BACKGROUND: Low wall shear stress (WSS) is predictive of aortic aneurysm growth and rupture. Yet, estimating WSS in a clinical setting is impractical, whereas measuring aneurysm geometry is feasible. This study investigates the association between saccular aneurysm geometry of the infrarenal aorta and WSS.
METHODS: Starting with a nonaneurysmal, patient-specific, computational fluid dynamics model of the aorta, saccular aneurysms of varying geometry were created by incrementally increasing the neck width and sac depth from 1 cm to 4 cm. The aspect ratio (the ratio between sac depth and neck width) varied between 0.25 and 4. The peak WSS, time-averaged WSS (TAWSS), and oscillatory shear index (OSI) were measured within the aneurysm sac.
RESULTS: Decreasing the neck width from 4 cm to 1 cm decreased the peak WSS by 69% and the TAWSS by 83%. Increasing the sac depth from 1 cm to 4 cm decreased the peak WSS by 55% and the OSI by 37%. The aspect ratio was negatively correlated to peak WSS (Rs -0.85; P < 0.001).
CONCLUSIONS: In saccular aneurysms of the infrarenal aorta, a smaller neck width, deeper aneurysm sac, and larger aspect ratio are associated with lower peak WSS.

BACKGROUND: Psoriasis, a chronic inflammatory skin condition, affects 4 % of the population and is associated with various comorbidities, making it a public health concern.
METHODS: We discuss the case of a 50-year-old man with severe erythrodermic psoriasis who presented with a ruptured saccular abdominal aortic aneurysm (AAA), requiring emergency surgery with good postoperative follow-up. shedding light on the link between psoriasis and cardiovascular complications.
CONCLUSIONS: Psoriasis severity correlates with cardiovascular risk and shares common development pathways with aortic aneurysms such as systemic and aortic inflammation, and arterial stiffness, emphasizing the importance of managing both skin symptoms and systemic inflammation to reduce vascular comorbidities. Psoriasis patients have a higher risk of AAA, warranting consideration for AAA screening. Controversies exist regarding corticosteroid therapy and choice of surgical intervention for AAA in psoriatic patients.
CONCLUSIONS: Psoriasis patients face an increased risk of AAA, highlighting the need for vigilant screening and comprehensive management. Further research is essential to understanding the pathophysiological connections between psoriasis and arterial diseases, guiding preventive strategies and optimal medical treatments for these high-risk patients.

BACKGROUND: Saccular abdominal aortic aneurysms (AAAs) are considered to be at higher risk of rupture than fusiform AAAs, but not much is known about the extent of this risk. Therefore, this study aimed to compare the rupture presentation between fusiform and saccular AAAs.
RESULTS: This is a retrospective cohort study on 27 290 patients who underwent primary endovascular repair for a degenerative AAA between 2016 and 2019, and who were registered in the National Clinical Database in Japan. At operation for nonruptured case, the aneurysm diameter was significantly smaller in saccular AAAs than in fusiform AAAs (median, 44.0 versus 51.0 mm; P<0.001). Similarly, aneurysm diameter at rupture was significantly smaller in saccular AAAs than in fusiform AAAs (median, 55.6 versus 68.0 mm; P<0.001). The likelihood of repair for rupture was significantly higher in saccular AAAs than in fusiform AAAs in the 40- to 54-mm diameter range, in which saccular morphology was found to be an independent risk factor for rupture against fusiform morphology by adjusting for sex and aneurysm diameter (odds ratio, 2.54 [95% CI, 1.75-3.69]). In addition, receiver-operating characteristic curve analysis revealed that the cutoff diameter to predict rupture was smaller in saccular AAAs than in fusiform AAAs (50.5 and 59.5 mm, respectively) based on the Youden index.
CONCLUSIONS: Saccular AAAs presented at smaller diameters than fusiform AAAs in patients with ruptured AAAs treated with endovascular aortic repair, which supports the idea that saccular AAAs should be treated at smaller diameters.

BACKGROUND: Conventional graft replacement for a juxtarenal abdominal aortic aneurysm (JRAAA) remains challenging for high-risk patients since it often requires the reconstruction of some visceral arteries.
METHODS: A 76-year-old woman was diagnosed with an 87 × 48 mm saccular JRAAA. Open graft replacement was contraindicated because of frailty and a past history of trans-thoracoabdominal esophagectomy. Chimney endovascular aortic repair (ChEVAR) with three chimney endografts was successfully performed without any endoleaks, and each visceral circulation was kept intact. The patient was discharged uneventfully on postoperative day 8. Significant shrinkage of the aneurysmal sac and preservation of flow through each chimney graft were observed on computed tomography 6 months postoperatively, with no significant increase in serum creatinine levels on laboratory testing.
CONCLUSIONS: ChEVAR can be a useful surgical option instead of conventional operations, especially for high-risk cases.

