Rare constellation of abdominal vascular injuries in blunt trauma: Left gastric artery pseudoaneurysms and dissection

Highlights • Traumatic visceral artery pseudoaneurysms and dissections are typically secondary to penetrating trauma involving splenic or hepatic vessels.• Solitary left gastric pseudoaneurysm and dissection in blunt trauma are rare, and best recognized using multi-detector multiphase CTA.• Pseudoaneurysms measuring less than 2.0 cm without symptoms of persistent abdominal pain or peritoneal signs can be managed conservatively.• Conservative management involves close observation, treatment with antithrombotic agents, and optimization of medical comorbidities.


Introduction
Abdominal visceral artery vascular aneurysms include both true aneurysms, which have all three layers of the arterial wall involved, and false aneurysms, also known as pseudoaneurysms, that lack complete involvement of all arterial wall layers. Distribution of aneurysms within the abdomen mainly occur in the splenic artery (60%) and hepatic artery (20%), with only 4% of aneurysms being found in the gastric and gastroepiploic arteries [1][2][3]. We detail a patient who presented to the emergency department in a delayed fashion in hemorrhagic shock secondary to abdominal vascular injuries after motor boat incident. Pseudoaneurysm of the left gastric artery and subsequent dissection was detected on computed tomography (CT) and was managed conservatively with close observation in a monitored setting and antithrombotic agents, by multidisciplinary team.

Case report
A 79-year-old Caucasian male, with a past medical history of atrial fibrillation on warfarin and metoprolol, and coronary artery disease on atorvastatin with previous coronary artery bypass graft- * Corresponding author.
ing and placement of a dual-function pacemaker/ implantable cardioverter defibrillator (ICD), was on a motor boat in a remote location. The patient's boat went over a wake of a larger boat passing by. He bounced off his seat in a vertical direction and subsequently landed on his tailbone. After the high impact fall, he complained of both immediate lower back and diffuse abdominal pain but did not seek out urgent medical help.
Two days after the initial incident, he started to become pale and diaphoretic; additionally, his ICD delivered three shocks over a 30-min period. He presented via ambulance service to a local community hospital in hemorrhagic shock with a blood pressure of 63/22 and heart rate of 118 beats/min. A primary survey was pertinently positive for hemodynamic instability and diffuse abdominal and lower thoracic spine tenderness.
He was resuscitated with 1 L of normal saline leading to an improvement of his pressure to 106/88. Initial laboratory investigations included a hemoglobin of 95 g/L, lactate of 6.1 mmol/L, creatinine of 129, and a supratherapeutic INR of 8.8. An initial non-contrast CT abdomen and pelvis showed moderate hemoperitoneum with sentinel clot in the left upper quadrant and pericolic gutter, as well as the area adjacent to the posterior wall of the stomach. An additional finding of a severely comminuted, minimally displaced burst fracture of the T10 vertebral body was noted (Fig. 3).   Based on clinical severity, the patient was transferred to the trauma service at a tertiary-care Level 1 trauma center.
Primary survey revealed a protected airway, spontaneous and bilateral air entry, and hemodynamic stability with a blood pressure of 100/60 and a heart rate of 88 beats/min. His abdomen continued to be mildly distended and tender without peritoneal signs, however the patient reported it had improved since his original presentation to the local hospital. Repeat laboratory investigations revealed a stable hemoglobin of 94 g/L, and correction of his INR to 1.2. Given his stable condition, he underwent a CT RIPIT (Rapid Imaging Protocol in Trauma) [4] and CT angiogram (CTA) of the abdomen and pelvis. His imaging revealed pseudoaneurysms of the left gastric artery measuring up to 6 mm with another 9 mm rounded area of increased attenuation along the lesser curve of the stomach (Figs. 1 and 2). No extravasation was seen. Decision was Over the next 72 h, the patient's vital signs and abdominal exams, improved and his hematological profile remained stable. Given the patient's CHADS score of 2, it was decided to hold therapeutic anticoagulation until the patient's bleeding risk decreased, however deep venous thrombosis prophylaxis was initiated. A repeat CTA was performed to follow the evolution of the two pseudoaneurysms. The imaging study revealed unchanged pseudoaneurysms but noted the distal aspect of the left gastric artery was attenuated in keeping with a focal dissection and intramural thrombus. Secondary to the dissection, the patient was started on 81 mg of aspirin daily. Over the next few days the patient continued to improve clinically, and was discharged home. The patient lived outside of the local area, and arrangements for close follow up were made.

