The spleen is one of the most commonly injured organs in blunt abdominal trauma, accounting for 49% of all visceral injuries. Physical examination and laboratory data are often nonspecific in the diagnosis of splenic injury.

Contrast-enhanced computed tomography (CT) is currently the imaging tool of choice for the evaluation of hemodynamically stable patients with accidental splenic injury with high-speed, wide application, high accuracy, and high accuracy. diagnostic accuracy and relatively non-invasive nature. CT scans can also accurately assess simultaneous abdominal injuries, such as retroperitoneal and abdominal wall injuries, and can rule out the presence of surgical injuries, such as bowel or pancreatic trauma. .

The use of CT has influenced the current trend in the management of splenic injuries towards nonsurgical management. Although the decision to use surgical intervention is often based on clinical criteria rather than imaging features, data from CT scans often increase the surgeon’s diagnostic confidence and play an important role in reduce the frequency of unnecessary exploratory laparotomy.

CT features of contusion-induced splenic injury

The main CT features of concussion-induced splenic injury are lacerations, nonperfusional areas, subcapsular and intraparenchymal hematomas, active bleeding, intra-abdominal hemorrhage (haemoperitoneum) and blood vessel damage. Tear lines and hematomas or contusions in the parenchyma can be clearly visualized using contrast-enhanced CT (Figures 1 and and 2).

Subcapsular haematomas appear as elliptical effusions consisting of low-density blood between the spleen and the spleen parenchyma that captures the contrast agent causing indentation or flattening of the underlying spleen. Free intraperitoneal blood in the perisplenic space did not exert this effect on the underlying splenic parenchyma (Figure 3).

Figure 1. Splenic tear line seen on contrast-enhanced CT scan with irregular hypoattenuating line (arrow). This was demonstrated intraoperatively in a 15-year-old male patient injured in a motorcycle accident. The patient made a stable recovery after splenectomy.

Figure 2. Intraparenchymal hematoma (arrow) seen on imaging CLVT with injection of contrast agent with localized hypodense areas in the splenic parenchyma taking drugs to increase concentration cover intact. This patient was traumatized in a motorcycle crash and was treated conservatively.

Figure 3a. A subcapsular hematoma (arrow) is seen with a perisplenic fluid collection concave the underlying parenchyma.

Figure 3b. Persplenic hematoma (arrow) is seen with perisplenic fluid collection without mass effect up adjacent parenchyma.

Intraperitoneal bleeding can be detected accurately on CT scans. When the patient is in the supine position, blood from the splenic injury passes through the diaphragm-colic ligament to the left paracolic fissure and the iliac fossa. Blood may also enter the right upper quadrant of the abdomen (Figure 4). In the past, intraperitoneal blood volume was considered a prognostic factor for the need for surgery in patients with splenic injury due to splenic injury. stamping; however, recent reports have detailed how successful nonsurgical treatment has been in patients with large amounts of intraperitoneal blood.

Active bleeding presents with a high-density area on CT with values ​​ranging from 85–350 HU due to extravasation of contrast agent (Figure 5). Contrast extravasation occurs in approximately 17.7% of patients with splenic injury and is a significant prognostic factor of conservative treatment failure.

Figure 4. Intraperitoneal haemorrhage due to splenic trauma in a 30-year-old male patient following assault. CT scan shows massive intra-abdominal bleeding (arrow) due to hilar splenic tear. This was confirmed intraoperatively with a blood loss of 1L. There were no other intra-abdominal lesions.

Figure 5. Active bleeding from splenic injury seen with contrast extravasation (arrow) in an 18-year-old male patient with a motorcycle accident. Approximately 2 L of blood loss was observed intraoperatively and splenectomy was performed for this patient.

CT .-based lesion classification system

Various CT-based classification systems have been developed for the assessment of splenic injury, with the goal of standardizing reporting, planning appropriate treatment, and allowing comparisons between facilities and studies. However, there is no classification system that correlates well with the need for surgical intervention. More recently, a better correlation between the newly proposed CT classification system and surgical intervention has been achieved if important CT features such as active bleeding, pseudoaneurysm, arteriovenous fistula, and arteriovenous fistula are obtained. The severity of intraperitoneal bleeding was included in the classification system. Radiologists should be familiar with CT-based classification systems to facilitate research and networking with surgeons. The most widely used CT grading system for splenic injury in trauma patients is based on the AAST scale (Table 1). The injuries mentioned in this article are classified as grade I (Figures 6 and 7), grade II (Figures 8–10), grade III (Figures 11–13), grade IV (Figure 14), or grade V (Figures 15 and 16).

Figure 6. Grade I splenic injury in a 17-year-old female patient in a motorcycle accident. Coronal reconstruction CT scan shows a 1-cm inferior capsule tear at the lower pole (arrow). The patient was treated conservatively with a stable recovery. Note the small accumulation of fluid around the spleen.

