Saccular splenic artery aneurysm with eccentric mural thrombus in a critically ill patient with septic shock, multiorgan dysfunction and cardiac arrest: A case report
Naba Kumar Roy1*, Gowdham Pannirselvam2
1Nursing Officer – ICU, Kauvery Hospital, Marathahalli, Bengaluru
2Sr. Nurse Educator, Kauvery Hospital, Marathahalli, Bengaluru.
*Correspondence
Abstract
Background
Splenic Artery Aneurysm (SAA) is an uncommon but potentially life-threatening visceral arterial abnormality. It may remain clinically silent and may be discovered incidentally during abdominal imaging performed for other acute conditions. Complications such as thrombosis, rupture, hemorrhage and hemodynamic instability can result in significant morbidity and mortality [1,2]. The clinical management becomes particularly challenging when SAA occurs in a critically ill patient with septic shock, acute kidney injury, chronic kidney disease, multiorgan dysfunction and cardiac arrest.
Case Presentation
A 72-year-old man with a known history of hypertension presented with abdominal pain and breathlessness and had persistent hypertension and hypoxemia. He had initially been evaluated at another hospital, where he was intubated and started on vasopressor support. Computed tomography of the abdomen and pelvis reportedly demonstrated a hypodense lesion in the caudate lobe extending toward the portal vein with minimal ascites. The patient subsequently presented to a tertiary-care hospital for further evaluation and management.
During the hospital course, he developed severe hemodynamic instability and pulseless electrical activity cardiac arrest. Cardiopulmonary resuscitation was initiated, with return of spontaneous circulation after two cycles. Further evaluation finalized septic shock, acute kidney injury on chronic kidney disease, multiorgan dysfunction syndrome and a saccular aneurysm of the splenic artery with eccentric mural thrombus. He was managed in the medical intensive care unit with mechanical ventilation, vasopressor and supportive therapy, antimicrobial treatment and close monitoring. Arterial and central venous access were established. Despite ongoing management, the patient and family elected discharge against medical advice after discussion of the clinical condition and risks.
Conclusion
This case highlights the diagnostic and therapeutic complexity of splenic artery aneurysm in a critically ill patient with septic shock and multiorgan dysfunction. Early recognition of visceral artery aneurysms on abdominal imaging is important because deterioration may occur rapidly, particularly in patients with hemodynamic instability. A multidisciplinary approach involving critical care, vascular/interventional specialists, nephrology and other relevant specialties is essential for individualized management [1,2].
Keywords: Splenic artery aneurysm; Mural thrombus; Septic shock; Multiorgan dysfunction; Cardiac arrest; Case report.
Introduction
Splenic Artery Aneurysm (SAA) is a rare vascular disorder involving abnormal dilatation of the splenic artery. Among visceral artery aneurysms, splenic artery aneurysms are among the most frequently encountered and may be increasingly detected incidentally because of the widespread use of ultrasonography, computed tomography and CT angiography. Most are clinically silent and are increasingly detected incidentally during abdominal imaging performed for other acute conditions. Complications such as thrombosis, rupture, haemorrhage and hemodynamic instability can result in significant morbidity and mortality [1,2].
A splenic artery aneurysm may be classified as a true aneurysm, involving the arterial wall, or a pseudoaneurysm, resulting from disruption of the arterial wall with containment by surrounding tissues. Morphologically, aneurysms may be fusiform or saccular. Saccular aneurysms represent focal outpouchings of the arterial wall and are clinically important because of their potential for thrombosis and rupture [1,2].
The clinical presentation of SAA varies from an incidental radiological finding to acute abdominal pain, gastrointestinal bleeding, hemodynamic instability and catastrophic intra-abdominal hemorrhage following rupture. Reported rupture risk varies across studies, and mortality can be substantial when rupture occurs [1,3].
The present case is clinically significant because the aneurysm was identified in a patient who was simultaneously experiencing septic shock, acute kidney injury on chronic kidney disease, multiorgan dysfunction and cardiac arrest requiring cardiopulmonary resuscitation. The coexistence of severe systemic illness and a visceral arterial aneurysm creates significant diagnostic and therapeutic challenges.
