Combined traumatic pulmonary and splenic pseudoaneurysms: what would you do?

Case presentation

A patient in their 60s was involved in a lateral-impact car crash on an offshore island in Taiwan. The patient was transported to a local emergency room (ER). On arrival at the ER, the patient’s initial vital signs were as follows: temperature 36°C, pulse 95 beats per minute, respiratory rate 20 breaths per minute, blood pressure 102/66 mm Hg, Glasgow Coma Scale score E4V5M6, and oxygen saturation (SpO_₂) 99%. The patient’s chief complaints were pain in the left lower chest, left flank, and left hip, accompanied by mild tachypnea and shortness of breath. Chest and abdominal CT (non-contrast and venous phases only) revealed multiple left rib fractures from the left 3rd to the 12th rib with flail segment, left hemopneumothorax, consolidation in the left lower lung without obvious vascular lesions, and a grade III splenic laceration. A stable type of pelvic fracture without contrast extravasation was also noted.

The patient received a chest tube, tranexamic acid, and blood products and was admitted to the intensive care unit (ICU). During the ICU stay, the patient remained hemodynamically stable without further blood transfusion. On hospital day 3, follow-up dynamic CT with arterial phase was performed due to concern for delayed vascular injuries. Surprisingly, this scan revealed a pseudoaneurysm in the left lower lobe pulmonary artery (figure 1) and splenic artery pseudoaneurysm (figure 2).

Figure 1. Follow-up contrast-enhanced dynamic chest and abdominal CT. Pulmonary artery pseudoaneurysm at the left lower lobe (LLL) is demonstrated in multiple phases. (a) Axial arterial phase showing focal contrast extravasation (arrow). (b) Lung window image revealing adjacent parenchymal consolidation (arrow). (c) Axial venous phase confirming the pseudoaneurysm (arrow). (d) Coronal venous phase view further delineates the vascular lesion (arrow).

Figure 2. Follow-up contrast-enhanced dynamic abdominal CT of the spleen. Dynamic CT reveals two distinct vascular lesions within the spleen. (a) Arterial phase shows a hyperenhancing lesion at the lower pole (arrow), compatible with a splenic artery pseudoaneurysm. (b) Corresponding venous phase image demonstrates early washout of the same lower pole lesion (arrow). (c) Arterial phase reveals a second enhancing lesion at the upper pole (arrow), suspicious for either a pseudoaneurysm or arteriovenous (A–V) shunt. (d) Venous phase shows persistent but reduced enhancement of the upper pole lesion (arrow), without definitive distinction between pseudoaneurysm and A–V shunting.

At this point, the patient remained hemodynamically stable and had no hemoptysis or abdominal symptoms.

What would you do?

Note: Neither embolization nor surgical stabilization of rib fractures (SSRF) is available in the offshore local hospital; however, the patient can be transferred to another facility for these procedures if indicated.

1. Observation for both splenic pseudoaneurysm and pulmonary artery pseudoaneurysm (PAP).

2. Transarterial embolization for both splenic pseudoaneurysm and PAP.

3. Splenectomy combined with SSRF and pulmonary lesion wedge resection.

4. Transarterial embolization of the splenic pseudoaneurysm combined with SSRF and pulmonary lesion wedge resection.

5. Other: any combination of observation, embolization, or surgery for the splenic and pulmonary lesions.

What we did and why (answer: 2)

Given the risk of rupture from either lesion and the potential for clinical deterioration, we arranged urgent air transfer to a tertiary trauma center with endovascular capabilities. On arrival (hospital day 3), the interventional radiologist prioritized the splenic artery pseudoaneurysms for embolization. Angiography revealed lesions in both upper and lower poles of the spleen, and successful embolization was achieved using coil occlusion of the splenic artery trunk and selective branches. We chose embolization over observation due to the high risk of non-operative failure in pseudoaneurysms and avoided splenectomy to preserve spleen function and reduce overwhelming postsplenectomy infection risk.^{1 2}

Pulmonary embolization was deferred due to the lack of a specialist that day. The following day, pulmonary angiography via femoral venous access was performed. A pseudoaneurysm arising from a segmental branch of the left lower lobe pulmonary artery was embolized using microcoils, with no residual contrast extravasation (figure 3). Although the rebleeding rate of untreated PAP remains unclear, and some case reports have shown successful outcomes with observation alone, we proceeded with embolization to prevent potential bleeding.^{3 4} A combined approach of SSRF and wedge resection of the PAP was an alternative treatment, but localizing the PAP can pose a challenge.

Figure 3. Pulmonary angiography and transarterial embolization of a pulmonary artery pseudoaneurysm. (a) Selective pulmonary artery angiography demonstrates a pseudoaneurysm arising from a segmental branch of the left lower lobe pulmonary artery (arrow). (b) Postembolization angiogram confirms successful occlusion of the pseudoaneurysm using microcoils, with no further contrast extravasation.

The patient recovered well, and intercostal nerve block with radiofrequency ablation was provided for pain control. The patient was discharged on hospital day 14 in stable condition. No complications occurred.

Discussion

PAP is a rare condition, most commonly arising from infection, primary or metastatic lung neoplasms, traumatic injury, or vasculitis.⁵ There were only case reports for traumatic PAP.^{4 6 7} Traumatic PAPs are classified as intravascular, typically catheter related (especially Swan-Ganz), or extravascular.⁸ Extravascular PAPs, similar to our case, most often result from penetrating trauma such as stab wounds or gunshot injuries.³ Because of their low incidence and the absence of large-scale studies, specific risk factors remain poorly defined and warrant further investigation. The clinical manifestations of PAP are non-specific. Hemoptysis is the most well-known symptom, while others may present with chest pain, dyspnea, or coughing.⁷ Most cases of PAP are detected through CT angiography, which is the preferred diagnostic modality.⁹ Angiography is considered the gold standard, as it provides both diagnostic and therapeutic capabilities in a single examination.¹⁰ The treatment options for PAP are not standardized. Most patients undergo endovascular treatment, while some have been managed with surgical wedge resection.^{7 11} Some studies have even reported spontaneous resolution or thrombosis of PAP after observation alone.⁴ The choice between surgical intervention and non-operative management, including endovascular treatment, depends on the patient’s stability.³ Endovascular embolization may reduce anesthesia-related risks compared with surgery, but pseudoaneurysms can rupture during the procedure, and complications such as lung infarction or abscess may occur.^{5 10} The optimal strategy remains uncertain due to the lack of large-scale comparative data.

This case illustrates several learning points. First, delayed vascular lesions such as pseudoaneurysms can develop even when initial imaging is negative. In our case, the absence of an arterial phase on the initial scan likely contributed to the missed findings. Based on this, we suggest that follow-up CT with arterial phase be considered in selected high-risk trauma patients within 72 hours. For splenic injuries, this includes patients with moderate to severe lesions (American Association for the Surgery of Trauma-Organ Injury Severity (AAST-OIS) grade ≥III) or those with a decreasing hematocrit.¹² For thoracic injuries, there is no established definition of high-risk patients. Potential features may include high-grade (AAST-OIS grade ≥III) pulmonary trauma, pulmonary hematocele, persistent hemoptysis, or injuries adjacent to major pulmonary vessels; however, current practice remains uncertain due to the lack of evidence-based criteria.

Second, the concurrent presence of both PAP and splenic pseudoaneurysms in blunt trauma is exceedingly rare, with no previous reports of such a combination to our knowledge. Both lesions were successfully treated with endovascular embolization. The discovery was incidental, but timely intervention likely prevented potentially catastrophic bleeding.