Molecular imaging of endothelial activation and mineralization in a mouse model of accelerated atherosclerosis.

PURPOSE: Preclinical imaging of endothelial activation and mineralization using both positron emission tomography (PET) and magnetic resonance (MR) remains scarce. PROCEDURES: A group of uremic ApoE-/- (Ur), non-uremic ApoE-/- (NUr), and control C57Bl/6 J mice (Ctl) were investigated. Mineralization process was assessed using sodium fluoride ([18F]NaF) PET, and MR imaging combined with intravenous injection of MPIO-αVCAM-1 was used to evaluate endothelial activation. Micro- and macrocalcifications were evaluated by flame atomic absorption spectroscopy and von Kossa staining, respectively. RESULTS: Ur mice showed an active and sustained mineralization process compared to Ctl mice (p = 0.002) using [18F]NaF PET imaging. Calcium plasma level was increased in Ur (2.54 ± 0.09 mM, n = 17) compared to NUr and Ctl mice (2.24 ± 0.01, n = 22, and 2.14 ± 0.02, n = 27, respectively; p < 0.0001). Likewise, vascular calcium content was increased in Ur (0.51 ± 0.06 µg Ca2+ per milligram of dry weight aorta, n = 11) compared to NUr (0.27 ± 0.05, n = 9, p = 0.013) and Ctl (0.28 ± 0.05, n = 11, p = 0.014). Ur mice also had a higher inflammatory state using MPIO-αVCAM-1 MR (p global = 0.01, post hoc analysis Ur vs. Ctl p = 0.003) associated with increased VCAM-1 expression (p global = 0.02). Aortic remodeling at the level of the brachiocephalic trunk, brachiocephalic trunk itself, and aortic arch in Ur mice was also demonstrated using MR. CONCLUSIONS: Preclinical molecular imaging allowed in vivo characterization of the early phase of atherosclerosis. [18F]NaF PET showed early and sustained vascular mineralization in uremic ApoE-/- mice. MPIO-αVCAM-1 MR imaging demonstrated aortic endothelial activation, predominantly in segments with vascular remodeling.

Performance Evaluation of a Dedicated Preclinical PET/CT System for the Assessment of Mineralization Process in a Mouse Model of Atherosclerosis.

PURPOSE: The purpose of this study was to assess the impact of positron emission tomography/X-ray computed tomography (PET/CT) acquisition and reconstruction parameters on the assessment of mineralization process in a mouse model of atherosclerosis. PROCEDURES: All experiments were performed on a dedicated preclinical PET/CT system. CT was evaluated using five acquisition configurations using both a tungsten wire phantom for in-plane resolution assessment and a bar pattern phantom for cross-plane resolution. Furthermore, the radiation dose of these acquisition configurations was calculated. The PET system was assessed using longitudinal line sources to determine the optimal reconstruction parameters by measuring central resolution and its coefficient of variation. An in vivo PET study was performed using uremic ApoE-/-, non-uremic ApoE-/-, and control mice to evaluate optimal PET reconstruction parameters for the detection of sodium [18F]fluoride (Na[18F]F) aortic uptake and for quantitative measurement of Na[18F]F bone influx (Ki) with a Patlak analysis. RESULTS: For CT, the use of 1 × 1 and 2 × 2 binning detector mode increased both in-plane and cross-plane resolution. However, resolution improvement (163 to 62 µm for in-plane resolution) was associated with an important radiation dose increase (1.67 to 32.78 Gy). With PET, 3D-ordered subset expectation maximization (3D-OSEM) algorithm increased the central resolution compared to filtered back projection (1.42 ± 0.35 mm vs. 1.91 ± 0.08, p < 0.001). The use of 3D-OSEM with eight iterations and a zoom factor 2 yielded optimal PET resolution for preclinical study (FWHM = 0.98 mm). These PET reconstruction parameters allowed the detection of Na[18F]F aortic uptake in 3/14 ApoE-/- mice and demonstrated a decreased Ki in uremic ApoE-/- compared to non-uremic ApoE-/- and control mice (p < 0.006). CONCLUSIONS: Optimizing reconstruction parameters significantly impacted on the assessment of mineralization process in a preclinical model of accelerated atherosclerosis using Na[18F]F PET. In addition, improving the CT resolution was associated with a dramatic radiation dose increase.

