CT-confirmed Grade 1-2 splenic injuries without evidence of active haemorrhage or pseudoaneurysm, anticoagulated patient, associated major injury, age 65 or limited physiologic reserve. - CT-confirmed Grade 1-2 splenic injuries without evidence of active haemorrhage or pseudoaneurysm, anticoagulated patient, associated major injury, age 65 or limited physiologic reserve.# TABLE OF CONTENTS

# PURPOSE
The purpose of this clinical practice guideline (CPG) is to review best evidence and generate expert consensus on recommendations for the management of isolated blunt splenic trauma in adult patients ( 5. With regard to selective versus non-selective angioembolization, what is the preferred approach to angioembolization in splenic injuries?

# III. TRANSFER TO HIGHER LEVEL OF CARE
- What are the indications for transfer of patients with blunt splenic injuries to a higher-level trauma center?
IV. ACUTE HOSPITAL CARE 7. What type and duration of monitoring are necessary for patients with blunt splenic injuries? 8. When is supplementary imaging required in the hospitalized patient?
- What activity restrictions should be imposed on patients with blunt splenic injuries, in hospital and post-discharge?

# V. VENOUS THROMBOEMBOLISM (VTE) PROPHYLAXIS
- What is the optimal timing for initiating deep vein thrombosis (DVT) prophylaxis in patients with blunt splenic injuries? The injury grade can be estimated from the radiology report. The radiologist should report: i. the presence/absence of hilar involvement, ii.
the percentage of splenic parenchymal injury/hematoma (50%), iii.
the presence of active bleeding, and iv.
presence of a pseudoaneurysm.
Generally, Grade 1 and 2 injuries are considered low grade injuries while Grade 3-5 are considered high grade injuries.

# ALGORITHM

# SUMMARY OF RECOMMENDATIONS
All recommendations are newly drafted by the Thoraco-Abdominal SAG, unless indicated otherwise.

# I. INITIAL ASSESSMENT AND MANAGEMENT
A. Initial resuscitation and management of the patient with blunt abdominal trauma should follow the Advanced Trauma Life Support (ATLS) principles.
B. In centres with surgical capability, the on-call general surgeon should be consulted promptly when a splenic injury is suspected or proven.

# II. OPERATIVE MANAGEMENT
A. In centres with general surgical capability, urgent splenectomy should be performed for a hemodynamically unstable patient with a splenic injury who is not responding to appropriate resuscitation.
B. Grade or severity of splenic injury is not, in and of itself, an indication for surgical management of the injured spleen. The decision to proceed to splenectomy should be based on the clinical presentation of the patient and situational context, which includes the capabilities of the site, resources available, presence of other injuries, transport availability, and transfer related issues.
C. A general surgeon should be involved early in decision-making for suspected or proven splenic injury. Tele-conferencing through Patient Transfer Network (PTN) to discuss optimal management (transport vs. splenectomy) should be performed. The conference call should include the sending physician, the receiving general surgeon and the receiving Trauma Team Leader (TTL) at the higher level of care (HLOC) trauma referral centre.

# III. NON-OPERATIVE MANAGEMENT
A. A trial of non-operative management (NOM) for splenic injury is indicated in patients with proven splenic injury who are hemodynamically stable after appropriate resuscitation. There are no absolute contraindications to a trial of NOM of known splenic injury in the hemodynamically stable or stabilized patient.
B. Hemodynamically stable patients with negligible risk- of ongoing or delayed hemorrhage may be safely managed, without higher level of care (HLOC) transfer, in a rural/remote facility provided at least 2 units of packed red blood cells are available. This management plan should be reviewed with a general surgeon and Trauma Team Leader (TTL) on call at the HLOC trauma referral centre in sites without surgical capabilities.
C. NOM of Grade 3-5 splenic injuries should only be considered in a hospital that has capabilities for physiologic monitoring and serial clinical evaluations by a general surgeon are possible. The hospital also needs 4 or more units of blood available, CT imaging, and 24-7 operating room access. Access to 24-7 interventional radiology for angiography/angioembolization is preferred but not essential. For transfer indications, see IV. TRANSFER TO HIGHER LEVEL OF CARE below.

