Blood Oxygen Level-Dependent MR Imaging of Lower Extremities in Peripheral Artery Disease and Its Correlation With Walking Performance.

BACKGROUND: A noninvasive and reliable approach to quantitatively measure muscle perfusion of lower extremity is needed to aid the diagnosis and treatment of peripheral artery disease (PAD). PURPOSE: To verify the reproductivity of using blood oxygen level-dependent (BOLD) imaging to evaluate perfusion in lower extremities, and explore its correlation with walking performance in patients with PAD. STUDY TYPE: Prospective observational study. SUBJECTS: Seventeen patients with lower extremity PAD (mean age: 67 ± 6 years, 15 males) and eight older adults (controls). FIELD STRENGTH/SEQUENCE: Dynamic multi-echo gradient echo T2* weighted imaging at 3T. ASSESSMENT: Perfusion was analyzed in regions of interest according to muscle groups. Perfusion parameters were measured, such as minimum ischemia value (MIV), time to peak (TTP), and gradient during reactive hyperemia (Grad) by two independent users. Walking performance experiments including short physical performance battery (SPPB) and 6-minute walk were tested in patients. STATISTICAL TESTS: BOLD parameters were compared using Mann-Whitney U test and Kruskal-Wallis test. Relations between parameters and walking performance were assessed by Mann-Whitney U test and Spearman's correlation coefficient. RESULTS: Good to perfect agreement was demonstrated for all perfusion parameters of interuser reproducibility, and the interscan reproducibility of MIV, TTP, and Grad was good. The TTP of the patients was longer than that of the controls (87.85 ± 38.85 s vs. 36.54 ± 7.27 s), while the Grad of patients was smaller (0.16 ± 0.12 msec/s vs. 0.24 ± 0.11 msec/s). Among PAD patients, the MIV was significantly lower in the low SPPB subgroup (score 6-8) than in the high SPPB group (score 9-12), and the TTP was negatively correlated with 6-minute walk distance (ρ = -0.549). DATA CONCLUSION: BOLD imaging method had overall good reproducibility for the perfusion assessment of calf muscles. The perfusion parameters were different between PAD patients and controls, and were correlated with lower extremity function. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Renal perfusion improvement in the perioperative period after unilateral endovascular revascularization in patients with atherosclerotic renal artery stenosis.

Background: The clinical benefits of endovascular treatment in renal artery stenosis (RAS) remain controversial. This study used an intraoperative renal perfusion imaging technique, called flat-panel detector parenchymal blood volume imaging (FD-PBV), to observe the change in renal perfusion after endovascular treatment in RAS. Materials and methods: In a prospective, single-center study, we assigned 30 patients with atherosclerotic RAS who underwent endovascular treatment between March 2016 and March 2021. The preoperative and postoperative results of renal perfusion, blood pressure, and renal function, were compared. Results: Both median kidney volume (p < 0.001) and median preoperative mean density of contrast medium (MDCM) (p = 0.028) increased significantly after endovascular treatment. The ratio of postoperative and preoperative MDCM differed greatly among the patients. For patients with preoperative MDCM <304.0 HU (Subgroup A, 15 cases), MDCM significantly increased after treatment (p = 0.001) and 12 (80.0%) patients had more than 10% increase in renal perfusion. For patients who had relatively high preoperative renal perfusion (MDCM ≥304.0 HU, Subgroup B, 15 cases), preoperative and postoperative MDCM were similar (p = 0.776). On the other hand, the serum creatinine levels significantly decreased in Subgroup A (p = 0.033) and fewer antihypertensive drugs were used after endovascular revascularization (p = 0.041). The preoperative and postoperative creatinine levels and number of antihypertensive drugs were similar in Subgroup B. Conclusions: During the perioperative period, RAS patients with relatively low preoperative renal perfusion levels had greater improvement in renal perfusion, renal function, and blood pressure control after endovascular treatment. The improvement of renal function needs to be confirmed by long-term follow-up.

Performance of 68Ga-Labeled Fibroblast Activation Protein Inhibitor PET/CT in Evaluation of Erdheim-Chester Disease: A Comparison with 18F-FDG PET/CT.