This case also emphasizes the importance of reviewing abdominal vascular structures carefully when imaging is performed in critically ill patients, even when the initial clinical concern is directed toward another abdominal or systemic pathology.
Anatomy of the Splenic Artery and Related Structures
Celiac trunk
The splenic artery originates most commonly from the celiac trunk, one of the major anterior branches of the abdominal aorta. The celiac trunk usually arises around the T12–L1 vertebral level and provides arterial supply to major foregut structures. Its classical branches are:
- Left gastric artery
- Common hepatic artery
- Splenic artery
The classical trifurcation pattern is present in most individuals, although anatomical variations are well documented [4,5].
Splenic artery
The splenic artery is usually the largest and one of the most tortuous branches of the celiac trunk. It travels toward the spleen along the superior/posterior aspect of the pancreas. Its tortuous anatomy has important implications for surgical and endovascular procedures [4,5].
During its course, the splenic artery gives branches supplying structures including:
- Stomach
- Pancreas
- Spleen
- Greater omentum through associated vascular branches
Near the spleen, the artery divides into terminal branches that enter the splenic hilum.
Anatomical variations in the origin, course and terminal branching pattern are relatively common. Therefore, detailed vascular imaging is important when planning intervention for a splenic artery aneurysm [4,5].
Spleen
The spleen is located in the left upper quadrant of the abdomen, beneath the left hemidiaphragm and posterior to the stomach. It is a highly vascular organ and receives its major arterial supply from the splenic artery.
The spleen performs several physiological functions:
- Filtration of circulating blood
- Removal of aged or abnormal erythrocytes
- Immune surveillance
- Antigen presentation
- Participation in humoral and cellular immune responses
- Storage of blood components
Because of its rich vascularity, disruption of the splenic arterial system can result in significant intra-abdominal hemorrhage [1,4].
Portal venous system
The portal venous system carries nutrient-rich blood from the gastrointestinal tract and spleen to the liver. The splenic vein joins the superior mesenteric vein to form the portal vein.
In the present case, the supplied medical record describes a hypodense lesion in the caudate lobe extending toward the portal vein with minimal ascites.
Physiology
The splenic artery supplies oxygenated arterial blood to the spleen. After entering the splenic hilum, the arterial branches progressively divide into smaller vessels and ultimately supply the splenic parenchyma.
The spleen participates in immune defense by removing circulating pathogens and abnormal blood cells. It also plays an important role in the clearance of senescent erythrocytes and participates in humoral and cellular immune responses [4]. The arterial system is exposed to continuous pulsatile blood pressure. Structural weakness of the arterial wall may result in progressive focal dilatation and aneurysm formation. Hemodynamic forces, inflammatory or degenerative changes, and certain systemic conditions may contribute to aneurysmal development [1,2]. When an aneurysm develops, disturbed blood flow within the aneurysmal sac can result in blood stasis and mural thrombus formation. In this patient, the imaging diagnosis specifically described a saccular splenic artery aneurysm with eccentric mural thrombus.
Pathophysiology
The development of a splenic artery aneurysm is multifactorial. Proposed mechanisms include degeneration or weakening of the arterial wall, atherosclerotic changes, inflammatory processes, portal hypertension, trauma, pregnancy-related hemodynamic changes and other vascular abnormalities [1,2].
The process can be represented as:
Arterial wall weakness
↓
Focal arterial dilatation
↓
Saccular aneurysm formation
↓
Abnormal blood flow and turbulence
↓
Blood stasis within aneurysmal sac
↓
Mural thrombus formation
↓
Potential thromboembolic or expansion-related complications
Aneurysmal rupture represents the most feared complication. Rupture can result in rapid intraperitoneal hemorrhage, hypovolemic shock and death. Published literature describes significant mortality associated with ruptured SAA [1,3].
In the present patient, the presence of eccentric mural thrombus is an important radiological characteristic. However, the available record does not establish whether the thrombus was responsible for any ischemic event, and this should not be claimed without supporting imaging or clinical evidence.
Sepsis, Septic Shock and Multiorgan Dysfunction
The patient was diagnosed with septic shock and multiorgan dysfunction. Sepsis results from a dysregulated host response to infection leading to life-threatening organ dysfunction.