# IV. ANGIOGRAPHY/ANGIOEMBOLIZATION
A. Emergent angiography/angioembolization is indicated in hemodynamically unstable patients with immediate access to interventional radiology who have responded to appropriate resuscitation and demonstrate active vascular extravasation on contrast CT. The higher level of care transfer of splenic injury patients that are or have been unstable for the purposes of urgent angioembolization is not recommended if the patient is in a centre with general surgical capability and can perform splenectomy.
B. Emergent angiography/angioembolization is indicated in hemodynamically stable patients with major free extravasation not likely to abate.
C. Angioembolization within 72 hours is indicated in hemodynamically stable or stabilized patients with pseudoaneurysm or arterio-venous fistula identified on CT or ultrasound imaging.
D. Patients with splenic injury demonstrating contrast blush on CT are at an elevated risk for failing non-operative management (NOM). The consulting surgeon and interventional radiologist should communicate once initial imaging is completed and collaborate on a management plan in the event of failure of NOM.
E. In centres without interventional radiology capability, if follow-up imaging demonstrates an indication for angioembolization, patients should be transferred under the care of a general surgeon to a higher level of care (HLOC) trauma referral centre for this procedure within 48 hours.
F. In the presence of a single vascular abnormality (contrast blush, pseudo-aneurysms, and arteriovenous fistula) in minor and moderate injuries, the currently available literature is inconclusive regarding whether proximal or distal embolization should be used. In general, selective angioembolization is preferred, where safe and feasible. 

# V. TRANSFER TO HIGHER LEVEL OF CARE (HLOC)
Immediate Transfer (< 24 hours):
A. Patients who are hemodynamically stable with associated major injuries requiring urgent higher level of care (e.g. traumatic brain injury) should be transferred promptly to a Level 1 or 2 trauma centre.
B. Hemodynamically stable patients with negligible risk- of ongoing or delayed hemorrhage may be safely managed, without higher level of care (HLOC) transfer, in a rural/remote facility provided at least 2 units of packed red blood cells are available. This management plan should be reviewed with a general surgeon and Trauma Team Leader (TTL) on call at the HLOC trauma referral centre in sites without surgical capabilities.
C. Patients with Grade 3-5 splenic injuries or associated major injury should be transferred to an appropriate trauma referral centre. Centres receiving these patients should have IR capability to facilitate angioembolization if needed. A general surgeon must be actively involved in the transfer process and the ongoing care of transferred patients.
D. The HLOC transfer of splenic injury patients that are or have been unstable for the purposes of urgent angioembolization is not recommended if the patient is in a centre with general surgical capability and can perform splenectomy.
E. For patients undergoing emergent splenectomy prior to HLOC transfer, arrangements for transfer through Patient Transfer Network (PTN) should be made as early as possible, preferably pre-operatively or intraoperatively to avoid delay.
Delayed Transfer (> 24 hours):
F. In centres without interventional radiology capability, if follow-up imaging demonstrates an indication for angioembolization, patients should be transferred under the care of a general surgeon to a HLOC trauma referral centre for this procedure within 48 hours.

# VI. ACUTE HOSPITAL CARE
A. Patients with Grade 1-2 splenic injuries can be monitored in a general surgery ward. The patient should have good IV access and assessed frequently for vital signs.
B. Patients with Grade 3-5 splenic injuries undergoing non-operative management (NOM) should be observed initially in a monitored intermediate care unit or intensive care unit (ICU). Appropriate initial monitoring includes the capacity to provide hourly vital signs as well as cardiac, oxygen saturation and urine output monitoring. Serial examination by a general surgeon is essential.
C. Hemoglobin should be monitored at regular intervals until stabilized.
D. It is recommended that therapeutic anticoagulation be reversed promptly in patients with high risk splenic injury, unless the risk of reversal is considered higher than the risk of splenic hemorrhage.
E. Repeat CT imaging in hemodynamically stable patients should be obtained within 72 hours postinjury for Grade 3-5 splenic injuries. Any changes in clinical status should prompt urgent reassessment, including laboratory investigations and/or CT as appropriate.
F. There is no need to restrict mobilization in patients with splenic injury and early mobilization is encouraged. Patients with high risk injuries- should remain supervised until assessed as safe to ambulate independently off unit.
*CT-confirmed Grade 3-5 splenic injuries, particularly with evidence of active haemorrhage or pseudoaneurysm, anticoagulated patient, associated major injury, age 65 or limited physiologic reserve.
G. Post-discharge, patients with Grade 3-5 splenic injuries should avoid contact sports or vigorous activities for at least 8 weeks. Patients with Grade 3-5 splenic injuries should be re-imaged prior to resuming high-risk activities.