Discussion
We report a case of left gastric pseudoaneurysms with development of multifocal dissections secondary to a blunt traumatic injury. After initial resuscitation, the patient was hemodynamically stable without peritoneal signs, as such we elected to manage the patient conservatively with medical therapy. Since his discharge, he has remained stable and asymptomatic.
Left gastric pseudoaneurysms are uncommon, and in the context of an associated arterial dissection, where a tear forms along the intima and forms a false lumen, is exceedingly rare. Additionally, in traumatic visceral artery pseudoaneurysm cases the etiology is more frequently observed in penetrating trauma, hence our case is a unique addition to the current literature [5].
Recognizing visceral abdominal vascular injuries can be accomplished using a variety of imaging modalities. Ultrasound provides a method with no radiation exposure and is low-cost and noninvasive. However, it is most useful for larger vessels, and is limited by technician expertise and prevalence of bowel gas that obscures visualization of mesenteric and retroperitoneal vessels. Multi-detector multiphase CT is the most frequently used modality, especially in trauma, as it provides further characterization of the vascular abnormality and illustrates approaches for endovascular management [1].
Given the rare presentation of traumatic left gastric vascular injury, there are no clear guidelines regarding treatment recommendations. Management has been based on expert opinion and published case reports (Table 1) where endovascular stenting and coiling are the mainstays of treatment [6][7][8][9][10]. Nonetheless, management should be individualized to the particular case and clinical presentation.
The management of traumatic and spontaneous visceral artery dissections is dependent on patient symptomology and clinical status [11][12][13][14]. Advancement in endovascular techniques have led to many surgeons electing to use stenting as an initial approach for patients with persistent abdominal pain, peritoneal signs, aneurysms greater than 2.0 cm, or presence of bowel ischemia [12,13]. Open surgical intervention with vessel over-sew or primary repair continues to be an option for definitive management, but is usually reserved for patients who have failed endovascular management or therapeutic anti-thrombotic therapy, as it carries higher risk of morbidity for patients [11,13]. Therefore, endovascular and open surgical approaches are recommended in patients who are hemodynamically unstable, have evidence of organ necrosis secondary to dissection, or when vessel rupture is present [13].
Recently, systematic reviews show that conservative management with close monitoring, antiplatelet agents or therapeutic anticoagulation are safe, and do not negatively impact patient outcome [11][12][13][14]. Antiplatelet agents or therapeutic anticoagulation are used to stabilize the vascular wall injury and prevent thrombotic occlusion. Medical therapy does require close monitoring for development of ischemia and signs of progression of vascular injury or rupture. Additionally, they require effective management of their co-morbidities, especially hypertension. For this patient, given the delayed presentation and no clear source for the hemoperitoneum and no active extravasation on the initial CT angiogram (CTA) scan, a decision was made to repeat a CTA and monitor the pseudoaneurysm. We also elected to monitor and perform serial abdominal exams without initiation of anti-coagulation. We initiated 81 mg daily aspirin once the repeat CTA showed no evolution of the vascular injuries and no further intra-abdominal pathology.

Conclusion
In summary, blunt trauma causing two left gastric pseudoaneurysms with multifocal dissections can be managed conservatively with administration of ASA. High fidelity imaging plays an important role in management of a stable patient with blunt traumatic visceral abdominal vascular injuries. However, instability or worsening symptoms should be considered for immediate endovascular treatment or surgical ligation.

Conflicts of interest
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Funding
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Consent
The patient gave his verbal and written informed consent to be included in this report as well as for publication of anonymized data and images. This can be provided to the editors, if required.