True Brachial Artery Aneurysm after Arteriovenous Fistula for Hemodialysis: Five Cases and Literature Review.

BACKGROUND: The donor artery after a long-standing arteriovenous fistula (AVF) for hemodialysis usually evolves exceptionally toward a true aneurysmal degeneration (AD). The purpose of this article was to describe true brachial artery AD in end-stage renal disease patients after AVF creation, as well as its influencing factors and treatment strategies. METHODS: We present a retrospective, observational, single-center study realized in Caen University Hospital's Vascular Surgery Department from May 1996 to November 2015. The inclusion criteria were true AD of the brachial artery after a vascular access for hemodialysis. A literature research, using the same criteria, was performed on the articles published between 1994 and 2015. The used databases included MEDLINE (via PubMed), EMBASE via OVID, Cochrane Library Database, and ResearchGate. RESULTS: Our series includes 5 patients. Twenty-one articles were found in the literature: 17 case reports, 3 series, and 1 review. The same triggering factors for AD (high flow and immunosuppressive treatment) were found. The mean age at the time of AVF creation, first renal transplantation, and AD's diagnosis were respectively 26 (range 15-49), 29.2, and 48.6 years (range 37-76) in our series versus 34 (range 27-39), 40.4 (range 28-55), and 55.5 years (range 35-75) in cases found in the literature. The time spread after AVF creation and aneurysmal diagnosis was about 20.6 years (range 18-25) in our study versus 20.5 years (range 9-29) in the case reports. Our surgical attitude corresponds principally to that described in the literature. Nevertheless, we describe for the first time one case of arterial transposition to exclude the brachial aneurysm using superficial femoral artery. CONCLUSIONS: Arterial aneurysm is a rare, but significant complication after a long-term creation of hemodialysis access. High flow and immunosuppression may accelerate this process. Young age of the patients may act as a benefic factor and delay the AD. Arterial transposition could be an option in the absence of any venous conduit, if anatomy does not permit the use of prosthetic grafts.

Periprocedural Myocardial Infarction After Carotid Endarterectomy and Stenting: Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Carotid angioplasty and stenting (CAS) is associated with higher risk of periprocedural stroke and death when compared with carotid endarterectomy (CEA). By contrast, the risk of myocardial infarction (MI) was higher after CEA than after CAS in randomized trials. However, numbers were small, and risk factors are unknown. METHODS: We performed a systematic review and a meta-analysis of studies published from January 1980 to June 2014 and collected unpublished data. We extracted data on 9 predefined risk factors (age, contralateral carotid occlusion, coronary artery disease, diabetes mellitus, sex, hypertension, peripheral artery disease, type stenosis, and clinical presentation). We selected studies with data available on MI in at least 1 subgroup, calculated absolute and relative risks, and identified differential effects on risks of MI. RESULTS: The 30-day absolute risk of MI was 0.87% (95% confidence interval, 0.69-1.07) after CEA and 0.70% (95% confidence interval, 0.54-0.88) after CAS (Pint=0.38). After CAS, patients with symptomatic stenosis and restenosis were at higher risk of MI, whereas men were at lower risk. After CEA, age, history of coronary artery disease, peripheral artery disease, and restenosis increased the risk of MI. Only the effect of sex differed between CAS and CEA with men being at lower risk of MI than women after CAS, whereas there was no difference between after CEA (Pint=0.01). CONCLUSIONS: The risk of MI after CEA and CAS did not significantly differ. Risk factors for MI are overall similar in both techniques except that men are at lower risk of MI after CAS but not after CEA.

Intimal angiosarcoma from the common femoral vein in a 27-year-old patient.

Intimal sarcoma is a rare and aggressive vascular pathology. The literature describes about 140 cases. Because of late diagnosis, the median survival time is only a few months. Presentations vary from the localization. The most common symptoms are intravascular obstruction or embolization. Diagnosis is difficult and vascular surgeons do not know the treatment very well. We present the first case of intimal angiosarcoma of the common femoral vein presenting with a deep venous thrombosis and discuss diagnosis and therapeutic approach.

Solitary kidney with renal artery aneurysm repaired by ex vivo reconstruction.