# VII. VENOUS THROMBOEMBOLISM (VTE) PROPHYLAXIS
A. Pharmacologic prophylaxis to prevent venous thromboembolism (VTE) can be used for patients with isolated blunt splenic injuries without increasing the failure rate of non-operative management. Although the optimal timing of safe initiation has not been determined, deep vein thrombosis (DVT) prophylaxis may be started as soon as possible after trauma and within 12 hours for every Grade of splenic injury (e.g. 36 hours for Grade 3 injury) or sooner if hemoglobin is stable.  B. Mechanical prophylaxis should be used in all patients with absolute contraindication to pharmacologic prophylaxis, except in patients with lower extremity trauma in which case mechanical prophylaxis is not efficacious. 

# SCIENTIFIC DISCUSSION
All recommendations are newly drafted by the Thoraco-Abdominal SAG, unless indicated otherwise. 

# I. INITIAL ASSESSMENT AND MANAGEMENT

# II. OPERATIVE MANAGEMENT

# KMQ-2. What are the indications for operative management (OM) of blunt splenic injuries? RECOMMENDATIONS
A. In centres with general surgical capability, urgent splenectomy should be performed for a hemodynamically unstable patient with a splenic injury who is not responding to appropriate resuscitation.
B. Grade or severity of splenic injury is not, in and of itself, an indication for surgical management of the injured spleen. The decision to proceed to splenectomy should be based on the clinical presentation of the patient and situational context, which includes the capabilities of the site, resources available, presence of other injuries, transport availability, and transfer related issues.
C. A general surgeon should be involved early in decision-making for suspected or proven splenic injury. Tele-conferencing through Patient Transfer Network (PTN) to discuss optimal management (transport vs. splenectomy) should be performed. The conference call should include the sending physician, the receiving general surgeon and the receiving Trauma Team Leader (TTL) at the higher level of care (HLOC) trauma referral centre. 

# KNOWLEDGE SYNTHESIS

# Additional Literature Support

# What is the success rate of non-operative management of blunt splenic injuries?
Overall reported success rate of observational management (without angiography) is 92-96 %. 3,4,5,6  Recent success rate of non-operative management (NOM) (i.e. observational management only + NOM with angioembolization) has been reported in the range of 93-100 %. 6,8 

# Success rate of observational management of blunt splenic injury by injury grade

# What are the complications of non-operative management of blunt splenic injury?
Complications in NOM in blunt splenic injury include progression to splenectomy, hemodynamic instability and/or evidence of ongoing bleeding, and delayed laparotomy for missed associated injury, resulting in re-admission or emergency laparotomy.
Overall reported failure rate of NOM is 4-15 % (according to a 2017 review of studies published 2000 onwards 9 ), with higher rates reported for high grade injuries: 

# What is the risk (probability) of delayed hemorrhage following non-operative management of splenic injuries?
Probability of delayed hemorrhage after NOM ranges from 0-15 % 6,16,17, with a higher probability in higher Grade injuries. 2 It is difficult to distinguish between delayed hemorrhage and hemorrhage that was missed on the initial CT. This is particularly the case with older studies that used older CT technology. For this reason, more recent studies that clearly indicate delayed hemorrhage have been consulted.

# What is the rate of spontaneous resolution of active hemorrhage detected as contrast blush on initial CT scan?
Probability of blush detected on CT leading to absence of extravasation on angiography ranges from 2.3-47 % 18,19,20 One retrospective study showed 100% (3/3) patients with contrast blush on initial CT had no blush on post-transfer repeat CT. 19 Conservatively estimated, NOM of splenic injury results in a success rate of >98% for Grade 1-2 injuries, >90% for Grade 3 injuries, and >75% for Grade 4-5 injuries. Angiography is variably used to achieve these rates. 

# IV. ANGIOGRAPHY / ANGIOEMBOLIZATION

# Additional Literature Support

# What is the success rate of angiography/angioembolizations in blunt splenic injuries?
Success rate of AG/AE range from 73-100%. 21 In severe injuries (Grades 4-5), difference in success rate between NOM with and without angioembolization can be as great as 78.4 %. 6 Failure rate of NOM without AG/AE can be as high as 26% in these injuries. 22 Conflicting evidence exists for the benefits of angioembolization in preventing splenectomy. 23,24 What are the complications of angiography/angioembolizations in blunt splenic injuries?
Major complications of AE include: delayed bleeding, total or subtotal splenic infarction, splenic abscesses, acute renal insufficiency, pseudocysts, and puncture-related complications. Rate of major complications range from 3.7-28.5 %. 1,2 Minor complications include fever, pleural effusion, coil migration, and partial splenic infarction. Rate of minor complications range from 23-61 %. 1,2 No randomized control trials exist comparing morbidity related to AG/AE and NOM without AG/AE.
A large prospective study found AG/AE-related morbidity of 47% compared to morbidity of 10% in NOM without AG/AE. 6 A large study of post-discharge complications in patients who received NOM found higher rate of thirty-day readmission among patients who received NOM with AE than patients who did not receive AE (12.8% vs. 7.4%, p=0.002). 25 KMQ-5. With regard to selective versus non-selective angioembolization, what is the preferred approach to angioembolization in splenic injuries?

