Clinically Silent Multi-Territory Aneurysms in Cadavers: A Case Report and Literature Review

Abstract

Aneurysms are permanent, focal dilations of vessels that are ≥150% of normal diameter. While single aneurysms are relatively common, the presence of multiple aneurysms in different vascular territories is uncommon, and consolidated discussions of such cases remain limited. We report the case of a 96-year-old male cadaver with extensive but clinically silent aortic aneurysms identified during routine anatomical dissection. A large abdominal tumor was also noted compressing the right renal artery. Additionally, we review published reports of multi-territory aneurysms, which highlight the heterogeneity in patients and presentation types, including genetic disorders that lead to aneurysmal disease. Rupture risk is multifactorial, influenced by size, morphology, multiplicity, growth rate, and thrombus burden. Multi-territory aneurysmal disease, though rare, represents a clinically significant entity that may remain undetected until rupture or incidental discovery. Four domains emerge as central to management: screening, risk factor modification, genetic considerations, and counseling. This cadaveric case illustrates the breadth of aneurysm presentations and reinforces the importance of broad screening strategies in their surveillance. It also highlights the roles of risk reduction, genetic evaluation, and patient-centered counseling in reducing morbidity and mortality from this often silent vascular pathology.

Introduction

Aneurysms represent aneurysmal dilations or enlargements of arteries that occur when the vessel wall loses structural integrity. Formally, an aneurysm is defined as a permanent and focal dilation of an artery measuring ≥150% of its normal diameter. ¹ The development of aneurysms reflects a combination of intrinsic arterial wall vulnerability and extrinsic hemodynamic stress. Degeneration of structural components of the vascular wall – particularly elastin and collagen – reduces the vessel’s ability to withstand pulsatile pressure, while high-flow and high-pressure environments further promote progressive dilation. ¹ This interaction explains the predilection of aneurysms for regions exposed to significant hemodynamic stress, such as the abdominal aorta and arterial bifurcations including the circle of Willis. ¹

Most aneurysms occur as isolated lesions and are frequently associated with atherosclerotic disease, advanced age, and male sex. ¹ However, aneurysms may also arise from infectious, inflammatory, traumatic, or congenital etiologies. ² In some patients, aneurysmal disease manifests in multiple vascular territories. While the presence of 2 aneurysms is not uncommon, extensive aneurysmal disease involving several arterial regions remains relatively rare. ³ The occurrence of multiple aneurysms often reflects systemic factors affecting vascular integrity, including connective tissue disorders, vasculitides, and genetic aortopathies. ² Conditions such as Marfan syndrome, Ehlers-Danlos syndrome, Loeys-Dietz syndrome, and certain somatic mutations affecting vascular signaling pathways may weaken the arterial wall throughout the vascular tree, predisposing patients to multi‑territory aneurysmal disease. ²

Despite these associations, reports describing multiple aneurysms across different vascular territories remain limited in the literature.

The following cases illustrate the heterogeneous clinical presentations and etiologies of multi-territory aneurysms. In 1989, Waters and Gaspar documented one of the earliest reported cases of multiple aneurysms in different vascular locations, describing an infrarenal abdominal aortic aneurysm associated with crossed‑fused renal ectopia in a 64‑year‑old man. ⁴ Imaging revealed aneurysms of the abdominal aorta and both common iliac arteries, highlighting the surgical challenges posed by coexisting vascular and anatomical anomalies.

Additional reports further demonstrate the variability in presentation and progression of aneurysmal disease. Okura et al described an asymptomatic 88‑year‑old man with a giant thoracic aortic aneurysm that expanded slowly over nearly 2 decades, emphasizing the potential for prolonged clinically silent disease. ⁵ Infectious etiologies have also been implicated; Kuki et al reported multiple mycotic aneurysms involving the aortic arch and thoraco‑abdominal aorta requiring staged surgical repair. ⁶ Similarly, Sasaki et al described a patient with acute type A aortic dissection accompanied by aneurysms of both the arch and abdominal aorta, demonstrating the complex interplay between acute aortic pathology and pre‑existing aneurysmal disease. ⁷

Multi‑territory aneurysms may also appear in younger patients when systemic or genetic factors are present. Gomes et al reported a pediatric patient with a phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutation and vasculitis who developed multiple visceral and aortic aneurysms. ⁸ Likewise, Durojaye et al described multiple saccular abdominal aortic aneurysms in an adult patient that ultimately ruptured before surgical intervention. ⁹ These cases underscore the diverse mechanisms that may contribute to aneurysm formation and highlight the importance of recognizing systemic contributors to widespread aneurysmal disease.