Erdheim-Chester disease (ECD) involves multiple organs and tissues and has diverse manifestations, which makes it difficult to distinguish lesions caused by ECD from those caused by other diseases. Variable degrees of fibrosis are present in ECD. Therefore, we conducted a prospective cohort study to explore the ability of 68Ga fibroblast activation protein inhibitor (68Ga-FAPI) PET/CT to detect lesions in ECD patients. Methods: Fourteen patients diagnosed with ECD, as confirmed by histology, were included in this study. For every patient, 68Ga-FAPI PET/CT and 18F-FDG PET/CT were conducted within 1 wk. The positive rate and SUVmax of the lesions in the involved organs were compared between the examinations. Results: The most commonly involved organs were bone (100%), heart (57.1%), lung (57.1%), kidney (42.9%), and peritoneum or omentum (35.7%); other common manifestations were intracranial infiltration (50%) and cutaneous infiltration (35.7%). 68Ga-FAPI PET/CT detected 64 of 67 lesions in 14 patients, whereas 18F-FDG PET/CT detected 51 of 67 lesions (P = 0.004). The SUVmax for 68Ga-FAPI PET/CT was significantly higher than the SUVmax for 18F-FDG PET/CT of the heart (4.9 ± 2.4 vs. 2.8 ± 1.2, respectively; P = 0.050), lung or pleura (6.8 ± 4.9 vs. 3.1 ± 1.3, respectively; P = 0.025), peritoneum or omentum (5.7 ± 3.6 vs. 2.8 ± 1.7, respectively; P = 0.032), and kidney or perinephric infiltration (4.9 ± 1.2 vs. 2.9 ± 1.1, respectively; P = 0.009). Conclusion: The detectivity of 68Ga-FAPI PET/CT is superior to that of 18F-FDG PET/CT. Moreover, 68Ga-FAPI PET/CT has a better image contrast and higher SUVmax for lesions in multiple organs including the heart, lungs, peritoneum, and kidneys. 68Ga-FAPI PET/CT is a promising tool to assess pathologic features and disease extent in ECD patients.

Effect of Endovascular Treatment on Urinary Obstruction Caused by Iliac Artery Aneurysm: A Case Series and Review of the Literature.

BACKGROUND: Endovascular aneurysm repair is superior to open surgical repair (OSR) in multiple aspects and is the mainstay for noninflammatory iliac artery aneurysm (IAA) treatment. However, for noninflammatory IAAs with neighboring structures compressed, the experience of endovascular treatment is limited. This case series study aimed to describe the experience of endovascular aneurysm repair of noninflammatory IAAs with urinary obstruction and to review the limited reports in the literature. METHODS: From December 2012 to July 2020, we reported 7 cases of noninflammatory IAAs combined with urinary obstruction that was treated successfully with endovascular treatment. The literature on noninflammatory IAAs combined with urinary obstruction was reviewed using the online databases PubMed, Embase, and the Cochrane Library. RESULTS: Thirty nine articles were found in the literature. OSR accounted for 80% of the treatment options in previous publications, while only 20% of patients accepted endovascular treatment. Hydronephrosis remission was observed in all patients treated by OSR, while the endovascular treatment group lacked long-term follow-up. In our retrospective study containing 7 cases, no complications, reintervention, or mortality was observed, all stents were patent, and all symptoms were relieved after the operation. Diameter reduction of the aneurysms was observed in 6/7 cases and the average aneurysm reduction was -24.1 ± 15.8 mm (P = 0.0097). Urinary obstruction faded in 5/7 cases where aneurysm shrinking was found simultaneously. CONCLUSIONS: This case series and literature review on noninflammatory IAAs combined with urinary obstruction suggests that the diameter of the responsible aneurysm may be reduced after endovascular treatment, which may also alleviate symptoms of urinary obstruction caused by noninflammatory IAAs.

Impaired pedal arch affects the treatment effect in patients with single tibial artery revascularization demonstrated by intraoperative perfusion.

Background: The treatment strategy for patients with multiple infrapopliteal artery occlusions remains controversial. In this study, we investigated how anatomic factors affect the treatment effect of infrapopliteal artery intervention and identified suitable intervention strategies for patients with multiple infrapopliteal artery occlusions. Methods: This was a prospective, single-center, observational cohort study. For each patient, the intrainterventional blood volume improvement of the dorsum and plantar surface was measured and classified into the direct perfused region (DR) or indirect perfused region (IR) on the basis of whether the supplying artery was revascularized. Digital subtraction angiography was performed to analyze how pedal arch patency affects blood communication between DR and IR. Results: A total of 38 patients treated with infrapopliteal intervention at the Department of Vascular Surgery of Peking Union Medical College Hospital from November 2016 to November 2020 were considered for inclusion in this study. Finally, 26 patients were included in the analysis. In patients with type III pedal arch, blood volume improvements for DR and IR were 70.50 (17.50, 191.75) and 11.25 (-10.25, 50.25) mL/1,000 mL, respectively (P=0.018). No significant difference was found between DR and IR in patients with type I pedal arch (P=0.208) and type II pedal arch (P=0.110). Conclusions: Impaired pedal arch has an adverse impact on foot collateral circulation. Patients with these conditions are more suitable for direct revascularization than other patients. Trial Registration: ClinicalTrials.gov identifier: NCT03248323.

Irisin Suppresses Nicotine-Mediated Atherosclerosis by Attenuating Endothelial Cell Migration, Proliferation, Cell Cycle Arrest, and Cell Senescence.

