AAST 2018 · CT imaging criteria

Spleen injury grades

Any single criterion assigns the grade.

Vascular injury or active bleeding: where it lands sets the grade (inside the splenic capsule versus beyond it into the peritoneum)

Confined within the splenic capsule

Grade IV

Beyond the spleen into the peritoneum

Grade V

Drawing key

Parenchyma and capsule
Artery
Vein
Subcapsular hematoma
Intraparenchymal hematoma
Laceration, with depth bracket
Vascular injury (pseudoaneurysm or AV fistula)
Active bleeding, contained within the capsule
Active bleeding, extending into the peritoneum
Devascularized or infarcted tissue

Labels in the drawings: PSA = pseudoaneurysm. Depth brackets measure a laceration from the capsule inward.

Grade I

AIS 2

Subcapsular hematoma < 10% surface area
Parenchymal laceration < 1 cm depth
Capsular tear

Grade II

AIS 2

Subcapsular hematoma 10–50% surface area
Intraparenchymal hematoma < 5 cm
Parenchymal laceration 1–3 cm

Grade III

AIS 3

Subcapsular hematoma > 50% surface area
Ruptured subcapsular or intraparenchymal hematoma ≥ 5 cm
Parenchymal laceration > 3 cm depth

Grade IV

AIS 4

Any injury with splenic vascular injury or active bleeding confined within the splenic capsule
Parenchymal laceration involving segmental or hilar vessels producing > 25% devascularization

Grade V

AIS 5

Any injury with splenic vascular injury and active bleeding extending beyond the spleen into the peritoneum
Shattered spleen

At operation or on pathology, grade V also includes hilar vascular injury that devascularizes the spleen.

All AAST grading scales and definitions →

Abbreviations

AAST

American Association for the Surgery of Trauma

ATLS

Advanced Trauma Life Support

AVF

Arteriovenous fistula

CDC

Centers for Disease Control and Prevention

DCS

Damage control surgery

EAST

Eastern Association for the Surgery of Trauma

FAST

Focused assessment with sonography for trauma

H/H

Hemoglobin / hematocrit

Hib

Haemophilus influenzae type b vaccine

Interventional radiology

MenACWY

Meningococcal conjugate vaccine (serogroups A, C, W, Y)

MenB

Meningococcal serogroup B vaccine

NOM

Non-operative management

OPSI

Overwhelming post-splenectomy infection

PCV

Pneumococcal conjugate vaccine; the number is the valency (PCV15, PCV20, PCV21)

PPSV23

23-valent pneumococcal polysaccharide vaccine

pRBC

Packed red blood cells

PSA

Pseudoaneurysm

SCD

Sequential compression device

Ultrasound

VTE

Venous thromboembolism

WSES

World Society of Emergency Surgery

WTA

Western Trauma Association

AAST 2018 · CT imaging criteria

Spleen injury grades

Any single criterion assigns the grade.

Vascular injury or active bleeding: where it lands sets the grade (inside the splenic capsule versus beyond it into the peritoneum)

Confined within the splenic capsule

Grade IV

Beyond the spleen into the peritoneum

Grade V

Drawing key

Parenchyma and capsule
Artery
Vein
Subcapsular hematoma
Intraparenchymal hematoma
Laceration, with depth bracket
Vascular injury (pseudoaneurysm or AV fistula)
Active bleeding, contained within the capsule
Active bleeding, extending into the peritoneum
Devascularized or infarcted tissue

Labels in the drawings: PSA = pseudoaneurysm. Depth brackets measure a laceration from the capsule inward.

Grade I

AIS 2

Subcapsular hematoma < 10% surface area
Parenchymal laceration < 1 cm depth
Capsular tear

Grade II

AIS 2

Subcapsular hematoma 10–50% surface area
Intraparenchymal hematoma < 5 cm
Parenchymal laceration 1–3 cm

Grade III

AIS 3

Subcapsular hematoma > 50% surface area
Ruptured subcapsular or intraparenchymal hematoma ≥ 5 cm
Parenchymal laceration > 3 cm depth

Grade IV

AIS 4

Any injury with splenic vascular injury or active bleeding confined within the splenic capsule
Parenchymal laceration involving segmental or hilar vessels producing > 25% devascularization

Grade V

AIS 5

Any injury with splenic vascular injury and active bleeding extending beyond the spleen into the peritoneum
Shattered spleen

At operation or on pathology, grade V also includes hilar vascular injury that devascularizes the spleen.

All AAST grading scales and definitions →