Mechanism of Stent Failure in a Patient with Fibromuscular Dysplasia following Renal Artery Stenting

Unique presentation of renovascular hypertension due to fibromuscular dysplasia

A 21-year-old female with a history of right nephrectomy due to trauma presented with several years of multidrug-resistant hypertension. Her workup included negative findings from autoimmune and vasculitides panels and urine catecholamine testing. Computed tomography showed an acute hairpin turn of her left renal artery. Intraoperatively, the artery demonstrated kinking with exhalation. She underwent excision of the diseased portion of the renal artery and an end-to-end anastomosis. Final pathologic examination demonstrated fibromuscular dysplasia. This is a unique case of mechanical artery kinking combined with fibromuscular dysplasia contributing to renovascular hypertension, for which open surgery was beneficial at improving the patient's hypertension.

Renovascular Disease and Mesenteric Vascular Disease

Renal artery stenosis is caused by atherosclerosis and fibromuscular dysplasia and is associated with ischemic nephropathy, renovascular hypertension, and accelerated cardiovascular disease. Routine screening for renal artery stenosis is not recommended but is reasonable in patients who have rapid onset of hypertension, resistant hypertension, progressive renal insufficiency, recurrent pulmonary edema, or repeat admissions for heart failure. Acute mesenteric ischemia is caused by arterial embolism or thrombosis, mesenteric venous thrombosis, or nonocclusive mesenteric ischemia, whereas chronic mesenteric ischemia is most often caused by arterial obstruction. This article reviews the epidemiology, pathophysiology, diagnosis, and management of these two conditions.

First international consensus on the diagnosis and management of fibromuscular dysplasia

This article is a comprehensive document on the diagnosis and management of fibromuscular dysplasia (FMD) which was commissioned by the Working Group 'Hypertension and the Kidney' of the European Society of Hypertension (ESH) and the Society for Vascular Medicine (SVM). This document updates previous consensus documents/scientific statements on FMD published in 2014 with full harmonization of the position of European and US experts. In addition to practical consensus-based clinical recommendations, including a consensus protocol for catheter-based angiography and percutaneous angioplasty for renal FMD, the document also includes the first analysis of the European/International FMD Registry and provides updated data from the US Registry for FMD. Finally, it provides insights on ongoing research programs and proposes future research directions for understanding this multifaceted arterial disease.

Assessments of Metals in Coastal Environments: State of Art

This study is an overview of the assessments of metal contamination in coastal environments for the past five decades. Research articles with evaluations in sediments and biota were quantified and had their content visited for the registry of (1) the source of metals (anthropogenic or natural), (2) assessed country/territory, (3) groups of organisms assessed, (4) trophic transfer evaluation, (5) spatio-temporal variations, and (6) metals evaluated. We found an increase in the number of assessments over the years, mainly from 2014. The majority of the assessments pointed to anthropogenic sources of metals. The United States, the United Kingdom, and China were the most assessed countries. "Mollusks" was the most assessed group of organisms, and only 17% of all sampled studies identified any trophic relation, although there has been an increase since 2013. Spatial variations were more frequent than spatio-temporal and temporal variations alone. Cadmium, copper, zinc, and lead were the top metals evaluated in both sediment and biota. We believe that these are all valuable information for researchers and policy makers interested in the topic.

First International Consensus on the diagnosis and management of fibromuscular dysplasia

This article is a comprehensive document on the diagnosis and management of fibromuscular dysplasia (FMD), which was commissioned by the working group ‘Hypertension and the Kidney’ of the European Society of Hypertension (ESH) and the Society for Vascular Medicine (SVM). This document updates previous consensus documents/scientific statements on FMD published in 2014 with full harmonization of the position of European and US experts. In addition to practical consensus-based clinical recommendations, including a consensus protocol for catheter-based angiography and percutaneous angioplasty for renal FMD, the document also includes the first analysis of the European/International FMD Registry and provides updated data from the US Registry for FMD. Finally, it provides insights on ongoing research programs and proposes future research directions for understanding this multifaceted arterial disease.

Clinical characteristics and treatment of renal artery fibromuscular dysplasia with percutaneous transluminal angioplasty: a long-term follow-up study

BACKGROUND

Renal artery fibromuscular dysplasia (RAFMD) is a non-atherosclerotic cause of renal artery stenosis often affecting the young. Percutaneous transluminal renal angioplasty (PTRA) is the treatment of choice but there are few studies of the outcome of the procedure.

METHODS

This retrospective analysis included 64 patients (56.2 % female; mean age at diagnosis, 28.0 years) with RAFMD who underwent PTRA between November 2003 and August 2015. Technical and clinical success rates and restenosis rates were evaluated.

RESULTS

Seventy-six procedures were performed on 64 RAFMD patients. Technical success was 96.9 %, as defined by <30 % residual stenosis, with stent placement required in 11 patients (17.2 %). In the short term (1 month), the majority (79.7 %) had an immediate clinical benefit, with cure of hypertension in 35.9 %, and improvement in hypertension and a lower requirement for antihypertensive medications in 43.8 %. In the long term (mean, 47.5 months; range, 5-141 months), the survival rate was 96.9 %, freedom from restenosis was 84.4 %, and 76.6 % of patients showed a sustained clinical benefit (cure rate 40.6 %, improvement rate 35.9 %). Eight patients were treated with a second procedure and two had a third procedure, with half of these patients showing an improvement in hypertension.

CONCLUSION

PTRA for symptomatic RAFMD is safe and clinically successful. More than half of patients experience an immediate clinical benefit with sustained long-term effects. For patients with restenosis, there was a good response to a second PTRA.

Three-Dimensional Modeling Analysis of Visceral Arteries and Kidneys during Respiration

BACKGROUND

Visceral arteries are commonly involved in endovascular repair of complex abdominal aortic aneurysms (AAAs). To improve repair techniques and reduce long-term complications involving visceral arteries, it is crucial to understand in vivo arterial geometry and the deformations due to visceral organ movement with respiration. This study quantifies deformation of the celiac, superior mesenteric (SMA), and renal arteries during respiration and correlates the deformations with diaphragmatic excursion.

METHODS

Sixteen patients with small AAAs underwent magnetic resonance angiography during inspiratory and expiratory breathholds. From geometric models of the aorta and visceral arteries, vessel length, branch angle, curvature, and positions were computed, along with degree of diaphragmatic excursion as indicated by kidney translation.

RESULTS

From inspiration to expiration, the celiac artery exhibited axial shortening of 4.8 ± 6.4% (P < 0.001) and a mean curvature increase of 0.03 ± 0.02 mm(-1), greater than other visceral arteries (P < 0.01). With expiration, the SMA, left and right renal arteries (LRA and RRA) angled upward by -9.8 ± 6.4°, -6.4 ± 6.4°, and -5.2 ± 5.0°, respectively (P < 0.005). All vessels translated superiorly (P < 0.0005) and posteriorly (P < 0.01), and the SMA translated rightward additionally (P < 0.005). The left and right kidneys translated by 22 ± 9 mm and 21 ± 9 mm, mostly superiorly (P < 0.001). Translations of all visceral arteries were moderately correlated to the right kidney (R > 0.50). Correlation of the LRA with the left kidney was greater than that of the RRA with the right kidney.

CONCLUSIONS

The celiac artery exhibited less branch angle change, and greater axial and curvature deformations than the other visceral arteries, due to the vicinity to the liver and influence of the median arcuate ligament. Correlation between visceral arteries and kidney translations revealed that diaphragmatic excursion affects vessel mobility. Weaker correlation of the RRA to the right kidney indicates mechanical shielding from the inferior vena cava.