In septic shock, systemic inflammation and endothelial dysfunction result in:
Infection
↓
Dysregulated immune response
↓
Inflammatory mediator release
↓
Vasodilatation + increased vascular permeability
↓
Reduced effective circulating volume
↓
Tissue hypoperfusion
↓
Cellular dysfunction
↓
Organ dysfunction
The kidneys are particularly vulnerable to hypoperfusion and inflammatory injury. In a patient with pre-existing chronic kidney disease, an additional acute insult can result in acute kidney injury on chronic kidney disease.
Current sepsis guidelines emphasize immediate recognition and resuscitation, appropriate antimicrobial treatment, hemodynamic support and continuous reassessment [6].
Case Presentation
A 72-year-old male with a known history of hypertension on regular medication presented with abdominal pain and breathlessness associated with persistent hypertension and hypoxemia.
He had initially been evaluated at another healthcare facility. According to the available clinical documentation, he was intubated and commenced on vasopressor support. CT imaging of the abdomen and pelvis reportedly showed a hypodense lesion involving the caudate lobe with extension toward the portal vein and minimal ascites.
Clinical examination
At admission, the documented vital signs included:
- Pulse: approximately 120/min
- Blood pressure: approximately 150/80 mmHg
- Respiratory rate: 30/min
- Temperature: 98.5°F
- SpO₂: 97% on 70% FiO₂
Systemic examination documented:
Respiratory system: Bilateral air entry present.
Cardiovascular system: S1 and S2 heard; no murmur documented.
Abdomen: Soft and nontender with bowel sounds present.
Central nervous system: E1V1M1 was documented. Pupils were approximately 3 mm, with the right pupil reacting and the left described as sluggishly reactive.
No cervical lymphadenopathy was documented.
Diagnostic Assessment
The principal diagnoses were:
- Septic shock
- Acute kidney injury on chronic kidney disease
- Multiorgan dysfunction syndrome
- Saccular aneurysm of the splenic artery with eccentric mural thrombus
- Cardiac arrest with cardiopulmonary resuscitation and return of spontaneous circulation
- Hypertension
The diagnosis of splenic artery aneurysm was based on imaging. The available documentation does not provide the aneurysm’s exact diameter, location along the splenic artery, CT angiographic characteristics, or evidence of rupture.
These details should be obtained from the original radiology/CT angiography report before submission because aneurysm size, morphology, location and relationship to adjacent structures are important for clinical interpretation and treatment planning [1,2].
Clinical Course and Management
During the emergency department course, the patient developed pulseless electrical activity cardiac arrest. Cardiopulmonary resuscitation was initiated and two cycles of CPR were administered, following which Return of Spontaneous Circulation (ROSC) was achieved. The patient was subsequently shifted to the medical intensive care unit for continued management. Arterial and central venous access were established. The patient received supportive treatment, intravenous fluids, antimicrobial therapy and vasoactive support as clinically indicated.
The medications documented during the hospital stay included:
- Adrenaline 1 mg IV stat, repeated as documented
- Sodium bicarbonate 100 mEq IV stat
- Calcium gluconate 10 mL IV stat
- Pause 1 g IV stat
- Vitamin K 10 mg IV
- Ceftazidime-avibactam with aztreonam
- Polymyxin
- Emrok 800 mg IV
- Pantoprazole 40 mg IV
- Hydrocortisone 50 mg IV every 6 hours
- Ipratropium/salbutamol nebulization
- Budesonide nebulization
- Tranexamic acid 1 g IV every 8 hours
The clinical team explained the severity of the patient’s condition, the potential for deterioration and the risks associated with discontinuation of hospital-based treatment. Despite these discussions, the patient/family elected to leave the hospital Against Medical Advice (AMA).
Discussion
Splenic artery aneurysms are uncommon but clinically important vascular lesions. The widespread use of cross-sectional abdominal imaging has increased the incidental detection of these lesions. Most patients are asymptomatic, but rupture can lead to catastrophic intra-abdominal bleeding [1,3]. The present case is distinctive because the SAA was identified in the setting of severe systemic illness characterized by septic shock, acute kidney injury superimposed on chronic kidney disease, multiorgan dysfunction and cardiac arrest.
