Primary Stenting of Right-Sided Subclavian Artery Stenosis Presenting as Subclavian Steal Syndrome: Report of 3 Cases and Literature Review.

BACKGROUND: Right-sided subclavian artery stenosis (SAS) is a rare cerebrovascular disease involving the upper extremities. Considering an endovascular approach for its management requires increased endovascular and catheterization skills when compared with the left side, due to the close approximation of the right subclavian artery origin, vertebral, and common carotid arteries. METHODS: Three patients suffering from proximal right-sided SAS were treated in our center through primary stenting. Percutaneous transfemoral and transbrachial approaches were used for vascular access, whereas in 2 cases an additional carotid protection device was deployed intraoperatively. RESULTS: Technical success was met in all 3 cases, with no intraoperative or postoperative complications being observed. All patients resumed ambulation and were uneventfully discharged the next day with dual antiplatelet medication. No recurrent stenosis was reported in duplex ultrasound scan during 6-month follow-up, with all patients reporting resolution of their symptoms. DISCUSSION: Subclavian artery stenosis is an uncommon vascular disease, showing a 4-fold left, rather than right-sided predisposition. Although a low-grade stenosis is usually asymptomatic and may remain unobserved, a severe stenosis may cause retrograde blood flow in the ipsilateral vertebral artery, leading to a medical condition with various clinical symptoms, known as subclavian steal syndrome. A number of open surgical techniques exist for management of subclavian artery stenosis, although a paradigm shift in the 21st century has led to the introduction of minimally invasive techniques for its treatment, with available modalities including angioplasty, stenting, and the kissing stent technique.

Urinary cystatin C as an early biomarker of acute kidney injury after open and endovascular abdominal aortic aneurysm repair.

BACKGROUND: Acute kidney injury (AKI) after open repair (OR) and endovascular repair (EVAR) of abdominal aortic aneurysm (AAA) is associated with increased mortality and hospital costs. Early detection of AKI is critical to prevent its progression. Recent findings demonstrate that elevated levels of urinary cystatin C (uCysC) may reflect tubular dysfunction. We prospectively evaluated whether uCysC can detect renal dysfunction earlier than serum creatinine (sCr). METHODS: In a prospective study, 126 consecutive patients (mean age ± SD, 69.1 ± 8.66 years) with AAA (EVAR = 87, OR = 39) were enrolled. sCr and uCysC were measured preoperatively (baseline) and at 6, 24, and 48 hr postoperatively. A final measurement was made on day 5. AKI was defined according to Acute Kidney Injury Network criteria. RESULTS: The incidence of AKI was significantly higher (χ(2) test, P < 0.05) in the OR group (n = 13, 33%) than in the EVAR group (n = 15, 17%). The baseline median (interquartile range) value of uCysC was significantly higher (t-test, P < 0.05) in patients of both groups (OR-EVAR) who developed AKI from those who did not (OR/AKI group: 0.06 [0.02-0.12] mg/L, EVAR/AKI group: 0.08 [0.05-0.11] mg/L versus no-AKI subjects: 0.04 [0.02-0.07] mg/L). Subsequent analysis showed that at 6 hr postoperatively, the patients who developed AKI increased their uCysC levels significantly from baseline (OR/AKI group: 0.58 [0.42-0.70] mg/L, EVAR/AKI group: 0.59 [0.30-1.07] mg/L). The median value of uCysC in AKI patients increased at 24 hr (OR/AKI group: 1.37 [0.78-3.40] mg/L, EVAR/AKI group: 2.11 [0.70-2.42] mg/L) and peaked at 48 hr (OR/AKI group: 6.16 [1.74-10.73] mg/L, EVAR/AKI group: 2.57 [1.21-7.40] mg/L), while no increase was observed among those who did not develop AKI at the same time points (0.06 [0.04-0.14] vs. 0.08 [0.04-0.19] mg/L). The diagnostic accuracy of uCysC at 6 hr post-surgery was excellent (area under the curve - receiver-operating characteristic [AUC-ROC] = 0.968), significantly higher than sCr (AUC-ROC = 0.844) and a cutoff value set at 0.30 mg/L can diagnose AKI with a sensitivity of 85.71% and a specificity of 98.97%. CONCLUSIONS: uCysC is superior to sCr in the early diagnosis of AKI following open and endovascular AAA repair.

Measurement of cystatin C in human urine by particle-enhanced turbidimetric immunoassay on an automated biochemistry analyzer.

BACKGROUND: Cystatin C (CysC), is produced by all the nucleated cells of the human body, is freely filtered by the kidney glomerulus and reabsorbed by the tubules. It is widely accepted that no tubular secretion of CysC occurs. Raised urinary levels are believed to indicate tubular damage. METHODS: We report here the validation of a quantitative assay to measure urinary cystatin C (uCysC) using a commercial CysC kit based on a latex particle-enhanced turbidimetric immunoassay (PETIA), on an automated biochemistry analyzer. The clinical relevance of this assay was tested on several kidney disease patients and a reference range was determined using healthy controls. RESULTS: The assay is precise (total CV<4%), and sensitive (limit of quantification=0.06 mg/dL, and limit of detection=0.02 mg/L). Calibration is stable for at least 30 days. The assay showed very good linearity over the studied interval (0.02 to 2.25mg/L). Recovery ranged from 101.62 to 106.49%. The analyte is stable, at 4°C for at least 2 days, and at 20°C for 48 h. The upper reference value was 0.12 mg/L Median uCysC concentration in 30 acute kidney injury patients (1.47 mg/L, interquartile range=0.27-3.87 mg/L) and was significantly higher than that in 25 patients with normal kidney function (0.05, 0.03-0.12; p<0.0001), 30 patients with chronic kidney disease (0.13, 0.05-0.77; p<0.0001) and 15 patients with pre-renal azotemia (0.15, 0.08-0.31; p<0.0001). CONCLUSION: Our data indicate that uCysC can be processed on automated biochemistry analyzers and its measurement could easily be added to a standard panel to screen kidney diseases.

Case report of a patient with iliac occlusive disease due to pseudoxantoma elasticum and review of the bibliography.

BACKGROUND: Pseudoxanthoma elasticum (PXE) is a rare genetic disorder characterized by progressive calcification and fragmentation of elastic fibers in the skin, the retina, and the cardiovascular system, and is also termed as elastorrhexia. The purpose of this case presentation is to report the case of a PXE patient with an atypical localization of atherosclerotic lesion (iliac arteries) and that this rare disease should always be included in the differential diagnosis of patients with premature atheromatosis. METHODS AND RESULTS: A 58-year-old patient, suffering from PXE, came to our clinic to seek advice for his severe lower limb claudication. The image of the magnetic resonance angiography of his aorta, iliac arteries, and lower limb arteries demonstrated total occlusion of the left common iliac artery and preocclusive stenosis of the orifice on the right common iliac artery. The patient was treated successfully by angioplasty with kissing stent placement at the iliac arteries, and 6 months later, he is symptom-free, with ankle-brachial indexes of 1.0 and 1.05 on the left and right legs, respectively. CONCLUSION: This case report presentation has a primary goal to show that the disease may cause atypical localizations of atherosclerosis (iliac arteries) and a secondary goal to demonstrate that endovascular treatment in these patients may be a safe and viable option. It is also a good opportunity for a brief review of the bibliography.