A 22-year-old pregnant female with pyelonephritis was found to have a 26-mm left renal artery aneurysm with unknown right kidney agenesis diagnosed by magnetic resonance imaging. Computed tomographic angiography with 3-dimensional reconstructions confirmed a saccular aneurysm localized at the bifurcation of the left posterior segmental artery. The patient ultimately underwent successful ex vivo left renal artery aneurysm repair with autotransplantation. Pathologic evaluation of the resected aneurysm confirmed the diagnosis of fibromuscular dysplasia. Fibromuscular dysplasia is the most common cause of renal artery stenosis and renovascular hypertension and can, in rare cases, be associated with the development of renal artery aneurysms.

Calcified obstructive disease of the aortic arch.

Coral reef aorta is described as rock-hard calcifications usually localized in the visceral part of the aorta. Rare cases of acquired coarctation of the descending aorta due to coral reefs have been mentioned in the literature. A more uncommon entity is the coral reef of the aortic arch. We are presenting a rare case of a 55-year old woman referred to our vascular department for bilateral lower limb claudication associated with resistant hypertension and anisotension. A thoracoabdominal computed tomography scan was subsequently performed and showed a preocclusive calcified lesion located at the termination of the aortic arch, involving the ostia of the left subclavian artery. An open surgical approach was decided upon and an aortic endarterectomy by transversal aortotomy was successfully performed. Although uncommon, acquired coarctation should be considered in all hypertensive patients presenting with bilateral lower limb claudication and blood pressure differences between the upper and lower extremities.

Feasibility of ambulatory percutaneous femoral access without the use of arterial closure systems.

BACKGROUND: To evaluate the feasibility of early ambulation in patients treated for peripheral occlusive lesions by femoral percutaneous access, without the use of closure systems and the application to ambulatory practice. METHODS: This single-center observational exploratory study was undertaken among 99 consecutive patients between August 1-December 31, 2011 (mean age: 72 years; 72 men) who were treated by percutaneous femoral route for peripheral arterial lesions. All the patients had a manual compression then pressure bandage. A clinical evaluation was carried out after 4 hours, seeking a local or a general complication and checking the procedure. Rising and walking in the unit of hospitalization were authorized in the absence of complication as of 4 hours postoperatively. All patients remained in hospital for at least 1 night, with a clinical revaluation before discharge. All patients were contacted by telephone at postoperative day 7 in order to verify the absence of local complications. All the individual factors and those related to the procedure were analyzed. RESULTS: With criteria of complications related to the gesture, 72 patients (72.7%) were considered ready to be discharged as of postoperative hour 4. Among the 27 patients who were not able to leave, 7 presented with an early local complication without reoperation, and 20 could not walk because of a necrotic lesion (n = 8), their advanced age (n = 4), morbid obesity (n = 2), or a choice of the surgeon in charge (n = 6). Twenty-five patients could, however, stroll after 12 hours. The mean duration of hospitalization was 1.3 days (range: 0-10 days). Two patients required distal amputation during the same hospitalization, and 1 underwent a femoropopliteal bypass after failure of a femoropopliteal recanalization. With univariate analysis, the treatment by anticoagulants and the duration of the hospitalization were the only factors significantly related to the impossibility of early ambulation. The occurrence of complications was linked with the experience of the surgeon, the age of the patient, and the female sex. Three patients, including 2 regarded as ready to walk by postoperative hour 4, were rehospitalized after 1 week for reoperation because of 1 major hematoma and 2 femoral false aneurysms. CONCLUSION: Percutaneous endovascular surgery by the femoral route without using an arterial closure system is feasible in an ambulatory practice in nearly 75% of cases. Particular monitoring must be done in the oldest patients, women, and those treated with anticoagulants.

Migration of a Kirschner pin from the shoulder to the lung, requiring surgery.

A 62-year-old woman underwent a reduction of a proximal reduced humeral fracture, which was fixed by 3 Kirschner pins. One year later, the orthopedic surgeon failed to remove one of the wires. The patient was lost to follow-up, and 4 years later, she presented with hemoptysis, revealing migration of the pin to the lung. The pin was removed through a thoracotomy. Migration to the lung is often revealed by hemoptysis or pneumothorax. Close follow-up and early removal of the pins are mandatory.