The presence of an eccentric mural thrombus within a saccular aneurysm suggests altered intra-aneurysmal flow and local blood stasis. Mural thrombus is frequently encountered in aneurysmal disease, although its presence alone does not necessarily establish imminent rupture or distal embolization. The clinical importance must therefore be interpreted together with aneurysm size, morphology, symptoms, growth, anatomical location and overall patient condition [1,2]. Management of SAA depends on several factors. These include symptoms, aneurysm size, growth, anatomical location, rupture status, pregnancy status, portal hypertension, pseudoaneurysm versus true aneurysm, and the patient’s overall surgical risk. Contemporary vascular guidelines provide recommendations for visceral artery aneurysm management and describe both open and endovascular treatment strategies [2].
Endovascular approaches, including embolization and covered stent placement in selected anatomical situations, have become important treatment options. A review of SAA management reported favorable outcomes with endovascular approaches and highlighted their role in patients for whom open surgery carries significant risk [1,3]. However, management becomes considerably more complicated in a patient with septic shock and multiorgan dysfunction. Severe hemodynamic instability, renal dysfunction, respiratory failure and recent cardiac arrest may substantially increase procedural risk. In such circumstances, treatment decisions require individualized assessment involving critical care, vascular surgery, interventional radiology, nephrology and other relevant specialties. The patient’s acute kidney injury on chronic kidney disease is another important consideration. AKI is commonly associated with severe systemic illness and hemodynamic disturbances. Current KDIGO guidance continues to emphasize serum creatinine and urine output as important measures of kidney function [7].
The patient’s cardiac arrest and subsequent ROSC further complicated the clinical picture. Pulseless electrical activity may occur in the setting of profound hypoxemia, metabolic abnormalities, severe sepsis, hypovolemia or other reversible causes. In this patient, multiple simultaneous critical illnesses were present, making attribution to a single mechanism inappropriate without additional clinical and laboratory data. An important aspect of this case is the need to distinguish association from causation. The available records demonstrate coexistence of SAA with septic shock, MODS, AKI on CKD and cardiac arrest, but they do not establish that the aneurysm caused the septic shock or cardiac arrest. Similarly, the available documentation does not establish whether the hepatic/caudate lesion represented an infectious focus, ischemic lesion, neoplastic lesion or another pathology.
Therefore, the case should be presented as a complex coexistence of a visceral arterial aneurysm and critical systemic illness rather than attributing all clinical deterioration to the aneurysm.
Clinical Significance
This case provides several important clinical lessons.
Careful review of abdominal imaging is essential: Visceral arterial abnormalities can be detected incidentally during CT performed for unrelated acute abdominal or systemic conditions [1,2].
SAA can be clinically silent: The absence of classical symptoms does not exclude clinically important aneurysmal disease [1].
Mural thrombus requires careful interpretation: The presence of mural thrombus indicates altered blood flow within the aneurysm but must be interpreted together with aneurysm morphology and clinical status [1,2].
Critical illness changes management priorities: When SAA occurs together with septic shock, MODS, AKI and cardiac arrest, immediate stabilization takes priority while the aneurysm is assessed for rupture risk and feasibility of intervention [2,6].
Multidisciplinary management is essential: Critical care, vascular surgery/interventional radiology, nephrology and other specialties may need to collaborate to determine the safest treatment strategy [2].
Conclusion
This case highlights the complex clinical scenario of a saccular splenic artery aneurysm with eccentric mural thrombus in a critically ill patient with septic shock, acute kidney injury on chronic kidney disease, multiorgan dysfunction and cardiac arrest. Although the aneurysm may not necessarily have been the primary cause of the patient’s acute deterioration, its identification is clinically important because splenic artery aneurysms can have potentially catastrophic complications, particularly rupture [1-3]. Early recognition, careful radiological characterization and multidisciplinary assessment are essential. In patients with severe systemic illness, management must balance immediate stabilization with assessment of aneurysm-related risks and the feasibility of definitive vascular intervention.
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