BACKGROUND: Morphologically, the risk of aortic aneurysm rupture is mainly evaluated based on its type (e.g., fusiform or saccular) and diameter. Based on the finite element analysis, peak wall stress has been identified as a more sensitive and specific predictor of rupture in recent years. Moreover, in finite analysis, the neck of aneurysm is the highest peak wall stress and is associated with the rupture point.
METHODS: A saccular aortic aneurysm (84 mm) was incidentally detected during preoperative examination for chronic empyema in a 74-year-old male patient with a history of polycythemia. Aortic arch graft replacement using an open stent was performed.
CONCLUSIONS: Morphologically, this case was associated with a very high risk of rupture; nevertheless, it did not rupture. In this case, a mural thrombus (likely formed due to polycythemia) covered the neck of aneurysm that is experiencing the highest peak wall stress and is associated with the rupture point. The mural thrombus decreased peak wall stress and could reduce the risk of rupture even for huge saccular aneurysms. Furthermore, the mural thrombus was fully occupied in aneurysms, such as during coil embolization. Thus, polycythemia could decrease the risk of rupture of huge saccular aneurysms.

Primary angiitis of central nervous system (PACNS) is a rare idiopathic vasculitis that typically involves small arteries. An 18-year-old woman was operated on for resection of a ruptured aneurysm in a cerebral artery. Multiple aneurysms of cerebral arteries had been detected by neuroimaging examinations since the age of 12, and she had been administered drugs following a diagnosis of PACNS since the age of 15. The resected aneurysm was a ruptured saccular aneurysm occurring in a medium-sized artery. Histologically, necrotizing arteritis of the polyarteritis nodosa (PAN) type was noted in the aneurysmal wall. It consisted of an admixture of acute and healing stages. In the acute stage, fibrinoid necrosis in the intima and media and intense inflammatory cell infiltrate in the entire wall were present. The inflammatory cells mainly consisted of lymphocytes, including plasma cells, neutrophils, and macrophages. In the healing stage, disappearance of fibrinoid necrosis, fibrosis in the intima and media, and scarce inflammatory cells were noted. The acute stage was mainly present near the ruptured site. From these findings, the aneurysm was considered to have been caused by necrotizing arteritis of the PAN type. Although saccular aneurysmal formation in a medium-sized artery is rare in PACNS, an understanding of aneurysms produced by necrotizing arteritis of the PAN type offers useful information for the diagnosis and treatment of PACNS.

We report a case of endovascular aortic repair (EVAR) for the abdominal aortic aneurysm complicated by a saccular aneurysm due to a penetrating atherosclerotic ulcer in the severely angulated proximal landing zone. To secure the zone, coil embolization of the saccular aneurysm was performed before stent grafting to treat the abdominal aortic aneurysm. To precisely follow the severely angled proximal neck, we used the Excluder stent-graft system inserted by the body floss technique method instead of the stiff wire method to avoid accordion folding the proximal landing zone. These techniques may expand the indications of EVAR.

Cerebral aneurysms secondary to human immunodeficiency virus vasculopathy are a diagnosis by exclusion and its mechanism is unknown. We report on a 21-year-old male with human immunodeficiency virus infection and suboptimal virological control, despite highly active antiretroviral therapy. An incidental discovery of multiple cerebral aneurysms occurred in this patient, who initially presented with signs of disorientation, acute psychosis, and a history of blunt cranial trauma. A non-contrasted computerized tomography scan of the encephalon showed no intracranial hemorrhage but multiple cerebral (saccular and fusiform) aneurysms. Subsequently, a non-urgent computerized tomography angiogram of the cerebral vasculature corroborated the existence of multiple cerebral aneurysms. Despite investigation, no secondary etiological factors for the aneurysmal condition were identified. The multitude of cerebral aneurysms was consequently ascribed to human immunodeficiency virus-associated vasculopathy. The patient was managed conservatively. At discharge, he was lucid and apsychotic. A unique aspect of the case is the presence of both fusiform and saccular cerebral aneurysms.

A zone 0 landing thoracic endovascular aortic repair was performed on a 69-year-old man with a saccular aortic arch aneurysm. Seven days after the surgery, the patient experienced diminished consciousness and lower limb paralysis. Stent graft collapse was seen on a computed tomography scan. Thereafter, the patient underwent total arch replacement and emergency stent graft removal.

Cystic medial necrosis is a disorder of large arteries, particularly the thoracic aorta, characterized by an accumulation of a basophilic ground substance in the media with cyst-like lesions. A male in his late 20s was brought to our trauma bay after he met with a road traffic accident with a complaint of abdominal pain. Clinical examination revealed tenderness in the left lumbar region. The contrast-enhanced computerized tomography revealed an aneurysm of size 11×9.6×9.2 cm in the left lateral aspect of the abdominal aorta at the origin of the left renal artery. Intraoperatively, an aneurysm of size 10×10 cm from the juxta renal abdominal aorta was identified, and aortic rent was repaired with a polyester graft. The tissue was sent for histopathology, which showed complicated atherosclerosis with cystic medial degeneration and aneurysmal rupture of the abdominal aorta containing thrombus. The patient had an uneventful postoperative course and is doing well without any complaints at a two-year follow-up.