Herein, we present a cadaveric case of clinically silent multi‑territory aortic aneurysms identified during routine anatomical dissection and review the existing literature describing similar presentations. This case provides further insight into the variability of aneurysmal disease and underscores the importance of considering systemic and genetic factors when multiple aneurysms are encountered.

Case Presentation

During a routine anatomical dissection of the thoracic cavity of a 96-year-old male cadaver by first year medical students at Baylor College of Medicine, Houston, Texas, the rib cage was removed to expose the pericardial sac, and the heart and lungs were subsequently removed as well. In the thoracic cavity, a saccular aneurysm measuring 3.2 cm in diameter was located on the descending thoracic aorta, near the posterior aspect of the left fourth intercostal space. A larger fusiform aneurysm measuring 4.9 cm in diameter extended along the descending thoracic aorta from the T6-T8 vertebral levels (Figure 1). The right chest cavity was undisturbed.

Figure 1.

Thick arrows are pointing to aneurysms. (a) A series of aortic aneurysms identified during anatomical dissection. (b) Superiorly, there is a 3.2 cm saccular aneurysm. (c) Inferiorly, a large 4.9 cm fusiform aneurysm along T6 to T8.

During dissection of the abdominal cavity, a large retroperitoneal mass was revealed originating from the right kidney; this tumor compressed the blood supply at the level of the right renal artery. Distal to the renal arteries, a large 6.2 cm aneurysm just inferior to the inferior mesenteric artery was identified (Figure 2). To allow for proper visualization of the aneurysms, the entire contents of the thoracic and abdominal cavity was removed, with the exception of the aorta, once the review of these cavities concluded.

Figure 2.

Six point two centimeter aneurysm inferior to superior mesenteric artery, marked by a thick arrow.

The cause of death of the donor, as well as family and personal history, are not shared to protect the privacy of the patient. The cause of death of the donor was not related to an aneurysm or CVD and the donor was not reported to have diabetes. There are no ethical or consent issues with regards to publication of finding.

Discussion

This patient was found to have seemingly silent, yet extensive, aortic aneurysms upon cadaveric dissection from the ascending to the abdominal aorta. A presentation like this illustrates how aneurysmal disease can remain undiagnosed in life, and underscores the clinical importance of timely screening in patients at high risk. There are 4 domains in which this is particularly relevant: screening in the general population, risk factor modification, genetic evaluation, and patient counseling.

Screening in the General Population

Screening remains the cornerstone of aneurysm prevention. The United States Preventive Services Task Force (USPSTF) recommends that asymptomatic men aged 65 to 75 years who have ever smoked undergo a one-time abdominal ultrasound. In 2007, the Screening Abdominal Aortic Aneurysms Very Efficiently (SAAAVE) Act was implemented to increase abdominal aortic aneurysm detection; however, despite these recommendations, screening rates remain low. By 2015, screening among Medicare-eligible men increased from only 0.2% to 1.4%. ¹⁰ In the private sector, from 2006 to 2017, a mere 38% of eligible men received an abdominal ultrasound. ¹¹ The Multicentre Aneurysm Screening Study (MASS) group found a 53% reduction in aneurysm-related deaths for those who were screened and exhibited a number needed to screen (NNS) of 297. Notably, this number is lower than those for several other commonly performed preventative/screening modalities including mammography for breast cancer, low dose CT of the chest for lung cancer, and colonoscopy for colon cancer. ¹² Given that progression to aneurysm rupture has mortality rates ranging from 10% to 58% depending on the anatomic location and management strategies, ¹³ appropriate screening is paramount.