# RECOMMENDATIONS
F. In the presence of a single vascular abnormality (contrast blush, pseudo-aneurysms, and arteriovenous fistula) in minor and moderate injuries, the currently available literature is inconclusive regarding whether proximal or distal embolization should be used. In general, selective angioembolization is preferred, where safe and feasible. 

# KNOWLEDGE SYNTHESIS
External Recommendations SAG's Rationale  In the presence of a single vascular abnormality (contrast blush, pseudo-aneurysms, and artero-venous fistula) in minor and moderate injuries, the currently available literature is inconclusive regarding whether proximal or distal embolization should be used. In the presence of multiple splenic vascular abnormalities or in the presence of a severe lesion, proximal or combined AG/AE should be used, after confirming the presence of a permissive pancreatic vascular anatomy.  Adopted first sentence. Replaced second sentence with preference for selective (i.e. proximal) angioembolization due to fewer minor complications reported in retrospective cohort studies (see below).

# Additional Literature Support

# What is the effectiveness of selective versus non-selective angioembolization? What are the complications?
No prospective studies or randomized controlled trials available on the subject.
No significant difference observed in overall failure rate between distal and proximal embolization.
No significant difference has been observed between proximal and distal embolization for incidence of major infarctions, infections or re-bleeding.
Higher rate of minor complications has been reported in distal than in proximal embolization (see C. Patients with Grade 3-5 splenic injuries or associated major injury should be transferred to an appropriate trauma referral centre. Centres receiving these patients should have IR capability to facilitate angioembolization if needed. A general surgeon must be actively involved in the transfer process and the ongoing care of transferred patients.
D. The HLOC transfer of splenic injury patients that are or have been unstable for the purposes of urgent angioembolization is not recommended if the patient is in a centre with general surgical capability and can perform splenectomy.
E. For patients undergoing emergent splenectomy prior to HLOC transfer, arrangements for transfer through Patient Transfer Network (PTN) should be made as early as possible, preferably pre-operatively or intraoperatively to avoid delay.
Delayed Transfer (> 24 hours):
F. In centres without interventional radiology capability, if follow-up imaging demonstrates an indication for angioembolization, patients should be transferred under the care of a general surgeon to a HLOC trauma referral centre for this procedure within 48 hours.

# KNOWLEDGE SYNTHESIS External Recommendations SAG's Rationale
None Recommendations regarding transfer to higher level of care were drafted, based on provincial realities and the expert opinion of the SAG. C. Hemoglobin should be monitored at regular intervals until stabilized.

# VI. ACUTE HOSPITAL CARE
D. It is recommended that therapeutic anticoagulation be reversed promptly in patients with high risk splenic injury, unless the risk of reversal is considered higher than the risk of splenic hemorrhage. 

# KNOWLEDGE SYNTHESIS

# Additional Literature Support

# What is the incidence of delayed splenic pseudoaneurysm formation by injury grade? Timing of formation?
Overall rate of incidence of delayed splenic pseudoaneurysm formation ranges from 3.0-15.4 % 17,28,29,30,31,32 to as high as 74 %. 33 A retrospective multicenter study 30 found incidence of delayed splenic pseudoaneurysm formation in 17.7 % of patients treated with initial observation and 11.9 % of patients treated with early angioembolization.   D. Regarding infection prophylaxis in asplenic and hyposplenic adult patients:  immunization against seasonal flu is recommended;  malaria prophylaxis is strongly recommended for travellers;  antibiotic therapy should be strongly considered in the event of any sudden onset of unexplained fever, malaise, chills or other constitutional symptoms, especially when medical review is not readily accessible; and  primary care providers should be aware of the splenectomy/angioembolization. Adopted and combined the two statements into one recommendation.

