Detecting Free Cholesterol Crystals in a Patient With Spontaneous Cholesterol Embolization Syndrome

Cholesterol Crystal Embolism in a Patient with Spontaneous Ruptured Aortic Plaques Identified by Non-Obstructive General Angioscopy

Cholesterol crystal (CC) embolism is a disease in which CCs from atherosclerotic lesions embolize peripheral arteries, causing organ dysfunction. In this case, a patient with spontaneously ruptured aortic plaques (SRAPs) identified by non-obstructive general angioscopy (NOGA) may have developed a CC embolism. This is the first report of a CC embolism in a patient with SRAPs identified using NOGA, which further supports the previously speculated pathogenesis of CC embolism due to SRAPs.

Different Characteristics and Interleukin-6 Ratios of Scattering-Type Aortic Plaques

Background Cholesterol crystals (CCs) are related to innate inflammation in spontaneously ruptured aortic plaques (SRAPs), and variability exists in the CCs and interleukin (IL)-6 ratio in SRAPs. Methods The prevalence of scattering-type ruptures that glittered against the light of angioscopic fibers (puff-chandelier ruptures) and those that did not (puff ruptures) was analyzed in 848 patients with suspected coronary artery disease. Overall, 177 puff-chandelier ruptures and 105 puff ruptures were sampled using nonobstructive general angioscopy (NOGA). The sampled plaques were analyzed by direct detection of CCs with polarized light microscopy. The characteristics of the plaque fragments from puff and puff-chandelier ruptures were compared. The Interleukin-6 (IL-6) ratios were calculated for 100 puff-chandelier ruptures and 100 puff ruptures. Results CCs were detected in 54% of puff-chandelier ruptures and 20% of puff ruptures. The longer and shorter dimensions of the puff ruptures were smaller than those of the puff-chandelier ruptures. CCs were more prevalent in puff chandeliers than in puff ruptures (54% vs. 20%, respectively; p<0.0001). The number of CCs was higher in puff chandeliers than in puff ruptures with CCs (median 12,727 (interquartile range (IQR) 3,636-25,909)/10 mL vs. median 3,182 ( IQR 909-9,318)/10 mL) in CC-positive samples (p=0.0120). The IL-6 ratio of puff-chandelier ruptures was higher than that of puff ruptures (p=0.0014). Conclusions Examination of plaque fragments from puff-chandelier and puff ruptures revealed a higher prevalence of CCs in puff-chandelier ruptures compared to puff ruptures. Puff chandeliers exhibited a significantly greater number of CCs, suggesting a potential correlation with inflammatory levels. The IL-6 ratio was also higher in puff-chandelier ruptures. Direct detection of CCs and hematoxylin and eosin staining for SRAPs demonstrated variations in CC degree and dimensions between puff-chandelier and puff ruptures. Puff-chandelier ruptures exhibited more CCs associated with innate inflammation and larger fragments than puff ruptures. NOGA proved effective in detecting diverse characteristics and inflammation levels, as indicated by IL-6, in scattering-type SRAPs.

Atherosclerosis of the aorta before blue toe syndrome: Spontaneously ruptured aortic plaques revealed by non-obstructive general angioscopy

A 50-year-old man who had undergone endovascular therapy 70 days previously was referred to us for the sudden onset of cyanosis with rest pain in the bilateral lower limbs. The patient was diagnosed with blue toe syndrome. Although computed tomography angiography showed irregular aortic wall thickness, preoperative aortic angioscopy detected a remarkable number of spontaneously ruptured aortic plaques, such as puff-chandelier ruptures, predominantly in the abdominal aorta. Continuous embolization of a large quantity of cholesterol crystals from puff-chandelier ruptures subsequently might be responsible for cholesterol embolization syndrome.

Learning objective

A patient presenting with cholesterol embolization syndrome had undergone a non-obstructive general angioscopy. We highlight the numerous spontaneously ruptured aortic plaques demonstrated by non-obstructive general angioscopy.

Novel Methods for Detecting Human Cholesterol Crystals from Sampled Blood

OBJECTIVE

Nonobstructive general angiography (NOGA) is a novel modality to detect and sample spontaneous ruptured aortic plaques (SRAPs). We aimed to establish novel methods to detect cholesterol crystals (CCs) in sampled SRAPs.

METHODS

Blood specimens containing SRAPs were obtained from patients using NOGA. Blood was instantly frozen on a glass slide and subsequently thawed for quantitative analysis and spread onto a filter paper that was rinsed using distilled water. Qualitative analysis was performed for the rinsed water using polarized light microscopy, and the filter paper was embedded in paraffin for histologic analysis.

RESULTS

The CCs were clearly observed after hemolysis using the instant freeze-thaw method. The filter paper rinse method indicated free CCs of varying shapes under polarized light microscopy without erythrocytes. On the filter paper, sampled SRAPs showed Lamé-like small particles. Histopathology revealed various atheromatous components.

CONCLUSION

A set of novel methods for detecting CCs from sampled blood was established.