Atherosclerotic disease has become the major cause of death worldwide. Smoking, as a widespread independent risk factor, further strengthens the health burden of atherosclerosis. Irisin is a cytokine that increases after physical activity and shows an atheroprotective effect, while its specific mechanism in the process of atherosclerosis is little known. The reversal effect of irisin on intimal thickening induced by smoking-mediated atherosclerosis was identified in Apoe -/- mice through the integrin αVß5 receptor. Endothelial cells treated with nicotine and irisin were further subjected to RNA-seq for further illustrating the potential mechanism of irisin in atherosclerosis, as well as the wound healing assays, CCK-8 assays, ß-gal staining and cell cycle determination to confirm phenotypic alterations. Endothelial differential expressed gene enrichment showed focal adhesion for migration and proliferation, as well as the P53 signaling pathway for cell senescence and cell cycle control. Irisin exerts antagonistic effects on nicotine-mediated migration and proliferation via the integrin αVß5/PI3K pathway. In addition, irisin inhibits nicotine-mediated endothelial senescence and cell cycle arrest in G0/G1 phase via P53/P21 pathway. This study further illustrates the molecular mechanism of irisin in atherosclerosis and stresses its potential as an anti-atherosclerotic therapy.

Infrapopliteal endovascular intervention and the angiosome concept: intraoperative real-time assessment of foot regions' blood volume guides and improves direct revascularization.

OBJECTIVE: There is no consensus for determining which vessel should be revascularized in patients with multiple diseased infrapopliteal arteries. The angiosome concept may guide a more efficient targeted direct revascularization. Therefore, we conducted a study to assess whether the regional evaluation of foot blood volume may guide direct revascularization (DR) and if it will lead to better perfusion improvement than indirect revascularization (IR). METHODS: We performed a prospective single-center observational cohort study in patients treated in the Department of Vascular Surgery of Peking Union Medical College Hospital from November 2016 to April 2019. Twenty-seven patients treated with endovascular intervention were included. The intraoperative parenchymal blood volume of different foot regions was obtained for each patient using C-arm CT before and after intervention. RESULTS: The intervention procedure significantly increased the overall blood volume (48.95 versus 81.97 ml/1000 ml, p = 0.002). Patients with direct revascularization had a 197% blood volume increase while patients with indirect revascularization had a 39% increase (p = 0.028). The preoperative blood volume was higher in patients with mild symptoms than in patients with severe symptoms (58.20 versus 30.45 ml/1000 ml, p = 0.039). However, in regard to postoperative blood volume, no significant difference was discovered between these two groups (75.05 versus 95.01 ml/1000 ml, p = 0.275). CONCLUSION: Based on quantitative measurements, we conclude that overall blood volume can rise significantly after the intervention. Revascularizing the supplying vessel of the ischemic area directly will result in better perfusion improvement than restoring blood supply through the collateral circulation. Preoperative blood volume is associated with preoperative symptoms. KEY POINTS: • Flat panel detector CT can obtain intraoperative perfusion status and guide treatment in endovascular intervention. • Revascularizing the supplying vessel of the ischemic area directly will result in better perfusion improvement than restoring the blood supply through the collateral circulation. • Patients with severer clinical manifestations have lower blood volumes.

Long-term outcomes of conservative treatment and endovascular treatment in patients with symptomatic spontaneous isolated superior mesenteric artery dissection: a single-center experience.

BACKGROUND: Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare vascular disorder, and the treatment strategies remain controversial. This study aimed to compare outcomes of conservative and endovascular treatments in symptomatic patients with SISMAD. METHODS: Forty-two consecutive SISMAD patients who were admitted to a single center between October 2009 and May 2018 were enrolled in this study. Based on their symptoms, 15 had conservative treatment, and 27 had endovascular treatment. The baseline characteristics, treatments, and follow-up results of the conservative group and endovascular group were analysed. RESULTS: The rates of symptom relief were 93.3% in the conservative group and 96.3% in the endovascular group. The procedure-related complications in the endovascular group included one case of pseudoaneurysm formation in the left brachial artery. During the follow-up period (median 28.5 months), a higher proportion of patients in the conservative group had symptom recurrence (42.9% in the conservative group versus 4.8% in the endovascular group, p < 0.001). Four patients in the conservative group and one patient in the endovascular group had additional endovascular intervention during follow-up. Compared with the conservative group, patients in the endovascular group had statistically significantly longer symptom-free survival (p = 0.014) and a higher rate of superior mesenteric artery (SMA) remodeling (p < 0.001). CONCLUSIONS: For symptomatic SISMAD, endovascularly treated patients had a lower rate of symptom recurrence and a higher rate of SMA remodeling in the long term. Prospective, multi-center studies are needed to confirm the long-term outcomes of both treatments.