# VIII. OVERWHELMING POST-SPLENECTOMY INFECTION PROPHYLAXIS

# Other vaccination indications
Adopted and combined the four statements into one recommendation for easier reading.

# KNOWLEDGE SYNTHESIS External Recommendations SAG's Rationale
None available With lack of scientific evidence or external clinical guidance on the management of delayed splenic pseudoaneurysms, a new recommendation was developed based on the SAG's expert opinion.

# RECOMMENDATIONS
F. There is no need to restrict mobilization in patients with splenic injury and early mobilization is encouraged. Patients with high risk injuries- should remain supervised until assessed as safe to ambulate independently off unit.
*CT-confirmed Grade 3-5 splenic injuries, particularly with evidence of active haemorrhage or pseudoaneurysm, anticoagulated patient, associated major injury, age 65 or limited physiologic reserve.
G. Post-discharge, patients with Grade 3-5 splenic injuries should avoid contact sports or vigorous activities for at least 8 weeks. Patients with Grade 3-5 splenic injuries should be re-imaged prior to resuming high-risk activities.

# KNOWLEDGE SYNTHESIS External Recommendations SAG's Rationale
- Activity restriction may be suggested for 4-6 weeks in minor injuries and up to 2-4 months in moderate and severe injuries.
 New recommendation has been created, based on recent evidence (see below) and expert opinion of the SAG.

# Additional Literature Support

# What is the risk of delayed hemorrhage in blunt splenic patients without activity restrictions?
Several recent studies have shown no association between early mobilization with minimal bed rest and delayed splenic hemorrhage both in adult 16,36,37,38 and pediatric 39,40,41 patients with blunt splenic injuries managed via NOM.

# Additional Literature Support

# What is the risk of developing thrombosis VTE prophylaxis after blunt splenic injuries?
A prospective study (n=147) found 5 % risk of developing VTE after trauma-related splenectomy. 42 A large retrospective study (n=6,162) found 1.97 times greater risk of VTE in splenic injury than in control, with a rate of 10.08 per 10,000 person-years (8.46 no splenectomy, 11.81 splenectomy). 43 A large prospective study (n=675) found increased risk for VTE with splenectomy (AOR 2.6, 95% CI 1.2 to 5.9). 44

# What is the incidence of hemorrhage in splenic patients with/without VTE prophylaxis?
Several retrospective studies indicate low-molecular weight heparin (LMWH) administration does not increase the failure rate of NOM 45,46 or increase the risk of bleeding events. 47

# External Recommendations SAG's Rationale
- Regarding infections prophylaxis in asplenic and hyposplenic adult and pediatric patients, immunization against seasonal flu is recommended for patients over 6 months of age.   Regarding infections prophylaxis in asplenic and hyposplenic adult and pediatric patients, Malaria prophylaxis is strongly recommended for travelers.   Regarding infections prophylaxis in asplenic and hyposplenic adult and pediatric patients, antibiotic therapy should be strongly considered in the event of any sudden onset of unexplained fever, malaise, chills or other constitutional symptoms, especially when medical review is not readily accessible.   Regarding infections prophylaxis in asplenic and hyposplenic adult and pediatric patients, primary care providers should be aware of the splenectomy/ angioembolization. 

# Additional Literature Support

# What is the risk of overwhelming post-splenectomy infection (OPSI) with splenectomy or splenic embolization after splenic injury?
Risk of overwhelming post-splenectomy infection (OPSI) with splenectomy or splenic embolization ranges from 0.05-23 %, 2,48 with the majority of infections occurring more than 2 years following the procedure. 49 A large retrospective study (n= 4,360) of blunt splenic trauma patients in California reported short-and long-term infectious complications by procedure 50 : 

# What is the optimal timing of vaccination?
All vaccines are best administered 2 weeks after surgery. If the patient is discharged earlier and there is concern that they might not return for follow-up, vaccines should be administered prior to discharge. 51 

# What is the effectiveness of vaccination? What is the effectiveness of repeat vaccination? Effectiveness and administration schedule of vaccination in asplenic/hyposplenic adults

# Additional Literature Support
For risk of delayed hemorrhage after non-operative management of blunt splenic injury, see page 17.
For the risk and timing of pseudoaneurysm formation after non-operative management of blunt splenic injury, see p. 24.

# KMQ-13.
What is the preferred management of delayed pseudoaneurysm?

# RECOMMENDATIONS
C. If a new pseudoaneurysm is noted on follow-up imaging, discussion with general surgery is recommended to determine best management, e.g. serial imaging vs. embolization.