Risk Factor Modification

Once an aortic aneurysm is identified, risk factor modification becomes critical to limit growth and reduce the likelihood of rupture; smoking cessation, for example, is a very effective lifestyle intervention. ² Pharmacologic management, such as beta-blockers and angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin receptor blockers, should be used to target blood pressure reduction, decrease wall stress, reduce vascular inflammation, and lower the risk of aneurysm rupture. Patients should receive surveillance imaging with ultrasound or CT, which should be used to track aneurysm expansion and determine optimal timing for surgical referral for repair when indicated. Linking early screening with structured risk-reduction programs can extend survival and improve quality of life. ²

Genetic and Hereditary Disorders

While most abdominal aneurysms are linked to atherosclerotic disease, pan-aortic involvement – as in this patient – raises suspicion for genetic and hereditary disorders, and referral to a geneticist is indicated. Multiple aneurysms will lead to an increased cumulative risk of rupture or thromboembolic complications. ³ In those with known genetic disorders known to affect the aorta, such as Marfan’s Syndrome, Ehlers-Danlos Syndrome, Loeys-Dietz Syndrome, bicuspid aortic valve, and others, screening is performed with an echocardiogram, CT, or MRI. ² The results allow to more accurately risk-stratify patients and better management of the underlying disease and reducing associated mortality. ² While screening in this population is similar to those without genetic risk factors, genetic evaluation and aortic imaging may additionally be indicated for first-degree relatives to increase early detection in asymptomatic family members and improve survival outcomes.

Counseling

Regardless of the specific risk factors, high-risk patients with extensive aortic disease should be counseled on the potential need for future surgical intervention. Additionally, there are other unique management decisions that are impacted by aneurysmal disease, particularly for female patients seeking to become pregnant. ² Patients with aortic aneurysms requiring antibiotic therapy should be counseled to avoid fluoroquinolones if possible, owing to the increased risk of aortic dissection. ² Knowledge of the patient’s anatomy and risk factors helps guide comprehensive risk-benefit discussions between patients and their physicians.

An important consideration raised by this case is the mechanism underlying prolonged asymptomatic survival in patients with extensive aneurysmal disease. Although aneurysm size is a well-established predictor of rupture risk, published data suggest that growth kinetics and biomechanical stability also influence clinical behavior. ¹³ Thoracic aortic aneurysms may enlarge relatively slowly in some patients, with reported mean growth rates in certain cohorts on the order of 0.1 cm/year, which may allow prolonged clinically silent disease.^13,14 Systematic review data further indicate that thoracic aneurysm growth rates vary widely, with faster expansion associated with factors such as larger size, distal location, and selected heritable aortopathies. ¹⁵ Similarly, observational data in infrarenal abdominal aortic aneurysms suggest that some patients with moderate-sized aneurysms may remain rupture-free for prolonged periods, although rupture risk rises with increasing diameter.^16,17 Additional factors, including wall composition, stress distribution, and intrnal thrombus burden, may also contribute to aneurysm stability; notably, 1 study found that greater thrombus burden was associated with slower abdominal aneurysm growth. ¹⁸ Case reports likewise support the possibility of prolonged silent progression, including a giant thoracic aneurysm that remained unruptured and asymptomatic over many years. ⁵ Taken together, these findings suggest that variability in growth dynamics likely contributes to explaining how some aneurysms remain clinically silent despite substantial size.

Conclusion

This cadaveric case demonstrates the silent yet extensive nature of multi-territory aortic aneurysms, emphasizing the importance of early detection and comprehensive management in these patients. Multiple aneurysms across thoracic and abdominal territories are uncommon and raise considerations for both acquired and genetic etiologies. Literature reports confirm that such cases span a wide demographic ranging from elderly patients with atherosclerotic disease to children with connective tissue or genetic disorders, highlighting the need for clinicians to maintain a broad differential when evaluating at-risk individuals. ⁸

Despite strong evidence that screening reduces aneurysm-related mortality, uptake remains low, leaving many patients undiagnosed until rupture or incidental discovery. This gap underscores the importance of expanding access to screening, implementing risk factor modification, and pursuing genetic evaluation when appropriate. Ultimately, integrating timely detection, tailored medical management, and patient-centered counseling can help reduce the morbidity and mortality associated with these often silent but life-threatening vascular features.