Figure 7. Grade I splenic injury in a 35-year-old male patient with an occupational accident. CT scan with injection contrast on The axial view shows a subcapsular hemorrhage (arrow) of less than 10% of the surface area. The patient was treated conservatively and recovered well.

Figure 8. Grade II splenic injury in a 13-year-old male patient with post-fight injury. CT scan shows a subcapsular hematoma occupying 30%–40% of the splenic surface area (arrow). The patient was treated conservatively and recovered stably.

Figure 9. Grade II splenic injury in a 14-year-old female patient with a motorcycle accident. A CT scan performed 2 days after the accident showed an intraparenchymal hematoma (arrow) < 4 cm in diameter and no capsular tear. Surgery was performed in this case because of the ongoing blood loss. There was laceration of the left broad ligament and bleeding from the branches of the left ovarian artery (image not shown). The sheath of the spleen is intact.

Figure 10. Grade II splenic injury in a 30-year-old male patient after assault. Take a shot CLVT shows a 2 cm laceration in the hilum of the spleen (arrow) confirmed intraoperatively.

Figure 11. Grade III splenic injury in a 15-year-old male patient injured during a football match. Take a shot CLVT with contrast injection above Axial view shows multiple lacerations and intraparenchymal hematomas (arrows). The patient was treated conservatively and recovered completely.

Figure 12. Grade III splenic injury in a 32-year-old patient in a motorcycle accident. Contrast-enhanced CT scan in axial view shows multiple intraparenchymal tears with subcapsular hematoma (arrow). Splenectomy was performed with a blood loss of 300 mL.

Figure 13. Grade III splenic injury in an 18-year-old male patient who was injured when a motorbike hit a buffalo. Take a shot CLVT Contrast injection on axial view shows superior pole tear (arrow). Surgical results confirmed a 6 cm long laceration with approximately 1 L of intra-abdominal blood. Splenectomy was performed.

Figure 14. Grade IV splenic injury in a 17-year-old male patient injured in a motorcycle accident. Take a shot CLVT Coronal reconstruction shows a large area of ​​devascularisation in the spleen. Splenectomy was performed for this patient.

Figure 15. Grade V splenic injury in an 18-year-old male patient after his motorcycle collided with a truck. Take a shot CLVT An axial contrast injection showed a ruptured spleen with massive intra-abdominal bleeding that was confirmed intraoperatively. Note the focal area of ​​high attenuation (arrow) due to active bleeding. Splenectomy was performed for this patient.

Figure 16. Grade V splenic injury in a 17-year-old male patient with a motorcycle accident. Take a shot CLVT The axial view shows the spleen is not perfused on contrast-enhanced imaging. Persplenic hyperattenuation (short arrow) due to contrast extravasation. The patient also had left kidney injury (long arrow).

Table 1: Classification of splenic injuries as recommended by the American Society for Trauma Surgery (AAST), revised 1994.

Advance one grade for multiple injury (up to Grade III)

Simplified diagram depicting injuries for each grade of splenic injury according to the 2018 AAST organ injury update.

CT features of late complications

There are a few complications associated with splenic injury. Late complications of splenic injury occur at least 48 hours after the initial injury and include pseudocyst, abscess, pseudoaneurysm, and late rupture. Late splenic rupture has been reported to occur in approximately 5%–6% of adults treated conservatively. Posttraumatic pseudocysts were reported in 0.44% of patients with splenic injury. Splenic abscess formation is a rare complication of blunt trauma (Figure 17). However, as conservative treatment tends to continue, this rare complication may become more common. Posttraumatic splenic artery pseudoaneurysm is also a rare complication that can occur after splenic trauma of any degree.

Figure 17. Splenic abscess as a complication of splenic trauma in a 43-year-old male patient. The patient reported about 1 week after the injury unremarkable with persistent abdominal pain. CT scan showed an intraparenchymal hematoma with multiple internal air sacs; This was confirmed intraoperatively.

Role of CT follow-up in splenic injury

Follow-up imaging can provide valuable information about the healing patterns of the spleen. CT scans showed clear complete healing of half of splenic injuries after 6 weeks. Complete healing of all degrees was observed 3 months after injury.

However, this information has not been shown to have a significant effect on trauma management or on patient outcomes, and therefore, follow-up CT scanning is not currently recommended.

Conclusion

The shift towards nonsurgical management of contusion-induced splenic injury in clinically stable trauma patients has been made possible by the widespread use of CT as imaging assessment. initial. CT scan accurately depicts different types of splenic injury and other important surgical features. Knowledge of the features of splenic lesions on CT is important for both radiologists and surgeons for optimal patient care.

References

Computed Tomography of Blunt Spleen Injury: A Pictorial Review

BS. LE THI NY NY – Nguyen Tri Phuong Hospital

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